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Displaying 32226 - 32250 of 74220

TheoH and Allan Deviation as Power-Law Noise Estimators

February 1, 2007
Author(s)
Jennifer A. Taylor, David A. Howe
A spectral interpretation using the frequency response of the Allan Variance is used to determine slopes of f α noise, commonly called ''power-law noise.'' This paper shows that TheoH provides significantly better determination of f α noise slopes at long

Thermophysical Properties Measurements and Models for Rocket Propellant RP-1: Phase I

February 1, 2007
Author(s)
Joe W. Magee, Thomas J. Bruno, Daniel G. Friend, Marcia L. Huber, Arno D. Laesecke, Eric Lemmon, Mark O. McLinden, Richard A. Perkins, J?rg Baranski, Jason A. Widegren
Accurate knowledge of thermophysical properties is a prerequisite to design efficient and cost-effective rocket engine systems that use the kerosene rocket propellant designated RP-1. A robust properties model that is based on reliable experimental

Characterization and Control of Lipid Layer Fluidity in Hybrid Bilayer Membranes

January 31, 2007
Author(s)
Neil A. Anderson, Lee J. Richter, John C. Stephenson, Kimberly A. Briggman
The main gel-to-liquid-crystal (LC) phase transition temperature, Tm, of the distal lipid layer in hybrid bilayer membranes (HBMs) under water was investigated using vibrational sum frequency spectroscopy (VSFS). VSFS has unique sensitivity to order

Mapping Mechanical Properties on the Nanoscale with Atomic Force Acoustic Microscopy

January 31, 2007
Author(s)
Donna C. Hurley, Malgorzata Kopycinska-Mueller, Tony B. Kos
We are developing tools that use the atomic force microscope (AFM) to measure mechanical properties with nanoscale spatial resolution. Contact-resonance-spectroscopy techniques such as atomic force acoustic microscopy (AFAM) involve the vibrational modes

Performance Analysis of Symbolic Road Recognition for On-Road Driving

January 31, 2007
Author(s)
Mike Foedisch, Craig I. Schlenoff, Rajmohan Madhavan
Previous approaches to road sensing, namely road detection were based on segmenting the sensor data, i.e. color camera image, into road and non-road areas. Performance evaluation for such algorithms could be performed in a relatively straightforward

Performance Evaluation of Integrated Vehicle-Based Safety Systems

January 31, 2007
Author(s)
Jack J. Ference, Sandor S. Szabo, Wassim G. Najm
This paper describes a program to develop and test an integrated crash warning system that addresses rear-end, lane change, and roadway departure crashes for passenger cars and heavy commercial trucks. One of the goals of this program is to facilitate the

Scanning Advanced Automobile Technology

January 31, 2007
Author(s)
Hamid Gharavi, K V. Prasad, P. Ioannou
The progress of some of the key electrical, electronics, communications, controls and software technologies that enable in-vehicle, vehicle-to-vehicle (V2V) and vehicle-to-infrastructure (V2I) functions is presented, in historical, current & futuristic

Technology Evaluations and Performance Metrics for Soldier-Worn Sensors for ASSIST

January 31, 2007
Author(s)
Brian Weiss, Craig I. Schlenoff, Michael O. Shneier, Ann Virts
The DARPA-funded Advanced Soldier Sensor Information Systems and Technology (ASSIST) project is aimed at developing soldier-worn sensors to increase a soldier s battlefield awareness during humanitarian and combat missions, provide them with data

Traversability Metrics for Urban Search and Rescue Robots on Rough Terrain

January 31, 2007
Author(s)
V Molino, Rajmohan Madhavan, Elena R. Messina, Anthony J. Downs, Adam S. Jacoff, Stephen B. Balakirsky
Rough terrain, such as the rubble that we would expect to find in urban disaster areas, will likely impede robot mobility. The goal of this paper is to find methods for quantifying the difficulty a robot should encounter traversing a region of rough

A Physics Based Approach to Modeling Grassland Fires

January 30, 2007
Author(s)
William E. Mell, M A. Jenkins, J Gould, P Cheney
Physics based coupled fire-atmosphere models are based on approximations to the governing equations of fluid dynamics, combustion, and the thermal degradation of solid fuel. They require significantly more computational resources than the most commonly

Combinatorial Materials Science: Measures of Success

January 30, 2007
Author(s)
Michael J. Fasolka, Eric J. Amis
points across parameter space. When designed effectively, combinatorial libraries explore a range of parameters in a rational and reliable manner. Second, where traditional experiments test and analyze samples in a one at a time mode, combinatorial

Effective-Range Description of a Bose Gas Under Strong Confinement

January 29, 2007
Author(s)
Pascal Naidon, Eite Tiesinga, William F. Mitchell, Paul S. Julienne
We point out in this paper that previous theories describing s-wave collisions of atomic bosons confined in 1D or 2D geometries can be extended to much tighter confinements by simply replacing the scattering length by the effective energy-dependent

Chemical Twinning of the Pyrochlore Structure in the System Bi 2 O 3-Nb 2O 5

January 28, 2007
Author(s)
Ian E. Grey, W G. Mumme, Terrell A. Vanderah, Robert S. Roth, C Bougerol-Chaillout
New ternary bismuth iron niobates having structures based on chemical twinning of pyrochlore are described. Bi5.67Nb10FeO35 has hexagonal symmetry, P63/mmc, a = 7.432(1) , c = 31.881(2) , Z = 2 and Bi9.3Nb16.9Fe1.1O57.8 has rhombohedral symmetry, R-3m, a =

Pattern-directed to isotropic dewetting transition in polymer films on micropatterned surfaces with differential surface energy contrast

January 27, 2007
Author(s)
D Julthongpiput, Wenhua Zhang, Jack F. Douglas, Alamgir Karim, Michael J. Fasolka
Surface chemical patterns can both cause and direct dewetting in overlying thin films. However, a key factor in this behavior, the magnitude of surface energy differences between pattern domains ( ?g ), is largely unevaluated. To probe the effect of this

Contact Mechanics of Layered Elastic Materials: Experiment and Theory

January 26, 2007
Author(s)
P M. McGuiggan, Jay S. Wallace, Douglas T. Smith, I Sridhar, Z Zheng, K L. Johnson
This paper reports an experimental and theoretical investigation of the indentation of a layered elastic solid, with special reference to the surface force apparatus (SFA). The contacting surfaces of the SFA comprise a 3-layer material: a thin mica surface

Leakage Effects in Microwave Power Measurements

January 26, 2007
Author(s)
Ronald A. Ginley, Denis X. LeGolvan, Ann F. Monke
Because microwave power measurements are used to support almost every segment of the microwave electronics industry, the accuracy of these measurements is critical. Recently, we have several different problems that affect microwave power measurements which

Leakage Effects on Microwave Power Measurements

January 26, 2007
Author(s)
Ronald A. Ginley, Denis X. LeGolvan, Ann F. Monke
Microwave power measurements are used to support almost every every segment of the microwave electronics industry. It is very important for these measurements to be as accurate as possible. Recently we have found several different problems that affect

Light Force in Ultracold Photoassociation

January 26, 2007
Author(s)
Eduardo Gomez, A T. Black, Lincoln Turner, Eite Tiesinga, Paul D. Lett
We study the time-resolved photoassociation of ultracold sodium in an optical dipole trap. The photoassociation laser excites pairs of atoms to molecular states of large total angular momentum at high intensities (above 20 kW/cm2). Such transitions are
Displaying 32226 - 32250 of 74220