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Displaying 17726 - 17750 of 74070

Challenges of Irradiance-mode Spectral Response Measurements

October 16, 2014
Author(s)
Behrang H. Hamadani, John F. Roller, Brian P. Dougherty, Howard W. Yoon
Irradiance-mode spectral response measurements of solar cells are important because they provide a direct, reliable and accurate route for determination of the short circuit current (Isc) of solar cells under air mass 1.5 standard reference spectrum. In

Faceting Control in Core/Shell GaN micropillars using Selective Epitaxy

October 15, 2014
Author(s)
Sergiy Krylyuk, Heayoung Yoon, Baomei Wen, Abhishek Motayed, Albert Davydov, Matt N. King
We report on fabricating large-area, vertically aligned GaN epitaxial core-shell micropillar arrays. The two-step process consisted of inductively coupled plasma (ICP) etch of lithographically patterned n-type GaN substrate followed by selective growth of

gamma-prime Phase Stability and Phase Equilibrium in Ternary Co-W-Al at 900 degC

October 15, 2014
Author(s)
Eric Lass, Maureen E. Williams, Carelyn E. Campbell, Kil-Won Moon, Ursula R. Kattner
Phase equilibria at 900 °C in the Co-rich Co-W-Al ternary system is investigated through isothermal annealing of six alloy compositions for times up to 8000 h. The volume fraction of the L12-gamma-prime phase co-existing with disordered FCC-gamma, B2 and

High-Power and High-Linearity Photodetector Modules for Microwave Photonic Applications

October 15, 2014
Author(s)
Frederick N. Baynes, Efthymios Rouvalis, Xiaojun Xie, Qiugui Zhou, Franklyn J. Quinlan, Tara M. Fortier, Scott A. Diddams, Andreas G. Steffan, Andreas Beling, Joe C. Campbell
We demonstrate hermetically packaged InGaAs/InP photodetector modules for high performance microwave photonic applications. The devices employ an advanced photodiode epitaxial layer known as the modified uni-traveling carrier photodiode (MUTC-PD) with

Mechanical property changes in porous low-k dielectric thin films during processing

October 15, 2014
Author(s)
Gheorghe Stan, Richard S. Gates, Premsagar P. Kavuri, Jessica Torres, David Michalak, Canay Ege, Jeff Bielefeld, Sean W. King
The design of future generations of Cu-low-k dielectric interconnects with reduced electronic crosstalk often requires engineering materials with an optimal trade off between their dielectric constant and elastic modulus. This is because the benefits

Modeling RP-1 fuel advanced distillation data using comprehensive two-dimensional gas chromatography coupled with time-of-flight mass spectrometry and partial least squares analysis

October 15, 2014
Author(s)
Thomas J. Bruno, Benjamin Kehimkar, Brendon Parsons, Jamin C. Hoggard, M. C. Billingsley, R. E. Synovec
Recent efforts in predicting rocket propulsion (RP-1) fuel performance through modeling put greater emphasis on obtaining detailed and accurate fuel properties, as well as to elucidate the relationships between fuel composition and their properties. Herein

Nanoscale Imaging of Photocurrent and Efficiency in CdTe Solar Cells

October 15, 2014
Author(s)
Leite Marina, maxim abashin, Henri Lezec, anthony gianfrancesco, Alec Talin, Nikolai Zhitenev
The local collection characteristics of grain interiors and grain boundaries in thin film CdTe polycrystalline solar cells are investigated using scanning photocurrent microscopy. The carriers are locally generated by light injected through a small

Parameter Estimation and Uncertainty Evaluation in a Low Rician K-Factor Reverberation-Chamber Environment

October 15, 2014
Author(s)
Chih-Ming Wang, Catherine A. Remley, Ansgar T. Kirk, Ryan J. Pirkl, Christopher L. Holloway, Dylan F. Williams, Paul D. Hale
In this paper we study statistical methods for estimating the Rician K-factor when this parameter is small. A fiducial approach for making statistical inference on the K-factor is discussed. The approach requires a Monte Carlo method to compute the

TEST AND CALIBRATION OF DISPLACEMENT MEASURING LASER INTERFEROMETERS

October 15, 2014
Author(s)
Jack A. Stone Jr.
At the National Institute of Standards and Technology (NIST), we have a capability to calibrate and test laser interferometer systems used to measure displacements. Recently our calibration protocol has been modified so as to bring it into accord with a

Hardening of Structures to Wildland-Urban Interface (WUI) Fire Expsoures

October 14, 2014
Author(s)
Samuel L. Manzello
Wildfires that spread into communities, referred to as Wildland-Urban Interface (WUI) fires, have destroyed communities throughout the world. In the USA, over 46 million homes in 70,000 communities are at risk of WUI fires [1-2]. These fires have destroyed

Exceptional Superionic Conductivity in Disordered Sodium Decahydro-closo-decaborate

October 13, 2014
Author(s)
Terrence J. Udovic, Motoaki Matsuo, Wan Si NMN Tang, Hui Wu, Vitalie Stavila, Alexei V. Soloninin, Roman V. Skoryunov, Olga A. Babanova, Alexander Skripov, John J. Rush, Atsushi Unemoto, Hitoshi Takamura, Shin-Ichi Orimo
Na 2B 10h 10 undergoes a transition from an ordered monoclinic phase to a disordered, face-centered-cubic phase near 370 K with the emergence of a vacancy-rich, mobile Na + sublattice exhibiting dramatic superionicity ({approximately equal}0.01 S cm -1 at

Nonparametric Estimates of Drift and Diffusion Profiles via Fokker-Planck Algebra

October 13, 2014
Author(s)
Steven P. Lund, Michael W. Halter, Joseph B. Hubbard
Diffusion processes superimposed upon deterministic motion play a key role in understanding and controlling the transport of matter, energy, momentum, and even information in physics, chemistry, material science, biology, and communications technology

Persistent Fe Moments in the Normal-State Collapsed-Tetragonal Phase of the Pressure-induced Superconductor Ca 0.67 Sr 0.33 Fe 2 As 2

October 13, 2014
Author(s)
J.R. Jeffries, Nicholas Butch, M.J. Lipp, J.A. Bradley, K. Kirshenbaum, Shanta Saha, J. Paglione, C. Kenny-Benson, Y. Xiao, P. Chow, W. J. Evans
Using non-resonant Fe Κ}β x-ray emission spectroscopy, we reveal that Sr-doping of CaFe 2As 2 decouples the Fe moment from the volume collapse transition, yielding a collapsed-tetragonal, para-magnetic normal state out of which superconductivity develops

Synthesis, Thermal Behaviors and Dehydrogenation Kinetics Studies on Lithiated Ethylenediamine

October 13, 2014
Author(s)
Juner Chen, Guotao Wu, Zhitao Xiong, Hui Wu, Yong Shen Chua, Wei Zhou, Bin Liu, Xiaohua Ju, Ping Chen
The lithiation of ethylenediamine by LiH is a step-wise process forming the partially lithiated intermidiates LiN(H)CH 2CH 2NH 2 and [LiN(H)CH 2CH 2NH 2][LiN(H)CH 2CH 2N(H)Li] 2 prior to the formation of dilithiated ethylenediamine LiN(H)CH 2CH 2N(H)Li. A
Displaying 17726 - 17750 of 74070