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NIST Authors in Bold

Displaying 30826 - 30850 of 74061

Characterizing Polymer Brushes via Surface Wrinkling

November 21, 2007
Author(s)
Heqing Huang, Jun Y. Chung, Adam J. Nolte, Christopher M. Stafford
We present the application of surface wrinkling to measure the properties of polymer brush layers tethered to the surface of a deformable silicone substrate. It is demonstrated that the wavelength of the wrinkling pattern linearly increases with the length

DUC in Context

November 21, 2007
Author(s)
Paul D. Over, Hoa T. Dang, Donna K. Harman
Recent years have seen increased interest in text summarization with emphasis on evaluation of prototype ststems. Many factors can affect the design of such evaluations, requiring choices among competing alternatives. This paper examines several major

Learning Traversability Models for Autonomous Mobile Vehicles

November 21, 2007
Author(s)
Michael O. Shneier, Tommy Chang, Tsai Hong Hong, William P. Shackleford
Autonomous mobile robots need to adapt their behavior to the terrain over which they drive, and to predict the traversability of the terrain so that they can effectively plan their paths. Such robots usually make use of a set of sensors to investigate the

Uncertainty budget for the NIST Electron Counting Capacitance Standard, ECCS- 1

November 21, 2007
Author(s)
Mark W. Keller, Neil M. Zimmerman, Ali L. Eichenberger
We measure a cryogenic, vacuum-gap capacitor by two methods: 1) charging it with a known number of electrons and measuring the resulting voltage, and 2) using a capacitance bridge traceable to the SI farad. We report a detailed uncertainty budget for the

A Step Towards CO2-Neutral Aviation

November 20, 2007
Author(s)
Andreja Brankovic, Robert C. Ryder, Robert C. Hendricks, Marcia L. Huber
An approximation method for evaluation of the caloric equations used in combustion chemistry simulations is described. The method is applied to generate the specific heat, static enthalpy, and Gibb's free energy equations for fuel mixtures of interest to

Block Copolymer Ordering With a Spatiotemporally Inhomogeneous Mobility

November 20, 2007
Author(s)
August W. Bosse, Jack F. Douglas, Brian Berry, Ronald L. Jones, Alamgir Karim
Motivated by recent measurements of zone annealing in block copolymer films at low temperatures, we implement a spatiotemporal mobility gradient with intrinsic variations associated with dynamic heterogeneities in the saddle point relaxation of a diblock

Bulk Silicon Is Susceptible to Fatigue

November 19, 2007
Author(s)
Sanjit Bhowmick, Juan J. Melendez-Martinez, Brian R. Lawn
It has long been held that bulk silicon is immune from fatigue. We present contrary evidence demonstrating severe fatigue in macroscale cracks produced in cyclic loading of single-crystal silicon with a sphere indenter. The key ingredient is a component of

Generation and Manipulation of H-Anim CAESAR Scan Bodies

November 19, 2007
Author(s)
Qiming Wang, Sanford P. Ressler
In this paper we present a procedure to create animated human models compliant with the H-Anim specification from 3D CAESAR scan bodies, which were captured using a whole body scan device. We also present a VRML prototype of an ¿Animated CAESAR Viewer¿ to

Porous Silicon Biosensor for MS2 Virus

November 19, 2007
Author(s)
Andrea Rossi, Lili Wang, Vytas Reipa, Thomas E. Murphy
Nanoporous silicon was discovered in the 1950 s and has unique properties due to quantum confinement effects. It is produced by electrochemical etching in HF containing electrolytes that allows to tune the pore diameter from a few nanometers up to several

High-Q GaN nanowire resonators and oscillators

November 16, 2007
Author(s)
Shawn M. Tanner, Jason M. Gray, Charles T. Rogers, Kristine A. Bertness, Norman Sanford
We report high mechanical quality factors Q for GaN nanowire cantilevers grown by molecular beam epitaxy. Nanowires with 30-500 nm diameters and 5-20 υm lengths having resonance frequencies from 400 kHz to 2.8 MHz were measured. Q near room temperature and

Characterization of 3-Color CARS in a 2-Pulse Broadband CARS Spectrum

November 15, 2007
Author(s)
Young Jong Lee, Marcus T. Cicerone, Yuexin Liu
We present a new and simple approach to broadband coherent anti-Stokes Raman scattering (CARS) microscopy that yields background-free vibrational spectra. We present evidence for a mechanism where two different frequency components in a continuum pulse

Guide to Storage Encryption Technologies for End User Devices

November 15, 2007
Author(s)
Karen A. Scarfone, Murugiah P. Souppaya, Matt Sexton
Many threats against end user devices, such as desktop and laptop computers, smart phones, personal digital assistants, and removable media, could cause information stored on the devices to be accessed by unauthorized parties. To prevent such disclosures

Magic Wavelengths for the np - ns Transitions in Alkali-Metal Atoms

November 15, 2007
Author(s)
B Arora, M S. Safronova, Charles W. Clark
Extensive calculations of the electric-dipole matrix elements in alkali-metal atoms are conducted using the relativistic all-order method. This approach is a linearized version of the coupled-cluster method, which sums infinite sets of many-body

Nothing is Brittle at the Nanoscale

November 15, 2007
Author(s)
Pradeep N. Namboodiri, Doo-In Kim, Jaroslaw Grobelny, T Hawa, B Henz, Michael R. Zachariah
Fracture of nanoscale contacts formed between spherical probes and flat samples is studied using an atomic force microscope (AFM) in ultra high vacuum environment. Analysis of the nonlinear elastic behavior observed during the fracture process in the force

Stable Navigation Solutions for Robots in Complex Environments

November 15, 2007
Author(s)
Christopher J. Scrapper Jr, Rajmohan Madhavan, Stephen B. Balakirsky
During the initial phase of a disaster response it is essential for responders to quickly and safely assess the overall situation. The use of rescue robots that can autonomously navigate and map these environments can help responders realize this goal

Thermodynamic Radiation Thermometry for the Next SI

November 15, 2007
Author(s)
Howard W. Yoon, Charles E. Gibson, V B. Khromchenko, George P. Eppeldauer, Robert R. Bousquet, Steven W. Brown, Keith R. Lykke
We describe the construction, the calibration and the use of the NIST Thermodynamic Radiation Thermometer (TRT) to measure the temperature of the gold-freezing temperature blackbody and a variable-temperature blackbody from 800 ?C to 2700 ?C. These

DSR-Based Directional Routing Protocol for Ad Hoc Networks

November 14, 2007
Author(s)
Bin Hu, Hamid Gharavi
In this paper, a Dynamic Source Routing (DSR)-based directional routing protocol is invoked for wireless ad hoc networks using directional antennas. This is designed to balance the trade-off between co-channel interferences from nodes hops away, and the
Displaying 30826 - 30850 of 74061