| Electromagnetic Field Control and Optimization Using Metamaterials |
Dec-2009 |
168 pages |
| Authors:
Jeffrey S McGuirk; AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH GRADUATE SCHOOL OF ENGINEERING AND MANAGEMENT
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 | Transformation optics has shown the ability to cloak an object from incident electromagnetic radiation is possible. However, the material parameters are inhomogeneous, anisotropic, and, in some instances, singular at various locations. In order for a cloak to be practically realized, simplified parameter sets are required. However, the simplified parameters result in a degradation in the cloaking function. Constitutive parameters for simplified two-dimensional cylindrical cloaks have been developed with two material ... |
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| Penetration Physics at the Meso-Scale |
06-Oct-2009 |
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| Authors:
Conrad W Felice; Y M Gupta; WASHINGTON STATE UNIV PULLMAN INST FOR SHOCK PHYSICS AND PHYSICS DEPT
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 | This effort focused on understanding the underlying physics through a multi-scale computational approach to quantify penetrator performance into particulate geologic materials at impact velocities up to 1,500 m/sec. The computational approach employed an explicit, updated Lagrangian finite element formulation that performed 2-D plain strain and axisymmetric analyses of multi-body systems subjected to shock wave loading. To capture the particulate response, a simple elastic-plastic constitutive model was used to represent the ... |
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| Source and Path Calibration in Regions of Poor Crustal Propagation using Temporary, Large-Aperture, High-Resolution Seismic Arrays |
30-Sep-2009 |
9 pages |
| Authors:
John L Nabelek; Jochen Braunmiller; W S Phillips; OREGON STATE UNIV CORVALLIS
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| Broadband seismic data acquired during the Hi-CLIMB field experiment are used to study seismic events and path propagation in the Nepal Himalaya and south-central Tibetan Plateau. Similarities in regional propagation between Tibet and Iran motivate this new study. The 2002-2005 Hi-CLIMB experiment consisted of 233 stations distributed along a dense 800 km linear north-south array extending from the Himalayan foreland into the central Tibetan Plateau. The main array was flanked ... |
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| Digital Control of Exchange Interaction in a Spin-based Silicon Quantum Computer |
07-Sep-2009 |
5 pages |
| Authors:
James C Sturm; Leonid P Rokhinson; PURDUE UNIV LAFAYETTE IN
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| The objective of the proposed work was to demonstrate that digital switching of the exchange interaction by real space electron transfer will provide a viable method for accurate control of inter-qubit interactions. In order to fix the strength of the exchange interaction at the fabrication stage we proposed a new technology for 3D confinement of electrons by abrupt epitaxial Si/SiGe interface. During the course of the project we developed CVD ... |
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| Numerical Model Study of the Tuscarawas River below Dover Dam, Ohio |
Sep-2009 |
58 pages |
| Authors:
Richard L Stockstill; Jane M Vaughan; ENGINEER RESEARCH AND DEVELOPMENT CENTER VICKSBURG MS COASTAL AND HYDRAULICS LAB
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| The U.S. Army Corps of Engineers, Huntington District (LRH) has been charged with upgrading Dover Dam to meet hydrologic design standards and address stability issues. The LRH requested that the U. S. Army Engineer Research and Development Center, Coastal and Hydraulics Laboratory (CHL), evaluate the flow conditions in the Tuscarawas River downstream of Dover Dam as part of a safety assurance program. The two-dimensional depth-averaged module of the Adaptive Hydraulics ... |
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| Predicting Electron Transport Using Simulated Axial Waves in a Radial-Axial Hybrid Hall Thruster Model |
Sep-2009 |
12 pages |
| Authors:
Michelle K Scharfe; Mark A Cappelli; Eduardo Fernandez; ENGINEERING RESEARCH AND CONSULTING INC (ERC INC) EDWARDS AFB CA
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| Axial waves predicted by a two-dimensional hybrid numerical model have been used to estimate electron cross field transport due to tilted waves with azimuthal components. Since the radial-axial hybrid simulation cannot model these tilted waves directly, the predicted axial waves are assumed to couple symmetrically into two counter-propagating axial-azimuthal waves. A linearized two-dimensional dispersion relation is solved to obtain the azimuthal component of wavenumber consistent with the frequency and axial ... |
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| Effect of Wall Sheaths on Ion Trajectories in a Hall Thruster Numerical Model |
Sep-2009 |
12 pages |
| Authors:
Regina M Sullivan; Joseph E Shepherd; Michelle K Scarfe; Ioannis G Mikellides; Lee K Johnson; CALIFORNIA INST OF TECH PASADENA
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| A 2D framework for solving the sheath equations near a dielectric corner has been developed and applied in a quasi 2D fashion to solve for sheath thickness and potential profile. When appropriate, boundary conditions were taken from an HPHall model of an SPT-70 Hall thruster. Ion paths within the sheath were also calculated. Results suggest that the radial acceleration provided by the sheath has the ability to produce significant changes ... |
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| Quantum Sensors Program |
Aug-2009 |
82 pages |
| Authors:
Z Dutton; S Guha; N Stelmakh; M Vasilyev; P Kumar; F Wong; J Shaprio; G Deibner; G Burdge; H Yuen; J Habif; HARRIS CORP MELBOURNE FL
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| The resolution of a homodyne LADAR can be enhanced significantly by applying quantum optical techniques in the receiver. With a quantum image enhancer (QIE) inserted between the receive optics and the detector of a LADAR, an angular cell resolution improvement of 10x can be realized. The QIE is comprised of two key elements-a squeezed vacuum injector (SVI) that restores the high spatial frequencies lost by attenuation in soft-aperture entrance optics ... |
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| Next Generation Highly Conducting Organic Films Using Novel Donor-Acceptor Molecules for Opto-Electronic Applications |
Jun-2009 |
16 pages |
| Authors:
Eric Forsythe; Jianmin Shi; David Morton; ARMY RESEARCH LAB ADELPHI MD SENSORS AND ELECTRON DEVICES DIRECTORATE
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| This two-year DRI is intended to address the Army's need for two-dimensional, conformal, large-area electronics by developing techniques that will lead to the printing of conducting organic materials as a primary build-block that will enable such low-cost, large area applications. In the first year, we worked on developing novel organic based molecules using the donor-acceptor design concepts and developing a more fundamental understanding of donor acceptor molecule stacking in order ... |
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| Gravitational and Magnetic Anomaly Inversion Using a Tree-Based Geometry Representation |
Jun-2009 |
24 pages |
| Authors:
George A Gazonas; Raymond A Wildman; ARMY RESEARCH LAB ABERDEEN PROVING GROUND MD WEAPONS AND MATERIALS RESEARCH DIRECTORATE
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| Gravitational and magnetic anomaly inversion of homogeneous 2D and 3D structures is treated using a geometric parameterization that can represent multiple, arbitrary polygons or polyhedra and a local-optimization scheme based on a hill-climbing method. This geometry representation uses a tree data structure, which defines a set of Boolean operations performed on convex polygons. A variable-length list of points, whose convex hull defines a convex polygon operand, resides in each leaf ... |
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| Application of the Backward-Smoothing Extended Kalman Filter to Attitude Estimation and Prediction using Radar Observations |
Jun-2009 |
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| Authors:
Kyle C Volpe; MASSACHUSETTS INST OF TECH CAMBRIDGE
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| The Lincoln Attitude Estimation System (LAES), a new tool being developed for the Space Situational Awareness Group (SSAG) at MIT Lincoln Laboratory, integrates several existing hardware and software systems, with a backward-smoothing extended Kalman filter (BSEKF). LAES is intended to determine the rotational motion of a freely tumbling spacecraft from a sequence of discrete-time radar images. The raw range-Doppler returns are collected using a ground-based sensor, which is owned and ... |
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| Characterization of Convective Boiling in Branching Channel Heat Sinks |
06-May-2009 |
17 pages |
| Authors:
Deborah V Pence; James A Liburdy; Vinod Narayanan; OREGON STATE UNIV CORVALLIS
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| Convective boiling and gas-liquid flows in branching microscale flow networks within disk-shaped heat sinks were studied experimentally. Void fraction and flow regime variations as a function of branch level were reported for gas-liquid flows and compared with existing void fraction correlations and regime maps, respectively. Two methods for assessing void fraction were used, with void fraction assessed using two-dimensional high-speed images providing the best assessment. Void fraction in convective boiling ... |
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| Considerations for Modeling Flow Control Structures in ADaptive Hydraulics (ADH) |
May-2009 |
8 pages |
| Authors:
Charlie Berger; Gaurav Savant; ENGINEER RESEARCH AND DEVELOPMENT CENTER VICKSBURG MS GEOTECHNICAL AND STRUCTURES LAB
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| This System-Wide Water Resources Program (SWWRP) technical note presents the incorporation of reversible flow-control structures to the two-dimensional (2-D) Shallow- Water (SW2) module of ADaptive Hydraulics (ADH). The SW2 module can model the obstruction to flow directly; however, the grid detail required for evaluating flow field impacts is cumbersome for the user to readily generate. This technical note details a quick and easy method to describe the structure and model ... |
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| Comparative Evaluation of Display Technologies for Collaborative Design Review |
Apr-2009 |
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| Authors:
Lochlan Magee; Ming Hou; Andrea Scipione; Mike Greenley; Justin G Hollands; DEFENCE RESEARCH AND DEVELOPMENT TORONTO (CANADA)
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| The effectiveness of five display technologies for supporting a collaborative workspace design review was compared. Participants searched for design flaws in a model of the front dashboard of a vehicle including an in-vehicle navigation system. The display types were 2D CRT, 3D CRT, 3D via Curved plasma display, a large DataWall display, and a cave automatic virtual environment (CAVE). Detection accuracy, time, and usability measures were obtained. The results indicated ... |
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| Two Dimensional Scattering Analysis of Data-Linked Support Strings for Bistatic Measurement Systems |
Mar-2009 |
93 pages |
| Authors:
William Keichel; AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH GRADUATE SCHOOL OF ENGINEERING AND MANAGEMENT
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| Use of data-linked strings to support a bistatic antenna is being considered as a possible improvement to indoor bistatic radar cross section measurement systems. Analysis of candidate data-linked strings is required to understand the potential clutter contribution posed by such a system. The main objective of this research is to determine the scattering properties of four data-linked support string samples. Another goal is to determine the material properties of the ... |
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| Direct Numerical Simulations of Diffusive Staircases in the Arctic |
Mar-2009 |
61 pages |
| Authors:
Gregory P Caro; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
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| The vertical transport of heat by the diffusive layer in the Arctic thermocline is a critical element of the high-latitude climate, and yet, after decades of research, the extant estimates remain highly controversial. Laboratory-based estimates of vertical heat fluxes originating from the thermohaline staircases of the thermocline are typically on the order of 0.1W/m2. This study suggests that these laboratory experiments underestimate the vertical heat fluxes and exceed their calculations ... |
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| An Investigation of Shock Wave Physics via Hybrid CFD-BGK Solution Methods for Nonequilibrium Flows |
Mar-2009 |
92 pages |
| Authors:
Brook I Bentley; AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH SCHOOL OF ENGINEERING AND MANAGEMENT
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| The Unified Flow Solver, a hybrid continuum-rarefied code, is used to investigate the internal structure of a normal shock wave for a Mach range of 1.55 to 9.0 for Argon, and 1.53 to 3.8 for diatomic Nitrogen. Reciprocal shock thickness, density, temperature, heat flux, and the velocity distribution function are calculated for a one-dimensional shock wave and compared with experimental data from Alsmeyer and DSMC results from Bird. Using the ... |
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| Three-Dimensional Feature Reconstruction with Dual Forward Looking Sonars for Unmanned Underwater Vehicle Navigation |
Mar-2009 |
83 pages |
| Authors:
Nevin A McChesney; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
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| Unmanned Underwater Vehicles frequently rely on two-dimensional sensors for information about their surroundings. These sensors do not provide adequate information for obstacle avoidance in cluttered maritime environments. To address that issue, a three-dimensional reconstruction of the environment utilizing occupancy grids and a prototype forward looking sonar will be considered. Providing the vehicle with three-dimensional views of the environment will allow for optimal route planning and an increase in successful missions ... |
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| An Advanced Tabu Search Approach to Solving the Mixed Payload Airlift Load Planning Problem |
Mar-2009 |
149 pages |
| Authors:
Robert L Nance; AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH GRADUATE SCHOOL OF ENGINEERING AND MANAGEMENT
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| This paper presents a new tabu search based two-dimensional bin packing algorithm which produces high quality solutions to the Mixed Payload Airlift Load Planning (MPALP) problem using C-5 and C-17 aircraft. This algorithm, called Mixed Payload Airlift Load Planning Tabu Search (MPALPTS), surpasses previous research conducted in this area because, in addition to pure pallet cargo loads, MPALPTS can accommodate rolling stock cargo (i.e. tanks, trucks, HMMMVs, etc.) while still ... |
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| Biomarkers for Amyotrophic Lateral Sclerosis in Active Duty Military (BALSAM) |
Feb-2009 |
56 pages |
| Authors:
David Millhorn; John Schlager; CINCINNATI UNIV OH
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| To compare serum samples from individuals diagnosed with amyotrophic lateral sclerosis (ALS) to serum samples from matched individuals who did not develop ALS. In this study we aim to identify candidate serum biomarkers that are unique for ALS and identify a subset of diagnostic serum biomarkers for early detection of ALS prior to the appearance of overt symptoms. Scope: The significance of a positive identification of protein biomarkers for ALS ... |
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| Detection of Rossby Waves in Multi-Parameters in Multi-Mission Satellite Observations and HYCOM Simulations in the Indian Ocean |
Jan-2009 |
12 pages |
| Authors:
Jay F Shriver; Bulusu Subrahmanyam; David M Heffner; David Cromwell; NAVAL RESEARCH LAB STENNIS SPACE CENTER MS OCEANOGRAPHY DIV
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| Rossby waves are difficult to detect with in situ methods. However, as we show in this paper, they can be clearly identified in multi-parameters in multi-mission satellite observations of sea surface height (SSH), sea surface temperature (SST) and ocean color observations of chlorophyll-a (chl-a), as well as 1/12-deg global HYbrid Coordinate Ocean Model (HYCOM) simulations of SSH, SST and sea surface salinity (SSS) in the Indian Ocean. While the surface ... |
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| Novel Presentation Methods for Technical Data |
Nov-2008 |
166 pages |
| Authors:
Krystal Thomas; David S Ebert; Sungye Kim; Insoo Woo; Ross Maciejewski; PURDUE UNIV LAFAYETTE IN SCHOOL OF ELECTRICAL AND COMPUTER ENGINEERING
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| This project developed effective visualization techniques for 2D technical data diagrams, such as schematic/wiring diagrams for use in maintenance, repair, and training. The techniques have been integrated into the Schematic Diagram Visualization (SDViz) software system that has numerous features to aid in navigation, diagnosis of faults, and traversal of multiple linked diagrams. These features include highlighting relationships between components and connectors, maintaining context between several related diagrams, animation of electrical/fluid/air ... |
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| Development of a Profiling Scanner |
01-Sep-2008 |
38 pages |
| Authors:
ARMY RESEARCH LAB ADELPHI MD SENSORS AND ELECTRON DEVICES DIRECTORATE
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| This report describes the design, operation, and performance of a two-dimensional (2-D) profiling scanner system using 16 laser diodes, 16 photo sensors, and a personal computer (PC) controller. A profiling scanner provides output images that reveal the size, height, and outline or shape of an object. This information can be useful in various military and related applications. The Radiometric Sensor Development and Applications Team of the Sensors and Electron Devices ... |
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| Detecting Planar Surfaces in Outdoor Urban Environments |
01-Sep-2008 |
26 pages |
| Authors:
Philip David; ARMY RESEARCH LAB ADELPHI MD COMPUTATIONAL AND INFORMATION SCIENCES DIRECTORATE
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| We describe an approach to automatically detect building facades in images of urban environments. This is an important problem in vision-based navigation, landmark recognition, and surveillance applications. In particular, with the proliferation of GPS- and camera-enabled cell phones, a backup geolocation system is needed when GPS satellite signals are blocked in so-called "urban canyons." Image line segments are first located, and then the vanishing points of these segments are determined ... |
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| A Baum-Welch Algorithm for Noisy Vector Fields for Classification and Synthesis of Textures Using Non-Symmetric Half-Plane |
Aug-2008 |
6 pages |
| Authors:
Paul M Baggenstoss; NAVAL UNDERSEA WARFARE CENTER DIV NEWPORT RI
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| In this paper we present a statistical model with a non-symmetric half-plane (NSHP) region of support for two-dimensional continuous-valued vector fields. It has the simplicity, efficiency, and ease of use of the well-known hidden Markov model (HMM) and associated Baum-Welch algorithms for time-series and other one-dimensional problems. At the same time, it is able to learn textures on a two-dimensional field. We describe a fast approximate forward procedure for computation ... |
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| Use of Eigenvector-Generated Scatter Plots in Clustering Image Data |
28-Jul-2008 |
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| Authors:
JERRY SILVERMAN; Charlene Caefer; AIR FORCE RESEARCH LAB HANSCOM AFB MA SENSORS DIRECTORATE/ELECTROMAGNETICS TECHNOLOGY DIV
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| Over the last few years we have been analyzing state-of-the-art spectral /temporal data of many events. Our goal was to develop specific techniques to classify and identify events based on these measurements. While the techniques evolved from one data type, we focus in this paper on the technique itself and its potential efficacy when applied to other data types. We use a Singular Value Decomposition (SVD) technique to cluster like ... |
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| Southeast Oahu Coastal Hydrodynamic Modeling with ADCIRC and STWAVE |
01-Jul-2008 |
61 pages |
| Authors:
Jane M Smith; Mary A Cialone; Mitchell E Brown; Kent K Hathaway; ENGINEER RESEARCH AND DEVELOPMENT CENTER VICKSBURG MS COASTAL AND HYDRAULICS LAB
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| This study provides the Honolulu District (POH) with numerical modeling tools for understanding nearshore circulation and sediment transport for Southeast Oahu (SEO). Circulation and wave models are developed and validated for this region and can be applied to assess sediment transport potential for various forcing conditions and to determine the likelihood of accretional and erosional areas within the model domain. Application of a wave model includes the generation of a ... |
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| High Order Accuracy Methods for Supersonic Reactive Flows |
25-Jun-2008 |
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| Authors:
David Gottlieb; Wai-Sun Don; BROWN UNIV PROVIDENCE RI DIV OF APPLIED MATHEMATICS
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| A multi-domain spectral method with stable and conservative penalty interface conditions for the numerical simulation of supersonic reactive recessed cavity flows with inhomogeneous grid is developed. The high order hybrid Spectral-WENO finite difference method under multi-domain framework is also introduced for the numerical solution of two dimensional nonlinear hyperbolic conservation laws in a Cartesian physical domain. A different approach in attempting to get more meaningful resultss is to model statistically ... |
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| An Interactive Parallel Coordinates Technique Applied to a Tropical Cyclone Climate Analysis |
06 JUN 2008 |
28 pages |
| Authors:
Chad A. Steed; Patrick J. Fitzpatrick; T. J. Jankun-Kelly; Amber N. Yancey; J. E. Swan II; NAVAL RESEARCH LAB STENNIS SPACE CENTER MS MARINE GEOSCIENCES DIV
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| An enhanced interactive variant to the parallel coordinates visualization technique is presented. An example of its capabilities is demonstrated on a hurricane climate dataset. Its capabilities include focus+context filtering, dynamic visual queries with sliders, statistical displays, relocatable axes, axis inversion, details-on-demand, a pop-up menu interface, and aerial perspective shading. Furthermore, parallel coordinates can visually depict the same correlations that weather scientists find meaningful. It is demonstrated that these interactive parallel ... |
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| The Diffusion Ordered Spectroscopy (DOSY) Pulse Sequence and Defence Applications |
01-May-2008 |
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| Authors:
Simon P Ovenden; David J Bourne; DEFENCE SCIENCE AND TECHNOLOGY ORGANISATION VICTORIA (AUSTRALIA) HUMAN PROTECTION AND PERFORMANCE DIV
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| This technical report will discuss all aspects of the DOSY two dimensional NMR experiment, including setting up the experiment, the collection of raw data, and the data processing required. Details of the DOSY experiment are explained through data collected on a variety of samples involving several chemical classes. At the end of the technical report is a discussion on the application of the DOSY pulse sequence to aspects of defence ... |
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| Near Source Energy Partitioning for Regional Waves in 2D and 3D Models |
30-Apr-2008 |
62 pages |
| Authors:
Ru-Shan Wu; Xiao-Bi Xie; Thome Lay; CALIFORNIA UNIV SANTA CRUZ
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| The complex excitation and energy partitioning mechanisms yielding regional phases are difficult to empirically separate by data analysis. Thus, numerical modeling approaches are valuable for investigating excitation and propagation of regional seismic phases. We use accurate full-wave simulations (2D and 3D finite-difference method, and 2D boundary element method) to calculate seismic wave excitation and propagation in near-source region. An embedded array slowness analysis is used for quantifying how energy will ... |
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| High Voltage Flux Compression Generators |
02-Apr-2008 |
50 pages |
| Authors:
Donna M Chato; Jay B Chase; Gerald F Kiutu; CARE'N LLC TRACY CA
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| Helical magnetic flux compression generators (HFCGs) have been in use for about five decades. There remain limitations to their performance. Recently and for the first time, calculations of high accuracy of HFCG output have been made. The calculated results assume that there are no electrical breakdowns in the generator resulting in a decrease of flux delivered. It has been very difficult to build high performance generators within desired size constraints ... |
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| Large-Signal Code TESLA: Current Status and Recent Development |
Apr-2008 |
3 pages |
| Authors:
Baruch Levush; Antonsen; Thomas M Jr; Khanh T Nguyen; David K Abe; Igor A Chernyavskiy; Alexander N Vlasov; Simon J Cooke; NAVAL RESEARCH LAB WASHINGTON DC
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| The optimization and design of new high-power, high-efficiency klystron amplifiers relies increasingly on effective nonlinear simulation tools. One such tool is the large-signal code TESLA, which was successfully applied for the modeling of single-beam and multiple-beam klystron devices at the Naval Research Laboratory and which is now used by number of U.S. companies. TESLA is a highly efficient fully electromagnetic two-dimensional code that solves self-consistently the electromagnetic field equations (including ... |
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| Wireless and Distributed Sensing of Shape and Health Monitoring of Morphing Structures |
28 MAR 2008 |
23 pages |
| Authors:
Jason Smoker; Amr Baz; MARYLAND UNIV COLLEGE PARK DEPT OF MECHANICAL ENGINEERING
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| This paper presents the development of the theoretical basis for the design of sensor networks for determining the 2-dimensional shape of morphing structures by monitoring simultaneously the bending and twist deflections. The proposed development is based on the non-linear theory of finite elements to extract the transverse linear and angular deflections of a plate-like structure. The sensors outputs are wirelessly transmitted to the command unit to simultaneously compute maps of ... |
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| Molecular Grid Membranes |
11 MAR 2008 |
11 pages |
| Authors:
Josef Michl; Thomas Magnera; COLORADO UNIV AT BOULDER
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| Regular two-dimensional covalent grids of monolayer thickness with molecular-size openings, reminiscent of a tennis net or chickenwire, will have many useful applications, among others as selective barrier materials and efficient passive or active separation membranes. We propose to synthesize a grid whose basic unit is Zn(II) porphyrin triply linked in the meso-meso, and both beta-beta positions four times by carbon-carbon bonds to each of its neighbors to form porphite sheets ... |
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| Two-Dimensional Electron Gas in Strained Silicon for Studying Ultra-Low Energy Electronic Processes |
10-Mar-2008 |
18 pages |
| Authors:
Ya-Hong Xie; Daniel Tsui; CALIFORNIA UNIV LOS ANGELES DEPT OF MATERIALS SCIENCE AND ENGINEERING
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| The proposed research focuses on the fabrication of high mobility 2D electron gases or low density for the understanding of correlated electron behavior under extreme conditions: low temperature and high magnetic field. The experimental efforts are in 3 related topics: (1) fabricate 2DES in strained Si with the highest achievable electron mobility; (2) fabricate 2DES in strained Si with low electron density; and (3) explore alternative approaches for fabricating strained ... |
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| Computational Design of Upperstage Chamber Aerospike and Cooling Jacket for Dual-Expander Rocket Engine |
MAR 2008 |
135 pages |
| Authors:
David F. Martin; AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH GRADUATE SCHOOL OF ENGINEERING AND MANAGEMENT
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| To increase the performance of the current US satellite launch capability, new rocket designs must be undertaken. One concept that has been around since the 50s but yet to be utilized on a launch platform is the aerospike, or plug nozzle. The aerospike nozzle concept demonstrates globally better performance compared to a conventional bell nozzle, since the expansion of the jet is not bounded by a wall and therefore can ... |
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| Development of Numerical Simulation Methods for Analysis of Laser Guided Arc Discharge |
29-Feb-2008 |
46 pages |
| Authors:
William Page; William Zimmerman; Brian Fisk; AIR FORCE RESEARCH LAB KIRTLAND AFB NM DIRECTED ENERGY DIRECTORATE
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| Modeling of the Use of USP laser pre-ionization as a guide path for a high voltage discharge in air was addressed. The physical processes involved are complex and span many orders of magnitude in the temporal and spatial resolution that must be considered. A two dimensional simulation model was produced that treats the problem in different time regimes with suitable approximations. The theoretical models and numerical models developed are described ... |
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| Advanced Narrowband Electromagnetic Size and Shape Determination |
15 FEB 2008 |
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| Authors:
S. Kusiak; MASSACHUSETTS INST OF TECH LEXINGTON LINCOLN LAB
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| This report discusses a fundamental radar imaging problem for narrowband electromagnetic waves that extends the recent results originally obtained in [1, 2] in the scalar, or acoustic, setting. In particular we demonstrate the ability to efficiently image three-dimensional convex conducting bodies by using the knowledge of the scattered electric field for one fixed monochromatic illumination of the target. In this problem our knowledge of the scattered electric wave is understood ... |
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| Development of Ultra Sensitive Piezoresistive Sensors Using AlAs 2D Electrons |
14 FEB 2008 |
16 pages |
| Authors:
Mansour Shayegan; TRUSTEES OF PRINCETON UNIV NEW JERSERY
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| The electronic properties of the two-dimensional (2D) electron systems in modulation-doped AlAs quantum wells are investigated, with the goal of developing this material as a sensor with an unprecedented, large sensitivity to stress and/or strain. Such a sensor may find use in various scanning probe microscopes, and in other applications where minute amounts of variables such as force, displacement, or pressure need to be measured. |
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| Deriving a Computational Theory of Visual Spatial Attention |
05 FEB 2008 |
3 pages |
| Authors:
GEORGE SPERLING; CALIFORNIA UNIV IRVINE
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| This research effort developed a computational theory for the control of human attention in two-dimensional visual tasks. Theory and experiments focused on the role of the spatial modulation transfer function for human vision, and on the characteristics and limitations of cortical receptive field processes. |
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| User's Guide: Fracture Mechanics Analysis of Reinforced Concrete Beams (FMARCB) |
JAN 2008 |
87 pages |
| Authors:
Guillermo A. Riveros; Vellore S. Gopalaratnam; Amos Chase; ENGINEER RESEARCH AND DEVELOPMENT CENTER VICKSBURG MS INFORMATION TECHNOLOGY LAB
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| A finite element package has been developed to perform nonlinear fracture mechanics analysis on reinforced concrete beams. The system consists of a graphic input/output interface and analysis routines using finite element techniques. Fracture Mechanics Analysis of Reinforced Concrete Beams (FMARCB) is a two-dimensional finite element program with triangular, isoparametric, bar, and interface elements. The system uses the discrete crack approach with a fictitious crack model to represent tensile concrete softening; ... |
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| Gesture Recognition Development for the Interactive Datawall |
JAN 2008 |
27 pages |
| Authors:
Naren Vira; HOWARD UNIV WASHINGTON DC
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| Hand gestures provide a useful interface for humans to interact with not only other humans but also machines. Especially for a high degree-of-freedom manipulation tasks such as the operation of 3D objects in virtual scenes, the traditional interface composed of a keyboard and mouse is neither intuitive nor easy to operate. In collaborative environments using large screen displays for display of both 3D and 2D information, participants would benefit greatly ... |
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| Isogeometric Analysis of the Cahn-Hilliard Phase-Field Model |
11 DEC 2007 |
47 pages |
| Authors:
Hector Gomez; Victor M. Calo; Yuri Bazilevs; Thomas J. Hughes; TEXAS UNIV AT AUSTIN
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| The Cahn-Hilliard equation involves fourth-order spatial derivatives. Finite element solutions are not common because primal variational formulations of fourth-order operators are well defined and integrable only if the finite element basis functions are piecewise smooth and globally C1-continuous. There are a very limited number of two-dimensional finite elements possessing C1-continuity applicable to complex geometries, but none in three-dimensions. We propose Isogeometric Analysis as a technology that possesses a unique combination ... |
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| Surface Plasmon Polariton Dependence on Metal Surface Morphology |
13 NOV 2007 |
39 pages |
| Authors:
Robert E. Peale; UNIVERSITY OF CENTRAL FLORIDA ORLANDO
|
| Generation and propagation of surface plasmons on nano-structured gold films was studied using optical and electron-beam techniques. Optical excitation of surface plasmons in Au-black films prepared by evaporation in moderate vacuum was observed. Initial indication of propagation of surface plasmons at visible-light frequencies over ~10 nm length scales was observed. A tunable terahertz detector based on two-dimensional plasmons in a semiconductor heterostructure was designed. These results have application to the ... |
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| NMR Identification and MS Conformation of the Scopolamine Neurotoxin |
NOV 2007 |
33 pages |
| Authors:
Terry J. Henderson; David B. Cullinan; Jonathan M. Oyler; EDGEWOOD CHEMICAL BIOLOGICAL CENTER ABERDEEN PROVING GROUND MD
|
| An unidentified white powder collected as evidence in an intelligence investigation was characterized exclusively by NMR analysis. A small fraction of the powder dissolved in D2O was subjected to quantitative 1H and 13C{1H} experiments and a series of two-dimensional correlation techniques, including 1H-1H COSY and NOESY as well as 1H-(exp 13)C HSQC and HMBC spectroscopy. These were used to elucidate the molecular structure of the powder's major component and positively ... |
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| Profiling Jet Fuel on Neurotoxic Components With Comprehensive Two-Dimensional GC |
NOV 2007 |
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| Authors:
Henk C. Trap; TNO DEFENCE SECURITY AND SAFETY RIJSWIJK (NETHERLANDS)
|
| Exposure to jet-propulsion fuel 8 (JP-8) is probably the most occurring chemical exposure within the military. The discussion on the possible adverse health effects of such an exposure is ongoing. Methodology is needed to identify and quantify low concentrations of potentially toxic components in the complex JP-8 matrix. Comprehensive GC (GCxGC), in which continuous two-dimensional separation occurs, was shown to be highly suitable for this purpose. =In combination with time-of-flight ... |
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| Validation of the Global Relocatable Tide/Surge Model PCTides |
17 OCT 2007 |
22 pages |
| Authors:
Pamela G. Posey; Richard A. Allard; Ruth H. Preller; Gretchen M. Dawson; NAVAL RESEARCH LAB STENNIS SPACE CENTER MS
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| The Naval Research Laboratory (NRL) has developed a global, relocatable, tide/surge forecast system called PCTides. This system was designed in response to a U.S. Navy requirement to rapidly produce tidal predictions anywhere in the world. The system is composed of a two-dimensional barotropic ocean model driven by tidal forcing only or in conjunction with surface wind and pressure forcing. PCTides is unique in its ability to forecast tidal parameters for ... |
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| BTEC Thermal Model |
OCT 2007 |
99 pages |
| Authors:
Lance J. Irvin; P. D. Maseberg; Gavin D. Buffington; III. Clark Clifton D.; Robert J. Thomas; Michael L. Edwards; Jacob Stolarski; FORT HAYS STATE UNIV HAYS KS
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| AFRL/RHDO has developed a configurable, laser-tissue interaction model that includes components from various areas of Biophysics. The model predicts heat transfer in biological tissue, in either one-dimension or two-dimensional cylindrical coordinates, and is coupled to an Arrhenius damage model. A simulation can be configured as a single run, or a damage-threshold search. Multiple models for describing the laser-tissue interaction are available, including linear absorption (1D, 2D), Monte Carlo scattering (2D) ... |
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| Multi-Camera, High-Speed Imaging System for Kinematics Data Collection |
21 SEP 2007 |
14 pages |
| Authors:
Jason Geder; William C. Sandberg; Ravi Ramamurti; NAVAL RESEARCH LAB WASHINGTON DC
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| A two-camera system was devised and created to determine the kinematics of flapping fin and flapping wing vehicles. Each camera is set up to capture triggered, high-speed (up to 10,000 frames per second) images of the appendage in a test environment. Using direct linear transforms, each camera is calibrated to convert image coordinates to an alternate coordinate system. Points of interest on the appendage are selected from each camera image ... |
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