2,822 research outputs found

    Moral and Spiritual Changes in the Last Years of the Soviet Union - Part One

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    See Part Two here: http://digitalcommons.georgefox.edu/ree/vol13/iss1/2

    Ethics in the Soviet Union today

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    https://stars.library.ucf.edu/prism/1721/thumbnail.jp

    Cost and U.S. public policy for new coal power plants with carbon capture and sequestration

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    This paper provides a financial analysis for new supercritical pulverized coal plants with carbon capture and sequestration (CCS) that compares the effects of two relevant climate policies. First, an updated cost estimate is presented for new supercritical pulverized coal plants, both with and without CCS. The capital cost escalation of recent years can be attributed to rising materials, plant supply, and plant contractor constraints. This estimate is then compared with recent estimates from public sources. Second, several current and proposed public policies relevant to CCS are presented. Finally, a financial analysis is performed to evaluate the effectiveness of two likely US carbon regulations on deploying Nth-plant CCS technology. The major conclusion is that the leading US carbon cap-and-trade bills will likely not be sufficient to deploy CCS technology in a manner consistent with a 550 ppm CO[subscript 2] stabilization scenario. A more aggressive carbon policy including CCS research, development, and demonstration must be considered to achieve this goal with significant CCS deployment.Massachusetts Institute of Technology. Carbon Sequestration InitiativeMIT Industrial Performance Cente

    The use of Fe3O4/Carbon composite fibers as anode materials in lithium ion batteries

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    In the present work, results on the synthesis and mass production of polymer/ceramic composite fibers through Forcespinning¼ (FS) are reported. Magnetite (Fe3O4), has been considered as a good anode material for Lithium‒Ion Batteries (LIBs) due to its high theoretical capacity (~924 mAhg-1), low cost, and low toxicity. The Fe3O4/carbon composite, in the present study, was achieved through Forcespinning iron (III) acetylacetonate /polyacrylonitrile (PAN) precursor solution with stabilization in air at 280°C followed by carbonization at 600°C under argon. The electrochemical cyclic performance of Fe3O4/C composite fibers was investigated by galvanostatic charge/discharge experiments. The results showed the Fe3O4/C composite fiber anode exhibited higher reversible capacity of 300 mAhg-1 after 100 cycles at a current density of 100 mAg-1 compared to that of carbon fibers, which was approximately100 mAhg-1. In addition, the Fe3O4/composite fiber anode showed improved capacity retention and better rate performance than pure carbon fibers

    Integration over song classification replicates: Song variant analysis in the hihi

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    Human expert analyses are commonly used in bioacoustic studies and can potentially limit the reproducibility of these results. In this paper, a machine learning method is presented to statistically classify avian vocalizations. Automated approaches were applied to isolate bird songs from long field recordings, assess song similarities, and classify songs into distinct variants. Because no positive controls were available to assess the true classification of variants, multiple replicates of automatic classification of song variants were analyzed to investigate clustering uncertainty. The automatic classifications were more similar to the expert classifications than expected by chance. Application of these methods demonstrated the presence of discrete song variants in an island population of the New Zealand hihi (Notiomystis cincta). The geographic patterns of song variation were then revealed by integrating over classification replicates. Because this automated approach considers variation in song variant classification, it reduces potential human bias and facilitates the reproducibility of the results

    The impact of a fast track area on quality and effectiveness outcomes: A Middle Eastern emergency department perspective

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    <p>Abstract</p> <p>Background</p> <p>Emergency department (ED) overcrowding is a ubiquitous problem with serious public health implications. The fast track area is a novel method which aims to reduce waiting time, patient dissatisfaction and morbidity. |The study objective was to determine the impact of a fast track area (FTA) on both effectiveness measures (i.e. waiting times [WT] and length of stay [LOS]) and quality measures (i.e. LWBS rates and mortality rates) in non-urgent patients. The secondary objective was to assess if a FTA negatively impacted on urgent patients entering the ED.</p> <p>Methods</p> <p>The study took place in a 500 bed, urban, tertiary care hospital in Abu Dhabi, United Arab Emirates. This was a quasi-experimental, which examined the impact of a FTA on a pre-intervention control group (January 2005) (n = 4,779) versus a post-intervention study group (January 2006) (n = 5,706).</p> <p>Results</p> <p>Mean WTs of Canadian Triage Acuity Scale (CTAS) 4 patients decreased by 22 min (95% CI 21 min to 24 min, <it>P </it>< 0.001). Similarly, mean WTs of CTAS 5 patients decreased by 28 min (95% CI 19 min to 37 min, <it>P </it>< 0.001) post FTA. The mean WTs of urgent patients (CTAS 2/3) were also significantly reduced after the FTA was opened (<it>P </it>< 0.001). The LWBS rate was reduced from 4.7% to 0.7% (95% CI 3.37 to 4.64; <it>P </it>< 0.001). Opening a FTA had no significant impact on mortality rates (<it>P </it>= 0.88).</p> <p>Conclusion</p> <p>The FTA improved ED effectiveness (WTs and LOS) and quality measures (LWBS rates) whereas mortality rate remained unchanged.</p

    Future Carbon Regulations and Current Investments in Alternative Coal-Fired Power Plant Designs

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    Abstract in HTML and technical report in PDF available on the Massachusetts Institute of Technology Joint Program on the Science and Policy of Global Change website (http://mit.edu/globalchange/www/).This paper assesses the role of uncertainty over future U.S. carbon regulations in shaping the current choice of which type of power plant to build. The pulverized coal technology (PC) still offer the lowest cost power— assuming there is no need to control emissions of carbon. The integrated coal gasification combined cycle technology (IGCC) may be cheaper if carbon must be captured. Since a plant built now will be operated for many years, and since carbon regulations may be instituted in the future, a U.S. electric utility must make the current investment decision in light of the uncertain future regulatory rules. This paper shows how this decision is to be made. We start by describing the economics of the two key coal-fired power plant technologies, PC and IGCC. We then analyze the potential costs of future carbon regulations, including the costs of retrofitting the plant with carbon capture technology and the potential cost of paying charges for emissions. We present the economics of each design in the form of a cash flow spreadsheet yielding the present value cost, and show the results for different scenarios of emissions regulation. We then discuss how to incorporate uncertainty about the future regulation of carbon emissions into the decision to build one plant design or the other. As an aid to decision making, we provide some useful benchmarks for possible future regulation and show how these benchmarks relate back to the relative costs of the two technologies and the optimal choice for the power plant investment. Few of the scenarios widely referenced in the public discussion warrant the choice of the IGCC technology. Instead, the PC technology remains the least costly. The level of future regulation required to justify a current investment in the IGCC technology appears to be very aggressive, if not out of the question. However, the current price placed on carbon emissions in the European Trading System, is higher than these benchmarks. If it is any guide to possible future penalties for emissions in the U.S., then current investment in the IGCC technology is warranted.This research was supported by the MIT Joint Program on the Science and Policy of Global Change and the MIT Carbon Sequestration Initiative. The MIT modeling facility used in this analysis was supported by the US Department of Energy, Office of Biological and Environmental Research [BER] (DE-FG02-94ER61937), the US Environmental Protection Agency (XA-83042801-0), the Electric Power Research Institute, and by a consortium of industry and foundation sponsors

    Analysing Friedel averages and differences

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    Various practical applications of the average (A) and difference (D) of Friedel opposites are described. Techniques based on the resonant-scattering contribution to Friedel differences are applied to see whether a crystal is centrosymmetric or not, and to determine the point group of the crystal. For the validation of a structural study, plots of Aobs against Amodel, and Dobs against Dmodel are used extensively. Moreover, it is useful to display both plots on the same graph. Intensity measurements on a crystal of NaClO3 were made at three different speeds, with two different radiations and two different diffractometers, and treated with two different software packages and four different absorption corrections. The evaluation of these numerous data sets reveals underlying deficiencies. For comparison, plots of Aobs against Amodel, and Dobs against Dmodel are presented for two centrosymmetric crystals

    Current and Nascent SETI Instruments

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    Here we describe our ongoing efforts to develop high-performance and sensitive instrumentation for use in the search for extra-terrestrial intelligence (SETI). These efforts include our recently deployed Search for Extraterrestrial Emissions from Nearby Developed Intelligent Populations Spectrometer (SERENDIP V.v) and two instruments currently under development; the Heterogeneous Radio SETI Spectrometer (HRSS) for SETI observations in the radio spectrum and the Optical SETI Fast Photometer (OSFP) for SETI observations in the optical band. We will discuss the basic SERENDIP V.v instrument design and initial analysis methodology, along with instrument architectures and observation strategies for OSFP and HRSS. In addition, we will demonstrate how these instruments may be built using low-cost, modular components and programmed and operated by students using common languages, e.g. ANSI C.Comment: 12 pages, 5 figures, Original version appears as Chapter 2 in "The Proceedings of SETI Sessions at the 2010 Astrobiology Science Conference: Communication with Extraterrestrial Intelligence (CETI)," Douglas A. Vakoch, Edito
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