3,443 research outputs found

    Linear Programming-Based Power Management for a Multi-Feeder Ultra-Fast DC Charging Station

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    The growing number of electric vehicles (EVs) affects the national electricity system in terms of power demand and load variation. Turning our attention to Italy, the number of vehicles on the road is 39 million; this represents a major challenge, as they will need to be recharged constantly when the transition to electric technology is complete. If we consider that the average power is 55 GW and the installed system can produce 120 GW of peak power, we can calculate that with only 5% of vehicles in recharging mode, the power demand increases to 126 GW, which is approximately 140% of installed power. The integration of renewable energy sources will help the grid, but this solution is less useful for handling large load variations that negatively affect the grid. In addition, some vehicles committed to public utility must have a reduced stop time and can be considered to have higher priority. The introduction of priorities implies that the power absorption limit cannot be easily introduced by limiting the number of charging vehicles, but rather by computing the power flow that respects constraints and integrates renewable and local storage power contributions. The problem formulated in this manner does not have a unique solution; in this study, the linear programming method is used to optimise renewable resources, local storage, and EVs to mitigate their effects on the grid. Simulations are performed to verify the proposed method

    Model Pembelajaran Peer-teaching Untuk Meningkatkan Kemampuan Verbal Mahasiswa Pgsd Fkip Ums

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    The problems of lecturing in Primary Education are lowering the ability of verbal communication.The student seldom gives good respond in the form of question, expostulationand or criticism. For the developed of verbal capacity, researcher applied the strategyof peer-teaching. Peer-Teaching is a lecturing model by functioned the student arelearning friend each other. There are six models, one of them is Jigsaw learning. Theimplementation of Jigsaw model is by counting six times, and each is observed by assistant.The general conclusion of the research is that it can improve the student's verbalcapacity until significant number (92,5 %). In detail it can be elaborated: a) The enthusiasmof the student in working task, getting better by the end of meeting counted 42students. b) The student activity of instruction of the material rounding into 43 students, c) The student of enough question and answer capacity rounding into the goodness are37 student, d) The interaction of student of good verbal remain to be good are 43 students.From final test also told that the final achievement of the students amount B

    Detection of Anomalous Microwave Emission in the Pleiades Reflection Nebula with WMAP and the COSMOSOMAS Experiment

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    We present evidence for anomalous microwave emission (AME) in the Pleiades reflection nebula, using data from the seven-year release of the Wilkinson Microwave Anisotropy Probe (WMAP) and from the COSMOSOMAS experiment. The flux integrated in a 1-degree radius around R.A.=56.24^{\circ}, Dec.=23.78^{\circ} (J2000) is 2.15 +/- 0.12 Jy at 22.8 GHz, where AME is dominant. COSMOSOMAS data show no significant emission, but allow to set upper limits of 0.94 and 1.58 Jy (99.7% C.L.) respectively at 10.9 and 14.7 GHz, which are crucial to pin down the AME spectrum at these frequencies, and to discard any other emission mechanisms which could have an important contribution to the signal detected at 22.8 GHz. We estimate the expected level of free-free emission from an extinction-corrected H-alpha template, while the thermal dust emission is characterized from infrared DIRBE data and extrapolated to microwave frequencies. When we deduct the contribution from these two components at 22.8 GHz the residual flux, associated with AME, is 2.12 +/- 0.12 Jy (17.7-sigma). The spectral energy distribution from 10 to 60 GHz can be accurately fitted with a model of electric dipole emission from small spinning dust grains distributed in two separated phases of molecular and atomic gas, respectively. The dust emissivity, calculated by correlating the 22.8 GHz data with 100-micron data, is found to be 4.36+/-0.17 muK/MJy/sr, a value that is rather low compared with typical values in dust clouds. The physical properties of the Pleiades nebula indicate that this is indeed a much less opaque object than others were AME has usually been detected. This fact, together with the broad knowledge of the stellar content of this region, provides an excellent testbed for AME characterization in physical conditions different from those generally explored up to now.Comment: Accepted for publication in ApJ. 12 pages, 8 figure

    Virtual gardening: Identifying problems and potential directions for 'ecological awareness' through soil management and plant recognition gaming

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    Games are increasingly proven to be effective learning tools through a multitude of methodologies and approaches and this is no different for issues relating to the environment and the place of humans within it. We collaborated with the Eden Project to create a mobile game addressing some concerns on the ecological awareness of visitors that they raised with us: a mobile garden management game with a plant recognition technology. Such a project proved a valuable opportunity to understand how a game for smart devices might promote short-term ecological awareness for a general audience. Using a research creation methodology, we analyse, document and run a limited empirical study through user experience testing on players to investigate if the game had an effect on their ecological awareness

    Design aspects of a CMC coating-like system for hot surfaces of aero engine components

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    Ceramic Matrix Composite (CMC) is an emerging material system that can be a game changer in the aerospace industry, both civil and military. CMCs components are, in fact, lighter and less prone to fatigue failure in a high temperature environment. However, at high temperatures, the diffusion of oxygen and water vapour inside the CMC can have detrimental effects. Therefore, the presence of protective coating is necessary to extend the life of CMC components. In the present work, a three-layers coating, consisting of a silicon bond (BND), adhesively bonded to the CMC, an Environment Barrier Coating (EBC) and a softer layer 3 (LAY3), is investigated for a CMC component. An aero-engine high pressure turbine seal segment was considered. Two design aspects are covered: (i) creep law is determined and calibrated in environment Abaqus from the experimental data of each coating layer available in the open literature, to provide a suitable instrument for the creep relaxation analyses of hot components; (ii) thickness sensitivity study of each layer of the coating is conducted to minimise the interface stresses of coating with substrate in order to mitigate cracking and removal/spalling phenomena when exposed to temperature gradients and to increase their service life. These two different aspects are combined together to predict the coating stress field as a function of service time
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