U.S. flag

An official website of the United States government

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

Search Publications

NIST Authors in Bold

Displaying 24851 - 24875 of 74175

Using Block Copolymer Self-Assembly to Imprint the Crystallization of Polymer Dendrites

August 10, 2011
Author(s)
Sangcheol Kim, Alamgir Karim, Jack F. Douglas, Christopher L. Soles, R M. Briber
We utilize the self-assembly of cylinder-forming block copolymer (BCP) films to create templates for dendritic polymer crystallization patterns. This templating was achieved by simply spin-casting thin films from a solution containing both the BCP

Analyses of a Cantilever-Beam Based Instrument for Evaluating the Development of Polymerization Stresses

August 9, 2011
Author(s)
Martin Chiang, Anthony A. Giuseppetti, Joy Dunkers, Jing Qian, Sheng Lin-Gibson, Gary E. Schumacher, Joseph M. Antonucci
Analytical and finite element analyses have been performed on a cantilever-beam based methodology (tensometer) for evaluating the development of stresses as the concomitant of constrained polymerization shrinkage. A guideline for designing a tensometer

Controlling Formation of Atomic Step Morphology on Micro-patterned Si (100)

August 9, 2011
Author(s)
Kai Li, Pradeep Namboodiri, Sumanth B. Chikkamaranahalli, Gheorghe Stan, Ravikiran Attota, Joseph Fu, Richard M. Silver
Micro scale features are fabricated on Si (100) surfaces using lithographic techniques and then thermally processed in an ultra high vacuum (UHV) environment. Samples are flash heated at 1200 °C and further annealed at 1050 °C for 18 hours. The surface

Design and Optimization of a Permeation Testing System for Polymer Coatings

August 8, 2011
Author(s)
Adrian E. Verwolf
Measurements of liquid permeation through freestanding Parylene C membranes were made using a high- performance testing system, which demonstrated fast response (≤ 30 seconds) to changing concentrations in the sweep gas stream and detectability of less

Hierarchical Nanomorphologies Promote Exciton Dissociation in Polymer/Fullerene Bulk Heterojunction Solar Cells

August 8, 2011
Author(s)
Wei Chen, Tao Xu, Feng He, Wei Wang, Cheng Wang, Joseph Strzalka, Yun Liu, Jianguo Wen, Dean J. Miller, Jihua Chen, Kunlun Hong, Luping Yu, Seth B. Darling
PTB7 semiconducting copolymer comprising thieno[3,4-b]thiophene and benzodithiophene alternating repeat units set a historic record of solar energy conversion efficiency (7.4%) in polymer:fullerene bulk heterojunction (BHJ) solar cells. To further improve

High-accuracy Fabry-Perot displacement interferometry using fiber lasers

August 8, 2011
Author(s)
Mathieu Durand, John R. Lawall, Yicheng Wang
We describe ongoing work in a Fabry-Perot interferometry system designed to measure displacements over a range of 50~mm with sub-pm uncertainty. The apparatus involves probing two nearby modes of the Fabry-Perot cavity with narrow-linewidth fiber telecom

Perpendicular ferromagnetic resonance measurements of damping and Lande g-factor in sputtered (Co 2 Mn) 1-x Ge x thin films

August 8, 2011
Author(s)
Thomas J. Silva, Hans T. Nembach, Justin M. Shaw, Michael Schneider, Matt Carey, Stefan Maat, Jeff Childress
X-ray diffraction (XRD), magnetometry, and ferromagnetic resonance (FMR) measurements were performed on sputtered thin films of the nominal Heusler alloy (Co 2Mn) 1-xGe x with varying Ge content and annealing temperature. XRD indicates some degree of L2 1

A new approach to prepare well-dispersed CaF2 nanoparticles by spray drying technique

August 5, 2011
Author(s)
Limin Sun, Laurence C. Chow, John E. Bonevich, James W. Mitchell
Previously, a nano-sized calcium fluoride (CaF2) was prepared using a spray drying method by simultaneously feeding Ca(OH)2 and NH4F solutions to a two-liquid nozzle. The aim of the present study was to prepare better-dispersed nano CaF2 particles by co

Charge state dependent energy deposition by ion impacts

August 5, 2011
Author(s)
Russell E. Lake, Joshua M. Pomeroy, Holger Grube, C E. Sosolik
We report on a measurement of craters in thin dielectric films formed by XeQ+ (26 Q 44) projectiles. Tunnel junction devices with ion-irradiated barriers were used to amplify the effect of charge-dependent cratering through the exponential dependence of

Electron-exchange assisted photon energy up-conversion in thin films of ?-conjugated polymeric composites

August 4, 2011
Author(s)
Panagiotis Keivanidis, Frederic Laquai, Joseph W. Robertson, Baluschev Stanislav, Josemon Jacob, Klaus Mullen, Gerhard Wegner
The mechanism of triplet-triplet annihilation (TTA) induced up-converted delayed luminescence is studied in two different binary organic systems consisting of platinum(II) octaethyl porphyrin mixed with either poly(fluorene) (PF26) or ladder-type

Hierarchical Structure and Dynamics of an Ionic Liquid 1-Octyl-3-methylimidazolium Chloride

August 3, 2011
Author(s)
Osamu Yamamuro, Takeshi Yamada, Maiko Kofu, Masamichi Nakakoshi, Michihiro Nagao
We have performed the heat capacity, neutron diffraction, and neutron quasielas- tic scattering measurements of an ionic liquid 1-octyl-3-methylimidazolium chloride (C8mimCl). The heat capacity data revealed that C8mimCl exhibits a glass tran- sition with

The 3-D Shape of Blasted and Crushed Rocks: From 20 ?m to 38 mm

August 3, 2011
Author(s)
Edward J. Garboczi, Michael Taylor, Xuefeng Liu
Granodiorite material from a rock quarry in California was prepared by first quarrying large boulders, and then crushing down to smaller sizes. A range of particle sizes, from 0.0175 mm to 45.1 mm, was scanned using X-ray computed tomography (X-ray CT) and

Light-Controlled Protein Dynamics Observed with Neutron Spin Echo Measurements

August 2, 2011
Author(s)
Shao-Chun Wang, Panteha Mirarefi, Antonio Faraone, Jr. Lee
A photo-responsive surfactant has been used as a means to control protein structure and dynamics with light illumination. This cationic azobenzene surfactant, azoTAB, which undergoes a reversible photoisomerization upon exposure to the appropriate
Displaying 24851 - 24875 of 74175
Was this page helpful?