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Öğe 7x7 CM2 MEMBRANLI MİKROBİYAL YAKIT HÜCRESİNİN PERFORMANSININ DENEYSEL OLARAK İNCELENMESİ(Selçuk Üniversitesi, 2018) Çoban, Necmettin; Dincer, Kevser; Çavuşoğlu, YunusMikroorganizmaları katalizör olarak kullanarak organik maddeleri direkt olarak elektrik enerjisine çevirebilen sistemler Mikrobiyal Yakıt Hücreleri (MYH)’dir. Bu çalışmada, 7x7 cm2 membranlı, aktif ve çökelme çamuru için farklı sıcaklıklarda (?Tçamur-çevre = 10°C, 12 °C, 14 °C, 16 °C), düşük (0.8 L/dak) ve yüksek bubble etkisinde (3 L/dak), 10 farklı direnç için akım ve gerilim değerleri ölçülerek, MYH’sinin performansı incelenmiştir. Performans parametreleri, gücün akıma göre değişimi, gücün gerilime göre değişimi ve akımın gerilime göre değişimidir. Tüm deneysel sonuçlar birlikte değerlendirildiğinde, maksimum gerilim, aktif çamurda, yüksek bubble etkisinde, ?Tçamur-çevre= 16 °C’de, R =990 ?’da, 0.366 V’tır. Maksimum güç aktif çamurda, düşük bubble etkisinde, ?Tçamur-çevre = 16 °C’de, R = 901 ?’da 0.114 mW’tır.Öğe Akışkan Olarak Hava, Oksijen, Karbondioksit Ve Azot Kullanılan Vorteks Tüpün Performansının İncelenmesi(2006) Dincer, Kevser; Başkaya, Şenol; Kirmaci, Volkan; Usta, Hüseyin; Uysal, B. ZühtüRanque-Hilsch vorteks tüpünden, girişteki basınca bağımlı olarak iki farklı sıcaklıkta akışkan elde edilmektedir. Genellikle, vorteks tüpünde basınçlı akışkan olarak, hava kullanılmaktadır. Havanın içinde %78,09 Azot, % 20,95 Oksijen, % 0,93 Argon, % 0,03 Karbondioksit ve çok az oranda da diğer gazlar bulunmaktadır. Bu çalışmada, akışkan olarak hava, O2, CO2 ve N2 gazı kullanılmıştır. Bu gazlar vorteks tüp sistemine, giriş basıncı (gösterge basıncı), 2 bar'dan 7 bar'a kadar 1 bar aralıklarla uygulanmıştır. Hava, O2, CO2, N2 gazlarının ısıtma-soğutma sıcaklık performansları deneysel olarak incelenmiş ve birbiri ile mukayese edilmiştir.Öğe Application of Response Surface Methodology to optimization of a standard Ranque-Hilsch vortex tube refrigerator(PERGAMON-ELSEVIER SCIENCE LTD, 2014) Bovand, Masoud; Valipour, Mohammad Sadegh; Dincer, Kevser; Eiamsa-ard, SmithIn the present study, an attempt is made to evaluate the effect of certain geometrical parameters on cooling performance of Ranque-Hilsch vortex tube (RHVT). Number of intakes in nozzle "n", cold orifice diameter "d(c)" and inlet pressure "P-i" are selected as influencing parameters at different levels n = 1, 2, 3; d(c) = 7, 9, 11 mm and P-i = 2, 2.5, 3 bar. The experiments are conducted based on three factors, two levels and central composite face centered design (CCF) with full factorial. The results are analyzed according to the principle of Response Surface Methodology (RSM). The equation to the response surface is developed using the design of experiments features of the commercial software package MINITAB-16. The goodness of fit of the regression model is examined using the Analysis of Variance (ANOVA) and the F-ratio test. The values of R-2 and R-2(adj.) are close to 100% which shows a very high correlation between the observed and predicted values. Results show sensitivity value of Delta T-c,T-max respect to n is negative (partial derivative Re/partial derivative A < 0). It means that increasing in n cause decreasing in Delta T-c,T-max and for low orifice diameter it has significant effect. The cold orifice diameter has more effect on Delta T-c,T-max. Its sensitivity value is 65.8% and 51.1% more than n and P-i, respectively. It is shown that for d*(c) < 0.5, (d*(c) = d(c)/D), increasing d*(c) causes the cold air temperature difference to increase and for d*(c) > 0.5, increasing d*(c) tends the cold air temperature difference to decrease. The results show that the optimum value of d*(c) the maximum cold air temperature difference and efficiency is d*(c) = 0.5. The RHVT was optimized using RSM based on CCD. The optimum values of n, d(c), and P-i were 2, 9.48 mm, and 3.2 bar respectively, where 46.44 degrees C (Delta T-c,T-max) could be obtained from the proposed model. (C) 2014 Elsevier Ltd.Öğe APPLICATION OF TAGUCHI METHOD FOR THE SYNTHESIS OF NANO-SIZED TiO2 POWDERS BY ACID-USED SOL-GEL METHOD(2017) Karanfil, Gamze Celep; Dincer, KevserThe acid-used sol-gel synthesis of nano-sized titania (TiO) powders has been studied systematically to optimize the processing parameters by Taguchi method that control crystallite size. In addition, crystallite and particle size of TiO2 powders were examined by X-ray diffraction (XRD) and transmission electron microscopy (TEM). For this purpose, the amount of acid, reaction temperature and reaction time were determined as control parameters. In order to achieve these objectives, Taguchi's L9 orthogonal design (3 parameter, 3 level) was used for the experiential design. In order to determine the optimal synthesis conditions for nanosized TiO2 powders, the signal-to-noise (S/N) ratio was used, which was calculated from crystallite size of the nano-sized TiO2powders using "the-smaller-the-better" appoachment. Besides, analysis of variance (ANOVA) was utilised to accomplish the statistical importance of the synthesis parameters. Experiments were fulfilled to verify the model at the chosen conditions and the particle size was determined according to XRD analysis as 46.98 nm. Moreover, the actual size of the synthesised nano-sized TiO2powders with the average size was 51.41 nm. Therefore, the Taguchi optimization method was a main tool in the optimization of the nanosized TiO2 powders synthesis process with less experiential tests and slightly cost-efficient approachment.Öğe Development of Cooling Performance of Clinker Cooler Process Based on Energy Audit(SPRINGER, 2018) Emami, Mohammadreza; Dincer, Kevser; Sogut, M. Ziya; Karakoc, T. Hikmet[Abstract not Available]Öğe Ekserji analiz metoduyla karşıt akışlı Ranque-Hilsch vorteks tüpün tapa açısının ekserji verimliliğine etkisinin değerlendirilmesi(2009) Dincer, Kevser; Başkaya, ŞenolBu çalışmada, hava girişinin 5 nozuldan sağlandığı, iç çapının 9 mm, uzunluğunun çapa oranı 12 olan Ranque- Hilsch vorteks tüpte, 30\circ, 60\circ, 90\circ, 120\circ,150\circo’lik konik uca sahip 5 mm çapındaki tapalara ait deneysel veriler kullanılmıştır. Sistem, termodinamik açık bir sistem olarak dikkate alınmıştır. RHVT’ün \sum\dot {E}_{gir}, \sum\dot {E}_{cks},İ, ekserji verimi hesaplanmış ve RHVT’ün ekserji band diyagramı sunulmuştur. Ekserji veriminin vorteks tüpe giriş basıncı olan P_{gir} ’in düşük değerlerinde düşük, P_{gir}’in artan değerlerinde ise yüksek çıktığı görülmüştür. Hesaplamalar sonucunda, sistemin ekserji veriminin 1,14 K ile 40,21 arasında değiştiği tespit edilmiş ve ?90\circ olduğunda ekserji veriminin yüksek olduğu belirlenmiştir.Öğe Experimental investigation of the effects of threefold type Ranque-Hilsch vortex tube and six cascade type Ranque-Hilsch vortex tube on the performance of counter flow Ranque-Hilsch vortex tubes(ELSEVIER SCI LTD, 2011) Dincer, KevserIn this study, performances of Ranque-Hilsh Vortex Tubes (RHVTs) were experimentally investigated under three different situations based on inlet pressure and the ratio of mass flow rate of the cold stream to the mass flow rate of the inlet stream (xi). 1st situation is the conventional RHVT. 2nd situation is the threefold cascade type RHVT. Here three RHVTs were used. 3rd situation deals with the six cascade type RHVT. In this case, six RHVTs were used. When all the test results under P-i = 360 kPa and P-i = 400 kPa pressure conditions are compared, it is found that the best performance occurs at the 3rd situation. Moreover, the performance of the 3rd situation at P-i = 400 kPa pressure is higher than that at P-i = 360 kPa. Maximum values of Delta T and xi are obtained as 67.6 degrees C and 0.9 for 3rd situation. (C) 2011 Elsevier Ltd and IIR. All rights reserved.Öğe FUZZY LOGIC MODELING OF PERFORMANCE OF MICROBIAL FUEL CELL WITH 10x10 AND 11x11 CM2 MEMBRANE(BAKU STATE UNIV, INST APPLIED MATHEMATICS, 2018) Tasdemir, Sakir; Hayder, Mustafa Akram; Dincer, Kevser[Abstract not Available]Öğe Investigation of Electrical Conductivity of Polyacrylonitrile (PAN) Nanofibers/Nano Particul (Ag, Cu, CNT and GNR)(TRANS TECH PUBLICATIONS LTD, 2017) Onal, Gurol; Erdal, Mehmet Okan; Dincer, KevserIn this study 1% Ag (silver), Cu (copper), CNT (carbon nanotube) and graphene nanoribbon (GNR) nanoparticle reinforced PAN fibers were prepared and the effects of nanoparticle reinforcements upon electrical conductivity were investigated. In experimental study, graphene nanoribbon powders were produced from multiwalled carbon nanotube (MWCNT) through using the chemical approach of Hummers method. Fiber layer was dissolved at room temperature in magnetic mixer with Polyacrylonitrile(PAN) and Dimethil Formamide (DMF) which was at the rate of 10 % by mass. Thus, a viscou gel solution was obtained then nanoparticles were added to the PAN/DMF solution and the solution was vigorously stirred for one hour at room temperature. After stirring that solution was continued for 15 m in ultrasonic bath. The polymeric solution was first transferred to a 5 mL syringe, which was connected to a capillary needle with an inside diameter of 0,8 mm. A copper electrode was attached to the needle, a DC power supply produces 25 kV against a grounded collector screen distant 15cm. With the syringe pump set at 2 mL/h, the electric force overcomes the surface tension of the solution at the capillary tip, and a jet emerges. Produced fibers were collected on the rotary collector which spins at 250 rpm. Nanofiber was dried at 60 degrees C for 12 h in vacuum oven. Eventually, nanofiber of polyacrylonitrile (PAN) reinforced by metallic nanoparticles and graphene nanoribbon (GNR) were prepared by electro spinning process. Electrical conductivity of the obtained nanofiber were studied by measuring the electrical resistance thanks to home-made plate electrodes.Öğe Investigation of Performance of Heating and Cooling of Counter Flow Ranque-Hilsch Tubes with L/D=15, 16, 17, 18 for Brass(TRANS TECH PUBLICATIONS LTD, 2013) Dincer, Kevser; Berber, Adnan; Ozen, Dilek NurIn this study, heating and cooling performances of counter flow Ranque-Hilsch vortex tubes (RHVTs) were experimentally investigated for brass. The vortex tubes were made of brass. Diameter of vortex tube (D) was 10 mm. Length of vortex tube (L) was 15D, 16D, 17D and18D. The number of nozzles (Nn) was 5. The conical edges of the plugs have a slope of 30 degrees angle. Working pressure of Ranque-Hilsch was 460 kPa (absolute). According to the experimental results, the maximum heating performance of the RHVT system was found to be 39,5 degrees C at P-17 and the maximum cooling performance of the RHVT in this study was found to be -28,6 degrees C at P-18. An increase in fraction of cold flow (xi) led to a increase in the heating performance.Öğe Karşıt Akışlı Ranque-Hilsch Vorteks Tüpünün Performansına Tapa Açısı Etkisinin Yapay Sinir Ağları Yöntemi ile Modellenmesi(2008) Dincer, Kevser; Taşdemir, Şakir; Başkaya, Şenol; Uysal, B. ZühtüBu çalışmada, deneysel verilerden yararlanılarak, karşıt akışlı Ranque-Hilsch vorteks tüpü (RHVT)’nün sıcak çıkış tarafındaki tapa uç açısının performansa etkisi yapay sinir ağı (YSA) ile modellenmiştir. Modellemede laboratuar ortamında yapılan deneysel çalışmalar sonucunda elde edilen veriler kullanılmıştır. Geliştirilen sistemde YSA uygulanan giriş parametreleri P, \xi ve \varnothing çıkış parametresi ise \Delta T’dir. YSA’dan elde edilen sonuçlar ile deneysel verilerin istatiksel analizleri yapılıp mukayese edildiğinde, iki grup verinin uyumlu olduğu tespit edilmiş ve aralarında anlamca hiçbir fark olmadığı görülmüştür. Sonuç olarak, bu çalışmayla YSA’nın RHVT’lerde güvenli bir şekilde kullanılabileceği ve çok sayıda deneysel dezavantajı minimuma indireceği gösterilmektedir.Öğe Modeling of the Effects of Cyclic Voltammetry (CV) Using Fuzzy Logic with Different Membership Functions for Proton Exchange Membrane Fuel Cell (PEM) with Polyvinyl Alcohol/Nano Silver (PVA/Ag)(TRANS TECH PUBLICATIONS LTD, 2017) Ersoyoglu, Ali Serhat; Ata, Sadik; Dincer, Kevser; Onal, Gurol; Yilmaz, YusufIn this study, the effects of cyclic voltammetry (CV) has been modeled with Rule-based mamdani-type fuzzy (RBMTF), by using experimental data for proton exchange membrane fuel cell with PVA/AG. In the system developed, RBMTF apply input parameters are CV, scan rate and time, output parameters are current density and voltage. 12300 values for experimental study also obtained with RBMTF. Membership functions (MFs) are the building blocks of fuzzy set theory, i.e., fuzziness in a fuzzy set is determined by its MF. Accordingly, the shapes of MFs are important for a particular problem since they effect on a fuzzy inference system. They may have different shapes like triangular, trapezoidal, Gaussian, etc. When the results obtained from RBMTF and statistical analyses of experimental data have been compared, it has been determined that the two groups of data are coherent, and that there is not a significant difference between them. As a result, this study indicates that RBMTF with different membership functions can be safely used for CV.Öğe Nanofiber tabakalı hava filtrelerinin partikül yakalama performanslarının incelenmesi(2018) Dincer, Kevser; Önal, Gürol; Selbes, Mehmet; Akdemir, AhmetBu çalışmada, 25-85 g/m2 gramaj arasındaki mikrofiber hava filtrelerininüzerine nanofiber kaplanarak çok küçük partikülleri yakalama performanslarıincelenmiştir. Filtrelerin performans tayini için basınç kaybı ve partikül yakalamatestleri yapılmıştır. Basınç kaybı deneylerinde filtrelere 0.3, 0.8, 1.3 m/s hızlarındahava, partikül yakalama testleri için ise 0.3 m/s hızında ortalama 100 nm çapındaformda toksik olmayan CaCO3 nanopartiküllü hava kullanılmıştır. Küçük fiberçapına sahip, kesit alanı büyük, rijit ve mukavim spunbond mikrofiber filtrelerinnanofiber tabaka kaplamaya elverişli olduğu ve optimum filtreleme sağladığıbelirlenmiştir. Küçük çaplı nanofiberlerin ince tabaka, büyük çaplı nanofiberlerinkalın tabakalı kaplanması filtreleme performansını arttırmaktadır. Nanofibertabaka kaplama ağırlığının artmasıyla performansın yükseldiği ve kritik birdeğerden sonra filtrenin tıkanarak ömrünü tamamladığı tespit edilmiştir.Öğe Rule-Based Mamdani-Type Fuzzy Modeling of Heating and Cooling Performances of Counter Flow Ranque-Hilsch Vortex Tubes with Different Geometric Construction for Brass(TRANS TECH PUBLICATIONS LTD, 2013) Ozen, Dilek Nur; Berber, Adnan; Dincer, KevserIn this study, thermal performances of counter flow Ranque-Hilsch vortex tubes were experimentally investigated and modeled with a Rule Based Mamdani-Type Fuzzy (RBMTF) modeling technique. The vortex tubes were made of brass. Diameter of vortex tube (D) was 10 mm. Length of vortex tube (L) was 10D, 11D, 12D, 13D, 14D. Input parameters (xi, L/D) and output parameters (Delta T-h, Delta T-c) were described by RBMTF if-then rules. 45 experimental data sets were used in the training step. R-2 for the Delta T-h was found to be 99.42 % and R-2 for the Delta T-c was 99.66 %. The actual values and RBMTF results demonstrated that RBMTF can be successfully used for the determination of heating and cooling performances of counter flow RHVT with different geometric constructions for brass.Öğe Rule-based Mamdani-type fuzzy modeling of heating and cooling performances of counter-flow Ranque-Hilsch vortex tubes with different geometric construction for steel(PERGAMON-ELSEVIER SCIENCE LTD, 2013) Berber, Adnan; Dincer, Kevser; Yilmaz, Yusuf; Ozen, Dilek NurIn this study, heating and cooling performances of counter-flow Ranque-Hilsch vortex tubes (RHVT) were experimentally investigated and modeled with a RBMTF (Rule-Based Mamdani-Type Fuzzy) modeling technique. Input parameters (xi, L/D) and output parameters Delta T-h, Delta T-c were described by RBMTF if-then rules. 81 experimental data sets were used in the training step. Numerical parameters of input and output variables were fuzzificated as linguistic variables: Very Very Low (L1), Very Low (L2), Low (L3), Negative Medium (L4), Medium (L5), Positive Medium (L6), High (L7), Very High (L8) and Very Very High (L9) linguistic classes. R-2 for the Delta T-h was found to be 99.60% and R-2 for the Delta T-c was 99.80%. The actual values and RBMTF results indicated that RBMTF can be successfully used for the determination of heating and cooling performances of counter-flow RHVT with different geometric constructions for steel. (C) 2013 Elsevier Ltd. All rights reserved.
