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Displaying 326 - 350 of 1719

The Effect of Plowing on Nanofriction

February 19, 2017
Author(s)
Stephen M. Hsu, Z C. Ying
Development of low friction surfaces has become an important issue for the development of reliable devices with moving components. The common way to measure nanofriction is to use a sharp tip sliding on a sample surface. High contact pressure at the tip

The Speed, Grain Boundary Morphology, and Composition Changes Resulting from DIGM

February 19, 2017
Author(s)
John W. Cahn, C M. Elliott, P C. Fife, O Penrose
We use the equations for steady-state diffusion-induced grain boundary motion (DIGM), derived from our phase-field model, [17] to predict the grain boundary morphology and speed of DIGM, as well as the resulting compositions profiles, when the specimen

Thermal Diffusivity of AIN Using the Photothermal Deflection Technique

February 19, 2017
Author(s)
E J. Gonzalez
The thermal conductivity of AIN specimens doped with Y2O3(5 wt.%) was determined using the photothermal deflection technique. The results agree within 10% of measurements previously made using the laser flash method. Thermal measurements on as-fired thin

Thermodynamics and Phase Diagrams

February 19, 2017
Author(s)
Ursula R. Kattner
Thermodynamics is a field of physics and chemistry. It uses mathematics to describe changes in energy and entropy (disorder) of a material that is subject to mechanical, thermal or chemical action. It is most frequently used to describe the conditions that

Transient Creep Cavity Growth in Structural Ceramics

February 19, 2017
Author(s)
A F. Bower, Tze J. Chuang
Long-term service life of a load-bearing ceramic component such as a turbine blade atelevated temperatures is often controlled by the rates of nucleation and growth of creepcavities at grain junctions and interfaces within the microstructure of the

Vapor Pressure and Thermal Stability of MgB 2 at 0.1 mPa Total Pressure

February 19, 2017
Author(s)
Lawrence P. Cook, R Klein, Winnie Wong-Ng
The vapor pressure of Mg(g) over MgB 2(cr) for the reaction 2 MgB 2(cr) Mg(g)+MgB 4(cr) has been measured thermogravimetrically from 900 degrees celsius to 1100 degrees celsius at 0.1 mPa(1 atm) total pressure using a modified Knudsen effusion method and

Versatile USAXS (Bonse-Hart) Facility for Advanced Materials Research

February 19, 2017
Author(s)
J Ilavsky, P Jemain, Andrew J. Allen, Gabrielle G. Long
The USAXS facility at UNICAT Sector 33 at the Advanced Photon Source (APS) is a world-class resource for advanced materials research emphasizing full-range charactrization of nanometer-scale to micrometer-scale microstructures. Receiving photons from an

Workshop on Purity and Dispersion Measurement Issues of Single Wall Carbon Nanotubes (SWCNTs)

February 19, 2017
Author(s)
Stephen W. Freiman, Richard R. Cavanagh, C K. Montgomery, Thomas J. Shaffner, S Arepalli, B Files, P Nikolaev
This document is an executive summary of a workshop organized jointly by the National Aeronautics and Space Administration, Lyndon B. Johnson Space Center (NASA/JSC) and the National Institute of Standards and Technology (NIST) was held on May 27-29, 2003

X-Ray Absorption Fine-Structure Determination of Ferroelectric Distortion in SrtiO 3 Thin Films grown on Si(001)

February 19, 2017
Author(s)
Joseph Woicik, F S. Aguirre-Tostado, A Herrera-Gomez, R Droopad, Z Yu, D G. Schlom, E Karapetrova, P Zschack, P Pianetta
Polarization-dependent x-ray absorption fine structure together with x-ray diffraction have been used to study the local structure in SrTiO 3 thin films grown on Si(001). Our data indicate that below a critical thickness of approximately 80 , the in-plane

Mechanical response of thermally annealed Nafion thin films

December 7, 2016
Author(s)
Bradley R. Frieberg, Kirt A. Page, Joshua R. Graybill, Marlon L. Walker, Gery R. Stafford, Christopher L. Soles
The proton exchange membranes (PEMs) in a hydrogen fuel cell experiences hundreds if not thousands of cycles between wet and dry conditions during their service life, which leads to swelling and shrinking of the membrane material. This can lead to

Scalable Manufacturing of Layer-by-Layer Membranes for Water Purification

December 1, 2016
Author(s)
Christopher M. Stafford
Water is critical to the health and security of our nation. And as our population expands and water scarcity becomes a reality, we as a people need to think creatively on how we safeguard access to clean water. The manufacturing of today’s state-of-the-art

Epoxy Composites Using Wood Pulp Components as Fillers

November 30, 2016
Author(s)
Douglas M. Fox, Noy Kaufman, Jeremiah W. Woodcock, Jeffrey W. Gilman, John R. Shields, Rick D. Davis, Szabolcs Matko, Mauro Zammarano, Chelsea S. Davis
The components of wood, especially lignin and cellulose, have great potential for improving the properties of polymer composites. In this chapter, we discuss some of the latest developments from our lab on incorporating wood based materials into epoxy

The influence of the aromatic character in the gas chromatography elution order: the case of polycyclic aromatic hydrocarbons

November 8, 2016
Author(s)
Jorge O. Ona Ruales, Walter B. Wilson, Federica Nalin, Lane C. Sander, Patricia Schubert, Stephen A. Wise
A link between the aromatic character of polycyclic aromatic hydrocarbons (PAHs) and gas chromatography (GC) elution order in columns with a polysiloxane backbone in the stationary phase is reported for the first time. The aromatic character was calculated

Film morphology evolution during solvent vapor annealing of highly efficient small molecule donor/acceptor blends

September 15, 2016
Author(s)
Sebastian Engmann, Hyun W. Ro, Andrew Herzing, Chad R. Snyder, Lee J. Richter, Paul Geraghty, David Jones
Solution-processable small molecule photovoltaics based on the novel molecular donor, benzodithiophene terthiophene rhodamine (BTR), recently have shown maximum power conversion efficiencies above 8% for active layer thicknesses up to 400 nm, using post

Giant surface conductivity enhancement in a carbon nanotube composite by ultraviolet light exposure

July 29, 2016
Author(s)
Christian J. Long, Nathan D. Orloff, Kevin A. Twedt, Thomas F. Lam, Luis Fernando Vargas Lara, Minhua Zhao, Bharath NMN Natarajan, Keana C. Scott, Eric Marksz, Tinh Nguyen, Jack F. Douglas, Jabez J. McClelland, Edward J. Garboczi, Jan Obrzut, James A. Liddle
Carbon nanotube composites are lightweight, multifunctional materials with readily adjustable mechanical and electrical properties—relevant to the aerospace, automotive, and sporting goods industries as high-performance building materials. Here, we combine

Ultraviolet/Ozone as a tool to control grafting density in surface-initiated controlled-radical polymerizations via ablation of bromine

July 21, 2016
Author(s)
Richard J. Sheridan, Sara V. Orski, Shinichiro Muramoto, Christopher M. Stafford, Kathryn L. Beers
We used an ultraviolet-ozone (UVO) cleaner to create substrates for atom-transfer radical polymerization (ATRP) with varying surface initiator coverage. We collected complementary time-of-flight secondary ion mass spectrometry (ToF-SIMS) and X-ray
Displaying 326 - 350 of 1719