919 resultados para energy efficient


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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Cooperative energy-transfer upconversion luminescence in Tb 3+/Yb 3+-codoped PbGeO 3-PbF 2-CdF 2 vitroceramic and its precursor glass under resonant and off-resonance infrared excitation, is investigated. Bright UV-visible emission signals around 384, 415, 438 nm, and 473-490, 545, 587, and 623 nm, identified as due to the 5D 3( 5G 6 → 7F J(J=6,5,4) and 5D 4 → 7F J(J=6,5,4,3) transitions, respectively, were readily observed. The results indicate that cooperative energy-transfer between ytterbium and terbium ions followed by excited-state absorption are the dominant upconversion excitation mechanisms herein involved. The comparison of the upconversion process in a vitroceramic sample and its glassy precursor revealed that the former present much higher upconversion efficiency. The dependence of the upconversion emission upon pump power, temperature, and doping content is also examined.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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The present study suggests the use of high energy ball milling to mix (to dope) the phase MgB2 with the AlB2 crystalline structure compound, ZrB2, with the same C32 hexagonal structure than MgB 2, in different concentrations, enabling the maintenance of the crystalline phase structures practically unaffected and the efficient mixture with the dopant. The high energy ball milling was performed with different ball-to-powder ratios. The analysis of the transformation and formation of phases was accomplished by X-ray diffractometry (XRD), using the Rietveld method, and scanning electron microscopy. As the high energy ball milling reduced the crystallinity of the milled compounds, also reducing the size of the particles, the XRD analysis were influenced, and they could be used as comparative and control method of the milling. Aiming the recovery of crystallinity, homogenization and final phase formation, heat treatments were performed, enabling that crystalline phases, changed during milling, could be obtained again in the final product. © (2010) Trans Tech Publications.

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This paper presents an efficient tabu search algorithm (TSA) to solve the problem of feeder reconfiguration of distribution systems. The main characteristics that make the proposed TSA particularly efficient are a) the way in which the neighborhood of the current solution was defined; b) the way in which the objective function value was estimated; and c) the reduction of the neighborhood using heuristic criteria. Four electrical systems, described in detail in the specialized literature, were used to test the proposed TSA. The result demonstrate that it is computationally very fast and finds the best solutions known in the specialized literature. © 2012 IEEE.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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This guideline jointly published by The UN Economic and Social Commission for Asia and the Pacific (ESCAP), the UN Economic Commission for Latin America and the Caribbean (ECLAC), and the UN Human Settlements Programme (UN-HABITAT), in partnership with the Urban Design Lab of the Earth Institute, Columbia University, provides practical tools for city planners and decision makers to reform urban planning and infrastructure design according to the principles of eco-efficiency and social inclusiveness. It includes case studies from the Republic of Korea, the Philippines, Japan and Sri Lanka.

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Belize is currently faced with several critical challenges associated with the production, distribution and use of energy. Despite an abundance of renewable energy resources, the country remains disproportionately dependent on imported fossil fuels, which exposes it to volatile and rising oil prices, limits economic development, and retards its ability to make the investments that are necessary for adapting to climate change, which pose a particularly acute threat to the small island states and low-lying coastal nations of the Caribbean. This transition from energy consumption and supply patterns that are based on imported fossil fuels and electricity towards a more sustainable energy economy that is based on environmentally benign, indigenous renewable energy technologies and more efficient use of energy requires concerted action as the country is already challenged by limited fiscal space which reduces its ability to provide some fiscal incentives, which have been proven to be effective tools for the promotion of sustainable energy markets in a number of countries. This report identifies the fiscal and regulatory barriers to implementation of energy efficiency measures and renewable energy technologies in Belize. Data and information were derived from stakeholder consultations conducted within the country. The major result of the assessment is that the transition of policies and plans into tangible action needs to be increased. In this regard, it is necessary to articulate sub-policies of the National Energy Policy to amend the Public Utilities Commission Act, to develop a grid interconnection policy, to establish minimum energy performance standards for buildings and equipment and to develop a public procurement policy. Finally, decisions on renewable energy and energy efficiency-related incentives from the Government formally requires decision-makers to solve what may be extremely complex optimization problems in order to obtain the lowest-cost provision of energy services to society, thereby weighing the cost of revenue losses with the benefits of fuel and infrastructure expansion savings. The establishment of a management system that is efficient, flexible, and transparent, which will facilitate the implementation of the strategic objectives and outputs in the time available, with the financial resources allocated is recommended. Support is required for additional institutional and capacity strengthening.

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This paper presents an assessment of an educational game for teaching the efficient use of electricity. Developed with Adobe Flash (R), it is a virtual board game where participants choose a car that starts the path and reaches the same final goal, going through a number of track steps defined in terms of a dice that each player rolls in turn. The car moves if the participant is able to correctly answer a question that is randomly generated by the software. The objective of the game is to answer questions related to energy efficiency promoting a healthy and attractive learning process for participants on concepts related to energy efficiency such as: the rational use of energy, the basic concepts of forms of energy generation, among others. The main objective of this paper is to assess the impact of the application of this virtual game in the teaching and learning process of high school students. Therefore, the game was applied in the discipline of physics in a class of junior high public school in the state of Sao Paulo. Initially, the class that had 43 students was divided into 10 groups of 4 students, and 1 group of 3 students. Each student group competed with one another. The idea was that each of them should indicate a student who was the representative of this group until only 4 group leaders were selected for the finals. At this stage, each student could interact with a group of up to ten students that acted as advisers. The adopted assessment process is based on the model proposed by Savi [7]. Then, at the end of the game, the students answered a prepared questionnaire based on the model proposed by Savi. According to Savi, although there are significant studies that show the importance of educational games for the process of cognitive development and learning concepts of students, there are few papers that present forms of assessing the potential of these resources. Thus, the assessment criteria proposed by Savi are based on the model of training evaluation by Kirkpatrick [3], taken as a reference to measure the efficiency of processes of continuing education courses for professionals. The authors assert that the metric of the evaluation proposed to assess the game is based on the first level of the model proposed by Kirkpatrick.

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