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Huntsville, AL, United States

The University of Alabama in Huntsville is a state-supported, public, coeducational research university, located in Huntsville, Alabama, United States, is accredited by the Southern Association of Colleges and Schools to award baccalaureate, master's and doctoral degrees, and is organized in seven colleges: business administration, education, engineering, honors college, liberal arts, nursing and science.UAH is one of three members of the University of Alabama System, which includes the University of Alabama at Birmingham and the University of Alabama located in Tuscaloosa. All three institutions operate independently, with only the president of each university reporting to the Board of Trustees of the system. The university enrollment is approximately 7,500. Wikipedia.

Despite the widely discussed role of whistler waves in mediating magnetic reconnection (MR), the direct connection between such waves and the MR has not been demonstrated by comparing the characteristic temporal and spatial features of the waves and the MR process. Using the whistler wave dispersion relation, we theoretically predict the experimentally measured rise time (τ rise) of a few microseconds for the fast rising MR rate in the Versatile Toroidal Facility at MIT. The rise time is closely given by the inverse of the frequency bandwidth of the whistler waves generated in the evolving current sheet. The wave frequencies lie much above the ion cyclotron frequency, but they are limited to less than 0.1% of the electron cyclotron frequency in the argon plasma. The maximum normalized MR rate R=0.35 measured experimentally is precisely predicted by the angular dispersion of the whistler waves. © 2011 American Physical Society. Source

Teixeira R.E.,University of Alabama in Huntsville
Green Chemistry

Microscopic algae occupies every photic niche on Earth and provides an efficient and inherently scalable sunlight energy capture and chemical storage mechanism. However, fuel production from algae remains outside economic viability due to limitations in biomass cultivation and feedstock extraction. In particular, extraction strategies require prohibitive energy inputs to breach the cell wall and separate lipids, while underutilizing polysaccharide- and protein-rich leftovers. Also due to focus on lipids, cultivars become either unstable or unproductive. Meanwhile, recent advances have demonstrated the synthesis of a variety of fuels and other chemicals from sugars and proteins. Here, the energy-efficient deconstruction of algae cell walls, resulting in release of cell contents, is reported. This occurs by dissolution and hydrolysis of wet algae biomass in ionic liquids without acids, bases or other catalysts. Deconstruction reached completion in <50 min regardless of algae species, at 100 to 140 °C and atmospheric pressure. Based on this finding, a simple process that converts wet algae biomass into constituent fractions is proposed and modeled. These results show it is possible to eliminate intensive energy demand currently hindering the economic viability of algae while co-producing sugar and protein feedstocks that tie into emerging fuel and chemical conversion paths. © 2012 The Royal Society of Chemistry. Source

The aim of the current study is to explore if there are differences between users and non-users of social network sites in terms of their sensation seeking, life-position indicators, shyness, and loneliness. Using data from a survey of adults 19-76 years old, results revealed that compared to an average Facebook user, a non-user is significantly older and scores higher on shyness and loneliness, is less socially active, and less prone to sensation seeking activities. Facebook is not a substitute channel of communication for those who are shy and lonely and lack face-to-face interactions. This study extends our knowledge of digital divide, uses and gratifications theory, and social enhancement hypothesis. © 2012 Elsevier Ltd. All rights reserved. Source

Sadeghi S.M.,University of Alabama in Huntsville
Applied Physics Letters

We study optical routing and switching of energy transfer between semiconductor quantum dots and metallic nanostructures. We demonstrate that in the presence of a metallic nanoshell, one can use quantum coherence to direct or switch energy transfer flow from a quantum dot to another quantum dot or to the nanoshell. Our results show that a quantum dot-metallic nanoshell system can act as a bistable energy switch formed via quantum mechanical control of energy transfer processes. © 2011 American Institute of Physics. Source

Sadeghi S.M.,University of Alabama in Huntsville
Physical Review B - Condensed Matter and Materials Physics

When a hybrid system consisting of a metallic nanoparticle and a semiconductor quantum dot interacts with a coherent light source (laser beam) the coherence generated in the quantum dot can significantly renormalize the plasmonic field. In this paper we study the impacts of such coherent-plasmonic processes when such a hybrid system interacts with amplitude-modulated laser fields. We demonstrate how such these processes allow the metallic nanoparticle to act as a nanoamplifier and a pulse controller for the quantum dot. We show that as a nanopulse controller the metallic nanoparticle can control the shapes of optical pulses experienced by the quantum dot, including dramatic modification of their widths. As a functional nanoamplifier the metallic nanoparticle can enhance high intensity parts of a pulse train while suppressing the parts that their intensities are less than a given value. Therefore, it not only can enhance the amplitudes of the optical pulses but also can make them return-to-zero pulses. © 2010 The American Physical Society. Source

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