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Öğe Examination of web-based PVGIS and sunny design web photovoltaic system simulation programs and assessment of reliability of the results(Batman Üniversitesi, 2017-12-31) Haydaroğlu, Cem; Gümüş, BilalDue to the polluting effect of fossil fuels on environment and their exhaustible nature, investments in renewable energy resources continue to increase. In order to benefit from solar energy which is one of these energy resources, 50 GW of new power plants were installed only in 2015. Following the "regulation on unlicensed electricity generation" issued to benefit from the renewable energy potential available in Turkey, the installation of systems that generate electricity from solar energy via photovoltaic power is rapidly increasing. The use of simulation software is very important in the design and analysis of photovoltaic solar power plants. In this way, it is possible to obtain production data and conduct investment analyses before the power plant is established. Some of the simulation programs are web-based. In this study, web-based solar energy simulation programs PVGIS and Sunny Design Web were investigated and the proximity of simulation results to the actual results was studied. Dicle University Solar Power Plant was selected as the study field in order to compare the simulation results of the software. Dicle University Solar Power Plant is a photovoltaic solar power plant established and operated within the Engineering Faculty of Dicle University for introduction, education, production and analysis purposes. In the study, simulation of the 250 kWp solar power plant established in Dicle University was performed with PVGIS and Sunny Design Web software by using installation parameters and thus, one-year production values were obtained. The results of both web-based programs are compared with each other and with the actual production values from the plant.Öğe N-type InP Schottky diodes with organic thin layer: Electrical and interfacial properties(Journal of Vacuum Science & Technology B, 2010-03) Güllü, Ömer; Turut, AbdulmecitThe rectifying junction characteristics of methyl red (MR) organic film on n-type InP substrate have been studied. It has been observed that MR-based structure shows an excellent rectifying behavior and that the MR film increases the effective barrier height by influencing the space charge region of the n-type InP. The barrier height and ideality factor values for this structure have been obtained as 0.75 eV and 1.93 from the forward bias current-voltage characteristics, respectively. By using capacitance-voltage characteristics at 1 MHz, the barrier height and the carrier concentration values have been calculated as 0.93 eV and 5.13×1015 cm−3, respectively. The energy distributions of the interface states and their relaxation times have been determined from the forward bias capacitance-frequency and conductance-frequency characteristics. Moreover, it was seen that both the interface-state density and the relaxation time of the interface states decreased with bias voltage from experimental results.Öğe Investigation of plasma arc cutting parameters with type-2 fuzzy set and system(De Gruyter, 2013-10) Çelik, Yahya Hışman; Özek, Cebeli; Bulut Özek, MüzeyyenThe objective of the present study was it to design a type-2 fuzzy set and system in order to predict surface roughness and hardness depending on the parameters (material thickness, cutting speed, arc voltage and current) of the plasma arc cutting process of S235JR sheet materials. Therefore, some experimental studies were conducted. The experimentally determined data were used to describe the type-2 fuzzy set and system. Type-2 fuzzy set and system was found to be usefull to predict surface roughnes and hardness. According to the obtained values, the best surface roughness and the values closest to the hardness of the raw material were obtained at 1500 mm/min cutting speed, 8 mm material thickness, 115 V arc voltage and 80 A current.Öğe Biodiesel production from inedible animal tallow and an experimental investigation of its use as alternative fuel in a direct injection diesel engine(Elsevier, 2009-02-15) Altun, Şehmus; Öner, CengizIn this study, a substitute fuel for diesel engines was produced from inedible animal tallow and its usability was investigated as pure biodiesel and its blends with petroleum diesel fuel in a diesel engine. Tallow methyl ester as biodiesel fuel was prepared by base-catalyzed transesterification of the fat with methanol in the presence of NaOH as catalyst. Fuel properties of methyl ester, diesel fuel and blends of them (5%, 20% and 50% by volume) were determined. Viscosity and density of fatty acid methyl ester have been found to meet ASTM D6751 and EN 14214 specifications. Viscosity and density of tallow methyl esters are found to be very close to that of diesel. The calorific value of biodiesel is found to be slightly lower than that of diesel. An experimental study was carried out in order to investigate of its usability as alternative fuel of tallow methyl ester in a direct injection diesel engine. It was observed that the addition of biodiesel to the diesel fuel decreases the effective efficiency of engine and increases the specific fuel consumption. This is due to the lower heating value of biodiesel compared to diesel fuel. However, the effective engine power was comparable by biodiesel compared with diesel fuel. Emissions of carbon monoxide (CO), oxides of nitrogen (NOx), sulphur dioxide (SO2) and smoke opacity were reduced around 15%, 38.5%, 72.7% and 56.8%, respectively, in case of tallow methyl esters (B100) compared to diesel fuel. Besides, the lowest CO, NOx emissions and the highest exhaust temperature were obtained for B20 among all other fuels. The reductions in exhaust emissions made tallow methyl esters and its blends, especially B20 a suitable alternative fuel for diesel and thus could help in controlling air pollution. Based on this study, animal tallow methyl esters and its blends with petroleum diesel fuel can be used a substitute for diesel in direct injection diesel engines without any engine modification.Öğe Fırat Üniversitesi kampüsünde gürültü kirliliğinin değerlendirilmesi(Batman Üniversitesi, 2018-06-27) Nacar Koçer, Nilüfer; Durmuş, BarbarosTrafik gürültüsü, insan sağlığını büyük ölçüde etkileyen ve giderek artan bir çevre sorunudur. Motorlu taĢıt sayısının hızla artmasıyla oluĢan trafik gürültüsü, çevrenin gürültüye maruz kalabileceği kirlilik kaynaklarından biri haline gelerek, kentsel yaĢam kalitesini kısıtlamaktadır. Bu çalıĢmanın temel amacı Elazığ Ġli Fırat Üniversitesi kampüsünde gürültü kirliliğinin belirlenmesidir. Bu amaçla trafiğin yoğun olduğu saatlerde günde dört sefer gürültü ölçümleri yapılmıĢtır. Gürültü ölçümleri sabah 07:00 - 10:00, öğlen 11.00 – 14.00, öğlenden sonra 16:00 –18:00 ve akĢam 19:00 – 20:00 saatleri arasında yapılmıĢtır. Yapılan çalıĢma sonucunda üniversite kampüs alanında gürültü seviyesinin en yüksek ve en düĢük olduğu kavĢaklar tespit edilmiĢtirÖğe English prepositions as function words are not as easy for language learners as normally supposed to be(Batman Üniversitesi, 2022-06-30) Yaş, EminPrepositions as function words and single monomorphemic words are the most basic words of the human language, especially in the context of maintaining daily life. They are probably the first lexes/words entered to the human’s linguistic repertoire, as their requirements in the language are so essential. Prepositions shows various relationships between lexes or phrases in sentences. Among these relationships time, points, position, direction and various degrees of mental or emotional attitudes seem to be significant. The purpose of the research is try to reveal what kind of challenges English prepositions have for the learners and also to confirm if they are as difficult as some linguists have stated before. Another purpose is to find out which features are more difficult among all their entity properties. The results of this study disclose that English prepositions possess very complex structures, different meanings and an associating duty of various types of part of speeches. In particular, those that construct the phrasal verbs require great effort for learning due to the loss of the meaning (sometimes partially, sometimes completely) they undergo. It has been understood that their properties such as steadily changing meaning and function make them quite difficult elements for learners of English.Öğe Effects of cutting parameters and point angle on thrust force and delamination in drilling of CFRP(De Gruyter, 2014-11-14) Çelik, Yahya Hışman; Kılıçkap, Erol; Yardımeden, AhmetParts made of composite materials are generally produced by near-net-shape technology. However, additional machining operations such as drilling are often required to facilitate components assembling. Drilling of composite materials is also a common process in the assembly of aerospace and automotive composite structures. During drilling, unlike the conventional materials, a few damage forms may take place. Among these damage forms, the delamination is the most important one. Therefore, the experimental studies carried out on drilling of CFRP composite materials for determining optimum processing parameters are of great importance. In this particular study, delamination in CFRP composites caused by drilling was investigated. The composite material was drilled under various spindle speeds, feed rates and drill point angles. The results showed that delamination and thrust forces were affected by cutting parameters. It was demonstrated that feed rate and drill point angle make the largest contribution to the overall performance.Öğe Coordinated design of TCSC and PSS by using PSO algorithm for enhancement of SMIB power system stability(Batman Üniversitesi, 2017) Ekinci, Serdar; Hekimoğlu, BaranThe main aim of this study is to investigate the enhancement of power system stability via individual and coordinated design of Thyristor Controlled Series Compensation (TCSC) and Power System Stabilizer (PSS) in single machine infinite bus (SMIB) power system. The coordinated design problem of PSS and TCSC-based controllers is formulated as an optimization problem with an eigenvalue-based objective function. Then, particle swarm optimization (PSO) algorithm is applied to search for optimal controller parameters. To compare the performance of PSS and TCSC-based controllers, both of them are designed independently at first and then in a coordinated manner for individual and coordinated applications. The proposed stabilizers are tested on a weakly connected power system subjected to various disturbances. The eigenvalue analysis and nonlinear simulation results show the robustness and the effectiveness of the proposed controllers and their ability to provide efficient damping of low frequency oscillations. Matlab/SIMULINK software package is used for the simulations.Öğe An exergy analysis of a concentric tube heat exchanger using hBN-water nanofluids(Inder Science Publishers, 2021) Budak Ziyadanoğulları, Neşe; Perçin, SüleymanThis study investigated the effects of using nanofluids prepared with hexagonal boron nitride (hBN) nanoparticles on the thermal performance and pressure drop of a concentric tube heat exchanger. Experiments were carried out with water-hBN nanofluids for stable, dispersed, 0.01%, 0.1% and 1% volume concentrations, at different flow rates and Reynolds numbers under parallel and counter-flow conditions. When the experimental results were examined, the exergy loss was higher in the parallel-flow heat exchanger compared to the counter-flow heat exchanger. The highest exergy loss value was obtained for distilled water at the highest Reynolds number (Re = 8,700) for parallel flow operation at 170 W. The exergy loss of water at the highest Reynolds number (Re = 8,700) for parallel flow operation increased by 15.7%, 24.8% and 49.8% for hBN-water concentrations of 0.01%, 0.1% and 1%, respectively. Exergy loss of water at the highest Reynold number (Re = 8,700) for counter flow operation increased by 11.3%, 17.3% and 29.2% for hBN-water concentrations of 0.01%, 0.1% and 1%, respectively. When evaluating the exergy analysis of the system, exergy losses due to pressure drops were negligible for both flows (parallel and counter).Öğe General conditions, problems and expectations of Syrian migrants in Turkey(Akademisyen Kitabevi, 2019-06-17) Türk, Emrullah; Nerse, SerdarThe directors of Academician Publishing House, have been conducting their commercial activities for a long time by transferring their 30 years of broadcasting experience to their legal entities. In the said period, it was proud to publish 750 books, particularly health and social sciences, cultural and artistic topics. The Academician, that defines the platform of being an international publishing house, is in the pursuit of creating a global brand in addition to broadcasting in Turkish and foreign languages. The books, which are considered as permanent documents of scientific and intellectual studies, are the witnesses of hundreds of years as an information recording platform. The future of the book, which has built on a solid basis with the invention of the printing press, will certainly have a place in our lives for a long period of time, even though it has moved into orbit of new inventions. Academician Publishing House has started the process of publishing books in international quality and quantity with its own name of “Scientific Research Book” series in Turkish and English. The publication process, which will take place in March and September every year, will continue with thematic sub titles. We owe to our thanks to all of our researchers who supported this process, which was starting with about 30 books, and to everyone in the background
