5,474 research outputs found

    Titanium-hydrogen interaction at megabar pressure

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    The process of transport of metal particles (ejecta\mathit{ejecta}) in gases is the subject of recent works in the field of nuclear energetics. We studied the process of dissolution of titanium ejecta in warm dense hydrogen at megabar pressure. Thermodynamic and kinetic properties of the process were investigated using classical and quantum molecular dynamics methods. We estimated the dissolution time of ejecta, the saturation limit of titanium atoms with hydrogen and the heat of dissolution. It was found that particles with a radius of 1 μm\mu m dissolve in hydrogen in time of 1.5102 μs1.5 \cdot 10^{-2} \ \mu s, while the process of mixing can be described by diffusion law. The presented approach demonstrates the final state of the titanium-hydrogen system as a homogenized fluid with completely dissolved titanium particles. This result can be generalized to all external conditions under which titanium and hydrogen are atomic fluids

    Impacts of battery characteristics, driver preferences and road network features on travel costs of a plug-in hybrid electric vehicle (PHEV) for long-distance trips

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    Cataloged from PDF version of article.In a road network with refueling and fast charging stations, the minimum-cost driving path of a plug-in hybrid electric vehicle (PHEV) depends on factors such as location and availability of refueling/fast charging stations, capacity and cost of PHEV batteries, and driver tolerance towards extra mileage or additional stopping. In this paper, our focus is long-distance trips of PHEVs. We analyze the impacts of battery characteristics, often-overlooked driver preferences and road network features on PHEV travel costs for long-distance trips and compare the results with hybrid electric and conventional vehicles. We investigate the significance of these factors and derive critical managerial insights for shaping the future investment decisions about PHEVs and their infrastructure. In particular, our findings suggest that with a certain level of deployment of fast charging stations, well established cost and emission benefits of PHEVs for the short range trips can be extended to long distance. Drivers׳ stopping intolerance may hamper these benefits; however, increasing battery capacity may help overcome the adverse effects of this intolerance

    A Note on Doubly Warped Product Contact CR-Submanifolds in trans-Sasakian Manifolds

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    Warped product CR-submanifolds in Kaehlerian manifolds were intensively studied only since 2001 after the impulse given by B.Y. Chen. Immediately after, another line of research, similar to that concerning Sasakian geometry as the odd dimensional version of Kaehlerian geometry, was developed, namely warped product contact CR-submanifolds in Sasakian manifolds. In this note we proved that there exists no proper doubly warped product contact CR-submanifolds in trans-Sasakian manifolds.Comment: 5 Latex page

    Minimum cost path problem for Plug-in Hybrid Electric Vehicles

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    Cataloged from PDF version of article.We introduce a practically important and theoretically challenging problem: finding the minimum cost path for plug-in hybrid electric vehicles (PHEVs) in a network with refueling and battery switching stations, considering electricity and gasoline as sources of energy with different cost structures and limitations. We show that this problem is NP-complete even though its electric vehicle and conventional vehicle special cases are polynomially solvable. We propose three solution techniques: (1) a mixed integer quadratically constrained program that incorporates non-fuel costs such as vehicle depreciation, battery degradation and stopping, (2) a dynamic programming based heuristic and (3) a shortest path heuristic. We conduct extensive computational experiments using both real world road network data and artificially generated road networks of various sizes and provide signifi- cant insights about the effects of driver preferences and the availability of battery switching stations on the PHEV economics. In particular, our findings show that increasing the number of battery switching stations may not be enough to overcome the range anxiety of the drivers

    What is the scientific basis for climate-smart agriculture?

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    Climate-smart agriculture (CSA) is a systematic approach to agricultural development. It intends to address climate change and food security challenges simultaneously across levels, from field management to national policy, with goals to 1) improve food security and agricultural productivity, 2) increase the resilience of farming systems to climate change, and 3) mitigate greenhouse gas (GHG) emissions or sequester carbon. After the introduction of the CSA concept in 2010, development organizations, national governments, and donors have quickly adopted a “climate-smart” agenda

    Development Of Al-B-C Master Alloy Under External Fields

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    This study investigates the application of external fields in the development of an Al-B-C alloy, with the aim of synthesizing in situ Al3BC particles. A combination of ultrasonic cavitation and distributive mixing was applied for uniform dispersion of insoluble graphite particles in the Al melt, improving their wettability and its subsequent incorporation into the Al matrix. Lower operating temperatures facilitated the reduction in the amount of large clusters of reaction phases, with Al3BC being identified as the main phase in XRD analysis. The distribution of Al3BC particles was quantitatively evaluated. Grain refinement experiments reveal that Al-B-C alloy can act as a master alloy for Al-4Cu and AZ91D alloys, with average grain size reduction around 50% each at 1wt%Al-1.5B-2C additions

    Bioactive supramolecular peptide nanofibers for regenerative medicine

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    Cataloged from PDF version of article.Recent advances in understanding of cell-matrix interactions and the role of the extracellular matrix (ECM) in regulation of cellular behavior have created new perspectives for regenerative medicine. Supramolecular peptide nanofiber systems have been used as synthetic scaffolds in regenerative medicine applications due to their tailorable properties and ability to mimic ECM proteins. Through designed bioactive epitopes, peptide nanofiber systems provide biomolecular recognition sites that can trigger specific interactions with cell surface receptors. The present Review covers structural and biochemical properties of the self-assembled peptide nanofibers for tissue regeneration, and highlights studies that investigate the ability of ECM mimetic peptides to alter cellular behavior including cell adhesion, proliferation, and/or differentiation. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

    Editorial

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