734 research outputs found
Solar Energy: A Fresh Look at the Sun
This paper was my attempt to give solar energy a voice in the midst of discussion about the growing problems with global warming, fossil fuels, and bio-fuels. In reading and studying these topics, it becomes clear that with or without considering the damage fossil fuels are doing to the planet, there are many economic and political reasons to seriously consider alternative sources of energy. However, switching to new sources should be done with careful consideration of their own pros and cons. In my reading about solar energy, the pros seemed undeniable and the cons seemed surmountable. Solar energy has not received the same level of hype or government support that fossil and bio-fuels have enjoyed. The public seems to know little about solar energy â how it works, its benefits, the misconceptions about its pitfalls, and its capabilities. Fortunately, other countries such as Japan and Germany have already taken the initiative to test out policies to support solar energy and have had great results. Unfortunately, the U.S. does not seem to be moving in the same direction. This paper was written with the intent to spread the idea of free, truly green energy, not just for the future, but for the present as well
Deformation of continental lithosphere : studies in the Ural mountains, the Adriatic region, and the western United States
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Earth, Atmospheric, and Planetary Sciences, 1989.Includes bibliographical references.by Sarah Elizabeth Kruse.Ph.D
InSAR detection of localized subsidence induced by sinkhole activity in suburban west-central Florida
Sinkhole activity in west-central Florida is a major hazard for people and property. Increasing frequency of sinkhole collapse is often related to an accelerated use of groundwater and land resources. In this work, we use radar interferometry acquired over a selected region in Hernando County in west-central Florida to observe small localized deformation possibly caused by sinkhole activity. The data used for the study consist of acquisitions from one TerraSAR-X frame covering a time span of approximately 1.7 years with spatial resolution of 0.25 by 0.60 m.We applied the Persistent Scatterer Interferometry (PSI) technique using the Stanford Method for Persistent Scatterers (StaMPS). Results reveal several areas of localized subsidence at rates ranging from -3:7 to -4:9mmyr-1. Ground truthing and background verification of the subsiding locations confirmed the relationship of the subsidence with sinkhole presence
Spatio-spectral characteristics of parametric down-conversion in waveguide arrays
High dimensional quantum states are of fundamental interest for quantum
information processing. They give access to large Hilbert spaces and, in turn,
enable the encoding of quantum information on multiple modes. One method to
create such quantum states is parametric down-conversion (PDC) in waveguide
arrays (WGAs) which allows for the creation of highly entangled photon-pairs in
controlled, easily accessible spatial modes, with unique spectral properties.
In this paper we examine both theoretically and experimentally the PDC process
in a lithium niobate WGA. We measure the spatial and spectral properties of the
emitted photon-pairs, revealing strong correlations between spectral and
spatial degrees of freedom of the created photons. Our measurements show that,
in contrast to prior theoretical approaches, spectrally dependent coupling
effects have to be taken into account in the theory of PDC in WGAs. To
interpret the results, we developed a theoretical model specifically taking
into account spectrally dependent coupling effects, which further enables us to
explore the capabilities and limitations for engineering the spatial
correlations of the generated quantum states.Comment: 26 pages, 11 figure
Use of Imaging Spectrometer Data and Multispectral Imagery for Improved Earthquake Response
Imaging and Applied Optics Technical Digest, 2012Multispectral imagery and imaging spectrometer data are used to develop prototype
map products for improved earthquake response. A tiered approach keyed to post-event
communications infrastructure is directed at providing critical information to emergency services personnel.This research is supported by the Science and Technology (S&T) Directorate, Department of Homeland Security (DHS). We gratefully acknowledge the participation of emergency responders and managers from the cities and counties of Monterey, Los Angeles, San Diego, and Riverside California. We also appreciate contributions during project definition stage and follow-ups by the California Emergency Management Agency (Cal EMA) and the Federal Emergency Management Agency (FEMA), the U.S. Geological Survey, and DHS. AVIRIS data were acquired by NASA/JPL. The LiDAR data were provided by the Association of Monterey Bay Area Governments, via a USGS grant through the American Reinvestment and Recovery Act of 2009. WV-2 data were provided by the National Geospatial Intelligence Agency (NGA) under the NextView imagery license agreement
Rheostats and Toggle Switches for Modulating Protein Function
A grant from the One-University Open Access Fund at the University of Kansas was used to defray the authorâs publication fees in this Open Access journal. The Open Access Fund, administered by librarians from the KU, KU Law, and KUMC libraries, is made possible by contributions from the offices of KU Provost, KU Vice Chancellor for Research & Graduate Studies, and KUMC Vice Chancellor for Research. For more information about the Open Access Fund, please see http://library.kumc.edu/authors-fund.xml.The millions of protein sequences generated by genomics are expected to transform protein engineering and personalized medicine. To achieve these goals, tools for predicting outcomes of amino acid changes must be improved. Currently, advances are hampered by insufficient experimental data about nonconserved amino acid positions. Since the property ânonconservedâ is identified using a sequence alignment, we designed experiments to recapitulate that context: Mutagenesis and functional characterization was carried out in 15 LacI/GalR homologs (rows) at 12 nonconserved positions (columns). Multiple substitutions were made at each position, to reveal how various amino acids of a nonconserved column were tolerated in each protein row. Results showed that amino acid preferences of nonconserved positions were highly context-dependent, had few correlations with physico-chemical similarities, and were not predictable from their occurrence in natural LacI/GalR sequences. Further, unlike the âtoggle switchâ behaviors of conserved positions, substitutions at nonconserved positions could be rank-ordered to show a ârheostaticâ, progressive effect on function that spanned several orders of magnitude. Comparisons to various sequence analyses suggested that conserved and strongly co-evolving positions act as functional toggles, whereas other important, nonconserved positions serve as rheostats for modifying protein function. Both the presence of rheostat positions and the sequence analysis strategy appear to be generalizable to other protein families and should be considered when engineering protein modifications or predicting the impact of protein polymorphisms
Den einen Lehrkräftemangel gibt es nicht. Ein Diskussionsbeitrag zur Differenzierung
Die mediale Berichterstattung, die politische Diskussion sowie der wissenschaftliche Diskurs zum (vermeintlich richtigen) Umgang mit dem Lehrkräftemangel in der Bundesrepublik Deutschland werden zunehmend sehr allgemein und somit verkßrzt gefßhrt. Wir mÜchten dazu anregen, in der mitunter pauschalen Diskussion die Perspektiven auf den Lehrkräftemangel zu differenzieren, um den vielfältigen Problemlagen gerecht zu werden. Wir unterscheiden in der folgenden Darstellung zwischen der räumlichen Dimension, der Differenzierung nach Schulformen und Lehrämtern sowie nach Unterrichtsfächern. (DIPF/Orig.
Postimpact deformation associated with the late Eocene Chesapeake Bay impact structure in southeastern Virginia
Upper Cenozoic strata covering the Chesapeake Bay impact structure in southeastern Virginia record intermittent differential movement around its buried rim. Miocene strata in a graben detected by seismic surveys on the York River exhibit variable thickness and are deformed above the crater rim. Fan-like interformational and intraformational angular unconformities within PlioceneâPleistocene strata, which strike parallel to the crater rim and dip2°â3° away from the crater center, indicate that deformation and deposition were synchronous.Concentric, large-scale crossbedded, bioclastic sand bodies of Pliocene age within ~20 km of the buried crater rim formed on offshore shoals, presumably as subsiding listric slump blocks rotated near the crater rim
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