National Technical Reports Library: 46 - Physics

1.5 Quasilinear Model for Alpha Particle-TAE Interaction in ARIES ACT-1.

We study the TAE interaction with alpha particle fusion products in ARIES ACT-I using the 1.5D quasilinear model. 1.5D uses linear analytic expressions for growth and damping rates of TAE pressure proles. NOVA-K simulations are conducted to validate ...

3D Gaussian Beam Modeling.

Long-term goals of this research are: provide the underwater acoustic research community and the US Navy with a practical 3D propagation model that can be used over a broad frequency range in passive and active sonar performance prediction, acoustic ...

3-D Sound Propagation and Acoustic Inversions in Shallow Water Oceans.

Sound propagation in the areas of continental shelves is complicated due to many three-dimensional (3-D) oceanographic and marine geologic features, such as shelfbreak frontal systems, nonlinear internal gravity waves and topographic variability. The ...

Accuracy Analysis of DSMC Chemistry Models Applied to a Normal Shock Wave.

A preliminary validation study of three DSMC chemistry models, two recent and one standard, is presented. First the 2D geometry and numerical approach used to simulate the shock experiments is verified. Next, 2 different vibrational relaxation models ...

Acoustic Blind Deconvolution and Source Localization in Shallow Ocean Environments.

The overall long-term goal for this project is to develop engineering tools that are useful to the Navy as it operates in uncertain, partially known, or unknown ocean environments. During the last year, this project has focused on further determining ...

Acoustic Coherent Backscatter Enhancement from Aggregations of Marine Animals.

LONG-TERM GOALS: The overall long-term goal for this project is to determine if and how acoustic coherent backscatter enhancement (ACBE) can be used for classification of active sonar returns in a wide variety of ocean environments. During its first ...

Acoustic Communications and Navigation for Mobile Under-Ice Sensors.

The long-term goals of this project are to create a new capability for under-ice acoustic navigation and communication, specifically in support of the ONR Marginal Ice Zone (MIZ) Departmental Research Initiative (DRI). The MIZ DRI field program will ...

Acoustic Metadata Management and Transparent Access to Networked Oceanographic Data Sets.

The long-term goals of this effort are to produce software capable of organizing and archiving metadata associated with the detection of marine mammals. The software provides a workbench for researchers to integrate queries for both biological and ph ...

Acoustic Propagation in Continental Shelf Break and Slope Environments.

The long-term goal of the research is to increase the physical understanding of acoustic propagation in continental shelf and slope environments in the 50-4000 Hz band. This includes both the physics of the seabed and the coupling to physical mechani ...

Advanced Jet Noise Exhaust Concepts in NASA's N+2 Supersonics Validation Study and the Environmentally Responsible Aviation Project's Upcoming Hybrid Wing Body Acoustics Test.

Acoustic and flow-field experiments were conducted on exhaust concepts for the next generation supersonic, commercial aircraft. The concepts were developed by Lockheed Martin (LM), Rolls-Royce Liberty Works (RRLW), and General Electric Global Researc ...

Advances in Domain Connectivity for Overset Grids Using the X-Rays Approach.

Advances in automation and robustness of the X-rays approach to domain connectivity for overset grids are presented. Given the surface definition for each component that makes up a complex configuration, the determination of hole points with appropri ...

Advancing Underwater Acoustic Communication for Autonomous Distributed Networks via Sparse Channel Sensing, Coding, and Navigation Support.

We have three objectives in this project: (1) Advanced communication techniques of sparse channel sensing and nonbinary LDPC coding. Underwater acoustic channels are naturally sparse, but how to effectively exploit the sparsity is a challenging task. ...

Aeroacoustics of Three-Stream Jets.

Results from acoustic measurements of noise radiated from a heated, three-stream, co-annular exhaust system operated at subsonic conditions are presented. The experiments were conducted for a range of core, bypass, and tertiary stream temperatures an ...

ALLTEM Multi-Axis Electromagnetic Induction System Demonstration and Validation.

Unexploded ordnance (UXO) is one of the most pressing problems facing the U.S. Department of Defense (DoD) and other government agencies that have lands that were once used for military training and are now closed or closing and being transferred to ...

Analyses of Noise from Reusable Solid Rocket Motor (RSRM) Firings.

NASA s Space Launch Vehicle (SLS) program has chosen the Reusable Solid Rocket Motor V (RSRMV) as the booster system for initial flights. Lift off acoustics continue to be a consideration in overall vehicle vibroacoustic evaluations and launch pad mo ...

Analysis and Modeling of Ocean Acoustic Fluctuations and Moored Observations of Philippine Sea Sound-Speed Structure.

The primary objective of this work is the development of accurate, and computationally efficient, reduced-physics acoustic propagation models for the prediction of the statistics of ocean acoustic signals in both shallow and deep-water environments. ...

Analysis of South China Sea Shelf and Basin Acoustic Transmission Data.

LONG-TERM GOALS My long-term research goals are: (1) The characterization, understanding, and prediction of the statistics (mean, variance and coherence) of low-frequency acoustic signals and ambient noise in the littoral zone. The signal statistics ...

Angular Dependence of High-Frequency (>200 kHz) Seafloor Acoustic Backscatter.

LONG-TERM GOALS: The long-term objectives of the proposed research are to develop a physics-based model of high-frequency sound scattering from stratified heterogeneous sediments. Such a model is needed to interpret the ever-increasing amount of seaf ...

Angular Distributions and the Physics of Charmed Meson Production at the 4.028 GeV Resonance.

A detailed study of angular distributions arising from D(anti D), D* anti D) , and D*(anti D)* production at (radical)s= 4.028 GeV is made, including the subsequent decays D*(yields)D(pi) and D* (yields) D(gamma). The production amplitudes are unique ...

APL - North Pacific Acoustic Laboratory.

The ultimate limitations to the performance of long-range sonar are due to ocean sound speed perturbations and the characteristics of the ambient acoustic noise field. Scattering and diffraction resulting from internal waves and other ocean processes ...

Applied Reverberation Modeling Workshop.

LONG TERM GOALS: Improve accuracy, fidelity, and speed of reverberation models for modeling, simulation, training and sonar system performance predictions. OBJECTIVES: The objective is to achieve more efficient transitions from the 6.1 basic research ...

Average Power and Brightness Scaling of Diamond Raman Lasers.

Diamond holds substantial promise as a high Raman gain laser material with outstanding power handling capability, yet despite this the highest reported output power from a diamond Raman laser prior to this project was approximately 1 W. This report d ...

Battle Damage Modeling.

Military structures are susceptible to high velocity impact due to both ballistic and blast loads. During a high velocity impact a shock wave much greater than static collapse resistance propagates through the material. Metallic structures usually un ...

Bayesian Ambient Noise Inversion for Geoacoustic Uncertainty Estimation.

This work has three main objectives: first, quantifying the ability to resolve seabed geoacoustic parameters using ambient noise measurements. Second, comparing those estimates to the ones obtained from active source inversion methods. Third, conside ...

Bayesian Inversion of Seabed Scattering Data (Special Research Award in Ocean Acoustics).

The specific objectives of this project are to carry out Bayesian inversion of scattering and reflection data to estimate seabed scattering and geoacoustic parameters and their uncertainties, and to investigate the relative importance of surface and ...

Biological Agent Neutralization/Computational Modeling Studies.

This research was a collaborative effort between experimental program at Auburn University and a computational modeling study at Pennsylvania State University. Determinations were made of the inactivation of aerosolized Bacillus Anthracis (Ba) single ...

Boron Nitride Substrates for High Mobility Chemical Vapor Deposited Graphene.

Chemical vapor deposited (CVD) graphene is often presented as a scalable solution to graphene device fabrication, but to date such graphene has exhibited lower mobility than that produced by exfoliation. Using a boron nitride underlayer, we achieve m ...

Bottom Interaction in Ocean Acoustic Propagation.

This project addresses 'the effects of environmental variability induced by ocean internal waves, internal tides and mesoscale processes, and by bathymetric features including seamounts and ridges, on the stability, statistics, spatial distribution a ...

Center for Plasma Eduge Simulation (CPES): Final Technical Report.

The overall goal of the CPES project was to develop a new integrated and predictive plasma edge simulation code package. This new capability was to consist of a fully kinetic model of neoclassical and turbulent transport in realistic tokamak edge geo ...

Computational Comparison of High Strain Rate Strength and Failure Models for Glass.

Computational studies are performed using the recent Holmquist- Johnson glass model and the earlier Johnson-Holmquist brittle material model. Although the JH-2 model has been adapted to provide reasonably accurate predictions for soda-lime glass, the ...

Computational Investigation of Gear Windage.

A CFD method has been developed for application to gear windage aerodynamics. The goals of this research are to develop and validate numerical and modeling approaches for these systems, to develop physical understanding of the aerodynamics of gear wi ...

Computational Study of the Structure and Mechanical Properties of the Molecular Crystal RDX.

Molecular crystals are commonly used as active pharmaceutical ingredients and high explosive materials. Like simpler crystalline materials, they possess a repeating lattice structure. However, the complexity of the structure-due to having several ent ...

Conservative and Non-Conservative Variability in the Inherent Optical Properties of Dissolved and Particulate Components in Seawater.

The long term goals of this project are to develop methods for separating the observed variability in the inherent optical properties (IOPs) into conservative and non-conservative components, with the goal to use optical measurements to simultaneousl ...

Controlling Inelastic Light Scattering Quantum Pathways in Graphene.

Inelastic light scattering spectroscopy has, since its first discovery been an indispensable tool in physical science for probing elementary excitations, such as phonons,magnons and plasmons in both bulk and nanoscale materials. In the quantum mechan ...

Core Noise: Overview of Upcoming LDI Combustor Test.

This presentation is a technical summary of and outlook for NASA-internal and NASA-sponsored external research on core (combustor and turbine) noise funded by the Fundamental Aeronautics Program Fixed Wing Project. The presentation covers: the emergi ...

Critical Performance Enhancement of Ultrahigh-Bandwidth Microwave Photonic Links through Nonlinear Photonic Signal Processing.

In the first quarter we have focused primarily on the amplitude-encoded link, distortion correction, and RIN transfer. We have experimentally analyzed the amplitude encoded link for gain and 3rd order distortion and are identifying the proper conditi ...

Determining Transmission Loss from Measured External and Internal Acoustic Environments.

An estimate of the internal acoustic environment in each internal cavity of a launch vehicle is needed to ensure survivability of Space Launch System (SLS) avionics. Currently, this is achieved by using the noise reduction database of heritage flight ...

Direct Writing of Graphene-based Nanoelectronics via Atomic Force Microscopy.

This project employs direct writing with an atomic force microscope (AFM) to fabricate simple graphene-based electronic components like resistors and transistors at nanometer-length scales. The goal is to explore their electrical properties for graph ...

Discovery of Sound in the Sea Website.

LONG-TERM GOALS: The long-term goal of this effort is to educate the public on the basic science of sound in the sea; how people and animals use underwater sound to accomplish many of the tasks for which we use light in air; and how sound in the ocea ...

Dynamics and Stability of Acoustic Wavefronts in the Ocean.

To develop a method of modeling sound propagation in an environment with multi-scale inhomogeneities, which preserves the efficiency and intuitive qualities of the ray theory but is free from spurious environmental sensitivity and strong perturbation ...

Effects of Sand Sediment Volume Heterogeneities on Sound Propagation and Scattering.

To model the effects of volume heterogeneities in: (1) scattering from sand sediments; and (2) in sound propagation within those sediments. A better understanding of the role of heterogeneities in both scattering and propagation could lead to improve ...

Efficient Acoustic Uncertainty Estimation for Transmission Loss Calculations.

LONG-TERM GOALS: The overall long-term goal for this project is to enhance the Navy's predictive capabilities in uncertain ocean environments. This project is a collaboration with Dr. Robert Zingarelli at the Naval Research Laboratory - Stennis Space ...

Efficient Inversion in Underwater Acoustics with Iterative and Sequential Bayesian Methods.

LONG TERM GOALS: The long term goal of this project is to develop efficient inversion algorithms for successful geoacoustic parameter estimation and source localization, exploiting (fully or partially) the physics of the propagation medium. Algorithm ...

Environmental Acoustics and Intensity Vector Acoustics with Emphasis on Shallow Water Effects and the Sea Surface.

To understand and predict key properties of the signal intensity vector field in forward propagation with emphasis on mid-frequency, shallow water propagation. Because of enabling technologies involving MEMS and bio-inspired transduction, tomorrow's ...

Evidence for Stable High Temperature Ferromagnetism in Fluorine Treated C60.

It is shown by magnetic field dependent ac susceptibility, magnetic force microscopy, and ferromagnetic resonance that exposure of C(sub 60) to fluorine at 160 deg C produces a stable ferromagnetic material with a Curie temperature well above room te ...

Expanded Processing Techniques for EMI Systems.

The goal of this project was to improve the data processing algorithms and optimize the instrument using the results and experience of prior MetalMapper UXO-discrimination demonstrations at the former Camp San Luis Obispo and the former Camp Butner. ...

Expansion of a Direct Simulation-Based Study of Radiance in a Dynamic Ocean.

The objective of the project is to apply advanced physics-based computational prediction capabilities, for oceanic radiative transfer, surface wave dynamics and near surface turbulence, to further understand the characteristics and obtain modeling pa ...

Experimental Investigation of Cavitation Induced Feedline Instability from an Orifice.

This paper details the results of an experimental investigation into the cavitation instabilities created by a circular orifice conducted at the University of Alabama in Huntsville Propulsion Research Center. This experiment was conducted in concert ...

Experimentally-Based Ocean Acoustic Propagation and Coherence Studies.

LONG TERM GOALS: The long term goal is to better understand fluctuating sound propagation conditions in two distinct ocean acoustic environment types. The first type is stratified shallow water where sound is highly bottom interacting. The second typ ...

Extension of the Time-Spectral Approach to Overset Solvers for Arbitrary Motion.

Forced periodic flows arise in a broad range of aerodynamic applications such as rotorcraft, turbomachinery, and flapping wing configurations. Standard practice involves solving the unsteady flow equations forward in time until the initial transient ...

Finite Element Approach for Multidimensional Inverse Heat Conduction.

An efficient technique for mapping thermal boundary conditions is described and demonstrated. The technique is based on a piece-wise polynomial approximation where the Laplacian derivatives in space are constrained using the heat equation. Measured v ...

Finite Element Method Mesh Study for Efficient Modeling of Piezoelectric Material.

The purpose of this study is to evaluate modeling of piezoceramic materials with maximum efficiency; that is high fidelity with shortest computer run time. To do this, the modeler varied the number of element layers and element types in each part to ...

Fluorescence of Optically Pumped Trapped Ions.

Narrow bandwidth laser excitation of the 2 (sup 3)s(sub 1) (yields) 2 (sup 3)P(sub J) (J= 0,1,2) transitions near 5485 (Angstrom) from 2 (sup 3)S(sub 1) Li(sup +) ions confined in an rf quadrupole trap has produced novel fluorescence response curves ...

Formation and Stability of Impurity 'Snakes' in Tokamak Plasmas.

New observations of the formation and dynamics of long-lived impurity-induced helical 'snake' modes in tokamak plasmas have recently been carried-out on Alcator C-Mod. The snakes form as an asymmetry in the impurity ion density that undergoes a seaml ...

Frequency-Based Spatial Correlation Assessments of the Ares I Subscale Acoustic Model Test Firings.

No abstract available. ...

Functional Entropy Variables: A New Methodology for Deriving Thermodynamically Consistent Algorithms for Complex Fluids, with Particular Reference to the Isothermal Navier-Stokes-Korteweg Equations.

We propose a new methodology for the numerical solution of the isothermal Navier-Stokes-Korteweg equations. Our methodology is based on a semi-discrete Galerkin method invoking functional entropy variables, a generalization of classical entropy varia ...

Geoacoustic Inversion in Shallow Water.

LONG TERM GOALS: The ability to predict transmission loss of sound propagating in shallow water is constrained by the knowledge of the geoacoustic properties of the bottom. The long term objectives of this research project are related to the investig ...

Giga-Hertz Electromagnetic Wave Science and Devices for Advanced Battlefield Communications.

Our work concentrated on on-wafer delay lines based on liquid crystals. These non-dispersive devices were tested in the range of 1-110 GHz and exhibit phase change on the order of 300 deg./cm. We have designed also series of other tunable devices bas ...

Graphene Plasmonics for Tunable Terahertz Metamaterials.

Plasmons describe collective oscillations of electrons. They have a fundamental role in the dynamic responses of electron systems and form the basis of research into optical metamaterials. Plasmons of two-dimensional massless electrons, as present in ...

High Fidelity Simulations of Plume Impingement to the International Space Station.

With the retirement of the Space Shuttle, the United States now depends on recently developed commercial spacecraft to supply the International Space Station (ISS) with cargo. These new vehicles supplement ones from international partners including t ...

High Frequency Acoustic Reflection and Transmission in Ocean Sediments.

Development of a physical model of high-frequency acoustic interaction with the ocean floor, including penetration through and reflection from smooth and rough water/sediment interfaces, scattering from the interface roughness and volume heterogeneit ...

High-Frequency Acoustic Propagation in Shallow, Energetic, Highly-Salt- Stratified Environments.

The long term goal of this research is to measure and understand high-frequency, line-of-sight acoustic propagation in an estuarine environment characterized by strong tidal flow, often large salinity stratification, high shear, high dissipation rate ...

Hybrid Approach for Characterizing Linear and Nonlinear Electromagnetic Scattering: Theory and Applications.

A hybrid physics-based solver is developed for studying the harmonic scattering of circuit-component-loaded objects. The proposed approach features a combination of three-dimensional (3-D) electromagnetic field simulations - of both the full-wave and ...

Hyperspectral Tethered Spectral Radiometer Buoy: Ocean Color Algorithm Development in Estuaries, Coastal Waters, and Marginal Seas.

The goal for this project was to upgrade a multispectral tethered spectral radiometer buoy to a hyperspectral version that would have the capability to resolved fine scale features in reflectance related to pigment absorption peaks. The scientific go ...

Impact of Masker Fringe and Masker Sparial Uncertainty on Sound Localization.

Signal-in-noise detection improves when the masker duration extends beyond that of the signal ('masker fringe') relative to the case in which the signal and masker are pulsed on/off simultaneously. This improvement has been attributed to the fact tha ...

Impact of Range-Dependent Sediment Properties on the Acoustic Field in 2-D Shallow Water Environments.

The goal of this research is to understand the effects of range- dependent sediment properties on the acoustic field in 2-D shallow water environments. This information, in part, is required to solve the statistical inference problem in inhomogeneous ...

Improving Attachments of Non-Invasive (Type III) Electronic Data Loggers to Cetaceans - Year Two Progress Report.

The overall goal of this project is to increase the longevity of suction cup attachments for short term archival tags such as the DTAG. Specifically, we are working to extend the routine attachment duration for suction-cup tags to multiple days, if n ...

Improving X-ray Optics Through Differential Deposition.

The differential deposition technique can in theory correct shell figures to approximate arcsecond value. We have received APRA funding and are building two custom system to demonstrate the technique on full shell and segmented optics. We hope to be ...

Impulse Noise Bearing and Amplitude Measurement and Analysis System (BAMAS).

The BAMAS project addresses SERDP CPSON 05-04 for improving the measurement, analysis, archiving and reporting of impulsive acoustic noise emanating from within a military installation. Impulsive noise events that cause public alarm are loud, high si ...

Influence of Containment on the Growth of Silicon-Germanium: A Materials Science Flight Project.

This investigation involves the comparison of results achieved from three types of crystal growth of germanium and germanium-silicon alloys: (1) Float zone growth (2) Bridgman growth (3) Detached Bridgman growth crystal The fundamental goal of the pr ...

Initial Experiments on Thermal Interface Materials for Electronics Packaging.

Initial experiments on thermal interface materials (TIMs) for millimeter-wave monolithic integrated circuit (MIMIC) packaging were performed. A variety of types of TIMs were evaluated for thermal performance, ease of use, and cost, with the focus bei ...

Integrated Modeling and Analysis of Physical Oceanographic and Acoustic Processes.

LONG TERM GOALS: The overarching long term goal is to improve ocean physical state and acoustic state predictive capabilities. The shorter-term goal fitting the scope of this project is to create a broadly applicable and portable continental shelf-ar ...

Integration of an Emerging Highly Sensitive Optical CO2 Sensor for Ocean Monitoring on an Existing Data Acquisition System SeaKeeper 1000 (trademark).

The novelly designed optical sensor for autonomous ocean monitoring works on equilibrium principles. When the pH-sensitive reagent solution sitting behind a gas-permeable membrane is exposed to seawater, the CO2 molecules present in the seawater diff ...

Interfacial Thermal Conductance Limit and Thermal Rectification Across Vertical Carbon Nanotube/Graphene Nanoribbon-Silicon Interfaces.

Various models were previously used to predict interfacial thermal conductance of vertical carbon nanotube (CNT)-silicon interfaces, but the predicted values were several orders of magnitude off the experimental data. In this work, we show that the C ...

Inverse Radiative Transfer Analysis for Ocean Optics.

The long-term goal of this research is to support the work of ocean optics experimentalists by developing analytical and numerical methods for solving radiative transfer inverse and forward problems. The ongoing research on inverse problems includes ...

Jet Noise Reduction Potential from Emerging Variable Cycle Technologies.

Jet Noise Reduction Potential From Emerging Variable Cycle Technologies.

Kalman Filters for UXO Detection: Real-Time Feedback and Small Target Detection.

Improvement in the detection and discrimination of UXO using the EMI regime has been consistent during the last two decades, in both instrument hardware and detection software. There is nonetheless still a disparity between the often idealized enviro ...

Laboratory and Field Studies of the Acoustics of Multiphase Ocean Bottom Materials.

LONG-TERM GOALS: The long-term scientific objective of this project is to increase our understanding of sound propagation in ocean bottom sediments, including water-saturated sands and muds, gas-bearing sands and muds, and sediments which support sea ...

Local Electronic Properties of Graphene on a BN Substrate via Scanning Tunneling Microscopy.

The use of boron nitride (BN) as a substrate for graphene nanodevices has attracted much interest since the recent report that BN greatly improves the mobility of charge carriers in graphene compared to standard SiO2 substrates. We have explored the ...

Long-Range Propagation through Internal Waves.

LONG-TERM GOALS: This project aims to understand the fluctuations in low frequency (100 Hz, for example) acoustical propagation in the ocean over long distances (50 km to thousands of km), as well as other effects of internal waves and other small-sc ...

Low Frequency Electromagnetic Pulse and Explosions.

This paper reviews and summarizes prior work related to low frequency (< 100 Hz) EMP (ElectroMagnetic Pulse) observed from explosions. It focuses on how EMP signals might, or might not, be useful in monitoring underground nuclear tests, based on the ...

Low Frequency Geoacoustic Inversion Method.

LONG TERM GOALS: The primary long term objective of this project is to: determine a fast and accurate inversion method to estimate bottom properties in shallow water. OBJECTIVES: The objectives of this year s work (FY11) included: to continue study o ...

Low-Frequency Scattering from Heterogeneous Elastic Sea Beds.

The long term scientific objective of this research is to improve our understanding the physics and mechanisms of acoustic bottom interaction and reverberation, including acoustic penetration, propagation, attenuation and scattering in elastic sea be ...

Magnetic Surface Modes and UXO/Clutter Classification and Discrimination.

The basic objective of this research project was to develop an improved understanding of the fundamental physics underlying classification and discrimination of unexploded ordnance (UXO) and clutter items using electromagnetic induction (EMI) data. T ...

Mathematical Modeling of Space-Time Variations in Acoustic Transmission and Scattering from Schools of Swim Bladder Fish (FY11 Annual Report).

The goal is the development of a time-domain acoustical method for investigating the spatial and temporal stochastic variations in fish density within fish schools, and thereby study the statistical fluctuations in the scattering of sound from these ...

Matrix-Free Newton-Krylov Parallel Implicit Implementation of the Absolute Nodal Coordinate Formulation.

This paper sets out to demonstrate three things: (1) implicit integration with ANCF is effective in handling very stiff systems when an accurate computation of the sensitivity matrix is part of the solution sequence; (2) parallel computing can provid ...

Measurements and Analysis of Reverberation, Target Echo, and Clutter: FY11 Annual Report for ONR.

LONG-TERM GOALS: The long-term goal of this work is to better understand and model reverberation, target echo, and clutter in shallow water environments, and to develop techniques for Rapid Environmental Assessment (REA) and environmentally adaptive ...

Middle Atlantic Bight Field Study: SUS Component.

Our long term objective is to investigate the feasibility of using broadband explosive sources such as SUS charges for inversion of oceanographic fields and sediment parameters. We have performed nonlinear inversions using a combination of global sea ...

MOCFE-Bone: The 3D MOC Mini-Application for Exascale Research.

MOCFE-Bone is a mini-application that simulates the main procedures in a 3D method of characteristics (MOC) code for numerical solution of the steady state neutron transport equation. 3D-MOC was chosen as a specific methodology of interest in exascal ...

Model to Test Electric Field Comparisons in a Composite Fairing Cavity.

Evaluating the impact of radio frequency transmission in vehicle fairings is important to sensitive spacecraft. This study shows cumulative distribution function (CDF) comparisons of composite a fairing electromagnetic field data obtained by computat ...

Modeling the Acoustic Channel for Simulation Studies.

The project started on 04/01/10, and the reporting period covers from 09/01/10 to 08/31/11. The main objective for this period was to gain deep insight on the propagation phenomena that most affect underwater acoustic systems, based on the experiment ...

Moment-Based Physical Models of Broadband Clutter due to Aggregations of Fish.

LONG-TERM GOALS: Contribute to a new understanding of what fish parameters control mid-frequency (MF; 1-10 kHz) biological clutter, including the relative influence of oceanographic phenomena; and provide benchmark data sets and statistical models fo ...

Morphology of Primary-Dendrite Array: Observations from Ground-Based and Space Station Processed Samples.

A systematic analysis of the effect of convection on the microstructural evolution in cast binary, ternary and commercial Al-Si based alloys. ...

MURI: Impact of Oceanographic Variability on Acoustic Communications.

LONG-TERM GOALS: Couple together analytical and numerical modeling of oceanographic and surface wave processes, acoustic propagation modeling, statistical descriptions of the waveguide impulse response between multiple sources and receivers, and the ...

NASA Environmentally Responsible Aviation High Overall Pressure Ratio Compressor Research Pre-Test CFD.

This paper describes a collaborative and cost-shared approach to reducing fuel burn under the NASA Environmentally Responsible Aviation project. NASA and General Electric (GE) Aviation are working together aa an integrated team to obtain compressor a ...

NASA Glenn Research Center Experience with LENR Phenomenon.

Since 1989 NASA Glenn Research Center (GRC) has performed some small-scale limited experiments that show evidence of effects claimed by some to be evidence of Low Energy Nuclear Reactions (LENR). The research at GRC has involved observations and work ...

Negative-Mass Instability in Nonlinear Plasma Waves.

The negative-mass instability (NMI), previously found in ion traps, appears as a distinct regime of the sideband instability in nonlinear plasma waves with trapped particles. As the bounce frequency of these particles decreases with the bounce action ...

Noise Measurements of the VAIIPR Fan.

This final report has been prepared by Honeywell Aerospace, Phoenix, Arizona, a unit of Honeywell International, Inc., documenting work performed during the period September 2004 through November 2005 for the National Aeronautics and Space Administra ...

Note on Two-Photon Coherent Antistokes Raman Scattering.

Difference-frequency mixing of two pump waves can in principle excite two coherent phonon waves via the parametric process. Only when the phonon excitation is small, can the nonlinear susceptibility of two-phonon coherent antiStokes Raman scattering ...

Numerical Modeling Efforts in Support of 3-D Environmental Variability and Acoustic Vector Field Studies.

The goals of this work were multi-faceted, consistent with the various efforts supported by this work. One aspect was the continued study of the effects of three-dimensional (3-D) environmental variability on propagation and the flow of energy in the ...

Ocean Bottom Seismometer Augmentation of the NPAL 2010-2011 Philippine Sea Experiment.

This project addresses the coherence and depth dependence of deep-water ambient noise and signals. Seafloor signals are studied in the band from 50-400Hz and seafloor ambient noise is studied in the band from 0.03 - 80Hz. On NPAL04 we observed a new ...

Ocean Variability Effects on Underwater Acoustic Communications.

This proposed research seeks to identify, explain, and ultimately predict, the factors that significantly alter the operational effectiveness of underwater acoustic communications through experimental work and theoretical analysis. The long-term goal ...

Office of Naval Research Graduate Traineeship Award in Ocean Acoustics for Ankita Deepak Jain.

OBJECTIVES A primary goal of this research is to model biological clutter in the continental shelf environments of the ocean. We aim to do this by modeling scattered returns from fish shoals in continental shelf environments using a full field matche ...

ONR Graduate Traineeship Award Update.

LONG-TERM GOALS: This project s goal is to explore ways of using ambient noise in the ocean to extract the physical characteristics of the ocean environment. In addition, this research is the the PI s Ph.D. research, leading to her completed Ph.D. th ...

Passive Ranging Using a Dispersive Spectrometer and Optical Filters.

Monocular passive ranging using atmospheric oxygen absorption has been demonstrated in the past using an FTS. These instruments are very sensitive to vibration making them di cult to use on an airborne platform. This work focuses on whether passive r ...

Physics of Acoustic Radiation from Jet Engine Inlets.

Numerical simulations of acoustic radiation from a jet engine inlet are performed using advanced computational aeroacoustics (CAA) algorithms and high-quality numerical boundary treatments. As a model of modern commercial jet engine inlets, the inlet ...

Physics of Radiation-driven Islands Near the Tokamak Density Limit.

In previous work, the onset criterion for radiation driven islands in combination with a simple cylindrical model of tokamak current channel behavior was shown to be consistent with the empirical scaling of the tokamak density limit. A number of the ...

Plasma Potential and Langmuir Probe Measurements in the Near-field Plume of the NASA-300M Hall Thruster.

In order to aid in the design of high-power Hall thrusters and provide experimental validation for existing modeling efforts, plasma potential and Langmuir probe measurements were performed in the near-field plume of the NASA-300M Hall thruster. A pr ...

Primary Dendrite Array: Observations from Ground-based and Space Station Processed Samples.

No abstract available. ...

Proceedings of the Technical Workshops for the Hydraulic Fracturing Study: Fate and Transport.

The goal of the technical workshops was three-fold: (1) inform EPA of the current technology and practices being used in hydraulic fracturing, (2) identify research related to the potential impacts of hydraulic fracturing on drinking water resources, ...

Proceedings of the Technical Workshops for the Hydraulic Fracturing Study: Water Resources Management.

In its Fiscal Year 2010 budget report, the U.S. House of Representatives Appropriation Conference Committee identified the need for a study of the potential impacts of hydraulic fracturing (HF) on drinking water resources. The Committee directed EPA ...

Project Themis: PIV Measurement of Elbow Flow through a Flow Conditioner.

This presentation provides data for validation of a CFD study done on a VORTAB flow conditioner. Objectives include achievement of a full- developed turbulent velocity profile for pipe flow. Secondary flow will cause a flow meter to register unexpect ...

Propagation and Ambient Noise Studies for Ocean Acoustics Applications.

Ocean ambient noise has been studied for decades. Much of the interest has been on determining the impact of noise on sonar performance. In this context, noise has generally been considered a nuisance and the research focus has been on methods to mea ...

Propagation and Scattering in a Variable Shallow Water Waveguide.

The long-term goal is to develop models for mid-frequency (1-10 kHz) acoustic propagation and scattering effects that can form the basis for model-based signal processing algorithms. Specifically, this includes deterministic propagation effects as en ...

Propagation of How-Frequency, Transient Acoustic Signals through a Fluctuating Ocean: Development of a 3D Scattering Theory and Comparison with NPAL Experimental Data.

Long-term goals: Development of a new, 3D, modal theory of low-frequency, long-range sound propagation through a fluctuating ocean, including both CW and transient acoustic signals. Comparison of theoretical and numerical results with NPAL experiment ...

Purified Self-Amplified Spontaneous Emission (pSASE) Free-Electron Lasers with Slippage-Boosted Filtering.

We propose a simple method to signicantly enhance the temporal coherence and spectral brightness of a self-amplied spontaneous emission (SASE) free-electron laser (FEL). In this puried SASE (pSASE) FEL, a few undulator sections (called slippage-boost ...

Quantifying Geoacoustic Uncertainty and Seabed Variability for Propagation Uncertainty.

LONG-TERM GOALS: Propagation and reverberation of acoustic fields in shallow waters depend strongly on the spatial variability of seabed geoacoustic parameters, and lack of knowledge of seabed variability is often a limiting factor in acoustic modeli ...

Quantifying, Predicting, and Exploiting Uncertainty (QPE).

The long term goal of our QPE work is to: (1) quantitatively understand what the uncertainties are in low frequency (10-1500 Hz) acoustic propagation and noise that are caused by variable and complex oceanography and seabed structure, (2) determine t ...

Quantum Yield Enhancement of Cd/Se Colloidal Quantum Dots by Variation of Surface Ligands.

Colloidal cadmium/selenium (Cd/Se) quantum dots (QDs) were synthesized with two different sets of ligands. The first used simple components, octadecene (ODE), which serves both as a solvent and a ligand, and oleic acid, which also serves as a ligand. ...

Realization and Integration of Large Lattice Mismatched Materials for Device Innovation: A Comprehensive Approach to the Underlying Science and Practical Application.

Critical DoD need for advanced, high performance, multi-functional devices and circuits is addressed in this work. The underlying technology need is materials integration: the monolithic or polylithic assembly of functional materials and devices and ...

Reduced-Order Model Based Feedback Control for Modified Hasegawa-Wakatani Model.

In this work, the development of model-based feedback control that stabilizes an unstable equilibrium is obtained for the Modified Hasegawa-Wakatani (MHW) equations, a classic model in plasma turbulence. First, a balanced truncation (a model reductio ...

Reynolds-Averaged Turbulence Model Assessment for a Highly Back-Pressured Isolator Flowfield.

The use of computational fluid dynamics in scramjet engine component development is widespread in the existing literature. Unfortunately, the quantification of model-form uncertainties is rarely addressed with anything other than sensitivity studies, ...

RF Exposure Analysis for Multiple Wi-Fi Devices In Enclosed Environment.

Wi-Fi devices operated inside a metallic enclosure have been investigation in the recent years. A motivation for this study is to investigate wave propagation inside an enclosed environment such as elevator, car, aircraft, and spacecraft. There are p ...

Scale Model Acoustic Test Overview.

No abstract available. ...

Science Drivers and Technical Challenges for Advanced Magnetic Resonance.

This report recaps the 'Science Drivers and Technical Challenges for Advanced Magnetic Resonance' workshop, held in late 2011. This exploratory workshop's goal was to discuss and address challenges for the next generation of magnetic resonance experi ...

Scientific Discovery with the Blue Gene/L.

This project succeeded in developing key software optimization tools to bring fundamental QCD calculations of nucleon structure from the Terascale era through the Petascale era and prepare for the Exascale era. It also enabled fundamental QCD physics ...

Seabed Geoacoustic Structure at the Meso-Scale.

LONG TERM GOALS: The long term science goals are to understand the nature of seabed variability at meso-scales O(101- 103) m and determine how meso-scale structures impact acoustic propagation, diffuse reverberation, and clutter. OBJECTIVES: The obje ...

Seabed Scattering Model from Low Frequency Reverberation Measurements in Shallow Water.

LONG-TERM GOALS: The long-term goal of this work is: to develop a low-frequency (LF) seabed scattering model from shallow-water (SW) reverberation measurements. The model can be used to predict SW reverberation and echo-to-reverberation ratio in a fr ...

Seafloor Shear Measurement Using Interface Waves.

The long term goal of our research is to improve the estimation of bottom properties by understanding and incorporating the effects produced by shear. The objectives of this proposal are to: (1) Develop an acoustic/seismic receive system for the esti ...

Sediment Acoustics: Wideband Model, Reflection Loss and Ambient Noise Inversion.

Physically sound models of acoustic interaction with the ocean floor including penetration, reflection and scattering in support of MCM and ASW needs. (1) Consolidation of the BIC08 model of sediment acoustics, its verification in a variety of sedime ...

Self-Assembly of 3-D Multifunctional Ceramic Composites for Photonics and Sensors.

Under MURI support, we are (1) demonstrating the formation of highly functional 3-D photonic crystals using interference lithography; the breakthrough tools are be gray-scale phase masks designed with genetic algorithms (GAs) and fabricated through s ...

Sequential Geoacoustic Filtering and Utilizing Ambient Noise for Geoacoustic Inversion.

The development of new geoacoustic inversion methods, their use in the analysis of shallow water experimental data, and evaluation of geoacoustic model and parameter uncertainties including the mapping of these uncertainties through to system perform ...

Shallow Water Propagation and Surface Reverberation Modeling.

The primary long-term goal is to measure and model high-frequency acoustic propagation in the presence of surface gravity waves and breaking waves to better understand the effects of surface reverberation on shallow water, underwater acoustic communi ...

Shallow Water Propagation.

LONG-TERM GOALS: Develop methods for deterministic and stochastic acoustic calculations in complex shallow water environments, specify their capabilities and accuracy, and apply them to explain experimental data and understand physical mechanisms of ...

Single Particle Spectra Associated with High-Multiplicity Events in 800 MeV/Nucleon Ar on KCl and Pb.

High-multiplicity events were selected in collisions of 800 HeV per nucleon Ar on KCl and Pb. In these events projectile fragments are highly suppressed, and the angular distributions of high-energy protons are almost isotropic in a moving frame whos ...

Soft-Gluon Dynamics for Heavy Quark-Antiquark Systems.

The interaction of a heavy quark-antiquark system with color gluons is classified according to the gluon energy, and a manifestly gauge-invariant multipole expansion scheme is constructed. This multipole expansion has useful applications to the study ...

Spatially Resolved Temperature and Water Vapor Concentration Distributions in Supersonic Combustion Facilities by TDLAT.

Detailed knowledge of the internal structure of high-enthalpy flows can provide valuable insight to the performance of scramjet combustors. Tunable Diode Laser Absorption Spectroscopy (TDLAS) is often employed to measure temperature and species conce ...

Spray Statistics and the Impact of Geometry in Gas-Centered Swirl Coaxial Injectors.

Optically dense sprays are often encountered in propulsion applications such as rocket engines. The density of these sprays prevents measurement of droplet diameters and quantitative assessment of spray quality. The lack of quantitative data hinders ...

Spurious Behavior of Shock-Capturing Methods: Problems Containing Stiff Source Terms and Discontinuities.

The goal of this paper is to relate numerical dissipations that are inherited in high order shock-capturing schemes with the onset of wrong propagation speed of discontinuities. For pointwise evaluation of the source term, previous studies indicated ...

Standoff Inverse Analysis and Manipulation of Electronic Systems.

The vision of SIAMES was to study the interaction between RF fields and electronic circuits, with the ultimate goal of rapid and accurate extraction of system, functional, and device information from external stimulus and monitoring of electronic sys ...

Structural Technology Evaluation and Analysis Program (STEAP). Delivery Order 0046: Multiscale Modeling of Composite Structures Subjected to Cyclic Loading.

This report documents four critical tasks concerned with the development and implementation of an advanced and novel modeling framework for predicting damage accumulation in composite structures undergoing monotonic and fatigue loadings. The critical ...

Surface Catalysis and Oxidation on Stagnation Point Heat Flux Measurements in High Enthalpy Arc Jets.

Heat flux sensors are routinely used in arc jet facilities to determine heat transfer rates from plasma plume. The goal of this study is to assess the impact of surface composition changes on these heat flux sensors. Surface compositions can change d ...

SW06 Data Analysis, Slope-Canyon Experiment Planning, and Long-Range Sound Propagation with Applications to the Arctic.

The long term goals of our shallow water acoustics work are to: (1) understand the nature of low frequency (10-1500 Hz) acoustic propagation and scattering in shallow water when strong oceanic variability is present in the form of fronts, eddies, bou ...

Temporally Evolving Mixing Layers.

Three high order shock-capturing schemes are compared for large eddy simulations (LES) of temporally evolving mixing layers (TML) for different convective Mach numbers (Mc) ranging from the quasi-incompressible regime to highly compressible supersoni ...

Three-Sublattice Model for a Triangular Lattice Gas.

A three-sublattice Bragg-Williams model of a triangular lattice gas with repulsive nearest-neighbor interactions is presented. It is intended to represent intercalated Li+ in LixTiS 2 . An order-isorder phase diagram and thermodynamic functions are c ...

Trajectory and Mixing Scaling Laws for Confined and Unconfined Transverse Jets.

Transverse jets play an important role in many propulsion-related applications including gas turbine burner dilution, exhaust from V/STOL aircraft, and fluidic thrust vectoring. Although this flow has received extensive research attention over severa ...

Transmission Electron Microscopy and Rutherford Backscattering Studies of Different Damage Structures in P(+) Implanted Si.

Cross-sectional transmission electron microscopy (TEM) and MeV He(sup +) channelling methods have been used to examine different damage structures present under the colour bands visible at the surface of a high dose rate P(sup +) implanted (111) Si i ...

Transport of Mass, Energy, and Entropy in Cryogenic Support Struts for Engineering Design.

Engineers working to understand and reduce cryogenic boil-off must solve a. variety of transport problems. An important class of nonlinear problems involves the thermal and mechanical design of cryogenic struts. These classic problems are scattered a ...

Transport Theory for Propagation and Reverberation.

Development of computationally efficient modeling methods for shallow water propagation and reverberation that can account for the effects of multiple forward scattering from waveguide boundary roughness and volume heterogeneity such as internal wave ...

Travel-Time and Amplitude Sensitivity Kernels.

LONG-TERM GOALS: Our long-term goal is to study the sensitivity behavior of travel-time and arrival-amplitude observables due to sound-speed perturbations in low-frequency, long-range acoustic propagation in the ocean. OBJECTIVES: The leading objecti ...

Two-Proton Correlation Measurements in 800- and 400- MeV/nucleon Heavy-Ion Reactions.

Energy and angular correlations of two protons emitted in collisions of C +C, C + Pb, Ne + NaF, Ar + KCl, at E(sub Beam)(sup Lab) = 800 MeV/A, and Ne + NaF at E(sub Beam)(sup Lab) = 400 MeV/A have been measured. A strong correlation due to p-p quasi- ...

Unified Approach to Passive and Active Ocean Acoustic Waveguide Remote Sensing.

OBJECTIVES AND APPROACH: Ocean acoustic waveguide remote sensing (OAWRS) is the basis for the primary undersea surveillance systems of the US Navy for both passive and active detection, localization, imaging and monitoring. Here OAWRS refers to all a ...

Unresolved Problems by Shock Capturing: Taming the Overheating Problem.

The overheating problem, first observed by von Neumann (1) and later studied extensively by Noh (2) using both Eulerian and Lagrangian formulations, remains to be one of the unsolved problems by shock capturing. It is historically well known to occur ...

Validation of Numerical Predictions of the Impact Forces and Hydrodynamics of a Deep-V Planing Hull.

The focus of this paper is to describe and document a recent effort to assess these numerical codes for the prediction of deep-V planing craft hydrodynamic forces and moments and evaluate how well NFA models the complex multiphase flows associated wi ...

Verification of Ares I Liftoff Acoustic Environments via the Ares I Scale Model Acoustic Test.

The Ares I Scale Model Acoustic Test (ASMAT) program was implemented to verify the predicted Ares I liftoff acoustic environments and to determine the acoustic reduction gained by using an above deck water sound suppression system. The test article i ...

Zonal Flow as Pattern Formation: Merging Jets and the Ultimate Jet Length Scale.

Zonal flows are well known to arise spontaneously out of turbulence. It is shown that for statistically averaged equations of quasigeostrophic turbulence on a beta plane, zonal flows and inhomogeneous turbulence fit into the framework of pattern form ...