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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 The comparison of engine performance and exhaust emission characteristics of sesame oil-diesel fuel mixture with diesel fuel in a direct injection diesel engine(Elsevier, 2008-01-09) Altun, Şehmus; Bulut, Hüsamettin; Öner, CengizThe use of vegetable oils as a fuel in diesel engines causes some problems due to their high viscosity compared with conventional diesel fuel. Various techniques and methods are used to solve the problems resulting from high viscosity. One of these techniques is fuel blending. In this study, a blend of 50% sesame oil and 50% diesel fuel was used as an alternative fuel in a direct injection diesel engine. Engine performance and exhaust emissions were investigated and compared with the ordinary diesel fuel in a diesel engine. The experimental results show that the engine power and torque of the mixture of sesame oil-diesel fuel are close to the values obtained from diesel fuel and the amounts of exhaust emissions are lower than those of diesel fuel. Hence, it is seen that blend of sesame oil and diesel fuel can be used as an alternative fuel successfully in a diesel engine without any modification and also it is an environmental friendly fuel in terms of emission parameters.Öğe Combustion, performance and emissions of a diesel power generator fueled with biodiesel-kerosene and biodiesel-kerosene-diesel blends(Elsevier, 2017-02-05) Bayındır, Hasan; Işık, Mehmet Zerrakki; Argunhan, Zeki; Yücel, Halit Lütfi; Aydın, HüseyinHigh percentages of biodiesel blends or neat biodiesel cannot be used in diesel engines due to high density and viscosity, and poor atomization properties that lead to some engine operational problems. Biodiesel was produced from canola oil by transesterification process. Test fuels were prepared by blending 80% of the biodiesel with 20% of kerosene (B80&K20) and 80% of the biodiesel with 10% of kerosene and 10% diesel fuel (B80&K10&D10). Fuels were used in a 4 cylinders diesel engine that was loaded with a generator. Combustion, performance and emission characteristics of the blend fuels and D2 in the diesel engine for certain loads of 3.6, 7.2 and 10.8 kW output power and 1500 rpm constant engine speed were experimented and deeply analyzed. It was found that kerosene contained blends had quite similar combustion characteristics with those of D2. Mass fuel consumption and Bscf were slightly increased for blend fuels. HC emissions slightly increased while NOx emissions considerably reduced for blends. It was resulted that high percentages of biodiesel can be a potential substitute for diesel fuel provided that it is used as blending fuel with certain amounts of kerosene.Öğe Hardness and wear behaviours of al matrix composites and hybrid composites reinforced with B 4 C and SiC(Springer Nature, 2019-01-15) Çelik, Yahya Hışman; Kılıçkap, ErolThe conversion into the desired shape of the metal powders using Powder Metallurgy (PM) method enables economically mass productions. This case allows producing parts with complex and high dimensional accuracy with no machining. In this study the composites and hybrid composites with Al matrix were produced using PM method with different ratios B4C and SiC. Microhardness and wear experiments of the produced composites were investigated. Wear experiments were performed at a constant speed of 0.5 m/s, application loads of 5, 10 and 15 N and sliding distances of 250, 500, and 750 m. Then, SEM images of composites and hybrid composites were captured. The increase of the reinforcement ratio in the composites contributed to the increase of the hardness. The highest hardness value was computed as 58.7 HV from 16% B4C reinforced composite. In addition, the increase in the reinforcement ratio contributed to the increase of the wear resistance. The increase in the load and sliding distance also increased the wear. The minimum weight loss was calculated as 18 mg from 5 N load, 250 m sliding distance and 16% SiC reinforced composite.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 Transverse impact and axial compression behaviors of glass/epoxy pipes subjected to seawater and impact loading(SAGE, 2013-07) Deniz, Mehmet Emin; Karakuzu, Ramazan; İçten, Bülent MuratThis article investigates the effects of seawater and impact loading on the impact behavior and compressive strength of impacted glass/epoxy composite pipes. The specimens were immersed into artificial seawater at laboratory conditions for 3, 6, 9, and 12 months. First, the impact tests were carried out on composite pipes at room temperature, and then, the axial compression tests were performed. The results of immersed samples were compared with that of reference specimens (dry). Seawater effect on the force-deflection behavior and failure mechanism is more than impact energy with increase in pipe diameter, while impact energy effect is more dominant than seawater effect for small diameters of the pipe. Compressive strength generally reduces with increase in seawater immersion time and specimen diameter except for the highest diameter.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 Grasshopper optimization algorithm for automatic voltage regulator system(IEEE, 2018-06-21) Ekinci, Serdar; Hekimoğu, BaranA novel design method is presented to determine optimum proportional-integral-derivative (PID) controller parameters of an automatic voltage regulator (AVR) system utilizing the grasshopper optimization algorithm (GOA). The proposed approach is a simple and effective algorithm that is able to solve many optimization problems even those with unknown search spaces effectively. The simplicity of algorithm provides high quality tuning of optimal PID controller parameters. The integral of time weighted squared error (ITSE) is used as the performance index to confirm the performance of the proposed GOA-PID controller. When compared to the other PID controllers based on Ziegler- Nichols (ZN), differential evolution (DE), and artificial bee colony (ABC) tuning methods, the proposed method is found highly effective and robust to improve AVR system's transient response.Öğe Laws doku enerji ölçümü tabanli k-NN siniflandirici modeli ile iris tanima sistemi(IEEE, 20013-06-13) Acar, Emrullah; Özerdem, Mehmet SiraçBiyometrik tanıma teknolojisi genellikle çok pahallı ve son derece önemli güvenlik uygulamaları ile ilişkili olmuştur.İris tanıma sistemi, etkili biyometrik tanımasistemlerinden biridir. Bu çalışmada, farklı insanlardan elde edilen gözimgelerininiçerdiği irisdokuözelliklerinegörekişilerin tanınmasıamaçlanmıştır. İmgeler CASIAiris veritabanındanelde edilmiştir. İmge dokusuna duyarlı yeni yöntemlerdenbiri olanLawsDoku Enerji Ölçümü (Laws TEM) kullanılarak, iris dokusunun belirli yerelalanlarındanöznitelik vektörleri elde edilmiştir. kEn Yakın Komşu (k-NN) sınıflandırıcıparametrelerinden komşu sayısı(k) farklı değerlerde alınarak, elde edilen öznitelik vektörleri k-NN sınıflandırıcısı ile ayrıştırılmıştır. Farklı komşu sayılarına göre sisteminperformans değerlerikarşılaştırılmıştır. Sonuç olarak en yüksek ortalama performans,k-NNsınıflandırıcısınınk=1ve 2komşularıyapısında % 80.74olarak gözlemlenmiştir.Öğe Investigation of cutting parameters affecting on tool wear and surface roughness in dry turning of Ti-6Al-4V using CVD and PVD coated tools(Springer Nature, 2017-06-01) Çelik, Yahya Hışman; Kılıçkap, Erol; Güney, MusaThere are some problems in the machining of titanium alloys with excellent properties such as high strength, good corrosion resistance, long service life and low weight. The leading problem appears to be the fast tool wear and the bad machining surface. Therefore, in this study, it was investigated whether cutting parameters have effect on tool wear and surface roughness by turning under dry cutting condition of Ti-6Al-4V alloy with excellent properties. CVD (TiCN + Al2O3 + TiN) and PVD (TiAlN) coated WC tools were used in the experiments. Then the Ti-6Al-4V alloy turned with the combinations of the different cutting speed, feed rate, cutting long and depth of cut. We observed that the tools wear in both CVD and PVD coated WC tools increased with increasing the cutting speed, feed rate, depth of cut and cutting length. However, while tools wear increased with increasing cutting speed, the surface roughness reduced to an optimum level. Especially, the surface roughness was worsened above the optimum level changing with increasing the feed rate, cutting length and depth of cut. The tool wear with PVD coated WC tools was observed to be less than the CVD coated WC tools. However, the values of the surface roughness obtained with PVD coated WC tools with increase in depth of cut, feed rate and cutting length has given us higher values when compared to CVD coated WC tools.
