775 research outputs found
Dynamics and control of the satellite power system
An investigation of the dynamics and control problems specifically related to the Satellite Power System (SPS), to assess performance of selected control concepts, and to identify and initiate development of advanced control technology that would enhance feasibility and performance of the SPS system was made. The initial stages of the study are reported
A Resonant Synchronous Vibration Based Approach for Rotor Imbalance Detection
This paper presents a methodology of detecting rotor imbalances, such as mass imbalance and crack-induced imbalance, using shaft synchronous vibrations. An iterative scheme is developed to identify parameters from measured synchronous vibration data. A detection system is integrated by using state-of-the-art commercial analysis equipment. A laboratory rotor test rig is used to verify the system integration and algorithm validation. A real engine test has been carried out and the results are reported
Secretary for Environmental Protection
As a measure of its commitment to good government and to transparency, the California Department of Toxic Substances Control has launched a comprehensive review of its permit process. During the past two years, stakeholder feedback and our own intemal observations have demonstrated that there is room for improvement in the process of permitting hazardous waste treatment, storage and disposalfacilities. Twenty-two businesses are working with outdated permits for various reasons, critics have complained the department does not have clear guidelines for when to deny a permit and businesses complain standards are unevenly applied. To continue providing a high level of protection, DTSC must review its hazardous waste management guidance and practices as they relate to our permitting program. As a result, we have contracted with California Personnel Services (CPS) to perform an outside review of our permit process. CPS is a self-supporting state agency, created in 1985 to improve the performance of government and non-profit agencies, as well as private companies. Bill Magavern, Senior Policy Advocate for the Coalition for Clean Air, and Tom McHefiry, a member of Gibson, Dunn & Crutcher's Environmental Litigation and Mass Tort Practice Group, ar
Phase diagram and magnetic properties of LaCaMnO compound for
In this article a detailed study of LaCaMnO () phase diagram using powder x-ray diffraction and magnetization
measurements is presented. Unfortunately, in the related literature no properly
characterized samples have been used, with consequence the smearing of the real
physics in this complicated system. As the present results reveal, there are
two families of samples. The first family concerns samples prepared in
atmosphere ( Atm) which are all ferromagnetic with Curie
temperature rising with . The second family concerns samples, where a post
annealing in nearly zero oxygen partial pressure is applied. These samples show
a canted antiferromagnetic structure for below , while
for an unconventional ferromagnetic insulated phase is
present below . The most important difference between nonstoichiometric
and stoichiometric samples concerning the magnetic behavior, is the anisotropy
in the exchange interactions, in the stoichiometric samples putting forward the
idea that a new orbital ordered phase is responsible for the ferromagnetic
insulating regime in the LaCaMnO compound
Serving the People of the Tennessee Valley: Perspectives on Learning, Growth and Management Internships
The purpose of this project was to examine three students’ different paths and perspectives of internships at the Tennessee Valley Authority (TVA) in the Learning, Growth and Management Department (LG&M). The need for this project was highlighted by a lack of internship practicum-based information presented in past research conferences. This poster first examines the different teams and functions of those teams that the interns were apart of during their internships at TVA. Then the project identifies types of jobs that I-O Psychology Masters candidates can expect to be qualified and/or recruited for within the constraints of TVA and the LG&M department. Next, key projects, and SIOP competencies strengthened through these projects, will be discussed. Finally, recommendations for students seeking internships and companies seeking to recruit top quality I-O students are given. In sum, while this project only examines three students’ paths at one company and in one department, we believe this information will help I-O psychology students identify internships that can develop important competencies that SIOP has designated as necessary to be a successful I-O psychology practitioner and offer helpful recommendations for students and companies alike
The Casimir energy of skyrmions in the 2+1-dimensional O(3)-model
One-loop quantum corrections to the classical vortices in 2+1 dimensional
O(3)-models are evaluated. Skyrme and Zeeman potential terms are used to
stabilize the size of topological solitons. Contributions from zero modes,
bound-states and scattering phase-shifts are calculated for vortices with
winding index n=1 and n=2. For both cases the S-matrix shows a pronounced
series of resonances for magnon-vortex scattering in analogy to the
well-established baryon resonances in hadron physics, while vortices with n>2
are already classically unstable against decay. The quantum corrections
destabilize the classically bound n=2 configuration. Approximate independence
of the results with respect to changes in the renormalization scale is
demonstrated.Comment: 24 pages LaTeX, 14 figure
Using Remotely Sensed Data and Watershed and Hydrodynamic Models to Evaluate the Effects of Land Cover Land Use Change on Aquatic Ecosystems in Mobile Bay, AL
Alabama coastal systems have been subjected to increasing pressure from a variety of activities including urban and rural development, shoreline modifications, industrial activities, and dredging of shipping and navigation channels. The impacts on coastal ecosystems are often observed through the use of indicator species. One such indicator species for aquatic ecosystem health is submerged aquatic vegetation (SAV). Watershed and hydrodynamic modeling has been performed to evaluate the impact of land cover land use (LCLU) change in the two counties surrounding Mobile Bay (Mobile and Baldwin) on SAV stressors and controlling factors (temperature, salinity, and sediment) in the Mobile Bay estuary. Watershed modeling using the Loading Simulation Package in C++ (LSPC) was performed for all watersheds contiguous to Mobile Bay for LCLU scenarios in 1948, 1992, 2001, and 2030. Remotely sensed Landsat-derived National Land Cover Data (NLCD) were used in the 1992 and 2001 simulations after having been reclassified to a common classification scheme. The Prescott Spatial Growth Model was used to project the 2030 LCLU scenario based on current trends. The LSPC model simulations provided output on changes in flow, temperature, and sediment for 22 discharge points into the estuary. These results were inputted in the Environmental Fluid Dynamics Computer Code (EFDC) hydrodynamic model to generate data on changes in temperature, salinity, and sediment on a grid throughout Mobile Bay and adjacent estuaries. The changes in the aquatic ecosystem were used to perform an ecological analysis to evaluate the impact on SAV habitat suitability. This is the key product benefiting the Mobile Bay coastal environmental managers that integrates the influences of temperature, salinity, and sediment due to LCLU driven flow changes with the restoration potential of SAVs. Data products and results are being integrated into NOAA s EcoWatch and Gulf of Mexico Data Atlas online systems for dissemination to coastal resource managers and stakeholders. Objective 1: Develop and utilize Land Use scenarios for Mobile and Baldwin Counties, AL as input to models to predict the affects on water properties (temperature,salinity,)for Mobile Bay through 2030. Objective 2: Evaluate the impact of land use change on seagrasses and SAV in Mobile Bay. Hypothesis: Urbanization will significantly increase surface flows and impact salinity and temperature variables that effect seagrasses and SAVs
Energy dependence of cumulative suprathermal and energetic particle fluence plots
Suprathermal and energetic particle flux variability can be statistically characterized in a number of ways. As time histories of flux integrals (cumulative fluences) are relevant both for practical reasons (radiation effects) and for a better understanding of the production and propagation processes, simple quantitative methods are of some interest. Previous studies (e.g. Mewaldt et al., 2001)[1] showed that the character of cumulative fluence plots changed substantially with energy. While at several MeV/nuc a few solar particle events predominate, at much lower energies similar contributions from many separate events of various origins were found. We shall now use a simple parametric method for comparisons, and mention some other possibilities. As in the Kolmogorov hypothesis test, the maximum vertical distance of normalized cumulative plots from the straight line valid for a constant flux will be shown to be useful. Small values of that parameter (called K here for Kolmogorov) indicate variation in many small steps, while large K-values correspond to the dominance of a small number of large events. Below a few MeV/nuc K-parameters will be shown to decrease with decreasing energies. Extrapolations to small energies will be mainly discussed
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