United States Naval Research Laboratory

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United States Naval Research Laboratory

Washington, DC, United States
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Lifeloc Technologies and United States Naval Research Laboratory | Date: 2017-05-10

The technology disclosed herein may be used to detect drugs with potential for abuse within a human subject. This technology may be particularly useful to discriminate between drugs of abuse (326), corresponding psychoactive compounds (328), and corresponding metabolite by-products (330, 332), which are often closely related and possess similar chemical structures. The disclosed technology uses infrared light reflectance characteristics particular to one or more chemical compounds to be detected for identification of those compounds within the human subject.

Phoenix A.A.,United States Naval Research Laboratory | Tarazaga P.A.,Virginia Polytechnic Institute and State University
Journal of Sound and Vibration | Year: 2017

The work herein proposes the use of the data-driven Loewner-framework for reduced order modeling as applied to dynamic Finite Element Models (FEM) of thermally morphing structures. The Loewner-based modeling approach is computationally efficient and accurately constructs reduced models using analytical output data from a FEM. This paper details the two-step process proposed in the Loewner approach. First, a random vibration FEM simulation is used as the input for the development of a Single Input Single Output (SISO) data-based dynamic Loewner state space model. Second, an SVD-based truncation is used on the Loewner state space model, such that the minimal, dynamically representative, state space model is achieved. For this second part, varying levels of reduction are generated and compared. The work herein can be extended to model generation using experimental measurements by replacing the FEM output data in the first step and following the same procedure. This method will be demonstrated on two thermally morphing structures, a rigidly fixed hexapod in multiple geometric configurations and a low mass anisotropic morphing boom. This paper is working to detail the method and identify the benefits of the reduced model methodology. © 2017.

Agency: GTR | Branch: NERC | Program: | Phase: Research Grant | Award Amount: 150.55K | Year: 2013

Forecasting the weather from days to two weeks in advance has typically focused on the troposphere, the layer of the atmosphere closest to the ground. A typical weather forecast first attempts to estimate what the atmosphere is like now, and then extrapolates forward in time, using a complex model of the atmosphere based on the basic physical laws of motion. Over the last 15 years, evidence has been growing that different parts of the atmosphere and Earth system can also be exploited to improve weather forecasts. One of these regions is the stratosphere, the layer directly above the troposphere. Because, temperatures increase with height in the stratosphere, winds and weather systems are quite different, and a distinct community of scientific researchers who study the stratosphere exists around the world. Through the work of this community, many weather forecasting centres have been encouraged to look to the stratosphere to improve their weather forecasts and have been modifying their weather forecasting models accordingly. What has been missing, however, is a concerted effort to understand how best to make use of the stratosphere to improve weather forecasts and to determine how much weather forecasts might benefit. This proposal will fund a new international scientific network which will bring scientists from around the world together to study the stratosphere and how it might be used to improve weather forecasts. The network is made up of scientists from universities and weather forecasting centres around the world and is supported by two other international scientific research bodies. The network will allow scientists to come together to discuss current research in this area and to plan and carry out a new experiment which will compare the stratosphere and its impact on weather forecasts in their weather forecasting models. At the end of the research project, the network members will work together to produce a report which will provide guidance to all weather forecasting centres on the use of the stratosphere for weather forecasting.

Boercker J.E.,United States Naval Research Laboratory | Foos E.E.,United States Naval Research Laboratory | Placencia D.,United States Naval Research Laboratory | Tischler J.G.,United States Naval Research Laboratory
Journal of the American Chemical Society | Year: 2013

The aspect ratio and yield of PbSe nanorods synthesized by the reaction of Pb-oleate with tris(diethylamino)phosphine selenide are highly sensitive to the presence of water, making it critical to control the amount of water present in the reaction. By carefully drying the reaction precursors and then intentionally adding water back into the reaction, the nanorod aspect ratio can be controlled from 1.1 to 10 and the yield from 1 to 14% by varying the water concentration from 0 to 204 mM. 31P{1H} and 1H NMR show that water reacts with tris(diethylamino)phosphine to create bis(diethylamido) phosphorous acid. It was determined that bis(diethylamido)phosphorous acid is responsible for the observed aspect ratio and yield changes. Finally, it was found that excess oleic acid in the reaction can also react with tris(diethylamino)phosphine to create bis(diethylamido)phosphorous acid, and upon the removal of both excess oleic acid and water, highly uniform, nonbranching nanorods were formed. © 2013 American Chemical Society.

Lin B.,United States Naval Research Laboratory
Methods in molecular biology (Clifton, N.J.) | Year: 2011

Transfected cell microarrays, arrays of cells expressing defined cDNAs, are promising technologies that can enable the functional analysis of many proteins in parallel. This technique has been adapted for the comparative functional analysis of single-chain antibodies (scFvs) and to facilitate the screening and characterization of these antibodies for their use in diagnostic and therapeutic applications. In this method, membrane-targeting expression vectors encoding scFvs are mixed with transfection reagents and are deposited at high density onto a microscope slide. Adherent mammalian cells are subsequently added to the printed array. Upon attachment to the substrate, the cells take up the plasmid DNA and express the particular protein encoded at each location. The result is an array whose features are micrometer-sized clusters of cells expressing defined genes. This approach provides for the high-throughput functional analysis of many different proteins in parallel and can be considerably more informative and cost-effective relative to more traditional protein expression techniques.

Pomfret M.B.,United States Naval Research Laboratory | Steinhurst D.A.,Nova Research Inc. | Owrutsky J.C.,United States Naval Research Laboratory
Energy and Fuels | Year: 2011

Near-infrared (NIR) thermal imaging is used to study anodes of anode-supported solid oxide fuel cells (SOFCs) when operating with alcohol fuels. Relative propensities for carbon formation can be determined from surface cooling under fuel flows and subsequent heating under oxidizing conditions at temperatures between 700 and 800 °C. Ethanol forms considerable amounts of carbon at all temperatures and voltages studied as evidenced by substantial cooling related to carbon reactions and heating under oxidizing conditions. Methanol operation depends greatly on cell temperature and voltage. At 700 °C, temperature changes resemble those with ethanol, suggesting carbon deposition is occurring. At 800 °C, there is less cooling, which indicates that the oxide flux at higher polarizations mitigates the effects of endothermic carbon reactions. Under oxidizing conditions after fuel exposure, the small observed temperature increase demonstrates that little carbon is formed. At 750 °C the cooling depends on voltage, revealing a set of conditions where cooling from endothermic reactions and heating from exothermic reactions are balanced. The results show that while dry ethanol is not a clean fuel under any of our conditions, methanol can be at higher temperatures. NIR thermal imaging proves a valuable stand-off technique for identifying cell deterioration in situ, with potential for process monitoring in operating SOFCs. © 2011 American Chemical Society.

Coffey T.,United States Naval Research Laboratory
Physics of Plasmas | Year: 2010

Relativistic, longitudinal plasma oscillations are studied for the case of a simple water bag distribution of electrons having cylindrical symmetry in momentum space with the axis of the cylinder parallel to the velocity of wave propagation. The plasma is required to obey the relativistic Vlasov-Poisson equations, and solutions are sought in the wave frame. An exact solution for the plasma density as a function of the electrostatic field is derived. The maximum electric field is presented in terms of an integral over the known density. It is shown that when the perpendicular momentum is neglected, the maximum electric field approaches infinity as the wave phase velocity approaches the speed of light. It is also shown that for any nonzero perpendicular momentum, the maximum electric field will remain finite as the wave phase velocity approaches the speed of light. The relationship to previously published solutions is discussed as is some recent controversy regarding the proper modeling of large amplitude relativistic plasma waves. © 2010 American Institute of Physics.

Lewis A.C.,United States Naval Research Laboratory | Qidwai S.M.,United States Naval Research Laboratory | Geltmacher A.B.,Research Applications Corporation
Metallurgical and Materials Transactions A: Physical Metallurgy and Materials Science | Year: 2010

Abstract: To determine statistically relevant microstructure-yield correlations in three-dimensional (3-D) microstructures, large volumes comprised of many grains must be studied. With the aim of limiting computational loads without reducing the fidelity of the volume being simulated, this work investigates the use of reduced constitutive parameters, specifically the number of available slip systems, to analyze initial plastic flow in the microstructure. This is performed by embedding a 3-D reconstruction of a single-phase beta-Ti microstructure in a finite element (FE) computational model and subjecting it to a number of loading conditions. Three separate singlecrystal plasticity formulations were used for each loading: reduced 12 slip systems (<111>{110} family), reduced 24 slip systems (<111>{110}+<111>{112} families), and full 48 slip systems (<111>{110}+<111>{112}+<111>{123} families). The analysis results show that the 24-slipsystem model accurately predicts the global stress-strain behavior and locations of initial yield under all loadings, with no more than 10 pct error in the spatial description of local state variables compared to the full 48-slip-system model. The 12-slip-system model generally follows the full model predictions and provides an even better cost improvement, but with errors in excess of 40 pct in local descriptions. Computational cost and data reduction are improved by 26 and 53 pct, respectively. © The Minerals, Metals & Materials Society and ASM International 2010.

Landi B.J.,Rochester Institute of Technology | Cress C.D.,United States Naval Research Laboratory | Raffaelle R.P.,Rochester Institute of Technology
Journal of Materials Research | Year: 2010

Recent advancements using carbon nanotube electrodes show the ability for multifunctionality as a lithium-ion storage material and as an electrically conductive support for other high capacity materials like silicon or germanium. Experimental data show that replacement of conventional anode designs, which use graphite composites coated on copper foil, with a freestanding silicon-[single-walled carbon nanotube (SWCNT)] anode, can increase the usable anode capacity by up to 20 times. In this work, a series of calculations were performed to elucidate the relative improvement in battery energy density for such anodes paired with conventional LiCoO2, LiFePO4, and LiNiCoAlO2 cathodes. Results for theoretical flat plate prismatic batteries comprising freestanding silicon-SWCNT anodes with conventional cathodes show energy densities of 275 Wh/kg and 600 Wh/L to be theoretically achievable; this is a 50% improvement over today's commercial cells. © 2010 Materials Research Society.

Lifeloc Technologies and United States Naval Research Laboratory | Date: 2015-08-27

The technology disclosed herein may be used to detect drugs with potential for abuse within a human subject. This technology may be particularly useful to discriminate between drugs of abuse, corresponding psychoactive compounds, and corresponding metabolite byproducts, which are often closely related and possess similar chemical structures. The disclosed technology uses infrared light reflectance characteristics particular to one or more chemical compounds to be detected for identification of those compounds within the human subject.

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