| Electronic Properties and Device Applications of III-V Compound Semiconductor Native Oxides |
02 MAR 2006 |
67 pages |
| Authors:
Douglas C. Hall; Patrick J. Fay; Thomas H. Kosel; Bruce A. Bunker; Russell D. Dupuis; NOTRE DAME UNIV IN DEPT OF ELECTRICAL ENGINEERING
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 | Notre Dame has demonstrated the first gallium arsenide (GaAs)-based metal-oxide-semiconductor field-effect-transistor (MOSFET) utilizing a native oxide gate dielectric which has excellent microwave frequency performance and, due to its low gate leakage, promises both low-power operation and potential for superior power amplifier devices. We have shown that the wet-thermal native oxides of the compound semiconductor indium aluminum phosphide (InAlP) can be scaled to thicknesses required for devices (10- 20 nm) and ... |
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| In Vitro Toxicity of Aluminum Nanoparticles in Rat Alveolar Macrophages |
MAR 2006 |
111 pages |
| Authors:
Andrew J. Wagner; AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH SCHOOL OF ENGINEERING AND MANAGEMENT
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| The purpose of this research is to characterize the in vitro cellular effects of rat lung macrophages to exposure to aluminum oxide nanoparticles (Al2O3-NP) (30 and 40nm) compared to aluminum nanoparticles (Al-NP) (50, 80, and 120nm). This study concentrates on cell viability, mitochondrial function, phagocytosis ability, and cytokine response. Results indicate no to minimal toxicological effects on macrophages exposed as high as 500 μg/ml for 24 hours with Al2O3-NP. However, ... |
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| Experimental Effects of Lime Application on Aquatic Macrophytes: 2. Growth Response Versus Treatment Time and Lime Concentration |
MAR 2006 |
14 pages |
| Authors:
William F. James; John W. Barko; ENGINEER RESEARCH AND DEVELOPMENT CENTER VICKSBURG MS
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| This research investigated the effects of applying lime (as calcium hydroxide; Ca(OH)2) either early or later in the life cycle on the growth, survivorship, and reproductive success of Sago Pondweed (Stuckenia pectinatus) in an outdoor experimental mesocosm setting. |
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| Phosphorus Equilibrium Characteristics for Soils in the Upper Eau Galle River Watershed, Wisconsin |
MAR 2006 |
7 pages |
| Authors:
William F. James; ENGINEER RESEARCH AND DEVELOPMENT CENTER VICKSBURG MS
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| The purpose of this demonstration was to examine phosphorus adsorption-desorption and equilibrium characteristics for soils collected from different land use practices in the Upper Eau Galle River watershed (Wisconsin). Land use practices included grazed pasture, row and perennial crop production, conservation reserve program or fallow land, and woodlots. This information will be important for watershed model algorithm improvements and applications that require categorization of soils as a function of phosphorus ... |
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| Dynamics of O(3P) Reactions with Gaseous Liquid and Solid Hydrocarbons |
MAR 2006 |
41 pages |
| Authors:
William L. Hase; TEXAS TECH UNIV LUBBOCK DEPT OF CHEMISTRY AND BIOCHEMISTRY
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| Prof. Hase has studied the reaction dynamics of oxygen atoms (triplet P state) with alkane hydrocarbons. In the initial phase, highly accurate ab initio quantum chemistry calculations (CASSCF, CASPT2, MRCI, with cc-pVTZ and cc-pVQZ basis sets) were applied to model reactions, including 0 + ethane and related reactions. In the second phase, a semiempirical quantum chemistry method, PM3-SRP, was developed by modifying and reparametrizing the standard PM3 method to fit ... |
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| Comparative Analysis of Airborne Chemical Exposure to Air Force Small Arms Range Instructors |
MAR 2006 |
196 pages |
| Authors:
Eric J. Cameron; AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH SCHOOL OF ENGINEERING AND MANAGEMENT
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| This study examines airborne chemical exposure to Air Force small arms range instructors during M16 firing of lead and lead-free bullets. Historical range information collected from 63 active duty Air Force bases identified that two thirds of the Air Force military ranges within the Continental United States are currently firing lead-free ammunition. Average 8-hr TWA exposures for lead during M16 firing of leaded ammunition were 17% of the Occupational Exposure ... |
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| Singlet Delta Oxygen: A Quantitative Analysis Using Off-Axis Integrated-Cavity-Output-Spectroscopy (ICOS) |
MAR 2006 |
111 pages |
| Authors:
Jeffrey E. Gallagher; AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH SCHOOL OF ENGINEERING AND MANAGEMENT/DEPT OF ENGINEERING PHYSICS
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| A new spectroscopic technique applicable to the detection of ultra-weak and for- bidden molecular transitions is presented. The method is based on off-axis integrated-cavity-output spectroscopy (ICOS). The primary goal for this research effort is to utilize the ICOS technique and demonstrate its ability to provide quantitative data of singlet delta oxygen. This thesis will focus on three areas of characterization to achieve this goal. First, the absolute line positions will ... |
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| Chlorine Dioxide Disinfection in the Use of Individual Water Purification Devices |
MAR 2006 |
15 pages |
| Authors:
Steven Clarke; William Bettin; ARMY CENTER FOR HEALTH PROMOTION AND PREVENTIVE MEDICINE ABERDEEN PROVING GROUND MD
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| Soldiers deployed beyond traditional field drinking water supplies must have access to microbiologically safe water. Using Individual Water Purification Devices (IWPDs) is one way to provide microbiologically safe water in these situations. These IWPDs must protect the Soldier from acute microbial health threats. Understanding the disinfection capabilities of chlorine dioxide to kill or inactivate disease-causing microorganisms is important in protecting soldiers, who are considering using this technology, from acute health ... |
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| Friction Stir Processing and Fusion Welding in Nickel Aluminum Propeller Bronze |
MAR 2006 |
87 pages |
| Authors:
Michael D. Fuller; NAVAL POSTGRADUATE SCHOOL MONTEREY CA DEPT OF MECHANICAL AND ASTRONAUTICAL ENGINEERING
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| Friction Stir Processing (FSP) is currently being developed for applications including as-cast Nickel- Aluminum Bronze (NAB). Fabrication and repair of the United States Navy's NAB propellers involve fusion welding of as-cast NAB and so it is probable that FSP is likely to encounter as deposited weld metal as well as the more slowly cooled as-cast material. Here, the microstructure and resulting distribution of mechanical properties was examined for a fusion ... |
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| Analysis of Bacterial Population and Distribution in the Developing Strata of a Constructed Wetland Used for Chlorinated Ethene Bioremediation |
MAR 2006 |
220 pages |
| Authors:
Jr Clausen Milton J.; AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH SCHOOL OF ENGINEERING
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| United States. These compounds attack the central nervous system in animals and can affect the photosynthesis of plants. These compounds are also resistant to degradation in the environment and, because of this, pose a risk to any ecosystem in which they are present. This study identified the dominant microbial species in a constructed treatment wetland at Wright-Patterson AFB, Dayton, Ohio using l6S rRNA gene sequence analysis. Samples were taken from ... |
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| Environmental Fate and Transport of a New Energetic Material, CL-20 |
MAR 2006 |
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| Authors:
Jalal Hawari; Vimal Balakrishnan; Ghalib Bardai; Bharat Bhushan; Sabine Dodard; Diane Fournier; Carl Groom; Annamaria Halasz; Fanny Monteil-Rivera; Pierre Y. Robidoux; Sylvie Rocheleau; Manon Sarrazin; Kathleen Savard; Geoffrey Sunahara; NATIONAL RESEARCH COUNCIL OF CANADA MONTREAL (QUEBEC) BIOTECHNOLOGY RESEARCH INST
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 | CL-20 is an emerging munition compound that may replace RDX and HMX, but little information is available on its environmental fate and ecological impact. Therefore the present report first describes the development and validation of an analytical method to analyze CL-20 in soil and water and the determination of key physicochemical parameters such as Kow (82.6), solubility (3.87 mg/L) and sorption/desorption parameters (Kd, Koc) of the chemical under various conditions ... |
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| Carrier Lifetime Dynamics of Epitaxial Layer HVPE Gallium Arsenide Using Time-Resolved Experiments |
MAR 2006 |
79 pages |
| Authors:
Wayne E. Eikenberry; AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH GRADUATE SCHOOL OF ENGINEERING AND MANAGEMENT
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| GaAs is a potential semiconductor material for producing both mid-infrared and terahertz radiation using the new technique of quasi-phase matching in an orientationally patterned GaAs (OP-GaAs) crystal. OP-GaAs is grown using a fast growth process called hydride vapor phase epitaxy (HVPE). Unfortunately, HVPE produces a high number of defects. These defects cause Shockley-Read-Hall recombination rates to dominate over Auger and radiative recombination rates. The carrier lifetime from four OP-GaAs samples ... |
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| Edible Oil Barriers for Treatment of Perchlorate Contaminated Groundwater |
16 FEB 2006 |
196 pages |
| Authors:
Robert C. Borden; Christie Zawtocki; Tony M. Lieberman; ATMOSPHERIC PLASMA SOLUTIONS RALEIGH NC
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| This final technical report documents the demonstration of emulsified edible oils for remediation of perchlorate in groundwater. The demonstration was conducted at a confidential site in Maryland with a mixed perchlorate and 1,1,1-TCA groundwater plume. The primary objective of this project was to evaluate the cost and performance of an emulsified oil permeable reactive barrier (PRB) to control the migration of perchlorate plumes at DoD installations. The performance of the ... |
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| A1GaAs/GaAs Heterostructure Solar Cells Grown by Molecular Beam Epitaxy |
14 FEB 2006 |
5 pages |
| Authors:
Suwaree Suraprapapich; Supachok Thainoi; Montri Sawadsaringkarn; Somsak Panyakeow; CHULALONGKORN UNIV BANGKOK (THAILAND) DEPT OF ELECTRICAL ENGINEERING
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| The contractor shall investigate the integration of quantum dots to the heterostructure of solar cells and the self alignment of quantum dots grown on high-index GaAs substrates for future nano-electronic device applications |
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| Optical Characterization of Micro Particles in Molecular Plasmas |
10 FEB 2006 |
16 pages |
| Authors:
Paul B. Davies; CAMBRIDGE UNIV (UNITED KINGDOM)
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| This report results from a contract tasking University of Cambridge as follows: Understanding the role of nano and micro sized particles in industrial processes and in the atmosphere using plasmas has become very important. The grantee proposes to develop a novel, sensitive and non-invasive diagnostic technique for probing the chemical composition of solid particle surfaces in dusty plasmas. Specifically, pulsed tuneable lasers will be used to excite whispering gallery modes ... |
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| Dynamic Consolidation of TaC and Nano-YSZ Powders (PREPRINT) |
07 FEB 2006 |
10 pages |
| Authors:
Lei Xu; Darrell Marchant; Lawrence Matson; B. S. Majumdar; NEW MEXICO INST OF MINING AND TECHNOLOGY SOCORRO DEPT OF METALLURGICAL AND MATERIALS ENGINEERING
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| The high melting point of TaC (3880 deg C), second amongst all known materials, along with good corrosion resistance makes TaC a potential candidate for Air Force applications. However, traditional methods of manufacturing, such as hot pressing or HIP-ing, give rise to rapid grain growth and low fracture toughness. In this work, we have utilized dynamic consolidation technique to overcome the grain growth problem, and thereby obtain stronger and more ... |
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| Processing of Multifunctional Epoxy Resins Modified with Silicon Based Nanomaterials (PREPRINT) |
07 FEB 2006 |
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| Authors:
Amy R. Spero; D. Marchant; J. Mabry; Lisa Viculis; AIR FORCE RESEARCH LAB EDWARDS AFB CA
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| Improvements in thermal and physical properties of epoxy resin systems have been demonstrated in the past through the influence of fillers. However, these improvements often come with a significant cost to processability. This paper examines the influence of nanofillers on a multifunctional epoxy resin system in terms of processability and thermal properties. The nanocomposites explored included nanosilica, linear calcium silicate (wollastonite), and polyhedral oligomeric silsesquioxane (POSS) in CYCOM 977-3 resin. ... |
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| Bis-imidazoles as Molecular Probes for Peripheral Sites of the Zinc Endopeptidase of Botulinum Neurotoxin Serotype A |
02 FEB 2006 |
10 pages |
| Authors:
Isidro Merino; Jason D. Thompson; Charles B. Millard; James J. Schmidt; Yuan-Ping Pang; MAYO CLINIC ROCHESTER MN MAYO CLINIC COLL OF MEDICINE
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| Botulinum neurotoxin serotype A (BoNTA) is highly toxic, and its antidote is currently unavailable. The essential light-chain subunit of BoNTA is a zinc endopeptidase that can be used as a target for developing antidotes. However, the development of high-affinity, small-molecule inhibitors of the endopeptidase is as challenging as the development of small-molecule inhibitors of protein-protein complexation, This is because the polypeptide substrate wraps around the circumference of the endopeptidase upon ... |
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| Selenium is a Chemotherapeutic Agent for the Treatment of Prostate Cancer |
FEB 2006 |
13 pages |
| Authors:
Susan J. Knox; STANFORD UNIV CA
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| A large body of data suggests that selenium supplementation may be used as a chemopreventive strategy to reduce the risk of prostate cancer. In spite of this, little is known regarding the use of selenium as a cancer therapy. High doses of selenite can deplete cells of the primary intracellular antioxidant, glutathione, and generate superoxide. The net effect of the metabolism of selenite is a profound alteration in the cellular ... |
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| Using Human Life Stage PBPK/PD Model Predictions of Perchlorate-Induced Iodide Inhibition to Inform Risk Assessment in Sensitive Populations |
FEB 2006 |
11 pages |
| Authors:
David R. Mattie; Teresa R. Sterner; Elaine A. Merrill; Rebecca A. Clewell; HENRY M JACKSON FOUNDATION FOR THE ADVANCEMENT OF MILITARY MEDICINE ROCKVILLE MD
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| Iodide inhibition was considered to be the key biochemical event preceding disruption of thyroid hormone homeostasis. The RfD was based on the No Observable Effect Level (NOEL) of 0.007 mg/kg-day, which resulted in no significant iodide inhibition in normal adults. An uncertainty factor of 10 was applied to the NOEL to account for intraspecies variability, including life-stage specific susceptibility. Recently, existing physiologically based pharmacokinetics/pharmacodynamic (PBPK/PD) models across life-stages in rat ... |
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| A Study of the Formation, Purification, Ligand Substitution Chemistry, and Application as a SWNT Growth Catalyst of the Nanocluster (Preprint) |
FEB 2006 |
55 pages |
| Authors:
Robin E. Anderson; Jr. Colorado Ramon; Christopher Crouse; Douglas Ogrin; Christopher L. Edwards; Elizabeth Whitsitt; Valerie C. Moore; Dorothy Koveal; Corina Lupu; Michael Stewart; RICE UNIV HOUSTON TX DEPT OF CHEMISTRY
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| The synthetic conditions for the isolation of the iron-molybdenum nanoc1uster FeMoC, along with its application as a catalyst precursor for VLS growth of SWNTs have been studied. As prepared FeMoC is contaminated with the Keplerate cage without the Keggin template; however, extraction of pure FeMoC may be accomplished by Soxhlet extraction with EtOH. The resulting EtOH solvate is consistent with the replacement of the water ligands coordinated to Fe being ... |
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| Effect of Residence Time on Net Nitrate Retention in Flow-Regulated Backwaters of the Upper Mississippi River |
FEB 2006 |
14 pages |
| Authors:
William F. James; William B. Richardson; David M. Soballe; John W. Barko; Harry L. Eakin; ENGINEER RESEARCH AND DEVELOPMENT CENTER VICKSBURG MS GEOTECHNICAL AND STRUCTURES LAB
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| This research investigated relationships between water residence time and net nitrate retention (i.e., loading minus discharge) in flow-controlled backwater systems of the Upper Mississippi River (UMR). Goals were to gain a better understanding of the management potential for removing nitrogen in large river systems by increasing connectivity between nitrogen-rich main channel areas and backwater habitats. Nitrogen (N) runoff to receiving streams and rivers, particularly in the form of nitrate-nitrite (NO3NO2-N), ... |
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| Predicting Dose-Response Relationships of Acute Cadmium Hepatoxicity and Metallothionein Regulation in the Rat Via In Vitro to In Vivo Extrapolation |
FEB 2006 |
44 pages |
| Authors:
Jeffery M. Gearhart; Diane M. Todd; John M. Frazier; Ellen L. Ebel; Jeffrey S. Eggers; Teresa R. Sterner; ALION SCIENCE AND TECHNOLOGY CORP DAYTON OH
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| The purpose of this effort was to utilize cadmium, a known toxicant of environmental and occupational concern, to develop an understanding of the relationships between chemical kinetics (rates of chemical movement into the body) and cellular dynamics (cellular response to chemical entering the cells) in order to predict early target organ toxicity and refine/validate a biologically-based kinetic model. This effort involved three studies. The first measured cadmium kinetics over 24 ... |
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| Growth, Characterization, and Application of InGaN with the Full-range Indium Content |
31 JAN 2006 |
33 pages |
| Authors:
Chih-Chung Yang; NATIONAL TAIWAN UNIV TAIPEI (TAIWAN) GRADUATE INST OF ELECTRO-OPTICAL ENGINEERING
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| InGaN was grown, covering the entire indium composition range, to characterize the various compositions of the material and to implement white-light generation. |
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| Production of Lunar Oxygen Through Vacuum Pyrolysis |
26 JAN 2006 |
71 pages |
| Authors:
John Matchett; GEORGE WASHINGTON UNIV WASHINGTON DC SCHOOL OF ENGINEERING AND APPLIED SCIENCE
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| Increasing efficiency of future space exploration will require that missions utilize non-terrestrial resources for propellant manufacture. The vacuum pyrolysis method of oxygen production from lunar regolith presents a viable option for in situ propellant production because of its simple operation involving limited resources from earth. Lunar regolith, the fine layer of pulverized rock across the entire lunar surface, is composed of approximately forty percent oxygen in the form of metal ... |
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| O+HCl Chemistry Models for Hypervelocity Collisions in DSMC |
09 JAN 2006 |
19 pages |
| Authors:
T. Ozawa; D. A. Levin; I. J. Wysong; PENNSYLVANIA STATE UNIV UNIVERSITY PARK
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| In earlier work, atmospheric-jet interaction flows were simulated using direct simulation Monte Carlo (DSMC) calculations for altitudes of 80, 120 and 160 km. At high altitudes, the O+HCl yields OH+Cl reaction was found to contribute the most to OH production. However, the total collision energy (TCE) reaction probability was often found to be unphysically greater than unity. In this work, we examine in detail different reaction models such as the ... |
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| Hall Mobility of Amorphous Ge2Sb2Te5 |
06 JAN 2006 |
4 pages |
| Authors:
S. A. Baily; David Emin; Heng Li; NEW MEXICO UNIV ALBUQUERQUE DEPT OF PHYSICS AND ASTRONOMY
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| The electrical conductivity, Seebeck coefficient, and Hall coefficient of 3 micron thick films of amorphous Ge2Sb2Te5 have been measured as functions of temperature from room temperature down to as low as 200 K. The electrical conductivity manifests an Arrhenius behavior. The Seebeck coefficient is p-type with behavior indicative of multi-band transport. The Hall mobility is n-type and low (near 0.07 cm2/V sec at room temperature). |
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| Effects of Phonon Coupling and Free Carriers on Band-Edge Emission at Room Temperature in n-type ZnO Crystals |
01-Jan-2006 |
4 pages |
| Authors:
Buguo Wang; N C Giles; Chunchuan Xu; M J Callahan; J S Neal; L A Boatner; AIR FORCE RESEARCH LAB HANSCOM AFB MA SENSORS DIRECTORATE
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| Room-temperature photoluminescence has been studied in II-type bulk ZnO crystals representing three different growth methods and having free-carrier concentrations (n) ranging from 10(exp 13) to 10(exp 18) /cu cm. The near-band-edge emission has both free-exciton and free-exciton-phonon contributions, with the strength of the phonon coupling dependent on sample defect concentrations. Band-gap shrinkage effects are used to explain a decrease in emission energy for the higher n values. Band filling and ... |
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| Hybrid Fiber Sizings for Enhanced Energy Absorption in Glass-Reinforced Composites |
JAN 2006 |
38 pages |
| Authors:
Robert E. Jensen; Steven H. McKnight; Dave P. Flanagan; Alan R. Teets; Donovan Haiiis; ARMY RESEARCH LAB ABERDEEN PROVING GROUND MD
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| Achieving high-impact energy absorption without loss of structural performance in a glass fiber-reinforced composite can be obtained through a "materials by design" approach of the fiber matrix interphase through modification of current commercially formulated silane-based fiber-sizing packages. In this report, we document our attempt to balance the structural and impact performance of glass-reinforced composites produced using a fiber-sizing package composed of mixed silane coupling agents to vary the reactivity of ... |
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| Treatment of M1 and M8 Propellant Hydrolysates with Immobilized Cell Bioreactors |
JAN 2006 |
59 pages |
| Authors:
Mark A. Guelta; Joseph J. Defrank; Mark V. Haley; EDGEWOOD CHEMICAL BIOLOGICAL CENTER ABERDEEN PROVING GROUND MD
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| Chemical agents in bulk form and chemical weapons in assembled rockets and mortars are scheduled to be destroyed in accordance with the Chemical Weapons Convention. Several technologies that include neutralization/biodegradation, supercritical water oxidation, and incineration have been selectively chosen to perform this task. Neutralization followed by biodegradation has been selected as the technology for the destruction of assembled chemical weapons by the Assembled Chemical Weapons Assessment (ACWA) program for mustard ... |
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| Ammonia-Based Hydrogen Source for Fuel Cell Applications |
JAN 2006 |
7 pages |
| Authors:
Lixiong Li; James A. Hurley; APPLIED RESEARCH ASSOCIATES INC TYNDALL AFB FL
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| Generation of hydrogen from the reaction of ammonia (NH3) with magnesium hydride (MgH2) was studies. Experiments were conducted at near ambient temperatures (75-150 deg C), which are lower than that required by ammonia cracking and/or metal hydride thermal decomposition reactions. Effects of selected catalysts/promoters for the production of hydrogen by the NH3-MgH2 reaction were evaluated. Addition of ammonium chloride (NH4Cl) accelerated the NH3-MgH2 reaction. MgH2 doped with either PdCl2 or ... |
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| Self-Pumped Photorefractive Gratings in Fe:KNbO3 (Preprint) |
JAN 2006 |
16 pages |
| Authors:
Dean R. Evans; G. Gook; J. L. Carns; M. A. Saleh; AIR FORCE RESEARCH LAB WRIGHT-PATTERSON AFB OH SURVIVABILITY AND SENSOR MATERIALS DIV/HARDENED MATERIALS
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| *High gain confirmed in off-axis geometries for Fe:KNbO3; *Mismatch between theory and experiment for mid-range crystal angles, especially for the a-c plane; *Large apparent variation in the effective trap density with crystal angle; *Modified theory gives a good fit to experimental data; *Mechanism for trap density anisotropy is unclear. |
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| Characterization of Temperature Dependent Index of Refraction and Thermo-Optic Coefficient for InAs and InSb (Preprint) |
JAN 2006 |
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| Authors:
Christopher DiRocco; Peter Powers; Glen D. Gillen; Shekhar Guha; DAYTON UNIV OH CENTER FOR ELECTRO-OPTICS
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| We demonstrate the use of interferometric techniques to measure the temperature dependence of the index of refraction and thermo-optic coefficient of infrared wafer-shaped optical materials, and report our results for InAs and InSb. |
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| Comparison of Insect Kinin Analogs With cis-Peptide Bond Motif 4-Aminopyroglutamate Identifies Optimal Stereochemistry for Diuretic Activity |
Jan-2006 |
8 pages |
| Authors:
Ronald J Nachman; Janusz Zabrocki; Geoffrey M Coast; Krzysztof Kaczmarek; Howard J Williams; A I Scott; SOUTHERN PLAINS AGRICULTURAL RESEARCH CENTER COLLEGE STATION TX AREAWIDE PEST MANAGEMENT RESEARCH UNIT
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| The insect kinins are present in a wide variety of insects and function as potent diuretic peptides, though they are subject to rapid degradation by internal peptidases. Insect kinin analogs incorporating stereochemical variants of (2S,4S)-4-aminopyroglutamate (APy), a cis-peptide bond motif, demonstrate significant activity in a cricket diuretic assay. Insect kinin analogs containing (2R,4R)- APy, (2S,4R)-APy and (2S,4S)-APy are essentially equipotent on an insect diuretic assay, with EC50 values of about ... |
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| Intrinsic Bonding Defects in Transition Metal Elemental Oxides |
Jan-2006 |
7 pages |
| Authors:
G Lucovsky; M D Ulrich; J Luening; H Seo; L B Fleming; P Lysaght; G Bersuker; NORTH CAROLINA STATE UNIV AT RALEIGH DEPT OF PHYSICS
|
| Gate dielectrics comprised of nanocrystalline HfO2 in gate stacks with thin SiO2/SiON interfacial transition regions display significant asymmetries with respect to trapping of Si substrate injected holes and electrons. Based on spectroscopic studies, and guided by ab initio theory, electron and hole traps in HfO2 and other transition metal elemental oxides are assigned to O-atom divacancies, clustered at internal grain boundaries. Three engineering solutions for defect reduction are identified: i) ... |
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| Embedding Luminescent Nanocrystals in Silica Sol-Gel Matrices |
2006 |
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| Authors:
Lindsey M. Sorensen; FLORIDA STATE UNIV TALLAHASSEE COLL OF ARTS AND SCIENCES
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| We have synthesized stable, highly luminescent silica xerogels as well as optically transparent, stable aerogels that were embedded with 2.5 nm and 6 nm CdSe and 6 nm InP quantum dots. By capping the quantum dot with 3-aminopropyltriethoxysilane, a dot is able to condense within the structure of a forming silica gel. This network keeps the quantum dot in place during the solvent exchange procedure necessary to form low-density silica ... |
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| Patterning of Narrow Au Nanocluster Lines Using V2O5 Nanowire Masks and Ion-Beam Milling |
2006 |
10 pages |
| Authors:
M. G. Ancona; S. E. Kooi; W. Kruppa; A. W. Snow; E. E. Foos; L. J. Whitman; D. Park; L. Shirey; NAVAL RESEARCH LAB WASHINGTON DC
|
| In recent years there has been considerable interest in metallic and semiconducting nanoclusters for a variety of reasons, not least of which is their potential for electronics and sensors. Although there are worthwhile applications of these clusters in devices at the micron scale, e.g., in chemical vapor sensing, the most intriguing possibilities arise when the numbers of clusters are reduced to a relative few and the inherent scalability associated with ... |
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| AC Operation of GaN:Er Thin Film Electroluminescent Display Devices |
2006 |
7 pages |
| Authors:
J. Heikenfeld; A. J. Steckl; CINCINNATI UNIV OH NANOELECTRONICS LAB
|
| Thin-film electroluminescence has been obtained from GaN:Er deposited directly on amorphous dielectric layers. Electroluminescent device (ELD) structures consisting of a dielectric/GaN/dielectric were formed on p(+)-Si substrates. In contrast to previous GaN:Er ELDs which used epitaxial growth conditions on crystalline substrates and were operated under direct current (DC) bias, these ELDs were operated under an alternating (AC) bias. A maximum luminance value of 300, 60, and 15 cd/m(2) has been achieved ... |
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| Fast Surface Temperature Measurement of Teflon Propellant in Pulsed Ablative Discharges Using HgCdTe Photovoltaic Cells (PREPRINT) |
2006 |
39 pages |
| Authors:
Erik L. Antonsen; Rodney L. Burton; Garrett A. Reed; Gregory G. Spanjers; ILLINOIS UNIV AT URBANA
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| High speed Mercury Cadmium Telluride photovoltaic detectors sensitive to infrared emission are investigated as a means of measuring real-time surface temperature on a micro-second timeframe pulsed ablative discharge with Teflon(TradeMark) as the ablated material. Analysis is used to derive a governing equation for detector output voltage for materials with wavelength dependent emissivity. The detector output voltage is experimentally calibrated against thermocouples embedded in heated Teflon. Experimental calibration is performed with ... |
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| Microstructural Mitigation of Hydrogen Environment Embrittlement of Ultra-High Strength AerMet(Trademark) 100 |
2006 |
33 pages |
| Authors:
Yongwon Lee; Richard P. Gangloff; VIRGINIA UNIV CHARLOTTESVILLE DEPT OF MATERIALS SCIENCE AND ENGINEERING
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| AerMet(exp TradeMark) 100, a secondary precipitation hardened martensitic steel, has excellent strength ((Sigmays = 1725 MPa) and toughness (K(sub IC) = 130 MP square root of am) when optimally tempered at 482C. However, it is susceptible to severe hydrogen environment assisted cracking (HEAC) in near-neutral 3.5% NaCl at very low threshold stress intensities (K(sub TH)) and with rapid Stage II plateau rates for subcritical crack propagation (da/dt(sub II). Interaction between ... |
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| 25.5 Betavoltaic Power Cells |
2006 |
5 pages |
| Authors:
C. J. Eiting; V. Krishnamoorthy; E. Romero; S. Jones; QYNERGY INC ALBUQUERQUE NM
|
| Betavoltaic power cells utilize beta-emitting radioisotopes and semiconductor devices to produce long-lived power in a variety of small for factors. Qynergy is developing betavoltaic power cells based on silicon carbide junction converters and 85Kr and 147Pm isotopes for a variety of applications. |
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| Xenon Feed System Progress |
2006 |
12 pages |
| Authors:
Joseph K. Barbaritis; Paul T. King; NORTHROP GRUMMAN SPACE AND MISSILE SYSTEMS CORP REDONDO BEACH CA SPACE TECHNOLOGY
|
| This paper reports on Moog's efforts to support the design, development, assembly and test of an electric propulsion xenon feed system for a flight technology demonstration program. Major accomplishments include: 1) Utilization of the Moog Proportional Flow Control Valve (PFCV), for the purpose of propellant isolation, pressure, and flow control. With pressure transducer feedback, the PFCV has successfully fed xenon to a 200 watt Hall Effect Thruster in a Technology ... |
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| Virus-Based Scaffolds for Organic/Inorganic Hybrid Materials |
2006 |
6 pages |
| Authors:
Matthew Francis; CALIFORNIA UNIV BERKELEY DEPT OF CHEMISTRY
|
| The central goal of these studies has been the integration of organic and inorganic components into well-defined structures using chemically functionalized viral capsids. Key strategies that have been explored include the use of new bioconjugation reactions to modify previously inaccessible sites on the protein surfaces and the preparation of water-soluble gold particles bearing reactive groups for biomolecules attachment. We have also developed a method for the attachment to viral capsids ... |
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| Improving Water Spray Efficacy for Fire Suppression via CO2 Addition at High Pressures and Low Temperatures: Evidence for CO2 Clathrate Hydrate Formation |
2006 |
13 pages |
| Authors:
Shawn E. Hunter; Lixiong Li; Doug Dierdorf; Timothy Armendinger; APPLIED RESEARCH ASSOCIATES INC TYNDALL AFB FL
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| This paper describes a technique for achieving a compact aqueous spray that incorporates CO2 into the spray at low temperatures (T < 10C) and high pressures (P > 10 MPa). A high-pressure spray apparatus was used to explore the effects of temperature (4-25 C), nominal CO2 mole fraction (0-0.12), in-line filter pore size (0.5-7 micrometer), and additives on the high-pressure (12-19 MPa) water spray patterns. Divergence of the high-pressure H2O-CO2 ... |
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| Chlorophyll a and Inorganic Suspended Solids in Backwaters of the Upper Mississippi River System: Backwater Lake Effects and Their Associations With Selected Environmental Predictors |
2006 |
3 pages |
| Authors:
James T. Rogala; Brian R. Gray; GEOLOGICAL SURVEY LA CROSSE WI UPPER MIDWEST ENVIRONMENTAL SCIENCES CENTER
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| The Long Term Resource Monitoring Program (LTRMP) uses a stratified random sampling design to obtain water quality statistics within selected study reaches of the Upper Mississippi River System (UMRS). LTRMP sampling strata are based on aquatic area types generally found in large rivers (e.g., main channel, side channel, backwater, and impounded areas). For hydrologically well-mixed strata (i.e., main channel), variance associated with spatial scales smaller than the strata scale is ... |
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| CHEM2D-OPP: A New Linearized Gas-Phased Ozone Photochemistry Parameterization for HIih-Altitude NWP and Climate Models |
2006 |
31 pages |
| Authors:
J. P. McCormack; S. D. Eckermann; D. E. Siskind; T. J. McGee; NAVAL RESEARCH LAB WASHINGTON DC
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| The new CHEM2D-Ozone Photochemistry Parameterization (CHEM2D-OPP) for high-altitude numerical weather prediction (NWP) systems and climate models specifies the net ozone photochemical tendency and its sensitivity to changes in ozone mixing ratio, temperature and overhead ozone column based on calculations from the CHEM2D interactive middle atmospheric photochemical transport model. We evaluate CHEM2D-OPP performance using both short-term (6-day) and long-term (1-year) stratospheric ozone simulations with the prototype high-altitude NOGAPS-ALPHA forecast model. An ... |
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| Dynamic Consolidation of TaC and Nano-YSZ Powders (POSTPRINT) |
2006 |
10 pages |
| Authors:
Lei Xu; Darrell Marchant; Lawrence Matson; B.S. Majumdar; NEW MEXICO INST OF MINING AND TECHNOLOGY SOCORRO DEPT OF METALLURGICAL AND MATERIALS ENGINEERING
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| The high melting point of tantalum carbide (3880 deg. C), second amongst all known materials, along with good corrosion resistance makes TaC a potential candidate for Air Force applications. However, traditional methods of manufacturing, such as hot pressing or HIP-ing, give rise to rapid grain growth and low fracture toughness. In this work, we have utilized dynamic consolidation technique to overcome the grain growth problem, and thereby obtain stronger and ... |
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| Low-Voltage Ferroelectric Phase Shifters From L- to C-Band |
2006 |
9 pages |
| Authors:
J. S. Kenney; Yong K. Yoon; Minsik Ahn; Mark G. Allen; Zhiyong Zhao; Xiaoyan Wang; Andrew Hunt; Dongsu Kim; GEORGIA INST OF TECH ATLANTA SCHOOL OF ELECTRICAL AND COMPUTER ENGINEERING
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| This paper describes the design, fabrication and test results of a family of integrated low voltage ferroelectric phase shifters ranging in frequency of operation from 0.7 GHz to 6 GHz. All devices use a common material system of BaxSr1-xTiO3 (BST) thin-films on Al2O3 (sapphire), allowing integration with high-Q inductors and other passive microwave elements. Novel bias structures have also been developed to reduce the voltages required to tune the materials, ... |
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| Large Resonant Third-order Optical Nonlinearity of CdSe Nanocrystal Quantum Dots |
2006 |
5 pages |
| Authors:
JaeTae Seo; SeongMin Ma; Qiguang Yang; Linwood Creekmore; Russell Battle; Herbert Brown; Ashley Jackson; Tifney Skyles; Bagher Tabibi; William Yu; SungSoo Jung; Min Namkung; HAMPTON UNIV VA DEPT OF PHYSICS
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| Resonant third-order nonlinear optical susceptibility and hyperpolarizability of CdSe nanocrystal quantum dots were revealed to be ~2.6 10(exp -20) 2.7 10(exp -19) sq m/V2 and ~2.2 10(exp -40) m5/V2 by using nanosecond degenerate four-wave mixing at 532 nm. The large nonlinearity of the CdSe nanocrystals is attributed to the resonant excitation and multiple nonlinear optical processes. |
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| Atomistic Simulations of Long-Range Strain and Spatial Asymmetry Molecular States of Seven Quantum Dots |
2006 |
5 pages |
| Authors:
Marek Korkusinski; Gerhard Klimeck; PURDUE UNIV LAFAYETTE IN
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| Coherent coupling and formation of molecular orbitals in vertically coupled quantum-dot molecules is studied for a seven-dot InAs/GaAs system. The electron states are computed using a nanoelectronic modelling tool NEMO-3D. The tool optimizes atomic positions in the sample with up to 64 million atoms in the frame of the atomistic VFF model. The resulting optimal interatomic distances are then used to formulate the 20-band sp3d5s* tight-binding Hamiltonian defined on a ... |
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Inorganic Chemistry
