| Processing for Highly Efficient AlGaN/GaN Emitters |
09-Sep-2009 |
14 pages |
| Authors:
Ilesanmi Adesida; ILLINOIS UNIV AT URBANA-CHAMAPAIGN
|
 | The fabrication of high-quality ohmic contacts on n- and p-type (Al,In)GaN is essential for improving the performance of optoelectronic devices, such as blue light emitting diodes, metal-semiconductor field effect transistors, HEMTs, and laser diodes. In particular, to realize solid-state UV emitters for chembioagent detection and general lighting, the formation of reliable ohmic contact systems for both n- and p-AlGaN with relatively high Al contents are indispensable. In conjunction with efforts ... |
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| Mass Spectrometric Analysis of the Electrospray Plume from an Externally Wetted Tungsten Ribbon Emitter |
Aug-2009 |
11 pages |
| Authors:
Yu-Hui Chiu; Brian W Ticknor; Shawn W Miller; AIR FORCE RESEARCH LAB HANSCOM AFB MA SPACE VEHICLES DIRECTORATE
|
| Angle-resolved mass spectrometry in conjunction with retarding potential energy analysis provides information on the mechanisms of ion field evaporation and spatial distributions of the emitted ions and droplets, the latter being of particular importance in the emitter array configuration. In the present study, we conduct mass spectrometric, retarding potential, and angular distribution measurements for ions. The angle resolved measurements indicate that the spray comprises a mixture of droplets and ions. ... |
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| Fokker-Planck Model for Thermal Smoothing in Inhomogeneous Laser-Matter Interactions |
24-Jul-2009 |
16 pages |
| Authors:
Michael J Keskinen; NAVAL RESEARCH LAB WASHINGTON DC
|
| Using a fully kinetic 2D Fokker-Planck model, the generation and evolution of ion density perturbations from nonuniform laser deposition in a plasma slab have been studied. It is found that significant smoothing of the ion density perturbations from nonuniform optically smoothed single beam laser deposition can be achieved on hydrodynamic time scales over a long range of scale sizes. In addition, it is observed that the Fokker-Planck model predicts more ... |
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| Solution Deposition Methods for Carbon Nanotube Field-Effect Transistors |
Jun-2009 |
32 pages |
| Authors:
Matthew Ervin; Natalie Salaets; ARMY RESEARCH LAB ADELPHI MD SENSORS AND ELECTRON DEVICES DIRECTORATE
|
| This study evaluated different methods for controlled deposition of carbon nanotubes (CNTs) from solution onto a silicon substrate to make CNT field-effect transistors (FETs). The goal of this deposition was to achieve reproducible device properties through more uniform CNT densities and other traits. This method serves as an easier, room temperature alternative to chemical vapor deposition growth. Three different types of CNT solutions were spun onto substrates: pristine tubes solubilized ... |
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| NPS CubeSat Launcher Design, Process and Requirements |
Jun-2009 |
129 pages |
| Authors:
Matthew R Crook; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
|
| Access to space has always been a challenge, especially for organizations with limited budgets. In the last decade a group of universities has overcome many of the obstacles associated with placing experiments on orbit by using a nano-satellite standard called the CubeSat. In addition to universities many private, commercial, and government organizations are now coming to appreciate the advantages of the CubeSat standard resulting in rapid growth in the CubeSat ... |
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| Nanodevices from Nanocomponents: Memory Logic and Mechanical Nanodevices |
11-May-2009 |
21 pages |
| Authors:
Charles J O'Connor; Jiye Fang; Leonard Spinu; Weilie Zhou; NEW ORLEANS UNIV LA
|
| The purpose of this report is to document the results of the complete effort for this project, which was to investigate the development of nanodevices from nanoscale components. The project focused on exploring the possibilities of employing nanoparticles and other nanocomponents to fabricate nanodevices. The four main components of the project were: quantum dot memory devices, multilevel logic devices, electromechanical devices, and nanosensor devices. |
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| Growth of Low Defect Density Gallium Nitride (GaN) Films on Novel Tantalum Carbide (TaC) Substrates for Improved Device Performance |
May-2009 |
34 pages |
| Authors:
M A Derenge; K A Jones; K W Kirchner; T S Zheleva; R D Vispute; ARMY RESEARCH LAB ADELPHI MD SENSORS AND ELECTRON DEVICES DIRECTORATE
|
| To potentially improve device performance, we attempted to grow gallium nitride (GaN) films with better crystalline quality (fewer mismatch dislocations) using a tantalum carbide (TaC) substrate, which is more closely lattice matched to GaN than currently used substrates. We created the TaC substrate, using pulse laser deposition (PLD) of TaC onto (0001) SiC substrates at tilde 1000 deg C, and grew GaN films, using metal organic chemical vapor deposition (MOCVD). ... |
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| 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
|
| 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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| Deposition of Amorphous Aluminum Alloys as a Replacement for Aluminum Cladding |
05-Feb-2009 |
22 pages |
| Authors:
Shmuel Eidelman; Ben Gauthier; Igor Vidensky; Nicole Tailleart; John Scully; ENIGMATICS INC COLLEGE PARK MD
|
| PRESENTATION OUTLINE: Background * Aging aircraft challenge * Multifunctional Coatings for AA-2024 * Desirable coating Attributes. * Project Overview * Alloy Development * Pulsed Thermal Spray * Nanostructured Al-Co-Ce * Cyclic Polarization * Sacrificial Anode/Inhibitor Release * ASTM B117 Salt Fog * Repairing Damage Samples * Summary * Future Work. |
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| Plasma-Based Surface Modification and Corrosion in High Temperature Environments |
05-Feb-2009 |
19 pages |
| Authors:
Todd Allen; Lizhen Tan; Kumar Sridharan; WISCONSIN UNIV-MADISON
|
| * Corrosion research at the University of Wisconsin is focused on two areas (i) plasma-based surface treatments to reduce corrosion, (ii) high temperature corrosion in harsh environments. * Plasma-based surface treatments (10 to 2000nm depth) have involved ion implantation and thin film deposition and atomic mixing approaches to mitigate corrosion and wear. * Specific testing equipment for corrosion testing in high temperatures and harsh environments such as supercritical water, molten ... |
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| Fabrication of Nanolaminates with Ultrathin Nanolayers Using Atomic Layer Deposition: Nucleation & Growth Issues |
Feb-2009 |
36 pages |
| Authors:
Steven M George; COLORADO UNIV AT BOULDER DEPT OF CHEMISTRY AND BIOCHEMISTRY
|
| This AFOSR grant concentrated on the fabrication of nanolaminates with ultrathin nanolayers using atomic layer deposition (ALD) and molecular layer deposition (MLD) techniques. Nanolaminates are multilayered thin film structures with nanometer dimensions and very high interfacial density. These multilayer structures can display novel properties that can be optimized by manipulating the thickness and composition of the individual nanolayers. During this grant, the research examined nucleation and growth issues involved in ... |
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| Manganese Research Health Project (MHRP) |
Feb-2009 |
146 pages |
| Authors:
Michael Aschner; Vanesssa A Fitsanakis; VANDERBILT UNIV NASHVILLE TN
|
| Manganese (Mn) and iron are essential metals for normal growth and development that compete for and share the same transporters. Thus, during periods of low dietary iron intake, the transport and deposition of Mn in the brain are increased. Conversely, high-risk populations for Mn intoxication, namely Mn miners and welders, may benefit from iron supplementation, which may lower their central nervous system (CNS) Mn burden. For the first 3 years, ... |
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| Tropical Cyclones within the Sedimentary Record: Analyzing Overwash Deposition from Event to Millennial Timescales |
Feb-2009 |
109 pages |
| Authors:
Jonathan D Woodruff; MASSACHUSETTS INST OF TECH CAMBRIDGE JOINT PROGRAM IN APPLIED OCEAN SCIENCE AND ENGINEERING
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| Tropical cyclone activity over the last 5000 years is investigated using overwash sediments from coastal lagoons on the islands of Vieques, Puerto Rico and Koshikijima, Japan. A simple sediment transport model can reproduce the landward fining deposits observed at Vieques, and reveals that although the record exhibits centennial-tomillennial changes in hurricane overwash frequency, the magnitude of these flooding events has remained relatively constant. Stochastic simulations of hurricane overwash show that ... |
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| Polyfibroblast: A Self-Healing and Galvanic Protection Additive |
29-Jan-2009 |
9 pages |
| Authors:
Jason J Benkoski; JOHNS HOPKINS UNIV LAUREL MD
|
| The goal of this project is to develop a primer additive that mimics the self-healing ability of skin by forming a polymer scar across scratches. Designed to work with existing military grade primers, Polyfibroblast consists of microscopic, hollow zinc tubes filled with a moisture-cured polyurethane-urea (MCPU). When scratched, the foaming action of a propellant ejects the resin from the broken tubes and completely fills the crack. No catalysts or curing ... |
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| Severe Tissue Trauma Triggers the Autoimmune State Systemic Lupus Erythematosus in the MRL/++ Lupus-Prone Mouse |
Jan-2009 |
15 pages |
| Authors:
K Anam; M Amare; S Naik; K A Szabo; T A Davis; NAVAL MEDICAL RESEARCH CENTER SILVER SPRING MD
|
| Tissue damage associated with a severe injury can result in profound inflammatory responses that may trigger autoimmune development in lupus-prone individuals. In this study, we investigated the role of a large full-thickness cutaneous bum injury on the early onset of autoimmune disease in lupus-prone MRL/++ mice. MRL/++ mice (chronic model) exhibit autoimmune symptoms at 70 weeks of age, whereas MRL/-Fas1pr mice (acute model) develop autoimmune disease in 1722 weeks due ... |
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| Synthesis of Hydrophobic and Oleophobic Nylon-Cotton Fabric Through Microwave Catalyzed Silane Attachment (PREPRINT) |
Dec-2008 |
12 pages |
| Authors:
Jeffrey R Owens; W B Salter; Ryan A Hayn; Rashelle S McDonald; Rachel A Sullivan; APPLIED RESEARCH ASSOCIATES INC TYNDALL AFB FL
|
| We report a microwave induced attachment of a perfluoroalkylsilane to produce highly hydrophobic and oleophobic (H -O) nylon -cotton material. A series of experiments explored the parameters of curing intervals, curing time, base catalysis, and concentration of silane. A single microwave interval of five seconds was able to produce H -O fabric when treated with a NH4OH catalyzed solution of 1% perfluorosilane in isopropyl alcohol. Contact angles for samples treated ... |
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| Threshold Voltage Improvement and Gate Leakage Current Reduction in a Multi-dot Room Temperature Operating Single Electron Transistor (RT-SET) |
Dec-2008 |
5 pages |
| Authors:
P S Karre; Paul L Bergstrom; Manoranjan Acharya; Daw D Cheam; MICHIGAN TECHNOLOGICAL UNIV HOUGHTON DEPT OF ELECTRICAL AND COMPUTER ENGINEERING
|
| The single-electron transistor (SET) is one of the best candidates for future nano electronic circuits because of its ultralow power consumption and small size. SET devices operate on the principle of Coulomb blockade, which is more prominent at dimensions of a few nano meters. Typically, the SET device consists of two capacitively coupled ultra small tunnel junctions with a nano island between them. The electron tunneling through the tunnel junctions ... |
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| River Diversions and Shoaling |
Nov-2008 |
22 pages |
| Authors:
Joseph V Jr; Letter; Pinkard; C F Jr; Nolan K Raphelt; ENGINEER RESEARCH AND DEVELOPMENT CENTER VICKSBURG MS COASTAL AND HYDRAULICS LAB
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| This Coastal and Hydraulics Engineering Technical Note describes the current knowledge of the potential impacts of river diversions on channel morphology, especially induced sedimentation in the river channel. Processes considered in this note are those most pertinent to riverine, as opposed to estuarine, aspects of diversions. In particular, this note provides general guidance on the physical process issues, outlines strategies for more effective application of existing tools, and summarizes the ... |
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| Electronic State Distributions of YBa2Cu3O7-x Laser Ablated Plumes |
Sep-2008 |
219 pages |
| Authors:
Patrick D Kee; AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH GRADUATE SCHOOL OF ENGINEERING AND MANAGEMENT
|
| Emission from YBCO laser-ablated plumes was studied to characterize the PLD process. A KrF laser was used to ablate a bulk YBCO target at oxygen pressures ranging from 50-400 mTorr. Spectra were collected for the 500-860 nm bandpass at target distances ranging from 31.4-55.0 mm. Line fluences were corrected for self-absorption, and state distributions were calculated using recently updated transition probabilities. Electronic temperatures ranged from 0.28 +/- 0.01 eV to ... |
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| High Yield Magnetic Nanoparticles Filled Multiwalled Carbon Nanotubes Using Pulsed Laser Deposition |
Aug-2008 |
3 pages |
| Authors:
Dereje Seifu; Shashi P Karna; MORGAN STATE UNIV BALTIMORE MD DEPT OF PHYSICS
|
| We present a high yield filling technique of multiwalled carbon nanotubes (MWNTs), grown vertically on a SiO2 substrate, with magnetic nanoparticles using pulsed laser deposition (PLD). Magnetization measurements in-plane and out-of- plane with respect to the sample surface indicate reasonable coercivity estimated at 0.4 T. The magnetic anisotropy is however found to be randomly oriented, indicating a polycrystalline structure. The unique difference between the in-plane and out-of-plane magnetizations is the ... |
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| High Current Density Scandate Cathodes for Future Vacuum Electronics Applications |
30 MAY 2008 |
28 pages |
| Authors:
CALABAZAS CREEK RESEARCH INC SAN MATEO CA
|
| This final report summarizes the achievements at Calabazas Creek Research, Inc. and Massachusetts Institute of Technology to develop and demonstrate techniques for fabricating high current density cathodes using scandium to lower the emission work function. Several techniques were investigated for depositing scandium on and beneath the surface of cathode emitters with techniques for replenishing that removed by normal surface erosion processes. Results indicate that several techniques can successfully provide the ... |
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| Portable Neutron Source |
30 MAY 2008 |
50 pages |
| Authors:
J. Davis; G. M. Petrov; NAVAL RESEARCH LAB WASHINGTON DC PLASMA PHYSICS DIV
|
| The angular distribution of neutrons formed in nuclear fusion reactions of a high-energy deuteron beam with a deuterated polyethylene (CD2) was investigated with a Monte Carlo ion beam-target deposition model. The initial conditions were obtained from a two-dimensional particle-in-cell laser-target deposition model. The neutron yield and its angular distribution were studied as a function of peak laser intensity, laser pulse duration and primary target thickness. The proposed scheme for neutron ... |
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| Magnesium Repair by Cold Spray |
MAY 2008 |
34 pages |
| Authors:
V. K. Champagne; P.F. Leyman; D. J. Helfritch; ARMY RESEARCH LAB ABERDEEN PROVING GROUND MD WEAPONS AND MATERIALS RESEARCH DIRECTORATE
|
| The U.S. Army has experienced significant corrosion problems with magnesium alloys that are used to fabricate aircraft components. The most severe of these are associated with large and expensive transmission and gearbox housings for rotorcraft, which have to be removed prematurely because of corrosion. Many of the parts cannot be reclaimed because there is not an existing technology that can restore them adequately for service. The U.S. Army Research Laboratory ... |
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| Studies of Real Roughness Effects for Improved Modeling and Control of Practical Wall-Bounded Turbulent Flows |
22 APR 2008 |
183 pages |
| Authors:
Kenneth T. Christensen; Yanhua Wu; ILLINOIS UNIV AT URBANA-CHAMPAIGN DEPT OF MECHANICAL SCIENCE AND ENGINEERING
|
| The present effort investigates the effects of practical roughness replicated from a turbine blade damaged by deposition of foreign materials or statistical and structural characteristics of wall turbulence. Two-dimensional particle image velocimetry (PIV) measurements are performed in the streamwise-wall-normal plane of turbulent boundary layers at momentum Reynolds numbers of 8000 and 13000. The surface conditions include a smooth wall and two highly-irregular rough walls. These rough surfaces have the same ... |
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| Thick Film Metastable Materials via Laser Processing |
18 APR 2008 |
7 pages |
| Authors:
Craig B. Arnold; PRINCETON UNIV NJ
|
| Over course of this project, the objective has evolved based on the results obtained. In the original proposal, our objective was basically to study the interaction between the incident laser and the multiphase materials that are used in laser direct write deposition in order to produce metastable phases of materials for improved performance in a variety of applications such as energy storage and corrosion resistant systems. Based on our results ... |
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| Re-Visiting 1-D Hypervelocity Penetration (Preprint) |
01-Apr-2008 |
13 pages |
| Authors:
David E Lambert; AIR FORCE RESEARCH LAB EGLIN AFB FL MUNITIONS DIRECTORATE
|
| Classical, one-dimensional theory of hydrodynamic penetration is used as the basis of establishing simplified analytical relationships describing energy, momentum, and power deposition during hypervelocity impact events. A concise overview of the 1-D model is given followed by a select grouping of terms into relationships that offer first-order criteria for making engineering design considerations on relevant applications and assist in the analysis of experimental observations. Momentum, energy, and power deposition are ... |
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| Extending Usable Lifetime of Plasmonic Silver Structures Designed for High Resolution Chemical Imaging and for Chemical and Biological Sensing |
Apr-2008 |
23 pages |
| Authors:
Carlos Barrios; Mark D Foster; AKRON UNIV OH
|
| The overall objective was to identify, from among different classes of coating schemes, the most fruitful approach for extending the lifetime of silver plasmonic structures used in high resolution optical spectroscopies for materials characterization or high sensitivity detection schemes. This enhanced durability will aid in Army efforts to develop high sensitivity, high selectivity schemes based on tip enhanced Raman spectroscopy (TERS) for chemical imaging and surface enhanced Raman spectroscopy (SERS) ... |
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| Innovative Growth and Defect Analysis of Group III - Nitrides for High Speed Electronics |
29 FEB 2008 |
84 pages |
| Authors:
Petra Specht; Eicke R. Weber; CALIFORNIA UNIV BERKELEY
|
| The project focused on novel techniques in growth and characterization which may enhance group III - nitride applications. On the growth side nitride deposition on diamond templates was characterized as the most promising novel growth techniques. The continuing progress can be supported applying the novel characterization technique described below. Local inhomogeneities are a common feature in group III - nitrides. With standard characterization methods such materials cannot be properly evaluated. ... |
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| Improved Thin Film Piezoelectrics for Actuator Applications |
04-Feb-2008 |
14 pages |
| Authors:
Susan Trolier-McKinstry; PENNSYLVANIA STATE UNIV UNIVERSITY PARK OFFICE OF SPONSORED PROGRAMS
|
| Thin film piezoelectrics for microelectromechanical systems offer large motions, often with low hysteresis, high available energy densities, as well as high sensitivity sensors with wide dynamic ranges, and low power requirements. Among ferroelectric films, the majority of the MEMS sensors and actuators developed have utilized lead zirconate titanate (PZT) films as the transducer. Randomly oriented PZT films show piezoelectric e31 ,f coefficients of about - 6 to 7 C/m2 at ... |
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| Chemical Patterning of Silicon Dioxide Substrates for Selective Deposition of Gold Nanoparticles and Fabrication of Single-Electron Transistors |
14-Jan-2008 |
8 pages |
| Authors:
Ulas Coskun; Henok Mebrahtu; Paul Huang; Jeremy Huang; Adriana Biasco; Alex Makarovski; Anne Lazarides; Thom LaBean; Gleb Finkelstein; DUKE UNIV DURHAM NC
|
| We describe a novel method to pattern SiO2 surfaces with colloidal gold nanoparticles by e-beam lithography and selective nanoparticle deposition. The simple technique allows us to deposit nanoparticles in continuous straight lines, just one nanoparticle wide and many nanoparticles long. We contact the pre-positioned nanoparticles with metal leads to form Single Electron Transistors (SETs). The Coulomb blockade pattern surprisingly does not show the parasitic random charges at low temperatures, indicating ... |
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| Protection of Polymer from Atomic-Oxygen Erosion using Al2O3 Atomic Layer Deposition Coatings |
Jan-2008 |
5 pages |
| Authors:
Russell Cooper; Timothy K Minton; Steven M George; Hari P Upadhyaya; Michael R Berman; Xiaohua Du; MONTANA STATE UNIV BOZEMAN DEPT OF CHEMISTRY AND BIOCHEMISTRY
|
| Thin films of Al2O3 grown using atomic layer deposition (ALD) techniques can protect polymers from erosion by oxygen atoms. To quantify this protection, polyimide substrates with the same chemical repeat unit as Kapton (registered trademark) were applied to quartz crystal microbalance (QCM) sensors. Al2O3 ALD films with varying thicknesses were grown on the polyimide substrates. The ALD-coated polyimide materials were then exposed to a hyperthermal atomic-oxygen beam. The mass loss ... |
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| Spintronic Nanodevices Defines by Nanolithography |
15 DEC 2007 |
15 pages |
| Authors:
Charles J. O'Connor; NEW ORLEANS UNIV LA
|
| The purpose of this report is to document the results of the complete effort for this project, which was to explore the possibilities of employing nanoparticles, nanostructured thin films, and nanowires in spintronic nanodevice fabrication by using e-beam lithography techniques at AMRl-UNO. |
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| Advances in SiGeSn Technology |
01-Dec-2007 |
16 pages |
| Authors:
Jose Menendez; John Kouvetakis; Richard A Soref; John Tolle; Vijay D'Costa; AIR FORCE RESEARCH LAB HANSCOM AFB MA SENSORS DIRECTORATE/ELECTROMAGNETICS TECHNOLOGY DIV
|
| We recently reported the CVD growth of binary Ge(1-y)Sn(y) and ternary Ge(1-y)Si(x)Sn(y) alloys directly on Si wafers using SnD(4), Ge(2)H(6) (di-germane), SiH(3)GeH(3), and (GeH(3))(2)SiH(2) sources. Ge(y)Sn(y) is an intriguing infrared material that undergoes an indirect-to-direct bandgap transition for y < 0.1. In addition, we have found that Ge(1-y)Sn(y) layers have ideal properties as templates for the subsequent deposition of other semiconductors: (a) they are strain-relaxed and have low threading-defect densities ... |
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| Novel Magnetic Devices |
12 OCT 2007 |
7 pages |
| Authors:
Ivan Schuller; CALIFORNIA UNIV SAN DIEGO LA JOLLA OFFICE OF CONTRACT AND GRANT ADMINISTRATION
|
| This project was dedicated to the development of novel magnetic devices relevant to applications in the fields of sensors, storage, non-volatile, reprogrammable spin-based electronics. The devices envisioned in this project explored novel physical phenomena and new functionalities not yet explored. More specifically, devices the initial idea was to explore three types of phenomena will be explored: ballistic magnetoresistance, magnetic field proximity effect and spin drag. These three phenomena would then ... |
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| Using a Near-Bed Sediment Flux Sensor to Measure Wave Formed Bedform Migrations and Formation Processes |
OCT 2007 |
|
| Authors:
Peter A. Traykovski; WOODS HOLE OCEANOGRAPHIC INSTITUTION MA
|
 | My research program focuses on identifying and quantifying sediment erosion, transport, and deposition processes on the continental shelf through state of the art observational techniques in both fine grained and sandy environments. In sandy environments, my goal is to understand the detailed interactions and feedbacks between hydrodynamics, bedforms, and the resulting sand transport. In fine-grained environments, I have been investigating the role fluid mud flows as a depositional mechanism in ... |
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| Materials Science of High-Temperature Superconducting Coated Conductor Materials |
OCT 2007 |
4 pages |
| Authors:
M. R. Beasley; STANFORD UNIV CA
|
| This program was broadly focused on the materials science of high temperature superconducting coated conductors, which are of potential interest for application in electric power systems of interest to the Air Force. The three main elements of the program were as follows: (1) understanding the basic materials science underlying the deposition of 123 YBCO at the high rates needed for economic manufacture of coated conductors; (2) exploration of variants of ... |
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| Ambient Volatility of Bis-(2-Chloroethyl) Sulfide |
OCT 2007 |
18 pages |
| Authors:
James H. Buchanan; Leonard C> Buettner; David E. Tevault; EDGEWOOD CHEMICAL BIOLOGICAL CENTER ABERDEEN PROVING GROUND MD
|
| The volatility of bis-(2-chloroethyl) sulfide (HI)) has been measured in the presence of water vapor using methodology recently developed at the U.S. Army Edgewood Chemical Biological Center. Contrary to predictions based on ideal behavior as described by Raoult's Law, the volatility of HI) is virtually independent of ambient humidity. This result suggests that the re-evaporation of HI) after deposition into the environment is a function of temperature, wind speed, and ... |
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| Preliminary Analysis of Particulate Infiltration into Space System Volumes |
30 SEP 2007 |
24 pages |
| Authors:
De-Ling Liu; Kenneth T. Luey; AEROSPACE CORP EL SEGUNDO CA LAB OPERATIONS
|
| To understand the dynamics of airborne particulate intrusion into a simulated space telescope and other space system volumes, a simple model was developed to predict the extent to which ambient particles penetrate through vent holes and enter the volume interiors after the purge is off. This report describes the mathematical modeling analysis, experimental data from laboratory studies, and field measurements from launch processing. It was found that the characteristic time ... |
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| Propellant Residues Deposition from Small Arms Munitions |
SEP 2007 |
43 pages |
| Authors:
Michael R. Walsh; Marianne E. Walsh; Susan R. Bigl; Nancy M. Perron; Dennis J. Lambert; Alan D. Hewitt; ENGINEERING RESEARCH AND DEVELOPMENT CENTER HANOVER NH COLD REGIONS RESEARCH AND ENGINEERING LAB
|
| Military live-fire training missions utilize a variety of energetic materials that are never completely consumed during firing. In February 2007, the U.S. Army Cold Regions Research and Engineering Laboratory teamed with the Vermont National Guard at Camp Ethan Allen to conduct tests to determine the propellant residues deposition related to the firing of small arms. Samples were collected from the snow surface at the firing points for 5.56-, 7.62-, 9-, ... |
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| Evaluation of Catalytic and Thermal Cracking in a JP-8 Fueled Pulsed Detonation Engine (Postprint) |
SEP 2007 |
15 pages |
| Authors:
Timothy M. Helfrich; Frederick R. Schauer; Royce P. Bradley; John L. Hoke; AIR FORCE RESEARCH LAB WRIGHT-PATTERSON AFB OH PROPULSION DIRECTORATE
|
| Pulsed detonation engines (PDEs) depend on rapid ignition and transition from deflagration to detonation. The prospect of converting the PDE from experimental to operational use necessitates a considerable reduction in the time required to ignite and detonate a liquid hydrocarbon fuel in air, such as JP-8. This research effort is focused on PDE operation enhancements using dual detonation tube, concentric-counter-flow heat exchangers to elevate the fuel temperature levels sufficiently to ... |
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| Molecular Modeling of Interfacial Behaviors of Nanomaterials |
MAY 2007 |
14 pages |
| Authors:
John Kieffer; MICHIGAN UNIV ANN ARBOR DEPT OF MATERIALS SCIENCE AND ENGINEERING
|
| During this project period we focused predominantly on explicit-atom MD simulations and first principles DFT calculations. This involved the force field parameterization for new molecules, i.e., cyclopentene, and the exploration of various DFT codes to identify the one most suitable for our purpose. We conducted several proof of concept studies, concentrating on the structural developments in the immediate vicinity of the surface with which the polymer comes into contact. These ... |
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| Minimization of Thruster Plume Effects on Spacecraft Surfaces |
MAY 2007 |
37 pages |
| Authors:
Peter J. Rohl; Juan Velez; Justin W. Koo; Michael Gorrilla; ADVATECH PACIFIC INC REDLANDS CA
|
| For the past several years, Advatech Pacific has been maintaining and enhancing the COLISEUM plume simulation environment under the direction of AFRL/PRSS. COLISEUM is a software environment used to model the propagation of a plasma plume and its interactions with solid surfaces (including both sputtering and re-deposition). A recent addition to the capabilities of COLISEUM is its integration with ModelCenter, the optimization and integration framework developed by Phoenix Integration. With ... |
|
| Advanced Materials Deposition for Semiconductor Nanostructures Using Supercritical Fluids |
APR 2007 |
78 pages |
| Authors:
Chien M. Wai; IDAHO UNIV MOSCOW
|
| Supercritical fluid carbon dioxide provides an attractive medium for depositing materials in small structures with high aspect ratios and poorly wettable substrates due to the fact that it is able to dissolve solutes like a liquid and transport dissolved materials like a gas. Metal and metal sulfide nanoparticles of controllable size can be synthesized in supercritical fluid carbon dioxide using water-in-CO2 microemulsion as template. Continuous tuning the size of metallic ... |
|
| Fabrication for Nanotechnology |
01 MAR 2007 |
65 pages |
| Authors:
Henne van Heeren; ENABLINGMNT DORDRECHT (NETHERLANDS)
|
| There is much discussion what nanotechnology really is: anything produced in the nanometer scale, manipulating atoms or small particles. Seeing the wide variety of materials and fabrication technologies one could better speak of nanotechnologies. In general the fabrication technologies could be divided into four groups: (1) Top-down nanofabrication; (2) Nanoparticles; (3) Bottom up and (4) Nanotubes. |
|
| Bio-Based Approaches to Inorganic Material Synthesis (Postprint) |
MAR 2007 |
7 pages |
| Authors:
Joseph M. Slocik; Morley O. Stone; Rajesh R. Naik; AIR FORCE RESEARCH LAB WRIGHT-PATTERSON AFB OH MATERIALS AND MANUFACTURING DIRECTORATE
|
| Nature is exquisite designer of inorganic materials using biomolecules as templates. Diatoms create intricate silica wall structures with fine features using the protein family of silaffins as templates. Marine sponges create silica spicules also using proteins, termed silicateins. In recent years, our group and others have used biomolecules as templates for the deposition of inorganic materials. In contrast with the traditional materials science approach, which requires high heat, extreme pH ... |
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| Precipitation Coating of Monazite on Woven Ceramic Fibers: 1. Feasibility (Postprint) |
FEB 2007 |
10 pages |
| Authors:
Geoff E. Fair; Randall S. Hay; Emmanuel E. Boakye; AIR FORCE RESEARCH LAB WRIGHT-PATTERSON AFB OH CERAMICS BRANCH
|
| Monazite coatings were deposited on woven cloths and tows of Nextel(trademark) 610 fibers by heterogeneous nucleation and growth using solution precursors. Initial experiments revealed two coating regimes in which monazite was either precipitated both in solution and onto the fiber surfaces or only onto the fiber surfaces depending on the precursor solution concentration and fiber surface area. In both cases, regions of tightly packed fibers within cloths were uncoated. Image ... |
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| Watershed Scale TMDL Model: Multidimensional Sediment Erosion, Transport, and Fate |
JAN 2007 |
12 pages |
| Authors:
Charles W. Downer; Aaron Byrd; ENGINEER RESEARCH AND DEVELOPMENT CENTER VICKSBURG MS
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| The purpose of this System-Wide Water Resources Program (SWWRP) technical note is to describe the new sediment transport routines in GSSHA, a watershed analysis and management tool that has the ability to simulate the movement of water, sediment, and associated constituents at fine-scale increments ( |
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| Characterization and Fate of Gun and Rocket Propellant Residues on Testing and Training Ranges: Interim Report 1 |
JAN 2007 |
221 pages |
| Authors:
Thomas F. Jenkins; Judith C. Pennington; Guy Ampleman; Sonia Thiboutot; Michael R. Walsh; Emmanuela Diaz; Katerina M. Dontsova; Alan D. Hewitt; Marianne E. Walsh; Susan R. Bigl; Susan Taylor; Denise K. MacMillan; Jay L. Clausen; Dennis Lambert; Nancy M. Perron; Marie C. Lapointe; Sylvie Brochu; Marc Brassard; Rob Stowe; Roccio Farinaccio; ENGINEERING RESEARCH AND DEVELOPMENT CENTER HANOVER NH COLD REGIONS RESEARCH AND ENGINEERING LAB
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| The objectives of the research described in this report are to characterize the deposition and accumulation of propellant residues at the various types of firing points at military firing ranges, develop process descriptors to allow estimation of environmental transport rates of individual energetic chemicals from these residues, and collect lysimeter and groundwater monitoring well samples to experimentally assess off-site transport of residues. Estimates of residue deposition are presented for the ... |
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| Parametric Study of Beta-Endpoint Energy in Direct Energy Converters |
JAN 2007 |
62 pages |
| Authors:
Kara Blaine; Marc Litz; ARMY RESEARCH LAB ADELPHI MD
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| Several solid-state materials have been identified for potential use as direct-energy-converter (DEC) for isotope-based batteries. Numerical simulations, using a nuclear scattering code (MCNPX), have been performed to determine the electron energy deposited in the material. Two different parametric studies were performed 1) varying Beta-endpoint energy of a spectrum illuminating layers of silicon-carbide (SiC), 2) the other varying the material layers while keeping the Beta-endpoint energy constant. The goal of the ... |
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| Stoichiometry and Characterization of Aluminum Oxynitride Thin Films by Ion-Beam-Assisted Pulsed Laser Deposition (Preprint) |
JAN 2007 |
23 pages |
| Authors:
J. S. Zabinski; J. J. Hu; J. E. Bultman; N. A. Pierce; A. A. Voevodin; DAYTON UNIV OH RESEARCH INST
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| Oxides are inherently stable in air at elevated temperatures and may serve as wear resistant matrices for solid lubricants. Aluminum oxide is a particularly good candidate for a matrix because it has good diffusion barrier properties and modest hardness. Most thin film deposition techniques that are used to grow alumina require high temperatures to impart crystallinity. Crystalline films are about twice as hard as amorphous ones. Unfortunately, the mechanical properties ... |
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