توجه: محتویات این صفحه به صورت خودکار پردازش شده و مقاله‌های نویسندگانی با تشابه اسمی، همگی در بخش یکسان نمایش داده می‌شوند.
۱A COMPARISON BETWEEN POWER XLPE AND EPR HIGH VOLTAGE CABLES
نویسنده(ها): ، ، ،
اطلاعات انتشار: ششمین کنفرانس بین‌المللی مسائل فنی و فیزیکی در مهندسی قدرت، سال
تعداد صفحات: ۵
The performance of XLPE and EPR as candidate for insulation of high voltage power cables are investigated. For a thorough electro–thermal life model of the electrical components, the individual aging phenomena of the representative electrical components as well as the general aging mechanisms of insulating materials are taken into account in this paper. The aging of insulating materials can be estimated by an electrical breakdown occurring in electrical components so that the relationship between lifetime, failure probability and reliability of electrical components may be studied using the life model, the probabilistic failure model, and the enlargement law which are reasonably able to investigate the cause and consequence of failure in high voltage cables networks. In this paper, a procedure for accurate life comparison, failure probability and reliability of polymer–insulated power is presented.<\div>

۲DRAWING THE MAXIMUM LIGHTNING OVERVOLTAGE PROFILE IN TRANSMISSION LINE
نویسنده(ها): ،
اطلاعات انتشار: ششمین کنفرانس بین‌المللی مسائل فنی و فیزیکی در مهندسی قدرت، سال
تعداد صفحات: ۵
Lightning is one of the factors producing overvoltages in power systems. In order to be prevented from its damaging effects, it should be considered as a serious factor for insulation coordination in power systems especially transmission lines. Therefore, the assessment of lightning overvoltages in transmission lines is a serious necessity. For this purpose, we used the transmission line theory. The distribution of the currents and voltages resulting from lightning on overhead lines in unload and matched line position and on overhead–cable line , also the distribution of currents and voltages resulting from several pulses of lightning have been assessed. In this paper, in addition to distribution of currents and voltages using the above mentioned theory, drawing the maximum overvoltage profile as function of the distance from exposed end, also overvoltage at a specific point of line have been take into consideration. Finally, voltage at the exposed end of line and maximum overvoltage profile have been drawn.<\div>

۳T–rough Ideal and T–rough Fuzzy Ideal in a Semigroup
نویسنده(ها): ، ،
اطلاعات انتشار: همایش منطقه ای پژوهشهای نوین در ریاضی، سال
تعداد صفحات: ۸
T–rough sets was introduced in [4]. Our aim in this paper is to introduce the concept of T–rough ideal , T–rough quotient ideal and T–rough fuzzy ideal and study on a set–valued homomorphism for semigroups. Rough sets were originally proposed in the presence of an equivalence relation. An equivalence relation is sometimes difficult to be obtained in rearward problems due to the vagueness and incompleteness of human knowledge. From this point of view, in this paper, we generalized some theorems that they are proved in [21].<\div>

۴Transformer Life Assessment under Harmonic Condition Using FEM
نویسنده(ها): ، ، ،
اطلاعات انتشار: بیست و سومین کنفرانس بین المللی برق، سال
تعداد صفحات: ۷
Harmonic currents, generated by non–linear loads, increase the losses and temperature inside the power transformer. The winding hot spot temperature is one of the mostcritical parameters that affect the useful life of the power transformers. This paper deals with the transformer field solution and the determination of field distribution on thecomponents of transformer. In addition the hot spot and top oil temperature will be determined. Last percentage of loss of transformer life time under harmonic condition will be analyzed.<\div>

۵The effect of bipolar plate material and clamping pressure on the performance of proton exchange membrane fuel cell
نویسنده(ها): ، ، ،
اطلاعات انتشار: هفتمین کنگره ملی مهندسی شیمی، سال
تعداد صفحات: ۹
The bipolar plate (BP) is one of the most important devices in the proton exchange membrane fuel cell (PEMFC). Recently, due to its better properties regarding metallic and graphite BP, this device, has mainly been made in the polymer–based composites with carbon fillers. In this research, some compositeswith graphite (G), expanded graphite (EG) and carbon fiber (CF) as fillers were made in two percentages. Then electrical resistivity (ER) of composite–BPs and their interface contact resistance (ICR) with GDL were measured in various clamping pressure (CP). In this research, the EC and ICR of composites, as theohmic resistance, were introduced into the electrochemical relations of one isothermal model of PEMFC.In addition, the formulation of pearmibility and diffusivity in gas diffusion layer (GDL) under the CP were derived. Afterwards the electrochemical performance (V–I curve) of PEMFC in various composites were obtained and analyzed. In addition, CP affecting ICR and GDL diffusivity were introduced into themodel so that the performance could be derived. The results indicated that the ER and ICR values of BP play a major function in the electrochemical performance but the ICR function is much greater than that of ER. Other results revealed that CP has a great effect upon ICR, thereby affecting the performance of PEMFC.<\div>

۶Interfacial of HAS and BSA with ZnS quantum dots coated by polyacrylicacide grafted onto sodium alginate by UV–vis spectroscopy
نویسنده(ها): ، ،
اطلاعات انتشار: دومین کنفرانس بین المللی یافته های نوین پژوهشی در شیمی و مهندسی شیمی، سال
تعداد صفحات: ۴
Due to their unique optical properties, quantum dots (QDs) are rapidly revolutionizing many areas of medicine and biology. Despite the remarkable speed of development of nanoscience, relatively little is known about the interaction of nanoscale objects with organism. In this work, interaction of ZnS QDs coated with polyacrylic acide grafted onto sodium alginate (PAA–g–SA) with human serum albumin (HSA) and bovine serum albumin (BSA) were investigated by UV–vis absorption. The obtained results suggest ground state complex formation between proteins and ZnS– Alg–g–PAA QDs.<\div>

۷Optimal Sizing of a Stand–alone Wind–Photovoltaic Hybrid System for Supplying a Remote Intermittent Load Considering the System Reliability and Using Firefly Algorithm
نویسنده(ها): ، ، ،
اطلاعات انتشار: کنفرانس بین المللی مهندسی برق، سال
تعداد صفحات: ۸
In this study, optimal Sizing of a standalone hybrid wind–photovoltaic (PV) system for supplying a remote intermittent load has been evaluated, considering the system reliability. Data of wind, sun radiation and loading are gathered during one year, from Ardebil, Iran. Firstly, some random values are generated in the allowable areas of wind and PV power in order to specify the optimal size of system components. Hourly charging and discharging of the battery during this interval is measured considering wind speed in a certain altitude and with actual solar radiation to the earth surface; finally, the ability of the system for supplying or not supplying the load is determined. The reliability criterion, the modified equivalent loss factor (ELF) is calculated and if the constraints are met, the cost is calculated. This procedure repeats until the cost is minimized under the desirable system reliability. The optimization results show that firefly algorithm performs better compared to some other studied heuristic algorithms such as Particle Swarm Optimization (PSO) and Genetic Algorithm (GA) in terms of accuracy and less calculation. The results prove the efficiency of the Firefly algorithm in determining the optimal size of the components of the studied system with consideration of the system reliability<\div>
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