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Displaying 1101 - 1125 of 1856

Electrical Conductivity and Relaxation in Poly(3-hexylthiophene)

November 25, 2009
Author(s)
Jan Obrzut, Kirt A. Page
ABSTRACT: We studied the complex conductivity of regio-regular poly(3-hexylthiophene) (P3HT) in the temperature range between 193K to 333 K (-80 C to 60 C) and in the frequency range from the direct current (DC) to 12 GHz. The identified relaxation process

A METHODOLOGY FOR DETECTING RESIDUAL PHOSPHORIC ACID IN POLYBENZOXAZOLE FIBERS

November 24, 2009
Author(s)
Eun S. Park, John R. Sieber, Charles M. Guttman, Kirk D. Rice, Kathleen M. Flynn, Stephanie S. Watson, Gale A. Holmes
There is great interest in the degradation of ballistic fibers from exposure to sunlight and high humidity, because it directly affects the lives of people who use protective ballistic armor. However, to date, no mechanism has been found to explain how

Electrical Characterization of Soluble Anthradithiophene Derivatives

November 19, 2009
Author(s)
Brad Conrad, Calvin Chan, Marsha A. Loth, John E. Anthony, David J. Gundlach
Organic semiconductors remain an active subject for device physics and material science because of their varied electrical properties and potential for low-cost, high-throughput roll-to-roll processing. Several high-mobility oligomers, such as pentacene

Mass transfer in two-phase microchannel flows

November 4, 2009
Author(s)
Jeffrey D. Martin, Steven D. Hudson
Drop-based microfluidic devices are becoming more common and molecular mass transfer and drop circulation are issues that affect the performance of such devices. Moreover, interfacial properties and surfactant mass transfer rates govern emulsion behavior

Poiseuille flow and drop circulation in microchannels

October 29, 2009
Author(s)
Steven D. Hudson
Microfluidics aims to control precisely the transport of fluids and suspended particles or drops. Here we calculate two characteristics of interest in rectangular microchannels, as a function of the cross-sectional aspect ratio. First, we present a

An Improved Fast I d -V ^d g Measurement Technology With Expanded Application Range

October 19, 2009
Author(s)
Chen Wang, Liangchun (. Yu, Jason P. Campbell, Kin P. Cheung, Yi Xuan, Peide Ye, John S. Suehle, David Zhang
Fast Id-Vg measurements on very high performance devices (very low channel ON-resistance) and larger area devices (therefore large gate capacitance) are subject to serious distortions. Methods to minimize these distortions are introduced in this paper

Effects of sample preparation on bacterial colonization of polymers

October 19, 2009
Author(s)
Diana N. Zeiger, Christopher Stafford, Yajun Cheng, Stefan D. Leigh, Sheng Lin-Gibson, Nancy Lin
Characterization of materials developed for medical usage frequently includes studies in which the materials are inoculated with bacteria in order to assess biofilm formation. Differences in the bacteria are considered to be due to the material alone; the

NBTI: Why Won't This Thing Go Away?

October 19, 2009
Author(s)
Jason P. Campbell
The negative-bias temperature instability (NBTI) is a reliability problem that, in the last ten years, has risen from relative obscurity to become the most important reliability problem in advanced pMOSFET devices. Even though a significant effort has been

Viscoelastic Properties of Confined Polymer Films Measured via Thermal Wrinkling

October 8, 2009
Author(s)
Kirt A. Page, Edwin Chan, Se Hyuk Im, Derek L. Patton, Rui Huang, Christopher Stafford
We present a new measurement technique to quantify the viscoelastic properties of polymer thin films. This approach utilizes thermally-induced surface wrinkling to measure the rubbery modulus and shear viscosity of polymer thin films. Specifically, by

Relative Photon-to-Carrier Efficiencies of Alternating Nanolayers of Zinc Phthalocyanine and C60 Multilayer Films Assessed by Time-Resolved Terahertz Spectroscopy

October 1, 2009
Author(s)
Okan Esenturk, Joseph S. Melinger, Paul A. Lane, Edwin J. Heilweil
Alternating multi-layer and 1:1 blended films of zinc phthalocyanine (ZnPc)and buckminsterfullerene (C60) were investigated as model active layers for solar cells by Time-Resolved Terahertz Spectroscopy (TRTS). Relative photon-to-carrier efficiencies 2

Size Measurement of Nanoparticles using Atomic Force Microscopy

October 1, 2009
Author(s)
Jaroslaw Grobelny, Frank W. DelRio, Pradeep Namboodiri, Doo-In Kim, Vincent A. Hackley, Robert F. Cook
In this assay protocol, procedures for dispersing gold nanoparticles on various surfaces such that they are suitable for imaging and height measurement via intermittent contact mode AFM are first described. The procedures for AFM calibration and operation

High-Voltage Capacitance Measurement System for SiC Power MOSFETs

September 24, 2009
Author(s)
Parrish Ralston, Tam H. Duong, Nanying Yang, David W. Berning, Colleen E. Hood, Allen R. Hefner Jr., Kathleen Meehan
Adequate modeling of a power MOSFET is dependent on accurate characterization of the inter-electrode capacitances. With the advent of high voltage silicon carbide (SiC) power MOSFETs, it has become important to develop a measurement system that can perform

A Coherent Approach for Interrogating Polybenzoxazole Fibers for Residual Phosphoric Acid

September 17, 2009
Author(s)
Gale A. Holmes, Eun S. Park, Charles M. Guttman, Kathleen M. Flynn, John R. Sieber, Stephanie S. Watson, Kirk D. Rice
Because of the premature failure of soft-body armor that contains the active fiber poly [(benzo-[1,2-d:5,4-d']-benzoxazole-2,6-diyl)-1,4-phenylene] (PBO), the Office of Law Enforcement Standards (OLES) at the National Institute of Standards and Technology

Studying Long-term Performance of a Nano-ZnO filled Waterborne Polyurethane Coating using Spectroscopies and Microscopies

September 9, 2009
Author(s)
Xiaohong Gu, Dongmei Zhe, Stephanie S. Watson, Guodong Chen, Minhua Zhao, Paul E. Stutzman, Deborah S. Jacobs, Tinh Nguyen, Joannie W. Chin, Jonathan W. Martin
Although inorganic UV absorbers such as zinc oxide (ZnO) and cerium oxide (CeO2) exhibit numerous advantages compared to organic UV absorbers, the mechanisms of how these nanoparticles affect the long-term performance of polymeric coatings are less than

Optical Properties of Rod-like Metallic Nanostructures: Insight from Theory and Experiment

September 3, 2009
Author(s)
Jinsong Duan, Kyoungweon Park, Robert I. MacCuspie, Richard A. Vaia, Ruth Pachter
In this work, we combined synthesis of metal Au and Au-Ag core-shell NRs, of high-purity and for a broad range of NR aspect ratios, with theoretical prediction, in order to gain an understanding of the optical response. Self-assembled NRs were also

Thin Film Solid State Proton NMR Measurements Using A Synthetic Mica Substrate: Polymer Blends

August 25, 2009
Author(s)
David L. VanderHart, Vivek Prabhu, Kristopher Lavery, Cindi L. Dennis, Ashwin Rao, Eric K. Lin
We demonstrate that a synthetic fluorophlogopite mica can be used as a proton-free, diamagnetic substrate for examining solid thin-film samples using conventional solid-state proton nuclear magnetic resonance (NMR) experiments. The context of this work
Displaying 1101 - 1125 of 1856