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Displaying 21501 - 21525 of 73929

All-angle negative refraction and active flat lensing of ultraviolet light

May 22, 2013
Author(s)
Ting Xu, Amit Agrawal, Maxim Abashin, Kenneth J. Chau, Henri Lezec
The ability of a left-handed medium to sustain backwards electromagnetic waves leads to counter-intuitive phenomena such as negative refraction. We report the experimental implementation of a three-dimensional negative-index metamaterial operating at an

Beyond the Business Cycle: The Need for a Technology-Based Growth Strategy1

May 22, 2013
Author(s)
Gregory C. Tassey
The onset of globalization leaves the competing nations of the world with two rather stark choices: (1) accept lower wages in order to compete in global markets, or (2) invest in productivity enhancing assets to enable dominance in enough high valued-added

Some Evidence of Technology's Impacts on Economic Growth

May 22, 2013
Author(s)
Gregory C. Tassey
Economic studies over several decades have consistently shown a strong impact of R&D investment on both productivity and output growth, with a number of these studies also implying significant underinvestment.

The Economic Benefits from Improved Cyber Security Infrastructure

May 22, 2013
Author(s)
Gregory C. Tassey
Leading government officials have warned that a "cyber 9/11" could happen at any time. A coordinated terrorist cyber attack on a massive scale could potentially shut down the domestic economy. Even without such a pervasive assault, banks, utilities, and

Frequency Correlated Bi-Photon Spectroscopy using a Tunable Up-Conversion Detector

May 21, 2013
Author(s)
Oliver T. Slattery, Lijun Ma, Paulina S. Kuo, Yong-Su Kim, Xiao Tang
We demonstrated a scheme for frequency correlated bi-photon spectroscopy using a strongly non- degenerate down-conversion source and a tunable up-conversion detector. In this scheme, the spectral function at one wavelength range of a remote object can be

Light-Wave Mixing and Scattering with Quantum Gases

May 21, 2013
Author(s)
Lu Deng, Chengjie Zhu, Edward W. Hagley
We present a general theoretical framework on light-wave mixing and scattering in quantum gases. We show that all such processes that originate from elementary excitations are stimulated Raman or hyper-Raman in nature. In the forward direction, the third

MIMO Capacity in 2-D and 3-D Isotropic Environments

May 21, 2013
Author(s)
Ryan J. Pirkl, Catherine A. Remley
We analyze the distribution of MIMO channel capacity for different antennas in 2-D and 3-D statistically isotropic environments. These represent possible test environments that may be generated by multi-probe anechoic and reverberation chambers

A Dynamic Human Body Computational Phantom for RF Propagation Study

May 20, 2013
Author(s)
John G. Hagedorn, Kamran Sayrafian, Judith E. Terrill
Recent advances in micro-electronics technology to build small radio-enabled implantable and wearable medical sensors have sparked considerable interest in further understanding the characteristics of radio frequency propagation inside the human body. As

Modulated photocurrent spectroscopy of CdTe/CdS solar cells-equivalent circuit analysis

May 20, 2013
Author(s)
Behrang H. Hamadani, John F. Roller, Kounavis Panagiotis, Nikolai B. Zhitenev, David J. Gundlach
We have used the technique of photocurrent modulated spectroscopy to investigate the dynamic response of charge carrier transport in thin film CdTe/CdS solar cells as a function of light bias and temperature over a broad excitation frequency range. The

A microscene approach to the evaluation of hyperspectral system level performance

May 18, 2013
Author(s)
David W. Allen, Ronald G. Resmini, Christopher Deloye
Assessing the ability of a hyperspectral imaging (HSI) system to detect the presence of a substance or to quantify abundance requires an understanding of the many factors in the end-to-end remote sensing scenario from scene to sensor to data exploitation

Bound-state field theory approach to proton structure effects in muonic hydrogen

May 17, 2013
Author(s)
Peter J. Mohr, J Griffith, J. Sapirstein
A bound-state field theory approach to muonic hydrogen is set up using a variant of the Furry representation in which the lowest-order Hamiltonian describes a muon in the presence of a point Coulomb field, but the origin of the binding field is taken to be

Investigation of NaY Zeolite with Adsorbed CO2 by Neutron Powder Diffraction

May 17, 2013
Author(s)
Winnie K. Wong-Ng, James A. Kaduk, Qingzhen Huang, Laura Espinal, Lan (. Li, Jacob W. Burress
The crystal structure of dehydrated NaY zeolite (Na-FAU structure type) with and without adsorbed CO2 has been determined at 4K and at room temperature (RT) using neutron powder diffraction techniques. The CO2-containing sample was prepared at -78 °C and 0

An Optimization Approach for Semantic-based XML Schema Matching

May 16, 2013
Author(s)
Jaewook Kim, Yun Peng, Nenad Ivezic, Jun H. Shin
We propose a novel solution for semantic-based XML schema matching, taking a mathematical programming approach. This method identifies the globally optimal solution for the problem of matching leaf nodes between two XML schema trees by reducing the tree-to

High-resolution infrared and electron-diffraction studies of trimethylenecyclopropane ([3]-radialene)

May 16, 2013
Author(s)
Corey Wright, Joshua Holmes, Joseph W. Nibler, Kenneth Hedberg, James D. White, Lise Hedberg, Alfons Weber, Thomas A. Blake
Combined high-resolution spectroscopic, electron-diffraction, and quantum theoretical methods are particularly advantageous for small molecules of high symmetry and can yield accurate structures that reveal subtle effects of electron delocalization on
Displaying 21501 - 21525 of 73929
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