An official website of the United States government
Here’s how you know
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.
Christopher Soles, Ryan Nieuwendaal, Huagen H. Peng
The wide-spread interest in the dynamical property of organic materials under strong states of confinement largely began with differential scanning calorimeter (DSC) measurements in the early 90's of the glass transition and heat capacity of glass forming
Sung Kim, Christopher L. Holloway, James R. Baker-Jarvis, Edward Kuester, A D. Scher
In this paper, we present the extraction for effective material parameters for a metamaterial from TE or TM waveguide measurements with generalized sheet transition conditions (GSTCs)used to provide electric and magnetic surface susceptibilities that
Atomic force microscopy (AFM) methods for quantitative measurements of elastic modulus on stiff (>10 GPa) materials typically require tip-sample contact forces in the hundreds of nanonewton to few micronewton range. Such large forces can incur sample
Eric L. Shirley, Joshua J. Kas, J. T. Vinson, Fernando D. Vila, John J. Rehr
Theoretical optical and x-ray spectra of model structures of water and ice are calculated using a many-body perturbation theory, Bethe-Salpeter equation (BSE) approach implemented in the valence- and core-excitation codes AI2NBSE and OCEAN. These codes use
A review on the use of sharp, fixed-profile indenters as materials probes is presented. Indentation is proposed as a simple but powerful methodology for evaluating basic mechanical propertieselastic modulus, hardness, toughness, etc.in all classes of
Andrew Allen, Jeffrey J. Thomas, Hamlin M. Jennings
Alkali-activated slag (AAS) paste was analyzed using small-angle neutron scattering. The scattering response indicates that the microstructure consists of a uniform matrix of hydration product with a high surface area studded with unhydrated cores of slag
Ward L. Johnson, Sudook A. Kim, Christine F. Rivenbark, Satoshi Uda
Maximization of the quality factors Q of langasite (LGS) and langatate (LGT) is necessary for optimal performance of acoustic resonators of these materials in frequency-control and high-temperature sensing applications. In this report, measurements and
The International Technology Roadmap for Semiconductors (ITRS) Emerging Research Materials (ERM) and Emerging Research Devices (ERD) Technology Workgroups have identified materials and devices that could enable continued increases in the density and
Timothy Weeks, Joseph D. McColskey, Mark D. Richards, Yong-Yi Wang, Zhou Honggang, Ming Liu, W. R. Tyson, James Gianetto, Marie A. Quintana, V. B. Rajan
Najib Cheggour, Xifeng Lu, T G. Holesinger, Theodore C. Stauffer, J Jiang, Loren F. Goodrich
A reversible strain effect on transport critical current I c was found in Bi 2Sr 2CaCu 2O 8+x (Bi-2212) high-temperature superconducting round wires. I c showed unambiguous reversibility at 4 K and 16 T up to an irreversible strain limit of about 0.3 % in
Till Gruendling, Christopher Barner-Kowollik, William E. Wallace, Charles M. Guttman, Anthony J. Kearsley
An overview is given of some new techniques in quantitative composition and molecular mass distribution measurement of synthetic polymers by mass spectrometry. New concepts in data analysis, including peak picking and integration, are also described.
Carbon materials typically have a high density of unpaired electronic spins but the exact nature of the defect sites that give rise to their magnetic properties are not yet well understood. In this work, the paramagnetic interactions between the unpaired
Three fundamental mechanical properties of supported glassy polystyrene films with thickness ranging from 250 nm to 9 nm were quantitatively determined by a recently developed wrinkling-cracking method. Films below about 40 nm showed a decrease in both
Peter M. Johnson, Joonsung (. Yoon, Jennifer Y. Kelly, John A. Howarter, Christopher Stafford
In membranes for reverse osmosis and nanofiltration, the discriminating layers consist of an interfacially polymerized polyamide film on a porous support. For reverse osmosis membranes, the dominant commercial interfacial film is a crosslinked network
Jessica M. Torres, Christopher Stafford, David Uhrig, Bryan D. Vogt
The modulus and Tg of a series of PS samples with varying architecture are examined in thin films as a function of thickness. The bulk-like, thick film Tg is independent of polymer architecture: linear, comb, centipede and 4 armed star PS. However for
Nabil Bassim, Bradley De Gregorio, A. D. Kilcoyne, Keana Scott, Tsngming Chou, S. Wirick, George Cody, Rhonda Stroud
Although focused ion beam (FIB) microscopy has been used successfully for milling patterns and creating ultra-thin transmission electron microscopy (TEM) sections of polymers and other soft materials, little has been documented regarding FIB-induced damage
Virgil Percec, Steven Hudson, Mihai Peterca, Pawaret Leowanawat, Emad Aqad, Robert Graf, Hans -. Spiess, Xiangbing Zeng, Goran Ungar, Paul A. Heiney
The dendronized perylene 3,4:9,10-tetracarboxylic acid bisimide (PBI) (3,4,5)12G1-3-PBI was recently shown to self-assemble in a complex helical column containing tetramers of PBI as the basic repeat unit. The tetramers contain a pair of two molecules
Santosh B. Rahane, Ryan M. Hensarling, Bradley J. Sparks, Christopher Stafford, Derek L. Patton
Fabrication of multifunctional surfaces with complexity approaching that found in nature requires the application of a modular approach to surface engineering. We describe a versatile post-polymerization modification strategy to synthesize multifunctional
Langasite (LGS), langatate (LGT), and similar piezoelectric crystals in the P321 crystal class have become an increasing focus of research during the past two decades, in relation to their application in high-temperature resonant acoustic sensing. The