909 resultados para U.S. Clean Coal Technology Demonstration Program
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"DOT-T-92-18."
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Mode of access: Internet.
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The first demonstration of heterogeneous catalysis within an oscillatory baffled flow reactor (OBR) is reported, exemplified by the solid acid catalysed esterification of organic acids, an important prototypical reaction for fine chemicals and biofuel synthesis. Suspension of a PrSOH-SBA-15 catalyst powder is readily achieved within the OBR under an oscillatory flow, facilitating the continuous esterification of hexanoic acid. Excellent semi-quantitative agreement is obtained between OBR and conventional stirred batch reaction kinetics, demonstrating efficient mixing, and highlighting the potential of OBRs for continuous, heterogeneously catalysed liquid phase transformations. Kinetic analysis highlights acid chain length (i.e. steric factors) as a key predictor of activity. Continuous esterification offers improved ester yields compared with batch operation, due to the removal of water by-product from the catalyst, evidencing the versatility of the OBR for heterogeneous flow chemistry and potential role as a new clean catalytic technology. © The Royal Society of Chemistry 2013.
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This report documents the results of a three million dollar traffic signal improvement demonstration program, known as the Iowa Motor Vehicle Fuel Reduction Program (the program). The program was funded with the use of oil overcharge funds and administered by the Iowa Departments of Natural Resources and Transportation. The objective of the program was to provide restitution to overcharged motorists by improving the efficiency of traffic signals. More efficient traffic signals reduce fuel consumption, delay, travel time, and automobile pollution while improving traffic safety. The program demonstrated the effectiveness of improving traffic signals and resulted in a 14.20-to-1 benefit-to-cost ratio.
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A search for depletion of the combined flux of active neutrino species over a 735 km baseline is reported using neutral-current interaction data recorded by the MINOS detectors in the NuMI neutrino beam. Such a depletion is not expected according to conventional interpretations of neutrino oscillation data involving the three known neutrino flavors. A depletion would be a signature of oscillations or decay to postulated noninteracting sterile neutrinos, scenarios not ruled out by existing data. From an exposure of 3.18 x 10(20) protons on target in which neutrinos of energies between similar to 500 MeV and 120 GeV are produced predominantly as nu(mu), the visible energy spectrum of candidate neutral-current reactions in the MINOS far detector is reconstructed. Comparison of this spectrum to that inferred from a similarly selected near-detector sample shows that of the portion of the nu(mu) flux observed to disappear in charged-current interaction data, the fraction that could be converting to a sterile state is less than 52% at 90% confidence level (C. L.). The hypothesis that active neutrinos mix with a single sterile neutrino via oscillations is tested by fitting the data to various models. In the particular four-neutrino models considered, the mixing angles theta(24) and theta(34) are constrained to be less than 11 degrees and 56 degrees at 90% C. L., respectively. The possibility that active neutrinos may decay to sterile neutrinos is also investigated. Pure neutrino decay without oscillations is ruled out at 5.4 standard deviations. For the scenario in which active neutrinos decay into sterile states concurrently with neutrino oscillations, a lower limit is established for the neutrino decay lifetime tau(3)/m(3) > 2.1 x 10(-12) s/eV at 90% C.L.
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It is unquestionable that an effective decision concerning the usage of a certain environmental clean-up technology should be conveniently supported. Significant amount of scientific work focussing on the reduction of nitrate concentration in drinking water by both metallic iron and nanomaterials and their usage in permeable reactive barriers has been worldwide published over the last two decades. This work aims to present in a systematic review of the most relevant research done on the removal of nitrate from groundwater using nanosized iron based permeable reactive barriers. The research was based on scientific papers published between 2004 and June 2014. It was performed using 16 combinations of keywords in 34 databases, according to PRISMA statement guidelines. Independent reviewers validated the selection criteria. From the 4161 records filtered, 45 met the selection criteria and were selected to be included in this review. This study's outcomes show that the permeable reactive barriers are, indeed, a suitable technology for denitrification and with good performance record but the long-term impact of the use of nanosized zero valent iron in this remediation process, in both on the environment and on the human health, is far to be conveniently known. As a consequence, further work is required on this matter, so that nanosized iron based permeable reactive barriers for the removal of nitrate from drinking water can be genuinely considered an eco-efficient technology.
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The evaluation’s overarching question was “Did the activities undertaken through the state’s LSTA plan achieve results related to priorities identified in the Act?” The evaluation was conducted and is organized according to the six LSTA priorities. The research design employed two major methodologies: 1. Data sources from Iowa Library Services / State Library of Iowa2 as well as U.S and state sources were indentified for quantitative analysis. These sources, which primarily reflect outputs for various projects, included: Statistics from the Public Library Annual Survey Statistics collected internally by Iowa Library Services such as number of libraries subscribing to sponsored databases, number of database searches, attendance at continuing education events, number of interlibrary loan transactions Evaluation surveys from library training sessions, professional development workshops and other programs supported by LSTA funds Internal databases maintained by Iowa Library Services Impact results from post training evaluations conducted by Iowa Library Services 2010 Iowa census data from the U.S. Census Bureau LSTA State Program Reports for the grant period 2. Following the quantitative analysis, the evaluator gathered qualitative data through interviews with key employees, a telephone focus group with district library consultants and two surveys: LSTA Evaluation Survey (Public Libraries) and LSTA Evaluation Survey (Academic Libraries). Both surveys provided sound samples with 43 representatives of Iowa’s 77 academic libraries and 371 representatives of Iowa’s 544 public libraries participating. Respondents represented libraries of all sizes and geographical areas. Both surveys included multiple choice and rating scale items as well as open-ended questions from which results were coded to identify trends, issues and recommendations.
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Conventional technology used in the treatment of wastewater has been pointed as a major environmental problem for sustainable development, since minimization is not addressed accordingly. Advanced oxidation processes (AOP), based on the formation of hydroxyl radical (OH), a powerful oxidant agent, have been considered to be a potential technology for the destruction of many toxic compounds. Photocatalysis using solar light, an AOP, has been studied for nearly 20 years and recently attracted great interest as a clean-up technology. However, solar detoxification processes have not yet achieved commercial success. This article presents an overview of reaction mechanisms at the surface of semiconductors used as photocatalysts (specially TiO2), when heterogeneous photocatalysis is used to remove hazardous compounds from contaminated sites.