74 research outputs found

    Technical Breakthrough Points and Opportunities in Transition Scenarios for Hydrogen as Vehicular Fuel

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    This technical reports is about investigating a generic case of hydrogen production/delivery/dispensing pathway evolution in a large population city, assuming that hydrogen fuel cell electric vehicles (FCEV) will capture a major share of the vehicle market by the year 2050. The range of questions that are considered includes (i) what is the typical succession of hydrogen pathways that minimizes consumer cost? (ii) what are the major factors that will likely influence this sequence

    Impacts of Variability and Uncertainty in Solar Photovoltaic Generation at Multiple Timescales

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    The characteristics of variability and uncertainty of PV solar power have been studied extensively. These characteristics can create challenges for system operators who must ensure a balance between generation and demand while obeying power system constraints at the lowest possible cost. A number of studies have looked at the impact of wind power plants, and some recent studies have also included solar PV. The simulations that are used in these studies, however, are typically fixed to one time resolution. This makes it difficult to analyze the variability across several timescales. In this study, we use a simulation tool that has the ability to evaluate both the economic and reliability impacts of PV variability and uncertainty at multiple timescales. This information should help system operators better prepare for increases of PV on their systems and develop improved mitigation strategies to better integrate PV with enhanced reliability. Another goal of this study is to understand how different mitigation strategies and methods can improve the integration of solar power more reliably and efficiently

    Обобщение результатов исследований теплообмена между потоком воздуха и оребренной поверхностью, полученной при подрезании ребер со смещением оси

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    The given paper contains an analysis and presents a generalization of experimental results pertaining to heat exchange between an air flow and a surface of a flat pipe when its finning is made with various values of displacement of a tool rotation axis relative to a symmetry axis of a blank.Criterion dependences obtained as result of experimental data generalization provide the possibility to use them for calculation of external heat exchange intensity and losses of pressure in heat exchangers made of aluminum flat fined tubes.Проведен анализ и представлено обобщение результатов экспериментальных исследований теплообмена между потоком воздуха и поверхностью плоской трубы, оребрение которой было выполнено с различными величинами смещения оси вращения инструмента относительно оси симметрии заготовки.Полученные в результате обобщения экспериментальных данных критериальные зависимости дают возможность использовать их при проведении расчетов интенсивности внешнего теплообмена и потерь давления в теплообменниках, изготовленных из плоских оребренных алюминиевых труб

    Planetary Dynamics and Habitable Planet Formation In Binary Star Systems

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    Whether binaries can harbor potentially habitable planets depends on several factors including the physical properties and the orbital characteristics of the binary system. While the former determines the location of the habitable zone (HZ), the latter affects the dynamics of the material from which terrestrial planets are formed (i.e., planetesimals and planetary embryos), and drives the final architecture of the planets assembly. In order for a habitable planet to form in a binary star system, these two factors have to work in harmony. That is, the orbital dynamics of the two stars and their interactions with the planet-forming material have to allow terrestrial planet formation in the habitable zone, and ensure that the orbit of a potentially habitable planet will be stable for long times. We have organized this chapter with the same order in mind. We begin by presenting a general discussion on the motion of planets in binary stars and their stability. We then discuss the stability of terrestrial planets, and the formation of potentially habitable planets in a binary-planetary system.Comment: 56 pages, 29 figures, chapter to appear in the book: Planets in Binary Star Systems (Ed. N. Haghighipour, Springer publishing company

    The Kidneys and Aldosterone/Mineralocorticoid Receptor System in Salt-Sensitive Hypertension

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    Strong evidence supports the ability of the aldosterone/mineralocorticoid receptor (MR) system to dominate long-term blood pressure control. It is also increasingly recognized as an important mediator of cardiovascular and renal diseases, particularly in the presence of excessive salt intake. In a subgroup of individuals with metabolic syndrome, adipocyte-derived aldosterone-releasing factors cause inappropriate secretion of aldosterone in the adrenal glands during salt loading, resulting in the development of salt-induced hypertension and cardiac and renal damage. On the other hand, emerging data reveal that aldosterone is not a sole regulator of MR activity. We have identified the signaling crosstalk between MR and small GTPase Rac1 as a novel pathway to facilitate MR signaling. Such a local control system for MR can also be relevant to the pathogenesis of salt-sensitive hypertension, and future studies will clarify the detailed mechanism for the intricate regulation of the aldosterone/MR cascade

    The Production and Qualification of Scintillator Tiles for the ATLAS Hadronic Calorimeter

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    The production of the scintillator tiles for the ATLAS Tile Calorimeter is presented. In addition to the manufacture and production, the properties of the tiles will be presented including light yield, uniformity and stability
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