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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 Dijital eğitimde eşitsizlikler : Kırsal-kentsel ayrımlar ve sosyoekonomik farklılaşmalar(İnsan ve Toplum / The Journal of Humanity and Society, 2020-12) Nerse, SerdarGelir ve ekonomi temelli eşitsizliklerin yanı sıra toplumu doğrudan etkileyen “sosyal eşitsizlikler” de yeterince anlaşılamamıştır. Bu nedenle farklı bileşenlerle eşitsizlikler en iyi ihtimalle ölçülmekte ve incelenmektedir. Sosyal eşitsizlik; yeni durum, olay ve sorunların gelişmesi nedeniyle göreceli olarak bir dizi yeni boyut, beklenti ve sonuç ortaya çıkarmaktadır. Küresel ve ulusal ölçekte yaşanan yeni gelişme, genişleme ve daralmalar, eğitimde eşitsizliğin tekrar tartışılması gerektiğini ortaya çıkarmıştır. Bu çalışmada da kırsal-kentsel ayrımlar ile sosyoekonomik farklılaşmalar temelinde Covid-19 salgını sürecinde dijital eğitimde ortaya çıkan eşitsizlikler incelenmiştir. Bu iki ayrıma bağlı olarak salgın sürecinde evde uzaktan eğitime katılmaya çalışan üniversite öğrencilerinin dijital medya, internet, bilgi ve iletişim teknolojilerine (DİB) erişim ve kullanımlarındaki eşitsizliklerin ortaya çıkarılması amaçlanmıştır. Yaş, cinsiyet, ikamet yeri, okuduğu sınıf ve sosyoekonomik statüsüne göre 3 ayrı üniversiteden seçilen toplam 16 öğrenci araştırmaya dâhil edilmiştir. Nitel yöntemin uygulandığı araştırmada, veriler, derinlemesine görüşmelerle elde edilmiştir. Görüşme verileri, Maxqda nitel veri analiz programıyla kategorileştirilmiş ve temalara dönüştürülmüştür. Açık, eksenel ve seçici kodlama neticesinde birleştirilen kategori ve temalar görselleştirilmiştir. Katılımcıların bireysel ve aile özellikleri, okulların çevresi ve mali kaynak durumları, kalkınma, özgürleşme, kültürlenme faktörleri etkileşimli şekilde eşitsizliği ortaya çıkarıcı etkiye sahip olduğu gibi dijital eğitim eşitsizliğinde kırsal-kentsel ayrım ve sosyoekonomik farklılaşmaların belirgin olduğu görülmektedir.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 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 A general view to political and economic events causing the collapse of Mamluk State(Energy Education Science&Technology, Part B, 2012-04) Ağır, Abdullah Mesut; Solak, Kemal; Şen, Mehmet Emin; Platin, İhsann this manuscript, the collapse of Mamluk State, which reigned in Egypt and Syria between the years 1250 and 1517 has been studied. Throughout our study, there found different reasons causing this collapse; the most important ones of which are political and economic. The fact that Mamluk System which had crucial role in Mamluk administration Mechanism and the problems lived along its north border are the fundamental collapsing reasons of the state. Indeed, the fights starting with Mongols and Armenians in the north of the state continued with Anatolian Turkmens and Timurids, eventually Ottomans coming from the same direction caused it to be collapsed. Mamluks were the commercial centre between east and west. At the same time, Syria owned a very industrious trade network between Anatolia. However, the geographical discoveries that Europeans carried out and the Portuguese not only military but also commercial activities in the Indian Ocean weakened Mamluks economically. In addition to this, military struggles along the north border of the state caused incompensable deficits in Mamlûk finance. Consequently, when all these negative aspects combined with an unmodernized army, Mamlûk State closed its era in 1517, when Ottoman army defeated it in Reydaniye, which was the end of a 267 year-old-state.Öğe Behaviour of bi adhesive in double strap joint with embedded to bending(Journal of Theoretical and Applied Mechanics, 2015-06-15) Adin, Hamit; Temiz, Şemsettin; Sülü, İsmail YasinIn this study, behaviour of bi-adhesive used in the repair of damaged parts was analyzed, using the finite element method. In a double-strap joint with an embedded patch, patch is embedded into the adherents for structural requirements. In addition, to increase the strength of the joint, two adhesives are used to bond the adherents. This approach reduces stress concentration at the overlap ends, increases the load capacity and delays the failure. These effects give rise to higher joint strength. For this purpose, a stiff adhesive, FM73 produced by Cytec Fiberite, was applied in the middle portion of the overlap, while a softer adhesive, SBT9244 from 3M, was applied towards the edges, prone to stress concentrations. Non-linear finite element analyses were carried out to predict the failure loads, to assist with the geometric design and to identify effective ratios of sizes to maximize joint strength. Key words: Bi-adhesive, double-strap joints, finite element analysis, mechanical properties, stress analysis, failure loadsÖğe Effects of particle reinforcement on the bending and compressive behaviors of composite pipes(Materials Testing, 2019-11) Adin, HamitIn this study, the effects of adding particles to composite pipes were examined. For the study, composite pipes reinforced with particles were produced by using structural epoxy adhesive and mica as the particle. Composite pipes oriented at [-45 °/+45 °] were manufactured by the hand lay-up method. The composite pipes were loaded axially for measuring bending and compressive strength. When bending and compression loads are applied in the experiments it was seen that the particle reinforced methods indicated in the literature have a great effect of on the strength of the bending and compressive behaviour. The results show that addition of particles enhances compressive and bending strength.
