Results 1 - 10 of 1976
Results 1 - 10 of 1976. Search took: 0.023 seconds
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[en] This report is the rounding-off account of the project Energy-economizing MEA. First the development in sub-projects is outlined resulting into the actual state of affairs. Next the extent of the spendings are discussed. Finally the attained energy economizing is estimated. (H.W.). 4 tabs
[en] In this report a package of energy-saving measures for NIKHEF-MEA are presented. The proposed measures have reference to the raising, in relatively short time, of the modulation frequency to the desired value when, in behalf of maintenance or tuning the repetition frequency is set low. A second group of measures consists in the limitation of the energy consumption of the cooling systems at MEA and AFBU. At MEA important economizations can be achieved by the limitation of the heat-leaching to outside when the accelerator is out of operation while at AFBU the tuning of the r.p.m. of the circulation pumps in the cooling systems seems to be attractive. As least measure of the package the power control of NIKHEF is incorporated. This should allow for exploiting the available power as economical as possible and for keeping the costs for electricity supply as low as possible. 4 tabs
[en] Energy industry initiatives during the 1970s and during the 1990s are compared. During the 1970s, the objective was to reduce energy consumption and to reduce dependency on foreign fuel. Today, the emphasis is on reducing energy costs and to improve net operating income. The challenges posed by the drive to reduce energy costs are discussed. As a tool in the drive to reduce energy cost, the energy assessment process was described. The process entails a detailed analysis of energy consumption, an investigation of energy rates and an assessment of site conditions and equipment, with a view towards an optimum combination that will lead to energy cost reductions
[en] Following the sharp increases in the price of energy over the last six years and the increasingly widespread incorporation of installations that offer added value to the establishment but which increase its energy expenditure (spas, swimming pools, gymnasiums, etc.), the hotel sector today is aware of the significance of energy as part of its operating costs. Proof of this is that fact that a large proportion of hotels have undertaken, or are considering carrying out, some form of measure to improve energy efficiency. (Author)
[en] This letter presents a methodology for an integrated energy-air quality model in a cost and impact trade-off framework, applicable at the regional scale. ETEM (the Energy Technology Environmental Model) minimizes the energy cost at a given level of sectoral emissions. An efficient, reduced-order Eulerian air quality model (TAPOM-Lite) simulates some consecutive days where the meteorological conditions are favorable to the occurrence of an ozone episode. A health impact function has been developed to perform the feedback from ozone concentrations to the energy cost. The decomposition optimization problem is solved using an Oracle-based technique. We report on an implementation for the Grand Duchy of Luxembourg, varying the parameters of the impact function.
[en] We address the problem of collective searching in which a group of walkers, guided by a leader, looks for randomly located target sites. In such a process, the necessity to maintain the group aggregated imposes a constraint in the foraging dynamics. We discuss four different models for the system collective behavior, with the leader and followers performing Gaussian as well as truncated Levy walks. In environments with low density of targets we show that Levy foraging is advantageous for the whole group, when compared with Gaussian strategy. Furthermore, certain extra rules must be incorporated in the individuals' dynamics, so that a compromise between the trend to keep the group together and the global efficiency of search is met. The exact character of these rules depends on specific details of the foraging process, such as regeneration of target sites and energy costs.
[en] In the study, 6082 Al and 7075 Al samples were subjected to a solution taking place at 580 °C for 1 min using ultrahigh frequency induction heating system (UHFIHS) and water was supplied at the end of the process. Artificially aging was then carried out at 190 °C for 2, 4, 6 and 8 min. In both applications, heating was carried out using an induction system with a frequency of 900 kHz and a power of 2.8 kW. For these aluminum series and shapes, induction heating and heat treatment costs in different shapes are calculated. In addition, the hardness values obtained from artificially aged 6082 Al and 7075 Al samples at 190 °C for 10 h were compared with conventional methods after 5 h at 540 °C for 5 h. As a result, the hardness values of 6082 Al samples, which were obtained in 10 h by conventional methods, were obtained by artificial aging for only 8 min using induction system.
[es]Muestras de las aleaciones 6082 A1 y 7075 A1 se sometieron a un tratamiento térmico en horno de inducción de ultraalta frecuencia (UHFIHS) a 580 ºC durante 1 min y suministro de agua al final del proceso. El envejecimiento artificial se llevó a cabo a 190 °C durante 2, 4, 6 y 8 min. En ambas aplicaciones, el calentamiento se llevó a cabo utilizando un sistema de inducción con una frecuencia de 900 kHz y una potencia de 2,8 kW. Para estas series y diseños de aluminio, se calcularon los costos del tratamiento térmico. Adicionalmente, se compararon los valores de dureza de las muestras de 6082 A1 y 7075 A1 envejecidas artificialmente a 190 °C durante 10 h con los métodos convencionales 540 °C durante 5 h. Los resultados de dureza de la muestra 6082 Al obtenidos en 10 h mediante métodos convencionales, tardaron sólo 8 min mediante el envejecimiento artificial con el sistema de inducción.
[en] The National Renewable Energy Laboratory's Thermal Test Facility in Golden, Colorado, was designed using a whole-building approach-looking at the way the building's systems worked together most efficiently. Researchers monitor the performance of the 11,000-square-foot building, which boasts an energy cost savings of 63% for heating, cooling, and lighting. The basic plan of the building can be adapted to many needs, including retail and warehouse space. The Thermal Test Facility contains office and laboratory space; research focuses on the development of energy-efficiency and renewable energy technologies that are cost-effective and environmentally friendly