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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 Numerical and experimental investigation of solar chimney power plant system performance(Taylor & Francis, 2020-03-15) Karakaya, Hakan; Durmuş, Aydın; Avcı, Ali SerkanA prototype of a solar chimney power plant was performed by modeling in this study. The performed prototype was experimentally confirmed. Temperature, velocity, and radiation values were measured to actualize the confirmation. Experimental data that were obtained to determine the performance of solar chimney whose prototype was actualized by the help of measured values were computationally analyzed. The geometry of a solar chimney in the analysis was bidimensionally (2D) drawn on an axis of symmetry. The numerical simulation was analyzed with computational fluid dynamics (CFD) method. Since analysis results show that there is turbulent flow in system (RNG), k-ɛ turbulence model was used. Continuity, momentum, and energy equations were applied to the solar chimney system via the finite volume method. Moreover, DO (discrete ordinates) model was inserted in analysis to evaluate the radiation effect in the collector area. In addition to all these, correlation results between SPSS 17 statistics program and data obtained were evaluated. Finally, with reference to the comparison between numerical and experimental results, data obtained and numerical data are close to each other; the prototype is applicable to the real systems.Öğe Türkistan’dan Tunceli’ye kurban inancı(Geleneksel Yayıncılık, 2017) Arslan, YusufToplumdan topluma kurbana yüklenen anlam, kurban kesim şekli, kurban sunuları değişiklik gösterse de, çoğunlukla her dinde ve gelenekte kurban, günahlardan arınma, tövbe, şükür gibi amaçlarla yapılmaktadır. 4000 yıllık bir tarihe sahip olan Türklerin gelenekleri incelendiğinde, kurban kesme ritüelinin eskiden beri sürdürüldüğü anlaşılmaktadır. İslamiyet’e dâhil olduktan sonra Türklerin kurban ritüellerinde bazı değişimler yaşanmıştır. Bazı ritüeller uygulamadan kalkarken bazıları yaşatılmıştır. Örneğin, eski Türklerde kurbanların başında gelen at, İslamiyet ile birlikte yerini koç, koyun, keçi, sığır gibi hayvanlara bırakmış ve at kurban etme geleneği unutulmuştur. Bununla birlikte, Şaman ayinlerinde kurban kesilmesi, mum yakılması geleneğinin Alevilerin cem ritüeli vesilesiyle olduğu gibi yaşatıldığı görülmektedir. Günümüzde, Aleviler arasında, eski Türk gelenek, görenek ve dinine ait motifler canlı şekilde izlenebilmektedir. Örneğin, Aleviler İslam’ı benimsemiş olmalarına karşın, İslam ile beraber eski Türklerin şaman/kam inancı, kopuz eşliğinde ibadet etme, sema, kadın/erkek bir arada ibadet etme, atalar kültü, dağ, ağaç ve nehirlere kutsallık atfetme biçimindeki inançlarını terk etmemişlerdir. İbadet dillerini de olduğu şekliyle, yani Türkçe olarak korumuşlardır. Alevilerin kurban ritüelleri, kimi değişimlere uğramışsa da, eski Türklerdeki birçok ritüeli bünyesinde korumuştur ve Aleviler yüzyıllardır eski Türk geleneklerindeki şekliyle kurbanlarını kesmişlerdir. Bu makalede, eski Türklerdeki kurban ritüelleriyle Tunceli Alevilerinin halk inançlarındaki kurban ritüeli karşılaştırılmış, benzerliklerin tespitine çalışılmıştır. Araştırma, nitel araştırma yöntemine göre gerçekleştirilmiştir. Araştırmanın verileri, 2015-2016 yıllarında Tunceli ve ilçelerinde, ziyaret yerlerinde yapılan yüz yüze mülakatlardan elde edilmiştir. Toplam görüşmeci sayısı sekiz olup görüşmeciler Tunceli il nüfusuna kayıtlıdır. Araştırmanın verileri, eski Türklerin kurban pratikleri ile Tunceli Alevilerinin kurban pratiklerinin dayandığı ortak bir geleneksel temel yapı olduğunu göstermiştir. Bir başka ifadeyle, Alevilerin kurban sunu/sungusu pratiklerinde, eski Türk geleneklerinin önemli oranda korunmuş olduğu anlaşılmıştır.Öğe PID controller design for controlling integrating processes with dead time using generalized stability boundary locus(IFAC Secretariat, 2018) Atiç, Serdal; Çökmez, Erdal; Peker, Fuat; Kaya, İbrahimThis paper proposes a method so that all PID controller tuning parameters, which are satisfying stability of any integrating time delay processes, can be calculated by forming the stability boundary loci. Processes having a higher order transfer function must first be modeled by an integrating plus first order plus dead time (IFOPDT) transfer function in order to apply the method. Later, IFOPDT process transfer function and the controller transfer function are converted to normalized forms to obtain the stability boundary locus in (KKcT, KKc(T2 / Ti)), (KKcT, KKcTd) and (KKc(T2/Ti), KKcTd) planes for PID controller design. PID controller parameter values achieving stability of the control system can be determined by the obtained stability boundary loci. The advantage of the method given in this study compared with previous studies in this subject is to remove the need of re-plotting the stability boundary locus as the process transfer function changes. That is, the approach results in somehow generalized stability boundary loci for integrating plus time delay processes under a PID controller. Application of the method has been clarified with examples.Öğe An analysis of sport managers' work stress levels in various variables(Horizon Research Publishing, 2018-12) Kılınç, Zühal; Dinçer, NevzatThis paper was conducted to measure the psychological and psychosomatic symptoms related with the sport managers’ work stress in public sector and federations. In this research, total 185 sport managers including 31 sport managers from the Central Organization of Sport General Directorate, 113 sport managers from the provincial organization, 41 sport managers from the Independent Sport Federations were included. The relevant managers were applied the work stress scale developed by Houso and Rizzo (1972). According to the results of the research, as sport managers get older, the averages of work stress seem to increase. In younger sport managers, the averages of work stress were found to be lower. When the participant sport managers’ education levels improve, their work stress points fall down. In the first period of service of sport managers, the averages of work stress were high, in next years they went down over time.Öğe An experimental investigation of the effect of thermophysical properties on time lag and decrement factor for building elements(Gazi University, 2020-06-01) Oktay, Hasan; Yumrutaş, Recep; Argunhan, ZekiThe time lag (TL) and decrement factor (DF) are essential for the heat storage capabilities of building elements, which strictly depend on the thermophysical properties of the elements. Many investigations are presented in literature arguing to find the influence of each thermophysical property on TL and DF by keeping the other properties constant. This study aims to investigate the effect of each property on TL and DF, utilizing relationships between the measurement values of the thermophysical properties of wall materials. Therefore, first, 132 new concrete wall samples were produced, and their thermophysical properties were tested. Secondly, TL and DF values for each building element are computed from the solution of the problem by Complex Finite Fourier Transform (CFFT) technique. Finally, a multivariate regression analysis has been performed, and the variations of each thermophysical property versus TL and DF are presented, and also the findings are compared with literature. The results show that each property alone (keeping the other properties constant) is not adequate to identify the thermal inertia and thermal performance of a wall element. Besides, 87.3 % decrease in thermal diffusivity corresponds to 6.03 h increase in the value of TL and 88.8 % decrease in value of DF; respectively, for W1 wall assembly.Öğe Determining relevant features in estimating short-term power load of a small house via feature selection by extreme learning machine(IEEE, 2017-11-02) Ertuğrul, Ömer Faruk; Sezgin, Necmettin; Öztekin, Abdulkerim; Tağluk, Mehmet EminEstimating short-term power load is a fundamental issue in the power distribution system. Since short-term power load is related to many parameters such as weather conditions, and time. The aim of this study is to determine the relevant parameters in estimating short-term power load not only in order to decrease the computational cost, but also to achieve higher success rates. Furthermore, by using selected features the required memory, equipment and communication costs are also decreased in real time applications. Feature selection by extreme learning machine method was used in determining relevant features. The short-term power loads of two houses (one of them has a power generation capability) were used in tests and achieved results showed lower error rates were obtained by using less number of features.Öğe Can hotel managers with social intelligence affect the emotions of employees?(Cogent OA, 2018-01-24) Genç, Volkan; Gülertekin Genç, SerayUsing the Multilevel Model of Emotional in Organizations, this study investigates whether managers’ levels of social intelligence affect employees’ emotional labor and the emotional climate of the workplace. In addition, the mediating effect of emotional labor on social intelligence and emotional climate is defined. A total of 276 surveys were distributed among the employees of a chain hotel in Istanbul. A structural equality modeling was used to explain the relationships between social intelligence, emotional labor, and emotional climate. The results reveal that social intelligence positively and significantly affects deep acting. It is also shown that social intelligence does not affect the emotional climate, and that emotional labor has no intermediary role. Practical results and recommendations are thus suggested for future research.Öğe The changes in the serum, liver, kidney protein and genomic DNA profiles in rats treated with 7,12-Dimethylbenz(A) anthracene and Plantago major L.(RJPBCS, 2014-01) Berber, İsmet; Ekin, Suat; Levent, Abdulkadir; Oto, Gökhan;In the study, the changes in the serum, liver, kidney protein and genomic DNA profiles in Wistar albino rats administrated to 7,12-dimethylbenz(a)anthracene (DMBA) and Plantagomajor L. were investigated. SDS-PAGE profiling of the serum proteins showed that the levels of two proteins molecular weighing 140.8 kDa and 46.8 kDa were significantly lower on the 0th day of treatment than on the 60th day of application in the groups. Furthermore, two proteins (34.5 and 22.3 kDa) were solely present in DMBA-treated liver cell lysates. On the contrary, the kidney protein profiles did not show significant banding variations in groups. Genomic DNA analysis also confirmed that DNA extracted from liver and kidney cells did not fragment in any of the groups after the 60th study day. The proteins 34.5 and 22.3 kDa in liver cell lysates at the 60th day in DMBA-treated group could be extra-prognostic indicators for severe DMBA toxicity.Öğe Performance and exhaust emissions of a DI diesel engine fueled with waste cooking oil and inedible animal tallow methyl esters(TÜBİTAK, 2011) Altun, ŞehmusThe performance and exhaust emissions of a direct injection diesel engine were experimentally investigated using 2 biodiesel fuels with promising economic perspective, one obtained from inedible animal tallow and the other from waste cooking oils. Inedible animal tallow, which is obtained from a mixture of slaughtered cattle and sheep fats collected from a local slaughterhouse during meat preparation process, was transesterified using methyl alcohol and an alkaline catalyst to produce the inedible animal tallow methyl ester. Biodiesel from waste cooking oil was produced from waste cooking oils and methyl alcohol via a transesterification reaction, and provided by a commercial biodiesel producer. In order to investigate the performance and exhaust emissions, the experiments were conducted at different engine speeds under the full load condition of the engine. The experimental results showed, compared with diesel fuel, that the biodiesel fuels resulted in a reduction in brake torque and in an increase in brake specific fuel consumption. Although both biodiesels caused reductions in carbon monoxide (CO), the NOx emissions were higher for waste cooking oil biodiesel and lower for inedible animal tallow biodiesel as compared to diesel fuel.
