| A Stepwise, Iterative Procedure to Constrain Stress Drop, Regional Attenuation Models, and Site Effects |
30-Sep-2009 |
11 pages |
| Authors:
W S Phillips; Mark D Fisk; ALLIANT TECHSYSTEMS INC SAN DIEGO CA
|
 | Accurate corrections for distance, source size, and site effects are needed for reliable use of regional seismic phases for discrimination and magnitude estimation. Procedures that simultaneously invert for attenuation, geometrical spreading, site, and source parameters have been shown to include many trade-offs and instabilities that have led to significantly inaccurate corrections for distance and source terms. Under previous work, we developed and applied an approach to constrain source parameters, including ... |
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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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| Design of Distributed Engine Control Systems for Stability Under Communication Packet Dropouts |
Aug-2009 |
8 pages |
| Authors:
Alireza R Behbahani; Rama K Yedavalli; Rohit K Belapurkar; OHIO STATE UNIV COLUMBUS
|
| In this paper, we address the issue of stability of Distributed Engine Control Systems under communication constraints and in particular for packet dropouts. We propose a control design procedure labeled Decentralized Distributed Full Authority Digital Engine Control (D2FADEC) based on a two level decentralized control framework. We show that, Packet Dropping Margin (PDM), which is a measure of stability robustness under packet dropouts, is largely dependent on the closed loop ... |
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| Combustion of Advanced Tactical Fuels Utilizing Boron Nanoparticles |
27-May-2009 |
10 pages |
| Authors:
Stephen M Masutani; HAWAII NATURAL ENERGY INST HONOLULU
|
| The design of high-energy-content synthetic fuels is an area of significant interest to the U.S. Department of Defense. Toward this end, the Naval Research Laboratory (NRL) has initiated an RD&D project to investigate the addition of coated boron nanoparticles to liquid fuels for gas turbine combustion applications. The Hawaii Natural Energy Institute (HNEI) of the University of Hawaii is collaborating with NRL on this project. HNEI is focusing on the ... |
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| Evaluation of a Proposed Drift Reduction Technology High-Speed Wind Tunnel Testing Protocol |
Mar-2009 |
11 pages |
| Authors:
W C Hoffmann; Y Lan; Bradley K Fritz; SOUTHERN PLAINS AGRICULTURAL RESEARCH CENTER COLLEGE STATION TX
|
| The U.S. Environmental Protection Agency EPA has initiated the development of protocols for measuring spray drift reduction technologies (DRTs) related to the application of agricultural protection chemicals. The DRT Program is an EPA-led initiative program to achieve improved environmental and human health protection through drift reduction by accelerating the acceptance and use of improved and cost-effective application technologies. The first step in implementing the DRT program is to develop a ... |
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| Spray Characterization of Thermal Fogging Equipment Typically Used in Vector Control |
Dec-2008 |
11 pages |
| Authors:
W C Hoffmann; Y Huang; Y Lan; B Quinn; D Szumlas; V L Smith; T Gwinn; B K Fritz; T W Walker; D Sykes; SOUTHERN PLAINS AGRICULTURAL RESEARCH CENTER COLLEGE STATION TX AREAWIDE PEST MANAGEMENT RESEARCH UNIT
|
| Droplet size spectra from different sprayers used to generate insecticide-laden fogs for controlling flying insects were measured by a laser diffraction instrument and Teflon-coated slides. The objectives of this work were to present not only information on spray-system droplet size generated by different sprayers, but to compare methodologies by which other similar systems can be evaluated and give applicators sprayer-system performance data. Data from 45 replicated spray tests, comprising 11 ... |
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| Mass Remaining During Evaporation of Sessile Drop |
01-Sep-2008 |
35 pages |
| Authors:
James E Danberg; SCIENCE APPLICATIONS INTERNATIONAL CORP (SAIC) ABINGDON MD
|
| A theory to predict the evaporation rate of HD (mustard agent) for the special case of a glass substrate has been developed. This is an important reference case for the wind tunnel and field test measurements of the HD evaporation rate. The HD drop is treated as a spherical segment with a constant base diameter characterized by the variation of the droplet shape factor (height to base diameter) or contact ... |
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| Evaporation of HD Droplets From Nonporous, Inert Surfaces in TGA Microbalance Wind Tunnels |
Sep-2008 |
47 pages |
| Authors:
Kenneth B Sumpter; Seok H Hong; Wendel J Shuely; Robert G Nickol; EDGEWOOD CHEMICAL BIOLOGICAL CENTER ABERDEEN PROVING GROUND MD RESEARCH AND TECHNOLOGY DIR
|
| The environmental fate of chemical warfare agents (CWAs) is important because the contact or vapor hazard is critical input for models used to support decisions on the level of individual protection at fixed sites. Two different microbalances, configured in a wind-tunnel geometry, were used to measure the evaporation and desorption rates from surfaces. The overall experimental design covers several neat and thickened agents and several material surfaces. The initial elements ... |
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| Secondary Breakup of Aerated Liquid Jets in Subsonic Crossflow (Postprint) |
FEB 2008 |
14 pages |
| Authors:
B. Miller; K. A. Sallam; M. Bingabr; K. Lin; C. Carter; OKLAHOMA STATE UNIV STILLWATER
|
| An experimental investigation of the secondary breakup of an aerated liquid jet in subsonic crossflow is described. The present test conditions were similar to those encountered in fuel injection in ramjet engines. Previous studies of spray structures of aerated liquid jet in crossflow have been limited to the dilute spray area (downstream distance > 100 jet diameter) using Phase Doppler Particle Analyzer (PDPA) and along the liquid surface using wet-holographic ... |
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| Effects of Wind Speed on Aerosol Spray Penetration in Adult Mosquito Bioassay Cages |
Jan-2008 |
9 pages |
| Authors:
Bradley K Fritz; W C Hoffman; Muhammad Farooq; Miriam F Cooperband; NAVY ENTOMOLOGY CENTER OF EXCELLENCE JACKSONVILLE FL
|
| Bioassay cages are commonly used to assess efficacy of insecticides against adult mosquitoes in the field. To correlate adult mortality readings to insecticidal efficacy and/or spray application parameters properly, it is important to know how the cage used in the bioassay interacts with the spray cloud containing the applied insecticide. This study compared the size of droplets, wind speed, and amount of spray material penetrating cages and outside of cages ... |
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| Collection Efficiencies of Various Airborne Spray Flux Samplers Used in Aerial Application Research |
Jan-2008 |
11 pages |
| Authors:
W C Hoffmann; Bradley K Fritz; AGRICULTURAL RESEARCH SERVICE COLLEGE STATION TX
|
| A low air speed, spray dispersion tunnel was constructed and used to evaluate the collection efficiency of passive spray flux collectors. The dispersion tunnel utilizes an air-assisted nozzle to generate a spray cloud with a D(sub V0.5) of 18.5 (+/-0.4)micrometers at air speeds ranging from 0.4-4.0 m/s. A sampling protocol was developed to minimize spray flux and air speed variation effects while providing a check on theoretical collection efficiency calculations. ... |
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| Effects of Water Hardness on Spray Droplet Size Under Aerial Application Conditions |
Jan-2008 |
|
| Authors:
Bradley K Fritz; Wesley C Hoffmann; William E Bagley; Yubin Lan; Daniel E Martin; AGRICULTURAL RESEARCH SERVICE COLLEGE STATION TX
|
 | Minerals and organic matter in spray carrier water can reduce the effectiveness of some plant protection products. Water hardness has been found to have a significant impact of the efficacy of some crop protection materials and has shown conflicting influence on spray droplet size. The objectives of this study were to determine the effects of water hardness on spray droplet size produced by two commonly-used aerial spray nozzles with and ... |
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| Enhancement of Drain-Down Capabilities of Submarine Antennae |
JUL 2007 |
16 pages |
| Authors:
Jim Dimas; Andrew J. Scardino; John A. Lewis; DEFENSE SCIENCE AND TECHNOLOGY ORGANIZATION VICTORIA (AUSTRALIA) MARITIME PLATFORMS DIV
|
| Water droplets on submarine antennae degrade signal transmission and increase signature. To improve antennae coating performance a surface which repels water is required. In this study several experimental coatings were compared for their ability to remove water droplets from their surface. The contact angle of a drop of water on each surface was recorded as well as the hysteresis, which is a measure of how easily a droplet will roll ... |
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| Human Effectiveness and Risk Characterization of Oleoresin Capsicum (OC) and Pelargonic Acid Vanillylamide (PAVA or Nonivamide) Hand-Held Devices |
MAY 2007 |
254 pages |
| Authors:
Lynne Haber; Patricia Nance; Andrew Maier; Paul Price; Eugene Olajos; Larry Bickford; Maureen McConnell; B. J. Klauenberg; TOXICOLOGY EXCELLENCE FOR RISK ASSESSMENT (TERA) CINCINNATI OH
|
| A Human Effectiveness and Risk Characterization (HERC) for oleoresin capsicum (OC) and pelargonic acid vanillylamide (PAVA or nonivamide) hand-held devices has been conducted in an effort organized by the Air Force Research Laboratory's (AFRL), Biobehavioral Systems Branch (RHDJ), in collaboration with the National Institute of Justice (NIJ), and the Edgewood Chemical and Biological Center (ECBC). The active ingredients in these devices are collectively termed capsaicinoids and act by peripheral sensory ... |
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| Self Assembled, Ultra-Hydrophobic Micro/Nano-Textured Surfaces |
APR 2007 |
26 pages |
| Authors:
Adam M. Rawlett; Joshua A. Orlicki; Nicole Zander; Afia Karikari; Tim Long; ARMY RESEARCH LAB ABERDEEN PROVING GROUND MD WEAPONS AND MATERIALS RESEARCH DIRECTORATE
|
| The formation of hierarchically ordered arrays of spherical cavities on polymer films is of interest due to potential applications in the reparation of photonic bandgaps materials, environmental sensors, and patterned light-emitting diodes. While many methods are known for the preparation of these porous materials, the breath figure approach has received significant scrutiny because of the simple and robust mechanism of pattern formation. Breath figures are patterned arrays of micrometer-sized defects ... |
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| A Method to Predict Atomization Performance in Gas-Centered Swirl-Coaxial Injectors |
27 MAR 2007 |
11 pages |
| Authors:
M. D. Lightfoot; S. A. Danczyk; D. G. Talley; AIR FORCE RESEARCH LAB EDWARDS AFB CA PROPULSION DIRECTORATE
|
| The ability to predict atomizer performance can reduce the cost of system development in many areas. This paper investigates the atomization efficiency and droplet distribution from films with strong gas-phase influences. A prediction of atomization efficiency based on a general theory of the droplet creation process is given. In this process a disturbance is created on the film surface then broken down into droplets via stripping. The theory relates the ... |
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| Factors Influencing the Mesoscale Variations in Marine Stratocumulus Albedo |
2007 |
12 pages |
| Authors:
D. A. Hegg; K. Nielsen; D. S. Covert; H. H. Jonsson; P. A. Durkee; WASHINGTON UNIV SEATTLE DEPT OF ATMOSPHERIC SCIENCES
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| Measurements of both horizontal gradients and vertical profiles of aerosols, cloud droplets and thermodynamic parameters in the cloud topped marine boundary layer off of central California are presented. They suggest that, while aerosols can indeed modulate cloud albedo, other parameters such as sea surface temperature may similarly affect cloud albedo. Additionally, the impact of aerosols, through sedimentation and precipitation, on cloud optical depths and thus albedo is not always in ... |
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| Formation of Contaminant Droplets on Surfaces |
15 DEC 2006 |
24 pages |
| Authors:
K. T. Luey; D. J. Coleman; AEROSPACE CORP EL SEGUNDO CA
|
| The effects of molecular film contamination on optical systems depend strongly on the film uniformity and thickness. Molecular films of uniform thickness are responsible for light transmission losses through absorption. For example, a partially darkened film of dioctyl phthalate 100 A thick may cause losses of about 2% in the visible spectrum. However, Ternet, et al, Villahermosa, et al, and others have shown that scattering from droplets or "puddles" can ... |
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| Mixing Dynamics of Supercritical Droplets and Jets (Revised To Include Appendices) |
AUG 2006 |
375 pages |
| Authors:
D. G. Talley; R. K. Cohn; E. B. Coy; B. Chehroudi; D. W. Davis; AIR FORCE RESEARCH LAB EDWARDS AFB CA SPACE AND MISSILE PROPULSION DIV
|
| This report summarizes a research program to understand the mixing dynamics of supercritical droplets and jets. The research was motivated by the recognition that pressures in modern liquid rocket engine combustion chambers tend to be higher than the critical pressure of one or more of the propellants. Prior to the beginning of this research, combustion processes were largely modeled using low pressure, subcritical spray combustion concepts. At supercritical pressures, however, ... |
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| Experimental and Numerical Study of Spacecraft Contamination Problems Associated With Gas and Gas-Droplet Thruster Plume Flows |
17 APR 2006 |
219 pages |
| Authors:
Mikhail S. Ivanov; RUSSIAN ACADEMY OF SCIENCES NOVOSIBIRSK INST OF THEORETICAL AND APPLIED MECHANICS
|
| The project consists of two large parts. The first part is the study of plume flows escaping into vacuum, and the second part deals with gasdroplet flows. These two parts are united by a common area of research, namely, contamination problems of space station surfaces due to thruster firing. The objective of the first part is accurate prediction of force and heat loads and contamination due to interaction of thruster ... |
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| Atomization Mechanism of Wall-Bounded Two-Phase Flows |
19 OCT 2005 |
14 pages |
| Authors:
M. D. Lightfoot; AIR FORCE RESEARCH LAB EDWARDS AFB CA PROPULSION DIRECTORATE
|
| The current understanding of droplet generation processes from liquid films is reviewed. Films are defined as liquids with one free and one wall-bound surface. In many of the systems where films occur, atomization is an undesirable side-effect of the two-phase flow. The motivation for this study, however, is a process where atomization from the film is the goal -- a gas-centered swirl coaxial rocket injector. Because atomization is often unwanted ... |
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| Breast Cancer Prevention by Fatty Acid Binding Protein MRG-Induced Pregnancy Like Mammary Gland Differentiation |
AUG 2005 |
10 pages |
| Authors:
Mingsheng Wang; LONG ISLAND JEWISH MEDICAL CENTER LAKE SUCCESS NY
|
| A mammary derived growth inhibitor related gene (MRG) was previously identified and characterized. MRG induces differentiation of mammary epithelial cells in vitro and its expression is associated with mammary differentiation. Overexpression of MRG in human breast cancer cells induced differentiation with changes in cellular morphology and a significant increase in the production of lipid droplets. Treatment of mouse mammary gland in organ culture with MRG protein resulted in a differentiated ... |
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| Light Actuation of Liquid by Optoelectrowetting |
01 JUN 2005 |
8 pages |
| Authors:
Pei Y. Chiou; Hyejin Moon; Hiroshi Toshiyoshi; Chang-Jin Kim; Ming C. Wu; CALIFORNIA UNIV LOS ANGELES DEPT OF ELECTRICAL ENGINEERING
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| Optical actuation of liquid droplets has been experimentally demonstrated for the first time using a novel optoelectrowetting (OEW) principle. The optoelectrowetting surface is realized by integrating a photoconductive material underneath a two-dimensional array of electrowetting electrodes. Contact angle change as large as 30 degrees has been achieved when illuminated by a light beam with an intensity of 65 mW/sq cm. A micro-liter droplet of deionized water has been successfully transported ... |
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| Investigation of Local Hydrogen Uptake in Rescaled Model Occluded Sites Using Crevice Scaling Laws |
APR 2005 |
46 pages |
| Authors:
John R. Scully; Michael Switzer; VIRGINIA UNIV CHARLOTTESVILLE DEPT OF MATERIALS SCIENCE AND ENGINEERING
|
| The effects of occluded site geometry and applied potential on hydrogen production and uptake in a martensitic stainless steel (Fe-l3Cr-8Ni-2Mo-1Al) were explored. On planar electrode surfaces, the total hydrogen concentration was found to increase exponentially with hydrogen overpotential. The x(exp 2)/gap scaling law, where x is the pit/crevice depth and "gap" is the pit/crevice width, was utilized to rescale model pits from micrometer to millimeter dimensions. Such rescaling enabled local ... |
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| Investigation and Development of Oil-Injection Nozzles for High-Cycle Fatigue Rotor Spin Test |
MAR 2005 |
113 pages |
| Authors:
Oscar R. Moreno; NAVAL POSTGRADUATE SCHOOL MONTEREY CA DEPT OF MECHANICAL AND ASTRONAUTICAL ENGINEERING
|
| Resonant excitation tests of rotor blades in vacuum spin pits using discrete oil jets showed that impact erosion of the blades could limit test times, but lower excitation amplitudes were produced using mist nozzles. Smaller diameter discrete jets might extend test times, but to fully prevent erosion, oil mist droplet size needed to be 30 microns or less. The present study examined both approaches. Prototype nozzles were developed to create ... |
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| Determining the Fine Structure of the Entrainment Zone in Cloud-Topped Boundary Layers |
MAR 2005 |
93 pages |
| Authors:
Michael S. Horner; NAVAL POSTGRADUATE SCHOOL MONTEREY CA DEPT OF METEOROLOGY
|
| The objective of this thesis is to obtain a better understanding of cloud-top entrainment through an in-depth analysis of entrainment-zone structure. In situ aircraft measurements taken during the Atlantic Stratocumulus Transition Experiment (ASTEX) were used for this purpose. Using data collected from multiple cloud-top penetrations, the presence of an interfacial layer in- between the top of the cloud mixed-layer and the base of the free atmosphere is identified and consequently ... |
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| Uniform Droplet Deposition of Thickened Chemical Agent Simulants By Supercritical Carbon Dioxide Viscosity Reduction |
16 NOV 2004 |
8 pages |
| Authors:
Michael V. Henley; Richard M. Weber; AIR FORCE RESEARCH LAB TYNDALL AFB FL
|
| Study of the fate of chemicals on substrates requires that those chemicals be applied to the substrate in a uniform and reproducible manner. Relatively simple means of droplet deposition of non-viscous chemicals are satisfactory, however thickened chemicals present problems using the same deposition techniques. By using supercritical carbon dioxide as a diluent, we were able to reduce the viscosity of various polymer-thickened chemicals and store them in a high-pressure reservoir. ... |
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| Agent Fate -- Measurement Of Chemical Warfare Agent Persistence On Contaminated Surfaces Under Controlled Environmental Conditions |
16 NOV 2004 |
|
| Authors:
Wesley Ercanbrack; Beryl Schwartz; Travis Losser; Tom Lindsey; SCIENCE AND TECHNOLOGY CORP HAMPTON VA
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| An innovative 16 cell test fixture was constructed at the Kendall Combined Chemical Test Facility (CCTF) located at Dugway Proving Ground's West Desert Test Center to measure the vapor hazard of chemical warfare agents on contaminated surfaces under controlled environmental conditions. Vegetation, aged CARC coated steel, MHE coated steel and soil were tested at 35 deg C with 50% relative humidity (RH) and a wind speed of 1.65 miles per ... |
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| Computational Analysis and Simulation of Toxic Particle Deposition in the Human Respiratory System |
10 NOV 2004 |
29 pages |
| Authors:
Clement Kleinstreuer; NORTH CAROLINA STATE UNIV AT RALEIGH
|
| Jet fuel with its performance enhancers is highly toxic and when inhaled may pose a significant health risk. Thus, for a scientific assessment of possible health effects from fuel exposure, it is crucial to know where and at what concentrations fuel aerosols and their vapors deposit in the human respiratory system in light of realistic inlet conditions. In contrast to human testing, and/or experimental deposition studies, computational fluid- particle dynamics ... |
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| Fibrin(ogen) -Mediated Extracellular Transport of Breast Cancer Cells by Macrophages: A New Idea Regarding Metastasis |
OCT 2004 |
24 pages |
| Authors:
Gregory S. Retzinger; CINCINNATI UNIV OH
|
| We set out to test the hypothesis that fibrin tethers existing between macrophages and breast cancer cells facilitate the extracellular transport of tumor cells by macrophages. We successfully developed a model system to test our hypothesis, and used it to collect preliminary evidence in support of our theory. During the course of our research, we discovered that fibrin-coated droplets of olive oil - like fibrin-coated macrophages - bind avidly to ... |
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| Water Mist Suppression of PMMA Boundary Layer Combustion - A Comparison of NanoMist and Spray Nozzle Performance |
20 SEP 2004 |
67 pages |
| Authors:
Chuka C. Ndubizu; Ramagopal Ananth; Frederick W. Williams; NAVY TECHNOLOGY CENTER FOR SAFETY AND SURVIVABILITY WASHINGTON DC
|
| Water is a multiphase fire-suppressing agent and its transport and distribution pose additional challenges that necessitate research efforts. This report compares the effects of ultra fine water mist (^3 micrometers) and regular spray nozzle mist (^30 micrometers) on forced flow boundary layer combustion of PMMA plate, where mist was introduced with the incoming air. With the spray nozzles, burning rate downstream was enhanced due to spray- induced turbulence, which enhanced ... |
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| A Model for Thermal Decomposition of Hydrogen Peroxide |
JUL 2004 |
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| Authors:
S. D. Heister; W. E. Anderson; J. H. Corpening; B. L. Austin; PURDUE UNIV LAFAYETTE IN SCHOOL OF AERONAUTICS AND ASTRONAUTICS
|
| A one-dimensional model has been developed to investigate the thermal decomposition of rocket grade hydrogen peroxide (HP) in a stream of previously decomposed HP products. The model developed assumes steady, one-dimensional adiabatic flow and includes basic mass balances, droplet evaporation, gas-phase decomposition kinetics, droplet dynamics, and control volume conservation laws. The code is adjustable for HP percent concentration for both main and secondary flows, massflow rates for both flows, and ... |
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| Swatch Test Results of Duraclean with Lycra Commercial Chemical Protective Gloves to Challenge by Chemical Warfare Agents |
JUL 2004 |
40 pages |
| Authors:
Robert S. Lindsay; Suzanne A. Procell; Elaina H. Harrison; EDGEWOOD CHEMICAL BIOLOGICAL CENTER ABERDEEN PROVING GROUND MD
|
| Swatches from Wiltshire Technologies, Incorporated (Carlsbad, CA), Duraclean with Lycra gloves were challenged with liquid droplets of sarin (GB) and mustard (HE)) using modifications of the static diffusion procedure described in TOP 8-2-501. The cumulative mass of each agent that permeated each swatch was determined over time, and the results for all swatches were used to determine an average cumulative mass for the gloves. From these data, a breakthrough time ... |
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| Dynamics of Droplet-Droplet and Droplet-Film Collision |
22 JUN 2004 |
19 pages |
| Authors:
C. K. Law; PRINCETON UNIV NJ
|
| The physical phenomena of droplet-droplet and droplet-film collision in the head-on orientation were studied experimentally and computationally, with emphasis on the transition between bouncing and merging of the liquid surfaces. Experimentally, the droplets (~300 m diameter) were generated using the ink-jet printing technique, and imaged using stroboscopy and high-speed cine-photography for the droplet-droplet and droplet-film collision events respectively. Computationally, the collision event was simulated using the front-tracking technique. For the ... |
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| Chemical and Biological Microassays in Freely Suspended Droplets on Novel Fluidic Chips |
MAY 2004 |
19 pages |
| Authors:
Orlin D. Velev; NORTH CAROLINA STATE UNIV AT RALEIGH
|
| We developed the principles of a platform for manipulation of freely suspended micro- and nanoliter droplets for micromanipulation and microassays. The liquid transport in such chips requires very low energy input due to the lack of microchannels or solid walls present in conventional microfluidic devices. Water droplets float on the surface of a denser perfluorinated liquid and are driven by alternating or constant electric fields created by addressable arrays of ... |
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| The "Hunting Effect" in the Cathode Region of a Vacuum Arc |
07 APR 2004 |
2 pages |
| Authors:
G. A. Mesyats; S. A. Barengolts; URALKABEL EKATERINBURG (RUSSIA)
|
| The interaction of liquid-metal droplets with plasma jets in the cathode region of a vacuum arc is considered based on the ecton model of a cathode spot. It is shown that the heating of a droplet which is in the zone of operation of a cathode spot can result in the transition of the droplet into the plasma state. |
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| Molecular Dynamics Simulations of Supercritical Sprays |
12 MAR 2004 |
9 pages |
| Authors:
Michael M. Micci; PENNSYLVANIA STATE UNIV UNIVERSITY PARK DEPT OF AEROSPACE ENGINEERING
|
| The objective of this program was to develop an accurate and fast simulation methodology for supercritical injection and mixing using molecular dynamics (MD). The use of MD allows the supercritical mixing to occur naturally' without the need for tracking phase boundaries and intrinsically includes all physical processes, material properties and equations of state in both subcritical and supercritical environments. MD also allows the tracking of injected liquid molecules into the ... |
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| Dynamics of Droplet Collision and Flame Motion |
08 MAR 2004 |
12 pages |
| Authors:
Chung K. Law; PRINCETON UNIV NJ DEPT OF MECHANICAL AND AEROSPACE ENGINEERING
|
| The present program aims to study the dynamics of droplet collision and flame-flow interaction that are of relevance to liquid-fueled turbulent combustion in propulsive devices. The investigation involves experimental, computational, and analytical components. The program recognizes the fundamental similarity between droplet collision and flame dynamics, especially from the computational viewpoint, in that both phenomena involve the tracking of deformable surfaces separating two media of vastly different densities. During the reporting ... |
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| A Versatile Droplet Sizing Spectrometer for Aerosol Hygroscopic Growth Measurements from Research Aircraft |
18 JAN 2004 |
20 pages |
| Authors:
Fredrick J. Brechtel; BRECHTEL MANUFACTURING INC HAYWARD CA
|
| The uptake of water by ambient aerosols at elevated relative humidity (RH) is ubiquitous and often results in large changes in particle size. Because the scattered light intensity from aerosols varies as the diameter taken to the sixth power, optical properties such as the aerosol extinction coefficient, single scatter albedo and optical depth will have strong particle size dependence. There are currently no viable techniques available to perform rapid size-resolved ... |
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| Effects of Prednisolone Acetate on Ocular Sulfur Mustard Injury in a Rabbit Model |
DEC 2003 |
22 pages |
| Authors:
C. Bossone; K. Newkirk; S. Schulz; R. Railer; M. Gazaway; M. Shutz; E. Clarkson; S. Estep; P. Subramarian; A. Castro; J. Clinkscales; B. Lukey; ARMY MEDICAL RESEARCH INST OF CHEMICAL DEFENSE ABERDEEN PROVING GROUND MD
|
| Eye injury from HD (sulfur mustard) exposure continues to remain a threat to soldiers in the battlefield. This study was designed to explore the effects of Pred-Forte (prednisolone) in treating ocular HD injury. Sixteen female New Zealand White rabbits were exposed to 0.51 mg of undiluted HD as a liquid droplet. One group (n=8) received 2 drops of Pred-Forte into the eye every 10 minutes for the first 30 minutes ... |
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| Environmental Fate of Toxic Chemicals on Surface Materials in Laboratory Wind Tunnels: Measured and Computed Wind Speeds and Flow Fields |
01-Jul-2003 |
|
| Authors:
Wendel Shuely; Daniel Weber; John Molnar; EDGEWOOD CHEMICAL BIOLOGICAL CENTER ABERDEEN PROVING GROUND MD
|
| An understanding of the fate and effects of chemical agents on material surfaces under environmental conditions is becoming critical as the probability of contamination increases for military and civilian airports and seaports and Homeland targets. The methodology is not available for measuring the fundamental evaporation, desorption, and decomposition of chemical agents as a function of time in a controlled laboratory wind tunnel. The methodologies under development can be classified by ... |
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| Omega-3 Fatty Acids and a Novel Mammary Derived Growth Inhibitor Fatty Acid Binding Protein MRG in Suppression of Mammary Tumor |
JUL 2003 |
11 pages |
| Authors:
Yiliang E. Liu; LONG ISLAND JEWISH-HILLSIDE MEDICAL CENTER NEW HYDE PARK NY
|
| A mammary derived growth inhibitor related gene (MRG) was previously identified and characterized. The present study is to test the hypothesis that MRG is a candidate mediator of the differentiating effect of pregnancy and lactation of breast epithelial cells and a candidate mediator of the tumor suppressing effect of n-3 fatty acid DHA on mammary tumors. MRG induces differentiation of mammary epithelial cells in vitro and its expression is associated ... |
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| Mixing Characteristics of Coaxial Injectors at High Gas/Liquid Momentum Ratios |
04 JUN 2003 |
11 pages |
| Authors:
P. A. Strakey; D. G. Talley; J. J. Hutt; AIR FORCE RESEARCH LAB EDWARDS AFB CA PROPULSION DIRECTORATE
|
| A study of the spray of a swirl coaxial gas-liquid injector operating at high-liquid momentum ratios is reported. Mixing and droplet size characteristics of the swirl injector are also compared to a shear coaxial injector, currently being used in the space shuttle main engine fuel preburner. The injectors were tested at elevated chamber pressures using water as a liquid oxygen stimulant and nitrogen and helium as gaseous hydrogen simulants. The ... |
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| An Experimental Study of High Heat Flux Removal Using Micro-Droplet Spray Cooling |
JUN 2003 |
61 pages |
| Authors:
Matthew A. Cryer; NAVAL POSTGRADUATE SCHOOL MONTEREY CA DEPT OF MECHANICAL ENGINEERING
|
| Recent studies have shown that thermophotovoltaic (TPV) technology is a promising source of high power density generation. Enhanced TPV systems can theoretically provide power densities of up to 100 W/cm2. The inherent ineffiencies in the system dictate that up to 90% of that energy is not converted to electrical power, and must be removed as waste heat to ensure that the components are maintained at a reasonable operating temperature. The ... |
|
| Interim Proposal for Molecular Beam Studies of Surfactants in Sulfuric Acid Aerosols: Comparisons Between Hydrocarbon and Fluorocarbon Alcohols |
01 MAY 2003 |
6 pages |
| Authors:
Gilbert M. Nathanson; WISCONSIN UNIV-MADISON DEPT OF CHEMISTRY
|
| Heterogeneous reactions of gas phase molecules with aqueous sulfuric acid aerosols play a significant role in the destruction of ozone in the stratosphere. These processes include the acid-catalyzed reactions of HCI and HBr with CIONO2 (BrONO2) and HOCI (HOBr) to generate photoactive halogen molecules, particularly in colder regions of the stratosphere where they are more soluble in the water-rich aerosols. Our objective is to determine the mechanisms and rate-limiting steps ... |
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| Time and Space Resolved Heat Transfer - Boiling and Droplet Cooling Studies Using Microheaters. Droplet and Spray Cooling Heat Transfer |
APR 2003 |
59 pages |
| Authors:
Jungho Kim; MARYLAND UNIV COLLEGE PARK DEPT OF MECHANICAL ENGINEERING
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| Heat transfer by phase change has long been an attractive method of cooling since large amounts of heat can be removed with relatively small temperature differences. The current study focused on making detailed measurements of the heat flux and interfacial motion of isolated droplets (with and without gas) as they impacted an isothermal surface at low and moderate superheats. The heat flux measurements were made using a novel heater array ... |
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| Modeling Dense Sprays in Liquid Rocket Engines |
07 JAN 2003 |
170 pages |
| Authors:
Stephen D. Heister; PURDUE UNIV LAFAYETTE IN SCHOOL OF AERONAUTICS AND ASTRONAUTICS
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| Models have been developed to address instabilities inside coaxial injectors and for basic description of primary atomization processes. The coaxial injector simulations have provided a database to quantify the amplitude and frequency of hydrodynamic instabilities within the submerged region of the injector for a variety of design conditions. Results compare favorably with experimental data showing that plume "flickering" frequencies are correctly predicted by the model. A new nonlinear primary atomization ... |
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| Superfluid Helium Droplet Spectroscopy Equipment Development |
2003 |
9 pages |
| Authors:
Roger E. Miller; NORTH CAROLINA UNIV AT CHAPEL HILL DEPTOF CHEMISTRY
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| The primary goal of this research has been the development of a new helium droplet spectrometer, based upon the use of a PPLN-OPO laser. Although the laser is commercially available, considerable development was required to make the system tunable. We have succeeded in this effort and the laser is now being used to carry out a range of studies related to our AFOSR funded research project dealing with the formation ... |
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| Breast Cancer Prevention by HormonallyInduced Mammary Gland Differentiation: The Role of a Novel Mammary Growth Inhibitor and Differentiation Factor |
OCT 2002 |
19 pages |
| Authors:
Yuenian E. Shi; LONG ISLAND JEWISH-HILLSIDE MEDICAL CENTER NEW HYDE PARK NY
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| A mammary derived growth inhibitor related gene and a fatty acid binding protein MRG was previously identified and characterized. The present study is to test the hypothesis that MRG is a candidate mediator of the differentiating effect of pregnancy and lactation on breast epithelial cells and up-regulation of MRG expression in young nulliparous females can mimic pregnancy- and lactation-induced mammary gland differentiation and prevent breast cancer incidence. Overexpression of MRG ... |
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| Bulk Chemical Source Term Accuracy Requirements |
AUG 2002 |
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| Authors:
Martin B. Richardson; Jay C. Willis; MEVATEC CORP HUNTSVILLE AL
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| Traditionally, chemical weapons effects analyses have assumed a lognormal agent drop size distribution. Used widely within the weapons effects sciences, the lognormal distribution is a relatively simple mathematical expression fully defined by only two numerical parameters: in essence, a mean and a standard deviation, or, in the proper terminology, a droplet Mass Median Diameter (MMD) and a geometric sigma. It has until recently appeared to describe adequately the drop sizes ... |
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Reports by Keyword(s)
DROPS
