FN Thomson Reuters Web of Science™ VR 1.0 PT J AU Wright, CHG Barrett, SF Ferguson, RD Rylander, HG Welch, AJ AF Wright, CHG Barrett, SF Ferguson, RD Rylander, HG Welch, AJ TI Initial in vivo results of a hybrid retinal photocoagulation system SO JOURNAL OF BIOMEDICAL OPTICS LA English DT Article DE retinal surgery; retinal tracking; photocoagulation; diabetic retinopathy; retinal tears ID TRACKING AB We describe initial in vivo experimental results of a new hybrid digital and analog design for retinal tracking and laser beam control. An overview of the design is given. The results show in vivo tracking rates which exceed the equivalent of 38 degrees/s in the eye. A robotically assisted lesion pattern is created for laser surgery to treat conditions such as diabetic retinopathy and retinal breaks. (C) 2000 Society of Photo-Optical instrumentation Engineers. [S1083-3668(00)0501-3]. C1 USAF Acad, Colorado Springs, CO 80840 USA. Univ Wyoming, Dept Elect Engn, Laramie, WY 82071 USA. Phys Sci Inc, Andover, MA 01810 USA. Univ Texas, Biomed Engn Program, Austin, TX 78712 USA. RP Wright, CHG (reprint author), USAF Acad, 2354 Fairchild Hall,Suite 2F6, Colorado Springs, CO 80840 USA. FU NEI NIH HHS [1R41EY10777] NR 11 TC 11 Z9 11 U1 0 U2 2 PU SPIE-INT SOCIETY OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, BELLINGHAM, WA 98225 USA SN 1083-3668 J9 J BIOMED OPT JI J. Biomed. Opt. PD JAN PY 2000 VL 5 IS 1 BP 56 EP 61 DI 10.1117/1.429969 PG 6 WC Biochemical Research Methods; Optics; Radiology, Nuclear Medicine & Medical Imaging SC Biochemistry & Molecular Biology; Optics; Radiology, Nuclear Medicine & Medical Imaging GA 279WW UT WOS:000085068900008 PM 10938767 ER PT J AU Moore, KD Barrack, RL Sychterz, CJ Sawhney, J Yang, AM Engh, CA AF Moore, KD Barrack, RL Sychterz, CJ Sawhney, J Yang, AM Engh, CA TI The effect of weight-bearing on the radiographic measurement of the position of the femoral head after total hip arthroplasty SO JOURNAL OF BONE AND JOINT SURGERY-AMERICAN VOLUME LA English DT Article AB Background: In most radiographic studies of polyethylene wear, investigators have used routine annual radiographs made,vith the patient in the supine position in order to measure penetration by the femoral head into the polyethylene liner, However, researchers have begun to question the effect of weight-bearing on the position of the head within the acetabular cup and, consequently the effect of weight-bearing on measurements of penetration by the head, The purpose of the current study was to determine the effect of weight-bearing on the two-dimensional radiographic position of the femoral head within the acetabular cup. Methods: Thirty-seven patients (forty-seven hips) who had had a total hip arthroplasty had radiographs made at one of two separate institutions. A set of anteroposterior radiographs was made for each patient: one radiograph was made,vith the patient supine and one was made with the patient upright bearing full weight on the replaced hip, At one of the institutions, a third anteroposterior radiograph was made with the patient in the same upright position but not bearing weight on the replaced hip. All measurements of the two-dimensional position of the head were performed by a single observer with use of a previously published computerized measurement system, Results: Data from both institutions revealed that measurements of the position of the head on radiographs made with the patient supine were strongly and significantly correlated with measurements of the position of the head on radiographs made,vith the patient bearing weight (r(2) > 0.93, p < 0.001 for both regressions), Examination of the differences between the measurements revealed no bias for one set of measurements to consistently underestimate or overestimate the values derived with use of the other method. Moreover, we found a nearly perfect relationship between the measurements of the position of the head on radiographs made,vith the patient standing and bearing weight and those on radiographs made,vith the patient standing but not bearing weight (r(2) = 0.97, p < 0.001, slope = 0.99, intercept = 0.02 millimeter), Conclusions: On the basis of these findings, there is no evidence that radiographs must be made,vith the patient bearing weight in order to accurately measure the position of the femoral head within the polyethylene liner. C1 Anderson Orthopaed Res Inst, Alexandria, VA USA. Tulane Univ, New Orleans, LA 70118 USA. RP Wilford Hall USAF Med Ctr, Lackland AFB, TX 78236 USA. OI Engh, Andy/0000-0002-7303-4776 NR 26 TC 28 Z9 29 U1 0 U2 3 PU JOURNAL BONE JOINT SURGERY PI NEEDHAM PA 20 PICKERING ST, NEEDHAM, MA 02492 USA SN 0021-9355 EI 1535-1386 J9 J BONE JOINT SURG AM JI J. Bone Joint Surg.-Am. Vol. PD JAN PY 2000 VL 82A IS 1 BP 62 EP 69 PG 8 WC Orthopedics; Surgery SC Orthopedics; Surgery GA 274HC UT WOS:000084759400008 PM 10653085 ER PT J AU Levandier, DJ Chiu, YH Dressler, RA AF Levandier, DJ Chiu, YH Dressler, RA TI Charge transfer and chemical reaction dynamics in hyperthermal O++NO collisions SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID GUIDED-ION-BEAM; MOLECULE REACTIONS; RATE-CONSTANT; O+; ENERGY; NO+; IONOSPHERE; DEPENDENCE; ATOMS; N-2 AB The O+(S-4)+NO(X (2)Pi(r)) collision system has been investigated in a guided-ion beam experiment. Absolute cross sections for production of NO+ and O-2(+) have been measured at collision energies from near thermal to similar to 12 eV. Time-of-flight measurements of the NO+ product recoil velocities, at collision energies of 1.3, 3.3, 5.2, and 9.1 eV confirm two hyperthermal charge transfer channels with thresholds at 0.2 and 2.0 eV. A kinematic analysis indicates mechanisms that give rise to spin-forbidden NO+(X (1)Sigma(+))+O(D-1) and endothermic NO+(a (3)Sigma(+))+O(P-3) products, respectively. The O-2(+)+N channel is observed to have a threshold of 0.7 +/- 0.1 eV. Time-of-flight studies of the O-2(+) product at collision energies of 3.3 and 5.9 eV indicate a complex-mediated mechanism. [S0021-9606(00)01101-6]. C1 USAF, Res Lab, Space Vehicles Directorate, Hanscom AFB, MA 01731 USA. Boston Coll, Inst Sci Res, Newton, MA 02159 USA. RP Levandier, DJ (reprint author), USAF, Res Lab, Space Vehicles Directorate, 29 Randolph Rd, Hanscom AFB, MA 01731 USA. NR 41 TC 3 Z9 3 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD JAN 1 PY 2000 VL 112 IS 1 BP 122 EP 129 DI 10.1063/1.480647 PG 8 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 269ZA UT WOS:000084506900015 ER PT J AU Ganley, JM Maji, AK Huybrechts, S AF Ganley, JM Maji, AK Huybrechts, S TI Explaining spring-in in filament wound carbon fiber/epoxy composites SO JOURNAL OF COMPOSITE MATERIALS LA English DT Article DE composite; spring-in; residual stress; carbon fiber/epoxy and filament winding ID CYLINDRICAL SEGMENTS; CURE SHRINKAGE; DEFORMATIONS; SHELLS AB Filament wound curved composite parts which are autoclave cured tend to exhibit "spring-in," a permanent deformation due to residual stresses (Stover, 1993). Spring-in is the tendency of a circular part to reduce it's radius of curvature upon radial cutting. The causes of spring-in and the associated residual stresses must be understood to ensure dimensional accuracy and safety of the final cured part. The purpose of this paper is to isolate and quantify the principle causes of spring-in in filament wound unidirectional autoclave cured carbon fiber/epoxy composite hoops. This paper first explores the causes of spring-in as given in the literature: through thickness inhomogeneity (Radford, 1993), part compaction (Meink, 1998), and anisotropy with initial curvature (Kollar, 1992). Next, the development of the residual stress profile through the fabrication and cure process is given along with the governing equations for the spring-in phenomenon. Finally, an experimental procedure is developed to obtain the residual stress profile in a thin composite part. This methodology involves progressive cutting (i.e., stress relief) and associated strain gage monitoring. The strain gage data is then combined with a finite element (FEM) analysis to determine the through-thickness residual stress profile. From the residual stress profile experiments, it was found that the principal cause of spring-in is not material anisotropy as was previously thought. Instead, the principle cause of spring-in was found to be the gradual thermal expansion of the mandrel during cure, which causes a "tension-lag" in the curing part. In addition, the compaction of the part during cure was found to have a nominal contribution to total spring-in. C1 Univ New Mexico, Dept Civil Engn, Albuquerque, NM 87131 USA. USAF, Res Lab, VSDV, Kirtland AFB, NM 87117 USA. RP Maji, AK (reprint author), Univ New Mexico, Dept Civil Engn, Albuquerque, NM 87131 USA. NR 17 TC 11 Z9 11 U1 1 U2 3 PU TECHNOMIC PUBL CO INC PI LANCASTER PA 851 NEW HOLLAND AVE, BOX 3535, LANCASTER, PA 17604 USA SN 0021-9983 J9 J COMPOS MATER JI J. Compos Mater. PY 2000 VL 34 IS 14 BP 1216 EP 1239 DI 10.1106/NX2Q-N3H6-0FD2-JB7B PG 24 WC Materials Science, Composites SC Materials Science GA 335VL UT WOS:000088265400004 ER PT J AU Madhukar, MS Genidy, MS Russell, JD AF Madhukar, MS Genidy, MS Russell, JD TI A new method to reduce cure-induced stresses in thermoset polymer composites, part I: Test method SO JOURNAL OF COMPOSITE MATERIALS LA English DT Article DE cure cycle; optimization; residual stresses; stress relaxation; thermoset polymer composites; volume changes ID RESIDUAL-STRESSES; TEMPERATURE; SHRINKAGE AB The inhomogeneous structure of polymeric composites causes internal stresses to develop due to matrix volume changes during processing. The volume changes occur during cure and during cooldown after the curl is completed. Most of the previous studies on residual stresses concentrated on stress development during cooldown. In this study, a new test method was used to monitor fiber stresses that develop during cure in single fiber model composites. The method was used to study the effect of changing the cure cycle on curing induced fiber stresses. It was seen that changing the cure cycle changes the resulting stress significantly. Also, it was shown that the cure-induced stresses and their contribution to final residual stresses vary for different resins. A cure cycle with almost zero cure-induced stresses is demonstrated. The new cycle was found to satisfy the cure requirements such as glass transition temperature and cure cycle duration. C1 Univ Tennessee, Dept Mech Aero & Engn Sci, Knoxville, TN 37996 USA. USAF, Res Lab, Mat & Mfg Directorate, Wright Patterson AFB, OH 45433 USA. RP Madhukar, MS (reprint author), Univ Tennessee, Dept Mech Aero & Engn Sci, 414 Dougherty Engn Bldg, Knoxville, TN 37996 USA. RI Madhukar, Madhu/P-4365-2015 NR 20 TC 22 Z9 24 U1 1 U2 12 PU TECHNOMIC PUBL CO INC PI LANCASTER PA 851 NEW HOLLAND AVE, BOX 3535, LANCASTER, PA 17604 USA SN 0021-9983 J9 J COMPOS MATER JI J. Compos Mater. PY 2000 VL 34 IS 22 BP 1882 EP 1904 DI 10.1106/HUCY-DY2B-2N42-UJBX PG 23 WC Materials Science, Composites SC Materials Science GA 367YU UT WOS:000090090800001 ER PT J AU Genidy, MS Madhukar, MS Russell, JD AF Genidy, MS Madhukar, MS Russell, JD TI A new method to reduce cure-induced stresses in thermoset polymer composites, part II: Closed loop feedback control system SO JOURNAL OF COMPOSITE MATERIALS LA English DT Article DE curl cycle; optimization; feedback control; residual stresses; stress relaxation; thermosets; volume changes AB A closed loop feedback control system has been developed to obtain cure cycles which reduce the cure-induced stresses in single fiber/matrix model composites. In this feedback system, thermal expansion and stress relaxation are used to counteract the stresses resulting from the chemical shrinkage. The feedback system is applied to two different fibers (carbon and glass) in four different resins [3501-6, 934, and 977-3 epoxies and 5250-4 bismaleimide (BMI)]. The completeness of the cure is verified by comparing glass transition temperature (T-g) for polymers cured using the standard cure cycles (cycles recommended by the prepreg manufactures) and the feedback cure cycles. The durations of the feedback cure cycles are within that of the standard cycles. Test results indicate that feedback cure cycles reduce the curvature of unsymmetrical laminates as a measure of residual stresses. C1 Univ Tennessee, Dept Mech Aero & Eng Sci, Knoxville, TN 37996 USA. USAF, Res Lab, Mat & Mfg Directorate, Wright Patterson AFB, OH 45433 USA. RP Madhukar, MS (reprint author), Univ Tennessee, Dept Mech Aero & Eng Sci, 414 Dougherty Eng Bldg, Knoxville, TN 37996 USA. RI Madhukar, Madhu/P-4365-2015 NR 7 TC 13 Z9 15 U1 2 U2 6 PU TECHNOMIC PUBL CO INC PI LANCASTER PA 851 NEW HOLLAND AVE, BOX 3535, LANCASTER, PA 17604 USA SN 0021-9983 J9 J COMPOS MATER JI J. Compos Mater. PY 2000 VL 34 IS 22 BP 1905 EP 1925 DI 10.1106/3M0Y-44XM-6WP8-WT7J PG 21 WC Materials Science, Composites SC Materials Science GA 367YU UT WOS:000090090800002 ER PT J AU Russell, JD Madhukar, MS Genidy, MS Lee, AY AF Russell, JD Madhukar, MS Genidy, MS Lee, AY TI A new method to reduce cure-induced stresses in thermoset polymer composites, part III: Correlating stress history to viscosity, degree of cure, and cure shrinkage SO JOURNAL OF COMPOSITE MATERIALS LA English DT Article ID CYCLE AB Non-thermoelastic effects such as cure shrinkage of a polymer can play a role in residual stresses in composite parts. Studies have shown that cure shrinkage can place significant stresses on fibers. Therefore. the cure cycle of 3501-6 epoxy resins was modified to change its curl shrinkage characteristics to minimize the stresses. New curl strategies were developed using volumetric dilatometry. differential scanning calorimetry, dielectric cure monitoring, and a unique single fiber stress test method. Cure cycles were modified to balance the resin's thermal expansion with its cure shrinkage. In some cases, a region of constant volume was achieved for a short time. However. the cure shrinkage eventually dominated over thermal expansion in all cycles as the polymer gelled. Changing the cure cycle affected the degree of cure at the point where the fiber/matrix interface developed as well as the amount of cure shrinkage occurring afterwards. A higher degree of cure at this point leads to longer stress relaxation time. Furthermore, less cure shrinkage at this point leads to less stress on the fibers. Also, slow heating rates allow more time for the polymer to relax and relieve stresses caused by cure shrinkage. Finally, a cure cycle that minimizes stresses due to cure shrinkage has been demonstrated. C1 Univ Tennessee, Dept Mech Aero & Eng Sci, Knoxville, TN 37996 USA. USAF, Res Lab, Mat & Mfg Directorate, Wright Patterson AFB, OH 45433 USA. Michigan State Univ, Dept Mat Sci & Engn, E Lansing, MI 48824 USA. RP Madhukar, MS (reprint author), Univ Tennessee, Dept Mech Aero & Eng Sci, 414 Dougherty Eng Bldg, Knoxville, TN 37996 USA. RI Madhukar, Madhu/P-4365-2015 NR 14 TC 28 Z9 31 U1 0 U2 10 PU TECHNOMIC PUBL CO INC PI LANCASTER PA 851 NEW HOLLAND AVE, BOX 3535, LANCASTER, PA 17604 USA SN 0021-9983 J9 J COMPOS MATER JI J. Compos Mater. PY 2000 VL 34 IS 22 BP 1926 EP 1947 DI 10.1106/UY9U-F2QW-2FKK-91KG PG 22 WC Materials Science, Composites SC Materials Science GA 367YU UT WOS:000090090800003 ER PT J AU Maller, SC AF Maller, SC TI Gingival fibroblast integrin subunit expression on different titanium implant surfaces. SO JOURNAL OF DENTAL RESEARCH LA English DT Meeting Abstract C1 Wilford Hall USAF Med Ctr, Lackland AFB, TX 78236 USA. Univ Texas, Hlth Sci Ctr, San Antonio, TX USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU AMER ASSOC DENTAL RESEARCH PI ALEXANDRIA PA 1619 DUKE ST, ALEXANDRIA, VA 22314 USA SN 0022-0345 J9 J DENT RES JI J. Dent. Res. PY 2000 VL 79 SI SI MA 546 BP 212 EP 212 PG 1 WC Dentistry, Oral Surgery & Medicine SC Dentistry, Oral Surgery & Medicine GA 277MH UT WOS:000084937000548 ER PT J AU Fisher, TD Murchison, DF Roberts, HW Flores, S AF Fisher, TD Murchison, DF Roberts, HW Flores, S TI Comparison of adhesive/mechanical resistance on cuspal reinforcement. SO JOURNAL OF DENTAL RESEARCH LA English DT Meeting Abstract C1 Wilford Hall USAF Med Ctr, San Antonio, TX 78236 USA. USAF, Dent Invest Serv, San Antonio, TX USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER ASSOC DENTAL RESEARCH PI ALEXANDRIA PA 1619 DUKE ST, ALEXANDRIA, VA 22314 USA SN 0022-0345 J9 J DENT RES JI J. Dent. Res. PY 2000 VL 79 SI SI MA 1047 BP 274 EP 274 PG 1 WC Dentistry, Oral Surgery & Medicine SC Dentistry, Oral Surgery & Medicine GA 277MH UT WOS:000084937001041 ER PT J AU Marquis, JA Murchison, DF Charlton, DG Cooley, RL AF Marquis, JA Murchison, DF Charlton, DG Cooley, RL TI Effect of air-powder abrasion prophylaxis on compomer surface roughness. SO JOURNAL OF DENTAL RESEARCH LA English DT Meeting Abstract C1 Wilford Hall USAF Med Ctr, Lackland AFB, TX 78236 USA. USAF, Dent Invest Serv, San Antonio, TX USA. Univ Texas, Hlth Sci Ctr, San Antonio, TX 78285 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER ASSOC DENTAL RESEARCH PI ALEXANDRIA PA 1619 DUKE ST, ALEXANDRIA, VA 22314 USA SN 0022-0345 J9 J DENT RES JI J. Dent. Res. PY 2000 VL 79 SI SI MA 1080 BP 278 EP 278 PG 1 WC Dentistry, Oral Surgery & Medicine SC Dentistry, Oral Surgery & Medicine GA 277MH UT WOS:000084937001075 ER PT J AU Leonard, D Charlton, D Hilton, T Roberts, H Zionic, A AF Leonard, D Charlton, D Hilton, T Roberts, H Zionic, A TI Minimum irradiance for polymerization of a hybrid and a microfill composite. SO JOURNAL OF DENTAL RESEARCH LA English DT Meeting Abstract C1 USAF, Dent Invest Serv, Brooks AFB, TX USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER ASSOC DENTAL RESEARCH PI ALEXANDRIA PA 1619 DUKE ST, ALEXANDRIA, VA 22314 USA SN 0022-0345 J9 J DENT RES JI J. Dent. Res. PY 2000 VL 79 SI SI MA 1776 BP 365 EP 365 PG 1 WC Dentistry, Oral Surgery & Medicine SC Dentistry, Oral Surgery & Medicine GA 277MH UT WOS:000084937001771 ER PT J AU Tallent, DK Moore, WS Murchison, DF Westbrook, SD AF Tallent, DK Moore, WS Murchison, DF Westbrook, SD TI Accuracy of proximal caries detection using lossy image techniques. SO JOURNAL OF DENTAL RESEARCH LA English DT Meeting Abstract C1 Wilford Hall USAF Med Ctr, San Antonio, TX 78236 USA. Univ Texas, Hlth Sci Ctr, San Antonio, TX USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER ASSOC DENTAL RESEARCH PI ALEXANDRIA PA 1619 DUKE ST, ALEXANDRIA, VA 22314 USA SN 0022-0345 J9 J DENT RES JI J. Dent. Res. PY 2000 VL 79 SI SI MA 3252 BP 550 EP 550 PG 1 WC Dentistry, Oral Surgery & Medicine SC Dentistry, Oral Surgery & Medicine GA 277MH UT WOS:000084937003246 ER PT J AU Lin, AL Biggs, WS Stephan, KT Carlson, KA Johnson, DA Yeh, CK AF Lin, AL Biggs, WS Stephan, KT Carlson, KA Johnson, DA Yeh, CK TI Salivary anticandidal activities in an early HIV(+) corhort. SO JOURNAL OF DENTAL RESEARCH LA English DT Meeting Abstract C1 Univ Texas, Hlth Sci Ctr, San Antonio, TX USA. Wilford Hall USAF Med Ctr, San Antonio, TX 78236 USA. STVHCS, GRECC, Audie L Murphy Vet Hosp, San Antonio, TX USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER ASSOC DENTAL RESEARCH PI ALEXANDRIA PA 1619 DUKE ST, ALEXANDRIA, VA 22314 USA SN 0022-0345 J9 J DENT RES JI J. Dent. Res. PY 2000 VL 79 SI SI MA 3383 BP 566 EP 566 PG 1 WC Dentistry, Oral Surgery & Medicine SC Dentistry, Oral Surgery & Medicine GA 277MH UT WOS:000084937003372 ER PT J AU Puttaiah, R Charlton, D Sargent, CM Anderson, K AF Puttaiah, R Charlton, D Sargent, CM Anderson, K TI Effects of a disinfectant on an elastomeric impression material. SO JOURNAL OF DENTAL RESEARCH LA English DT Meeting Abstract C1 Baylor Coll Dent, TAMUS HSC, Dallas, TX 75246 USA. USAF, DIS, San Antonio, TX USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU AMER ASSOC DENTAL RESEARCH PI ALEXANDRIA PA 1619 DUKE ST, ALEXANDRIA, VA 22314 USA SN 0022-0345 J9 J DENT RES JI J. Dent. Res. PY 2000 VL 79 SI SI MA 3784 BP 616 EP 616 PG 1 WC Dentistry, Oral Surgery & Medicine SC Dentistry, Oral Surgery & Medicine GA 277MH UT WOS:000084937003776 ER PT J AU Roberts, HW Charlton, DG Murchison, DF AF Roberts, HW Charlton, DG Murchison, DF TI Effect of flowable resin on leakage at amalgam margin defects. SO JOURNAL OF DENTAL RESEARCH LA English DT Meeting Abstract C1 USAF, Dent Invest Serv, Brooks AFB, TX USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER ASSOC DENTAL RESEARCH PI ALEXANDRIA PA 1619 DUKE ST, ALEXANDRIA, VA 22314 USA SN 0022-0345 J9 J DENT RES JI J. Dent. Res. PY 2000 VL 79 SI SI MA 3779 BP 616 EP 616 PG 1 WC Dentistry, Oral Surgery & Medicine SC Dentistry, Oral Surgery & Medicine GA 277MH UT WOS:000084937003770 ER PT J AU Yaghjian, AD Shore, RA AF Yaghjian, AD Shore, RA TI Incremental diffraction coefficients for plane conformal strips with application to bistatic scattering from the disk - Reply SO JOURNAL OF ELECTROMAGNETIC WAVES AND APPLICATIONS LA English DT Editorial Material C1 USAF, Res Lab, Hanscom AFB, MA 01742 USA. RP Yaghjian, AD (reprint author), USAF, Res Lab, Hanscom AFB, MA 01742 USA. NR 1 TC 0 Z9 0 U1 1 U2 3 PU VSP BV PI ZEIST PA PO BOX 346, 3700 AH ZEIST, NETHERLANDS SN 0920-5071 J9 J ELECTROMAGNET WAVE JI J. Electromagn. Waves Appl. PY 2000 VL 14 IS 6 BP 881 EP 883 DI 10.1163/156939300X01652 PG 3 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 340BF UT WOS:000088512700019 ER PT J AU Akerson, JJ Tassoudji, MA Yang, YE Kong, JA AF Akerson, JJ Tassoudji, MA Yang, YE Kong, JA TI Finite Difference Time Domain (FDTD) Impedance Boundary Condition for thin finite conducting sheets - Abstract SO JOURNAL OF ELECTROMAGNETIC WAVES AND APPLICATIONS LA English DT Article C1 USAF Acad, Colorado Springs, CO 80840 USA. RP Akerson, JJ (reprint author), USAF Acad, Colorado Springs, CO 80840 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU VSP BV PI ZEIST PA PO BOX 346, 3700 AH ZEIST, NETHERLANDS SN 0920-5071 J9 J ELECTROMAGNET WAVE JI J. Electromagn. Waves Appl. PY 2000 VL 14 IS 11 BP 1573 EP 1575 DI 10.1163/156939300X00347 PG 3 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 413HR UT WOS:000167607400011 ER PT J AU Paschkewitz, JS Pratt, DM AF Paschkewitz, JS Pratt, DM TI Electrohydrodynamic (EHD) heat transfer enhancement in an aviation working fluid: Effect of electrode material and polarity SO JOURNAL OF ENHANCED HEAT TRANSFER LA English DT Article DE electrohydrodynamic; EHD; electrode material; polarity effects ID INJECTION; LIQUIDS; OXIDATION; CHARGE AB Electrohydrodynamic heat transfer enhancement in the aviation coolant PAO was examined using a concentric wire-cylinder test section. Stainless steel (alloy 304), brass (alloy 260), and bronze (alloy 510) wire electrodes were used with both negative and positive polarity. The outer tube was 316 stainless steel. Bronze gave enhancements over an order of magnitude greater than either brass or stainless steel, with smaller increases in pressure drop and lower electrical power requirements for both positive and negative polarities. Several explanations are given for the differences in performance are discussed. C1 USAF, Res Lab, VAAL, Mech & Thermal Syst Branch, Wright Patterson AFB, OH 45433 USA. RP Paschkewitz, JS (reprint author), USAF, Res Lab, VAAL, Mech & Thermal Syst Branch, 2210 8th St,Bldg 146,Rm 225, Wright Patterson AFB, OH 45433 USA. NR 19 TC 3 Z9 6 U1 0 U2 4 PU GORDON BREACH SCI PUBL LTD PI READING PA C/O STBS LTD, PO BOX 90, READING RG1 8JL, BERKS, ENGLAND SN 1065-5131 J9 J ENHANC HEAT TRANSF JI J. Enhanc. Heat Transf. PY 2000 VL 7 IS 6 BP 371 EP 383 PG 13 WC Thermodynamics; Engineering, Mechanical SC Thermodynamics; Engineering GA 366VM UT WOS:000090027000002 ER PT J AU Paschkewitz, JS Smajdek, MA Pratt, DM AF Paschkewitz, JS Smajdek, MA Pratt, DM TI "On-demand" electrohydrodynamic (EHD) heat transfer enhancement using an anionic surfactant SO JOURNAL OF ENHANCED HEAT TRANSFER LA English DT Article DE transient; EHD; surfactant; injection/dissociation; electrodynamic; "on-demand" enhancement ID WIRE-CYLINDER GEOMETRY; NONPOLAR LIQUIDS; CONDUCTION; INJECTION; CHARGE AB Transient heat transfer enhancement performance with electrohydrodynamic (EHD) augmentation was characterized using a single-phase transformer oil in a concentric wire-cylinder test section. Performance using the oil alone was inconsistent, but the addition of an anionic surfactant gave reproducible enhancements with rapid response times. The impact of surfactant concentration on enhancement behavior was investigated in both the transient and steady state regimes. For both high and low concentrations of surfactant additive, current response to step voltage changes occurred within 300 msec, and enhancement response lagged due to the thermal mass of the test article. In the steady state, the high concentration of the additive resulted in a much higher electrical power requirement but gave better enhancement and pressure drop behavior for a given enhancement than the low concentration. Mechanisms for the positive effect of the surfactant additive are analyzed and electrochemical rate constants are obtained. Implications for the design of controllable EHD-enhanced heat transfer systems are articulated. C1 USAF, Res Lab, VAAC, Mech & Thermal Syst Branch, Wright Patterson AFB, OH 45433 USA. RP Paschkewitz, JS (reprint author), USAF, Res Lab, VAAC, Mech & Thermal Syst Branch, Bldg 146,Rm 225,2210 8th St, Wright Patterson AFB, OH 45433 USA. NR 21 TC 1 Z9 1 U1 0 U2 0 PU GORDON BREACH SCI PUBL LTD PI READING PA C/O STBS LTD, PO BOX 90, READING RG1 8JL, BERKS, ENGLAND SN 1065-5131 J9 J ENHANC HEAT TRANSF JI J. Enhanc. Heat Transf. PY 2000 VL 7 IS 6 BP 385 EP 409 PG 25 WC Thermodynamics; Engineering, Mechanical SC Thermodynamics; Engineering GA 366VM UT WOS:000090027000003 ER PT J AU Brautigam, DH Albert, JM AF Brautigam, DH Albert, JM TI Radial diffusion analysis of outer radiation belt electrons during the October 9, 1990, magnetic storm SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID RELATIVISTIC ELECTRONS; GEOSYNCHRONOUS ORBIT; ENERGETIC PARTICLES; PITCH-ANGLE; SOLAR-WIND; MAGNETOSPHERE; JANUARY; ACCELERATION; CRRES; CLOUD AB The response of outer radiation belt relativistic electrons to the October 9, 1990, magnetic storm is analyzed in detail using a radial diffusion model and data from the Combined Release and Radiation Effects Satellite (CRRES) and the Los Alamos National Laboratory (LANL) geosynchronous satellite 1989-046. Electron measurements are expressed in terms of phase space density as a function of the three adiabatic invariants determined from CRRES magnetic field data and the Tsyganenko 1989 Kp-dependent magnetic field model. The radial diffusion model is implemented with a time-dependent radial diffusion coefficient parameterized by Kp, and a time-dependent outer boundary condition scaled by geosynchronous electron data, The results show that radial diffusion propagates outer boundary variations into the heart of the outer radiation belt, accounting for both significant decreases and increases in the <1 MeV electron flux throughout that region. It is further shown that the gradual increase throughout the recovery phase of the >1 MeV electrons is inconsistent with the radial diffusion model given the parameter regime chosen for this study. Greatly enhanced whistler chorus waves observed by CRRES throughout the recovery phase suggest that a possible explanation for the inconsistency may be electron acceleration via wave-particle interaction. C1 USAF, Res Lab, Space Vehicles Directorate, Hanscom AFB, MA 01731 USA. Boston Coll, Inst Sci Res, Boston, MA USA. RP Albert, JM (reprint author), USAF, Res Lab, Space Vehicles Directorate, Hanscom AFB, MA 01731 USA. NR 58 TC 279 Z9 283 U1 0 U2 13 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD JAN 1 PY 2000 VL 105 IS A1 BP 291 EP 309 DI 10.1029/1999JA900344 PG 19 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 275AF UT WOS:000084796700024 ER PT J AU Spillman, MS AF Spillman, MS TI Robust longitudinal flight control design using linear parameter-varying feedback SO JOURNAL OF GUIDANCE CONTROL AND DYNAMICS LA English DT Article ID H-INFINITY CONTROL; SYSTEMS AB A linear parameter-varying (LPV) control approach is examined to determine if it is practical to use for large-envelope Eight control designs. The basic approach is combined with mu analysis to reduce conservatism, and the resulting mixed LPV/mu approach is used to design a longitudinal LPV controller for the F-16 Variable Stability In-Flight Simulator Test Aircraft. Implementation issues are discussed, and the controller is modified accordingly. The final closed-loop system is tested for robust stability and handling qualities throughout the subsonic flight envelope. High fidelity nonlinear simulations are also used to verify performance. C1 USAF, Res Lab, Air Vehicles Directorate, Wright Patterson AFB, OH 45433 USA. RP Spillman, MS (reprint author), USAF, Res Lab, Air Vehicles Directorate, Wright Patterson AFB, OH 45433 USA. NR 19 TC 16 Z9 17 U1 0 U2 1 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 USA SN 0731-5090 J9 J GUID CONTROL DYNAM JI J. Guid. Control Dyn. PD JAN-FEB PY 2000 VL 23 IS 1 BP 101 EP 108 DI 10.2514/2.4492 PG 8 WC Engineering, Aerospace; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA 275AX UT WOS:000084798200012 ER PT J AU Melendez, RF Wilcox, M Schluter, ML AF Melendez, RF Wilcox, M Schluter, ML TI Lucifer Yellow incorporation into rabbit lens epithelial cells is dependent upon illumination. SO JOURNAL OF INVESTIGATIVE MEDICINE LA English DT Meeting Abstract C1 Univ New Mexico, Sch Med, Albuquerque, NM 87131 USA. USAF Acad, Colorado Springs, CO 80840 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU LIPPINCOTT WILLIAMS & WILKINS PI PHILADELPHIA PA 530 WALNUT ST, PHILADELPHIA, PA 19106-3621 USA SN 1081-5589 J9 J INVEST MED JI J. Invest. Med. PD JAN PY 2000 VL 48 IS 1 SU S MA 185 BP 34A EP 34A PG 1 WC Medicine, General & Internal; Medicine, Research & Experimental SC General & Internal Medicine; Research & Experimental Medicine GA 302CD UT WOS:000086346600192 ER PT J AU Kerecman, J Barlow-Walden, L Easton, J Castro, R AF Kerecman, J Barlow-Walden, L Easton, J Castro, R TI Ion transport properties of premature baboon airway epithelial cells in primary culture. SO JOURNAL OF INVESTIGATIVE MEDICINE LA English DT Meeting Abstract C1 Univ Texas, Hlth Sci Ctr, Dept Pediat, San Antonio, TX 78285 USA. Wilford Hall USAF Med Ctr, San Antonio, TX 78236 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU LIPPINCOTT WILLIAMS & WILKINS PI PHILADELPHIA PA 530 WALNUT ST, PHILADELPHIA, PA 19106-3621 USA SN 1081-5589 J9 J INVEST MED JI J. Invest. Med. PD JAN PY 2000 VL 48 IS 1 SU S MA 816 BP 151A EP 151A PG 1 WC Medicine, General & Internal; Medicine, Research & Experimental SC General & Internal Medicine; Research & Experimental Medicine GA 302CD UT WOS:000086346600816 ER PT J AU Boinard, P Pethrick, RA Banks, WM Crane, RL AF Boinard, P Pethrick, RA Banks, WM Crane, RL TI Non destructive evaluation of adhesively bonded composite structures using high frequency dielectric spectroscopy SO JOURNAL OF MATERIALS SCIENCE LA English DT Article AB Over the last ten years, the application of high frequency dielectric techniques for the assessment of adhesively bonded structures has been investigated. The technique has been used for the study of adhesively bonded aluminium structures and its application to carbon fibre reinforced plastic (CFRP) bonded structures forms the basis of this paper. The electrical conductivity of the carbon fibres in the CFRP composite materials is sufficiently high for adhesively bonded structures to exhibit the properties of a wave-guide. The non-conductive adhesive behaves as a dielectric. The time domain data allows the integrity of the structure to be explored and is sensitive to the orientation of the fibres at the adherent-adhesive interface. Furthermore, a good correlation is shown between time domain dielectric spectroscopy and gravimetric results. This study indicates that the success obtained in the application of high frequency dielectric measurements to adhesively bonded aluminium structures is also applicable to CFRP bonded structures. The dielectric studies not only indicate a new way to assess the state of such a structure but also are producing new insight into the application of dielectric time domain response (TDR) measurement to non-isotropic materials. (C) 2000 Kluwer Academic Publishers. C1 Univ Strathclyde, Dept Pure & Appl Chem, Glasgow G1 1XL, Lanark, Scotland. Univ Strathclyde, Dept Mech Engn, Glasgow G1 1XL, Lanark, Scotland. USAF, Res Lab, Mat Directorate, Non Destruct Evaluat Branch, Wright Patterson AFB, OH 45433 USA. RP Pethrick, RA (reprint author), Univ Strathclyde, Dept Pure & Appl Chem, Thomas Graham Bldg,295 Cathedral St, Glasgow G1 1XL, Lanark, Scotland. NR 15 TC 18 Z9 19 U1 0 U2 7 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0022-2461 J9 J MATER SCI JI J. Mater. Sci. PY 2000 VL 35 IS 6 BP 1331 EP 1337 DI 10.1023/A:1004717704215 PG 7 WC Materials Science, Multidisciplinary SC Materials Science GA 281XD UT WOS:000085186000004 ER PT J AU Bao, G Fang, XH Tan, WH Van, T AF Bao, G Fang, XH Tan, WH Van, T TI Evanescent energy in square and circular fibers SO JOURNAL OF MATHEMATICAL CHEMISTRY LA English DT Article DE evanescent energy; optical fibers; single-molecule detection; finite element method AB A finite element method is presented to find the propagation characteristics of an optical fiber with arbitrary cross section. This method uses a non-local boundary operator to reduce the infinite problem (open waveguide) to a bounded one. Evanescent energy in circular and square fibers of the same core area are computed and compared to show that square fibers can be effectively used in single molecule detection. C1 Michigan State Univ, Dept Math, E Lansing, MI 48824 USA. Univ Florida, Dept Chem, Gainesville, FL 32611 USA. USAF, Inst Technol, ENC, Wright Patterson AFB, OH 45433 USA. RP Bao, G (reprint author), Michigan State Univ, Dept Math, E Lansing, MI 48824 USA. EM bao@math.msu.edu; xfang@chem.ufl.edu; tan@chem.ufl.edu; Tri.Van@afit.af.mil RI Tan, Weihong/A-5412-2008; Bao, Gang/F-1746-2014; Bao, Gang/B-8955-2015 OI Tan, Weihong/0000-0002-8066-1524; NR 11 TC 0 Z9 0 U1 1 U2 3 PU SPRINGER PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0259-9791 EI 1572-8897 J9 J MATH CHEM JI J. Math. Chem. PY 2000 VL 27 IS 4 BP 251 EP 265 DI 10.1023/A:1018889304472 PG 15 WC Chemistry, Multidisciplinary; Mathematics, Interdisciplinary Applications SC Chemistry; Mathematics GA 421EQ UT WOS:000168049500001 ER PT J AU Heidler, JT AF Heidler, JT TI Historical memoir of the war in West Florida and Louisiana in 1814-15, with an atlas SO JOURNAL OF MILITARY HISTORY LA English DT Book Review C1 USAF Acad, Colorado Springs, CO 80840 USA. RP Heidler, JT (reprint author), USAF Acad, Colorado Springs, CO 80840 USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU SOC MILITARY HISTORY PI LEXINGTON PA C/O VIRGINIA MILITARY INST, GEORGE C MARSHALL LIBRARY, LEXINGTON, VA 24450-1600 USA SN 0899-3718 J9 J MILITARY HIST JI J. Mil. Hist. PD JAN PY 2000 VL 64 IS 1 BP 201 EP 201 DI 10.2307/120808 PG 1 WC History SC History GA 266EW UT WOS:000084288500023 ER PT J AU Sandi, G Gerald, RE Scanlon, LG Johnson, CS Klingler, RJ Rathke, JW AF Sandi, G Gerald, RE Scanlon, LG Johnson, CS Klingler, RJ Rathke, JW TI Molecular orbital and Li-7 nmr investigation of the influence of curved lattices in lithium intercalated carbon anodes SO JOURNAL OF NEW MATERIALS FOR ELECTROCHEMICAL SYSTEMS LA English DT Article DE molecular orbital calculations; in situ Li-7NMR; carbon electrodes; corannulene electrodes ID CORANNULENE; ELECTROCHEMISTRY; ELECTRODES AB We have performed molecular orbital (MO) calculations, electrochemical, and NMR studies to elucidate the influence of curved and planar carbon lattices on the nature of lithium bonding in lithium intercalated carbon anodes, in order to correlate molecular structure with that required far high-capacity lithium carbon anodes. Electrodes were mane of corannulene (C20H10) and graphite. The voltage profile of corannulene is very similar to that obtained for disordered carbons and the capacity delivered in the first cycle corresponds to 802 mAh/g (reversible capacity of 464 mAh/g). Based on the NMR and MO studies, it was found that Li-corannulene complexes can have lithium character only, with a high tendency to form clusters. C1 Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA. Argonne Natl Lab, Div Chem Technol, Argonne, IL 60439 USA. USAF, Res Lab, Battery Branch, Wright Patterson AFB, OH 45433 USA. RP Sandi, G (reprint author), Argonne Natl Lab, Div Chem, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 20 TC 14 Z9 14 U1 0 U2 4 PU ECOLE POLYTECHNIQUE MONTREAL PI MONTREAL PA C P 6079, SUCC CENTRE-VILLE, MONTREAL, QC H3C 3A7, CANADA SN 1480-2422 J9 J NEW MAT ELECT SYST JI J. New Mat.Electrochem. Syst. PD JAN PY 2000 VL 3 IS 1 BP 13 EP 19 PG 7 WC Electrochemistry; Materials Science, Multidisciplinary SC Electrochemistry; Materials Science GA 296ZZ UT WOS:000086057800004 ER PT J AU Millhouse, PT Kramer, SC King, PI Mykytka, EF AF Millhouse, PT Kramer, SC King, PI Mykytka, EF TI Identifying optimal fan compressor pressure ratios for the mixed-stream turbofan engine SO JOURNAL OF PROPULSION AND POWER LA English DT Article AB This paper describes a heuristic approach for determining the optimal fan compressor pressure ratio for a fixed set of mixed-stream turbofan engine parameters. During the aircraft design process, it is important to select an engine design that minimizes fuel consumption while producing the thrust required by the various aircraft mission Eight conditions. Although the most fuel-efficient values of such parameters as bypass ratio and high-pressure compressor (core) pressure ratio depend on the integrated effects of the various flight altitudes, Mach numbers, and thrusts required throughout the mission, it is possible to heuristically locate the most efficient fan compressor pressure ratio to complement other engine parameters independent of the mission, At this optimal value, thrust specific fuel consumption is approximately minimized and specific thrust is approximately maximized at all flight conditions. Exploiting the observed engine performance characteristics, optimal fan compressor pressure ratios were successfully located for a wide range of bypass ratios and core compressor pressure ratios across a variety of on- and off design flight conditions. C1 NRO, Chantilly, VA USA. USAF, Inst Technol, Dept Aeronaut & Astronaut, Wright Patterson AFB, OH 45433 USA. Univ Dayton, Dept Engn Management & Syst, Dayton, OH 45469 USA. RP Millhouse, PT (reprint author), NRO, 14675 Lee Rd, Chantilly, VA USA. NR 6 TC 2 Z9 2 U1 0 U2 0 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 USA SN 0748-4658 J9 J PROPUL POWER JI J. Propul. Power PD JAN-FEB PY 2000 VL 16 IS 1 BP 79 EP 86 DI 10.2514/2.5534 PG 8 WC Engineering, Aerospace SC Engineering GA 274LF UT WOS:000084766800012 ER PT J AU Bowersox, RDW Wier, RC Glawe, DD Gogineni, S AF Bowersox, RDW Wier, RC Glawe, DD Gogineni, S TI Measurements of turbulent flow structure in supersonic curved wall boundary layers SO JOURNAL OF PROPULSION AND POWER LA English DT Article C1 Univ Alabama, Dept Mech & Aerosp Engn, Tuscaloosa, AL 35487 USA. USAF, Res Lab, Armament Directorate, Eglin AFB, FL 32542 USA. USAF, Res Lab, Propuls Sci & Adv Concepts Div, Wright Patterson AFB, OH 45433 USA. Innovat Sci Solut Inc, Dayton, OH 45440 USA. RP Bowersox, RDW (reprint author), Univ Alabama, Dept Mech & Aerosp Engn, Tuscaloosa, AL 35487 USA. NR 6 TC 4 Z9 4 U1 0 U2 2 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 USA SN 0748-4658 J9 J PROPUL POWER JI J. Propul. Power PD JAN-FEB PY 2000 VL 16 IS 1 BP 153 EP 154 DI 10.2514/2.5546 PG 2 WC Engineering, Aerospace SC Engineering GA 274LF UT WOS:000084766800023 ER PT J AU Burnley, VS Culick, FEC AF Burnley, VS Culick, FEC TI Comment on "Triggering of longitudinal combustion instabilities in rocket motors: Nonlinear combustion response" SO JOURNAL OF PROPULSION AND POWER LA English DT Editorial Material C1 USAF, Phillips Lab, Propuls Directorate, Edwards AFB, CA 93523 USA. CALTECH, Pasadena, CA 91125 USA. RP Burnley, VS (reprint author), USAF, Phillips Lab, Propuls Directorate, Edwards AFB, CA 93523 USA. NR 8 TC 0 Z9 0 U1 1 U2 2 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 USA SN 0748-4658 J9 J PROPUL POWER JI J. Propul. Power PD JAN-FEB PY 2000 VL 16 IS 1 BP 164 EP 165 DI 10.2514/2.5551 PG 2 WC Engineering, Aerospace SC Engineering GA 274LF UT WOS:000084766800027 ER PT J AU Alfano, S Burns, R Pohlen, D Wirsig, G AF Alfano, S Burns, R Pohlen, D Wirsig, G TI Predictive avoidance for ground-based laser illumination SO JOURNAL OF SPACECRAFT AND ROCKETS LA English DT Article AB Predictive avoidance determines discrete windows of time for safe laser illumination from a ground-based laser platform. That is, the analysis identifies time periods during which the laser will not inadvertently illuminate a satellite. The geometry of the problem is utilized to filter satellites that cannot possibly be illuminated by a specific laser platform. Further, several nongeometric filters are introduced to filter remaining satellites by removing those which cannot lie illuminated by the platform in a specified period. Both sets of filters improve the efficiency of the analysis by reducing the number of state propagations necessary. A method For determining the times of possible accidental illumination using cubic polynomial approximation is also presented. Finally, a test case is run that considers the entire catalog of objects publicly available from the U.S. Space Command. The complete analysis, which considers the entire catalog as potential victims for one target satellite pass, yields verified results in less than 3.5 s on a laptop personal computer running at 266 MHz. C1 US Space Command, Peterson AFB, CO 80914 USA. USAF, Res Lab, Space Vehicles Directorate, Kirtland AFB, NM 87117 USA. RP Alfano, S (reprint author), US Space Command, Peterson AFB, CO 80914 USA. NR 5 TC 4 Z9 4 U1 0 U2 0 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 USA SN 0022-4650 J9 J SPACECRAFT ROCKETS JI J. Spacecr. Rockets PD JAN-FEB PY 2000 VL 37 IS 1 BP 122 EP 128 DI 10.2514/2.3535 PG 7 WC Engineering, Aerospace SC Engineering GA 285EB UT WOS:000085375800016 ER PT J AU Dutton, RE Pagano, NJ Kim, RY Parthasarathy, TA AF Dutton, RE Pagano, NJ Kim, RY Parthasarathy, TA TI Modeling the ultimate tensile strength of unidirectional glass-matrix composites SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article ID MICROMECHANICAL FAILURE MODES; FIBER COMPOSITES; MECHANICAL-PROPERTIES; LAMINATED COMPOSITES; CERAMIC COMPOSITES; BRITTLE; INTERFACE; FRACTURE AB The ultimate tensile strengths of a unidirectional glass-matrix composite were measured as a function of fiber volume fraction. The results were compared with predictions, using a refined solution of the stress field generated by an axisymmetric damage model, which incorporated the effect of stress concentration in the fiber caused by the presence of a matrix crack both before and after deflection at the fiber/matrix interface. Two possible locations for the fiber failure were considered: (1) at a transverse matrix crack, near a bonded fiber/coating interface and (2) at the tip of a debond, at the fiber/coating interface. At low fiber volume fractions, the measured ultimate tensile strength matched the prediction calculated, assuming no crack deflection. For higher volume fractions, the predictions calculated for a debonded crack matched the observed values. The model results were relatively insensitive to debond length and interfacial shear stress for the range of values in this study. In comparison, the global load-sharing model, which does not account for the stress singularity at the fiber/matrix interface, was found to overpredict the values of the ultimate tensile strength for all fiber volume fractions, An important contribution of the present work was to introduce the use of fiber volume fraction as a parameter for testing theoretical predictions of the mode of fiber failure. C1 USAF, Res Lab, AFRL MLLM, Mat & Mfg Directorate, Wright Patterson AFB, OH 45433 USA. Univ Dayton, Res Inst, Dayton, OH 45469 USA. Universal Energy Syst Inc, Dayton, OH 45432 USA. RP Dutton, RE (reprint author), USAF, Res Lab, AFRL MLLM, Mat & Mfg Directorate, Wright Patterson AFB, OH 45433 USA. RI Parthasarathy, Triplicane/B-7146-2011 OI Parthasarathy, Triplicane/0000-0002-5449-9754 NR 17 TC 18 Z9 18 U1 0 U2 5 PU AMER CERAMIC SOC PI WESTERVILLE PA 735 CERAMIC PLACE, PO BOX 6136, WESTERVILLE, OH 43081-6136 USA SN 0002-7820 J9 J AM CERAM SOC JI J. Am. Ceram. Soc. PD JAN PY 2000 VL 83 IS 1 BP 166 EP 174 DI 10.1111/j.1151-2916.2000.tb01166.x PG 9 WC Materials Science, Ceramics SC Materials Science GA 291XE UT WOS:000085764000025 ER PT J AU Huang, TH Rahaman, MN Mah, TI Parthasarathay, TA AF Huang, TH Rahaman, MN Mah, TI Parthasarathay, TA TI Anisotropic grain growth and microstructural evolution of dense mullite above 1550 degrees C SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article ID TOUGHENED SILICON-CARBIDE; MECHANICAL-PROPERTIES; FRACTURE-TOUGHNESS; SHAPE FACTORS; CERAMICS; SI3N4 AB Mullite powder with a nearly stoichiometric composition was hot-pressed at 1550 degrees C to produce an almost fully dense microstructure of fine, nearly uniaxial grains. The grain growth of the dense mullite was investigated during subsequent annealing at temperatures in the range of 1550-1750 degrees C, Grain growth was relatively slow at 1550 degrees C and the microstructure remained nearly equiaxial, Annealing at temperatures above the eutectic temperature (similar to 1590 degrees C) produced fairly rapid anisotropic grain growth. At 1750 degrees C, the anisotropic grain growth can be divided into two stages. In the first stage, the initial microstructure with an anisometric shape factor of 1.7 evolved rapidly into a microstructure with a shape factor of 2.7, consisting of a significant fraction of highly elongated grains. In the second stage, the microstructure evolved slowly into a system consisting of somewhat "blocky" grains with a shape factor of 2.2. The Al2O3 content of the mullite grains increased slightly and reached an equilibrium value during the first stage of anisotropic grain growth. For the samples annealed at 1750 degrees C, the indentation fracture toughness (2.5 +/- 0.2 MPa . m(1/2)) was almost independent of the anisometric shape factor. The interaction between the indentation cracks and the microstructure showed a predominantly transgranular mode of crack propagation. The data indicate that while a network of highly elongated grains can be developed by the present approach, some further manipulation of the grain boundary chemistry is required for an improvement of the fracture toughness. C1 Univ Missouri, Dept Ceram Engn, Rolla, MO 65401 USA. USAF, Res Lab, Mat & Mfg Directorate, WL MLLN, Wright Patterson AFB, OH 45433 USA. RP Huang, TH (reprint author), Univ Missouri, Dept Ceram Engn, Rolla, MO 65401 USA. NR 39 TC 39 Z9 41 U1 0 U2 6 PU AMER CERAMIC SOC PI WESTERVILLE PA 735 CERAMIC PLACE, PO BOX 6136, WESTERVILLE, OH 43081-6136 USA SN 0002-7820 J9 J AM CERAM SOC JI J. Am. Ceram. Soc. PD JAN PY 2000 VL 83 IS 1 BP 204 EP 210 DI 10.1111/j.1151-2916.2000.tb01171.x PG 7 WC Materials Science, Ceramics SC Materials Science GA 291XE UT WOS:000085764000030 ER PT J AU Radsick, T Saruhan, B Schneider, H AF Radsick, T Saruhan, B Schneider, H TI Damage tolerant oxide/oxide fiber laminate composites SO JOURNAL OF THE EUROPEAN CERAMIC SOCIETY LA English DT Article; Proceedings Paper CT International Workshop on Oxide/Oxide Composites (Oxide/Oxide 98) CY JUN 22-24, 1998 CL IRSEE, GERMANY SP USAF, United States European Off, USA, United States European Off, USN, United States European Off DE aluminosilicate fibers; composites; laminates; mechanical properties; mullite matrix ID CERAMIC-COMPOSITE; MULLITE; INTERFACES AB Oxide-fiber/oxide-matrix composites were developed using non-infiltrated woven fiber layers between matrix-infiltrated fiber layers in order to achieve damage tolerant behavior. A fiber interface coating was not used. This technique enables damage tolerance in materials with strong fiber-matrix bonding and under oxidizing conditions. Fabrication of composites was carried out through a slurry infiltration technique. Slurries for fiber (Nextel(TM) 720, 3M) infiltration were prepared using a submicron alpha-Al2O3 powder coated with an amorphous SiO2-layer through a sol-gel process. Hot-pressing was used to densify and bond the laminate layers together, followed by pressureless heat-treatment to allow mullite to form. Room temperature three-point bending tests were performed on as-received samples and on samples which underwent long-term annealing at high temperatures (1200-1300 degrees C) in air. Subsequent examination revealed that due to the lack of a fiber interface coating, matrix-infiltrated fiber layers behaved in a quasi-monolithic manner with little or no crack deflection. Layers of non-infiltrated fibers, however, provided damage tolerance by deflecting cracks in the plane of the laminate and by serving as a mechanical bond between matrix-infiltrated layers. The laminate composites demonstrate reasonable room-temperature fracture strength both in the as-received state (88 MPa) and after exposure to 1300 degrees C air for 200 h (72 MPa) along with extensive fracture deflection through the layers of non-infiltrated fiber. Composite properties, specifically fracture strength and damage tolerance, can be tailored by varying lay-up and processing parameters such as fiber-matrix ratio and type of fiber weave. (C) 2000 Elsevier Science Ltd. All rights reserved. C1 German Aerosp Ctr, Inst Mat Res, DLR, D-51147 Cologne, Germany. USAF, Res Lab, Wright Patterson AFB, OH 45433 USA. RP Schneider, H (reprint author), German Aerosp Ctr, Inst Mat Res, DLR, D-51147 Cologne, Germany. NR 11 TC 5 Z9 8 U1 0 U2 1 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0955-2219 J9 J EUR CERAM SOC JI J. European Ceram. Soc. PY 2000 VL 20 IS 5 BP 545 EP 550 DI 10.1016/S0955-2219(99)00252-6 PG 6 WC Materials Science, Ceramics SC Materials Science GA 293NB UT WOS:000085858000004 ER PT J AU Cinibulk, MK AF Cinibulk, MK TI Hexaluminates as a cleavable fiber-matrix interphase: synthesis, texture development, and phase compatibility SO JOURNAL OF THE EUROPEAN CERAMIC SOCIETY LA English DT Article; Proceedings Paper CT International Workshop on Oxide/Oxide Composites (Oxide/Oxide 98) CY JUN 22-24, 1998 CL IRSEE, GERMANY SP USAF, United States European Off, USA, United States European Off, USN, United States European Off DE aluminosilicate fibers; CaAl12O19; coatings; grain growth; interfaces; mechanical properties; YAG ID YTTRIUM-ALUMINUM-GARNET; BOEHMITE-DERIVED ALUMINA; CERAMIC COMPOSITES; LIQUID-PHASE; INTERFACIAL ROUGHNESS; CALCIUM HEXALUMINATE; ELECTRON-MICROSCOPY; CRYSTAL-STRUCTURE; SILICON-CARBIDE; SINGLE-CRYSTALS AB The current state of research on hexaluminates as a potential cleavable oxide fiber-matrix interphase is reviewed. Calcium hexaluminate was used initially to produce highly textured fiber coatings and interphases in single-crystal alumina fiber-based ceramic-matrix composites. Cracks were shown to deflect and propagate within the interphase by cleavage. Critical strain-energy release rates of 2.2 J/m(2) were measured for highly textured polycrystalline CaAl12O19 interphases. Subsequent work has focused on lowering the temperature for synthesis and texturing of both calcium- and lanthanum-based hexaluminates. Doping of hexaluminates, primarily with transition-metal oxides, allows for their formation at temperatures as low as 1000 degrees C. Grain-growth rates are about an order of magnitude greater than for undoped powders. Textured coatings have been grown on single-crystal YAG plates at 1200 degrees C. However, there does not seem to be an adequate driving force for grain growth and texturing of the coatings on polycrystalline alumina fibers (Nextel(TM) 610) at 1200 degrees C, the maximum processing temperature for these fibers. The lack of a more refractory, commercially available fiber that is phase compatible with the hexaluminates currently limits further development of a hexaluminate fiber-matrix interphase. (C) 2000 Elsevier Science Ltd. All rights reserved. C1 USAF, Res Lab, Mat & Mfg Directorate, Wright Patterson AFB, OH 45433 USA. RP Cinibulk, MK (reprint author), Universal Energy Syst Inc, Dayton, OH 45432 USA. NR 97 TC 24 Z9 26 U1 0 U2 9 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0955-2219 J9 J EUR CERAM SOC JI J. European Ceram. Soc. PY 2000 VL 20 IS 5 BP 569 EP 582 DI 10.1016/S0955-2219(99)00255-1 PG 14 WC Materials Science, Ceramics SC Materials Science GA 293NB UT WOS:000085858000007 ER PT J AU Hay, RS Boakye, E Petry, MD AF Hay, RS Boakye, E Petry, MD TI Effect of coating deposition temperature on monazite coated fiber SO JOURNAL OF THE EUROPEAN CERAMIC SOCIETY LA English DT Article; Proceedings Paper CT International Workshop on Oxide/Oxide Composites (Oxide/Oxide 98) CY JUN 22-24, 1998 CL IRSEE, GERMANY SP USAF, United States European Off, USA, United States European Off, USN, United States European Off DE aluminosilicate fibers; coating; grain growth; interfaces; LaPO4; mechanical properties ID CERAMIC-MATRIX COMPOSITES; TENSILE-STRENGTH; THIN-FILMS; CAPILLARY INSTABILITIES; BEHAVIOR; ALUMINA; YTTRIUM; INTERPHASE; LANTHANUM; OXIDE AB Monazite (LaPO4) was continuously coated on 3M Nextel(TM) 720 fiber tows with an ethanolic precursor using hexadecane for immiscible liquid displacement. Coating deposition temperatures were varied from 900 to 1300 degrees C. Fibers coated at 900 degrees C were heat-treated up to 100 h at 1200 degrees C. Coated fibers were characterized by analytical TEM, and tensile strengths were measured by single filament tensile tests. The monazite precursor was characterized by X-ray, DTA/TGA, and mass spectrometry. Microstructure evolution was complex and may have involved recrystallization of large defective grains into smaller grains and then subsequent growth of these grains, along with coarsening of porosity. After 100 h at 1200 degrees C there was significant roughening of the coating-fiber interface, with facetting of alumina grains in the fiber and some lanthanum segregation to these facetted boundaries. Spheroidization of thin coatings was also observed. Tensile strength of coated fiber decreased with increasing deposition temperature and with time at temperature after deposition. Possible reasons for the strength decrease are discussed. Published by Elsevier Science Ltd. C1 USAF, Res Lab, Mat Directorate, Wright Patterson AFB, OH 45433 USA. Universal Energy Syst Inc, Dayton, OH 45432 USA. RP Hay, RS (reprint author), USAF, Res Lab, Mat Directorate, Wright Patterson AFB, OH 45433 USA. NR 47 TC 34 Z9 35 U1 1 U2 12 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0955-2219 J9 J EUR CERAM SOC JI J. European Ceram. Soc. PY 2000 VL 20 IS 5 BP 589 EP 597 DI 10.1016/S0955-2219(99)00257-5 PG 9 WC Materials Science, Ceramics SC Materials Science GA 293NB UT WOS:000085858000009 ER PT J AU Josyula, E AF Josyula, E TI Computational study of vibrationally relaxing gas past blunt body in hypersonic flows SO JOURNAL OF THERMOPHYSICS AND HEAT TRANSFER LA English DT Article; Proceedings Paper CT AIAA 37th Aerospace Sciences Meeting CY JAN 11-14, 1999 CL RENO, NEVADA SP Amer Inst Aeronaut & Astronaut ID SHOCK-WAVES; NONEQUILIBRIUM; DISSOCIATION; RELAXATION; NITROGEN AB Numerical simulations are presented of a steady-state, hypersonic Row over a two-dimensional cylinder of 1 m radius under conditions where the relaxation of the vibrational modes is significant. A Mach 6.5 nitrogen flow was simulated at freestream pressures of 50, 250, and 500 Pa, with a freestream translational temperature of 300 K. Two different freestream vibrational temperatures, 300 K (causing vibrational heating) and 4000 K (causing vibrational cooling) were considered to study the effects on the flowfield. An upwind-difference numerical scheme was used to solve the inviscid Euler equations coupled to the vibrational kinetic models of diatomic nitrogen, assumed as an anharmonic oscillator of 40 quantum levels using two sets of reaction rates. Comparison with previously reported computations showed a maximum variation of 10% in translational and first-level vibrational temperature along the surface due to differences in numerical schemes and grid densities; variation caused hy the two different reaction rate sets was less than 2%. The vibrational cooling case showed a 10% higher shock-standoff distance than the vibrational heating case. The population distribution for the cooling Ease was non-Boltzmann due to nonresonant energy exchanges in the postshock region, greater in the shoulder region than in the stagnation region. An increase in freestream pressure for the cooling case increased the shock-standoff distance and non-Boltzmann behavior in the postshock region and near the surface. There was, however, a larger equilibrium region in between, in the stagnation region. C1 USAF, Res Lab, Air Vehicles Directorate, Wright Patterson AFB, OH 45433 USA. RP Josyula, E (reprint author), USAF, Res Lab, Air Vehicles Directorate, Wright Patterson AFB, OH 45433 USA. NR 19 TC 20 Z9 20 U1 0 U2 4 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 USA SN 0887-8722 J9 J THERMOPHYS HEAT TR JI J. Thermophys. Heat Transf. PD JAN-MAR PY 2000 VL 14 IS 1 BP 18 EP 26 DI 10.2514/2.6505 PG 9 WC Thermodynamics; Engineering, Mechanical SC Thermodynamics; Engineering GA 277YX UT WOS:000084962100002 ER PT J AU Hiers, RS AF Hiers, RS TI Critical behavior in small particle combustion SO JOURNAL OF THERMOPHYSICS AND HEAT TRANSFER LA English DT Article; Proceedings Paper CT AIAA 37th Aerospace Sciences Meeting CY JAN 11-14, 1999 CL RENO, NEVADA SP Amer Inst Aeronaut & Astronaut AB Small particles combusting under free molecular conditions are shown to exhibit critical behavior under conditions of high collision efficiency. At a particular collision efficiency, the particle behavior transitions from noncritical to critical (or runaway) behavior, Noncritical behavior is defined as a finite particle temperature at burnout, whereas critical behavior implies an infinitely increasing particle temperature at burnout. The critical collision efficiency is derived from the governing equations for free molecular combustion of small particles. The critical collision efficiency is shown to be a function of the specific heats of the gas and the particle and is independent of the particle size. Analytic and numerical results are compared. Particle radiation is included in the numerical results. The inclusion of radiation does not effect the critical collision efficiency, although radiation does decrease the rate of particle temperature increase. C1 Sverdrup Technol Inc, Space & Missiles Dept, AEDC Grp, Arnold Engn Dev Ctr, Arnold AFB, TN 37389 USA. RP Hiers, RS (reprint author), Sverdrup Technol Inc, Space & Missiles Dept, AEDC Grp, Arnold Engn Dev Ctr, Arnold AFB, TN 37389 USA. NR 14 TC 7 Z9 7 U1 0 U2 3 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 USA SN 0887-8722 J9 J THERMOPHYS HEAT TR JI J. Thermophys. Heat Transf. PD JAN-MAR PY 2000 VL 14 IS 1 BP 53 EP 58 DI 10.2514/2.6489 PG 6 WC Thermodynamics; Engineering, Mechanical SC Thermodynamics; Engineering GA 277YX UT WOS:000084962100006 ER PT J AU Shin, EE Morgan, RJ Zhou, JM Lincoln, J Jurek, R Curliss, DB AF Shin, EE Morgan, RJ Zhou, JM Lincoln, J Jurek, R Curliss, DB TI Hygrothermal durability and thermal aging behavior prediction of high-temperature polymer-matrix composites and their resins SO JOURNAL OF THERMOPLASTIC COMPOSITE MATERIALS LA English DT Article ID BISMALEIMIDE; CURE AB Prediction of the cure-induced T-g increases and associated matrix and composite mechanical property deterioration of BMI systems in real service environments is attempted by network structure interrelations with mechanical and thermal properties as a function of composition (initial monomer ratio) and time-temperature cure cycles. Tensile and flexural properties of four BMI compositions at six different cure cycles (or degree of cure) have been determined at three temperatures, 23 degrees C, 177 degrees C, and 250 degrees C, and correlated to T-g and density of the systems. Systematic studies on hygrothermal durability of bismaleimide (BMI) and various polyimide (PI)-carbon fiber composites and neat resins were conducted. The combined effects of moisture and thermal exposures such as hygrothermal spikes up to 250 degrees C and hygrothermal aging under various time-temperature-moisture conditions including accelerated aging at saturated steam environment(160 degrees C and 110 psi) on microscopic damage, polymer-matrix physical structural state, and residual properties of those composites and neat resins are presented. The onset of blistering in moist K3B PI C fiber composites occurred at 229 degrees C during the thermal spiking. It is evident that the hygrothermal performance stability is one of the prime guidelines in future aerospace applications, especially for PI composites. The physical and chemical structural state of PI matrices such as K3B and AFR700B as a function of hygrothermal exposure are discussed in terms of hydrolytic chemical degradation, moisture vapor-induced physical damage, and molecularly locked-in water. Those structural stares are characterized by systematic weight monitoring H-2 NMR, and various thermal, mechanical property measurements using D2O water environment. C1 Michigan State Univ, Adv Mat Engn Expt Stn, AMEES, Midland, MI 48640 USA. Mat Directorate, Wright Lab, WL, MLBC, Wright Patterson AFB, OH 45433 USA. RP Shin, EE (reprint author), Michigan State Univ, Adv Mat Engn Expt Stn, AMEES, 2203 Eastman Ave, Midland, MI 48640 USA. NR 21 TC 7 Z9 7 U1 1 U2 13 PU TECHNOMIC PUBL CO INC PI LANCASTER PA 851 NEW HOLLAND AVE, BOX 3535, LANCASTER, PA 17604 USA SN 0892-7057 J9 J THERMOPLAST COMPOS JI J. Thermoplast. Compos. Mater. PD JAN PY 2000 VL 13 IS 1 BP 40 EP 57 DI 10.1106/WKTW-G6RL-DNJF-EAK7 PG 18 WC Materials Science, Composites SC Materials Science GA 278QZ UT WOS:000085001600004 ER PT J AU Brooks, JP Tripp, HF AF Brooks, JP Tripp, HF TI Bioabsorbable weave technique for repair of pectus excavatum SO JOURNAL OF THORACIC AND CARDIOVASCULAR SURGERY LA English DT Article; Proceedings Paper CT American-College-of-Chest-Physicians Annual Meeting CY NOV 10, 1998 CL TORONTO, CANADA SP Amer Coll Chest Physicians ID COMPLICATION; MIGRATION C1 Brooke Army Med Ctr, Dept Cardiothorac Surg, Ft Sam Houston, TX 78234 USA. Wilford Hall USAF Med Ctr, Dept Gen Surg, Lackland AFB, TX 78236 USA. RP Tripp, HF (reprint author), SDC, MCHE, Dept Cardiothorac Surg, Bldg 3600,3851 Roger Brooke Dr, Ft Sam Houston, TX 78234 USA. NR 7 TC 1 Z9 1 U1 0 U2 0 PU MOSBY-YEAR BOOK INC PI ST LOUIS PA 11830 WESTLINE INDUSTRIAL DR, ST LOUIS, MO 63146-3318 USA SN 0022-5223 J9 J THORAC CARDIOV SUR JI J. Thorac. Cardiovasc. Surg. PD JAN PY 2000 VL 119 IS 1 BP 176 EP 178 DI 10.1016/S0022-5223(00)70238-8 PG 3 WC Cardiac & Cardiovascular Systems; Respiratory System; Surgery SC Cardiovascular System & Cardiology; Respiratory System; Surgery GA 276BZ UT WOS:000084856900036 PM 10612782 ER PT J AU Previc, FH Beer, J Liotti, M Blakemore, C Fox, P AF Previc, FH Beer, J Liotti, M Blakemore, C Fox, P TI Is "ambient vision" distributed in the brain? Effects of wide-field-view visual yaw motion on PET activation SO JOURNAL OF VESTIBULAR RESEARCH-EQUILIBRIUM & ORIENTATION LA English DT Article DE spatial orientation; laterality; functional imagings humans ID VESTIBULAR STIMULATION AB Ambient vision comprises the visual functions that are associated with the maintenance of spatial orientation and that depend on peripheral, preconscious visual inputs. Although a limited number of brain areas appear to be activated by coherent wide-field-of-view (WFOV) motion in more than one axis, a diffuse pattern of lateralized brain activity occurs in response to clockwise or counterclockwise ambient visual roll motion [15]. In the present study involving positron emission tomography (PET), a similar finding was shown for rightward versus leftward yaw stimulation. A total of 18 PET scans were obtained from six subjects in response to either leftward or rightward WFOV motion in a collimated display subtending > 100 degrees horizontally. Rightward stimulation elicited mainly activation throughout the right hemisphere, whereas leftward stimulation elicited mainly activation throughout the left hemisphere. These findings provide further evidence that the ambient vision signal is either processed or transmitted throughout the entire brain, as befits a visual function that is fundamental to all other perceptual systems. C1 USAF, Res Lab, Flight Mot Effects Branch, Brooks AFB, TX USA. Veridian Inc, San Antonio, TX USA. Univ Texas, Hlth Sci Ctr, Res Imaging Ctr, San Antonio, TX USA. Univ Oxford, Dept Physiol, Oxford, England. RP Previc, FH (reprint author), Litton TASC, 4241 Woodcock Dr,Ste B-100, San Antonio, TX 78228 USA. RI Fox, Peter/B-4725-2010 OI Fox, Peter/0000-0002-0465-2028 NR 16 TC 0 Z9 0 U1 0 U2 0 PU IOS PRESS PI AMSTERDAM PA NIEUWE HEMWEG 6B, 1013 BG AMSTERDAM, NETHERLANDS SN 0957-4271 J9 J VESTIBUL RES-EQUIL JI J. Vestib. Res.-Equilib. Orientat. PY 2000 VL 10 IS 4-5 BP 221 EP 225 PG 5 WC Neurosciences; Otorhinolaryngology SC Neurosciences & Neurology; Otorhinolaryngology GA 425UL UT WOS:000168310000006 PM 11354435 ER PT S AU Brasseur, JK Andersen, G Haris, PAT Knize, RJ AF Brasseur, JK Andersen, G Haris, PAT Knize, RJ BE Kamerman, GW Singh, UN Werner, C Molebny, VV TI Daytime holographic Raman lidar system SO LASER RADAR TECHNOLOGY AND APPLICATIONS V SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Laser Radar Technology and Applications V CY APR 26-28, 2000 CL ORLANDO, FL SP SPIE DE Raman lidar; lidar; holographic optical elements ID TEMPERATURE PROFILES AB We present a holographic Raman lidar system, which can provide temperature profiles of the atmosphere. The Raman lidar has the potential to operate continuously over a 24hr period, with a predicted accuracy of 1% at altitudes greater than 20km. The distinguishing feature of our lidar that allows 24hr measurements is the holographic optical element. The holographic optical element can resolve individual rotational Raman lines at high efficiency. Furthermore, this high resolution substantially increases the signal to noise of the lidar system, thereby allowing daytime measurements with out appreciable increase in error. C1 USAF Acad, Dept Phys, Laser & Opt Res Ctr, Colorado Springs, CO 80840 USA. RP Brasseur, JK (reprint author), USAF Acad, Dept Phys, Laser & Opt Res Ctr, Colorado Springs, CO 80840 USA. NR 16 TC 1 Z9 1 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-3661-5 J9 P SOC PHOTO-OPT INS PY 2000 VL 4035 BP 13 EP 21 DI 10.1117/12.397798 PG 9 WC Remote Sensing; Optics; Physics, Applied SC Remote Sensing; Optics; Physics GA BR61N UT WOS:000166958000002 ER PT S AU Richmond, R Stettner, R Glessner, J AF Richmond, R Stettner, R Glessner, J BE Kamerman, GW Singh, UN Werner, C Molebny, VV TI Eye safe laser radar focal plane array for three-dimensional imaging SO LASER RADAR TECHNOLOGY AND APPLICATIONS V SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Laser Radar Technology and Applications V CY APR 26-28, 2000 CL ORLANDO, FL SP SPIE DE laser radar imaging; three-dimensional imaging; eye safe laser radar AB Previous efforts to develop 3-D laser radar (ladar) imagers have required multiple laser pulses and complex stable scanning and timing systems in order to generate images. This paper describes the progress that has been made in a program developing an approach that will enable a complete 3-D ladar image (angle-angle-range) to be captured with a single pulse. It has been previously reported that a unique processor chip was designed and fabricated that was intended to be bump bonded directly behind a detector array, the sensor provides separate independent range finder circuitry for each pixel. The time-of-flight for each pixel is recorded on the chip and the values are then read out serially. This approach allows the range resolution to be determined by the laser pulse width and electronics bandwidth and to be independent of image framing rates. The original version of this concept is a 32x32-pixel device. A silicon photo-diode array was bonded to the processor chip. This limited the useful wavelength of the sensor 1 micron and below. Images generated using this sensor will be presented. The effects of shot-to-shot fluctuations, turbulence and scintillation on image quality will be discussed. The next generation, under development at this time, will also be presented. This sensor will be a 64x64-pixel device, The detectors will be electron-capture anode plates and the device will be sealed into an image intensifier tube. The photocathode material will be InGaAs, engineered to be sensitive to 1.5 microns. Results from the photocathode development effort, including quantum efficiency and micro-channel plate gain will be presented. C1 USAF, Res Lab, Wright Patterson AFB, OH 45433 USA. RP Richmond, R (reprint author), USAF, Res Lab, Wright Patterson AFB, OH 45433 USA. NR 2 TC 7 Z9 7 U1 0 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-3661-5 J9 P SOC PHOTO-OPT INS PY 2000 VL 4035 BP 172 EP 178 DI 10.1117/12.397790 PG 7 WC Remote Sensing; Optics; Physics, Applied SC Remote Sensing; Optics; Physics GA BR61N UT WOS:000166958000017 ER PT S AU Paxton, AH Latham, WP AF Paxton, AH Latham, WP BE Kudryashov, AV Paxton, AH TI Stable resonators with graded-phase (aspherical) mirrors SO LASER RESONATORS III SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT 3rd Conference on Laser Resonators CY JAN 26-28, 2000 CL SAN JOSE, CA SP SPIE AB Aspherical (graded-phase) mirrors [1-5] are potentially useful in stable resonators to obtain a desired intensity distribution at the output of a low-loss or moderate-loss resonator. The mode volume for single-mode operation can also be increased over that which can be obtained using a stable resonator. Much of the work on this concept to date has concentrated on resonators that have a super-gaussian mode at the output mirror. Here we explore some concepts involving other amplitude distributions that may be used to further enlarge the mode volume, although the output distribution may not be as desirable as the super gaussian. C1 USAF, Res Lab, DEOB, Kirtland AFB, NM 87117 USA. RP Paxton, AH (reprint author), USAF, Res Lab, DEOB, Kirtland AFB, NM 87117 USA. NR 5 TC 0 Z9 0 U1 0 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-3547-3 J9 P SOC PHOTO-OPT INS PY 2000 VL 3930 BP 45 EP 49 DI 10.1117/12.385411 PG 5 WC Optics SC Optics GA BQ31R UT WOS:000087916300005 ER PT S AU Bochove, EJ Denman, CA AF Bochove, EJ Denman, CA BE Kudryashov, AV Paxton, AH TI Analytical and numerical resonator analysis of spectral beam combining of Yb fiber lasers SO LASER RESONATORS III SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT 3rd Conference on Laser Resonators CY JAN 26-28, 2000 CL SAN JOSE, CA SP SPIE AB An analytical/numerical approach, based on the Van Vleck Green function, was developed in order to analyze spectrally multiplexed beam combining of a linear array of fiber lasers, in which a blazed diffraction grating located in an external cavity plays the role of a spatially dispersive element. The focus is on the laser-external cavity coupling, which determines excess cavity loss, as affected by primary aberrations of the transform lens. Other issues are also touched upon, however, such as beam quality and bandwidth dependence on element location, and the optimization of the latter. Analytical results were supported by a more general numerical implementation. Typical values for bandwidth were found optimally as low as a few GHz, which, being substantially narrower than the free-running fiber laser line-width, maximum power limits are foreseeably determined by stimulated light scattering. A rough but encouraging degree of agreement of the resonator theory with independent lens aberration calculations and preliminary experiments performed at MIT/LL using triplet and quadruplet transform lenses was encountered so far. C1 USAF, Res Lab, DELO, Kirtland AFB, NM 87117 USA. RP Bochove, EJ (reprint author), USAF, Res Lab, DELO, Kirtland AFB, NM 87117 USA. NR 7 TC 0 Z9 0 U1 2 U2 4 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-3547-3 J9 P SOC PHOTO-OPT INS PY 2000 VL 3930 BP 222 EP 233 DI 10.1117/12.385406 PG 12 WC Optics SC Optics GA BQ31R UT WOS:000087916300023 ER PT S AU Stokes, SD Eaton, FD Miller, JE AF Stokes, SD Eaton, FD Miller, JE BE Steiner, TD Merritt, PH TI Optical turbulence measurement and acoustic sounder calibration using hot-wire anemometers SO LASER WEAPONS TECHNOLOGY SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Laser Weapons Technology CY APR 24-25, 2000 CL ORLANDO, FL SP SPIE AB Optical turbulence conditions at a mountain peak (North Oscura Peak, NM) have been calculated using two hot-wire anemometers. The anemometers (running in constant current made, with a very low overheat ratio) measure temperature fluctuations. Combining the fluctuating temperature data with wind velocity data, local temperature and pressure, and invoking Taylor's hypothesis. the optical turbulence parameters can be calculated. These parameters include temperature structure parameter (C-t(2)) and the refractive index structure parameter (C-n(2)). The two probes are positioned at different elevations above the ground, thus the vertical optical turbulence gradient can be calculated. This relationship is used to calibrate an acoustic sounder. Optical turbulence data collected fi om the hot-wire anemometers as well as the acoustic sounder will be compared to meteorological events measured locally. Many days of data have been collected and will be shown, of particular interest is the relationship between optical turbulence and solar radiation, as well as wind speed and direction. The diurnal relationship of the optical turbulence gradient will also be shown. As well as the effect of this parameter on the acoustic sounder calibration. C1 USAF, Res Lab, Directed Energy Directorate, Kirtland AFB, NM 87117 USA. RP Stokes, SD (reprint author), USAF, Res Lab, Directed Energy Directorate, Kirtland AFB, NM 87117 USA. NR 10 TC 4 Z9 5 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-3660-7 J9 P SOC PHOTO-OPT INS PY 2000 VL 4034 BP 2 EP 11 DI 10.1117/12.391858 PG 10 WC Optics SC Optics GA BQ75K UT WOS:000089403300001 ER PT S AU Miller, JE Eaton, FD Stokes, SD AF Miller, JE Eaton, FD Stokes, SD BE Steiner, TD Merritt, PH TI Acoustic sounder system design for measurement of optical turbulence and wind profiles SO LASER WEAPONS TECHNOLOGY SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Laser Weapons Technology CY APR 24-25, 2000 CL ORLANDO, FL SP SPIE DE refractive index structure parameter; acoustic sounder; fine wire sensors; atmospheric propagation; atmospheric turbulence; sodar AB An Acoustic Sounder System has been installed on the side of the cliff at North Oscura Peak, WSMR to provide important refractive index structure parameter, Cn(2) data for laser propagation tests. The acoustic sounder system records echo information that is used to provide 3 dimensional wind and optical turbulence profiles. The received signal is the product of the interaction of the transmitted acoustic pulse with the small scale atmospheric temperature variations. This information is displayed as a time-height display of the signal intensity. The frequency of the received signals are processed and converted into time histories of the horizontal wind field. The data from the Acoustic Sounder is calibrated with the hot-wire anemometer temperature structure parameter (C-t(2)) data, and meteorological data measured locally to produce the C-n(2) profile. The design and location of the Acoustic Sounder System will be discussed along with the methodology of extracting the turbulence. Many days of data have been collected and representative data will be shown. C1 USAF, Res Lab, Directed Energy Directorate, Kirtland AFB, NM 87117 USA. RP Miller, JE (reprint author), USAF, Res Lab, Directed Energy Directorate, Kirtland AFB, NM 87117 USA. NR 4 TC 2 Z9 2 U1 0 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-3660-7 J9 P SOC PHOTO-OPT INS PY 2000 VL 4034 BP 12 EP 21 DI 10.1117/12.391866 PG 10 WC Optics SC Optics GA BQ75K UT WOS:000089403300002 ER PT S AU Eaton, FD Miller, JE Stokes, SD Underwood, KH AF Eaton, FD Miller, JE Stokes, SD Underwood, KH BE Steiner, TD Merritt, PH TI Optical turbulence measurements at a mountain ridge SO LASER WEAPONS TECHNOLOGY SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Laser Weapons Technology CY APR 24-25, 2000 CL ORLANDO, FL SP SPIE DE refractive index structure parameter; sodar; fine wire sensors; atmospheric propagation; complex terrain ID STRUCTURE PARAMETER; SODAR AB The optical turbulence conditions at a mountain ridge (North Oscuro Peak, White Sands Missile Range, NM) were determined fi-om observations of fine wire sensors and a sodar (sonic detection and ranging). Both instruments provided the temperature structure parameter (C-T(2)) from which the refractive index structure parameter (C-n(2)) was calculated using local measurements of temperature and pressure. The fine wire measurements were used to calibrate the sodar. Atmospheric measurements shown include wind speed and direction, temperature, and solar radiation sensed horizontally as well as parallel to the west-facing slope. Of particular emphasis is the relationship of the sodar observations to solar radiation and wind speed and direction. The results are explained in terms of the geometry of the site and the mountain-valley wind regime, Results are shown as average range profiles of C-n(2) sensed at various zenith angles at different times of the day and as contours of C-n(2) in a vertical plane oriented normal to the west-facing slope. C1 USAF, Res Lab, Directed Energy Directorate, Kirtland AFB, NM 87117 USA. RP Eaton, FD (reprint author), USAF, Res Lab, Directed Energy Directorate, Kirtland AFB, NM 87117 USA. NR 18 TC 2 Z9 3 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-3660-7 J9 P SOC PHOTO-OPT INS PY 2000 VL 4034 BP 22 EP 32 DI 10.1117/12.391875 PG 11 WC Optics SC Optics GA BQ75K UT WOS:000089403300003 ER PT S AU Beland, RR Roadcap, JR AF Beland, RR Roadcap, JR BE Steiner, TD Merritt, PH TI Analysis of atmospheric effects on stellar scintillation SO LASER WEAPONS TECHNOLOGY SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Laser Weapons Technology CY APR 24-25, 2000 CL ORLANDO, FL SP SPIE DE scintillometer; optical turbulence; index of refraction; Rytov theory; atmospheric dispersion AB Atmospheric effects on normalized stellar irradiance fluctuations for the weak fluctuation regime are examined. Both monochromatic and polychromatic effects are considered. Calculations are performed using a Rytov theory which explicitly includes refractive effects arising from the polychromatic stellar source. The atmospheric turbulence along the path is specified in a spherical shell or "onion-skin" model using a vertical profile specified by either the Clear 1 model or actual thermosonde measurements. Finite optical bandwidth, receiver aperture size, and variable turbulent inner scale are also included. Good agreement is found between,ground-based measurements and model results in the weak scintillation regime. It is also shown that refraction effects can significantly alter the wavelength dependence of scintillation as well as produce a leveling off and decrease of scintillation with increasing zenith angle that could be misinterpreted as saturation. C1 USAF, Res Lab, Hanscom AFB, MA 01731 USA. RP Beland, RR (reprint author), USAF, Res Lab, Hanscom AFB, MA 01731 USA. NR 8 TC 1 Z9 1 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-3660-7 J9 P SOC PHOTO-OPT INS PY 2000 VL 4034 BP 33 EP 40 DI 10.1117/12.391876 PG 8 WC Optics SC Optics GA BQ75K UT WOS:000089403300004 ER PT S AU Oppenheimer, MW Pachter, M AF Oppenheimer, MW Pachter, M BE Steiner, TD Merritt, PH TI Algorithm development for real-time control of the AirBorne Laser SO LASER WEAPONS TECHNOLOGY SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Laser Weapons Technology CY APR 24-25, 2000 CL ORLANDO, FL SP SPIE DE adaptive optics; Kalman Filtering; atmospheric compensation AB Two wave fronts are of interest in the AirBorne Laser, namely, the inbound wave front from the "beacon" and the outbound wave front of the high-energy laser (HEL). Since these two wave fronts propagate through different regions of the atmosphere and at different time instants, the spatial-temporal correlation between the Zernike polynomials' phase expansion coefficients representing these wave fronts must be determined. Using this correlation information, an underlying linear, stochastic, dynamical system that represents the atmosphere is identified. The wave front sensor and deformable mirror dynamics are also modeled. These models are then used in a Kalman filter which provides estimates of the outbound wave front's Zernike coefficients using measurements of the inbound wave front. A linear quadratic controller is also developed so that conjugation, that is, atmospheric compensation, can be performed. The designed adaptive optics control system's performance is evaluated in a simulated experiment. C1 USAF, Inst Technol, Dept Elect Engn, Wright Patterson AFB, OH 45433 USA. RP Oppenheimer, MW (reprint author), USAF, Inst Technol, Dept Elect Engn, 2950 P St,Bldg 640, Wright Patterson AFB, OH 45433 USA. NR 6 TC 1 Z9 1 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-3660-7 J9 P SOC PHOTO-OPT INS PY 2000 VL 4034 BP 201 EP 212 DI 10.1117/12.391872 PG 12 WC Optics SC Optics GA BQ75K UT WOS:000089403300021 ER PT S AU Lott, JA Ledentsov, NN Ustinov, VM Maleev, NA Zhukov, AE Kovsh, AR Maximov, MV Volovik, BV Alferov, ZI Bimberg, D AF Lott, JA Ledentsov, NN Ustinov, VM Maleev, NA Zhukov, AE Kovsh, AR Maximov, MV Volovik, BV Alferov, ZI Bimberg, D GP IEEE IEEE TI Room temperature continuous wave InAs-InGaAs quantum dot VCSELs on GaAs substrates emitting at 1.3 mu m SO LEOS 2000 - IEEE ANNUAL MEETING CONFERENCE PROCEEDINGS, VOLS. 1 & 2 SE IEEE Lasers and Electro-Optics Society (LEOS) Annual Meeting LA English DT Proceedings Paper CT 13th Annual Meeting of the IEEE Lasers-and-Electro-Optics-Society CY NOV 13-16, 2000 CL RIO GRANDE, PR SP IEEE, Laser & Electroopt Soc, IEEE, Networking World ID LASER C1 USAF, Inst Technol, Dept Elect & Comp Engn, Wright Patterson AFB, OH 45433 USA. RP Lott, JA (reprint author), USAF, Inst Technol, Dept Elect & Comp Engn, Wright Patterson AFB, OH 45433 USA. RI Zhukov, Alexey/A-5523-2014; Maleev, Nikolay/D-7873-2014; Maximov, Mikhail/A-8562-2014 OI Zhukov, Alexey/0000-0002-4579-0718; NR 4 TC 2 Z9 2 U1 0 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1092-8081 BN 0-7803-5947-X J9 IEEE LEOS ANN MTG PY 2000 BP 304 EP 305 PG 2 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA BR17V UT WOS:000165806400155 ER PT S AU Russell, TH Roh, WB Marciante, JR AF Russell, TH Roh, WB Marciante, JR GP IEEE IEEE TI Incoherent laser beam combining via stimulated Brillouin scattering in multimode fibers SO LEOS 2000 - IEEE ANNUAL MEETING CONFERENCE PROCEEDINGS, VOLS. 1 & 2 SE IEEE Lasers and Electro-Optics Society (LEOS) Annual Meeting LA English DT Proceedings Paper CT 13th Annual Meeting of the IEEE Lasers-and-Electro-Optics-Society CY NOV 13-16, 2000 CL RIO GRANDE, PR SP IEEE, Laser & Electroopt Soc, IEEE, Networking World C1 USAF, AFIT ENP, Wright Patterson AFB, OH 45433 USA. RP Russell, TH (reprint author), USAF, AFIT ENP, 2950 P St, Wright Patterson AFB, OH 45433 USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1092-8081 BN 0-7803-5947-X J9 IEEE LEOS ANN MTG PY 2000 BP 593 EP 594 PG 2 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA BR17V UT WOS:000165806400299 ER PT S AU Moore, GT AF Moore, GT GP IEEE IEEE TI Prospects for diffraction-limited high-power multi-mode fiber amplifiers and amplifier arrays using SBS phase conjugation SO LEOS 2000 - IEEE ANNUAL MEETING CONFERENCE PROCEEDINGS, VOLS. 1 & 2 SE IEEE Lasers and Electro-Optics Society (LEOS) Annual Meeting LA English DT Proceedings Paper CT 13th Annual Meeting of the IEEE Lasers-and-Electro-Optics-Society CY NOV 13-16, 2000 CL RIO GRANDE, PR SP IEEE, Laser & Electroopt Soc, IEEE, Networking World ID STIMULATED BRILLOUIN-SCATTERING C1 USAF, Res Lab, Directed Energy Directorate, AFRL DELO, Kirtland AFB, NM 87117 USA. RP Moore, GT (reprint author), USAF, Res Lab, Directed Energy Directorate, AFRL DELO, 3550 Aberdeen Ave SE, Kirtland AFB, NM 87117 USA. NR 7 TC 0 Z9 0 U1 0 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1092-8081 BN 0-7803-5947-X J9 IEEE LEOS ANN MTG PY 2000 BP 595 EP 596 PG 2 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA BR17V UT WOS:000165806400300 ER PT J AU Haefner, J Holcomb, T AF Haefner, J Holcomb, T TI The Picard group of a structural matrix algebra SO LINEAR ALGEBRA AND ITS APPLICATIONS LA English DT Article DE preordered sets; partially ordered sets; incidence rings; Picard group; automorphisms ID GRADED EQUIVALENCE; CROSSED-PRODUCTS; AUTOMORPHISMS; RINGS AB We investigate the Picard group of a structural matrix (or incidence) algebra A of a finite preordered set P over a field and we consider five interrelated problems. Our main technique involves establishing a connection between the group of outer automorphisms Out(A) of A and the group of outer automorphisms of the basic algebra (A) over tilde which is an incidence algebra of the associated partially ordered set (P) over tilde of P. We discuss necessary and sufficient conditions for Out(A) to be a natural invariant for the Morita equivalence class of A, and necessary and sufficient conditions for M-n(K) to be strongly graded by a group G and coefficient ring A containing n primitive, orthogonal idempotents. (C) 2000 Published by Elsevier Science Inc. All rights reserved. C1 Univ Colorado, Dept Math, Colorado Springs, CO 80933 USA. USAF Acad, Dept Math, Colorado Springs, CO 80840 USA. RP Haefner, J (reprint author), Univ Colorado, Dept Math, Colorado Springs, CO 80933 USA. NR 25 TC 1 Z9 1 U1 0 U2 0 PU ELSEVIER SCIENCE INC PI NEW YORK PA 655 AVENUE OF THE AMERICAS, NEW YORK, NY 10010 USA SN 0024-3795 J9 LINEAR ALGEBRA APPL JI Linear Alg. Appl. PD JAN 1 PY 2000 VL 304 IS 1-3 BP 69 EP 101 DI 10.1016/S0024-3795(99)00200-1 PG 33 WC Mathematics, Applied; Mathematics SC Mathematics GA 272UW UT WOS:000084670200004 ER PT S AU Yeates, AT Dudis, DS Wilkes, JS AF Yeates, AT Dudis, DS Wilkes, JS BE Eich, M Kuzyk, MG Lawson, CM Norwood, RA TI Nonlinear optical properties of the salts of "diffuse" anions SO LINEAR, NONLINEAR, AND POWER-LIMITING ORGANICS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Linear, Nonlinear, and Power-Limiting Organics CY JUL 31-AUG 03, 2000 CL SAN DIEGO, CA SP SPIE AB A new class of materials, which demonstrates a potentially high third-order nonlinear optical (NLO) response based on highly polarizable anions, is discussed. Two examples of such ions included in this article are trithiocarbonate (CS32-) and aci-nitro-dithioacetate (NO2CHCS22-). The NLO response of any real materials containing these ions will be highly dependent on the nature of the cation present. It is expected that smaller and more localizing cations will have a smaller NLO response. We have performed ab initio finite-field computations of several anions along with some salts of the aci-nitro-dithioacetate anion to illustrate this effect. C1 USAF, Res Lab, Wright Patterson AFB, OH 45433 USA. RP Yeates, AT (reprint author), USAF, Res Lab, Wright Patterson AFB, OH 45433 USA. NR 9 TC 4 Z9 4 U1 1 U2 2 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-3751-4 J9 P SOC PHOTO-OPT INS PY 2000 VL 4106 BP 334 EP 337 DI 10.1117/12.408521 PG 4 WC Chemistry, Physical; Materials Science, Multidisciplinary; Optics; Physics, Condensed Matter SC Chemistry; Materials Science; Optics; Physics GA BR65Z UT WOS:000167102600036 ER PT S AU Restaino, SR Baker, JT Dayton, D Finkner, LG AF Restaino, SR Baker, JT Dayton, D Finkner, LG BE Shashidhar, R Gnade, B TI Experimental results from an adaptive optics system based on a dual frequency nematic device. SO LIQUID CRYSTAL MATERIALS, DEVICES, AND FLAT PANEL DISPLAYS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Liquid Crystal Materials, Devices, and Flat Panel Displays CY JAN 27-28, 2000 CL SAN JOSE, CA SP Soc Imaging Sci & Technol, SPIE ID CRYSTAL PHASE MODULATOR; LIQUID-CRYSTAL; LIGHT; PERFORMANCE AB The use of liquid crystal devices for wavefront control has been suggested and implemented by several authors. Our group has been at the forefront of the development of this technology. In this paper we report some preliminary experimental results on the use of Nematic based liquid crystal devices. Several experimental efforts have been carried out in the past few months. One of the main aims was to characterize a new devices that uses dual frequency nematic material. C1 USAF, Res Lab, DEBS, Kirtland AFB, NM 87117 USA. RP Restaino, SR (reprint author), USAF, Res Lab, DEBS, 3550 Aberdeen SE, Kirtland AFB, NM 87117 USA. NR 16 TC 0 Z9 0 U1 0 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-3573-2 J9 P SOC PHOTO-OPT INS PY 2000 VL 3955 BP 54 EP 57 DI 10.1117/12.379982 PG 4 WC Engineering, Electrical & Electronic; Optics SC Engineering; Optics GA BP99Q UT WOS:000086845600006 ER PT B AU Fellner, JP Marsh, RA AF Fellner, JP Marsh, RA BE Surampudi, S Marsh, RA Ogumi, Z Prakash, J TI Use of pulse current and AC impedance characterization to enhance lithium-ion battery performance SO LITHIUM BATTERIES, PROCEEDINGS SE ELECTROCHEMICAL SOCIETY SERIES LA English DT Proceedings Paper CT International Symposium on Lithium Batteries of the 196th Electrochemical-Society Fall Meeting CY OCT 17-22, 1999 CL HONOLULU, HI SP Electrochem Soc, Battery Div, Electrochem Soc, Energy Technol Div AB Performance of lithium-ion batteries at low temperatures and/or high rates is relatively poor due to high cell internal impedance. AC impedance spectroscopy was utilized to determine the impedance characteristics of lithium-ion cells as a function of state-of-charge, temperature, and cycle number. From this impedance characterization, optimal pulse current discharge times and discharge battery temperatures were selected to enhance the lithium-ion battery discharge performance. C1 USAF, Res Lab, Prop Directorate, Wright Patterson AFB, OH 45433 USA. RP Fellner, JP (reprint author), USAF, Res Lab, Prop Directorate, 1950 5th St, Wright Patterson AFB, OH 45433 USA. NR 4 TC 0 Z9 0 U1 0 U2 0 PU ELECTROCHEMICAL SOCIETY INC PI PENNINGTON PA 65 S MAIN ST, PENNINGTON, NJ 08534-2839 USA BN 1-56677-248-6 J9 ELEC SOC S PY 2000 VL 99 IS 25 BP 657 EP 663 PG 3 WC Electrochemistry SC Electrochemistry GA BQ33W UT WOS:000088014200066 ER PT B AU Fenner, LM AF Fenner, LM BE Simon, RJ TI There then, where now? Military women in the 21st century SO LOOK BACKWARD AND FORWARD AT AMERICAN PROFESSIONAL WOMEN AND THEIR FAMILIES LA English DT Proceedings Paper CT 4th Annual Conference of the Womens Freedom Network CY OCT 18, 1997 CL WASHINGTON, D.C. C1 USAF, Washington, DC 20330 USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU UNIV PRESS AMER PI LANHAM PA 4720 BOSTON WAY, LANHAM, MD 20706 USA BN 0-7618-1581-3 PY 2000 BP 83 EP 89 PG 7 WC Family Studies; Women's Studies SC Family Studies; Women's Studies GA BQ06D UT WOS:000087021700011 ER PT J AU Gschwender, LJ Snyder, CE AF Gschwender, LJ Snyder, CE TI High temperature oxidative stability of C3F7O[CF(CF3)CF2O](x)C3F7 and CF3(OCF2CF2CF2)(y)CF3 perfluoropolyalkylethers and formulations in the presence of metals (c) SO LUBRICATION ENGINEERING LA English DT Article ID POLY(HEXAFLUOROPROPENE OXIDE) FLUIDS; LUBRICANTS AB Perfluoropolyalkylethers (PFPAEs) are being extensively evaluated as candidate high temperature future gas turbine engine oils for the US Air Force. In order to better recommend fluid formulations for an operational engine system, the following matrix of base fluids, additives and metals was evaluated in high temperature oxidation experiments.. Two commercially available base fluids ere used, both with C3F6O repeating backbone units, one linear and the other branched. Four performance improving additives were used at 1% by weight: a perfluoroalkyldiphenylether, a perfluoroalkyltriphenylether, a tri(perfluoropolyalkyletherphenyl) phosphine and a perfluoropolyalkylether bis-benzothiazole. Two sets of metal coupons were used: one set of steels (4140, 52100 410, M50 and 440C) and the other set Ti and Ti alloys (6Al4V, pure Ti and 4Al4Mn). Test temperatures were 260 degrees C to 370 degrees C. In addition, the linear fluid with 1% tri(perfluoropolyalkyletherphenyl) phosphine was also evaluated at 330 degrees C in the presence of thin dense chrome plated M-50, inconel, silver waspaloy and Haynes 214 metals. The data are presented and generalizations noted. C1 Wright Patterson AFB, Wright Patterson AFB, OH USA. RP Gschwender, LJ (reprint author), Wright Patterson AFB, Wright Patterson AFB, OH USA. NR 14 TC 0 Z9 0 U1 1 U2 1 PU SOC TRIBOLOGISTS & LUBRICATION ENGINEERS PI PARK RIDGE PA 840 BUSSE HIGHWAY, PARK RIDGE, IL 60068 USA SN 0024-7154 J9 LUBR ENG JI Lubric. Eng. PD JAN PY 2000 VL 56 IS 1 BP 17 EP 22 PG 6 WC Engineering, Mechanical SC Engineering GA 273UX UT WOS:000084727200007 ER PT J AU Leitner, G Westmoreland, D Knapp, M Spencer, K Merback, J Kuzik, V Temmel, W Schubert, K Porta, S AF Leitner, G Westmoreland, D Knapp, M Spencer, K Merback, J Kuzik, V Temmel, W Schubert, K Porta, S TI Stress compatibility and electrolyte dynamics of sports majors (SM) and language majors (LM) at examination time SO MAGNESIUM-BULLETIN LA English DT Article ID MAGNESIUM AB Objectivation of a so called school stress was tried to be achieved by measuring blood gas, electrolyte, lactate and blood glucose alterations after standardized cycle ergometry (post stress provocation test, Porta et al. 1993) out of different basal situations and with two different groups of probands. Since catecholamines and many of their effects are additive, reaction to cycle ergometry depends upon basal values and personal circumstances. Basal values have been altered by applying one and the same test once during relative school stress free autumn and once during busy examination time in January. Personal circumstances were taken into consideration by testing a group of more sedentary female Language majors against a group of nearly professionally managed soccer players from the same school and the same average age of about 17. It turned out that already basal values in autumn and January were significantly different in many cases. Reaction to exercise was also much more pronounced in January in both groups. However. the sport group obviously could take higher stress levels at examination time significantly better than the language majors, a fact deducible by significantly different basal values of higher pH and lower pCO(2) and much lower exercise induced alterations in lactate (ca.50 %), much less decrease in base excess, higher pH and many other parameters. Physical training seems to diminish psychologically induced catecholamine effects significantly. Of special importance seems to be the low magnesium status of the female probands and the much better situation in sportsmen, in spilt of intensive training. Instructions by trainers could be the reason. The more so, as the satisfactory Mg status of autumn deteriorates in the winter off season rime. Thus, impact of school stress is measurable not only by psychological but also by serological methods, which may even be of mutual support. The upsetting magnesium situation. especially of our female probands should be carefully followed up concerning a possible general deficiency. C1 Inst Appl Stress Res, A-8490 Bad Radkersburg, Austria. Karl Franzens Univ Graz, Inst Pathophysiol, Graz, Austria. USAF Acad, Dept Biol, Colorado Springs, CO 80840 USA. Sechenov Inst Physiol & Biochem, St Petersburg, Russia. Karl Franzens Univ Graz, Dept Internal Med, Div Nephrol, Graz, Austria. RP Porta, S (reprint author), Inst Appl Stress Res, Hauptpl 2-4, A-8490 Bad Radkersburg, Austria. NR 6 TC 1 Z9 1 U1 0 U2 2 PU KARL F HAUG VERLAG, HUTHIG GMBH PI HEIDELBERG PA IM WEIHER 10, 69121 HEIDELBERG, GERMANY SN 0172-908X J9 MAGNESIUM-B JI Magnes.-Bull. PY 2000 VL 22 IS 3 BP 66 EP 71 PG 6 WC Biochemistry & Molecular Biology; Endocrinology & Metabolism SC Biochemistry & Molecular Biology; Endocrinology & Metabolism GA 362QM UT WOS:000089789800003 ER PT J AU Leitner, G Westmoreland, D Knapp, M Spencer, K Merback, J Kuzik, V Weger, M Pfannhauser, W Porta, S AF Leitner, G Westmoreland, D Knapp, M Spencer, K Merback, J Kuzik, V Weger, M Pfannhauser, W Porta, S TI Stress induced electrolyte and blood gas changes with and without a six days oral treatment with elderberry (Sambucus Nigra L.) concentrate SO MAGNESIUM-BULLETIN LA English DT Article AB Elderberry juice has a very high content of phenolic compounds. These phenolic constituents of the elderberry have been the focus of attention in recent studies. By a very delicate process the constituents of the elderberry can be concentrated. In the liquid product the anthocyanins are concentrated eleven- and nine-fold respectively containing 130 000 mg/l of anthocyanines and 30 000 mg/l of catechins. The capsule formula (400 mg dry powder per capsule) contains 140 mg of anthocyanins and 34 mp of catechins each. We investigated the impact of a daily intake of 7 000 mg of anthocyanins and 1 700 mg of catechins on 15 human probands. Their reaction to a standardized bicycle ergometry before and after six days of elderberry concentrate treatment was tested by determination of blood gases, ionized electrolytes, lactate and blood glucose. Basal values before ergometric workload showed significant differences after the elderberry concentrate treatment: pH from 7,372 to 7,428 (p = 0.00003), pCO(2) from 40,2 to 33,2 (p = 0.000006), HCO3 from 22,74 to 21,24 (p = 0.0014), pO(2) from 79 to 65 mmHg (p = 0.0004), O-2 saturation from 94.8 to 92,7 (p = 0.01). Lactate. blood sugar, calcium and sodium were not significantly different before and after elderberry treatment. However, ionized magnesium was significantly lower after treatment (iMg from 0,54 to 0,46 mmol/L, p = 0.0001). The impact of the standardized ergometric workload before and after treatment also resulted in various alterations of the parameters measured: after elderberry treatment O2 sat significantly increased after ergometry (p = 0,002), magnesium and blood glucose significantly decreased (p = 0.0004 and p = 0,04, resp.). Lactate delta values were significantly increased after treatment (D = 0,04). Treatment with elderberry concentrate seems to lead to a considerable increase of metabolism, shown by decreased basal values of pCO(2), increased pH and - interestingly - at the same time decreased pO(2) accompanied by decreased magnesium levels. Thus, tissue seems to take up more oxygen (n spite of increased pH) due to and resulting in increased breathing frequency. This and a more pronounced blood glucose and lactate alteration after ergometry along with a drastic fall in ionized serum magnesium are indicators of a boosted metabolism. We suggest that treatment with anthocyanines and polphenoles is increasing metabolic turnover leading to a magnesium deficient status in the long run. In further investigations the feasibility of an accompanying magnesium substitution to stabilize metabolic effects should be undertaken. C1 Inst Appl Stress Res, A-8490 Bad Radkersburg, Austria. Karl Franzens Univ Graz, Dept Internal Med, Div Nephrol, Graz, Austria. Karl Franzens Univ Graz, Inst Pathophysiol, Graz, Austria. USAF Acad, Dept Biol, Colorado Springs, CO 80840 USA. IM Sechenov Evolut Physiol & Biochem Inst, St Petersburg 194223, Russia. Graz Tech Univ, Inst Biochem & Foodchem, Dept Foodchem, A-8010 Graz, Austria. RP Porta, S (reprint author), Inst Appl Stress Res, Hauptpl 2-4, A-8490 Bad Radkersburg, Austria. NR 7 TC 1 Z9 1 U1 1 U2 3 PU KARL F HAUG VERLAG, HUTHIG GMBH PI HEIDELBERG PA IM WEIHER 10, 69121 HEIDELBERG, GERMANY SN 0172-908X J9 MAGNESIUM-B JI Magnes.-Bull. PY 2000 VL 22 IS 3 BP 72 EP 76 PG 5 WC Biochemistry & Molecular Biology; Endocrinology & Metabolism SC Biochemistry & Molecular Biology; Endocrinology & Metabolism GA 362QM UT WOS:000089789800004 ER PT J AU Leitner, G Porta, S Westmoreland, D Knapp, M Spencer, K Merback, J Leitner, T AF Leitner, G Porta, S Westmoreland, D Knapp, M Spencer, K Merback, J Leitner, T TI An experiment to correct magnesium deficiency in Austrian rural areas by magnesium rich foodstuff SO MAGNESIUM-BULLETIN LA English DT Article AB 15 female students of a rural agricultural school have been subjected to a standardized cycle ergometry, whereby blood gases, electrolytes, lactate and blood glucose were measured before and after exercise. During the following 10 days a calcium and magnesium enriched diet was provided and afterwards the same blood sampling and ergometry exercise was carried out once mole. It turned out, that a magnesium enriched diet was just able to increase the average, hypomagnesemic ionised serum levels (from 0.44 +/- 0.01 SEM mM/l to 0.46 +/- 0.01 SEM mM/l). Even that would have been to no avail, unless a magnesium rich mineral water (206 mg of magnesium/l) would have been offered at the same time. Obviously, the most important prohibiting factor for a sufficient magnesium intake in the female age group of about 16 is a general avoidance of food in order to reach or keep up slenderness. Although there were no diet induced alterations of the averages of blood gas reactions to ergometry to be seen, ensuing proportionalities of individual base excess and pH, base excess and lactate, but not lactate - pH values suggest a decreased lipolysis after increased magnesium diet in those participants with sufficient uptake [1, 2]. A low calory magnesium supplement has been recommended. C1 Inst Appl Stress Res, A-8490 Bad Radkersburg, Austria. Karl Franzens Univ Graz, Inst Pathophysiol, Graz, Austria. USAF Acad, Dept Biol, Colorado Springs, CO 80840 USA. RP Porta, S (reprint author), Inst Appl Stress Res, Hauptplatz 2-4, A-8490 Bad Radkersburg, Austria. NR 6 TC 2 Z9 2 U1 0 U2 1 PU KARL F HAUG VERLAG, HUTHIG GMBH PI HEIDELBERG PA IM WEIHER 10, 69121 HEIDELBERG, GERMANY SN 0172-908X J9 MAGNESIUM-B JI Magnes.-Bull. PY 2000 VL 22 IS 4 BP 87 EP 91 PG 5 WC Biochemistry & Molecular Biology; Endocrinology & Metabolism SC Biochemistry & Molecular Biology; Endocrinology & Metabolism GA 393MR UT WOS:000166474700002 ER PT S AU Chun, FK Russell, CT AF Chun, FK Russell, CT BE Ohtani, S Fujii, R Hesse, M Lysak, RL TI Statistical characteristics of field-aligned currents in the earth's inner magnetosphere SO MAGNETOSPHERIC CURRENT SYSTEMS SE GEOPHYSICAL MONOGRAPH SERIES LA English DT Proceedings Paper CT Conference on Magnetospheric Current Systems CY JAN 10-15, 1999 CL KONA, HI SP Amer Geophys Union, Natl Sci Fdn, NASA, USN Off Naval Res ID BIRKELAND CURRENTS; DISTURBANCE FIELD; SUBSTORMS AB Field-aligned currents (FACs) play a major role in the solar wind-magnetospheric interaction by electrodynamically coupling magnetospheric and ionospheric plasmas, so that stresses applied to the outer magnetospheric plasma are transmitted to the ionosphere and ultimately to the upper atmosphere. FACs have been studied extensively since 1967 and most of our statistical knowledge and understanding of this coupling mechanism is based on data from low-altitude polar orbiting satellites. In this paper, we present results from a statistical study of the inner magnetosphere FACs. Specifically, we examine their current intensity, current density, current sheet thickness, and current sheet velocity. Our data extends over the first 360 orbits of ISEE-1 and 2, and ranges over all local times and from altitudes between 2-9 R-E. We extrapolate our data down to ionospheric altitudes for comparison with low-altitude FACs. We also determine the location of the FACs as well as how closely they resemble sheets of current. We find that. quasi-stationary FACs (FACs which move very slowly compared to transient events) are magnetospheric extensions of the low-altitude region 1 and 2 currents. Inner magnetosphere FAC characteristics are, consistent with the region 1 and 2 currents, with densities on the order of a few muA/m(2). Velocities and thickness extrapolated to the ionosphere are also consistent with auroral structures. Current sense and location also resemble region 1 and 2 currents, with inner magnetosphere FACs flowing into the ionosphere on the dawn side poleward of the outward flowing currents, and opposite for the dusk side. Finally, we find that the currents are most sheet-like in the dawn and dusk sectors and least two dimensional at noon and midnight. C1 USAF Acad, Dept Phys, Colorado Springs, CO 80840 USA. RP Chun, FK (reprint author), USAF Acad, Dept Phys, 2354 Fairchild Dr,Suite 2A31, Colorado Springs, CO 80840 USA. OI Russell, Christopher/0000-0003-1639-8298 NR 15 TC 1 Z9 1 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0065-8448 BN 0-87590-976-0 J9 GEOPH MONOG SERIES PY 2000 VL 118 BP 237 EP 243 PG 7 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA BV01G UT WOS:000177598400023 ER PT J AU Bhat, GS Wapner, PG Hoffman, WP AF Bhat, GS Wapner, PG Hoffman, WP TI Processing of a high temperature imide copolymer into hollow fibers SO MATERIALS AND MANUFACTURING PROCESSES LA English DT Article AB Hollow fibers spun from synthetic fiber forming polymers have been of interest, especially for producing high-bulk, low-density fabrics. Such fibers produced from a high temperature resistant polymer provide a number of advantages in certain applications. Ultem, a polyetherimide resin marketed by General Electric company, is a copolymer with ether molecules between imide groups and is thermoplastic. Being an amorphous thermoplastic polyimide, the Ultem resin combines the high performance associated with exotic specialty polymers and the good processability of typical engineering plastics. Equipment was built at the Air Force Research Laboratory of Edwards AFB, CA to spin hollow fibers. The spinneret designed has a hollow tube supported in the center of the orifice, and an inert gas is injected through the needle to maintain the tubular shape until the solidification of the fiber. Using that set-up, fibers were spun from Ultem under several different conditions. Effect of some of the processing conditions on the evolution of structure and properties during hollow fiber formation is discussed. C1 Univ Tennessee, Text Sci Program, Knoxville, TN 37996 USA. USAF, Res Lab, Sparta Inc, Edwards AFB, CA 93524 USA. USAF, Res Lab, PRSM, Edwards AFB, CA 93524 USA. RI Bhat, Gajanan/F-1937-2010 OI Bhat, Gajanan/0000-0003-4485-7586 NR 22 TC 0 Z9 0 U1 0 U2 2 PU MARCEL DEKKER INC PI NEW YORK PA 270 MADISON AVE, NEW YORK, NY 10016 USA SN 1042-6914 J9 MATER MANUF PROCESS JI Mater. Manuf. Process. PY 2000 VL 15 IS 4 BP 533 EP 545 DI 10.1080/10426910008913004 PG 13 WC Engineering, Manufacturing; Materials Science, Multidisciplinary SC Engineering; Materials Science GA 355VT UT WOS:000089409800004 ER PT J AU Prasad, YVRK Seshacharyulu, T Medeiros, SC Frazier, WG AF Prasad, YVRK Seshacharyulu, T Medeiros, SC Frazier, WG TI Microstructural modeling and process control during hot working of commercial Ti-6Al-4V: Response of lamellar and equiaxed starting microstructures SO MATERIALS AND MANUFACTURING PROCESSES LA English DT Article ID SUPERPLASTIC DEFORMATION CHARACTERISTICS; TITANIUM-ALLOYS; CAVITATION AB The microstructural changes that occur during hot deformation of Ti-6Al-4V alloy with beta transformed (beta(t)) and equiaxed alpha-beta ((alpha+beta)(e)) Starting microstructures have been modeled in the temperature range 750-1100 degrees C and strain rate range 0.0003-10 s(-1). The stress-strain behavior, the kinetic parameters, and the processing maps have been compared for these two preforms with a view to evaluate the mechanisms of hot deformation and to establish correlations between the microstructural changes and the process parameters. The beta(t) preform exhibits continuous flow softening behavior below the transus (alpha-beta range) and is harder than the (alpha+beta)(e) preform. In the beta range, the stress-strain curves were of steady-state type except at the highest strain rate where oscillations have been observed. In the alpha-beta range, the apparent activation energies for hot deformation are 455 and 330 kJ/mole for the beta(t) and (alpha+beta)(e) preforms respectively and the stress exponents are similar. In the beta range, the apparent activation energy is in the range 172-210 KJ/mole which is close to that for self diffusion in beta titanium. The grain size variation with temperature and strain rate could be correlated with the Zener-Hollomon (Z) parameter. Deformed at slow strain rates in the two phase range, the beta(t) preform undergoes a microstructural conversion by the process of globularization of lamellar colony structure. The optimum parameters for globularization are 960 degrees C/0.0003 s(-1). The size of globules is not dependent on strain but on temperature and strain rate of deformation and could be correlated with Z. The (alpha+beta)(e) preform, on the other hand, deforms superplastically and the optimum processing parameters are 825 degrees C/0.0003 s(-1). In this domain, the variation of or grain size with Z is linear on a log-log scale. The processing windows are similar in both the preforms except at the lower temperature limit which is higher for the beta(t) preform by about 100 degrees C than the (alpha+beta)(e) preform. The beta phase undergoes dynamic recrystallization irrespective of the preform structure and the resulting grain size is dependent on the Z parameter. Both the preforms exhibit flow instabilities when deformed in the two phase range at higher strain rates and these are manifested as adiabatic shear bands causing flow localization. C1 USAF, Mat Proc Design Branch, MLMR, Mat & Mfg Directorate, Wright Patterson AFB, OH 45433 USA. NR 27 TC 10 Z9 10 U1 1 U2 10 PU MARCEL DEKKER INC PI NEW YORK PA 270 MADISON AVE, NEW YORK, NY 10016 USA SN 1042-6914 J9 MATER MANUF PROCESS JI Mater. Manuf. Process. PY 2000 VL 15 IS 4 BP 581 EP 604 DI 10.1080/10426910008913007 PG 24 WC Engineering, Manufacturing; Materials Science, Multidisciplinary SC Engineering; Materials Science GA 355VT UT WOS:000089409800007 ER PT S AU Power, GJ AF Power, GJ BE Schmalz, MS TI Content-dependent, frame-selective video compression SO MATHEMATICS AND APPLICATIONS OF DATA/IMAGE CODING, COMPRESSION, AND ENCRYPTION III SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Mathematics and Applications of Data/Image Coding, Compression, and Encryption III CY AUG 02, 2000 CL SAN DIEGO, CA SP SPIE, Soc Ind & Appl Math DE video compression; velocital information feature; data storage and retrieval; video transmission; motion imagery; image sequence analysis AB The transmission and storage of digital video currently requires more bandwidth than is typically available. Emerging applications such as video-on-demand, web cameras, and collaborative tools with video conferencing are pushing the limits of the transmission media to provide video to the desktop computer. Lossy compression has succeeded in meeting some of the video demand, but it suffers from artifacts and low resolution. This paper introduces a content-dependent, frame-selective compression technique which is developed wholly as a preconditioner that can be used with existing digital video compression techniques. The technique is heavily dependent on a priori knowledge of the general content of the video which uses content knowledge to make smart decisions concerning the frames selected for storage or transmission. The velocital information feature of each frame is calculated to determine the frames with the most active changes. The velocital information feature along with a priori knowledge of the application allows prioritization of the frames. Frames are assigned priority values with the higher priority frames being selected for transmission based on available bandwidth. The technique is demonstrated for two applications: an airborne surveillance application and a worldwide web camera application. The airborne surveillance application acquires digital infrared video of targets at a standard frame rate of 30 frames per second, but the imagery suffers from infrared sensor artifacts and spurious noise. The web camera application selects frames at a slow rate but suffers from artifacts due to lighting and reflections. The results of using content-dependent, frame-selective video compression shows improvement in image quality along with reduced transmission bandwidth requirements. C1 USAF, Res Lab, Wright Patterson AFB, OH 45433 USA. RP Power, GJ (reprint author), USAF, Res Lab, Wright Patterson AFB, OH 45433 USA. NR 3 TC 0 Z9 0 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-3767-0 J9 P SOC PHOTO-OPT INS PY 2000 VL 4122 BP 149 EP 158 DI 10.1117/12.409244 PG 10 WC Computer Science, Information Systems; Computer Science, Theory & Methods; Mathematics, Applied SC Computer Science; Mathematics GA BR66C UT WOS:000167102900014 ER PT S AU Zawada, LP Goecke, KE AF Zawada, LP Goecke, KE BE Jenkins, MG LaraCurzio, E Gonczy, ST TI Testing methodology for measuring transthickness tensile strength for ceramic matrix composites SO MECHANICAL, THERMAL AND ENVIRONMENTAL TESTING AND PERFORMANCE OF CERAMIC COMPOSITES AND COMPONENTS SE AMERICAN SOCIETY FOR TESTING AND MATERIALS SPECIAL TECHNICAL PUBLICATION LA English DT Proceedings Paper CT Symposium on Environmental, Mechanical, and Thermal Properties and Performance of Continuous Fiber Ceramic Composite (CFCC) Materials and Components CY MAY 18, 1999 CL SEATTLE, WA SP Amer Soc Testing & Mat, Comm E08 Fatigue & Fracture, Amer Soc Testing & Mat, Comm D30 Adv Composites DE adhesive; ceramic matrix composite; fixtures; methodology; transthickness tension; oxide/oxide ID INTERLAMINAR TENSILE; BEHAVIOR; WOVEN AB This paper discusses experimental methods and test results from a program established to evaluate the transthickness tensile strength of ceramic matrix composites (CMC). Experimental techniques discussed include adhesives, test specimen design, gripping, and fixturing. Testing apparatus and testing protocol are addressed. In addition to addressing experimental techniques, two studies were conducted. The first study investigated the effect of test specimen geometry using circular and square cross section test specimens. The circular button type test specimens were 19 mm in diameter, while the square test specimens were 16.8 mm on a side. Analysis of the test results revealed no statistically significant difference between the two test specimen geometries. The second study involved a mini-round-robin test program undertaken to evaluate a draft test standard and to evaluate the accuracy of the test method. In addition, transthickness tensile strength results from several different CMCs are presented. An attempt is made to correlate between the measured transthickness tensile strength and the varying CMC microstructures investigated. C1 USAF, Res Lab, Ceram Dev & Mat Behav Branch, Met Ceram & NDE Div,Mat & Mfg Directorate, Wright Patterson AFB, OH 45433 USA. RP Zawada, LP (reprint author), USAF, Res Lab, Ceram Dev & Mat Behav Branch, Met Ceram & NDE Div,Mat & Mfg Directorate, Wright Patterson AFB, OH 45433 USA. NR 20 TC 1 Z9 1 U1 0 U2 1 PU AMERICAN SOCIETY TESTING AND MATERIALS PI W CONSHOHOCKEN PA 100 BARR HARBOR DRIVE, W CONSHOHOCKEN, PA 19428-2959 USA SN 1040-1695 BN 0-8031-2872-X J9 AM SOC TEST MATER PY 2000 VL 1392 BP 62 EP 85 DI 10.1520/STP15006S PG 24 WC Materials Science, Ceramics; Materials Science, Characterization & Testing SC Materials Science GA BR55G UT WOS:000166791500005 ER PT S AU John, R Buchanan, DJ Zawada, LP AF John, R Buchanan, DJ Zawada, LP BE Jenkins, MG LaraCurzio, E Gonczy, ST TI Notch-sensitivity of a woven oxide/oxide ceramic matrix composite SO MECHANICAL, THERMAL AND ENVIRONMENTAL TESTING AND PERFORMANCE OF CERAMIC COMPOSITES AND COMPONENTS SE AMERICAN SOCIETY FOR TESTING AND MATERIALS SPECIAL TECHNICAL PUBLICATION LA English DT Proceedings Paper CT Symposium on Environmental, Mechanical, and Thermal Properties and Performance of Continuous Fiber Ceramic Composite (CFCC) Materials and Components CY MAY 18, 1999 CL SEATTLE, WA SP Amer Soc Testing & Mat, Comm E08 Fatigue & Fracture, Amer Soc Testing & Mat, Comm D30 Adv Composites DE ceramic matrix composite; creep; fracture; notch-sensitivity; notch strength; oxide/oxide; sustained loading ID BEHAVIOR AB Oxide/oxide ceramic matrix composites (CMC) are currently being demonstrated in high-temperature aerospace applications. An oxide/oxide CMC under consideration by the U.S. Air Force is Nextel720/AS, which consists of an alumina-silica matrix (AS) reinforced with a woven Nexte1720 fiber mat. The fracture behavior of notched Nextel720/AS at room and expected service temperatures is discussed in this paper. Specimens with semi-circular and narrow double-edge notches were tested under monotonic loading in laboratory air at 23 to 1200 degreesC, and under sustained (creep) loading at 1100 degreesC. The results show that Nextel720/AS is notch-insensitive at low temperatures (less than or equal to 1000 degreesC) and approximate to 22% notch-sensitive at higher temperatures (greater than or equal to 1100 degreesC) under tensile loading. At 1100 degreesC, the notch-sensitivity increased significantly under sustained loading. C1 USAF, Res Lab, Mat & Mfg Directorate, MLLN, Wright Patterson AFB, OH 45433 USA. RP John, R (reprint author), USAF, Res Lab, Mat & Mfg Directorate, MLLN, Wright Patterson AFB, OH 45433 USA. NR 17 TC 1 Z9 1 U1 2 U2 2 PU AMERICAN SOCIETY TESTING AND MATERIALS PI W CONSHOHOCKEN PA 100 BARR HARBOR DRIVE, W CONSHOHOCKEN, PA 19428-2959 USA SN 1040-1695 BN 0-8031-2872-X J9 AM SOC TEST MATER PY 2000 VL 1392 BP 172 EP 181 DI 10.1520/STP15013S PG 10 WC Materials Science, Ceramics; Materials Science, Characterization & Testing SC Materials Science GA BR55G UT WOS:000166791500012 ER PT B AU Ewing, RL Lamont, GB Abdel-Aty-Zohdy, HS AF Ewing, RL Lamont, GB Abdel-Aty-Zohdy, HS BE Courtois, B Guillemot, N Kamarinos, G Stehelin, G TI Multidisciplinary collaborative design course for system-on-a-chip (SOC) SO MICROELECTRONICS EDUCATION LA English DT Proceedings Paper CT 3rd European Workshop on Microelectronics Education (EWME) CY MAY 18-19, 2000 CL ST UNIV, FUVEAU, FRANCE HO ST UNIV C1 USAF, Res Lab, Informat Directorate, Wright Patterson AFB, OH 45433 USA. NR 5 TC 0 Z9 0 U1 0 U2 0 PU SPRINGER PI DORDRECHT PA PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS BN 0-7923-6456-2 PY 2000 BP 257 EP 260 PG 4 WC Education & Educational Research SC Education & Educational Research GA BR26R UT WOS:000165970600058 ER PT S AU Roberts, ML Temple, MA Raines, RA Magee, EP AF Roberts, ML Temple, MA Raines, RA Magee, EP GP IEEE IEEE TI Initial acquisition performance of a transform domain communication system: Modeling and simulation results SO MILCOM 2000: 21ST CENTURY MILITARY COMMUNICATIONS CONFERENCE PROCEEDINGS, VOLS 1 AND 2: ARCHITECTURES & TECHNOLOGIES FOR INFORMATION SUPERIORITY SE IEEE Military Communications Conference LA English DT Proceedings Paper CT IEEE 21st Century Military Communications Conference (MILCOM 2000) CY OCT 22-25, 2000 CL LOS ANGELES, CA SP IEEE, COMSOC, AFCEA AB Initial acquisition performance of a Transform Domain Communication System (TDCS) is characterized via modeling and simulation (M&S). A TDCS with interference suppression capability differs from typical spread spectrum systems in two primary ways: 1) spectrally crowded regions are avoided via adaptive spectral notching, and 2) no carrier modulation is employed. Thus, minimal signal structure exists for synchronization purposes. Initial TDCS acquisition performance was investigated for various synchronization codewords and several acquisition methods, e.g., direct time correlation (DTC) and German's technique [1], using both peak and threshold detection techniques. MATLAB (R) simulation results indicate a TDCS can achieve a high probability of detection (P(d) > 0.9) for relatively low input Signal-to-Noise Ratios (SNRs), as low as -23 dB for peak detection and -21 dB for threshold detection. Extensive computer simulations and subsequent analysis indicates that a TDCS can adequately acquire and accurately align a locally generated reference waveform with the received noise-like TDCS signal. C1 Air Force Informat Warfare Ctr, Kelly AFB, San Antonio, TX 78243 USA. RP Roberts, ML (reprint author), Air Force Informat Warfare Ctr, Kelly AFB, San Antonio, TX 78243 USA. NR 8 TC 1 Z9 3 U1 1 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 2155-7578 BN 0-7803-6521-6 J9 IEEE MILIT COMMUN C PY 2000 BP 1119 EP 1123 PG 5 WC Computer Science, Hardware & Architecture; Computer Science, Information Systems; Engineering, Electrical & Electronic; Telecommunications SC Computer Science; Engineering; Telecommunications GA BR85L UT WOS:000167781800216 ER PT J AU Staal, MA Cigrang, JA Fiedler, E AF Staal, MA Cigrang, JA Fiedler, E TI Disposition decisions in US Air Force basic trainees assessed during mental health evaluations SO MILITARY PSYCHOLOGY LA English DT Article ID MILITARY AB A small but significant percentage of people entering the U.S. Air Force are evaluated during Basic Military Training for mental-health-related issues. These trainees are referred for mental health evaluation for various reasons related to their adjustment to the training environment or past history. Many variables may contribute to the disposition decisions made by the psychologists concerning these new recruits during the evaluation process. However, the specific variables that distinguish different groups have not been systematically studied, and the decision-making process has not been operationally defined. The purpose of this study was to develop empirically derived profiles of the 4 trainee disposition groups that distinguished trainees needing hospitalization due to emotional instability, those requiring immediate separation from the Air Force but did not need hospitalization, those who required administrative separation from the Air Force but did not necessitate immediate care or removal, and those who were typically returned to duty although temporarily distressed. Eight variables that contributed to classification decisions in 86% to 90% of trainees were identified. Several key variables that were previously believed to be highly influential in the decision-making process were revealed to be noncontributory to classification. Specific results and the possible application of these findings are discussed further. C1 Behav Hlth Serv, 377th Med Grp, Kirtland AFB, NM USA. Behav Anal Serv, 59th Med Wing, Lackland AFB, TX USA. Psychol Res Serv, 59th Med Wing, Lackland AFB, TX USA. RP Staal, MA (reprint author), USAF Acad, Dept Behav Sci & Leadership, 2354 Fairchild Dr,Suite 6J59B, Colorado Springs, CO 80840 USA. NR 17 TC 6 Z9 6 U1 0 U2 0 PU LAWRENCE ERLBAUM ASSOC INC PI MAHWAH PA 10 INDUSTRIAL AVE, MAHWAH, NJ 07430-2262 USA SN 0899-5605 J9 MIL PSYCHOL JI Milit. Psychol. PY 2000 VL 12 IS 3 BP 187 EP 203 DI 10.1207/S15327876MP1203_2 PG 17 WC Psychology, Multidisciplinary SC Psychology GA 341UF UT WOS:000088607500002 ER PT J AU Carretta, TR Zelenski, WE Ree, MJ AF Carretta, TR Zelenski, WE Ree, MJ TI Basic attributes test (BAT) retest performance SO MILITARY PSYCHOLOGY LA English DT Article ID APTITUDE; SELECTION; SCORES AB The Basic Attributes Test (BAT) contributes to a U.S. Air Force pilot selection composite known as the Pilot Candidate Selection Method(PCSM). When PCSM was operationally implemented in 1993, no retests were permitted on the BAT. To determine the effects of retesting on mean score change and reliability, the BAT was administered to 477 college students who were then retested after 2 weeks, 3 months, or 6 months. Several important findings were observed. First, about 70% of the students exhibited score improvement on retest, regardless of length of retest interval. Those who performed poorly on the ist test generally exhibited larger improvements than those who performed well on the ist test. Second, practice effects diminished as the length of the retest interval increased. For a 6-month retest interval, it was expected that the mean increase in PCSM scores would be about 6 percentile points. The results suggest that BAT retests could be permitted no less than 6 months after initial testing. Third, and very important, BAT scores demonstrated acceptable reliability. The reliability of the psychomotor composite ranged from .775 to .800, and the reliabilities for the other subtests ranged from .474 to .871. C1 HECI, AFRL, Wright Patterson AFB, OH 45433 USA. 71st Flying Training Wing, Vance AFB, OK USA. Our Lady Lake Univ, Dept Psychol, San Antonio, TX USA. RP Carretta, TR (reprint author), HECI, AFRL, 2210 8th St,Area B,Bldg 146,Room 122, Wright Patterson AFB, OH 45433 USA. NR 19 TC 1 Z9 1 U1 1 U2 3 PU LAWRENCE ERLBAUM ASSOC INC PI MAHWAH PA 10 INDUSTRIAL AVE, MAHWAH, NJ 07430-2262 USA SN 0899-5605 J9 MIL PSYCHOL JI Milit. Psychol. PY 2000 VL 12 IS 3 BP 221 EP 232 DI 10.1207/S15327876MP1203_4 PG 12 WC Psychology, Multidisciplinary SC Psychology GA 341UF UT WOS:000088607500004 ER PT J AU van den Berg, W Tascilar, M Offerhaus, GJA Albores-Saavedra, J Wenig, BM Hruban, RH Gabrielson, E AF van den Berg, W Tascilar, M Offerhaus, GJA Albores-Saavedra, J Wenig, BM Hruban, RH Gabrielson, E TI Pancreatic mucinous cystic neoplasms with sarcomatous stroma: Molecular evidence for monoclonal origin with subsequent divergence of the epithelial and sarcomatous components SO MODERN PATHOLOGY LA English DT Article DE carcinosarcoma; K-ras; loss of heterozygosity; neoplasms; pancreas ID SPINDLE-CELL-CARCINOMA; GENETIC PROGRESSION; ADENOCARCINOMA; MUTATIONS; TUMORS; BREAST; ALLELOTYPE; LESIONS; CANCER; LIVER AB Neoplasms with mixed carcinomatous and sarcomatous growth patterns occur in many organs and tissues. The pathogenesis of these cancers is thought to be either the result of two independent neoplastic processes merging to form a single tumor, or a neoplasm of monoclonal origin that develops phenotypic diversity. To address this issue, we characterized molecular alterations in separately microdissected epithelial and sarcomatous areas in three cases of pancreatic mucinous cystic neoplasms with sarcomatous stroma. Using microsatellite markers for six chromosomal loci commonly deleted in infiltrating ductal adenocarcinomas of the pancreas, we found genetic alterations to be virtually identical between the sarcomatous and epithelial components of two of the three neoplasms. In the third neoplasm, we found allelic losses and retentions to be identical at five of the six chromosomal loci, but at a single locus, we noted allelic loss in the neoplastic epithelial component but not the sarcomatous component. The same neoplasms were also analyzed for activating point mutations in codon 12 of the K-ras gene by using mutant-enriched polymerase chain reaction and allele-specific oligonucleotide hybridization. A K-ras mutation was identified in the epithelial component of one of the three neoplasms (the same tumor with an additional allelic loss in the neoplastic epithelial cells), but the sarcomatous component of this tumor was wild-type at codon 12 of K-ras, as were both components of the other two neoplasms. Overall, these results suggest a monoclonal origin with subsequent divergence of the neoplastic epithelial and sarcomatous portions of these neoplasms. C1 Univ Amsterdam, Dept Pathol, Amsterdam, Netherlands. Univ Texas, SW Med Ctr, Dept Pathol, Dallas, TX USA. USAF, Inst Pathol, Baltimore, MD USA. Johns Hopkins Med Inst, Dept Pathol, Baltimore, MD 21205 USA. Johns Hopkins Med Inst, Dept Oncol, Baltimore, MD 21205 USA. RP Gabrielson, E (reprint author), Johns Hopkins Bayview Med Ctr, 4940 Eastern Ave, Baltimore, MD 21224 USA. FU NCI NIH HHS [P50CA-62924] NR 33 TC 34 Z9 34 U1 2 U2 3 PU LIPPINCOTT WILLIAMS & WILKINS PI PHILADELPHIA PA 530 WALNUT ST, PHILADELPHIA, PA 19106-3621 USA SN 0893-3952 J9 MODERN PATHOL JI Mod. Pathol. PD JAN PY 2000 VL 13 IS 1 BP 86 EP 91 DI 10.1038/modpathol.3880013 PG 6 WC Pathology SC Pathology GA 277KB UT WOS:000084931800012 PM 10658914 ER PT S AU Cowan, WD AF Cowan, WD BE Motamedi, ME Goring, R TI Materials impacts on micro-opto-electro-mechanical systems SO MOEMS AND MINIATURIZED SYSTEMS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on MOEMS and Miniaturized Systems CY SEP 18-20, 2000 CL SANTA CLARA, CA SP SPIE, Semiconductor Equipment & Mat Int, Solid State Technol, Sandia Natl Labs DE micro-electro-mechanical systems; micro-opto-electro-mechanical systems; MEMS; MOEMS; micromirrors ID STRESS MEASUREMENTS; POLYSILICON; DEVICES; STRAIN; FILMS; MEMS AB Micro-Optical-Electro-Mechanical Systems (MOEMS) employ batch fabrication processes to construct miniature devices with macroscopic functionality. Surface micromachined MOEMS structures are manufactured by the deposition and patterning of thin films. In marked contrast with conventional fabrication processes land bulk micromachining, the thin film materials used in surface micromachined structures are formed as the device is processed. In general, the material properties of thin films are not controlled during deposition, and are only measured after processing is completed. Characterization methods include wafer curvature measurements and a variety of test structures. None of the thin film characterization techniques currently employed is entirely satisfactory and all methods rely on process repeatability to be useful. The ultimate optical performance of MOEMS depends directly on the materials properties of the thin films employed. Differing residual material stresses and residual stress gradients cause curvature which degrades the optical performance of nominally flat reflecting surfaces. For multilayer structures like most micromirrors curvature due to the bimetallic effect can not be ignored. Recent work in which foundry processes were used to fabricate low-cost deformable mirrors (MEM-DMs) for adaptive optics illustrates the impact of residual material stress on system level optical performance. In other MOEMS devices residual material stress can be exploited to produce unique structures. More precise monitoring and control of film stress during deposition remains as a challenge for MEMS and MOEMS. This paper will address the principal materials issues for MOEMS and suggest both design and process control solutions. C1 USAF, Res Lab, Mat & Mfg Directorate, ML, Wright Patterson AFB, OH 45433 USA. RP Cowan, WD (reprint author), USAF, Res Lab, Mat & Mfg Directorate, ML, 3005 P St, Wright Patterson AFB, OH 45433 USA. NR 16 TC 3 Z9 3 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-3834-0 J9 P SOC PHOTO-OPT INS PY 2000 VL 4178 BP 30 EP 41 DI 10.1117/12.396478 PG 12 WC Engineering, Electrical & Electronic; Optics SC Engineering; Optics GA BR35P UT WOS:000166175100004 ER PT B AU Wilkes, JS Castle, PJ Schoske, R Humphrey, CJ Layo, FB Slanger, R AF Wilkes, JS Castle, PJ Schoske, R Humphrey, CJ Layo, FB Slanger, R BE Trulove, PC DeLong, HC Stafford, GR Deki, S TI Polymer extractions by room temperature chloroaluminate molten salts SO MOLTEN SALTS XII, PROCEEDINGS SE ELECTROCHEMICAL SOCIETY SERIES LA English DT Proceedings Paper CT 12th International Symposium on Molten Salts CY OCT 17-22, 1999 CL HONOLULU, HI SP Electrochem Soc, Div Phys Electrochem, Electrochem Soc, Div High Temp Mat, Electrochem Soc, Div Electrodeposit, USAF, Off Sci Res, European Off Aersp Res & Dev ID IONIC LIQUIDS; ELECTROCHEMISTRY; CHLORIDE; SYSTEM; HCL AB We report here the extraction of polymers by essentially nonvolatile ionic liquids. The particular molten salts used in this study are 1-ethyl-3-methylimidazolium chloride/aluminum chloride mixtures (EMIC/AlCl3). This salt is conveniently handled as a liquid at room temperature, and it has negligible vapor pressure for most compositions up to several hundred degrees. This ionic liquid is easy to prepare, and its chemical and physical properties are well described. The compositions of the EMIC/AlCl3 were basic (EMIC>AlCl3), neutral (EMIC=AlCl3), acidic (EMIC beta(-omega; 0, omega) > beta (0; 0, 0). C1 USAF, Res Lab, Space Vehicles Directorate, Kirtland AFB, NM 87117 USA. RP Karna, SP (reprint author), USAF, Res Lab, Space Vehicles Directorate, 9550 Aberdeen Ave,Bldg 914, Kirtland AFB, NM 87117 USA. NR 26 TC 0 Z9 0 U1 0 U2 0 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 USA SN 0272-9172 BN 1-55899-487-4 J9 MATER RES SOC SYMP P PY 2000 VL 579 BP 169 EP 178 PG 10 WC Materials Science, Characterization & Testing; Optics; Physics, Applied; Physics, Condensed Matter SC Materials Science; Optics; Physics GA BR76J UT WOS:000167460000021 ER PT S AU Wood, BE Green, BD Hall, DF Uy, OM Cain, RP Galica, GA Boies, MT Bertrand, WT AF Wood, BE Green, BD Hall, DF Uy, OM Cain, RP Galica, GA Boies, MT Bertrand, WT BE Chen, PTC Uy, OM TI Update of the midcourse space experiment (MSX) satellite measurements of contaminant films using QCMs SO OPTICAL SYSTEMS CONTAMINATION AND DEGRADATION II: EFFECTS, MEASUREMENTS, AND CONTROL SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Optical Systems Contamination and Degradation II CY AUG 02-03, 2000 CL SAN DIEGO, CA SP SPIE DE midcourse space experiment; MSX; QCM; TQCM; CQCM; SPIRIT 3 ID QUARTZ-CRYSTAL MICROBALANCES AB The Midcourse Space Experiment (MSX) satellite was launched on April 24, 1996. This paper provides an update of the quartz crystal microbalance (QCM) data accumulated over these last four years in space. The MSX is the only known experiment that has provided continuous contamination monitoring for such an extended length of time. The five QCMs on board the satellite have provided on-orbit data that have been invaluable in characterizing contamination levels around the spacecraft and inside the cryogenic Spatial Infrared Imaging Telescope (SPIRIT 3). One of the QCMs, the cryogenic QCM (CQCM), located internal to SPIRIT 3, was mounted adjacent to the primary mirror and provided contamination accretion measurements during the 10-month lifetime of SPIRIT 3. Real-time monitoring of contaminant mass deposition on the primary mirror was provided by this CQCM which was cooled to the same temperature as the mirror - approximately 20K. Thermogravimetric analyses (TGAs) on the CQCM provided insight into the amount and species of contaminants condensed on the SPIRIT 3 primary mirror during various spacecraft activities. The four temperature-controlled QCMs (TQCMs) were mounted on external surfaces of the spacecraft for monitoring contaminant deposition. The TQCMs operated at approximately -50 degreesC and were positioned strategically to monitor the silicone and organic contaminant flux arriving at specific locations. Updated time histories of contaminant thickness deposition for each of the QCMs are presented. Gradual contaminant thickness increase was observed during the first year in space. During the second year, the QCM frequencies (contaminant film thickness) began to decrease, with the time of onset depending on QCM location. Possible explanations for this interesting behavior are discussed. C1 Sverdrup Technol Inc, AEDC Grp, Arnold Engn Dev Ctr, Arnold AFB, TN USA. RP Wood, BE (reprint author), Sverdrup Technol Inc, AEDC Grp, Arnold Engn Dev Ctr, Arnold AFB, TN USA. NR 11 TC 2 Z9 2 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-3741-7 J9 P SOC PHOTO-OPT INS PY 2000 VL 4096 BP 1 EP 10 DI 10.1117/12.400820 PG 10 WC Engineering, Aerospace; Optics SC Engineering; Optics GA BR09A UT WOS:000165629100001 ER PT S AU Grote, JG Zetts, JS Drumond, JP Nelson, RL Hopkins, FK AF Grote, JG Zetts, JS Drumond, JP Nelson, RL Hopkins, FK BE Park, YS Chen, RT TI Effect of dielectric constant on modulation voltage for nonlinear optic polymer based optoelectronic devices SO OPTOELECTRONIC INTEGRATED CIRCUITS IV SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Optoelectronic Integrated Circuits IV CY JAN 26-27, 2000 CL SAN JOSE, CA SP SPIE DE nonlinear optic polymer; optoelectronic; electrooptic modulator; conductive polymer; dielectric constant ID ELECTROOPTIC MATERIALS; CHROMOPHORES AB Presented is the effect of using various cladding Layers with different dielectric constants on the applied modulation voltage for NLO polymer based integrated OE devices. The dielectric constants of the core and cladding materials used for nonlinear optic (NLO) polymer based integrated optoelectronic (OE) devices ate typically very similar in magnitude. This suggests that even for low modulation rates, only 20% to 25% of the applied modulation voltage (voltage between the electrodes) is being dropped across the core region. With this small percentage of applied voltage reaching the NLO core layer. it becomes necessary to apply 4 to 5 times higher modulation voltage in order to achieve the desired pi phase change through the core. C1 USAF, Res Lab, Mat & Mfg Directorate, AFRL,MLPO, Wright Patterson AFB, OH 45433 USA. RP Grote, JG (reprint author), USAF, Res Lab, Mat & Mfg Directorate, AFRL,MLPO, Wright Patterson AFB, OH 45433 USA. NR 18 TC 5 Z9 5 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-3567-8 J9 P SOC PHOTO-OPT INS PY 2000 VL 3950 BP 108 EP 116 DI 10.1117/12.382152 PG 9 WC Engineering, Electrical & Electronic; Optics SC Engineering; Optics GA BQ27Z UT WOS:000087783700012 ER PT S AU Ferris, DD Currie, NC AF Ferris, DD Currie, NC BE Smith, RM Appleby, R TI Overview of current technology in MMW radiometric sensors for law enforcement applications SO PASSIVE MILLIMETER-WAVE IMAGING TECHNOLOGY IV SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Passive Millimeter-Wave Imaging Technology IV CY APR 26, 2000 CL ORLANDO, FL SP SPIE DE millimeter wave; MMW; concealed weapon detection; CWD; radiometric imager AB This paper discusses the current state-of-the-art in millimeter-wave radiometric imagers being developed for law enforcement use within the United States. The most prevalent application at present is the detection of concealed weapons (guns, knives, etc.) with a secondary application involving the detection of drugs and explosives. Three main topics will be addressed: the phenomenology of concealed weapon detection at millimeter wavelengths, the promise and short comings of first generation radiometric imagers, and the characteristics of second generation systems currently under development. The phenomenology discussion will include theoretical aspects as well as the effects of environment including: indoors versus outdoors (sky illumination), clothing effects, and weapon composition (metal versus plastic or ceramic). The first generation system discussion will present imagery obtained with single detectors which indicated the promise of the technology, and will discuss the problems encountered in the initial attempts to produce focal plane arrays. The discussion of second generation sensors win showcase several systems that have attempted to overcome the first generation problems including systems from Millivision, Thermotrex, Lockheed Martin, and TRW. Examples of second generation imagery will also be presented. C1 USAF, Res Lab, Rome, NY 13441 USA. RP Ferris, DD (reprint author), USAF, Res Lab, Rome, NY 13441 USA. NR 4 TC 9 Z9 10 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-3658-5 J9 P SOC PHOTO-OPT INS PY 2000 VL 4032 BP 61 EP 71 PG 11 WC Optics; Imaging Science & Photographic Technology SC Optics; Imaging Science & Photographic Technology GA BQ87Z UT WOS:000089913900009 ER PT J AU Kropas-Hughes, CV Rogers, SK Oxley, ME Kabrisky, M AF Kropas-Hughes, CV Rogers, SK Oxley, ME Kabrisky, M TI Backpropagation of an image similarity metric for Autoassociative Neural Networks SO PATTERN ANALYSIS AND APPLICATIONS LA English DT Article DE Autoassociative Neural Networks; error function; image compression; visual difference predictor ID PRINCIPAL COMPONENT ANALYSIS AB Autoassociative Neural Networks (AANNs) are most commonly used fur image data compression. The goal of an AANN for image data is to have the network output be 'similar' to the input. Most of the research in this area use backpropagation training with Mean-Squared Error (MSE) as the optimisation criteria. This paper presents an alternative error function called the Visual Difference Predictor (VDP) based on concepts from the human-visual system. Using the VDP as the error function provides a criteria to train an AANN more efficiently, and results in faster convergence of the weights, while producing an output image perceived to be very similar by a human observer. C1 USAF, Res Lab, Mat & Mfg Directorate, AFRL,MLMR, Wright Patterson AFB, OH 45433 USA. Qualia Comp Inc, Beavercreek, OH USA. USAF, Inst Technol, Dept Math, Wright Patterson AFB, OH 45433 USA. USAF, Inst Technol, Dept Elect Engn, Wright Patterson AFB, OH 45433 USA. RP Kropas-Hughes, CV (reprint author), USAF, Res Lab, Mat & Mfg Directorate, AFRL,MLMR, 2977 P St, Wright Patterson AFB, OH 45433 USA. NR 17 TC 0 Z9 0 U1 1 U2 1 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 1433-7541 J9 PATTERN ANAL APPL JI Pattern Anal. Appl. PY 2000 VL 3 IS 1 BP 31 EP 38 DI 10.1007/s100440050004 PG 8 WC Computer Science, Artificial Intelligence SC Computer Science GA 300FH UT WOS:000086242100003 ER PT J AU Cunningham, DW Billock, VA Tsou, BH AF Cunningham, D. W. Billock, V. A. Tsou, B. H. TI Spatiotemporal discrimination thresholds for dynamic random fractal (1/f) textures SO PERCEPTION LA English DT Meeting Abstract C1 [Cunningham, D. W.; Billock, V. A.] Logicon Tech Serv, HECV, Dayton, OH 45437 USA. [Tsou, B. H.] USAF, HECV, Res Lab, Wright Patterson AFB, OH 45433 USA. EM douglas.cunningham@tuebingen.mpg.de NR 0 TC 0 Z9 0 U1 0 U2 0 PU PION LTD PI LONDON PA 207 BRONDESBURY PARK, LONDON NW2 5JN, ENGLAND SN 0301-0066 J9 PERCEPTION JI Perception PY 2000 VL 29 SU S BP 104 EP 104 PG 1 WC Ophthalmology; Psychology; Psychology, Experimental SC Ophthalmology; Psychology GA V17AR UT WOS:000207910600314 ER PT J AU Post, DL Chelette, TL Allnutt, RA AF Post, D. L. Chelette, T. L. Allnutt, R. A. TI Effects of +G(z) on colour vision SO PERCEPTION LA English DT Meeting Abstract C1 [Post, D. L.] USAF, Visual Display Syst Branch, Res Lab, Wright Patterson AFB, OH 45433 USA. [Chelette, T. L.] USAF, Accelerat Effects & Escape Branch, Res Lab, AFRL HEPA, Wright Patterson AFB, OH 45433 USA. [Allnutt, R. A.] USAF, Expt Safety Off, Res Lab, AFRL HEH, Wright Patterson AFB, OH 45433 USA. EM david.post@wpafb.af.mil NR 0 TC 0 Z9 0 U1 0 U2 0 PU PION LTD PI LONDON PA 207 BRONDESBURY PARK, LONDON NW2 5JN, ENGLAND SN 0301-0066 J9 PERCEPTION JI Perception PY 2000 VL 29 SU S BP 109 EP 109 PG 1 WC Ophthalmology; Psychology; Psychology, Experimental SC Ophthalmology; Psychology GA V17AR UT WOS:000207910600328 ER PT J AU Brungart, DS Rabinowitz, WM Durlach, NI AF Brungart, DS Rabinowitz, WM Durlach, NI TI Evaluation of response methods for the localization of nearby objects SO PERCEPTION & PSYCHOPHYSICS LA English DT Article ID SOUND LOCALIZATION AB Four response methods for indicating the perceived locations of nearby objects were evaluated: the direct-location (DL) method, where a response pointer is moved directly to the perceived location of the target; the large-head (LH) and small-head (SH) methods, where the pointer is moved to the target location relative to a full-scale or half-scale manikin head; and the verbal report (VR) method, where the spherical coordinates of the target location are indicated verbally. Measurements with a visual target indicated that the DL method was relatively unbiased and considerably more accurate than the other methods, which were all roughly equivalent. Correcting for bias improved accuracy in the LH, SH, and VR responses, but not to the level of the uncorrected DL responses. Replacing the visual target with an acoustic stimulus approximately doubled the errors with the DL response but indicated similar performance in the front and rear hemispheres. The results suggest that DL is the most appropriate response method for close-range localization experiments. C1 USAF, Res Lab, HECB, Wright Patterson AFB, OH 45433 USA. MIT, Cambridge, MA 02139 USA. RP Brungart, DS (reprint author), USAF, Res Lab, HECB, 2610 7th St, Wright Patterson AFB, OH 45433 USA. NR 10 TC 15 Z9 15 U1 0 U2 2 PU PSYCHONOMIC SOC INC PI AUSTIN PA 1710 FORTVIEW RD, AUSTIN, TX 78704 USA SN 0031-5117 J9 PERCEPT PSYCHOPHYS JI Percept. Psychophys. PD JAN PY 2000 VL 62 IS 1 BP 48 EP 65 DI 10.3758/BF03212060 PG 18 WC Psychology; Psychology, Experimental SC Psychology GA 285HH UT WOS:000085383300004 PM 10703255 ER PT S AU Saxler, A AF Saxler, A BE Brown, GJ Razeghi, M TI A review of the electrical properties of AlxGa1-xN materials for UV photodetector applications SO PHOTODETECTORS: MATERIALS AND DEVICES V SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Photodetectors - Materials and Devices V CY JAN 26-28, 2000 CL SAN JOSE, CA SP SPIE DE GaN; gallium nitride; AlGaN; aluminum gallium nitride; Hall effect; ultraviolet photodetectors; short-period superlattice; p-type doping; magnesium doping ID MOLECULAR-BEAM EPITAXY; CHEMICAL-VAPOR-DEPOSITION; DOPED GAN FILMS; P-TYPE CONDUCTION; N-TYPE GAN; PHASE EPITAXY; ION-IMPLANTATION; GALLIUM NITRIDE; MG; ACCEPTOR AB In this paper, recent developments in the electrical characterization and doping of AlxGa1-xN will be reviewed. The properties important for the development of solar-blind UV photodetectors will be stressed. For many of the military and commercial applications of UV photodetectors, the photodetectors must be solar-blind with cutoff wavelengths of less than about 280 nm. This means that for devices based on the AlxGa1-xN system, the aluminum mole fraction for the active region is nearly 40%. One of the implications for devices is that as the energy gap is increased, doping becomes much more difficult. Therefore, one of the main thrusts of this paper will be the p-type and n-type doping of AlxGa1-xN. In addition to the study of the doping of bulk-like AlxGa1-xN, the use of AlxGa1-xN based superlattices to reduce the dopant ionization energy will be presented. Because GaN is likely to be used for contact layers in solar-blind devices and as an active Layer in visible-blind devices, the electrical properties of this better studied binary material will be reported. The role of electrically active defects and unintentional dopants will also be discussed. C1 USAF, Res Lab, Mat & Mfg Directorate, Sensor Mat Branch, Wright Patterson AFB, OH 45433 USA. RP Saxler, A (reprint author), USAF, Res Lab, Mat & Mfg Directorate, Sensor Mat Branch, Wright Patterson AFB, OH 45433 USA. NR 78 TC 2 Z9 2 U1 2 U2 3 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-3565-1 J9 P SOC PHOTO-OPT INS PY 2000 VL 3948 BP 330 EP 341 DI 10.1117/12.382134 PG 12 WC Instruments & Instrumentation; Optics SC Instruments & Instrumentation; Optics GA BQ18U UT WOS:000087385100032 ER PT S AU Power, GJ Awwal, AAS AF Power, GJ Awwal, AAS BE Iftekharuddin, KM Awwal, AAS TI Optoelectronic complex inner product for evaluating duality of image segmentation SO PHOTONIC DEVICES AND ALGORITHMS FOR COMPUTING II SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Photonic Devices and Algorithms for Computing II CY AUG 02-03, 2000 CL SAN DIEGO, CA SP SPIE DE segmentation; vision; recognition; performance; synthetic aperture radar; segmentation quality; quality metric AB In automatic target recognition and machine vision applications, segmentation of the images is a key step. Poor segmentation reduces the recognition performance. For some imaging systems such as MRI and Synthetic Aperture Radar (SAR) it is difficult even for humans to agree on the location of the edge which allows for segmentation. A real-time dynamic approach to determine the quality of segmentation can enable vision systems to refocus or apply appropriate algorithms to ensure high quality segmentation for recognition. A recent approach to evaluate the quality of image segmentation uses percent-pixels-different (PPD). For some cases, PPD provides a reasonable quality evaluation, but it has a weakness in providing a measure for how well the shape of the segmentation matches the true shape. This paper introduces the complex inner product approach for providing a goodness measure for evaluating the segmentation quality based on shape. The complex inner product approach is demonstrated on SAR target chips obtained from the Moving and Stationary Target Acquisition and Recognition (MSTAR) program sponsored by the Defense Advanced Research Projects Agency (DARPA) and the Air Force Research Laboratory (AFRL). The results are compared to the PPD approach. A design for an optoelectronic implementation of the complex inner product for dynamic segmentation evaluation is introduced. C1 USAF, Res Lab, Target Recognit Branch, AFRL SNAT, Wright Patterson AFB, OH 45433 USA. RP Power, GJ (reprint author), USAF, Res Lab, Target Recognit Branch, AFRL SNAT, Bldg 620,2241 Avionics Circle, Wright Patterson AFB, OH 45433 USA. NR 6 TC 1 Z9 1 U1 0 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-3759-X J9 P SOC PHOTO-OPT INS PY 2000 VL 4114 BP 13 EP 19 DI 10.1117/12.408548 PG 7 WC Computer Science, Hardware & Architecture; Optics; Telecommunications SC Computer Science; Optics; Telecommunications GA BR89D UT WOS:000167920800002 ER PT S AU Grote, JG Zetts, JS Nelson, RL Hopkins, FK AF Grote, JG Zetts, JS Nelson, RL Hopkins, FK BE Iftekharuddin, KM Awwal, AAS TI Conductive cladding layers for electrode poled nonlinear optic polymer electro-optics SO PHOTONIC DEVICES AND ALGORITHMS FOR COMPUTING II SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Photonic Devices and Algorithms for Computing II CY AUG 02-03, 2000 CL SAN DIEGO, CA SP SPIE DE nonlinear optic polymer; opto-electronic; electro-optic modulator; conductive polymer; dielectric constant ID CHROMOPHORES; MODULATORS; DEVICE; REFLECTION; SYSTEMS AB We have demonstrated an enhancement in the effective electro-optic (EO) coefficient of electrode poled nonlinear optical polymers using a conductive polymer cladding. We have also demonstrated the lowest poling voltage to date, 300 V, for a 2 mum thick NLO polymer core and 2 mum thick conductive polymer cladding structure asymmetric waveguide structure. With the cladding material more conductive than the core material, the majority of the applied poling voltage is dropped across the core, maximizing poling efficiency and, hence, realizing a higher EO coefficient. These results show promise for lower operating voltage devices. C1 MLPS, AFRL, Mat & Mfg Directorate, USAF,Res Lab, Wright Patterson AFB, OH 45433 USA. RP Grote, JG (reprint author), MLPS, AFRL, Mat & Mfg Directorate, USAF,Res Lab, Wright Patterson AFB, OH 45433 USA. NR 29 TC 11 Z9 11 U1 0 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-3759-X J9 P SOC PHOTO-OPT INS PY 2000 VL 4114 BP 101 EP 109 DI 10.1117/12.408544 PG 9 WC Computer Science, Hardware & Architecture; Optics; Telecommunications SC Computer Science; Optics; Telecommunications GA BR89D UT WOS:000167920800012 ER PT S AU Potasek, MJ Kim, S AF Potasek, MJ Kim, S BE Iftekharuddin, KM Awwal, AAS TI High bandwidth free space optics SO PHOTONIC DEVICES AND ALGORITHMS FOR COMPUTING II SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Photonic Devices and Algorithms for Computing II CY AUG 02-03, 2000 CL SAN DIEGO, CA SP SPIE DE nonlinear optics; three-dimensional optical propagation; free space optics ID NORMALLY DISPERSIVE MEDIA; LIGHT-PULSES; COLLAPSE; 4.4KM; LINK AB Free-space interconnections for optical computing and information processing require an understanding of the three dimensional propagation of ultrahigh bandwidth optical pulses. Unlike optical fibers that are basically waveguides, free space propagation involves additional phenomenon such as self-focusing. In order to understand the properties of unguided or free space propagation for interconnections it is necessary to use a three dimensional spatial grid as well as the usual temporal grid. We derived an expression for the propagation of free space optical pulses for data rates on the order of hundreds of terabits/sec. Our formulation incorporates physical parameters such as the pulse duration, pulse intensity and free space characteristics. Numerical calculations show the spatiotemporal pulse distortion for free space propagation. C1 USAF, Res Lab, Brooks AFB, TX 78235 USA. RP Potasek, MJ (reprint author), USAF, Res Lab, 2503 Gillingham Dr,Bldg 175E, Brooks AFB, TX 78235 USA. NR 26 TC 0 Z9 0 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-3759-X J9 P SOC PHOTO-OPT INS PY 2000 VL 4114 BP 236 EP 245 DI 10.1117/12.408561 PG 10 WC Computer Science, Hardware & Architecture; Optics; Telecommunications SC Computer Science; Optics; Telecommunications GA BR89D UT WOS:000167920800027 ER PT S AU Grote, JG Taylor, EW Zetts, JS Winter, JE Sanchez, AD Craig, D Hopkins, FK AF Grote, JG Taylor, EW Zetts, JS Winter, JE Sanchez, AD Craig, D Hopkins, FK BE Taylor, EW TI Optical transmission and thermal heating effects due to irradiation of nonlinear optic and conductive polymers for spaced based electrooptic applications SO PHOTONICS FOR SPACE ENVIRONMENTS VII SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT 7th Photonics for Space Environments Conference (PSE VII) CY JUL 31-AUG 01, 2000 CL SAN DIEGO, CA SP SPIE DE nonlinear optic polymer; conductive polymer; proton particles; proton irradiation; radiation effects AB A nonlinear optic (NLO) polymer blend of disperse red 1 (DR1) in poly methyl methacrylate (PMMA), spin cast on an indium tin oxide (ITO) coated borosilicate glass substrate and a conductive polymer blend of polyethylene dioxythiophene/poly styrene sulphonate (Baytron P) in poly vinyl alcohol (PVA), spin cast on an uncoated borosilicate glass substrate were irradiated by 63.3 MeV protons to a dose of 1 Mrad (Si) of proton particles. The pre and post irradiated optical transmission characteristics of these polymer films over a wavelength range of 400-2000 nn, as well as in-situ thermal heating generated by irradiation are presented. C1 USAF, Res Lab, MLPO, Wright Patterson AFB, OH 45433 USA. RP Grote, JG (reprint author), USAF, Res Lab, MLPO, Bldg 651,3005 P St,Suite 6, Wright Patterson AFB, OH 45433 USA. NR 7 TC 1 Z9 1 U1 1 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-3779-4 J9 P SOC PHOTO-OPT INS PY 2000 VL 4134 BP 31 EP 36 DI 10.1117/12.405350 PG 6 WC Engineering, Aerospace; Optics SC Engineering; Optics GA BR51P UT WOS:000166690800005 ER PT B AU Ferland, DR Boggs, KG Niekamp, S Christ, JA Agrawal, A Goltz, MN AF Ferland, DR Boggs, KG Niekamp, S Christ, JA Agrawal, A Goltz, MN BE Wickramanayake, GB Gavaskar, AR TI Chlorinated hydrocarbon treatment using a horizontal flow treatment well system SO PHYSICAL AND THERMAL TECHNOLOGIES: REMEDIATION OF CHLORINATED AND RECALCITRANT COMPOUNDS LA English DT Proceedings Paper CT 2nd International Conference on Remediation of Chlorinated and Recalcitrant Compounds CY MAY 22-25, 2000 CL MONTEREY, CA SP Battelle, EnviroMetal Technologies Inc, Geomatrix Consultants Inc, Naval Facilities Engn Command, Parsons Engn Sci Inc, Regenesis ID SITU AB Horizontal flow treatment well (HFTW) systems with in-well catalytic reactors, which are proposed for in situ destruction of chlorinated hydrocarbon contaminants dissolved in groundwater, are modeled. In an HFTW system, wells equipped with in-well catalytic reactors recirculate contaminated groundwater, No contaminated water is pumped to the surface. Due to groundwater recirculation, the contaminant makes multiple passes through the catalytic reactors, so the system achieves greater concentration reductions than would be attainable by a single-pass through the reactor. Palladium (Pd) has been found to catalyze the dehalogenation of chlorinated hydrocarbons completely and rapidly in the presence of molecular hydrogen (H-2) as the sole electron donor. Laboratory column studies were conducted to obtain kinetic parameters for dehalogenation of chlorinated ethenes in a Pd/H-2 reactor. These parameters are then incorporated into a model that accounts for both the recirculating flow through an HFTW system and the reaction kinetics of an in-well Pd/H-2 reactor. The model is used as a tool to design a system to treat trichloroethylene-contaminated groundwater at a hypothetical site. C1 USAF, Inst Technol, Wright Patterson AFB, OH 45433 USA. RP Ferland, DR (reprint author), USAF, Inst Technol, Wright Patterson AFB, OH 45433 USA. NR 3 TC 1 Z9 1 U1 0 U2 0 PU BATTELLE PRESS PI COLUMBUS PA 505 KING AVE, COLUMBUS, OH 43201 USA BN 1-57477-099-3 PY 2000 BP 253 EP 260 PG 8 WC Engineering, Environmental; Environmental Sciences; Water Resources SC Engineering; Environmental Sciences & Ecology; Water Resources GA BR65S UT WOS:000167101900033 ER PT J AU Eastes, RW AF Eastes, RW TI Emissions from the N-2 Lyman-Birge-Hopfield bands in the Earth's atmosphere SO PHYSICS AND CHEMISTRY OF THE EARTH PART C-SOLAR-TERRESTIAL AND PLANETARY SCIENCE LA English DT Article; Proceedings Paper CT 2nd TIGER Symposia A Program for Thermospheric-Iono spheric Geospheric Research CY 1999 CL ST PETERSBURG, RUSSIA ID ULTRAVIOLET DAYGLOW; VIBRATIONAL POPULATIONS; SOLAR MAXIMUM; RESOLUTION; STATES; AURORA; N2 AB Recent work on the N-2 Lyman-Birge-Kopfield (LBH) band (a(1)Pi(g)-X(1)Sigma(g)(+)) emissions from the Earth's aurora and daytime airglow has shown that models can give good agreement with observations by including cascading between the singlet (a(1)Pi(g), w(1)Delta(u) and a'(1)/Sigma(u)(-)) states. Both radiative and collision induced transitions contribute to the cascading. The collision induced transitions involve a process - sometimes referred to as collision-induced electronic transitions (CIET) - which has not been included in most models of the LBH bands from the Earth's atmosphere. Cascading not only improves the fit to the relative vibrational populations observed, it also increases the emission from the LBH bands, by a factor of similar to 1.6 in the daytime airglow. Such an increase is consistent with recent work by Budzien et al. [1994] and Link et al, [1994]. In the aurora some calculations have included radiative cascading but not CIET, which is expected to be more important in typical auroras. However, the calculations involving CIET are based on extrapolation from laboratory measurements. These extrapolations are a source of significant uncertainty in the calculations. (C) 2000 Elsevier Science Ltd. All rights reserved. C1 USAF, Res Lab, Space Vehicles Directorate, Hanscom AFB, MA 01731 USA. RP Eastes, RW (reprint author), USAF, Res Lab, Space Vehicles Directorate, Hanscom AFB, MA 01731 USA. NR 19 TC 5 Z9 6 U1 2 U2 2 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1464-1917 J9 PHYS CHEM EARTH PT C JI Phys. Chem. Earth Pt. C-Solar-Terr. Planet. Sci. PY 2000 VL 25 IS 5-6 BP 523 EP 527 DI 10.1016/S1464-1917(00)00069-6 PG 5 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 348BX UT WOS:000088965500037 ER PT S AU Gavrielides, A Kovanis, V Erneux, T Nizette, M AF Gavrielides, A Kovanis, V Erneux, T Nizette, M BE Binder, RH Blood, P Osinski, M TI Phase locked modulations of optically injected laser diodes SO PHYSICS AND SIMULATION OF OPTOELECTRONIC DEVICES VIII, PTS 1 AND 2 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Physics and Simulation of Optoelectronic Devices VIII CY JAN 24-28, 2000 CL SAN JOSE, CA SP SPIE ID PERIODICALLY PERTURBED BIFURCATION; SEMICONDUCTOR-LASER; HOPF-BIFURCATION; GENERATION; STABILITY; DYNAMICS; SUBJECT AB Recent experiments using lasers subject to strong external injection (Simpson, Opt. Commun. 170, 93 (1999)) have demonstrated that adding a small reference current modulation to the de-bias current can easily lock the oscillation frequency of the laser to the reference frequency. Tunable, locked outputs from 9.5 to 13.1 GHz have been obtained. We explain why synchronization is readily achieved at high injection rates. We describe the locking phenomenon in detail and derive useful analytical expressions for the frequencies and locking range in terms of the laser parameters. C1 USAF, Res Lab, Nonlinear Opt Ctr, Kirtland AFB, NM 87117 USA. RP Gavrielides, A (reprint author), USAF, Res Lab, Nonlinear Opt Ctr, 3550 Aberdeen Ave SE, Kirtland AFB, NM 87117 USA. NR 22 TC 5 Z9 5 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-3561-9 J9 P SOC PHOTO-OPT INS PY 2000 VL 3944 BP 627 EP 638 DI 10.1117/12.391470 PN 1&2 PG 12 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA BR32Y UT WOS:000166107500063 ER PT S AU Goldstein, DH AF Goldstein, DH BE Chenault, DB Duggin, MJ Egan, WG Goldstein, DH TI Polarimetric characterization of federal standard paints SO POLARIZATION ANALYSIS, MEASUREMENT, AND REMOTE SENSING III SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Polarization Analysis, Measurement, and Remote Sensing III CY AUG 02-04, 2000 CL SAN DIEGO, CA SP SPIE, Remote Sensing Soc DE polarimetry; spectropolarimeter; Mueller matrix; paint; polarizance ID MUELLER MATRIX; SPECTROPOLARIMETRY AB A limited polarimetric characterization of paint samples on aluminum substrates is presented. Twelve painted aluminum panels, representing various colors, reflectances, and surface finishes, were examined in a spectropolarimetric reflectometer. Data were analyzed in detail for the 0.9 to 1.0 micrometer wavelength region, although data were taken over a wider spectral range. Polarizance was measured for the twelve samples at eight input beam incidence angles. All observations were made from normal to the sample. Characterization of the surface roughness of the samples was done using profilometers. It was found that as the incidence beam angle increases, the polarizance increases; and as the reflectance of the sample decreases, the polarizance increases. C1 USAF, Res Lab, Eglin AFB, FL 32542 USA. RP Goldstein, DH (reprint author), USAF, Res Lab, 101 W Eglin Blvd, Eglin AFB, FL 32542 USA. NR 7 TC 14 Z9 25 U1 0 U2 2 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-3778-6 J9 P SOC PHOTO-OPT INS PY 2000 VL 4133 BP 112 EP 123 DI 10.1117/12.406618 PG 12 WC Remote Sensing; Optics SC Remote Sensing; Optics GA BR58B UT WOS:000166853900012 ER PT S AU Fetrow, MP Sposato, SH Bishop, KP Caudill, TR AF Fetrow, MP Sposato, SH Bishop, KP Caudill, TR BE Chenault, DB Duggin, MJ Egan, WG Goldstein, DH TI Spectral polarization signatures of materials in the LWIR SO POLARIZATION ANALYSIS, MEASUREMENT, AND REMOTE SENSING III SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Polarization Analysis, Measurement, and Remote Sensing III CY AUG 02-04, 2000 CL SAN DIEGO, CA SP SPIE, Remote Sensing Soc DE infrared polarization; polarization signatures AB The emitted polarization signature of materials is of interest for use in discriminating targets from cluttered backgrounds. In addition, spectrally varying polarization signatures might be used for material identification or to separate target and environment radiance contributions. A spectrally filtered LWIR Imaging Polarimeter (LIP) has been constructed and used in the lab and in the field to make signature measurements of controlled targets; In addition, a full-stokes FTIR Polarization Spectrometer (FSP) has been constructed for higher spectral resolution measurements of materials. This paper will discuss the instruments, calibration methods, general operation, and results characterizing the emitted polarization properties of materials as a function of wavelength. C1 USAF, Res Lab, Kirtland AFB, NM 87117 USA. RP Fetrow, MP (reprint author), USAF, Res Lab, 3550 Aberdeen SE, Kirtland AFB, NM 87117 USA. NR 10 TC 4 Z9 4 U1 2 U2 2 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-3778-6 J9 P SOC PHOTO-OPT INS PY 2000 VL 4133 BP 249 EP 260 DI 10.1117/12.406633 PG 12 WC Remote Sensing; Optics SC Remote Sensing; Optics GA BR58B UT WOS:000166853900026 ER PT J AU Pogue, RT Natarajan, LV Siwecki, SA Tondiglia, VP Sutherland, RL Bunning, TJ AF Pogue, RT Natarajan, LV Siwecki, SA Tondiglia, VP Sutherland, RL Bunning, TJ TI Monomer functionality effects in the anisotropic phase separation of liquid crystals SO POLYMER LA English DT Article DE polymer-dispersed liquid crystal; morphology; grating ID BRAGG GRATINGS; FINE DROPLETS; POLYMER; MORPHOLOGY; FILMS AB Holographic gratings formed through the anisotropic phase separation of liquid crystals show promise as switchable optical elements. In order to form useful elements, however, it is necessary to control the nanoscale morphologies within the grating films. In this manuscript, we evaluate the role of monomer functionality on the morphology and the electro-optical properties of both gratings and conventional scattering polymer-dispersed liquid crystal (PDLC) films. Both of these structures are formed using polymerization-induced phase separation (PIPS) of liquid crystals from a cross-linked polymer formed through free-radical photo-polymerization. Floodlit (uniform illumination) films and holographic gratings (from non-uniform illumination caused by the interference of two laser beams) were made using monomers with 2-5 acrylate groups, while keeping the LC concentration constant in the syrups. The morphologies of these films were examined using low voltage scanning electron microscopy (LVSEM). In all cases, very small LC domains were formed with little indication of growth or coalescence. Lowering monomer functionality reduced the volume fraction of phase-separated domains in the floodlit samples. For the grating samples, the local volume fraction and the LC domain sizes decreased substantially as the monomer functionality was decreased. Using detailed image analysis, differences in the anisotropy of the domains was also probed. A much stronger tendency to form anisotropically-shaped domains was observed for the higher functional syrups. These domain anisotropy differences are correlated with the number of reactive double bonds per monomer and are suggestive of local environmental differences exerted at the time of the domain formation. (C) 1999 Elsevier Science Ltd. All rights reserved. C1 Sci Applicat Int Corp, Dayton, OH 45431 USA. USAF, Res Lab, MLPJ, Mat & Mfg Directorate, Wright Patterson AFB, OH 45432 USA. RP Pogue, RT (reprint author), Sci Applicat Int Corp, 4031 Colonel Glenn Hwy, Dayton, OH 45431 USA. NR 26 TC 73 Z9 75 U1 1 U2 17 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0032-3861 J9 POLYMER JI Polymer PD JAN PY 2000 VL 41 IS 2 BP 733 EP 741 DI 10.1016/S0032-3861(99)00196-2 PG 9 WC Polymer Science SC Polymer Science GA 252LU UT WOS:000083503600038 ER PT S AU Yeh, HH Sparks, A AF Yeh, HH Sparks, A GP AACC AACC AACC TI Geometry and control of satellite formations SO PROCEEDINGS OF THE 2000 AMERICAN CONTROL CONFERENCE, VOLS 1-6 SE Proceedings of the American Control Conference LA English DT Proceedings Paper CT 2000 American Control Conference (ACC 2000) CY JUN 28-30, 2000 CL CHICAGO, IL SP Amer Automat Control Council, IFAC, US Natl Member Org, Int Federat Automat Control AB Satellite formations based on the solutions to Hill's equations have amazingly simple geometric shapes. This paper shows that all such formations around a leader satellite in a circular orbit are determined by the intersection of a plane and an elliptic cylinder of eccentricity root3/2, in a moving coordinate system fixed to the leader. The parametric equations of these formations lead to a method of deploying the satellites in a formation. These equations are also essential in the design of tracking controls to herd the member satellites into a desired formation after the initial deployment, and to nudge them back into formation as soon as they start drifting due to perturbations. The adjustable parameters in these equations are key to the reconfiguration of formations from one plane to another, enabling us to aim and re-aim a satellite array which is used as sensing device. C1 USAF, VACA, Wright Patterson AFB, OH 45433 USA. RP USAF, VACA, Wright Patterson AFB, OH 45433 USA. NR 8 TC 14 Z9 18 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 0743-1619 BN 0-7803-5519-9; 0-7803-5520-2 J9 P AMER CONTR CONF PY 2000 BP 384 EP 388 PG 5 WC Automation & Control Systems SC Automation & Control Systems GA BR32L UT WOS:000166106200078 ER PT S AU Sparks, A AF Sparks, A GP AACC AACC AACC TI Satellite formationkeeping control in the presence of gravity perturbations SO PROCEEDINGS OF THE 2000 AMERICAN CONTROL CONFERENCE, VOLS 1-6 SE PROCEEDINGS OF THE AMERICAN CONTROL CONFERENCE LA English DT Proceedings Paper CT 2000 American Control Conference (ACC 2000) CY JUN 28-30, 2000 CL CHICAGO, IL SP Amer Automat Control Council, IFAC, US Natl Member Org, Int Federat Automat Control AB The performance of linear control laws for satellite formation-keeping in the presence of gravity perturbations is considered. Control using a linear quadratic regulator to minimize the error between the actual and desired relative satellite motion is assessed for its ability to maintain a particular formation geometry in the presence of the earth oblateness gravity perturbation. The desired formation geometry is based on the solution to the linear, unperturbed relative motion equations. Specifically, a formation of satellites is chosen whose projected motion onto the earth's tangential plane is a one kilometer circle. It is shown that the linear control laws maintain the formation within error bounds in the presence of gravity perturbations. Furthermore, simulations provide estimates of the maneuvering propellant required to maintain such a formation? providing a baseline for future studies involving formations based on less taxing desired trajectories and more carefully chosen control strategies. C1 USAF, Res Lab, AFRL VACA, Wright Patterson AFB, OH 45433 USA. RP Sparks, A (reprint author), USAF, Res Lab, AFRL VACA, 2210 8th St, Wright Patterson AFB, OH 45433 USA. NR 15 TC 19 Z9 22 U1 0 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 0743-1619 BN 0-7803-5520-2 J9 P AMER CONTR CONF PY 2000 BP 844 EP 848 PG 5 WC Automation & Control Systems SC Automation & Control Systems GA BR32L UT WOS:000166106200175 ER PT S AU Schumacher, CJ Kumar, R AF Schumacher, CJ Kumar, R GP AACC AACC AACC TI Adaptive control of UAVs in close-coupled formation flight SO PROCEEDINGS OF THE 2000 AMERICAN CONTROL CONFERENCE, VOLS 1-6 SE PROCEEDINGS OF THE AMERICAN CONTROL CONFERENCE LA English DT Proceedings Paper CT 2000 American Control Conference (ACC 2000) CY JUN 28-30, 2000 CL CHICAGO, IL SP Amer Automat Control Council, IFAC, US Natl Member Org, Int Federat Automat Control AB This paper studies the control of multiple UAV's flying in a close-coupled formation for the purposes of drag reduction. A controller design methodology for use in the trail vehicle in a two-UAV formation is presented. The LQR outer-loop tracks relative position commands and generates body-axis rate commands for the inner loop. The adaptive dynamic inversion inner-loop tracks these input commands using only minimal knowledge of the aircraft dynamics. The controller is tested in a two-vehicle formation flight simulation. Excellent command tracking and performance are achieved without use of specific knowledge of the formation flight effects. Simulation results demonstrate that the proposed controller design enables the trail UAV to maneuver in the lead UAV's wake, and to hold a desired position in the vortex. C1 AFRL, VACA, Wright Patterson AFB, OH 45433 USA. RP Schumacher, CJ (reprint author), AFRL, VACA, 2210 8th St,Bldg 146,Room 305, Wright Patterson AFB, OH 45433 USA. NR 9 TC 8 Z9 10 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 0743-1619 BN 0-7803-5520-2 J9 P AMER CONTR CONF PY 2000 BP 849 EP 853 PG 5 WC Automation & Control Systems SC Automation & Control Systems GA BR32L UT WOS:000166106200176 ER PT S AU Pachter, M Sillence, J AF Pachter, M Sillence, J GP AACC AACC AACC TI Loop gain estimation for adaptive control SO PROCEEDINGS OF THE 2000 AMERICAN CONTROL CONFERENCE, VOLS 1-6 SE PROCEEDINGS OF THE AMERICAN CONTROL CONFERENCE LA English DT Proceedings Paper CT 2000 American Control Conference (ACC 2000) CY JUN 28-30, 2000 CL CHICAGO, IL SP Amer Automat Control Council, IFAC, US Natl Member Org, Int Federat Automat Control AB The identification of a linear discrete-time control system's open-loop gain is addressed. The classical Kalman filter theory for state estimation in linear control systems is extended, and the control system's loop gain and states are jointly estimated. A rigourous analysis of the measurement situation on hand yields explicit formulae for the loop gain's unbiased estimate and estimation error's covariance. C1 USAF, ENG, Dept Elect & Comp Engn, Wright Patterson AFB, OH 45433 USA. RP Pachter, M (reprint author), USAF, ENG, Dept Elect & Comp Engn, Wright Patterson AFB, OH 45433 USA. NR 3 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 0743-1619 BN 0-7803-5520-2 J9 P AMER CONTR CONF PY 2000 BP 3208 EP 3213 PG 6 WC Automation & Control Systems SC Automation & Control Systems GA BR32L UT WOS:000166106200657 ER PT B AU Van Veldhuizen, DA Lamont, GB AF Van Veldhuizen, DA Lamont, GB GP IEEE IEEE TI On measuring multiobjective evolutionary algorithm performance SO PROCEEDINGS OF THE 2000 CONGRESS ON EVOLUTIONARY COMPUTATION, VOLS 1 AND 2 SE IEEE Congress on Evolutionary Computation LA English DT Proceedings Paper CT 2000 Congress on Evolutionary Computation (CEC2000) CY JUL 16-19, 2000 CL LA JOLLA, CA SP IEEE Neural Network Council, Evolutionary Programming Soc, Inst Elect Engineers, Parallel Problem Solving Nat, EvoNet, Evolut Artificielle, ANTS, SEAL AB Solving optimisation problems with multiple (often conflicting) objectives is generally a quite difficult goal. Evolutionary Algorithms (EAs) were initially extended and applied during the mid-eighties in an attempt to stochastically solve problems of this generic class. During the past decade a multiplicity of Multiobjective EA (MOEA) techniques have been proposed and applied to many scientific and engineering applications. Our discussion's intent is to rigorously define and execute a quantitative MOEA performance comparison methodology. Almost all comparisons cited in the current literature visually compare algorithmic results, resulting in only relative conclusions. Our methodology gives a basis for absolute conclusions regarding MOEA performance. Selected results from its execution with four MOEAs are presented and described. C1 USAF, Inst Technol, Dept Elect & Comp Engn, Grad Sch Engn, Wright Patterson AFB, OH 45433 USA. RP USAF, Inst Technol, Dept Elect & Comp Engn, Grad Sch Engn, Wright Patterson AFB, OH 45433 USA. EM david.vanveldhuizen@brooks.af.mil; gary.lamont@afit.af.mil NR 17 TC 73 Z9 73 U1 1 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-6375-2 J9 IEEE C EVOL COMPUTAT PY 2000 BP 204 EP 211 PG 8 WC Computer Science, Theory & Methods; Engineering, Electrical & Electronic SC Computer Science; Engineering GA BQ87A UT WOS:000089884700029 ER PT B AU Fausz, JL Richie, DJ AF Fausz, JL Richie, DJ GP IEEE IEEE IEEE TI Flywheel simultaneous attitude control and energy storage using a VSCMG configuration SO PROCEEDINGS OF THE 2000 IEEE INTERNATIONAL CONFERENCE ON CONTROL APPLICATIONS LA English DT Proceedings Paper CT Joint 2000 Conference on Control Applications and Computer-Aided Control Systems Design Symposium CY SEP 25-27, 2000 CL ANCHORAGE, AK SP IEEE Control Syst Soc, Amer Soc Mech Engineers, European Union Control Assoc, Soc Instrument & Control Engineers ID SPEED AB Space vehicle programs consistently endeavor to reduce satellite bus mass to increase payload capacity and/or reduce launch and fabrication costs. At the same time, performance demands on satellite systems continue to increase, creating a formidable challenge to space vehicle technology development. Flywheel-based systems providing both energy storage and attitude control functionality address both of these issues. In particular, the Flywheel Attitude Control: Energy Transmission and Storage (FACETS) system should combine all or part of the energy storage, attitude control, and power management and distribution (PMAD) subsystems into a single system, thus significantly decreasing bus mass land volume). The control problem of mechanically-based simultaneous energy storage and attitude control is far from trivial, however, even in its simplest conceivable form. While decoupling the attitude control and energy storage may be a workable solution to the problem, research in related areas suggests it may not be the best approach. It has been shown that simultaneous momentum management and power tracking can be accomplished with four or mole wheels in reaction wheel mode using the null subspace of the angular momentum dynamics of the wheels. In this Ray the energy storage or power tracking function does not induce attitude disturbance torques to the spacecraft. Furthermore, the null subspace was shown to be sufficient for tracking a variety of practical satellite power profiles. For some applications, however, reaction wheels produce insufficient control torque and control moment gyros (CMGs) are required. This paper extends the null subspace approach for simultaneous power tracking and attitude control, proven for flywheels in a reaction wheel mode, to an array of flywheels in a CMG configuration. C1 USAF, Res Lab, Space Vehicle Component Technol, Kirtland AFB, NM 87117 USA. RP Fausz, JL (reprint author), USAF, Res Lab, Space Vehicle Component Technol, Kirtland AFB, NM 87117 USA. NR 6 TC 14 Z9 18 U1 0 U2 2 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-6563-1 PY 2000 BP 991 EP 995 DI 10.1109/CCA.2000.897602 PG 5 WC Automation & Control Systems; Robotics SC Automation & Control Systems; Robotics GA BR49F UT WOS:000166634800170 ER PT B AU Repperger, DW Djouadi, S AF Repperger, DW Djouadi, S BE Groumpos, PP Koussoulas, NT Polycarpou, M TI An adaptive learning system yielding unbiased parameter estimates SO PROCEEDINGS OF THE 2000 IEEE INTERNATIONAL SYMPOSIUM ON INTELLIGENT CONTROL LA English DT Proceedings Paper CT IEEE International Symposium on Intelligent Control/8th IEEE Mediterranean Conference on Control and Automation CY JUL 17-19, 2000 CL UNIV PATRAS, RION, GREECE SP IEEE, Minist Dev, Gen Sceretariat Res & Technol, Tech Chamber Greece, Univ Patras, Res Comm, European Commiss, ICIMS Network Excellence, European Commiss, AMETMAS Network Excellence, European Commiss, Human Potential Programme High Level Sci Conf HO UNIV PATRAS DE adaptive control; learning system AB A learning system involving model reference adaptive control (MRAC) algorithms is studied in which the Lyapunov function and its associated time derivative are simultaneously quadratic functions of both the position tracking error and the parameter estimation error. An implementation method is described which expands results from [5]. Initially it appears that the condition of persistent excitation (PE) need not be explicitly satisfied, however, this condition is actually implicit in the requirements for a solution. C1 USAF, Res Lab, AFRL, HECP, Wright Patterson AFB, OH 45433 USA. RP Repperger, DW (reprint author), USAF, Res Lab, AFRL, HECP, Wright Patterson AFB, OH 45433 USA. NR 5 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-6491-0 PY 2000 BP 139 EP 144 DI 10.1109/ISIC.2000.882913 PG 6 WC Automation & Control Systems; Engineering, Electrical & Electronic SC Automation & Control Systems; Engineering GA BR45D UT WOS:000166445300029 ER PT B AU Repperger, DW Phillips, CA AF Repperger, DW Phillips, CA BE Groumpos, PP Koussoulas, NT Polycarpou, M TI Developing intelligent control from a biological perspective to examine paradigms for activation utilizing pneumatic muscle actuators SO PROCEEDINGS OF THE 2000 IEEE INTERNATIONAL SYMPOSIUM ON INTELLIGENT CONTROL LA English DT Proceedings Paper CT IEEE International Symposium on Intelligent Control/8th IEEE Mediterranean Conference on Control and Automation CY JUL 17-19, 2000 CL UNIV PATRAS, RION, GREECE SP IEEE, Minist Dev, Gen Sceretariat Res & Technol, Tech Chamber Greece, Univ Patras, Res Comm, European Commiss, ICIMS Network Excellence, European Commiss, AMETMAS Network Excellence, European Commiss, Human Potential Programme High Level Sci Conf HO UNIV PATRAS DE intelligent control; biological paradigms; pneumatic muscle actuation AB Intelligent Control of a pair of actuating muscles is synthesized from a biological paradigm of controlling these muscles (agonistic and antagonist) as they work in conjunction to provide actuation to a system (exoskeleton for a human). An investigation of muscle dynamics in humans and other animals is first conducted. Using the analogies from living muscle action, a paradigm is described on how to control such a system from an energy perspective subject to the biological constraints induced via the muscle dynamics. A discussion on the use of pneumatic muscle technology to power an exoskeleton suit is then presented. C1 USAF, Res Lab, AFRL, HECP, Wright Patterson AFB, OH 45433 USA. RP Repperger, DW (reprint author), USAF, Res Lab, AFRL, HECP, Wright Patterson AFB, OH 45433 USA. NR 8 TC 1 Z9 1 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-6491-0 PY 2000 BP 205 EP 210 DI 10.1109/ISIC.2000.882924 PG 6 WC Automation & Control Systems; Engineering, Electrical & Electronic SC Automation & Control Systems; Engineering GA BR45D UT WOS:000166445300040 ER PT B AU Bullock, RK McIntyre, GA Hill, RR AF Bullock, RK McIntyre, GA Hill, RR BE Joines, JA Barton, RR Kang, K Fishwick, PA TI Using agent-based modeling to capture airpower strategic effects SO PROCEEDINGS OF THE 2000 WINTER SIMULATION CONFERENCE, VOLS 1 AND 2 LA English DT Proceedings Paper CT 2000 Winter Simulation Conference (WSC '00) CY DEC 10-13, 2000 CL ORLANDO, FL SP Assoc Comp Machinery, Special Interest Grp Simulat, Amer Stat Assoc, IEEE, Comp Soc, IEEE, Syst, Man, & Cybernet Soc, Inst Ind Engineers, Inst Operat Res & Management Sci, Coll Simulat, NIST, Soc Comp Simulat Int AB A irpower's strength lies in quickly striking the enemy directly where they are vulnerable while being unhampered by geography and surface forces. Airpower theory suggests the effects of these strikes propagate throughout an opponent's military system yielding catastrophic output or strategic effects. Despite this theory being a cornerstone of US Air Force doctrine, current Air Force models do not seem to capture airpower's inherent strength. Since these models are used to support budgetary decision making, the US may not be funding the airpower capability it needs. This effort focuses on developing an approach to capture strategic effects in models. The approach establishes a basis for the effects in military theory as well as the field of Complex Adaptive Systems. Using these concepts as a foundation, a simulation model called the Hierarchical Interactive Theater Model (HITM) is constructed and exercised. HITM output depicts a cascading deterioration in force effectiveness and eventual total collapse resulting from destruction of vital targets. This outcome is consistent with the expected results of strikes against centers of gravity defined in Air Force doctrine suggesting agent-based modeling is an effective way to simulate strategic effects at the operational level of war. C1 USAF, Studies & Analyses Agcy, Pentagon ADM, Washington, DC 20330 USA. RP Bullock, RK (reprint author), USAF, Studies & Analyses Agcy, Pentagon ADM, Washington, DC 20330 USA. NR 7 TC 1 Z9 1 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-6580-1 PY 2000 BP 1739 EP 1746 PG 8 WC Computer Science, Interdisciplinary Applications; Computer Science, Software Engineering SC Computer Science GA BR62V UT WOS:000166981000238 ER PT S AU Yeh, HH Nelson, E Sparks, A AF Yeh, HH Nelson, E Sparks, A GP IEEE CONTROL SYSTEMS SOCIETY IEEE CONTROL SYSTEMS SOCIETY IEEE CONTROL SYSTEMS SOCIETY TI Nonlinear tracking control for satellite formations SO PROCEEDINGS OF THE 39TH IEEE CONFERENCE ON DECISION AND CONTROL, VOLS 1-5 SE IEEE Conference on Decision and Control LA English DT Proceedings Paper CT 39th IEEE Conference on Decision and Control CY DEC 12-15, 2000 CL SYDNEY, AUSTRALIA SP IEEE Control Syst Soc, SIAM, INFORMS ID SYSTEMS AB A tracking control law using a sliding mode framework is derived to control a satellite formation. Hill's relative motion equations are used to model the follower satellite's motion relative to the leader. To minimize fuel required to maintain the formation, each satellite is constrained to reside near a natural orbit. Control forces axe applied only to maintain the desired relative motion by correcting for initial offsets and perturbation effects that tend to disperse the formation. The control law is modified to account for the discontinuous nature of the control forces available with the satellite propulsive thrusters. Numerical simulations using a high-fidelity, nonlinear model demonstrate the control law performance for the full nonlinear dynamics with high order perturbations. C1 USAF, AFRL, VACA, Wright Patterson AFB, OH 45433 USA. RP USAF, AFRL, VACA, Wright Patterson AFB, OH 45433 USA. NR 12 TC 13 Z9 13 U1 0 U2 2 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 0743-1546 BN 0-7803-6638-7 J9 IEEE DECIS CONTR P PY 2000 BP 328 EP 333 PG 6 WC Automation & Control Systems; Computer Science, Theory & Methods; Operations Research & Management Science; Robotics SC Automation & Control Systems; Computer Science; Operations Research & Management Science; Robotics GA BT12Z UT WOS:000172029000060 ER PT S AU Hall, JK Pachter, M AF Hall, JK Pachter, M GP IEEE CONTROL SYSTEMS SOCIETY IEEE CONTROL SYSTEMS SOCIETY IEEE CONTROL SYSTEMS SOCIETY TI Formation maneuvers in three dimensions SO PROCEEDINGS OF THE 39TH IEEE CONFERENCE ON DECISION AND CONTROL, VOLS 1-5 SE IEEE CONFERENCE ON DECISION AND CONTROL - PROCEEDINGS LA English DT Proceedings Paper CT 39th IEEE Conference on Decision and Control CY DEC 12-15, 2000 CL SYDNEY, AUSTRALIA SP IEEE Control Syst Soc, SIAM, INFORMS AB The flying of aircraft in formation necessitates the extension of the theory of formation flight control to allow for three dimensional formation maneuvers. A leader and wingman formation is considered. A rotating reference frame attached to the wingman is used and special attention is given to the motion of the leader relative to the wingman. A seven state, three input, and three disturbance signal control system which models the dynamics of a two-aircraft formation in three dimensional space is developed. Two formation flight control concepts are investigated. A proportional, integral, and derivative automatic control system to maintain the wing aircraft in the specified formation geometry despite the leader's maneuvers is designed, and its performance is examined in simulation experiments. C1 USAF, Inst Technol, Wright Patterson AFB, OH 45433 USA. RP Hall, JK (reprint author), USAF, Inst Technol, Wright Patterson AFB, OH 45433 USA. NR 6 TC 5 Z9 5 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 0191-2216 BN 0-7803-6638-7 J9 IEEE DECIS CONTR P PY 2000 BP 364 EP 369 PG 6 WC Automation & Control Systems; Computer Science, Theory & Methods; Operations Research & Management Science; Robotics SC Automation & Control Systems; Computer Science; Operations Research & Management Science; Robotics GA BT12Z UT WOS:000172029000066 ER PT S AU Brehm, TE Maybeck, PS AF Brehm, TE Maybeck, PS GP IEEE CONTROL SYSTEMS SOCIETY IEEE CONTROL SYSTEMS SOCIETY IEEE CONTROL SYSTEMS SOCIETY TI Generalized LQG design by filter and controller model selection SO PROCEEDINGS OF THE 39TH IEEE CONFERENCE ON DECISION AND CONTROL, VOLS 1-5 SE IEEE CONFERENCE ON DECISION AND CONTROL - PROCEEDINGS LA English DT Proceedings Paper CT 39th IEEE Conference on Decision and Control CY DEC 12-15, 2000 CL SYDNEY, AUSTRALIA SP IEEE Control Syst Soc, SIAM, INFORMS AB This paper investigates a generalization of the conventional approach to LQG control design. First we investigate removing the assumption that the Kalman filter as the observer is necessarily based on the same model as the best plant model. The controller gain matrix design is performed as usual, based on the optimal solution to the deterministic design for the best model of the real-world plant. For the next case, we also remove this controller design restriction to investigate robustness to uncertainties in the plant model. The filter and controller gain matrices are both determined by models possibly other than the plant model. We relate the plant model to the filter and controller design models by a position correlation (mean square error on output) measure in order to determine optimal performance. C1 USAF, Inst Technol, Dept Elect & Comp Engn, Wright Patterson AFB, OH 45433 USA. RP Brehm, TE (reprint author), USAF, Inst Technol, Dept Elect & Comp Engn, Wright Patterson AFB, OH 45433 USA. NR 5 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 0191-2216 BN 0-7803-6638-7 J9 IEEE DECIS CONTR P PY 2000 BP 2700 EP 2705 PG 6 WC Automation & Control Systems; Computer Science, Theory & Methods; Operations Research & Management Science; Robotics SC Automation & Control Systems; Computer Science; Operations Research & Management Science; Robotics GA BT12Z UT WOS:000172029000483 ER PT S AU Pachter, M AF Pachter, M GP IEEE CONTROL SYSTEMS SOCIETY IEEE CONTROL SYSTEMS SOCIETY IEEE CONTROL SYSTEMS SOCIETY TI Stochastic modeling based DGPS estimation algorithm SO PROCEEDINGS OF THE 39TH IEEE CONFERENCE ON DECISION AND CONTROL, VOLS 1-5 SE IEEE CONFERENCE ON DECISION AND CONTROL - PROCEEDINGS LA English DT Proceedings Paper CT 39th IEEE Conference on Decision and Control CY DEC 12-15, 2000 CL SYDNEY, AUSTRALIA SP IEEE Control Syst Soc, SIAM, INFORMS AB A novel kinematic differential GPS algorithm is presented. Specifically, the accurate relative and absolute positioning of a team, or formation, of mobile vehicles is considered. The measurement situation on hand is correctly modeled, a stochastic framework is developed, and a novel centralized estimation algorithm is rigorously derived. C1 USAF, Inst Technol, ENG, Wright Patterson AFB, OH 45433 USA. RP Pachter, M (reprint author), USAF, Inst Technol, ENG, Wright Patterson AFB, OH 45433 USA. NR 5 TC 1 Z9 1 U1 0 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 0191-2216 BN 0-7803-6638-7 J9 IEEE DECIS CONTR P PY 2000 BP 5192 EP 5197 PG 6 WC Automation & Control Systems; Computer Science, Theory & Methods; Operations Research & Management Science; Robotics SC Automation & Control Systems; Computer Science; Operations Research & Management Science; Robotics GA BT12Z UT WOS:000172029000947 ER PT B AU Clark, N Furth, P AF Clark, N Furth, P GP IEEE IEEE IEEE TI Design and performance evaluation of a silicon eye using micro-mirrors SO PROCEEDINGS OF THE 43RD IEEE MIDWEST SYMPOSIUM ON CIRCUITS AND SYSTEMS, VOLS I-III LA English DT Proceedings Paper CT 43rd IEEE Midwest Symposium on Circuits and Systems CY AUG 08-11, 2000 CL LANSING, MI SP IEEE Circuits & Syst Soc, Michigan State Univ, Dept Elect Engn ID SQUARES AB We have developed a new paradigm, based on massively parallel analog processing coupled with a MEMs micro-mirror device, for developing intelligent vision systems that is capable of performing adaptive optics at rates exceeding I kHz and 3D imaging at bandwidths exceeding 100 Hz. The design and modeling methodologies associated with our smart vision chip are presented along with experimental results that characterize its performance. We also present design and modeling methodologies of our micro-mirror devices along with experimental results that characterize their performance in typical adaptive optic systems. Finally, we present modeling and simulation methodologies of adaptive optics systems along with experimental results used to design and test an adaptive-optic system. The design and modeling methodologies that are presented lend themselves to facilitating the design and development of a wide variety other sophisticated vision systems. In addition to speed, our approach offers advantages in low cost batch fabrication, compact size, low power consumption, and radiation tolerance, making it ideal for many applications. C1 USAF, Res Lab, Kirtland AFB, NM 87117 USA. RP Clark, N (reprint author), USAF, Res Lab, Kirtland AFB, NM 87117 USA. NR 8 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-6475-9 PY 2000 BP 1078 EP 1081 PG 4 WC Engineering, Electrical & Electronic SC Engineering GA BT15J UT WOS:000172099300251 ER PT B AU Clark, N Furth, P AF Clark, N Furth, P GP IEEE IEEE IEEE TI Intelligent Star Tracker SO PROCEEDINGS OF THE 43RD IEEE MIDWEST SYMPOSIUM ON CIRCUITS AND SYSTEMS, VOLS I-III LA English DT Proceedings Paper CT 43rd IEEE Midwest Symposium on Circuits and Systems CY AUG 08-11, 2000 CL LANSING, MI SP IEEE Circuits & Syst Soc, Michigan State Univ, Dept Elect Engn AB We describe our Intelligent Star Tracker System. The Intelligent Star Tracker System incorporates an adaptive optic catadioptric telescope in a silicon carbide housing. Leveraging off of our active optic technologies, the novel active pixel position sensors (APPS) enable wide dynamic range and allows simultaneous imagery of faint and bright stars in a single image, Moreover, the A-PPS, in conjunction with the adaptive optics technologies, offer unprecedented accuracy in altitude and navigation applications. C1 USAF, Res Lab, Kirtland AFB, NM 87117 USA. RP Clark, N (reprint author), USAF, Res Lab, Kirtland AFB, NM 87117 USA. NR 9 TC 0 Z9 3 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-6475-9 PY 2000 BP 1430 EP 1433 PG 4 WC Engineering, Electrical & Electronic SC Engineering GA BT15J UT WOS:000172099300331 ER PT J AU Ratner, A Driscoll, JF Donbar, JM Carter, CD Mullin, JA AF Ratner, A Driscoll, JF Donbar, JM Carter, CD Mullin, JA TI Reaction zone structure of non-premixed turbulent flames in the "Intensely Wrinkled" regime SO PROCEEDINGS OF THE COMBUSTION INSTITUTE LA English DT Article; Proceedings Paper CT 28th International Symposium on Combustion CY JUL 30-AUG 04, 2000 CL UNIV EDINBURGH, EDINBURGH, SCOTLAND HO UNIV EDINBURGH ID NONPREMIXED FLAMES; SIMULATIONS; COMBUSTOR AB Simultaneous images of the CH and OH reaction zones are reported for "Intensely Wrinkled" premixed flames, to determine whether reaction zones retain their thin "laminar flamelet" structure or become "distributed reaction zones." Intensely Wrinkled Flames (IWFs) were achieved by using a special burner with large coflow air velocities to obtain a normalized turbulence intensity (u '/(U) over bar) of; 3.6. which is 10 times greater than time turbulence intensity within jet flames. The images were used to measure profiles of the flame surface density (Sigma) and the average CH layer thickness (<()over bar>(CH)); it is argued that these parameters are the ones that should be used to assess new large eddy simulations (LESs), rather than insensitive parameters such as mean concentrations. In the regime of IWFs. the CH reaction zones remained as thin as those measured in laminar jet flames (i.e.. less than 1 min thick) and had the appearance of flamelets. These thin reaction zones were extin guished before they became thickened by intense turbulence, which provides experimental evidence to support laminar flamelet modeling concepts, "Shredded flames" occurred, within which the reaction zones were short, discontinuous segments, and. the degree of flame wrinkling was significantly larger than in jet flames. Shredded flames have not been observed previously. There is no evidence of small-scale wrinkling of the reaction zones at scales less than half the integral scale. The images showed where the instantaneous stoichiometric contour is located. since it exists at the boundary between the CH and OH layers. Flame surface densities were typically 0.3 mm(-1). C1 Univ Michigan, Dept Aerosp Engn, Ann Arbor, MI 48109 USA. AFRL, PRSS, Wright Patterson AFB, OH 45433 USA. Innovat Sci Solut Inc, Dayton, OH 45440 USA. Univ Alberta, Edmonton, AB T6G 2M7, Canada. Univ So Calif, Los Angeles, CA 90089 USA. RP Ratner, A (reprint author), Univ Michigan, Dept Aerosp Engn, Ann Arbor, MI 48109 USA. NR 20 TC 14 Z9 14 U1 0 U2 1 PU COMBUSTION INST PI PITTSBURGH PA 5001 BAUM BOULEVARD, STE 635, PITTSBURGH, PA 15213-1851 USA SN 0082-0784 J9 P COMBUST INST JI Proc. Combust. Inst. PY 2000 VL 28 BP 245 EP 252 PN 1 PG 8 WC Thermodynamics; Energy & Fuels; Engineering, Chemical; Engineering, Mechanical SC Thermodynamics; Energy & Fuels; Engineering GA 451HQ UT WOS:000169795900032 ER PT J AU Donbar, JM Gruber, MR Jackson, TA Carter, CD Mathur, T AF Donbar, JM Gruber, MR Jackson, TA Carter, CD Mathur, T TI OH planar laser-induced fluorescence imaging in a hydrocarbon-fueled scramjet combustor SO PROCEEDINGS OF THE COMBUSTION INSTITUTE LA English DT Article; Proceedings Paper CT 28th International Symposium on Combustion CY JUL 30-AUG 04, 2000 CL UNIV EDINBURGH, EDINBURGH, SCOTLAND HO UNIV EDINBURGH ID SPRAY AB Planar laser-induced fluorescence (PLIF) imaging of OH has been completed through the piloting section of a hydrocarbon-fueled scramjet. This pilot consists of flush-wall fuel injection followed by a recess, or cavity, in one wall. Images were obtained for both gaseous (ethylene) and liquid (JP-7) fuel combustion. For the gaseous-fuel tests, ethylene as introduced through four flush-wall, low-angle injectors placed upstream of the cavity. For the liquid-fuel tests, injection was normal to the crossflow through seven injectors (four in the bottom wall, three in the top wall). Introducing a small amount of aas into the liquid in the bottom wall injectors enhanced atomization of the liquid column. Flight conditions between Mach 4 and 5 anti dynamic pressures between 23.9 and 71.7 kPa are simulated. Instantaneous images show the dynamics of the combustion process, suggest the process is premixed in nature, and reveal the presence of large-scale structures. Average images at different axial locations show the effects of total temperature and dynamic pressure on the combustion process. Increasing temperature broadens the time-averaged flame zone, while increasing dynamic pressure tends to force the flame against the combustor sidewall. At a given axial location, the time-averaged reaction zone for ethylene is larger than thai for JP-7. C1 USAF, Res Lab, Propuls Sci & Adv Concepts Div, Wright Patterson AFB, OH 45433 USA. Innovat Sci Solut Inc, Dayton, OH 45440 USA. Taitech Inc, Beavercreek, OH 45430 USA. Purdue Univ, W Lafayette, IN 47907 USA. Worcester Polytech Inst, Worcester, MA 01609 USA. RP Donbar, JM (reprint author), USAF, Res Lab, Propuls Sci & Adv Concepts Div, Wright Patterson AFB, OH 45433 USA. NR 19 TC 14 Z9 14 U1 0 U2 11 PU COMBUSTION INST PI PITTSBURGH PA 5001 BAUM BOULEVARD, STE 635, PITTSBURGH, PA 15213-1851 USA SN 0082-0784 J9 P COMBUST INST JI Proc. Combust. Inst. PY 2000 VL 28 BP 679 EP 687 PN 1 PG 9 WC Thermodynamics; Energy & Fuels; Engineering, Chemical; Engineering, Mechanical SC Thermodynamics; Energy & Fuels; Engineering GA 451HQ UT WOS:000169795900084 ER PT J AU Welle, EJ Roberts, WL Decroix, ME Carter, CD Donbar, JM AF Welle, EJ Roberts, WL Decroix, ME Carter, CD Donbar, JM TI Simultaneous particle-imaging velocimetry and OH planar laser-induced fluorescence measurements in an unsteady counterflow propane/air diffusion flame SO PROCEEDINGS OF THE COMBUSTION INSTITUTE LA English DT Article; Proceedings Paper CT 28th International Symposium on Combustion CY JUL 30-AUG 04, 2000 CL UNIV EDINBURGH, EDINBURGH, SCOTLAND HO UNIV EDINBURGH ID EXTINCTION; AIR AB To study the transient response of a diffusion flame to an unsteady flowfield, quantitative measurements of velocity using particle-imaging velocimetry, and OH measurements, using planar laser-induced fluorescence, were made simultaneously in an oscillating counterflow diffusion flame. These non-intrusive measurements were performed to spatially and temporally resolve flowfield and flame characteristics as a function of initial steady strain rate and forcing frequency. For the forcing frequencies considered in this study, die strain rate fluctuations were found to lag the velocity fluctuations, but the phase difference decreased with increasing Forcing frequency. At lower forcing frequencies, the width of the OH field responded quasi-steadily, but as the forcing frequency increased, the OH field showed transient effects. The dilatation velocity. defined as the difference between the minimum velocity in die preheat zone and the maximum velocity in the reaction zone, was used as a flame temperature indicator. The dilatation velocity revealed that the phase difference between the velocity and the temperature increased with increasing forcing frequency, confirming the existence of a diffusion limited response. The results presented here help to illuminate the interconnecting relationships between the chemistry, fluid dynamics, amid reactant transport times. C1 N Carolina State Univ, Dept Mech & Aerosp Engn, Raleigh, NC 27695 USA. Univ Calif Los Alamos Natl Lab, Grp DX2, Los Alamos, NM 87545 USA. Innovat Sci Solut Inc, Dayton, OH 45440 USA. USAF, Res Lab, PRSS, Wright Patterson AFB, OH 45433 USA. RP Welle, EJ (reprint author), N Carolina State Univ, Dept Mech & Aerosp Engn, Box 7910, Raleigh, NC 27695 USA. NR 14 TC 9 Z9 9 U1 1 U2 2 PU COMBUSTION INST PI PITTSBURGH PA 5001 BAUM BOULEVARD, STE 635, PITTSBURGH, PA 15213-1851 USA SN 0082-0784 J9 P COMBUST INST JI Proc. Combust. Inst. PY 2000 VL 28 BP 2021 EP 2027 PN 2 PG 7 WC Thermodynamics; Energy & Fuels; Engineering, Chemical; Engineering, Mechanical SC Thermodynamics; Energy & Fuels; Engineering GA 452QN UT WOS:000169870400068 ER PT J AU Katta, VR Roquemore, WM AF Katta, VR Roquemore, WM TI Response of hydrogen-air opposing-jet diffusion flame to different types of perturbations SO PROCEEDINGS OF THE COMBUSTION INSTITUTE LA English DT Article; Proceedings Paper CT 28th International Symposium on Combustion CY JUL 30-AUG 04, 2000 CL UNIV EDINBURGH, EDINBURGH, SCOTLAND HO UNIV EDINBURGH ID VORTEX AB Studies on the structure of a strained flame in a steady or unsteady state are important to the understanding of turbulent-flame behavior. A numerical investigation was performed to explore the similarities and differences in unsteady flame structures that were established through various modes of perturbation in an opposed-jet diffusion flame. A diluted hydrogen-nitrogen mixture was used as the fuel. Vortices were driven toward the flame surface with different velocities from the air side, the fuel side, or both sides. Changes in the structure of the flame during its interaction with the incoming vortex/vortices were investigated using a time-dependent CFDC code that incorporates 13 species and 74 reactions. Calculations have identified two types of unsteady flames: traveling and stationary. It was found that when a vortex was issued from either the air or the fuel side, the flame not only became strained but also moved with the vortex head, creating a traveling unsteady flame. On the other hand, if two vortices were issued, one from each side of the flame, then the flame was subjected to an unsteady strain rate however, it was locked in a spatial location, leading to a stationary unsteady flame. The structures of theses two types of unsteady flames near the extinction limits were studied. Stationary unsteady flames were also established by flue tuating the fuel and air jets simultaneously and sinusoidally, and their structures were compared with those obtained during the vortex-flame interactions. It was found that in comparison with stationary unsteady flames, traveling unsteady flames can be subjected to higher strain rates without causing extinction. C1 Innovat Sci Solut Inc, Dayton, OH 45440 USA. USAF, Res Lab, Prop Directorate, Wright Patterson AFB, OH 45433 USA. Vanderbilt Univ, Nashville, TN 37232 USA. N Carolina State Univ, Raleigh, NC 27695 USA. RP Katta, VR (reprint author), Innovat Sci Solut Inc, 2766 Indian Ripple Rd, Dayton, OH 45440 USA. NR 25 TC 16 Z9 16 U1 0 U2 3 PU COMBUSTION INST PI PITTSBURGH PA 5001 BAUM BOULEVARD, STE 635, PITTSBURGH, PA 15213-1851 USA SN 0082-0784 J9 P COMBUST INST JI Proc. Combust. Inst. PY 2000 VL 28 BP 2055 EP 2062 PN 2 PG 8 WC Thermodynamics; Energy & Fuels; Engineering, Chemical; Engineering, Mechanical SC Thermodynamics; Energy & Fuels; Engineering GA 452QN UT WOS:000169870400072 ER PT J AU Thevenin, D Renard, PH Fiechtner, GJ Gord, JR Rolon, JC AF Thevenin, D Renard, PH Fiechtner, GJ Gord, JR Rolon, JC TI Regimes of non-premixed flame-vortex interactions SO PROCEEDINGS OF THE COMBUSTION INSTITUTE LA English DT Article; Proceedings Paper CT 28th International Symposium on Combustion CY JUL 30-AUG 04, 2000 CL UNIV EDINBURGH, EDINBURGH, SCOTLAND HO UNIV EDINBURGH ID DIFFUSION FLAME; TURBULENT COMBUSTION; DYNAMICS; LAMINAR AB Detailed studies of flame-vortex interactions are extremely valuable to improve our understanding of turbulent combustion regimes. Combined experimental and numerical studies have already been performed in the premixed case during previous investigations. Therefore, we decided to carry out a detailed experimental investigation on the regimes observed during interaction of a vortex ring and a non-premixed, diluted, hydrogen/air, laminar counterflow flame. To obtain the needed information, several optical diagnostic techniques have been used, in particular, planar laser-induced fluorescence (PLIF) of acetone to quantify vortex structure and speed, simultaneous OH PLIF and Rayleigh measurements, and simultaneous OH PLIF and particle-imaging velocimetry (PIV) measurements. A post-processing of the results combined with direct simulations using detailed chemistry and transport models to check the quality of the postprocessing procedures has led to the construction of a spectral interaction diagram. Eight interaction types were found, emphasizing the relative importance of competing physical phenomena such as straining, curvature, wrinkling. roll-up, and extinction. In particular, we observe two different types of extinction, one due to the combined action of curvature and straining, and the other purely due to straining effects. It was also observed that many vortices are too small or dissipate too rapidly to influence the flame. In other cases, the vortex ring can lead to the formation of pockets of oxidizer burning in the fuel part of the domain. These regimes and the limits between them have important implications for the modeling of turbulent non-premixed combustion. C1 Ecole Cent Paris, Lab EM2C, F-92295 Chatenay Malabry, France. CNRS, F-92295 Chatenay Malabry, France. Innovat Sci Solut Inc, Dayton, OH 45440 USA. USAF, Prop Directorate, Res Lab, Wright Patterson AFB, OH 45433 USA. N Carolina State Univ, Raleigh, NC 27695 USA. RP Thevenin, D (reprint author), Ecole Cent Paris, Lab EM2C, Grande Voie Vignes, F-92295 Chatenay Malabry, France. RI Hang, Chen/H-5336-2011; OI Thevenin, Dominique/0000-0001-7599-9574 NR 34 TC 21 Z9 21 U1 1 U2 4 PU COMBUSTION INST PI PITTSBURGH PA 5001 BAUM BOULEVARD, STE 635, PITTSBURGH, PA 15213-1851 USA SN 0082-0784 J9 P COMBUST INST JI Proc. Combust. Inst. PY 2000 VL 28 BP 2101 EP 2108 PN 2 PG 8 WC Thermodynamics; Energy & Fuels; Engineering, Chemical; Engineering, Mechanical SC Thermodynamics; Energy & Fuels; Engineering GA 452QN UT WOS:000169870400078 ER PT S AU Burke, WJ Erickson, GM AF Burke, WJ Erickson, GM BE Wilson, A TI Bursty bulk flows: Some electrodynamic considerations SO PROCEEDINGS OF THE FIFTH INTERNATIONAL CONFERENCE ON SUBSTORMS SE ESA SPECIAL PUBLICATIONS LA English DT Proceedings Paper CT 5th International Conference on Substorms CY MAY 16-20, 2000 CL ARCTIC & ANTARCTIC RES INST CONGRESS CTR, ST PETERSBURG, RUSSIA SP Russian Fdn Basic Res, Int Assoc Geomagnetism & Aeronom, European Space Agcy HO ARCTIC & ANTARCTIC RES INST CONGRESS CTR ID PLASMA SHEET; DAYSIDE MAGNETOPAUSE; MAGNETOSPHERE; MAGNETOTAIL; SIGNATURES AB CRRES measurements of simultaneous electric and magnetic fields at Pi 2 frequencies indicate that the braking of bursty bulk flow (BBF) structures is not important for triggering substorms, We explore the hypothesis that BBFs are accelerated at near earth neutral lines in the magnetosphere. During enhanced reconnection episodes, plasma streaming across magnetic fields induces westward polarization electric field. Initially, pressure balance does not apply along the flux tube as the equatorial portion contains an excess of directed plasma energy, electrically decoupled from the ionosphere. The BBF plasma brakes by sharing energy with ambient plasma on earthward portions of the flux tube. Braking generates eastward polarization currents j(p). Since j(p) . E < 0, decelerating BBF plasma acts as a generator radiating MHD waves. Alfven waves propagating toward the ionosphere accelerate ambient plasma on earthward portions of flux tubes to the E x B velocity. The mass-loading action of Alfven waves acts as a drag on the BBF plasma as earthward momentum is imparted to ions and electrons at off equatorial latitudes. Alfven waves reaching the ionosphere further dissipate BBF energy as Joule heat. Large amplitude Alfven waves generated by the BBFs may carry more field-aligned current than can be supplied by electrons in the atmospheric loss cone, resulting in parallel potential drops. Consequent AKR and auroral brightenings are observed during BBF encounters. C1 USAF, Res Lab, Space Vehicles Directorate, Hanscom AFB, MA 01731 USA. RP Burke, WJ (reprint author), USAF, Res Lab, Space Vehicles Directorate, 29 Randolph Rd, Hanscom AFB, MA 01731 USA. NR 22 TC 0 Z9 0 U1 0 U2 0 PU ESA PUBLICATIONS DIVISION C/O ESTEC PI 2200 AG NOORDWIJK PA PO BOX 299, 2200 AG NOORDWIJK, NETHERLANDS SN 0379-6566 BN 92-9092-772-0 J9 ESA SP PUBL PY 2000 VL 443 BP 153 EP 156 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BR50E UT WOS:000166662000032 ER PT B AU Hartrum, TC Graham, RP AF Hartrum, TC Graham, RP GP IEEE IEEE TI The AFIT wide spectrum object modeling environment: An awsome beginning SO PROCEEDINGS OF THE IEEE 2000 NATIONAL AEROSPACE AND ELECTRONICS CONFERENCE: ENGINEERING TOMORROW LA English DT Proceedings Paper CT 51st National Aerospace and Electronics Conference (NAECON 2000) CY OCT 10-12, 2000 CL DAYTON, OH SP IEEE, Dayton Sect, IEEE, Aerosp & Electr Syst Soc DE formal methods; software engineering; software synthesis AB Over the past several years, the Air Force Institute of Technology (AFIT) has been developing a formal-based software synthesis system, the AFIT Wide Spectrum Object modeling Environment (AWSOME), along with a specification language AWL (AFIT Wide-spectrum Language). Several tools have been developed, including a parser for the AWL syntax, an interactive object editor, a Java code generator, and a generator for database schemas and SQL queries. This paper describes the formal object-oriented meta-model, the AWL specification language, and transformations from specification to code, along with current and future tools and applications. C1 USAF, Inst Technol, ENG, Wright Patterson AFB, OH 45433 USA. RP Hartrum, TC (reprint author), USAF, Inst Technol, ENG, Wright Patterson AFB, OH 45433 USA. NR 29 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-6262-4 PY 2000 BP 35 EP 42 DI 10.1109/NAECON.2000.894889 PG 8 WC Engineering, Aerospace; Engineering, Electrical & Electronic SC Engineering GA BR24C UT WOS:000165927900002 ER PT B AU Noe, PA Hartrum, TC AF Noe, PA Hartrum, TC GP IEEE IEEE TI Extending the notation of Rational Rose 98 for use with formal methods SO PROCEEDINGS OF THE IEEE 2000 NATIONAL AEROSPACE AND ELECTRONICS CONFERENCE: ENGINEERING TOMORROW LA English DT Proceedings Paper CT 51st National Aerospace and Electronics Conference (NAECON 2000) CY OCT 10-12, 2000 CL DAYTON, OH SP IEEE, Dayton Sect, IEEE, Aerosp & Electr Syst Soc DE formal methods; software engineering AB The Unified Modeling Language (UML) has been incorporated into the CASE tool, Rational Rose98, offering the user the capability of specifying systems using UML notation, Booch notation, or Rumbaugh notation. Through this research effort, Rose98 has been extended to allow formal notation to be entered in the class diagram text fields. Rose scripts were developed to transform the resulting extended Rose model into Z (zed) specifications in (LTEX)-T-A format. Z specifications are developed for the object model, dynamic model, and functional model based on information gathered from the class diagram and state transition diagram of the Rose model. These specifications can then be parsed into a tool supporting formal methods and Ada code can be automatically generated. C1 USAF, HQ Personnel Ctr, DPDXF, Randolph AFB, TX 78150 USA. RP Noe, PA (reprint author), USAF, HQ Personnel Ctr, DPDXF, Randolph AFB, TX 78150 USA. NR 15 TC 1 Z9 1 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-6262-4 PY 2000 BP 43 EP 50 DI 10.1109/NAECON.2000.894890 PG 8 WC Engineering, Aerospace; Engineering, Electrical & Electronic SC Engineering GA BR24C UT WOS:000165927900003 ER PT B AU Banaszak, D AF Banaszak, D GP IEEE IEEE TI Remote control structural exciters for structural data acquisition system calibrations SO PROCEEDINGS OF THE IEEE 2000 NATIONAL AEROSPACE AND ELECTRONICS CONFERENCE: ENGINEERING TOMORROW LA English DT Proceedings Paper CT 51st National Aerospace and Electronics Conference (NAECON 2000) CY OCT 10-12, 2000 CL DAYTON, OH SP IEEE, Dayton Sect, IEEE, Aerosp & Electr Syst Soc DE calibration; vibration; structures; exciters; statistics; experimental design; remote control AB The Air Force invented a new calibration technique, which allows one person to perform multiple end-to-end mechanical calibrations of structural dynamics measurement systems. An end-to-end calibration means a full calibration of instrumentation from the physical input to the transducer to the output where the analog or digital signal is normally analyzed. It is difficult to stimulate mounted and embedded transducers with known physical inputs. Normally two people calibrate-one at the transducer holds or attaches the exciter and one operates the recorder. This new technique uses remote control structural exciters to stimulate measurement transducers contained in structures, with a measurable input level, and the output signal is communicated to a data recorder. The Air Force demonstrated this patented technique by using accelerometers in the laboratory. A commercial off-the-shelf vibration paging system sends a signal from a master control unit to individual exciters that stimulate accelerometers mounted on structures. A reference accelerometer measures the input. Engineers validated the technique using eight different exciters in a completely randomized block design experiment consisting of three 2-level factors: material, structural thickness and excitation mode. The engineers measured amplitude, frequency and transfer function between the accelerometers. This paper describes the invention and looks at potential field applications to insure data integrity in structural data acquisition systems on aging commercial and military vehicles. C1 USAF, Res Lab, Air Vehicles Directorate, Wright Patterson AFB, OH 45433 USA. RP Banaszak, D (reprint author), USAF, Res Lab, Air Vehicles Directorate, Wright Patterson AFB, OH 45433 USA. NR 8 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-6262-4 PY 2000 BP 95 EP 104 DI 10.1109/NAECON.2000.894897 PG 10 WC Engineering, Aerospace; Engineering, Electrical & Electronic SC Engineering GA BR24C UT WOS:000165927900010 ER PT B AU Bowman, JC AF Bowman, JC GP IEEE IEEE TI Methods for rapid computation of RCS in aircraft design SO PROCEEDINGS OF THE IEEE 2000 NATIONAL AEROSPACE AND ELECTRONICS CONFERENCE: ENGINEERING TOMORROW LA English DT Proceedings Paper CT 51st National Aerospace and Electronics Conference (NAECON 2000) CY OCT 10-12, 2000 CL DAYTON, OH SP IEEE, Dayton Sect, IEEE, Aerosp & Electr Syst Soc DE Radar Cross Section; rapid computation; method of moments; physical optics; RCS approximation; fitting models; aircraft conceptual design ID ELECTROMAGNETIC SCATTERING PROBLEMS; NUMERICAL DIFFRACTION COEFFICIENTS; INTEGRAL-EQUATIONS; NURBS SURFACES; ALGORITHM AB Techniques are presented for improving the computational performance of radar cross section (RCS) prediction for aircraft. The motivation is to bring RCS and other electromagnetic requirements into a multidisciplinary, integrated design environment where optimization is likely to be employed. Techniques directly applicable to the Method of Moments and high frequency approximations will be discussed. C1 USAF, Res Lab, VASD, Wright Patterson AFB, OH 45433 USA. RP Bowman, JC (reprint author), USAF, Res Lab, VASD, 2210 8th St, Wright Patterson AFB, OH 45433 USA. NR 26 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-6262-4 PY 2000 BP 118 EP 125 DI 10.1109/NAECON.2000.894900 PG 8 WC Engineering, Aerospace; Engineering, Electrical & Electronic SC Engineering GA BR24C UT WOS:000165927900013 ER PT B AU Kowal, BW AF Kowal, BW GP IEEE IEEE TI A variable structure control system for the propulsion controlled automatic landing of a contemporary large transport aircraft SO PROCEEDINGS OF THE IEEE 2000 NATIONAL AEROSPACE AND ELECTRONICS CONFERENCE: ENGINEERING TOMORROW LA English DT Proceedings Paper CT 51st National Aerospace and Electronics Conference (NAECON 2000) CY OCT 10-12, 2000 CL DAYTON, OH SP IEEE, Dayton Sect, IEEE, Aerosp & Electr Syst Soc DE Propulsion Controlled Aircraft; Variable Structure Control Systems AB Propulsion Controlled Aircraft (PCA) techniques address the problem of controlling an aircraft through only the propulsion system after the primary flight control system has failed. There have been several major commercial accidents in which over 1200 people have lost their lives due to these type of accidents. In addition during the Vietnam War it is estimated that 18% of the aircraft lost... around 1800 aircraft... were lost due to flight control system failures. PCA techniques hate been shown to have the potential to prevent some of these commercial aircraft accidents and have also been shown to have the potential to significantly improve military aircraft survivability to flight control system damage or failures. This paper will present a brief history of accidents that might have been avoided through PCA techniques and will apply the modern nonlinear Variable Structure Control System (VSCS) method to the aircraft PCA problem for a contemporary large transport aircraft. The VSCS controller will be compared with a classical Linear controller for the task of glide slope tracking. The robustness of the VSCS controller to sensor noise and model uncertainty will be evaluated. It will be shown that the VSCS controller performs as well as the classical controller with improved robustness to model uncertainty. C1 EN, Aeronaut Syst Ctr, Wright Patterson AFB, OH 45433 USA. RP Kowal, BW (reprint author), EN, Aeronaut Syst Ctr, Wright Patterson AFB, OH 45433 USA. NR 15 TC 1 Z9 1 U1 0 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-6262-4 PY 2000 BP 187 EP 194 DI 10.1109/NAECON.2000.894909 PG 8 WC Engineering, Aerospace; Engineering, Electrical & Electronic SC Engineering GA BR24C UT WOS:000165927900022 ER PT B AU Kuperman, GG Whitaker, RD Brown, SM AF Kuperman, GG Whitaker, RD Brown, SM GP IEEE IEEE TI "Cyber warrior": Information superiority through advanced multi-sensory command and control technologies SO PROCEEDINGS OF THE IEEE 2000 NATIONAL AEROSPACE AND ELECTRONICS CONFERENCE: ENGINEERING TOMORROW LA English DT Proceedings Paper CT 51st National Aerospace and Electronics Conference (NAECON 2000) CY OCT 10-12, 2000 CL DAYTON, OH SP IEEE, Dayton Sect, IEEE, Aerosp & Electr Syst Soc DE information warfare; command and control; human system interface; cognitive systems engineering AB This paper explores the functions of a conceptual, future "watch center" whose mission is to support Air Force information assurance requirements. A cognitive systems engineering approach is described through the insertion of multi-sensory, user interface technologies may be accomplished. C1 USAF, Res Lab, AFRL, HECA, Wright Patterson AFB, OH 45433 USA. RP Kuperman, GG (reprint author), USAF, Res Lab, AFRL, HECA, Wright Patterson AFB, OH 45433 USA. NR 21 TC 0 Z9 0 U1 0 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-6262-4 PY 2000 BP 263 EP 271 DI 10.1109/NAECON.2000.894920 PG 9 WC Engineering, Aerospace; Engineering, Electrical & Electronic SC Engineering GA BR24C UT WOS:000165927900033 ER PT B AU O'Malley, SA Self, AL Deloach, SA AF O'Malley, SA Self, AL Deloach, SA GP IEEE IEEE TI Comparing performance of static versus mobile multiagent systems SO PROCEEDINGS OF THE IEEE 2000 NATIONAL AEROSPACE AND ELECTRONICS CONFERENCE: ENGINEERING TOMORROW LA English DT Proceedings Paper CT 51st National Aerospace and Electronics Conference (NAECON 2000) CY OCT 10-12, 2000 CL DAYTON, OH SP IEEE, Dayton Sect, IEEE, Aerosp & Electr Syst Soc DE multiagent systems; mobile agents; static agents AB This paper analyzes the performance differences between static and mobile multiagent systems. To do so, we developed solutions to a distributed text search problem, each using a different approach to multiagent systems (static versus mobile) on an isolated test network Changes were then made to the agent environment, various constraints applied, and the resulting effect on the systems measured. Each system was evaluated using a number of performance metrics to demonstrate the strengths and weaknesses of the respective approach. C1 USAF, Inst Technol, Dept Elect & Comp Engn, Wright Patterson AFB, OH 45433 USA. RP O'Malley, SA (reprint author), USAF, Inst Technol, Dept Elect & Comp Engn, Wright Patterson AFB, OH 45433 USA. NR 6 TC 1 Z9 1 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-6262-4 PY 2000 BP 282 EP 289 DI 10.1109/NAECON.2000.894922 PG 8 WC Engineering, Aerospace; Engineering, Electrical & Electronic SC Engineering GA BR24C UT WOS:000165927900035 ER PT B AU Blasch, E Hanselman, P AF Blasch, E Hanselman, P GP IEEE IEEE TI Information fusion for information superiority SO PROCEEDINGS OF THE IEEE 2000 NATIONAL AEROSPACE AND ELECTRONICS CONFERENCE: ENGINEERING TOMORROW LA English DT Proceedings Paper CT 51st National Aerospace and Electronics Conference (NAECON 2000) CY OCT 10-12, 2000 CL DAYTON, OH SP IEEE, Dayton Sect, IEEE, Aerosp & Electr Syst Soc DE sensor and information fusion; information superiority; joint battlespace infosphere AB Information superiority requires the integration and exploitation of multiple data sets from a variety of sources over time and space. To collect, reduce, and enhance data, fusion can process, refine, and provide information to the correct user. This paper will discuss the importance of information fusion to information superiority through the level of data preprocessing, object, situation, and impact assessment, and user and process refinement. The contributions of the information-superiority fusion model is the control of user access acid refinement in the distribution of information. C1 USAF, Res Lab, AFRL, SNAS, Wright Patterson AFB, OH 45433 USA. RP Blasch, E (reprint author), USAF, Res Lab, AFRL, SNAS, Wright Patterson AFB, OH 45433 USA. NR 9 TC 1 Z9 2 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-6262-4 PY 2000 BP 290 EP 297 DI 10.1109/NAECON.2000.894923 PG 8 WC Engineering, Aerospace; Engineering, Electrical & Electronic SC Engineering GA BR24C UT WOS:000165927900036 ER PT B AU Van Cleave, D Rattan, KS AF Van Cleave, D Rattan, KS GP IEEE IEEE TI Tuning of fuzzy logic controller using neural network SO PROCEEDINGS OF THE IEEE 2000 NATIONAL AEROSPACE AND ELECTRONICS CONFERENCE: ENGINEERING TOMORROW LA English DT Proceedings Paper CT 51st National Aerospace and Electronics Conference (NAECON 2000) CY OCT 10-12, 2000 CL DAYTON, OH SP IEEE, Dayton Sect, IEEE, Aerosp & Electr Syst Soc DE fuzzy control; neural networks; neuro-fuzzy control; feedforward control and learning system AB The transformation of expert's knowledge to control rules in a fuzzy logic controller has not been formalized and arbitrary choices concerning, for example, the shape of membership functions have to be made. The quality of a fuzzy controller can be drastically affected by the choice of membership functions. Thus, methods for tuning fuzzy logic controllers are needed. In this paper, neural networks and fuzzy logic are combined to solve the problem of tuning fuzzy logic controllers. The neuro-fuzzy controller uses the neural network learning techniques to tune the membership functions while keeping the semantics of the fuzzy logic controller intact. Both the architecture and the tuning algorithm are presented for a general neuro-fuzzy controller. From this, a procedure to tune a proportional fuzzy controller is obtained. The algorithm for off-line tuning of the fuzzy controller is demonstrated with a numerical example. C1 USAF, Res Lab, AFRL, IFSC, Wright Patterson AFB, OH 45433 USA. RP Van Cleave, D (reprint author), USAF, Res Lab, AFRL, IFSC, Wright Patterson AFB, OH 45433 USA. NR 16 TC 5 Z9 5 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-6262-4 PY 2000 BP 305 EP 312 DI 10.1109/NAECON.2000.894925 PG 8 WC Engineering, Aerospace; Engineering, Electrical & Electronic SC Engineering GA BR24C UT WOS:000165927900038 ER PT B AU Ratazzi, EP AF Ratazzi, EP GP IEEE IEEE TI Microelectromechanical devices for multimode communication systems SO PROCEEDINGS OF THE IEEE 2000 NATIONAL AEROSPACE AND ELECTRONICS CONFERENCE: ENGINEERING TOMORROW LA English DT Proceedings Paper CT 51st National Aerospace and Electronics Conference (NAECON 2000) CY OCT 10-12, 2000 CL DAYTON, OH SP IEEE, Dayton Sect, IEEE, Aerosp & Electr Syst Soc DE microelectromechanical system; software defined radio; multiband communication; tunable filter; Joint Tactical Radio System AB Several new microelectromechanical (MEM) devices are being applied in the development of a 20 MHz to 40 GHz, multimode digital programmable software radio known as Ultra Comm. Utilization of these MEM devices, along with numerous other miniaturization technologies, has allowed the Ultra Comm program to achieve unprecedented advances in size, weight, power and performance. MEM devices are used extensively for tunable filters, radio frequency (RF) switches, and tunable matching networks. These devices have the characteristic of extremely high-Q operation (filters, resonators) and/or low insertion loss/high isolation (switches), while drawing negligible quiescent current because of the electrostatic principles upon which they operate. In addition to a detailed description of the MEM devices being developed and utilized by Ultra Comm, this paper will describe the overall radio architecture used and highlight some of the other advanced technologies being employed. C1 USAF, Res Lab, AFRL, IFGC, Rome, NY 13441 USA. RP Ratazzi, EP (reprint author), USAF, Res Lab, AFRL, IFGC, Rome, NY 13441 USA. NR 12 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-6262-4 PY 2000 BP 346 EP 353 DI 10.1109/NAECON.2000.894931 PG 8 WC Engineering, Aerospace; Engineering, Electrical & Electronic SC Engineering GA BR24C UT WOS:000165927900044 ER PT B AU Mckeehen, PD Speed, MG AF Mckeehen, PD Speed, MG GP IEEE IEEE TI Integration of genesis in a MITL/HITL simulation environment SO PROCEEDINGS OF THE IEEE 2000 NATIONAL AEROSPACE AND ELECTRONICS CONFERENCE: ENGINEERING TOMORROW LA English DT Proceedings Paper CT 51st National Aerospace and Electronics Conference (NAECON 2000) CY OCT 10-12, 2000 CL DAYTON, OH SP IEEE, Dayton Sect, IEEE, Aerosp & Electr Syst Soc DE modeling; simulation; real-time; man-in-the-loop; hardware-in-the-loop AB This paper discusses the use of GENeral Environment for the Simulation of Integrated Systems (GENESIS) in the modeling and 6 DOF simulation of aerospace vehicles. While the emphasis is on the modeling and simulation of the VISTA/F-16, GENESIS simulations of the Innovative Control Effectors (ICE) tailless aircraft configuration, and a hypervelocity vehicle configuration are also discussed. The approach to the recent integration of GENESIS and the GENESIS-based non-realtime VISTA / F-16 simulation into the Air Force Research Laboratory Sensors Directorate's Integrated Demonstrations and Applications Laboratory (IDAL) Man - In - The - Loop / Hardware - In - The - Loop ( MITL / HITL) simulation facility's software executive is also described. C1 USAF, Res Lab, AFRL, SNZW, Wright Patterson AFB, OH 45433 USA. RP Mckeehen, PD (reprint author), USAF, Res Lab, AFRL, SNZW, Wright Patterson AFB, OH 45433 USA. NR 9 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-6262-4 PY 2000 BP 368 EP 374 DI 10.1109/NAECON.2000.894934 PG 7 WC Engineering, Aerospace; Engineering, Electrical & Electronic SC Engineering GA BR24C UT WOS:000165927900047 ER PT B AU McDonald, JT Talbert, ML AF McDonald, JT Talbert, ML GP IEEE IEEE TI Agent-based architecture for modeling and simulation integration SO PROCEEDINGS OF THE IEEE 2000 NATIONAL AEROSPACE AND ELECTRONICS CONFERENCE: ENGINEERING TOMORROW LA English DT Proceedings Paper CT 51st National Aerospace and Electronics Conference (NAECON 2000) CY OCT 10-12, 2000 CL DAYTON, OH SP IEEE, Dayton Sect, IEEE, Aerosp & Electr Syst Soc DE agents; simulation reuse; model integration; AOIS; SUPPRESSOR; MSFD; JIMM AB The Department of Defense (DOD) has an extensive family of models used to digitally simulate the mission level interactions of weapon systems. Interoperability and reuse of the underlying data files used to create simulation scenarios are of particular interest to the modeling community. We develop an architecture to support simulation interoperability by combining three key technologies: object-oriented data modeling, an underlying persistence mechanism, and an agent-oriented analysis and design methodology. We use object-oriented modeling techniques to encapsulate and organize the syntactic information contained in scenario database files while we examine the semantic information of these objects for data integration purposes. The agent architecture provides a communication capability to support collaborative development and information brokering. We demonstrate our architecture by means of prototypical applications that implement the foundational information agent layer. C1 USAF, Operat Test & Evaluat Ctr, HQ AFOTEC, Kirtland AFB, NM 87117 USA. RP McDonald, JT (reprint author), USAF, Operat Test & Evaluat Ctr, HQ AFOTEC, Kirtland AFB, NM 87117 USA. NR 8 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-6262-4 PY 2000 BP 375 EP 382 DI 10.1109/NAECON.2000.894935 PG 8 WC Engineering, Aerospace; Engineering, Electrical & Electronic SC Engineering GA BR24C UT WOS:000165927900048 ER PT B AU Palazotto, AN Naboulsi, SK AF Palazotto, AN Naboulsi, SK GP IEEE IEEE TI The modeling of a torus solar array SO PROCEEDINGS OF THE IEEE 2000 NATIONAL AEROSPACE AND ELECTRONICS CONFERENCE: ENGINEERING TOMORROW LA English DT Proceedings Paper CT 51st National Aerospace and Electronics Conference (NAECON 2000) CY OCT 10-12, 2000 CL DAYTON, OH SP IEEE, Dayton Sect, IEEE, Aerosp & Electr Syst Soc AB The focus of this paper is on the geometric imperfection in a parabolic shape associated with inflated structures which are built by joining together the main envelope (i.e. the reflector and canopy), the torus, and catenary support. The parabolic inflated structure is modeled using the finite element method incorporating the commercial finite element code ABAQUS. The purpose of the torus is to provide a stable boundary condition for the main envelope. Furthermore, the type of boundary condition imposed on the main envelope affect the shape of the inflated structure. The interaction between the torus and the reflector-canopy is investigated. C1 USAF, Inst Technol, Dept Aeronaut & Astronaut, Wright Patterson AFB, OH 45433 USA. RP Palazotto, AN (reprint author), USAF, Inst Technol, Dept Aeronaut & Astronaut, Wright Patterson AFB, OH 45433 USA. NR 14 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-6262-4 PY 2000 BP 399 EP 405 DI 10.1109/NAECON.2000.894938 PG 7 WC Engineering, Aerospace; Engineering, Electrical & Electronic SC Engineering GA BR24C UT WOS:000165927900051 ER PT B AU McQuay, WK AF McQuay, WK GP IEEE IEEE TI Distributed collaborative environments for the 21(st) century engineer SO PROCEEDINGS OF THE IEEE 2000 NATIONAL AEROSPACE AND ELECTRONICS CONFERENCE: ENGINEERING TOMORROW LA English DT Proceedings Paper CT 51st National Aerospace and Electronics Conference (NAECON 2000) CY OCT 10-12, 2000 CL DAYTON, OH SP IEEE, Dayton Sect, IEEE, Aerosp & Electr Syst Soc AB Distributed collaboration is an emerging technology for the 21(st) century that will significantly change how business is conducted in the defense and commercial sectors. Collaboration involves two ol more geographically dispersed individuals working together to share and exchange data, information, knowledge, and actions. The product of the collaboration is defined broadly to include, for example, writing a report, creating software, designing hardware, or developing an alternative course of action for the commander. Distributed collaborative environments (DCE) provide the framework and integrate models, simulations, domain specific tools, and virtual test beds to facilitate collaboration between the multiple disciplines needed in the enterprise. The Air Force Research Laboratory (AFRL) is conducting a lending edge program in developing distributed collaborative technologies targeted to the Air Force's implementation of a simulation-aided acquisition and test process, distributed mission training, and distributed command and control. Geographically separated teams of government and industry engineers, scientists, managers, and procurement specialists will be able to jointly develop advanced technology products. The team will be able to access,widely distributed computer-based engineering tools, models and simulations, databases, and research facilities. DCE will reduce the cost of development and ownership, reduce duplication of effort, improve quality of design, and result bl faster time to product. The research is focusing on the open standards agent-based framework, product and process modeling, structural architecture, and the integration technologies - the glue to integrate the software components. DCE is the underlying infrastructure that makes communication between the diverse simulations and other assets possible and manages the overall flow of the experiment. The AFRL Collaborative Environment concept will foster a major cultural change in how the acquisition, training, and operational communities conduct business. C1 USAF, Res Lab, Wright Patterson AFB, OH 45433 USA. RP McQuay, WK (reprint author), USAF, Res Lab, 2241 Av Circle, Wright Patterson AFB, OH 45433 USA. NR 5 TC 2 Z9 2 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-6262-4 PY 2000 BP 407 EP 414 DI 10.1109/NAECON.2000.894939 PG 8 WC Engineering, Aerospace; Engineering, Electrical & Electronic SC Engineering GA BR24C UT WOS:000165927900052 ER PT B AU Eggleston, RG Young, MJ Whitaker, RD AF Eggleston, RG Young, MJ Whitaker, RD GP IEEE IEEE TI Work-Centered Support System technology: A new interface client technology for the battlespace infosphere SO PROCEEDINGS OF THE IEEE 2000 NATIONAL AEROSPACE AND ELECTRONICS CONFERENCE: ENGINEERING TOMORROW LA English DT Proceedings Paper CT 51st National Aerospace and Electronics Conference (NAECON 2000) CY OCT 10-12, 2000 CL DAYTON, OH SP IEEE, Dayton Sect, IEEE, Aerosp & Electr Syst Soc DE collaborative support; decision aiding; direct manipulation; graphical user interface; human-computer interaction; information overload; interface agents; network-centered interface design; visualization; Work Centered Support System AB Information superiority is a strategic goal of the US Air Force. To achieve this goal the Air Force aims to produce a battlespace infosphere that will provide an unprecedented degree of connectivity and availability of raw data and value-added information for warfighter use. The essential challenge of the infosphere is to be able to provide the right information, at the right time, in the right form to enable warfighters to take effective, coordinated action. Although the infosphere's core web and agent technologies are clearly able to provide a heterogeneous infosphere, improved interface technologies are also needed to address problems of information overload and how to provide support to specific end-users without the support tools themselves becoming an impediment to task performance. We have developed a prototype Work-Centered Support System software client as a means to address these interface issues. The WCSS approach achieves effective support in a software agent environment by blending direct manipulation, work field organization, and decision, collaborative, and product development aiding in a manner that is tailored to both formal and informal characteristics of user work. In this pager we describe the philosophy behind and characteristics of the WCSS technology. We illustrate the technology with a discussion of an interactive WCSS prototype designed to improve support to military airlift mission planners at the headquarter level. C1 USAF, Res Lab, HE, Wright Patterson AFB, OH 45433 USA. RP Eggleston, RG (reprint author), USAF, Res Lab, HE, Wright Patterson AFB, OH 45433 USA. NR 7 TC 4 Z9 4 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-6262-4 PY 2000 BP 499 EP 506 DI 10.1109/NAECON.2000.894953 PG 8 WC Engineering, Aerospace; Engineering, Electrical & Electronic SC Engineering GA BR24C UT WOS:000165927900065 ER PT B AU Cerny, C Blumgold, R Cook, J Bibyk, S Fisher, J Siferd, R Ren, SY AF Cerny, C Blumgold, R Cook, J Bibyk, S Fisher, J Siferd, R Ren, SY GP IEEE IEEE TI Detailed analysis of enhancement-mode technologies for the development of high performance, power conserving, mixed-signal integrated circuits SO PROCEEDINGS OF THE IEEE 2000 NATIONAL AEROSPACE AND ELECTRONICS CONFERENCE: ENGINEERING TOMORROW LA English DT Proceedings Paper CT 51st National Aerospace and Electronics Conference (NAECON 2000) CY OCT 10-12, 2000 CL DAYTON, OH SP IEEE, Dayton Sect, IEEE, Aerosp & Electr Syst Soc AB An important aspect in developing digital receivers is the reduction of analog components, which tend to be temperature sensitive and require calibration and result in a reduction in receiver accuracy. Digital receivers are a long-term goal of the Air Force, which strive for increased functionality and interactive capability amongst air, space and ground based platforms. Therefore, in the proper designing of that digital receiver an intricate tradespace exists in order to maintain the power performance relationship needed to meet platform requirements, and reducing acquisition and lifecycle costs. This paper summarizes efforts to completely analyze two complementary enhancement-mode technologies, GaAs CHFET and SOI CMOS, which could be implemented at the front end of the digital receiver and result in an appropriate power/performance improvement. This effort begins with a detailed radio frequency (RF) characterization of each technology, the building of a complete RF model, and the correct choice of enhancement-mode, high performance mixed-signal circuit designs. This type of ground level approach is critical to any future digital receiver architecture where platform power budget constraints must be met, while producing the maximum performance. C1 SND, AFRL, Wright Patterson AFB, OH 45433 USA. RP Cerny, C (reprint author), SND, AFRL, 2241 Av Circle, Wright Patterson AFB, OH 45433 USA. NR 8 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-6262-4 PY 2000 BP 532 EP 540 DI 10.1109/NAECON.2000.894957 PG 9 WC Engineering, Aerospace; Engineering, Electrical & Electronic SC Engineering GA BR24C UT WOS:000165927900069 ER PT B AU Roberts, ML Temple, MA Raines, RA Stephens, JP AF Roberts, ML Temple, MA Raines, RA Stephens, JP GP IEEE IEEE TI Transform domain communications: Interference-avoidance and acquisition capabilities SO PROCEEDINGS OF THE IEEE 2000 NATIONAL AEROSPACE AND ELECTRONICS CONFERENCE: ENGINEERING TOMORROW LA English DT Proceedings Paper CT 51st National Aerospace and Electronics Conference (NAECON 2000) CY OCT 10-12, 2000 CL DAYTON, OH SP IEEE, Dayton Sect, IEEE, Aerosp & Electr Syst Soc DE spread spectrum; transform domain filtering; spectral shaping; interference suppression; synchronization; acquisition; signal detection; communication systems; transform domain communications; interference avoidance AB This research characterizes the initial acquisition performance of a TDCS via modeling and simulation. As previously demonstrated, a TDCS provides an effective interference suppression capability and differs from traditional spread spectrum systems in two primary ways: 1) spectrally crowded regions are avoided via adaptive spectral notching, and 2) no carrier modulation is employed; rather; "noise-like" basis functions are data modulated. Relevant TDCS research has unrealistically assumed perfect synchronization conditions, a vitally important and complete element of most digital communication systems. This research investigated initial TDCS acquisition performance for various synchronization codewords and several acquisition methods, e.g., direct time correlation (DTC) and German's technique, using both peak and threshold detection techniques. Theoretical development and MATLAB(R) simulation results indicate a TDCS can achieve a high probability of detection (P-D > 0.9) for relatively low input Signal-to-Noise Ratios (SNRs), as low as -23 dB for peak detection and -21 dB far threshold detection. For peak detection, DTC provides the best acquisition performance, i.e., the highest P-D for a given input SNR and fixed probability of false alarm, P-FA. For threshold detection with fixed P-FA of 0.01, DTC provides the best acquisition performance for SNRs below -12 dB, and German's technique provides the best acquisition performance above -12 dB. DTC results are shown to approximate matched filter performance while providing reasonable improvement over radiometric processing. Extensive computer simulations and subsequent analysis indicate that a TDCS cart adequately acquire and accurately align a locally generated reference waveform with a received noise-like TDCS signal. C1 USAF, Informat Warfare Ctr, Kelly AFB, TX 78243 USA. RP Roberts, ML (reprint author), USAF, Informat Warfare Ctr, Kelly AFB, TX 78243 USA. NR 10 TC 7 Z9 7 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-6262-4 PY 2000 BP 610 EP 617 DI 10.1109/NAECON.2000.894969 PG 8 WC Engineering, Aerospace; Engineering, Electrical & Electronic SC Engineering GA BR24C UT WOS:000165927900081 ER PT B AU Berridge, WT Talbert, ML AF Berridge, WT Talbert, ML GP IEEE IEEE TI Scene-centric identification and retrieval of Unmanned Aerial Vehicle (UAV) video segments SO PROCEEDINGS OF THE IEEE 2000 NATIONAL AEROSPACE AND ELECTRONICS CONFERENCE: ENGINEERING TOMORROW LA English DT Proceedings Paper CT 51st National Aerospace and Electronics Conference (NAECON 2000) CY OCT 10-12, 2000 CL DAYTON, OH SP IEEE, Dayton Sect, IEEE, Aerosp & Electr Syst Soc DE information retrieval; multimedia; Unmanned Aerial Vehicle; imagery indexing; telemetry AB With the acceptance of Unmanned Aerial Vehicles (UAVs) as a primary platform within the Department of Defense(1) (DOD) for gathering intelligence data, the amount of video information being recorded, analyzed, and archived continues to grow. Mechanisms for quickly locating and retrieving video segments of interest amongst the many hours of recorded video are required to accommodate the rapid turnaround expected in today's wartime planning environments. This paper demonstrates that attributes extracted or calculated from existing mission-related data (specifically telemetry and target data) can be indexed to support random access into archived video streams. These indexes allow video segments to be retrieved based on image characteristics and basic content thus supporting the search for clear, highly detailed images of targets and areas of interest. C1 AEDC SDC, Arnold Res Lab, Arnold AFB, TN USA. RP Berridge, WT (reprint author), AEDC SDC, Arnold Res Lab, Arnold AFB, TN USA. NR 3 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-6262-4 PY 2000 BP 794 EP 800 DI 10.1109/NAECON.2000.894995 PG 7 WC Engineering, Aerospace; Engineering, Electrical & Electronic SC Engineering GA BR24C UT WOS:000165927900107 ER PT B AU Clough, BT AF Clough, BT GP IEEE IEEE TI UAV autonomous control system reliability - What should it be, and how do we reach it? SO PROCEEDINGS OF THE IEEE 2000 NATIONAL AEROSPACE AND ELECTRONICS CONFERENCE: ENGINEERING TOMORROW LA English DT Proceedings Paper CT 51st National Aerospace and Electronics Conference (NAECON 2000) CY OCT 10-12, 2000 CL DAYTON, OH SP IEEE, Dayton Sect, IEEE, Aerosp & Electr Syst Soc C1 AF Res Lab, Controls Automat, Kirtland AFB, NM 87117 USA. RP Clough, BT (reprint author), AF Res Lab, Controls Automat, Kirtland AFB, NM 87117 USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-6262-4 PY 2000 BP 807 EP 807 DI 10.1109/NAECON.2000.894997 PG 1 WC Engineering, Aerospace; Engineering, Electrical & Electronic SC Engineering GA BR24C UT WOS:000165927900109 ER PT B AU Barfield, F AF Barfield, F GP IEEE IEEE TI Autonomous collision avoidance - The technical requirements SO PROCEEDINGS OF THE IEEE 2000 NATIONAL AEROSPACE AND ELECTRONICS CONFERENCE: ENGINEERING TOMORROW LA English DT Proceedings Paper CT 51st National Aerospace and Electronics Conference (NAECON 2000) CY OCT 10-12, 2000 CL DAYTON, OH SP IEEE, Dayton Sect, IEEE, Aerosp & Electr Syst Soc DE autonomous control; automatic collision avoidance; time-to-escape; flyborg rules; UAV AB Autonomous collision avoidance is necessary if Unmanned Aerial Vehicles (UAVs) an to "blacken the sky" in massed attacks, accompany manned fighters on combat missions, and transition civil airspace. These vehicles will, in some manner, have to "see and avoid" other aircraft. An automated air collision avoidance system will fulfill a part of this need. It will automatically maneuver an aircraft, at the last instant, to avoid an air-to-air collision. It will function in a manner similar to a pilot avoiding a collision. It is a system that must be reliable, verifiable, and partially redundant, forming the last line of defense against collisions. It must provide nuisance free operation and allow safe interoperability. The requirements for such as system will be discussed in detail. Of particular interest are criteria to enable a safe, nuisance foe system that will have embedded rules of the road for all encounters. Autonomous control of unmanned aerial vehicles is a goal for the US Air Force in the future. However, flying multiple unmanned vehicles in the same tactical airspace with manned fighters presents very challenging problems. Autonomous collision avoidance is a necessary step in moving toward this goal. C1 USAF, Res Lab, Automated Air Collis Avoidance Program, VACC, Wright Patterson AFB, OH 45433 USA. RP Barfield, F (reprint author), USAF, Res Lab, Automated Air Collis Avoidance Program, VACC, Wright Patterson AFB, OH 45433 USA. NR 0 TC 6 Z9 6 U1 0 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-6262-4 PY 2000 BP 808 EP 813 DI 10.1109/NAECON.2000.894998 PG 6 WC Engineering, Aerospace; Engineering, Electrical & Electronic SC Engineering GA BR24C UT WOS:000165927900110 ER PT B AU Douglas, JS Lamont, GB AF Douglas, JS Lamont, GB BE Arabnia, HR TI Unifying traditional software engineering methods for effective distributed object system design SO PROCEEDINGS OF THE INTERNATIONAL CONFERENCE ON PARALLEL AND DISTRIBUTED PROCESSING TECHNIQUES AND APPLICATIONS, VOLS I-V LA English DT Proceedings Paper CT International Conference on Parallel and Distributed Processing Techniques and Applications (PDPTA 2000) CY JUN 26-29, 2000 CL LAS VEGAS, NV SP Comp Sci Res, Educ & Applicat Press, Informat Processing Soc Japan, SIGMPS, Int Technol Inst, Java High Performance Comp Res Grp, Korea Informat Processing Soc, World Sci & Engn Soc DE distributed objects; components; scalability; threads; tasks CORBA; OMG AB This paper describes a distributed object system design method that combines an away of traditional software design techniques and uses design patterns and a scalability model to develop a N-tier architecture. The paper addresses generic distributed object system development using the Object Management Group's (OMG) Common Object Request Broker Architecture (CORBA). Specifically, this investigation addresses distributed object system development techniques as applied to the Air Force Weather Agency (AFWA) application domain and concentrates on Terminal Aerodrome Forecast (TAF) validation, publication, and metrics processing problems. The resulting design is shown to be an extensible, efficient, and scalable. C1 USAF, Inst Technol, Grad Sch Engn, Wright Patterson AFB, OH 45433 USA. RP Douglas, JS (reprint author), USAF, Inst Technol, Grad Sch Engn, Wright Patterson AFB, OH 45433 USA. NR 10 TC 0 Z9 0 U1 0 U2 0 PU C S R E A PRESS PI ATHENS PA 115 AVALON DR, ATHENS, GA 30606 USA BN 1-892512-52-1 PY 2000 BP 2423 EP 2429 PG 7 WC Computer Science, Hardware & Architecture; Computer Science, Information Systems; Computer Science, Software Engineering; Computer Science, Theory & Methods SC Computer Science GA BR82C UT WOS:000167676300332 ER PT S AU Wegner, PM Adams, DF AF Wegner, PM Adams, DF GP SEM SEM TI Causes of bending in the Wyoming Combined Loading Compression (CLC) Test Method SO PROCEEDINGS OF THE SEM IX INTERNATIONAL CONGRESS ON EXPERIMENTAL MECHANICS SE PROCEEDINGS OF THE INTERNATIONAL CONGRESS ON EXPERIMENTAL MECHANICS LA English DT Proceedings Paper CT SEM 9th International Congress on Experimental Mechanics CY JUN 05-08, 2000 CL ORLANDO, FL SP British Soc Strain Measurement, Chinese Soc Mech Engineers, Japan Soc Mech Engineers Mat & Mech Div, Machinery Failure Pervent Technol Soc, Korean Soc, Mech Engineers, Mat & Fracture Div, SEM Republic China Local Sect, Shock & Vibrat Informat Analy Ctr, strain Soc South Africa AB A parametric study revealed that specimen quality, load train alignment, and fixture dimensional tolerances all have a large effect on the amount of specimen bending during a compression test. Based on experimental observations, several recommendations to minimize the amount of specimen bending were developed. C1 USAF, Kirtland AFB, NM 87117 USA. RP Wegner, PM (reprint author), USAF, 3550 Aberdeen Ave SE, Kirtland AFB, NM 87117 USA. NR 5 TC 0 Z9 0 U1 0 U2 0 PU SOC EXPERIMENTAL MECHANICS INC PI BETHEL PA 7 SCHOOL ST, BETHEL, CT 06801 USA SN 1046-672X BN 0-91205-369-0 J9 P INT CONG EXPERIT M PY 2000 BP 34 EP 37 PG 2 WC Engineering, Mechanical; Mechanics; Physics, Applied SC Engineering; Mechanics; Physics GA BU51C UT WOS:000176203100010 ER PT S AU Ganley, J AF Ganley, J GP SEM SEM TI Structural issues associated with the University Nanosatellite Program SO PROCEEDINGS OF THE SEM IX INTERNATIONAL CONGRESS ON EXPERIMENTAL MECHANICS SE PROCEEDINGS OF THE INTERNATIONAL CONGRESS ON EXPERIMENTAL MECHANICS LA English DT Proceedings Paper CT SEM 9th International Congress on Experimental Mechanics CY JUN 05-08, 2000 CL ORLANDO, FL SP British Soc Strain Measurement, Chinese Soc Mech Engineers, Japan Soc Mech Engineers Mat & Mech Div, Machinery Failure Pervent Technol Soc, Korean Soc, Mech Engineers, Mat & Fracture Div, SEM Republic China Local Sect, Shock & Vibrat Informat Analy Ctr, strain Soc South Africa AB The University Nanosatellite Program is a DoD / NASA sponsored program, in partnership with academia, to demonstrate advanced nanosatellite technologies. The teaming arrangement involves University constructed nanosatellites that will be launched from the Space Shuttle Orbiter on an Air Force Research Laboratory deployment platform. The launch and operation of nanosatellites, especially in the Shuttle environment, involves unique structural challenges, including shock loading, structural stiffness and materials issues. These issues will be discussed in this paper. C1 USAF, Kirtland AFB, NM 87117 USA. RP Ganley, J (reprint author), USAF, 3550 Aberdeen Ave SE, Kirtland AFB, NM 87117 USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU SOC EXPERIMENTAL MECHANICS INC PI BETHEL PA 7 SCHOOL ST, BETHEL, CT 06801 USA SN 1046-672X BN 0-91205-369-0 J9 P INT CONG EXPERIT M PY 2000 BP 38 EP 41 PG 2 WC Engineering, Mechanical; Mechanics; Physics, Applied SC Engineering; Mechanics; Physics GA BU51C UT WOS:000176203100011 ER PT S AU Mollenhauer, DH AF Mollenhauer, DH GP SEM SEM TI An experimental/analytical correlation of the elastic response of a model composite under Interlaminar tension SO PROCEEDINGS OF THE SEM IX INTERNATIONAL CONGRESS ON EXPERIMENTAL MECHANICS SE PROCEEDINGS OF THE INTERNATIONAL CONGRESS ON EXPERIMENTAL MECHANICS LA English DT Proceedings Paper CT SEM 9th International Congress on Experimental Mechanics CY JUN 05-08, 2000 CL ORLANDO, FL SP British Soc Strain Measurement, Chinese Soc Mech Engineers, Japan Soc Mech Engineers Mat & Mech Div, Machinery Failure Pervent Technol Soc, Korean Soc, Mech Engineers, Mat & Fracture Div, SEM Republic China Local Sect, Shock & Vibrat Informat Analy Ctr, strain Soc South Africa AB The elastic surface strain distribution of a model composite made from silicon carbide fibers and epoxy was quantified using moire interferometry. The specimen had a cruciform geometry with two rows of fibers perpendicular to the loading direction. The fibers spanned the width of the specimen parallel to and in the center of the unloaded arms of the cruciform geometry. Moire measurements were obtained at three load levels. A finite element model (FEM) of the specimen was constructed and analyzed. The experiment and modeling were repeated on a cruciform specimen without fibers. In all cases, comparison between the moire and FEM strain distributions showed excellent agreement in both the distribution shape and the magnitude of obtained strain data. This agreement is important to establish the veracity of micromechanical calculations for structural graphite-resin composites, where the influence of the small fiber diameters (0.007 mm) may not be measurable with the moire technique. C1 USAF, Res Lab, MLBC, Mat & Mfg Directorate,Nonmet Mat Div, Wright Patterson AFB, OH 45433 USA. RP Mollenhauer, DH (reprint author), USAF, Res Lab, MLBC, Mat & Mfg Directorate,Nonmet Mat Div, 2941 P St Rm 136, Wright Patterson AFB, OH 45433 USA. NR 6 TC 0 Z9 0 U1 0 U2 0 PU SOC EXPERIMENTAL MECHANICS INC PI BETHEL PA 7 SCHOOL ST, BETHEL, CT 06801 USA SN 1046-672X BN 0-91205-369-0 J9 P INT CONG EXPERIT M PY 2000 BP 413 EP 416 PG 4 WC Engineering, Mechanical; Mechanics; Physics, Applied SC Engineering; Mechanics; Physics GA BU51C UT WOS:000176203100113 ER PT S AU Bechel, VT Tandon, GP AF Bechel, VT Tandon, GP GP SEM SEM TI A technique to determine processing effects on interfacial adhesion SO PROCEEDINGS OF THE SEM IX INTERNATIONAL CONGRESS ON EXPERIMENTAL MECHANICS SE PROCEEDINGS OF THE INTERNATIONAL CONGRESS ON EXPERIMENTAL MECHANICS LA English DT Proceedings Paper CT SEM 9th International Congress on Experimental Mechanics CY JUN 05-08, 2000 CL ORLANDO, FL SP British Soc Strain Measurement, Chinese Soc Mech Engineers, Japan Soc Mech Engineers Mat & Mech Div, Machinery Failure Pervent Technol Soc, Korean Soc, Mech Engineers, Mat & Fracture Div, SEM Republic China Local Sect, Shock & Vibrat Informat Analy Ctr, strain Soc South Africa ID COMPOSITES AB Recent research has shown that radiation (electron-beam) cured graphite/epoxy composites have, in general, reduced off-axis strengths. ((1,2)) 21 The source of the relatively low interlaminar shear strength and transverse strength may be a result of a poor interface. Determining the level of fiber/matrix adhesion in these composites and evaluating future interface modifications presents several challenges. The fragmentation test cannot be used on state-of-the-art e-beam composites due to the limited matrix strain-to-failure (< 2 %). The fiber indentation test has been used on e-beam cured model composites to gain valuable information, but the results have been ambiguous at times. Fiber indentation data can be difficult to interpret for several reasons, including the lack of a rigorous method of accounting for the residual stress state and the presence of a free-edge singularity. The current investigation establishes an experimental technique for determining interfacial normal strength in a typical e-beam cured graphite/epoxy composite as a function of processing conditions that may significantly alter the residual stress state. The technique developed is a modification to the geometry, debond detection method, and analysis of the cruciform test. C1 USAF, Res Lab, Struct Mat Branch, Wright Patterson AFB, OH 45433 USA. RP Bechel, VT (reprint author), USAF, Res Lab, Struct Mat Branch, 2941 P St,Rm 136, Wright Patterson AFB, OH 45433 USA. NR 8 TC 3 Z9 3 U1 1 U2 1 PU SOC EXPERIMENTAL MECHANICS INC PI BETHEL PA 7 SCHOOL ST, BETHEL, CT 06801 USA SN 1046-672X BN 0-91205-369-0 J9 P INT CONG EXPERIT M PY 2000 BP 420 EP 423 PG 2 WC Engineering, Mechanical; Mechanics; Physics, Applied SC Engineering; Mechanics; Physics GA BU51C UT WOS:000176203100115 ER PT S AU Shelley, JS DeVries, KL AF Shelley, JS DeVries, KL GP SEM SEM TI Degradation of nylon-6/clay nanocomposites in NOx SO PROCEEDINGS OF THE SEM IX INTERNATIONAL CONGRESS ON EXPERIMENTAL MECHANICS SE PROCEEDINGS OF THE INTERNATIONAL CONGRESS ON EXPERIMENTAL MECHANICS LA English DT Proceedings Paper CT SEM 9th International Congress on Experimental Mechanics CY JUN 05-08, 2000 CL ORLANDO, FL SP British Soc Strain Measurement, Chinese Soc Mech Engineers, Japan Soc Mech Engineers Mat & Mech Div, Machinery Failure Pervent Technol Soc, Korean Soc, Mech Engineers, Mat & Fracture Div, SEM Republic China Local Sect, Shock & Vibrat Informat Analy Ctr, strain Soc South Africa ID HYBRID AB Nylon-6 is an important engineering polymer that, in its fully spherulitic (bulk) form, has many applications in gears, rollers, and other long life cycle components. In 1993, Toyota commercialized a nylon-6/clay nanocomposite out of which it produced the timing belt cover for the 1993 Camry. Although these hybrid nanocomposites show significant improvements in their mechanical response characteristics, including yield strength and heat distortion temperature, little is known about the degradation of these properties due to environmental pollutants like NOx. Nylon-6 fibers are severely degraded by interaction with NOx and other pollutants, showing a strong synergism between applied load and environmental degradation. While the nanocomposites show a significant reduction in permeability of gases and water due to the incorporation of lamellar clay, their susceptibility to non-diffusional mechano-chemical degradation is unknown. The fracture toughness of these nylon-6/clay nanocomposites increases, not as a function of clay content, but as a function of the volume of nylon-6 polymer chains influenced by the clay lamellae surfaces. Both the clay and the constrained volume offer the nanocomposites some protection from the deleterious effects of NOx. The time-to-failure at a given stress intensity factor as a function of clay content and constrained volume will be discussed along with fracture toughness of the materials. C1 USAF, Res Lab, Prop Directorate, AFRLPRRE, Edwards AFB, CA 93524 USA. RP Shelley, JS (reprint author), USAF, Res Lab, Prop Directorate, AFRLPRRE, 4 Draco Dr, Edwards AFB, CA 93524 USA. NR 14 TC 0 Z9 0 U1 0 U2 0 PU SOC EXPERIMENTAL MECHANICS INC PI BETHEL PA 7 SCHOOL ST, BETHEL, CT 06801 USA SN 1046-672X BN 0-91205-369-0 J9 P INT CONG EXPERIT M PY 2000 BP 567 EP 570 PG 4 WC Engineering, Mechanical; Mechanics; Physics, Applied SC Engineering; Mechanics; Physics GA BU51C UT WOS:000176203100152 ER PT S AU Miller, TC Liu, CT AF Miller, TC Liu, CT GP SEM SEM TI The effects of pressure on fracture of a rubbery particulate composite SO PROCEEDINGS OF THE SEM IX INTERNATIONAL CONGRESS ON EXPERIMENTAL MECHANICS SE PROCEEDINGS OF THE INTERNATIONAL CONGRESS ON EXPERIMENTAL MECHANICS LA English DT Proceedings Paper CT SEM 9th International Congress on Experimental Mechanics CY JUN 05-08, 2000 CL ORLANDO, FL SP British Soc Strain Measurement, Chinese Soc Mech Engineers, Japan Soc Mech Engineers Mat & Mech Div, Machinery Failure Pervent Technol Soc, Korean Soc, Mech Engineers, Mat & Fracture Div, SEM Republic China Local Sect, Shock & Vibrat Informat Analy Ctr, strain Soc South Africa C1 USAF, Res Lab, AFRL, PRSM, Edwards AFB, CA USA. RP Miller, TC (reprint author), USAF, Res Lab, AFRL, PRSM, 10 E Saturn Blvd, Edwards AFB, CA USA. NR 7 TC 0 Z9 0 U1 0 U2 0 PU SOC EXPERIMENTAL MECHANICS INC PI BETHEL PA 7 SCHOOL ST, BETHEL, CT 06801 USA SN 1046-672X BN 0-91205-369-0 J9 P INT CONG EXPERIT M PY 2000 BP 792 EP 795 PG 4 WC Engineering, Mechanical; Mechanics; Physics, Applied SC Engineering; Mechanics; Physics GA BU51C UT WOS:000176203100213 ER PT S AU Liu, CT AF Liu, CT GP SEM SEM TI Micro-macro behavior near the crack tip in a particulate composite material SO PROCEEDINGS OF THE SEM IX INTERNATIONAL CONGRESS ON EXPERIMENTAL MECHANICS SE PROCEEDINGS OF THE INTERNATIONAL CONGRESS ON EXPERIMENTAL MECHANICS LA English DT Proceedings Paper CT SEM 9th International Congress on Experimental Mechanics CY JUN 05-08, 2000 CL ORLANDO, FL SP British Soc Strain Measurement, Chinese Soc Mech Engineers, Japan Soc Mech Engineers Mat & Mech Div, Machinery Failure Pervent Technol Soc, Korean Soc, Mech Engineers, Mat & Fracture Div, SEM Republic China Local Sect, Shock & Vibrat Informat Analy Ctr, strain Soc South Africa C1 USAF, Res Lab, AFRl, PRSM, Edwards AFB, CA 93524 USA. RP Liu, CT (reprint author), USAF, Res Lab, AFRl, PRSM, 10 E Saturn Blvd, Edwards AFB, CA 93524 USA. NR 4 TC 0 Z9 0 U1 0 U2 0 PU SOC EXPERIMENTAL MECHANICS INC PI BETHEL PA 7 SCHOOL ST, BETHEL, CT 06801 USA SN 1046-672X BN 0-91205-369-0 J9 P INT CONG EXPERIT M PY 2000 BP 850 EP 852 PG 3 WC Engineering, Mechanical; Mechanics; Physics, Applied SC Engineering; Mechanics; Physics GA BU51C UT WOS:000176203100227 ER PT S AU Liu, CT Miller, TC AF Liu, CT Miller, TC GP SEM SEM TI Effect of crack size on initiation and growth behavior in a particulate composite material SO PROCEEDINGS OF THE SEM IX INTERNATIONAL CONGRESS ON EXPERIMENTAL MECHANICS SE PROCEEDINGS OF THE INTERNATIONAL CONGRESS ON EXPERIMENTAL MECHANICS LA English DT Proceedings Paper CT SEM 9th International Congress on Experimental Mechanics CY JUN 05-08, 2000 CL ORLANDO, FL SP British Soc Strain Measurement, Chinese Soc Mech Engineers, Japan Soc Mech Engineers Mat & Mech Div, Machinery Failure Pervent Technol Soc, Korean Soc, Mech Engineers, Mat & Fracture Div, SEM Republic China Local Sect, Shock & Vibrat Informat Analy Ctr, strain Soc South Africa C1 USAF, Res Lab, Edwards AFB, CA 93524 USA. RP Liu, CT (reprint author), USAF, Res Lab, 10 E Saturn Blvd, Edwards AFB, CA 93524 USA. NR 4 TC 0 Z9 0 U1 0 U2 0 PU SOC EXPERIMENTAL MECHANICS INC PI BETHEL PA 7 SCHOOL ST, BETHEL, CT 06801 USA SN 1046-672X BN 0-91205-369-0 J9 P INT CONG EXPERIT M PY 2000 BP 1017 EP 1020 PG 4 WC Engineering, Mechanical; Mechanics; Physics, Applied SC Engineering; Mechanics; Physics GA BU51C UT WOS:000176203100272 ER PT B AU Hedges, RA Suter, BW AF Hedges, RA Suter, BW GP IEEE IEEE TI The numerical spread as a measure of non-stationarity: Boundary effects in the numerical expected ambiguity function SO PROCEEDINGS OF THE TENTH IEEE WORKSHOP ON STATISTICAL SIGNAL AND ARRAY PROCESSING LA English DT Proceedings Paper CT 10th IEEE Workshop on Statistical Signal and Array Processing CY AUG 13-16, 2000 CL POCONO MANOR, PA SP IEEE, Signal Proc Soc AB Establishing measures for local stationarity is an open problem in the field of time-frequency analysis. One promising theoretical measure, known as the spread, provides a means for quantifying potential correlation between signal elements. In previous papers we investigated the issue of implementing such a measure for discrete signals. The numerical spread was introduced [1] as a means of applying and investigating the techniques previously only studied theoretically. When implementing such a scheme it became necessary to augment the covariance matrix so that the resulting ambiguity space has a uniform resolution. In this paper we compare three extension schemes: zero padding, circular extension, and edge replication, to determine which provides the best estimate of the numerical spread. Based on our results, we determined that the method of normalized edge replication is least likely to inflate the estimate of the spread. C1 USAF, Res Lab, IFGC, Griffiss AFB, NY 13441 USA. RP Hedges, RA (reprint author), USAF, Res Lab, IFGC, 525 Brooks Rd, Griffiss AFB, NY 13441 USA. NR 7 TC 1 Z9 1 U1 0 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-5988-7 PY 2000 BP 252 EP 256 DI 10.1109/SSAP.2000.870122 PG 5 WC Engineering, Electrical & Electronic SC Engineering GA BR09H UT WOS:000165630400054 ER PT B AU Oxley, ME Reid, TF Suter, BW AF Oxley, ME Reid, TF Suter, BW GP IEEE IEEE TI Locally stationary processes SO PROCEEDINGS OF THE TENTH IEEE WORKSHOP ON STATISTICAL SIGNAL AND ARRAY PROCESSING LA English DT Proceedings Paper CT 10th IEEE Workshop on Statistical Signal and Array Processing CY AUG 13-16, 2000 CL POCONO MANOR, PA SP IEEE, Signal Proc Soc DE stochastic process; stationary; piecewise stationary; locally stationary ID TIME-SERIES AB The signals that arise in Air Force applications typically has noise that can be modeled as a non-stationary stochastic process. But, there may be intervals of time where the noise behaves more like a stationary process. This motivates the study of locally stationary stochastic processes. We rigorously define locally stationary stochastic processes and present their properties and relationships to stationary processes. C1 USAF, Inst Technol, Dept Math & Stat, Wright Patterson AFB, OH 45433 USA. RP Oxley, ME (reprint author), USAF, Inst Technol, Dept Math & Stat, 2950 P St, Wright Patterson AFB, OH 45433 USA. NR 7 TC 1 Z9 1 U1 1 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-5988-7 PY 2000 BP 257 EP 261 DI 10.1109/SSAP.2000.870123 PG 5 WC Engineering, Electrical & Electronic SC Engineering GA BR09H UT WOS:000165630400055 ER PT S AU Washburn, D Butts, R AF Washburn, D Butts, R BE Roggemann, MC TI Does the detailed turbulence profile matter? SO PROPAGATION AND IMAGING THROUGH THE ATMOSPHERE IV SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Propagation and Imaging through the Atmosphere IV CY AUG 03, 2000 CL SAN DIEGO, CA SP SPIE, Remote Sensing Soc AB The profile of atmospheric turbulence strength along a laser propagation or imaging path is thought to significantly influence performance. We use wave optics simulation to evaluate performance under random variations of turbulence profiles along a 50-km propagation path. Performance is given by power in the bucket (PIB) strehl in a lambda /D bucket. For a point source and under the conditions we investigated, we conclude that, in addition to the Rytov parameter, knowledge of r(0) can significantly improve performance prediction. C1 USAF, Res Lab, Directed Energy Directorate, Kirtland AFB, NM 87117 USA. RP Washburn, D (reprint author), USAF, Res Lab, Directed Energy Directorate, Kirtland AFB, NM 87117 USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-3770-0 J9 P SOC PHOTO-OPT INS PY 2000 VL 4125 BP 1 EP 6 DI 10.1117/12.409289 PG 6 WC Astronomy & Astrophysics; Geochemistry & Geophysics; Remote Sensing; Optics SC Astronomy & Astrophysics; Geochemistry & Geophysics; Remote Sensing; Optics GA BR66E UT WOS:000167103900001 ER PT S AU Whiteley, MR AF Whiteley, MR BE Roggemann, MC TI Rytov parameter estimation by use of differential-tilt measurements SO PROPAGATION AND IMAGING THROUGH THE ATMOSPHERE IV SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Propagation and Imaging through the Atmosphere IV CY AUG 03, 2000 CL SAN DIEGO, CA SP SPIE, Remote Sensing Soc DE scintillation; differential tilt; Rytov theory ID ATMOSPHERIC-TURBULENCE; SCINTILLATION; COMPENSATION AB The 'Rytov parameter' is a common name given to the log-amplitude variance predicted by an approximate solution to Maxwell's equations for propagation through media with random index of refraction (Rytov theory). Empirical evidence suggests that the Rytov parameter is a non-observable in many practical experiments where the variance of irradiance saturates, an effect not predicted by the standard theory. Nevertheless, the Rytov parameter is useful as an indicator of integrated turbulence strength for extended propagation and thus a desirable experimental quantity to estimate. In this work, we propose an optical configuration and related analysis techniques that provide a practical method for determining the Rytov parameter when scintillometry-based methods fail. This method employs differential-tilt measurements, resulting in a measurable quantity which is proportional to the Rytov parameter and for which Rytov theory is a good approximation. The differential-tilt technique is also insensitive to gimbal motion and additive noise. We illustrate that this method provides approximately 5% relative error in determining the Rytov parameter and may be used to characterize atmospheric turbulence well beyond the limits of conventional scintillometry. C1 USAF, Res Lab, Airborne Laser Technol Branch, Kirtland AFB, NM 87117 USA. RP Whiteley, MR (reprint author), USAF, Res Lab, Airborne Laser Technol Branch, 3550 Aberdeen Ave SE, Kirtland AFB, NM 87117 USA. NR 17 TC 1 Z9 1 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-3770-0 J9 P SOC PHOTO-OPT INS PY 2000 VL 4125 BP 7 EP 20 DI 10.1117/12.409299 PG 14 WC Astronomy & Astrophysics; Geochemistry & Geophysics; Remote Sensing; Optics SC Astronomy & Astrophysics; Geochemistry & Geophysics; Remote Sensing; Optics GA BR66E UT WOS:000167103900002 ER PT S AU Whiteley, MR AF Whiteley, MR BE Roggemann, MC TI Compensation efficiencies of conventional tracking and higher-order beam control in extended turbulence SO PROPAGATION AND IMAGING THROUGH THE ATMOSPHERE IV SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Propagation and Imaging through the Atmosphere IV CY AUG 03, 2000 CL SAN DIEGO, CA SP SPIE, Remote Sensing Soc DE adaptive optics; wave-front compensation; extended turbulence ID ATMOSPHERIC-TURBULENCE AB Conventional beam control techniques are often divided into two categories. "Tracking" control addresses the stabilization of the beam on a target, whereas "higher-order" control addresses the broadening of the beam due to atmospheric aberrations. For scenarios where strong turbulence is distributed throughout the entire propagation path, the effectiveness of conventional beam control techniques is greatly reduced over less-stressing scenarios. In this case, the effect on objective measures of beam compensation performance is not equally distributed between tracking and higher-order control. In this study, we have developed an analytic framework in which to quantify the efficiency of each type of control with respect to standard compensation performance metrics. This analysis highlights that the performance of each type of control must be assessed relative to the other. Using wave-optics simulation along with our analytic framework, we quantify the efficiency of a centroid tracker and an adaptive optics system using standard least-squares reconstruction with a point-source beacon for atmospheric Rytov parameter values of 0.1 < R < 1.0. We find that for R < 0.4, both tracking and higher-order control contribute equally to the observed performance degradation. For R > 0.5, however, conventional higher-order control is the principal source of compensation performance degradation. C1 USAF, Res Lab, Directed Energy Directorate, Kirtland AFB, NM 87117 USA. RP Whiteley, MR (reprint author), USAF, Res Lab, Directed Energy Directorate, 3550 Aberdeen Ave SE, Kirtland AFB, NM 87117 USA. NR 12 TC 3 Z9 3 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-3770-0 J9 P SOC PHOTO-OPT INS PY 2000 VL 4125 BP 21 EP 32 DI 10.1117/12.409302 PG 12 WC Astronomy & Astrophysics; Geochemistry & Geophysics; Remote Sensing; Optics SC Astronomy & Astrophysics; Geochemistry & Geophysics; Remote Sensing; Optics GA BR66E UT WOS:000167103900003 ER PT J AU Linster, BG AF Linster, BG TI Just playing. Game theory and the social contract, vol 2 SO PUBLIC CHOICE LA English DT Book Review C1 USAF Acad, Colorado Springs, CO 80840 USA. RP Linster, BG (reprint author), USAF Acad, Colorado Springs, CO 80840 USA. NR 1 TC 1 Z9 1 U1 0 U2 0 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0048-5829 J9 PUBLIC CHOICE JI Public Choice PD JAN PY 2000 VL 102 IS 1-2 BP 172 EP 175 PG 6 WC Economics; Political Science SC Business & Economics; Government & Law GA 268KE UT WOS:000084412200011 ER PT J AU Baldwin, RO Davis, NJ Kobza, JE Midkiff, SF AF Baldwin, RO Davis, NJ Kobza, JE Midkiff, SF TI Real-time queueing theory: A tutorial presentation with an admission control application SO QUEUEING SYSTEMS LA English DT Article DE queueing theory; real-time; admission control ID SERVICE; SYSTEM AB Real-time scheduling, or scheduling with respect to a deadline, is critical in many application areas such as telecommunications, control systems, and manufacturing. This paper presents a novel approach to real-time scheduling based on a queueing theory model. Using real-time queueing theory (RTQT), one can analytically determine the distribution of the lead-time profile (i.e., the time until the deadline is reached) of customers waiting for service. Emphasis is placed on the development of the equations used to determine the lead-time profile distribution. The development of the GI/G/1 case is presented and confirmed using simulation. Simulation results confirm prior research for the M/M/1 and GI/M/1 case. As a practical application, RTQT is used to implement a packet admission control algorithm for a telecommunications network. Using this algorithm, packet lateness was reduced by up to 31%. C1 USAF, Dept Elect & Comp Engn, Inst Technol, Wright Patterson AFB, OH 45433 USA. Virginia Polytech Inst & State Univ, Bradley Dept Elect & Comp Engn, Blacksburg, VA 24061 USA. Virginia Polytech Inst & State Univ, Dept Ind & Syst Engn, Blacksburg, VA 24061 USA. RP USAF, Dept Elect & Comp Engn, Inst Technol, Wright Patterson AFB, OH 45433 USA. EM rusty.baldwin@afit.af.mil; ndavis@vt.edu; jkobza@vt.edu; midkiff@vt.edu OI Kobza, John/0000-0003-4709-8255; Midkiff, Scott/0000-0003-4933-7360 NR 22 TC 7 Z9 7 U1 0 U2 0 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0257-0130 EI 1572-9443 J9 QUEUEING SYST JI Queueing Syst. PY 2000 VL 35 IS 1-4 BP 1 EP 21 DI 10.1023/A:1019177624198 PG 21 WC Computer Science, Interdisciplinary Applications; Operations Research & Management Science SC Computer Science; Operations Research & Management Science GA 337EU UT WOS:000088345100001 ER PT S AU Bernstein, NP Brost, GA Hayduk, MJ Hunter, JR Nichter, JE Payson, PM Repak, PL AF Bernstein, NP Brost, GA Hayduk, MJ Hunter, JR Nichter, JE Payson, PM Repak, PL BE Pirich, AR Goutzoulis, AP Repak, PL TI Why photonic systems for space? SO RADIO FREQUENCY PHOTONIC DEVICES AND SYSTEMS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Radio Frequency Photonic Devices and Systems CY JUL 31-AUG 01, 2000 CL SAN DIEGO, CA SP SPIE DE space; photonics; signal processing; A/D converters; true time delay AB Future space-based platforms can and will benefit from the implementation of photonics in both analog and digital subsystems. This paper will discuss potential applications and advantages to the platforms through the use of photonics. C1 USAF, Res Lab, Sensors Directorate, Rome, NY 13441 USA. RP Bernstein, NP (reprint author), USAF, Res Lab, Sensors Directorate, 25 Elect Pkwy, Rome, NY 13441 USA. NR 5 TC 0 Z9 0 U1 0 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-3757-3 J9 P SOC PHOTO-OPT INS PY 2000 VL 4112 BP 1 EP 6 DI 10.1117/12.399378 PG 6 WC Optics; Telecommunications SC Optics; Telecommunications GA BR62A UT WOS:000166962400001 ER PT S AU Hayduk, MJ Bussjager, RJ Getbehead, MA Louthain, JA AF Hayduk, MJ Bussjager, RJ Getbehead, MA Louthain, JA BE Pirich, AR Goutzoulis, AP Repak, PL TI Recent advancements in photonic converters SO RADIO FREQUENCY PHOTONIC DEVICES AND SYSTEMS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Radio Frequency Photonic Devices and Systems CY JUL 31-AUG 01, 2000 CL SAN DIEGO, CA SP SPIE DE analog to digital converter; photonic converter; saturable absorbers; timing jitter ID DISPERSION AB Analog-to-digital converters (ADCs) are an essential component of digital receiver systems. Progress at advancing the electronic ADC modules has been very slow due in large part to the difficulties in fabricating the electronic circuitry required for very high resolution and high sampling rate converters. This slow progress has resulted in a bottleneck between the received analog signal and the digital signal processing system. Single or multiple analog signal down conversion stages are required in digital receivers to down convert the received analog signal to an intermediate frequency (IF) that can be processed by the electronic ADC. There has been much recent interest in the use of photonics for direct digitization of the analog signal at the received RF frequency thus eliminating the need for analog down conversion. This paper reviews some of the recent research advancements in photonic ADCs. We will especially focus on the development of a novel photonic ADC module that uses semiconductor saturable absorbers to perform the data quantization. We will also present recent results in the development of a mode-locked fiber laser used as the sampling source in this photonic ADC architecture. C1 USAF, Res Lab, Sensors Directorate, Griffiss AFB, NY 13441 USA. RP Hayduk, MJ (reprint author), USAF, Res Lab, Sensors Directorate, 25 Elect Pkwy, Griffiss AFB, NY 13441 USA. NR 14 TC 0 Z9 0 U1 1 U2 3 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-3757-3 J9 P SOC PHOTO-OPT INS PY 2000 VL 4112 BP 28 EP 37 DI 10.1117/12.399392 PG 10 WC Optics; Telecommunications SC Optics; Telecommunications GA BR62A UT WOS:000166962400005 ER PT S AU Bernstein, NP AF Bernstein, NP BE Pirich, AR Goutzoulis, AP Repak, PL TI An inexpensive method of demonstrating microwave fiber optics SO RADIO FREQUENCY PHOTONIC DEVICES AND SYSTEMS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Radio Frequency Photonic Devices and Systems CY JUL 31-AUG 01, 2000 CL SAN DIEGO, CA SP SPIE DE microwave demonstrations; fiber optics; low-cost; laboratory examples AB When asked to demonstrate the performance of fiber optics engineers often resort to hundreds of thousand dollars worth of test equipment including plotters and displays to show a screen view and to prove the viability of the photonic system. This paper will present a relatively inexpensive and unusual method of allowing visitors to see and hear operation of a microwave link versus that of a coaxial coupled RF link. C1 USAF, Res Lab, SNDR, Griffiss AFB, NY 13441 USA. RP Bernstein, NP (reprint author), USAF, Res Lab, SNDR, 25 Elect Pkwy, Griffiss AFB, NY 13441 USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-3757-3 J9 P SOC PHOTO-OPT INS PY 2000 VL 4112 BP 48 EP 55 DI 10.1117/12.399394 PG 8 WC Optics; Telecommunications SC Optics; Telecommunications GA BR62A UT WOS:000166962400007 ER PT B AU Klauenberg, BJ AF Klauenberg, BJ BE Klauenberg, BJ Miklavcic, D TI NATO involvement in radio frequency radiation (RFR) research and health safety SO RADIO FREQUENCY RADIATION DOSIMETRY AND ITS RELATIONSHIP TO THE BIOLOGICAL EFFECTS OF ELECTROMAGNETIC FIELDS SE NATO ADVANCED SCIENCE INSTITUTE SERIES, SUB-SERIES 3, HIGH TECHNOLOGY LA English DT Proceedings Paper CT NATO Advanced Research Workshop on Radio Frequency Radiation Dosimetry and its Relationship to the Biological Effects of Electromagnetic Fields CY OCT 12-16, 1998 CL GOZD MARTULJEK, SLOVENIA SP NATO, Sci Affairs Div, High Technol Area, NATO, Res & Technol Org, USAF, Res Lad, USAF, Secur Assistance Command, USAF, European Off Aerosp Res & Dev, European BioElectromagnet Assoc, Bioelectromagnet Soc, Holaday Ind Inc, Univ Ljubljana, Agr Inst Slovenia, Elletra 2000, Minist Def, Minist Environm, Minist Sci & Technol, Minist Foreign Affairs, Minist Hlth, Inst Publ Hlth C1 USAF, Res Lab, Human Effectiveness Directorate, Directed Energy Bioeffects Div,Radio Frequency Ra, Brooks AFB, TX 78235 USA. RP Klauenberg, BJ (reprint author), USAF, Res Lab, Human Effectiveness Directorate, Directed Energy Bioeffects Div,Radio Frequency Ra, Brooks AFB, TX 78235 USA. NR 13 TC 0 Z9 0 U1 0 U2 0 PU SPRINGER PI DORDRECHT PA PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS BN 0-7923-6404-X J9 NATO ASI 3 HIGH TECH PY 2000 VL 82 BP 1 EP 10 PG 10 WC Engineering, Electrical & Electronic; Medicine, Research & Experimental SC Engineering; Research & Experimental Medicine GA BR40S UT WOS:000166318800002 ER PT B AU Murphy, MR AF Murphy, MR BE Klauenberg, BJ Miklavcic, D TI United States air force support of radio frequency radiation health and safety: Bioeffects, dosimetry, and standards SO RADIO FREQUENCY RADIATION DOSIMETRY AND ITS RELATIONSHIP TO THE BIOLOGICAL EFFECTS OF ELECTROMAGNETIC FIELDS SE NATO ADVANCED SCIENCE INSTITUTE SERIES, SUB-SERIES 3, HIGH TECHNOLOGY LA English DT Proceedings Paper CT NATO Advanced Research Workshop on Radio Frequency Radiation Dosimetry and its Relationship to the Biological Effects of Electromagnetic Fields CY OCT 12-16, 1998 CL GOZD MARTULJEK, SLOVENIA SP NATO, Sci Affairs Div, High Technol Area, NATO, Res & Technol Org, USAF, Res Lad, USAF, Secur Assistance Command, USAF, European Off Aerosp Res & Dev, European BioElectromagnet Assoc, Bioelectromagnet Soc, Holaday Ind Inc, Univ Ljubljana, Agr Inst Slovenia, Elletra 2000, Minist Def, Minist Environm, Minist Sci & Technol, Minist Foreign Affairs, Minist Hlth, Inst Publ Hlth ID ELECTROMAGNETIC-RADIATION; RADIOFREQUENCY RADIATION; EXPOSURE; CANCER; PRONE; MICE; MHZ C1 USAF, Res Lab, Human Effectiveness Directorate, Directed Energy Bioeffects Div, Brooks AFB, TX 78235 USA. RP Murphy, MR (reprint author), USAF, Res Lab, Human Effectiveness Directorate, Directed Energy Bioeffects Div, 8315 Hawks Rd, Brooks AFB, TX 78235 USA. NR 41 TC 0 Z9 0 U1 0 U2 0 PU SPRINGER PI DORDRECHT PA PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS BN 0-7923-6404-X J9 NATO ASI 3 HIGH TECH PY 2000 VL 82 BP 11 EP 19 PG 9 WC Engineering, Electrical & Electronic; Medicine, Research & Experimental SC Engineering; Research & Experimental Medicine GA BR40S UT WOS:000166318800003 ER PT B AU Hurt, WD AF Hurt, WD BE Klauenberg, BJ Miklavcic, D TI Absorption characteristics and measurement concepts SO RADIO FREQUENCY RADIATION DOSIMETRY AND ITS RELATIONSHIP TO THE BIOLOGICAL EFFECTS OF ELECTROMAGNETIC FIELDS SE NATO ADVANCED SCIENCE INSTITUTE SERIES, SUB-SERIES 3, HIGH TECHNOLOGY LA English DT Proceedings Paper CT NATO Advanced Research Workshop on Radio Frequency Radiation Dosimetry and its Relationship to the Biological Effects of Electromagnetic Fields CY OCT 12-16, 1998 CL GOZD MARTULJEK, SLOVENIA SP NATO, Sci Affairs Div, High Technol Area, NATO, Res & Technol Org, USAF, Res Lad, USAF, Secur Assistance Command, USAF, European Off Aerosp Res & Dev, European BioElectromagnet Assoc, Bioelectromagnet Soc, Holaday Ind Inc, Univ Ljubljana, Agr Inst Slovenia, Elletra 2000, Minist Def, Minist Environm, Minist Sci & Technol, Minist Foreign Affairs, Minist Hlth, Inst Publ Hlth ID SYSTEMS C1 USAF, Res Lab, Brooks AFB, TX 78235 USA. RP Hurt, WD (reprint author), USAF, Res Lab, 8308 Hawks Rd, Brooks AFB, TX 78235 USA. NR 24 TC 2 Z9 2 U1 0 U2 0 PU SPRINGER PI DORDRECHT PA PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS BN 0-7923-6404-X J9 NATO ASI 3 HIGH TECH PY 2000 VL 82 BP 39 EP 52 PG 14 WC Engineering, Electrical & Electronic; Medicine, Research & Experimental SC Engineering; Research & Experimental Medicine GA BR40S UT WOS:000166318800007 ER PT B AU Mason, PA Ziriax, JM Hurt, WD Walters, TJ Ryan, KL Nelson, DA Smith, KI D'Andrea, JA AF Mason, PA Ziriax, JM Hurt, WD Walters, TJ Ryan, KL Nelson, DA Smith, KI D'Andrea, JA BE Klauenberg, BJ Miklavcic, D TI Recent advancements in dosimetry measurements and modeling SO RADIO FREQUENCY RADIATION DOSIMETRY AND ITS RELATIONSHIP TO THE BIOLOGICAL EFFECTS OF ELECTROMAGNETIC FIELDS SE NATO ADVANCED SCIENCE INSTITUTE SERIES, SUB-SERIES 3, HIGH TECHNOLOGY LA English DT Proceedings Paper CT NATO Advanced Research Workshop on Radio Frequency Radiation Dosimetry and its Relationship to the Biological Effects of Electromagnetic Fields CY OCT 12-16, 1998 CL GOZD MARTULJEK, SLOVENIA SP NATO, Sci Affairs Div, High Technol Area, NATO, Res & Technol Org, USAF, Res Lad, USAF, Secur Assistance Command, USAF, European Off Aerosp Res & Dev, European BioElectromagnet Assoc, Bioelectromagnet Soc, Holaday Ind Inc, Univ Ljubljana, Agr Inst Slovenia, Elletra 2000, Minist Def, Minist Environm, Minist Sci & Technol, Minist Foreign Affairs, Minist Hlth, Inst Publ Hlth ID DIELECTRIC-PROPERTIES; BIOLOGICAL-SYSTEMS; RHESUS-MONKEY; FDTD METHOD; MICROWAVE; EXPOSURE; RATS; ABSORPTION; RESOLUTION; TISSUES C1 USAF, Res Lab, Human Effectiveness Directorate, Directed Energy Bioeffects Div, Brooks AFB, TX 78235 USA. RP USAF, Res Lab, Human Effectiveness Directorate, Directed Energy Bioeffects Div, Brooks AFB, TX 78235 USA. EM patrick.mason@afrlars.brooks.af.mil; john.ziriax@afrlars.brooks.af.mil; william.hurt@afrlars.brooks.af.mil; thomas.walters@afrlars.brooks.af.mil; john.dandrea@navy.brooks.af.mil NR 52 TC 34 Z9 36 U1 1 U2 1 PU SPRINGER PI DORDRECHT PA PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS BN 0-7923-6405-8; 0-7923-6404-X J9 NATO ASI 3 HIGH TECH PY 2000 VL 82 BP 141 EP 155 PG 15 WC Engineering, Electrical & Electronic; Medicine, Research & Experimental SC Engineering; Research & Experimental Medicine GA BR40S UT WOS:000166318800019 ER PT B AU Kiel, JL AF Kiel, JL BE Klauenberg, BJ Miklavcic, D TI Molecular dosimetry SO RADIO FREQUENCY RADIATION DOSIMETRY AND ITS RELATIONSHIP TO THE BIOLOGICAL EFFECTS OF ELECTROMAGNETIC FIELDS SE NATO ADVANCED SCIENCE INSTITUTE SERIES, SUB-SERIES 3, HIGH TECHNOLOGY LA English DT Proceedings Paper CT NATO Advanced Research Workshop on Radio Frequency Radiation Dosimetry and its Relationship to the Biological Effects of Electromagnetic Fields CY OCT 12-16, 1998 CL GOZD MARTULJEK, SLOVENIA SP NATO, Sci Affairs Div, High Technol Area, NATO, Res & Technol Org, USAF, Res Lad, USAF, Secur Assistance Command, USAF, European Off Aerosp Res & Dev, European BioElectromagnet Assoc, Bioelectromagnet Soc, Holaday Ind Inc, Univ Ljubljana, Agr Inst Slovenia, Elletra 2000, Minist Def, Minist Environm, Minist Sci & Technol, Minist Foreign Affairs, Minist Hlth, Inst Publ Hlth ID EXPOSURE; CELLS; DNA; DIAZOLUMINOMELANIN C1 USAF, Res Lab, Brooks AFB, TX 78235 USA. RP Kiel, JL (reprint author), USAF, Res Lab, 8308 Hawks Rd, Brooks AFB, TX 78235 USA. NR 14 TC 0 Z9 0 U1 0 U2 0 PU SPRINGER PI DORDRECHT PA PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS BN 0-7923-6404-X J9 NATO ASI 3 HIGH TECH PY 2000 VL 82 BP 227 EP 237 PG 11 WC Engineering, Electrical & Electronic; Medicine, Research & Experimental SC Engineering; Research & Experimental Medicine GA BR40S UT WOS:000166318800026 ER PT B AU Merritt, JH Heynick, LN AF Merritt, JH Heynick, LN BE Klauenberg, BJ Miklavcic, D TI Teratologic effects of exposure to radio frequency radiation SO RADIO FREQUENCY RADIATION DOSIMETRY AND ITS RELATIONSHIP TO THE BIOLOGICAL EFFECTS OF ELECTROMAGNETIC FIELDS SE NATO ADVANCED SCIENCE INSTITUTE SERIES, SUB-SERIES 3, HIGH TECHNOLOGY LA English DT Proceedings Paper CT NATO Advanced Research Workshop on Radio Frequency Radiation Dosimetry and its Relationship to the Biological Effects of Electromagnetic Fields CY OCT 12-16, 1998 CL GOZD MARTULJEK, SLOVENIA SP NATO, Sci Affairs Div, High Technol Area, NATO, Res & Technol Org, USAF, Res Lad, USAF, Secur Assistance Command, USAF, European Off Aerosp Res & Dev, European BioElectromagnet Assoc, Bioelectromagnet Soc, Holaday Ind Inc, Univ Ljubljana, Agr Inst Slovenia, Elletra 2000, Minist Def, Minist Environm, Minist Sci & Technol, Minist Foreign Affairs, Minist Hlth, Inst Publ Hlth ID MICROWAVE-RADIATION; BRAIN-DEVELOPMENT; IRRADIATION; MICE; EMBRYOS; GROWTH; UTERO; RATS; TERM C1 USAF, Res Lab, Radio Frequency Radiat Branch, Brooks AFB, TX 78235 USA. RP Merritt, JH (reprint author), USAF, Res Lab, Radio Frequency Radiat Branch, Brooks AFB, TX 78235 USA. NR 36 TC 0 Z9 0 U1 0 U2 0 PU SPRINGER PI DORDRECHT PA PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS BN 0-7923-6404-X J9 NATO ASI 3 HIGH TECH PY 2000 VL 82 BP 383 EP 391 PG 9 WC Engineering, Electrical & Electronic; Medicine, Research & Experimental SC Engineering; Research & Experimental Medicine GA BR40S UT WOS:000166318800042 ER PT B AU Mason, PA AF Mason, PA BE Klauenberg, BJ Miklavcic, D TI Summary of session J: The dosimetry handbook SO RADIO FREQUENCY RADIATION DOSIMETRY AND ITS RELATIONSHIP TO THE BIOLOGICAL EFFECTS OF ELECTROMAGNETIC FIELDS SE NATO ADVANCED SCIENCE INSTITUTE SERIES, SUB-SERIES 3, HIGH TECHNOLOGY LA English DT Proceedings Paper CT NATO Advanced Research Workshop on Radio Frequency Radiation Dosimetry and its Relationship to the Biological Effects of Electromagnetic Fields CY OCT 12-16, 1998 CL GOZD MARTULJEK, SLOVENIA SP NATO, Sci Affairs Div, High Technol Area, NATO, Res & Technol Org, USAF, Res Lad, USAF, Secur Assistance Command, USAF, European Off Aerosp Res & Dev, European BioElectromagnet Assoc, Bioelectromagnet Soc, Holaday Ind Inc, Univ Ljubljana, Agr Inst Slovenia, Elletra 2000, Minist Def, Minist Environm, Minist Sci & Technol, Minist Foreign Affairs, Minist Hlth, Inst Publ Hlth C1 USAF, Res Lab, Human Effectiveness Directorate, Directed Energy Bioeffects Div, Brooks AFB, TX 78235 USA. RP Mason, PA (reprint author), USAF, Res Lab, Human Effectiveness Directorate, Directed Energy Bioeffects Div, Brooks AFB, TX 78235 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SPRINGER PI DORDRECHT PA PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS BN 0-7923-6404-X J9 NATO ASI 3 HIGH TECH PY 2000 VL 82 BP 545 EP 546 PG 2 WC Engineering, Electrical & Electronic; Medicine, Research & Experimental SC Engineering; Research & Experimental Medicine GA BR40S UT WOS:000166318800061 ER PT B AU Mitchell, JC AF Mitchell, JC BE Klauenberg, BJ Miklavcic, D TI Historical perspective on the radio frequency radiation dosimetry handbook - Yesterday, today, and tomorrow SO RADIO FREQUENCY RADIATION DOSIMETRY AND ITS RELATIONSHIP TO THE BIOLOGICAL EFFECTS OF ELECTROMAGNETIC FIELDS SE NATO ADVANCED SCIENCE INSTITUTE SERIES, SUB-SERIES 3, HIGH TECHNOLOGY LA English DT Proceedings Paper CT NATO Advanced Research Workshop on Radio Frequency Radiation Dosimetry and its Relationship to the Biological Effects of Electromagnetic Fields CY OCT 12-16, 1998 CL GOZD MARTULJEK, SLOVENIA SP NATO, Sci Affairs Div, High Technol Area, NATO, Res & Technol Org, USAF, Res Lad, USAF, Secur Assistance Command, USAF, European Off Aerosp Res & Dev, European BioElectromagnet Assoc, Bioelectromagnet Soc, Holaday Ind Inc, Univ Ljubljana, Agr Inst Slovenia, Elletra 2000, Minist Def, Minist Environm, Minist Sci & Technol, Minist Foreign Affairs, Minist Hlth, Inst Publ Hlth C1 USAF, Res Lab AFMC2, Dept Air Force, Washington, DC 20330 USA. RP Mitchell, JC (reprint author), USAF, Res Lab AFMC2, Dept Air Force, Washington, DC 20330 USA. NR 12 TC 0 Z9 0 U1 0 U2 0 PU SPRINGER PI DORDRECHT PA PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS BN 0-7923-6404-X J9 NATO ASI 3 HIGH TECH PY 2000 VL 82 BP 547 EP 553 PG 7 WC Engineering, Electrical & Electronic; Medicine, Research & Experimental SC Engineering; Research & Experimental Medicine GA BR40S UT WOS:000166318800062 ER PT J AU Bhattacharyya, A Beach, TL Basu, S Kintner, PM AF Bhattacharyya, A Beach, TL Basu, S Kintner, PM TI Nighttime equatorial ionosphere: GPS scintillations and differential carrier phase fluctuations SO RADIO SCIENCE LA English DT Article ID F-REGION IRREGULARITIES; SPREAD-F; GHZ SCINTILLATIONS; RADAR OBSERVATIONS; INSITU; SPECTRUM; VHF AB The presence of scintillation-producing irregularities in the nighttime equatorial ionosphere, in the path of Global Positioning System (GPS) signals received at an equatorial station, causes dual-frequency measurements of the differential carrier phase of GPS L1 and L2 signals to have a contribution from phase scintillations on the two signals. Dual-frequency data for fluctuations in the total electron content (TEC) along the path of GPS signals to the equatorial station Ancon (1.5 degrees dip), sampled at a rate of 1 Hz, are used to separate this contribution from the slower TEC variations. Rapid fluctuations in the differential carrier phase, usually on timescales < 100 s, which result from diffraction, are seen to follow the pattern of intensity scintillations on the L1 signal. Intensity scintillations are also related to the variations in TEC which arise from density fluctuations associated with ionospheric irregularities. An approximate version of the transport-of-intensity equation, based on a phase screen description of the irregularities, suggests that a quantitative measure of intensity scintillations may be provided by the derivative of rate of change of TEC index (DROTI), obtained from the second derivative of TEC. This equation also yields the dependence of the scaling factor between DROTI and S-4 On the Fresnel frequency. Comparison of DROTI computed from relative TEC data to corresponding S-4 indices indicates that there may be lesser uncertainity in a quantitative relation between the two than between the index ROTI, introduced in recent years, and S-4 Power spectral analysis of TEC fluctuations and simultaneous intensity scintillations on L1 signal, recorded at Ancon, does not indicate any simple dependence of the scaling factor between DROTI and S-4 on the spectral characteristics. C1 USAF, Res Lab, AFRLVSBI, Bedford, MA 01731 USA. Cornell Univ, Sch Elect Engn, Ithaca, NY 14853 USA. RP Bhattacharyya, A (reprint author), USAF, Res Lab, AFRLVSBI, 29 Randolph Rd, Bedford, MA 01731 USA. NR 28 TC 41 Z9 42 U1 0 U2 7 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0048-6604 J9 RADIO SCI JI Radio Sci. PD JAN-FEB PY 2000 VL 35 IS 1 BP 209 EP 224 DI 10.1029/1999RS002213 PG 16 WC Astronomy & Astrophysics; Geochemistry & Geophysics; Meteorology & Atmospheric Sciences; Remote Sensing; Telecommunications SC Astronomy & Astrophysics; Geochemistry & Geophysics; Meteorology & Atmospheric Sciences; Remote Sensing; Telecommunications GA 281LF UT WOS:000085161000016 ER PT B AU Liu, CT AF Liu, CT BE Cardon, AH Fukuda, H Reifsnider, KL Verchery, G TI Effects of microstructure on damage evolution, strain inhomogeneity, and fracture in a particulate composite SO RECENT DEVELOPMENTS IN DURABILITY ANALYSIS OF COMPOSITE SYSTEMS LA English DT Proceedings Paper CT 4th International Conference on Durability Analysis of Composite Systems (DURACOSYS99) CY JUL 11-14, 1999 CL BRUSSELS, BELGIUM SP Free Univ Brussels, Fdn SCi Res, Flemish Reg, Virginia Polytechn Inst & State Univ, USN, Off Res, USA, European Res Off, Sci Univ Tokyo, Univ Bourgogne ID CRACK-GROWTH AB In this study, the effects of microstructure of a particulate composite material on the local behavior near the crack tip was investigated. A large deformation digital correlation technique was used to determine the local strain fields within 2 mm of the crack tip and a real-time x-ray technique was used to determine the damage field near the crack tip. The experimental results were analyzed and are discussed. C1 USAF, AFRL, OlAC,PRSM, Res Lab, Edwards, CA USA. RP Liu, CT (reprint author), USAF, AFRL, OlAC,PRSM, Res Lab, Edwards, CA USA. NR 10 TC 0 Z9 0 U1 0 U2 0 PU A A BALKEMA PUBLISHERS PI LEIDEN PA SCHIPHOLWEG 107C, PO BOX 447, 2316 XC LEIDEN, NETHERLANDS BN 90-5809-103-1 PY 2000 BP 77 EP 83 PG 7 WC Materials Science, Composites SC Materials Science GA BP89E UT WOS:000086522100008 ER PT S AU Berger, SD Welsh, BM AF Berger, SD Welsh, BM GP IEEE IEEE TI Dual channel matched filter performance bound SO RECORD OF THE IEEE 2000 INTERNATIONAL RADAR CONFERENCE SE IEEE Radar Conference LA English DT Proceedings Paper CT 2000 IEEE Radar Conference CY MAY 07-12, 2000 CL ALEXANDRIA, VA SP Natl Capital Area Council, IEEE, Aerosp & Electr Syst Soc, Radar Syst Panel, Inst Elect Engineers, ITT Gilfillan, Lockheed Martin, Northrop Grumman, Raytheon Co, SAIC, Syst & Electr Inc AB Recently, we proposed a dual channel matched filtering system as a replacement for single channel matched filtering system that requires a transformation that block diagonalizes the correlation matrix. In this paper, we analyze a suboptimal dual channel system that uses a non-block diagonalizing transformation. We provide a lower bound for the efficiency of the suboptimal dual channel system relative to the optimal system. We also propose criterion for selecting the non-block diagonalizing transformation that appears to provide a reliable indication of the average efficiency. C1 USAF, Res Lab, Kirtland AFB, NM 87117 USA. RP Berger, SD (reprint author), USAF, Res Lab, Kirtland AFB, NM 87117 USA. NR 6 TC 0 Z9 0 U1 0 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1097-5764 BN 0-7803-5776-0 J9 IEEE RAD CONF PY 2000 BP 289 EP 293 DI 10.1109/RADAR.2000.851848 PG 5 WC Engineering, Electrical & Electronic; Telecommunications SC Engineering; Telecommunications GA BQ62Y UT WOS:000089015800056 ER PT S AU Pittman, TS Pyati, VP AF Pittman, TS Pyati, VP GP IEEE IEEE TI A climatology-based model for long-term prediction of radar beam refraction SO RECORD OF THE IEEE 2000 INTERNATIONAL RADAR CONFERENCE SE Radar Conference LA English DT Proceedings Paper CT 2000 IEEE Radar Conference CY MAY 07-12, 2000 CL ALEXANDRIA, VA SP Natl Capital Area Council, IEEE, Aerosp & Electr Syst Soc, Radar Syst Panel, Inst Elect Engineers, ITT Gilfillan, Lockheed Martin, Northrop Grumman, Raytheon Co, SAIC, Syst & Electr Inc AB Hitherto, radar beam bending has been predicted using four-thirds earth or standard atmosphere. A new and more accurate model has been developed using a mix of raytracing and climatology. Usually a microwave beam traveling through the atmosphere bends towards the earth with a radius of curvature greater than the earth's surface. However, seasonal and climatic variations influence the amount and direction of bending, and at times create temperature or moisture inversions that tend to redirect the energy along the earth's surface leaving gaping holes where there is no coverage. In this work, iterative raytracing is used to determine the most direct path from the radar to the target through the climatologically predicted refractive atmosphere. Height measurement error is calculated by comparing the geographic path to the refracted path. Only vertical refractivity variation is taken into account, and the effects of ducting and exponential refractivity are both modeled. As a test, the model computed height errors at 17 locations worldwide for a hypothetical target at 10,000 feet and 60 nautical miles. The predicted errors varied from 100 feet to 2260 feet as against the standard atmosphere predicted height error of 804 it. The model traces to all targets when no ducting is modeled, to all targets outside the duct with surface ducting, and to some targets outside the duct with elevated ducting. In the remaining cases, adjacent rays sometimes cross, causing ambiguity in the estimation and, usually, tracing failure. C1 84th Radar Evaluat Squadron, Hill AFB, UT USA. RP Pittman, TS (reprint author), 84th Radar Evaluat Squadron, Hill AFB, UT USA. NR 18 TC 0 Z9 0 U1 0 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1097-5764 BN 0-7803-5776-0 J9 RADAR CONF PY 2000 BP 359 EP 364 DI 10.1109/RADAR.2000.851860 PG 6 WC Engineering, Electrical & Electronic; Telecommunications SC Engineering; Telecommunications GA BQ62Y UT WOS:000089015800068 ER PT S AU Chen, PY Wicks, MC AF Chen, PY Wicks, MC GP IEEE IEEE TI A procedure for detecting the number of signal components in a radar measurement SO RECORD OF THE IEEE 2000 INTERNATIONAL RADAR CONFERENCE SE Radar Conference LA English DT Proceedings Paper CT 2000 IEEE Radar Conference CY MAY 07-12, 2000 CL ALEXANDRIA, VA SP Natl Capital Area Council, IEEE, Aerosp & Electr Syst Soc, Radar Syst Panel, Inst Elect Engineers, ITT Gilfillan, Lockheed Martin, Northrop Grumman, Raytheon Co, SAIC, Syst & Electr Inc ID NOISE C1 USAF, Res Lab, Rome, NY 13440 USA. RP Chen, PY (reprint author), USAF, Res Lab, Rome, NY 13440 USA. NR 21 TC 2 Z9 2 U1 1 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1097-5764 BN 0-7803-5776-0 J9 RADAR CONF PY 2000 BP 451 EP 456 DI 10.1109/RADAR.2000.851876 PG 6 WC Engineering, Electrical & Electronic; Telecommunications SC Engineering; Telecommunications GA BQ62Y UT WOS:000089015800084 ER PT S AU Maher, J Callahan, M Lynch, D AF Maher, J Callahan, M Lynch, D GP IEEE IEEE TI Effects of clutter modeling in evaluating STAP processing for space-based radars SO RECORD OF THE IEEE 2000 INTERNATIONAL RADAR CONFERENCE SE IEEE Radar Conference LA English DT Proceedings Paper CT 2000 IEEE Radar Conference CY MAY 07-12, 2000 CL ALEXANDRIA, VA SP Natl Capital Area Council, IEEE, Aerosp & Electr Syst Soc, Radar Syst Panel, Inst Elect Engineers, ITT Gilfillan, Lockheed Martin, Northrop Grumman, Raytheon Co, SAIC, Syst & Electr Inc C1 USAF, Res Lab, Rome, NY 13440 USA. RP Maher, J (reprint author), USAF, Res Lab, Rome, NY 13440 USA. NR 7 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1097-5764 BN 0-7803-5776-0 J9 IEEE RAD CONF PY 2000 BP 565 EP 570 DI 10.1109/RADAR.2000.851896 PG 6 WC Engineering, Electrical & Electronic; Telecommunications SC Engineering; Telecommunications GA BQ62Y UT WOS:000089015800104 ER PT S AU Himed, B Michels, JH AF Himed, B Michels, JH GP IEEE IEEE TI Performance analysis of the multi-stage Wiener filter SO RECORD OF THE IEEE 2000 INTERNATIONAL RADAR CONFERENCE SE Radar Conference LA English DT Proceedings Paper CT 2000 IEEE Radar Conference CY MAY 07-12, 2000 CL ALEXANDRIA, VA SP Natl Capital Area Council, IEEE, Aerosp & Electr Syst Soc, Radar Syst Panel, Inst Elect Engineers, ITT Gilfillan, Lockheed Martin, Northrop Grumman, Raytheon Co, SAIC, Syst & Electr Inc ID ADAPTIVE RADAR AB This paper studies the effects of several parameters on the detection performance of a novel space-time adaptive technique, termed the multi-stage Wiener filter. This technique offers full space-lime adaptive processing at a reduced computational cost. Focus is on the effects of several parameters on the performance of the proposed approach. Parameters considered are the number of stages required, sensitivity to over/under-estimating this number, effects of internal clutter motion (ICM), aircraft crab angle, presence of jammers and training data size. A comparative analysis with two rank reducing approaches, namely, the eigencanceler and the cross-spectral metric, has also been included. Both simulations and measured data results are provided. C1 USAF, Res Lab, SNRT, Rome, NY 13440 USA. RP Himed, B (reprint author), USAF, Res Lab, SNRT, Rome, NY 13440 USA. NR 13 TC 0 Z9 1 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1097-5764 BN 0-7803-5776-0 J9 RADAR CONF PY 2000 BP 729 EP 734 DI 10.1109/RADAR.2000.851925 PG 6 WC Engineering, Electrical & Electronic; Telecommunications SC Engineering; Telecommunications GA BQ62Y UT WOS:000089015800132 ER PT S AU Adve, RS Wicks, MC Hale, TB Antonik, P AF Adve, RS Wicks, MC Hale, TB Antonik, P GP IEEE IEEE TI Ground moving target indication using knowledge based space time adaptive processing SO RECORD OF THE IEEE 2000 INTERNATIONAL RADAR CONFERENCE SE IEEE Radar Conference LA English DT Proceedings Paper CT 2000 IEEE Radar Conference CY MAY 07-12, 2000 CL ALEXANDRIA, VA SP Natl Capital Area Council, IEEE, Aerosp & Electr Syst Soc, Radar Syst Panel, Inst Elect Engineers, ITT Gilfillan, Lockheed Martin, Northrop Grumman, Raytheon Co, SAIC, Syst & Electr Inc C1 USAF, Res Lab, SNRT, Rome, NY 13440 USA. RP Adve, RS (reprint author), USAF, Res Lab, SNRT, Rome, NY 13440 USA. NR 8 TC 1 Z9 1 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1097-5764 BN 0-7803-5776-0 J9 IEEE RAD CONF PY 2000 BP 735 EP 740 DI 10.1109/RADAR.2000.851926 PG 6 WC Engineering, Electrical & Electronic; Telecommunications SC Engineering; Telecommunications GA BQ62Y UT WOS:000089015800133 ER PT S AU Michels, JH Himed, B Rangaswamy, M AF Michels, JH Himed, B Rangaswamy, M GP IEEE IEEE TI Evaluation of the normalized parametric adaptive matched filter STAP test in airborne radar clutter SO RECORD OF THE IEEE 2000 INTERNATIONAL RADAR CONFERENCE SE Radar Conference LA English DT Proceedings Paper CT 2000 IEEE Radar Conference CY MAY 07-12, 2000 CL ALEXANDRIA, VA SP Natl Capital Area Council, IEEE, Aerosp & Electr Syst Soc, Radar Syst Panel, Inst Elect Engineers, ITT Gilfillan, Lockheed Martin, Northrop Grumman, Raytheon Co, SAIC, Syst & Electr Inc ID COMPOUND-GAUSSIAN CLUTTER AB The performance of a recently proposed parametric space-time adaptive processing (STAP) detection method is considered here and compared with several candidate algorithms. Specifically, we consider signal detection in additive disturbance consisting of compound-Gaussian clutter plus Gaussian thermal white noise. Consideration is given to both detection and constant false alarm Fate (CFAR) robustness with respect to clutter texture power variations. Finally, the performance of the new test is assessed using smalt training data support size. C1 USAF, AFRL, Rome, NY 13440 USA. RP Michels, JH (reprint author), USAF, AFRL, 26 Elect Pkwy, Rome, NY 13440 USA. NR 30 TC 1 Z9 1 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1097-5764 BN 0-7803-5776-0 J9 RADAR CONF PY 2000 BP 769 EP 774 DI 10.1109/RADAR.2000.851932 PG 6 WC Engineering, Electrical & Electronic; Telecommunications SC Engineering; Telecommunications GA BQ62Y UT WOS:000089015800139 ER PT S AU Himed, B Salama, Y Michels, JH AF Himed, B Salama, Y Michels, JH GP IEEE IEEE TI Improved detection of close proximity targets using two-step NHD SO RECORD OF THE IEEE 2000 INTERNATIONAL RADAR CONFERENCE SE IEEE Radar Conference LA English DT Proceedings Paper CT 2000 IEEE Radar Conference CY MAY 07-12, 2000 CL ALEXANDRIA, VA SP Natl Capital Area Council, IEEE, Aerosp & Electr Syst Soc, Radar Syst Panel, Inst Elect Engineers, ITT Gilfillan, Lockheed Martin, Northrop Grumman, Raytheon Co, SAIC, Syst & Electr Inc ID GAUSSIAN CLUTTER; RADAR DETECTION AB In airborne radar adaptive signal processing, the covariance matrix is usually estimated using secondary (training) data cells taken from adjacent range cells located symmetrically around the test cell. In non-homogeneous clutter, many of these data cells may lack the lid property, resulting in estimation performance loss. Nonhomogeneity detectors have been introduced in order to achieve more representative data selection. The generalized inner product (GIP) has been shown to work well with measured data. In this paper, we introduce a variation of the GIP to filter out the non-representative data. Moreover, the proposed approach makes use of equalized data based on the GIP. Results using the MCARM database show improved performance. C1 USAF, Res Lab, SNRT, Rome, NY 13440 USA. RP Himed, B (reprint author), USAF, Res Lab, SNRT, Rome, NY 13440 USA. NR 21 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1097-5764 BN 0-7803-5776-0 J9 IEEE RAD CONF PY 2000 BP 781 EP 786 DI 10.1109/RADAR.2000.851934 PG 6 WC Engineering, Electrical & Electronic; Telecommunications SC Engineering; Telecommunications GA BQ62Y UT WOS:000089015800141 ER PT J AU Gallemore, RP Jumper, JM McCuen, BW Jaffe, GJ Postel, EA Toth, CA AF Gallemore, RP Jumper, JM McCuen, BW Jaffe, GJ Postel, EA Toth, CA TI Diagnosis of vitreoretinal adhesions in macular disease with optical coherence tomography SO RETINA-THE JOURNAL OF RETINAL AND VITREOUS DISEASES LA English DT Article; Proceedings Paper CT Annual Meeting of the Association-for-Research-in-Vision-and-Ophthalmology CY MAY 10-15, 1998 CL FT LAUDERDALE, FLORIDA SP Assoc Res Vis & Ophthalmol DE optical coherence tomography; vitreomacular traction syndrome; macular hole; cystoid macular edema; epiretinal membrane; diabetic retinopathy ID VITREOMACULAR TRACTION SYNDROME; POSTERIOR VITREOUS DETACHMENT; SURGICAL-MANAGEMENT; VITRECTOMY; EDEMA; MEMBRANES AB Purpose: To compare the relative incidence of vitreoretinal adhesions associated with partial vitreous separation within the macula diagnosed with optical coherence tomography (OCT) with that of those diagnosed with biomicroscopy. \ Methods: The authors obtained linear cross-sectional retinal images using OCT in patients with selected macular diseases. Additional studies included biomicroscopy, fundus photography, fluorescein angiography, and B-scan ultrasonography. Results: Optical coherence tomography was performed on 132 eyes of 119 patients. Vitreoretinal adhesions within the macula were identified using OCT in 39 eyes (30%) with the following diagnoses: idiopathic epiretinal membrane (n = 13), diabetic retinopathy (n = 7), idiopathic macular hole (n = 7), cystoid macular edema (n = 7), and vitreomacular traction syndrome (n = 5). Biomicroscopy identified vitreoretinal adhesions in only 11 eyes(8%). Two distinct vitreoretinal adhesion patterns were identified with OCT, each associated with partial separation of the posterior hyaloid face: focal (n = 25) and multifocal (n = 14). Conclusions: Optical coherence tomography is more sensitive than biomicroscopy in identifying vitreoretinal adhesions associated with macular disease. C1 Duke Univ, Ctr Eye, Durham, NC USA. Univ Calif Los Angeles, Sch Med, Jules Stein Eye Inst, Los Angeles, CA 90024 USA. Retina Vitreous Associates Med Grp, Los Angeles, CA USA. Wilford Hall USAF Med Ctr, Dept Ophthalmol, San Antonio, TX 78236 USA. RP Toth, CA (reprint author), Duke Univ, Med Ctr, Dept Ophthalmol, Box 3802,Erwin Rd, Durham, NC 27710 USA. RI toth, cynthia/F-5614-2011 FU NEI NIH HHS [P30EY05722] NR 23 TC 106 Z9 111 U1 0 U2 0 PU LIPPINCOTT WILLIAMS & WILKINS PI PHILADELPHIA PA 530 WALNUT ST, PHILADELPHIA, PA 19106-3621 USA SN 0275-004X J9 RETINA-J RET VIT DIS JI Retin.-J. Retin. Vitr. Dis. PY 2000 VL 20 IS 2 BP 115 EP 120 DI 10.1097/00006982-200003000-00001 PG 6 WC Ophthalmology SC Ophthalmology GA 403LB UT WOS:000167042400001 PM 10783942 ER PT J AU Jumper, JM Machemer, R Gallemore, RP Jaffe, GJ AF Jumper, JM Machemer, R Gallemore, RP Jaffe, GJ TI Exudative retinal detachment and retinitis associated with acquired syphilitic uveitis SO RETINA-THE JOURNAL OF RETINAL AND VITREOUS DISEASES LA English DT Article; Proceedings Paper CT Meeting of the Retina-Society CY SEP 26-27, 1998 CL WASHINGTON, D.C. SP Retina Soc DE retinal detachment; retinitis; syphilis ID OCULAR SYPHILIS; DIAGNOSIS AB Purpose: To describe three cases of exudative retinal detachment and focal retinitis associated with acquired syphilitic uveitis, Methods: Three patients who were referred for evaluation of uveitis were examined. Slit-lamp examination, ophthalmoscopy, B-scan ultrasonography, fundus photography, and fluorescein angiography were performed before and after therapy. Results: Each patient had uveitis with exudative retinal detachment, periphlebitis, and focal retinitis. Laboratory testing (fluorescent treponemal antibody absorption) revealed positive serology for active syphilis in all cases. Human immunodeficiency virus antibody testing was negative in all patients. Retinal detachment resolved in all cases after treatment with intravenous penicillin. Despite resolution of subretinal fluid, visual acuity remained poor in eyes in which the macula was detached. Conclusion: Syphilis is a cause of exudative retinal detachment. Antibiotic therapy can lead to retinal reattachment. Early recognition and treatment may prevent severe vision loss. C1 Duke Univ, Ctr Eye, Durham, NC 27710 USA. Wilford Hall USAF Med Ctr, Dept Ophthalmol, Lackland AFB, TX 78236 USA. Retina Vitreous Associates Med Grp, Los Angeles, CA USA. RP Jaffe, GJ (reprint author), Duke Univ, Ctr Eye, Box 3802, Durham, NC 27710 USA. NR 9 TC 29 Z9 30 U1 0 U2 0 PU LIPPINCOTT WILLIAMS & WILKINS PI PHILADELPHIA PA 530 WALNUT ST, PHILADELPHIA, PA 19106-3621 USA SN 0275-004X J9 RETINA-J RET VIT DIS JI Retin.-J. Retin. Vitr. Dis. PY 2000 VL 20 IS 2 BP 190 EP 194 DI 10.1097/00006982-200003000-00012 PG 5 WC Ophthalmology SC Ophthalmology GA 403LB UT WOS:000167042400012 PM 10783953 ER PT J AU Jumper, JM Gallemore, RP McCuen, BW Toth, CA AF Jumper, JM Gallemore, RP McCuen, BW Toth, CA TI Features of macular hole closure in the early postoperative period using optical coherence tomography SO RETINA-THE JOURNAL OF RETINAL AND VITREOUS DISEASES LA English DT Article; Proceedings Paper CT Annual Meeting of the Association-for-Research-in-Vision-and-Ophthalmology CY MAY 10-15, 1998 CL FT LAUDERDALE, FLORIDA SP Assoc Res Vis & Ophthalmol DE macular hole; optical coherence tomography; silicone oil ID GAS TAMPONADE; SURGERY AB Purpose: Studying the retina in the early postoperative period after macular hole surgery is difficult because of the limitation of imaging of the fundus through a gas tamponade, Silicone oil was shown recently to be an effective alternative to gas for macular hole repair, The authors hypothesized that optical coherence tomography (OCT) could be performed through silicone oil to study early macular hole closure, Methods: Fourteen patients with idiopathic full-thickness macular holes underwent repair, including vitrectomy and silicons fill of the vitreous cavity, Silicone oil was removed 5 to 18 weeks later in a second operative procedure. Optical coherence tomography images were obtained preoperatively (n = 14), on the first postoperative day (n = 7), after 1 week (n = 4), after 1 month (n = 14), and after silicone oil removal (n = 14), Results: By the first postoperative day, the retina was flat and the hole was open or closed in all patients, By I month, 9 of 14 patients had flat retinas and closed holes, whereas the other 5 patients had flat retinas and open holes. All patients who had an open hole after I month had a reopening of the hole after silicone oil removal. Conclusions: Flattening of the retina with resolution of the foveal cysts after macular hole repair occurs by the first postoperative day. Closure of the horizontal retinal separation is variable but occurs by the first postoperative month in cases of successful macular hole repair, Persistent retinal separation after 1 month may be predictive of hole reopening. C1 Duke Univ, Ctr Eye, Vitreoretinal Serv, Durham, NC 27710 USA. Wilford Hall USAF Med Ctr, Dept Ophthalmol, Lackland AFB, TX 78236 USA. Retina Vitreous Associates Med Grp, Los Angeles, CA USA. RP Toth, CA (reprint author), Duke Univ, Ctr Eye, Vitreoretinal Serv, Box 3802, Durham, NC 27710 USA. RI toth, cynthia/F-5614-2011 FU NEI NIH HHS [P30EY05722] NR 12 TC 41 Z9 44 U1 0 U2 1 PU LIPPINCOTT WILLIAMS & WILKINS PI PHILADELPHIA PA 530 WALNUT ST, PHILADELPHIA, PA 19106-3621 USA SN 0275-004X J9 RETINA-J RET VIT DIS JI Retin.-J. Retin. Vitr. Dis. PY 2000 VL 20 IS 3 BP 232 EP 237 DI 10.1097/00006982-200005000-00001 PG 6 WC Ophthalmology SC Ophthalmology GA 403LC UT WOS:000167042500001 PM 10872926 ER PT S AU Denny, LR Baur, JW Alexander, MD Kannan, R Kirkpatrick, SM Clarson, SJ AF Denny, LR Baur, JW Alexander, MD Kannan, R Kirkpatrick, SM Clarson, SJ BE Adams, PJ Elsworth, SA Petkauskos, MJ Walton, TC TI Two-photon absorption induced photopolymerization SO REVOLUTIONARY MATERIALS: TECHNOLOGY AND ECONOMICS SE INTERNATIONAL SAMPE TECHNICAL CONFERENCE SERIES LA English DT Proceedings Paper CT 32nd International SAMPE Technical Conference CY NOV 05-09, 2000 CL BOSTON, MA SP Soc Advancement Mat & Process Engn DE custom processing; curing agents AB Organic two-photon chromophores undergo a process called two-photon absorption in which light is absorbed in the infrared wavelength range, which in turn can initiate photochemistry using either the two-photon excited molecule or its up-converted fluorescence emission. One type of photochemistry for which the two-photon up-conversion can be used is photopolymerization. Organic/polymeric materials often exhibit non-resonant linear absorption in the ultraviolet (uv) wavelength range, while in near infrared (NIR) wavelengths little or no absorption is observed. As a result NIR light can penetrate much deeper into the organic materials to initiate photocuring throughout the resin. Thus, using this NIR photocure technique, it is possible to photocure objects thicker than those fabricated with traditional ultraviolet curing. Novel two-photon organic chromophores developed in the Air Force Research Laboratory (AFRL) and by other research groups exhibit large effective two-photon cross-section values, which provide efficient excited molecular states or localized uv/visible fluorescence required for photocure. The utilization of up-conversion photochemical processing provides a relatively new processing method for fabrication of structures ranging from precisely patterned nanostructures to thick structures (>1cm). This research evaluates the advantages and limitations of this new polymer processing technique and the critical factors influencing the reaction. C1 USAF, Res Lab, MLBP, Wright Patterson AFB, OH 45433 USA. RP Denny, LR (reprint author), USAF, Res Lab, MLBP, Bldg 654, Wright Patterson AFB, OH 45433 USA. NR 5 TC 0 Z9 0 U1 0 U2 0 PU SOC ADVANCEMENT MATERIAL & PROCESS ENGINEERING PI COVINA PA 1161 PARKVIEW DR,, COVINA, CA 91724-3748 USA SN 0892-2624 BN 0-938994-89-1 J9 INT SAMPE TECH CONF PY 2000 VL 32 BP 712 EP 717 PG 3 WC Engineering, Aerospace; Materials Science, Multidisciplinary; Materials Science, Characterization & Testing; Materials Science, Coatings & Films; Materials Science, Composites SC Engineering; Materials Science GA BR79P UT WOS:000167557000068 ER PT S AU Ghim, BT Spicer, MS Wallace, EM AF Ghim, BT Spicer, MS Wallace, EM BE Adams, PJ Elsworth, SA Petkauskos, MJ Walton, TC TI Air force coatings technology integration office SO REVOLUTIONARY MATERIALS: TECHNOLOGY AND ECONOMICS SE INTERNATIONAL SAMPE TECHNICAL CONFERENCE SERIES LA English DT Proceedings Paper CT 32nd International SAMPE Technical Conference CY NOV 05-09, 2000 CL BOSTON, MA SP Soc Advancement Mat & Process Engn DE coatings; finishing techniques; testing/evaluation AB The Air Force Research Laboratory's Materials and Manufacturing Directorate has constructed a one-of-a-kind test facility at Wright-Patterson AFB, Ohio, that will save millions of dollars in aircraft stripping and painting costs during the next decade, and significantly reduce associated hazardous waste caused by paint activities. The new facility operated by the Air Farce Coating Technology Integration Office (CTIO), will provide Air Logistic Centers (ALCs), System Program Office directors and users with advanced integrated systems using emerging coating system technologies, and will trouble shoot problems with existing aircraft field-level coating systems. The facility will improve overall coatings performance, directly benefiting aircraft mission preparedness. C1 USAF, Res Lab, Logist Syst Support Branch, Wright Patterson AFB, OH 45433 USA. RP Ghim, BT (reprint author), USAF, Res Lab, Logist Syst Support Branch, Wright Patterson AFB, OH 45433 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SOC ADVANCEMENT MATERIAL & PROCESS ENGINEERING PI COVINA PA 1161 PARKVIEW DR,, COVINA, CA 91724-3748 USA SN 0892-2624 BN 0-938994-89-1 J9 INT SAMPE TECH CONF PY 2000 VL 32 BP 889 EP 902 PG 4 WC Engineering, Aerospace; Materials Science, Multidisciplinary; Materials Science, Characterization & Testing; Materials Science, Coatings & Films; Materials Science, Composites SC Engineering; Materials Science GA BR79P UT WOS:000167557000084 ER PT B AU Michels, JH Rangaswamy, M Himed, B AF Michels, JH Rangaswamy, M Himed, B GP IEEE IEEE IEEE TI Performance of STAP tests in compound-Gaussian clutter SO SAM 2000: PROCEEDINGS OF THE 2000 IEEE SENSOR ARRAY AND MULTICHANNEL SIGNAL PROCESSING WORKSHOP LA English DT Proceedings Paper CT 1st IEEE Sensor Array and Multichannel Signal Processing Workshop (SAM 2000) CY MAR 16-17, 2000 CL CAMBRIDGE, MA SP IEEE, Signal Proc Soc, MIT, Lincoln Lab ID RADAR DETECTION AB The performance of a parametric space-time adaptive processing (STAP) method is presented here. Specifically, we consider signal detection in additive disturbance containing compound-Gaussian clutter plus additive Gaussian thermal white noise. Performance is compared to the normalized adaptive matched filter. We focus on the issues of detection and false alarm probabilities, CFAR, and robustness with respect to clutter texture power variations. C1 USAF, Res Lab, SNRT, Rome, NY 13440 USA. RP Michels, JH (reprint author), USAF, Res Lab, SNRT, Rome, NY 13440 USA. NR 15 TC 1 Z9 1 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-6339-6 PY 2000 BP 250 EP 255 DI 10.1109/SAM.2000.878008 PG 6 WC Computer Science, Information Systems; Computer Science, Theory & Methods; Engineering, Electrical & Electronic; Telecommunications SC Computer Science; Engineering; Telecommunications GA BR23E UT WOS:000165922900053 ER PT J AU Du, J Longobardi, J Latham, WP Kar, A AF Du, J Longobardi, J Latham, WP Kar, A TI Weld geometry and tensile strength in laser welded thin sheet metals SO SCIENCE AND TECHNOLOGY OF WELDING AND JOINING LA English DT Article ID TEMPERATURE PROFILES; SCANNING LASER; BEAM AB Weld geometries and their effects on the ultimate tensile strength (UTS) of welded specimens were studied experimentally for type 316 stainless steel sheets. Bead on plate welding with 0.1 and 0.2 mm thick workpieces and lap welding with 0.1 mm thick workpieces were carried out. The results showed that the strength of lap welds is influenced by the weld geometry to a large extent. A three-dimensional quasi-steady state heat conduction model was developed to understand the heat flow mechanism during laser welding of sheet metals of finite thickness. The temperature distribution and weld geometry were calculated using the mathematical model and the theoretical results were found to compare well with experimental data. More energy is used to produce melt pools in thinner workpieces than in thicker ones. The model can be used to select suitable process parameters to achieve a predetermined UTS by controlling the weld geometry. C1 Univ Cent Florida, Sch Opt, Ctr Res & Educ Opt & Lasers, Laser Aided Mfg Mat & Microproc Lab, Orlando, FL 32816 USA. Met Tech Ind, Iowa City, IA 50126 USA. USAF, Res Lab, Directed Energy Directorate, Kirtland AFB, NM 87117 USA. RP Du, J (reprint author), Univ Cent Florida, Sch Opt, Ctr Res & Educ Opt & Lasers, Laser Aided Mfg Mat & Microproc Lab, Orlando, FL 32816 USA. NR 21 TC 7 Z9 7 U1 1 U2 6 PU I O M COMMUNICATIONS LTD INST MATERIALS PI LONDON PA 1 CARLTON HOUSE TERRACE, LONDON SW1Y 5DB, ENGLAND SN 1362-1718 J9 SCI TECHNOL WELD JOI JI Sci. Technol. Weld. Join. PY 2000 VL 5 IS 5 BP 304 EP 309 DI 10.1179/136217100101538353 PG 6 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA 376VT UT WOS:000165478000005 ER PT J AU Tanriver, U Longobardi, J Latham, WP Kar, A AF Tanriver, U Longobardi, J Latham, WP Kar, A TI Effects of absorptivity, shielding gas speed, and contact media on sheet metal laser welding SO SCIENCE AND TECHNOLOGY OF WELDING AND JOINING LA English DT Article ID STEEL AB A three-dimensional quasi-steady state heat conduction model is developed for laser welding of sheet metals. The heat flux at the surface of the workpiece is considered to be due to a moving Gaussian laser beam. An analytical expression is obtained for the temperature distribution by solving the conduction problem using the Fourier integral transform technique. this expression is used to locate the melting temperature isotherm, and thereby determine the weld depth and width. Experimental and theoretical results for the weld depths and widths are illustrated for different welding parameters such as the laser power absorptivity, welding speed, and shielding gas speed. The theory and experiment are found to agree reasonably well. The effects of absorptivity, shielding gas speed, and heat loss due to different contact media at the bottom surface of the workpiece are also investigated, and are found to be significant for thin metal laser welding. C1 Univ Cent Florida, Sch Opt, Ctr Res & Educ Opt & Lasers, Mech Mat & Aerosp Engn Dept,Laser Aided Mfg Mat &, Orlando, FL 32816 USA. Met Tech Ind, Iowa City, IA 50126 USA. USAF, Res Lab, Directed Energy Directorate, Kirtland AFB, NM 87117 USA. RP Tanriver, U (reprint author), Univ Cent Florida, Sch Opt, Ctr Res & Educ Opt & Lasers, Mech Mat & Aerosp Engn Dept,Laser Aided Mfg Mat &, Orlando, FL 32816 USA. NR 15 TC 8 Z9 8 U1 1 U2 6 PU I O M COMMUNICATIONS LTD INST MATERIALS PI LONDON PA 1 CARLTON HOUSE TERRACE, LONDON SW1Y 5DB, ENGLAND SN 1362-1718 J9 SCI TECHNOL WELD JOI JI Sci. Technol. Weld. Join. PY 2000 VL 5 IS 5 BP 310 EP 316 DI 10.1179/136217100101538362 PG 7 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA 376VT UT WOS:000165478000006 ER PT B AU Medeiros, SC Prasad, YVRK Frazier, WG Srinivasan, R AF Medeiros, SC Prasad, YVRK Frazier, WG Srinivasan, R BE Mishra, B Yamauchi, C TI Modeling grain size during hot working of IN 718 SO SECOND INTERNATIONAL CONFERENCE ON PROCESSING MATERIALS FOR PROPERTIES LA English DT Proceedings Paper CT 2nd International Conference on Processing Materials for Properties CY NOV 05-08, 2000 CL SAN FRANCISCO, CA SP Minerals, Met & Mat Soc, Min & Mat Proc Inst Japan ID PROCESSING MAP; MICROSTRUCTURAL CONTROL; DEFORMATION AB Aerospace gas turbine disks operate in an environment of relatively high stresses caused by centrifugal forces and elevated temperatures. These severe conditions necessitate the need for materials with good high temperature strength and low cycle fatigue resistance. One class of alloys used for this task is the nickel base superalloys, out of which, IN 718 is the most: widely used in the aerospace industry[1]. The properties of IN 718 are attributed to the combined effects of the chemistry, heat treatment, and microstructure. The chemistry is tailored not only for solid solution strengthening but also for precipitation hardening developed during heat treatment, which combined with a fine grained microstructure lead to excellent mechanical properties such as low cycle fatigue resistance and elevated temperature strength. The properties of a gas turbine disk are sensitive to the microstructure, in particular the grain size, which is dependent on the processing history. The ability to precisely control the microstructural development during forging is dependent on controlling the process so that the workpiece is deformed within a "safe" region where no microstructural damage or flow instabilities occur. The microstructural mechanisms during deformation may themselves vary within the "safe" region and it is desirable to determine them within the range of parameters that are commonly used in industrial processing. The objective of this work is to establish a relationship between the grain size and the process control parameters i.e., temperature and strain rate, in the hot working of IN 178. C1 USAF, Res Lab, Mat Proc Design Branch, Wright Patterson AFB, OH 45433 USA. RP Medeiros, SC (reprint author), USAF, Res Lab, Mat Proc Design Branch, 2977 P St,Bldg 653 Rm 205, Wright Patterson AFB, OH 45433 USA. NR 9 TC 0 Z9 0 U1 0 U2 0 PU MINERALS, METALS & MATERIALS SOC PI WARRENDALE PA 184 THORN HILL RD, WARRENDALE, PA 15086-7514 USA BN 0-87339-495-X PY 2000 BP 411 EP 415 PG 5 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering; Mining & Mineral Processing SC Materials Science; Metallurgy & Metallurgical Engineering; Mining & Mineral Processing GA BR45F UT WOS:000166445900080 ER PT B AU Parsons, TL Huffines, GR Cox, CC AF Parsons, TL Huffines, GR Cox, CC GP AMS AMS TI Distance criteria for safe operations when lightning is present SO SECOND SYMPOSIUM ON ENVIRONMENTAL APPLICATIONS LA English DT Proceedings Paper CT 2nd Symposium on Environmental Applications CY JAN 09-14, 2000 CL LONG BEACH, CA SP Amer Meteorol Soc C1 USAF, Inst Technol, AFIT ENP, Wright Patterson AFB, OH 45433 USA. RP Huffines, GR (reprint author), USAF, Inst Technol, AFIT ENP, Wright Patterson AFB, OH 45433 USA. NR 7 TC 0 Z9 0 U1 0 U2 0 PU AMER METEOROLOGICAL SOCIETY PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108 USA PY 2000 BP 50 EP 52 PG 3 WC Environmental Sciences; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA BS13K UT WOS:000168779300009 ER PT S AU Blasch, E Huang, S AF Blasch, E Huang, S BE Dasarathy, BV TI Multilevel feature-based fuzzy fusion for target recognition SO SENSOR FUSION: ARCHITECTURES, ALGORITHMS, AND APPLICATIONS IV SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Sensor Fusion: Architectures, Algorithms, and Applications IV CY APR 25-28, 2000 CL ORLANDO, FL SP SPIE DE sensor fusion; target recognition; classification; identification; neurofuzzy ID ARTIFICIAL NEURAL NETWORKS; RULES; SEARCH AB Information fusion includes the integration of feature data, expert knowledge, and algorithms. For example, in automatic target recognition (ATR) features of size, color, and motion can be fused to assess the combination of multi-modal information. A neurofuzzy fusion of features captures the multilevel language content of sensory information by fusing neural network data analysis with rule-based decision making. Additionally, the neurofuzzy architecture can effectively fuse coarse and fine abstracted feature data at the content level for decision making. In this paper, we investigate a multilevel neuro-fuzzy feature-based architecture for synthetic aperture radar (SAR) target recognition. C1 SNAS, AFRL, Wright Patterson AFB, OH 45433 USA. RP Blasch, E (reprint author), SNAS, AFRL, 2241 Avion Cir, Wright Patterson AFB, OH 45433 USA. NR 28 TC 1 Z9 1 U1 0 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-3677-1 J9 P SOC PHOTO-OPT INS PY 2000 VL 4051 BP 279 EP 288 DI 10.1117/12.381640 PG 10 WC Computer Science, Information Systems; Remote Sensing; Optics SC Computer Science; Remote Sensing; Optics GA BQ32A UT WOS:000087919700027 ER PT S AU Hinman, M Marcinkowski, J AF Hinman, M Marcinkowski, J BE Dasarathy, BV TI Final results on enhanced all source fusion (EASF) SO SENSOR FUSION: ARCHITECTURES, ALGORITHMS, AND APPLICATIONS IV SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Sensor Fusion: Architectures, Algorithms, and Applications IV CY APR 25-28, 2000 CL ORLANDO, FL SP SPIE DE data fusion; information fusion; situation refinement; threat refinement AB The report will highlight the final results of an Advanced Technology Demonstration effort for an enhanced all source fusion (EASF) system recently developed at the Fusion Technology Branch, Air Force Research Laboratory/IFEA. It will describe an innovative approach of traditional fusion algorithms and heuristic reasoning techniques to significantly improve the detection, identification, location and tracking of mobile red, blue and gray components of the electronic environment. C1 USAF, Res Lab, IFEA, Rome, NY 13441 USA. RP Hinman, M (reprint author), USAF, Res Lab, IFEA, 32 Brooks Rd, Rome, NY 13441 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-3677-1 J9 P SOC PHOTO-OPT INS PY 2000 VL 4051 BP 389 EP 396 DI 10.1117/12.381653 PG 8 WC Computer Science, Information Systems; Remote Sensing; Optics SC Computer Science; Remote Sensing; Optics GA BQ32A UT WOS:000087919700038 ER PT J AU Gunapala, SD Bandara, SV Liu, JK Luong, EM Rafol, SB Mumolo, JM Ting, DZ Bock, JJ Ressler, ME Werner, MW LeVan, PD Chehayeb, R Kukkonen, CA Levy, M LeVan, P Fauci, MA AF Gunapala, SD Bandara, SV Liu, JK Luong, EM Rafol, SB Mumolo, JM Ting, DZ Bock, JJ Ressler, ME Werner, MW LeVan, PD Chehayeb, R Kukkonen, CA Levy, M LeVan, P Fauci, MA TI Quantum well infrared photodetector research and development at jet propulsion laboratory SO SENSORS AND MATERIALS LA English DT Review DE infrared detectors; long-wavelength infrared; multi quantum well; multi-color; focal plane arrays ID FOCAL-PLANE ARRAY; QWIP ARRAY; CAMERA; FABRICATION AB One of the simplest device realizations of the classic particle in-the-box problem of basic quantum mechanics is the quantum well infrared photodetector (QWIP). In this paper we discuss the effect of focal plane array nonuniformity on the performance, optimization of the detector design, material growth and processing that has culminated in the realization of large format, long-wavelength QWIP cameras, holding forth great promise for many applications in the 6-18 micron wavelength range in science, medicine, defense and industry. In addition, we present the recent developments in long-wave-length/very long-wavelength dualband QWIP imaging camera for various applications. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. USAF, Res Lab, Kirtland AFB, NM 87117 USA. Univ So Calif Hosp, Los Angeles, CA 90027 USA. OmniCorder Technol Inc, Stony Brook, NY 11790 USA. NR 29 TC 13 Z9 13 U1 0 U2 1 PU MYU, SCIENTIFIC PUBLISHING DIVISION PI TOKYO PA 1-23-3-303 SENDAGI, TOKYO, 113-0022, JAPAN SN 0914-4935 J9 SENSOR MATER JI Sens. Mater. PY 2000 VL 12 IS 6 BP 327 EP 351 PG 25 WC Instruments & Instrumentation; Materials Science, Multidisciplinary SC Instruments & Instrumentation; Materials Science GA 399TD UT WOS:000166827700001 ER PT J AU Kalns, J Ryan, KL Mason, PA Bruno, JG Gooden, R Kiel, JL AF Kalns, J Ryan, KL Mason, PA Bruno, JG Gooden, R Kiel, JL TI Oxidative stress precedes circulatory failure induced by 35-GHz microwave heating SO SHOCK LA English DT Article DE nitration; peroxynitrite; 3-nitrotyrosine; radio frequency radiation; microwaves; blood pressure ID ROSTRAL VENTROLATERAL MEDULLA; SPLANCHNIC ARTERY-OCCLUSION; ISCHEMIA-REPERFUSION INJURY; NITRIC-OXIDE SYNTHASE; HEMORRHAGIC-SHOCK; RAT MODEL; PEROXYNITRITE PRODUCTION; IN-VIVO; RESPONSES; INFLAMMATION AB Sustained whole-body exposure of anesthetized rats to 35-GHz radio frequency radiation produces localized hyperthermia and hypotension, leading to circulatory failure and death. The physiological mechanism underlying the induction of circulatory failure by 35-GHz microwave (MW) heating is currently unknown. We hypothesized that oxidative stress may play a role in the pathophysiology of MW-induced circulatory failure and examined this question by probing organs for 3-nitrotyrosine (3-NT), a marker of oxidative stress. Animals exposed to low durations of MW that increased colonic temperature but were insufficient to produce hypotension showed a 5- to 12-fold increase in 3-NT accumulation in lung, liver, and plasma proteins relative to the levels observed in control rats that were not exposed to MW. 3-NT accumulation in rats exposed to MW of sufficient duration to induce circulatory shock returned to low, baseline levels. Leukocytes obtained from peripheral blood showed significant accumulation of 3-NT only at exposure levels associated with circulatory shock. 3-NT was also found in the villus tips and vasculature of intestine and within the distal tubule of the kidney but not in the irradiated skin of rats with MW-induced circulatory failure. The relationship between accumulation in liver, lung, and plasma proteins and exposure duration suggests either that nitro adducts are formed in the first 20 min of exposure and are then cleared or that synthesis of nitro adducts decreases after the first 20 min of exposure. Taken together, these findings suggest that oxidative stress occurs in many organs during MW heating. Because nitration occurs after microwave exposures that are not associated with circulatory collapse, systemic oxidative stress, as evidenced by tissue accumulation of 3-NT, is not correlated with circulatory failure in this model of shock. C1 Veridian Engn Inc, Brooks AFB, TX 78235 USA. Davis Hyperbar Lab, Brooks AFB, TX 78235 USA. USAF, Res Lab, Directed Energy Bioeffects Div, Brooks AFB, TX 78235 USA. Trinity Univ, Dept Biol, San Antonio, TX 78212 USA. Univ Texas, Hlth Sci Ctr, San Antonio, TX 78284 USA. RP Kalns, J (reprint author), USAFSAM AFI, 2602 W Gate Rd, Brooks AFB, TX 78235 USA. NR 37 TC 18 Z9 21 U1 1 U2 1 PU BIOMEDICAL PRESS PI AUGUSTA PA 1021 15TH ST, BIOTECH PARK STE 9,, AUGUSTA, GA 30901 USA SN 1073-2322 J9 SHOCK JI Shock PD JAN PY 2000 VL 13 IS 1 BP 52 EP 59 DI 10.1097/00024382-200013010-00010 PG 8 WC Critical Care Medicine; Hematology; Surgery; Peripheral Vascular Disease SC General & Internal Medicine; Hematology; Surgery; Cardiovascular System & Cardiology GA 269QN UT WOS:000084489200010 PM 10638670 ER PT S AU Foster, JC Glenn, JG Gunger, M AF Foster, JC Glenn, JG Gunger, M BE Furnish, MD Chhabildas, LC Hixson, RS TI Meso-scale origins of the low-pressure equation of state and high rate mechanical properties of plastic bonded explosives SO SHOCK COMPRESSION OF CONDENSED MATTER-1999, PTS 1 AND 2 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 11th Conference of the American-Physical-Society-Topical-Group on Shock Compression of Condensed Matter CY JUN 27-JUL 02, 1999 CL SNOWBIRD, UT SP Amer Phys Soc Top Grp AB Most modern high explosives are formulated from a selection of energetic crystalline materials and plastics to create a material that accommodates the performance and sensitivity characteristic of the desired application. These materials are exposed to a variety of thermal-mechanical loads during their service life. Recent interest has focused research on safety and survivability under conditions that produce long duration, low amplitude loads as compared to she stimuli used to initiate detonation. The interest in the safety problem is on ignition of deflagration rather than initiation of detonation. A fully coupled thermal-mechanical-chemical kinetics representation of the problem is contained in a modified form of the Frank-Kamenetskii eqautions.(2) Experimental techniques have been developed to characterize the low-pressure equation of state (3) and the high-rate mechanical behavior of a representative material.(4) This work addresses samples recovered from these experiments that have been subjected to extensive analysis using scanning electron microscopy (SEM). These data illustrate the presence of stress chains and stress bridging commonly observed in free particle beds among the high explosive particle embedded in the polymer. The mechanical and thermodynamic properties of the explosive crystal are quite different from those of the polymer. Significant inelastic response of the explosive crystal is apparent even in specimens that appear to have undergone only elastic deformation. The explosive crystals are clearly cleaved during the collapse of the stress bridges during the apparent elastic response of the bulk material. C1 USAF, Munit Directorate, Eglin AFB, FL 32542 USA. RP Foster, JC (reprint author), USAF, Munit Directorate, 101 W, Eglin AFB, FL 32542 USA. NR 5 TC 7 Z9 7 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 1-56396-923-8 J9 AIP CONF PROC PY 2000 VL 505 BP 703 EP 706 PG 4 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA BQ23D UT WOS:000087647600163 ER PT S AU Foster, JC Jones, SE Toness, O DeAngelis, RJ Rule, WK AF Foster, JC Jones, SE Toness, O DeAngelis, RJ Rule, WK BE Furnish, MD Chhabildas, LC Hixson, RS TI Analytical estimate for mass loss from a high velocity rigid penetrator SO SHOCK COMPRESSION OF CONDENSED MATTER-1999, PTS 1 AND 2 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 11th Conference of the American-Physical-Society-Topical-Group on Shock Compression of Condensed Matter CY JUN 27-JUL 02, 1999 CL SNOWBIRD, UT SP Amer Phys Soc Top Grp AB Analytical models of the penetration process focus on estimating depth of penetration based on target density, target strength (sometimes associated with the unconfined compressive strength of the target for geological targets), the areal density of the penetrator (W/A), and the impact velocity. In this paper, an expression for work is used in conjunction with thermodynamic considerations to devise a simple estimate for mass lost by a high velocity projectile during the penetration process. The result shows that the mass loss is directly proportional to the tunnel length and the target shear strength. The constant of proportionality is not easy to deduce, however, in that it contains an unusual factor from the work analysis. A method for estimating target shear under high pressure from penetration experiments is introduced. C1 USAF, Res Lab, Munit Directorate, Eglin AFB, FL 32542 USA. RP Foster, JC (reprint author), USAF, Res Lab, Munit Directorate, Eglin AFB, FL 32542 USA. NR 10 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 1-56396-923-8 J9 AIP CONF PROC PY 2000 VL 505 BP 1125 EP 1128 PG 4 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA BQ23D UT WOS:000087647600261 ER PT B AU Chamillard, AT Braun, KA AF Chamillard, AT Braun, KA BE Impagliazzo, J TI Evaluating programming ability in an introductory computer science course SO SIGCSE 2000: PROCEEDINGS OF THE THIRTY-FIRST SIGCSE TECHNICAL SYMPOSIUM ON COMPUTER SCIENCE EDUCATION SE SIGCSE BULLETIN : A QUARTERLY PUBLICATION OF THE SPECIAL INTEREST GROUP ON COMPUTER SCIENCE EDUCATION LA English DT Proceedings Paper CT 31st SIGCSE Technical Symposium on Computer Science Education CY MAR 08-12, 2000 CL AUSTIN, TX SP Assoc Comp Machinery, Special Interest Grp Comp Sci Educ, SIG DE programming ability; programming evaluation; introductory computer science; collaborative learning AB There are numerous ways to evaluate student programming ability, all of which have benefits and drawbacks. In this paper we discuss how we have combined a number of those evaluation techniques Po assess student programming ability in an introductory computer science course and statistically analyze the relationships of student performance using the different evaluation techniques. C1 USAF Acad, Dept Comp Sci, Colorado Springs, CO 80840 USA. RP Chamillard, AT (reprint author), USAF Acad, Dept Comp Sci, Colorado Springs, CO 80840 USA. NR 3 TC 3 Z9 3 U1 0 U2 0 PU ASSOC COMPUTING MACHINERY PI NEW YORK PA 1515 BROADWAY, NEW YORK, NY 10036-9998 USA BN 1-58113-213-1 J9 SIGCSE BULL PY 2000 VL 32 IS 1 SI 2000 BP 212 EP 216 PG 5 WC Computer Science, Interdisciplinary Applications; Education, Scientific Disciplines SC Computer Science; Education & Educational Research GA BP78G UT WOS:000086166400043 ER PT S AU Gustafson, SC Crabtree, PN Thomas, RW AF Gustafson, SC Crabtree, PN Thomas, RW BE Drummond, OE TI Vision-based super-resolution for recognizing small targets SO SIGNAL AND DATA PROCESSING OF SMALL TARGETS 2000 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Signal and Data Processing of Small Targets 2000 CY APR 24-27, 2000 CL ORLANDO, FL SP SPIE AB Regions of interest that contain small targets often cover a small number of pixels, e.g., 100 or fewer. For such regions vision-based super-resolution techniques are feasible that would be infeasible for regions that cover a large number of pixels. One such technique centers basis functions (such as Gaussians) of the same width on all pixels and adjusts their amplitudes so that the sum of the basis functions integrated over each pixel is its gray value. This technique implements super-resolution in that the sum of basis functions determines the gray values of sub-pixels of any size. The resulting super-resolved visualizations, each characterized by a different basis function width, may enable the recognition of small targets that would otherwise remain. unrecognized. C1 USAF, Inst Technol, AFIT, ENG, Wright Patterson AFB, OH 45433 USA. RP Gustafson, SC (reprint author), USAF, Inst Technol, AFIT, ENG, Wright Patterson AFB, OH 45433 USA. NR 3 TC 0 Z9 0 U1 0 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-3674-7 J9 P SOC PHOTO-OPT INS PY 2000 VL 4048 BP 68 EP 71 DI 10.1117/12.392020 PG 4 WC Computer Science, Artificial Intelligence; Engineering, Electrical & Electronic; Remote Sensing; Optics SC Computer Science; Engineering; Remote Sensing; Optics GA BR56Y UT WOS:000166833000007 ER PT S AU Caefer, CE Silverman, J DiSalvo, S Taylor, RW AF Caefer, CE Silverman, J DiSalvo, S Taylor, RW BE Drummond, OE TI Post-processing of point target detection sinusoidal filters SO SIGNAL AND DATA PROCESSING OF SMALL TARGETS 2000 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Signal and Data Processing of Small Targets 2000 CY APR 24-27, 2000 CL ORLANDO, FL SP SPIE DE staring IR camera; point target detection; cloud clutter; triple temporal filter; post-processing and moving platform ID STARING IR IMAGERY; CLOUD CLUTTER AB In previous conferences, we described a powerful class of temporal filters with excellent signal to clutter gains in evolving cloud scenes of consecutive IR sequences. The generic temporal filter is a zero-mean damped sinusoid, implemented recursively. The full algorithm, a triple temporal filter (TTF), consists of a sequence of two zero-mean damped sinusoids followed by an exponential averaging filter. The outputs of the first two filters are weakened at strong local edges. Analysis of a real-world database led to two optimized filters: one dedicated to noise-dominated scenes, the other to cloud clutter-dominated scenes; a dual-channel fusion of the two filters has also been implemented in hardware. This paper describes the post-processing and thresholding of the outputs of the filter algorithms. Post-processing on each output frame is implemented by a simple spatial algorithm which searches for maximum linear or pseudo-linear streaks made up of three linked pixels. The output histogram after post-processing is more robust to histogram-based thresholding and in some cases has improved signal to clutter ratio. The threshold is based on a simple level-occupancy (binary) histogram in which the first gap of 4 empty levels is determined and a threshold established based on this gap value and the number of occupied levels in the histogram above the gap. The post-processing and thresholding of the filter outputs are now operating in real-time hardware. Preliminary flight tests on a small aircraft of the algorithms in real-time operation demonstrate the viability of the approach on a moving platform. Specific examples and a video of the real-time performance on a fixed and moving platform will be presented at the conference. C1 USAF, Sensors Directorate, Res Lab, Hanscom AFB, MA 01731 USA. RP Caefer, CE (reprint author), USAF, Sensors Directorate, Res Lab, Hanscom AFB, MA 01731 USA. NR 5 TC 2 Z9 2 U1 1 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-3674-7 J9 P SOC PHOTO-OPT INS PY 2000 VL 4048 BP 104 EP 111 DI 10.1117/12.391970 PG 8 WC Computer Science, Artificial Intelligence; Engineering, Electrical & Electronic; Remote Sensing; Optics SC Computer Science; Engineering; Remote Sensing; Optics GA BR56Y UT WOS:000166833000011 ER PT S AU Musick, S Kastella, K AF Musick, S Kastella, K BE Kadar, I TI Track and bias estimation without data association SO SIGNAL PROCESSING, SENSOR FUSION, AND TARGET RECOGNITION IX SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Signal Processing, Sensor Fusion, and Target Recognition IX CY APR 24-26, 2000 CL ORLANDO, FL SP SPIE DE nonlinear filter; bias estimation; stochastic methods; Fokker-Planck equation; data association AB Previous nonlinear filtering research has shown that by directly estimating the probability density of the target state, weak and closely spaced targets can be tracked without performing data association. Data association imposes a heavy burden, both in its design where complex data management structures are required and in its execution which often requires many computer cycles. Therefore, avoiding data association can have advantages. However, some have suggested that data association is required to estimate and correct sensor biases that are nearly always present so avoiding it is not a practical option. This paper demonstrates that target numbers, target tracks, and sensor biases can all be estimated simultaneously using association-free nonlinear methods, thereby extending the useful range of these methods while preserving their inherent advantages. C1 USAF, Res Lab, Sensors Directorate, Wright Patterson AFB, OH 45433 USA. RP Musick, S (reprint author), USAF, Res Lab, Sensors Directorate, Wright Patterson AFB, OH 45433 USA. NR 13 TC 1 Z9 1 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-3678-X J9 P SOC PHOTO-OPT INS PY 2000 VL 4052 BP 258 EP 269 DI 10.1117/12.395091 PG 12 WC Automation & Control Systems; Computer Science, Artificial Intelligence; Computer Science, Cybernetics; Engineering, Electrical & Electronic SC Automation & Control Systems; Computer Science; Engineering GA BR51K UT WOS:000166690400026 ER PT S AU Wang, SP Powell, A Redwing, J Piner, E Saxler, AW AF Wang, SP Powell, A Redwing, J Piner, E Saxler, AW BE Carter, CH Devaty, RP Rohrer, GS TI Generation and properties of semi-insulating SiC substrates SO SILICON CARBIDE AND RELATED MATERIALS - 1999 PTS, 1 & 2 SE MATERIALS SCIENCE FORUM LA English DT Article; Proceedings Paper CT International Conference on Silicon Carbide and Related Materials CY OCT 10-15, 1999 CL RES TRIANGLE PK, NORTH CAROLINA SP NASA, Glenn Res Ctr, USAF, Res Lab, mat & Mfg Directoirate, USN, Off Res, Def Res & Engn, Cree Inc, Charles & Colvard Inc, ABB Semicond, Sterling Semicond Inc, ATMI Inc, Epigress AB, Aixtron AG, Northrop Grumman, Siemens AG, EMCORE Inc, GE, Corp R & D, Litton Airton, II-VI Inc DE GaN device on SI-SiC; resistivity; semi-insulating (SI); SiC substrates ID VAPOR TRANSPORT; GROWTH AB Semi-insulating SiC crystals were grown by sublimation Physical Vapor Transport technique and semi-insulating 6H-SiC substrate wafers up to 2 " in diameter were fabricated. Resistivity measurement and high temperature Hall measurement results showed that a large segment of a SiC boule grown in this process was semi-insulating. To evaluate these SI SiC substrates, GaN thin films and device structures were grown on the semi-insulating SiC substrates and device characterization results are presented. C1 ATMI Inc, Danbury, CT 06810 USA. Epitron Inc, Phoenix, AZ 85027 USA. USAF, Res Lab, MLPO, Wright Patterson AFB, OH 45433 USA. RP Wang, SP (reprint author), ATMI Inc, 7 Commerce Dr, Danbury, CT 06810 USA. RI Piner, Edwin/B-5359-2016 NR 7 TC 4 Z9 5 U1 0 U2 0 PU TRANS TECH PUBLICATIONS LTD PI ZURICH-UETIKON PA BRANDRAIN 6, CH-8707 ZURICH-UETIKON, SWITZERLAND SN 0255-5476 J9 MATER SCI FORUM PY 2000 VL 338-3 BP 17 EP 20 PG 4 WC Materials Science, Multidisciplinary; Materials Science, Coatings & Films SC Materials Science GA BR27W UT WOS:000165996700004 ER PT S AU Mitchel, WC Saxler, A Perrin, R Goldstein, J Smith, SR Evwaraye, AO Solomon, JS Brady, M Tsvetkov, V Carter, CH AF Mitchel, WC Saxler, A Perrin, R Goldstein, J Smith, SR Evwaraye, AO Solomon, JS Brady, M Tsvetkov, V Carter, CH BE Carter, CH Devaty, RP Rohrer, GS TI Vanadium-free semi-insulating 4H-SiC substrates SO SILICON CARBIDE AND RELATED MATERIALS - 1999 PTS, 1 & 2 SE MATERIALS SCIENCE FORUM LA English DT Article; Proceedings Paper CT International Conference on Silicon Carbide and Related Materials CY OCT 10-15, 1999 CL RES TRIANGLE PK, NORTH CAROLINA SP NASA, Glenn Res Ctr, USAF, Res Lab, mat & Mfg Directoirate, USN, Off Res, Def Res & Engn, Cree Inc, Charles & Colvard Inc, ABB Semicond, Sterling Semicond Inc, ATMI Inc, Epigress AB, Aixtron AG, Northrop Grumman, Siemens AG, EMCORE Inc, GE, Corp R & D, Litton Airton, II-VI Inc DE 4H-SiC; admittance spectroscopy; Hall effect; physical vapor transport; semi-insulating material ID SILICON-CARBIDE AB We report the demonstration of semi-insulating bulk 4H-SiC without the use of vanadium doping. Single crystal boules were grown by the physical vapor transport method and sliced into wafers. The semi-insulating material was examined with temperature dependent Hall effect, optical admittance spectroscopy, optical absorption and secondary ion mass spectrometry. The material was insulating at room temperature and was not measurable until near 300 degreesC where the resistivity was 4X10(7) Omega . cm. The thermal activation energy is 1.1 eV as determined by temperature dependent Hall effect. Optical admittance spectroscopy detected the 1.1 eV level but did not observe any response in the band around 1.6 eV where the vanadium donor response has previously been detected. Vanadium was below the 10(15) cm(-3) detection limit of our SIMS system. The identity of the defect responsible for the 1.1 eV level has not been identified. C1 USAF, Res Lab, Mat & Mfg Directorate, Wright Patterson AFB, OH 45433 USA. Univ Dayton, Dayton, OH 45469 USA. Cree Res Inc, Durham, NC 27703 USA. RP Mitchel, WC (reprint author), USAF, Res Lab, Mat & Mfg Directorate, 3005 P St,Suite 6, Wright Patterson AFB, OH 45433 USA. NR 7 TC 24 Z9 25 U1 0 U2 1 PU TRANS TECH PUBLICATIONS LTD PI ZURICH-UETIKON PA BRANDRAIN 6, CH-8707 ZURICH-UETIKON, SWITZERLAND SN 0255-5476 J9 MATER SCI FORUM PY 2000 VL 338-3 BP 21 EP 24 PG 4 WC Materials Science, Multidisciplinary; Materials Science, Coatings & Films SC Materials Science GA BR27W UT WOS:000165996700005 ER PT S AU McDaniel, GY Fenstermaker, ST Walker, DE Lampert, WV Mukhopadhyay, SM Holloway, PH AF McDaniel, GY Fenstermaker, ST Walker, DE Lampert, WV Mukhopadhyay, SM Holloway, PH BE Carter, CH Devaty, RP Rohrer, GS TI Quantified conditions for reduction of ESO contamination during SiC metalization SO SILICON CARBIDE AND RELATED MATERIALS - 1999 PTS, 1 & 2 SE MATERIALS SCIENCE FORUM LA English DT Article; Proceedings Paper CT International Conference on Silicon Carbide and Related Materials CY OCT 10-15, 1999 CL RES TRIANGLE PK, NORTH CAROLINA SP NASA, Glenn Res Ctr, USAF, Res Lab, mat & Mfg Directoirate, USN, Off Res, Def Res & Engn, Cree Inc, Charles & Colvard Inc, ABB Semicond, Sterling Semicond Inc, ATMI Inc, Epigress AB, Aixtron AG, Northrop Grumman, Siemens AG, EMCORE Inc, GE, Corp R & D, Litton Airton, II-VI Inc DE adsorption kinetics; Auger Electron Spectroscopy; surface kinetics ID AUGER-ELECTRON SPECTROSCOPY; BEAM; CONTACTS; OXYGEN AB In metalization work, controlled semiconductor surfaces and interfaces are necessary. Trace impurities such as carbon and oxygen at the metal/semiconductor interface may improve or degrade the electrical characteristics of a desired contact. In this study, Auger Electron Spectroscopy (AES) was used to investigate electron stimulated oxidation (ESO) of SiC. The research focused on chamber conditions necessary to prevent oxide formation on SiC surfaces during thin film metal deposition. Oxidation rate was studied as a function of beam exposure ton and off), primary electron beam energy, E-p, (3-6 keV), electron beam current, I-p, (25-500 nA), and total chamber pressure. Oxidation rate had a stronger correlation to overall chamber pressure rather than the partial pressure of H2O, CO, or CO2 alone. Oxidation rate decreased slightly as E-p was increased. Rate of oxidation increased at higher pressures (2.2 x 10(-7) Torr) with respect to I-p but was nearly independent of I-p at lower pressures (7.1 x 10-9 Torr). No oxide growth was detectable to AES in the absence of exposure to the electron beam. C1 USAF, Res Lab, Wright Patterson AFB, OH 45433 USA. Wright State Univ, Dayton, OH 45435 USA. Univ Florida, Gainesville, FL 32611 USA. RP McDaniel, GY (reprint author), USAF, Res Lab, Wright Patterson AFB, OH 45433 USA. NR 18 TC 0 Z9 0 U1 0 U2 0 PU TRANS TECH PUBLICATIONS LTD PI ZURICH-UETIKON PA BRANDRAIN 6, CH-8707 ZURICH-UETIKON, SWITZERLAND SN 0255-5476 J9 MATER SCI FORUM PY 2000 VL 338-3 BP 407 EP 410 PG 4 WC Materials Science, Multidisciplinary; Materials Science, Coatings & Films SC Materials Science GA BR27W UT WOS:000165996700098 ER PT S AU Capano, MA Cooper, JA Melloch, MR Saxler, A Mitchel, WC AF Capano, MA Cooper, JA Melloch, MR Saxler, A Mitchel, WC BE Carter, CH Devaty, RP Rohrer, GS TI Ionization energies and electron mobilities in phosphorus- and nitrogen-implanted 4H-silicon carbide SO SILICON CARBIDE AND RELATED MATERIALS - 1999 PTS, 1 & 2 SE MATERIALS SCIENCE FORUM LA English DT Article; Proceedings Paper CT International Conference on Silicon Carbide and Related Materials CY OCT 10-15, 1999 CL RES TRIANGLE PK, NORTH CAROLINA SP NASA, Glenn Res Ctr, USAF, Res Lab, mat & Mfg Directoirate, USN, Off Res, Def Res & Engn, Cree Inc, Charles & Colvard Inc, ABB Semicond, Sterling Semicond Inc, ATMI Inc, Epigress AB, Aixtron AG, Northrop Grumman, Siemens AG, EMCORE Inc, GE, Corp R & D, Litton Airton, II-VI Inc DE electron mobility; ionization energies; nitrogen implantation; phosphorus implantation ID ION-IMPLANTATION; DONORS AB Comparisons are made between the carrier concentrations, ionization energies, and electron mobilities in 4H-SiC samples implanted with similar doses of nitrogen or phosphorus, and annealed at 1300 degreesC or 1700 degreesC for 10 min in argon. Ionization energies of 53 meV and 93 meV are measured from phosphorus-implanted 4H-SiC, and are assigned to the hexagonal and cubic lattice positions in 4H-SiC, respectively. The corresponding ionization energies for nitrogen-implanted 4H-SiC are 42 meV and 84 meV, respectively. Phosphorus is not activated to the same extent that nitrogen is, and the carrier concentrations are about a factor of five lower for phosphorus-implanted 4H-SiC annealed at 1300 degreesC than for nitrogen-implanted 4H-SiC annealed at the same temperature. A higher mobility measured from phosphorus-implanted 4H-SiC is observed, but is not sufficiently high to offset the lower carrier concentration of this material. For the doses considered in this study, the resistivity of nitrogen-implanted 4H-SiC is lower than the resistivity of phosphorus-implanted 4H-SiC following anneals at either 1300 degreesC or 1700 degreesC. C1 Purdue Univ, Sch Elect & Comp Engn, W Lafayette, IN 47907 USA. USAF, Res Lab, Mat & Mfg Directorate, Wright Patterson AFB, OH 45433 USA. RP Capano, MA (reprint author), Purdue Univ, Sch Elect & Comp Engn, 1285 EE Bldg, W Lafayette, IN 47907 USA. NR 8 TC 8 Z9 8 U1 0 U2 0 PU TRANS TECH PUBLICATIONS LTD PI ZURICH-UETIKON PA BRANDRAIN 6, CH-8707 ZURICH-UETIKON, SWITZERLAND SN 0255-5476 J9 MATER SCI FORUM PY 2000 VL 338-3 BP 703 EP 706 PG 4 WC Materials Science, Multidisciplinary; Materials Science, Coatings & Films SC Materials Science GA BR27W UT WOS:000165996700171 ER PT S AU Chafai, M Jimenez, J Martin, E Mitchel, WC Saxler, A Perrin, R AF Chafai, M Jimenez, J Martin, E Mitchel, WC Saxler, A Perrin, R BE Carter, CH Devaty, RP Rohrer, GS TI MicroRaman and Hall effect study of n-type bulk 4H-SiC SO SILICON CARBIDE AND RELATED MATERIALS - 1999 PTS, 1 & 2 SE MATERIALS SCIENCE FORUM LA English DT Article; Proceedings Paper CT International Conference on Silicon Carbide and Related Materials CY OCT 10-15, 1999 CL RES TRIANGLE PK, NORTH CAROLINA SP NASA, Glenn Res Ctr, USAF, Res Lab, mat & Mfg Directoirate, USN, Off Res, Def Res & Engn, Cree Inc, Charles & Colvard Inc, ABB Semicond, Sterling Semicond Inc, ATMI Inc, Epigress AB, Aixtron AG, Northrop Grumman, Siemens AG, EMCORE Inc, GE, Corp R & D, Litton Airton, II-VI Inc DE 4H polytype; Hall; phonons; plasmon; Raman; temperature phonon shift ID RAMAN-SPECTROSCOPY AB N-type 4H-SiC crystals are studied by Hall effect and Raman spectroscopy. The transport parameters, n and mu, Obtained by both procedures are compared for a series of samples with different nitrogen concentrations. A good agreement between both is obtained. A Raman study in the temperature range between 300 and 650 K is also carried out, the temperature dependence of phonon parameters and plasmons is reported, and the results are compared with high temperature Hall effect measurements. C1 ETSII, Fis Mat Condensada, ES-47011 Valladolid, Spain. LETI, Fac Sci, Dept Phys, Mekness 50003, Morocco. USAF, Res Lab MLPO, Mat Directorate, Wright Patterson AFB, OH 45433 USA. RP Chafai, M (reprint author), ETSII, Fis Mat Condensada, ES-47011 Valladolid, Spain. NR 8 TC 1 Z9 1 U1 0 U2 0 PU TRANS TECH PUBLICATIONS LTD PI ZURICH-UETIKON PA BRANDRAIN 6, CH-8707 ZURICH-UETIKON, SWITZERLAND SN 0255-5476 J9 MATER SCI FORUM PY 2000 VL 338-3 BP 707 EP 710 PG 4 WC Materials Science, Multidisciplinary; Materials Science, Coatings & Films SC Materials Science GA BR27W UT WOS:000165996700172 ER PT S AU Mitchel, WC Brown, J Buckanan, D Bertke, R Malalingham, K Orazio, FD Pirouz, P Tseng, HJR Ramabadran, UB Roughani, B AF Mitchel, WC Brown, J Buckanan, D Bertke, R Malalingham, K Orazio, FD Pirouz, P Tseng, HJR Ramabadran, UB Roughani, B BE Carter, CH Devaty, RP Rohrer, GS TI Comparison of mechanical and chemomechanical polished SiC wafers using photon backscattering SO SILICON CARBIDE AND RELATED MATERIALS - 1999 PTS, 1 & 2 SE MATERIALS SCIENCE FORUM LA English DT Article; Proceedings Paper CT International Conference on Silicon Carbide and Related Materials CY OCT 10-15, 1999 CL RES TRIANGLE PK, NORTH CAROLINA SP NASA, Glenn Res Ctr, USAF, Res Lab, mat & Mfg Directoirate, USN, Off Res, Def Res & Engn, Cree Inc, Charles & Colvard Inc, ABB Semicond, Sterling Semicond Inc, ATMI Inc, Epigress AB, Aixtron AG, Northrop Grumman, Siemens AG, EMCORE Inc, GE, Corp R & D, Litton Airton, II-VI Inc DE 4H-SiC; atomic force microscopy; chemomechanical polish; micro Raman; Photon Backscattering; transmission electron microscopy ID SILICON-CARBIDE; DEFECTS AB We report a study of subsurface damage in 8 degrees off axis 4H-SiC wafers using Photon Backscattering (PBS) along with atomic force microscopy, transmission electron microscopy and micro-Raman spectroscopy. PBS is a non-distructive subsurface defect detection technique that has been used for evaluation of silicon and gallium arsenide wafers. We have used PBS to evaluate as-received wafers from various suppliers as well as chemomechanical polished wafers. PBS results are compared with TEM, AFM and micro-Raman. As received wafers all show signs of mechanical polishing induced scratches. Chemomechanical polished wafers are scratch free and do not show directional damage typical of mechanical polishing seen in PBS maps of as-received wafers. C1 USAF, Res Lab, Mat & Mfg Directorate, Wright Patterson AFB, OH 45433 USA. VTI Inc, Dayton, OH 45431 USA. Case Western Reserve Univ, Dept Mat Sci & Engn, Cleveland, OH 44106 USA. Kettering Univ, Ann Arbor, MI USA. RP Mitchel, WC (reprint author), USAF, Res Lab, Mat & Mfg Directorate, 3005 P St,Suite 6, Wright Patterson AFB, OH 45433 USA. NR 4 TC 12 Z9 12 U1 0 U2 2 PU TRANS TECH PUBLICATIONS LTD PI ZURICH-UETIKON PA BRANDRAIN 6, CH-8707 ZURICH-UETIKON, SWITZERLAND SN 0255-5476 J9 MATER SCI FORUM PY 2000 VL 338-3 BP 841 EP 844 PG 4 WC Materials Science, Multidisciplinary; Materials Science, Coatings & Films SC Materials Science GA BR27W UT WOS:000165996700203 ER PT S AU Liu, S Potts, G Scofield, J AF Liu, S Potts, G Scofield, J BE Carter, CH Devaty, RP Rohrer, GS TI Thermal stability in vacuum and in air of Al/Ni/W based ohmic contacts to p-type SiC SO SILICON CARBIDE AND RELATED MATERIALS - 1999 PTS, 1 & 2 SE MATERIALS SCIENCE FORUM LA English DT Article; Proceedings Paper CT International Conference on Silicon Carbide and Related Materials CY OCT 10-15, 1999 CL RES TRIANGLE PK, NORTH CAROLINA SP NASA, Glenn Res Ctr, USAF, Res Lab, mat & Mfg Directoirate, USN, Off Res, Def Res & Engn, Cree Inc, Charles & Colvard Inc, ABB Semicond, Sterling Semicond Inc, ATMI Inc, Epigress AB, Aixtron AG, Northrop Grumman, Siemens AG, EMCORE Inc, GE, Corp R & D, Litton Airton, II-VI Inc DE ohmic contacts; silicon carbide; thermal stability AB The Al/Ni/W contact demonstrated excellent thermal stability after being aged at 600 degreesC in a high vacuum of 1x10(-6) mmHg for 1022 hours. No degradation in contact resistivity was found after the aging. However, 1 hour aging in air severely degraded the ohmic characteristics of the Al/Ni/W contact. An Al/Ni/W/Mo contact showed ohmic behavior at 300 degreesC in air for 186 hours, while an Al/Ni/W/Au contact displayed good thermal stability at 600 degreesC in air for over 100 hours. In order to avoid the problem of metal oxidation in air and at elevated temperatures, we have proposed and tested a new approach to improving the in-air thermal stability of the Al/Ni/W ohmic contact by adding a top conductive oxide layer to the contact. C1 Univ Dayton, Dayton, OH 45469 USA. USAF, Res Lab, AFRL, Wright Patterson AFB, OH 45433 USA. RP Liu, S (reprint author), Univ Dayton, 300 Coll Pk, Dayton, OH 45469 USA. NR 4 TC 16 Z9 17 U1 1 U2 1 PU TRANS TECH PUBLICATIONS LTD PI ZURICH-UETIKON PA BRANDRAIN 6, CH-8707 ZURICH-UETIKON, SWITZERLAND SN 0255-5476 J9 MATER SCI FORUM PY 2000 VL 338-3 BP 1021 EP 1024 PG 4 WC Materials Science, Multidisciplinary; Materials Science, Coatings & Films SC Materials Science GA BR27W UT WOS:000165996700248 ER PT S AU Carter, GE Casady, JB Bonds, J Okhuysen, ME Scofield, JD Saddow, SE AF Carter, GE Casady, JB Bonds, J Okhuysen, ME Scofield, JD Saddow, SE BE Carter, CH Devaty, RP Rohrer, GS TI Preliminary investigation of SiC on silicon for biomedical applications SO SILICON CARBIDE AND RELATED MATERIALS - 1999 PTS, 1 & 2 SE MATERIALS SCIENCE FORUM LA English DT Article; Proceedings Paper CT International Conference on Silicon Carbide and Related Materials CY OCT 10-15, 1999 CL RES TRIANGLE PK, NORTH CAROLINA SP NASA, Glenn Res Ctr, USAF, Res Lab, mat & Mfg Directoirate, USN, Off Res, Def Res & Engn, Cree Inc, Charles & Colvard Inc, ABB Semicond, Sterling Semicond Inc, ATMI Inc, Epigress AB, Aixtron AG, Northrop Grumman, Siemens AG, EMCORE Inc, GE, Corp R & D, Litton Airton, II-VI Inc DE 3C; biomedical probe; MEMS; microelectromechanical; reactive ion etching; RIE; SF6 ID SYSTEM AB Reactive ion etching experiments were conducted with the intent of constructing a 3C-SiC on silicon heart probe to be used for biomedical applications. Experiments were performed with 3C-SiC as well as 4H-SiC in order to optimize the process for the heart probe construction. The heart probes were patterned on 3C-SiC on silicon to create a hybrid device that would combine the strength and inertness of the 3C-SiC material with the electronic compatibility of Si material to provide a complete probe suitable for reliable and disposable use required by the medical industry. C1 Mississippi State Univ, Dept Elect & Comp Engn, Emerging Mat Res Lab, Mississippi State, MS 39762 USA. USAF, Res Lab, Wright Patterson AFB, OH 45433 USA. RP Carter, GE (reprint author), Mississippi State Univ, Dept Elect & Comp Engn, Emerging Mat Res Lab, Mississippi State, MS 39762 USA. NR 10 TC 11 Z9 11 U1 0 U2 0 PU TRANS TECH PUBLICATIONS LTD PI ZURICH-UETIKON PA BRANDRAIN 6, CH-8707 ZURICH-UETIKON, SWITZERLAND SN 0255-5476 J9 MATER SCI FORUM PY 2000 VL 338-3 BP 1149 EP 1152 PG 4 WC Materials Science, Multidisciplinary; Materials Science, Coatings & Films SC Materials Science GA BR27W UT WOS:000165996700280 ER PT B AU Ahoujja, M Yeo, YK Hengehold, RL Guido, LJ Mitev, P Johnstone, DK Kim, YH AF Ahoujja, M Yeo, YK Hengehold, RL Guido, LJ Mitev, P Johnstone, DK Kim, YH BE Jagadish, C Welham, NJ TI Influence of arsenic doping on the electrical properties of GaN epitaxial layers grown by MOCVD SO SIMC-XI: 2000 INTERNATIONAL SEMICONDUCTING AND INSULATING MATERIALS CONFERENCE, PROCEEDINGS LA English DT Proceedings Paper CT 11th International Semiconducting and Insulating Materials Conference (SIMC-XI) CY JUL 03-07, 2000 CL CANBERRA, AUSTRALIA SP IEEE Electron Devices Soc, Australian Natl Univ, AIXTRON, Oxford Instruments Plasma Technol, Ledex Corp, IEEE ACT Sect, IEEE Electron Devices Soc, Australian Chapter, Lasers & Electro-Opt Soc, Australian Mat Res Soc ID DEEP AB The influence of arsenic doping on the electrical properties of GaN films grown on sapphire substrates by metalorganic chemical vapor deposition has been investigated using temperature dependent Hall-effect and deep-level transient spectroscopy measurements. With an increase in arsine flow rate from 1.5 to 400 sccm, the carrier concentration increases from 8.6x10(16) to 7.5x10(17) cm(-3) while the mobility ranges from 250 to 400 cm(2)/Vs. Two deep electron trap levels were observed at around 0.22 and 0.60 eV from the undoped GaN sample, whereas the deep level at around 0.22 eV was not observed in the As-doped samples. C1 USAF, Inst Technol, Wright Patterson AFB, OH 45433 USA. RP Ahoujja, M (reprint author), USAF, Inst Technol, Wright Patterson AFB, OH 45433 USA. NR 9 TC 0 Z9 0 U1 0 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-5815-5 PY 2000 BP 27 EP 30 DI 10.1109/SIM.2000.939191 PG 4 WC Engineering, Electrical & Electronic; Physics, Condensed Matter SC Engineering; Physics GA BT02S UT WOS:000171690800005 ER PT S AU Knize, RJ White, WR Zhdanov, BV AF Knize, RJ White, WR Zhdanov, BV BE SanchezMondragon, JJ TI Undergraduate laser and optical physics laboratory course at the United States Air Force Academy SO SIXTH INTERNATIONAL CONFERENCE ON EDUCATION AND TRAINING IN OPTICS AND PHOTONICS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT 6th International Conference on Education and Training in Optics and Photonics CY JUL 28-30, 1999 CL CANCUN, MEXICO SP Int Commiss Opt, Opt Soc Amer, SPIE, Univ Autonoma Estado Morelos, Mexico, Univ Guanajuato, Mexico, Acad Mexicana Optica, Secretaria Educ Publica, Consejo Nacl Cienca & Technol, Univ Amer Puebla, Inst Natl Astrofisica, Optica Electronica, Centro Investigaciones Opticas, CICESE, Univ Nacl Autonoma Medixo, Natl Sci Fdn DE lasers; optics; education; modulators; optical waveguides; laser kinetics; CO2 lasers; harmonic generation; optical correlators AB We have developed a new senior-level undergraduate laboratory course at the US Air Force Academy. The students perform six experiments that include; optical modulators, waveguiding, laser kinetics, CO2 lasers, harmonic generation and the measurement of ultrashort laser pulses. These experiments were chosen so that there is an integrated theme of lasers and optics, to teach experimental methods and reinforce fundamental physics concepts. C1 USAF Acad, Dept Phys, Laser & Opt Res Ctr, Colorado Springs, CO 80840 USA. RP Knize, RJ (reprint author), USAF Acad, Dept Phys, Laser & Opt Res Ctr, Colorado Springs, CO 80840 USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-3322-5 J9 P SOC PHOTO-OPT INS PY 2000 VL 3831 BP 183 EP 188 DI 10.1117/12.388726 PG 4 WC Engineering, Electrical & Electronic; Optics SC Engineering; Optics GA BQ51B UT WOS:000088548900023 ER PT S AU Haskett, SA Weis, SC Doggrell, LJ Sciulli, D Mienk, T Ganley, J Maly, JR Jurisson, K AF Haskett, SA Weis, SC Doggrell, LJ Sciulli, D Mienk, T Ganley, J Maly, JR Jurisson, K BE Horais, BJ Twiggs, RJ TI EELV Secondary Payload adapter (ESPA) SO SMALL PAYLOADS IN SPACE SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Small Payloads in Space CY AUG 03-04, 2000 CL SAN DIEGO, CA SP SPIE DE small satellites; Secondary Payload Adapter; evolved expendable launch vehicle AB Despite growing international interest in small satellites, high dedicated expendable launch vehicle costs and the lack of secondary launch opportunities continue to hinder the full exploitation of small satellite technology. In the United States, the Department of Defense (DoD), NASA, other government agencies, commercial companies, and many universities use small satellites to perform space experiments, demonstrate new technology, and test operational prototype hardware. In addition, the DoD continues to study the role of small satellites in fulfilling operational mission requirements. However, the US lacks sufficient small satellite launch capability. Furthermore, US government agencies are restricted to the use of US launch vehicles, which eliminates many affordable launch opportunities. In an effort to increase the number of space experiments that can be flown with a small, fixed budget, the DoD Space Test Program (STP) has teamed with the Air Force Research Laboratory Space Vehicles Directorate (AFRL/VS) to develop a low-cost solution for the small satellite launch problem Our solution, which can be implemented on both Boeing and Lockheed-Martin Evolved Expendable Launch Vehicle-Medium (EELV-M) boosters, is called the EELV Secondary Payload Adapter (ESPA). ESPA will increase the number of launch opportunities for 180kg-class (or smaller) satellites at prices highly competitive with other secondary launch services worldwide. C1 USAF, Space Test Program, Kirtland AFB, NM 87117 USA. RP Haskett, SA (reprint author), USAF, Space Test Program, 3550 Aberdeen Ave SE, Kirtland AFB, NM 87117 USA. NR 0 TC 1 Z9 1 U1 1 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-3781-6 J9 P SOC PHOTO-OPT INS PY 2000 VL 4136 BP 27 EP 35 DI 10.1117/12.406654 PG 9 WC Engineering, Aerospace SC Engineering GA BR62D UT WOS:000166963700004 ER PT S AU Denoyer, KK AF Denoyer, KK BE Jacobs, JH TI Lessons learned from 20th century AFRL smart structures space experiments SO SMART STRUCTURES AND MATERIAL 2000: INDUSTRIAL AND COMMERCIAL APPLICATIONS OF SMART STRUCTURES TECHNOLOGIES SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Smart Structures and Materials 2000 Conference CY MAR 05-09, 2000 CL NEWPORT BEACH, CA SP SPIE, Soc Exptl Mech, Amer Soc Mech Engn, BFGoodrich, Def Adv Res Projects Agcy, USA Res Off, USAF Res Lab, Ceram Soc Japan, Intelligent Mat Forum, Japan DE smart structures; space experiments; overview; Air Force; lessons learned; vibration suppression; control AB The late 20(th) century has seen the evolution of smart structures technology from theoretical studies and bench level experimentation to demonstration on complex ground test articles and flight demonstration. This paper will discuss the role that the Air Force Research Laboratory (AFRL) and its government, industry, and academic partners have played in making this transition occur. The focus of the paper is on the flight experiments and large ground based demonstrations that have been led by AFRL over the past decade. A review is made of intended objectives, achievements, and lessons learned from these various activities. Directions for future research and activities that could motivate transition of the technology to operational systems are also discussed. C1 USAF, Res Lab, Kirtland AFB, NM 87117 USA. RP Denoyer, KK (reprint author), USAF, Res Lab, Kirtland AFB, NM 87117 USA. NR 26 TC 2 Z9 2 U1 0 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-3609-7 J9 P SOC PHOTO-OPT INS PY 2000 VL 3991 BP 104 EP 115 DI 10.1117/12.388151 PG 12 WC Engineering, Aerospace; Engineering, Industrial; Engineering, Mechanical; Materials Science, Multidisciplinary; Optics SC Engineering; Materials Science; Optics GA BQ59X UT WOS:000088917900012 ER PT S AU Erwin, RS Denoyer, KK AF Erwin, RS Denoyer, KK BE Jacobs, JH TI 1000 days on-orbit: Lessons learned from the ACTEX-I flight experiment SO SMART STRUCTURES AND MATERIAL 2000: INDUSTRIAL AND COMMERCIAL APPLICATIONS OF SMART STRUCTURES TECHNOLOGIES SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Smart Structures and Materials 2000 Conference CY MAR 05-09, 2000 CL NEWPORT BEACH, CA SP SPIE, Soc Exptl Mech, Amer Soc Mech Engn, BFGoodrich, Def Adv Res Projects Agcy, USA Res Off, USAF Res Lab, Ceram Soc Japan, Intelligent Mat Forum, Japan AB This paper presents a review of the Air Force Research Laboratory (AFRL) Advanced Controls Technology Experiment (ACTEX-I) Program. Representing the first space-demonstration of smart structures technology, the ACTEX-I program has met or exceeded all program goals at each stage, beginning with the program initiation in 1991 through launch in 1996 to the conclusion of the Guest Investigator program and program conclusion in 1999. This paper will provide a summary of the ACTEX-I program from the AFRL, perspective, focusing on lessons learned from the program both positive and negative. C1 USAF, Res Lab, Space Vehicles Directorate, VSSV, Kirtland AFB, NM 87117 USA. RP Erwin, RS (reprint author), USAF, Res Lab, Space Vehicles Directorate, VSSV, Bldg 472,3550 Aberdeen Ave SE, Kirtland AFB, NM 87117 USA. NR 9 TC 0 Z9 0 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-3609-7 J9 P SOC PHOTO-OPT INS PY 2000 VL 3991 BP 116 EP 121 DI 10.1117/12.388152 PG 6 WC Engineering, Aerospace; Engineering, Industrial; Engineering, Mechanical; Materials Science, Multidisciplinary; Optics SC Engineering; Materials Science; Optics GA BQ59X UT WOS:000088917900013 ER PT S AU Ninneman, RR Denoyer, KK AF Ninneman, RR Denoyer, KK BE Jacobs, JH TI Middeck active control experiment reflight (MACE II): Lessons learned and reflight status SO SMART STRUCTURES AND MATERIAL 2000: INDUSTRIAL AND COMMERCIAL APPLICATIONS OF SMART STRUCTURES TECHNOLOGIES SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Smart Structures and Materials 2000 Conference CY MAR 05-09, 2000 CL NEWPORT BEACH, CA SP SPIE, Soc Exptl Mech, Amer Soc Mech Engn, BFGoodrich, Def Adv Res Projects Agcy, USA Res Off, USAF Res Lab, Ceram Soc Japan, Intelligent Mat Forum, Japan DE active structural control; adaptive structural control; lessons learned; controls experiment AB The Air Force Research Laboratory (AFRL) is sponsoring the Middeck Active Control Experiment Reflight (MACE II) Program. MACE II is a manned space experiment (requires astronaut assembly and operations) that evaluates the capabilities of adaptive control of flexible structures in the zero-g environment of the Space Shuttle's Middeck. MACE II has grown out of lessons learned from the original MACE flight and from AFRL, sponsored structural control experiments. Previous experiments required extensive testing and "tuning" for their particular test environment to meet their performance expectations. Such a process is too inefficient to be seriously considered for operational systems, especially space-based systems were access is limited. MACE II takes the next logical step by evaluating the capability of adaptive structural control algorithms. AFRL has assembled a team of five small businesses and Universities to develop and evaluate several adaptive control methodologies. In addition, AFRL has recruited a second science team led by the Massachusetts Institute of Technology (MIT) to evaluate control systems for time-varying and geometrically nonlinear systems. This paper is an overview of the AFRL science team only. C1 USAF, Res Lab, Kirtland AFB, NM 87117 USA. RP Ninneman, RR (reprint author), USAF, Res Lab, Kirtland AFB, NM 87117 USA. NR 12 TC 1 Z9 1 U1 0 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-3609-7 J9 P SOC PHOTO-OPT INS PY 2000 VL 3991 BP 131 EP 137 DI 10.1117/12.388154 PG 7 WC Engineering, Aerospace; Engineering, Industrial; Engineering, Mechanical; Materials Science, Multidisciplinary; Optics SC Engineering; Materials Science; Optics GA BQ59X UT WOS:000088917900015 ER PT S AU Agnes, GS Rogers, JW AF Agnes, GS Rogers, JW BE Werely, NM TI Piezoelectric excitation of inflatable space structures for modal testing SO SMART STRUCTURES AND MATERIAL 2000: SMART STRUCTURES AND INTEGRATED SYSTEMS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Smart Structures and Materials 2000 Conference CY MAR 05-09, 2000 CL NEWPORT BEACH, CA SP SPIE, Soc Exptl Mech, Amer Soc Mech Engn, BFGoodrich, Def Adv Res Projects Agcy, USA Res Off, USAF Res Lab, Ceram Soc Japan, Intelligent Mat Forum, Japan DE inflatable structures; modal analysis; vibration testing; piezoelectric AB Precision inflatable space structures promise revolutionary change in spacecraft design over the next decade. Given the variety of previous applications and the potential of future concepts, development of advanced design tools is underway. Validation of these models requires experimental analysis of both ground and orbiting test articles. The present study examined the suitability of piezoelectric polymer materials (namely PVDF) to excite an inflated structure for modal testing. Experiments were undertaken using both a conventional electrodynamic shaker and a small sheet of PVDF bonded to an inflated torus. In addition, a linear finite element model of an inflated torus is compared to the experimental results. The results demonstrate the potential for PVDF to excite inflatable ground test articles. C1 USAF, Inst Technol, Dept Aeronaut & Astronaut, Wright Patterson AFB, OH 45433 USA. RP Agnes, GS (reprint author), USAF, Inst Technol, Dept Aeronaut & Astronaut, Wright Patterson AFB, OH 45433 USA. NR 11 TC 1 Z9 1 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-3603-8 J9 P SOC PHOTO-OPT INS PY 2000 VL 3985 BP 806 EP 816 DI 10.1117/12.388883 PG 11 WC Automation & Control Systems; Engineering, Electrical & Electronic; Materials Science, Ceramics SC Automation & Control Systems; Engineering; Materials Science GA BQ59C UT WOS:000088899900074 ER PT S AU Khot, NS Oz, H AF Khot, NS Oz, H BE Varadan, VV TI Wing shaping for optimum roll performance using independent modal-space control technique SO SMART STRUCTURES AND MATERIALS 2000: MATHEMATICS AND CONTROL IN SMART STRUCTURES SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Smart Structures and Materials 2000 Conference CY MAR 05-09, 2000 CL NEWPORT BEACH, CA SP SPIE, Soc Exptl Mech, Amer Soc Mech Engn, BFGoodrich, Def Adv Res Projects Agcy, USA Res Off, USAF Res Lab, Ceram Soc Japan, Intelligent Mat Forum, Japan AB A technique for deforming a flexible wing to achieve a specified roll rate within a specified time at different Mach Numbers is examined. Rather than using an aileron system for roll, antisymmetric elastic twist and camber is determined to achieve the required rolling moment for a specified roll rate. The elastic twist and camber is achieved by providing a system of actuating elements distributed within the internal substructure of the wing to provide control forces. The modal approach is used to develop the dynamic equilibrium equations which culminates in the steady roll maneuver of a wing subjected to aerodynamic loads and the actuating forces. The distribution of actuating forces to achieve the specified steady flexible roll rate within a specified time was determined by using Independent Modal-Space Control (IMSC) design approach. Here, a full-scale realistic wing is considered for the assessment of the strain energy required to produce the antisymmetric twist and camber deformation to achieve the specified roll performance. C1 USAF, Res Lab, VASD, Wright Patterson AFB, OH 45433 USA. RP Khot, NS (reprint author), USAF, Res Lab, VASD, 2210 8th St, Wright Patterson AFB, OH 45433 USA. NR 15 TC 0 Z9 0 U1 0 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-3602-X J9 P SOC PHOTO-OPT INS PY 2000 VL 3984 BP 80 EP 91 DI 10.1117/12.388782 PG 12 WC Automation & Control Systems; Engineering, Electrical & Electronic; Materials Science, Multidisciplinary SC Automation & Control Systems; Engineering; Materials Science GA BQ59B UT WOS:000088899700008 ER PT S AU McNeese, MD Rentsch, JR Perusich, K AF McNeese, MD Rentsch, JR Perusich, K GP IEEE IEEE TI Modeling, measuring, and mediating teamwork: The use of fuzzy cognitive maps and team member schema similarity to enhance (BMCI)-I-3 decision making SO SMC 2000 CONFERENCE PROCEEDINGS: 2000 IEEE INTERNATIONAL CONFERENCE ON SYSTEMS, MAN & CYBERNETICS, VOL 1-5 SE IEEE INTERNATIONAL CONFERENCE ON SYSTEMS, MAN, AND CYBERNETICS, CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT IEEE International Conference on Systems, Man and Cybernetics CY OCT 08-11, 2000 CL NASHVILLE, TN SP IEEE Inc, Syst Man & Cybernet Soc AB A research study is reported which utilizes an AWACS-based distributed decision making environment to assess: a) team interaction b) a cognitive interface containing team-level cues, c) a cognitive interface with information mediation. The hypothesis suggests that when teams are afforded an interface that supports increased communications about team member schemas and shared situation awareness (modeled by joint cognitive processes), then team performance will increase. Results show partial support for the hypothesis for the AWACS scenarios tested. The team member schema similarity (TMSS) cues were shown to be a useful component in team effectiveness. Conclusions suggest how this research can be extended and utilized for developing cognitive interfaces and collaborative computing systems that produce shared situation awareness in complex settings. C1 USAF, Res Lab, Wright Patterson AFB, OH 45433 USA. RP McNeese, MD (reprint author), USAF, Res Lab, Wright Patterson AFB, OH 45433 USA. NR 20 TC 1 Z9 1 U1 0 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1062-922X BN 0-7803-6583-6 J9 IEEE SYS MAN CYBERN PY 2000 BP 1081 EP 1086 PG 6 WC Computer Science, Cybernetics; Engineering, Electrical & Electronic SC Computer Science; Engineering GA BR32T UT WOS:000166106900188 ER PT S AU Pack, DJ AF Pack, DJ GP IEEE IEEE TI A fast object recognition system using object appearances SO SMC 2000 CONFERENCE PROCEEDINGS: 2000 IEEE INTERNATIONAL CONFERENCE ON SYSTEMS, MAN & CYBERNETICS, VOL 1-5 SE IEEE INTERNATIONAL CONFERENCE ON SYSTEMS, MAN, AND CYBERNETICS, CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT IEEE International Conference on Systems, Man and Cybernetics CY OCT 08-11, 2000 CL NASHVILLE, TN SP IEEE Inc, Syst Man & Cybernet Soc DE object recognition; eigenspace; appearance model; image compression; and singular value decomposition AB This paper presents a novel appearance model-based fast object recognition system. The speed is achieved by avoiding much of the image processing required for feature extraction and by compactly representing object models in a subspace. Raw images of an object are transformed into an object model in an eigenvector space after a simple process that compresses the data size using a low pass spatial filter along with an interpolation method. The validity of the proposed scheme is demonstrated by a working model-airplane recognition system. C1 USAF Acad, Dept Elect Engn, Colorado Springs, CO 80840 USA. RP Pack, DJ (reprint author), USAF Acad, Dept Elect Engn, Colorado Springs, CO 80840 USA. NR 4 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1062-922X BN 0-7803-6583-6 J9 IEEE SYS MAN CYBERN PY 2000 BP 2781 EP 2788 PG 8 WC Computer Science, Cybernetics; Engineering, Electrical & Electronic SC Computer Science; Engineering GA BR32T UT WOS:000166106900484 ER PT J AU Borgarino, M Plana, R Fendler, M Vilcot, JP Mollot, F Barette, J Decoster, D Graffeuil, J AF Borgarino, M Plana, R Fendler, M Vilcot, JP Mollot, F Barette, J Decoster, D Graffeuil, J TI Low frequency noise behaviour of InP/InGaAs heterojunction bipolar waveguide phototransistors SO SOLID-STATE ELECTRONICS LA English DT Article ID TRANSISTORS; ALGAAS; GAAS AB In this paper we report on both the DC and low frequency noise (LFN) properties of InP/InGaAs heterojunction bipolar phototransistors (HPTs) featuring waveguide type illumination. Both DC and LFN measurements demonstrate the good quality of these devices. In particular, they exhibit a 1/f noise figure-of-merit of 2.10(-8) mu m(2), which is exceptionally very good in the field of the compound semiconductor HBTs, where values around 10(-7) mu m(2) are usually reported. (C) 2000 Elsevier Science Ltd. Ail rights reserved. C1 CNRS, Lab Anal & Architecture Syst, F-31077 Toulouse 4, France. CNRS, Inst Elect & Microelect Nord, UMR 8520, F-59652 Villeneuve Dascq, France. USAF, Res Lab, Wright Patterson AFB, OH 45433 USA. RP Borgarino, M (reprint author), CNRS, Lab Anal & Architecture Syst, 7 Ave Colonel Roche, F-31077 Toulouse 4, France. RI Borgarino, Mattia/N-3540-2015 OI Borgarino, Mattia/0000-0001-9678-592X NR 13 TC 5 Z9 5 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0038-1101 J9 SOLID STATE ELECTRON JI Solid-State Electron. PD JAN PY 2000 VL 44 IS 1 BP 59 EP 62 DI 10.1016/S0038-1101(99)00246-4 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied; Physics, Condensed Matter SC Engineering; Physics GA 276QE UT WOS:000084888200008 ER PT B AU Fosness, E Peffer, A Denoyer, K AF Fosness, E Peffer, A Denoyer, K BE Johnson, SW Chua, KM Galloway, R Richter, P TI Overview of spacecraft deployment and release devices efforts at the Air Force Research Laboratory SO SPACE 2000, PROCEEDINGS LA English DT Proceedings Paper CT 7th International Conference and Exposition on Engineering, Construction, Operations, and Business in Space CY FEB 27-MAR 02, 2000 CL ALBUQUERQUE, NM SP Amer Soc Civil Engineers, Aerosp Div, Amer Astronaut Soc, NASA, SandiA Natl Labs, Natl Space Soc, Int Assoc Automat & Robot Construct, Univ New Mexico, Dept Civil Engn, Space Daily, Spacenews Com, Bechtel Grp, Fluor Global Serv AB The Air Force Research Laboratory-Space Vehicles Directorate (AFRL) has been actively developing low shock, non-pyrotechnic spacecraft release and deployment devices to mitigate problems with traditional pyrotechnic devices. Specifically, pyrotechnic devices produce high shock, contamination. and have costly handling requirements due to their hazardous nature. AFRL has provided funding to Lockheed Martin Astronautics and Starsys Research Corporation for development and test of several shape memory alloy (SMA) actuated release devices. Through both ground testing and on-orbit performance, these devices have been shown to reduce shock by at least an order of magnitude. while remaining comparable in size and mass to pyrotechnic devices. Flight heritage includes the U.S. Air Force MightySat I Shape Memory Alloy Release Device (SMARD) experiment that successfully tired and tested two SMA devices. A discussion of low-shock technology, current projects, and future potential is presented along with on-orbit test results. C1 USAF, Res Lab, Albuquerque, NM 87117 USA. RP Fosness, E (reprint author), USAF, Res Lab, AFRL-VS, Albuquerque, NM 87117 USA. NR 2 TC 1 Z9 1 U1 0 U2 0 PU AMER SOC CIVIL ENGINEERS PI NEW YORK PA UNITED ENGINEERING CENTER, 345 E 47TH ST, NEW YORK, NY 10017-2398 USA BN 0-7844-0479-8 PY 2000 BP 312 EP 318 PG 7 WC Engineering, Aerospace; Engineering, Civil SC Engineering GA BQ36D UT WOS:000088122100036 ER PT B AU Guerrero, J Fosness, ER Qassim, K AF Guerrero, J Fosness, ER Qassim, K BE Johnson, SW Chua, KM Galloway, R Richter, P TI Overview of multifunctional structure efforts at the Air Force Research Laboratory SO SPACE 2000, PROCEEDINGS LA English DT Proceedings Paper CT 7th International Conference and Exposition on Engineering, Construction, Operations, and Business in Space CY FEB 27-MAR 02, 2000 CL ALBUQUERQUE, NM SP Amer Soc Civil Engineers, Aerosp Div, Amer Astronaut Soc, NASA, SandiA Natl Labs, Natl Space Soc, Int Assoc Automat & Robot Construct, Univ New Mexico, Dept Civil Engn, Space Daily, Spacenews Com, Bechtel Grp, Fluor Global Serv AB Growing cost restrictions on advanced military, as well as commercial space systems demand greater efficiency in spacecraft subsystems to provide higher payload mass fractions. Spacecraft structures have typically been viewed as essential but unproductive components of satellites. Multifunctional structures (MFS) is a concept that incorporates various spacecraft functions (thermal management, electrical cabling, etc) onto the bus structure, thereby providing necessary weight and volume savings that enable next generation systems. This paper summarizes various MFS programs being developed at the Air Force Research Laboratory's (AFRL) Space Vehicles Directorate (VS), that could potentially revolutionize the efficiency of spacecraft structures. Developmental MFS efforts at the AFRL include the following technology areas: avionic subsystems that utlize High Density Interconnect (HDI) techniques to manufacture Multichip Modules (MCM), flexible interconnect design and fabrication, the replacement of conventional round wire cabling with embedded copper traces, smart array structures, lightweight flexible solar array development, thin film lithium battery development, composite radiation shielding materials and techniques, and more. These technologies have been and will be demonstrated on various spacecraft with eventual application to existing and future operational spacecraft systems. C1 USAF, Res Lab, Kirtland AFB, NM 87117 USA. RP Guerrero, J (reprint author), USAF, Res Lab, 3550 Aberdeen Ave SE, Kirtland AFB, NM 87117 USA. NR 2 TC 1 Z9 1 U1 1 U2 3 PU AMER SOC CIVIL ENGINEERS PI NEW YORK PA UNITED ENGINEERING CENTER, 345 E 47TH ST, NEW YORK, NY 10017-2398 USA BN 0-7844-0479-8 PY 2000 BP 319 EP 326 PG 8 WC Engineering, Aerospace; Engineering, Civil SC Engineering GA BQ36D UT WOS:000088122100037 ER PT B AU Kozola, B Maji, A Griffin, S AF Kozola, B Maji, A Griffin, S BE Johnson, SW Chua, KM Galloway, R Richter, P TI Design and thermal analysis of a composite mirror structure SO SPACE 2000, PROCEEDINGS LA English DT Proceedings Paper CT 7th International Conference and Exposition on Engineering, Construction, Operations, and Business in Space CY FEB 27-MAR 02, 2000 CL ALBUQUERQUE, NM SP Amer Soc Civil Engineers, Aerosp Div, Amer Astronaut Soc, NASA, SandiA Natl Labs, Natl Space Soc, Int Assoc Automat & Robot Construct, Univ New Mexico, Dept Civil Engn, Space Daily, Spacenews Com, Bechtel Grp, Fluor Global Serv AB The surrogate mirrors for the DOT (Deployable Optical Telescope) testbed were designed for structural stiffness, lightweight, and minimal thermal distortion. The primary structure consisted of a tripod made with pultruded composite rods connected to invar blocks, which carried the glass reflectors. A finite element model of the mirror was developed to study the tradeoffs in using different materials. Pultruded rods were produced at site and the Coefficient of Thermal Expansion (CTE) of the pultruded rods was measured with laser interferometry. C1 USAF, Res Lab, AFRL, VSDV, Albuquerque, NM USA. RP Kozola, B (reprint author), USAF, Res Lab, AFRL, VSDV, Albuquerque, NM USA. NR 2 TC 0 Z9 0 U1 0 U2 0 PU AMER SOC CIVIL ENGINEERS PI NEW YORK PA UNITED ENGINEERING CENTER, 345 E 47TH ST, NEW YORK, NY 10017-2398 USA BN 0-7844-0479-8 PY 2000 BP 336 EP 341 PG 6 WC Engineering, Aerospace; Engineering, Civil SC Engineering GA BQ36D UT WOS:000088122100039 ER PT B AU Khot, NS Bhungalia, AA Hartong, AR AF Khot, NS Bhungalia, AA Hartong, AR BE Johnson, SW Chua, KM Galloway, R Richter, P TI Deformation of a flexible structure using an actuating system for enhancing performance SO SPACE 2000, PROCEEDINGS LA English DT Proceedings Paper CT 7th International Conference and Exposition on Engineering, Construction, Operations, and Business in Space CY FEB 27-MAR 02, 2000 CL ALBUQUERQUE, NM SP Amer Soc Civil Engineers, Aerosp Div, Amer Astronaut Soc, NASA, SandiA Natl Labs, Natl Space Soc, Int Assoc Automat & Robot Construct, Univ New Mexico, Dept Civil Engn, Space Daily, Spacenews Com, Bechtel Grp, Fluor Global Serv AB A technique of deforming a flexible wing to achieve a specified roll rate at all dynamic pressures is examined. The flexible structure is obtained by using optimization approach. Rather than using an aileron system for roll, antisymmetric elastic twist and camber is determined to achieve the required rolling moment for a specified roll rate. The elastic twist and camber is achieved by providing a system of actuating elements distributed within the internal substructure of the wing to provide control forces. The modal approach is used to develop equilibrium equations for the steady roll maneuver of a wing subjected to aerodynamic loads and the actuating forces, The distribution of actuating forces to achieve specified flexible roll rate was determined by using an iterative procedure in conjunction with an optimal control design approach. Here, a full-scale realistic wing is considered for the assessment of strain energy as a measure of the necessary power required to produce the antisymmetric twist and camber deformation to achieve the required roll performance at different Mach numbers. C1 USAF, Res Lab, Air Vehicle Directorate, Struct Div, Wright Patterson AFB, OH 45433 USA. RP Khot, NS (reprint author), USAF, Res Lab, Air Vehicle Directorate, Struct Div, Wright Patterson AFB, OH 45433 USA. NR 3 TC 0 Z9 0 U1 1 U2 1 PU AMER SOC CIVIL ENGINEERS PI NEW YORK PA UNITED ENGINEERING CENTER, 345 E 47TH ST, NEW YORK, NY 10017-2398 USA BN 0-7844-0479-8 PY 2000 BP 384 EP 390 PG 7 WC Engineering, Aerospace; Engineering, Civil SC Engineering GA BQ36D UT WOS:000088122100046 ER PT B AU Snead, JM AF Snead, JM BE Johnson, SW Chua, KM Galloway, R Richter, P TI The astral highway: A national space infrastructure SO SPACE 2000, PROCEEDINGS LA English DT Proceedings Paper CT 7th International Conference and Exposition on Engineering, Construction, Operations, and Business in Space CY FEB 27-MAR 02, 2000 CL ALBUQUERQUE, NM SP Amer Soc Civil Engineers, Aerosp Div, Amer Astronaut Soc, NASA, SandiA Natl Labs, Natl Space Soc, Int Assoc Automat & Robot Construct, Univ New Mexico, Dept Civil Engn, Space Daily, Spacenews Com, Bechtel Grp, Fluor Global Serv AB This paper discusses the need for a national space transportation and in-space logistical support infrastructure. It proposes that this space infrastructure be built through a partnership of the Government and private industry. A scenario and schedule for developing this infrastructure and suggested technical approaches for building its primary elements are described. C1 USAF, Res Lab, Wright Patterson AFB, OH 45433 USA. RP Snead, JM (reprint author), USAF, Res Lab, Wright Patterson AFB, OH 45433 USA. NR 5 TC 0 Z9 0 U1 0 U2 0 PU AMER SOC CIVIL ENGINEERS PI NEW YORK PA UNITED ENGINEERING CENTER, 345 E 47TH ST, NEW YORK, NY 10017-2398 USA BN 0-7844-0479-8 PY 2000 BP 537 EP 548 PG 12 WC Engineering, Aerospace; Engineering, Civil SC Engineering GA BQ36D UT WOS:000088122100065 ER PT J AU Shea, MA Smart, DF AF Shea, MA Smart, DF TI Cosmic ray implications for human health SO SPACE SCIENCE REVIEWS LA English DT Review ID INTERPLANETARY SPACE; AIRCRAFT ALTITUDES; PROTON EVENTS; SOLAR; RADIATION; ENVIRONMENT; PARTICLES; MODEL AB There appears to be concern among some people about the possible effects of cosmic radiation on everyday life. The amount of cosmic radiation that reaches the Earth and its environment is a function of solar cycle, altitude and latitude. The possible effect of naturally occurring cosmic radiation on airplane crews and space flight personal is a subject of current study. This paper discusses the variables controlling the cosmic ray flux in the atmosphere and describes models and software that have been developed that provide quantitative information about the cosmic radiation exposure at flight altitudes. The discussion is extended to include the cosmic radiation exposure to manned spacecraft. C1 USAF, Res Lab, VSBS, Hanscom AFB, Bedford, MA 01731 USA. RP USAF, Res Lab, VSBS, Hanscom AFB, 29 Randolph Rd, Bedford, MA 01731 USA. EM sssrc@email.msn.com NR 48 TC 18 Z9 18 U1 0 U2 2 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0038-6308 EI 1572-9672 J9 SPACE SCI REV JI Space Sci. Rev. PY 2000 VL 93 IS 1-2 BP 187 EP 205 DI 10.1023/A:1026544528473 PG 19 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 376YD UT WOS:000165484100011 ER PT J AU Shea, MA Smart, DF AF Shea, MA Smart, DF TI Fifty years of cosmic radiation data SO SPACE SCIENCE REVIEWS LA English DT Review AB Cosmic radiation has been measured by a variety of techniques since 1933. This paper presents the evolution of data acquisition, processing, and availability of cosmic radiation data from the early years to the present time. Information on the worldwide network of neutron monitor stations and the availability of these cosmic radiation records is included. C1 USAF, Res Lab, VSBS, Hanscom AFB, Bedford, MA 01731 USA. RP USAF, Res Lab, VSBS, Hanscom AFB, 29 Randolph Rd, Bedford, MA 01731 USA. EM sssrc@email.msn.com NR 30 TC 29 Z9 29 U1 0 U2 1 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0038-6308 EI 1572-9672 J9 SPACE SCI REV JI Space Sci. Rev. PY 2000 VL 93 IS 1-2 BP 229 EP 262 DI 10.1023/A:1026500713452 PG 34 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 376YD UT WOS:000165484100013 ER PT J AU Smart, DF Shea, MA Fluckiger, EO AF Smart, DF Shea, MA Fluckiger, EO TI Magnetospheric models and trajectory computations SO SPACE SCIENCE REVIEWS LA English DT Review ID VERTICAL CUTOFF RIGIDITIES; MAGNETIC-FIELD; GEOMAGNETIC-FIELD; COSMIC-RAYS; ISOTOPIC COMPOSITION; SOLAR PARTICLES; CHARGE-STATE; POLAR CAPS; PROTONS; RADIATION AB The calculation of particle trajectories in the Earth's magnetic field has been a subject of interest since the time of Stormer. The fundamental problem is that the trajectory-tracing process involves using mathematical equations that have `no solution in closed form'. This difficulty has forced researchers to use the `brute force' technique of numerical integration of many individual trajectories to ascertain the behavior of trajectory families or groups. As the power of computers has improved over the decades, the numerical integration procedure has grown more tractable and while the problem is still formidable, thousands of trajectories can be computed without the expenditure of excessive resources. As particle trajectories are computed and the characteristics analyzed we can determine the cutoff rigidity of a specific location and viewing direction and direction and deduce the direction in space of various cosmic ray anisotropies. Unfortunately, cutoff rigidities are not simple parameters due to the chaotic behavior of the cosmic-ray trajectories in the cosmic ray penumbral region. As the computational problem becomes more manageable, there is still the issue of the accuracy of the magnetic field models. Over the decades, magnetic field models of increasing complexity have been developed and utilized. The accuracy of trajectory calculations employing contemporary magnetic field models is sufficient that cosmic ray experiments can be designed on the basis of trajectory calculations. However, the Earth's magnetosphere is dynamic and the most widely used magnetospheric models currently available are static. This means that the greatest uncertainly in the application of charged particle trajectories occurs at low energies. C1 USAF, Res Lab, VSBS, Space Vehicles Directorate, Bedford, MA 01731 USA. Univ Bern, Inst Phys, CH-3012 Bern, Switzerland. RP USAF, Res Lab, VSBS, Space Vehicles Directorate, 29 Randolph Rd, Bedford, MA 01731 USA. EM sssrc@mail.msn.com NR 93 TC 87 Z9 87 U1 0 U2 1 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0038-6308 EI 1572-9672 J9 SPACE SCI REV JI Space Sci. Rev. PY 2000 VL 93 IS 1-2 BP 305 EP 333 DI 10.1023/A:1026556831199 PG 29 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 376YD UT WOS:000165484100016 ER PT S AU Wilkinson, DC Shea, MA Smart, DF AF Wilkinson, DC Shea, MA Smart, DF BE Rostoker, G TI A case history of solar and galactic space weather effects on the geosynchronous communications satellite TDRS-1 SO SPACE WEATHER: PHYSICS AND APPLICATIONS SE ADVANCES IN SPACE RESEARCH LA English DT Article; Proceedings Paper CT D0 5 Symposium of COSPAR Scientific Commission D Held at the 32nd COSPAR Scientific Assembly CY JUL 12-19, 1998 CL NAGOYA, JAPAN SP Comm Space Res, Sci Comm Solar Terr Phys, Int Union Geodesy & Geophys, Int Assoc Geomagnetism & Aeron ID UPSETS AB Energetic particles of both galactic and solar origin have the potential to cause state changes in memory devices used on-board spacecraft. The particular memory device used in the attitude control system of the Tracking and Data Relay System (TDRS-1) lends itself to the study of this phenomena due to its high susceptibility to such upsets. An eight-year record of TDRS-1 on-orbit upsets reflect the solar cycle variation in galactic radiation as well as radiation enhancements due to solar events. The proton and alpha particle data from the GOES space environment monitor are used to illustrate the radiation environment responsible for these upsets. (C) 2000 COSPAR. Published by Elsevier Science Ltd. C1 NOAA, Natl Geophys Data Ctr, Boulder, CO 80303 USA. USAF, Res Lab, VSBS, Bedford, MA 01731 USA. RP Wilkinson, DC (reprint author), NOAA, Natl Geophys Data Ctr, 325 Broadway, Boulder, CO 80303 USA. NR 5 TC 3 Z9 3 U1 0 U2 1 PU PERGAMON PRESS LTD PI OXFORD PA THE BOULEVARD LANGFORD LANE KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0273-1177 J9 ADV SPACE RES PY 2000 VL 26 IS 1 BP 27 EP 30 DI 10.1016/S0273-1177(99)01022-4 PG 4 WC Astronomy & Astrophysics; Meteorology & Atmospheric Sciences SC Astronomy & Astrophysics; Meteorology & Atmospheric Sciences GA BP89M UT WOS:000086534000004 ER PT S AU Yokoyama, N Kamide, Y Cliver, EW AF Yokoyama, N Kamide, Y Cliver, EW BE Rostoker, G TI Energy injection rate of the ring current estimated from Dst SO SPACE WEATHER: PHYSICS AND APPLICATIONS SE ADVANCES IN SPACE RESEARCH LA English DT Article; Proceedings Paper CT D0 5 Symposium of COSPAR Scientific Commission D Held at the 32nd COSPAR Scientific Assembly CY JUL 12-19, 1998 CL NAGOYA, JAPAN SP Comm Space Res, Sci Comm Solar Terr Phys, Int Union Geodesy & Geophys, Int Assoc Geomagnetism & Aeron ID GEOMAGNETIC STORMS AB We have estimated the energy injection rate for geomagnetic storms from the hourly Dst variation and an assumed decay constant for the ring current. It is found that intense storms do not require both long and strong energy injections to the ring current. Intense short-lived injections as well as weaker energy inputs of longer duration can produce storms of equal magnitude for any given Dst size range. (C) 2000 COSPAR. Published by Elsevier Science Ltd. C1 Natl Space Dev Agcy Japan, Tsukuba, Ibaraki 3058505, Japan. Nagoya Univ, Solar Terr Environm Lab, Toyokawa 4428507, Japan. USAF, Res Lab, Hanscom AFB, MA 01731 USA. RP Yokoyama, N (reprint author), Natl Space Dev Agcy Japan, Tsukuba, Ibaraki 3058505, Japan. NR 8 TC 0 Z9 0 U1 0 U2 0 PU PERGAMON PRESS LTD PI OXFORD PA THE BOULEVARD LANGFORD LANE KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0273-1177 J9 ADV SPACE RES PY 2000 VL 26 IS 1 BP 107 EP 110 DI 10.1016/S0273-1177(99)01034-0 PG 4 WC Astronomy & Astrophysics; Meteorology & Atmospheric Sciences SC Astronomy & Astrophysics; Meteorology & Atmospheric Sciences GA BP89M UT WOS:000086534000016 ER PT S AU Owens, JK Niehuss, KO Vaughan, WW Shea, MA AF Owens, JK Niehuss, KO Vaughan, WW Shea, MA BE Rostoker, G TI NASA Marshall engineering thermosphere model - 1999 version (MET-99) and implications for satellite lifetime predictions SO SPACE WEATHER: PHYSICS AND APPLICATIONS SE ADVANCES IN SPACE RESEARCH-SERIES LA English DT Review CT D0 5 Symposium of COSPAR Scientific Commission D Held at the 32nd COSPAR Scientific Assembly CY JUL 12-19, 1998 CL NAGOYA, JAPAN SP Comm Space Res, Sci Comm Solar Terr Phys, Int Union Geodesy & Geophys, Int Assoc Geomagnetism & Aeron AB The use of thermospheric density models in the prediction of atmospheric drag (the major perturbation for orbiting spacecraft) is of great importance. Issues associated with these predictions include lifetime estimates, orbit determination and tracking, attitude dynamics, and re-entry prediction. Logistics planning through attitude control requirements and re-boost planning are also influenced by future orbital altitude density estimates. The MET-99 model and its predecessors were developed to provide the inputs needed to address these issues. The sensitivity of the future estimation of solar activity, and thus thermospheric density and the prediction of a satellite's lifetime, to the selection of Solar Cycle 23 minimum other than the conventionally identified mathematical minimum is shown. This can produce about 25 percent error in predicted satellite lifetime for a typical low Earth orbit example. (C) 2000 COSPAR. Published by Elsevier Science Ltd. C1 NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. Univ Alabama, Huntsville, AL 35899 USA. USAF, Res Lab, Bedford, MA 01731 USA. RP Owens, JK (reprint author), NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. NR 10 TC 6 Z9 6 U1 0 U2 0 PU PERGAMON PRESS LTD PI OXFORD PA THE BOULEVARD LANGFORD LANE KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0273-1177 J9 ADV SPACE RES-SERIES PY 2000 VL 26 IS 1 BP 157 EP 162 DI 10.1016/S0273-1177(99)01042-X PG 6 WC Astronomy & Astrophysics; Meteorology & Atmospheric Sciences SC Astronomy & Astrophysics; Meteorology & Atmospheric Sciences GA BP89M UT WOS:000086534000024 ER PT S AU McLaughlin, CA Carter, S AF McLaughlin, CA Carter, S BE Kluever, CA Neta, B Hall, CD Hanson, JM TI Attitude maneuvers for MightySat II.1 hyperspectral data collects SO SPACEFLIGHT MECHANICS 2000, VOL 105, PTS I AND II SE ADVANCES IN THE ASTRONAUTICAL SCIENCES LA English DT Proceedings Paper CT AAS/AIAA 10th Space Flight Mechanics Meeting CY JAN 23-26, 2000 CL CLEARWATER, FL SP Amer Astronaut Soc, Amer Inst Aeronaut & Astronaut ID IMAGER; PERFORMANCE AB The characteristics of the Fourier Transform Hyperspectral Imager on MightySat II.1 have a significant effect on the attitude maneuvers required for data collection. In order to obtain the desired image characteristics for a given group of instrument settings the velocity of the swath across the ground must be precisely maintained. This requires the spacecraft to maneuver constantly during the data collection This paper examines the design of the attitude maneuver and how the different instrument settings affect the required attitude maneuver. The image characteristics for the different instrument settings are also examined. C1 USAF, Res Lab, Space Vehicles Directorate, Kirtland AFB, NM 87117 USA. RP McLaughlin, CA (reprint author), USAF, Res Lab, Space Vehicles Directorate, 3550 Aberdeen Ave SE, Kirtland AFB, NM 87117 USA. NR 15 TC 0 Z9 0 U1 0 U2 0 PU UNIVELT INC PI SAN DIEGO PA PO BOX 28130, SAN DIEGO, CA 92128 USA SN 1081-6003 BN 0-87703-470-2 J9 ADV ASTRONAUT SCI PY 2000 VL 105 BP 703 EP 722 PN 1&2 PG 20 WC Engineering, Aerospace SC Engineering GA BQ99H UT WOS:000165304900043 ER PT S AU McKay, BE Dahlke, SR AF McKay, BE Dahlke, SR BE Kluever, CA Neta, B Hall, CD Hanson, JM TI Optimal trajectories for secondary payloads from geosynchronous transfer orbits to the moon SO SPACEFLIGHT MECHANICS 2000, VOL 105, PTS I AND II SE ADVANCES IN THE ASTRONAUTICAL SCIENCES LA English DT Proceedings Paper CT AAS/AIAA 10th Space Flight Mechanics Meeting CY JAN 23-26, 2000 CL CLEARWATER, FL SP Amer Astronaut Soc, Amer Inst Aeronaut & Astronaut AB Trajectories that provide fuel efficient transfers from Geosynchronous Transfer Orbits (GTO) to the Moon are examined in this paper. These trajectories are becoming more important as relatively inexpensive launch options to GTO are now available by launching as a secondary payload. The main focus of this research is to explore possibilities for reaching lunar orbit via methods other than launching directly into the lunar orbit plane or waiting in a parking orbit for orbit perturbations to create favorable transfer conditions. Through the use of carefully chosen bi-elliptic type transfers or transfer orbits with optimally placed plane changes, this research shows that relatively efficient transfers to the Moon can be obtained from GTO. C1 USAF Acad, Dept Astronaut, Colorado Springs, CO 80840 USA. RP McKay, BE (reprint author), USAF Acad, Dept Astronaut, Colorado Springs, CO 80840 USA. NR 8 TC 0 Z9 0 U1 0 U2 1 PU UNIVELT INC PI SAN DIEGO PA PO BOX 28130, SAN DIEGO, CA 92128 USA SN 1081-6003 BN 0-87703-470-2 J9 ADV ASTRONAUT SCI PY 2000 VL 105 BP 1141 EP 1158 PN 1&2 PG 18 WC Engineering, Aerospace SC Engineering GA BQ99H UT WOS:000165304900069 ER PT S AU Granholm, GR Proulx, RJ Cefola, PJ Nazarenko, AI Yurasov, V AF Granholm, GR Proulx, RJ Cefola, PJ Nazarenko, AI Yurasov, V BE Kluever, CA Neta, B Hall, CD Hanson, JM TI Near-real time atmospheric density correction using NAVSPASUR Fence observations SO SPACEFLIGHT MECHANICS 2000, VOL 105, PTS I AND II SE ADVANCES IN THE ASTRONAUTICAL SCIENCES LA English DT Proceedings Paper CT AAS/AIAA 10th Space Flight Mechanics Meeting CY JAN 23-26, 2000 CL CLEARWATER, FL SP Amer Astronaut Soc, Amer Inst Aeronaut & Astronaut AB Mismodeled drag effects are one of the most significant sources of error for low-altitude and highly eccentric orbits. It is currently estimated that predicted densities can differ by as much as 30% from real world conditions even using the best exosphere/thermosphere models (such as MSISE-90 or Jacchia-Roberts '71)(1). However, we can use observations from frequently tracked objects in the space catalog to provide an "atmosphere correction service" to users desiring more precise orbit determination for a given target orbit. Observations will be in the form of direction cosines from the NAVSPASUR Fence, a multi-static radar system deployed across the southern United States. Using high-precision special perturbation techniques, orbital elements and ballistic factors will be estimated for 200-300 space objects with perigee heights distributed between 200 and 600 km. The difference between the locally estimated ballistic factor and the time-averaged or "true" ballistic factor can be taken as a measurement of the difference between the modeled and true atmospheric densities. These density variation measurements are used to construct a time and altitude-dependent density correction model. The model coefficients can be treated as samples of a stochastic process and predicted using linear stochastic filtering methods. A thorough mathematical description of density variation estimation, forecasting algorithms, and the NAVSPASUR Fence is presented, along with a detailed outline of operational considerations for an atmosphere correction service. C1 USAF, Cambridge, MA 02139 USA. RP Granholm, GR (reprint author), USAF, 555 Technol Sq, Cambridge, MA 02139 USA. NR 13 TC 0 Z9 0 U1 1 U2 1 PU UNIVELT INC PI SAN DIEGO PA PO BOX 28130, SAN DIEGO, CA 92128 USA SN 1081-6003 BN 0-87703-470-2 J9 ADV ASTRONAUT SCI PY 2000 VL 105 BP 1219 EP 1234 PN 1&2 PG 16 WC Engineering, Aerospace SC Engineering GA BQ99H UT WOS:000165304900073 ER PT B AU Spottswood, SM Wolfe, HF Brown, DL AF Spottswood, SM Wolfe, HF Brown, DL BE Ferguson, NS Wolfe, HF Ferman, MA Rizzi, SA TI The effects of record length on determining the cumulative damage of a ceramic matrix composite beam SO STRUCTURAL DYNAMICS: RECENT ADVANCES, VOLS 1 & 2, PROCEEDINGS LA English DT Proceedings Paper CT 7th International Conference on Recent Advances in Structural Dynamics CY JUL 24-27, 2000 CL UNIV SOUTHAMPTON, INST SOUND & VIBRAT RES, SOUTHAMPTON, ENGLAND SP USAF, European Off Aerosp Res & Dev, UASF, Res Lab, Wright Patterson AFB, Parks Coll,Engn & Aviat, St Louis Univ, NASA, Langley Res Ctr, Struct Acoust Branch HO UNIV SOUTHAMPTON, INST SOUND & VIBRAT RES AB The effect of record length on the calculated fatigue life was determined for ceramic matrix composite (CMC) Blackglas(TM) beams. The root mean square (RMS) strain and peak probability density functions (PPDFs) are critical variables in the estimation of fatigue life. Therefore, accurate estimation of fatigue life requires the convergence of the previously mentioned variables. In this analysis, the statistical moments, including the mean, variance, skewness and kurtosis for the input/output signals of various time segments of a 70-minute time history were determined. The time history was divided into cumulative segments, allowing the properties to reach convergence as the duration of the respective cumulative record increased. Results indicate convergence of the RMS values for both the input and output signals was achieved within the first 60 seconds. In addition, PPDFs for the same cumulative data segments were determined for the input and output signals. Results indicate convergence of the PPDFs within the first 60 seconds. Fatigue life calculations and cumulative damage plots also indicate convergence in approximately 60 seconds. Fatigue life and cumulative damage comparisons made with a modified Rayleigh distribution, yielded significantly more conservative results. C1 USAF, Flight Dynam Directorate, Struct Div, Res Lab, Wright Patterson AFB, OH 45433 USA. RP Spottswood, SM (reprint author), USAF, Flight Dynam Directorate, Struct Div, Res Lab, 2145 5th St Ste 2, Wright Patterson AFB, OH 45433 USA. NR 13 TC 1 Z9 1 U1 0 U2 0 PU INST SOUND VIBRATION RESEARCH PI SOUTHAMPTON PA THE UNIVERSITY, SOUTHAMPTON S09 5NH, ENGLAND BN 0-85432-721-5 PY 2000 BP 785 EP 799 PG 15 WC Engineering, Mechanical; Mechanics SC Engineering; Mechanics GA BR55R UT WOS:000166796300059 ER PT B AU Lee, J AF Lee, J BE Ferguson, NS Wolfe, HF Ferman, MA Rizzi, SA TI Effects of temperature dependent physical properties on the response of thermally buckled plates SO STRUCTURAL DYNAMICS: RECENT ADVANCES, VOLS 1 & 2, PROCEEDINGS LA English DT Proceedings Paper CT 7th International Conference on Recent Advances in Structural Dynamics CY JUL 24-27, 2000 CL UNIV SOUTHAMPTON, INST SOUND & VIBRAT RES, SOUTHAMPTON, ENGLAND SP USAF, European Off Aerosp Res & Dev, UASF, Res Lab, Wright Patterson AFB, Parks Coll,Engn & Aviat, St Louis Univ, NASA, Langley Res Ctr, Struct Acoust Branch HO UNIV SOUTHAMPTON, INST SOUND & VIBRAT RES ID BEHAVIOR AB Under plate heating by a uniform temperature rise above the ambient temperature, we have obtained simple analytical expressions of static single-mode analysis to include the temperature-dependent physical properties. The critical bucking temperature is lowered but the post-buckled plate displacement is raised as the plate temperature increases. This qualitatively confirms the numerical computations of previous investigators. We have further found that the temperature-dependent properties decrease the static normal x-stress and increase the static x-strain based on the post-buckled plate displacements. Surprisingly, when we formulate a single-mode stochastic dynamics, the RMS x-stress and x-strain are also decreased and increased by the temperature-dependent physical properties. More than that, the percent decreases in static and RMS x-stress are nearly the same, so are the percent increases in static and RMS x-strain. C1 USAF, Res Lab, VASS, Wright Patterson AFB, OH 45433 USA. RP Lee, J (reprint author), USAF, Res Lab, VASS, Wright Patterson AFB, OH 45433 USA. NR 20 TC 0 Z9 0 U1 0 U2 0 PU INST SOUND VIBRATION RESEARCH PI SOUTHAMPTON PA THE UNIVERSITY, SOUTHAMPTON S09 5NH, ENGLAND BN 0-85432-721-5 PY 2000 BP 847 EP 862 PG 16 WC Engineering, Mechanical; Mechanics SC Engineering; Mechanics GA BR55R UT WOS:000166796300063 ER PT S AU Lombard, CM Ghosh, AK Semiatin, SL AF Lombard, CM Ghosh, AK Semiatin, SL BE Berbon, PB Berbon, MZ Sakuma, T Langdon, TG TI Analysis of cavitation in a near-gamma titanium aluminide during high temperature/superplastic deformation SO SUPERPLASTICITY-CURRENT STATUS AND FUTURE POTENTIAL SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT Symposium on Superplasticity-Current Status and Future Potential held at the 1999 MRS Fall Meeting CY NOV 29-DEC 01, 1999 CL BOSTON, MA SP Mat Res Soc, USA, Off Res, Lawrence Livermore Natl Lab ID CAVITY GROWTH; ALLOYS AB The superplastic flow behavior of a near-gamma titanium aluminide (Ti-45.5Al-2Cr-2Nb) is determined under uniaxial tension in as-rolled or rolled-and-heat treated conditions (1177 degrees C/4 hr or 1238 degrees C/2 hr). Cavitation characteristics, including cavity growth rates, are established via isothermal, constant strain rate tests conducted at 10(-4) to 10(-2) s(-1) and temperatures between 900 degrees C and 1200 degrees C. Differences in cavitation as a function of initial structure, strain, strain rate and temperature are noted. Cavity growth is found to be largely plasticity controlled. Experimental growth rates are compared with equations that predict rates as a function of strain rate sensitivity. Although the equations assume no coalescence and no nucleation of new cavities, which are experimentally observed, they are useful in predicting actual growth rates. C1 USAF, Res Lab, Mat & Mfg Directorate, AFRL,MLLM, Wright Patterson AFB, OH 45433 USA. RP Lombard, CM (reprint author), USAF, Res Lab, Mat & Mfg Directorate, AFRL,MLLM, Wright Patterson AFB, OH 45433 USA. RI SEMIATIN, SHELDON/E-7264-2017 NR 15 TC 0 Z9 0 U1 0 U2 0 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 USA SN 0272-9172 BN 1-55899-509-9 J9 MATER RES SOC SYMP P PY 2000 VL 601 BP 73 EP 78 PG 6 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA BQ35C UT WOS:000088094300011 ER PT S AU Sanderson, RB Baxley, FO Montgomery, JB AF Sanderson, RB Baxley, FO Montgomery, JB BE Watkins, WR Clement, D Reynolds, WR TI Correlated two color mid-infrared background characteristics SO TARGETS AND BACKGROUNDS VI: CHARACTERIZATION, VISUALIZATION, AND THE DETECTION PROCESS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Targets and Backgrounds VI: Characterization, Visualization, and the Detection Process CY APR 24-26, 2000 CL ORLANDO, FL SP SPIE DE infrared sensors; backgrounds; target detection AB Multicolor discrimination techniques provide a useful approach to suppressing background clutter and reducing false alarm rates in warning sensors. To assess discrimination performance, it is necessary to understand the statistics of each band as well as inter-band correlations. This paper describes background measurements from an airborne platform collected using a two-color prototype staring missile-warning sensor. The sensor is a commercial 256x256 InSb camera with filter wheel integrated into a 90 deg. x 90 deg. optic. The two colors lie in the carbon dioxide red spike region and in the window region below 4 micrometers. These bands are useful for detecting the combustion of hydrocarbons in the presence of background clutter. The sensor looks straight down from the aircraft and data is collected at frame rates from 10 to 100 Hz. Extensive background data has been collected over a wide range of scenes representing industrial, urban, rural, mountainous, and shoreline terrain The data has been analyzed to provide correlated statistics of these spectral bands for both the underlying background structure and discrete false alarm sources This data provides a basis for estimating the performance of spectral discrimination and optimizing processing algorithms for the suppression of clutter and rejection of false alarms. C1 USAF, Res Lab, SNJW, Wright Patterson AFB, OH 45433 USA. RP Sanderson, RB (reprint author), USAF, Res Lab, SNJW, Wright Patterson AFB, OH 45433 USA. NR 3 TC 0 Z9 0 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-3655-0 J9 P SOC PHOTO-OPT INS PY 2000 VL 4029 BP 102 EP 109 DI 10.1117/12.392517 PG 8 WC Optics; Imaging Science & Photographic Technology SC Optics; Imaging Science & Photographic Technology GA BR65Y UT WOS:000167102500012 ER PT S AU Lowry, HS Holt, LL Dalbey, RZ Tonucci, RJ AF Lowry, HS Holt, LL Dalbey, RZ Tonucci, RJ BE Watkins, WR Clement, D Reynolds, WR TI Temporal measurements and scene projection testing of NAWC's fiber array projector using AEDC's laser-based direct write scene generator SO TARGETS AND BACKGROUNDS VI: CHARACTERIZATION, VISUALIZATION, AND THE DETECTION PROCESS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Targets and Backgrounds VI: Characterization, Visualization, and the Detection Process CY APR 24-26, 2000 CL ORLANDO, FL SP SPIE DE acousto-optic; scene projection; infrared; radiometric; fiber-optic arrays; crosstalk AB The operation of the Direct Write Scene Generator (DWSG) at the Arnold Engineering Development Center (AEDC) to drive a fiber array projection system is reported. The fiber array absorbs the input radiation from the laser-based system and produces broadband infrared output through blackbody cavities fabricated on the ends of the optical fibers. A test program was accomplished to quantify the performance of the fiber array with respect to input laser power and optical pulse width. Static and dynamic scenes were also projected with the device and recorded with an IR camera system. This paper presents the results of this work. C1 Sverdrup Technol Inc, AEDC Grp, Arnold AFB, TN USA. RP Lowry, HS (reprint author), Sverdrup Technol Inc, AEDC Grp, Arnold AFB, TN USA. NR 5 TC 0 Z9 0 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-3655-0 J9 P SOC PHOTO-OPT INS PY 2000 VL 4029 BP 267 EP 277 DI 10.1117/12.392534 PG 11 WC Optics; Imaging Science & Photographic Technology SC Optics; Imaging Science & Photographic Technology GA BR65Y UT WOS:000167102500029 ER PT B AU Dunn, SC AF Dunn, SC GP ASEM ASEM TI An empirical study of motivational aspects pertaining to project and functional management in matrix organizations SO TECHNICAL MANAGEMENT: KEY TO ENTERPRISE SUCCESS IN THE 21ST CENTURY LA English DT Proceedings Paper CT 21st National Conference of the American-Society-for-Engineering-Management CY OCT 04-07, 2000 CL GEORGE WASHINGTON UNIV, WASHINGTON, D.C. SP Amer Soc Engn Management HO GEORGE WASHINGTON UNIV ID JOB-SATISFACTION; META-ANALYSIS; PERFORMANCE AB The project form of work delivery is widely used for a variety of applications, growing from roots in the large weapon and space systems projects of the 1950's and 60's. The matrix structure was developed as a means to integrate project delivery into existing functional/line type organizations and it continues to be used in many forms by contemporary organizations. Project teams in a matrix structure are assembled by collecting individuals from supporting organizations with specific skills required for that project-thus, their management guidance comes typically from one functional manager and one or more project managers. Historically, the functional manager has been identified with the oversight and well being of the employee while the project manager is focused on project deliverables. Very little empirical research has been accomplished that examines the behavioral aspects of this multiple manager form as it pertains to project team members. This paper documents a study of 222 individuals from 18 matrix-type organizations that examines who provides influence or control for factors that result in job satisfaction or job dissatisfaction. Factors developed by Frederick Herzberg were used in the study, with an examination of factor groupings Herzberg terms hygiene (or maintenance) factors and motivators. This study provides empirical evidence that project managers bear a significant responsibility for the well-being of the project team members, in that functional managers have control or influence the hygiene factors while project managers have significant control or influence the motivator factors. C1 Sverdrup Technol Inc, AEDC Grp, Arnold AFB, TN 37389 USA. NR 22 TC 0 Z9 0 U1 1 U2 4 PU AMER SOC ENGINEERING MANAGEMT PI ROLLA PA 310 HARRIS HALL, UMR, ROLLA, MO 65401 USA PY 2000 BP 510 EP 518 PG 9 WC Engineering, Multidisciplinary; Management SC Engineering; Business & Economics GA BY20J UT WOS:000188242100068 ER PT S AU Grote, JG Drummond, JP Zetts, JS Nelson, RL Hopkins, FK Zhang, C Dalton, LR Steier, WH AF Grote, JG Drummond, JP Zetts, JS Nelson, RL Hopkins, FK Zhang, C Dalton, LR Steier, WH BE Nashimoto, K Pachter, R Wessels, BW Shmulovich, J Jen, AKY Lewis, K Sutherland, R Perry, JW TI Enhanced electrooptic activity of NLO polymers via the use of conductive polymers SO THIN FILMS FOR OPTICAL WAVEGUIDE DEVICES AND MATERIALS FOR OPTICAL LIMITING SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT Symposium Z on Thin Films for Optical Waveguide Devices/Symposium PP on Materials for Optical Limiting III held at the 1999 MRS Fall Meeting CY NOV 30-DEC 03, 1999 CL BOSTON, MA SP Mat Res Soc, Fuji Xerox Co Ltd, Shinkosha Co Ltd, USAF, Res Lab, Def Res Agcy ID CHROMOPHORES; OPTICS; DEVICE AB We have demonstrated a 3 to 13 times increase in the effective electro-optic (EO) coefficient of electrode poled nonlinear optical polymers using a conductive polymer cladding, compared to using passive polymer claddings. We have also demonstrated the lowest poling voltage to date, 300 V, for a 2 mum thick NLO polymer film. Since the cladding material is more conductive than the core material, the majority of the applied poling voltage is dropped across the core, realizing a higher EO coefficient than for conventional devices using passive polymer claddings and has the potential for in-situ poling. These results show promise for shorter, lower operating voltage devices. C1 USAF, Res Lab, Mat & Mfg Directorate, MLPO, Wright Patterson AFB, OH 45433 USA. RP Grote, JG (reprint author), USAF, Res Lab, Mat & Mfg Directorate, MLPO, Wright Patterson AFB, OH 45433 USA. OI Zhang, Cheng/0000-0001-8206-5171 NR 17 TC 5 Z9 5 U1 0 U2 0 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 USA SN 0272-9172 BN 1-55899-505-6 J9 MATER RES SOC SYMP P PY 2000 VL 597 BP 109 EP 115 PG 7 WC Materials Science, Multidisciplinary; Optics SC Materials Science; Optics GA BR05D UT WOS:000165506500016 ER PT S AU Becker, RJ AF Becker, RJ BE Nashimoto, K Pachter, R Wessels, BW Shmulovich, J Jen, AKY Lewis, K Sutherland, R Perry, JW TI Maximum cross sections for excited state and two-photon absorption SO THIN FILMS FOR OPTICAL WAVEGUIDE DEVICES AND MATERIALS FOR OPTICAL LIMITING SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT Symposium Z on Thin Films for Optical Waveguide Devices/Symposium PP on Materials for Optical Limiting III held at the 1999 MRS Fall Meeting CY NOV 30-DEC 03, 1999 CL BOSTON, MA SP Mat Res Soc, Fuji Xerox Co Ltd, Shinkosha Co Ltd, USAF, Res Lab, Def Res Agcy AB There is a maximum value for any nonlinear process, which can be found on the basis of fundamental quantum mechanics. With regard to single photon processes, there is a maximum absorption cross section, sigma (a), which any molecule may reach. The maximum is 1.13 x 10(-17) lambdaQ/n cm(2), where lambda is the wavelength of the light, n is the refractive index of the host medium, and Q is the quality factor ascribed to the absorption line width. Thus large cross sections can only be obtained at the expense of a narrow operating range. The maximum is set by fundamental physics. Since nonlinear phenomena are highly resonant, the maxima of higher-order processes are also a strong function of the width of the resonance and the peak wavelength. In the case of two-photon absorption the peak value of the maximum cross section, sigma (2N) or delta, is roughly 3.5 x 10(-32) lambda (4)nQ cm(4)/GW, or about 7 x 10(-57)lambda (3)nQ cm(4)/photon. No value for a nonlinear coefficient is meaningful in the absence of the width of the resonance, the wavelength, and the refractive index of the medium at the wavelength of the measurement. The basic quantity of interest is the linear electronic polarizability. This fundamental quantity determines not only the absorption for the various processes of interest, but also the surface tension and the closely related solubility parameter. All scale with the polarizability alpha. The polarizability has a maximum value of e(2)/m omega (2); consequently the absorption cross sections have a corresponding ceiling. The maximum value for the peak in a resonant polarizability curve is set by a balance between the Coulomb potential energy of the electron and its kinetic energy. Hence it is an inherent property of the electron itself, irrespective of the molecular orbital in which it finds itself. All that the particular quantum configuration of the molecule does is partition the line strength for absorption among various possible transitions. The extreme case is when virtually all the strength is concentrated in a single transition, an inherently resonant condition. C1 USAF, Res Lab, Mat & Mfg Directorate, Wright Patterson AFB, OH 45433 USA. RP Becker, RJ (reprint author), USAF, Res Lab, Mat & Mfg Directorate, Wright Patterson AFB, OH 45433 USA. NR 2 TC 0 Z9 0 U1 0 U2 0 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 USA SN 0272-9172 BN 1-55899-505-6 J9 MATER RES SOC SYMP P PY 2000 VL 597 BP 295 EP 306 PG 12 WC Materials Science, Multidisciplinary; Optics SC Materials Science; Optics GA BR05D UT WOS:000165506500039 ER PT S AU Day, PN Nguyen, KA Pachter, R AF Day, PN Nguyen, KA Pachter, R BE Nashimoto, K Pachter, R Wessels, BW Shmulovich, J Jen, AKY Lewis, K Sutherland, R Perry, JW TI Ab initio design of two-photon absorbing materials SO THIN FILMS FOR OPTICAL WAVEGUIDE DEVICES AND MATERIALS FOR OPTICAL LIMITING SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT Symposium Z on Thin Films for Optical Waveguide Devices/Symposium PP on Materials for Optical Limiting III held at the 1999 MRS Fall Meeting CY NOV 30-DEC 03, 1999 CL BOSTON, MA SP Mat Res Soc, Fuji Xerox Co Ltd, Shinkosha Co Ltd, USAF, Res Lab, Def Res Agcy ID EFFECTIVE FRAGMENT POTENTIALS; EXCITED-STATES; SOLVATION; FORMAMIDE; MODEL AB Two-photon absorbing materials such as conjugated polyenes show promise as nonlinear optical materials. Prediction of two-photon absorption frequencies and cross-sections has been limited by the high level of ab initio calculations that must be carried out in order to accurately calculate excited state energies and transition dipole moments, by the size of many of the compounds of interest, and by the difficulty of handling condensed phase effects in the calculations. We have carried out geometry optimizations at the multi-configurational self-consistent field level on a small polyene, hexatriene, both in the gas-phase and in solution, with the solvent effects being modeled by the effective fragment potential. The excited-state energies have been calculated by the multiconfigurational quasidegenerate perturbation theory. Transition dipole moment calculations have also been carried out, from which the two-photon absorption cross-section can be estimated. The results indicate that just one or two solvent molecules can have a large effect on the nonlinear optical properties of two-photon absorbing materials. C1 USAF, Res Lab, Mat & Mfg Directorate, MLPJ, Wright Patterson AFB, OH 45433 USA. RP Day, PN (reprint author), USAF, Res Lab, Mat & Mfg Directorate, MLPJ, Wright Patterson AFB, OH 45433 USA. NR 20 TC 0 Z9 0 U1 0 U2 0 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 USA SN 0272-9172 BN 1-55899-505-6 J9 MATER RES SOC SYMP P PY 2000 VL 597 BP 313 EP 318 PG 6 WC Materials Science, Multidisciplinary; Optics SC Materials Science; Optics GA BR05D UT WOS:000165506500041 ER PT S AU Nguyen, KA Day, PN Pachter, R AF Nguyen, KA Day, PN Pachter, R BE Nashimoto, K Pachter, R Wessels, BW Shmulovich, J Jen, AKY Lewis, K Sutherland, R Perry, JW TI A study towards the design of materials for nonlinear optical applications using first principle calculations SO THIN FILMS FOR OPTICAL WAVEGUIDE DEVICES AND MATERIALS FOR OPTICAL LIMITING SE Materials Research Society Symposium Proceedings LA English DT Proceedings Paper CT Symposium Z on Thin Films for Optical Waveguide Devices/Symposium PP on Materials for Optical Limiting III held at the 1999 MRS Fall Meeting CY NOV 30-DEC 03, 1999 CL BOSTON, MA SP Mat Res Soc, Fuji Xerox Co Ltd, Shinkosha Co Ltd, USAF, Res Lab, Def Res Agcy ID COMPACT EFFECTIVE POTENTIALS; MOLECULAR-ORBITAL METHODS; EXPONENT BASIS-SETS; GAUSSIAN-TYPE BASIS; ORGANIC-MOLECULES; PORPHYRINS; EFFICIENT; ATOMS AB Electronic structure calculations are carried out to predict properties of reverse saturable absorption (RSA) materials that are important in nonlinear optical (NLO) applications. The RSA dyes under investigation are zinc porphyrins with a combination of halogen and phenyl substituents. The computed data include electronic spectra for the ground and triplet excited states as well as ionization potentials. These properties are important in predicting the performance of NLO materials. Since comprehensive data are not available, we begin with the basic porphyrin unit, then systematically replace the peripheral hydrogens of porphin with halogen and phenyl groups to study the substituent effects. The results of halogenated porphyrins and halogenated tetraphenylporphyrins provide insightful accounts of effects of phenyl, fluoro, chloro, and bromo substituents on the spectra of these systems. The computed spectra and IPs are in excellent agreement with available experimental data. C1 USAF, Res Lab, Mat & Mfg Directorate, MLPJ, Wright Patterson AFB, OH 45433 USA. RP Nguyen, KA (reprint author), USAF, Res Lab, Mat & Mfg Directorate, MLPJ, Wright Patterson AFB, OH 45433 USA. EM Kiet.Nguyen@afrl.af.mil NR 29 TC 0 Z9 0 U1 0 U2 0 PU MATERIALS RESEARCH SOC PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 USA SN 0272-9172 BN 1-55899-505-6 J9 MATER RES SOC SYMP P PY 2000 VL 597 BP 325 EP 330 PG 6 WC Materials Science, Multidisciplinary; Optics SC Materials Science; Optics GA BR05D UT WOS:000165506500043 ER PT S AU Kirkpatrick, SM Clark, C Sutherland, RL AF Kirkpatrick, SM Clark, C Sutherland, RL BE Nashimoto, K Pachter, R Wessels, BW Shmulovich, J Jen, AKY Lewis, K Sutherland, R Perry, JW TI Single state absorption spectra of novel nonlinear optical materials SO THIN FILMS FOR OPTICAL WAVEGUIDE DEVICES AND MATERIALS FOR OPTICAL LIMITING SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT Symposium Z on Thin Films for Optical Waveguide Devices/Symposium PP on Materials for Optical Limiting III held at the 1999 MRS Fall Meeting CY NOV 30-DEC 03, 1999 CL BOSTON, MA SP Mat Res Soc, Fuji Xerox Co Ltd, Shinkosha Co Ltd, USAF, Res Lab, Def Res Agcy AB During the absorption of a laser pulse of moderate length, the leading edge can experience excited state absorption out of the first singlet state. The measurement of this excited state absorption spectrum can only be accurately probed using short pulse pump-probe techniques. Specifically, we examine the excited state absorption of AF-380 in THF using ultrafast transient white light absorption spectroscopy (TWLA). This material has been the focus of several investigations due to it's purported large two-photon absorption cross-section, the discrepancies between long and short pulse measurements, and it's use in holographic two-photon induced photopolymerization. It is believed that a substantial excited state absorbance can account for the difference in two-photon cross section measurements. It is also possible that this excited state exhibits coherence for time scales that can affect further absorption of longer pump pulses. We examine the transient absorption of this species, as well as polarization and free carrier effects and discuss the possible implications with regards to measurement techniques. C1 USAF, Res Lab, Mat & Mfg Directorate, Wright Patterson AFB, OH 45433 USA. RP Kirkpatrick, SM (reprint author), USAF, Res Lab, Mat & Mfg Directorate, Wright Patterson AFB, OH 45433 USA. NR 10 TC 1 Z9 1 U1 0 U2 0 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 USA SN 0272-9172 BN 1-55899-505-6 J9 MATER RES SOC SYMP P PY 2000 VL 597 BP 333 EP 338 PG 6 WC Materials Science, Multidisciplinary; Optics SC Materials Science; Optics GA BR05D UT WOS:000165506500044 ER PT S AU Cooper, TM Sowards, LA Natarajan, LV Kirkpatrick, S Chandra, S McLean, DG Spangler, CW AF Cooper, TM Sowards, LA Natarajan, LV Kirkpatrick, S Chandra, S McLean, DG Spangler, CW BE Nashimoto, K Pachter, R Wessels, BW Shmulovich, J Jen, AKY Lewis, K Sutherland, R Perry, JW TI Spectroscopic investigations of dithienyl polyenes SO THIN FILMS FOR OPTICAL WAVEGUIDE DEVICES AND MATERIALS FOR OPTICAL LIMITING SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT Symposium Z on Thin Films for Optical Waveguide Devices/Symposium PP on Materials for Optical Limiting III held at the 1999 MRS Fall Meeting CY NOV 30-DEC 03, 1999 CL BOSTON, MA SP Mat Res Soc, Fuji Xerox Co Ltd, Shinkosha Co Ltd, USAF, Res Lab, Def Res Agcy ID SINGLET-STATES; FLUORESCENCE; ABSORPTION; PHOTOCHEMISTRY; SPECTRA AB To understand the properties of light-sensitive compounds used in optical limiters having photoinduced charge transfer mechanisms, we have investigated the photophysics of a series of di(2-thienyl-3,4-butyl)polyenes. Spectroscopic measurements were obtained as a function of the number of double bonds(n = 1-8). From analysis of the bandshape of the emission spectra, we found evidence of vibronic coupling between the S-1 and S-2 excited states. The degree of coupling increased with solvents of high refractive index. The appearance of the cis band in absorption spectra of dithienyl polyenes having 6-8 double bonds suggested equilibria between s-cis and s-trans conformers. The cis band intensity increased in lower polarity solvents, implying solvent-induced conformation changes in these dyes. Trends in the data reflected the ordering, energy gap between and mixing of B-1(u)* and (1)A(s)* excited state configurations. C1 USAF, Res Lab, MLPJ, Wright Patterson AFB, OH 45433 USA. RP Cooper, TM (reprint author), USAF, Res Lab, MLPJ, 3005 P St Ste 1, Wright Patterson AFB, OH 45433 USA. NR 14 TC 0 Z9 0 U1 0 U2 0 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 USA SN 0272-9172 BN 1-55899-505-6 J9 MATER RES SOC SYMP P PY 2000 VL 597 BP 351 EP 356 PG 6 WC Materials Science, Multidisciplinary; Optics SC Materials Science; Optics GA BR05D UT WOS:000165506500047 ER PT S AU Pooler, ES Clark, CM Kirkpatrick, SM AF Pooler, ES Clark, CM Kirkpatrick, SM BE Nashimoto, K Pachter, R Wessels, BW Shmulovich, J Jen, AKY Lewis, K Sutherland, R Perry, JW TI Photophorescence studies of reverse saturable absorption materials SO THIN FILMS FOR OPTICAL WAVEGUIDE DEVICES AND MATERIALS FOR OPTICAL LIMITING SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT Symposium Z on Thin Films for Optical Waveguide Devices/Symposium PP on Materials for Optical Limiting III held at the 1999 MRS Fall Meeting CY NOV 30-DEC 03, 1999 CL BOSTON, MA SP Mat Res Soc, Fuji Xerox Co Ltd, Shinkosha Co Ltd, USAF, Res Lab, Def Res Agcy ID METAL AB Phosphorescence studies of reverse saturable absorption materials (RSA) are discussed. Absorption and emission measurements of an RSA material, specifically Zinc 2,3,7,8,12,13,17,18-octabromo-5,10,15,20-tetraphenylporphyrin (ZnOBP), are performed in a proprietary host polymer. Spectra are analyzed to estimate the relative energy level of the first triplet state of ZnOBP with respect to the ground state. C1 USAF, Res Lab, Mat & Mfg Directorate, Wright Patterson AFB, OH 45433 USA. RP Pooler, ES (reprint author), USAF, Res Lab, Mat & Mfg Directorate, Wright Patterson AFB, OH 45433 USA. NR 6 TC 0 Z9 0 U1 0 U2 0 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 USA SN 0272-9172 BN 1-55899-505-6 J9 MATER RES SOC SYMP P PY 2000 VL 597 BP 383 EP 387 PG 5 WC Materials Science, Multidisciplinary; Optics SC Materials Science; Optics GA BR05D UT WOS:000165506500051 ER PT S AU Strawser, RE Cortez, R O'Keefe, MJ Leedy, KD Ebel, JL Henderson, HT AF Strawser, RE Cortez, R O'Keefe, MJ Leedy, KD Ebel, JL Henderson, HT BE Vinci, R Kraft, O Moody, N Besser, P Shaffer, E TI Film stress influence of bilayer metallization on the structure of RF MEMS switches SO THIN FILMS-STRESSES AND MECHANICAL PROPERTIES VIII SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT Symposium V on Thin Films-Stresses and Mechanical Properties VIII held at the 1999 MRS Fall Meeting CY NOV 29-DEC 03, 1999 CL BOSTON, MA SP Mat Res Soc, Adv Micro Devices Inc, AMIA Labs, Appl Mat Inc, Dow Chem Co, Hysitron Inc, IBM, T J Watson Res Ctr, Lucent Technol, Micron Syst Corp, Novellus Syst Inc, MTS Syst Corp, Seagate Technol Inc ID CIRCUITS; DEVICES AB The performance of microelectromechanical systems (MEMS) switches is highly dependent on the switches' constituent materials. The switch material must be able to provide both structural integrity and high electrical conductivity. Cantilever beams, doubly clamped beams, and membranes are typical MEMS structures used in microwave/millimeter wave applications. In this study, cantilever and doubly clamped beam microswitches were fabricated on GaAs substrates using evaporated bilayers of titanium and gold metallization in which the total thickness was held constant at 1.5 mum while the gold thickness varied from 0.5 mum to 1.5 mum. The lengths of the cantilevers varied from 300 to 500 mum and the doubly clamped beams varied from 600 to 800 mum. An upward deflection of the gold dominated cantilever beams indicated an increasing tensile stress gradient. Results of microwave characterization demonstrated higher switch isolation (off-resistance) for shorter beam switches at the expense of higher insertion loss (on-resistance) and actuation voltage. A discussion of the observed released microswitch structure within the context of the measured film stresses and electrical performance will be presented. C1 USAF, Res Lab, Sensors Directorate, Wright Patterson AFB, OH 45433 USA. RP Strawser, RE (reprint author), USAF, Res Lab, Sensors Directorate, Wright Patterson AFB, OH 45433 USA. NR 14 TC 1 Z9 1 U1 0 U2 0 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 USA SN 0272-9172 BN 1-55899-502-1 J9 MATER RES SOC SYMP P PY 2000 VL 594 BP 213 EP 218 PG 6 WC Materials Science, Coatings & Films; Physics, Applied SC Materials Science; Physics GA BR05C UT WOS:000165506400034 ER PT S AU Leedy, KD O'Keefe, MJ Grant, JT AF Leedy, KD O'Keefe, MJ Grant, JT BE Vinci, R Kraft, O Moody, N Besser, P Shaffer, E TI Stress, microstructure and temperature stability of reactive sputter deposited Ta(N) thin films SO THIN FILMS-STRESSES AND MECHANICAL PROPERTIES VIII SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT Symposium V on Thin Films-Stresses and Mechanical Properties VIII held at the 1999 MRS Fall Meeting CY NOV 29-DEC 03, 1999 CL BOSTON, MA SP Mat Res Soc, Adv Micro Devices Inc, AMIA Labs, Appl Mat Inc, Dow Chem Co, Hysitron Inc, IBM, T J Watson Res Ctr, Lucent Technol, Micron Syst Corp, Novellus Syst Inc, MTS Syst Corp, Seagate Technol Inc ID TA-N; TANTALUM; COPPER; BARRIERS AB Interest in tantalum nitride thin films for use as diffusion barriers in Cu-based microelectronic interconnects merits the study of tantalum nitride thin film properties as a function of deposition conditions and elevated temperature exposure. In this investigation, the influence of nitrogen content and post deposition annealing on the stress, microstructure and resistivity of Ta(N) films was analyzed. Ta(N) thin films were deposited by reactive de magnetron sputtering of a Ta target in Ar/N-2 gas mixtures. With an increasing N-2 to Ar flow ratio, the as-deposited crystal structure of the films changed from beta -Ta to bcc Ta with N in solid solution to TaN0.1 to Ta2N and finally to TaN. The as-deposited Ta(N) stress, grain size and resistivity of the Alms were found to be strongly dependent on the phase(s) present. Films with less than 20 at. % nitrogen concentration displayed large compressive stress increases during 650 degreesC anneals in flowing N-2. Phase transformations to Ta2N occurred after 650 degreesC anneals in films with nitrogen concentrations from similar to 15 to 25 at. %. Microstructural characterization using transmission electron microscopy and x-ray diffraction, and chemical analysis by x-ray photoelectron spectroscopy and Auger electron spectroscopy of the Ta(N) films were used to identify the as-deposited and transformed phases. C1 USAF, Res Lab, Sensors Directorate, Wright Patterson AFB, OH 45433 USA. RP Leedy, KD (reprint author), USAF, Res Lab, Sensors Directorate, Wright Patterson AFB, OH 45433 USA. NR 14 TC 2 Z9 2 U1 0 U2 1 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 USA SN 0272-9172 BN 1-55899-502-1 J9 MATER RES SOC SYMP P PY 2000 VL 594 BP 427 EP 432 PG 6 WC Materials Science, Coatings & Films; Physics, Applied SC Materials Science; Physics GA BR05C UT WOS:000165506400066 ER PT J AU John, PJ Cutler, JN Sanders, JH AF John, PJ Cutler, JN Sanders, JH TI Tribological behavior of a multialkylated cyclopentane oil under ultrahigh vacuum conditions SO TRIBOLOGY LETTERS LA English DT Article DE vacuum; tribology; multialkylated cyclopentane; oil; lubrication; decomposition; space; hydrogenolysis; hydrocracking; tribochemistry; heterogeneous catalysis by iron ID AMORPHOUS-CARBON; DIAMOND FILMS; RAMAN; PERFLUOROPOLYETHERS; LUBRICATION; STEEL AB An ultrahigh vacuum, ball-on-flat test apparatus has been built to study the performance of candidate oils intended for spacecraft applications. Tests have been conducted on a multi-alkylated cyclopentane base oil using steel halls and disks. Different results are obtained when this oil is tested under vacuum conditions than when it is tested under a nitrogen environment. These differences are dramatic when the tests are conducted under starved conditions. Analyses of gases evolved during rubbing reveal that large quantities of methane are evolving from the process. A mechanism is proposed whereby oxide-free steel surfaces combine with tribological activity to crack the hydrocarbon oil to produce CHchi radicals, These CHchi radicals abstract hydrogen from the surrounding oil to produce methane. The increased volatility of the oil fragments remaining after methane formation leads to material loss by evaporation, thereby explaining the differences in vacuum and nitrogen performance of the oil. An ultrahigh vacuum, ball-on-flat test apparatus has been built to study the performance of candidate oils intended for spacecraft applications. Tests have been conducted on a multi-alkylated cyclopentane base oil using steel halls and disks. Different results are obtained when this oil is tested under vacuum conditions than when it is tested under a nitrogen environment. These differences are dramatic when the tests are conducted under starved conditions. Analyses of gases evolved during rubbing reveal that large quantities of methane are evolving from the process. A mechanism is proposed whereby oxide-free steel surfaces combine with tribological activity to crack the hydrocarbon oil to produce CHchi radicals, These CHchi radicals abstract hydrogen from the surrounding oil to produce methane. The increased volatility of the oil fragments remaining after methane formation leads to material loss by evaporation, thereby explaining the differences in vacuum and nitrogen performance of the oil. C1 Univ Dayton, Res Inst, Dayton, OH 45469 USA. USAF, Res Lab, AFRL MLBT, Mat Directorate, Wright Patterson AFB, OH 45433 USA. RP John, PJ (reprint author), Univ Dayton, Res Inst, 300 Coll Pk, Dayton, OH 45469 USA. NR 29 TC 14 Z9 14 U1 0 U2 5 PU BALTZER SCI PUBL BV PI BUSSUM PA PO BOX 221, 1400 AE BUSSUM, NETHERLANDS SN 1023-8883 J9 TRIBOL LETT JI Tribol. Lett. PY 2000 VL 9 IS 3-4 BP 167 EP 173 PG 7 WC Engineering, Chemical; Engineering, Mechanical SC Engineering GA 434ZZ UT WOS:000168846900007 ER PT J AU Patton, ST Cowan, WD Eapen, KC Zabinski, JS AF Patton, ST Cowan, WD Eapen, KC Zabinski, JS TI Effect of surface chemistry on the tribological performance of a MEMS electrostatic lateral output motor SO TRIBOLOGY LETTERS LA English DT Article DE MEMS tribology; surface chemistry; adsorbed water; self-assembled monolayer; wear ID FLUORIDE-TREATED SI(100); METAL-PARTICLE TAPES; MICROMACHINED MICROENGINES; MICROMECHANICAL STRUCTURES; MODE PERFORMANCE; ADHESION; FRICTION; RELIABILITY; STICTION; SILICON AB The effect of surface chemistry on the tribological performance and reliability of a MEMS lateral output motor is reported. Relative humidity (RH) and octadecyltrichlorosilane (OTS) self-assembled monolayer (SAM) coatings were used to change surface chemistry. Electrical and tribological performance of uncoated and OTS-coated motors were found to be dependent on RH. For uncoated motors, excessive wear of sliding contacts and welding (permanent adhesion) of static contacts were observed at 0.1% RH. Degradation of electrostatic force and high static friction (stiction) forces limited dynamic performance and reliability and caused device sticking at and above 70% RH. Around 50% RH, uncoated motors exhibited negligible wear, low adhesion, and a wear life at least three orders of magnitude longer than in the dry environment (experiments were stopped without failure after about one billion cycles). Water vapor behaved as a gas phase replenishable lubricant by providing a protective adsorbed film. The OTS coating broadened the operating envelope to 30-50% RH and reduced stiction. which allowed better dynamic performance at high RH. The OTS coating improved durability at 0.1% RH, but it was still poor. At high RH, stiction problems reoccurred when the OTS coating was worn away. By controlling and balancing surface chemistry (adsorbed water and OTS), excellent performance, low friction and wear, and excellent durability were attained with the lateral output motor. C1 Univ Dayton, Res Inst, Dayton, OH 45469 USA. USAF, Res Lab, Mat & Mfg Directorate, Wright Patterson AFB, OH 45433 USA. RP Patton, ST (reprint author), Univ Dayton, Res Inst, Dayton, OH 45469 USA. NR 34 TC 87 Z9 89 U1 1 U2 10 PU BALTZER SCI PUBL BV PI BUSSUM PA PO BOX 221, 1400 AE BUSSUM, NETHERLANDS SN 1023-8883 J9 TRIBOL LETT JI Tribol. Lett. PY 2000 VL 9 IS 3-4 BP 199 EP 209 DI 10.1023/A:1018817123441 PG 11 WC Engineering, Chemical; Engineering, Mechanical SC Engineering GA 434ZZ UT WOS:000168846900011 ER PT J AU Cutler, JN Sanders, JH Zabinski, JS John, PJ McCutchen, JR Kasten, LS Tan, KH AF Cutler, JN Sanders, JH Zabinski, JS John, PJ McCutchen, JR Kasten, LS Tan, KH TI Surface chemistry of new lubrication systems for high-speed spacecraft bearings SO TRIBOLOGY LETTERS LA English DT Article DE XANES; X-ray absorption; antiwear films; spacecraft lubrication ID RAY-ABSORPTION-SPECTROSCOPY; SI L-EDGE; FLUORESCENCE MEASUREMENTS; CHEMICAL CHARACTERIZATION; ZDDP AB Multialkylated cyclopentane (MAC) and silahydrocarbon (SiHC) are primary candidates for future spacecraft applications due to their high viscosity and good viscosity-temperature profile, low vapor pressure and good lubricating properties. In this work, the friction, wear and associated tribochemistry of these fluids, both unformulated and formulated with 2% aryl phosphate ester (TPP), were investigated. A Plint reciprocating wear rig equipped with an environmental chamber that was filled with dry air or nitrogen was used to produce boundary lubrication conditions. The resulting specimens were examined by X-ray absorption near-edge structure (XANES) spectroscopy in order to gain some understanding of how the base fluid and additive function. Several relationships were discovered among friction, wear and tribochemistry within the wear scar. First, the wear rate in both unformulated and formulated fluids was higher in a dry nitrogen environment than in dry air. Second, when tested in air, unformulated silahydrocarbon acts as its own antiwear additive by decomposing to a silicon oxide glass within the wear track thereby eliminating additive issues such as solubility, evaporation and concentration effects. Third, the antiwear properties of silahydrocarbon oil are hindered by the presence of a phosphate additive. Both the oil and additive form an oxide glass within the wear track and compete for active growth sites. Fourth, the chain length of the polyphosphate glass formed in the wear track controls the antiwear performance of the film. The phosphate additive in multialkylated cyclopentane decomposed to a polyphosphate glass in both dry air to generate a good antiwear film (short to medium chain length polyphosphate) and nitrogen to form a poor antiwear film (long chain length polyphosphate). C1 Univ Dayton, Res Inst, Dayton, OH 45469 USA. USAF, RL, MLBT, Mat & Mfg Directorate, Wright Patterson AFB, OH 45433 USA. Univ Wisconsin, Canadian Synchrotron Radiat Facil, Madison, WI 53589 USA. RP Cutler, JN (reprint author), Univ Dayton, Res Inst, Dayton, OH 45469 USA. NR 22 TC 7 Z9 8 U1 4 U2 6 PU BALTZER SCI PUBL BV PI BUSSUM PA PO BOX 221, 1400 AE BUSSUM, NETHERLANDS SN 1023-8883 J9 TRIBOL LETT JI Tribol. Lett. PY 2000 VL 8 IS 1 BP 17 EP 23 DI 10.1023/A:1019166630462 PG 7 WC Engineering, Chemical; Engineering, Mechanical SC Engineering GA 300EZ UT WOS:000086241300003 ER PT J AU Zabinski, JS Sanders, JH Nainaparampil, J Prasad, SV AF Zabinski, JS Sanders, JH Nainaparampil, J Prasad, SV TI Lubrication using a microstructurally engineered oxide: performance and mechanisms SO TRIBOLOGY LETTERS LA English DT Article DE microstructure; lubricious oxides; engineered; ZnO; friction; wear; vacuum; relative humidity; moisture; adsorption ID PULSED-LASER DEPOSITION; DIAMOND-LIKE CARBON; ZINC-OXIDE; ZNO FILMS; TRIBOLOGICAL PROPERTIES; ANION VACANCIES; RUTILE TIO2-X; RF; TEMPERATURE; COATINGS AB Oxide coatings have the potential to lubricate over a wide range of environmental conditions. However, oxides are typically brittle, form abrasive wear debris, and have high friction. ZnO is no exception; hot-pressed 1-2 mu m ZnO has a friction coefficient of about 0.6 and causes extensive wear on steel counterfaces. Microstructural engineering may be used to permit plastic deformation and the formation of lubricious transfer films. The work presented here focuses on controlling the microstructure and chemistry within ZnO to provide low-friction and long-life coatings (e.g., mu=0.1-0.2, 1M+ sliding cycles). Coatings having a (0001) columnar texture with good crystallinity along the c-axis wear quickly and generate substantial wear debris. Depositions that create a (0001) texture with a mosaic substructure within the columns deform plastically. Here, nanocrystalline structures may enhance grain boundary sliding and contribute to plastic deformation and low friction. Dislocation motion within ZnO is enhanced by oxygen adsorption, which may further reduce friction by lowering shear strength. In addition, it is likely that defects arising from oxygen deficiency and the high surface-to-volume ratio of nanostructures, promote adsorption of water and/or oxygen. The adsorbed species can reduce friction through passivation of dangling or strained bonds. The complex interaction of mechanical and surface chemical effects result in millions of dry sliding cycles on nanostructured coatings in 50% RH air. In addition, the coatings have low friction in vacuum. Coating characterization and performance are discussed and a mechanism to explain the tribological properties is proposed. C1 USAF, Mat & Mfg Directorate, Res Lab, MLBT, Wright Patterson AFB, OH 45433 USA. USAF, Systran Fed Corp, Res Lab, MLBT, Wright Patterson AFB, OH 45433 USA. Univ Dayton, Res Inst, USAF, Res Lab,MLBT, Wright Patterson AFB, OH 45433 USA. RP Zabinski, JS (reprint author), USAF, Mat & Mfg Directorate, Res Lab, MLBT, Wright Patterson AFB, OH 45433 USA. EM Jeffrey.Zabinski@AFRL.AF.MIL NR 66 TC 42 Z9 43 U1 3 U2 20 PU SPRINGER/PLENUM PUBLISHERS PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 1023-8883 EI 1573-2711 J9 TRIBOL LETT JI Tribol. Lett. PY 2000 VL 8 IS 2-3 BP 103 EP 116 DI 10.1023/A:1019187202237 PG 14 WC Engineering, Chemical; Engineering, Mechanical SC Engineering GA 340CR UT WOS:000088516000004 ER PT S AU Kiel, JL Parker, JE Alls, JL Kalns, J Holwitt, EA Stribling, LJV Morales, PJ Bruno, JG AF Kiel, JL Parker, JE Alls, JL Kalns, J Holwitt, EA Stribling, LJV Morales, PJ Bruno, JG BE House, JA Kocan, KM Gibbs, EPJ TI Rapid recovery and identification of anthrax bacteria from the environment SO TROPICAL VETERINARY DISEASES: CONTROL AND PREVENTION IN THE CONTEXT OF THE NEW WORLD ORDER SE ANNALS OF THE NEW YORK ACADEMY OF SCIENCES LA English DT Article; Proceedings Paper CT 5th Biennial Conference of the Society-for-Tropical-Veterinary-Medicine CY JUN 12-16, 1999 CL KEY WEST, FLORIDA SP Int Fdn Sci, Merial Anim Hlth, Minist Affaires Etrangres, USDA, ARS, USDA, APHIS, USDA, CSREES, USDA, FAS, USDA, T STAR, Univ Florida ID TUMOR-NECROSIS-FACTOR; NITRIC-OXIDE; BACILLUS-SUBTILIS; PEROXYNITRITE; SPORULATION; OXIDATION; TYROSINE; PROTEINS; KINASE; SPO0A AB Bacillus anthracis has been recognized as a highly likely biological warfare or terrorist agent. We have designed culture techniques to rapidly isolate and identify "live" anthrax from suspected environmental release. A special medium (3AT medium) allows for discrimination between closely related bacilli and non-pathogenic strains. Nitrate was found to be a primary factor influencing spore formation in Bacillus anthracis. Nitrate reduction in anthrax is not an adaptation to saprophytic environmental existence, but it is a signal to enhance environmental survival upon the death of the anthrax host, which can be mimicked in culture. C1 Veridian Inc, San Antonio, TX 78216 USA. Conceptual MindWorks Inc, San Antonio, TX 78228 USA. Univ Texas, Hlth Sci Ctr, Dept Radiol, Div Radiat Oncol, San Antonio, TX 78284 USA. USAF, Directed Energy Bioffect Div, Human Effectiveness Directorate, Res Lab, Brooks AFB, TX 78235 USA. RP Kiel, JL (reprint author), AFRL, HEDB, 8308 Hawks Rd, Brooks AFB, TX 78235 USA. NR 40 TC 3 Z9 3 U1 0 U2 3 PU NEW YORK ACAD SCIENCES PI NEW YORK PA 2 EAST 63RD ST, NEW YORK, NY 10021 USA SN 0077-8923 BN 1-57331-281-9 J9 ANN NY ACAD SCI JI Ann.NY Acad.Sci. PY 2000 VL 916 BP 240 EP 252 PG 13 WC Multidisciplinary Sciences; Veterinary Sciences SC Science & Technology - Other Topics; Veterinary Sciences GA BT09T UT WOS:000171939300030 PM 11193628 ER PT B AU DeLo, DP Bieler, TR Semiatin, SL AF DeLo, DP Bieler, TR Semiatin, SL BE Mishra, RS Semiatin, SL Suryanarayana, C Thadhani, NN Lowe, TC TI Microstructure and texture evolution during equal channel angular extrusion of Ti-6Al-4V SO ULTRAFINE GRAINED MATERIALS LA English DT Proceedings Paper CT Symposium on Ultrafine Grained Materials at the 2000TMS Annual Meeting CY MAR 12-16, 2000 CL NASHVILLE, TN SP Minerals Met & Mat Soc, MPMD Div AB Microstructure and texture evolution during the equal channel angular extrusion (ECAE) of Ti-6Al-4V with a colony alpha starting microstructure were established. Preforms were extruded either one or two passes using preheat temperatures of 845, 900, and 955 degrees C. In all cases the as-extruded material exhibited partially globularized, directional microstructures. Preforms extruded in a single pass and subsequently heat treated at 925 degrees C for 4 hours developed an equiaxed structure with an alpha grain size of approximately 8 mu m; heat-treated grain sizes were slightly coarser for samples given two passes. Unlike the starting plate material which showed a very strong texture, the alpha-phase textures developed during ECAE were relatively weak except for material given two passes without a rotation between passes. C1 USAF, Res Lab, Mat & Mfg Directorate, AFRL,MLLM, Wright Patterson AFB, OH 45433 USA. RP DeLo, DP (reprint author), USAF, Res Lab, Mat & Mfg Directorate, AFRL,MLLM, Wright Patterson AFB, OH 45433 USA. RI SEMIATIN, SHELDON/E-7264-2017 NR 10 TC 14 Z9 14 U1 0 U2 2 PU MINERALS, METALS & MATERIALS SOC PI WARRENDALE PA 184 THORN HILL RD, WARRENDALE, PA 15086-7514 USA BN 0-87339-472-0 PY 2000 BP 257 EP 266 PG 10 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA BQ57P UT WOS:000088805300025 ER PT J AU Cespedes, RD AF Cespedes, RD TI Collagen injection or artificial sphincter for postprostatectomy incontinence: Collagen SO UROLOGY LA English DT Editorial Material ID URINARY-INCONTINENCE; RADICAL PROSTATECTOMY; LONG-TERM; THERAPY; EXPERIENCE C1 Wilford Hall USAF Med Ctr, Dept Urol, Lackland AFB, TX 78236 USA. RP Cespedes, RD (reprint author), Wilford Hall USAF Med Ctr, Dept Urol, Lackland AFB, TX 78236 USA. NR 14 TC 15 Z9 15 U1 0 U2 0 PU ELSEVIER SCIENCE INC PI NEW YORK PA 655 AVENUE OF THE AMERICAS, NEW YORK, NY 10010 USA SN 0090-4295 J9 UROLOGY JI UROLOGY PD JAN PY 2000 VL 55 IS 1 BP 5 EP 7 DI 10.1016/S0090-4295(99)00418-5 PG 3 WC Urology & Nephrology SC Urology & Nephrology GA 275BL UT WOS:000084799500003 PM 10654884 ER PT J AU Rodriguez, R Chan, DY Bishoff, JT Chen, RB Kavoussi, LR Choti, MA Marshall, FF AF Rodriguez, R Chan, DY Bishoff, JT Chen, RB Kavoussi, LR Choti, MA Marshall, FF TI Renal ablative cryosurgery in selected patients with peripheral renal masses SO UROLOGY LA English DT Article ID INTRAOPERATIVE SONOGRAPHY; CRYOTHERAPY; TUMORS; MODEL; CRYOABLATION AB Objectives. To present the preliminary results of renal ablative cryosurgery in selected patients. Methods. Seven patients were treated, all of whom had small peripheral tumors and chose not to undergo partial or radical nephrectomy. Four patients underwent a rib-sparing flank incision; the remaining three underwent laparoscopy. All tumors were biopsied before cryoablation. Intraoperative ultrasound was used to monitor the cryolesion. Results. There were no intraoperative complications. The estimated blood loss averaged 111 mt. To date, 6 of the 7 patients have undergone at least one follow-up computed tomography scan (14.2 months average follow-up); all these scans demonstrated partial resolution of the lesion. Clinically, the patients tolerated the procedure without any renal complications or significant changes in creatinine. Conclusions. This limited clinical trial has demonstrated the feasibility of treating small peripherally located renal tumors with cryosurgery with minimal morbidity and a favorable outcome. Further studies are necessary to determine the long-term efficacy of this treatment modality. (C) 2000, Elsevier Science Inc. C1 Johns Hopkins Hosp, James Buchanan Brady Urol Inst, Baltimore, MD 21287 USA. Johns Hopkins Bayview Hosp, Baltimore, MD USA. Johns Hopkins Hosp, Dept Surg, Baltimore, MD 21287 USA. Wilford Hall USAF Med Ctr, Lackland AFB, TX 78236 USA. Cleveland Clin, Ft Lauderdale, FL USA. Emory Clin, Dept Urol, Atlanta, GA 30322 USA. RP Rodriguez, R (reprint author), Johns Hopkins Hosp, James Buchanan Brady Urol Inst, Marburg 1,600 N Wolfe St, Baltimore, MD 21287 USA. NR 19 TC 68 Z9 70 U1 0 U2 0 PU ELSEVIER SCIENCE INC PI NEW YORK PA 655 AVENUE OF THE AMERICAS, NEW YORK, NY 10010 USA SN 0090-4295 J9 UROLOGY JI UROLOGY PD JAN PY 2000 VL 55 IS 1 BP 25 EP 30 DI 10.1016/S0090-4295(99)00394-5 PG 6 WC Urology & Nephrology SC Urology & Nephrology GA 275BL UT WOS:000084799500008 PM 10654889 ER PT B AU Robin, JS Irvine, CE AF Robin, JS Irvine, CE GP USENIX USENIX TI Analysis of the Intel Pentium's ability to support a secure virtual machine monitor SO USENIX ASSOCIATION PROCEEDINGS OF THE NINTH USENIX SECURITY SYMPOSIUM LA English DT Proceedings Paper CT 9th USENIX Security Symposium CY AUG 14-17, 2000 CL DENVER, CO SP USENIX Assoc ID SYSTEMS AB A virtual machine monitor (VMM) allows multiple operating systems to run concurrently on virtual machines (VMs) on a single hardware platform. Each VM can be treated as an independent operating system platform. A secure VMM would enforce an overarching security policy on its VMs. The potential benefits of a secure VMM for PCs include: a more secure environment, familiar COTS operating systems and applications, and enormous savings resulting from the elimination of the need for separate platforms when both high assurance policy enforcement, and COTS software are required. This paper addresses the problem of implementing secure VMMs on the Intel Pentium architecture. The requirements for various types of VMMs are reviewed. We report an analysis of the virtualizability of all of the approximately 250 instructions of the Intel Pentium platform and address its ability to support a VMM. Current "virtualization" techniques for the Intel Pentium architecture are examined and several security problems are identified. An approach to providing a virtualizable hardware base for a highly secure VMM is discussed. C1 USAF, Washington, DC 20330 USA. RP Robin, JS (reprint author), USAF, Washington, DC 20330 USA. NR 35 TC 12 Z9 16 U1 0 U2 0 PU USENIX ASSOC PI BERKELEY PA SUITE 215, 2560 NINTH ST, BERKELEY, CA 94710 USA BN 1-880446-18-9 PY 2000 BP 129 EP 144 PG 16 WC Computer Science, Information Systems; Computer Science, Theory & Methods; Engineering, Electrical & Electronic SC Computer Science; Engineering GA BR62X UT WOS:000166981300010 ER PT B AU Shin, SH AF Shin, SH BE Cheng, CJ Kim, DH TI Legal aspects of the peaceful use of the Far East aerospace SO UTILIZATION OF THE WORLD'S AIR SPACE AND FREE OUTER SPACE IN THE 21ST CENTURY LA English DT Proceedings Paper CT International Conference on Air and Space Policy, Law and Industry for the 21st Century CY JUN 23-25, 1997 CL SEOUL, SOUTH KOREA SP Korean Assoc Air & Space Law, Republic of Korea Air Force Acad, Soong Sil Univ, Inst Legal Studies, Leiden Univ, Int Inst Air & Space Law, Soochow Univ, Sch Law, Asian Inst Int Air & Space Law, Soc Study Law & Policy Space Utilizat, McGill Univ, Inst Air & Space Law, Minist Construct & Transportat, Korean Air, Korea Airports Author, Hankuk Aviat Univ, China Aviat Dev Fdn, KLM Royal Dutch Airlines, Schiphol Airport, Civil Aviat Author Netherlands, Embassy Netherlands, Asiana Airlines, Japan Airlines, Seoul Bar Assoc, Hyundai Business Grp, Hanwha Grp, Samsung Aerosp, Daewoo Heavy Ind Assoc, Korea Aerosp Ind Assoc C1 USAF Acad, Fac Board, Colorado Springs, CO 80840 USA. NR 26 TC 0 Z9 0 U1 0 U2 0 PU KLUWER LAW INTERNATIONAL PI THE HAGUE PA PO BOX 85889, 2508 CN THE HAGUE, NETHERLANDS BN 90-411-1376-2 PY 2000 BP 251 EP 267 PG 17 WC Law SC Government & Law GA BR34X UT WOS:000166171400019 ER PT S AU Schulthess, M Levine, M Bell, K Leonard, S Vanik, M AF Schulthess, M Levine, M Bell, K Leonard, S Vanik, M BE Breckinridge, JB Jakobsen, P TI A joint NASA and DoD deployable optics space experiment SO UV, OPTICAL, AND IR SPACE TELESCOPES AND INSTRUMENTS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on UV, Optical, and IR Space Telescopes and Instruments CY MAR 29-31, 2000 CL MUNICH, GERMANY SP SPIE, European SO Observ, DFM Engn Inc AB Future NASA and DoD space missions will require high precision large optical telescopes in space. Given size and weight constraints, as well as cost considerations these structures will need to be lightweight and deployable. The deployment and phasing of large deployable optical systems presents numerous technical challenges and currently presents high risk to future systems. One of these challenges includes predicting on-orbit optical performance using ground-validated models. The Interferometry Program EXperiment (IPEX) which monitored the on-orbit dynamics of a free-flying 9-bay articulated truss, demonstrated significant behavior changes from a 1-g to a 0-g environment [1]. The Air Force Research Lab is proposing a DoD partnership with NASA on NEXUS; a deployable optics flight demonstrator scheduled to launch in 2004. NEXUS is designed to demonstrate technologies for the Next Generation Space Telescope, primarily the deployment and wave front control of a 2.8 meter optical telescope in space. The platform will be extensively instrumented to provide valuable and relevant information on the performance impacts of micro- and nano-dynamics. The NEXUS technology demonstrator will enable the DoD and NASA to answer critical questions and enable model validation on the effects of micro-dynamics and nano-strains on 0-g system performance, effects that are not readily or easily determined from ground testing. NEXUS will also provide a validation for the process used to set mechanical requirements, and to perform the appropriate suite of ground tests and analyses at the component and system level for accurate on-orbit optical performance prediction. This paper will provide an overview of a proposed NEXUS flight experiment, an overview to the Space Based Laser program's Integrated Flight Experiment (IFX), background on the micro and nano-dynamics issues facing future large optical payloads in space, and the technical objectives for proposing this joint flight experiment. C1 USAF, Res Lab, Directed Energy Directorate, Kirtland AFB, NM 87118 USA. RP Schulthess, M (reprint author), USAF, Res Lab, Directed Energy Directorate, Kirtland AFB, NM 87118 USA. NR 11 TC 1 Z9 1 U1 0 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-3638-0 J9 P SOC PHOTO-OPT INS PY 2000 VL 4013 BP 568 EP 579 DI 10.1117/12.393996 PG 12 WC Astronomy & Astrophysics; Instruments & Instrumentation; Optics SC Astronomy & Astrophysics; Instruments & Instrumentation; Optics GA BQ70H UT WOS:000089219600056 ER PT S AU Andersen, G Knize, RJ AF Andersen, G Knize, RJ BE Breckinridge, JB Jakobsen, P TI Holographically corrected telescope with temporal update SO UV, OPTICAL, AND IR SPACE TELESCOPES AND INSTRUMENTS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on UV, Optical, and IR Space Telescopes and Instruments CY MAR 29-31, 2000 CL MUNICH, GERMANY SP SPIE, European SO Observ, DFM Engn Inc DE holography; telescope design; adaptive optics; aberrations; next generation space telescope ID RESOLUTION; MICROSCOPE AB Next generation optical space telescopes with apertures >10m for imaging, lidar, communications and directed energy focussing will be unable to use conventional technologies which are impractical or too costly. Our solution is to construct a telescope from a lightweight, membrane primary, which is holographically corrected for surface distortions, in situ. In order to design a practical space telescope, a scheme by which temporal variations in the mirror surface, caused by thermal and gravitational stresses must be found. We present evidence that a primary static hologram combined with a secondary adaptive optics system may be the least expensive and simplest approach. C1 USAF Acad, Laser & Opt Res Ctr, HQ, USADA DFP, Colorado Springs, CO 80840 USA. RP Andersen, G (reprint author), USAF Acad, Laser & Opt Res Ctr, HQ, USADA DFP, Suite 2A31,2354 Fairchild Dr, Colorado Springs, CO 80840 USA. NR 17 TC 4 Z9 4 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-3638-0 J9 P SOC PHOTO-OPT INS PY 2000 VL 4013 BP 587 EP 594 DI 10.1117/12.393997 PG 8 WC Astronomy & Astrophysics; Instruments & Instrumentation; Optics SC Astronomy & Astrophysics; Instruments & Instrumentation; Optics GA BQ70H UT WOS:000089219600058 ER PT S AU Fender, J AF Fender, J BE Breckinridge, JB Jakobsen, P TI Future trends in large space optics SO UV, OPTICAL, AND IR SPACE TELESCOPES AND INSTRUMENTS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on UV, Optical, and IR Space Telescopes and Instruments CY MAR 29-31, 2000 CL MUNICH, GERMANY SP SPIE, European SO Observ, DFM Engn Inc AB Large space optics technologies are developed for government supported civilian and defense applications. Within a funding constrained environment, partnerships among members of the large space optics community serve to accelerate the pace of technology development and insertion of technology products into space operations. Although missions and operating requirements are quite different for the partners, NASA and DOD have teamed to address areas of common concern. One particularly successful partnership activity is aimed at significantly reducing areal density, cost and fabrication time for large optics. Other opportunities are being explored among the government partners. C1 USAF, Res Lab, Space Vehicles Directorate, Kirtland AFB, NM 87117 USA. RP Fender, J (reprint author), USAF, Res Lab, Space Vehicles Directorate, Kirtland AFB, NM 87117 USA. NR 0 TC 3 Z9 4 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-3638-0 J9 P SOC PHOTO-OPT INS PY 2000 VL 4013 BP 682 EP 686 DI 10.1117/12.394005 PG 5 WC Astronomy & Astrophysics; Instruments & Instrumentation; Optics SC Astronomy & Astrophysics; Instruments & Instrumentation; Optics GA BQ70H UT WOS:000089219600069 ER PT B AU Barker, D AF Barker, D GP IEEE COMPUTER SOCIETY IEEE COMPUTER SOCIETY TI Requirements modeling technology - A vision for better, faster, and cheaper systems SO VHDL INTERNATIONAL USERS FORUM FALL WORKSHOP, PROCEEDINGS LA English DT Proceedings Paper CT Fall Workshop of the VHDL International Users Forum (VIUF 2000) CY OCT 18-20, 2000 CL ORLANDO, FL SP IEEE Comp Soc, Tech Comm Design Automat, IEEE Circuits & Syst Soc, VHDL Int AB This paper discusses a vision, motivation, and objectives for a new engineering technology based on the Rosetta System Level Design Language (SLDL) that we call "requirements modeling". Requirements modeling is what systems engineers and systems analysts do with Rosetta SLDL. Rosetta SLDL is information technology that supports the specification of multi-technology, multifaceted, multi-discipline systems. Until the Rosetta SLDL emerged, no good way existed to help the design team "get its arms around" all of the requirements for a complex system. Requirements related issues are the most common source of systems engineering problems and they impact all aspects of product development. Requirements models help design teams stay "on the same page" with each other. Requirements modeling reduces cycle time, reduces costs, reduces the probability of overruns, and helps with support and sustainment of the product. Requirements models will be the input to many new and enhanced design automation tools and processes. The benefits of requirements modeling technology are wide reaching, because system requirements touch everything and everyone associated with a product. C1 USAF, Informat Directorate, AFRL, IFTA,Res Lab, Wright Patterson AFB, OH 45433 USA. RP Barker, D (reprint author), USAF, Informat Directorate, AFRL, IFTA,Res Lab, Wright Patterson AFB, OH 45433 USA. NR 0 TC 3 Z9 3 U1 0 U2 0 PU IEEE COMPUTER SOC PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, PO BOX 3014, LOS ALAMITOS, CA 90720-1264 USA BN 0-7695-0890-1 PY 2000 BP 3 EP 6 DI 10.1109/VIUF.2000.890177 PG 4 WC Computer Science, Hardware & Architecture; Engineering, Electrical & Electronic SC Computer Science; Engineering GA BR14K UT WOS:000165733000001 ER PT S AU Claypoole, RL Baraniuk, RG AF Claypoole, RL Baraniuk, RG BE Aldroubi, A Laine, AF Unser, MA TI A multiresolution wedgelet transform for image processing SO WAVELET APPLICATIONS IN SIGNAL AND IMAGE PROCESSING VIII PTS 1 AND 2 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Wavelet Applications in Signal and Image Processing VIII CY JUL 31-AUG 04, 2000 CL SAN DIEGO, CA SP SPIE, Soc Ind & Appl Math DE wavelets; wedgelets; lifting; denoising AB Edges in images convey a great deal of information, but wavelet transforms do not provide an economical representation. Thus, popular wavelet-based compression and restoration techniques perform poorly in the presence of edges. We present here a new multiresolution wedgelet transform based on the lifting construction. This transform provides an economical edge representation and thus offers the potential for improved image processing. We demonstrate this potential with applications in image denoising. C1 USAF, Inst Technol, Dept Elect & Comp Engn, Wright Patterson AFB, OH 45433 USA. RP Claypoole, RL (reprint author), USAF, Inst Technol, Dept Elect & Comp Engn, Wright Patterson AFB, OH 45433 USA. NR 13 TC 3 Z9 3 U1 0 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-3764-6 J9 P SOC PHOTO-OPT INS PY 2000 VL 4119 BP 253 EP 262 PN 1-2 PG 10 WC Computer Science, Theory & Methods; Mathematics, Applied SC Computer Science; Mathematics GA BR66B UT WOS:000167102800023 ER PT S AU Hedges, RA AF Hedges, RA BE Aldroubi, A Laine, AF Unser, MA TI Canonical angles, subspace partitioning, and hyrbrid wavelet packets SO WAVELET APPLICATIONS IN SIGNAL AND IMAGE PROCESSING VIII PTS 1 AND 2 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Wavelet Applications in Signal and Image Processing VIII CY JUL 31-AUG 04, 2000 CL SAN DIEGO, CA SP SPIE, Soc Ind & Appl Math DE wavelet packets; canonical correlations; canonical angles; best basis; subspace methods AB In previous work, hybrid wavelet packets were introduced as a generalization of wavelet packets in which the choice of quadrature mirror filter (QMF) is selected adaptively within the wavelet packet analysis. This was motivated by the observation that for certain classes of signals, the choice of appropriate QMF is not only signal dependent, but ma? be scale dependent as well. Best Basis selection was generalized to provide a means of optimizing the representation of a given signal. This method can be viewed as an adaptive partitioning of signal subspaces. In such a scheme it is important to determine a small number of QMFs which will provide some diversity in the partitioning of the subspaces. In the current work, canonical correlations and canonical angles are used to quantify the difference between subspaces spanned by two filter pairs. Preliminary results indicate the utility of this method as a data independent metric for filter comparison. C1 USAF, Res Lab, Griffiss AFB, NY 13441 USA. RP Hedges, RA (reprint author), USAF, Res Lab, Griffiss AFB, NY 13441 USA. NR 16 TC 0 Z9 0 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-3764-6 J9 P SOC PHOTO-OPT INS PY 2000 VL 4119 BP 547 EP 555 DI 10.1117/12.408643 PN 1-2 PG 9 WC Computer Science, Theory & Methods; Mathematics, Applied SC Computer Science; Mathematics GA BR66B UT WOS:000167102800053 ER PT B AU O'Loughlin, EJ Burris, DR AF O'Loughlin, EJ Burris, DR BE Means, JL Hinchee, RE TI Reductive dehalogenation of trichloroethene mediated by wetland dog-transition metal complexes SO WETLANDS & REMEDIATION: AN INTERNATIONAL CONFERENCE LA English DT Proceedings Paper CT International Wetlands and Remediation Conference CY NOV 16-17, 1999 CL SALT LAKE CITY, UT SP Battelle Mem Inst, US Dept Def, Environm Secur Technol Certificat Program, Strateg EnvironmRes & Dev, Morrison Knudsen Corp, USN, Naval Facilities Engn Command, Parsons Engn Sci Inc ID DECHLORINATION AB Natural attenuation of chlorinated solvents, such as trichloroethene (TCE), within aquifers is often slow, leading to long contaminant plumes which can reach surface water discharge points such as wetlands. Though suboxic environments, such as high organic carbon wetland sediments, are often sufficiently reducing to make reductive dechlorination reactions thermodynamically favorable, the transfer of electrons from reduced species to a chlorinated solvent is often kinetically constrained. The reduction rate may be enhanced in the presence of compounds capable of facilitating the transfer of electrons from a bulk reductant to the chlorinated solvent of interest. Ni and Cu complexes with dissolved organic carbon (DOC) in wetland sediment porewaters and surface water were able to mediate the reductive dehalogenation of TCE using Ti(III) citrate as the bulk reductant. The reactions were pseuo-first-order with half lives typically less than 2 h. Reaction rates were comparable for systems containing Ni or Cu Aldrich humic acid complexes. Dechlorination was complete, with the dominant products being ethene and ethane. The mass balance was near 100% and chlorinated intermediates were either absent or at extremely low concentrations. C1 USAF, Res Lab, Tyndall AFB, FL 32403 USA. RP O'Loughlin, EJ (reprint author), USAF, Res Lab, Tyndall AFB, FL 32403 USA. RI O'Loughlin, Edward/C-9565-2013 OI O'Loughlin, Edward/0000-0003-1607-9529 NR 12 TC 3 Z9 3 U1 0 U2 2 PU BATTELLE PRESS PI COLUMBUS PA 505 KING AVE, COLUMBUS, OH 43201 USA BN 1-57477-089-6 PY 2000 BP 1 EP 8 PG 8 WC Engineering, Environmental; Environmental Sciences; Water Resources SC Engineering; Environmental Sciences & Ecology; Water Resources GA BQ66X UT WOS:000089140400001 ER PT S AU Lamberson, SE AF Lamberson, SE BE Lapucci, A Ciofini, M TI The Airborne Laser SO XIII INTERNATIONAL SYMPOSIUM ON GAS FLOW AND CHEMICAL LASERS AND HIGH-POWER LASER CONFERENCE SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT XIIIth International Symposium on Gas Flow and Chemical Lasers and High-Power Laser Conference CY SEP 18-22, 2000 CL FLORENCE, ITALY SP Italian Natl Inst Appl Opt, ENEA, CNR, SPIE, El En SpA, European Off Aerosp Res & Dev, Consorzio CEO AB The US Air Force Airborne Laser (ABL) is a major weapon system development by the United States Air Force to provide an airborne, multi-megawatt laser system with a state-bf-the-art atmospheric compensation system to destroy enemy theater ballistic missiles at long ranges. This system will provide both deterrence and defense against the use of such weapons during regional conflicts. This paper provides an overview of the ABL weapon system including: the notional operational concept, the development approach and schedule, the overall aircraft configuration, the technologies being incorporated in the ABL, and the risk reduction approach being utilized to ensure program success. C1 USAF, Space & Missile Syst Ctr, Airborne Laser Syst Program Off, Kirtland AFB, NM 87117 USA. RP Lamberson, SE (reprint author), USAF, Space & Missile Syst Ctr, Airborne Laser Syst Program Off, Kirtland AFB, NM 87117 USA. NR 0 TC 4 Z9 4 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-3847-2 J9 P SOC PHOTO-OPT INS PY 2000 VL 4184 BP 1 EP 6 PG 6 WC Engineering, Electrical & Electronic; Optics; Physics, Applied; Physics, Atomic, Molecular & Chemical SC Engineering; Optics; Physics GA BS07T UT WOS:000168561900001 ER PT S AU Helms, CA AF Helms, CA BE Lapucci, A Ciofini, M TI Review of the US Air Force Research Laboratory's 10-kW RADICL laser SO XIII INTERNATIONAL SYMPOSIUM ON GAS FLOW AND CHEMICAL LASERS AND HIGH-POWER LASER CONFERENCE SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT XIIIth International Symposium on Gas Flow and Chemical Lasers and High-Power Laser Conference CY SEP 18-22, 2000 CL FLORENCE, ITALY SP Italian Natl Inst Appl Opt, ENEA, CNR, SPIE, El En SpA, European Off Aerosp Res & Dev, Consorzio CEO DE chemical oxygen-iodine laser; RADICL; COIL; oxygen-iodine laser research ID OXYGEN-IODINE LASER; EFFICIENCY AB The US Air Force Research Laboratory has actively pursued the development of the Chemical Oxygen-Iodine Laser (COIL) since its invention in 1977(1). The power scaling potential of the COIL was verified in the late 1980's on the RotoCOIL device, which was later decommissioned. A smaller COIL teststand (ReCOIL) was then upgraded with a rotating-disk oxygen generator and a variable-height slit nozzle to become the principal testbed for continued COIL development The modified device was named the Research Assessment Device Iodine Chemical Laser (RADICL). RADICL has supported several major test campaigns during the past 9 years, many of which have been published. These include 2-D gain maps(2), iodine dissociation studies(3), magnetic gain-switching demonstrations, mode-locking(5), metal cutting/fiber delivery demonstrations, and more recently measurements of water concentration and oxygen yield(6). A review of the major results of these test programs and previously unpublished data are presented. C1 USAF, Res Lab, Directed Energy Directorate, Kirtland AFB, NM 87117 USA. RP Helms, CA (reprint author), USAF, Res Lab, Directed Energy Directorate, Kirtland AFB, NM 87117 USA. NR 7 TC 0 Z9 0 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-3847-2 J9 P SOC PHOTO-OPT INS PY 2000 VL 4184 BP 13 EP 18 PG 6 WC Engineering, Electrical & Electronic; Optics; Physics, Applied; Physics, Atomic, Molecular & Chemical SC Engineering; Optics; Physics GA BS07T UT WOS:000168561900003 ER PT S AU Henshaw, TL Manke, GC Madden, TJ Hager, GD Berman, MR AF Henshaw, TL Manke, GC Madden, TJ Hager, GD Berman, MR BE Lapucci, A Ciofini, M TI A new chemically pumped I (P-2 (1/2) -> P-2 (3/2)) laser at 1.315 mu m SO XIII INTERNATIONAL SYMPOSIUM ON GAS FLOW AND CHEMICAL LASERS AND HIGH-POWER LASER CONFERENCE SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT XIIIth International Symposium on Gas Flow and Chemical Lasers and High-Power Laser Conference CY SEP 18-22, 2000 CL FLORENCE, ITALY SP Italian Natl Inst Appl Opt, ENEA, CNR, SPIE, El En SpA, European Off Aerosp Res & Dev, Consorzio CEO DE chemical laser; iodine laser; energy transfer laser; NCl (a(1)Delta) metastables; azides ID TEMPERATURE-DEPENDENCE; RATE CONSTANTS; ATOMIC IODINE; NCL(A(1)DELTA); TRANSITION; CL+HN3; FLOW AB CW laser action has been demonstrated on the electronic I* (P-2(1/2)) --> I (P-2(3/2)) transition of atomic iodine at 1.315 mum from the NCI (a(1)Delta) + I (P-2 (3/2)) energy transfer reaction. The stimulated emission was generated in a transverse subsonic now device when hydrogen azide, HN3, was injected into a flow of iodine and chlorine atoms. The measured laser output power was 180 mW. C1 USAF, Res Lab, High Power Gas Lasers Directorate, Kirtland AFB, NM 87117 USA. RP Henshaw, TL (reprint author), USAF, Res Lab, High Power Gas Lasers Directorate, Kirtland AFB, NM 87117 USA. NR 12 TC 0 Z9 0 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-3847-2 J9 P SOC PHOTO-OPT INS PY 2000 VL 4184 BP 36 EP 39 PG 4 WC Engineering, Electrical & Electronic; Optics; Physics, Applied; Physics, Atomic, Molecular & Chemical SC Engineering; Optics; Physics GA BS07T UT WOS:000168561900008 ER PT J AU Pullins, SH Dressler, RA Torrents, R Gerlich, D AF Pullins, SH Dressler, RA Torrents, R Gerlich, D TI Guided-ion beam measurements of Ar+ + Ar symmetric charge-transfer cross sections at ion energies ranging from 0.2 to 300 eV SO ZEITSCHRIFT FUR PHYSIKALISCHE CHEMIE-INTERNATIONAL JOURNAL OF RESEARCH IN PHYSICAL CHEMISTRY & CHEMICAL PHYSICS LA English DT Article DE symmetric charge-transfer; guided-ion beam technique; integral and differential cross section ID CROSS-SECTIONS; CHARGE-TRANSFER; POTENTIAL CURVES; COLLISIONS; STATES; DEPENDENCE; IONIZATION AB Guided-Ion Beam (GIB) measurements of the Ar+ + Ar symmetric charge-transfer (SCT) system are presented for ion energies ranging from 0.2 to 300 eV. Two methods are applied to distinguish primary and secondary ions: (i) based on isotopic-labeling, (ii) based on significant laboratory velocity differences. The absolute cross sections measured with these methods are in excellent agreement at energies above 1 eV. The experimental results are compared with semi-classical calculations performed with various published Ar-2(+) potentials. The calculations including spin-orbit effects lie within 10% of the isotope-selected and attenuation measurements at all investigated ion energies. The present results lie significantly above the simple Rapp and Francis model [1]. Important errors in the latter approach are painted out and a correct one-electron model is proposed. First measurements of the differential cross section at 0.5 eV collision energy are briefly mentioned. C1 Tech Univ Chemnitz, D-09107 Chemnitz, Germany. USAF, Res Lab, Space Vehicles Directorate, Bedford, MA 01731 USA. RP Tech Univ Chemnitz, D-09107 Chemnitz, Germany. EM gerlich@physik.tu-chemnitz.de NR 32 TC 32 Z9 32 U1 0 U2 1 PU WALTER DE GRUYTER GMBH PI BERLIN PA GENTHINER STRASSE 13, D-10785 BERLIN, GERMANY SN 0942-9352 J9 Z PHYS CHEM JI Z. Phys. Chemie-Int. J. Res. Phys. Chem. Chem. Phys. PY 2000 VL 214 BP 1279 EP 1297 DI 10.1524/zpch.2000.214.9.1279 PN 9 PG 19 WC Chemistry, Physical SC Chemistry GA 360HU UT WOS:000089661000009 ER PT J AU Medeiros, SC Prasad, YVRK Frazier, WG Srinivasan, R AF Medeiros, SC Prasad, YVRK Frazier, WG Srinivasan, R TI Modeling grain size during hot deformation of IN 718 SO SCRIPTA MATERIALIA LA English DT Article DE IN 718; hot working; microstructure C1 USAF, Mat Proc Design Branch, Mat & Mfg Directorate, Res Lab, Wright Patterson AFB, OH 45433 USA. Wright State Univ, Dayton, OH 45435 USA. RP Medeiros, SC (reprint author), USAF, Mat Proc Design Branch, Mat & Mfg Directorate, Res Lab, Wright Patterson AFB, OH 45433 USA. NR 6 TC 4 Z9 4 U1 0 U2 5 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1359-6462 J9 SCRIPTA MATER JI Scr. Mater. PD DEC 17 PY 1999 VL 42 IS 1 BP 17 EP 23 DI 10.1016/S1359-6462(99)00316-4 PG 7 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA 273PM UT WOS:000084716100004 ER PT J AU Rao, SI Hazzledine, PM AF Rao, SI Hazzledine, PM TI Atomistic simulation of tiny glide loops in FCCNi SO SCRIPTA MATERIALIA LA English DT Article DE atomistic simulations; dislocation loops; nucleation; nickel ID DISLOCATIONS C1 USAF, Res Lab, Mat & Mfg Directorate, MLLM, Wright Patterson AFB, OH 45433 USA. Universal Energy Syst Inc, Dayton, OH 45432 USA. RP Rao, SI (reprint author), USAF, Res Lab, Mat & Mfg Directorate, MLLM, Wright Patterson AFB, OH 45433 USA. NR 14 TC 0 Z9 0 U1 1 U2 2 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1359-6462 J9 SCRIPTA MATER JI Scr. Mater. PD DEC 17 PY 1999 VL 42 IS 1 BP 57 EP 60 DI 10.1016/S1359-6462(99)00310-3 PG 4 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA 273PM UT WOS:000084716100010 ER PT J AU Ornstein, DL Zacharski, LR AF Ornstein, DL Zacharski, LR TI Coronary artery disease in men and women SO NEW ENGLAND JOURNAL OF MEDICINE LA English DT Letter ID IRON C1 Wilford Hall USAF Med Ctr, Lackland AFB, TX 78236 USA. Vet Affairs Med & Reg Off Ctr, White River Junction, VT 05009 USA. RP Ornstein, DL (reprint author), Wilford Hall USAF Med Ctr, Lackland AFB, TX 78236 USA. NR 4 TC 0 Z9 0 U1 0 U2 0 PU MASSACHUSETTS MEDICAL SOC PI WALTHAM PA WALTHAM WOODS CENTER, 860 WINTER ST,, WALTHAM, MA 02451-1413 USA SN 0028-4793 J9 NEW ENGL J MED JI N. Engl. J. Med. PD DEC 16 PY 1999 VL 341 IS 25 BP 1933 EP 1934 PG 2 WC Medicine, General & Internal SC General & Internal Medicine GA 264XZ UT WOS:000084210200015 PM 10610476 ER PT J AU Buffington, J Chandler, P Pachter, M AF Buffington, J Chandler, P Pachter, M TI On-line system identification for aircraft with distributed control effectors SO INTERNATIONAL JOURNAL OF ROBUST AND NONLINEAR CONTROL LA English DT Article DE identification; allocation; adaptive; control AB An algorithm is presented for the identification of aircraft stability derivatives and distributed control derivatives, in real time. Feedback control correlates the effecters' displacement with the aerodynamic angles, while the most commonly used control allocation algorithms correlate the effecters. The result is that valid derivative estimation is not possible. This paper addresses the effector identification problem by including decorrelating excitation into the control allocation cost function while still satisfying the desired control moment, and therefore does not introduce any residual perturbations into the motion variables. A two-step identification algorithm is used where the stability derivative and a generalized control derivative are identified in the first step. Results are shown for a stability axis roll maneuver with the stability and control derivatives being identified for five differential lateral directional effecters. Published in 1999 by John Wiley & Sons, Ltd. This article is a US Government work and is in the public domain in the United States. C1 USAF, AFRL, VAAD, Wright Patterson AFB, OH 45433 USA. USAF, AFIT, ENG, Wright Patterson AFB, OH 45433 USA. RP Buffington, J (reprint author), USAF, AFRL, VAAD, Wright Patterson AFB, OH 45433 USA. NR 14 TC 18 Z9 19 U1 0 U2 1 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX PO19 1UD, ENGLAND SN 1049-8923 J9 INT J ROBUST NONLIN JI Int. J. Robust Nonlinear Control PD DEC 15 PY 1999 VL 9 IS 14 BP 1033 EP 1049 DI 10.1002/(SICI)1099-1239(19991215)9:14<1033::AID-RNC451>3.0.CO;2-# PG 17 WC Automation & Control Systems; Engineering, Electrical & Electronic; Mathematics, Applied SC Automation & Control Systems; Engineering; Mathematics GA 266LZ UT WOS:000084302600004 ER PT J AU Maybeck, PS AF Maybeck, PS TI Multiple model adaptive algorithms for detecting and compensating sensor and actuator/surface failures in aircraft flight control systems SO INTERNATIONAL JOURNAL OF ROBUST AND NONLINEAR CONTROL LA English DT Article DE multiple model adaptive estimation; failure detection; flight control; actuator/sensor failures ID VISTA F-16 AB Multiple model adaptive estimation (MMAE) methods have been incorporated into the design of a flight control system for the variable in-flight stability test aircraft (VISTA) F-16, providing it with the capability to detect and compensate for sensor and control surface/actuator failures. The algorithm consists of a 'front end' estimator for the control system, composed of a bank of parallel Kalman filters, each matched to a specific hypothesis about the failure status of the system (fully functional or a failure in any one sensor or surface/actuator), and a means of blending the filter outputs through a probability-weighted average. For multiple failures, a hierarchical structure is used to keep the number of online filters to a minimum. To compensate for failed control surfaces or actuators, a 'back end' algorithm redistributes control commands (that would normally be sent to surfaces detected as having failed) to the non-failed surfaces, accomplishing the same control action on the aircraft. Failures are demonstrated detectable in less than one second, even at low dynamic pressure (20 000 ft and 0.4 Mach), with an aircraft output nearly identical to that anticipated from a fully functional aircraft in the same environment. Published in 1999 by John Wiley & Sons, Ltd. This article is a US Government work and is in the public domain in the United States. C1 USAF, Inst Technol, Dept Elect & Comp Engn, ENG, Wright Patterson AFB, OH 45433 USA. RP Maybeck, PS (reprint author), USAF, Inst Technol, Dept Elect & Comp Engn, ENG, 2950 P St,Bldg 640, Wright Patterson AFB, OH 45433 USA. NR 31 TC 86 Z9 89 U1 0 U2 7 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX PO19 1UD, ENGLAND SN 1049-8923 J9 INT J ROBUST NONLIN JI Int. J. Robust Nonlinear Control PD DEC 15 PY 1999 VL 9 IS 14 BP 1051 EP 1070 PG 20 WC Automation & Control Systems; Engineering, Electrical & Electronic; Mathematics, Applied SC Automation & Control Systems; Engineering; Mathematics GA 266LZ UT WOS:000084302600005 ER PT J AU Steinberg, ML Page, AB AF Steinberg, ML Page, AB TI Nonlinear adaptive flight control with genetic algorithm design optimization SO INTERNATIONAL JOURNAL OF ROBUST AND NONLINEAR CONTROL LA English DT Article DE flight control; adaptive control; nonlinear control; genetic algorithm AB This paper examines the use of a nonlinear adaptive control law for multi-axis control of a high-performance aircraft with stabilator, aileron and rudder failures. The control law is based on a backstepping design approach with fixed parameter optimization done using a stochastic genetic algorithm. The control law is demonstrated on a six-degree-of-freedom simulation with nonlinear aerodynamic and engine models, actuator models with saturation, and turbulence. There are substantial differences between the control law design and simulation models, which are used to demonstrate some robustness aspects of this control law. To deal with actuator saturation, the Lyapunov function is modified so that the growth of integrated error and the rate of change of parameter growth are both reduced when the surface commands are growing at a rate that will likely saturate the actuators. Published in 1999 by John Wiley & Sons, Ltd. This article is a US Government work and is in the public domain in the United States. C1 USAF, Air Syst Command, Patuxent River, MD 20670 USA. RP Steinberg, ML (reprint author), USAF, Air Syst Command, Bldg 2187,CST 5, Patuxent River, MD 20670 USA. NR 40 TC 15 Z9 15 U1 0 U2 1 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX PO19 1UD, ENGLAND SN 1049-8923 J9 INT J ROBUST NONLIN JI Int. J. Robust Nonlinear Control PD DEC 15 PY 1999 VL 9 IS 14 BP 1097 EP 1115 DI 10.1002/(SICI)1099-1239(19991215)9:14<1097::AID-RNC454>3.0.CO;2-9 PG 19 WC Automation & Control Systems; Engineering, Electrical & Electronic; Mathematics, Applied SC Automation & Control Systems; Engineering; Mathematics GA 266LZ UT WOS:000084302600007 ER PT J AU Alley, TG Brueck, SRJ Wiedenbeck, M AF Alley, TG Brueck, SRJ Wiedenbeck, M TI Secondary ion mass spectrometry study of space-charge formation in thermally poled fused silica SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID 2ND-ORDER NONLINEARITY; GLASS; WATER; FIBER AB Applying a dc electric field across a fused silica sample at elevated temperatures followed by cooling the sample with the field applied (thermal poling) leads to a second-order nonlinearity that has been linked to the formation of a space-charge region in bulk glass. The first microscopic information on the extent of the space-charge region and its behavior with poling time is reported using secondary ion mass spectrometry to monitor the distribution of charged impurities. Lithium and sodium ions are observed to form depletion regions. Potassium and sodium ions as well as a hydrogenated species appear to be injected from the surface. The extent of the space-charge region evolves approximately logarithmically with poling time well after the nonlinearity as measured by second-harmonic generation has been established. The evolution of the space charge region can be qualitatively understood by an ion-exchange model that allows interaction of two ionic carriers with vastly different mobilities. (C) 1999 American Institute of Physics. [S0021-8979(99)02524-4]. C1 Univ New Mexico, Ctr High Technol Mat, Albuquerque, NM 87106 USA. Univ New Mexico, Inst Meteorit, Albuquerque, NM 87106 USA. Univ New Mexico, Adv Mat Lab, Albuquerque, NM 87106 USA. Univ New Mexico, Dept Phys & Astron, Albuquerque, NM 87106 USA. Univ New Mexico, Dept Elect & Comp Engn, Albuquerque, NM 87106 USA. RP Alley, TG (reprint author), USAF, Res Lab, Laser Div, DELO, Kirtland AFB, NM 87117 USA. RI Brueck, Steven/A-6383-2013; OI Brueck, Steven/0000-0001-8754-5633 NR 22 TC 60 Z9 60 U1 0 U2 9 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD DEC 15 PY 1999 VL 86 IS 12 BP 6634 EP 6640 DI 10.1063/1.371736 PG 7 WC Physics, Applied SC Physics GA 259VX UT WOS:000083915600002 ER PT J AU Setzler, SD Schunemann, PG Pollak, TM Ohmer, MC Goldstein, JT Hopkins, FK Stevens, KT Halliburton, LE Giles, NC AF Setzler, SD Schunemann, PG Pollak, TM Ohmer, MC Goldstein, JT Hopkins, FK Stevens, KT Halliburton, LE Giles, NC TI Characterization of defect-related optical absorption in ZnGeP2 SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID ELECTRON-PARAMAGNETIC-RESONANCE; NUCLEAR DOUBLE-RESONANCE; ZINC VACANCY; GROWN ZNGEP2; CDGEAS2; AGGASE2 AB A broad optical absorption band with a peak near 1 mu m is present in most single crystals of ZnGeP2. These same crystals have an electron paramagnetic resonance (EPR) signal which has been assigned to singly ionized zinc vacancies. A direct correlation between the intensity of the optical absorption at 1 mu m and the intensity of the EPR signal has been established using a set of ZnGeP2 crystals where this absorption varied widely. These results suggest that the singly ionized zinc vacancy acceptor plays a direct role in the electronic transition(s) responsible for the 1 mu m optical absorption. In separate experiments, it was found that illuminating the ZnGeP2 crystals with a He-Ne laser (632.8 nm) while at temperatures near 25 K produces an increase in the absorption at 1 mu m and an increase in the zinc vacancy EPR spectrum. These latter results provide further evidence that the absorption at 1 mu m is associated with the singly ionized zinc vacancy acceptor. (C) 1999 American Institute of Physics. [S0021-8979(99)07624-0]. C1 Sanders, Nashua, NH 03061 USA. USAF, Res Lab, Wright Patterson AFB, OH 45433 USA. W Virginia Univ, Dept Phys, Morgantown, WV 26506 USA. RP Setzler, SD (reprint author), Sanders, Nashua, NH 03061 USA. NR 17 TC 39 Z9 40 U1 2 U2 12 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD DEC 15 PY 1999 VL 86 IS 12 BP 6677 EP 6681 DI 10.1063/1.371743 PG 5 WC Physics, Applied SC Physics GA 259VX UT WOS:000083915600009 ER PT J AU Goldstein, JT Ehrlich, C AF Goldstein, JT Ehrlich, C TI Atom and cluster diffusion on Re(0001) SO SURFACE SCIENCE LA English DT Article DE adatoms; clusters; rhenium; single crystal surfaces; surface diffusion ID SURFACE-DIFFUSION; LATTICE STEPS; BINDING-SITES; IR; PT(111); IR(111); GROWTH; W(211); RE; RECONSTRUCTION AB Diffusion of Re and W adatoms and Re clusters has been surveyed on the close-packed (0001) surface of rhenium, the first study of atom motion on an hcp metal. From the temperature dependence of the diffusivity, the activation energies to diffusion are found to be 11.11+/-0.43 and 11.04+/-0.34 kcal mol(-1) for Re and W adatoms. The respective prefactors amount to 6.13(x 2.6(+/-1)) x 10(-6) and 2.17(x 2.7(+/-1)) x 10(-3) cm(2) s(-1). The energy barrier for single adatom motion over the step edge is estimated to be 15.7 +/-0.4 and 19.3 +/-0.4 kcal mol(-1) for Re and W. Before descending the step edge, the adatoms become trapped at the edge, and have to overcome a barrier of similar to 13 kcal mol(-1) to return to the plane's center. The behavior of clusters containing from two to eight Re atoms has also been examined. Rotational Brownian motion is observed for Re(4) under the influence of a strong imaging held. The activation energies for diffusion of Re clusters on Re(0001) are found to bear a striking resemblance to those of Ir clusters on the Ir(111) surface. Comparison of single atom diffusion on Re(0001) with that on other densely packed surfaces reveals that the diffusion barriers do not scale quantitatively with the cohesive energy. (C) 1999 Elsevier Science B.V. All rights reserved. C1 Univ Illinois, Mat Res Lab, Urbana, IL 61801 USA. Univ Illinois, Dept Phys, Urbana, IL 61801 USA. RP Goldstein, JT (reprint author), USAF, Res Lab, MLPO, 3005 P St Suite 6, Wright Patterson AFB, OH 45433 USA. NR 33 TC 10 Z9 10 U1 1 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0039-6028 J9 SURF SCI JI Surf. Sci. PD DEC 10 PY 1999 VL 443 IS 1-2 BP 105 EP 115 DI 10.1016/S0039-6028(99)00950-4 PG 11 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA 267XW UT WOS:000084385400014 ER PT J AU Salah, MM Raines, RA Temple, MA Bailey, TG AF Salah, MM Raines, RA Temple, MA Bailey, TG TI Approach for deriving performance bounds of punctured turbo codes SO ELECTRONICS LETTERS LA English DT Article AB The average upper bound for punctured turbo codes is derived from knowledge of the conditional weight enumerating function of the original low-rate code. A novel approach to generating these bounds, hypergeometric puncturing, is introduced, which enables the performance to be averaged over all possible puncturing positions at a required code rate. C1 USAF, Inst Technol, Dept Elect & Comp Engn, Wright Patterson AFB, OH 45433 USA. RP Salah, MM (reprint author), USAF, Inst Technol, Dept Elect & Comp Engn, Wright Patterson AFB, OH 45433 USA. NR 4 TC 1 Z9 1 U1 0 U2 0 PU IEE-INST ELEC ENG PI HERTFORD PA MICHAEL FARADAY HOUSE SIX HILLS WAY STEVENAGE, HERTFORD SG1 2AY, ENGLAND SN 0013-5194 J9 ELECTRON LETT JI Electron. Lett. PD DEC 9 PY 1999 VL 35 IS 25 BP 2191 EP 2192 DI 10.1049/el:19991464 PG 2 WC Engineering, Electrical & Electronic SC Engineering GA 272ZX UT WOS:000084682300027 ER PT J AU Srinivas, GN Hamilton, TP Boatz, JA Lammertsma, K AF Srinivas, GN Hamilton, TP Boatz, JA Lammertsma, K TI Theoretical studies of B2Lin (n=1-4) SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID HYPERVALENT 1ST-ROW MOLECULES; GAUSSIAN-2 THEORY; LITHIUM; STABILITIES; EXTENSIONS; PRINCIPLES; CHEMISTRY; EXCHANGE; ENERGIES; BORON AB Structures and energies of the binary B2Lin (n = 1-4) clusters are predicted with the HF, MP2, and B3LYP methods using the 6-31G(d) basis set, including energy evaluations at G2MP2 and CBS-Q and the larger 6-311+G(2d) basis set for B3LYP. All systems except B2Li4 are also computed with the CASSCF method because of spin contamination for several of the open-shell systems. These were followed by energy evaluations with multiconfigurational perturbation theory. The global B2Li minimum has a C-2v triangular form of which the B-2(1) State is 13 kcal/mol more stable than the (2)A(1) state. A bent double Li-bridged structure (C-2v) is the global B2Li2 minimum with a 2.0 kcal/mol inversion barrier. The global minimum for B2Li3 is a triple Li-bridged propellane-like structure (D-3h), and for B2Li4 it is the quadruple Li-bridged structure (D-4h). All these structure have a high degree of ionicity, but in B2Li4 stabilization through LiLi interactions also become important. Structural patterns for the isomers of these clusters are examined. Cohesive energies (B2Lin --> B-2 + Li-n) and Li and Li-2 elimination energies are analyzed in terms of cluster stabilities. C1 Univ Alabama, Dept Chem, Birmingham, AL 35294 USA. USAF, Res Lab, AFRL, PRSP, Edwards AFB, CA 93524 USA. Vrije Univ Amsterdam, Dept Chem, NL-1081 HV Amsterdam, Netherlands. RP Lammertsma, K (reprint author), Univ Alabama, Dept Chem, Birmingham, AL 35294 USA. NR 39 TC 3 Z9 3 U1 0 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1089-5639 J9 J PHYS CHEM A JI J. Phys. Chem. A PD DEC 2 PY 1999 VL 103 IS 48 BP 9931 EP 9937 DI 10.1021/jp992105y PG 7 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 263EX UT WOS:000084113100044 ER PT J AU Gaitonde, DV Shang, JS Garrison, TJ Zheltovodov, AA Maksimov, AI AF Gaitonde, DV Shang, JS Garrison, TJ Zheltovodov, AA Maksimov, AI TI Three-dimensional turbulent interactions caused by asymmetric crossing-shock configurations SO AIAA JOURNAL LA English DT Article; Proceedings Paper CT AIAA 28th Fluid Dynamics Conference CY JUN 29-JUL 02, 1997 CL SNOWMASS VILLAGE, COLORADO SP Amer Inst Aeronaut & Astronaut ID BOUNDARY-LAYER INTERACTION AB A further understanding is developed of the physics of three-dimensional shock-wave/turbulent boundary-layer interactions produced by asymmetric double-fin geometries. A numerical method is employed to reproduce the mean flow of an experimental test matrix of six configurations composed of all combinations of 7-, 11-, and 15-deg fins, yielding interactions of various degrees of asymmetry and strength. The nature of asymmetric interactions is discussed with particular emphasis on the case where the two sharp fins have angles of 7 and 15 deg, respectively. The flowfield can be described in terms of a vortical structure impinging on a side wall and becoming aligned in a direction parallel to it. Details of the shock pattern and vorticity field are correlated with the streamline structure and assimilated within the framework developed in previous work for symmetric interactions. The changes occurring with increasing interaction strength in the total pressure map and vorticity field are elucidated. C1 USAF, Res Lab, Air Vehicles Directorate, Wright Patterson AFB, OH 45433 USA. Louisiana State Univ, Dept Mech Engn, Baton Rouge, LA 70803 USA. Russian Acad Sci, Inst Theoret & Appl Mech, Separated Flows Res Grp, Novosibirsk 630090, Russia. RP Gaitonde, DV (reprint author), USAF, Res Lab, Air Vehicles Directorate, Wright Patterson AFB, OH 45433 USA. NR 23 TC 12 Z9 12 U1 0 U2 2 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 USA SN 0001-1452 J9 AIAA J JI AIAA J. PD DEC PY 1999 VL 37 IS 12 BP 1602 EP 1608 DI 10.2514/2.660 PG 7 WC Engineering, Aerospace SC Engineering GA 263JB UT WOS:000084120600009 ER PT J AU Jumper, GY Beland, RR Roadcap, JR Cote, OR AF Jumper, GY Beland, RR Roadcap, JR Cote, OR TI Effect of compressible flow on perceived temperature fluctuations measured by moving sensor SO AIAA JOURNAL LA English DT Article; Proceedings Paper CT AIAA 29th Plasmadynamics and Lasers Conference CY JUN 15-18, 1998 CL ALBUQUERQUE, NEW MEXICO SP Amer Inst Aeronaut & Astronaut ID RADAR MEASUREMENTS; DISSIPATION RATE; TURBULENCE; LAYER; VELOCITY AB Equations are developed for the effect of velocity fluctuations on a moving temperature sensor. The impact of these fluctuations on perceived fluctuations of the index of refraction is computed. The magnitude of this effect is estimated using known ranges of fluctuations in atmospheric temperature-and velocity. By the use of a method to estimate velocity fluctuations from temperature fluctuations and concurrently measured atmospheric data, balloon derived fluctuation data are used to estimate the perceived fluctuations df a faster moving sensor. We conclude that normally observed velocity fluctuations, if uncorrected, can have a significant impact on the perceived optical properties in the troposphere for higher velocity temperature sensors. C1 USAF, Res Lab, Battlespace Environm Div, Hanscom AFB, MA 01731 USA. RP Jumper, GY (reprint author), USAF, Res Lab, Battlespace Environm Div, Hanscom AFB, MA 01731 USA. NR 35 TC 4 Z9 4 U1 0 U2 0 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 USA SN 0001-1452 J9 AIAA J JI AIAA J. PD DEC PY 1999 VL 37 IS 12 BP 1609 EP 1616 DI 10.2514/2.642 PG 8 WC Engineering, Aerospace SC Engineering GA 263JB UT WOS:000084120600010 ER PT J AU Cina, SJ Thompson, WC Fischer, JR Brown, DK Titus, JM Smialek, JE AF Cina, SJ Thompson, WC Fischer, JR Brown, DK Titus, JM Smialek, JE TI A study of various morphologic variables and troponin I in pericardial fluid as possible discriminators of sudden cardiac death SO AMERICAN JOURNAL OF FORENSIC MEDICINE AND PATHOLOGY LA English DT Article DE death; troponin; heart; autopsy; sudden death; cTnI ID ACUTE MYOCARDIAL-INFARCTION; CARDIOVASCULAR-DISEASE; POSTMORTEM DIAGNOSIS; CORONARY DEATH; AUTOPSY; PATHOLOGY; NECROPSY; ENZYMES; HEART AB Pathologists frequently examine victims of sudden cardiac death. In some cases, a firm diagnosis of cardiac-related death can be made based on conclusive gross and histologic findings. In many other cases, we find evidence supportive of, but not diagnostic of, cardiac death (e.g., atherosclerotic coronary artery disease, cardiomegaly, myocardial scarring). A final cohort consists of cases of sudden death with minimal to mild cardiac disease, no other significant pathology, and negative toxicologic studies. This prospective study compared 38 cardiac-related deaths with 52 control cases with respect to concentrations of pericardial cardiac troponin I (cTnI), heart weight, evidence of old and/or recent myocardial injury, and presence of significant coronary artery disease. The influence of documented chest trauma and/or perimortem cardiopulmonary resuscitation (CPR) on levels of cTnI was also analyzed. Even though median cTnI levels were significantly higher in cardiac deaths than in controls (p = .003), cTnI was not found to be a significant predictor of cardiac deaths, as determined by discriminant analysis (p = .52). Heart weight >500 g, evidence of old and recent myocardial injury, and significant coronary artery disease were seen statistically more often in cardiac deaths than in controls (p less than or equal to .005 in each case), and median age was significantly higher in cardiac deaths than in controls (p = .001). Based on a stepwise logistic regression model, significant coronary artery disease, old and recent myocardial injury, and heart weight >500 g were found to contribute significantly to the prediction of cardiac death. Finally, neither chest injury nor CPR significantly affected concentrations of cTnI in pericardial fluid. These data confirm that the presence of acute and remote myocardial injury, significant coronary artery disease, and cardiomegaly (heart weight >500 g) strongly supports the diagnosis of a cardiac-related death. In contrast to a recently published report, we do not find that elevated concentrations of cTnI in pericardial fluid are strong indicators of cardiac-related deaths using our methodology. C1 Wilford Hall USAF Med Ctr, Lackland AFB, TX 78236 USA. RP Cina, SJ (reprint author), Off Chief Med Examiner State Maryland, 111 Penn St, Baltimore, MD 21201 USA. NR 27 TC 12 Z9 13 U1 0 U2 0 PU LIPPINCOTT WILLIAMS & WILKINS PI PHILADELPHIA PA 530 WALNUT ST, PHILADELPHIA, PA 19106-3621 USA SN 0195-7910 J9 AM J FOREN MED PATH JI Am. J. Forensic Med. Pathol. PD DEC PY 1999 VL 20 IS 4 BP 333 EP 337 DI 10.1097/00000433-199912000-00004 PG 5 WC Medicine, Legal; Pathology SC Legal Medicine; Pathology GA 267AC UT WOS:000084331600004 PM 10624925 ER PT J AU Fang, R Pilcher, JA Putnam, AT Smith, T Smith, DL AF Fang, R Pilcher, JA Putnam, AT Smith, T Smith, DL TI Accuracy of surgeon-performed gallbladder ultrasound SO AMERICAN JOURNAL OF SURGERY LA English DT Article; Proceedings Paper CT 51st Annual Meeting of the Southwestern-Surgical-Congress CY APR 18-21, 1999 CL CORONADO, CALIFORNIA SP SW Surg Congress ID BLUNT ABDOMINAL-TRAUMA; CHOLECYSTECTOMY AB BACKGROUND: Symptomatic cholelithiasis is among the most common of general surgery referrals. With an appropriate clinical presentation, definitive diagnosis requires documentation of gallstones by ultrasonography (US). The authors evaluated the accuracy of surgeon-performed US for identifying gallstones in patients with a nonacute indication for study. METHODS: Patients referred for symptomatic cholelithiasis and who provided informed consent received an US examination by one or more of the surgical investigators. Surgeon-performed US findings were correlated with radiologist US findings and pathologic diagnoses. RESULTS: Seventy-seven patients received a total of 128 examinations by the investigators. Surgeon-performed US examination agreed with the radiologist US findings for 112 of 122 studies (92%) with a sensitivity of 100% and a specificity of 95%. Surgeon-performed US findings correlated with the pathologic diagnoses for 83 of 86 studies (97%). CONCLUSIONS: Surgeons can perform gallbladder US in the nonacute setting with a high degree of accuracy. Am J Surg. 1999;178:475-479. (C) 1999 by Excerpta Medica, Inc. C1 Wilford Hall USAF Med Ctr, Dept Gen Surg, Lackland AFB, TX 78236 USA. RP Fang, R (reprint author), Wilford Hall USAF Med Ctr, Dept Gen Surg, 959 MDOS MMKG,2200 Bergquist Dr,suite 1, Lackland AFB, TX 78236 USA. NR 15 TC 9 Z9 9 U1 0 U2 0 PU CAHNERS PUBL CO PI NEW YORK PA 249 WEST 17 STREET, NEW YORK, NY 10011 USA SN 0002-9610 J9 AM J SURG JI Am. J. Surg. PD DEC PY 1999 VL 178 IS 6 BP 475 EP 478 DI 10.1016/S0002-9610(99)00225-1 PG 4 WC Surgery SC Surgery GA 276ZV UT WOS:000084909000014 PM 10670856 ER PT J AU Subramanian, S Bowyer, MW Egan, JC Knolmayer, TJ AF Subramanian, S Bowyer, MW Egan, JC Knolmayer, TJ TI Attenuation of renal ischemia-reperfusion injury with selectin inhibition in a rabbit model SO AMERICAN JOURNAL OF SURGERY LA English DT Article; Proceedings Paper CT 51st Annual Meeting of the Southwestern-Surgical-Congress CY APR 18-21, 1999 CL CORONADO, CALIFORNIA SP SW Surg Congress ID ISCHEMIA/REPERFUSION INJURY; MONOCLONAL-ANTIBODY; ACID AB BACKGROUND: The selectin glycoproteins are involved in the pathogenesis of renal ischemiare-perfusion injury, We investigated the ability of glycyrrhizin, a known selectin inhibitor, to attenuate renal ischemia-reperfusion injury. METHODS: Eighteen New Zealand white rabbits underwent midline laparotomy with renal artery cross-clamping, After 30 minutes of reperfusion, group 1 (control, n = 10) animals received a saline infusion, while group 2 (GLY, n = 8) animals received a glycyrrhizin infusion. Renal function was compared between the two groups after 72 hours of reperfusion. A t test was utilized, with alpha set at P <0.05. RESULTS: Group 1 and group 2 animals had similar baseline renal function. However, after 72 hours of reperfusion, group 1 animals had a significantly higher mean blood urea nitrogen creatinine ratio than group 2 animals (P <0.01), indicating preserved renal function in rabbits treated with glycyrrhizin. CONCLUSIONS: Selectin blockade using glycyrrhizin attenuates renal ischemia-reperfusion injury when given 30 minutes after the onset of reperfusion in a rabbit model, Am J Surg. 1999;178: 573-576. (C) 1999 by Excerpta Medica, Inc. C1 David Grant Med Ctr, Dept Surg, SGCQ, Travis AFB, CA 94535 USA. RP Subramanian, S (reprint author), David Grant Med Ctr, Dept Surg, SGCQ, 101 Bodin Circle, Travis AFB, CA 94535 USA. NR 16 TC 16 Z9 19 U1 0 U2 0 PU CAHNERS PUBL CO PI NEW YORK PA 249 WEST 17 STREET, NEW YORK, NY 10011 USA SN 0002-9610 J9 AM J SURG JI Am. J. Surg. PD DEC PY 1999 VL 178 IS 6 BP 573 EP 575 DI 10.1016/S0002-9610(99)00238-X PG 3 WC Surgery SC Surgery GA 276ZV UT WOS:000084909000069 PM 10670875 ER PT J AU Murray, DJ Vallance, BJ AF Murray, DJ Vallance, BJ TI Security studies for the 21st century. SO ARMED FORCES & SOCIETY LA English DT Book Review C1 USAF Acad, Colorado Springs, CO 80840 USA. RP Murray, DJ (reprint author), USAF Acad, Colorado Springs, CO 80840 USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU TRANSACTION PERIOD CONSORTIUM PI PISCATAWAY PA DEPT 4010, RUTGERS UNIV, 35 BERRUE CIRCLE, PISCATAWAY, NJ 08854-8042 USA SN 0095-327X J9 ARMED FORCES SOC JI Armed Forces Soc. PD WIN PY 1999 VL 25 IS 2 BP 333 EP 335 DI 10.1177/0095327X9902500209 PG 3 WC Political Science; Sociology SC Government & Law; Sociology GA 187FW UT WOS:000079777000009 ER PT J AU Wakin, MM AF Wakin, MM TI The scroll or the sword? Dilemmas of religion and military service in Israel. SO ARMED FORCES & SOCIETY LA English DT Book Review C1 USAF, Washington, DC 20330 USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU TRANSACTION PERIOD CONSORTIUM PI PISCATAWAY PA DEPT 4010, RUTGERS UNIV, 35 BERRUE CIRCLE, PISCATAWAY, NJ 08854-8042 USA SN 0095-327X J9 ARMED FORCES SOC JI Armed Forces Soc. PD WIN PY 1999 VL 25 IS 2 BP 338 EP 340 DI 10.1177/0095327X9902500211 PG 3 WC Political Science; Sociology SC Government & Law; Sociology GA 187FW UT WOS:000079777000011 ER PT J AU Gallimore, JJ Brannon, NG Patterson, FR Nalepka, JP AF Gallimore, JJ Brannon, NG Patterson, FR Nalepka, JP TI Effects of FOV and aircraft bank on pilot head movement and reversal errors during simulated flight SO AVIATION SPACE AND ENVIRONMENTAL MEDICINE LA English DT Article DE helmet-mounted displays; spatial orientation; field of view; opto-kinetic cervical reflex; head movements; control reversal errors ID AVIATION SPATIAL ORIENTATION; POSITION; REFLEX AB Background: Recent studies have shown that while flying under Visual meteorological conditions (VMC) pilots tilt their head to keep the horizon stabilized on their fovea. This reflex, referred to as Opto-Kinetic Cervical Reflex (OKCR), may improve spatial awareness by establishing the horizon retinal image as a stabilized primary visual-spatial cue. Since the limited field of View (FOV) provided by helmet-mounted displays (HMDs) significantly decreases visual stimuli, the purpose of this research was to determine how reduced FOV affects head movements. Hypotheses: As FOV is decreased, there will be a significant reduction in OKCR-induced head movement. Reduced FOV will also increase control reversal errors. Methods: Twelve pilots completed simulated flight tasks in a stationary dome. Head tilt, pitch, and yaw were examined as a function of aircraft bank and FOV(40 degrees, 60 degrees and 100 degrees circular). The number of control reversal errors was analyzed to investigate signs of spatial disorientation. Results:During VMC manuevers pilots exhibited significant OKCR; however there were no significant differences among the three levels of FOV. FOV significantly affected head pitch movements under both VMC and instrument meteorological conditions (IMC). Pilots yawed their heads in the direction of aircraft bank under VMC. Pilots committed 22 reversal errors out of 72 trials (30.55%). The magnitude of the error was largest for the 40 degrees FOV condition. Conclusions: Pilots exhibit the OKCR under all tested levels of FOV and also make head yaw movements in order to keep the way point in sight during banking maneuvers. Pilots demonstrated stick reversal errors when transitioning from following a lead aircraft under both VMC and IMC conditions. C1 Wright State Univ, Dept Biomed & Human Factors Engn, Russ Engn Ctr 207, Dayton, OH 45435 USA. USN, Aerosp Med Res Lab, Pensacola, FL USA. USAF, Res Lab, Wright Patterson AFB, OH 45433 USA. RP Gallimore, JJ (reprint author), Wright State Univ, Dept Biomed & Human Factors Engn, Russ Engn Ctr 207, Dayton, OH 45435 USA. NR 9 TC 9 Z9 9 U1 0 U2 1 PU AEROSPACE MEDICAL ASSOC PI ALEXANDRIA PA 320 S HENRY ST, ALEXANDRIA, VA 22314-3579 USA SN 0095-6562 J9 AVIAT SPACE ENVIR MD JI Aviat. Space Environ. Med. PD DEC PY 1999 VL 70 IS 12 BP 1152 EP 1160 PG 9 WC Public, Environmental & Occupational Health; Medicine, General & Internal; Sport Sciences SC Public, Environmental & Occupational Health; General & Internal Medicine; Sport Sciences GA 258VF UT WOS:000083859300002 PM 10596767 ER PT J AU Boyan, BD Sylvia, VL Liu, YH Sagun, R Cochran, DL Lohmann, CH Dean, DD Schwartz, Z AF Boyan, BD Sylvia, VL Liu, YH Sagun, R Cochran, DL Lohmann, CH Dean, DD Schwartz, Z TI Surface roughness mediates its effects on osteoblasts via protein kinase A and phospholipase A(2) SO BIOMATERIALS LA English DT Article DE protein kinase A; PKA; phospholipase A(2); PLA(2); surface roughness; osteoblasts; MG63 cells; titanium; 1,25-(OH)(2)D-3 ID GROWTH-FACTOR-BETA; IMPLANT MATERIALS; EXTRACELLULAR-MATRIX; MEMBRANE-RECEPTOR; TITANIUM SURFACES; ARACHIDONIC-ACID; CELLS MG63; INVITRO; DIFFERENTIATION; PROLIFERATION AB Earlier studies have shown that implant surface roughness influences osteoblast proliferation, differentiation, matrix synthesis and local factor production. Moreover, the responsiveness of osteoblasts to systemic hormones, such as 1,25-(OH)(2)D-3, at the implant surface is also influenced by surface roughness and this effect is mediated by changes in prostaglandins. At present, it is not known which signaling pathways are involved in mediating cell response to surface roughness and how 1,25-(OH)(2)D-3 treatment alters the activation of these pathways. This paper reviews a series of studies that have addressed this question. MG63 osteoblast-like cells were cultured on commercially pure titanium (cpTi) surfaces of two different roughnesses (R-a 0.54 and 4.92 mu m) in the presence of control media or media containing 1,25-(OH)(2)D-3 or 1,25-(OH)(2)D-3 plus H8 (a protein kinase A inhibitor) or quinacrine (a phospholipase A(2) inhibitor). At harvest, the effect of these treatments on cell number and alkaline phosphatase specific activity was measured. Compared to cultures grown on the smooth surface, cell number was reduced on the rough surface. 1,25-(OH)(2)D-3 inhibited cell number on both surfaces and inhibition of protein kinase A in the presence of 1,25-(OH)(2)D-3 restored cell number to that seen in the control cultures. Inhibition of phospholipase A(2) in the presence of 1,25-(OH)(2)D-3 caused a further reduction in cell number on the smooth surface, and partially reversed the inhibitory effects of 1,25-(OH)(2)D-3 on the rough surface. Alkaline phosphatase specific activity was increased in cultures grown on the rough surface compared with those grown on the smooth surface; 1,25-(OH)(2)D-3 treatment increased enzyme specific activity on both surfaces. Cultures treated with H8 and 1,25-(OH)(2)D-3 displayed enzyme specific activity that approximated that seen in control cultures. Inhibition of phospholipase A(2) also inhibited the 1,25-(OH)(2)D-3-dependent effect on the smooth surface, but on the rough surface there was an inhibition of the 1,25-(OH)(2)D-3 effect as well as a partial inhibition of the surface roughness-dependent effect. The results indicate that surface roughness and 1,25-(OH)(2)D-3 mediate their effects through phospholipase A(2), which catalyzes one of the rate-limiting steps in prostaglandin E-2 production. Further downstream, prostaglandin E-2 activates protein kinase A. (C) 1999 Elsevier Science Ltd. All rights reserved. C1 Univ Texas, Hlth Sci Ctr, Dept Orthopaed, San Antonio, TX 78229 USA. Univ Texas, Hlth Sci Ctr, Dept Periodont, San Antonio, TX 78229 USA. Univ Texas, Hlth Sci Ctr, Dept Biochem, San Antonio, TX 78229 USA. Wilford Hall USAF Med Ctr, Lackland AFB, TX 78236 USA. Univ Gottingen, Dept Orthopaed, D-3400 Gottingen, Germany. Hebrew Univ Jerusalem, Hadassah Fac Dent Med, Jerusalem, Israel. RP Boyan, BD (reprint author), Univ Texas, Hlth Sci Ctr, Dept Orthopaed, Mail Code 7774,7703 Floyd Curl Dr, San Antonio, TX 78229 USA. FU NIDCR NIH HHS [DE-05937] NR 40 TC 90 Z9 93 U1 0 U2 2 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0142-9612 J9 BIOMATERIALS JI Biomaterials PD DEC PY 1999 VL 20 IS 23-24 BP 2305 EP 2310 DI 10.1016/S0142-9612(99)00159-3 PG 6 WC Engineering, Biomedical; Materials Science, Biomaterials SC Engineering; Materials Science GA 266BQ UT WOS:000084281100011 PM 10614936 ER PT J AU Previc, FH AF Previc, FH TI Dopamine and the origins of human intelligence SO BRAIN AND COGNITION LA English DT Review DE dopamine; cognition; thermoregulation; human evolution; nonhuman intelligence ID ATTENTION DEFICIT DISORDER; RIGHT-HEMISPHERE LANGUAGE; PROGRESSIVE MATRICES TEST; TEMPORAL-LOBE EPILEPSY; SPATIAL WORKING-MEMORY; VERTICAL EYE-MOVEMENTS; PARKINSONS-DISEASE; COGNITIVE DEFICITS; PREFRONTAL CORTEX; HUMAN BRAIN AB A general theory is proposed that attributes the origins of human intelligence to an expansion of dopaminergic systems in human cognition. Dopamine is postulated to be the key neurotransmitter regulating six predominantly left-hemispheric cognitive skills critical to human language and thought: motor planning, working memory, cognitive flexibility, abstract reasoning, temporal analysis/sequencing, and generativity. A dopaminergic expansion during early hominid evolution could have enabled successful chase-hunting in the savannas of sub-Saharan Africa, given the critical role of dopamine in counteracting hyperthermia during endurance activity. In turn, changes in physical activity and diet may have further increased cortical dopamine levels by augmenting tyrosine and its conversion to dopamine in the central nervous system (CNS), By means of the regulatory action of dopamine and other substances, the physiological and dietary changes may have contributed to the vertical elongation of the body, increased brain size, and increased cortical convolutedness that occurred during human evolution. Finally, emphasizing the role of dopamine in human intelligence may offer a new perspective on the advanced cognitive reasoning skills in nonprimate lineages such as cetaceans and avians, whose cortical anatomy differs radically from that of primates. (C) 1999 Academic Press. C1 USAF, Res Lab, Human Effectiveness Directorate, Flight Stress Protect Div,Flight Mot Effects Bran, Brooks AFB, TX USA. RP Previc, FH (reprint author), TASC, LITTON, 4241 Woodcock Dr,Ste B-100, San Antonio, TX 78228 USA. NR 305 TC 104 Z9 108 U1 5 U2 26 PU ACADEMIC PRESS INC PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0278-2626 J9 BRAIN COGNITION JI Brain Cogn. PD DEC PY 1999 VL 41 IS 3 BP 299 EP 350 DI 10.1006/brcg.1999.1129 PG 52 WC Neurosciences; Psychology, Experimental SC Neurosciences & Neurology; Psychology GA 264WC UT WOS:000084205100004 PM 10585240 ER PT J AU Rowles, DM Fraser, SL AF Rowles, DM Fraser, SL TI Amphotericin B lipid complex (ABLC)-associated hypertension: Case report and review SO CLINICAL INFECTIOUS DISEASES LA English DT Article AB Amphotericin B (AmB) continues to be the mainstay of therapy for serious fungal infections, despite ifs relatively toxic side-effect profile. Lipid preparations of the medication have been marketed in the past few years in an attempt to reduce same of these side effects, especially nephrotoxicity. Although 6 cases of severe hypertension associated with the use of AmB deoxycholate have been reported in the literature, no cases of hypertension associated with a Lipid-containing preparation of the medication have been reported. We report here the first case of severe hypertension associated with the infusion of AmB lipid complex (ABLC)in a patient with multiple intraperitoneal and urinary fungal pathogens. We also provide a brief review of the previously reported cases of hypertension associated with the deoxycholate formulation of AmB. C1 Wilford Hall USAF Med Ctr, Dept Infect Dis, Lackland AFB, TX 78236 USA. Brooke Army Med Ctr, Dept Med, Ft Sam Houston, TX 78234 USA. RP Rowles, DM (reprint author), 74th MDOS-SGOM,4881 Sugar Maple Dr, Wright Patterson AFB, OH 45433 USA. NR 9 TC 10 Z9 11 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 1058-4838 J9 CLIN INFECT DIS JI Clin. Infect. Dis. PD DEC PY 1999 VL 29 IS 6 BP 1564 EP 1565 DI 10.1086/313533 PG 2 WC Immunology; Infectious Diseases; Microbiology SC Immunology; Infectious Diseases; Microbiology GA 273DW UT WOS:000084693400043 PM 10585814 ER PT J AU Ting, T Jones, R Chiu, WK Marshall, IH Greer, JM AF Ting, T Jones, R Chiu, WK Marshall, IH Greer, JM TI Composite repairs to rib stiffened panels SO COMPOSITE STRUCTURES LA English DT Article; Proceedings Paper CT 10th International Conference on Composite Structures (ICCS-10) CY NOV 15-17, 1999 CL MONASH UNIV, MELBOURNE, AUSTRALIA SP Monash Univ, Dept Mech Engn, USA Off Res, Far E, USAF Off Sci Res, Asian Off Aerosp Res & Dev, Australian Composite Struct Soc, CRC Adv Composit Structures HO MONASH UNIV DE bonded repair; composites; boron patches; stiffened wing skins; fracture AB There are several methods available for obtaining a first estimate for the design of composite repairs to cracks in thin metallic skins. One approach uses analytical formulae, which build on an analogy with the problem of a bonded symmetric lap joint (Rose LRF. An application of the inclusion analogy for bonded reinforcements. Int J Solid Struct 1981;17:827-838; Fredell RS. Damage tolerant repair techniques for pressurized aircraft fuselages. PhD Thesis, Delft University of Technology, June 1994; Baker AA, Jones R. Bonded repair of aircraft structures. Dordrecht: Martinus Nijhoff, 1988). The present paper extends this methodology to include the bonded repair to rib stiffened wing skins. To this end the present paper presents the results of a series of 3-D finite element analysis of various composite repair configurations. This study reveals that, after repair, the stress intensity factors exhibits an asymptotic behaviour as the crack length increases and that this stress intensity factor is a weak function of the stiffener spacing. (C) 2000 Elsevier Science Ltd. All rights reserved. C1 Monash Univ, Dept Mech Engn, Clayton, Vic 3168, Australia. USAF Acad, Dept Mech Engn, Ctr Aircraft Struct Life Extens, HQ USAFA DEFM, Colorado Springs, CO 80840 USA. RP Ting, T (reprint author), Monash Univ, Dept Mech Engn, Clayton, Vic 3168, Australia. OI jones, rhys/0000-0003-3197-2796 NR 9 TC 54 Z9 54 U1 0 U2 10 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0263-8223 J9 COMPOS STRUCT JI Compos. Struct. PD DEC PY 1999 VL 47 IS 1-4 BP 737 EP 743 DI 10.1016/S0263-8223(00)00046-5 PG 7 WC Materials Science, Composites SC Materials Science GA 353XJ UT WOS:000089300500039 ER PT J AU Gazitt, Y Shaughnessy, P Montgomery, W AF Gazitt, Y Shaughnessy, P Montgomery, W TI Apoptosis-induced by trail and TNF-alpha in human multiple myeloma cells is not blocked by bcl-2 SO CYTOKINE LA English DT Article DE apoptosis; bcl-2; Fas; TNF; TRAIL ID DEXAMETHASONE-INDUCED APOPTOSIS; NECROSIS-FACTOR-ALPHA; NF-KAPPA-B; FAS ANTIGEN; MEDIATED APOPTOSIS; MOLECULAR-CLONING; LEUKEMIA-CELLS; DEATH; RESISTANCE; FAMILY AB TRAIL, the ligand for the newly discovered DR-4 and DR-5 receptor is a member of the tumour necrosis factor (TNF) family of death signal tranduction proteins with a mechanism of cell death, similar to the Pas and Pas ligand (Fas-L) system. Here, we provide first time evidence that TRAIL and TNF-alpha are potent inducers of apoptosis in multiple myeloma (MM) cell lines and freshly isolated myeloma cells, TRAIL effectively induced extensive apoptosis in 8226 and ARP-1 MM cells in a time- and dose-dependent manner reaching 80% within 48 h of treatment with a dose of 160 ng/ml, Bcl-2 transfected 8226 and ARP-1 cells were equally sensitive to apoptosis by TRAIL, Apoptosis with TNF alpha reached >60% within 48 h of treatment with a dose of 160 ng/ml, In addition to MM cell lines, freshly isolated, how-sorted myeloma cells from 8 different MM patients expressing variable levels of bcl-2 were equally sensitive to both TRAIL and TNF-alpha, We have previously shown that anti-Fas-induced apoptosis is not blocked by endogenous or ectopic bcl-2 in MM cell lines. Here we extend our observation with Pas to include TNF-alpha and TRAIL to the apoptotic signals that are not be blocked by bcl-2, in LMM cells, (C) 1999 Academic Press. C1 Univ Texas, Hlth Sci Ctr, Dept Med Hematol, San Antonio, TX 78284 USA. Wilford Hall USAF Med Ctr, San Antonio, TX 78284 USA. RP Gazitt, Y (reprint author), Univ Texas, Hlth Sci Ctr, Dept Med, Div Hematol, 7703 Floyd Curl Dr, San Antonio, TX 78284 USA. NR 45 TC 59 Z9 60 U1 0 U2 0 PU W B SAUNDERS CO PI PHILADELPHIA PA INDEPENDENCE SQUARE WEST CURTIS CENTER, STE 300, PHILADELPHIA, PA 19106-3399 USA SN 1043-4666 J9 CYTOKINE JI Cytokine PD DEC PY 1999 VL 11 IS 12 BP 1010 EP 1019 DI 10.1006/cyto.1999.0536 PG 10 WC Biochemistry & Molecular Biology; Cell Biology; Immunology SC Biochemistry & Molecular Biology; Cell Biology; Immunology GA 274QC UT WOS:000084775700003 PM 10623426 ER PT J AU Morris, MG Speier, C Hoffer, JA AF Morris, MG Speier, C Hoffer, JA TI An examination of procedural and object-oriented systems analysis methods: Does prior experience help or hinder performance? SO DECISION SCIENCES LA English DT Article ID DESIGN; METHODOLOGIES; WORKLOAD; PARADIGM; MODELS AB Interest in object-oriented analysis (OOA) and object-oriented design (OOD) has expanded rapidly over the last several years. Proponents of OOA and OOD have called the shift to these methods "revolutionary" and have cited a number of impressive claims with respect to their use. However, empirical research investigating these claims remains in its infancy. Moreover, an examination of the literature reveals inconclusive and often conflicting results for OOA and OOD methods relative to traditional data and/or procedural techniques. This paper presents the results of an empirical study that examined both experienced and novice systems analysts using both procedural and object-oriented techniques. This research examined whether experience in using procedural methods helped or hindered performance using OOA and compared procedural and OOA methods on the subjective mental workload induced. A human problem-solving model adopted from Newell and Simon (1972) provided the theoretical framework for this study. Dependent variables include subjective mental workload, solution quality, time to perform task, and attitudinal measures. Although some of these dependent variables have been used in past research, we believe this is the first time that subjective mental workload (SMW) has been examined in an IS context. Our results indicate that both novice and experienced subjects demonstrate higher SMW when using OOA. Tn addition, as a group, novices prefer object-oriented techniques and find these techniques easier as compared to experienced subjects. C1 USAF, Inst Technol, Dept Grad Acquisit Management, Wright Patterson AFB, OH 45433 USA. Michigan State Univ, Eli Broad Sch Business, E Lansing, MI 48824 USA. Univ Dayton, Dept MIS & Decis Sci, Dayton, OH 45469 USA. RP Morris, MG (reprint author), USAF, Inst Technol, Dept Grad Acquisit Management, 2950 P St, Wright Patterson AFB, OH 45433 USA. NR 48 TC 17 Z9 17 U1 3 U2 5 PU DECISION SCIENCES INST, GEORGIA STATE UNIV PI ATLANTA PA COLLEGE OF BUSINESS ADMN, UNIVERSITY PLAZA, ATLANTA, GA 30303 USA SN 0011-7315 J9 DECISION SCI JI Decis. Sci. PD WIN PY 1999 VL 30 IS 1 BP 107 EP 136 DI 10.1111/j.1540-5915.1999.tb01603.x PG 30 WC Management SC Business & Economics GA 287QW UT WOS:000085518100006 ER PT J AU Jackson, JA Kloeber, JM Ralston, BE Deckro, RF AF Jackson, JA Kloeber, JM Ralston, BE Deckro, RF TI Selecting a portfolio of technologies: An application of decision analysis SO DECISION SCIENCES LA English DT Article AB The Department of Energy is faced with the critical and complex decision of selecting technologies for waste site remediation. This research focuses on developing a decision support tool which assists the decision maker to find an optimal portfolio. A portfolio consists of selecting the appropriate processes for a remediation site and, subsequently, selecting a technology for each process so that the decision maker's objectives are achieved. The measures supporting the objectives are risk, life-cycle cost, and time required for remediation. The model uses exponential attribute utility functions with an additive objective function. The model provides the decision maker with estimates of the cost and time distributions, and their associated utility. Cumulative frequency distributions illustrate the dominance of technology choices and the variance in the results. The model permits sensitivity analysis in the form of rainbow and tornado diagrams to display the effects of changes in the values of the input variables. Overall, the model provides a generic technology selection tool that can be used to make better informed decisions and may be easily manipulated to reflect changes in the remediation process. C1 JAWP, IDA, Alexandria, VA 22311 USA. USAF, Inst Technol, Dept Operat Sci, Wright Patterson AFB, OH 45433 USA. RP Jackson, JA (reprint author), JAWP, IDA, 1801 N Beauregard St, Alexandria, VA 22311 USA. NR 25 TC 12 Z9 12 U1 1 U2 8 PU DECISION SCIENCES INST, GEORGIA STATE UNIV PI ATLANTA PA COLLEGE OF BUSINESS ADMN, UNIVERSITY PLAZA, ATLANTA, GA 30303 USA SN 0011-7315 J9 DECISION SCI JI Decis. Sci. PD WIN PY 1999 VL 30 IS 1 BP 217 EP 238 DI 10.1111/j.1540-5915.1999.tb01607.x PG 22 WC Management SC Business & Economics GA 287QW UT WOS:000085518100010 ER PT J AU Tubbs, J AF Tubbs, J TI Air apparent SO FOREIGN POLICY LA English DT Letter C1 USAF, Woodbridge, VA USA. RP Tubbs, J (reprint author), USAF, Woodbridge, VA USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU CARNEGIE ENDOWMENT INTL PEACE PI WASHINGTON PA 2400 N STREET NW, WASHINGTON, DC 20037 USA SN 0015-7228 J9 FOREIGN POLICY JI Foreign Policy PD WIN PY 1999 IS 117 BP 170 EP + DI 10.2307/1149583 PG 2 WC International Relations SC International Relations GA 264QB UT WOS:000084192000021 ER PT J AU Post, DL Geiselman, EE Goodyear, CD AF Post, DL Geiselman, EE Goodyear, CD TI Benefits of color coding weapons symbology for an airborne helmet-mounted display SO HUMAN FACTORS LA English DT Article AB We assessed the advantages of a color-coded weapons symbology for a helmet-mounted display over monochrome symbology by measuring military pilots' performance while they flew air-to-air combat in a simulator. The pilots fired missiles significantly sooner without sacrificing probability of kill when using the color-coded symbology, demonstrating a substantial practical benefit of color. Actual or potential applications of this work include the design of color codes for helmet-mounted and other displays that use complex symbology to assist performance on cognitively challenging tasks. C1 AFRL, HECV, Wright Patterson AFB, OH 45433 USA. Chuck Discount Stats, Waynesville, OH USA. RP Post, DL (reprint author), AFRL, HECV, 2255 H St,Rm 300, Wright Patterson AFB, OH 45433 USA. NR 14 TC 8 Z9 9 U1 1 U2 2 PU HUMAN FACTORS SOC PI SANTA MONICA PA BOX 1369, SANTA MONICA, CA 90406 USA SN 0018-7208 J9 HUM FACTORS JI Hum. Factors PD DEC PY 1999 VL 41 IS 4 BP 515 EP 523 DI 10.1518/001872099779656798 PG 9 WC Behavioral Sciences; Engineering, Industrial; Ergonomics; Psychology, Applied; Psychology SC Behavioral Sciences; Engineering; Psychology GA 302EN UT WOS:000086352900001 PM 10774123 ER PT J AU Bolia, RS D'Angelo, WR McKinley, RL AF Bolia, RS D'Angelo, WR McKinley, RL TI Aurally aided visual search in three-dimensional space SO HUMAN FACTORS LA English DT Article ID LOCALIZATION; PERFORMANCE; DISPLAY; TARGET; FIELD AB We conducted an experiment to evaluate the effectiveness of spatial audio displays on target acquisition performance, Participants performed a visual search task with and without the aid of a spatial audio display. Potential target locations ranged between plus and minus 180 degrees in azimuth and from -70 degrees to +90 degrees in elevation. Independent variables included the number of visual distracters present (1, 5, 10, 25, 50) and the spatial audio condition (no spatial audio, free-field spatial audio, virtual spatial audio). Results indicated that both free-field and virtual audio cues engendered a significant decrease in search times. Potential applications of this research include the design of spatial audio displays for aircraft cockpits and ground combat vehicles. C1 AFRL, HECP, Wright Patterson AFB, OH 45433 USA. Univ Connecticut, Ctr Hlth, Farmington, CT USA. RP Bolia, RS (reprint author), AFRL, HECP, 2255 H St,Bldg 33, Wright Patterson AFB, OH 45433 USA. NR 12 TC 32 Z9 32 U1 1 U2 4 PU HUMAN FACTORS SOC PI SANTA MONICA PA BOX 1369, SANTA MONICA, CA 90406 USA SN 0018-7208 J9 HUM FACTORS JI Hum. Factors PD DEC PY 1999 VL 41 IS 4 BP 664 EP 669 DI 10.1518/001872099779656789 PG 6 WC Behavioral Sciences; Engineering, Industrial; Ergonomics; Psychology, Applied; Psychology SC Behavioral Sciences; Engineering; Psychology GA 302EN UT WOS:000086352900013 PM 10774135 ER PT J AU Repperger, DW AF Repperger, DW TI Patented technology - A source for innovation and knowledge SO IEEE CONTROL SYSTEMS MAGAZINE LA English DT Article ID ARTERIAL C1 USAF, Res Lab, Wright Patterson AFB, OH 45433 USA. RP Repperger, DW (reprint author), USAF, Res Lab, Wright Patterson AFB, OH 45433 USA. NR 9 TC 0 Z9 0 U1 1 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0272-1708 J9 IEEE CONTR SYST MAG JI IEEE Control Syst. Mag. PD DEC PY 1999 VL 19 IS 6 BP 71 EP 76 PG 6 WC Automation & Control Systems SC Automation & Control Systems GA 258ZL UT WOS:000083869500009 ER PT J AU Kendrick, KR Helms, CA Quillen, BG AF Kendrick, KR Helms, CA Quillen, BG TI Determination of singlet-oxygen generator efficiency on a 10-kW class supersonic chemical oxygen-iodine laser (RADICL) SO IEEE JOURNAL OF QUANTUM ELECTRONICS LA English DT Article DE chemical lasers; gas lasers; iodine lasers; laser measurements; oxygen generator; singlet-delta oxygen AB With the advent of the Air Force Airborne Laser program, the emphasis of chemical oxygen-iodine laser (COIL) research has shifted ton ard improving the overall efficiency. A keg component of the COIL is the singlet-oxygen generator (SOG), To assess the efficiency of the SOG, an accurate method of determining the yield of O-2(a(1)Delta(g)), [O-2(a(1)Delta(g))]/[O-2(total)] where [O-2(total)] = [O2(a(1)Delta(g))] + [O-2(X(3)Sigma(g)(-))], has been developed. Absorption measurements of ground-state oxygen utilizing the magnetic-dipole transition, O-2(X(3)Sigma(g)(-))(nu=o) O-2(b(1)Sigma(g)(+))(nu=o) centered at 762 nm, have been obtained using a scanning-diode laser in conjunction with a multiple-pass Herriott-cell and balanced-ratiometric detection on the 10-kW class supersonic COIL (RADICL), A series of experiments was designed and conducted to test the efficiency of the SOG under various conditions. C1 USAF, Res Lab, Directed Energy Directorate, Chem & Gas Lasar Facil, Kirtland AFB, NM 87117 USA. USAF, Res Lab,Chem Oxygen Iodine Laser Res Program, Directed Energy Directorate, Gas & Chem Lasar Branch, Kirtland AFB, NM 87117 USA. RP Kendrick, KR (reprint author), USAF, Res Lab, Directed Energy Directorate, Chem & Gas Lasar Facil, Kirtland AFB, NM 87117 USA. NR 18 TC 19 Z9 19 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9197 J9 IEEE J QUANTUM ELECT JI IEEE J. Quantum Electron. PD DEC PY 1999 VL 35 IS 12 BP 1759 EP 1764 DI 10.1109/3.806577 PG 6 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA 262RT UT WOS:000084080800002 ER PT J AU Newell, TC Bossert, DJ Stintz, A Fuchs, B Malloy, KJ Lester, LF AF Newell, TC Bossert, DJ Stintz, A Fuchs, B Malloy, KJ Lester, LF TI Gain and linewidth enhancement factor in InAs quantum-dot laser diodes SO IEEE PHOTONICS TECHNOLOGY LETTERS LA English DT Article DE linewidth enhancement factor; quantum dots; semiconductor laser ID SEMICONDUCTOR-LASERS AB Amplified spontaneous emission measurements are investigated below threshold in InAs quantum-dot lasers emitting at 1.22 mu m, The dot layer of the laser was grown in a strained quantum well (QW) on a GaAs substrate. Ground state gain is determined from cavity mode Fabry-Perot modulation. As the injection current increases, the gain rises super-linearly while changes in the index of refraction decrease, Below the onset of gain saturation, the linewidth enhancement factor is as small as 0.1, which is significantly lower than that reported for QW lasers. C1 Univ New Mexico, Ctr High Technol Mat, Albuquerque, NM 87106 USA. USAF, Res Lab, Kirtland AFB, NM 87117 USA. RP Newell, TC (reprint author), Univ New Mexico, Ctr High Technol Mat, Albuquerque, NM 87106 USA. RI Malloy, Kevin/E-5994-2010 NR 14 TC 216 Z9 219 U1 1 U2 22 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 1041-1135 J9 IEEE PHOTONIC TECH L JI IEEE Photonics Technol. Lett. PD DEC PY 1999 VL 11 IS 12 BP 1527 EP 1529 DI 10.1109/68.806834 PG 3 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA 263AL UT WOS:000084100400001 ER PT J AU Cheung, JFY Wicks, MC Genello, GJ Kurz, L AF Cheung, JFY Wicks, MC Genello, GJ Kurz, L TI A statistical theory for optimal detection of moving objects in variable corruptive noise SO IEEE TRANSACTIONS ON IMAGE PROCESSING LA English DT Article DE analysis of variance; contrast function; detection of edges; F-statistic; generalized likelihood ratio test; Graeco-Latin squares design; least squares estimation; moving edges; moving objects; polynomial approximation ID OPTICAL-FLOW; IMAGE SEQUENCES; RIGID BODY; MOTION; OCCLUSION AB In this paper, the classical analysis of variance is extended to three-dimensional (3-D) Graeco-Latin squares design for multiframe processing applications. Conspicuous physical features, including edges, lines, and corners, can then be expressed as contrast functions. This enables the development of a new methodology for detecting moving objects embedded in noise. The new detector exploits spatial and temporal information uniformly most powerful in a Gaussian environment with unknown and time-varying noise variance. Also found is that a moving object detector based on contrast functions coincides with a sufficient statistic of the generalized likelihood ratio test. Extensive image analysis demonstrates the practicality of the detector and compares favorably to other classes of detectors. C1 Polytech Univ, Dept Elect Engn, Brooklyn, NY 11201 USA. RP Cheung, JFY (reprint author), USAF, Res Lab, SNRT, I-13441 Rome, Italy. NR 27 TC 2 Z9 3 U1 2 U2 3 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 1057-7149 J9 IEEE T IMAGE PROCESS JI IEEE Trans. Image Process. PD DEC PY 1999 VL 8 IS 12 BP 1772 EP 1787 DI 10.1109/83.806622 PG 16 WC Computer Science, Artificial Intelligence; Engineering, Electrical & Electronic SC Computer Science; Engineering GA 261VP UT WOS:000084031200010 PM 18267453 ER PT J AU Tabib-Azar, M Katz, JL LeClair, SR AF Tabib-Azar, M Katz, JL LeClair, SR TI Evanescent microwaves: A novel super-resolution noncontact nondestructive imaging technique for biological applications SO IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT LA English DT Article DE biological materials; electromagnetic properties of materials; microwave imaging; material characterization; nearfield imaging; super-resolution imaging ID MICROSCOPE AB Scanning tunneling microscopes (STM) and atomic force microscopes (AFM) are used to study biological materials. These methods, often capable of achieving atomic resolutions, reveal fascinating information regarding the inner workings of these materials. However, both STM and AFM require physical contact to the specimen. In the case of STM the specimen needs to be conducting as well. Here we introduce a new method for imaging biological materials through air or a suitable liquid using decaying or evanescent fields at the tip of a properly designed microwave resonator. This novel method involves the use of an evanescent microwave probe (EMP) and it is capable of imaging a variety of nonuniformities in biological materials including conductivity, permittivity, and density variations. EMP is a noncontact and nondestructive sensor and it does not require conducting specimens. Its spatial resolution is currently around 0.4 mu m at 1 GHz, We have used this probe to map nonuniformities in a variety of materials including metals, semiconductors, insulators, and biological and botanical samples. Here we discuss applications of EMP imaging in bone, teeth, botanical, and agricultural specimens. C1 Case Western Reserve Univ, Dept Elect Engn & Comp Sci, Cleveland, OH 44106 USA. Case Western Reserve Univ, Dept Biomed Engn, Cleveland, OH 44106 USA. USAF, Res Lab, Mat Mfg Directorate, Wright Patterson AFB, OH 45433 USA. RP Tabib-Azar, M (reprint author), Case Western Reserve Univ, Dept Elect Engn & Comp Sci, Cleveland, OH 44106 USA. NR 17 TC 43 Z9 44 U1 1 U2 8 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9456 J9 IEEE T INSTRUM MEAS JI IEEE Trans. Instrum. Meas. PD DEC PY 1999 VL 48 IS 6 BP 1111 EP 1116 DI 10.1109/19.816123 PG 6 WC Engineering, Electrical & Electronic; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA 277GU UT WOS:000084925000018 ER PT J AU Karna, SP Kurtz, HA Shedd, WM Pugh, RD Singaraju, BK AF Karna, SP Kurtz, HA Shedd, WM Pugh, RD Singaraju, BK TI New fundamental defects in a-SiO2 SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 1999 IEEE Nuclear and Space Radiation Effects Conference (NSREC 99) CY JUL 12-16, 1999 CL NORFOLK, VIRGINIA SP IEEE Nuclear & Plasma Sci Soc, Raduat Effects Comm, Def Threat Redyct Agcy, Sandia Natl Lab, NASA Goddard Space Flight Ctr, Jet Propuls Lab, Air Force Res Lab ID ELECTRON-SPIN-RESONANCE; HYPERFINE COUPLING-CONSTANTS; DEPOSITED SILICON DIOXIDE; ABINITIO CONFIGURATION-INTERACTION; SWITCHING OXIDE TRAPS; BORDER TRAPS; INTERFACE TRAPS; E' CENTERS; STRUCTURAL DEFECTS; AMORPHOUS SIO2 AB The atomic structure and spin properties of two previously undescribed amorphous silicon dioxide fundamental point defects have been characterized for the first time by ab initio quantum mechanical calculations. Both defects are electrically neutral trivalent silicon centers in the oxide. One of the defects, the X-center, is determined to have an O2Si=Si(up arrow)atomic structure. The other defect, called the Y-center, is found to have an OSi2=Si-up arrow structure. Calculated electronic and electrical properties of the new defect centers are consistent with the published characteristics of the oxide switching trap or border trap precursors. C1 USAF, Res Lab, VSSE, Kirtland AFB, NM 87117 USA. Univ Memphis, Dept Chem, Memphis, TN 38152 USA. RP Karna, SP (reprint author), USAF, Res Lab, VSSE, 3550 Aberdeen Ave SE, Kirtland AFB, NM 87117 USA. NR 44 TC 16 Z9 16 U1 0 U2 2 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD DEC PY 1999 VL 46 IS 6 BP 1544 EP 1552 DI 10.1109/23.819119 PN 1 PG 9 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 279RG UT WOS:000085058500033 ER PT J AU Vanheusden, K Korambath, PP Kurtz, HA Karna, SP Fleetwood, DM Shedd, WM Pugh, RD AF Vanheusden, K Korambath, PP Kurtz, HA Karna, SP Fleetwood, DM Shedd, WM Pugh, RD TI The effect of near-interface network strain on proton trapping in SiO2 SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 1999 IEEE Nuclear and Space Radiation Effects Conference (NSREC 99) CY JUL 12-16, 1999 CL NORFOLK, VIRGINIA SP IEEE Nuclear & Plasma Sci Soc, Raduat Effects Comm, Def Threat Redyct Agcy, Sandia Natl Lab, NASA Goddard Space Flight Ctr, Jet Propuls Lab, Air Force Res Lab ID ANNEALED SI/SIO2/SI STRUCTURES; MOBILE PROTONS; THIN-FILMS; GENERATION AB The buildup of positive charge during annealing in forming gas at 600 degrees C was compared for various types of Si/SiO2 interfaces. Our data suggest a correlation between the presence of stressed bonds in the SiO2 network near the Si/SiO2 interface, and the ratio of fixed vs, mobile positive charge (protons) detected near the interface after performing a forming-gas-annealing. We further propose that the presence-of these stressed bonds near the interface is correlated with the oxygen deficiency at the interface and with the confinement of the oxide due to the presence of a Si cover layer. A model based on first-principles quantum mechanical calculations shows a significant decrease in the overall proton binding energy with increasing network strain near the interface. These calculations support our model of mobile proton generation at Si/SiO2 interfaces with large densities of stressed bonds. C1 USAF, Res Lab, Kirtland AFB, NM 87117 USA. Univ Memphis, Dept Chem, Memphis, TN 38152 USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Vanheusden, K (reprint author), USAF, Res Lab, 3550 Aberdeen Ave SE, Kirtland AFB, NM 87117 USA. NR 14 TC 16 Z9 16 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD DEC PY 1999 VL 46 IS 6 BP 1562 EP 1567 DI 10.1109/23.819121 PN 1 PG 6 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 279RG UT WOS:000085058500035 ER PT J AU Kurtz, HA Karna, SP AF Kurtz, HA Karna, SP TI Proton mobility in a-SiO2 SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 1999 IEEE Nuclear and Space Radiation Effects Conference (NSREC 99) CY JUL 12-16, 1999 CL NORFOLK, VIRGINIA SP IEEE Nuclear & Plasma Sci Soc, Raduat Effects Comm, Def Threat Redyct Agcy, Sandia Natl Lab, NASA Goddard Space Flight Ctr, Jet Propuls Lab, Air Force Res Lab ID SIO2; INTERFACE; STATES AB A model for proton mobility in a-SiO2 is developed. Theoretical first-principles calculations are performed to test this model by obtaining pathways and activation energies for proton motion. C1 Univ Memphis, Dept Chem, Memphis, TN 38152 USA. USAF, Kirtland AFB, NM 87117 USA. RP Kurtz, HA (reprint author), Univ Memphis, Dept Chem, Memphis, TN 38152 USA. NR 15 TC 26 Z9 26 U1 1 U2 3 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD DEC PY 1999 VL 46 IS 6 BP 1574 EP 1577 DI 10.1109/23.819123 PN 1 PG 4 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 279RG UT WOS:000085058500037 ER PT J AU Reineke, DM Pohl, EA Murdock, WP AF Reineke, DM Pohl, EA Murdock, WP TI Maintenance-policy cost-analysis for a series system with highly-censored data SO IEEE TRANSACTIONS ON RELIABILITY LA English DT Article DE total time on test; censored data; survival analysis; Kaplan-Meier estimator; piecewise exponential estimator; maximum likelihood estimator; optimal age replacement ID AGE AB This paper considers the problem of estimating the optimal age-replacement time for a series arrangement of functional subsystems when data are subject to high levels of random censoring on the right. The system does not have redundant components. Simulation is used to compare the performance of the Kaplan-Meier Estimator (KME), the Piecewise Exponential Estimator (PEXE) and the Maximum Likelihood Estimator (MLE) in estimating the optimal replacement time for the system, as well as for each component, under high levels of random censorship. Monte Carlo analysis is used to estimate 'average optimal age replacement times' determined using total time on test (TTT) transforms based on the KME, PEXE, and MLE methods. The optimal replacement time is used to calculate a value which is used to compare the relative long-run cost per unit-time for each method. The differences between using system-level data vs component-level data to construct a maintenance policy are examined. With respect to cost effectiveness, the results identify the crucial factor in determining whether to perform system-level maintenance or component-level maintenance; that factor is the ratio of the 'cost of performing preventive maintenance' and the 'penalty cost of experiencing a system failure'. For the ratios used in this study (0.1 to 0.5) a 'component-level maintenance policy' is more cost effective than a 'system-level maintenance policy'. The results also show that for a correctly specified model and for large sample sizes (n = 2500), the age replacement times provided by the MLE are more accurate than those provided by the KME and PEXE, especially under high levels of censoring. C1 Univ Wisconsin, Dept Math, La Crosse, WI 54601 USA. USAF, Off Secretary Def, Pentagon, Washington, DC 20310 USA. USAF, Inst Technol, Dept Operat Sci, Wright Patterson AFB, OH 45433 USA. USAF, Inst Technol, Dayton, OH USA. RP Reineke, DM (reprint author), Univ Wisconsin, Dept Math, 1725 State St, La Crosse, WI 54601 USA. NR 12 TC 3 Z9 3 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9529 J9 IEEE T RELIAB JI IEEE Trans. Reliab. PD DEC PY 1999 VL 48 IS 4 BP 413 EP 419 DI 10.1109/24.814524 PG 7 WC Computer Science, Hardware & Architecture; Computer Science, Software Engineering; Engineering, Electrical & Electronic SC Computer Science; Engineering GA 271UZ UT WOS:000084613200013 ER PT J AU Yih, KA AF Yih, KA TI Effect of radiation on natural convection about a truncated cone SO INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER LA English DT Article ID BOUNDARY-LAYER FLOW; VERTICAL PLATE AB A boundary layer analysis is presented to investigate numerically the effect of radiation on natural convection flow of an optically dense viscous fluid over an isothermal truncated cone in this paper. The nonsimilar governing equations are obtained by using a suitable transformation and solved by the Keller box method. Numerical results for the dimensionless velocity profiles, the dimensionless temperature profiles, the local friction coefficient and the local Nusselt number are graphically presented for the dimensionless distance xi, the Prandtl number Pr = 0.7, the radiation-conduction parameter R-d and the surface temperature parameter H. It is shown that increasing xi, R-d and H increases the local Nusselt number. The local friction coefficient decreases with increasing the above three parameters. Whereas, for the larger value of R-d and H, the variation of the local friction coefficient with xi has the phenomenon of maximum. Furthermore, the local friction coefficient and the local Nusselt number of the truncated cone approach those of the inclined plate (full cone) for the case of xi=0 (xi --> infinity). (C) 1999 Elsevier Science Ltd. All rights reserved. C1 USAF, Aeronaut Technol Sch, Dept Gen Course, Kaohsiung 903952, Taiwan. RP USAF, Aeronaut Technol Sch, Dept Gen Course, Kaohsiung 903952, Taiwan. NR 19 TC 28 Z9 29 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0017-9310 EI 1879-2189 J9 INT J HEAT MASS TRAN JI Int. J. Heat Mass Transf. PD DEC PY 1999 VL 42 IS 23 BP 4299 EP 4305 DI 10.1016/S0017-9310(99)00092-7 PG 7 WC Thermodynamics; Engineering, Mechanical; Mechanics SC Thermodynamics; Engineering; Mechanics GA 236ZY UT WOS:000082630200004 ER PT J AU Baird, JK King, TR AF Baird, JK King, TR TI A Wien displacement law for impact radiation SO INTERNATIONAL JOURNAL OF IMPACT ENGINEERING LA English DT Article; Proceedings Paper CT 6th Symposium on Hypervelocity Impact (HVIS 98) CY NOV 17-19, 1998 CL HUNTSVILLE, ALABAMA SP Army Res Lab, Army Res Off, Ernst Mach Inst, European Res Off, Lawrence Livermore Natl Lab, NASA Marshall Space Flight Ctr, Sandia Natl Lab, Univ Alabama, Huntsville, US Army Aviat & Missile Command AB A flash of radiation is produced when a hypervelocity projectile strikes a target, By the term hypervelocity, we mean a collision in which the sound speeds characterizing the materials in the target and the projectile are less than the impact velocity, When the temperature and pressure ahead of the shock are low, it can be shown that the temperature, T-o, behind the shock varies quadratically with impact velocity, v. If the shocked material and the radiation it emits are in thermodynamic equilibrium, the initial intensity of the radiation varies according to T-o(4), so that we obtain, finally, I similar to V-8. Because I is the total radiated power per unit area of the source, integrated over all wavelengths, it can be accurately measured only by a detector with a very wide spectral response, If a detector having a limited spectral response is used instead, one observes I similar to V-Z, where the value of z depends on the detector, Although such a detector will not, in general, be able to confirm the V-8 rule, it may be able to confirm that the wavelength of maximum emission satisfies lambda(max) similar to 1/V-2, a result which can be derived from the Wien displacement law under the same assumptions used to obtain the velocity dependence of the source intensity, To confirm the Wien law, the response time of the detector must be less than 1 ns for a shock release temperature of 188 kK and less than 1 mu s for shock release temperature of 18 kK, Between these limits, the required response time decreases as the release temperature increases, (C) 1999 Elsevier Science Ltd. All rights reserved. C1 Univ Alabama, Dept Chem, Huntsville, AL 35899 USA. USAF, Res Lab, Kirtland AFB, NM 87117 USA. RP Baird, JK (reprint author), Univ Alabama, Dept Chem, Huntsville, AL 35899 USA. NR 12 TC 2 Z9 4 U1 0 U2 3 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0734-743X J9 INT J IMPACT ENG JI Int. J. Impact Eng. PD DEC PY 1999 VL 23 IS 1 BP 39 EP 49 DI 10.1016/S0734-743X(99)00060-3 PN 1 PG 11 WC Engineering, Mechanical; Mechanics SC Engineering; Mechanics GA 270EB UT WOS:000084521500007 ER PT J AU King, T Shively, J AF King, T Shively, J TI Shock-data constraints on interatomic potentials for condensed matter SO INTERNATIONAL JOURNAL OF IMPACT ENGINEERING LA English DT Article; Proceedings Paper CT 6th Symposium on Hypervelocity Impact (HVIS 98) CY NOV 17-19, 1998 CL HUNTSVILLE, AL SP Army Res Lab, Army Res Off, Ernst Mach Inst, European Res Off, Lawrence Livermore Natl Lab, NASA Marshall Space Flight Ctr, Sandia Natl Lab, Univ Alabama, Huntsville, US Army Aviat & Missile Command ID UNIVERSAL FEATURES; REPULSIVE FORCES; EQUATION; STATE; METALS AB It is customary to represent the shock Hugoniot as a linear relation between shock velocity and the particle velocity behind the shock It has been recently shown that the coefficients appearing in the general expansion of shock velocity as a power series in particle velocity can be calculated, to arbitrary order, from the derivatives of the shock pressure with respect to volume, evaluated at the initial state. The first two coefficients in the expansion have a simple relation to the interatomic potential describing the material. Most such potentials contain just two parameters (roughly, a "strength" parameter and a "shape" parameter), which can be conveniently extracted from the shock parameters. We present results for the values of the potential parameters, for several commonly-used forms of potential determined by least-squares fitting of the shock data to nonlinear Hugoniots. The results obtained sometimes differ from those obtained on the assumption of a linear Hugoniot. (C) 1999 Elsevier Science Ltd. All rights reserved. C1 USAF, Res Lab, Kirtland AFB, NM 87111 USA. Calif State Univ Northridge, CME Dept, Northridge, CA 91330 USA. RP King, T (reprint author), USAF, Res Lab, Phillips Res Site, Kirtland AFB, NM 87111 USA. NR 21 TC 0 Z9 0 U1 1 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0734-743X EI 1879-3509 J9 INT J IMPACT ENG JI Int. J. Impact Eng. PD DEC PY 1999 VL 23 IS 1 BP 455 EP 466 DI 10.1016/S0734-743X(99)00095-0 PN 1 PG 12 WC Engineering, Mechanical; Mechanics SC Engineering; Mechanics GA 270EB UT WOS:000084521500042 ER PT J AU Roybal, R Tlomak, P Stein, C Stokes, H AF Roybal, R Tlomak, P Stein, C Stokes, H TI Simulated space debris impact experiments on toughened laminated thin solar cell cover glass SO INTERNATIONAL JOURNAL OF IMPACT ENGINEERING LA English DT Article; Proceedings Paper CT 6th Symposium on Hypervelocity Impact (HVIS 98) CY NOV 17-19, 1998 CL HUNTSVILLE, ALABAMA SP Army Res Lab, Army Res Off, Ernst Mach Inst, European Res Off, Lawrence Livermore Natl Lab, NASA Marshall Space Flight Ctr, Sandia Natl Lab, Univ Alabama, Huntsville, US Army Aviat & Missile Command AB Increasing demands on the design criteria of space craft components have driven efforts to develop advanced space debris ground simulation techniques suitable to be incorporated into a space environmental effects chamber. A laser driven flyer method suitable in such a chamber was used to conduct an initial investigation of space debris impact on a new toughened solar cell coverglass material. Damage characteristics, including mechanical damage and contamination generated by impact with a 3mm diameter, 3 micron thick aluminum particle accelerated to 4.5 km/s, were looked at. Scanning electron microscopy, optical microscopy, and spectrophotometry were used to measure the mechanical damage and the loss of solar transmission. Because of the limited number of impact tests made in this initial study a quantitative analysis was not possible. However, much insight was obtained from the observed damage. (C) 1999 Elsevier Science Ltd. All rights reserved. C1 USAF, Res Lab, Space Vehicles Directorate, VSSE, Kirtland AFB, NM 87117 USA. Def Res Agcy, Dept Space, Space Debris Grp, Farnborough GU14 0LX, Hants, England. RP Roybal, R (reprint author), USAF, Res Lab, Space Vehicles Directorate, VSSE, 3550 Aberdeen Ave, Kirtland AFB, NM 87117 USA. NR 10 TC 13 Z9 14 U1 0 U2 7 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0734-743X J9 INT J IMPACT ENG JI Int. J. Impact Eng. PD DEC PY 1999 VL 23 IS 1 BP 811 EP 821 DI 10.1016/S0734-743X(99)00126-8 PN 2 PG 11 WC Engineering, Mechanical; Mechanics SC Engineering; Mechanics GA 270ED UT WOS:000084521700028 ER PT J AU Whitman, DH Connaughton, B AF Whitman, DH Connaughton, B TI Model surgery prediction for mandibular midline distraction osteogenesis SO INTERNATIONAL JOURNAL OF ORAL AND MAXILLOFACIAL SURGERY LA English DT Article DE distraction osteogenesis; model surgery; stereolithography AB Mandibular midline distraction osteogenesis is available as a treatment option for the correction of mandibular transverse arch deficiency. A model surgery technique is presented here through a case report that will allow the surgeon to predict the amount of transverse expansion that can be gained by this procedure. Utilizing measurements from a three-dimensional stereolithography model, the mandibular cast is mounted on a semi-adjustable articulator. The maxillary model is mounted onto the articulator using an interocclusal record. Acrylic straps are fabricated that relate the condylar elements of the articulator to the right and left mandibular dental segments. The mandibular model is sectioned at the midline, the hemi-mandibular segments are rotated laterally until the desired midline expansion is achieved and the mandibular model is luted into its new position. The post-expansion relationship of the maxillary and mandibular arches can be visualized on the articulator and provide useful information to the surgeon and orthodontist. C1 David Grant Med Ctr, Dept Oral & Maxillofacial Surg, Travis AFB, CA 94535 USA. Univ Oklahoma, Coll Dent Med, Oklahoma City, OK USA. RP Whitman, DH (reprint author), David Grant Med Ctr, Dept Oral & Maxillofacial Surg, 101 Bodin Circle, Travis AFB, CA 94535 USA. NR 2 TC 11 Z9 12 U1 0 U2 1 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0901-5027 J9 INT J ORAL MAX SURG JI Int. J. Oral Maxillofac. Surg. PD DEC PY 1999 VL 28 IS 6 BP 421 EP 423 DI 10.1034/j.1399-0020.1999.280604.x PG 3 WC Dentistry, Oral Surgery & Medicine; Surgery SC Dentistry, Oral Surgery & Medicine; Surgery GA 265LT UT WOS:000084246200004 PM 10609742 ER PT J AU Schoeppner, GA Pagano, NJ AF Schoeppner, GA Pagano, NJ TI Stress fields and energy release rates in cross-ply laminates (vol 35, pg 1025, 1998) SO INTERNATIONAL JOURNAL OF SOLIDS AND STRUCTURES LA English DT Correction C1 USAF, Res Lab, Nonmet Mat Div, Mech & Surface Interact Branch,Mat Directorate, Wright Patterson AFB, OH 45433 USA. RP Schoeppner, GA (reprint author), USAF, Res Lab, Nonmet Mat Div, Mech & Surface Interact Branch,Mat Directorate, 2941 P Stress,Suite 1, Wright Patterson AFB, OH 45433 USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0020-7683 J9 INT J SOLIDS STRUCT JI Int. J. Solids Struct. PD DEC PY 1999 VL 36 IS 34 BP 5327 EP 5327 PG 1 WC Mechanics SC Mechanics GA 222JD UT WOS:000081780400008 ER PT J AU Adler-Golden, S Smith, DR Vail, J Berk, A Nadile, R Jeong, L AF Adler-Golden, S Smith, DR Vail, J Berk, A Nadile, R Jeong, L TI Simulations of mesospheric and thermospheric IR radiance measured in the CIRRIS-1A shuttle experiment SO JOURNAL OF ATMOSPHERIC AND SOLAR-TERRESTRIAL PHYSICS LA English DT Article ID SPACELAB 3 OBSERVATIONS; UPPER-ATMOSPHERE; ATOMIC OXYGEN; TEMPERATURE PROFILES; MIDDLE ATMOSPHERE; CARBON-DIOXIDE; LIMB RADIANCE; NITRIC-OXIDE; WATER-VAPOR; MODEL AB Comprehensive simulations of upper atmospheric limb radiance from 2.5 to 25 mu m, carried out using a moderate-resolution non-LTE code and a series of model atmospheres, are compared with data from the 1991 CIRRIS-1A shuttle experiment. Good agreement, typically within a factor of two, is found at most wavelengths over a order-of-magnitude range in spectral radiance. The comparisons yield information on the temperature profile, the production and concentrations of odd-oxygen and odd-hydrogen species in the mesopause region and NO in the thermosphere, and the kinetics of CO2 vibrational states. (C) 2000 Elsevier Science Ltd. All rights reserved. C1 USAF, Res Lab, Space Vehicles Directorate, Hanscom AFB, MA 01731 USA. Spectral Sci Inc, Burlington, MA 01803 USA. MIT, Lincoln Lab, Lexington, MA 02173 USA. RP Smith, DR (reprint author), USAF, Res Lab, Space Vehicles Directorate, Hanscom AFB, MA 01731 USA. NR 46 TC 4 Z9 6 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1364-6826 J9 J ATMOS SOL-TERR PHY JI J. Atmos. Sol.-Terr. Phys. PD DEC PY 1999 VL 61 IS 18 BP 1397 EP 1410 DI 10.1016/S1364-6826(99)00096-6 PG 14 WC Geochemistry & Geophysics; Meteorology & Atmospheric Sciences SC Geochemistry & Geophysics; Meteorology & Atmospheric Sciences GA 288BB UT WOS:000085541000007 ER PT J AU Heckman, JD Ehler, W Brooks, BP Aufdemorte, TB Lohmann, CH Morgan, T Boyan, BD AF Heckman, JD Ehler, W Brooks, BP Aufdemorte, TB Lohmann, CH Morgan, T Boyan, BD TI Bone morphogenetic protein but not transforming growth factor-beta enhances bone formation in canine diaphyseal nonunions implanted with a biodegradable composite polymer SO JOURNAL OF BONE AND JOINT SURGERY-AMERICAN VOLUME LA English DT Article ID SKULL DEFECTS; CARTILAGE; TISSUE; REPAIR; CHROMATOGRAPHY; OSTEOGENESIS; INVITRO; MUSCLE; DOGS AB Background: The purpose of the present study was to create an effective bone-graft substitute for the treatment of a diaphyseal nonunion. Methods: A standardized nonunion was established in the midportion of the radial diaphysis in thirty mongrel dogs by creating a three-millimeter segmental bone defect (at least 2 percent of the total length of the bone). The nonunion was treated with implantation of a carrier comprised of poly(DL-lactic acid) and polyglycolic acid copolymer (50:50 polglactic acid-polyglycolic acid [PLG50]) containing canine purified bone morphogenetic protein (BMP) or recombinant human transforming growth factor-beta (TGF-beta 1), or both, or the carrier without BMP or TGF-beta 1, Five groups, consisting of sis dogs each, were treated with implantation of the carrier alone, implantation of the carrier with fifteen milligrams of BR IP, implantation of the carrier with 1.5 milligrams of BR IP, implantation of the carrier with fifteen milligrams of BMP and ten nanograms of TGF-beta 1, or implantation of the carrier,vith ten nanograms of TGF-beta 1, At twelve weeks after implantation, the radii were examined radiographically and the sites of nonunion were examined histomorphometrically. Results: We found that implantation of the polylactic acid-polyglycolic acid carrier alone or in combination with ten nanograms of TGF-beta 1 failed to induce significant radiographic or histomorphometric evidence of healing at the site of the nonunion. The radii treated with the carrier enriched,vith either 1.5 or fifteen milligrams of BMP showed significantly increased periosteal and endosteal bone formation on histomorphometric (p < 0.05) and radiographic (p < 0.02) analysis. Conclusions: Bone formation in a persistent osseous defect that is similar to an ununited diaphyseal fracture is increased when species-specific BMP incorporated into a polylactic acid-polyglycolic acid carrier is implanted at the site of the nonunion. TGF-beta 1 at a dose of ten nanograms per implant did not induce a similar degree of bone formation or potentiate the effect of BMP in this model. Clinical Relevance: The biodegradable implant containing BMP that was used in the present study to treat diaphyseal nonunion is an effective bone-graft substitute. C1 Univ Texas, Hlth Sci Ctr, Dept Orthopaed, San Antonio, TX 78284 USA. Univ Texas, Hlth Sci Ctr, Dept Pathol, San Antonio, TX 78284 USA. Audie L Murphy Mem Vet Adm Hosp, San Antonio, TX 78284 USA. Wilford Hall USAF Med Ctr, Lackland AFB, TX USA. RP Heckman, JD (reprint author), Univ Texas, Hlth Sci Ctr, Dept Orthopaed, 7703 Floyd Curl Dr, San Antonio, TX 78284 USA. FU NIDCR NIH HHS [DE08603] NR 60 TC 77 Z9 87 U1 0 U2 1 PU JOURNAL BONE JOINT SURGERY INC PI NEEDHAM PA 20 PICKERING ST, NEEDHAM, MA 02192 USA SN 0021-9355 J9 J BONE JOINT SURG AM JI J. Bone Joint Surg.-Am. Vol. PD DEC PY 1999 VL 81A IS 12 BP 1717 EP 1729 PG 13 WC Orthopedics; Surgery SC Orthopedics; Surgery GA 264WM UT WOS:000084206000009 PM 10608383 ER PT J AU Williams, S Dressler, RA Chiu, YH AF Williams, S Dressler, RA Chiu, YH TI Photodissociation dynamics of N-4(+) in the 300-670 nm range SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID COLLISION-INDUCED DISSOCIATION; ORBITAL ANGULAR-MOMENTUM; (N2O,H2O)(+) CLUSTER ION; SEQUENTIAL BOND-ENERGIES; TRIATOMIC-MOLECULES; A2A1-X2B1 TRANSITIONS; TRANSLATIONAL ENERGY; CHARGE-TRANSFER; N4+; DISTRIBUTIONS AB The photodissociation of N-4(+) produced in a supersonic jet ion source is studied in an octopole ion guide at selected wavelengths in the 300-670 nm range. The N-2(+) photofragment recoil velocity distributions are measured using the guided-ion beam time-of-flight (GIB-TOF) technique. The derived kinetic energy release distributions are structureless at all photon energies. The average anisotropy parameter, , ranges between 0.7 and 1.2. The absolute magnitude and photon energy dependence of both average kinetic energy release, < E-T'>, and are inconsistent with a previously assumed impulsive mechanism. Experiments are also conducted with N-4(+) produced with similar to 0.6 eV internal excitation. This results in a reduction of the observed kinetic energy release and anisotropy parameter, implying that different regions of the excited state surfaces are accessed when ion vibrational modes are excited. The observations can be rationalized by invoking excited states with bent equilibrium geometries, consistent with valence-bond calculations of Langenberg [Langenberg , Chem. Phys. 221, 225 (1997)]. (C) 1999 American Institute of Physics. [S0021-9606(99)00645-5]. C1 USAF, Res Lab, Space Vehicles Directorate, Hanscom AFB, MA 01731 USA. Boston Coll, Inst Sci Res, Newton, MA 02159 USA. RP Williams, S (reprint author), USAF, Res Lab, Space Vehicles Directorate, 29 Randolph Rd, Hanscom AFB, MA 01731 USA. NR 42 TC 4 Z9 4 U1 2 U2 4 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD DEC 1 PY 1999 VL 111 IS 21 BP 9634 EP 9641 DI 10.1063/1.480296 PG 8 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 255TC UT WOS:000083685400024 ER PT J AU Klesges, RC Haddock, CK Lando, H Talcott, GW AF Klesges, RC Haddock, CK Lando, H Talcott, GW TI Efficacy of forced smoking cessation and an adjunctive behavioral treatment on long-term smoking rates SO JOURNAL OF CONSULTING AND CLINICAL PSYCHOLOGY LA English DT Article AB This study evaluated the efficacy of a 6-week forced ban on smoking and brief behavioral counseling on long-term smoking rates. Participants were active-duty enrollees in U.S. Air Force basic military training over a 1-year period (N = 25,996). All participants were under a 6-week ban from tobacco products, and 75% were randomized to a brief smoking cessation intervention, with the other 25% randomized to a control condition. At 1-year follow-up, 18% of smokers were abstinent; women, ethnic minorities, and those intending to stay quit at baseline were more likely to be abstinent. Among smokers not planning to remain abstinent at baseline, those receiving the intervention were 1.73 times more likely to be abstinent. Over time, substantial smoking initiation occurred among nonsmokers (8% of never smokers, 26% of experimental smokers, and 43% of ex-smokers). Forced cessation is associated with good levels of long-term cessation, and brief behavioral interventions enhance cessation in certain subgroups. C1 Univ Memphis, Prevent Ctr, Memphis, TN 38119 USA. Univ Missouri, Dept Psychol, Kansas City, MO 64110 USA. Univ Minnesota, Sch Publ Hlth, Div Epidemiol, Minneapolis, MN 55455 USA. USAF, Surg Gen Off, Bolling AFB, Washington, DC 20330 USA. RP Klesges, RC (reprint author), Univ Memphis, Prevent Ctr, 5350 Poplar Ave,Suite 675, Memphis, TN 38119 USA. FU NHLBI NIH HHS [HL-53478] NR 17 TC 54 Z9 54 U1 0 U2 2 PU AMER PSYCHOLOGICAL ASSOC PI WASHINGTON PA 750 FIRST ST NE, WASHINGTON, DC 20002-4242 USA SN 0022-006X J9 J CONSULT CLIN PSYCH JI J. Consult. Clin. Psychol. PD DEC PY 1999 VL 67 IS 6 BP 952 EP 958 PG 7 WC Psychology, Clinical SC Psychology GA 260XP UT WOS:000083979000013 PM 10596516 ER PT J AU Xie, QH Van Nostrand, JE Jones, RL Sizelove, J Look, DC AF Xie, QH Van Nostrand, JE Jones, RL Sizelove, J Look, DC TI Electrical and optical properties of undoped GaSb grown by molecular beam epitaxy using cracked Sb-1 and Sb-2 SO JOURNAL OF CRYSTAL GROWTH LA English DT Article DE epitaxy; Sb-1; Sb-2; free exciton ID GALLIUM ANTIMONIDE; PHASE EPITAXY; PHOTOLUMINESCENCE; SUPERLATTICE; LASERS; PERFORMANCE; ALLOYS AB In this paper, we report on the electrical and optical properties of undoped GaSb samples grown by MBE using Sb-1 as well as Sb-2 produced in a conventional antimony cracker. We establish the existence of Sb-1 and then extract the mole fraction of Sb-1 in the antimony beam as a function of the cracking zone temperature based on a combined analysis of mass spectrometry data and ion gauge flux reading. We find that the Sb-1 mole fraction becomes greater than 90% for cracking zone temperature above 950 degrees C. A series of undoped GaSb samples are grown over a wide range of substrate temperature, V/III ratio and cracking zone temperature. The undoped GaSb samples grown at 550 degrees C show p-type conductivity with a room-temperature hole mobility and hole concentration of similar to 730 cm(2) v(-1) s(-1) and similar to 3 x 10(16) cm(-3), respectively. The hole mobility and hole concentration are essentially independent of the V/III ratio over a range of 1.2-4. Decreasing the growth temperature to 440 degrees C leads to a simultaneous decrease in hole mobility, residual hole concentration and photoluminescence intensity. Hole mobility and: hole concentration do not depend strongly on the cracking zone temperature in the range 790-1000 degrees C; however, the optical intensity of the samples grown using Sb-1 is approximately one order of magnitude stronger than those using Sb-2. Besides the commonly seen bound exciton transitions at 805 (BE1), 803 (BE2), 800 (BE3) and 796 meV (BE4), a free exciton transition at similar to 809.4 meV (4 K) is observed in the samples grown with Sb-1 at 550 degrees C, indicating a greatly reduced density of nonradiative recombination centers. (C) 1999 Elsevier Science B.V. All rights reserved. C1 Wright State Univ, Semicond Res Ctr, Dayton, OH 45435 USA. USAF, Res Lab, Mat & Mfg Directorate, Wright Patterson AFB, OH 45433 USA. RP Xie, QH (reprint author), Wright State Univ, Semicond Res Ctr, Dayton, OH 45435 USA. NR 35 TC 15 Z9 15 U1 1 U2 12 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-0248 J9 J CRYST GROWTH JI J. Cryst. Growth PD DEC PY 1999 VL 207 IS 4 BP 255 EP 265 DI 10.1016/S0022-0248(99)00379-6 PG 11 WC Crystallography; Materials Science, Multidisciplinary; Physics, Applied SC Crystallography; Materials Science; Physics GA 267WG UT WOS:000084381800001 ER PT J AU Xie, QH Brown, JL Jones, RL Van Nostrand, JE AF Xie, QH Brown, JL Jones, RL Van Nostrand, JE TI Shape stabilization and size equalization of InGaAs self-organized quantum dots SO JOURNAL OF ELECTRONIC MATERIALS LA English DT Article DE quantum dots; molecular beam epitaxy (MBE); shape stabilization; size equalization; atomic force microscopy (AFM) ID MOLECULAR-BEAM EPITAXY; SURFACE-MORPHOLOGY; IN-SITU; ISLANDS; GAAS(100); GROWTH; TRANSITION; GAAS(001); STRESS; LASER AB We report a simultaneous shape stabilization and size equalization after shape transformation of InGaAs self-organized quantum dots (QDs) formed via a fractional monolayer (ML) deposition technique. The density of QD increases rapidly from an initial value of 110 +/- 10/mu m(2) (at a total deposition of 4 ML) to 270 +/- 30/mu m(2) (at 5 ML) and saturates at a level of 240 +/- 20/mu m(2) (at 10 ML). At an intermediate stage of 7 ML deposition, bimodal QD height (peaked at 8.5 nm and 14.5 nm) and aspect ratio (peaked at 0.18 and 0.26) distributions occur, confirming the QD shape transformation from a shallower to a steeper shape. The eventual convergence in lateral size, height and aspect ratio is the direct result of the simultaneous QD size equalization and shape stabilization. The QD size and shape evolution is also substantiated by the Iom temperature (4 K) photoluminescence (PL) data taken from samples with QDs capped by GaAs. C1 Wright State Univ, Semicond Res Ctr, Dayton, OH 45435 USA. USAF, Res Lab, Mat & Mfg Directorate, Wright Patterson AFB, OH 45433 USA. RP Xie, QH (reprint author), Wright State Univ, Semicond Res Ctr, Dayton, OH 45435 USA. NR 21 TC 4 Z9 4 U1 0 U2 0 PU MINERALS METALS MATERIALS SOC PI WARRENDALE PA 420 COMMONWEALTH DR, WARRENDALE, PA 15086 USA SN 0361-5235 J9 J ELECTRON MATER JI J. Electron. Mater. PD DEC PY 1999 VL 28 IS 12 BP L42 EP L45 DI 10.1007/s11664-999-0147-2 PG 4 WC Engineering, Electrical & Electronic; Materials Science, Multidisciplinary; Physics, Applied SC Engineering; Materials Science; Physics GA 268ZB UT WOS:000084449600032 ER PT J AU Slinker, SP Fedder, JA Emery, BA Baker, KB Lummerzheim, D Lyon, JG Rich, FJ AF Slinker, SP Fedder, JA Emery, BA Baker, KB Lummerzheim, D Lyon, JG Rich, FJ TI Comparison of global MHD simulations with AMIE simulations for the events of May 19-20, 1996 SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID INTERPLANETARY MAGNETIC-FIELD; LATITUDE ELECTRIC POTENTIALS; IONOSPHERIC ELECTRODYNAMICS; NUMERICAL-SIMULATION; EARTHS MAGNETOSPHERE; CIRCULATION MODEL; GRAND CHALLENGE; ENERGY; CONDUCTANCES; CONVECTION AB Using WIND-measured solar wind data, we have simulated the magnetosphere for the time between 1200 UT May 19 and 0200 UT May 20, 1996, with a three-dimensional MHD model. This time period has been chosen as an International Solar-Terrestrial Physics/Global Geospace Science event for community study, and there is a large set of data with which to compare. In this paper we will compare the simulation predictions with results from the Assimilative Mapping of Ionospheric Electrodynamics (AMIE) analysis. We show comparisons for the convection, the auroral precipitation, the ionospheric conductances, the field-aligned currents, and the Joule heating distribution. The results concentrate on four time periods when the two DMSP spacecraft, F12 and F13, and the POLAR spacecraft were passing over the northern (summer) polar region. The comparisons show excellent agreement with the F13 electric field measurements. The ionospheric convection patterns agree well. between the simulation and the AMIE analysis with the cross polar potential drop somewhat higher in the MHD model. The auroral electron precipitation energy flux from the MHD model is too low, particularly in the late morning, when compared with the POLAR UVI data because of the lack of electron drift physics in the model. We show how the MHD auroral input can be improved by adjusting the parameters in the auroral precipitation model. C1 Johns Hopkins Univ, Appl Phys Lab, Laurel, MD 20723 USA. USN, Res Lab, Div Plasma Phys, Washington, DC 20375 USA. George Mason Univ, Inst Computat Sci & Informat, Fairfax, VA 22030 USA. Natl Ctr Atmospher Res, High Altitude Observ, Boulder, CO 80307 USA. Johns Hopkins Univ, Appl Phys Lab, Laurel, MD USA. Univ Alaska, Inst Geophys, Hanover, NH USA. USAF, Res Lab, Space Vehicles Directorate, Hanscom AFB, MA USA. RP Slinker, SP (reprint author), Johns Hopkins Univ, Appl Phys Lab, Johns Hopkins Rd, Laurel, MD 20723 USA. NR 35 TC 41 Z9 41 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD DEC 1 PY 1999 VL 104 IS A12 BP 28379 EP 28395 DI 10.1029/1999JA900403 PG 17 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 266UN UT WOS:000084318800034 ER PT J AU Heinemann, M AF Heinemann, M TI Role of collisionless heat flux in magnetospheric convection SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID ANISOTROPIC MAGNETOHYDROSTATIC PLASMA; MAGNETIC-FIELDS; ELECTRON-PRECIPITATION; CURRENTS; REPRESENTATIONS; SIMULATION AB A fluid model of magnetospheric convection appropriate for the inner magnetosphere, including the effects of heat flux in collisionless plasma, is presented. The plasma is assumed to be isotropic, with the flow speed much less than the thermal speed, and parallel electric fields and loss cone effects are neglected; the effects of slow time variations of the magnetic field are included. The classical transport coefficients are considered and, except for the collisionless heat flux, shown to be negligible in plasma in the inner magnetosphere. Beginning with three-dimensional two-fluid equations, we derive two-dimensional equations for transport of mass and energy mapped to the magnetospheric equator. The equation of mass transport, derived from the mass conservation equations, is equivalent to those obtained in previous studies [e.g., Peymirat and Fontaine, 1994]. The equation of energy transport contains the effects of collisionless heat conduction that represents the transport of energy in the rest frame of the species and has hitherto been neglected in magnetospheric fluid and MHD models. The energy transport equation is shown to be equivalent to that of Peymirat and Fontaine [1994] if the heat flux is neglected. The two equations are coupled first-order partial differential equations; they can be uncoupled by taking linear combinations. The uncoupled equations show that the effect of the collisionless heat flux is to spread information across the fluid drift paths in a manner quite different from that of fluid flow neglecting heat flux. C1 USAF, Res Lab, Space Vehicle Directorate, Hanscom AFB, MA 01731 USA. RP Heinemann, M (reprint author), USAF, Res Lab, Space Vehicle Directorate, Hanscom AFB, MA 01731 USA. NR 18 TC 21 Z9 22 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD DEC 1 PY 1999 VL 104 IS A12 BP 28397 EP 28410 DI 10.1029/1999JA900401 PG 14 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 266UN UT WOS:000084318800035 ER PT J AU Griffin, S Huybrechts, S Lane, SA AF Griffin, S Huybrechts, S Lane, SA TI An adaptive Herschel-Quincke tube SO JOURNAL OF INTELLIGENT MATERIAL SYSTEMS AND STRUCTURES LA English DT Article AB Acoustic side branches and mufflers are commonly used to attenuate harmonic disturbances in ducts. This work introduces a variation to the classic Herschel-Quincke tube side-branch configuration to adaptively attenuate the propagation of plane wave disturbances along a duct. Through the use of an active membrane or piston element within the tube, the transmission loss characteristics of the tube apparatus can be made to adapt to changes in the disturbance frequency. This permits tracking of tonal disturbances over a wide bandwidth in order to maintain optimal attenuation. The theory for an adaptive Herschel-Quincke tube is presented, and the corresponding transmission loss is derived and given in terms of the tube geometry, piston mass, stiffness and damping. As an illustrative example, analytical results are presented using a PVDF membrane as an equivalent piston. The derivation of the equivalent piston mass and stiffness of the membrane as a function of applied voltage is also presented. Analytical results illustrate how the transmission loss of the adaptive Herschel-Quincke tube can be varied as a function of the voltage applied to the membrane in order to track changes in the disturbance. C1 Jackson & Tull Engn, Albuquerque, NM 87106 USA. USAF, Res Lab, Kirtland AFB, NM 87117 USA. RP Lane, SA (reprint author), Jackson & Tull Engn, 1900 Randolph Rd SE,Suite H, Albuquerque, NM 87106 USA. NR 8 TC 4 Z9 4 U1 0 U2 3 PU TECHNOMIC PUBL CO INC PI LANCASTER PA 851 NEW HOLLAND AVE, BOX 3535, LANCASTER, PA 17604 USA SN 1045-389X J9 J INTEL MAT SYST STR JI J. Intell. Mater. Syst. Struct. PD DEC PY 1999 VL 10 IS 12 BP 956 EP 961 DI 10.1106/J2FL-17L3-B7JV-8492 PG 6 WC Materials Science, Multidisciplinary SC Materials Science GA 373YE UT WOS:000165317000003 ER PT J AU Chen, JK Beraun, JE Tzou, DY AF Chen, JK Beraun, JE Tzou, DY TI A dual-phase-lag diffusion model for interfacial layer growth in metal matrix composites SO JOURNAL OF MATERIALS SCIENCE LA English DT Article ID REINFORCED SUPERALLOY COMPOSITES; REACTION ZONE GROWTH; TEMPERATURE AB The time dependence of a reinforcement-matrix interfacial layer growth (RMILG) in most metal matrix composites (MMC's) is not t(1/2) as described by Fick's law. Moreover, the RMILG vs. t(1/2) could be linear for relatively short and long times, and an anomaloustransition behavior exhibits in between. In this paper, a dual-phase-lag diffusion (DPLD) model is proposed to characterize the RMILG kinetics. Unlike Fick's law, it accounts for the two lagging times required for the processes of interdiffusion and chemical reaction. This unique feature empowers the DPLD model to capture the multiple stages response over the entire RMILG history. Model validation is verified with the experimental results of seven different MMC systems. (C) 1999 Kluwer Academic Publishers. C1 USAF, Phillips Lab, Laser Effects Branch, Kirtland AFB, NM 87117 USA. Univ Missouri, Dept Mech & Aerosp Engn, Columbia, MO 65211 USA. RP Chen, JK (reprint author), USAF, Phillips Lab, Laser Effects Branch, Kirtland AFB, NM 87117 USA. NR 11 TC 26 Z9 26 U1 1 U2 2 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0022-2461 J9 J MATER SCI JI J. Mater. Sci. PD DEC PY 1999 VL 34 IS 24 BP 6183 EP 6187 DI 10.1023/A:1004738408250 PG 5 WC Materials Science, Multidisciplinary SC Materials Science GA 256GB UT WOS:000083716600033 ER PT J AU Lair, AV AF Lair, AV TI A necessary and sufficient condition for existence of large solutions to semilinear elliptic equations SO JOURNAL OF MATHEMATICAL ANALYSIS AND APPLICATIONS LA English DT Article DE large solution; elliptic equation; semilinear equation AB We consider the semilinear equation Delta u = p(x)f(u) on a domain Omega subset of or equal to R-n, n greater than or equal to 3, where f is a nonnegative, nondecreasing continuous function which vanishes at the origin, and p is a nonnegative continuous function with the property that any zero of p is contained in a bounded domain in Omega such that p is positive on its boundary. For Omega bounded, we show that a nonnegative solution u satisfying u(x) --> infinity as x --> delta Omega exists if and only if the function psi(s) = integral(0)(s) f(t) dt satisfies integral(1)(infinity)(psi(s))(-1/2) ds < infinity. For Omega unbounded (including Omega = R-n), we show that a similar result holds where u(x)--> infinity as \ x \ --> infinity within Omega and u(x) --> infinity as x --> delta Omega if p(x) decays to zero rapidly as \ x \ --> infinity. (C) 1999 Academic Press. C1 USAF, Inst Technol, Dept Math & Stat, ENC, Wright Patterson AFB, OH 45433 USA. RP Lair, AV (reprint author), USAF, Inst Technol, Dept Math & Stat, ENC, 2950 P St, Wright Patterson AFB, OH 45433 USA. NR 14 TC 85 Z9 89 U1 0 U2 0 PU ACADEMIC PRESS INC PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0022-247X J9 J MATH ANAL APPL JI J. Math. Anal. Appl. PD DEC 1 PY 1999 VL 240 IS 1 BP 205 EP 218 DI 10.1006/jmaa.1999.6609 PG 14 WC Mathematics, Applied; Mathematics SC Mathematics GA 261KM UT WOS:000084008400014 ER PT J AU Burns, DJ Helbig, HF AF Burns, DJ Helbig, HF TI A system for automatic electrical and optical characterization of microelectromechanical devices SO JOURNAL OF MICROELECTROMECHANICAL SYSTEMS LA English DT Article DE automatic characterization; electrical characterization; image analysis; LabView; microelectromechanical systems (MEMS); optical characterization; quality factor; resonance curves; resonant frequency; resonators; testing; virtual instruments AB A new optical method for characterizing the performance of microelectromechanical systems (MEMS) is described that is significantly faster and simpler than previously described optical methods. The method uses video imaging under continuous illumination to effectively remove the upper limit imposed by other methods on the frequency of motions that can be measured. It can be used to-measure the motions of any visible structure, whether or not an electrical or optical sensor for that motion has been incorporated. The magnitude of the displacement of a target, such as the edge of a sinusoidally vibrating shuttle mass, is obtained from a single frame of video taken during motion plus a reference frame taken when the target is at rest. The speed of this technique facilitates hands-on testing of prototypes and is especially attractive for production environments. An automated MEMS microresonator testbed is described that performs on-line resonance curve parameter extractions of resonant frequency (f(0)) and quality factor (Q) from electrical measurements, which are derived from output comb-drive current measurements using established methods, and from simultaneous optical measurements using the new method. Results obtained using these methods for design evaluation of microfabricated lateral resonators are discussed, and favorable benchmark comparisons of the optical results with results from a MEMS testbed at the Massachusetts Institute of Technology are presented. [432]. C1 USAF, Res Lab, Informat Directorate, Rome, NY 13441 USA. RP Burns, DJ (reprint author), USAF, Res Lab, Informat Directorate, Rome, NY 13441 USA. NR 6 TC 56 Z9 63 U1 1 U2 5 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 1057-7157 J9 J MICROELECTROMECH S JI J. Microelectromech. Syst. PD DEC PY 1999 VL 8 IS 4 BP 473 EP 482 DI 10.1109/84.809063 PG 10 WC Engineering, Electrical & Electronic; Nanoscience & Nanotechnology; Instruments & Instrumentation; Physics, Applied SC Engineering; Science & Technology - Other Topics; Instruments & Instrumentation; Physics GA 265DE UT WOS:000084225400016 ER PT J AU Hassan, W Nagy, PB AF Hassan, W Nagy, PB TI Experimental investigation of the grain noise in interferometric detection of ultrasonic waves SO JOURNAL OF NONDESTRUCTIVE EVALUATION LA English DT Article DE ultrasonic backscattering; grain noise; laser interferometers; super-resolution nearfield acoustic microscopy ID MICROSCOPE; SCATTERING AB Besides their other obvious advantages over conventional ultrasonic sensors, laser interferometers offer optical diffraction limited apertures that are far smaller than the acoustic wavelength in the specimen under inspection. This unique feature can be exploited for the purposes of super-resolution near-field acoustic microscopy, which detects the rapidly decaying evanescent vibrations produced by surface and near-surface scatterers such as small fatigue cracks, pores, anomalous grains, etc. However, higher resolution also means higher sensitivity to inherent microscopic material inhomogeneities. In this paper, experimental results are presented for the incoherent material noise in 2024 aluminum and Ti-6Al-4V titanium alloys at two different nominal frequencies of 5 and 10 MHz. It is shown that the incoherent grain noise significantly increases as the illuminated spot size decreases. Above the acoustic wavelength, the observed phenomenon is mainly due to the increasing sensitivity of the receiver to propagating scattered waves generated in the interior of the specimen. Below the acoustic wavelength, the further increasing material noise is mainly due to evanescent vibrations caused by nearby scatterers. C1 USAF, Res Lab, Mat & Mfg Directorate, Met Ceram & NDE Div, Wright Patterson AFB, OH 45433 USA. Univ Cincinnati, Dept Aerosp Engn & Engn Mech, Cincinnati, OH 45221 USA. RP Hassan, W (reprint author), USAF, Res Lab, Mat & Mfg Directorate, Met Ceram & NDE Div, Wright Patterson AFB, OH 45433 USA. RI Nagy, Peter/O-5404-2016 OI Nagy, Peter/0000-0001-5715-2409 NR 27 TC 2 Z9 2 U1 1 U2 4 PU SPRINGER/PLENUM PUBLISHERS PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0195-9298 J9 J NONDESTRUCT EVAL JI J. Nondestruct. Eval. PD DEC PY 1999 VL 18 IS 4 BP 139 EP 147 DI 10.1023/A:1022600204760 PG 9 WC Materials Science, Characterization & Testing SC Materials Science GA 361PP UT WOS:000089731700003 ER PT J AU Dunlap, CJ AF Dunlap, CJ TI The police-ization of the military SO JOURNAL OF POLITICAL & MILITARY SOCIOLOGY LA English DT Article AB This essay will briefly review the background of the use of the armed forces in a police capacity, discuss the growth of that role in the 1980s and 1990s, and forecast an even greater expansion into that role in the near future due to the emerging threat of "catastrophic terrorism." It will contend that this increased reliance on military resources far policing is not in the interest of either the armed forces or the public. Finally, it will make same observations with a view towards minimizing the dangers of police-ization of the military while ensuring the Nation's public safety. C1 USAF, Washington, DC 20330 USA. RP Dunlap, CJ (reprint author), USAF, Washington, DC 20330 USA. NR 42 TC 7 Z9 7 U1 1 U2 2 PU JOURNAL POLITICAL MILITARY SOCIOLOGY PI DE KALB PA DEPT SOCIOLOGY, NORTHERN ILLINOIS UNIV, DE KALB, IL 60115-2854 USA SN 0047-2697 J9 J POLIT MIL SOCIOL JI J. Polit. Mil. Soc. PD WIN PY 1999 VL 27 IS 2 BP 217 EP 232 PG 16 WC Political Science; Sociology SC Government & Law; Sociology GA 276CJ UT WOS:000084857800003 ER PT J AU Parthasarathy, TA Boakye, E Cinibulk, MK Perry, MD AF Parthasarathy, TA Boakye, E Cinibulk, MK Perry, MD TI Fabrication and testing of oxide/oxide microcomposites with monazite and hibonite as interlayers SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article ID CERAMIC-MATRIX COMPOSITES; INTERFACES; ALUMINA; CRACKING; FRACTURE; COATINGS; BEHAVIOR AB Oxide/oxide microcomposites were fabricated and tested to evaluate the effectiveness of monazite (LaPO4) and hibonite (CaAl12O19) as interlayers in sapphire-reinforced Al2O3-matrix composites. For interlayer thicknesses of 0.3-0.5 mu m, both interlayers showed evidence of crack deflection; however, debond lengths in hibonite-coated specimens were limited to just a small fraction of the fiber diameter. Monazite-coated specimens showed multiple matrix cracks and extensive debonding at the coating/matrix interface. Composite strengths were relatively high for both coatings, considering the fiber strength degradation during processing, The strengths were greater than the calculated matrix cracking stresses. However, the mean strengths were not significantly different from those of the control specimens, although coated composites had higher Weibull moduli. The lack of difference in strength is attributed to porosity in the matrix, The results imply that matrix density needs to be >85% to evaluate novel interface strategies reliably. C1 USAF, Mat & Mfg Directorate, Res Lab, MLLN, Wright Patterson AFB, OH 45433 USA. RP Parthasarathy, TA (reprint author), Universal Energy Syst Inc, Dayton, OH 45432 USA. RI Parthasarathy, Triplicane/B-7146-2011 OI Parthasarathy, Triplicane/0000-0002-5449-9754 NR 26 TC 28 Z9 28 U1 1 U2 5 PU AMER CERAMIC SOC PI WESTERVILLE PA 735 CERAMIC PLACE, PO BOX 6136, WESTERVILLE, OH 43081-6136 USA SN 0002-7820 J9 J AM CERAM SOC JI J. Am. Ceram. Soc. PD DEC PY 1999 VL 82 IS 12 BP 3575 EP 3583 PG 9 WC Materials Science, Ceramics SC Materials Science GA 291XD UT WOS:000085763900042 ER PT J AU Quinlan, KP AF Quinlan, KP TI A study of hydrogen evolution at irradiated p-InP electrodes in nitric acid solutions SO JOURNAL OF THE ELECTROCHEMICAL SOCIETY LA English DT Article ID MECHANISM AB Recent investigations of the photoelectrochemical (PEC) etching of p-InP in nitric acid showed an unusual property where hydrogen is not evolved with the formation of metallic indium. Zn order to fend the cause of this lack of hydrogen evolution at the irradiated p-InP electrode, the inhibition of the reduction of nitric acid was studied. Sulfamic acid has been shown to completely inhibit the reduction of nitric acid. With sulfamic acid, hydrogen is evolved at the irradiated p-InP electrode in nitric acid. The lack of hydrogen evolution in the PEC etching is attributed to the reaction of the nascent hydrogen atoms, formed on the p-InP electrode, with an active species involved in the reduction of nitric acid. In the presence of sulfamic acid, the hydrogen atoms combine to evolve hydrogen. Experiments showed that the reduction of nitric acid has no effect on the PEC etching of the p-InP in nitric acid. (C) 1999 The Electrochemical Society. S0013-4651(99)04-056-2. All rights reserved. C1 USAF, Res Lab, Electromagnet Technol Div SNHX, Hanscom AFB, Bedford, MA 01731 USA. RP Quinlan, KP (reprint author), USAF, Res Lab, Electromagnet Technol Div SNHX, Hanscom AFB, Bedford, MA 01731 USA. NR 24 TC 3 Z9 3 U1 1 U2 15 PU ELECTROCHEMICAL SOC INC PI PENNINGTON PA 65 SOUTH MAIN STREET, PENNINGTON, NJ 08534 USA SN 0013-4651 J9 J ELECTROCHEM SOC JI J. Electrochem. Soc. PD DEC PY 1999 VL 146 IS 12 BP 4514 EP 4516 DI 10.1149/1.1392666 PG 3 WC Electrochemistry; Materials Science, Coatings & Films SC Electrochemistry; Materials Science GA 265PE UT WOS:000084251900028 ER PT J AU Druger, SD Bronk, BV AF Druger, SD Bronk, BV TI Internal and scattered electric fields in the discrete dipole approximation SO JOURNAL OF THE OPTICAL SOCIETY OF AMERICA B-OPTICAL PHYSICS LA English DT Article ID POLARIZED-LIGHT SCATTERING; ENHANCED ENERGY-TRANSFER; SMALL PARTICLES; GRAINS; RAMAN AB The calculated scattering matrix elements and interior electric fields for a dielectric sphere based on the discrete dipole approximation (DDA) are compared with the exact Mie solution for homogeneous and composite spheres. For homogeneous spheres the macroscopic average field produced at each DDA dipole site by the incident field combined with the field from all DDA sites is found to be approximated by the factor (n(1)(2) + 2)/3 multiplied by the Mie macroscopic field, where nl is the refractive index. This holds to surprising accuracy, considering the finite wavelength and the small number of dipoles used in the DDA approximation. The approximate relation is most accurate near the center of the sphere and least accurate at the interface. The relation also holds for electric fields within composite spheres, with poorer agreement near each interface, where the refractive index changes. The dependence of this relation on parameters of the model is examined. (C) 1999 Optical Society of America [S0740-3224(99)00812-7]. C1 Northwestern Univ, Dept Phys & Astron, Evanston, IL 60208 USA. USAF, Res Lab, Edgewood Chem & Biol Ctr, Aberdeen Proving Ground, MD 21010 USA. RP Druger, SD (reprint author), Northwestern Univ, Dept Phys & Astron, Evanston, IL 60208 USA. NR 20 TC 12 Z9 12 U1 0 U2 3 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 0740-3224 J9 J OPT SOC AM B JI J. Opt. Soc. Am. B-Opt. Phys. PD DEC PY 1999 VL 16 IS 12 BP 2239 EP 2246 DI 10.1364/JOSAB.16.002239 PG 8 WC Optics SC Optics GA 262JT UT WOS:000084064300010 ER PT J AU Canby-Hagino, ED Caballero, RD Harmon, WJ AF Canby-Hagino, ED Caballero, RD Harmon, WJ TI Intraluminal, pneumatic lithotripsy for the removal of encrusted urinary catheters SO JOURNAL OF UROLOGY LA English DT Article DE ureter; lithotripsy; urinary catheterization; stents; urinary calculi AB Purpose: Urologists frequently treat patients requiring long-term urinary drainage with a percutaneous nephrostomy tube or ureteral stent. When such tubes are neglected and become encrusted, removal challenges even experienced urologists. We describe a new, minimally invasive technique for safely and rapidly removing encrusted, occluded tubes using the Swiss Lithoclast dagger pneumatic lithotriptor. Materials and Methods: Patients presenting with an encrusted urinary catheter were evaluated by excretory urography for renal function and obstruction. Gentle manual extraction of the tube was attempted, followed by traditional extracorporeal shockwave lithotripsy and/or ureteroscopy. When the tube was not extracted, patients were then treated with intraluminal insertion of a pneumatic Lithotripsy probe. Results: One patient presented with an encrusted, occluded nephrostomy tube and 2 had an encrusted, occluded, indwelling ureteral stent. None was removed by manual traction. Intralulminal encrustations prevented the pigtail portions of these tubes from uncoiling and removal. In each case a pneumatic lithotripsy probe was inserted into the lumen of the catheter and advanced in a jackhammer-like fashion. This technique resulted in disruption of the intraluminal encrustations and straightening of the tubes so that they were removed in an atraumatic manner. Conclusions: Intraluminal pneumatic lithotripsy is a safe, easy and rapid technique for removing encrusted urinary catheters. It is unique in that the pneumatic lithotripsy probe functions in an aqueous and nonaqueous environment, and dislodges intraluminal calcifications. We recommend its use as first Line treatment for removing encrusted urinary catheters. C1 Wilford Hall USAF Med Ctr, Dept Urol, San Antonio, TX 78236 USA. Clin Urol Wellness, Lexington, KY USA. RP Harmon, WJ (reprint author), Wilford Hall USAF Med Ctr, Dept Urol, MMKU, 2200 Bergquist Dr,Suite 1, Lackland AFB, TX 78236 USA. NR 4 TC 7 Z9 7 U1 0 U2 0 PU LIPPINCOTT WILLIAMS & WILKINS PI PHILADELPHIA PA 530 WALNUT ST, PHILADELPHIA, PA 19106-3621 USA SN 0022-5347 J9 J UROLOGY JI J. Urol. PD DEC PY 1999 VL 162 IS 6 BP 2058 EP 2060 DI 10.1016/S0022-5347(05)68100-1 PG 3 WC Urology & Nephrology SC Urology & Nephrology GA 254XL UT WOS:000083639500056 PM 10569569 ER PT J AU Leger, TJ Wolff, JM Beran, PS AF Leger, TJ Wolff, JM Beran, PS TI Improved determination of aeroelastic stability properties using a direct method SO MATHEMATICAL AND COMPUTER MODELLING LA English DT Article DE unsteady aerodynamics; boundary conditions; transonic flow; flutter aeroelasticity AB The ability to accurately predict transonic flutter boundaries is investigated using an enhanced direct computational method. Steady characteristic and unsteady approximate nonreflecting characteristic far-field boundary conditions are utilized to more accurately model the aerodynamic Row physics in a direct method. In order to accomplish this, the aerodynamic model is modified to lock the movement of the far-field grid points while allowing the airfoil surface points to move freely. This is accomplished by introducing a linear weighting function in the grid deformation model. The direct method is based on a discretization of the Euler equations and a coupled set of structural dynamics equations representative of a pitch-and-plunge airfoil with trailing edge flap. The coupled equations are expanded to specify a Hopf-bifurcation point, which defines an incipient flutter state. In addition, the direct continuation method is extended by an analytic computation of the path tangent vector for pseudo-arclength continuation (PAC). A flapped NACA 64A006 airfoil, executing pitch and plunge motion, is utilized to demonstrate the ability of the enhanced boundary conditions to accurately calculate flutter boundaries for reduced domain sizes. Both zero and nonzero angle of attack results are shown to highlight the improved accuracy of the boundary conditions. Each boundary condition modification resulted in analysis improvements, with the steady characteristic model demonstrating significant improvements in the nonlinear flow regime. For a 1 degrees static pretwist analysis at a freestream Mach number of 0.84, the enhanced model resulted in over a 75% decrease in the flutter speed error. In addition, flutter boundary solutions are presented which demonstrate the capability of the PAC model to compute variations in structural parameters. The airfoil-fluid mass ratio and structural damping parameters are varied for both subsonic and transonic flow conditions, with nonlinear effects observed for the transonic results. (C) 1999 Elsevier Science Ltd All rights reserved. C1 Wright State Univ, Dept Mech & Mat Engn, Dayton, OH 45435 USA. USAF, Res Lab, Wright Patterson AFB, OH 45433 USA. RP Leger, TJ (reprint author), Wright State Univ, Dept Mech & Mat Engn, Dayton, OH 45435 USA. NR 12 TC 2 Z9 2 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0895-7177 J9 MATH COMPUT MODEL JI Math. Comput. Model. PD DEC PY 1999 VL 30 IS 11-12 BP 95 EP 110 DI 10.1016/S0895-7177(99)00200-9 PG 16 WC Computer Science, Interdisciplinary Applications; Computer Science, Software Engineering; Mathematics, Applied SC Computer Science; Mathematics GA 266QJ UT WOS:000084310400008 ER PT J AU Shell, EB Semiatin, SL AF Shell, EB Semiatin, SL TI Effect of initial microstructure on plastic flow and dynamic globularization during hot working of Ti-6Al-4V SO METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE LA English DT Article ID TI-6AL-2SN-4ZR-2MO-0.1SI AB Plastic flow behavior and globularization kinetics during subtransus hot working were determined for Ti-6Al-4V with three different transformed beta microstructures. These conditions consisted of fine lamellar colonies, a mixture of coarse colonies and acicular alpha, and acicular alpha. Isothermal hot compression tests were performed on cylindrical samples at subtransus temperatures and strain rates typical of ingot breakdown (i.e., T similar to 815 degrees C to 955 degrees C, epsilon(radical anion) similar to 0.1 s(-1)). For all three material conditions, true stress-true strain curves exhibited a peak stress followed by noticeable flow softening; the values of peak stress and flow softening rate showed little dependence on starting microstructure. On the other hand, the kinetics of dynamic globularization varied noticeably with microstructure. By and large, the globularization rate under a given set of deformation conditions was most rapid for the fine acicular microstructure and least rapid for the mixed coarse-colony/acicular structure. At temperatures close to the beta transus, however, the difference in globularization rates for the three microstructures was less, an effect attributed to the rapid (continuous) coarsening of the laths in the acicular microstructure during preheating prior to hot working. The absence of a correlation between the globularization kinetics and the observed flow softening at low strains suggested platelet/lath bending and kinking as the primary deformation mechanism that controls the shape of the flow curves. C1 Univ Dayton, Dept Chem Engn, Dayton, OH 45469 USA. USAF, Res Lab, Mat & Mfg Directorate, AFRL,MLLM, Wright Patterson AFB, OH 45433 USA. RP Shell, EB (reprint author), Univ Dayton, Dept Chem Engn, Dayton, OH 45469 USA. RI SEMIATIN, SHELDON/E-7264-2017 NR 21 TC 85 Z9 93 U1 1 U2 25 PU MINERALS METALS MATERIALS SOC PI WARRENDALE PA 420 COMMONWEALTH DR, WARRENDALE, PA 15086 USA SN 1073-5623 J9 METALL MATER TRANS A JI Metall. Mater. Trans. A-Phys. Metall. Mater. Sci. PD DEC PY 1999 VL 30 IS 12 BP 3219 EP 3229 DI 10.1007/s11661-999-0232-4 PG 11 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA 269DK UT WOS:000084460900019 ER PT J AU Neuhauser, KM Neuhauser, TS Drehner, D Blackwood, GV AF Neuhauser, KM Neuhauser, TS Drehner, D Blackwood, GV TI Death among US Air Force basic trainees, 1956 to 1996 SO MILITARY MEDICINE LA English DT Article ID SICKLE-CELL TRAIT; UNITED-STATES; SUDDEN-DEATH; SUICIDE; RECRUITS; MILITARY; RHABDOMYOLYSIS; VACCINE; ILLNESS; RISK AB Background: Basic military training in the U.S. Air Force exposes recruits to multiple environmental and psychological stressors. Deaths often prompt examination of the training process. Methods: This retrospective case study evaluates recruit deaths at Lackland Air Force Base between 1956 and 1996 in terms of demographic, clinical, and environmental variables. Results: Eighty-five deaths occurred, with 81% being natural, 13% suicide, 4% accidental, and 2% not classified. Ninety-four percent of recruits who died were male, and 60% were 17 to 19 years of age. The average death rate was 2.8/100,000 recruits. Seven recruits were sickle cell trait (SCT)-positive. The relative risk for nontraumatic deaths between expected SCT-positive and non-SCT-positive populations was 23.53 (confidence interval, 19.55-30.01). Thirty-five percent (30 recruits) died from cardiac causes, resulting in a death rate of 1.0/100,000 trainees. Thirty-three percent (28 recruits) died primarily from infections. Six deaths were due to heat stroke, 11 to suicide, and 3 to accidents. Conclusion: As a result of improvements in immunizations, changes in hydration and exercise policies, limited access to vehicles, close supervision, the "buddy system," and the institution of the Navy-Air Force Medical Evaluation Test, only a few deaths occurred in any given year. C1 Wilford Hall USAF Med Ctr, Lackland AFB, TX 78236 USA. RP Neuhauser, KM (reprint author), Wilford Hall USAF Med Ctr, Lackland AFB, TX 78236 USA. NR 42 TC 29 Z9 30 U1 1 U2 3 PU ASSN MILITARY SURG US PI BETHESDA PA 9320 OLD GEORGETOWN RD, BETHESDA, MD 20814 USA SN 0026-4075 J9 MIL MED JI Milit. Med. PD DEC PY 1999 VL 164 IS 12 BP 841 EP 847 PG 7 WC Medicine, General & Internal SC General & Internal Medicine GA 266QF UT WOS:000084310100005 ER PT J AU Duong, D Bohannon, S Ross, MC AF Duong, D Bohannon, S Ross, MC TI The clinical nurse researcher in a military setting: Bringing practice into research SO MILITARY MEDICINE LA English DT Article AB The clinical nurse researcher (CNR) is emerging as an integral part of every major medical center. The CNR has six basic roles: facilitate the conduct of research projects; stimulate staff to conduct research; upgrade the research skills of the staff; participate on committees related to research; conduct and disseminate research; and obtain funding for research studies. Readiness issues for military missions, health promotion, and disease management and prevention are consistently of interest. The CNR should be an active participant on the institutional review board and should conduct primary studies that further the reputation of the facility. The viability of any military research program today is contingent on procurement of funding; therefore, the CNR must refine skills in grantsmanship. The demands of the medical facility and the needs of the staff must be a prime consideration in the development of the role of the CNR. C1 Keesler Med Ctr, Clin Res Lab, Keesler AFB, MS 39534 USA. RP Duong, D (reprint author), Keesler Med Ctr, Clin Res Lab, 81st MDSS SGSFE,301 Fisher St, Keesler AFB, MS 39534 USA. NR 9 TC 0 Z9 0 U1 0 U2 0 PU ASSN MILITARY SURG US PI BETHESDA PA 9320 OLD GEORGETOWN RD, BETHESDA, MD 20814 USA SN 0026-4075 J9 MIL MED JI Milit. Med. PD DEC PY 1999 VL 164 IS 12 BP 863 EP 866 PG 4 WC Medicine, General & Internal SC General & Internal Medicine GA 266QF UT WOS:000084310100008 ER PT J AU Selby, DM Clark, B Cina, SJ AF Selby, DM Clark, B Cina, SJ TI Accuracy of death certification in two tertiary care military hospitals SO MILITARY MEDICINE LA English DT Article AB To determine the number and type of errors in death certifications, death certificates and corresponding postmortem examination results for 98 patients were analyzed at two tertiary care military hospitals. Of the 98 death certificates, errors were found in 36 (37%). The most prevalent type of error was the use of a nonspecific diagnosis as the underlying cause of death (22 of 36 errors, 61%). No errors were found in the listed manner of death. Given the high prevalence of errors found in death certification, recommendations are made to ensure the proper completion of death certificates. In addition, it is suggested that for patients who are to undergo postmortem examination, the immediate, any intermediate, and the underlying cause of death may be listed as "pending" so that the clinician can use the autopsy results in the completion of the death certificate. C1 Wilford Hall USAF Med Ctr, Dept Pathol, Med Wing 59, MTLP, Lackland AFB, TX 78236 USA. RP Selby, DM (reprint author), Wilford Hall USAF Med Ctr, Dept Pathol, Med Wing 59, MTLP, 2200 Bergquist Dr Suite 1, Lackland AFB, TX 78236 USA. NR 3 TC 17 Z9 18 U1 0 U2 1 PU ASSN MILITARY SURG US PI BETHESDA PA 9320 OLD GEORGETOWN RD, BETHESDA, MD 20814 USA SN 0026-4075 J9 MIL MED JI Milit. Med. PD DEC PY 1999 VL 164 IS 12 BP 897 EP 899 PG 3 WC Medicine, General & Internal SC General & Internal Medicine GA 266QF UT WOS:000084310100016 ER PT J AU O'Brien, N Missey, M Powers, P Dominic, V Schepler, KL AF O'Brien, N Missey, M Powers, P Dominic, V Schepler, KL TI Electro-optic spectral tuning in a continuous-wave, asymmetric-duty-cycle, periodically poled LiNbO3 optical parametric oscillator SO OPTICS LETTERS LA English DT Article ID LITHIUM-NIOBATE AB We demonstrate electro-optic spectral tuning in a continuous-wave periodically poled LiNbO3 (PPLN) optical parametric oscillator (OPO). We achieve 8.91 cm(-1) of rapid spectral tuning, with a linear tuning rate of 2.89 cm(-1)/(kV/mm), by applying electric fields up to +/-1.5 kV/mm across the crystal while it is operating within the OPO. Intentionally poling the PPLN crystal with an asymmetric domain structure enables tuning, and numerical predictions closely match the experimental observations. The tuning is considerably larger than the typical operational bandwidth of the OPO, indicating that we are in fact shifting the gain curve of the PPLN crystal. (C) 1999 Optical Society of America. C1 Univ Dayton, Dept Electroopt, Dayton, OH 45469 USA. USAF, Res Lab, AFRL SNJT, WPAFB, Wright Patterson AFB, OH 45433 USA. RP O'Brien, N (reprint author), Univ Dayton, Dept Electroopt, 300 Coll Pk, Dayton, OH 45469 USA. RI Schepler, Kenneth/D-3730-2015; OI Schepler, Kenneth/0000-0001-9658-2305 NR 10 TC 52 Z9 52 U1 0 U2 6 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 0146-9592 J9 OPT LETT JI Opt. Lett. PD DEC 1 PY 1999 VL 24 IS 23 BP 1750 EP 1752 DI 10.1364/OL.24.001750 PG 3 WC Optics SC Optics GA 260PW UT WOS:000083959900032 PM 18079923 ER PT J AU Roberts, RD Kyllonen, PC AF Roberts, RD Kyllonen, PC TI Morningness-eveningness and intelligence: early to bed, early to rise will likely make you anything but wise! SO PERSONALITY AND INDIVIDUAL DIFFERENCES LA English DT Article DE circadian rhythms; diurnal preference; morningness-eveningness; intelligence; working memory; processing speed ID CIRCADIAN-RHYTHM QUESTIONNAIRES; PSYCHOMETRIC EQUIVALENCE; INDIVIDUAL-DIFFERENCES; SHIFT WORK; SCALE; POPULATION; GAINS; TESTS; IQ AB Research examining various psychological correlates of circadian type (also known as diurnal preference) has been, over the years, quite expansive. A notable omission within this research program would appear a systematic exploration of the relation between intelligence and morningness-eveningness. The present study redressed this imbalance, 420 participants performed two self-report inventories assessing circadian type, as well as measures of intelligence from two psychometric batteries: CAM-IV and the ASVAB. The results indicate that, contrary to conventional folk wisdom, evening-types are more likely to have higher intelligence scores. This result is discussed in relation to current theories concerning the nature of human cognitive abilities. (C) 1999 Elsevier Science Ltd. All rights reserved. C1 Univ Sydney, Dept Psychol, Sydney, NSW 2006, Australia. USAF, Res Lab, Human Effectiveness Directorate, Brooks AFB, TX USA. RP Roberts, RD (reprint author), Univ Sydney, Dept Psychol, Sydney, NSW 2006, Australia. OI Kyllonen, Patrick C./0000-0002-6517-4576 NR 45 TC 73 Z9 75 U1 2 U2 20 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0191-8869 J9 PERS INDIV DIFFER JI Pers. Individ. Differ. PD DEC PY 1999 VL 27 IS 6 BP 1123 EP 1133 DI 10.1016/S0191-8869(99)00054-9 PG 11 WC Psychology, Social SC Psychology GA 235RZ UT WOS:000082557500010 PM 11542922 ER PT J AU Sawyer, JE Latham, WR Pritchard, RD Bennett, WR AF Sawyer, JE Latham, WR Pritchard, RD Bennett, WR TI Analysis of work group productivity in an applied setting: Application of a time series panel design SO PERSONNEL PSYCHOLOGY LA English DT Article ID TASK COMPONENT COMPLEXITY; ORGANIZATIONAL PRODUCTIVITY; MONETARY INCENTIVES; GROUP-PERFORMANCE; GOAL COMMITMENT; STRATEGIES AB We provide a demonstration of a time series panel analysis applied under typical field research conditions characterized by (a) a small number of groups (b) all of which experience an intervention (thus there is no traditional control group), and (c) perform noncomparable tasks. The time series techniques allow a direct test of Naylor, Pritchard, and Ilgen's (1980) theory of behavior in organizations applied to work group productivity in a large-scale study of work groups conducted by Pritchard and colleagues (1989), The responses of 5 work groups to priority scores for 37 indicators of productivity over 23 months were used to predict month-by-month changes in productivity for each of the 37 group products, The results show that group productivity improvements can be explained by feedback including priority scores derived from nonlinear contingency functions of the productivity indicators. Furthermore, groups differed in their response to priority feedback. Goal setting positively affected productivity gain consistently across work groups, after the effects of priority feedback and the interaction of work groups with priority feedback were accounted for. implications for group performance strategies and appropriate applications of the time series panel analysis are discussed. C1 Univ Delaware, Dept Business Adm, Newark, DE 19716 USA. Univ Delaware, Dept Econ, Newark, DE 19716 USA. Texas A&M Univ, College Stn, TX 77843 USA. USAF, Res Lab, Warfighter Training Res Div, Mesa, AZ USA. RP Sawyer, JE (reprint author), Univ Delaware, Dept Business Adm, Newark, DE 19716 USA. EM sawyerj@be.udel.edu NR 26 TC 6 Z9 6 U1 1 U2 6 PU WILEY-BLACKWELL PI MALDEN PA COMMERCE PLACE, 350 MAIN ST, MALDEN 02148, MA USA SN 0031-5826 J9 PERS PSYCHOL JI Pers. Psychol. PD WIN PY 1999 VL 52 IS 4 BP 927 EP 967 DI 10.1111/j.1744-6570.1999.tb00185.x PG 41 WC Psychology, Applied; Management SC Psychology; Business & Economics GA 266DL UT WOS:000084285300004 ER PT J AU Budd, FC AF Budd, FC TI An air force model of psychologist-chaplain collaboration SO PROFESSIONAL PSYCHOLOGY-RESEARCH AND PRACTICE LA English DT Article ID CLERGY AB Clients bring to therapy sessions a diverse background of spiritual beliefs and religious orientations that they perceive as valuable resources and coping skills. Yet, not all psychologists know how to address effectively these beliefs and orientations. The author uses case examples to describe his experience within the United States Air Force community gained while establishing a collaberative relationship with the clergy. Recommendations include the following: how to start the collaboration, establishing a collegial relationship, pursuing continuing education on faith factors in counseling, how to utilize pastoral counselors, marketing your respect for the clergy, and capitalizing on the value of clergy in providing continuing education to psychologists. C1 USAF, Washington, DC 20330 USA. RP Budd, FC (reprint author), 204 W Hill Blvd, Charleston, SC 29404 USA. NR 29 TC 13 Z9 13 U1 0 U2 2 PU AMER PSYCHOLOGICAL ASSOC PI WASHINGTON PA 750 FIRST ST NE, WASHINGTON, DC 20002-4242 USA SN 0735-7028 J9 PROF PSYCHOL-RES PR JI Prof. Psychol.-Res. Pract. PD DEC PY 1999 VL 30 IS 6 BP 552 EP 556 DI 10.1037/0735-7028.30.6.552 PG 5 WC Psychology, Multidisciplinary SC Psychology GA 259LF UT WOS:000083894800004 ER PT J AU Golden, MC Resing, KA Collins, BD Willis, MC Koch, TH AF Golden, MC Resing, KA Collins, BD Willis, MC Koch, TH TI Mass spectral characterization of a protein-nucleic acid photocrosslink SO PROTEIN SCIENCE LA English DT Article DE bromodeoxyuridine; mass spectrometry; photocrosslinking; sequencing ID FIBROBLAST GROWTH-FACTOR; INDUCED CROSS-LINKING; BINDING DOMAIN; DNA-POLYMERASE; RNA LIGANDS; SPECTROMETRY; PEPTIDE; IDENTIFICATION; 5-BROMOURACIL; DERIVATIVES AB A photocrosslink between basic fibroblast growth factor (bFGF(155)) and a high affinity ssDNA oligonucleotide was characterized by positive ion electrospray ionization mass spectrometry (ESIMS). The DNA was a 61-mer oligonucleotide photoaptamer bearing seven bromodeoxyuridines, identified by in vitro selection. Specific photocrosslinking of the protein to the oligonucleotide was achieved by 308 nm XeCl excimer laser excitation. The crosslinked protein-nucleic acid complex was proteolyzed with trypsin. The resulting peptide crosslink was purified by PAGE, eluted, and digested by snake venom phosphodiesterase/alkaline phosphatase. Comparison of the oligonucleotide vs, the degraded peptide crosslink by high performance liquid chromatography coupled to an electrospray ionization triple quadrupole mass spectrometer showed a single ion unique to the crosslinked material. Sequencing by collision induced dissociation (MS/MS) on a triple quadrupole mass spectrometer revealed that this ion was the nonapeptide TGQYKLGSK (residues 130-138) crosslinked to a dinucleotide at Tyr133. The MS/MS spectrum indicated sequential fragmentation of the oligonucleotide to uracil covalently attached to the nonapeptide followed by fragmentation of the peptide bonds. Tyr133 is located within the heparin binding pocket, suggesting that the in vitro selection targeted this negative ion binding region of bFGF(155). C1 Univ Colorado, Dept Chem & Biochem, Boulder, CO 80309 USA. Gilead Sci Inc, Nexstar Div, Boulder, CO 80301 USA. USAF Acad, Dept Chem, Colorado Springs, CO 80840 USA. RP Koch, TH (reprint author), Univ Colorado, Dept Chem & Biochem, Campus Box 215, Boulder, CO 80309 USA. FU NIAMS NIH HHS [AR43768] NR 31 TC 37 Z9 39 U1 1 U2 6 PU CAMBRIDGE UNIV PRESS PI NEW YORK PA 40 WEST 20TH STREET, NEW YORK, NY 10011-4211 USA SN 0961-8368 J9 PROTEIN SCI JI Protein Sci. PD DEC PY 1999 VL 8 IS 12 BP 2806 EP 2812 PG 7 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 266RP UT WOS:000084314100029 PM 10631998 ER PT J AU Bronowicki, AJ Abhyankar, NS Griffin, SF AF Bronowicki, AJ Abhyankar, NS Griffin, SF TI Active vibration control of large optical space structures SO SMART MATERIALS & STRUCTURES LA English DT Article AB The paper describes techniques for designing and implementing active damping systems for large optical support structures. Each step in the design process is illustrated with results from the Advanced Composites with Embedded Sensors and Actuators (ACESA) vibration control system. The system is installed on a space based laser structural simulator at the Air Force Research Laboratory's Advanced Space Structure Research Experiments facility. The ACESA system consists of three large tubular active members; embedded lead zirconate-titanate (PZTs) wafers in each strut, which allows control of deformation axially and in two bending planes; 400 V drive electronics for each active member; and a nine-channel, digitally programmable, analogue control electronics unit. Design begins with the determination of the critical modes through a gain factor analysis. Actuators are located through modal strain energy analysis. Using piezostructural analysis methods, sensing and actuation functions are included in the open- and closed-loop dynamic simulations. The simulation includes local strain feedthrough effects through a static correction. Damping is applied to all modes in the frequency range up to 100 Hit, with fundamental modes achieving 20% damping, two orders of magnitude greater than the intrinsic damping level. The actuator PZTs used for active damping were also experimentally shunted with resistive elements in an attempt to introduce passive damping, although the effect was barely measurable. This demonstrates that active damping gives three orders of magnitude better performance than a passive resistive shunt in a controlled comparison. C1 TRW Space & Elect Grp, Redondo Beach, CA 90278 USA. Dynacs Engn, Albuquerque, NM 87123 USA. USAF, Res Lab, Space Vehicles Directorate, Kirtland AFB, NM 87117 USA. EM allen.bronowicki@trw.com; abhyankn@plk.af.mil; griffins@plk.af.mil NR 30 TC 15 Z9 16 U1 1 U2 2 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0964-1726 J9 SMART MATER STRUCT JI Smart Mater. Struct. PD DEC PY 1999 VL 8 IS 6 BP 740 EP 752 DI 10.1088/0964-1726/8/6/304 PG 13 WC Instruments & Instrumentation; Materials Science, Multidisciplinary SC Instruments & Instrumentation; Materials Science GA 270VM UT WOS:000084557900005 ER PT J AU Davis, L Hyland, D Yen, G Das, A AF Davis, L Hyland, D Yen, G Das, A TI Adaptive neural central for space structure vibration suppression SO SMART MATERIALS & STRUCTURES LA English DT Article AB Despite recent advances in efficiency, current methodologies for space structure control design still engage significant human resources for engineering development and routine maintenance. The adaptive neural control (ANC) program is part of an effort to develop neural network based controllers capable of self-optimization, on-line adaptation and autonomous fault detection and control recovery. This development in addition supports the long-term space exploration objectives for which autonomous spacecraft involving self-reliant control systems are a necessity. The ANC program comprises two phases. The first, basic phase focused an the development of efficient and completely autonomous neural network feedforward control for the case of broadband disturbances. Algorithms were developed that work with no prior modeling information about the system to be controlled and adapt to changing conditions, while minimizing or eliminating the introduction of extraneous training signals. The algorithms were demonstrated experimentally on an optical structure testbed at Harris. The second phase of the program demonstrated a more complex neural controller on the advanced space structures technology research experiments (ASTREX) test facility at the Air Force Research Laboratory capable of the fault-tolerant adaptive control of multiple sensors and actuators. This system used six actuation channels of the existing ACESA struts on the ASTREX structure to simultaneously cancel three independent tonal disturbances in the 10-15 Hz band, measured at non-collocated sensors on the secondary tower of the structure. The system demonstrated impressive fault-recovery performance, maintaining good cancellation performance with successive actuators disabled. Cancellation of individual tones was between 25 and 55 dB, with over 27 dB attenuation realized root mean square. The algorithm required very low computational throughput, operating at a sample rate of 1/20 Hz. The results of the ANC program show that adaptive cancellation systems can reduce vibrations in precision structures without prior modeling information and can adapt successfully to certain failures in actuators or sensors, optimally reconfiguring themselves without human intervention. These capabilities should significantly reduce the expense of designing and maintaining vibration control systems for spacecraft. C1 Planning Syst Inc, Melbourne, FL 32902 USA. Univ Michigan, Dept Aerosp Engn, Ann Arbor, MI 48109 USA. Oklahoma State Univ, Sch Elect Engn, Stillwater, OK 74078 USA. USAF, Res Lab, Space Vehicle Technol Div, Kirtland AFB, NM 87117 USA. NR 30 TC 16 Z9 17 U1 0 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0964-1726 J9 SMART MATER STRUCT JI Smart Mater. Struct. PD DEC PY 1999 VL 8 IS 6 BP 753 EP 766 DI 10.1088/0964-1726/8/6/305 PG 14 WC Instruments & Instrumentation; Materials Science, Multidisciplinary SC Instruments & Instrumentation; Materials Science GA 270VM UT WOS:000084557900006 ER PT J AU Nye, TW Manning, RA Qassim, K AF Nye, TW Manning, RA Qassim, K TI Performance of active vibration control technology: the ACTEX flight experiments SO SMART MATERIALS & STRUCTURES LA English DT Article AB This paper discusses the development and results of two intelligent structures space-flight experiments, each of which could affect architecture designs of future spacecraft. The first, the advanced controls technology experiment I(ACTEX I), is a variable stiffness tripod structure riding as a secondary payload on a classified spacecraft. It has been operating well past its expected life since becoming operational in 1996. Over 60 on-orbit experiments have been run on the ACTEX I flight experiment. These experiments form the basis for in-space controller design problems and for concluding lifetime/reliability data on the active control components. Transfer functions taken during the life of ACTEX I have shown consistent predictability and stability in structural behavior, including consistency with those measurements taken on the ground prior to a three year storage period and the launch event. ACTEX I can change its modal characteristics by employing its dynamic change mechanism that varies preloads in portions of its structure. Active control experiments have demonstrated maximum vibration reductions of 29 dB and 16 dB in the first two variable modes of the system, while operating over a remarkable on-orbit temperature range of -80 degrees C to 129 OC. The second experiment, ACTEX II, was successfully designed, ground-tested, and integrated on an experimental Department of Defense satellite prior to its loss during a launch vehicle failure in 1995. ACTEX II also had variable modal behavior by virtue of a two-axis gimbal and added challenges of structural flexibility by being a large deployable appendage. Although the loss of ACTEX II did not provide space environment experience, ground testing resulted in space qualifying the hardware and demonstrated 21 dB, 14 dB, and 8 dB reductions in amplitude of the first three primary structural modes. ACTEX II could use either active and/or passive techniques to affect vibration suppression. Both experiments trailblazed spacecraft bus smart structures by developing over 20 new technologies. As pathfinders, experience was gained in the implications of space system analyses, verification tests, and for ways to leverage this technology to meet new satellite performance requirements. C1 TRW Space & Elect Grp, Syst Engn, Redondo Beach, CA 90278 USA. TRW Space & Elect Grp, Dynam & Test Engn, Redondo Beach, CA 90278 USA. USAF, Res Lab, Vehicle Technol Branch, Kirtland AFB, NM 87117 USA. NR 18 TC 6 Z9 7 U1 1 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0964-1726 J9 SMART MATER STRUCT JI Smart Mater. Struct. PD DEC PY 1999 VL 8 IS 6 BP 767 EP 780 DI 10.1088/0964-1726/8/6/306 PG 14 WC Instruments & Instrumentation; Materials Science, Multidisciplinary SC Instruments & Instrumentation; Materials Science GA 270VM UT WOS:000084557900007 ER PT J AU Cobb, RG Sullivan, JM Das, A Davis, LP Hyde, TT Davis, T Rahman, ZH Spanos, JT AF Cobb, RG Sullivan, JM Das, A Davis, LP Hyde, TT Davis, T Rahman, ZH Spanos, JT TI Vibration isolation and suppression system for precision payloads in space SO SMART MATERIALS & STRUCTURES LA English DT Article AB This paper describes the design and performance testing of a vibration isolation and suppression system (VISS) which can be used to isolate a precision payload from spacecraft borne disturbances. VISS utilizes six hybrid isolation struts in a hexapod configuration. Central to the concept is a novel hybrid actuation concept which provides both passive isolation and active damping. The passive isolation is provided using a flight proven D-strut design. The passive design is supplemented by a voice-coil based active system. The active system is used to enhance the performance of the passive isolation system at lower frequencies, and provide the capability to steer the payload. C1 USAF, Res Lab, Kirtland AFB, NM 87117 USA. Honeywell Satellite Syst Operat, Glendale, AZ 85308 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. NR 19 TC 69 Z9 82 U1 8 U2 26 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0964-1726 J9 SMART MATER STRUCT JI Smart Mater. Struct. PD DEC PY 1999 VL 8 IS 6 BP 798 EP 812 DI 10.1088/0964-1726/8/6/309 PG 15 WC Instruments & Instrumentation; Materials Science, Multidisciplinary SC Instruments & Instrumentation; Materials Science GA 270VM UT WOS:000084557900010 ER PT J AU Bronowicki, AJ Das, A Wada, BK AF Bronowicki, AJ Das, A Wada, BK TI Special issue on smart structures for space - Preface SO SMART MATERIALS & STRUCTURES LA English DT Editorial Material C1 USAF, Res Lab, Washington, DC USA. Jet Prop Lab, Pasadena, CA 91109 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0964-1726 J9 SMART MATER STRUCT JI Smart Mater. Struct. PD DEC PY 1999 VL 8 IS 6 BP U3 EP U3 PG 1 WC Instruments & Instrumentation; Materials Science, Multidisciplinary SC Instruments & Instrumentation; Materials Science GA 270VM UT WOS:000084557900001 ER PT J AU Cutler, JN Sanders, JH John, PJ De Stasio, G Gilbert, B Tan, K AF Cutler, JN Sanders, JH John, PJ De Stasio, G Gilbert, B Tan, K TI Chemical characterization of antiwear films generated by Tris-[p-(perfluoroalkylether)phenyl] phosphine using X-ray absorption spectroscopy SO WEAR LA English DT Article DE antiwear films; Tris-[p-(perfluoroalkylether)phenyl] phosphine; X-ray absorption spectroscopy ID PERFLUOROPOLYALKYLETHER LIQUID LUBRICANTS; SOLUBLE ADDITIVES; BEARING STEELS; WEAR BEHAVIOR; HIGH-VACUUM; PERFLUOROPOLYETHERS; TEMPERATURE; FLUIDS; DEGRADATION; CHEMISTRY AB Perfluoropolyalkylethers (PFPAEs) are primary candidates as high temperature oils for the next generation of turbine engines due to their chemical and thermal stability. However, the usefulness of the PFPAE base fluids are hindered by corrosive wear in dry environments. This problem can be minimized and overall wear properties improved by the addition of soluble additives, such as Tris-[ p-(perfluoroalkylether)phenyl] phosphine (PH3). Currently, little work has been reported on the mechanism by which this additive actually improves overall wear performance. This paper provides critical insight regarding the interactions of the PFPAE additive PH3 with Fe-based alloys in a pin-on-flat tribological environment. It is found that the PH3 decomposes on the surface, within the wear track, forming a tribofilm composed of a polyphosphate glassy material. At low relative humidity (similar to 0%), the polyphosphate antiwear film substantial improves the wear performance of the fluid which is reflected by a decrease of similar to 325% in width of the measured wear scar. Contrasting this result, at high relative humidity (similar to 50%), little improvement is found in the wear properties of the fluid. This is due to the formation of carboxylate multilayers produced by PFPAEs in a moist environment, which serve as their own antiwear film. The formation and protective propel-ties of these films are controlled by three important environmental factors. First, oxygen must be present in order to form the polyphosphate. Second, tribomechanical scission and hydrolysis of the additive is required to drive the reaction to completion. At low humidity, a large amount of unreacted and intermediate material was found within the wear track. Third, the test temperature combined with the relative humidity was shown to control the overall useful lifetime of the additive, in order to gain some understanding on how this additive works, a series of tribological experiments were performed at different temperatures, relative humidities and rubbing times. The worn specimens were examined by X-ray absorption near edge structure spectroscopy (XANES) and imaging photoelectron spectromicroscopy (MEPHISTO). (C) 1999 Elsevier Science S.A;. All rights reserved. C1 USAF, Res Lab, MLBT, Mat & Mfg Directorate, Wright Patterson AFB, OH 45433 USA. Univ Dayton, Res Inst, Dayton, OH 45469 USA. CNR, Ist Struttura Mat, I-00133 Rome, Italy. Ecole Polytech Fed Lausanne, Inst Phys Appl, CH-1015 Lausanne, Switzerland. Univ Wisconsin, Canadian Synchrotron Radiat Facil, Stoughton, WI 53589 USA. RP Cutler, JN (reprint author), USAF, Res Lab, MLBT, Mat & Mfg Directorate, Wright Patterson AFB, OH 45433 USA. RI Gilbert, Pupa/A-6299-2010 OI Gilbert, Pupa/0000-0002-0139-2099 NR 47 TC 9 Z9 10 U1 0 U2 5 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0043-1648 J9 WEAR JI Wear PD DEC PY 1999 VL 236 IS 1-2 BP 165 EP 178 DI 10.1016/S0043-1648(99)00283-5 PG 14 WC Engineering, Mechanical; Materials Science, Multidisciplinary SC Engineering; Materials Science GA 271JP UT WOS:000084590700020 ER PT J AU Gorbunov, VV Fuchigami, N Hazel, JL Tsukruk, VV AF Gorbunov, VV Fuchigami, N Hazel, JL Tsukruk, VV TI Probing surface microthermal properties by scanning thermal microscopy SO LANGMUIR LA English DT Letter ID FILMS AB Scanning thermal microscopy (SThM) was used for probing surface microthermal properties of a wide range of materials from polymers to metals. We demonstrated that SThM measurements in contact mode can provide unique capabilities of unambiguous measurements of localized thermal conductivity of a wide variety of surfaces with sensitivity better than 0.05 W m(-1) K-1 and lateral resolution in the range from 0.03 mu m for hard materials to 1 mu m for compliant materials. Variation of surface microthermal conductivity correlates fairly well with known bulk values for hard materials. For compliant materials, significant contribution of local deformation to measured values of thermal response is noted. C1 Iowa State Univ, Dept Mat Sci & Engn, Ames, IA 50011 USA. Natl Acad Sci, Metal Polymer Inst, Gomel 246550, Byelarus. USAF, MLBP, Res Lab, Wright Patterson AFB, OH 45433 USA. RP Tsukruk, VV (reprint author), Iowa State Univ, Dept Mat Sci & Engn, Ames, IA 50011 USA. NR 21 TC 39 Z9 39 U1 1 U2 12 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0743-7463 J9 LANGMUIR JI Langmuir PD NOV 23 PY 1999 VL 15 IS 24 BP 8340 EP 8343 DI 10.1021/la990913a PG 4 WC Chemistry, Multidisciplinary; Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA 259ZC UT WOS:000083923000002 ER PT J AU Comtois, J Michalicek, A Cowan, W Butler, J AF Comtois, J Michalicek, A Cowan, W Butler, J TI Surface-micromachined polysilicon MOEMS for adaptive optics SO SENSORS AND ACTUATORS A-PHYSICAL LA English DT Article; Proceedings Paper CT 1998 IEEE/LEOS Topical Meeting on Optical MEMS CY JUL 20-22, 1998 CL MONTEREY, CALIFORNIA SP IEEE, LEOS DE MOEMS; MUMPS; SUMMiT; adaptive optics; surface-micromachining ID MICROMIRROR ARRAYS; DESIGN AB This paper presents an overview of Air Force research and development programs in micro-opto-electro-mechanical systems (MOEMS) for adaptive optics using commercially available surface-micromachined polysilicon fabrication processes. Adaptive optic systems are a growing area of interest because advanced technologies are now becoming available to make these systems lightweight, low power, and compact. In short, they are becoming practical for space;missile, and man-portable applications. The technologies that are making this possible include highly integrated low power electronics, new processing architectures for error sensing and control, flexible high density packaging, and especially MOEMS. Micromirror design, mirror array design, and design tradeoffs are discussed, as well as high density packaging for combining MEMS-specific die with standard electronic die. The micromirror devices described below were developed for adaptive optic systems, and for exploring the design, manufacture, and actuation options made possible by the commercial surface-micromachining fabrication processes. (C) 1999 Elsevier Science S.A. All rights reserved. C1 USAF, Res Lab, Kirtland AFB, NM 87117 USA. USAF, Res Lab, Wright Patterson AFB, OH 45433 USA. RP Comtois, J (reprint author), USAF, Res Lab, Bldg 915,Room 134,3550 Adedrdeen St SE, Kirtland AFB, NM 87117 USA. NR 12 TC 23 Z9 25 U1 0 U2 2 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0924-4247 J9 SENSOR ACTUAT A-PHYS JI Sens. Actuator A-Phys. PD NOV 23 PY 1999 VL 78 IS 1 BP 54 EP 62 DI 10.1016/S0924-4247(99)00204-6 PG 9 WC Engineering, Electrical & Electronic; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA 265CB UT WOS:000084222600008 ER PT J AU Lyday, C AF Lyday, C TI Maybe rapid decompression SO AVIATION WEEK & SPACE TECHNOLOGY LA English DT Letter C1 USAF, Denver, CO USA. RP Lyday, C (reprint author), USAF, Denver, CO USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU MCGRAW HILL INC PI NEW YORK PA 1221 AVENUE OF THE AMERICAS, NEW YORK, NY 10020 USA SN 0005-2175 J9 AVIAT WEEK SPACE TEC JI Aviat. Week Space Technol. PD NOV 22 PY 1999 VL 151 IS 21 BP 6 EP 6 PG 1 WC Engineering, Aerospace SC Engineering GA 260PE UT WOS:000083958400001 ER PT J AU Gamble, LJ Diffey, WM Cole, ST Fork, RL Jones, DK Nelson, TR Loehr, JP Ehret, JE AF Gamble, LJ Diffey, WM Cole, ST Fork, RL Jones, DK Nelson, TR Loehr, JP Ehret, JE TI Simultaneous measurement of group delay and transmission of a one-dimensional photonic crystal SO OPTICS EXPRESS LA English DT Article ID PULSES AB We characterize both the group delay and the transmission of a layered semiconductor structure in a single easily interpreted plot. The data spans a 50 nm wide spectral range with 1.7 nanometer wavelength resolution, and a 1.3 picosecond wide temporal range with temporal resolution of tens of femtoseconds. Specific data for a 28 period GaAs/AlAs layered photonic band-gap structure that characterizes both group delay and transmission of multiple photonic resonances in a single display are presented and compared to theory. (C) 1999 Optical Society of America. C1 Univ Alabama, Dept Elect & Comp Engn, Huntsville, AL 35899 USA. Middle Tennessee State Univ, Murfreesboro, TN 37132 USA. USAF, Res Lab, Wright Patterson AFB, OH 45433 USA. RP Gamble, LJ (reprint author), Univ Alabama, Dept Elect & Comp Engn, Huntsville, AL 35899 USA. NR 9 TC 7 Z9 7 U1 1 U2 2 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 1094-4087 J9 OPT EXPRESS JI Opt. Express PD NOV 22 PY 1999 VL 5 IS 11 BP 267 EP 272 PG 6 WC Optics SC Optics GA 258RJ UT WOS:000083852300004 PM 19401731 ER PT J AU Andersen, G Knize, RJ AF Andersen, G Knize, RJ TI Holographically corrected telescope for high-bandwidth optical communications SO APPLIED OPTICS LA English DT Article AB We present a design for an optical data communications receiver-transmitter pair based on the holographic correction of a large diameter, poor-quality, reflecting primary mirror. The telescope has a narrow bandwidth (<0.1 nm) with good signal frequency isolation (>60 dB) and is scalable to meter-class apertures. We demonstrate the correction of a reflector telescope with over 2000 waves of aberration to diffraction-limited operation, capable of handling data transmission rates up to 100 GHz. (C) 1999 Optical Society of America OCIS codes: 090.1000, 060.4510, 110.6770, 120.4640. C1 USAF Acad, Laser & Opt Res Ctr, Colorado Springs, CO 80840 USA. RP USAF Acad, Laser & Opt Res Ctr, Suite 2A31,2354 Fairchild Dr, Colorado Springs, CO 80840 USA. EM geoff.andersen@usafa.af.mil NR 12 TC 10 Z9 11 U1 0 U2 0 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 1559-128X EI 2155-3165 J9 APPL OPTICS JI Appl. Optics PD NOV 20 PY 1999 VL 38 IS 33 BP 6833 EP 6835 DI 10.1364/AO.38.006833 PG 3 WC Optics SC Optics GA 256UC UT WOS:000083743900005 PM 18324223 ER PT J AU Quinn, DW Oxley, ME Vosika, DC AF Quinn, DW Oxley, ME Vosika, DC TI The boundary element method applied to a moving free boundary problem SO INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING LA English DT Article DE moving boundary; free boundary; boundary element method; diffusion equation; contaminant transport AB In this paper a boundary problem is considered for which the boundary is to be determined as part of the solution. A time-dependent problem involving linear diffusion in two spatial dimensions which results in a moving free boundary is posed. The fundamental solution is introduced and Green's Theorem is used to yield a non-linear system of integral equations for the unknown solution and the location of the boundary. The boundary element method is used to obtain a numerical solution to this system of integral equations which in turn is used to obtain the solution of the original problem. Graphical results for a two-dimensional problem are presented. Published in 1999 by John Wiley & Sons, Ltd. C1 USAF, Dept Math & Stat, Grad Sch Engn, Inst Technol, Wright Patterson AFB, OH 45433 USA. RP Quinn, DW (reprint author), USAF, Dept Math & Stat, Grad Sch Engn, Inst Technol, 2950 P St, Wright Patterson AFB, OH 45433 USA. NR 19 TC 1 Z9 1 U1 1 U2 1 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX PO19 1UD, ENGLAND SN 0029-5981 J9 INT J NUMER METH ENG JI Int. J. Numer. Methods Eng. PD NOV 20 PY 1999 VL 46 IS 8 BP 1335 EP 1346 PG 12 WC Engineering, Multidisciplinary; Mathematics, Interdisciplinary Applications SC Engineering; Mathematics GA 252KZ UT WOS:000083501800010 ER PT J AU Lacbawan, FL White, BJ Anguiano, A Rigdon, DT Ball, KD Bromage, GB Yang, XJ DiFazio, MP Levin, SW AF Lacbawan, FL White, BJ Anguiano, A Rigdon, DT Ball, KD Bromage, GB Yang, XJ DiFazio, MP Levin, SW TI Rare interstitial deletion (2)(p11.2p13) in a child with pericentric inversion (2)(p11.2q13) of paternal origin SO AMERICAN JOURNAL OF MEDICAL GENETICS LA English DT Article DE chromosome 2; pericentric inversion; interstitial deletion 2p12; unequal crossingover ID PARACENTRIC INVERSION; CHROMOSOME 2; DUPLICATION; ASSOCIATION; CARRIERS AB An unbalanced 46,XY,der(2)del(2) (p11.2p13) inv(2)(p11.2q13) karyotype was found in a phenotypically abnormal child with a de novo interstitial deletion of band 2p12 associated with an inv(2)(p11.2q13) inherited from the father. The inv(a) is generally considered a benign familial variant without significant reproductive consequences. However, our findings led us to consider a previously proposed mechanism of unequal meiotic crossing over at the base of a parental inversion loop, which could lead to either a deletion or duplication of a segment adjacent to the inverted region in the offspring. This phenomenon has been reported in other inversions of chromosomes 1, 7, 13, 15, and 17 and may explain the origin of the deletion in our patient. Although repetitive sequences might be present around such inversions, which could predispose to de novo deletions independently of the inversion, current evidence including this case favors a proposed causal relationship between the parental inversion and the deletion in the child. Our review and results suggest there could be a small risk for a related imbalance to couples with an inv(2)(p11.2q13). For del(2)(p11.2p13), which is rare, a more distinct phenotype has been proposed herein. Our patient shared several findings with the three previously published cases, namely the broad nasal bridge, abnormal ears, high-arched palate, psychomotor retardation, and micrognathia, However, our patient also had sensorineural hearing loss and significant hypotonia, which have not been previously reported, thereby expanding our understanding of this rare deletion. Published 1999 Wiley-Liss, Inc.(dagger) C1 Walter Reed Army Med Ctr, Dept Pediat, Genet Sect, Washington, DC 20307 USA. Walter Reed Army Med Ctr, Dept Neurol, Washington, DC 20307 USA. NHGRI, Med Genet Branch, NIH, Bethesda, MD USA. Nichols Inst, Quest Diagnost, Dept Cytogenet, San Juan Capistrano, CA USA. USAF, Ctr Med Genet, Kessler AFB, MS USA. RP Levin, SW (reprint author), Walter Reed Army Med Ctr, Dept Pediat, Genet Sect, Bldg 38, Washington, DC 20307 USA. NR 17 TC 15 Z9 15 U1 0 U2 1 PU WILEY-LISS PI NEW YORK PA DIV JOHN WILEY & SONS INC, 605 THIRD AVE, NEW YORK, NY 10158-0012 USA SN 0148-7299 J9 AM J MED GENET JI Am. J. Med. Genet. PD NOV 19 PY 1999 VL 87 IS 2 BP 139 EP 142 DI 10.1002/(SICI)1096-8628(19991119)87:2<139::AID-AJMG5>3.0.CO;2-J PG 4 WC Genetics & Heredity SC Genetics & Heredity GA 253LV UT WOS:000083558800005 PM 10533028 ER PT J AU Nguyen, KA Day, PN Pachter, R AF Nguyen, KA Day, PN Pachter, R TI Ground and triplet excited structures and spectroscopic properties of halogenated zinc meso-tetraphenylporphyrin SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID DENSITY-FUNCTIONAL THEORY; COMPACT EFFECTIVE POTENTIALS; MOLECULAR-ORBITAL METHODS; EXPONENT BASIS-SETS; GAUSSIAN-TYPE BASIS; ELECTRONIC-STRUCTURE; EXCITATION-ENERGIES; COUPLING REACTIONS; ORGANIC-MOLECULES; RESPONSE THEORY AB Structures of the ground and tripler excited state of zinc meso-tetraphenylporphyrin (ZnTPP) and its beta-octahalogenated derivatives (ZnTPPX8 with X = F, Cl, and Br) have been predicted using density functional theory (DFT) with Becke's three-parameter functional. The excitation energies: computed by singles CI and time-dependent DFT (TDDFT), are consistent with the observed trends, with TDDFT values in near quantitative agreement with experiment. For ZnTPPBr8, we found that geometry distortion contributes about one-third of the redshifts observed for the Q and B bands in the ground-state spectrum. The results for ZnTPPX8 and the nonphenylated ZnPX8 provide insightful accounts of effects of phenyl, fluoro, chloro, and bromo substituents on the excitation energies of these systems. The computed singlet-triplet (S-0-T-1) splitting of ZnTPP is in excellent agreement with experiment. The S-0-T-1 splitting is predicted to be significantly (0.4-0.5 eV) redshifted upon beta-chlorination and beta-bromination. C1 USAF, Res Lab, Mat & Mfg Directorate, MLPJ, Wright Patterson AFB, OH 45433 USA. RP Nguyen, KA (reprint author), USAF, Res Lab, Mat & Mfg Directorate, MLPJ, Wright Patterson AFB, OH 45433 USA. NR 64 TC 38 Z9 39 U1 1 U2 8 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1089-5639 J9 J PHYS CHEM A JI J. Phys. Chem. A PD NOV 18 PY 1999 VL 103 IS 46 BP 9378 EP 9382 DI 10.1021/jp993208j PG 5 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 260XL UT WOS:000083978700031 ER PT J AU Shelton, BS Wong, MM Zhu, TG Eiting, CJ Lambert, DJH Lin, DE Kwon, HK Dupuis, RD AF Shelton, BS Wong, MM Zhu, TG Eiting, CJ Lambert, DJH Lin, DE Kwon, HK Dupuis, RD TI Dependence of device characteristics on the intrinsic material properties of high-performance AlGaN/GaN HEMTs SO PHYSICA STATUS SOLIDI A-APPLIED RESEARCH LA English DT Article; Proceedings Paper CT 3rd International Conference on Nitride Semiconductors (ICNS 99) CY JUL 05-09, 1999 CL MONTPELLIER, FRANCE SP ICNS ID POWER AB High electron mobility transistors (HEMTs) based on AlGaN/GaN structures have become very attractive for high-power and high-frequency applications as epitaxial layer quality steadily improves The key advantages of these devices lie in the large conduction-band offset, enhanced mobility, and dense sheet charge as a result of the two-dimensional electron gas and the piezoelectric effect of the AlGaN/GaN structure. In this study, relationships were developed between the intrinsic material properties and the performance of HEMT devices. Furthermore, we demonstrate high-performance, long-gate-length AlGaN/GaN heterojunction field-effect transistors. C1 Univ Texas, Ctr Microelect Res, PRC, Austin, TX 78712 USA. USAF, Res Lab, Mat & Mfg Directorate, Wright Patterson AFB, OH 45433 USA. RP Dupuis, RD (reprint author), Univ Texas, Ctr Microelect Res, PRC, MER 1-606D-R9900, Austin, TX 78712 USA. NR 6 TC 5 Z9 5 U1 1 U2 4 PU WILEY-V C H VERLAG GMBH PI BERLIN PA MUHLENSTRASSE 33-34, D-13187 BERLIN, GERMANY SN 0031-8965 J9 PHYS STATUS SOLIDI A JI Phys. Status Solidi A-Appl. Res. PD NOV 16 PY 1999 VL 176 IS 1 BP 213 EP 217 DI 10.1002/(SICI)1521-396X(199911)176:1<213::AID-PSSA213>3.0.CO;2-9 PG 5 WC Materials Science, Multidisciplinary; Physics, Applied; Physics, Condensed Matter SC Materials Science; Physics GA 261WA UT WOS:000084032200041 ER PT J AU McGlasson, DL Beard, BM AF McGlasson, DL Beard, BM TI Unexpectedly high levels of FVII when monitoring Coumadin patients with unstable INR. SO BLOOD LA English DT Meeting Abstract C1 Wilford Hall USAF Med Ctr, Coumadin Clin, Hematol Oncol Clin, Lackland AFB, TX 78236 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER SOC HEMATOLOGY PI WASHINGTON PA 1200 19TH ST, NW, STE 300, WASHINGTON, DC 20036-2422 USA SN 0006-4971 J9 BLOOD JI Blood PD NOV 15 PY 1999 VL 94 IS 10 SU 1 MA 3653 BP 109B EP 109B PN 2 PG 1 WC Hematology SC Hematology GA 257PM UT WOS:000083790700497 ER PT J AU Shaughnessy, PJ Kissack, B Bickford, DJ Ririe, DW Hensley, RE Smith, R Schroeder, MT AF Shaughnessy, PJ Kissack, B Bickford, DJ Ririe, DW Hensley, RE Smith, R Schroeder, MT TI Correlation of CD34 percentage and volume of bone marrow collected for allogeneic bone marrow harvests. SO BLOOD LA English DT Meeting Abstract C1 Wilford Hall USAF Med Ctr, San Antonio, TX 78236 USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU AMER SOC HEMATOLOGY PI WASHINGTON PA 1200 19TH ST, NW, STE 300, WASHINGTON, DC 20036-2422 USA SN 0006-4971 J9 BLOOD JI Blood PD NOV 15 PY 1999 VL 94 IS 10 SU 1 MA 1444 BP 323A EP 323A PN 1 PG 1 WC Hematology SC Hematology GA 257PH UT WOS:000083790301492 ER PT J AU Gazitt, Y Callander, N Freytes, CO Shaughnessy, P Tsai, TW Alsina, M Anderson, JE Devore, P AF Gazitt, Y Callander, N Freytes, CO Shaughnessy, P Tsai, TW Alsina, M Anderson, JE Devore, P TI A randomized prospective study of peripheral blood stem cell (PBSC) mobilization with cyclophosphamide (CTX) in combination with G-CSF, GM-CSF, or sequential GM-CSF followed by G-CSF, in non-Hodgkin's lymphoma (NHL) patients. SO BLOOD LA English DT Meeting Abstract C1 Univ Texas, Hlth Sci Ctr, San Antonio, TX USA. Audie L Murphy Vet Adm Hosp, San Antonio, TX USA. Wilford Hall USAF Med Ctr, San Antonio, TX 78236 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER SOC HEMATOLOGY PI WASHINGTON PA 1200 19TH ST, NW, STE 300, WASHINGTON, DC 20036-2422 USA SN 0006-4971 J9 BLOOD JI Blood PD NOV 15 PY 1999 VL 94 IS 10 SU 1 MA 4736 BP 338B EP 338B PN 2 PG 1 WC Hematology SC Hematology GA 257PM UT WOS:000083790701580 ER PT J AU Shaughnessy, PJ Ririe, DW Ornstein, DL Kissack, B Bickford, DJ Lanzkron, S Bachier, C Nanez, A LeMaistre, CF AF Shaughnessy, PJ Ririe, DW Ornstein, DL Kissack, B Bickford, DJ Lanzkron, S Bachier, C Nanez, A LeMaistre, CF TI Evidence of an autoantibody inhibiting engraftment in a patient with systemic lupus erythematosus (SLE) treated with high dose immunosupression and autologous stem cell rescue. SO BLOOD LA English DT Meeting Abstract C1 Wilford Hall USAF Med Ctr, Lackland AFB, TX 78236 USA. Texas Transplant Inst, San Antonio, TX USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER SOC HEMATOLOGY PI WASHINGTON PA 1200 19TH ST, NW, STE 300, WASHINGTON, DC 20036-2422 USA SN 0006-4971 J9 BLOOD JI Blood PD NOV 15 PY 1999 VL 94 IS 10 SU 1 MA 4843 BP 362B EP 362B PN 2 PG 1 WC Hematology SC Hematology GA 257PM UT WOS:000083790701687 ER PT J AU Ririe, D Shaughnessy, P Moore, R Ornstein, D AF Ririe, D Shaughnessy, P Moore, R Ornstein, D TI Excellent results in the treatment of severe aplastic anemia (SAA) using cyclophosphamide (CY) and anti-thymocyte globulin (ATG) as the preparative regimen in allogeneic bone marrow transplantation (BMT). SO BLOOD LA English DT Meeting Abstract C1 Wilford Hall USAF Med Ctr, San Antonio, TX 78236 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER SOC HEMATOLOGY PI WASHINGTON PA 1200 19TH ST, NW, STE 300, WASHINGTON, DC 20036-2422 USA SN 0006-4971 J9 BLOOD JI Blood PD NOV 15 PY 1999 VL 94 IS 10 SU 1 MA 4956 BP 386B EP 386B PN 2 PG 1 WC Hematology SC Hematology GA 257PM UT WOS:000083790701800 ER PT J AU Shaughnessy, PJ Ririe, DW Raybon, KB Schroeder, MT Snyder, MJ AF Shaughnessy, PJ Ririe, DW Raybon, KB Schroeder, MT Snyder, MJ TI High dose chemotherapy with BCNU, cytarabine, cyclophosphamide, and etoposide (BACE) and autologous stem cell rescue for relapsed, chemotherapy sensitive non Hodgkin's lymphoma (NHL) and Hodgkin's disease (HD). SO BLOOD LA English DT Meeting Abstract C1 Wilford Hall USAF Med Ctr, Lackland AFB, TX 78236 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER SOC HEMATOLOGY PI WASHINGTON PA 1200 19TH ST, NW, STE 300, WASHINGTON, DC 20036-2422 USA SN 0006-4971 J9 BLOOD JI Blood PD NOV 15 PY 1999 VL 94 IS 10 SU 1 MA 5042 BP 406B EP 406B PN 2 PG 1 WC Hematology SC Hematology GA 257PM UT WOS:000083790701886 ER PT J AU Gazitt, Y Fey, V Shaughnessy, P Devore, P AF Gazitt, Y Fey, V Shaughnessy, P Devore, P TI A randomized prospective study of peripheral blood stem cell (PBSC) mobilization with cyclophosphamide (CTX) in combination with G-CSF, GM-CSF, or sequential GM-CSF followed by G-CSF, in non-hodgkin's lymphoma (NHL) patients: Co-mobilization of dendritic cells and NK cells. SO BLOOD LA English DT Meeting Abstract C1 Univ Texas, Hlth Sci Ctr, San Antonio, TX USA. VA Hosp, San Antonio, TX USA. Wilford Hall USAF Med Ctr, San Antonio, TX 78236 USA. NR 0 TC 4 Z9 4 U1 0 U2 0 PU AMER SOC HEMATOLOGY PI WASHINGTON PA 1200 19TH ST, NW, STE 300, WASHINGTON, DC 20036-2422 USA SN 0006-4971 J9 BLOOD JI Blood PD NOV 15 PY 1999 VL 94 IS 10 SU 1 MA 2828 BP 637A EP 637A PN 1 PG 1 WC Hematology SC Hematology GA 257PH UT WOS:000083790302877 ER PT J AU Reynolds, DC Look, DC Jogai, B Litton, CW Collins, TC Harris, MT Callahan, MJ Bailey, JS AF Reynolds, DC Look, DC Jogai, B Litton, CW Collins, TC Harris, MT Callahan, MJ Bailey, JS TI Strain splitting of the Gamma(5) and Gamma(6) free excitons in ZnO SO JOURNAL OF APPLIED PHYSICS LA English DT Article AB High-quality ZnO crystals have been grown by vapor-phase techniques and by the hydrothermal method. Depending on the surface preparation technique, some hydrothermally grown crystals contain strain. These strains result in energy shifts of the free excitons as well as relaxation of the selection rules. The Gamma(6) unallowed exciton is observed in these samples without the application of a magnetic field. The Gamma(6) exciton is also observed to split in a strain field, consistent with the Gamma(9) symmetry for the top valence band in ZnO. The Gamma(5) and Gamma(6) excitons have been observed to split in the strain field. The splitting is believed due to combined strain and electron-hole spin exchange. (C) 1999 American Institute of Physics. [S0021-8979(99)08022-6]. C1 Wright State Univ, Semicond Res Ctr, Dayton, OH 45435 USA. USAF, Res Lab, Mat & Mfg Directorate, Wright Patterson AFB, OH 45433 USA. Oklahoma State Univ, Stillwater, OK 74078 USA. USAF, Res Lab, Sensors Directorate, Hanscom AFB, MA 01731 USA. Solid State Sci Corp, Hollis, NH 03049 USA. RP Reynolds, DC (reprint author), Wright State Univ, Semicond Res Ctr, Dayton, OH 45435 USA. NR 7 TC 18 Z9 18 U1 1 U2 6 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD NOV 15 PY 1999 VL 86 IS 10 BP 5598 EP 5600 DI 10.1063/1.371566 PG 3 WC Physics, Applied SC Physics GA 251GH UT WOS:000083435900041 ER PT J AU Basov, N Hager, G Ionin, A Kotkov, A Kurnosov, A McCord, J Napartovich, A Seleznev, L Turkin, N AF Basov, N Hager, G Ionin, A Kotkov, A Kurnosov, A McCord, J Napartovich, A Seleznev, L Turkin, N TI Pulsed first-overtone CO laser with output efficiency higher than 10% SO OPTICS COMMUNICATIONS LA English DT Article ID DELTA-UPSILON=2 AB Output efficiency as high as 11% and specific output energy up to similar to 50 J/1 Amagat were experimentally obtained for a cryogenically cooled multiline pulsed first-overtone (FO) CO laser for the first time. The longest generated wavelength was 4.1 mu m, corresponding to the 37 --> 35 vibrational transition. FO CO lasing was observed within an initial gas temperature interval of 100-220 K. Theoretical calculations based on the experimental data predict that the FO CO laser efficiency can be increased up to 20%. High efficiency and high specific output energy obtained in the experiment places the FO CO laser amongst other high-power lasers. (C) 1999 Published by Elsevier Science B.V. All rights reserved. C1 PN Lebedev Phys Inst, Moscow 117924, Russia. Troitsk Inst Innovat & Fus Res, Troitsk, Moscow Region, Russia. USAF, Res Lab, Kirtland AFB, NM USA. RP Ionin, A (reprint author), PN Lebedev Phys Inst, Leninsky Prospect 53, Moscow 117924, Russia. RI Selenev, Leonid/K-7441-2015; Ionin, Andrey/M-3857-2015; Napartovich, Anatoly/C-1081-2016; Kotkov, Andrei/K-7590-2015 OI Selenev, Leonid/0000-0002-8121-9914; Ionin, Andrey/0000-0003-3119-4592; Kotkov, Andrei/0000-0001-5967-0840 NR 11 TC 16 Z9 17 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0030-4018 J9 OPT COMMUN JI Opt. Commun. PD NOV 15 PY 1999 VL 171 IS 1-3 BP 107 EP 112 DI 10.1016/S0030-4018(99)00524-6 PG 6 WC Optics SC Optics GA 260QE UT WOS:000083960700017 ER PT J AU McKay, J Schepler, KL Catella, GC AF McKay, J Schepler, KL Catella, GC TI Efficient grating-tuned mid-infrared Cr2+: CdSe laser SO OPTICS LETTERS LA English DT Article ID ZINC CHALCOGENIDES AB Room-temperature, all-solid-state, broadly tunable laser operation of Cr2+-doped CdSe has been demonstrated. Pumping with a Q-switched Tm, Ho:YLF laser running at a 1-kHz repetition rate achieved broadband output of 500 mW at 2.6 mu m with 48% absorbed power slope efficiency. With reduced efficiency, as much as 815 mW of power was obtained. With a diffraction grating, the Cr2+:CdSe laser was tuned from 2.3 to 2.9 mu m with 10-nm bandwidth (FWHM) and output power up to 350 mW. (C) 1999 Optical Society of America. C1 USAF, Res Lab, AFRL, SNJT, Wright Patterson AFB, OH 45433 USA. Cleveland Crystals Inc, Cleveland, OH 44110 USA. RP McKay, J (reprint author), USAF, Res Lab, AFRL, SNJT, 3109 P St, Wright Patterson AFB, OH 45433 USA. RI Schepler, Kenneth/D-3730-2015; OI Schepler, Kenneth/0000-0001-9658-2305 NR 4 TC 72 Z9 74 U1 0 U2 4 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 0146-9592 J9 OPT LETT JI Opt. Lett. PD NOV 15 PY 1999 VL 24 IS 22 BP 1575 EP 1577 DI 10.1364/OL.24.001575 PG 3 WC Optics SC Optics GA 256UY UT WOS:000083745900012 PM 18079868 ER PT J AU Steinhubl, SR Tan, WA Foody, JM Topol, EJ AF Steinhubl, SR Tan, WA Foody, JM Topol, EJ TI Ticlopidine and TTP after coronary stenting - Reply SO JAMA-JOURNAL OF THE AMERICAN MEDICAL ASSOCIATION LA English DT Letter C1 Wilford Hall USAF Med Ctr, San Antonio, TX 78236 USA. Cleveland Clin Fdn, Cleveland, OH 44195 USA. RP Steinhubl, SR (reprint author), Wilford Hall USAF Med Ctr, San Antonio, TX 78236 USA. NR 6 TC 0 Z9 0 U1 0 U2 0 PU AMER MEDICAL ASSOC PI CHICAGO PA 515 N STATE ST, CHICAGO, IL 60610 USA SN 0098-7484 J9 JAMA-J AM MED ASSOC JI JAMA-J. Am. Med. Assoc. PD NOV 10 PY 1999 VL 282 IS 18 BP 1718 EP 1719 PG 2 WC Medicine, General & Internal SC General & Internal Medicine GA 251XJ UT WOS:000083471400014 ER PT J AU Wysong, IJ AF Wysong, IJ TI Comment on: An intermolecular potential for nitrogen from a multi-property analysis SO MOLECULAR PHYSICS LA English DT Editorial Material AB A paper by Cappelletti et al. (1998, Molec. Phys. 93, 485) utilizes classical trajectory effective cross-sections to predict the rotational collision number for nitrogen gas. It is suggested that use of the rotational heat capacity, rather than the total internal heat capacity, will give a more meaningful conversion of the cross-sections into relaxation time. In addition, an error in the formula for first-order collision number is corrected. C1 USAF, Res Lab, PRSA, Edwards AFB, CA 93524 USA. RP Wysong, IJ (reprint author), USAF, Res Lab, PRSA, Edwards AFB, CA 93524 USA. RI Wysong, Ingrid/E-6592-2011 OI Wysong, Ingrid/0000-0003-0591-6862 NR 6 TC 0 Z9 0 U1 0 U2 2 PU TAYLOR & FRANCIS LTD PI LONDON PA ONE GUNPOWDER SQUARE, LONDON EC4A 3DE, ENGLAND SN 0026-8976 J9 MOL PHYS JI Mol. Phys. PD NOV 10 PY 1999 VL 97 IS 9 BP 1069 EP 1071 DI 10.1080/002689799163145 PG 3 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 256XZ UT WOS:000083752900006 ER PT J AU Steinhubl, SR Kottke-Marchant, K Moliterno, DJ Rosenthal, ML Godfrey, NK Coller, BS Topol, EJ Lincoff, AM AF Steinhubl, SR Kottke-Marchant, K Moliterno, DJ Rosenthal, ML Godfrey, NK Coller, BS Topol, EJ Lincoff, AM TI Attainment and maintenance of platelet inhibition through standard dosing of abciximab in diabetic and nondiabetic patients undergoing percutaneous coronary intervention SO CIRCULATION LA English DT Article DE platelets; diabetes mellitus; abciximab; angioplasty ID IIB/IIIA RECEPTOR BLOCKADE; GLYCOPROTEIN IIB/IIIA; NONENZYMATIC GLYCATION; RANDOMIZED TRIAL; UNSTABLE ANGINA; FUNCTION ASSAY; MELLITUS; ANGIOPLASTY; PROTEINS; 7E3 AB Background-Although the effectiveness of abciximab (c7E3 Fab; ReoPro) in large populations of patients undergoing a percutaneous coronary intervention has been consistently proved in clinical trials, it is unknown whether all patients achieve and maintain target inhibition during treatment. Diabetic patients in particular are a subgroup of patients with known underlying platelet abnormalities whose long-term response to abciximab has been shown to vary from that of nondiabetic patients. Methods and Results-Forty-nine diabetic and 51 nondiabetic patients who received adjunctive abciximab therapy during percutaneous coronary interventions were evaluated prospectively. The degree of platelet function inhibition was determined immediately after the abciximab bolus, 8 hours after the bolus (during the 12-hour abciximab infusion), and the next morning (13 to 26 hours after the bolus) with the use of a rapid platelet function assay (Accumetrics). After the abciximab bolus, platelet function was inhibited by 95 +/- 4% (mean +/- SD). By 8 hours, the average percent inhibition had decreased to 88 +/- 9%, with 13% of patients with <80% inhibition. The next morning (mean 19 hours after the bolus), mean inhibition was 71 +/- 14%. A difference was not found between diabetics and nondiabetics, nor was any physiological parameter found to be predictive of the response to abciximab. Conclusions-Although the majority of patients achieve and maintain greater than or equal to 80% platelet inhibition during the 12-hour infusion with standard-dose abciximab, there is substantial variability among patients. Diabetic status does not appear to influence this variability. C1 Wilford Hall USAF Med Ctr, Dept Cardiol, Lackland AFB, TX 78236 USA. Cleveland Clin Fdn, Dept Cardiol, Cleveland, OH 44195 USA. Cleveland Clin Fdn, Joseph J Jacobs Ctr Thrombosis & Vasc Biol, Cleveland, OH 44195 USA. Cleveland Clin Fdn, Dept Clin Pathol, Cleveland, OH 44195 USA. Cleveland Clin Fdn, Dept Biostat & Epidemiol, Cleveland, OH 44195 USA. Mt Sinai Sch Med, Dept Med, Div Hematol, New York, NY USA. RP Steinhubl, SR (reprint author), Wilford Hall USAF Med Ctr, Dept Cardiol, 2200 Bergquist Dr, Lackland AFB, TX 78236 USA. OI Topol, Eric/0000-0002-1478-4729 FU NHLBI NIH HHS [HL-19278] NR 26 TC 74 Z9 75 U1 0 U2 0 PU LIPPINCOTT WILLIAMS & WILKINS PI PHILADELPHIA PA 530 WALNUT ST, PHILADELPHIA, PA 19106-3621 USA SN 0009-7322 J9 CIRCULATION JI Circulation PD NOV 9 PY 1999 VL 100 IS 19 BP 1977 EP 1982 PG 6 WC Cardiac & Cardiovascular Systems; Peripheral Vascular Disease SC Cardiovascular System & Cardiology GA 253WE UT WOS:000083579300013 PM 10556224 ER PT J AU Sane, DC Braden, GA Michelson, AD Furman, MI Mueller, M Kottke-Marchant, K Steinhubl, SR AF Sane, DC Braden, GA Michelson, AD Furman, MI Mueller, M Kottke-Marchant, K Steinhubl, SR TI Ultegra(TM) rapid platelet function assay (U-RPFA) correlates with the degree of abciximbab platelet inhibition measured by receptor occupancy: Results of a multicenter study SO CIRCULATION LA English DT Meeting Abstract C1 Wake Forest Univ, Sch Med, Winston Salem, NC 27109 USA. Univ Massachusetts, Sch Med, Worcester, MA USA. Lindner Ctr, Cincinnati, OH USA. Cleveland Clin Fdn, Cleveland, OH 44195 USA. Wilford Hall USAF Med Ctr, San Antonio, TX 78236 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU LIPPINCOTT WILLIAMS & WILKINS PI PHILADELPHIA PA 530 WALNUT ST, PHILADELPHIA, PA 19106-3621 USA SN 0009-7322 J9 CIRCULATION JI Circulation PD NOV 2 PY 1999 VL 100 IS 18 SU S MA 794 BP 153 EP 153 PG 1 WC Cardiac & Cardiovascular Systems; Peripheral Vascular Disease SC Cardiovascular System & Cardiology GA 250YD UT WOS:000083417100794 ER PT J AU Duong, DN Kim, MT Ross, CM AF Duong, DN Kim, MT Ross, CM TI The prevalence of HBP and risk factors for Vietnamese Americans SO CIRCULATION LA English DT Meeting Abstract C1 USAF, Biloxi, MS USA. Johns Hopkins Univ, Sch Nursing, Baltimore, MD USA. Univ S Alabama, Mobile, AL 36688 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU LIPPINCOTT WILLIAMS & WILKINS PI PHILADELPHIA PA 530 WALNUT ST, PHILADELPHIA, PA 19106-3621 USA SN 0009-7322 J9 CIRCULATION JI Circulation PD NOV 2 PY 1999 VL 100 IS 18 SU S MA 1124 BP 217 EP 217 PG 1 WC Cardiac & Cardiovascular Systems; Peripheral Vascular Disease SC Cardiovascular System & Cardiology GA 250YD UT WOS:000083417101123 ER PT J AU Steinhubl, SR Balog, C Topol, EJ AF Steinhubl, SR Balog, C Topol, EJ TI Ticlopidine pretreatment prior to stenting is associated with a sustained reduction in cardiac events out to 1 year: Results from the EPISTENT trial SO CIRCULATION LA English DT Meeting Abstract C1 Wilford Hall USAF Med Ctr, San Antonio, TX 78236 USA. Cleveland Clin Fdn, Cleveland, OH 44195 USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU LIPPINCOTT WILLIAMS & WILKINS PI PHILADELPHIA PA 530 WALNUT ST, PHILADELPHIA, PA 19106-3621 USA SN 0009-7322 J9 CIRCULATION JI Circulation PD NOV 2 PY 1999 VL 100 IS 18 SU S MA 1993 BP 380 EP 380 PG 1 WC Cardiac & Cardiovascular Systems; Peripheral Vascular Disease SC Cardiovascular System & Cardiology GA 250YD UT WOS:000083417101991 ER PT J AU Yuhanna, IS Aschner, JL Kirsch, E Shaul, PW AF Yuhanna, IS Aschner, JL Kirsch, E Shaul, PW TI Role of calcium in the rapid activation of endothelial nitric oxide synthase by estrogen SO CIRCULATION LA English DT Meeting Abstract C1 Univ Texas, SW Med Ctr, Dallas, TX USA. Wake Forest Univ, Sch Med, Winston Salem, NC 27109 USA. Wilford Hall USAF Med Ctr, Lackland AFB, TX 78236 USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU LIPPINCOTT WILLIAMS & WILKINS PI PHILADELPHIA PA 530 WALNUT ST, PHILADELPHIA, PA 19106-3621 USA SN 0009-7322 J9 CIRCULATION JI Circulation PD NOV 2 PY 1999 VL 100 IS 18 SU S MA 2542 BP 482 EP 483 PG 2 WC Cardiac & Cardiovascular Systems; Peripheral Vascular Disease SC Cardiovascular System & Cardiology GA 250YD UT WOS:000083417102538 ER PT J AU Steinhubl, SR Kottke-Marchant, K Michelson, AD Furman, MI Kerelakes, DJ Mueller, M Sane, DC Braden, GA AF Steinhubl, SR Kottke-Marchant, K Michelson, AD Furman, MI Kerelakes, DJ Mueller, M Sane, DC Braden, GA TI Rapid bedside measurement of platelet aggregation in patients undergoing PCI and treated with abciximab: Results of a multi-center study of ultegra-rapid platelet function assay (U-RPFA) SO CIRCULATION LA English DT Meeting Abstract C1 Wilford Hall USAF Med Ctr, San Antonio, TX 78236 USA. Cleveland Clin Fdn, Cleveland, OH 44195 USA. Univ Massachusetts, Sch Med, Worcester, MA 01605 USA. Lindner Ctr, Cincinnati, OH USA. Wake Forest Univ, Sch Med, Winston Salem, NC 27109 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU LIPPINCOTT WILLIAMS & WILKINS PI PHILADELPHIA PA 530 WALNUT ST, PHILADELPHIA, PA 19106-3621 USA SN 0009-7322 J9 CIRCULATION JI Circulation PD NOV 2 PY 1999 VL 100 IS 18 SU S MA 4520 BP 856 EP 856 PG 1 WC Cardiac & Cardiovascular Systems; Peripheral Vascular Disease SC Cardiovascular System & Cardiology GA 250YD UT WOS:000083417104510 ER PT J AU Ornstein, DL Pipas, JM Rigas, JR AF Ornstein, DL Pipas, JM Rigas, JR TI Recent advances in cancer chemotherapy SO ACADEMIC RADIOLOGY LA English DT Review ID CELL LUNG-CANCER; PHASE-II TRIAL; METASTATIC BREAST-CANCER; ADVANCED COLORECTAL-CANCER; FIRST-LINE THERAPY; ANTITUMOR-ACTIVITY; 2ND-LINE TREATMENT; RANDOMIZED TRIAL; TOPOISOMERASE-I; 3-HOUR INFUSION C1 Dartmouth Hitchcock Med Ctr, Norris Cotton Canc Ctr, Dept Med, Hematol & Oncol Sect, Lebanon, NH 03766 USA. Dartmouth Coll, Hitchcock Med Ctr, Dartmouth Med Sch, Hanover, NH 03756 USA. RP Ornstein, DL (reprint author), Wilford Hall USAF Med Ctr, Med Operat Squadron MMIH 759, 2200 Bergquist Dr,Ste 1, Lackland AFB, TX 78236 USA. NR 105 TC 0 Z9 0 U1 0 U2 0 PU ASSOC UNIV RADIOLOGISTS PI OAK BROOK PA 820 JORIE BLVD, OAK BROOK, IL 60523-2251 USA SN 1076-6332 J9 ACAD RADIOL JI Acad. Radiol. PD NOV PY 1999 VL 6 IS 11 BP 696 EP 705 DI 10.1016/S1076-6332(99)80120-2 PG 10 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA 296PX UT WOS:000086033900008 PM 10894074 ER PT J AU Gummadi, LNB Palazotto, AN AF Gummadi, LNB Palazotto, AN TI Nonlinear dynamic finite element analysis of composite cylindrical shells considering large rotations SO AIAA JOURNAL LA English DT Article ID HIGHER-ORDER THEORY; PANELS AB A new nonlinear finite element formulation is developed for the nonlinear dynamics of shell structures. Using a vectorial approach, the kinematics that can be used to describe very large displacements and large rotations are derived. Green strain measures and second Piola Kirchhoff stress measures are used in the determination of the total potential. A displacement-based eight-noded cylindrical shell element with a total of 36 degrees of freedom is developed. Several numerical examples are dynamically analyzed to observe the characteristics of large displacements and large rotations. A convergence study was carried out to establish the numerical accuracy of the model. The most efficient and accurate model was used. C1 USAF, Inst Technol, Dept Aeronaut & Astronaut, Wright Patterson AFB, OH 45433 USA. RP Gummadi, LNB (reprint author), USAF, Inst Technol, Dept Aeronaut & Astronaut, Wright Patterson AFB, OH 45433 USA. NR 20 TC 5 Z9 5 U1 0 U2 1 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 USA SN 0001-1452 J9 AIAA J JI AIAA J. PD NOV PY 1999 VL 37 IS 11 BP 1489 EP 1494 DI 10.2514/2.628 PG 6 WC Engineering, Aerospace SC Engineering GA 255AM UT WOS:000083647400019 ER PT J AU Johnstone, DK Yeo, YK Hengehold, RL Turner, GW AF Johnstone, DK Yeo, YK Hengehold, RL Turner, GW TI Control of surface states in GaSb/AlxGa1-xAsySb1-y/GaxIn1-xSb/AlxGa1-xAsySb1-y quantum well structures SO APPLIED PHYSICS LETTERS LA English DT Article ID MOLECULAR-BEAM EPITAXY; DIODE-LASERS; DEEP LEVELS; GROWTH; GASB AB GaSb-based lasers show advanced capabilities over other material for the far-infrared wavelength range. However, for quantum-well (QW) laser structures of AlxGa1-xAsySb1-y/GaxIn1-xAsySb1-y/AlxGa1-xAsySb1-y grown on GaSb, each component element etches at a different rate, making it difficult to achieve quality surfaces sufficiently free of defects. Thus, in this letter, the effects on the surface quality of GaSb-based laser materials have been studied using phosphoric acid etching, boron trichloride reactive ion etching (RIE), and a postetch sulfur treatment. In addition, the quality of the surface is compared for two barriers of AlAs0.07Sb0.93 and Al0.9Ga0.1As0.07Sb0.93, based on current-voltage measurements as a function of temperature. The best surfaces were produced by RIE and by using as much Ga in the barriers as the device operation allows. A generation center in the Ga0.81In0.19As0.12Sb0.88 was found at 0.14 eV for QW diodes with low surface conduction. (C) 1999 American Institute of Physics. [S0003-6951(99)01844-6]. C1 USAF, Inst Technol, Wright Patterson AFB, OH 45433 USA. MIT, Lincoln Lab, Lexington, MA 02173 USA. RP Johnstone, DK (reprint author), USAF, Off Sci Res, Arlington, VA 22203 USA. NR 15 TC 2 Z9 2 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD NOV 1 PY 1999 VL 75 IS 18 BP 2779 EP 2781 DI 10.1063/1.125147 PG 3 WC Physics, Applied SC Physics GA 248VB UT WOS:000083295500025 ER PT J AU Davis, JK He, ZQ Somerville, CC Spain, JC AF Davis, JK He, ZQ Somerville, CC Spain, JC TI Genetic and biochemical comparison of 2-aminophenol 1,6-dioxygenase of Pseudomonas pseudoalcaligenes JS45 to meta-cleavage dioxygenases: divergent evolution of 2-aminophenol meta-cleavage pathway SO ARCHIVES OF MICROBIOLOGY LA English DT Article DE Pseudomonas; 2-aminophenol; catechol; dioxygenase; meta-cleavage pathway; biodegradation ID ESCHERICHIA-COLI; NUCLEOTIDE-SEQUENCE; CATABOLIC PATHWAY; EXTRADIOL DIOXYGENASES; CATECHOL DIOXYGENASES; MOLECULAR-CLONING; RING FISSION; NITROBENZENE; DEGRADATION; METAPYROCATECHASE AB Nitrobenzene is degraded to pyruvate and acetaldehyde by Pseudomonas pseudoalcaligenes JS45 via a reductive pathway, and by Comamonas sp. JS765 via an oxidative pathway. Although the initial reactions in the degradation of nitrobenzene by the two bacteria are totally different, the lower pathways are similar and converge at the level of 4-oxalocrotonate. In order to further investigate the biochemical properties and reveal the evolutionary relationships between the two lower pathways, the genes encoding the 2-aminophenol 1,6-dioxygenase were cloned and sequenced. 2-Aminophenol 1,6-dioxygenase from P. pseudoalcaligenes JS45 and catechol 2,3-dioxygenase from Comamonas sp. JS765 were able to act on both catechol and 2-aminophenol, but catechol was a suicide substrate of 2-aminophenol 1,6-dioxygenase. The activity of 2-aminophenol 1,6-dioxygenase was restored after removal of catechol and incubation with ascorbate and FeCl2. Both the alpha-subunit (AmnA) and the beta-subunit (AmnB) of the dioxygenase from P. pseudoalcaligenes JS45 show a high degree of identity to the corresponding subunits of the ring-fission dioxygenase from Pseudomonas sp. AP-3: 67% for the alpha-subunit. and 84% for the beta-subunit. Sequence similarity studies suggest that the beta-subunits of both 2-aminophenol 1,6-dioxygenases are distantly related to homoprotocatechuate 2,3-dioxygenase from Escherichia coli strains W and C and then to catechol 2,3-dioxygenase from Alcaligenes eutrophus. Four active-site-relevant histidines are conserved in AmnB, but not in AmnA. The lack of conserved histidines indicates the absence of an Fe2+ binding site in AmnA, which explains the previous observations of only approximately one Fe2+ per two subunits in the 2-aminophenol 1,6-dioxygenases from P. pseudoalcaligenes JS45. The aminophenol 1,6-dioxygenase genes are located upstream of the 2-aminomuconic semialdehyde dehydrogenase gene, and a putative member of the YjgF protein family is upstream of the dioxygenase genes. Transcriptional analysis indicates that the YjgF-like protein, 2-aminophenol 1,6-dioxygenase, and 2-aminomuconic semialdehyde dehydrogenase are coordinately transcribed. A putative ORF similar to part of the RNA helicase genes is downstream of the dehydrogenase gene. Both the novel organization of the genes and the phylogeny of the dioxygenases and dehydrogenase indicate that the 2-aminophenol pathway in P. pseudoalcaligenes JS45 represents an example of a distant divergent evolution of meta-cleavage pathways. C1 USAF, Res Lab, MLRQ, Tyndall AFB, FL 32403 USA. RP Spain, JC (reprint author), USAF, Res Lab, MLRQ, 139 Barnes Dr,Suite 2, Tyndall AFB, FL 32403 USA. OI He, Zhongqi/0000-0003-3507-5013 NR 54 TC 25 Z9 27 U1 0 U2 10 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 0302-8933 J9 ARCH MICROBIOL JI Arch. Microbiol. PD NOV PY 1999 VL 172 IS 5 BP 330 EP 339 DI 10.1007/s002030050787 PG 10 WC Microbiology SC Microbiology GA 249LB UT WOS:000083333600008 PM 10550475 ER PT J AU Yamane, GK AF Yamane, GK TI Accidental injection of a US Air Force aviator by a pralidoxime chloride auto-injector: A case report SO AVIATION SPACE AND ENVIRONMENTAL MEDICINE LA English DT Article DE pralidoxime chloride; nerve agent; auto-injector; military personnel; antidote ID PHARMACOKINETICS; VOLUNTEERS AB To counter the threat of organophosphate nerve agents, military personnel may be issued auto-injectors containing pralidoxime chloride. This drug helps to dephosphorylate the nerve agent-acetylcholinesterase complex and, thus, regenerate the enzyme. In non-poisoned persons, pralidoxime chloride is rapidly excreted by the kidneys and is fairly well tolerated. We present the first reported case of an accidental injection of an Air Force aviator by an auto-injector. The patient recovered well with no specific treatment needed. The pharmacology and toxicology of pralidoxime chloride are discussed. C1 USAF, Sch Aerosp Med, Brooks AFB, TX 78235 USA. RP Yamane, GK (reprint author), USAF, Sch Aerosp Med, 2602 W Gate Rd, Brooks AFB, TX 78235 USA. NR 12 TC 3 Z9 4 U1 0 U2 2 PU AEROSPACE MEDICAL ASSOC PI ALEXANDRIA PA 320 S HENRY ST, ALEXANDRIA, VA 22314-3579 USA SN 0095-6562 J9 AVIAT SPACE ENVIR MD JI Aviat. Space Environ. Med. PD NOV PY 1999 VL 70 IS 11 BP 1110 EP 1112 PG 3 WC Public, Environmental & Occupational Health; Medicine, General & Internal; Sport Sciences SC Public, Environmental & Occupational Health; General & Internal Medicine; Sport Sciences GA 251KP UT WOS:000083445100009 PM 10608609 ER PT J AU Gee, MR Kruyer, WB AF Gee, MR Kruyer, WB TI Case report of an aviator with a single episode of altered consciousness due to hymenoptera hypersensitivity SO AVIATION SPACE AND ENVIRONMENTAL MEDICINE LA English DT Article DE aerospace medicine; diagnosis; differential; desensitization; immunologic; treatment outcome; hypersensitivity; hymenoptera; consciousness disorders; anaphylaxis; seizures; arrhythmia ID ALLERGY AB This case is presented to: a) emphasize the importance of a careful history, including interviewing witnesses and considering a complete differential diagnosis when evaluating aviators with a history of an episode of altered consciousness; and b) demonstrate an appropriate use of literature review, subspecialty consultations, and U.S. Air Force Aeromedical Guidelines to arrive at an aeromedical disposition for an unusual case. A military aviator experienced an episode of syncope/near syncope, initially felt to be caused by a primary seizure or an arrhythmia. Subsequent thorough evaluation included careful history taking, extensive interviewing of witnesses, subspecialty consultations, review of appropriate literature and deliberation by a board of experienced military aeromedical physicians. Cardiac and neurologic diagnoses were considered but careful history and witness interviews revealed that the aviator had sustained an insect sting just minutes before the episode. Evaluation by allergy specialists, including skin testing, identified him as being hypersensitive to Hymenoptera stings. A diagnosis of hypersensitivity reaction to a Hymenoptera sting was determined to be the cause of the altered consciousness episode. Review of the literature revealed that immunotherapy for Hymenoptera sensitivity reduces the risk of future anaphylaxis to only 1-2% after maintenance dose is achieved. Consideration of the risk of future events and the success of rush immunotherapy resulted in a recommendation for a waiver to return the aviator to unrestricted flying duties. The importance of diligent history taking must never be forgotten. In this aviator it led to the correct diagnosis and definitive therapy. in addition, appropriate consideration of the literature and knowledge of outcome rates allowed a return to unrestricted flying for this aviator. If the original diagnosis of seizure or arrhythmia had been accepted, this aviator would have been disqualified without waiver and a valuable flying asset would have been lost. C1 USAF, Sch Aerosp Med, Aeronaut Conservat Serv, San Antonio, TX 78216 USA. RP Gee, MR (reprint author), USAF, Sch Aerosp Med, Aeronaut Conservat Serv, 12701 West Ave 1524, San Antonio, TX 78216 USA. NR 9 TC 1 Z9 1 U1 0 U2 0 PU AEROSPACE MEDICAL ASSOC PI ALEXANDRIA PA 320 S HENRY ST, ALEXANDRIA, VA 22314-3579 USA SN 0095-6562 J9 AVIAT SPACE ENVIR MD JI Aviat. Space Environ. Med. PD NOV PY 1999 VL 70 IS 11 BP 1113 EP 1116 PG 4 WC Public, Environmental & Occupational Health; Medicine, General & Internal; Sport Sciences SC Public, Environmental & Occupational Health; General & Internal Medicine; Sport Sciences GA 251KP UT WOS:000083445100010 PM 10608610 ER PT J AU Hallion, RP AF Hallion, RP TI The 1999 Louis H. Bauer Lecture: Aerospace medicine nears the millennium: Adaptation, anticipation, and advancement SO AVIATION SPACE AND ENVIRONMENTAL MEDICINE LA English DT Article; Proceedings Paper CT 70th Annual Scientific Meeting of the Aerospace Medical Assiciation CY MAY 17, 1999 CL DETROIT, MICHIGAN DE aerospace medicine history; Louis H-Bauer Lecture; airplane; aircrew safety; performance; technology C1 USAF, HQ, HO, Hist & Museums Program, Bolling AFB, DC 20332 USA. RP Hallion, RP (reprint author), USAF, HQ, HO, Hist & Museums Program, 200 McChord St,Box 94, Bolling AFB, DC 20332 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AEROSPACE MEDICAL ASSOC PI ALEXANDRIA PA 320 S HENRY ST, ALEXANDRIA, VA 22314-3579 USA SN 0095-6562 J9 AVIAT SPACE ENVIR MD JI Aviat. Space Environ. Med. PD NOV PY 1999 VL 70 IS 11 BP 1117 EP 1124 PG 8 WC Public, Environmental & Occupational Health; Medicine, General & Internal; Sport Sciences SC Public, Environmental & Occupational Health; General & Internal Medicine; Sport Sciences GA 251KP UT WOS:000083445100011 PM 10608611 ER PT J AU Sankaranarayanan, K Shan, X Kevrekidis, IG Sundaresan, S AF Sankaranarayanan, K Shan, X Kevrekidis, IG Sundaresan, S TI Bubble flow simulations with the lattice Boltzmann method SO CHEMICAL ENGINEERING SCIENCE LA English DT Article; Proceedings Paper CT 4th International Conference on Gas-Liquid and Gas-Liquid-Solid Reactor Engineering CY AUG 23-25, 1999 CL DELFT, NETHERLANDS SP Kramers Lab Fysische Technol DE lattice Boltzmann method; bubbly flow; bubble rise velocity ID MODEL AB In an effort to establish benchmarks for the application of the lattice Boltzmann method to bubbly flow simulations, we compute bubbles in periodic boxes as a function of the Eotvos and Morton numbers and compare the results with established empirical correlations. (C) 1999 Elsevier Science Ltd. All rights reserved. C1 Princeton Univ, Dept Chem Engn, Princeton, NJ 08544 USA. USAF, PL, GPOF, Res Lab, Hanscom AFB, MA 01731 USA. RP Sankaranarayanan, K (reprint author), Princeton Univ, Dept Chem Engn, Princeton, NJ 08544 USA. RI Shan, Xiaowen/H-2836-2013 OI Shan, Xiaowen/0000-0002-6350-9248 NR 9 TC 37 Z9 41 U1 2 U2 9 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0009-2509 J9 CHEM ENG SCI JI Chem. Eng. Sci. PD NOV PY 1999 VL 54 IS 21 BP 4817 EP 4823 DI 10.1016/S0009-2509(99)00199-2 PG 7 WC Engineering, Chemical SC Engineering GA 229NG UT WOS:000082200200013 ER PT J AU Osswald, SS Keller, RA Elston, DM AF Osswald, SS Keller, RA Elston, DM TI What is your diagnosis? Amelanotic melanoma SO CUTIS LA English DT Article ID LENTIGO-MALIGNA MELANOMA C1 USAF, Washington, DC 20330 USA. USA, Washington, DC 20310 USA. RP Osswald, SS (reprint author), USAF, Washington, DC 20330 USA. NR 7 TC 3 Z9 3 U1 0 U2 0 PU EXCERPTA MEDICA INC PI NEW YORK PA 245 WEST 17TH STREET, NEW YORK, NY 10011 USA SN 0011-4162 J9 CUTIS JI Cutis PD NOV PY 1999 VL 64 IS 5 BP 302 EP + PG 2 WC Dermatology SC Dermatology GA 257HY UT WOS:000083777500002 PM 10582151 ER PT J AU Elston, DM AF Elston, DM TI What's eating you? Psocoptera (book lice, psocids) SO CUTIS LA English DT Article C1 Wilford Hall USAF Med Ctr, San Antonio, TX 78236 USA. RP Elston, DM (reprint author), MMID, Serv Dermatol, 59th Med Wing,2200 Berquist Dr,Suite 1, Lackland AFB, TX 78236 USA. NR 3 TC 6 Z9 7 U1 0 U2 0 PU EXCERPTA MEDICA INC PI NEW YORK PA 245 WEST 17TH STREET, NEW YORK, NY 10011 USA SN 0011-4162 J9 CUTIS JI Cutis PD NOV PY 1999 VL 64 IS 5 BP 307 EP 308 PG 2 WC Dermatology SC Dermatology GA 257HY UT WOS:000083777500003 PM 10582152 ER PT J AU Ervin, JS Zabarnick, S Binns, E Dieterle, G Davis, D Obringer, C AF Ervin, JS Zabarnick, S Binns, E Dieterle, G Davis, D Obringer, C TI Investigation of the use of JP-8+100 with cold flow enhancer additives as a low-cost replacement for JPTS SO ENERGY & FUELS LA English DT Article ID JET FUEL AB Aircraft operation at high altitude can subject jet fuel to extremely low temperature conditions. At such temperatures, fuels have an increased viscosity which limits the ability of the fuel to flow and, at the lowest temperatures, may result in partial solidification of the fuel due to freezing. JPTS is a specialty fuel that has excellent thermal-oxidative stability characteristics and a low freeze-point temperature. Unfortunately, JPTS costs nearly three times as much as the more readily available JP-8 fuel. In addition, replacement of JPTS with JP-8 has important logistical advantages. Thus, it would be advantageous to have a JP-8 fuel that has thermal-oxidative and low-temperature characteristics that are similar to those of JPTS. The JP-8+100 additive package that has been developed previously provides JP-8 fuels with very low surface deposition characteristics. However, enhancement of the low-temperature behavior of JP-8 has not been addressed. The current work studies the potential of developing low-temperature additives for JP-8+100 fuel. One objective was to experimentally determine if a class of additives commonly used in diesel fuels, cold flow enhancers, could effectively be used in kerosene-based fuels, such as JP-8+100. The additives were blended with a representative JP-8+100 fuel. The resulting fuel blends were evaluated in a low-temperature (-73 degrees C) test facility. Both the amount of solidified fuel remaining in the tank after the flowing fuel had been drained (i.e., "hold-up") and the reduction in fuel flow rate from that at 21 degrees C were measured. Some of the additives significantly enhanced the cold flow characteristics. The best cold flow additive candidate was tested in two thermal stability test systems and showed no detrimental effect on deposit formation. These results suggest that an additive can enhance the low-temperature properties of JP-8+100 such that it can be used as a low-cost replacement for JPTS fuel. C1 Univ Dayton, Res Inst, Dayton, OH 45469 USA. USAF, Res Lab, Wright Patterson AFB, OH 45433 USA. RP Ervin, JS (reprint author), Univ Dayton, Res Inst, Dayton, OH 45469 USA. NR 13 TC 8 Z9 8 U1 1 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0887-0624 J9 ENERG FUEL JI Energy Fuels PD NOV-DEC PY 1999 VL 13 IS 6 BP 1246 EP 1251 DI 10.1021/ef9901600 PG 6 WC Energy & Fuels; Engineering, Chemical SC Energy & Fuels; Engineering GA 258DC UT WOS:000083822000020 ER PT J AU McHugh, CP AF McHugh, CP TI Notes on the sand flies (Diptera : Psychodidae) of southern Arizona SO ENTOMOLOGICAL NEWS LA English DT Article ID LUTZOMYIA-ANTHOPHORA DIPTERA; LEISHMANIA-MEXICANA; NEOTOMA-MICROPUS; TEXAS; TRANSMISSION; FLY AB Two hundred twenty-eight sand flies were collected during a total of 30 trap nights conducted at two locations in southern Arizona. Lutzomyia apache was the species most commonly collected; Lu. anthophora, Lu. californica and an undescribed species of Lutzomyia also were present. Data on the abundance, trophic status, sex ratio, fecundity and geographic distribution of these insects are presented. C1 Inst Environm Safety & Occupat Hlth Risk Anal, RSRH, Brooks AFB, TX 78235 USA. RP McHugh, CP (reprint author), Inst Environm Safety & Occupat Hlth Risk Anal, RSRH, 2513 Kennedy Circle, Brooks AFB, TX 78235 USA. NR 15 TC 3 Z9 3 U1 0 U2 1 PU AMER ENTOMOL SOC PI PHILADELPHIA PA 1900 BENJ FRANKLIN PARKWAY, PHILADELPHIA, PA 19103-1195 USA SN 0013-872X J9 ENTOMOL NEWS JI Entomol. News PD NOV-DEC PY 1999 VL 110 IS 5 BP 297 EP 301 PG 5 WC Entomology SC Entomology GA 263LQ UT WOS:000084126500008 ER PT J AU Smart, MC Ratnakumar, BV Whitcanack, L Surampudi, S Byers, J Marsh, R AF Smart, MC Ratnakumar, BV Whitcanack, L Surampudi, S Byers, J Marsh, R TI Performance characteristics of lithium-ion cells for NASA's Mars 2001 Lander application SO IEEE AEROSPACE AND ELECTRONIC SYSTEMS MAGAZINE LA English DT Article AB NASA requires lightweight rechargeable batteries for future missions to Mars and the outer planets that are capable of operating over a wide range of temperatures, with high specific energy and energy densities. Due to the attractive performance characteristics, lithium-ion batteries have been identified as the battery chemistry of choice for a number of future applications, including Mars revers and landers. The Mars 2001 Lander (Mars Surveyor Program MSP 01) will be one of the first missions which will utilize lithium-ion technology. This application will require two lithium-ion batteries, each being 28 V (eight cells), 25 Ah and 8 kg. In addition to the requirement of being able to supply at least 200 cycles and 90 days of operation on the surface of Mars, the battery must be capable of operation (both charge and discharge) at temperatures as low as -20 degrees C. To assess the viability of lithium-ion cells for these applications, a number of performance characterization tests have been performed, including: assessing the room temperature cycle life, low temperature cycle life (-20 degrees C), rate capability as a function of temperature, pulse capability, self-discharge and storage characteristics, as well as mission profile capability, This paper will describe the Mars 2001 Lander mission battery requirements and will contain results of the cell testing conducted to-date in support of the mission. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Lockheed Martin Astronaut Corp, Denver, CO USA. USAF, Res Lab, Wright Patterson AFB, OH 45433 USA. RP Smart, MC (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 12 TC 12 Z9 12 U1 0 U2 3 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0885-8985 J9 IEEE AERO EL SYS MAG JI IEEE Aerosp. Electron. Syst. Mag. PD NOV PY 1999 VL 14 IS 11 BP 36 EP 42 DI 10.1109/62.809207 PG 7 WC Engineering, Aerospace; Engineering, Electrical & Electronic SC Engineering GA 262TB UT WOS:000084081600007 ER PT J AU McCord, JE Miller, HC Hager, G Lampson, AI Crowell, PG AF McCord, JE Miller, HC Hager, G Lampson, AI Crowell, PG TI Experimental investigation of an optically pumped mid-infrared carbon monoxide laser SO IEEE JOURNAL OF QUANTUM ELECTRONICS LA English DT Article DE carbon monoxide laser; fundamental band laser; mid-infrared laser; optically pumped molecular laser ID COLLISIONAL ENERGY-TRANSFER; ROTATIONAL-EXCITATION; IOS APPROXIMATION; CO; ACCURACY; TEMPERATURES; LINES; BAND; AR; HE AB Results from a dual experimental/theoretical investigation of an optically pumped room-temperature carbon monoxide (CO) laser are discussed. Re-vibrational transitions in the (2, 0) overtone of CO at 2.3 mu m were pumped with an optical parametric oscillator to generate lasing on (2, 1) band transitions near 4.7 mu m. During the build-up of the laser pulse, only rotational redistribution of the initial optically pumped population was observed in the resolved CO spectra. Calculations describing the CO laser pulse dynamics and collisional relaxation rates support this observation. The addition of helium and argon bath gases enhanced the rotational relaxation process. A pressure-dependent loss mechanism that degrades optical efficiency has been identified and possible causes are discussed. C1 Logicon, RDA, Albuquerque, NM 87106 USA. USAF, Res Lab, Kirtland AFB, NM 87117 USA. RP McCord, JE (reprint author), USAF, Res Lab, Kirtland AFB, NM 87117 USA. NR 37 TC 16 Z9 17 U1 1 U2 2 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9197 J9 IEEE J QUANTUM ELECT JI IEEE J. Quantum Electron. PD NOV PY 1999 VL 35 IS 11 BP 1602 EP 1612 DI 10.1109/3.798082 PG 11 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA 250UJ UT WOS:000083406300005 ER PT J AU Gu, GX Sparks, A Banda, SS AF Gu, GX Sparks, A Banda, SS TI An overview of rotating stall and surge control for axial flow compressors SO IEEE TRANSACTIONS ON CONTROL SYSTEMS TECHNOLOGY LA English DT Article DE bifurcation; compressor; jet engine; rotating stall; surge ID ACTIVE SUPPRESSION; STABILIZATION; SYSTEMS AB Modeling and control for axial flow compression systems have received great attention in recent years. The objectives are to suppress rotating stall and surge, to extend the stable operating range of the compressor system, and to enlarge domains of attraction of stable equilibria using feedback control methods. The success of this research field will significantly improve compressor performance and thus future aeroengine performance. This paper surveys the research literature and summarizes the major developments in this active research field, focusing on the modeling and control perspectives to rotating stall and surge for axial flow compressors. C1 Louisiana State Univ, Dept Elect & Comp Engn, Baton Rouge, LA 70803 USA. USAF, Air Vehicles Directorate, Res Lab, Wright Patterson AFB, OH 45433 USA. RP Gu, GX (reprint author), Louisiana State Univ, Dept Elect & Comp Engn, Baton Rouge, LA 70803 USA. NR 44 TC 33 Z9 36 U1 3 U2 19 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 1063-6536 J9 IEEE T CONTR SYST T JI IEEE Trans. Control Syst. Technol. PD NOV PY 1999 VL 7 IS 6 BP 639 EP 647 DI 10.1109/87.799664 PG 9 WC Automation & Control Systems; Engineering, Electrical & Electronic SC Automation & Control Systems; Engineering GA 251ET UT WOS:000083432200002 ER PT J AU Lang, KA AF Lang, KA TI Rectal budesonide for ulcerative colitis: Bottoms up! SO INFLAMMATORY BOWEL DISEASES LA English DT Article C1 Wilford Hall USAF Med Ctr, Dept Gastroenterol, Lackland AFB, TX 78236 USA. RP Lang, KA (reprint author), Wilford Hall USAF Med Ctr, Dept Gastroenterol, Lackland AFB, TX 78236 USA. NR 5 TC 0 Z9 0 U1 0 U2 0 PU LIPPINCOTT WILLIAMS & WILKINS PI PHILADELPHIA PA 530 WALNUT ST, PHILADELPHIA, PA 19106-3621 USA SN 1078-0998 J9 INFLAMM BOWEL DIS JI Inflamm. Bowel Dis. PD NOV PY 1999 VL 5 IS 4 BP 312 EP 313 PG 2 WC Gastroenterology & Hepatology SC Gastroenterology & Hepatology GA 256EJ UT WOS:000083712700017 ER PT J AU Dodd, DE Leahy, HF Feldmann, ML English, JH Vinegar, A AF Dodd, DE Leahy, HF Feldmann, ML English, JH Vinegar, A TI Reproductive toxicity screen of trifluoroiodomethane (CF3I) in Sprague-Dawley rats SO INHALATION TOXICOLOGY LA English DT Article ID THYROID-GLAND; INHALATION AB CF3I is being considered by the U.S. Air Force as a replacement for Halon 1301 for fire-extinguishing requirements in unoccupied spaces. The purpose of this study was to determine and evaluate the potential for CF3I to produce reproductive toxicity and to provide additional information on the effect of CF3I exposure on the thyroid. Groups of 16 male and 16 female rats were exposed (6 h/day) to CF3I vapor at concentrations of 0 (control), 0.2, 0.7, and 2.0% using whole-body inhalation chambers. Prior to mating, rats were exposed to CF3I for 4 wk (5 days/wk). Exposures were 7 days/wk during the periods of mating (2 wk), gestation (3 wk), and lactation (3 wk). First-generation pups were not exposed to CF3I vapor. In parental animals, there were no clinical signs of toxicity except for a minimal decrease in mean body weight in female rats at 2.0% CF3I. At necropsy, gross findings, mean serum chemistry levels, mean hematology values, mean bone marrow micronuclei scores, and mean organ weights were similar for all exposure groups, including the air control group. Statistically significant differences did not show a pattern and/or were considered incidental. There were no treatment-elated microscopic tissue findings, including the thyroid organ. Analysis of reproductive indices and parameters indicates CF3I is nor a reproductive toxicant. Results of serum thyroid hormone levels (e.g., T-3, T-4, rT(3), and TSH), showed concentration-related increaser in TSH, T-4, and rT(3). T-3 levels were decreased. First-generation pup survival and mean body weights were similar in all exposure groups, including the control. Exposure of 2.0% CF3I vapor for approximately 14 wk produced minimal general toxicity and no reproductive toxicity in Sprague-Dawley rats. On the basis of reproductive indices and parameters, the NOAEL for this study is 2.0% CF3I. C1 Mantech Environm Technol Inc, Tox Hazards Res, Dayton, OH 45437 USA. USA, Med Res Unit, Wright Patterson AFB, OH USA. RP Dodd, DE (reprint author), Mantech Environm Technol Inc, Tox Hazards Res, POB 31009, Dayton, OH 45437 USA. NR 14 TC 7 Z9 7 U1 0 U2 1 PU TAYLOR & FRANCIS INC PI PHILADELPHIA PA 325 CHESTNUT ST, SUITE 800, PHILADELPHIA, PA 19106 USA SN 0895-8378 J9 INHAL TOXICOL JI Inhal. Toxicol. PD NOV PY 1999 VL 11 IS 11 BP 1041 EP 1055 PG 15 WC Toxicology SC Toxicology GA 259PJ UT WOS:000083902000004 PM 10562696 ER PT J AU Harter, JA AF Harter, JA TI Comparison of contemporary FCG life prediction tools SO INTERNATIONAL JOURNAL OF FATIGUE LA English DT Article; Proceedings Paper CT Engineering Foundation Conference on Fatigue Damage of Structural Materials II CY SEP 07-11, 1998 CL HYANNIS, MASSACHUSETTS SP Engn Fdn, USN, USAF DE AFGROW FASTRAN; crack closure; life prediction; crack growth AB This paper summarizes a comparison of closure-based load interaction models used in two popular crack-growth-life prediction programs (FASTRAN and AFGROW) being used by government, industry, and academia. The load interaction models used in both codes appear to result in reasonable life predictions based on a limited amount of test data. The spectrum load interaction models used in these programs are examined in some detail. Load interaction models based on crack closure are arguably the most widely accepted today. The FASTRAN approach uses a widely accepted crack closure concept, which assumes that closure is the result of the plastic wake behind the crack tip. This model requires the use of a single crack growth rate vs. effective Delta K curve that must be determined by the user in advance for all materials. The AFGROW approach uses crack growth rate data models that are widely available in the open literature and makes no assumption on the cause of the closure phenomenon. (C) 1999 Elsevier Science Ltd. All rights reserved. C1 USAF, Res Lab, VASE, Wright Patterson AFB, OH 45433 USA. RP Harter, JA (reprint author), USAF, Res Lab, VASE, Wright Patterson AFB, OH 45433 USA. NR 7 TC 16 Z9 16 U1 0 U2 0 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0142-1123 J9 INT J FATIGUE JI Int. J. Fatigue PD NOV PY 1999 VL 21 SU S BP S181 EP S185 PG 5 WC Engineering, Mechanical; Materials Science, Multidisciplinary SC Engineering; Materials Science GA 263MN UT WOS:000084128600020 ER PT J AU Lanning, DB Haritos, GK Nicholas, T AF Lanning, DB Haritos, GK Nicholas, T TI Influence of stress state on high cycle fatigue of notched Ti-6Al-4V specimens SO INTERNATIONAL JOURNAL OF FATIGUE LA English DT Article; Proceedings Paper CT Engineering Foundation Conference on Fatigue Damage of Structural Materials II CY SEP 07-11, 1998 CL HYANNIS, MASSACHUSETTS SP Engn Fdn, USN, USAF DE high cycle fatigue; notches; stress concentration factors; titanium alloys AB The high cycle fatigue (HCF) notch size effect is investigated for Ti-6Al-4V flat dogbone specimens with two notch sizes, each having an elastic stress concentration factor of K-t=2.72. Points were generated on a constant Life Haigh diagram using a step-loading technique. The notch size effect is compared with previous results obtained from circumferentially notched cylindrical specimens in terms of the biaxial state of stress at the notch root and von Mises effective stress. Within the range of dimensions tested, there is limited dependence of the fatigue limit upon the notch root radius. Stresses at the notch root and the fatigue notch factor are examined as a function of uniaxial stress, effective stress, notch plasticity, and notch root radius. (C) 1999 Elsevier Science Ltd. All rights reserved. C1 USAF, Inst Technol, Wright Patterson AFB, OH 45433 USA. USAF, Res Lab, MLLN, Wright Patterson AFB, OH 45433 USA. RP Nicholas, T (reprint author), USAF, Inst Technol, AFIT EN,2950 P St,Bldg 640, Wright Patterson AFB, OH 45433 USA. NR 11 TC 18 Z9 18 U1 0 U2 2 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0142-1123 J9 INT J FATIGUE JI Int. J. Fatigue PD NOV PY 1999 VL 21 SU S BP S87 EP S95 PG 9 WC Engineering, Mechanical; Materials Science, Multidisciplinary SC Engineering; Materials Science GA 263MN UT WOS:000084128600009 ER PT J AU Nicholas, T AF Nicholas, T TI Critical issues in high cycle fatigue SO INTERNATIONAL JOURNAL OF FATIGUE LA English DT Article; Proceedings Paper CT Engineering Foundation Conference on Fatigue Damage of Structural Materials II CY SEP 07-11, 1998 CL HYANNIS, MASSACHUSETTS SP Engn Fdn, USN, USAF DE high cycle fatigue; fatigue initiation; damage tolerance; turbine engines; material behavior ID CRACK AB High cycle fatigue (HCF) failures in materials used in rotating components of gas turbine engines have often been found to be attributable to fatigue loading on materials which have sustained damage from other sources. Damage can be present in the form of initial material or manufacturing defects, or can develop during service operation. Three major sources of in-service damage have been identified which can alter the HCF resistance individually or in conjunction with one another: low cycle fatigue (LCF), foreign object damage (FOD), and fretting. Methodologies for treating such damage in establishing material allowables are considered. Some recent results on the effects of damage on the Haigh (Goodman) diagram and a discussion of the life management aspects of HCF are presented. (C) 1999 Published by Elsevier Science Ltd. All rights reserved. C1 USAF, Res Lab, Mat & Mfg Directorate, Wright Patterson AFB, OH 45433 USA. RP Nicholas, T (reprint author), USAF, Res Lab, Mat & Mfg Directorate, Wright Patterson AFB, OH 45433 USA. NR 17 TC 70 Z9 70 U1 1 U2 3 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0142-1123 J9 INT J FATIGUE JI Int. J. Fatigue PD NOV PY 1999 VL 21 SU S BP S221 EP S231 PG 11 WC Engineering, Mechanical; Materials Science, Multidisciplinary SC Engineering; Materials Science GA 263MN UT WOS:000084128600024 ER PT J AU Ruschau, JJ John, R Thompson, SR Nicholas, T AF Ruschau, JJ John, R Thompson, SR Nicholas, T TI Fatigue crack nucleation and growth rate behavior of laser shock peened titanium SO INTERNATIONAL JOURNAL OF FATIGUE LA English DT Article; Proceedings Paper CT Engineering Foundation Conference on Fatigue Damage of Structural Materials II CY SEP 07-11, 1998 CL HYANNIS, MASSACHUSETTS SP Engn Fdn, USN, USAF DE laser shock peening; fatigue; crack initiation; crack growth rate; FOD; foreign object damage AB The fatigue nucleation and crack growth rate (FCGR) characteristics of Laser Shocked Peened (LSP) titanium 6Al-4V were examined and compared with unprocessed material. While crack initiation behavior of smooth (K-t=1.0) LSP processed samples is similar to baseline material, a marked improvement is observed in the notched (K-t>1) fatigue strength of LSP processed samples over unprocessed samples. Similar trends were noted for specimens that had been subjected to simulated foreign object damage (FOD) and subsequently fatigue tested. The FCGR resistance of LSP processed samples tested at low stress ratios (R) is likewise shown to be significantly greater than for unprocessed, baseline material and is due to the large residual compressive stresses, which reduce the locally applied stress. Advantages in FCGR resistance diminish at higher R. Differences in growth rate behavior are accounted for by using the effective stress intensity range, Delta K-eff. The rationale of using Delta K-eff is further demonstrated through fractographic investigations. (C) 1999 Elsevier Science Ltd. All rights reserved. C1 Univ Dayton, Res Inst, Dayton, OH 45469 USA. USAF, Res Lab, Mat & Mfg Directorate, Wright Patterson AFB, OH 45433 USA. RP Ruschau, JJ (reprint author), Univ Dayton, Res Inst, Dayton, OH 45469 USA. NR 11 TC 42 Z9 44 U1 0 U2 9 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0142-1123 J9 INT J FATIGUE JI Int. J. Fatigue PD NOV PY 1999 VL 21 SU S BP S199 EP S209 PG 11 WC Engineering, Mechanical; Materials Science, Multidisciplinary SC Engineering; Materials Science GA 263MN UT WOS:000084128600022 ER PT J AU Vasudevan, AK Cammett, JT Nicholas, T Jata, KV AF Vasudevan, AK Cammett, JT Nicholas, T Jata, KV TI Fatigue damage in structural materials II - 7-11 September 1998 - Hyannis, Massachusetts, USA - Foreword SO INTERNATIONAL JOURNAL OF FATIGUE LA English DT Editorial Material C1 Off Naval Res, Arlington, VA 22217 USA. USN, Aviat Depot, Arlington, VA USA. USAF, Res Lab, Arlington, VA USA. RP Vasudevan, AK (reprint author), Off Naval Res, Arlington, VA 22217 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0142-1123 J9 INT J FATIGUE JI Int. J. Fatigue PD NOV PY 1999 VL 21 SU S BP SV EP SV PG 1 WC Engineering, Mechanical; Materials Science, Multidisciplinary SC Engineering; Materials Science GA 263MN UT WOS:000084128600001 ER PT J AU Maruyama, B Hunt, WH AF Maruyama, B Hunt, WH TI Discontinuously reinforced aluminum: Current status and future direction SO JOM-JOURNAL OF THE MINERALS METALS & MATERIALS SOCIETY LA English DT Editorial Material ID MECHANICAL-PROPERTIES C1 USAF, Res Lab, AFRLMLLM,Mat & Mfg Directorate, Met Ceram & Nondestruct Evaluat Div, Wright Patterson AFB, OH 45433 USA. RP Maruyama, B (reprint author), USAF, Res Lab, AFRLMLLM,Mat & Mfg Directorate, Met Ceram & Nondestruct Evaluat Div, 2230 10th St,Suite 1, Wright Patterson AFB, OH 45433 USA. NR 14 TC 38 Z9 44 U1 1 U2 2 PU MINERALS METALS MATERIALS SOC PI WARRENDALE PA 420 COMMONWEALTH DR, WARRENDALE, PA 15086 USA SN 1047-4838 J9 JOM-J MIN MET MAT S JI JOM-J. Miner. Met. Mater. Soc. PD NOV PY 1999 VL 51 IS 11 BP 59 EP 61 DI 10.1007/s11837-999-0225-1 PG 3 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering; Mineralogy; Mining & Mineral Processing SC Materials Science; Metallurgy & Metallurgical Engineering; Mineralogy; Mining & Mineral Processing GA 256BT UT WOS:000083706000013 ER PT J AU Hunt, WH Maruyama, B AF Hunt, WH Maruyama, B TI The world still won't beat a path to your door: Transitioning DRA to the marketplace SO JOM-JOURNAL OF THE MINERALS METALS & MATERIALS SOCIETY LA English DT Article C1 USAF, Res Lab, AFRLMLLM,Div Mat & Mfg Directorate, Met Ceram & Nondestruct Evaluat Div, Wright Patterson AFB, OH 45433 USA. RP Maruyama, B (reprint author), USAF, Res Lab, AFRLMLLM,Div Mat & Mfg Directorate, Met Ceram & Nondestruct Evaluat Div, 2230 10th St,Suite 1, Wright Patterson AFB, OH 45433 USA. NR 9 TC 9 Z9 9 U1 0 U2 0 PU MINERALS METALS MATERIALS SOC PI WARRENDALE PA 420 COMMONWEALTH DR, WARRENDALE, PA 15086 USA SN 1047-4838 J9 JOM-J MIN MET MAT S JI JOM-J. Miner. Met. Mater. Soc. PD NOV PY 1999 VL 51 IS 11 BP 62 EP 64 DI 10.1007/s11837-999-0226-0 PG 3 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering; Mineralogy; Mining & Mineral Processing SC Materials Science; Metallurgy & Metallurgical Engineering; Mineralogy; Mining & Mineral Processing GA 256BT UT WOS:000083706000014 ER PT J AU Pandey, AB Chawla, N AF Pandey, AB Chawla, N TI The fracture toughness and fatigue behavior of DRA SO JOM-JOURNAL OF THE MINERALS METALS & MATERIALS SOCIETY LA English DT Article ID METAL-MATRIX COMPOSITE; VOLUME FRACTION; ALLOY COMPOSITES; PARTICLE-SIZE; MICROSTRUCTURE; STRENGTH C1 USAF, Res Lab, Mat & Mfg Directorate, Wright Patterson AFB, OH 45433 USA. UES Inc, Washington, DC USA. Arizona State Univ, Dept Chem Bio & Mat Engn, Tempe, AZ 85287 USA. RP Pandey, AB (reprint author), USAF, Res Lab, Mat & Mfg Directorate, Wright Patterson AFB, OH 45433 USA. RI Chawla, Nikhilesh/A-3433-2008 OI Chawla, Nikhilesh/0000-0002-4478-8552 NR 28 TC 2 Z9 2 U1 1 U2 2 PU MINERALS METALS MATERIALS SOC PI WARRENDALE PA 420 COMMONWEALTH DR, WARRENDALE, PA 15086 USA SN 1047-4838 J9 JOM-J MIN MET MAT S JI JOM-J. Miner. Met. Mater. Soc. PD NOV PY 1999 VL 51 IS 11 BP 69 EP 72 DI 10.1007/s11837-999-0228-y PG 4 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering; Mineralogy; Mining & Mineral Processing SC Materials Science; Metallurgy & Metallurgical Engineering; Mineralogy; Mining & Mineral Processing GA 256BT UT WOS:000083706000016 ER PT J AU Eastep, FE Tischler, VA Venkayya, VB Khot, NS AF Eastep, FE Tischler, VA Venkayya, VB Khot, NS TI Aeroelastic tailoring of composite structures SO JOURNAL OF AIRCRAFT LA English DT Article AB A wing-design optimization study is conducted on a composite wing. The objective is to evaluate the effect of the composite layup orientation on the optimized weight while satisfying constraints on strength, roll-reversal velocity, and flutter velocity. The wing optimization studies are presented with the composite layups oriented at 5-deg increments up to +/-20 deg from the midspar of the wing. The multidisciplinary optimization system, ASTROS, was used in the design study. This study, although not conclusive, indicates that optimal designs when subjected to multiple structural constraints are relatively insensitive to the orientation of the laminate layup. C1 Univ Dayton, Dept Mech & Aerosp Engn, Dayton, OH 45469 USA. USAF, Res Lab, Air Vehicle Directorate, Struct Div, Wright Patterson AFB, OH 45433 USA. RP Eastep, FE (reprint author), Univ Dayton, Dept Mech & Aerosp Engn, Dayton, OH 45469 USA. NR 11 TC 23 Z9 24 U1 0 U2 2 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 USA SN 0021-8669 J9 J AIRCRAFT JI J. Aircr. PD NOV-DEC PY 1999 VL 36 IS 6 BP 1041 EP 1047 DI 10.2514/2.2546 PG 7 WC Engineering, Aerospace SC Engineering GA 264NF UT WOS:000084187800019 ER PT J AU Cody, JT Valtier, S AF Cody, JT Valtier, S TI A gas chromatography-mass spectrometry method for the quantitation of clobenzorex SO JOURNAL OF ANALYTICAL TOXICOLOGY LA English DT Article ID METABOLITES; AMPHETAMINE; STIMULANTS; URINE C1 Wilford Hall USAF Med Ctr, Clin Res Squadron, Lackland AFB, TX 78236 USA. RP Cody, JT (reprint author), Wilford Hall USAF Med Ctr, Clin Res Squadron, 1255 Wilford Hall Loop, Lackland AFB, TX 78236 USA. NR 13 TC 4 Z9 4 U1 0 U2 2 PU PRESTON PUBLICATIONS INC PI NILES PA 7800 MERRIMAC AVE PO BOX 48312, NILES, IL 60648 USA SN 0146-4760 J9 J ANAL TOXICOL JI J. Anal. Toxicol. PD NOV-DEC PY 1999 VL 23 IS 7 BP 603 EP 608 PG 6 WC Chemistry, Analytical; Toxicology SC Chemistry; Toxicology GA 258BT UT WOS:000083818800008 PM 10595847 ER PT J AU Mitchel, WC Perrin, R Goldstein, J Saxler, A Roth, M Smith, SR Solomon, JS Evwaraye, AO AF Mitchel, WC Perrin, R Goldstein, J Saxler, A Roth, M Smith, SR Solomon, JS Evwaraye, AO TI Fermi level control and deep levels in semi-insulating 4H-SiC SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID VANADIUM; DEFECT; GAAS; 4H AB Temperature dependent Hall effect, optical admittance spectroscopy, and optical absorption measurements of semi-insulating bulk 4H-SiC are reported. Both intentionally vanadium doped material and commercial grade semi-insulating material were investigated. The carrier concentration versus inverse temperature results from Hall effect measurements up to 1000 K indicated the samples were dominated by one of two deep levels near midgap. In addition to the deep donor level of substitutional vanadium, E-c-1.6 eV, we observed another level at E-c-1.1 eV in some samples, indicating that levels other than the vanadium donor can pin the Fermi level in semi-insulating SiC. Optical admittance measurements on the semi-insulating material indicate the presence of levels at E-c-1.73 and 1.18 eV that were previously observed in conducting samples with this technique and we attribute these levels to the same defects producing the 1.1 and 1.6 eV levels seen by Hall effect. Secondary ion mass spectroscopy measurements of dopant and impurity concentrations are reported. Even though vanadium is present in all of these samples, along with other impurities we are at present unable to definitively identify the 1.1 eV level. (C) 1999 American Institute of Physics. [S0021- 8979(99)03621-X]. C1 USAF, Res Lab, Mat & Mfg Directorate, MLPO, Wright Patterson AFB, OH 45433 USA. Univ Dayton, Dept Phys, Dayton, OH 45469 USA. Univ Dayton, Res Inst, Dayton, OH 45469 USA. RP Mitchel, WC (reprint author), USAF, Res Lab, Mat & Mfg Directorate, MLPO, Wright Patterson AFB, OH 45433 USA. NR 17 TC 35 Z9 38 U1 1 U2 10 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD NOV 1 PY 1999 VL 86 IS 9 BP 5040 EP 5044 DI 10.1063/1.371476 PG 5 WC Physics, Applied SC Physics GA 246XA UT WOS:000083189100047 ER PT J AU Shen, A Liu, HC Szmulowicz, F Buchanan, M Gao, M Brown, GJ Ehret, J AF Shen, A Liu, HC Szmulowicz, F Buchanan, M Gao, M Brown, GJ Ehret, J TI Optimizing well doping density for GaAs/AlGaAs p-type quantum well infrared photodetectors SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID PERFORMANCE; ABSORPTION AB Effects of well doping density on the performance of GaAs/AlGaAs p-type quantum well infrared photodetectors are systematically studied. We find that for devices covering the 3-5 mu m wavelength region and operating at about 100 K, the optimum two-dimensional doping density is in the range 1-2x10(12) cm(-2), which maximizes the background limited infrared performance temperature and dark current limited detectivity. Increasing the doping density not only enhances the peak absorption but also broadens the linewidth pronouncedly. (C) 1999 American Institute of Physics. [S0021-8979(99)06621-9]. C1 Natl Res Council Canada, Inst Microstruct Sci, Ottawa, ON K1A 0R6, Canada. USAF, Res Lab, Mat Directorate, Wright Patterson AFB, OH 45433 USA. RP Shen, A (reprint author), Natl Res Council Canada, Inst Microstruct Sci, Ottawa, ON K1A 0R6, Canada. NR 18 TC 18 Z9 19 U1 1 U2 4 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD NOV 1 PY 1999 VL 86 IS 9 BP 5232 EP 5236 DI 10.1063/1.371504 PG 5 WC Physics, Applied SC Physics GA 246XA UT WOS:000083189100075 ER PT J AU Basu, S Groves, KM Quinn, JM Doherty, P AF Basu, S Groves, KM Quinn, JM Doherty, P TI A comparison of TEC fluctuations and scintillations at Ascension Island SO JOURNAL OF ATMOSPHERIC AND SOLAR-TERRESTRIAL PHYSICS LA English DT Article; Proceedings Paper CT 2nd Annual Workshop on Ionospheric Determination for Ocean Altimetry and GPS Surface Reflection CY DEC 01-03, 1998 CL ARCADIA, CALIFORNIA SP NASA, USN, Jet Propuls Lab ID GPS PHASE FLUCTUATIONS; F-REGION; EQUATORIAL IONOSPHERE; IRREGULARITIES AB With increasing reliance on space-based platforms for global navigation and communication, concerns about the impact of ionospheric scintillation on these systems have become a high priority. Recently, the Air Force Research Laboratory (AFRL) performed amplitude scintillation measurements of L1 (1.575 MHz) signals from GPS satellites at Ascension Island (14.45 degrees W, 7.95 degrees S; magnetic latitude 16 degrees S) during February-April, 1998, to compare amplitude scintillations with fluctuations of the total electron content (TEC). Ascension Island is located in the South Atlantic under the southern crest of the equatorial anomaly of F2 ionization where scintillations will be much enhanced during the upcoming solar maximum period. Ascension Island is included in the global network of the International GPS Service (IGS) and the GPS receivers in this network report the carrier to noise (CIN) ratio, the dual frequency carrier phase and pseudorange data at 30-s intervals. Such data with a sampling interval of 30 s were analyzed to determine TEC, the rate of change of TEC (ROT) and also ROTI, defined as the standard deviation of ROT. The spatial scale of ROTI, sampled at 30 s interval, will correspond to 6 km when the vector sum of the ionospheric projection of the satellite velocity and the irregularity drift orthogonal to the propagation path is of the order of 100 m/s. On the other hand, the scale-length of the amplitude scintillation index corresponds to the Fresnel dimension which is about 400 m for the GPS L1 frequency and an ionospheric height of 400 km. It is shown that, in view of the co-existence of large and small scale irregularities in equatorial irregularity structures, during the early evening hours, and small magnitude of irregularity drifts, ROTI measurements can be used to predict the presence of scintillation causing irregularities. The quantitative relationship between ROTI and S4, however, varies considerably due to variations of the ionospheric projection of the satellite velocity and the ionospheric irregularity drift. During the post-midnight period, due to the decay of small scale irregularities leading to a steepening of irregularity power spectrum, ROTI, on occasions, may not be associated with detectable levels of scintillation. In view of the power law type of irregularity power spectrum, ROTI will, in general, be larger than S4 and the ratio, ROTI/S4, in the present dataset is found to vary between 2 and 10. At high latitudes, where the ionospheric motion, driven by large electric fields of magnetospheric origin, is much enhanced during magnetically active periods, ROTI/S4 may be considerably larger than that in the equatorial region. (C) 2000 Elsevier Science Ltd. All rights reserved. C1 USAF, Res Lab, VSBI, Hanscom AFB, MA 01731 USA. Boston Coll, Inst Sci Res, Chestnut Hill, MA 02467 USA. RP Basu, S (reprint author), USAF, Res Lab, VSBI, 29 Randolph Rd, Hanscom AFB, MA 01731 USA. NR 15 TC 96 Z9 105 U1 0 U2 10 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1364-6826 J9 J ATMOS SOL-TERR PHY JI J. Atmos. Sol.-Terr. Phys. PD NOV PY 1999 VL 61 IS 16 BP 1219 EP 1226 DI 10.1016/S1364-6826(99)00052-8 PG 8 WC Geochemistry & Geophysics; Meteorology & Atmospheric Sciences SC Geochemistry & Geophysics; Meteorology & Atmospheric Sciences GA 282HH UT WOS:000085211900004 ER PT J AU Russell, CT Chi, PJ Angelopoulos, V Goedecke, W Chun, FK Le, G Moldwin, MB Reeves, GD AF Russell, CT Chi, PJ Angelopoulos, V Goedecke, W Chun, FK Le, G Moldwin, MB Reeves, GD TI Comparison of three techniques for locating a resonating magnetic field line SO JOURNAL OF ATMOSPHERIC AND SOLAR-TERRESTRIAL PHYSICS LA English DT Article ID RESONANCE; FREQUENCIES; PULSATIONS; DENSITY AB Three techniques for locating field lines in the magnetosphere that contain standing ULF pulsations are compared using dynamic spectra. The first technique compares ratios of the H- and D-components of the magnetic field at a single site; the second examines the ratios of the I-I-components at neighboring sites along a magnetic meridian; and the third displays the phase difference between H-components at neighboring sites. We find that the H:D ratio at a single station appears to detect magnetospheric standing waves but not their precise location. In contrast, the dual station I-I-ratio technique is sensitive to resonances local to the stations and has advantages over the widely used phase-gradient technique. In contrast to the latter technique calculating the H-power ratio does not require precise timing and provides two resonant locations, not one. We also find that the stations used need not be strictly confined to a single magnetic meridian. Resonance signatures can be detected with stations up to 1300 km in east-west separation. In our initial data near L = 2 multiple-harmonic structure is generally not observed. The resonant wave period, when assumed to be the fundamental of the standing Alfven wave, gives densities in the range 3000-8000 amu/cm(3). These mass densities agree with in situ observations at earlier epochs. The equatorial. mass density varies most during the day (by over a factor of two for the case studied) at L = 1.86 and much less (20%) at L = 2.2. This is consistent with a constant upward flux of ions over this latitude range flowing into a flux tube whose volume increases rapidly with increasing L-value. (C) 2000 Elsevier Science Ltd. All rights reserved. C1 Univ Calif Los Angeles, Dept Geophys & Planetary Phys, Los Angeles, CA 90024 USA. Univ Calif Los Angeles, Dept Earth & Space Sci, Los Angeles, CA 90024 USA. Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. Colorado Sch Mines, Boulder, CO USA. USAF Acad, Colorado Springs, CO 80840 USA. Florida Inst Technol, Dept Phys & Space Sci, Melbourne, FL 32901 USA. Los Alamos Natl Lab, Los Alamos, NM USA. RP Russell, CT (reprint author), Univ Calif Los Angeles, Dept Geophys & Planetary Phys, Los Angeles, CA 90024 USA. EM ctrussel@igpp.ucla.edu RI Moldwin, Mark/F-8785-2011; Le, Guan/C-9524-2012; Reeves, Geoffrey/E-8101-2011; OI Moldwin, Mark/0000-0003-0954-1770; Le, Guan/0000-0002-9504-5214; Reeves, Geoffrey/0000-0002-7985-8098; Russell, Christopher/0000-0003-1639-8298 NR 15 TC 10 Z9 10 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1364-6826 J9 J ATMOS SOL-TERR PHY JI J. Atmos. Sol.-Terr. Phys. PD NOV PY 1999 VL 61 IS 17 BP 1289 EP 1297 DI 10.1016/S1364-6826(99)00066-8 PG 9 WC Geochemistry & Geophysics; Meteorology & Atmospheric Sciences SC Geochemistry & Geophysics; Meteorology & Atmospheric Sciences GA 285KN UT WOS:000085388400005 ER PT J AU Lohmann, CH Sagun, R Sylvia, VL Cochran, DL Dean, DD Boyan, BD Schwartz, Z AF Lohmann, CH Sagun, R Sylvia, VL Cochran, DL Dean, DD Boyan, BD Schwartz, Z TI Surface roughness modulates the response of MG63 osteoblast-like cells to 1,25-(OH)(2)D-3 through regulation of phospholipase A(2) activity and activation of protein kinase A SO JOURNAL OF BIOMEDICAL MATERIALS RESEARCH LA English DT Article DE osteoblasts; titanium; surface roughness; phospholipase A(2); protein kinase C; protein kinase A; 1,25(OH)(2)D-3; in vitro ID VITAMIN-D METABOLITES; ZONE CHONDROCYTE CULTURES; GROWTH-FACTOR-BETA; CARTILAGE CELLS; C ACTIVITY; ALKALINE-PHOSPHATASE; MEMBRANE-RECEPTOR; ARACHIDONIC-ACID; TITANIUM; DIFFERENTIATION AB Implant surface roughness influences osteoblast proliferation, differentiation, and local factor production. Moreover, the responsiveness of osteoblasts to systemic hormones such as 1,25-(OH)(2)D-3 is altered by the effects of surface roughness; on the roughest Ti surfaces the effects of roughness and 1,25-(OH)(2)D-3 are synergistic. Prostaglandin E-2 (PGE(2)) appears to be involved in mediating the effects of surface roughness on the cells, as well as in the response to 1,25-(OH)(2)D-3. However, it is not yet known through which signaling pathways surface roughness exerts its effects on the response of osteoblasts to 1,25-(OH)(2)D-3. The present study examined the potential role of protein kinase A (PKA), phospholipase A(2)(PLA(2)), and protein kinase C (PKC) in this process. MG63 osteoblast-like human osteosarcoma cells were cultured on cpTi disks with R-a values of 0.54 mu m (PT), 4.14 mu m (SLA), or 4.92 mu m (TPS). PKA was inhibited by adding H8 to the cultures; similarly, PLA(2) was inhibited with quinacrine or activated with melittin, and PKC was inhibited with chelerythrine. Inhibitors or activators were included in the culture media through the entire culture period or fur the last 24 h of culture. In addition, cultures were treated for 24 h with inhibitors or activators in the presence of 1,25-(OH)(2)D-3. The effects on cell number and alkaline phosphatase specific activity were determined after 24 h; PKC activity was determined after 9 min and at 24 h. Cell number was reduced on rough surfaces, and alkaline phosphatase activity was increased. 1,25-(OH)(2)D-3 had a synergistic effect with surface roughness on alkaline phosphatase. However, neither surface roughness nor 1,25-(OH)(2)D-3 had an effect on PKC. H8 treatment for 24 h inhibited cell. number and alkaline phosphatase on all surfaces; however, when it was present throughout the culture period, the PKA inhibitor had no effect on cell number, but decreased alkaline phosphatase-specific activity. H8 reduced the 1,25-(OH)(2)D-3-mediated effect on cell number and alkaline phosphatase. Quinacrine inhibited cell proliferation and alkaline phosphatase on all surfaces and further reduced the 1,25-(OH)(2)D-3-dependent decreases in both parameters. Melittin had no effect when applied for 24 h and did not modify the 1,25-(OH)(2)D-3 effect; however, when present throughout the culture period, it caused a decrease in proliferation and an increase in enzyme activity. Chelerythrine, the PKC inhibitor, only inhibited cell proliferation when it was present throughout the entire culture period. However, it decreased alkaline phosphatase in cultures treated for 24 h, but increased enzyme activity when it was present for the entire culture period. The results indicate that surface roughness and 1,25-(OH)(2)D-3 both mediate their effects through PLA(2) which catalyzes the rate-limiting step in PGE(2) production. Further downstream, PGE(2) activates PKA. Surface rough ness-dependent effects are also mediated through PKC, but only after the cells have reached confluence and are undergoing phenotypic maturation. The effect of surface roughness on responsiveness to 1,25-(OH)(2)D-3 is mediated through PLA(2)/PKA and not through PKC. (C) 1999 John Wiley & Sons, Inc. C1 Univ Texas, Hlth Sci Ctr, Dept Orthopaed, San Antonio, TX 78284 USA. Univ Texas, Hlth Sci Ctr, Dept Periodont, San Antonio, TX 78284 USA. Univ Texas, Hlth Sci Ctr, Dept Biochem, San Antonio, TX 78284 USA. Univ Gottingen, Dept Orthopaed, D-3400 Gottingen, Germany. Wilford Hall USAF Med Ctr, Lackland AFB, San Antonio, TX USA. Hebrew Univ Jerusalem, Hadassah Fac Dent Med, Dept Periodont, Jerusalem, Israel. RP Boyan, BD (reprint author), Univ Texas, Hlth Sci Ctr, Dept Orthopaed, 7703 Floyd Curl Dr, San Antonio, TX 78284 USA. FU NIDCR NIH HHS [DE-05937] NR 50 TC 66 Z9 66 U1 1 U2 1 PU JOHN WILEY & SONS INC PI NEW YORK PA 605 THIRD AVE, NEW YORK, NY 10158-0012 USA SN 0021-9304 J9 J BIOMED MATER RES JI J. Biomed. Mater. Res. PD NOV PY 1999 VL 47 IS 2 BP 139 EP 151 DI 10.1002/(SICI)1097-4636(199911)47:2<139::AID-JBM4>3.0.CO;2-2 PG 13 WC Engineering, Biomedical; Materials Science, Biomaterials SC Engineering; Materials Science GA 230KW UT WOS:000082251200004 PM 10449625 ER PT J AU Shtessel, Y Buffington, J Banda, S AF Shtessel, Y Buffington, J Banda, S TI Multiple timescale flight control using reconfigurable sliding modes SO JOURNAL OF GUIDANCE CONTROL AND DYNAMICS LA English DT Article ID VARIABLE STRUCTURE CONTROL; CONTROL-SYSTEMS; STABILITY AB A dual-timescale aircraft Eight-control problem is addressed via continuous sliding-mode control. Sliding-surface boundary-lager reconfiguration is used to account for actuator dynamics, deflection limits, and rate limits. A reconfigurable sliding-mode flight controller is designed that achieves robust, high-accuracy tracking of outer-loop command angles before and after damage to an aircraft. Angular rate commands are robustly tracked in an inner loop. The reconfigurable flight-control strategy is based on a continuous sliding-mode controller with direct boundary-layer adaptation for reconfiguration. On-line explicit system or damage identification is not required. The reconfigurable sliding-mode Eight-control technique is applied to a nonlinear Eight-dynamics model of an F-16 aircraft. Computer simulations demonstrate stability and high-accuracy tracking performance without violation of actuator limits. C1 Univ Alabama, Dept Elect & Comp Engn, Huntsville, AL 35899 USA. USAF, Res Lab, VAAD, Wright Patterson AFB, OH 45433 USA. RP Shtessel, Y (reprint author), Univ Alabama, Dept Elect & Comp Engn, Huntsville, AL 35899 USA. NR 21 TC 50 Z9 57 U1 0 U2 5 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 USA SN 0731-5090 J9 J GUID CONTROL DYNAM JI J. Guid. Control Dyn. PD NOV-DEC PY 1999 VL 22 IS 6 BP 873 EP 883 DI 10.2514/2.4465 PG 11 WC Engineering, Aerospace; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA 255FJ UT WOS:000083658600016 ER PT J AU Baughn, JW Anderson, MR Mayhew, JE Wolf, JD AF Baughn, JW Anderson, MR Mayhew, JE Wolf, JD TI Hysteresis of thermochromic liquid crystal temperature measurement based on hue SO JOURNAL OF HEAT TRANSFER-TRANSACTIONS OF THE ASME LA English DT Article DE heat transfer; image processing; instrumentation; measurement techniques; temperature ID HEAT-TRANSFER C1 Univ Calif Davis, Dept Mech & Aeronaut Engn, Davis, CA 95616 USA. USAF Acad, Dept Aeronaut, Colorado Springs, CO 80840 USA. RP Baughn, JW (reprint author), Univ Calif Davis, Dept Mech & Aeronaut Engn, 1 Shields Ave, Davis, CA 95616 USA. NR 23 TC 34 Z9 34 U1 0 U2 1 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 0022-1481 J9 J HEAT TRANS-T ASME JI J. Heat Transf.-Trans. ASME PD NOV PY 1999 VL 121 IS 4 BP 1067 EP 1072 DI 10.1115/1.2826057 PG 6 WC Thermodynamics; Engineering, Mechanical SC Thermodynamics; Engineering GA 261HD UT WOS:000084003000035 ER PT J AU Viggiano, AA Hunton, DE AF Viggiano, AA Hunton, DE TI Airborne mass spectrometers: Four decades of atmospheric and space research at the Air Force research laboratory SO JOURNAL OF MASS SPECTROMETRY LA English DT Review DE airborne mass spectrometers; atmospheric research; space research ID ION COMPOSITION MEASUREMENTS; FLOWING AFTERGLOW TECHNIQUE; CRRES CHEMICAL RELEASES; SHUTTLE ENVIRONMENT; NEGATIVE-IONS; EXPANSION CHARACTERISTICS; IONIZATION MECHANISMS; MOLECULE REACTIONS; LOWER IONOSPHERE; RATE CONSTANTS AB Mass spectrometry is a versatile research tool that has proved to be extremely useful for exploring the fundamental nature of the earth's atmosphere and ionosphere and in helping to solve operational problems facing the Air Force and the Department of Defense. In the past 40 years, our research group at the Air Force Research Laboratory has flown quadrupole mass spectrometers of many designs on nearly 100 sounding rockets, nine satellites, three Space Shuttles and many missions of high-altitude research aircraft and balloons. We have also used our instruments in ground-based investigations of rocket and jet engine exhaust, combustion chemistry and microwave breakdown chemistry, This paper is a review of the instrumentation and techniques needed for space research, a summary of the results from many of the experiments, and an introduction to the broad field of atmospheric and space mass spectrometry in general, Copyright (C) 1999 John Wiley & Sons, Ltd. C1 USAF, Res Lab, Space Vehicles Directorate, Hanscom AFB, Bedford, MA 01731 USA. RP Viggiano, AA (reprint author), USAF, Res Lab, Space Vehicles Directorate, Hanscom AFB, 29 Randolph Rd, Bedford, MA 01731 USA. NR 107 TC 17 Z9 17 U1 2 U2 9 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX PO19 1UD, ENGLAND SN 1076-5174 J9 J MASS SPECTROM JI J. Mass Spectrom. PD NOV PY 1999 VL 34 IS 11 BP 1107 EP 1129 DI 10.1002/(SICI)1096-9888(199911)34:11<1107::AID-JMS880>3.0.CO;2-I PG 23 WC Biophysics; Chemistry, Organic; Spectroscopy SC Biophysics; Chemistry; Spectroscopy GA 258WE UT WOS:000083862000001 PM 10548806 ER PT J AU Ptaszek, AJ AF Ptaszek, AJ TI Immediate tibiocalcaneal arthrodesis with interposition fibular autograft for salvage after talus fracture: A case report SO JOURNAL OF ORTHOPAEDIC TRAUMA LA English DT Article AB Treatment goals in the operative management of talus fractures include prompt, anatomic, open reduction with rigid internal fixation; functional outcome is measured by degree of arthrosis, pain. range of motion, limb length, cosmesis, and return to premorbid activities. If restoration of the articular surfaces is precluded secondary to comminution, immediate and/or staged reconstructive salvage procedures must be considered. This report describes an immediate reconstructive procedure for salvage after a comminuted talus fracture with an ipsilateral tibia fracture. A standard antegrade tibial nail extending into the calcaneus was selected to stabilize both fracture sites. The technique of tibiocalcaneal arthrodesis using interposition fibular autograft and intramedullary fixation is presented as a unique treatment option. C1 Wilford Hall USAF Med Ctr, Dept Orthopaed Surg, Foot & Ankle Serv, Lackland AFB, San Antonio, TX 78236 USA. RP Ptaszek, AJ (reprint author), Wilford Hall USAF Med Ctr, Dept Orthopaed Surg, Foot & Ankle Serv, Lackland AFB, San Antonio, TX 78236 USA. NR 11 TC 3 Z9 3 U1 0 U2 0 PU LIPPINCOTT WILLIAMS & WILKINS PI PHILADELPHIA PA 530 WALNUT ST, PHILADELPHIA, PA 19106-3621 USA SN 0890-5339 J9 J ORTHOP TRAUMA JI J. Orthop. Trauma PD NOV PY 1999 VL 13 IS 8 BP 589 EP 592 DI 10.1097/00005131-199911000-00014 PG 4 WC Orthopedics; Sport Sciences SC Orthopedics; Sport Sciences GA 252RW UT WOS:000083516900014 PM 10714788 ER PT J AU Rudd, RW Bange, AA Rudd, KD Montalvo, R AF Rudd, RW Bange, AA Rudd, KD Montalvo, R TI Preparing teeth to receive a removable partial denture SO JOURNAL OF PROSTHETIC DENTISTRY LA English DT Article ID INSERTION; PLANES; DESIGN AB The success or failure of a removable partial denture is dependent on many factors. To achieve success, the practitioner must develop and sequence a sound treatment plan based on clinical and radiographic evidence. These findings must be carefully considered in prosthesis design and mouth preparation. Particular attention must be given to the proper placement of guiding planes and well-made rest seats and the use of surveyed crowns on abutment teeth. This article describes the rationale, importance, and clinical procedures for abutment preparation for removable partial dentures. C1 LLC, Rudd Dent Lab, Colorado Springs, CO USA. USAF, Haughton, LA 71037 USA. Univ Texas, Hlth Sci Ctr, Sch Dent, Dept Prosthodont, San Antonio, TX 78285 USA. RP Rudd, RW (reprint author), 3269 W Carefree Circle, Colorado Springs, CO 80917 USA. NR 30 TC 19 Z9 21 U1 1 U2 7 PU MOSBY-YEAR BOOK INC PI ST LOUIS PA 11830 WESTLINE INDUSTRIAL DR, ST LOUIS, MO 63146-3318 USA SN 0022-3913 J9 J PROSTHET DENT JI J. Prosthet. Dent. PD NOV PY 1999 VL 82 IS 5 BP 536 EP 549 DI 10.1016/S0022-3913(99)70052-1 PG 14 WC Dentistry, Oral Surgery & Medicine SC Dentistry, Oral Surgery & Medicine GA 259VL UT WOS:000083914600009 PM 10559725 ER PT J AU Naboulsi, S Mall, S AF Naboulsi, S Mall, S TI Methodology to analyse aerospace structures repaired with a bonded composite patch SO JOURNAL OF STRAIN ANALYSIS FOR ENGINEERING DESIGN LA English DT Article DE patch repair; bonded composite patch; adhesively bonded patch; ageing aircraft; fracture and fatigue; finite element; crack growth ID FATIGUE-CRACK GROWTH; ALUMINUM PANELS; PLATE AB Adhesively bonded composite repair of metallic structures is one of the candidate technologies that has enormous potential in the ageing aircraft. A computational tool to analyse the repaired aerospace structure using an adhesively bonded composite patch is presented. This involves the three-layer technique based on the two-dimensional finite element method for adhesively bonded composite patch repair of cracked structures. This technique is capable of characterizing the crack growth and debond growth behaviour, as well as predicting the fatigue life extension of the repaired structure with a perfectly or imperfectly bonded patch. Also? the thermal effects which may develop during bonding or during service and the non-linear material behaviour of the adhesive are incorporated in this technique. The results from the three-layer technique show good agreement with experimental results as well as a previous investigator's published numerical results. Besides the accuracy of the technique, the advantage of the two-dimensional three-layer technique is cost-effectiveness when compared with the three-dimensional finite element or performing expensive experiments on various patch configurations for design purposes. An overview of the three-layer technique to investigate a cracked metallic plate repaired with bonded composite patch is presented in this paper. C1 USAF, Inst Technol, Mat & Mfg Directorate, ENY, Wright Patterson AFB, OH 45433 USA. USAF, Inst Technol, Dept Aeronaut & Astronaut, ENY, Wright Patterson AFB, OH 45433 USA. RP Mall, S (reprint author), USAF, Inst Technol, Mat & Mfg Directorate, ENY, 2950 P St,Bldg 640, Wright Patterson AFB, OH 45433 USA. NR 40 TC 11 Z9 11 U1 2 U2 3 PU PROFESSIONAL ENGINEERING PUBLISHING LTD PI BURY ST EDMUNDS PA NORTHGATE AVENUE,, BURY ST EDMUNDS IP32 6BW, SUFFOLK, ENGLAND SN 0309-3247 J9 J STRAIN ANAL ENG JI J. Strain Anal. Eng. Des. PD NOV PY 1999 VL 34 IS 6 BP 395 EP 412 DI 10.1243/0309324991513849 PG 18 WC Engineering, Mechanical; Mechanics; Materials Science, Characterization & Testing SC Engineering; Mechanics; Materials Science GA 271ZP UT WOS:000084625800003 ER PT J AU Griffin, S Hansen, C Cazzolato, B AF Griffin, S Hansen, C Cazzolato, B TI Feedback control of structurally radiated sound into enclosed spaces using structural sensing SO JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA LA English DT Article ID ACTIVE CONTROL; ACOUSTIC RADIATION; TRANSMISSION; POWER; MODES AB A technique is developed that addresses sensor and actuator placement and feedback control of structural/acoustic problems that can be described as a flexible structure surrounding an acoustic cavity. Specifically, this work is directed at the space launch vehicle problem, where it is assumed that it is not possible to obtain, in advance of a required control output, a coherent measurement of the disturbance or to directly measure the quantity to be controlled. These assumptions necessitate the use of structural sensing to predict the sound pressure,:in the cavity and of feedback control to reduce the radiated sound. A method for selecting sensor and actuator positions based on a transformation of the problem into radiation modes is covered as well as an optimal feedback control approach which allows the control of radiated pressure into a defined subvolume of the cavity: using only structural actuators and sensors. Finally, an example problem is completed which draws: on all of the theoretical development to suppress radiated sound within a subvolume. [S0001-4966(99)02711-3]. C1 USAF, Res Lab, Kirtland AFB, NM 87117 USA. Univ Adelaide, Dept Mech Engn, Adelaide, SA 5001, Australia. RP Griffin, S (reprint author), USAF, Res Lab, 3550 Aberdeen Ave SE, Kirtland AFB, NM 87117 USA. RI Cazzolato, Benjamin/A-8330-2008; Hansen, Colin/A-8327-2008; OI Hansen, Colin/0000-0002-1444-4716; Cazzolato, Benjamin/0000-0003-2308-799X NR 19 TC 16 Z9 17 U1 0 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0001-4966 J9 J ACOUST SOC AM JI J. Acoust. Soc. Am. PD NOV PY 1999 VL 106 IS 5 BP 2621 EP 2628 DI 10.1121/1.428132 PG 8 WC Acoustics; Audiology & Speech-Language Pathology SC Acoustics; Audiology & Speech-Language Pathology GA 257MN UT WOS:000083785800030 ER PT J AU Kramb, VA John, R Zawada, LP AF Kramb, VA John, R Zawada, LP TI Notched fracture behavior of an oxide/oxide ceramic-matrix composite SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article ID FATIGUE AB The fracture behavior of an oxide/oxide ceramic-matrix composite, alumina/alumina-silica (Nextel610/AS), was investigated at 23 degrees and 950 degrees C using a single edge notched specimen geometry with clamped ends. Crack growth and damage progression were monitored during the tests using optical microscopy, ultrasonic C-scans, and crack mouth opening displacement, The net section strength of Nextel610/AS was less than the unnotched ultimate tensile strength. The failure mode was nonbrittle with considerable nonlinear deformation prior to and after the peak load at 23 degrees and 950 degrees C. The effect of temperature on the notched strength was significant. Net section failure stress decreased 50% when temperature was increased from 23 degrees to 950 degrees C, Observations of damage progression indicated that the reduction in notch strength with temperature was associated with self-similar crack growth at 950 degrees C, Ultrasonic C-scans were found to be an effective method of monitoring damage progression. Ultrasonic attenuation ahead of the notch tip was correlated with surface matrix cracks and exposed fiber lengths on the fracture surface. C1 USAF, Res Lab, MLLN, Mat & Mfg Directorate, Wright Patterson AFB, OH 45433 USA. RP Kramb, VA (reprint author), USAF, Res Lab, MLLN, Mat & Mfg Directorate, Wright Patterson AFB, OH 45433 USA. NR 21 TC 40 Z9 42 U1 3 U2 10 PU AMER CERAMIC SOC PI WESTERVILLE PA 735 CERAMIC PLACE, PO BOX 6136, WESTERVILLE, OH 43081-6136 USA SN 0002-7820 J9 J AM CERAM SOC JI J. Am. Ceram. Soc. PD NOV PY 1999 VL 82 IS 11 BP 3087 EP 3096 PG 10 WC Materials Science, Ceramics SC Materials Science GA 291XC UT WOS:000085763800023 ER PT J AU Roberts, TM Petropoulos, PG AF Roberts, TM Petropoulos, PG TI Asymptotics and energy estimates for electromagnetic pulses in dispersive media (vol 13, pg 1204, 1996) SO JOURNAL OF THE OPTICAL SOCIETY OF AMERICA A-OPTICS IMAGE SCIENCE AND VISION LA English DT Correction C1 USAF, Res Lab, SNHA, Hanscom AFB, MA 01731 USA. New Jersey Inst Technol, Dept Math, Newark, NJ 07102 USA. RP Roberts, TM (reprint author), USAF, Res Lab, SNHA, Hanscom AFB, MA 01731 USA. RI Petropoulos, Peter/M-6495-2013; OI Petropoulos, Peter/0000-0003-1532-8861 NR 4 TC 6 Z9 7 U1 0 U2 0 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 0740-3232 J9 J OPT SOC AM A JI J. Opt. Soc. Am. A-Opt. Image Sci. Vis. PD NOV PY 1999 VL 16 IS 11 BP 2799 EP 2800 DI 10.1364/JOSAA.16.002799 PG 2 WC Optics SC Optics GA 249MF UT WOS:000083336300025 ER PT J AU Prabakharan, S Teichman, JMH Spore, SS Sabanegh, E Glickman, RD McLean, RJC AF Prabakharan, S Teichman, JMH Spore, SS Sabanegh, E Glickman, RD McLean, RJC TI Proteus mirabilis viability after lithotripsy of struvite calculi SO JOURNAL OF UROLOGY LA English DT Article DE Proteus mirabilis; urinary calculi; lithotripsy; urinary tract infections ID SHOCK-WAVE LITHOTRIPSY; INFECTION STONES; ELECTROHYDRAULIC LITHOTRIPSY; ABSORPTION-COEFFICIENT; STAGHORN CALCULI; PULSE DURATION; LASER-ABLATION; URINARY-TRACT; YAG LASER; BACTERIA AB Purpose: We tested the hypotheses that Proteus mirabilis viability of struvite calculi differs after exposure to different Lithotripsy modalities and that the photothermal mechanism of holmium:YAG Lithotripsy is antibacterial. Materials and Methods: Human calculi of known struvite composition (greater than 90% magnesium ammonium phosphate hexohydrate) were incubated with P. mirabilis. Calculi were randomly distributed and fragmented with no lithotripsy (controls), or shock wave, intracorporeal ultrasonic, electrohydraulic, pneumatic, holmium:YAG or pulsed dye laser lithotripsy. After lithotripsy fragments were sonicated and specimens were serially plated for 48 hours at 38C. Bacterial counts and the rate of bacterial sterilization were compared. Results: Median bacterial counts (colony-forming units per mi.) were 8 x 10(6) in controls and 3 x 10(6) in shock wave, 3 x 10(7) in ultrasonic, 4 x 10(5) in electrohydraulic, 8 x 10(6) in pneumatic, 5 x 10(4) in holmium:YAG and 1 x 10(6) in pulsed dye laser lithotripsy cases (p <0.001). The rate of bacterial sterilization was 50% for holmium:YAG lithotripsy treated stones versus 0% for each of the other cohorts (p <0.01). Conclusions: P. mirabilis viability varies among lithotrites. The photothermal mechanism of holmium:YAG lithotripsy is antibacterial. C1 SW Texas State Univ, Dept Biol, San Marcos, TX 78666 USA. Univ Texas, Hlth Sci Ctr, Div Urol, San Antonio, TX USA. Univ Texas, Hlth Sci Ctr, Dept Ophthalmol, San Antonio, TX USA. Wilford Hall USAF Med Ctr, Div Urol, Lackland AFB, TX 78236 USA. RP Prabakharan, S (reprint author), SW Texas State Univ, Dept Biol, San Marcos, TX 78666 USA. NR 29 TC 12 Z9 15 U1 0 U2 0 PU LIPPINCOTT WILLIAMS & WILKINS PI PHILADELPHIA PA 530 WALNUT ST, PHILADELPHIA, PA 19106-3621 USA SN 0022-5347 J9 J UROLOGY JI J. Urol. PD NOV PY 1999 VL 162 IS 5 BP 1666 EP 1669 DI 10.1016/S0022-5347(05)68192-X PG 4 WC Urology & Nephrology SC Urology & Nephrology GA 243MQ UT WOS:000083002200028 PM 10524893 ER PT J AU Jenniskens, P Butow, SJ AF Jenniskens, P Butow, SJ TI The 1998 Leonid multi-instrument aircraft campaign - an early review SO METEORITICS & PLANETARY SCIENCE LA English DT Article; Proceedings Paper CT Workshop on the Leonid Multi-Instrument Aircraft Campaign CY APR 12-15, 1999 CL MOFFETT FIELD, CA ID METEOR STREAM ACTIVITY; COMETARY DUST TRAILS; AIRBORNE LIDAR; TEMPEL-TUTTLE; STORMS; DYNAMICS; SPECTRA; DANGER; SHOWER; ORBITS AB The 1998 return of the Leonid shower was the target of the Leonid multi-instrument aircraft campaign (Leonid MAC), an unusual two-aircraft astronomical research mission executed near Okinawa, Japan. The prospect of a meteor storm brought 28 researchers of 7 nationalities together in a concerted effort to observe the shower by imaging, spectroscopic, and ranging techniques. This paper is a review of the major science issues that are behind the deployment of each of the present array of instruments and describes the interconnection of the various experiments. This was NASA's first astrobiology mission. The mission also aimed to study contemporary issues in planetary astronomy, in atmospheric sciences, and concerning the satellite impact hazard. First results of the participating observers are discussed and put in context, in preparation for the deployment of a planned second mission in November of 1999. C1 NASA, Ames Res Ctr, SETI Inst, Moffett Field, CA 94035 USA. USAF, RQS ACC 129, Calif Air Natl Guard, Moffett Fed Airfield, Moffett Field, CA 94035 USA. RP Jenniskens, P (reprint author), NASA, Ames Res Ctr, SETI Inst, Mail Stop 239-4, Moffett Field, CA 94035 USA. EM peter@max.arc.nasa.gov NR 79 TC 49 Z9 49 U1 0 U2 0 PU WILEY-BLACKWELL PI MALDEN PA COMMERCE PLACE, 350 MAIN ST, MALDEN 02148, MA USA SN 1086-9379 J9 METEORIT PLANET SCI JI Meteorit. Planet. Sci. PD NOV PY 1999 VL 34 IS 6 BP 933 EP 943 PG 11 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 259FZ UT WOS:000083885000013 ER PT J AU von Zahn, U Gerding, M Hoffner, J McNeil, WJ Murad, E AF von Zahn, U Gerding, M Hoffner, J McNeil, WJ Murad, E TI Iron, calcium, and potassium atom densities in the trails of Leonids and other meteors: Strong evidence for differential ablation SO METEORITICS & PLANETARY SCIENCE LA English DT Article; Proceedings Paper CT Workshop on the Leonid Multi-Instrumetn Aircraft Campaign CY APR 12-15, 1999 CL MOFFETT FIELD, CALIFORNIA ID COSMIC DUST; MICROMETEORITES; ATMOSPHERE; LIDAR; MODEL AB We report on studies of the Fe, Ca, and K atom densities in the trails of meteors. The measurements of the densities were taken simultaneously and in a common volume by three ground-based lidars. We report and analyze the data obtained during two nights of Leonid showers (1996 and 1998 November 16/17) and of one night five days after the 1998 Leonids. The lidar-observed trails of Leonids differ from those of other meteor showers in both their mean altitude and in mean metal composition. The Leonid trails show a highly depressed Ca/Fe abundance ratio in comparison to CI meteoritic composition. Our observations are interpreted with the help of a numerical model that describes the ablation processes occurring during the high-speed entry of meteoroids into the Earth's atmosphere. We conclude that for the lidar-observed meteoroids, the ablation process occurs differentially for the three elements. This leads to a mixture of metals in the meteor trails, the composition of which is strongly altitude dependent and at any one altitude deviates significantly from a CI meteoritic composition. The model predicts differing altitudes and durations of trail observations for different showers, allowing us to tentatively assign the origin to the observed trails. C1 Leibniz Inst Atmospher Phys, D-18225 Kuhlungsborn, Germany. Radex Inc, Bedford, MA 01730 USA. USAF, Res Lab, Hanscom AFB, MA 01731 USA. RP von Zahn, U (reprint author), Leibniz Inst Atmospher Phys, D-18225 Kuhlungsborn, Germany. NR 27 TC 55 Z9 55 U1 0 U2 1 PU METEORITICAL SOC PI FAYETTEVILLE PA DEPT CHEMISTRY/BIOCHEMISTRY, UNIV ARKANSAS, FAYETTEVILLE, AR 72701 USA SN 0026-1114 J9 METEORIT PLANET SCI JI Meteorit. Planet. Sci. PD NOV PY 1999 VL 34 IS 6 BP 1017 EP 1027 PG 11 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 259FZ UT WOS:000083885000023 ER PT J AU Safar, JA Davis, RD Overton, JD AF Safar, JA Davis, RD Overton, JD TI Effect of saliva contamination on the bond of dentin to resin-modified glass-ionomer cement SO OPERATIVE DENTISTRY LA English DT Article ID ENAMEL; LONGEVITY AB This in vitro study compared the shear bond strength of a resin-modified glass-ionomer restorative material (Fuji II LC) bonded to saliva-contaminated dentin versus noncontaminated dentin. Seventy-five extracted human molar teeth were randomly divided into five groups of 15 samples each. The dentin was treated with 10% polyacrylic acid for 20 seconds, rinsed, and dried. The acid-treated dentin surfaces in Groups 1-4 were contaminated with saliva. In Group 1, the saliva was air thinned. In Groups 2-4, saliva was dried completely with compressed air. The saliva-contaminated dentin in Group 3 was rinsed and dried. The saliva-contaminated dentin in Group 4 was rinsed, dried, treated with 10% polyacrylic acid, and dried. Specimens in Group 5 received no contamination. The resin-modified glass-ionomer cement restorative material was mixed and applied to the dentin surfaces. Following placement of the restorative material and 7 days of storage, the specimens were thermocycled 300 times. Using the Instron Universal Testing Machine, a shear force was applied to the restorative material. Shear bond strength values were compared among the groups using a one-way ANOVA and Student-Neuman-Keuls Multiple Range Test (alpha = 0.05). The noncontaminated specimens (Group 5) were significantly stronger than the contaminated specimens (Groups 1-4), There were no significant differences in bond strength among the groups containing contaminated specimens. Salivary contamination occurring after dentin etching significantly reduced the bond strength of the resin-modified glass-ionomer restorative material to dentin. Neither rinsing nor rinsing and reetching resulted in bond strengths as great as to noncontaminated dentin. C1 81st Dent Squadron, Keesler AFB, MS 39534 USA. RP Safar, JA (reprint author), USAF, Washington, DC 20330 USA. NR 20 TC 10 Z9 11 U1 0 U2 1 PU UNIV WASHINGTON PI SEATTLE PA SCHOOL DENTISTRY SM-57, SEATTLE, WA 98195 USA SN 0361-7734 J9 OPER DENT JI Oper. Dent. PD NOV-DEC PY 1999 VL 24 IS 6 BP 351 EP 357 PG 7 WC Dentistry, Oral Surgery & Medicine SC Dentistry, Oral Surgery & Medicine GA 250PE UT WOS:000083396100007 PM 10823084 ER PT J AU Uyehara, MY Davis, RD Overton, JD AF Uyehara, MY Davis, RD Overton, JD TI Cuspal reinforcement in endodontically treated molars SO OPERATIVE DENTISTRY LA English DT Article ID COMPLEX AMALGAM RESTORATIONS; BONDED AMALGAM; FRACTURE-RESISTANCE; STRENGTH; TEETH; PINS AB This in vitro study compared the ability of horizontal pins and a dental adhesive to reinforce the facial cusps of endodontically treated mandibular molars. Seventy-two mandibular molars were divided into six groups and mounted in acrylic blocks (n = 12). In Groups 1-5 standardized endodontic access and instrumentation in the coronal one-third of each root canal were completed. In Groups 1-4 the lingual cusps were reduced, leaving the buccal cusps intact. The facial cusps of the teeth in each group received one of the following modes of reinforcement: Group 1-no reinforcement; Group 2-dentin adhesive (Amalgambond Plus); Group 3-two horizontal TMS Minim Dins; Group 4-two horizontal TMS Minim pins and Amalgambond Plus. Teeth in Group 5 were prepared for and restored with a complete cuspal coverage amalgam restoration using four vertical TMS Minim pins. Group 6 consisted of intact natural teeth. Using an Instron Universal Testing Machine, the lingual slope of the facial cusp of each specimen was loaded to failure using a compressive force applied at an angle 60 degrees to the long axis of the tooth. The mean fracture strengths for all groups were analyzed using a one-way ANOVA and Student-Newman-Keuls multiple range test (alpha = 0.05). Fracture patterns and modes of failure were also evaluated. Results: The intact teeth (Group 6) were significantly more fracture resistant than all other groups, with the exception of Group 4 (combination of Dins and adhesive). Group 1 (nonreinforced teeth) was significantly weaker than all other groups. Groups 2-4 (specimens with reinforced cusps) were not significantly different from each other. The use of horizontal pins or a combination of horizontal pins plus dentin adhesive for cuspal reinforcement resulted in significantly more teeth demonstrating favorable fracture patterns than did the use of adhesives alone. Conclusion: The buccal cusps of endodontically treated mandibular molars reinforced with a combination of horizontal pins and dentin adhesive were not significantly weaker than intact teeth. Of the restored teeth, those which had buccal cusps reinforced with horizontal pins and those treated with complete cuspal coverage amalgam restorations exhibited the most favorable restorative prognosis following cusp fracture. C1 81st Dent Squadron, Keesler AFB, MS 39534 USA. RP Uyehara, MY (reprint author), USAF, Washington, DC 20330 USA. NR 20 TC 15 Z9 15 U1 0 U2 2 PU UNIV WASHINGTON PI SEATTLE PA SCHOOL DENTISTRY SM-57, SEATTLE, WA 98195 USA SN 0361-7734 J9 OPER DENT JI Oper. Dent. PD NOV-DEC PY 1999 VL 24 IS 6 BP 364 EP 370 PG 7 WC Dentistry, Oral Surgery & Medicine SC Dentistry, Oral Surgery & Medicine GA 250PE UT WOS:000083396100009 PM 10823086 ER PT J AU LoRusso, FJ Font, RL AF LoRusso, FJ Font, RL TI Use of agar in ophthalmic pathology - A technique to improve the handling and diagnosis of temporal artery biopsies, subfoveal membranes, lens capsules, and other ocular tissues SO OPHTHALMOLOGY LA English DT Article AB Design: Prospective laboratory methodology study. Purpose: Certain tissues, by virtue of their shape and extreme thinness or pliability, are difficult to position correctly during routine paraffin embedding to provide the optimal orientation for histopathologic studies. Biopsy specimens from temporal arteries must be sampled at different points along the length of the artery. Other tissues such as subfoveal neovascular membranes and fragments of lens capsule lack the thickness and rigidity to be positioned on edge to yield cross-sectional views. The authors' technique improves the orientation and thereby maximizes the histologic information obtained from such specimens. Methods and Materials: From January 1, 1990, to April 30, 1999, the authors studied 500 consecutive temporal artery biopsy specimens and 200 successive subfoveal neovascular membranes. Results: Cutting a 20-mm cylindrical fragment of temporal artery at 1- to 1,5-mm intervals yielded approximately 13 to 20 cross-sections along the length of the artery. When the specimens were positioned together and embedded in agar, the pathologist could easily study multiple cross-sections of the artery. Additionally, using the agar technique, the authors were able to obtain cross-sections of other specimens submitted, such as subfoveal neovascular membranes, and studied each of the different layers to evaluate the disease process. By the same method, the authors placed small fragments of lens capsule with underlying cortex on edge and readily identified short, gram-positive coccobacilli consistent with Propionibacterium acnes endophthalmitis. Conclusion: The agar technique can greatly improve the quality of diagnostic information gleaned from temporal artery biopsy specimens and other small tissue samples. C1 Baylor Coll Med, Cullen Eye Inst, Ophthalm Pathol Lab, Dept Ophthalmol, Houston, TX 77030 USA. Univ Texas, Hlth Sci Ctr, Dept Ophthalmol, San Antonio, TX 78285 USA. USAF, Sch Aerosp Med, San Antonio, TX USA. RP Font, RL (reprint author), Baylor Coll Med, Cullen Eye Inst, Ophthalm Pathol Lab, Dept Ophthalmol, Houston, TX 77030 USA. FU NEI NIH HHS [EY02520] NR 3 TC 11 Z9 11 U1 0 U2 0 PU ELSEVIER SCIENCE INC PI NEW YORK PA 655 AVENUE OF THE AMERICAS, NEW YORK, NY 10010 USA SN 0161-6420 J9 OPHTHALMOLOGY JI Ophthalmology PD NOV PY 1999 VL 106 IS 11 BP 2106 EP 2108 DI 10.1016/S0161-6420(99)90491-8 PG 3 WC Ophthalmology SC Ophthalmology GA 251KZ UT WOS:000083446000020 PM 10571345 ER PT J AU Ghebremichael, F Knize, RJ AF Ghebremichael, F Knize, RJ TI Polymer relaxations determined by use of a temporally and thermally stable interferometer SO OPTICS LETTERS LA English DT Article ID DIELECTRIC-RELAXATION AB We describe a phase-controlled, highly stable interferometer that is ideal for use in long-time and high-temperature studies. We recorded output intensity variations of <0.2% for over 6 h at temperatures up to 150 degrees C. The setup was used to study in situ the temperature and frequency characteristics of a thin polymer film composed of 4-dimethylamino-4'-nitrostilbene doped into poly(methyl methacrylate). The mobility of the dopant molecules, which governed the electro-optic property of the film, was used to probe the dye-doped polymer's rheology. We demonstrate one application of the interferometer in probing both the alpha and the beta relaxations of the polymer. (C) 1999 Optical Society of America. C1 USAF Acad, Dept Phys, Laser Opt Res Ctr, Colorado Springs, CO 80840 USA. RP Ghebremichael, F (reprint author), USAF Acad, Dept Phys, Laser Opt Res Ctr, Colorado Springs, CO 80840 USA. NR 11 TC 1 Z9 1 U1 1 U2 2 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 0146-9592 J9 OPT LETT JI Opt. Lett. PD NOV 1 PY 1999 VL 24 IS 21 BP 1481 EP 1483 DI 10.1364/OL.24.001481 PG 3 WC Optics SC Optics GA 254EB UT WOS:000083598000013 PM 18079839 ER PT J AU Eiting, CJ Lambert, DJH Kwon, HK Shelton, BS Wong, MM Zhu, TG Dupuis, RD AF Eiting, CJ Lambert, DJH Kwon, HK Shelton, BS Wong, MM Zhu, TG Dupuis, RD TI Characterization of AlGaN/GaN heterostructures grown by metalorganic chemical vapor deposition SO PHYSICA STATUS SOLIDI B-BASIC RESEARCH LA English DT Article; Proceedings Paper CT 3rd International Conference on Nitride Semiconductors (ICNS 99) CY JUL 04-09, 1999 CL MONTPELLIER, FRANCE ID POWER AB We report the growth and characterization of high-quality AlGaN/GaN heterojunctions by low-pressure metalorganic chemical vapor deposition. We have measured the mobility, mu(n), and sheet charge density, n(s) of the interfacial two-dimensional electron gas (2DEG) as a function of Al composition, substrate orientation, and modulation doping. We have also attempted to correlate these results with (102) X-ray diffraction linewidths and surface roughness measured by atomic force microscopy. Interestingly, we do not find any correlation between the roughness of the wafer surface and the 2DEG concentration or mobility Inserting a short NH3/H-2 purge immediately before initiating the AlGaN growth improves the 2DEG mobility in these AlGaN/GaN structures. By optimizing the growth conditions, we have achieved Al0.30Ga0.70N/GaN heterostructures on (0001) sapphire with 2DEG mobilities in excess of mu(n) = 1300 cm(2)/Vs at 300 K and 4500 cm(2)/Vs at 100 K with n(s) similar to 9.4 x 10(12) cm(-2). C1 Univ Texas, Microelect Res Ctr, PRC, MER, Austin, TX 78712 USA. USAF, Res Lab, Mat & Mfg Directorate, Wright Patterson AFB, OH 45433 USA. RP Dupuis, RD (reprint author), Univ Texas, Microelect Res Ctr, PRC, MER, 1-600D-R9900, Austin, TX 78712 USA. NR 6 TC 5 Z9 5 U1 2 U2 4 PU WILEY-V C H VERLAG GMBH PI BERLIN PA MUHLENSTRASSE 33-34, D-13187 BERLIN, GERMANY SN 0370-1972 J9 PHYS STATUS SOLIDI B JI Phys. Status Solidi B-Basic Res. PD NOV PY 1999 VL 216 IS 1 BP 193 EP 197 DI 10.1002/(SICI)1521-3951(199911)216:1<193::AID-PSSB193>3.0.CO;2-K PG 5 WC Physics, Condensed Matter SC Physics GA 264QX UT WOS:000084193900038 ER PT J AU Patnaik, SS Pachter, R AF Patnaik, SS Pachter, R TI Anchoring characteristics and interfacial interactions in a polymer dispersed liquid crystal: a molecular dynamics study SO POLYMER LA English DT Article DE molecular modeling; PDLC; anchoring ID ELECTROOPTICAL SWITCHING CHARACTERISTICS; ALKYL FUNCTIONAL-GROUP; II FORCE-FIELDS; ATOMISTIC SIMULATION; ALKANE MOLECULES; VOLUME HOLOGRAMS; BRAGG GRATINGS; MORPHOLOGY; GRAPHITE; NMR AB Molecular dynamics (MD) simulations were carried out to gain an understanding of the interfacial interactions and the phase separation process in a polymer dispersed liquid crystalline (PDLC) system. The most important components of the PDLC system of interest are: E7 (an eutectic mixture of cyanobiphenyl liquid crystals), a crosslinked polyacrylate, and octanoic acid (OA). The miscibility of the different components was investigated and the anchoring characteristics of 4-n-pentyl-4'-cyanobiphenyl (5CB) molecules on the penta-acrylate polymer surface were analyzed. The effects of introducing ct surfactant on the miscibility and the anchoring strengths were also studied. Bilayers of polymer and liquid crystal (LC) of different alignments, show that an amorphous 5CB structure on the polymer surface was energetically most favorable, whereas homeotropic alignment had the next higher energy and planar alignment was the least favorable. Calculated solubility parameters indicate that prior to polymerization, the prepolymer and LC are miscible and OA is equally immiscible with both of them. Upon polymerization, the polymer is no longer miscible with the LC; phase separation occurs and OA acts as a surfactant forming a layer between the polymer and the LC. Anchoring energies calculated from the interfacial tensions indicate that the LC and polymer interface is strong, On addition of the surfactant, the anchoring energy at the interface of the LC and the surfactant becomes weaker. This decrease in anchoring strength may be one of the major factors responsible for a reduction in droplet size and also a lowering of critical held for switching, both of which are observed experimentally in volume holograms made of these PDLC materials. (C) 1999 Elsevier Science Ltd. All rights reserved. C1 USAF, Res Lab, Mat & Mfg Directorate, MLPJ, Wright Patterson AFB, OH 45433 USA. RP Patnaik, SS (reprint author), USAF, Res Lab, Mat & Mfg Directorate, MLPJ, Wright Patterson AFB, OH 45433 USA. NR 32 TC 62 Z9 66 U1 4 U2 29 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0032-3861 J9 POLYMER JI Polymer PD NOV PY 1999 VL 40 IS 23 BP 6507 EP 6519 DI 10.1016/S0032-3861(98)00851-9 PG 13 WC Polymer Science SC Polymer Science GA 228JF UT WOS:000082132800028 ER PT J AU Gerzeski, R AF Gerzeski, R TI Attempts to enhance the properties of EPON 830-4,4 '-Methylene Bis Cyclohexylamine epoxy resin systems by exposing them to 0.1290 to 0.8810 tesla magnetic fields while thermally curing them SO POLYMER ENGINEERING AND SCIENCE LA English DT Article ID EMULSION POLYMERIZATION; POLYACETYLENE; ORIENTATION AB This effort determined if enhancements to the properties of fully cured EPON 830-4,4'-Methylene Bis Cyclohexylamine epoxy resin systems (ERSs) could be induced by thermally curing them, while also simultaneously exposing them to economically generated magnetic fields (MFs). Stoichiometric mixes were cured for 5 hours at 121 degrees C while being exposed to MFs between 0.1290 and 0.8810 Tesla. Exposed and control specimens were simultaneously cast from the same mix in each run. The resulting specimens were mechanically and thermally tested to find any property differences. This effort: determined that under these conditions there were no modifications to the properties of MF exposed, fully thermally cured, ERSs relative to their controls. C1 USAF, Res Lab, Wright Patterson AFB, Fairborn, OH 45324 USA. RP Gerzeski, R (reprint author), USAF, Res Lab, Wright Patterson AFB, POB 287, Fairborn, OH 45324 USA. NR 28 TC 1 Z9 1 U1 0 U2 4 PU SOC PLASTICS ENG INC PI BROOKFIELD PA 14 FAIRFIELD DR, BROOKFIELD, CT 06804-0403 USA SN 0032-3888 J9 POLYM ENG SCI JI Polym. Eng. Sci. PD NOV PY 1999 VL 39 IS 11 BP 2150 EP 2158 DI 10.1002/pen.11604 PG 9 WC Engineering, Chemical; Polymer Science SC Engineering; Polymer Science GA 261JY UT WOS:000084007100003 ER PT J AU Elliott, GS Beutner, TJ AF Elliott, GS Beutner, TJ TI Molecular filter based planar Doppler velocimetry SO PROGRESS IN AEROSPACE SCIENCES LA English DT Review ID LASER-INDUCED FLUORESCENCE; SPECTRAL RESOLUTION LIDAR; HIGH-SPEED FLOWS; RAYLEIGH-SCATTERING; GLOBAL VELOCIMETRY; IODINE MOLECULE; TEMPERATURE; VELOCITY; SYSTEM; PARAMETERS AB Molecular filter based diagnostics are continuing to gain popularity as a research tool for investigations in areas of aerodynamics, fluid mechanics, and combustion. This class of diagnostics has gone by many terms including Filtered Rayleigh Scattering, Doppler Global Velocimetry, and Planar Doppler Velocimetry. The majority of this article reviews recent advances in Planar Doppler Velocimetry in measuring up to three velocity components over a planar region in a flowfield. The history of the development of these techniques is given with a description of typical systems, components, and levels of uncertainty in the measurement. Current trends indicate that uncertainties on the order of 1 m/s are possible with these techniques. A comprehensive review is also given on the application of Planar Doppler Velocimetry to laboratory flows, supersonic flows, and large scale subsonic wind tunnels. The article concludes with a description of future trends, which may simplify the technique, followed by a description of techniques which allow multi-property measurements (i.e. velocity, density, temperature, and pressure) simultaneously. (C) 1999 Elsevier Science Ltd. All rights reserved. C1 Rutgers State Univ, Dept Mech & Aerosp Engn, Piscataway, NJ 08854 USA. USAF, Off Sci Res, Arlington, VA USA. RP Rutgers State Univ, Dept Mech & Aerosp Engn, Piscataway, NJ 08854 USA. EM gelliott@jove.rutgers.edu NR 97 TC 53 Z9 54 U1 1 U2 5 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0376-0421 J9 PROG AEROSP SCI JI Prog. Aeosp. Sci. PD NOV PY 1999 VL 35 IS 8 BP 799 EP 845 DI 10.1016/S0376-0421(99)00008-1 PG 47 WC Engineering, Aerospace SC Engineering GA 263XX UT WOS:000084151500002 ER PT J AU Schmitt, GF AF Schmitt, GF TI USAF materials and manufacturing research: A legacy of achievements, a vision for the future SO SAMPE JOURNAL LA English DT Article AB Ever since the Wright Brothers defied the skeptics of powered flight almost 100 years ago, man has sought to make a better "flying machine." For more than 82 years, the men and women of Air Force Research Laboratory's Materials and Manufacturing Directorate and their predecessors have been right in the thick of that search. While the Directorate today looks vastly different than it did in the beginning, cone thing remains unchanged - the dedication of its talented workforce to provide the best material's and manufacturing technologies for the best Air Force in the world. Their long legacy of achievements, that started with the development of plywood, continues unabated headed into the 21(st) century. The accomplishments listed below are but a few of many derived from their research. While the early Directorate was comprised of only DoD civilian and military personnel performing in-house research, the Directorate today has evolved into a triad research team of DoD military and civilians along with DoD contractors. While much of the research today is performed contractor facilities, the Directorate's in-house research team is just as important today as it was through the early years. Its strong in-house basic re,search team is providing cutting edge research that will lead to materials for the 21(st) century Air Force. Additionally, in-house researchers involved in exploratory and advanced development projects provide leadership to guide contractual research with industry and universities. They also guide the transition between research and application. While the developments throughout this article are a direct result of the military-civilian-contractor team they would have been impossible without involvement from the Directorate's strong, forward-looking in-house researchers. C1 USAF, Res Lab, Tech Informat Ctr, Mat & Mfg Directorate, Wright Patterson AFB, OH 45433 USA. RP Schmitt, GF (reprint author), USAF, Res Lab, Tech Informat Ctr, Mat & Mfg Directorate, Wright Patterson AFB, OH 45433 USA. NR 0 TC 0 Z9 0 U1 0 U2 2 PU SAMPE PUBLISHERS PI COVINA PA 1161 PARKVIEW DRIVE, COVINA, CA 91722 USA SN 0091-1062 J9 SAMPE J JI Sampe J. PD NOV-DEC PY 1999 VL 35 IS 6 BP 25 EP 33 PG 9 WC Engineering, Multidisciplinary; Materials Science, Multidisciplinary SC Engineering; Materials Science GA 256WY UT WOS:000083750500007 ER PT J AU Wu, RLC Miyoshi, K Lanter, WC Wrbanek, JD DeJoseph, CA AF Wu, RLC Miyoshi, K Lanter, WC Wrbanek, JD DeJoseph, CA TI Growth and tribological properties of amorphous hydrogenated carbon nitride produced by ion-beam technique SO SURFACE & COATINGS TECHNOLOGY LA English DT Article; Proceedings Paper CT 26th International Conference on Metallurgical Coating and Thin Films CY APR 12-15, 1999 CL SAN DIEGO, CALIFORNIA SP Div Amer Vacuum Soc, Vacuum Metallurgy & Thin Films DE carbon nitride; ion-beam technique; tribology ID DIAMOND; COATINGS AB Hydrogenated carbon nitride (H-CNx) films have been deposited on a variety of substrates using a 20 cm diameter r.f.-excited (13.56 MHz) ion gun and a four-axis substrate scanner. Mixtures of methane and nitrogen were used to generate various hydrocarbon and nitrogen-containing ions. The effects of r.f. power (99-600 W), N-2/CH4 gas mixture (0.2-3), total pressure, and ion energy (200-1750 eV) on the film deposition rate, chemical composition, and tribological properties have been systematically investigated. A quadrupole mass spectrometer and a total ion current measuring device were utilized to monitor the ion compositions of the gas mixtures of N-2/CH4 during the deposition for quality control and process optimization. The predominate ion species in the gas mixture of N-2/CH4 is CH3+, and as more nitrogen was added into the iron source with CH4, the ionic species of N-2(+), N+, NH4+, NH3+, NH2+, HCN+, CN+, and N2H2+ were relatively increased. RES and proton recoil techniques were used to analyze the as-deposited films. Unidirectional sliding friction experiments in UHV, humid air, and dry nitrogen were conducted to measure the coefficient of friction and wear behavior of these films. The tribological properties of H-CNx films were compared with those of polycrystalline diamond (PCD) and diamond-like carbon (DLC) films studied previously. The correlation between the deposition parameters on the amorphous H-CNx film growth rate, nitrogen content, and tribological properties is discussed. (C) 1999 Elsevier Science S.A. All rights reserved. C1 K Syst Corp, Beavercreek, OH 45432 USA. NASA, Lewis Res Ctr, Cleveland, OH 44135 USA. USAF, Res Lab, Wright Patterson AFB, OH 45433 USA. RP Wu, RLC (reprint author), K Syst Corp, 1522 Marsetta Dr, Beavercreek, OH 45432 USA. EM rlwu@aol.com NR 7 TC 4 Z9 4 U1 1 U2 3 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0257-8972 J9 SURF COAT TECH JI Surf. Coat. Technol. PD NOV PY 1999 VL 120 BP 573 EP 578 DI 10.1016/S0257-8972(99)00447-8 PG 6 WC Materials Science, Coatings & Films; Physics, Applied SC Materials Science; Physics GA 262ED UT WOS:000084051900089 ER PT J AU Cockerham, KP Cockerham, GC Stutzman, R Hidayat, AA Depper, MH Turbin, RE Kennerdell, JS AF Cockerham, KP Cockerham, GC Stutzman, R Hidayat, AA Depper, MH Turbin, RE Kennerdell, JS TI The clinical spectrum of schwannomas presenting with visual dysfunction: A clinicopathologic study of three cases SO SURVEY OF OPHTHALMOLOGY LA English DT Review DE neurilemoma; schwannoma; tumor ID TUMOR; NERVE AB Schwannomas (neurilemomas) are benign tumors that arise from Schwann cells in the peripheral nervous system. The most commonly involved nerves that cause neuro-ophthalmic manifestations are cranial nerves V and VIII. In this series of three women, schwannomas presented as intraconal masses that mimicked a cavernous hemangioma, a superior orbital mass transgressing the superior orbital fissure, and an expansive frontal lobe mass with clinical symptoms and signs of increased intracranial pressure. Although all three complained of visual blur-ring, none of our patients presented with Vth or VIIIth cranial nerve dysfunction. Histopathologic studies demonstrated well-circumscribed, encapsulated spindle-cell lesions with classic Antoni A and B patterns. Histopathologic examination is essential to confirm the diagnosis of a schwannoma that may be otherwise clinically confusing. Direct optic nerve compression, globe indentation with induced hyperopia, or increased intracranial pressure with optic nerve compromise may be responsible for visual symptoms. A multidisciplinary approach is often required because of the size and location of schwannomas. (C) 1999 by Elsevier Science Inc. All rights reserved. C1 Allegheny Gen Hosp, Dept Ophthalmol, Pittsburgh, PA 15212 USA. Ophthalmol Serv, Andrews AFB, MD USA. Walter Reed Army Med Ctr, Ophthalmol Serv, Washington, DC 20307 USA. Armed Forces Inst Pathol, Dept Ophthalm Pathol, Washington, DC 20306 USA. Walter Reed Army Med Ctr, Dept Radiol, Washington, DC 20307 USA. RP Cockerham, KP (reprint author), Allegheny Ophthalm & Orbital Associates, 420 E North Ave,Suite 116, Pittsburgh, PA 15212 USA. NR 14 TC 16 Z9 16 U1 0 U2 1 PU ELSEVIER SCIENCE INC PI NEW YORK PA 655 AVENUE OF THE AMERICAS, NEW YORK, NY 10010 USA SN 0039-6257 J9 SURV OPHTHALMOL JI Surv. Ophthalmol. PD NOV-DEC PY 1999 VL 44 IS 3 BP 226 EP 234 DI 10.1016/S0039-6257(99)00100-9 PG 9 WC Ophthalmology SC Ophthalmology GA 258TJ UT WOS:000083855000003 PM 10588441 ER PT J AU Chan, YP AF Chan, YP TI Facility location: A survey of applications and methods SO TRANSPORTATION SCIENCE LA English DT Book Review C1 USAF, Inst Technol, Dept Operat Sci, Wright Patterson AFB, OH 45433 USA. RP Chan, YP (reprint author), USAF, Inst Technol, Dept Operat Sci, Wright Patterson AFB, OH 45433 USA. NR 4 TC 0 Z9 1 U1 0 U2 1 PU INST OPERATIONS RESEARCH MANAGEMENT SCIENCES PI LINTHICUM HTS PA 901 ELKRIDGE LANDING RD, STE 400, LINTHICUM HTS, MD 21090-2909 USA SN 0041-1655 J9 TRANSPORT SCI JI Transp. Sci. PD NOV PY 1999 VL 33 IS 4 BP 429 EP 430 PG 2 WC Operations Research & Management Science; Transportation; Transportation Science & Technology SC Operations Research & Management Science; Transportation GA 257WT UT WOS:000083806000008 ER PT J AU Buryachenko, VA Rammerstorfer, FG AF Buryachenko, VA Rammerstorfer, FG TI On the thermoelasticity of random structure particulate composites SO ZEITSCHRIFT FUR ANGEWANDTE MATHEMATIK UND PHYSIK LA English DT Article DE micromechanics; effective thermoelastic properties ID EFFECTIVE ELASTOPLASTIC BEHAVIOR; STRESS FLUCTUATIONS; MATRIX COMPOSITES AB We consider a linearly thermoelastic composite medium, which consists of a homogeneous matrix containing statistically uniform random set of ellipsoidal coated inclusions. Effective properties (such as compliance, thermal expansion, stored energy) as well as first and second statistical moments of stresses in the components are estimated for the general case of nonhomogeneity of the thermoelastic inclusion properties. The micromechanical approach is based on the Green's function technique as well as on the generalization of the "multiparticle effective field method" (MEFM), previously proposed for the analysis of composites with homogeneous inclusions, see e.g. Buryachenko and Kreher (J. Mech. Phys. Solids (1995) 43, 1105-1125). In the framework of the effective field hypothesis one obtains the generalization of the classical formula by Rosen and Hashin (Int. J. Engng. Sci. (1970), 8, 157-173) for composites with identical coated inclusions, which is exact for two-component composites. The application of the theory is demonstrated by the prediction of the overall yield surface of composite materials. C1 Vienna Univ Technol, Inst Light Weight Struct & Aerosp Engn, Christian Doppler Lab Micromech Mat, A-1040 Vienna, Austria. RP Buryachenko, VA (reprint author), USAF, Res Lab, AFRL, MLBM, Wright Patterson AFB, OH 45433 USA. EM buryach@aol.com RI Rammerstorfer, Franz/R-9329-2016 NR 17 TC 5 Z9 5 U1 0 U2 1 PU BIRKHAUSER VERLAG AG PI BASEL PA VIADUKSTRASSE 40-44, PO BOX 133, CH-4010 BASEL, SWITZERLAND SN 0044-2275 J9 Z ANGEW MATH PHYS JI Z. Angew. Math. Phys. PD NOV PY 1999 VL 50 IS 6 BP 934 EP 947 DI 10.1007/s000330050187 PG 14 WC Mathematics, Applied SC Mathematics GA 270TV UT WOS:000084553100005 ER PT J AU Marshall, TC Rust, WD Stolzenburg, M Roeder, WP Krehbiel, PR AF Marshall, TC Rust, WD Stolzenburg, M Roeder, WP Krehbiel, PR TI A study of enhanced fair-weather electric fields occurring soon after sunrise SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID THUNDERSTORM CONVECTIVE REGIONS; PRECIPITATION; SYSTEMS AB In this paper we describe several series of electric field soundings made in the lowest few hundred meters above the ground on 6 days at Kennedy Space Center in Florida. These soundings are used to determine the charge density and thickness of the charged electrode layer just above the surface of the Earth both before and after sunrise during fair weather. On most of the days considered, there was an anomalous enhancement in the ground-level electric field that was probably associated with the "sunrise effect" previously described by others. At our tether site we found that the electrode-layer charge density began increasing at about the same time as the local enhancement in the electric field magnitude at the ground. Shortly before the peak in the local E enhancement, the electrode-layer charge density decreased while the charge thickness increased; these changes were coincident with a decrease in relative humidity, a shift in the average wind direction, and increases in the fluctuations in relative humidity, wind speed, and wind direction. The typical decrease in charge density was from 0.2 to 0.05 nC m(-3), while the charge layer thickness increased from less than 20 m to almost 200 m. Our measurements suggest that enhanced positive electrode layers accumulate before sunrise very close to the surface because there is relatively little radioactivity in the soil or air. Local, upward mixing of the denser, low-lying, electrode-layer charge may account for the observed sunrise enhancement in electric field. The larger enhancements observed at some sites may indicate that upward convection is supplemented by advection of denser charge from above water surfaces a few tens of meters (or less) from the measurement sites. C1 Univ Mississippi, Dept Phys & Astron, University, MS 38677 USA. NOAA, ERL, Natl Severe Storms Lab, Norman, OK 73069 USA. USAF, 45th Weather Squadron, Patrick AFB, FL 32925 USA. New Mexico Inst Min & Technol, Dept Phys, Socorro, NM 87801 USA. RP Marshall, TC (reprint author), Univ Mississippi, Dept Phys & Astron, University, MS 38677 USA. EM marshall@phy.olemiss.edu; drust@nsslgate.nssl.noaa.gov; mstolzen@phy.olemiss.edu; william.roeder@pafb.af.mil; khrehbiel@ibis.nmt.edu OI Stolzenburg, Maribeth/0000-0001-8773-8101 NR 23 TC 16 Z9 18 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X EI 2169-8996 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD OCT 27 PY 1999 VL 104 IS D20 BP 24455 EP 24469 DI 10.1029/1999JD900418 PG 15 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 249KN UT WOS:000083332400017 ER PT J AU Woodward, C Kajihara, S AF Woodward, C Kajihara, S TI Density of thermal vacancies in gamma-Ti-Al-M, M = Si, Cr, Nb, Mo, Ta or W SO ACTA MATERIALIA LA English DT Article DE theory and modeling; intermetallic; vacancy, lattice defects; creep; intermetallic ID POINT-DEFECTS; ALLOYS AB Modifications to alloy chemistry are often used to tailor the intrinsic flow behavior of structural materials. Models of creep in intermetallic alloys must account for the influence of chemistry on the available intrinsic creep mechanisms. As in simple metals the presence of vacancies strongly influences bulk diffusion processes in these materials. Limiting the density of constitutional and thermal vacancies by alloying may produce materials with enhanced creep properties. The energy of intrinsic and substitutional point defects in L1(0) TiA1 is calculated within a first principles, local density functional theory framework. Relaxed structures and energies for vacancies, antisites and solid solutions are calculated using a planewave-pseudopotential method. Calculated defect energies are used within a canonical ensemble formalism to estimate the point defect densities as a function of temperature and composition. The density of vacancies is found to be sensitive to the underlying stoichiometry of TiA1. The dependence of the vacancy concentration for solid solutions of Si, Cr, Nb, Mo, Ta and W is also predicted. (C) 1999 Acta Metallurgica Inc. Published by Elsevier Science Ltd. All rights reserved. C1 USAF, Res Lab, Mat & Mfg Directorate, Wright Patterson AFB, OH 45433 USA. RP Woodward, C (reprint author), Universal Energy Syst Inc, Mat Res Div, 4401 Dayton Xenia Rd, Dayton, OH 45432 USA. NR 24 TC 9 Z9 9 U1 1 U2 8 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1359-6454 J9 ACTA MATER JI Acta Mater. PD OCT 26 PY 1999 VL 47 IS 14 BP 3793 EP 3798 DI 10.1016/S1359-6454(99)00231-1 PG 6 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA 254DM UT WOS:000083596700007 ER PT J AU Storey, DF Dolan, MJ Anderson, SA Meier, PA Walter, EA AF Storey, DF Dolan, MJ Anderson, SA Meier, PA Walter, EA TI Seminal plasma RANTES levels positively correlate with seminal plasma HIV-1 RNA levels SO AIDS LA English DT Letter ID PROTEIN-1 C1 Wilford Hall USAF Med Ctr, Dept Med, Infect Dis Serv, Lackland AFB, TX 78236 USA. Wilford Hall USAF Med Ctr, Henry M Jackson Fdn, Lackland AFB, TX 78236 USA. RP Storey, DF (reprint author), Wilford Hall USAF Med Ctr, Dept Med, Infect Dis Serv, Lackland AFB, TX 78236 USA. NR 8 TC 8 Z9 8 U1 0 U2 0 PU LIPPINCOTT WILLIAMS & WILKINS PI PHILADELPHIA PA 530 WALNUT ST, PHILADELPHIA, PA 19106-3621 USA SN 0269-9370 J9 AIDS JI Aids PD OCT 22 PY 1999 VL 13 IS 15 BP 2169 EP 2171 DI 10.1097/00002030-199910220-00023 PG 3 WC Immunology; Infectious Diseases; Virology SC Immunology; Infectious Diseases; Virology GA 249KA UT WOS:000083331200023 PM 10546873 ER PT J AU Rao, SI Hazzledine, PM AF Rao, SI Hazzledine, PM TI Simulation of an edge source in the Cu-Ni multilayer system SO SCRIPTA MATERIALIA LA English DT Article ID THIN-FILMS; DISLOCATIONS; FE C1 MLLM, WL, Wright Lab, Mat Directorate, Wright Patterson AFB, OH 45433 USA. Universal Energy Syst Inc, Dayton, OH 45432 USA. RP Rao, SI (reprint author), MLLM, WL, Wright Lab, Mat Directorate, Wright Patterson AFB, OH 45433 USA. NR 24 TC 4 Z9 4 U1 0 U2 2 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1359-6462 J9 SCRIPTA MATER JI Scr. Mater. PD OCT 22 PY 1999 VL 41 IS 10 BP 1085 EP 1090 DI 10.1016/S1359-6462(99)00257-2 PG 6 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA 251RF UT WOS:000083458100010 ER PT J AU Arnold, ST Williams, S Dotan, I Midey, AJ Morris, RA Viggiano, AA AF Arnold, ST Williams, S Dotan, I Midey, AJ Morris, RA Viggiano, AA TI Flow tube studies of benzene charge transfer reactions from 250 to 1400 K SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID AB-INITIO CALCULATIONS; RATE CONSTANTS; TEMPERATURE-DEPENDENCE; TRAJECTORY CALCULATIONS; BRANCHING RATIOS; RADICAL-CATION; FRAGMENT IONS; DISSOCIATION; ENERGY; C6H6+ AB Temperature dependent rate constants and product branching fractions are reported for reactions of the atmospheric plasma cations NO+, O-2(+), O+, N+, N-2(+), and N-4(+) with benzene, as measured from 250 to 500 K by the selected ion flow tube technique. For the reactions of O-2(+) and N-2(+), data have also been obtained between 500 and 1400 K in a high-temperature flowing afterglow. These are among the first determinations of ion-molecule branching fractions above 600 K. Temperature dependent rate constants and product branching fractions are also reported for the reactions of benzene with Kr+, Ar+, Ne+, and F+. All reactions were found to proceed at the collision rate at all temperatures studied. With increasing reactant ion recombination energy, the mechanism changed from association and nondissociative charge transfer to dissociative charge transfer. Primary and secondary dissociation products were observed. Some of the reactivity in the N+ and F+ reactions is attributed to chemical channels. The temperature dependent branching fractions are converted to product ion breakdown curves and compared to previous studies. The current results exhibit a kinetic shift, resulting from slow fragmentation of the C6H6+* complex, combined with collisional stabilization of the complex by the He buffer gas. The pressure dependence of the N+ reaction was examined from 0.35 to 0.8 Torr. The flow tube data provide the first breakdown curve for the C5H3+ product and further indicate that C5H3+ is relatively unreactive, consistent with it having the cyclic ethynyl cyclopropene ion structure. The C3H3+ product was shown to have a cyclic structure, while the C4H4+ product was found to be a mixture of linear and cyclic isomers. The isomeric mixture of C4H4+ products was quantified as a function of the C6H6+* excess energy. A schematic reaction coordinate diagram representing the primary dissociation channels of C6H6+ is constructed from previous experimental and theoretical work. A possible reaction pathway for the C5H3+ product is discussed. C1 USAF, Res Lab, Space Vehicles Directorate, Hanscom AFB, MA 01731 USA. Open Univ Israel, Dept Nat & Life Sci, Tel Aviv, Israel. RP Viggiano, AA (reprint author), USAF, Res Lab, Space Vehicles Directorate, 29 Randolph Rd, Hanscom AFB, MA 01731 USA. NR 41 TC 41 Z9 41 U1 1 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1089-5639 J9 J PHYS CHEM A JI J. Phys. Chem. A PD OCT 21 PY 1999 VL 103 IS 42 BP 8421 EP 8432 DI 10.1021/jp991928k PG 12 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 251DT UT WOS:000083429900011 ER PT J AU Kozodoy, P Smorchkova, YP Hansen, M Xing, HL DenBaars, SP Mishra, UK Saxler, AW Perrin, R Mitchel, WC AF Kozodoy, P Smorchkova, YP Hansen, M Xing, HL DenBaars, SP Mishra, UK Saxler, AW Perrin, R Mitchel, WC TI Polarization-enhanced Mg doping of AlGaN/GaN superlattices SO APPLIED PHYSICS LETTERS LA English DT Article ID GAN AB The hole-transport properties of Mg-doped AlGaN/GaN superlattices are carefully examined. Variable-temperature Hall-effect measurements indicate that the use of such superlattices enhances the average hole concentration at a temperature of 120 K by over five orders of magnitude compared to a bulk GaN film (the enhancement at room temperature is a factor of 9). An unusual modulation-doping scheme, which has been realized using molecular-beam epitaxy, has yielded high-hole-mobility superlattices and conclusively demonstrated the pivotal role of piezoelectric and spontaneous polarization in determining the band structure of the superlattices. (C) 1999 American Institute of Physics. [S0003-6951(99)04442-3]. C1 Univ Calif Santa Barbara, Dept Elect & Comp Engn, Santa Barbara, CA 93106 USA. Univ Calif Santa Barbara, Dept Mat, Santa Barbara, CA 93106 USA. USAF, Res Lab, AFRL MLPO, Wright Patterson AFB, OH 45433 USA. RP Kozodoy, P (reprint author), Univ Calif Santa Barbara, Dept Elect & Comp Engn, Santa Barbara, CA 93106 USA. NR 11 TC 97 Z9 100 U1 2 U2 29 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD OCT 18 PY 1999 VL 75 IS 16 BP 2444 EP 2446 DI 10.1063/1.125042 PG 3 WC Physics, Applied SC Physics GA 245LU UT WOS:000083111100034 ER PT J AU Das, GP Dudis, DS AF Das, GP Dudis, DS TI An approximate ab initio sum-over-states approach to the calculation of non-linear optical properties in organic molecules SO CHEMICAL PHYSICS LETTERS LA English DT Article ID 2-PHOTON ABSORPTION; HYPERPOLARIZABILITIES; POLYENES AB We present an ab initio formulation of a modified sum-over-states method to perform calculations on the non-linear optical (NLO) properties for intermediate and large molecular systems. A benchmark application to the trans-octatetraene molecule is presented with comparison to other ab initio calculations. The method is also used to compute some key NLO parameters for the molecules di-alkyl-amino-nitro-stilbene and 3,4-methoxy-2,5-bis-(benzo-thiazolyl-2)thiophene treated earlier at the semi-empirical level by the present authors. (C) 1999 Elsevier Science B.V. All rights reserved. C1 USAF, RL, MLBP, Wright Patterson AFB, OH 45433 USA. RP Das, GP (reprint author), USAF, RL, MLBP, Wright Patterson AFB, OH 45433 USA. NR 13 TC 13 Z9 13 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0009-2614 J9 CHEM PHYS LETT JI Chem. Phys. Lett. PD OCT 15 PY 1999 VL 312 IS 1 BP 57 EP 64 DI 10.1016/S0009-2614(99)00922-7 PG 8 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 247CT UT WOS:000083203600008 ER PT J AU Talbot, RW Dibb, JE Scheuer, EM Kondo, Y Koike, M Singh, HB Salas, LB Fukui, Y Ballenthin, JO Meads, RF Miller, TM Hunton, DE Viggiano, AA Blake, DR Blake, NJ Atlas, E Flocke, F Jacob, DJ Jaegle, L AF Talbot, RW Dibb, JE Scheuer, EM Kondo, Y Koike, M Singh, HB Salas, LB Fukui, Y Ballenthin, JO Meads, RF Miller, TM Hunton, DE Viggiano, AA Blake, DR Blake, NJ Atlas, E Flocke, F Jacob, DJ Jaegle, L TI Reactive nitrogen budget during the NASA SONEX mission SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID CATALYTIC REDUCTION TECHNIQUE; PEROXYACETYL NITRATE PAN; NOY; TROPOSPHERE; ATMOSPHERE AB The SASS Ozone and Nitrogen Oxides Experiment (SONEX) over the North Atlantic during October/November 1997 offered an excellent opportunity to examine the budget of reactive nitrogen in the upper troposphere (8 - 12 km altitude). The median measured total reactive nitrogen (NO,) mixing ratio was 425 parts per trillion by volume (pptv). A data set merged to the HNO3 measurement time resolution was used to calculate NOy (NOy sum) by summing the reactive nitrogen species (a combination of measured plus modeled results) and comparing it to measured NOy (NOy meas.). Comparisons were done for tropospheric air (O-3 <100 parts per billion by volume (ppbv)) and stratospherically influenced air (O-3 > 100 ppbv) with both showing good agreement between NOy sum and NOy meas. (slope >0.9 and r(2) approximate to 0.9). The total reactive nitrogen budget in the upper troposphere over the North Atlantic appears to be dominated by a mixture of NOx (NO + NO2), HNO3, and PAN. In tropospheric air median values of NOx/NOy were approximate to 0.25, HNO3/NOy approximate to 0.35 and PAN/NOy approximate to 0.17. Particulate NO3- and alkyl nitrates together composed <10% of NOy, while model estimated HNO4 averaged 12%. For the air parcels sampled during SONEX, there does not appear to be a large reservoir of unidentified NOy compounds. C1 Univ New Hampshire, Inst Study Earth Oceans & Space, Durham, NH 03824 USA. Nagoya Univ, Solar Terr Environm Lab, Aichi 442, Japan. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. USAF, Res Lab, VSBP, Hanscom AFB, MA 01731 USA. Univ Calif Irvine, Dept Chem, Irvine, CA USA. Natl Ctr Atmospher Res, Div Atmospher Chem, Boulder, CO 80307 USA. Harvard Univ, Dept Earth & Planetary Sci, Cambridge, MA 02138 USA. RP Talbot, RW (reprint author), Univ New Hampshire, Inst Study Earth Oceans & Space, Durham, NH 03824 USA. RI Koike, Makoto/F-4366-2011; Kondo, Yutaka/D-1459-2012; Atlas, Elliot/J-8171-2015 NR 18 TC 40 Z9 41 U1 0 U2 5 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD OCT 15 PY 1999 VL 26 IS 20 BP 3057 EP 3060 DI 10.1029/1999GL900589 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 246JE UT WOS:000083160000002 ER PT J AU Lo, I Chen, SJ Tu, LW Mitchel, WC Tu, RC Su, YK AF Lo, I Chen, SJ Tu, LW Mitchel, WC Tu, RC Su, YK TI Effect of electron-electron interactions on a two-dimensional electron gas in II-VIZnS0.06Se0.94/Zn0.8Cd0.2Se quantum wells SO PHYSICAL REVIEW B LA English DT Article ID D EXCHANGE INTERACTION; GAAS-ALXGA1-XAS HETEROSTRUCTURES; GAAS/ALXGA1-XAS HETEROSTRUCTURES; WEAK LOCALIZATION; INVERSION-LAYERS; SPIN RESONANCE; MAGNETORESISTANCE; OSCILLATIONS; TRANSPORT AB A magnetotransport study has been performed in II-VI ZnS0.06Se0.94 / Zn0.8Cd0.2Se quantum wells. We observed the quantum effects of weak localization and electron-electron interactions on the two-dimensional electron gas in the Zn0.8Cd0.2Se well. The effective mass of electrons in this highly correlated system, determined from Shubnikov-de Haas measurements, exhibits a strong magnetic field dependence: m*m(0) = 0.143 + 0.0027 B-2. The mass enhancement is attributed to the "dressing" of electrons by the many-particle effect due to electron-electron interactions. [S0163-1829(99)50540-7]. C1 Natl Sun Yat Sen Univ, Dept Phys, Kaohsiung 80424, Taiwan. USAF, Mat Directorate, Res Lab, Wright Patterson AFB, OH 45433 USA. Natl Cheng Kung Univ, Dept Elect Engn, Tainan 70101, Taiwan. RP Lo, I (reprint author), Natl Sun Yat Sen Univ, Dept Phys, Kaohsiung 80424, Taiwan. NR 34 TC 1 Z9 1 U1 0 U2 1 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD OCT 15 PY 1999 VL 60 IS 16 BP R11281 EP R11284 DI 10.1103/PhysRevB.60.R11281 PG 4 WC Physics, Condensed Matter SC Physics GA 253KB UT WOS:000083554800011 ER PT J AU Gonzalez, E Bamshad, M Sato, N Mummidi, S Dhanda, R Catano, G Cabrera, S McBride, M Cao, XH Merrill, G O'Connell, P Bowden, DW Freedman, BI Anderson, SA Walter, EA Evans, JS Stephan, KT Clark, RA Tyagi, S Ahuja, SS Dolan, MJ Ahuja, SK AF Gonzalez, E Bamshad, M Sato, N Mummidi, S Dhanda, R Catano, G Cabrera, S McBride, M Cao, XH Merrill, G O'Connell, P Bowden, DW Freedman, BI Anderson, SA Walter, EA Evans, JS Stephan, KT Clark, RA Tyagi, S Ahuja, SS Dolan, MJ Ahuja, SK TI Race-specific HIV-1 disease-modifying effects associated with CCR5 haplotypes SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Article ID CHEMOKINE RECEPTOR-5; PROGRESSION; GENE; TRANSMISSION; INFECTION; VARIANTS; ALLELE; VIRUS; POLYMORPHISMS; MUTATION AB Genetic variation in CC chemokine receptor 5 (CCR5), the major HIV-1 coreceptor, has been shown to influence HIV-1 transmission and disease progression. However, it is generally assumed that the same CCR5 genotype (or haplotype) has similar phenotypic effects in different populations. To test this assumption, we used an evolutionary-based classification of CCR5 haplotypes to determine their associated HIV-1 disease-modifying effects in a large well-characterized racially mixed cohort of HIV-1-seropositive individuals, We demonstrate that the spectrum of CCR5 haplotypes associated with disease acceleration or retardation differs between African Americans and Caucasians. Also, we show that there is a strong interactive effect between CCR5 haplotypes with different evolutionary histories. The striking population-specific phenotypic effects associated with CCR5 haplotypes emphasize the importance of understanding the evolutionary context in which disease susceptibility genes are expressed. C1 Wilford Hall USAF Med Ctr, Infect Dis Serv, Lackland AFB, TX 78236 USA. Univ Texas, Hlth Sci Ctr, Dept Med, San Antonio, TX 78229 USA. Univ Texas, Hlth Sci Ctr, Dept Pathol, San Antonio, TX 78229 USA. S Texas Vet Hlth Care Syst, Audie L Murphy Div, San Antonio, TX 78229 USA. Univ Utah, Dept Pediat, Salt Lake City, UT 84112 USA. Worldwide Clin Trials, Kennesaw, GA 30144 USA. Brooke Army Med Ctr, Dept Clin Invest, Ft Sam Houston, TX 78234 USA. Wake Forest Univ, Sch Med, Dept Biochem, Winston Salem, NC 27157 USA. Wake Forest Univ, Sch Med, Dept Med, Winston Salem, NC 27157 USA. Publ Hlth Res Inst City New York Inc, Dept Mol Genet, New York, NY 10016 USA. RP Ahuja, SK (reprint author), Wilford Hall USAF Med Ctr, Infect Dis Serv, Lackland AFB, TX 78236 USA. RI Mummidi, Srinivas/C-1004-2008 OI Mummidi, Srinivas/0000-0002-4068-6380 FU NHLBI NIH HHS [HL43521, R01 HL043521]; NIAID NIH HHS [AI43279, AI46326, R01 AI043279, R01 AI046326, R21 AI046326, R37 AI046326] NR 24 TC 183 Z9 188 U1 1 U2 6 PU NATL ACAD SCIENCES PI WASHINGTON PA 2101 CONSTITUTION AVE NW, WASHINGTON, DC 20418 USA SN 0027-8424 J9 P NATL ACAD SCI USA JI Proc. Natl. Acad. Sci. U. S. A. PD OCT 12 PY 1999 VL 96 IS 21 BP 12004 EP 12009 DI 10.1073/pnas.96.21.12004 PG 6 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 246MD UT WOS:000083166800059 PM 10518566 ER PT J AU Nicolaou, PD Semiatin, SL AF Nicolaou, PD Semiatin, SL TI Modeling of cavity coalescence during tensile deformation SO ACTA MATERIALIA LA English DT Article DE cavitation; growth; coalescence; plastic deformation ID SUPERPLASTIC DEFORMATION; GROWTH; FRACTURE; CAVITATION; BEHAVIOR; FAILURE AB The effect of material properties such as the cavity growth rate and initial cavity population on cavity coalescence during uniaxial tensile deformation was determined. To this end, a two-dimensional model that treats the growth of a random array of spherical cavities inside a deforming tension specimen was developed. Simulation results included predictions of the conditions under which cavity coalescence occurs, the variation of average cavity radius and fraction of cavities which have coalesced as a function of strain, and the evolution of cavity size distribution as a function of strain, cavity growth rate, and cavity population. For a given cavity density, it was found that the fraction of cavities which has coalesced is independent of the cavity growth rate and varies linearly with the cavity volume fraction; a relationship between the fraction of coalesced cavities and the cavity volume fraction was established from the simulation results. In addition, simulation predictions of average cavity radius as a function of strain were compared to previous relations for cavitation under conditions involving growth and coalescence. Predictions of average cavity size as a function of strain from the present work gave good agreement with previous experimental and theoretical work of Stowell and Filling. (C) 1999 Acta Metallurgica Inc. Published by Elsevier Science Ltd. AN rights reserved. C1 Silver & Baryte Ores Min Co SA, Athens 10672, Greece. USAF, Res Lab, Mat & Mfg Directorate, MLLM, Wright Patterson AFB, OH 45433 USA. RP Nicolaou, PD (reprint author), Silver & Baryte Ores Min Co SA, 21A Amerikis Str, Athens 10672, Greece. RI SEMIATIN, SHELDON/E-7264-2017 NR 17 TC 15 Z9 16 U1 0 U2 2 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1359-6454 J9 ACTA MATER JI Acta Mater. PD OCT 8 PY 1999 VL 47 IS 13 BP 3679 EP 3686 DI 10.1016/S1359-6454(99)00237-2 PG 8 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA 249JX UT WOS:000083330900015 ER PT J AU Visbal, MR Gaitonde, DV AF Visbal, MR Gaitonde, DV TI High-order-accurate methods for complex unsteady subsonic flows SO AIAA JOURNAL LA English DT Article; Proceedings Paper CT AIAA 36th Aerospace Sciences Meeting CY JAN 12-15, 1998 CL RENO, NEVADA SP Amer Inst Aeronaut & Astronaut ID FINITE-DIFFERENCE SCHEMES; SIMULATIONS AB Several issues related to the application of very high-order schemes for the finite difference simulation of the full Navier-Stokes equations are investigated. The schemes utilize an implicit approximately factored time-integration method coupled with spatial fourth- and sixth-order compact-difference formulations and a filtering strategy of up to tenth order. For this last aspect a consistent optimization approach is developed to treat points near the boundary resulting in minimal degradation of accuracy. The problems investigated exhibit many of the challenging features of practical flows and include several with complications introduced by curvilinear meshes, viscous effects, unsteadiness, and three-dimensionality. The high-order method is observed to be very robust for every problem considered. The algorithm is demonstrated to be highly accurate compared to both second-order and upwind-biased methods. For several cases, particularly very-low-Mach-number flows, filtering is determined to be a superior alternative to scalar damping. C1 USAF, Res Lab, Computat Sci Branch, Aeronaut Sci Div,Air Vehicles Directorate,VAAC, Wright Patterson AFB, OH 45433 USA. RP Visbal, MR (reprint author), USAF, Res Lab, Computat Sci Branch, Aeronaut Sci Div,Air Vehicles Directorate,VAAC, Wright Patterson AFB, OH 45433 USA. NR 31 TC 193 Z9 193 U1 0 U2 7 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 USA SN 0001-1452 J9 AIAA J JI AIAA J. PD OCT PY 1999 VL 37 IS 10 BP 1231 EP 1239 DI 10.2514/2.591 PG 9 WC Engineering, Aerospace SC Engineering GA 243BR UT WOS:000082977700011 ER PT J AU Chenault, CF Beran, PS Bowersox, RDW AF Chenault, CF Beran, PS Bowersox, RDW TI Numerical investigation of supersonic injection using a Reynolds-Stress turbulence model SO AIAA JOURNAL LA English DT Article; Proceedings Paper CT AIAA/ASME/SAE/ASEE 34th Joint Propulsion Conference and Exhibit CY JUL 12-15, 1998 CL CLEVELAND, OH SP Amer Inst Aeronaut & Astronaut, ASME, SAE, ASEE ID NAVIER-STOKES EQUATIONS; ANGLED INJECTION; CROSS-FLOW AB The full, three-dimensional Favre-averaged Navier-Stokes equations, coupled with the second-order Zhang et al. (Zhang, H., So, R., Gatski, T., and Speziale, C.,"A Near-Wall Second-Order Closure for Compressible Turbulent Flows," Near-Wall Turbulent Flows, edited by R. So, C. Speziale, and a. Launder, Elsevier, New York, 1993, ppt 209-218) Reynolds-stress turbulence and K-epsilon models, were used to numerically simulate a 25 deg, Mach 1.8 injection into a Mach 3.0 crossflow. Detailed comparisons with experimental data were performed. Analysis of the Reynolds-stress turbulence model simulation results revealed physically consistent and accurate predictions for mean flow and turbulent quantities, whereas the simulations with the K-epsilon model resulted in nonphysical and inconsistent turbulence predictions. Analysis of the three-dimensional flowfield simulation with the Reynolds-stress turbulence model shows that the shock structure downstream of the oblique barrel shock was a mirrored Image of the leeward side of the oblique barrel shock. Furthermore, the downstream location where vortical motion was initiated in the jet plume was caused by the recompression shock-induced vortices. These vortices were generated through the combined effects of the inflow air upwash behind the plume and the mirrored oblique barrel shock. C1 USAF, Inst Technol, Air Vehicle Directorate, Aeronaut Sci Div,Dept Aeronaut & Astronaut, Wright Patterson AFB, OH 45433 USA. Univ Alabama, Dept Mech & Aerosp Engn, Tuscaloosa, AL 35487 USA. RP USAF, Inst Technol, Air Vehicle Directorate, Aeronaut Sci Div,Dept Aeronaut & Astronaut, Wright Patterson AFB, OH 45433 USA. EM clarence.chenault@va.wpafb.af.mil NR 36 TC 36 Z9 39 U1 0 U2 0 PU AMER INST AERONAUTICS ASTRONAUTICS PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091-4344 USA SN 0001-1452 EI 1533-385X J9 AIAA J JI AIAA J. PD OCT PY 1999 VL 37 IS 10 BP 1257 EP 1269 DI 10.2514/2.594 PG 13 WC Engineering, Aerospace SC Engineering GA 243BR UT WOS:000082977700014 ER PT J AU Roane, DW Griger, DR AF Roane, DW Griger, DR TI An approach to diagnosis and initial management of systemic vasculitis SO AMERICAN FAMILY PHYSICIAN LA English DT Article ID NECROTIZING VASCULITIS; WEGENER GRANULOMATOSIS; INFECTION; VIRUS AB Systemic vasculitis occurs in a heterogeneous group of primary disorders or can be a manifestation of infection, an adverse drug reaction, malignancy or a connective tissue disease. A vasculitic process should be suspected in patients with unexplained ischemia or multiple organ involvement, especially when such features as polymyalgia rheumatica, inflammatory arthritis, palpable purpura, glomerulonephritis or multiple mononeuropathy are also present. The clinical features of systemic vasculitis depend on the organs involved and, in turn, organ involvement is largely influenced by the size of the affected blood vessels. The diagnostic work-up should be tailored to the clinical situation and geared toward a tissue or angiographic diagnosis, bearing in mind that the findings from these studies are not always pathognomonic. Emphasis should also be placed on exclusion of a secondary process. The diagnosis of the specific type of vasculitis may be made on the basis of the clinical features and the histopathologic or angiographic findings. Initial therapy for most types of systemic vasculitis consists of high-dose corticosteroids, with the addition of immunosuppressive therapy in certain patients. C1 David Grant Med Ctr, Travis AFB, CA USA. RP Roane, DW (reprint author), USAF, MC, 411-1 Napa St, Travis AFB, CA 94535 USA. NR 19 TC 11 Z9 13 U1 0 U2 0 PU AMER ACAD FAMILY PHYSICIANS PI KANSAS CITY PA 8880 WARD PARKWAY, KANSAS CITY, MO 64114-2797 USA SN 0002-838X J9 AM FAM PHYSICIAN JI Am. Fam. Physician PD OCT 1 PY 1999 VL 60 IS 5 BP 1421 EP 1430 PG 10 WC Primary Health Care; Medicine, General & Internal SC General & Internal Medicine GA 246FL UT WOS:000083153700012 PM 10524486 ER PT J AU Hall, M Jackson, M Johnson, JT Schultze, H Fortenberry, D Bright, C Hua, H Ying, JR Sykes, P AF Hall, M Jackson, M Johnson, JT Schultze, H Fortenberry, D Bright, C Hua, H Ying, JR Sykes, P TI Comparison of 7 antigens for serodiagnosis of gastrointestinal cancers SO AMERICAN JOURNAL OF CLINICAL PATHOLOGY LA English DT Meeting Abstract C1 Univ So Mississippi, Hattiesburg, MS 39406 USA. USAF, Med Ctr, Wright Patterson AFB, OH 45433 USA. Thomas F Puckett Lab, Hattiesburg, MS USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER SOC CLIN PATHOLOGISTS PI CHICAGO PA 2100 W HARRISON ST, CHICAGO, IL 60612 USA SN 0002-9173 J9 AM J CLIN PATHOL JI Am. J. Clin. Pathol. PD OCT PY 1999 VL 112 IS 4 MA 65 BP 554 EP 554 PG 1 WC Pathology SC Pathology GA 239DV UT WOS:000082754300075 ER PT J AU Chernoff, EJ Nunes, M White, B McClellan, J Coll, E Maggio, K Levin, S AF Chernoff, EJ Nunes, M White, B McClellan, J Coll, E Maggio, K Levin, S TI Fragile X premutation status in a male with mental retardation. SO AMERICAN JOURNAL OF HUMAN GENETICS LA English DT Meeting Abstract C1 NICHD, Heritable Disorders Branch, NIH, Bethesda, MD USA. USAF, Ctr Med Genet, Med Grp 81, Keesler AFB, MS USA. Nichols Inst, Quest Diagnost, San Juan Capistrano, CA USA. Walter Reed Army Med Ctr, Dept Dermatol, Washington, DC 20307 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0002-9297 J9 AM J HUM GENET JI Am. J. Hum. Genet. PD OCT PY 1999 VL 65 IS 4 SU S MA 781 BP A145 EP A145 PG 1 WC Genetics & Heredity SC Genetics & Heredity GA 241JQ UT WOS:000082879800784 ER PT J AU Compton, JG DiGiovanna, JJ Johnston, K Fleckman, P Bale, SJ AF Compton, JG DiGiovanna, JJ Johnston, K Fleckman, P Bale, SJ TI The absent granular layer histology in Ichthyosis vulgaris is linked to the dermal differentiation complex on chromosome 1. SO AMERICAN JOURNAL OF HUMAN GENETICS LA English DT Meeting Abstract C1 NIAMSD, NIH, Bethesda, MD 20892 USA. Brown Univ, Dept Dermatol, Providence, RI 02912 USA. 1st Med Grp, Serv Dermatol, Langley AFB, VA USA. Univ Washington, Dept Med Dermatol, Seattle, WA 98195 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0002-9297 J9 AM J HUM GENET JI Am. J. Hum. Genet. PD OCT PY 1999 VL 65 IS 4 SU S MA 513 BP A98 EP A98 PG 1 WC Genetics & Heredity SC Genetics & Heredity GA 241JQ UT WOS:000082879800515 ER PT J AU Fries, MH Holt, C Carpenter, I Martin, L Hume, R Flanagan, J Daniels, J Hudson, G Cadman, M Weatherly, R Nunes, ME AF Fries, MH Holt, C Carpenter, I Martin, L Hume, R Flanagan, J Daniels, J Hudson, G Cadman, M Weatherly, R Nunes, ME TI Discrimination of diagnostic criteria for testing for BRCA1/2. SO AMERICAN JOURNAL OF HUMAN GENETICS LA English DT Meeting Abstract C1 USAF, Ctr Med Genet, Keesler Med Ctr, Keesler AFB, MS USA. Madigan Army Med Ctr, Ft Lewis, WA USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0002-9297 J9 AM J HUM GENET JI Am. J. Hum. Genet. PD OCT PY 1999 VL 65 IS 4 SU S MA 1182 BP A214 EP A214 PG 1 WC Genetics & Heredity SC Genetics & Heredity GA 241JQ UT WOS:000082879801181 ER PT J AU Srinivasan, P McClellan, J Nunes, ME AF Srinivasan, P McClellan, J Nunes, ME TI An empiric method to determine sensitivity and allele frequency for Cystic Fibrosis genetic testing. SO AMERICAN JOURNAL OF HUMAN GENETICS LA English DT Meeting Abstract C1 Univ Texas, Med Branch, Galveston, TX 77550 USA. USAF, Ctr Med Genet, Keesler AFB, MS 39534 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0002-9297 J9 AM J HUM GENET JI Am. J. Hum. Genet. PD OCT PY 1999 VL 65 IS 4 SU S MA 2313 BP A409 EP A409 PG 1 WC Genetics & Heredity SC Genetics & Heredity GA 241JQ UT WOS:000082879802316 ER PT J AU Van Tuinen, P Mootnick, AR Kingswood, SC Hale, DW Kumamoto, AT AF Van Tuinen, P Mootnick, AR Kingswood, SC Hale, DW Kumamoto, AT TI Complex, compound inversion/translocation polymorphism in an ape: Presumptive intermediate stage in the karyotypic evolution of the agile gibbon Hylobates agilis SO AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY LA English DT Article DE cytogenetics; taxonomy; captive management; Hylobatidae; reciprocal translocation; meiosis ID PERICENTRIC-INVERSION; REARRANGEMENTS; CHROMOSOMES; BEHAVIOR; POSITION; SYNAPSIS; MOUSE AB Karyotypic variation in five gibbon species of the subgenus Hylobates (2n = 44) was assessed in 63 animals, 23 of them wild born. Acquisition of key specimens of Hylobates agilis (agile gibbon), whose karyotype had been problematic due to unresolved structural polymorphisms, led to disclosure of a compound inversion/translocation polymorphism. A polymorphic region of chromosome 8 harboring two pericentric inversions, one nested within the other, was in turn bissected by one breakpoint of a reciprocal translocation. In double-inversion + translocation heterozygotes, the theoretical meiotic pairing configuration is a double inversion loop, with four arms of a translocation quadrivalent radiating from the loop. Electronmicroscopic analysis of synaptonemal complex configurations consistently revealed translocation quadrivalents but no inversion loops. Rather, nonhomologous pairing was evident in the inverted region, a condition that should preclude crossing over and the subsequent production of duplication-deficiency gametes. This is corroborated by the existence of normal offspring of compound heterozygotes, indicating that fertility may not be reduced despite the topological complexity of this polymorphic system. The distribution of inversion and translocation morphs in these taxa suggests application of cytogenetics in identifying gibbon specimens and avoiding undesirable hybridization in captive breeding efforts. (C) 1999 Wiley-Liss, Inc. C1 Med Coll Wisconsin, Dept Pathol, Milwaukee, WI 53226 USA. Int Ctr Gibbon Studies, Santa Clarita, CA USA. Zool Soc San Diego, Ctr Reprod Endangered Species, San Diego, CA USA. USAF, Dept Biol, Colorado Springs, CO USA. RP Van Tuinen, P (reprint author), Med Coll Wisconsin, Dept Pathol, POB 26509, Milwaukee, WI 53226 USA. NR 47 TC 17 Z9 18 U1 0 U2 3 PU WILEY-LISS PI NEW YORK PA DIV JOHN WILEY & SONS INC, 605 THIRD AVE, NEW YORK, NY 10158-0012 USA SN 0002-9483 J9 AM J PHYS ANTHROPOL JI Am. J. Phys. Anthropol. PD OCT PY 1999 VL 110 IS 2 BP 129 EP 142 DI 10.1002/(SICI)1096-8644(199910)110:2<129::AID-AJPA2>3.0.CO;2-M PG 14 WC Anthropology; Evolutionary Biology SC Anthropology; Evolutionary Biology GA 241XQ UT WOS:000082909500002 PM 10502239 ER PT J AU Coalson, JJ Winter, VT Siler-Khodr, T Yoder, BA AF Coalson, JJ Winter, VT Siler-Khodr, T Yoder, BA TI Neonatal chronic lung disease in extremely immature baboons SO AMERICAN JOURNAL OF RESPIRATORY AND CRITICAL CARE MEDICINE LA English DT Article ID HYALINE-MEMBRANE DISEASE; RESPIRATORY-DISTRESS SYNDROME; BIRTH-WEIGHT INFANTS; BRONCHOPULMONARY DYSPLASIA; ALVEOLAR MACROPHAGE; PREMATURE BABOON; INFLAMMATORY MEDIATORS; PATHOGENESIS; GROWTH; BRONCHIOLITIS AB A borderline viability model of bronchopulmonary dysplasia (BPD)/chronic lung disease of infancy (CLD) with pathophysiologic parameters consistent with those in extremely immature humans with BPD/CLD is described. After prenatal steroid treatment of pregnant dams, 12 premature baboons were delivered by cesarean-section at 125 d (term gestation, 185 d), treated with exogenous surfactant, and maintained on appropriate oxygen and positive pressure ventilation for at least 1 to 2 mo. In spite of appropriate oxygenation (median F-1O2 at 28 d = 0.32; range, 0.21 to 0.50) and ventilatory strategies to prevent volutrauma, the baboons exhibited pulmonary pathologic lesions known to occur in extremely immature humans of less than 1,000 g: alveolar hypoplasia, variable saccular wall fibrosis, and minimal, if any, airway disease. The CLD baboon lungs showed significantly decreased alveolization and internal surface area measurements when compared with term and term + 2-mo air-breathing controls. A decrease in capillary vasculature was evident by PECAM staining, accompanied by dysmorphic changes. Significant elevations of TNF-alpha, IL-6, IL-8 levels, but not of IL-1b and IL-10, in tracheal aspirate fluids were present at various times during the period of ventilatory support, supporting a role for mediator-induced autoinflammation. IL-8 levels were elevated in necropsy lavages of animals with significant lung infection. This model demonstrates that impaired alveolization and capillary development occur in immature lungs, even in the absence of marked hyperoxia and high ventilation settings. C1 Univ Texas, Hlth Sci Ctr, Dept Pathol, San Antonio, TX 78284 USA. Univ Texas, Hlth Sci Ctr, Dept Obstet & Gynecol, San Antonio, TX 78284 USA. SW Fdn Biomed Res, San Antonio, TX 78284 USA. Wilford Hall USAF Med Ctr, Dept Pediat, San Antonio, TX 78236 USA. RP Coalson, JJ (reprint author), Univ Texas, Hlth Sci Ctr, Dept Pathol, 7703 Floyd Curl Dr, San Antonio, TX 78284 USA. FU NHLBI NIH HHS [HL52636, HL52646] NR 58 TC 323 Z9 330 U1 0 U2 3 PU AMER LUNG ASSOC PI NEW YORK PA 1740 BROADWAY, NEW YORK, NY 10019 USA SN 1073-449X J9 AM J RESP CRIT CARE JI Am. J. Respir. Crit. Care Med. PD OCT PY 1999 VL 160 IS 4 BP 1333 EP 1346 PG 14 WC Critical Care Medicine; Respiratory System SC General & Internal Medicine; Respiratory System GA 244VG UT WOS:000083071000036 PM 10508826 ER PT J AU Kirkpatrick, SM Baur, JW Clark, CM Denny, LR Tomlin, DW Reinhardt, BR Kannan, R Stone, MO AF Kirkpatrick, SM Baur, JW Clark, CM Denny, LR Tomlin, DW Reinhardt, BR Kannan, R Stone, MO TI Holographic recording using two-photon-induced photopolymerization SO APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING LA English DT Article ID 2-PHOTON ABSORPTION; 3-DIMENSIONAL MICROFABRICATION; POLYMERIZATION AB Molecular excitation via the simultaneous absorption of two photons can lead to improved three-dimensional control of photochemical or photophysical processes due to the quadratic dependence of the absorption probability on the incident radiation intensity. This has lead to the development of improved three-dimensional fluorescence imaging, optical data storage, and microfabrication. The latter of these involves the fabrication of three-dimensional structures using a spatial variation in the incident intensity within a photopolymerizable resin. In the past, the translation of the focal plane of a tightly focused laser beam was used to induce localized photopolymerization and fabrication of three-dimensional structures. Here we report the first successful demonstration of large-area patterning via ultrafast holography-based two-photon polymerization of a commercially available optical resin and a large two-photon cross-section dye (AF380). This opens tremendous possibilities for the wide-spread use of two-photon absorption for the three-dimensional control of photoinduced processes. C1 USAF, Res Lab, Mat & Mfg Directorate, Wright Patterson AFB, OH 45433 USA. RP Kirkpatrick, SM (reprint author), USAF, Res Lab, Mat & Mfg Directorate, Wright Patterson AFB, OH 45433 USA. NR 19 TC 49 Z9 55 U1 1 U2 7 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 0947-8396 J9 APPL PHYS A-MATER JI Appl. Phys. A-Mater. Sci. Process. PD OCT PY 1999 VL 69 IS 4 BP 461 EP 464 DI 10.1007/s003390051033 PG 4 WC Materials Science, Multidisciplinary; Physics, Applied SC Materials Science; Physics GA 241XN UT WOS:000082909300018 ER PT J AU Smith, M Trummel, DE Dolz, M Cina, SJ AF Smith, M Trummel, DE Dolz, M Cina, SJ TI A simplified method for postmortem coronary angiography using gastrograffin SO ARCHIVES OF PATHOLOGY & LABORATORY MEDICINE LA English DT Article ID ANEURYSM AB Objective.-To assess the adequacy of perfusion of the heart at autopsy with a gastrograffin and dye mixture to obtain rapid postmortem angiograms while simultaneously documenting the vascular distribution of the myocardium. Background.-Postmortem coronary angiography is occasionally used in the evaluation of suspected cardiac deaths. Angiography provides legal documentation and can serve to guide subsequent cardiac dissection. Multiple techniques have been suggested in the literature for coronary angiography using infusion of radio-opaque silicone or gelatin. These techniques are cumbersome and require equipment generally not available in autopsy suites. Methods.-Following removal of the heart, a mixture of gastrograffin and colored dyes is injected into each coronary artery via a syringe. The coronary arteries are ligated and radiographs are obtained. After fixation, the heart is dissected In the usual manner. Results.-Adequate postmortem coronary angiograms are routinely obtained with this method. The coronary arterial distribution within the myocardium is easily documented at both the gross and microscopic levels because of the presence of differential coloration. Conclusions.-The aforementioned technique using a gastrograffin and dye mixture provides a simplified approach to postmortem angiography. The novelty of the procedure stems from the low cost, ease of implementation, dual ability to assess vascular anatomy radiologically (gastrograffin), and gross distribution and histologic findings of dependent tissue using the light microscope (colored dye). This technique is inexpensive, rapid, and easily used, making it more suitable for general hospital practice and medical examiners' offices than previously described methods. C1 Wilford Hall USAF Med Ctr, Brooke Army Med Ctr, Combined Pathol Residency Program, San Antonio, TX 78236 USA. Wilford Hall USAF Med Ctr, Reg Armed Forces Med Examiners Off, Lackland AFB, TX 78236 USA. RP Cina, SJ (reprint author), Wilford Hall USAF Med Ctr, Dept Pathol, Lackland AFB, TX 78236 USA. NR 26 TC 5 Z9 8 U1 0 U2 0 PU COLLEGE AMER PATHOLOGISTS PI NORTHFIELD PA C/O KIMBERLY GACKI, 325 WAUKEGAN RD, NORTHFIELD, IL 60093-2750 USA SN 0003-9985 J9 ARCH PATHOL LAB MED JI Arch. Pathol. Lab. Med. PD OCT PY 1999 VL 123 IS 10 BP 885 EP 888 PG 4 WC Medical Laboratory Technology; Medicine, Research & Experimental; Pathology SC Medical Laboratory Technology; Research & Experimental Medicine; Pathology GA 246EW UT WOS:000083152300005 PM 10506439 ER PT J AU Cina, SJ Radentz, SS Smialek, JE AF Cina, SJ Radentz, SS Smialek, JE TI A case of familial angiolipomatosis with Lisch nodules SO ARCHIVES OF PATHOLOGY & LABORATORY MEDICINE LA English DT Article ID BANNAYAN-ZONANA-SYNDROME; IRIS AB Familial angiolipomatosis is a rare syndrome that may be confused clinically with neurofibromatosis type 1. This condition is most often inherited in an autosomal recessive manner; however, several reports have been published suggesting an autosomal dominant mode of inheritance. Angiolipomatosis, although somewhat disfiguring, is a benign condition with no known association with malignant neoplasms. This is in contradistinction to neurofibromatosis, an autosomal dominant syndrome associated with a myriad of benign and malignant neoplasms. It is, therefore, important to discriminate this entity from neurofibromatosis when a patient presents with multiple subcutaneous tumors and a family history of similar lesions. Described is a case of a prison inmate with a history of seizures and "neurofibromatosis" without clinical documentation. Lisch nodules were noted on the irides. Postmortem examination showed multiple subcutaneous yellow tumors on the chest and arms. Fine-needle aspiration of 1 mass yielded adipose tissue with prominent vessels; histologic sections of another mass showed angiolipoma. The remainder of the autopsy showed significant coronary artery disease and a remote cerebral infarction of the temporal lobe but no signs of neurofibromatosis. We feel that the presence of multiple angiolipomas in combination with Lisch nodules lends credence to the proposed relationship between fatty tumors and neurofibromatosis suggested by other authors. C1 Wilford Hall USAF Med Ctr, Dept Pathol, Off Armed Forces Med Examiner, Lackland AFB, TX 78236 USA. Off Chief Med Examiner State Maryland, Baltimore, MD USA. RP Cina, SJ (reprint author), Wilford Hall USAF Med Ctr, Dept Pathol, Off Armed Forces Med Examiner, Lackland AFB, TX 78236 USA. NR 20 TC 14 Z9 14 U1 0 U2 0 PU COLLEGE AMER PATHOLOGISTS PI NORTHFIELD PA C/O KIMBERLY GACKI, 325 WAUKEGAN RD, NORTHFIELD, IL 60093-2750 USA SN 0003-9985 J9 ARCH PATHOL LAB MED JI Arch. Pathol. Lab. Med. PD OCT PY 1999 VL 123 IS 10 BP 946 EP 948 PG 3 WC Medical Laboratory Technology; Medicine, Research & Experimental; Pathology SC Medical Laboratory Technology; Research & Experimental Medicine; Pathology GA 246EW UT WOS:000083152300017 PM 10506451 ER PT J AU Lavallee, PJ Fonseca, VP AF Lavallee, PJ Fonseca, VP TI Survey of USAF flight surgeons regarding clinical preventive services, using CHD as an indicator SO AVIATION SPACE AND ENVIRONMENTAL MEDICINE LA English DT Review DE exercise; diet; cholesterol; HDL; CHD; medical education ID CORONARY-ARTERY DISEASE; MIDDLE-AGED MEN; HEART-DISEASE; CHOLESTEROL LEVELS; LIFE-STYLE; LIPOPROTEIN METABOLISM; PHYSICAL EXERCISE; SERUM-LIPIDS; RISK-FACTORS; LOW-FAT AB Background: A recent Department of Defense study revealed that nonpharmacologic therapy is not well documented in medical records of individuals identified at risk for coronary heart disease (CHD). Exercise and weight control are often underemphasized relative to dietary and medication interventions, even in medical journal review articles on management of dyslipidemia. Methods: A literature review of interventions consisting of exercise alone or with diet is presented. A brief survey was developed to assess the knowledge and beliefs of USAF flight surgeons regarding training received for, and delivery of, clinical preventive services. In addition, the respondents were given a scenario patient with high cholesterol to manage. Results and Discussion: The literature review demonstrates the beneficial effect of exercise alone or with dietary interventions on reducing total cholesterol and increasing high-density lipoprotein (HDL). The survey reveals that USAF flight surgeons believe that more preventive medicine training is needed in the USAF flight surgeon course, graduate medical education, and medical school. Given a scenario patient with hypercholesterolemia, the flight surgeons believe that nonpharmacologic therapy with consults to the base Health and Wellness Center (HAWC), along with follow-up by the physician, is appropriate initial medical treatment rather than pharmacologic therapy. Conclusions: The primary treatment for prevention of CHD should be an organized exercise and diet program. This treatment is proven effective through clinical trials and is supported by the flight surgeon survey results. Additional benefits of an organized exercise and diet program include decreased obesity with its associated complications, decreased incidence of hypertension, decreased cancer risk, and decreased risk for diabetes mellitus. C1 USAF, Sch Aerosp Med, MC, Brooks AFB, TX 78235 USA. Off Prevent & Hlth Serv Assessment, Brooks AFB, TX USA. RP Lavallee, PJ (reprint author), USAF, Sch Aerosp Med, MC, 2602 W Gate Rd, Brooks AFB, TX 78235 USA. NR 60 TC 3 Z9 3 U1 0 U2 0 PU AEROSPACE MEDICAL ASSOC PI ALEXANDRIA PA 320 S HENRY ST, ALEXANDRIA, VA 22314-3579 USA SN 0095-6562 J9 AVIAT SPACE ENVIR MD JI Aviat. Space Environ. Med. PD OCT PY 1999 VL 70 IS 10 BP 1029 EP 1037 PG 9 WC Public, Environmental & Occupational Health; Medicine, General & Internal; Sport Sciences SC Public, Environmental & Occupational Health; General & Internal Medicine; Sport Sciences GA 241ZP UT WOS:000082914000013 PM 10519484 ER PT J AU Dille, JR AF Dille, JR TI Record and around the world flights through Singapore by women SO AVIATION SPACE AND ENVIRONMENTAL MEDICINE LA English DT Article DE female aviators; historic flights; fatigue AB Women's efforts to fly as military pilots during World War I were unsuccessful. However, their numbers and achievements increased and, in 1929, they formed the Ninety-Nines and held the first Women's Air Derby, where male pilots escorted them and mechanics were available. In May 1930, England's Amy Johnson became the first woman to fly solo from England to Australia. She was flying for the Air Transport Auxiliary in England when she was killed in an aircraft accident in 1941. New Zealander lean Batten set new records over the same course in May 1934, from England to New Zealand in Oct. 1936 and from Australia to England in Oct. 1937. Routes were typically via Singapore as were round-the-world efforts by Amelia Earhart (1937), loan Merriam Smith (1964), Sheila Scott (1966), and Ann Pellegreno (1967). Accounts frequently mention severe weather including monsoon storms. Adequacy of flight planning has been questioned for some. Jerrie Mock, the first woman to fly around the world alone, in 1964, was asked by Saigon Radio ii she had a man aboard. Further successes and independence for women in aviation have been slow, bur steady. C1 USAF, FAA, Norman, OK 73069 USA. RP Dille, JR (reprint author), USAF, FAA, 335 Merkle Dr, Norman, OK 73069 USA. NR 8 TC 0 Z9 0 U1 0 U2 1 PU AEROSPACE MEDICAL ASSOC PI ALEXANDRIA PA 320 S HENRY ST, ALEXANDRIA, VA 22314-3579 USA SN 0095-6562 J9 AVIAT SPACE ENVIR MD JI Aviat. Space Environ. Med. PD OCT PY 1999 VL 70 IS 10 BP 1038 EP 1040 PG 3 WC Public, Environmental & Occupational Health; Medicine, General & Internal; Sport Sciences SC Public, Environmental & Occupational Health; General & Internal Medicine; Sport Sciences GA 241ZP UT WOS:000082914000014 PM 10519485 ER PT J AU Sullivan, TP AF Sullivan, TP TI Thermal desorption: The basics SO CHEMICAL ENGINEERING PROGRESS LA English DT Article C1 USAF, Peterson AFB, Headquaters Space Command, Colorado Springs, CO USA. RP Sullivan, TP (reprint author), USAF, Peterson AFB, Headquaters Space Command, Colorado Springs, CO USA. NR 37 TC 2 Z9 2 U1 0 U2 1 PU AMER INST CHEMICAL ENGINEERS PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 0360-7275 J9 CHEM ENG PROG JI Chem. Eng. Prog. PD OCT PY 1999 VL 95 IS 10 BP 49 EP 56 PG 8 WC Engineering, Chemical SC Engineering GA 250CB UT WOS:000083370500022 ER PT J AU Baur, JW Alexander, MD Banach, M Denny, LR Reinhardt, BA Vaia, RA Fleitz, PA Kirkpatrick, SM AF Baur, JW Alexander, MD Banach, M Denny, LR Reinhardt, BA Vaia, RA Fleitz, PA Kirkpatrick, SM TI Molecular environment effects on two-photon-absorbing heterocyclic chromophores SO CHEMISTRY OF MATERIALS LA English DT Article ID 2-PHOTON ABSORPTION; DESIGN AB Over the past several years, organic molecules exhibiting significant two-photon absorbance and subsequent up-converted fluorescence have been of intense interest for a wide variety of applications including data storage, imaging, and optical limiting. However, the establishment of structure-property relationships for some asymmetric molecules has been hindered by the sensitivity of these nonlinear optical properties to the local molecular environment and to the pulse width of the incident radiation. To understand the influence of the local molecular environment on the excited states of these two-photon-absorbing molecules, the linear absorbance, the single-photon-excited photoluminescence, and the two-photon-excited photoluminescence of a series of heterocyclic dyes are examined. The stabilization of the longest-lived one-photon-excited state by the local molecular environment can be described by mean field interactions with solvent molecules as given by the Lippert equation. Because the same stabilization dominates the two-photon-induced longest-lived excited state, the influence of the local molecular environment on the two-photon luminescence can be predicted using the Lippert equation and one-photon experiments. These results support models that suggest excited-state absorption is the primary cause of sensitivity of the "effective" two-photon cross-section to the pulse-width and the local molecular environment. C1 USAF, Res Lab, Polymer Branch AFRL MLBP, Wright Patterson AFB, OH 45433 USA. USAF, Res Lab, Laser Hardening Branch AFRL MLPJ, Wright Patterson AFB, OH 45433 USA. Sci Applicat Int Corp, Dayton, OH 45431 USA. RP Baur, JW (reprint author), USAF, Res Lab, Polymer Branch AFRL MLBP, Wright Patterson AFB, OH 45433 USA. NR 24 TC 79 Z9 82 U1 3 U2 7 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0897-4756 J9 CHEM MATER JI Chem. Mat. PD OCT PY 1999 VL 11 IS 10 BP 2899 EP 2906 DI 10.1021/cm990258s PG 8 WC Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA 248DY UT WOS:000083261100038 ER PT J AU Ahoujja, M Mitchel, WC Elhamri, S Newrock, RS Lo, I AF Ahoujja, M Mitchel, WC Elhamri, S Newrock, RS Lo, I TI Effects of conduction band offset on two-dimensional electron gas in delta-doped InGaAs-based heterostructures SO CHINESE JOURNAL OF PHYSICS LA English DT Article ID SUBBAND POPULATION; QUANTUM-WELLS; MOBILITY; SCATTERING AB Electron transport properties of delta-doped AlInAs/InGaAs and AlAsSb/InGaAs heterostructures lattice-matched to InP substrates are investigated using the Shubnikovde Haas oscillations and the Hall effect. The Fast Fourier transform of the magnetoresistance shows that both the ground and first excited subbands in the InGaAs channel are occupied. The mobility in the second subband is higher than that in the first subband in both heterostructures. This is attributed to the fact that electrons in the first subband are, on average, closer to the interface and are therefore scattered more strongly by ionized impurities, The dependence of the mobility on carrier concentration suggests that intersubband scattering rate is more dominant in structures with higher conduction band offsets. Alloy scattering, on the other hand, is found to be more dominant in the higher band offset system. C1 USAF, Mat Directorate, Wright Patterson AFB, OH 45433 USA. Univ Dayton, Dept Phys, Dayton, OH 45469 USA. Univ Cincinnati, Dept Phys, Cincinnati, OH 45221 USA. Natl Sun Yat Sen Univ, Dept Phys, Kaohsiung, Taiwan. RP Ahoujja, M (reprint author), USAF, Mat Directorate, Wright Patterson AFB, OH 45433 USA. NR 17 TC 2 Z9 2 U1 1 U2 1 PU PHYSICAL SOC REPUBLIC CHINA PI TAIPEI PA CHINESE JOURNAL PHYSICS PO BOX 23-30, TAIPEI 10764, TAIWAN SN 0577-9073 J9 CHINESE J PHYS JI Chin. J. Phys. PD OCT PY 1999 VL 37 IS 5 BP 519 EP 527 PG 9 WC Physics, Multidisciplinary SC Physics GA 245DU UT WOS:000083091600009 ER PT J AU Watson, KA Lyons, KM Donbar, JM Carter, CD AF Watson, KA Lyons, KM Donbar, JM Carter, CD TI Observations on the leading edge in lifted flame stabilization SO COMBUSTION AND FLAME LA English DT Article ID LASER-INDUCED FLUORESCENCE; JET DIFFUSION FLAMES; TURBULENT AB The objective of this paper is to report some of the first experimental evidence for the "leading edge" flame as the stabilization mechanism in lifted jet diffusion flames [1-5]. CH fluorescence has been used to indicate the flame front location (i.e., region of chemical reaction) and thereby characterize features of the stabilization region [5, 6]. The "leading edge" flame phenomenon reported within refers to the outward-extending branch of CH fluorescence at the base of the streamwise CH zones. Whether the "leading edge" flame is a special case of the more general triple flame is a question which remains unanswered. It is evident from previous computational studies [7, 8] that the triple flame, when interacting with a vortex or pair of vortices, can take on characteristics of the "leading edge" flames introduced in the present study. Veynante ct al. [8] illustrate the contortion of the premixed branches of the triple flame by the flowfield where the premixed branches are swept into the trailing diffusion flame. These simulated triple flame/vortex interactions are consistent with the results of this study which show a trailing diffusion flame and the leading edge reaction zone structure. (C) 1999 by The Combustion Institute. C1 N Carolina State Univ, Dept Mech & Aerosp Engn, Raleigh, NC 27695 USA. USAF, Res Lab, Wright Patterson AFB, OH 45433 USA. Innovat Sci Solut Inc, Dayton, OH 45440 USA. RP Lyons, KM (reprint author), N Carolina State Univ, Dept Mech & Aerosp Engn, Raleigh, NC 27695 USA. NR 14 TC 46 Z9 46 U1 0 U2 0 PU ELSEVIER SCIENCE INC PI NEW YORK PA 655 AVENUE OF THE AMERICAS, NEW YORK, NY 10010 USA SN 0010-2180 J9 COMBUST FLAME JI Combust. Flame PD OCT PY 1999 VL 119 IS 1-2 BP 199 EP 202 DI 10.1016/S0010-2180(99)00056-5 PG 4 WC Thermodynamics; Energy & Fuels; Engineering, Multidisciplinary; Engineering, Chemical; Engineering, Mechanical SC Thermodynamics; Energy & Fuels; Engineering GA 228HB UT WOS:000082130100018 ER PT J AU Chen, JK Beraun, JE Jih, CJ AF Chen, JK Beraun, JE Jih, CJ TI Completeness of corrective smoothed particle method for linear elastodynamics SO COMPUTATIONAL MECHANICS LA English DT Article ID HYDRODYNAMICS; SPH; SIMULATIONS; DYNAMICS; IMPACT; FLOWS AB Two different solution algorithms of the corrective smoothed particle method (CSPM) are developed and examined with linear elastodynamic problems. One is to use the corrective first derivative approximations to solve the stress-based momentum equations, with stresses evaluated from the strains. This is an approach that has widely been adopted in smoothed particle hydrodynamics (SPH) methods. The other is new, in which the corrective second derivative approximations are used to directly solve the displacement-based Navier equations. The former satisfies the nodal completeness condition but lacks integrability; on the contrary, the latter is truly complete. Numerical tests show that the latter outperforms the former as well as other existing SPH methods, as expected. C1 USAF, Res Lab, Directed Energy Directorate, Kirtland AFB, NM 87117 USA. Ford Res Lab, Vehicle Elect Syst Dept, Dearborn, MI 48121 USA. RP Chen, JK (reprint author), USAF, Res Lab, Directed Energy Directorate, Kirtland AFB, NM 87117 USA. NR 32 TC 33 Z9 41 U1 1 U2 4 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 0178-7675 J9 COMPUT MECH JI Comput. Mech. PD OCT PY 1999 VL 24 IS 4 BP 273 EP 285 DI 10.1007/s004660050516 PG 13 WC Mathematics, Interdisciplinary Applications; Mechanics SC Mathematics; Mechanics GA 253DW UT WOS:000083542200007 ER PT J AU Kerans, RJ Hay, RS Parthasarathy, TA AF Kerans, RJ Hay, RS Parthasarathy, TA TI Structural ceramic composites SO CURRENT OPINION IN SOLID STATE & MATERIALS SCIENCE LA English DT Review ID MICROMECHANICAL FAILURE MODES; HIGH-TEMPERATURE OXIDATION; BRITTLE-MATRIX COMPOSITES; SIC-BASED FIBERS; SILICON-CARBIDE; MECHANICAL-PROPERTIES; CALCIUM HEXALUMINATE; OXIDE COMPOSITES; TENSILE-STRENGTH; BORON-NITRIDE AB Major recent advances: Near-stoichiometric, small-diameter SiC fibers with excellent properties are now available. A new polycrystalline oxide fiber offers significantly improved temperature limits. Oxide fiber coatings to substitute for C and BN for deflecting cracks and promoting distributed damage appear feasible. Two show substantial low-temperature plasticity in constrained loading. Properties of SiC-BN-SiC and coatingless oxide composites have been improved markedly, but combustion atmospheres have proven more problematic than thought for the former. (C) 2000 Elsevier Science Ltd. All rights reserved. C1 USAF, Res Lab, MLLN, Mat Directorate, Wright Patterson AFB, OH 45433 USA. RP Kerans, RJ (reprint author), USAF, Res Lab, MLLN, Mat Directorate, Wright Patterson AFB, OH 45433 USA. EM ronald.kerans@afrl.af.mil RI Parthasarathy, Triplicane/B-7146-2011 OI Parthasarathy, Triplicane/0000-0002-5449-9754 NR 61 TC 13 Z9 15 U1 3 U2 10 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1359-0286 J9 CURR OPIN SOLID ST M JI Curr. Opin. Solid State Mat. Sci. PD OCT PY 1999 VL 4 IS 5 BP 445 EP 451 DI 10.1016/S1359-0286(99)00046-7 PG 7 WC Materials Science, Multidisciplinary; Physics, Applied; Physics, Condensed Matter SC Materials Science; Physics GA 350KF UT WOS:000089099300006 ER PT J AU Fullerton, R Linster, BG McKee, M Slate, S AF Fullerton, R Linster, BG McKee, M Slate, S TI An experimental investigation of research tournaments SO ECONOMIC INQUIRY LA English DT Article AB Research tournaments are predicted to encourage R&D. Recent theoretical developments in research tournaments are grounded in search theory. Although the economic intuition behind tournaments is straightforward, computing equilibrium strategies is complex. The participants compute a stopping rule based on the number of participants, the prize and the cost of research. It is an empirical question whether agents will behave as predicted or will employ simple "rule of thumb" strategies such as faking a predetermined number of draws. This paper reports the results of a series of laboratory experiments designed to test the predictions of the search model of tournaments. (JEL C9, D8). C1 USAF Acad, Colorado Springs, CO 80840 USA. Univ New Mexico, Albuquerque, NM 87131 USA. RP Fullerton, R (reprint author), USAF Acad, Colorado Springs, CO 80840 USA. NR 11 TC 15 Z9 15 U1 2 U2 5 PU WESTERN ECONOMIC ASSOC INT PI HUNTINGTON BEACH PA 7400 CENTER AVE SUITE 109, HUNTINGTON BEACH, CA 92647-3039 USA SN 0095-2583 J9 ECON INQ JI Econ. Inq. PD OCT PY 1999 VL 37 IS 4 BP 624 EP 636 PG 13 WC Economics SC Business & Economics GA 248CA UT WOS:000083256700004 ER PT J AU Stauffer, TB Antworth, CP Burr, EM MacIntyre, WG AF Stauffer, TB Antworth, CP Burr, EM MacIntyre, WG TI Quadricyclane hydration kinetics in natural waters SO ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY LA English DT Article DE quadricyclane; hydration kinetics; buffer catalysis; chlorination ID HYDROLYSIS; SOIL AB Hydration rates of quadricyclane were measured over a pH range of 3 to 8 in phosphate buffer, carbonate buffer, and nitric acid solutions. Norbornadiene was a minor impurity in the quadricyclane, and its hydration rate was also measured. Hydration products were exo-5-norbornen-2-ol (bicyclo[2.2.1]hept-5-ene-2-ol) and nortricyclyl alcohol (tricyclo[2.2.1.0(3,5)]heptane-2-ol). Diol formation was not detected. Quadricyclane hydration in solutions containing chloride ions formed the alcohols and their chlorinated analogs. A mechanism consistent with observed kinetics and reaction products involving two carbocation intermediates is proposed. Comparison of reaction rates was used to determine the role of buffer catalysis and chlorination reactions in natural waters. Phosphate buffer catalysis was shown to be important, and rate constants for all phosphate species were calculated. Comparison of hydration rates in nitric acid and carbonate buffer indicated that catalysis by carbonate species for this reaction is unimportant in surface waters. Catalytic effects of other buffers in some natural waters appear possible. Proper buffer selection is important if laboratory-measured hydration rates of quadricyclane are to be applied to natural water systems. C1 Virginia Inst Marine Sci, Coll William & Mary, Gloucester Point, VA 23062 USA. USAF, Res Lab, Tyndall AFB, FL 32403 USA. Appl Res Associates, Tyndall AFB, FL 32403 USA. RP MacIntyre, WG (reprint author), Virginia Inst Marine Sci, Coll William & Mary, Gloucester Point, VA 23062 USA. NR 14 TC 1 Z9 1 U1 1 U2 3 PU SETAC PRESS PI PENSACOLA PA 1010 NORTH 12TH AVE, PENSACOLA, FL 32501-3370 USA SN 0730-7268 J9 ENVIRON TOXICOL CHEM JI Environ. Toxicol. Chem. PD OCT PY 1999 VL 18 IS 10 BP 2237 EP 2242 PG 6 WC Environmental Sciences; Toxicology SC Environmental Sciences & Ecology; Toxicology GA 240FD UT WOS:000082814500017 ER PT J AU Method, MW AF Method, MW TI Clinical course of ovarian cancer patients after stimulation of HAMA following radioimmunoscintigraphy (RIS) using MoAb B72.2 prior to reassessment laparotomy SO EUROPEAN JOURNAL OF CANCER LA English DT Meeting Abstract C1 USAF, Keesler Med Ctr, Keesler AFB, MS 39534 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0959-8049 J9 EUR J CANCER JI Eur. J. Cancer PD OCT PY 1999 VL 35 SU 5 MA 98 BP S55 EP S55 PG 1 WC Oncology SC Oncology GA 251GE UT WOS:000083435600100 ER PT J AU McMahon, BJ Christensen, CJ Gretch, DR Williams, JL Sullivan, DG Bruden, D Carithers, RL Hennessy, TW Homan, CE Deubner, H AF McMahon, BJ Christensen, CJ Gretch, DR Williams, JL Sullivan, DG Bruden, D Carithers, RL Hennessy, TW Homan, CE Deubner, H TI Alanine aminotransferase (ALT) levels over time in anti-HCV-positive persons who are HCV RNA positive compared with persons who are HCV RNA negative but riba positive. SO HEPATOLOGY LA English DT Meeting Abstract C1 Alaska Native Med Ctr, Anchorage, AK USA. Univ Washington, Seattle, WA 98195 USA. CDC, Artic Invest Program, Anchorage, AK USA. Elmendorf AFB, Anchorage, AK USA. NR 0 TC 3 Z9 4 U1 0 U2 1 PU W B SAUNDERS CO PI PHILADELPHIA PA INDEPENDENCE SQUARE WEST CURTIS CENTER, STE 300, PHILADELPHIA, PA 19106-3399 USA SN 0270-9139 J9 HEPATOLOGY JI Hepatology PD OCT PY 1999 VL 30 IS 4 SU S MA 789 BP 358A EP 358A PN 2 PG 1 WC Gastroenterology & Hepatology SC Gastroenterology & Hepatology GA 239XE UT WOS:000082794700788 ER PT J AU Greenwood, AD Jin, JM AF Greenwood, AD Jin, JM TI A field picture of wave propagation in inhomogeneous dielectric lenses SO IEEE ANTENNAS AND PROPAGATION MAGAZINE LA English DT Article DE dielectric lens; wave propagation; scattering; radiation; finite-element method AB This article presents the radiation and scattering patterns, and the interior field distributions, of three inhomogeneous dielectric lenses: the Luneburg, Maxwell fish-eye, and Eaton-Lippmann lenses. The purpose is to provide a picture of wave propagation through these lenses. A better understanding of the field picture, especially the nature of the focal points, is helpful to the practical design of the lenses. C1 USAF, Res Lab, Directed Energy Directorate, Kirtland AFB, NM 87117 USA. Univ Illinois, Dept Elect & Comp Engn, Ctr Computat Electromagnet, Urbana, IL 61801 USA. RP USAF, Res Lab, Directed Energy Directorate, Kirtland AFB, NM 87117 USA. EM greenwoa@plk.af.mil; j-jinl@uiuc.edu NR 30 TC 30 Z9 30 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA SN 1045-9243 EI 1558-4143 J9 IEEE ANTENN PROPAG M JI IEEE Antennas Propag. Mag. PD OCT PY 1999 VL 41 IS 5 BP 9 EP 18 DI 10.1109/74.801510 PG 10 WC Engineering, Electrical & Electronic; Telecommunications SC Engineering; Telecommunications GA 250BJ UT WOS:000083368900003 ER PT J AU Beliveau, A Spencer, GT Thomas, KA Roberson, SL AF Beliveau, A Spencer, GT Thomas, KA Roberson, SL TI Evaluation of MEMS capacitive accelerometers SO IEEE DESIGN & TEST OF COMPUTERS LA English DT Article AB Three different capacitive accelerometers were evaluated above and below their maximum g-sensing levels to determine their linearity, response times, lag times, pulse duration, survivability levels, and failure modes. C1 USAF, Res Lab, Munit Directorate, Eglin AFB, FL 32542 USA. Appl Res Associates Inc, Tyndall AFB, FL USA. RP Roberson, SL (reprint author), AFRL MNMF, 306 W Eglin Blvd, Eglin AFB, FL 32542 USA. NR 8 TC 42 Z9 44 U1 0 U2 15 PU IEEE COMPUTER SOC PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, PO BOX 3014, LOS ALAMITOS, CA 90720-1314 USA SN 0740-7475 J9 IEEE DES TEST COMPUT JI IEEE Des. Test Comput. PD OCT-DEC PY 1999 VL 16 IS 4 BP 48 EP 56 DI 10.1109/54.808209 PG 9 WC Computer Science, Hardware & Architecture; Engineering, Electrical & Electronic SC Computer Science; Engineering GA 259EG UT WOS:000083881100017 ER PT J AU Berger, SD Welsh, BM AF Berger, SD Welsh, BM TI Performance of a dual channel matched filter system SO IEEE TRANSACTIONS ON AEROSPACE AND ELECTRONIC SYSTEMS LA English DT Article AB We analyze the signal-to-interference plus noise ratio (SINR) performance of a dual channel matched tilter system under the assumption that the input interference plus noise signal for one channel is uncorrelated with the input signal for the other channel. We develop an exact expression for the normalized SINR as a function of random variables with known distributions and then, using a Taylor series expansion, we derive approximate expressions for the mean and variance of the normalized SINR. One can easily show that under the assumption of uncorrelated inputs and known correlation matrices that the dual channel matched filter system is equivalent to a single channel matched filter designed to process both input signals. We also show that when estimated correlation matrices are used in place of the true correlation matrices the dual channel matched filter system achieves nearly the same normalized SINR performance as the single channel matched filter system with half the secondary data. The results suggest that, with the proper preprocessing to decorrelate the input signal, a single channel matched filter system can be replaced by a dual channel matched filter system of smaller size, leading to a reduction in the secondary data requirements and potentially, to a reduction in the computational cost. C1 USAF, Res Lab, Space Vehicles Directorate, Kirtland AFB, NM 87117 USA. Mission Res Corp, Dayton, OH 45430 USA. RP Berger, SD (reprint author), USAF, Res Lab, Space Vehicles Directorate, 3550 Aberdeen Ave SE, Kirtland AFB, NM 87117 USA. NR 11 TC 2 Z9 2 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9251 J9 IEEE T AERO ELEC SYS JI IEEE Trans. Aerosp. Electron. Syst. PD OCT PY 1999 VL 35 IS 4 BP 1429 EP 1438 DI 10.1109/7.805459 PG 10 WC Engineering, Aerospace; Engineering, Electrical & Electronic; Telecommunications SC Engineering; Telecommunications GA 256EZ UT WOS:000083714100029 ER PT J AU Holter, H Steyskal, H AF Holter, H Steyskal, H TI Infinite phased-array analysis using FDTD periodic boundary conditions - Pulse scanning in oblique directions SO IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION LA English DT Article DE FDTD; numerical analysis; periodic structures; phased array ID TIME-DOMAIN ANALYSIS AB Unit cell analysis of infinite phased arrays in the finite difference time domain (FDTD) is performed by implementation of periodic boundary conditions. The technique allows for pulse excitation and oblique scan directions in both the cardinal and intercardinal planes. To our knowledge, this is the first paper presenting FDTD computations for intercardinal pulse scanning in oblique directions. The ordinary Yee lattice is used, which makes the algorithm easy to incorporate in an already existing FDTD code. Nonperiodic boundaries are truncated by Berenger's perfectly matched layer (PML). Active impedance of an infinite dipole array is calculated with the new method and validation is performed via the "element-by-element" approach, i.e., by a conventional FDTD simulation of a corresponding large finite array. Excellent agreement is found and the technique has been numerically stable in all cases analyzed. C1 Royal Inst Technol, Dept Electromagnet Theory, S-10044 Stockholm, Sweden. USAF, Res Lab, Hanscom AFB, MA 01731 USA. RP Holter, H (reprint author), Royal Inst Technol, Dept Electromagnet Theory, S-10044 Stockholm, Sweden. NR 16 TC 40 Z9 40 U1 0 U2 2 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-926X J9 IEEE T ANTENN PROPAG JI IEEE Trans. Antennas Propag. PD OCT PY 1999 VL 47 IS 10 BP 1508 EP 1514 DI 10.1109/8.805893 PG 7 WC Engineering, Electrical & Electronic; Telecommunications SC Engineering; Telecommunications GA 258VN UT WOS:000083860100003 ER PT J AU Sheldon, SN Osmon, C AF Sheldon, SN Osmon, C TI Piloted simulation of an F-16 flight control system designed using quantitative feedback theory SO INTERNATIONAL JOURNAL OF ROBUST AND NONLINEAR CONTROL LA English DT Article DE QFT; piloted simulation; handling qualities; robust control AB This paper is a summary of an effort to evaluate a high-performance flight control system in a piloted simulation. A flight control system was designed for the VISTA F-16 using the techniques of quantitative feedback theory. Quantitative feedback theory is a robust frequency domain design technique that provided for the incorporation of handling qualities in the design specifications.:The design was accomplished as a Master's thesis, and addresses the subsonic flight envelope including changes in configuration. Handling qualities were evaluated in a high-fidelity, manned simulation of the system. The resulting system would require a few refinements to meet level 1 handling quality specifications, Published in 1999 by John Wiley & Sons, Ltd. This article is a US Government work and is in the public domain in the United States. C1 Veridian Inc, Dayton, OH 45431 USA. USAF, Res Lab, AFRL, VACC, Wright Patterson AFB, OH 45433 USA. RP Sheldon, SN (reprint author), Veridian Inc, 5200 Springfield Pike,Suite 200, Dayton, OH 45431 USA. NR 8 TC 0 Z9 0 U1 0 U2 1 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX PO19 1UD, ENGLAND SN 1049-8923 J9 INT J ROBUST NONLIN JI Int. J. Robust Nonlinear Control PD OCT PY 1999 VL 9 IS 12 BP 841 EP 855 PG 15 WC Automation & Control Systems; Engineering, Electrical & Electronic; Mathematics, Applied SC Automation & Control Systems; Engineering; Mathematics GA 246PJ UT WOS:000083172400003 ER PT J AU Bryant, LR AF Bryant, LR TI Onset of erosive osteoarthritis in a teenage girl SO JCR-JOURNAL OF CLINICAL RHEUMATOLOGY LA English DT Article DE erosive osteoarthritis; inflammatory osteoarthritis ID ARTHRITIS; JOINTS; WOMEN; RISK AB Erosive osteoarthritis is a disorder that predominantly affects the hands of postmenopausal or middle aged women. Ages usually range from 30 to 83 years. Although the etiology of erosive osteoarthritis is not known, a lack of estrogen hormones has been implicated in the pathogenesis. We report a patient with onset of symptoms at age 16 and a diagnosis at age 21. She has aggressive inflammatory involvement of the distal interphalangeal joints and characteristic radiographic changes with central erosions. She is not postmenopausal nor does she have any conditions that are believed to be possible associations with erosive osteoarthritis. To the best of our knowledge, this is the youngest reported patient with erosive osteoarthritis in the literature. C1 Wilford Hall USAF Med Ctr, Dept Rheumatol, MMIR, Lackland AFB, TX 78236 USA. RP Bryant, LR (reprint author), Wilford Hall USAF Med Ctr, Dept Rheumatol, MMIR, 2200 Bergquist Dr,Ste 1, Lackland AFB, TX 78236 USA. NR 18 TC 0 Z9 0 U1 0 U2 0 PU LIPPINCOTT WILLIAMS & WILKINS PI PHILADELPHIA PA 530 WALNUT ST, PHILADELPHIA, PA 19106-3621 USA SN 1076-1608 J9 JCR-J CLIN RHEUMATOL JI JCR-J. Clin. Rheumatol. PD OCT PY 1999 VL 5 IS 5 BP 285 EP 288 DI 10.1097/00124743-199910000-00009 PG 4 WC Rheumatology SC Rheumatology GA 243UE UT WOS:000083015000009 PM 19078410 ER PT J AU Chun, IS Reneker, DH Fong, H Fang, XY Deitzel, J Tan, NB Kearns, K AF Chun, IS Reneker, DH Fong, H Fang, XY Deitzel, J Tan, NB Kearns, K TI Carbon nanofibers from polyacrylonitrile and mesophase pitch (vol 31, pg 36, 1999) SO JOURNAL OF ADVANCED MATERIALS LA English DT Correction C1 Univ Akron, Inst Polymer Sci, Akron, OH 44325 USA. USA, Res Lab, Weap & Mat Res Directorate, Aberdeen Proving Ground, MD USA. USAF, Wright Lab, AFMC, Wright Patterson AFB, OH 45433 USA. RP Chun, IS (reprint author), Univ Akron, Inst Polymer Sci, Akron, OH 44325 USA. NR 1 TC 1 Z9 1 U1 1 U2 9 PU SAMPE PUBLISHERS PI COVINA PA 1161 PARKVIEW DRIVE, COVINA, CA 91722 USA SN 1070-9789 J9 J ADV MATER JI J. Adv. Mater. PD OCT PY 1999 VL 31 IS 4 BP 7 EP 7 PG 1 WC Materials Science, Multidisciplinary SC Materials Science GA 244DR UT WOS:000083037000003 ER PT J AU Maji, AK Sanchez, L Acree, R AF Maji, AK Sanchez, L Acree, R TI Processing variables and their effect on pultruded composites SO JOURNAL OF ADVANCED MATERIALS LA English DT Article ID PULTRUSION AB Precision pultruded composites are widely used for lightweight durable structural components in space structures, civil infrastructure applications, recreational gear (such as archery arrows and fishing rods), and other applications. Important qualities of these structural components include part straightness, high stiffness, low void content, and low coefficient of thermal expansion. Understanding the controllable variables in pultrusion processing is critical in establishing the influence on the physical and mechanical properties of the end product. The primary focus of this research was to determine the effects of four independent pultrusion process variables (die temperature, fiber volume fraction, pull speed, and misalignment of pullers) on the processibility (governed by pull force) and the properties of the end product (curvature and flexural modulus). C1 Univ New Mexico, Dept Civil Engn, Albuquerque, NM 87131 USA. USAF, Res Lab, VSDV, Albuquerque, NM USA. RP Maji, AK (reprint author), Univ New Mexico, Dept Civil Engn, Albuquerque, NM 87131 USA. NR 13 TC 4 Z9 4 U1 1 U2 5 PU SAMPE PUBLISHERS PI COVINA PA 1161 PARKVIEW DRIVE, COVINA, CA 91722 USA SN 1070-9789 J9 J ADV MATER JI J. Adv. Mater. PD OCT PY 1999 VL 31 IS 4 BP 14 EP 26 PG 13 WC Materials Science, Multidisciplinary SC Materials Science GA 244DR UT WOS:000083037000005 ER PT J AU Baden, KL Valtier, S Cody, JT AF Baden, KL Valtier, S Cody, JT TI Metabolic production of amphetamine following multidose administration of clobenzorex SO JOURNAL OF ANALYTICAL TOXICOLOGY LA English DT Article ID DRUG C1 Wilford Hall USAF Med Ctr, Clin Res Squadron, Med Wing 59, MSR, Lackland AFB, TX 78236 USA. Dept Internal Med, Med Wing 59, Lackland AFB, TX 78236 USA. RP Cody, JT (reprint author), Wilford Hall USAF Med Ctr, Clin Res Squadron, Med Wing 59, MSR, 1255 Wilford Hall Loop, Lackland AFB, TX 78236 USA. NR 6 TC 6 Z9 6 U1 1 U2 2 PU PRESTON PUBLICATIONS INC PI NILES PA 7800 MERRIMAC AVE PO BOX 48312, NILES, IL 60648 USA SN 0146-4760 J9 J ANAL TOXICOL JI J. Anal. Toxicol. PD OCT PY 1999 VL 23 IS 6 BP 511 EP 517 PG 7 WC Chemistry, Analytical; Toxicology SC Chemistry; Toxicology GA 242TL UT WOS:000082957700019 PM 10517559 ER PT J AU Hensley, D Cody, JT AF Hensley, D Cody, JT TI Simultaneous determination of amphetamine, methamphetamine, methylenedioxyamphetamine (MDA), methylenedioxymethamphetamine (MDMA), and methylenedioxyethylamphetamine (MDEA) enantiomers by GC-MS SO JOURNAL OF ANALYTICAL TOXICOLOGY LA English DT Article ID METABOLITE 3,4-METHYLENEDIOXYAMPHETAMINE MDA; 3,4-METHYLENEDIOXYMETHAMPHETAMINE MDMA; 3,4-METHYLENEDIOXY-N-ETHYLAMPHETAMINE MDE; STEREOSELECTIVE DISPOSITION; GAS-CHROMATOGRAPHY; RAT-BRAIN; URINE; ELECTROPHORESIS; QUANTITATION; CYCLODEXTRIN C1 Wilford Hall USAF Med Ctr, Clin Res Squadron, Lackland AFB, TX 78236 USA. RP Cody, JT (reprint author), Wilford Hall USAF Med Ctr, Clin Res Squadron, 1255 Wilford Hall Loop, Lackland AFB, TX 78236 USA. NR 13 TC 48 Z9 49 U1 1 U2 3 PU PRESTON PUBLICATIONS INC PI NILES PA 7800 MERRIMAC AVE PO BOX 48312, NILES, IL 60648 USA SN 0146-4760 J9 J ANAL TOXICOL JI J. Anal. Toxicol. PD OCT PY 1999 VL 23 IS 6 BP 518 EP 523 PG 6 WC Chemistry, Analytical; Toxicology SC Chemistry; Toxicology GA 242TL UT WOS:000082957700020 PM 10517560 ER PT J AU Joshi, RP Kayasit, P Islam, N Schamiloglu, E Fleddermann, CB Schoenberg, J AF Joshi, RP Kayasit, P Islam, N Schamiloglu, E Fleddermann, CB Schoenberg, J TI Simulation studies of persistent photoconductivity and filamentary conduction in opposed contact semi-insulating GaAs high power switches SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID GALLIUM-ARSENIDE SWITCHES; IMPACT IONIZATION; HIGH-VOLTAGE; SEMICONDUCTOR SWITCHES; IMPURITY BREAKDOWN; LOCK-ON; MODEL; DIODES AB A self-consistent, two-dimensional, time-dependent, drift-diffusion model is developed to simulate the response of high power photoconductive switches. Effects of spatial inhomogeneities associated with the contact barrier potential are incorporated and shown to foster filamentation. Results of the dark current match the available experiment data. Persistent photoconductivity is shown to arise at a high bias even under the conditions of spatial uniformity. Filamentary currents require an inherent spatial inhomogeneity, and are more likely to occur for low optical excitation. Under strong uniform illumination, the spatial nonuniformities were quenched as a result of a polarization-induced collapse in the internal fields. However, strong electric fields resulting at the contacts create a bipolar plasma, and hence, a virtual "double injection." (C) 1999 American Institute of Physics. [S0021-8979(99)05119-1]. C1 Old Dominion Univ, Dept Elect & Comp Engn, Norfolk, VA 23529 USA. Univ New Mexico, Dept Elect & Comp Engn, Albuquerque, NM 87131 USA. USAF, Res Lab, Kirtland AFB, NM 87117 USA. RP Joshi, RP (reprint author), Old Dominion Univ, Dept Elect & Comp Engn, Norfolk, VA 23529 USA. NR 37 TC 13 Z9 14 U1 4 U2 6 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD OCT 1 PY 1999 VL 86 IS 7 BP 3833 EP 3843 DI 10.1063/1.371295 PG 11 WC Physics, Applied SC Physics GA 237JL UT WOS:000082652400055 ER PT J AU Della-Rose, DJ Sojka, JJ Zhu, L AF Della-Rose, DJ Sojka, JJ Zhu, L TI Resolving geomagnetic disturbances using "K-like" geomagnetic indices with variable time intervals SO JOURNAL OF ATMOSPHERIC AND SOLAR-TERRESTRIAL PHYSICS LA English DT Article ID MODELS AB One of the efforts of the space weather community is to find better near real-time indices of geomagnetic activity. Many models developed for, and used by, space weather forecasters rely on the Kp/ap indices. However, the 3-h time interval between index computations is now considered a shortfall with regard to specifying and forecasting phenomena known to have faster time constants, e.g., auroral electrojet variations during a substorm. Therefore these indices have been targeted for high-time resolution development. Our study addresses this question by attempting to develop a "K-like" station index with a variable time interval. By comparing the distributions of these different time interval indices with the traditional 3-h K index an immediate difficulty is uncovered. Namely, the new distribution has a markedly different average index value. Hence no straightforward use of these indices in lieu of the traditional K index is possible. However, we demonstrate that, through a simple re-normalization process, the frequency distribution of our variable-time indices can be made to approximate the 3-h K index distribution. Further, when the temporal variability of the 3-h K index is compared against both a "sliding" 3-h index and a 15-min index, it is found that the 15-min index is significantly better at reproducing the station geomagnetic variability. The question not addressed here, but one that needs to be raised, concerns the possible difference in physical processes reflected by the 3-h index vs the shorter time interval indices. If there is no difference, then after a suitable range-to-index conversion these higher time resolution indices could potentially be used in place of the traditional 3-h station K index. (C) 1999 Elsevier Science Ltd. All rights reserved. C1 Utah State Univ, Ctr Atmospher & Space Sci, Logan, UT 84322 USA. USAF, Washington, DC 20330 USA. RP Sojka, JJ (reprint author), Utah State Univ, Ctr Atmospher & Space Sci, Logan, UT 84322 USA. NR 16 TC 6 Z9 7 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1364-6826 J9 J ATMOS SOL-TERR PHY JI J. Atmos. Sol.-Terr. Phys. PD OCT PY 1999 VL 61 IS 15 BP 1179 EP 1194 DI 10.1016/S1364-6826(99)00078-4 PG 16 WC Geochemistry & Geophysics; Meteorology & Atmospheric Sciences SC Geochemistry & Geophysics; Meteorology & Atmospheric Sciences GA 283UE UT WOS:000085293700008 ER PT J AU DiCarlo, CD Roach, WP Gagliano, DA Boppart, SA Hammer, DX Cox, AB Fujimoto, JG AF DiCarlo, CD Roach, WP Gagliano, DA Boppart, SA Hammer, DX Cox, AB Fujimoto, JG TI Comparison of optical coherence tomography imaging of cataracts with histopathology SO JOURNAL OF BIOMEDICAL OPTICS LA English DT Article DE cataracts; histopathology; lens; monkey; optical coherence tomography AB This paper presents a comparison of in vitro optical coherence tomography (OCT) captured cataract images to subsequent histopathological examination of the lenticular opacities. OCT Imaging was performed on anesthetized Rhesus monkeys, known as the delayed effects colony (DEC), with documented cataracts. These monkeys were exposed to several types of radiation during the mid and late 1960s. The radiation and age related cataracts in these animals were closely monitored using a unique grading system developed specifically for the DEC. In addition to this system, a modified version of a common cataract grading scheme for use in humans was applied. Of the original 18 monkeys imaged, lenses were collected at necropsy from seven of these animals, processed, and compared to OCT images, Results showed a direct correlation between the vertical OCT images and the cataractous lesions seen on corresponding histopathologic sections of the lenses. Based on the images obtained and their corresponding documented comparison to histopathology, OCT showed tremendous potential to aid identification and characterization of cataracts. There can be artifactual problems with the images related to movement and shadows produced by opacities. However, with the advent of increased speed in imaging and multiplanar imaging,;these disadvantages may easily be overcome. (C) 1999 Society of Photo-Optical Instrumentation Engineers. [S1083-3668(99)00404-9]. C1 Uniformed Serv Univ Hlth Sci, Dept Anat & Cell Biol, Bethesda, MD 20814 USA. Uniformed Serv Univ Hlth Sci, Dept Prevent Med & Biometr, Bethesda, MD 20814 USA. USA, War Coll, Carlisle, PA USA. MIT, Dept Elect Engn & Comp Sci, Elect Res Lab, Cambridge, MA 02139 USA. Univ Texas, Dept Biomed Engn, Austin, TX 78712 USA. Armstrong Lab, Radiofrequency Radiat Div, Brooks AFB, TX 78235 USA. RP DiCarlo, CD (reprint author), Uniformed Serv Univ Hlth Sci, Dept Anat & Cell Biol, Bethesda, MD 20814 USA. RI Boppart, Stephen/C-7338-2009 NR 13 TC 9 Z9 9 U1 0 U2 1 PU SPIE-INT SOCIETY OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, BELLINGHAM, WA 98225 USA SN 1083-3668 J9 J BIOMED OPT JI J. Biomed. Opt. PD OCT PY 1999 VL 4 IS 4 BP 450 EP 458 DI 10.1117/1.429951 PG 9 WC Biochemical Research Methods; Optics; Radiology, Nuclear Medicine & Medical Imaging SC Biochemistry & Molecular Biology; Optics; Radiology, Nuclear Medicine & Medical Imaging GA 260NQ UT WOS:000083957100010 PM 23014618 ER PT J AU Franklin, RE Perram, GP AF Franklin, RE Perram, GP TI Collisional dynamics of Bi-2 A(0(u)(+)). I. Quantum-resolved vibrational energy transfer for v '=0-4 SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID X BAND SYSTEM; B3-PI(O+) STATE; LASER; BI2 AB Vibrational-to-translational energy transfer between the lowest vibrational levels (v(')=0-4) of the A(0(u)(+)) state of Bi-2 has been investigated using spectrally resolved, laser-induced fluorescence techniques. The small vibrational spacing (omega(e)(')similar or equal to 132 cm(-1)) leads to highly nonadiabatic conditions, particularly for the Bi-2(A)-He collision pair. However, the Delta v=-1 transition probabilities for collisions with the rare gases range from 0.75% to 1.75% per collision, considerably lower than would be anticipated from standard vibrational energy transfer theory. Multiquantum (Delta v(')=+/- 2) transfer rates are low, consistent with the low anharmonicity of the A(0(u)(+)) state. The rates for Delta v(')=+/- 1 transitions scale linearly with vibrational quantum number as expected near the bottom of this nearly harmonic potential. (C) 1999 American Institute of Physics. [S0021-9606(99)01237-4]. C1 USAF, Inst Technol, Dept Engn Phys, Wright Patterson AFB, OH 45433 USA. RP Franklin, RE (reprint author), AFRL DE, Kirtland AFB, NM 87117 USA. OI Perram, Glen/0000-0002-4417-3929 NR 22 TC 4 Z9 4 U1 0 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD OCT 1 PY 1999 VL 111 IS 13 BP 5757 EP 5763 DI 10.1063/1.479872 PG 7 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 238UW UT WOS:000082732100013 ER PT J AU Cunningham, JA Goltz, MN Roberts, PV AF Cunningham, Jeffrey A. Goltz, Mark N. Roberts, Paul V. TI SIMPLIFIED EXPRESSIONS FOR SPATIAL MOMENTS OF GROUND-WATER CONTAMINANT PLUMES SO JOURNAL OF HYDROLOGIC ENGINEERING LA English DT Article AB Ground-water aquifers are an important source of water for domestic, agricultural, and industrial use, but they are often contaminated by hazardous chemicals. In this note, the writers consider the transport of a sorbing contaminant in an infinite, macroscopically homogeneous aquifer. Nonequilibrium sorption is controlled by diffusion into the grains of the porous medium. For this problem, previous work by Goltz and Roberts has presented analytical solutions for the spatial moments of the contaminant plume. The solutions of Goltz and Roberts are given in terms of infinite integrals that can be difficult to evaluate. In this note, the writers demonstrate that the zeroth spatial moment can be represented as an infinite sum rather than as an infinite integral; in most cases, the sum is more easily evaluated than the integral. Also, we show a method for simplifying the expression for the first spatial moment. The modified expression still requires the evaluation of an infinite integral, but the new integral is much better behaved than the previous expression, greatly simplifying the numerical evaluation of the first moment. C1 [Cunningham, Jeffrey A.; Roberts, Paul V.] Stanford Univ, Dept Civil & Environm Engn, Stanford, CA 94305 USA. [Goltz, Mark N.] USAF, Dept Engrg & Envir Mgmt, Inst Technol, Wright Patterson AFB, OH 45433 USA. RP Cunningham, JA (reprint author), Stanford Univ, Dept Civil & Environm Engn, Stanford, CA 94305 USA. EM cunning@leland.stanford.edu OI Goltz, Mark/0000-0003-3601-6453 FU National Science Foundation (NSF); U.S. Environmental Protection Agency (EPA) [U-914736-01, R-824768-01-0] FX This material is based upon work supported by the National Science Foundation (NSF) through a graduate fellowship and by the U.S. Environmental Protection Agency (EPA) through fellowship U-914736-01 and grant R-824768-01-0. Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the writers and do not necessarily reflect the views of NSF or EPA. NR 13 TC 8 Z9 8 U1 0 U2 1 PU ASCE-AMER SOC CIVIL ENGINEERS PI RESTON PA 1801 ALEXANDER BELL DR, RESTON, VA 20191-4400 USA SN 1084-0699 J9 J HYDROL ENG JI J. Hydrol. Eng. PD OCT PY 1999 VL 4 IS 4 BP 377 EP 380 DI 10.1061/(ASCE)1084-0699(1999)4:4(377) PG 4 WC Engineering, Civil; Environmental Sciences; Water Resources SC Engineering; Environmental Sciences & Ecology; Water Resources GA V15AS UT WOS:000207775500011 ER PT J AU Ahuja, SS Reddick, RL Sato, N Montalbo, E Kostecki, V Zhao, WG Dolan, MJ Melby, PC Ahuja, SK AF Ahuja, SS Reddick, RL Sato, N Montalbo, E Kostecki, V Zhao, WG Dolan, MJ Melby, PC Ahuja, SK TI Dendritic cell (DC)-based anti-infective strategies: DCs engineered to secrete IL-12 are a potent vaccine in a murine model of an intracellular infection SO JOURNAL OF IMMUNOLOGY LA English DT Article ID INTERFERON-GAMMA-RECEPTOR; IN-VIVO; IMMUNE-RESPONSE; IFN-GAMMA; MYCOBACTERIAL INFECTION; VISCERAL LEISHMANIASIS; NAKED DNA; T-CELLS; INTERLEUKIN-12; DISEASES AB Infections with intracellular pathogens such as Leishmania donovani and Mycobacterium tuberculosis pose serious health problems worldwide. Effective vaccines for these pathogens are not available. Furthermore, despite optimal therapy, disease progression is often seen with several intracellular infections. For these reasons, we initiated studies to develop novel anti-infective vaccine and treatment strategies that couple the potent Ag-presenting capacity of dendritic cells (DC) with paracrine delivery of potent anti-infective cytokines such as IL-12 to local immune response sites. We tested this strategy in a murine model of visceral leishmaniasis, Adoptive transfer of DCs pulsed ex vivo with soluble L. donovani Ags (SLDA) to naive mice induced the Ag-specific production of IFN-gamma, and increased the percentage of activation markers on spleen lymphocytes. SLDA-pulsed DCs engineered by retroviral gene transfer techniques to secrete high levels of biologically active murine IL-12 augmented this immune response further. In several different vaccination and immunotherapy protocols, compared with sham-treated mice, animals receiving SLDA-pulsed DCs either before or following infection had 1-3 log lower parasite burdens, and this protection was associated with a pronounced enhancement in the parasite-specific IFN-gamma response, The augmentation of this protection by IL-12-engineered DCs was striking. First, live parasites were not detected in the liver of mice vaccinated with IL-12-transduced, SLDA-pulsed DCs, Second, this parasitological response was associated with a nearly normal liver histology, In contrast, parasites and granulomas were found in mice vaccinated with SLDA-pulsed, nontransduced DCs. Collectively, these studies provide the rationale for the development of potent DC-based immunotherapies. C1 Univ Texas, Hlth Sci Ctr, Dept Med, San Antonio, TX 78284 USA. Univ Texas, Hlth Sci Ctr, Dept Pathol, San Antonio, TX 78284 USA. Univ Texas, Hlth Sci Ctr, Dept Microbiol, San Antonio, TX 78284 USA. S Texas Vet Hlth Care Syst, Audie L Murphy Div, San Antonio, TX 78284 USA. Wilford Hall USAF Med Ctr, Dept Med, Infect Dis Serv, Lackland AFB, TX 78236 USA. RP Ahuja, SS (reprint author), Univ Texas, Hlth Sci Ctr, Dept Med, 7703 Floyd Curl Dr, San Antonio, TX 78284 USA. FU NIAID NIH HHS [AI43279] NR 55 TC 100 Z9 107 U1 0 U2 2 PU AMER ASSOC IMMUNOLOGISTS PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814 USA SN 0022-1767 J9 J IMMUNOL JI J. Immunol. PD OCT 1 PY 1999 VL 163 IS 7 BP 3890 EP 3897 PG 8 WC Immunology SC Immunology GA 238ZP UT WOS:000082744900043 PM 10490989 ER PT J AU Sciulli, D Inman, DJ AF Sciulli, D Inman, DJ TI Isolation design for fully flexible systems SO JOURNAL OF INTELLIGENT MATERIAL SYSTEMS AND STRUCTURES LA English DT Article AB It is commonly suggested that vibration isolators should be designed with a low-frequency mount, that is, the isolator frequency is much less than the first mode of the system being isolated. This is a direct result of the single-degree-of-freedom (SDOF) isolator model which states that the best performing isolator is the one that has the lowest natural frequency. When flexibility is included in the isolator design, the low-frequency mount design still performs best in an overall sense. However, with system flexibility being modeled, the isolator can now be designed between the modes of the flexible system. These types of isolator mounts tend to have a coupling effect, that is, the frequencies around the isolator mount have such a strong interaction between each other that when isolator damping is present, multiple system modes are attenuated. Therefore, this paper fully explores the choice of isolator mount frequency and isolator placement for fully flexible systems. Results show that a low-frequency mount design considering base and equipment flexibility, will have the first natural frequency shift by as much as 15.6%. For a mid-frequency mount design, the shift of the first three modes can be as high as 34.9%, 26.6% and 11.3%, respectively. Also, when base and system flexibility is considered, isolator placement becomes a critical issue. There can be as much as 16% difference in the first mode for a low-frequency mount design and as high as 25% difference for a mid-frequency mount design. C1 Virginia Polytech Inst & State Univ, Blacksburg, VA 24061 USA. USAF, Res Lab, VSDV, Kirtland AFB, NM 87117 USA. RP Inman, DJ (reprint author), Virginia Polytech Inst & State Univ, Blacksburg, VA 24061 USA. NR 20 TC 1 Z9 3 U1 0 U2 2 PU TECHNOMIC PUBL CO INC PI LANCASTER PA 851 NEW HOLLAND AVE, BOX 3535, LANCASTER, PA 17604 USA SN 1045-389X J9 J INTEL MAT SYST STR JI J. Intell. Mater. Syst. Struct. PD OCT PY 1999 VL 10 IS 10 BP 813 EP 824 DI 10.1106/BQLE-95F6-E0AR-A2YX PG 12 WC Materials Science, Multidisciplinary SC Materials Science GA 365KY UT WOS:000089951500009 ER PT J AU Neiberg, MS AF Neiberg, MS TI Battle cries and lullabies: Women in war from prehistory to the present SO JOURNAL OF MILITARY HISTORY LA English DT Book Review C1 USAF Acad, Colorado Springs, CO 80840 USA. RP Neiberg, MS (reprint author), USAF Acad, Colorado Springs, CO 80840 USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU SOC MILITARY HISTORY PI LEXINGTON PA C/O VIRGINIA MILITARY INST, GEORGE C MARSHALL LIBRARY, LEXINGTON, VA 24450-1600 USA SN 0899-3718 J9 J MILITARY HIST JI J. Mil. Hist. PD OCT PY 1999 VL 63 IS 4 BP 952 EP 953 DI 10.2307/120558 PG 2 WC History SC History GA 240HA UT WOS:000082818800007 ER PT J AU Grotelueschen, ME AF Grotelueschen, ME TI America and the Great War, 1914-1920 SO JOURNAL OF MILITARY HISTORY LA English DT Book Review C1 USAF Acad, Colorado Springs, CO 80840 USA. RP Grotelueschen, ME (reprint author), USAF Acad, Colorado Springs, CO 80840 USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU SOC MILITARY HISTORY PI LEXINGTON PA C/O VIRGINIA MILITARY INST, GEORGE C MARSHALL LIBRARY, LEXINGTON, VA 24450-1600 USA SN 0899-3718 J9 J MILITARY HIST JI J. Mil. Hist. PD OCT PY 1999 VL 63 IS 4 BP 993 EP 993 DI 10.2307/120589 PG 1 WC History SC History GA 240HA UT WOS:000082818800038 ER PT J AU Petersen, EJ Irish, SM Lyons, CL Miklaski, SF Bryan, JM Henderson, NE Masullo, LN AF Petersen, EJ Irish, SM Lyons, CL Miklaski, SF Bryan, JM Henderson, NE Masullo, LN TI Reliability of water volumetry and the figure of eight method on subjects with ankle joint swelling SO JOURNAL OF ORTHOPAEDIC & SPORTS PHYSICAL THERAPY LA English DT Article DE ankle swelling; measurement reliability ID INTERMITTENT PNEUMATIC COMPRESSION; GEL PACK APPLICATION; EDEMA AB Study Design: Single-group repeated measures with 2 raters. Objectives: To determine the interrater and intrarater reliability of water volumetry and the figure of eight method on subjects with ankle joint swelling. Background: Measurements of ankle swelling are commonly performed to determine the nature and stage of injury and to monitor progress made during rehabilitation. Water volumetry and the figure of eight method are 2 techniques used to measure ankle swelling. Methods and Measures: Twenty-nine subjects with ankle swelling were measured by 2 raters with the hypothesis that both measurement techniques would be reliable. Each rater performed 3 measurements of the swollen ankle using both measurement techniques during a single test session. The order of the rater and of the measurement technique was randomized, and the raters were blinded to each other's measurements. Results: We found high interrater reliability for both the water volumetry (ICC [intraclass correlation coefficient] = 0.99) and figure of eight methods (ICC = 0.98). Additionally, intrarater reliability was high for both raters using both methods (ICCs = 0.98-0.99). Conclusions: Both methods are reliable measures of ankle swelling. The authors recommend the figure of eight method because of its ease of use, time efficiency, and cost effectiveness. However, water volumetry may be more appropriate when measuring diffuse lower-extremity swelling. Reliability of these 2 methods was established using subjects with foot or ankle pathology. Therefore, the results are applicable and generalizable to the clinical setting. C1 USA Baylor Univ Grad Program Phys Therapy, AMEDDC&S, Ft Sam Houston, TX 78234 USA. Winn Army Community Hosp, Ft Stewart, GA USA. Eisenhower Army Med Ctr, Ft Gordon, GA USA. 96th Med Grp, Eglin AFB, FL USA. 12th Med Grp, Randolph AFB, TX USA. Madigan Army Med Ctr, Ft Lewis, WA, Australia. RP Bryan, JM (reprint author), USA Baylor Univ Grad Program Phys Therapy, AMEDDC&S, 3115 Scott Rd, Ft Sam Houston, TX 78234 USA. NR 25 TC 31 Z9 34 U1 1 U2 2 PU J O S P T, ALLIANCE GROUP COMMUNICATIONS PI LAWRENCE PA 810 EAST 10TH ST, PO BOX 1897, LAWRENCE, KS 66044-8897 USA SN 0190-6011 J9 J ORTHOP SPORT PHYS JI J. Orthop. Sports Phys. Ther. PD OCT PY 1999 VL 29 IS 10 BP 609 EP 615 PG 7 WC Orthopedics; Rehabilitation; Sport Sciences SC Orthopedics; Rehabilitation; Sport Sciences GA 249VK UT WOS:000083353800008 PM 10560070 ER PT J AU Amer, MS Busbee, J Leclair, SR Maguire, JF Johns, J Voevodin, A AF Amer, MS Busbee, J Leclair, SR Maguire, JF Johns, J Voevodin, A TI Non-destructive, in situ measurements of diamond-like-carbon film hardness using Raman and Rayleigh scattering SO JOURNAL OF RAMAN SPECTROSCOPY LA English DT Article ID AMORPHOUS-CARBON; SPECTRA; SPECTROSCOPY; OVERCOATS; MEDIA AB Diamond-like Carbon (DLC) coatings have recently proven to be suitable for a number of tribological applications. Hardness of the DCL coating is very important for such application, An in-situ, non-destructive technique to measure the film hardness would be crucial for process control and quality control of DLC coatings. In this study, Raman and Rayleigh scattering were-investigated as potential techniques for nondestructive measurements of DLC film hardness, Features in both Raman and Rayleigh spectra were correlated with film hardness as measured by nano-indentation technique. Regarding the Raman spectra of the film, a linear correlation was found between film hardness and area under diamond related peak at 1332 cm(-1). Regarding the Rayleigh scattering, a linear relationship was, also, found between the film hardness and the height of the Rayleigh line. Raman and Rayleigh scattering have shown huge potential to be used as non-destructive, in-situ techniques to measure DLC coating hardness, Copyright (C) 1999 John Wiley & Sons, Ltd. C1 Wright State Univ, Dept Mech & Mat Engn, Dayton, OH 45435 USA. USAF, Res Lab, Wright Patterson AF Base, Dayton, OH 45435 USA. RP Amer, MS (reprint author), Wright State Univ, Dept Mech & Mat Engn, Dayton, OH 45435 USA. RI Amer, Maher/A-1802-2009; Voevodin, Andrey/I-6684-2013 NR 20 TC 12 Z9 12 U1 0 U2 5 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX PO19 1UD, ENGLAND SN 0377-0486 J9 J RAMAN SPECTROSC JI J. Raman Spectrosc. PD OCT PY 1999 VL 30 IS 10 BP 947 EP 950 DI 10.1002/(SICI)1097-4555(199910)30:10<947::AID-JRS463>3.0.CO;2-8 PG 4 WC Spectroscopy SC Spectroscopy GA 251WM UT WOS:000083469400012 ER PT J AU Brungart, DS Durlach, NI Rabinowitz, WM AF Brungart, DS Durlach, NI Rabinowitz, WM TI Auditory localization of nearby sources. II. Localization of a broadband source SO JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA LA English DT Article ID SOUND LOCALIZATION AB Although many researchers have examined auditory localization for relatively distant sound sources, Little is known about the spatial perception of nearby sources. Ln the region within 1 m of a listener's head, defined as the "proximal region," the interaural level difference increases dramatically as the source approaches the head, while the interaural time delay is roughly independent of distance. An experiment has been performed to evaluate proximal-region localization performance. An auditory point source was moved to a random position within 1 m of the subject's head, and the subject responded by pointing to the perceived location of the sound with an electromagnetic position sensor. The overall angular error (17 degrees) was roughly comparable to previously measured results in distal-region experiments; Azimuth error increased slightly as the sound source approached the head, but elevation performance was essentially independent of source distance. Distance localization performance was generally better than has been reported in distal-region experiments and was strongly dependent on azimuth, with the stimulus-response correlation ranging from 0.85 to the side of the head to less than 0.4 in the median plane. The results suggest that the enlarged binaural difference cues found in the head-related transfer function (HRTF) for nearby sources are important to auditory distance perception in the proximal region. (C) 1999 Acoustical Society of America. [S0001-4966(99)04310-6]. C1 MIT, Elect Res Lab, Cambridge, MA 02139 USA. RP Brungart, DS (reprint author), USAF, Res Lab, Human Effectiveness Directorate, Washington, DC 20330 USA. NR 31 TC 69 Z9 70 U1 1 U2 7 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0001-4966 J9 J ACOUST SOC AM JI J. Acoust. Soc. Am. PD OCT PY 1999 VL 106 IS 4 BP 1956 EP 1968 DI 10.1121/1.427943 PN 1 PG 13 WC Acoustics; Audiology & Speech-Language Pathology SC Acoustics; Audiology & Speech-Language Pathology GA 244VK UT WOS:000083071300034 PM 10530020 ER PT J AU Petry, MD Mah, TI AF Petry, MD Mah, TI TI Effect of thermal exposures on the strengths of Nextel (TM) 550 and 720 filaments SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article ID CERAMIC-MATRIX COMPOSITES; MECHANICAL-BEHAVIOR; TENSILE-STRENGTH; FIBERS AB The effects of thermal exposure on the strengths of Nextel(TM) 550 and 720 tows, bare and coated with carbon, were determined by room-temperature tensile testing of single filaments extracted from tows that had been exposed to different thermal environments (i,e,, air or vacuum) at temperatures from 550 degrees to 1400 degrees C, The results help define the allowable composite processing conditions when using these tows. A 28% drop in the strength of Nextel 550 filaments occurred after a thermal exposure at 1100 degrees C for 2 h in air. After an exposure of 1300 degrees C/2 h/air, a strength degradation of similar to 47% resulted. Filaments exposed above 1100 degrees C under vacuum showed more severe strength degradation than filaments exposed in air. The observed strength degradation may stem from a combination of phase transformations of the alumina, the onset of mullite crystallization, and/or exaggerated mullite grain growth. Strength after heat treatment under vacuum at 1050 degrees and 1150 degrees C did not deteriorate as rapidly as after heat treatment under vacuum between 950 degrees and 1050 degrees C or between 1150 degrees and 1250 degrees C, This may be a result of the competition between healing of flaws by the amorphous silica and its evaporation (leading to an increase in its viscosity or loss) and/or densification of the filaments. Nextel 720 filaments exhibited about 9% strength loss after an exposure at 1100 degrees C/2 h/air, The filaments maintained 75% of their strength after a 1300 degrees C/2 h/air heat treatment. The observed strength degradation may stem from thermal grooving, grain growth, and/or annealing of the mullite subgrain boundaries. Thermal exposure of >10 h at 1300 degrees C was required to produce measurable grain growth. Strength loss between 1200 degrees and 1300 degrees C (air heat treatment) was not as great as between 1100 degrees and 1200 degrees C or 1300 degrees and 1300 degrees C. C1 USAF, Res Lab, MLLN, Mat & Mfg Directorate, Wright Patterson AFB, OH 45433 USA. RP Petry, MD (reprint author), USAF, Res Lab, MLLN, Mat & Mfg Directorate, Wright Patterson AFB, OH 45433 USA. NR 31 TC 25 Z9 26 U1 3 U2 9 PU AMER CERAMIC SOC PI WESTERVILLE PA 735 CERAMIC PLACE, PO BOX 6136, WESTERVILLE, OH 43081-6136 USA SN 0002-7820 J9 J AM CERAM SOC JI J. Am. Ceram. Soc. PD OCT PY 1999 VL 82 IS 10 BP 2801 EP 2807 PG 7 WC Materials Science, Ceramics SC Materials Science GA 291XB UT WOS:000085763700035 ER PT J AU Lin, CC Zangvil, A Ruh, R AF Lin, CC Zangvil, A Ruh, R TI Microscopic mechanisms of oxidation in SiC-whisker-reinforced mullite/ZrO2 matrix composites SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article ID SILICON-CARBIDE COMPOSITES; MICROSTRUCTURE; ZIRCONIA; ALUMINA; KINETICS; BEHAVIOR; NITRIDE; CRYSTALS; CERAMICS AB The oxidation of SiC whiskers, contained in alkoxide-derived mullite-based matrices and exposed in air at 1000-1350 degrees C for up to 1000 h, has been studied by analytical TEM, high-resolution SEM, and XRD. Silicon carbide whiskers were effectively protected from oxidation when embedded in a pure mullite matrix, but oxidized considerably when embedded in mullite/ZrO2 matrices. The oxidation mechanisms varied with matrix composition and exposure temperature. At 1350 degrees C the amorphous layer first crystallized as cristobalite, then gradually incorporated alumina. At later times, the mullite portion of the mullite/ZrO2 matrix dissolved extensively into the layer. Also, the zirconia particles reacted with silica to form zircon, At 1200 degrees C less extensive interdiffusion and chemical reaction occurred, and the silica layer devitrified into cristobalite and quartz, At 1000 degrees C no interdiffusion or chemical reaction was seen, and the silica layer tended to devitrify into quartz, The thickness of the oxide layer around a SiC whisker in a particular matrix depended on the morphology and composition of grains abutting it or adjacent to it. C1 Natl Tsing Hua Univ, Dept Mat Sci & Engn, Hsinchu 300, Taiwan. Univ Illinois, Frederick Seitz Mat Res Lab, Urbana, IL 61801 USA. USAF, Wright Lab, Wright Patterson AFB, OH 45433 USA. RP Lin, CC (reprint author), Natl Tsing Hua Univ, Dept Mat Sci & Engn, Hsinchu 300, Taiwan. NR 31 TC 6 Z9 6 U1 0 U2 0 PU AMER CERAMIC SOC PI WESTERVILLE PA 735 CERAMIC PLACE, PO BOX 6136, WESTERVILLE, OH 43081-6136 USA SN 0002-7820 J9 J AM CERAM SOC JI J. Am. Ceram. Soc. PD OCT PY 1999 VL 82 IS 10 BP 2833 EP 2840 PG 8 WC Materials Science, Ceramics SC Materials Science GA 291XB UT WOS:000085763700040 ER PT J AU Milonni, PW Fearn, H Telle, JM Fugate, RQ AF Milonni, PW Fearn, H Telle, JM Fugate, RQ TI Theory of continuous-wave excitation of the sodium beacon SO JOURNAL OF THE OPTICAL SOCIETY OF AMERICA A-OPTICS IMAGE SCIENCE AND VISION LA English DT Article ID LASER GUIDE STAR; ADAPTIVE OPTICS AB We extend our previous analysis of the sodium beacon [J. Opt. Soc. Am. A 15, 217 (1998)] to the case of continuous-wave excitation. Various effects that could be ignored in the case of pulsed excitation, such as the geomagnetic field, the recoil of the sodium atoms upon absorption and emission, and collisions of the sodium atoms with other mesospheric species, are included. Spin-relaxation collisions are among the most important of these effects for the cases considered. Analytical approximations to numerical results are presented, and using a semi-empirical estimate for Na-O-2 spin relaxation, we compute photon returns in good agreement with recently reported measurements at the Steward Observatory. (C) 1999 Optical Society of America [S0740-3232(99)01209-0]. C1 Univ Calif Los Alamos Natl Lab, Atom & Opt Theory Grp T4, Los Alamos, NM 87545 USA. Univ New Mexico, Kirtland AFB, NM 87117 USA. USAF, Res Lab, Starfire Opt Range, Kirtland AFB, NM 87117 USA. Calif State Univ Fullerton, Dept Phys, Fullerton, CA 92634 USA. RP Milonni, PW (reprint author), Univ Calif Los Alamos Natl Lab, Atom & Opt Theory Grp T4, POB 1663, Los Alamos, NM 87545 USA. NR 27 TC 38 Z9 39 U1 4 U2 7 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 0740-3232 J9 J OPT SOC AM A JI J. Opt. Soc. Am. A-Opt. Image Sci. Vis. PD OCT PY 1999 VL 16 IS 10 BP 2555 EP 2566 DI 10.1364/JOSAA.16.002555 PG 12 WC Optics SC Optics GA 240QL UT WOS:000082836600029 ER PT J AU Reagan, MK Bowman, WJ AF Reagan, MK Bowman, WJ TI Transient studies of G-induced capillary flow SO JOURNAL OF THERMOPHYSICS AND HEAT TRANSFER LA English DT Article AB A transient, one-dimensional numerical code is developed to model liquid motion in a square groove. Transient body forces up to 0.51 m/s(2) are investigated. Axial variation in liquid level, shear stress and heat transfer between the groove wall and the liquid, evaporation, and body forces are accounted for in the model. Dryout and rewet of the groove are allowed; the front location is determined using conservation of mass. An experiment is presented that measures the depth of liquid in the groove and the dryout and rewet front locations during a transient. Within the uncertainty of the measurements, the code predicts the correct liquid distribution and front locations. C1 USAF, Inst Technol, Dept Aeronaut & Astronaut, Wright Patterson AFB, OH 45433 USA. Brigham Young Univ, Dept Mech Engn, Provo, UT 84602 USA. RP Reagan, MK (reprint author), USAF, Inst Technol, Dept Aeronaut & Astronaut, Wright Patterson AFB, OH 45433 USA. NR 14 TC 2 Z9 2 U1 1 U2 2 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 USA SN 0887-8722 J9 J THERMOPHYS HEAT TR JI J. Thermophys. Heat Transf. PD OCT-DEC PY 1999 VL 13 IS 4 BP 537 EP 543 DI 10.2514/2.6473 PG 7 WC Thermodynamics; Engineering, Mechanical SC Thermodynamics; Engineering GA 251KH UT WOS:000083444500018 ER PT J AU Murdock, CS Schneider, M Fontenelle, LJ AF Murdock, CS Schneider, M Fontenelle, LJ TI Toxic lead levels treated with 2,3-dimercaptosuccinic acid and surgery SO JOURNAL OF TRAUMA-INJURY INFECTION AND CRITICAL CARE LA English DT Article ID SUCCIMER; WOUNDS C1 Keesler Med Ctr, Dept Surg, Keesler AFB, MS 39534 USA. Vet Affairs Hosp, Biloxi, MS USA. RP Murdock, CS (reprint author), Keesler Med Ctr, Dept Surg, 301 Fisher St,STE 1A132, Keesler AFB, MS 39534 USA. NR 10 TC 2 Z9 2 U1 0 U2 0 PU LIPPINCOTT WILLIAMS & WILKINS PI PHILADELPHIA PA 530 WALNUT ST, PHILADELPHIA, PA 19106-3621 USA SN 1079-6061 J9 J TRAUMA JI J. Trauma-Injury Infect. Crit. Care PD OCT PY 1999 VL 47 IS 4 BP 766 EP 767 DI 10.1097/00005373-199910000-00025 PG 2 WC Critical Care Medicine; Surgery SC General & Internal Medicine; Surgery GA 247FE UT WOS:000083209800029 PM 10528615 ER EF