Physical Sciences

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Originally begun as an investigation to detect attempts to tap into an electrical cable, the emergence of modern encryption hardware rendered impractical attempts to protect communication media...

Long-term stress testing of silicon carbide (SiC) semiconductor devices is required to determine suitability for power electronics applications. During testing, preventable...

Briefs: Physical Sciences
Advanced Lithium Ion Systems for Military Vehicles

The higher energy and power density of Li-Ion battery technology offers a significant reduction in the weight and volume for hybrid electric vehicle (HEV) battery systems compared to lead acid and nickel metal hydride technologies. Saft’s High Power Li-ion battery technology has demonstrated...

Briefs: Physical Sciences
MEMS-Based Optical Limiter

Protecting optical sensors and detectors against excessive input signals is not only important for dealing with unintentional overloads, but also central for protecting sensors against intentional high-intensity...

Briefs: Physical Sciences
Reducing Thicknesses of PbZrₓTi₁₋ₓO₃ Films in Capacitors

A document describes experiments performed to determine effects of reducing the thicknesses of films of lead zirconate titanate (PbZrxTi1-xO3, wherein 0<x<1) used as ferroelectric dielectric layers in some capacitors. The fabrication of...

Briefs: Sensors/Data Acquisition
Tightly Coupled INS, GPS, and Imaging Sensors for Precision Geolocation

To address the issue of poor georegistration performance for small unmanned aerial vehicles (UAVs), navigation and target-location accuracy improvements achievable by tightly integrating an image-based feature-tracking algorithm with Global Positioning System (GPS) and a...

Briefs: Physical Sciences
Measurement of Transient Heat Flux and Surface Temperature Using Embedded Temperature Sensors

A report describes approximate solutions for surface temperature and heat flux for two embedded temperature sensors. The solutions were verified and the range of validity was established using several methods including comparisons with an exact...

A study of the aeroacoustics of a turbojet-engine test cell has been performed as one step in the development of a computational aeroacoustics capability (CAA) that could provide...

Briefs: Physical Sciences
Imaging and Spectral Measurements of Explosions

A document describes experiments performed to investigate rates of delivery of energy onto targets from different explosive formulations. The experiments were designed to measure relative positions of blast fireballs and leading shock fronts; determine whether different explosive formulations...

Autonomous rotorcraft provide improved capability in performing military missions such as reconnaissance, targeting, border patrol, and environmental sensing. A common difficulty in...

Briefs: Physical Sciences
Studies of Dynamic Fracture in Brittle Materials

A program of research spanning several years ending in November 2005 was dedicated primarily to formulation and analysis of canonical boundary- value problems in mathematical modeling of dynamic fracture in brittle materials. The sub-topics within the broad topic of dynamic fracture in brittle...

A recently invented acceleration strain transducer is based on the principle of a conventional spring-and-mass acceleration transducer combined with a linear strain sensor that...

A computational-simulation study of the flow of air through a thermo-anemometer chamber was performed to resolve what originally seemed to be an anomaly in the measurement data obtained by use of...

Briefs: Mechanical & Fluid Systems
Characterization of a MEMS Directional Sound Sensor

There is a wide range of potential military applications in which ambiguity in bearing occurs with respect to sound. For example, autonomous unmanned aerial vehicles (UAVs) could employ a...

A high-speed imaging system has been devised as a noninvasive means of collecting data on the kinematics of working models of developmental underwater or aerial vehicles that would utilize...

Briefs: Physical Sciences
Synthesizing Pseudo-Finer-Resolution MODIS Data Products

A document discusses a methodology for synthesizing finerresolution data products from outputs of the Moderate Resolution Imaging Spectroradiometer (MODIS) instruments aboard NASA's Terra and Aqua satellites. Typical MODIS ocean color data have 1-km resolution, but those in five wavelength...

A research and development effort now in progress is focused on nano-structured ferromagnetic- wire/insulator composite materials to be used as the magnetic-core materials of sensors for...

Automating large-scale material handling systems that involve picking up or retrieving items via cranes or robot arms can yield big benefits, particularly in harsh or...

Briefs: Physical Sciences
Advanced Concepts for Space Access

A paper summarizes commonly proposed advanced launch concepts, including both concepts that employ propellant and propellant-less concepts. A wide range of advanced launch concepts have been proposed in an effort to revolutionize space access through either a significant reduction in launch costs or significant...

A method for providing a time code for multiple streams of simultaneously received data has been developed in order to allow reconstruction of the data after asynchronous transfer. It is often...

The Flowslide, developed by Royal Boon Edam Group Holding BV, is a combination of a revolving door and curved sliding panels, installed at Charles de Gaulle Airport, Paris. The...

Briefs: Physical Sciences
Digital-Image Data Acquisition System for Turbulent Mixing and Combustion

An equipment and instrumentation system for high-speed digital image data acquisition and processing includes components for Planar Laser Induced Fluorescence (PLIF), flame-speed, and ignition and extinction measurements of laminar flames at variable pressure; tracking...

Briefs: Physical Sciences
Perspective on Research in Laser Propulsion

A document summarizes the history of research on laser propulsion, starting with the first publication of the laser-propulsion concept in the year 1969, proceeding through studies of laser propulsion within the broader context of advanced propulsion systems in general, and culminating in...

Briefs: Physical Sciences
Some Advances in Understanding of Environmental Fatigue

A research program has yielded advances in understanding of numerous aspects of environmental crack propagation in aerospace aluminum alloys. From one perspective, the objective of this program was to quantitatively establish governing crack-tip-mechanics conditions and damage mechanisms...

An experimental study of the mechanical behavior of cracked aluminum specimens repaired with composite-material patches has yielded findings that may eventually contribute to the...

The two-transmission method is an improved method of determining, from microwave measurements, the complex permeability and complex permittivity of a sample of a material typified...

Polymer composites that are photorefractive at visible and near- infrared wavelengths, and devices that exploit their photorefractivity, have been demonstrated. Potential...

Briefs: Physical Sciences
Detecting Explosives by Use of LIBS

Laser-induced breakdown spectros - copy (LIBS) has been investigated for potential utility as a means of detecting trace amounts of chemical explosives and residues thereof in lawenforcement, forensic...

Briefs: Physical Sciences
Mixing and Combustion in Turbulent, High-Speed Flows

A collection of reports presents a detailed description of a research program that focused on fundamental investigations of mixing and combustion in turbulent subsonic and supersonic flows like those encountered in high-speed air-breathing aircraft engines. The research included close...

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