| The Detection of Protective Antigen (PA) Associated with Spores of Bacillus Anthracis and the Effects of Anti-PA Antibodies on Spore Germination and Macrophage Interactions |
22 APR 2005 |
19 pages |
| Authors:
C. K. Cote; C. A. Rossi; A. S. Kang; P. R. Morrow; J. S. Lee; S. L. Welkos; ARMY MEDICAL RESEARCH INST OF INFECTIOUS DISEASES FORT DETRICK MD
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 | The protective antigen (PA) component of the anthrax toxins is an essential virulence factor of Bacillus anthracis and is the major protective immunogen. The kinetics of PA production during growth of B. anthracis, and the roles of anti-PA antibody in host immunity are not clearly defined. Production of PA by the vegetative organisms peaks during the shift from exponential to stationary phase of growth. Recently, PA was also found to ... |
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| Experimental Transmission of Karshi and Langat (Tick-Borne Encephalitis Virus Complex) Viruses by Ornithodoros Ticks (Acari: Argasidae) |
2004 |
6 pages |
| Authors:
M. J. Turell; C. N. Mores; J. S. Lee; J. J. Paragas; D. Shermuhemedova; ARMY MEDICAL RESEARCH INST OF INFECTIOUS DISEASES FORT DETRICK MD VIROLOGY DIV
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| Selected species of mosquitoes and Ornithodoros ticks were evaluated for their potential to transmit Karshi and Langat (tick-borne encephalitis virus complex) viruses in the laboratory. Although there was no evidence of replication of Karshi virus in any of the mosquito species tested (Aedes albopictus (Skuse), Ochlerotatus taeniorhynchus (Wiedemann), or Culex pipiens (L.), Karshi virus replicated in and was transmitted by all three species of Ornithodoros ticks tested (Ornithodoros parkeri Cooley, ... |
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| Characteristics of Mullite Prepared from Co-Precipitated 3Al2O3-2SiO2 Powders |
92 |
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| Authors:
J. S. Lee; S. C. Yu; NATIONAL CHENG KUNG UNIV TAINAN (TAIWAN)**
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 | Diphasic gels were prepared by a precipitated process from the mixed solutions of colloidal silica and aluminum nitrate. High-purity stoichiometric mullite powders were produced by calcination of the products of these gels, with an exothermic reaction occurring at 1300 C. The chemical and structural evolutions, as a function of thermal treatment, have been characterized by differential thermal analysis, thermogravimetric analysis, X-ray diffraction, infrared spectroscopy, and electron microscopy. The components of ... |
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| Studies of ECCM Improvements for Frequency-Hopping CPFSK Systems |
30 MAY 90 |
130 pages |
| Authors:
J. S. Lee; L. E. Miller; R. H. French; LEE (J S) ASSOCIATES INC ARLINGTON VA
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| The performance of frequency-hopping CPFSK modulations (such as used in several Army radio systems) in the presence of worst-case partial-band noise jamming (WCPBNJ) is derived for both limiter-discriminator and differential detector forms of receiver. The transmitter is assumed to repeat the data L times on different hops, and the receiver combines the L chips for each data symbol in a way to mitigate the effects of the jamming. Hard-decision combining ... |
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| Composition and Temperature Dependence of Tensile Properties of Austenitic Fe-Mn-Al-C Alloys |
15 JUL 89 |
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| Authors:
Y. G. Kim; J. M. Han; J. S. Lee
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| The effects of aluminum addition (0-4 wt.%) to Fe-26Mn-Al alloys and carbon addition (0.1-0.3 wt.%) to Fe-30Mn-1Al-C alloys on tensile properties, especially tensile elongation, were investigated from room temperature to 4 K. The transformation of austenite to deformation twins during the tests was very beneficial in enhancing tensile elongation at cryogenic temperatures. The amount of deformation twins formed during plastic deformation was not the major factor for maximum elongation, but ... |
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| The Diversity ECCM Performance of Frequency-Hopping CPFSK in Partial- Band Noise Jamming |
25 MAY 88 |
210 pages |
| Authors:
L. E. Miller; R. H. French; J. S. Lee; H. M. Kwon; LEE (J S) ASSOCIATES INC ARLINGTON VA
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| A thorough analysis is made of the uncoded probability of error achieved by by a hopped CPFSK (narrowband digital FM) radio link while subject to partial band noise jamming. Included in the analysis are the effects of thermal noise, FM clicks, and intersymbol interference, in addition to the jamming. For both limiter-discriminator and differential detection, it is shown that a repeat diversity combining method of summing detector samples does not ... |
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| Oxidation Behavior of Nickel Beryllide |
88 |
|
| Authors:
J. S. Lee; T. G. Nieh; LOCKHEED MISSILES AND SPACE CO INC PALO ALTO CA RESEARCH AND DEVELOPMENT DIV
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| The oxidation behavior has been investigated in NiBe and pure Be from 800-1200 C. A protective BeO scale formed on NiBe at temperatures below 1100 C resulting in excellent oxidation resistance. At temperatures above 1100 C the oxidation rate increased dramatically. The oxidation resistance of NiBe was superior to that of pure Be due to the better adherence of the oxide scale in the NiBe. |
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| The Effectiveness of Random MFSK (Multiple Frequency-Shift-Keying) Frequency-Hopping ECCM Radios against Worst-Case Partial-Band Noise Jamming |
AUG 86 |
519 pages |
| Authors:
L. E. Miller; R. H. French; L. J. Cowles; J. S. Lee; LEE (J S) ASSOCIATES INC ARLINGTON VA
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| The system analyzed for bit error rate (BER) performance is frequency-hopped (FH) multiple frequency-shift-keying (MFSK) wherein the M symbol frequency assignments are independently and randomly chosen on each hop, and the information transmission is repeated L times (L-hop diversity) for a soft symbol decision. This FH/RMFSK system is intended to counter systematic follow-on jamming. The reported analysis is of the system's BER in worst-case partial-band noise jamming (WCPBNJ). To be ... |
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| A Dynamic Small Angle X-Ray Scattering Study of Stressed Kevlar 49 Epoxy Composites, |
29 APR 1985 |
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| Authors:
J. S. Lee; J. F. Fellers; M. Y. Tang; J. S. Lin
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| Work efforts are described which concern the mechanism of failure of unidirectional Kevlar fiber reinforced epoxy composites as studied by SAXS while in a state of tensile stress. For comparative purposes, the unmodified epoxy and Kevlar fibers are also considered. The main aims were: 1)to elucidate the possible damage accumulation process in the form of microvoids before complete failure of the components of the composites and in the composites using ... |
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| Optimum Jamming Effects on Frequency-Hopping M-ary FSK (Frequency-Shift Keying) Systems under Certain ECCM (Electronic Counter-Countermeasures) Receiver Design Strategies |
OCT 1984 |
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| Authors:
J. S. Lee; L. E. Miller; R. H. French; Y. K. Kim; A. P. Kadrichu; LEE (J S) ASSOCIATES INC ARLINGTON VA
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| The performance of M-ary frequency-shift-keying frequency-hopping systems using multiple hops per symbol waveform is derived and evaluated for the cases of worst-case partial-band noise jamming and worst-case partial-band tone jamming. The analyses include the effects of the jamming under certain ECCM receiver design strategies. The receiver design strategies include the convention square-law linear combiner and the several types of unconventional nonlinear combiners. The ECCM receiver design employing the nonlinear combiners ... |
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| SAXS STUDIES OF KEVLAR FIBER, EPOXY AND THEIR COMPOSITE STRUCTURE |
MAR 83 |
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| Authors:
J. F. Fellers; J. S. Lee; J. L. White; J. S. Lin; R. W. Hendricks
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| the 10 meter small angle x-ray facilities of the oak ridge national laboratory were used to study samples placed in a state of controlled uniaxial tension. thus a cured epoxy resin could be studied from a state of zero stress up to its fracture point. in doing so it was found that x-linked epoxies do not microvoid or show other responses typically found in linear glassy polymers. kevlar fiber under ... |
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| Effect of High Temperature Thermomechanical Treatment on the Mechanical Properties of Vanadium-Modified AISI 4330 Steel |
JUN 81 |
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| Authors:
J. S. Lee; J. S. Chun
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| The favorable influence of thermomechanical treatment at high temperatures on the mechanical properties of vanadium-modified 4330 steel was studied by examining the recovery and recrystallization of hot-deformed austenite and carbide precipitates. As amount of deformation during treatment increased so did the strength and toughness properties. |
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| Detection Performance of an FM Correlator. |
MAR 1979 |
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| Authors:
J. S. Lee; L. E. Miller; LEE (J S) ASSOCIATES INC ARLINGTON VA
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| Detection of a carrier frequency-modulated by a Gaussian random process is studied for a detector consisting of the filtered product of two FM limiter/discriminator outputs. Results show that high detection probabilities can be achieved for appropriate values of receiver parameters. (Author) |
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| ACTIVATED SINTERING OF TUNGSTEN-COPPER CONTACT MATERIALS |
79 |
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| Authors:
I. H. Moon; J. S. Lee
|
| nickel or cobalt additions were made to w-cu compacts to determine whether the substitution of co for ni would improve their sintering characteristics and their properties as contact materials. for alloys with small proportions of cu, co was more effective in promoting sintering than ni, whereas in those alloys with a high cu content neither addition affected the sintering process. despite their different sintering characteristics, no significant differences were detected ... |
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| SMOOTH LIMITING OF TWO SIGNALS IN A NARROWBAND SYSTEM. |
15 JUL 1970 |
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| Authors:
J. S. Lee; J. H. Hughen; NAVAL RESEARCH LAB WASHINGTON D C
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| The performance of a bandpass smooth limiter which is represented by the error function is analyzed when the input is a sum of two signals. Two input cases are considered: sine wave plus sine wave and sine wave plus narrowband Gaussian noise. Corresponding to various input ratios, output ratios of inband signals are obtained and displayed graphically as a function of a parameter q which specifies the degree of the ... |
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Reports by Author
