6,228 research outputs found
Soybean, 1962-1966
Cover title."University of Missouri Agricultural Experiment Station in cooperation with Agricultural Research Service, U.S. Dept. Agriculture.
Transformation of spin information into large electrical signals via carbon nanotubes
Spin electronics (spintronics) exploits the magnetic nature of the electron,
and is commercially exploited in the spin valves of disc-drive read heads.
There is currently widespread interest in using industrially relevant
semiconductors in new types of spintronic devices based on the manipulation of
spins injected into a semiconducting channel between a spin-polarized source
and drain. However, the transformation of spin information into large
electrical signals is limited by spin relaxation such that the magnetoresistive
signals are below 1%. We overcome this long standing problem in spintronics by
demonstrating large magnetoresistance effects of 61% at 5 K in devices where
the non-magnetic channel is a multiwall carbon nanotube that spans a 1.5 micron
gap between epitaxial electrodes of the highly spin polarized manganite
La0.7Sr0.3MnO3. This improvement arises because the spin lifetime in nanotubes
is long due the small spin-orbit coupling of carbon, because the high nanotube
Fermi velocity permits the carrier dwell time to not significantly exceed this
spin lifetime, because the manganite remains highly spin polarized up to the
manganite-nanotube interface, and because the interfacial barrier is of an
appropriate height. We support these latter statements regarding the interface
using density functional theory calculations. The success of our experiments
with such chemically and geometrically different materials should inspire
adventure in materials selection for some future spintronicsComment: Content highly modified. New title, text, conclusions, figures and
references. New author include
A Threat Assessment and Security Analysis of the Three Sports Facilities of Indiana University-Purdue University, Indianapolis NCAA Softball Fields, Carroll Stadium, and the IU Natatorium
This research report provides a security assessment of the Softball Fields, Carroll Stadium, and the Natatorium Complex at Indiana University-Purdue University Indianapolis (IUPUI). The purpose of this report is to prevent and mitigate harm to visitors and these facilities which resulting from human-made or natural disasters. Research is guided by the hypothesis that these facilities- due to their respective importance, locations, and attendance patterns are in harm’s way; and that certain strategies of prevention, protection, and mitigation coupled with effective preparedness, response, and recovery can lessen risk, improve security and provide
A THREAT ASSESSMENT AND SECURITY ANALYSIS 5
added resilience. Further, “harm’s way” is considered to be either a natural disaster or a human-made disaster, accident, active provocation, or act of terrorism. Methods of analysis include applied research; predominantly utilizing qualitative data with some quantitative investigation.
Results of this assessment illustrate that these venues possess numerous vulnerabilities to both natural and human-made threats that if exposed, could result in serious consequences. The two most likely natural hazards identified include straight-line winds and tornadoes. Further, the most likely human threats to these facilities arise from a potential terrorist vehicle attack (TVA) and an active shooter. This project also identifies a specific need for additional planning to prevent an IED or VBIED attack on the Natatorium.
Common themes from the attached three case studies reveal that given theses vulnerabilities, the following safety and security adjustments are recommended:
Surveillance equipment
Metal detectors
Security bollards or other temporary barriers
Evacuation routes and shelter in place plans
Special event security procedures
Weather related technology and protocols
Staff training for emergency situation
Investigation of radioactivity-induced backgrounds in EXO-200
The search for neutrinoless double-beta decay (0{\nu}{\beta}{\beta}) requires
extremely low background and a good understanding of their sources and their
influence on the rate in the region of parameter space relevant to the
0{\nu}{\beta}{\beta} signal. We report on studies of various {\beta}- and
{\gamma}-backgrounds in the liquid- xenon-based EXO-200 0{\nu}{\beta}{\beta}
experiment. With this work we try to better understand the location and
strength of specific background sources and compare the conclusions to
radioassay results taken before and during detector construction. Finally, we
discuss the implications of these studies for EXO-200 as well as for the
next-generation, tonne-scale nEXO detector.Comment: 9 pages, 7 figures, 3 table
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