| An Elegant Low-cost Materials Solution for Achieving Low Insertion Loss, Affordable Tunable Filters for Next Generation Mobile Communications Platforms |
Apr-2009 |
18 pages |
| Authors:
M W Cole; E Ngo; R J Tan; ARMY RESEARCH LAB ABERDEEN PROVING GROUND MD WEAPONS AND MATERIALS RESEARCH DIRECTORATE
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 | The effect ultraviolet (UV)-assisted annealing on the structural, dielectric, and insulating properties of barium strontium titanate (BST) thin films was investigated. The material properties of BST films, prepared by RF sputter deposition, annealed via conventional thermal annealing and UV-assisted thermal annealing process protocols were compared and evaluated. The x-ray diffraction results showed contracted lattice constants and enhanced crystallinity for the RF sputtered BST films annealed via the UV-assist treatment. Isothermal-temporal ... |
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| Thermal Conductivity Reduction in Fullerene-Enriched p-Type Bismuth Telluride-Based Composites (Preprint) |
Apr-2009 |
24 pages |
| Authors:
Terry M Tritt; J E Spowart; N Gothard; AIR FORCE RESEARCH LAB WRIGHT-PATTERSON AFB OH MATERIALS AND MANUFACTURING DIRECTORATE
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| We present a systematic study of the effects of fullerene nano-inclusions upon a p-type bismuth-antimony-telluride matrix, where the ultimate goal is maximizing the figure of merit by reducing the thermal conductivity. Nanocomposites consisting of a bismuth telluride matrix with fullerene inclusions have been prepared both by mechanical mixing and ball milling, with the final consolidation in each case achieved by uniaxial hot pressing. A series of samples was produced with ... |
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| Synthesis and Characterization of Functionalized Eight-Membered Cyclic Silicates |
24-Mar-2009 |
2 pages |
| Authors:
Timothy Haddad; Joseph Mabry; Brian M Moore; AIR FORCE RESEARCH LAB EDWARDS AFB CA PROPULSION DIRECTORATE
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| Inorganic fillers are extensively used to modify polymer properties. Additionally, many nanoparticle fillers have been found to increase the thermal oxidative stability of modified plastics. Typically, good nano-dispersion is required to obtain significant property improvements. This is often achieved by compatibilizing the inorganic filler with the polymer host. The addition of organic groups to an inorganic particle leads to improved blending characteristics, while reactive groups increase their mechanical robustness if ... |
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| Toward Mechanically-Robust Omniphobic Composite Coatings using Fluoroalkyl-Modified Silica (Preprint) |
24-Mar-2009 |
3 pages |
| Authors:
Raymond Campos; Timothy S Haddad; Joseph Mabry; ENGINEERING RESEARCH AND CONSULTING INC (ERC INC) EDWARDS AFB CA
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| The wide applicability of non-wetting materials has generated a surge in commerical, military, and academic materials research. Previous studies have elucidated three parameters useful in the development of non-wetting surfaces: chemical functionality (high fluorine content), multiple scales of surface roughness (nano and micro), and surface geometry (re-entrant curvature). These parameters have been used in the development of materials that are superhydrophobic and superoleophobic. Although many of these surfaces exhibit the ... |
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| Terahertz Diode Development |
23-Mar-2009 |
24 pages |
| Authors:
Lester F Eastman; Quentin Diduck; Barbaros Aslan; CORNELL UNIV ITHACA NY OFFICE OF SPONSORED PROGRAMS
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| The research efforts to develop a high-efficiency, moderate power THz device are discussed. The device structure is based upon the crystalline properties of GaN and its ability to handle large power and high fields. Physical device models were developed that include thermal and electrical simulations. Several device structures were produced in conjunction with the model development Initial negative differential conduction results from fabricated devices are presented as are the designs ... |
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| Biofilm Formation by a Metabolically Versatile Bacterium |
19-Mar-2009 |
8 pages |
| Authors:
Caroline S Harwood; WASHINGTON UNIV SEATTLE OFFICE OF SPONSORED PROGRAMS
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| Rhodopseudomonas palustris is a photosynthetic bacterium that has good potential as a biocatalyst for the production of hydrogen gas, a biofuel. With this award we conducted basic studies to facilitate the development of a process where R. palustris cells grown on surfaces as biofilms, produce hydrogen gas using energy from the sun and electrons from agricultural waste. We characterized five new Rhodopseudomonas genome sequences and isolated and described R. palustris ... |
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| Pairing Heterocyclic Cations with closo-Icosahedral Borane and Carborane Anions. I. Benchtop Aqueous Synthesis of Binary Triazolium and Imidazolium Salts with Limited (Preprint) |
03-Mar-2009 |
28 pages |
| Authors:
Stefan Schneider; Jerry A Boatz; Scott A Shackelford; John L Bellatire; Amanda K Wheaton; Herman L Ammon; Steven H Strauss; AIR FORCE RESEARCH LAB EDWARDS AFB CA PROPULSION DIRECTORATE
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| Tailoring the chemical and physical properties of molecular materials by rational design to increase density, reduce toxicity, or to improve overall stability characteristics continues to be an important research endeavor. Achieving this by the structural modification of neutral organic compounds offers a limited scope of opportunities. Organic-like solid and liquid salts significantly enhance this flexibility for properties tailoring by pairing different classical heterocyclic cations with a plethora of different counteranions. ... |
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| A New Method for Growth and Analysis of Next-generation Infrared (IR) Detector Materials |
Mar-2009 |
20 pages |
| Authors:
John D Demaree; Stefan Svensson; ARMY RESEARCH LAB ABERDEEN PROVING GROUND MD WEAPONS AND MATERIALS RESEARCH DIRECTORATE
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| This report describes the development of a new analysis and crystal growth method for next generation infrared materials, namely, dilute nitride III-V semiconductors, which may be used in future low-cost night vision systems. The key to this method is isotopic enrichment of nitrogen-15 during material growth via molecular beam epitaxy, which allows enhanced detection of nitrogen using resonant nuclear reaction analysis. We synthesized films of gallium arsenide nitride (GaAsN) using ... |
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| The Effects of Temperature and Electron Radiation on the Electrical Properties of AlGaN/GaN Heterostructure Field Effect Transistors |
Mar-2009 |
120 pages |
| Authors:
Jeffrey T Moran; AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH GRADUATE SCHOOL OF ENGINEERING AND MANAGEMENT
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| AlGaN/GaN Heterostructure Field Effect Transistors (HFETs) have come under increased study, in recent years, owing to their highly desirable material and electrical properties, ruggedness, and survivability even during and after exposure to extreme temperature and radiation environments. These devices or similar devices constructed of AlGaN and/or GaN materials are being researched for their potential applications in many military and space based systems. In this study, unpassivated and SiN passivated Al(0.27)Ga(0.73)N/GaN ... |
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| Computational Design of ZrO2-SiO2 Coatings for Oxidation of ZrB2/ZrC Composites Containing ZrSix Intermetallics at 1700 degrees C |
Mar-2009 |
23 pages |
| Authors:
Arturo Bronson; Jack Chessa; TEXAS UNIV AT EL PASO
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| The research group investigated specifically the microstructural phases by integrating the computational mechanics and strategic experimentation of a ZrB2/ZrC/Zr-Si composite at ultrahigh temperatures (=1700 degrees C) in an oxidizing atmosphere. The objective of the proposed research was to study the computational aided design of ZiO2-Si02 coatings for ZrB2/ZrC/Zr-Si composite developed by reacting B4C with Zr-Si melts through the following two integrated research thrusts: (1) Investigate the effect of microstructural design ... |
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| Combined Experimental and Computational Study of Plastic Deformation in Crystals and Bicrystals for the Development of Multi-Length Scale Constitutive Models |
28-Feb-2009 |
11 pages |
| Authors:
Jeffrey W Kysar; COLUMBIA UNIV NEW YORK DEPT OF MECHANICAL ENGINEERING
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| The experimental effort concentrated on wedge indentation under quasistatic conditions in single crystals of Ni, Cu, and Al as well as bicrystals of Al. Wedge indenters with included angles of 60-deg, 90-deg, and 120-deg were used in the single crystals and an included angle of 90-deg was used near the train boundary of the Al bicrystal. the lattice rotations were experimentally determined via EBSD. The experimental results were processed to ... |
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| Smart Polymer Surfaces |
27-Feb-2009 |
7 pages |
| Authors:
Jeffrey T Koberstein; COLUMBIA UNIV NEW YORK
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| In many materials applications it is highly desirable to design and control the properties and behavior of surfaces. The task of modifying surfaces to control properties is a daunting one because many surface characteristics are related to the nature of chemical and physical structure on a molecular level. The overall goal of this research is to develop new methods for the molecular design and fabrication of smart surfaces with properties ... |
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| Comparative Environmental Toxicology Assessment of White and Red Phosphorous Munitions, Eagle River Flats Firing Range, Ft. Richardson, Alaska |
26-Feb-2009 |
16 pages |
| Authors:
William S Eck; M S Johnson; ARMY CENTER FOR HEALTH PROMOTION AND PREVENTIVE MEDICINE ABERDEEN PROVING GROUND MD
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| Eagle River Flats Firing Range is used as an impact area by troops training at Ft. Richardson, AK. Firing of white phosphorous munitions was suspended in February 1990 because of mortality to migratory waterfowl. The Commander of Ft. Richardson is seeking to begin firing red phosphorous munitions to support troop training. This report assesses the comparative toxicity of white and red phosphorous munitions with special consideration for waterfowl and other ... |
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| Investigation on the Solubility of GaN in Supercritical Ammonia Containing Acidic, Neutral, and Some Basic Mineralizers |
19-Feb-2009 |
5 pages |
| Authors:
Dirk Ehrentraut; TOHOKU UNIV SENDAI (JAPAN)
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| The ammonothermal growth technique to fabricate large size (2 inch) gallium nitride (GaN) crystals has recently seen increased interest due to the achievements in the technique published over the last 2-3 years. The first ever 2 inch GaN bulk crystal, to be reported in the April 2009 issue of MRS Bulletin, holds the great promise that ammonothermally produced GaN may become an important GaN substrate material due to the superior ... |
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| Preparation and Applications of Active Nanostructures as Biosensors |
04-Feb-2009 |
4 pages |
| Authors:
Chung-Yuan Mou; Tien-Sung Lin; NATIONAL TAIWAN UNIV TAIPEI (TAIWAN) DEPT OF CHEMISTRY
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| This project synthesized active mesoporous silicas with nanospaces to immobilize proteins or fragments of DNA to determine their biosensing utility via electrochemical and spectroscopic methods. |
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| Four-Channel Threshold Detector With Optical Isolation |
Feb-2009 |
26 pages |
| Authors:
Mark R Morgenstern; ARMY RESEARCH LAB ADELPHI MD SENSORS AND ELECTRON DEVICES DIRECTORATE
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| The four-channel window comparator discussed in this report is a safety switch that can be used to limit a range of test variables such as voltages, currents, temperatures or other values that can be scaled to a voltage within +-13 V. This device is simple, reliable, rugged, and requires no external control hardware or software. This module is scalable and reconfigurable to support nearly any test apparatus. |
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| Comparison of Slip Cast to Hot Pressed Boron Carbide |
Feb-2009 |
14 pages |
| Authors:
T Sano; E S Chin; B Paliwal; M W Chen; ARMY RESEARCH LAB ABERDEEN PROVING GROUND MD WEAPONS AND MATERIALS RESEARCH DIRECTORATE
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| To meet the possible increase in future demand for armor materials, an increase in the throughput during manufacturing is necessary. One possibility is the use of the slip casting and sintering technique to form ceramic armor compacts as an alternative to current hot pressing techniques. Dynamic uniaxial compression tests with the Kolsky bar were conducted on two types of slip cast boron carbide, and compared with results from the standard ... |
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| Oxidation of ZrB2 and ZrB2-SiC Ceramics With Tungsten Additions (Preprint) |
Feb-2009 |
11 pages |
| Authors:
S C Zhang; W G Fahrenholtz; G E Hilmas; MISSOURI UNIV-ROLLA DEPT OF MATERIALS SCIENCE AND ENGINEERING
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| The effect of tungsten additions on the oxidation behavior of zirconium diboride-based ceramics was studied. Four mole percent tungsten carbide was added to ZrB2. The oxidation behavior was studied using thermal gravimetric analysis and isothermal testing in flowing air. Upon heating to 1500 degrees C, the mass gain decreased from approx. 14 milligrams/(square centimeter) for nominally pure ZrB2 to approx. 4.5 milligrams/(square centimeter) for tungsten containing ZrB2. After heating to ... |
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| Corrosion Protection of Aluminum Alloys by Vanadate Pigments in Epoxy Primers |
Feb-2009 |
19 pages |
| Authors:
M Iannuzzi; K Evans; J E Ramos-Nervi; CORROSION AND MATERIALS TECHNOLOGY LAB DUBLIN OH
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| ONGOING WORK (1) Artificial scratch cell: The artificial scratch cell setup is being used to further evaluate whether meta-vanadates released from the coating could protect bare Al surfaces. (2) Coating degradation: A detailed EIS analysis on coatings with and without intentional defects is also being conducted. Results thus far have shown lower break point frequencies and larger Z(10mHz) values when vanadates were added to the primer in line with the ... |
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| Tunable, Room Temperature Light-emitting Diodes Based on Strained Si/SiGe Heterostructures |
24-Jan-2009 |
5 pages |
| Authors:
G Sun; H H Cheng; R A Soref; NATIONAL TAIWAN UNIV TAIPEI CENTER FOR CONDENSED MATTER SCIENCES
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| This is the report of a project to engineer SiGe/Si heterostructures for a type-I band alignment in which the emission intensity at around 1 micrometer is enhanced over conventional Si-based diodes, and to develop sight-emitting diodes based on the novel type-I SiGe/Si heterostructure. |
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| Abiotic Reductive Dechlorination of Tetrachloroethylene and Trichloroethylene in Anaerobic Environments |
15 Jan 2009 |
74 pages |
| Authors:
Elizabeth C Butler; Yiran Dong; Xiaoming Liang; Tomasz Kuder; R P Philp; Lee R Krumholz; OKLAHOMA UNIV NORMAN
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| Tetrachloroethylene (PCE) and trichloroethylene (TCE) are among the most frequently detected ground water contaminants at industrial sites, including many DoD facilities. Due to the high cost and uneven performance of traditional remediation technologies, monitored natural attenuation is emerging as a new technology for ground water remediation of pollutants such as these. In addition, there is growing interest in active remediation technologies that employ abiotic minerals. PCE and TCE are susceptible ... |
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| Experimental and Numerical Analysis of Radiometric Forces on a Heated Circular Vane in Argon (Preprint) |
13-Jan-2009 |
16 pages |
| Authors:
N Gimelshein; S Gimelshein; N Selden; C Ngalande; A Ketsdever; AIR FORCE RESEARCH LAB EDWARDS AFB CA PROPULSION DIRECTORATE
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| Radiometric force on a 0.12m circular vane is studied experimentally and numerically over a wide range of pressures that cover the flow regimes from near free molecular to near continuum. In the experiment, the vane is resistively heated to about 419 K on one side and 394 K on the other side, and immersed in a rarefied argon gas. The radiometric force is then measured on a nano- Newton thrust ... |
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| Wavelength Tuning Limitations in Optically Pumped Type-II Antimonide Lasers |
07-Jan-2009 |
6 pages |
| Authors:
A P Ongstad; R Kaspi; G C Dente; M L Tilton; J R Chavez; R Barresi; AIR FORCE RESEARCH LAB KIRTLAND AFB NM
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| In this paper, we examine the wavelength tuning limitations of type-II antimonide lasers containing InAs/InGaSb/InAs quantum wells. Wavelength tuning is accomplished by varying the thickness of the InAs electron wells while keeping all else fixed. In principle, these wells can be tuned from lambda approximately equal 2.5 m out to far IR wavelengths by increasing the thickness of the InAs layers. However, a practical upper limit of lambda approximately equal ... |
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| Enhanced Mass Transport in Ultrarapidly Heated Ni/Si Thin-Film Multilayers |
Jan-2009 |
7 pages |
| Authors:
L P Cook; W F Egelhodd; C B Montgomery; C E Campbell; U R Kattner; I Levin; W Wong-Ng; S Eustis; N Bassim; R E Cavicchi; M D Vaudin; NATIONAL INST OF STANDARDS AND TECHNOLOGY GAITHERSBURG MD
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| We investigated multilayer and bilayer Ni/Si thin films by nanodifferential scanning calorimetry nano-DSC at ultrarapid scan rates, in a temperature-time regime not accessible with conventional apparatus. DSC experiments were completed at slower scan rates as well, where it was possible to conduct parallel rapid thermal annealing experiments for comparison. Post experimental characterization was accomplished by x-ray diffraction, and by transmission electron microscopy TEM and energy-filtered TEM of thin cross sections ... |
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| In Silico Pharmacophore Model for Tabun-Inhibites Acetylcholinesterase Reactivators: A study of Their Stereoelectronic Properties |
Jan-2009 |
12 pages |
| Authors:
Richard K Gordon; Apurba K Bhattacharjee; Kamil Kuca; Kamil Musilek; WALTER REED ARMY INST OF RESEARCH SILVER SPRING MD
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| Organophosphorus (OP) nerve agents that inhibit acetylcholinesterase (AChE; EC 3.1.1.7) function in the nervous system, causing acute intoxication. If untreated, death can result. Inhibited AChE can be reactivated by oximes, antidotes for OP exposure. However, OP intoxication caused by the nerve agent tabun (GA) is particularly resistant to oximes, which poorly reactivate GA-inhibited AChE. In an attempt to develop a rational strategy for the discovery and design of novel reactivators ... |
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| Demonstration of a Full-Scale Fluidized Bed Bioreactor for the Treatment of Perchlorate at Low Concentrations in Groundwater |
Jan 2009 |
255 pages |
| Authors:
Todd S Webster; Paul Togna; BASIN WATER INC RANCHO CUCAMONGA CA
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| This study demonstrated the treatment of low and high concentration levels of perchlorate laden groundwater to potable-like water using a biological fluidized bed reactor (FBR) treatment train. The objectives were to demonstrate: (1) complete treatment of nitrate and perchlorate to drinking water standards using a only a biological inoculum from the incoming groundwater and (2) the use of a downstream post aeration vessel, multimedia filter, and LGAC to produce a ... |
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| Synthesis and Photovoltaic Application of Coper (I) Sulfide Nanocrystals |
22 Dec 2008 |
19 pages |
| Authors:
Yue Wu; Cyrus Wadia; Wanli Ma; Bryce Sadtler; A P Alivisatos; CALIFORNIA UNIV BERKELEY LAWRENCE BERKELEY LAB
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| We present the rational synthesis of colloidal copper(I) sulfide nanocrystals and demonstrate their application as an active light absorbing component in combination with CdS nanorods to make a solution-processed solar cell with 1.6 percent power conversion efficiency on both conventional glass substrates and flexible plastic substrates with stability over a 4 month testing period. |
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| Stability Improvements of DNA Photonic Devices |
20-Dec-2008 |
16 pages |
| Authors:
Naoya Ogata; OGATA RESEARCH LAB HOKKAIDO (JAPAN)
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| Recent research results on DNA-lipid complexes have shown various attractive features on E/O or O/E devices, optical memories, switches and sensors by intercalating optical dye into DNA double helix、while DNA devices absorbed water under high humidity which led to decreases of optical functions. However, it is possible to improve the stability of DNA devices by encapsulating the DNA-lipid complexes into sol-gel materials or synthetic polymers so that water permeation is ... |
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| Near Field Scanning Optical Microscopy (NSOM) of Nano Devices |
Dec-2008 |
77 pages |
| Authors:
Chun H Low; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
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| This thesis aims to investigate the optical properties of nano-devices using the technique of Near-Field Scanning Optical Microscopy (NSOM). A unique set-up to perform Atomic Force Microscopy (AFM) and NSOM simultaneously in a scanning electron microscope (SEM) to collect spatially resolved luminescence and image transport on nano-scale structures, particularly nanowires, will allow direct determination of transport parameters, such as minority carrier mobility and diffusion length that are vital to the ... |
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| Evaluation of the Snap Sampler for Sampling Ground Water Monitoring Wells for Inorganic Analytes |
Dec-2008 |
74 pages |
| Authors:
Louise V Parker; Nathan D Mulherin; Gordon E Gooch; ENGINEER RESEARCH AND DEVELOPMENT CENTER HANOVER NH COLD REGIONS RESEARCH AND ENGINEERING LAB
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| Abstract: Laboratory studies and a field demonstration were conducted to determine the ability of the Snap Sampler to recover representative concentrations of inorganic analytes, including metals, from ground water. For the laboratory studies, concentrations of analytes in Snap Sampler samples were compared with concentrations of the analytes in samples collected from a standpipe (i.e., control samples). These studies clearly demonstrated that Snap Sampler concentrations were comparable to control sample concentrations. ... |
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| Aptamer Selection Express: A Novel Method for Rapid Single-Step Selection and Sensing of Aptamers |
Dec-2008 |
10 pages |
| Authors:
Maomian Fan; Shelly Roper; Carrie Andrews; Amity Allman; John Bruno; Jonathan Kiel; CONCEPTUAL MINDWORKS INC SAN ANTONIO TX
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| This article describes a new DNA capture element (DCE) sensing system, based on the quenching and dequenching of a double-stranded aptamer. This system shows very good sensitivity and thermal stability. While quenching, dequenching, and separating the DCE systems made from different aptamers (all selected by SELEX), an alternative method to rapidly select aptamers was developed the Aptamer Selection Express (ASExp). This process has been used to select aptamers against different ... |
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| Fabrication of High Strength Metal-Carbon Nanotube Composites |
Dec-2008 |
6 pages |
| Authors:
D A Wiegand; F J Owens; A Goyal; Z Iqbal; ARMY ARMAMENT RESEARCH DEVELOPMENT AND ENGINEERING CENTER PICATINNY ARSENAL NJ
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| A major objective of Army technology is the development of lighter and stronger platforms such as armored vehicles for Future Combat systems and Future Force. Here we show that carbon nanotubes could be the basis of such a possibility. It is shown for the first time that a carbon nanotube-iron composite, iron being the principle component of steel, has significantly enhanced mechanical strength. The major challenge has been to develop ... |
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| Nondestructive Evaluation (NDE) of Sintered Silicon Carbide and its Correlation to Microstructure and Mechanical Properties |
Dec-2008 |
9 pages |
| Authors:
Steven Miller; Ernest Chin; William Green; James Campbell; Douglas M Slusark; M V Demirbas; Andrew Portune; Richard A Haber; Raymond Brennan; RUTGERS - THE STATE UNIV PISCATAWAY NJ
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| High density is a critical acceptance criterion for armor ceramics. Quantifying the difference in density between what would be considered to be a good or bad region is complicated. As density is reduced from theoretical, does this infer the presence of defects? The minimum acceptable density that ensures favorable ballistic performance is unknown. This question concerns not only the presence of defective regions, which may include pores or inclusions, but ... |
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| Dynamic Failure Processes Under Confining Stress in AlON, a Transparent Polycrystalline Ceramic |
Dec-2008 |
9 pages |
| Authors:
James W McCauley; B Paliwal; K T Ramesh; Mingwei Chen; SANDIA NATIONAL LABS ALBUQUERQUE NM
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| An experimental technique is developed to impose a planar lateral confinement in a prismatic specimen (with rectangular cross-section); the setup enabled a controlled and homogeneous stress state with high lateral compressive stresses. A transparent polycrystalline aluminum oxynitride (AlON) specimen was used for the study. The statically pre-compressed specimen was then subjected to axial dynamic compressive loading using a modified compression Kolsky bar setup. Experimental design was performed using 3D computational ... |
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| Novel Devices Using Multifunctional ZnO and Its Nanostructures |
Dec-2008 |
9 pages |
| Authors:
Yicheng Lu; R H Wittstruck; D Mackie; H Shen; Pavel Reyes; Ziqing Duan; Hanhong Chen; Gaurav Saraf; Jun Zhu; Jian Zhong; A Ballato; RUTGERS - THE STATE UNIV PISCATAWAY NJ DEPT OF ELECTRICAL AND COMPUTER ENGINEERING
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| Zinc oxide (ZnO) is a promising wide band gap semiconductor. It has a direct energy band gap, Eg of 3.3eV at room temperature. ZnO can be alloyed with CdO and MgO to form the ternaries CdxZn1-xO and MgxZn1-xO, extending the direct energy band from 2.8eV to 4.0eV. Through proper doping, it also can be made transparent and conductive, piezoelectric, or ferromagnetic. ZnO based single crystal nanostructures can be grown at ... |
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| Metastable Polymeric Nitrogen From N2H2 Alloys |
Dec-2008 |
9 pages |
| Authors:
Jennifer A Ciezak; Timothy A Jenkins; ARMY RESEARCH LAB ABERDEEN PROVING GROUND MD
|
| Studies of high-density binary mixtures of simple molecular solids have uncovered a new aspect of high pressure chemistry. In contrast 10 the many previous studies on relatively inert mixtures, here we show that high pressures can lead 10 unexpected behavior in reactive compounds. Raman studies were performed on nitrogen and hydrogen binary alloys al room temperature to 83 GPa To pressures of 30 GPa, large vibron deviations from those of ... |
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| Piezomems Devices for Advanced Communications and Phased Array Radar |
Dec-2008 |
5 pages |
| Authors:
Daniel Judy; Ronald G Polcawich; Jeffrey S Pulskamp; ARMY RESEARCH LAB ADELPHI MD SCIENCES AND ELECTRON DEVICES DIRECTORATE
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| In this article, we report on the successful demonstration of lead zirconate titanate (PZT) thin film based MEMS devices for use in radio frequency (RF) systems. Individual series switches and single pole multi-throw switching elements operating at or below 10 V have been developed capable of operating over a wide temperature range. The switch technology also provides an enabling technology for low voltage, mechanical logic. Along with switches and phase ... |
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| Reversible Polymer Hydrogels |
Dec-2008 |
4 pages |
| Authors:
V M Boddu; N Naismith; H Patel; R C Flowers; ENGINEER RESEARCH AND DEVELOPMENT CENTER CHAMPAIGN IL CONSTRUCTION ENGINEERING RESEARCH LAB
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| Temperature sensitive hydrogels based on N-isopropyl acrylamide (NIPA) and acryloyl glucosamine (AG) were synthesized using ammonium persulfate (APS) as initiator, N,N,N',N' -tetramethylenediamene (TEMED) as activator, and N,N'-methylene bisacrylamide (BIS) as cross-linker. The hydrogels were characterized using FTIR spectral analysis to investigate the chemical composition of the hydrogels. Swelling studies of the gel in water at room temperature to relate the swelling characteristics to the chemical composition were conducted. Further, the ... |
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| Common Trends in the Relationships Between Chemical and Physical Properties and Molecular Structure of Nitramine, Cage Nitramine, and Nitroaromatic Energetics |
Dec-2008 |
7 pages |
| Authors:
Mohammad Qasim; Jerzy Leszczynski; Leonid Gorb; Minori Uchimiya; Brett Moore; Lyssa Taylor; Matthew Middleton; ENGINEER RESEARCH AND DEVELOPMENT CENTER VICKSBURG MS
|
| Chemical and physical properties of nitroaromatic and nitramine explosives were related to their molecular structure with the objective of predicting types, sites and rates of reactivity as well as prediction of transformation intermediate and final products, stability, and toxicity potential. Understanding these relationships is intrinsic to the development of computational chemistry (CC) protocols for basic research into new compounds as well as for specific applications to military sites. Our comparisons ... |
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| Rational Selection of Tailored Amendment Mixtures and Composites for In Situ Remediation of Contaminated Sediments |
Dec 2008 |
63 pages |
| Authors:
Upal Ghosh; Brian E Reed; Seokjoon Kwon; Jeff Thomas; Todd Bridges; Daniel Farrar; Victor Magar; Laura Levine; MARYLAND UNIV BALTIMORE COUNTY BALTIMORE MD
|
| Emerging laboratory-scale research by our group and others has shown that contaminant transport pathways and bioavailability can be interrupted in-situ by modifying and enhancing the contaminant assimilation capacity of natural sediments. This is achieved by adding amendments such as activated carbon for binding persistent organic pollutants and natural minerals such as apatites, zeolites, or bauxite for the binding of toxic metals in sediments. This research was focused on advancing in-situ ... |
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| Efficient THZ Source Based on Cascaded Optical Down-Conversion in Orientation-Patterned GaAs Structures |
20-Nov-2008 |
34 pages |
| Authors:
Xiaojun Yu; Walter Hurlbut; Vladimir Kozlov; James Harris; Anjie Lin; Paulina Kuo; Joe Schaar; Martin Fejer; Konstantin Vodopyanov; Candace Lynch; David Bliss; Yun-Shik Lee; STANFORD UNIV CA EDWARD L GINZTON LAB OF PHYSICS
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| The goal of this DARPA TIFT project was to demonstrate an efficient room temperature source for THz imaging systems based on optical down-conversion in an orientation-patterned GaAs microstructure, incorporated into an optical resonant cavity, and pumped by a compact solid state laser. The main achievements are: (1) quasi-phase-matched (QPM) GaAs microstructures with periodic reversal of crystalline orientation, including orientation-patterned GaAs (OPGaAs), diffusion-bonded GaAs (DB-GaAs) and optically-contacted GaAs (OC-GaAs) suitable for ... |
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| Phase Stabilization of Ammonium Nitrate |
04-Nov-2008 |
19 pages |
| Authors:
Claude Merrill; Louis A Dee; AIR FORCE RESEARCH LAB EDWARDS AFB CA PROPULSION DIRECTORATE
|
| Ammonium nitrate (AN) as an ingredient for solid propellants has problems caused by a large volume phase change in normal operational temperature range, difficulty in keeping dry at relative humidities above 30%, 91 degrees F phase change making smaller AN particles causing propellant grain growth during temperature cycling, and caking behavior that creates a need for processing into propellant relatively soon after grinding to retain small particle sizes. Interference of ... |
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| High-Pressure Freezing, Crystal Structure Studies and Si-CF3 Bond Polarizability of Trimethyl(trifluoromethyl)silane (Postprint) |
Nov-2008 |
7 pages |
| Authors:
Ashwani Vij; Anna Olejniczak; Andrzej Katrusiak; ADAM MICKIEWICZ UNIV POZNAN (POLAND)
|
| Trimethyl(trifluoromethyl)silane, (CH3)3SiCF3, has been in situ pressure frozen in a diamond anvil cell and its structure determined at 0.90(5) GPa/296 K by single-crystal X-ray diffraction. The crystal is monoclinic, space group P21/m, with the molecules lying on crystallographic mirror planes. The CH3 and CF3 groups assume the fully staggered conformation. The 14-fold coordination scheme of the molecules is similar to those in (CH3)3SiCl polymorphs, but different from that in crystalline ... |
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| Microstructure and Properties of WC Spheres |
Nov-2008 |
32 pages |
| Authors:
Jeffrey J Swab; Justin Pritchett; Andrew A Wereszczak; Osama M Jadaan; ARMY RESEARCH LAB ABERDEEN PROVING GROUND MD
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| Tungsten carbide (WC) spheres are used as projectiles to study the ballistic performance of armor materials and systems. In order to properly understand and model the interaction between the projectile and the armor, it is necessary to have properties of both. In this study, the physical and mechanical properties of two commercially available WC spheres (nominally 0.25 inch in diameter) used in some ballistic impact studies were determined. One WC ... |
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| Carbon Dioxide Corrosion and Acetate: A Hypothesis on the Influence of Microorganisms |
Nov-2008 |
7 pages |
| Authors:
Brenda J Little; Joseph M Suflita; Tommy J Phelps; NAVAL RESEARCH LAB STENNIS SPACE CENTER MS OCEANOGRAPHY DIV
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| It is our hypothesis that fermentative acetogenic, and sulfate-reducing bacteria residing in pipeline facilities can influence corrosion through the production of carbon dioxide and acetate under the prevailing anaerobic conditions. The exacerbation of carbon dioxide corrosion of carbon steel in the presence of acetic acid is a well-known phenomenon in the oil industry. Both chemical compounds can be produced and consumed by microorganisms during the anaerobic biodegradation of organic matter-- ... |
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| Test of Surfactant-Based Dermal Wound Cleansers on Sulfur Mustard-Exposed Human Keratinocytes in an In Vitro Wound Healing Model |
Nov-2008 |
22 pages |
| Authors:
Claudia L Henemyre-Harris; Angela L Adkins; Augustine H Chuang; John S Graham; ARMY MEDICAL RESEARCH INST OF CHEMICAL DEFENSE ABERDEEN PROVING GROUND MD
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| Sulfur mustard is a chemical warfare agent that causes vesication in human skin. These blisters make the victims more susceptible to infection and delay healing of the skin. The first step in treating wounds is to cleanse the wound to prevent infection. Many dermal wound cleaners are commercially available, but little research has been conducted using these products in conjunction with SM-induced cutaneous injury. This study evaluated the impact of ... |
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| Conference on the Physics, Chemistry and Biology of Water (3rd) Held in West Dover, Vermont on October 16-19, 2008 (Abstracts) |
27-Oct-2008 |
34 pages |
| Authors:
Thomas Lowell; VERMONT PHOTONICS TECHNOLOGIES CORP BELLOWS FALLS VT
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| The 3rd Annual Conference on the Physics, Chemistry and Biology of Water was held in West Dover, Vermont October 16th thru 19th, 2008. The conference was organized by Vermont Photonics Technologies Corporation of Bellows Falls, Vermont, and was attended by an international group of 51 scientists who presented 31 papers during the 4 days. The cost of organizing this event was approximately $43,000, offset by attendance fees, sponsorship by 2 ... |
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| Perchlorate Contamination of Drinking Water: Regulatory Issues and Legislative Actions |
16-Oct-2008 |
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| Authors:
Mary Tiemann; LIBRARY OF CONGRESS WASHINGTON DC CONGRESSIONAL RESEARCH SERVICE
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 | Perchlorate is the explosive component of solid rocket fuel, fireworks, road flares, and other products. Used heavily by the Department of Defense (DOD) and related industries, perchlorate also occurs naturally and is present in some organic fertilizer. This soluble, persistent compound has been detected in drinking water supplies, especially in California. It also has been found in milk and many foods. Because of this widespread occurrence, concern over the potential ... |
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| Silica Nanofiber Combat Hemostat (SINCH) |
13-Oct-2008 |
24 pages |
| Authors:
Robert H Daniels; Esther Li; Oscar Abilez; Chengpei Xu; Christopher Zarins; NANOSYS PALO ALTO CA
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| We screened a panel of nanomaterials and identified high aspect ratio silica nanofibers (>100) as the best promoter of coagulation in vitro. These materials require combination with a carrier in order to provide adequate handling characteristics. We evaluated a panel of carrier material candidates for their ability to improve handling, act as a bulking agent, and improve hemostatic performance. Preliminary tests identified a combination of silica nanofibers and glass microspheres ... |
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| Flux Pinning Enhancement in YBa2Cu3O7-x Films with BaSnO3 Nanoparticles |
01-Oct-2008 |
7 pages |
| Authors:
P N Barnes; Chakrapani V Varanasi; J Burke; L Brunke; I Maartense; T J Haugan; E A Stinzianni; K A Dunn; P Haldar; AIR FORCE RESEARCH LAB WRIGHT-PATTERSON AFB OH PROPULSION DIRECTORATE
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| Nanoparticles of BaSnO3 were incorporated into YBa2Cu3O7-x (YBCO) films on LaAlO3 substrates for magnetic flux pinning enhancements. More than an order of magnitude improvement in the high field magnetization Jc at 6 T at 77 K was observed as compared to regular YBCO films. The irreversibility field (Hirr) was increased to 8.5 T at 77 K and to 13.4 T at 65 K. The in-field transport current measurements confirmed an ... |
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Inorganic Chemistry
