United States Department of the Army

About: United States Department of the Army is a government organization based out in Arlington, Virginia, United States. It is known for research contribution in the topics: Poison control & Population. The organization has 32668 authors who have published 42453 publications receiving 947075 citations. The organization is also known as: DA & U.S. Department of the Army.

Central crack in plane orthotropic rectangular sheet

Abstract: The plane problem of a central crack in a rectangular sheet of orthotropic material is considered. The solution is found by an extension of the modified mapping-collocation technique, originally formulated for plane isotropic analysis. Application of the technique outlined in this paper for plane orthotropic problems to a wider class of geometries and loading is evident. The numerical results indicate a dependence of the orthotropic stress intensity factors on both geometric and elastic constants over a certain parameter range.

Lassa Virus Infection of Rhesus Monkeys: Pathogenesis and Treatment with Ribavirin

Abstract: Rhesus monkeys were experimentally infected with Lassa virus to establish their suitability as a nonhuman primate model for the human disease and to test the protective efficacy of ribavirin, an antiviral drug. Six of 10 untreated control monkeys died after subcutaneous inoculation of 10(6.1) plaque-forming units of Lassa virus (strain Josiah). Infectivity titrations of tissue homogenates from the six dead monkeys indicated significant replication in all tissues tested except the central nervous system. This distribution of virus was confirmed by direct immunofluorescence examination of cryostat-sectioned tissues. Ribavirin was beneficial in the treatment of two groups of infected monkeys. Four monkeys first treated on the day of viral inoculation experienced only mild clinical disease; four monkeys first treated five days later experienced a more severe illness. None of the eight monkeys treated with ribavirin died. Viremia titers and elevations of levels of serum transaminases in treated monkeys were significantly lower than in controls. Ribavirin may be beneficial in the treatment of humans exposed to this life-threatening virus.

Theoretical Energy Density of Li–Air Batteries

Abstract: A model for predication of the gravimetric and volumetric energy densities of Li-air batteries using aqueous electrolytes is developed. The theoretical gravimetric/volumetric capacities and energy densities are calculated based on the minimum weight of the electrolyte and volume of air electrode needed for completion of the electrochemical reaction with Li metal as an anode electrode. It was determined that both theoretical gravimetric/volumetric capacities and energy densities are dependent on the porosity of the air electrode. For instance, at a porosity of 70%, the maximum theoretical cell capacities are 435 mAh/g and 509 mAh/cm 3 in basic electrolyte, and 378 mAh/g and 452 mAh/cm 3 in acidic electrolyte. The maximum theoretical cell energy densities are 1300 Wh/kg and 1520 Wh/L in basic electrolyte, and 1400 Wh/kg and 1680 Wh/L in acidic electrolyte. The significant deduction of cell capacity from specific capacity of Li metal is due to the bulky weight requirement from the electrolyte and air electrode materials. In contrast, the Li-air battery using a nonaqueous electrolyte does not consume electrolyte during the discharge process and has high cell energy density. For Li-air batteries using both aqueous and nonaqueous electrolytes, the weight increases by 8-13% and the volume decreases by 8-20% after the cell is fully discharged.

A system for change detection and human recognition in voxel space using the Microsoft Kinect sensor

Abstract: Previously, we put forth a new computer vision system for indoor well-being monitoring of elderly populations based on the use of multiple stereo camera pairs. That approach involves combining the strengths of image space with three dimensional volume element (voxel) space techniques. However, that system is fundamentally limited because it is based on color imagery from visible light cameras. In this article, we extend our prior research and consider a new, inexpensive infrared depth camera device, the Microsoft Kinect. Advantages, such as the ability to operate 24–7 in low-to-no light conditions, and shortcomings are detailed. In addition, we discuss necessary algorithmic extensions to our mixed image and voxel space framework for the Kinect sensor. Experiments are performed in a laboratory designed to resemble an elders living quarter. Vision findings are evaluated using our prior high-level linguistic summarization of human activity work. Preliminary results indicate that the Kinect sensor does indeed work in a wider range of operating conditions and it can produce activity descriptions that match that of a human.

A heat shock operon in Coxiella burnetti produces a major antigen homologous to a protein in both mycobacteria and Escherichia coli.

Abstract: A gene library from the DNA of Coxiella burnetii has been constructed in the cosmid vector pHC79. A particular clone, pJB196, reacted strongly with Coxiella-specific antibodies elicited in a number of different species of animals. This clone produced two abundant C. burnetii-specific polypeptides, a 14-kilodalton nonimmunoreactive protein and a 62-kilodalton immunoreactive protein. Sequencing identified two open reading frames, encoding polypeptides of 10.5 and 58.3 kilodaltons. The only transcriptional control element observed on the 5' side of the initiation codon resembled a heat shock promoter. This heat shock promoter was functionally regulated in Escherichia coli, since both proteins were produced by growth conditions at 37 degrees C and neither protein was detected at 23 degrees C. There were four sequences from the literature that were highly homologous (greater than 50%) to the 62-kilodalton protein from C. burnetii. Three were from Mycobacterium species and represent the immunodominant antigen of this genus. The other was from E. coli, detected as a gene that complements or suppresses a temperature-sensitive RNase activity. Since the recombinant protein was immunogenic, it may serve as an efficacious vaccine against C. burnetii and other pathogenic microorganisms that express the conserved antigen.