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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 Taming the late Quaternary phylogeography of the Eurasiatic wild ass through ancient and modern DNA(PLoS One, 2017-04-19) Gündem, Can Yumni; Bennett, E Andrew; Champlot, Sophie; Peters, Joris; Arbuckle, Benjamin S; Guimaraes, Silvia; Pruvos, Mlanie; David, Shirli Bar; Davis, Simon J M; Gautier, Mathieu; Kaczensky, Petra; Kuehn, Ralph; Mashkour, Marjan; Morales, Arturo; Muiz, Morales; Pucher, Erich; Tournepiche, Jean François; Uerpmann, HansPeter; Blşescu, Adrian; Germonpr, Mietje; Moull, Pierre Elie; Ötzan, Aliye; Walzer, Chris; Grange, Thierry; Geigl, Eva MariaTaxonomic over-splitting of extinct or endangered taxa, due to an incomplete knowledge of both skeletal morphological variability and the geographical ranges of past populations, continues to confuse the link between isolated extant populations and their ancestors. This is particularly problematic with the genus Equus. To more reliably determine the evolution and phylogeographic history of the endangered Asiatic wild ass, we studied the genetic diversity and inter-relationships of both extinct and extant populations over the last 100,000 years, including samples throughout its previous range from Western Europe to Southwest and East Asia. Using 229 bp of the mitochondrial hypervariable region, an approach which allowed the inclusion of information from extremely poorly preserved ancient samples, we classify all non-African wild asses into eleven clades that show a clear phylogeographic structure revealing their phylogenetic history. This study places the extinct European wild ass, E. hydruntinus, the phylogeny of which has been debated since the end of the 19th century, into its phylogenetic context within the Asiatic wild asses and reveals recent mitochondrial introgression between populations currently regarded as separate species. The phylogeographic organization of clades resulting from these efforts can be used not only to improve future taxonomic determination of a poorly characterized group of equids, but also to identify historic ranges, interbreeding events between various populations, and the impact of ancient climatic changes. In addition, appropriately placing extant relict populations into a broader phylogeographic and genetic context can better inform ongoing conservation strategies for this highly-endangered species.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 Fluorescence properties and electrochemical behavior of some schiff bases derived from n-aminopyrimidine(Springer Nature, 2014-03) Gülcan, Mehmet; Doğrul, Ümit; Öztürk Ürüt, Gülsiye; Levent, Abdulkadir; Akbaş, EsvetA series of Schiff bases (L 1, L 2 and L 3 ) were prepared by refluxing aromatic aldehydes with N-Aminopyrimidine derivatives in methanol and ethanol. The structures of synthesized compounds were characterized by FTIR, 1H NMR, 13C NMR and microanalysis. The electrochemical behaviors of the Schiff base ligands were also discussed. Moreover, the evaluation of absorption and emission properties of the structures were carried out in five different solvents. The products show visible absorption maxima in the range of 304-576 nm, and emission maxima from 636 to 736 nm in all solvents tested.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 Combined effects of thermal barrier coating and blending with diesel fuel on usability of vegetable oils in diesel engines(Elsevier, 2013) Aydın, HüseyinThe possibility of using pure vegetable oils in a thermally insulated diesel engine has been experimentally investigated. Initially, the standard diesel fuel was tested in the engine, as base experiment for comparison. Then the engine was thermally insulated by coating some parts of it, such as piston, exhaust and intake valves surfaces with zirconium oxide (ZrO2). The main purpose of engine coating was to reduce heat rejection from the walls of combustion chamber and to increase thermal efficiency and thus to increase performance of the engine that using vegetable oil blends. Another aim of the study was to improve the usability of pure vegetable oils in diesel engines without performing any fuel treatments such as pyrolysis, emulsification and transesterification. Pure inedible cottonseed oil and sunflower oil were blended with diesel fuel. Blends and diesel fuel were then tested in the coated diesel engine. Experimental results proved that the main purpose of this study was achieved as the engine performance parameters such as power and torque were increased with simultaneous decrease in fuel consumption (bsfc). Furthermore, exhaust emission parameters such as CO, HC, and Smoke opacity were decreased. Also, sunflower oil blends presented better performance and emission parameters than cottonseed oil blends.Öğe Hydrothermal synthesis of magnetic nanocomposite from biowaste matrix by a green and one-step route: Characterization and pollutant removal ability(Elsevier, 2019-04) Sayğılı, HasanThis study aimed to produce an industrial waste-based novel magnetic nanocomposite (Fe@GPHC) by a facile and one-step hydrothermal carbonization (HTC) method. In order to characterize of Fe@GPHC, X-ray fluorescence spectroscopy (XRF), Scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDX), X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), Brunauer-Emmett-Teller (BET), Vibrating-sample magnetometer (VSM), and elemental (ultimate) analyses were applied. Characterization results showed that during the HTC process, the Fe nanoparticles (FeNPs) were successfully incorporated on biowaste matrix. In addition, the Fe@GPHC was used to test its adsorptive property. For this, methylene blue (MB) and methyl orange (MO) were selected as a simulated pollutant. A batch method was used to perform the adsorption experiments. The maximum adsorption capacity of Fe@GPHC was 11 mg g(-1) and 8.9 mg g(-1) for MB and MO, respectively. This study provides a feasible and simple approach to design and synthesis of high-performance functional magnetic material in a cost-effective way.Öğe Determination of fatigue life of the unidirectional GFRP/Al hybrid composite laminates(Elsevier, 2019-06) Deniz, Mehmet Emin; Aydın, FıratThis paper investigates the effects of loading rate and fiber orientation on the fatigue behavior of the unidirectional glass-fiber reinforced-plastic/aluminum (GFRP/Al) hybrid laminated (GLARE-2) plates. Fatigue tests were performed at three kinds of stress ratios (R = 0.3, 0.1, and −0.1) on specimens with different fiber orientations, θ = 0° 15° 30° 45° 60° 75° and 90° in the GFRP layers. All the fatigue results to be presented in this article were obtained in repeated tension-tension and tension-compression at stress ratios of 0.3, 0.1, and −0.1, and the results were compared with each other. It has been shown that the specimens have the highest fatigue life in the fiber orientation direction at R = 0.3 loading rate. Also, it has been shown that the fatigue life of the specimens decreases as the loading rate decreases.Öğe Performance and emission analysis of cottonseed oil methyl ester in a diesel engine(Elsevier, 2010-03) Aydın, Hüseyin; Bayındır, HasanIn this study, performance and emissions of cottonseed oil methyl ester in a diesel engine was experimentally investigated. For the study, cottonseed oil methyl ester (CSOME) was added to diesel fuel, numbered D2, by volume of 5%(B5), 20%(B20), 50%(B50) and 75%(B75) as well as pure CSOME (B100). Fuels were tested in a single cylinder, direct injection, air cooled diesel engine. The effects of CSOME-diesel blends on engine performance and exhaust emissions were examined at various engine speeds and full loaded engine. The effect of B5, B20, B50, B75, B100 and D2 on the engine power, engine torque, bsfc's and exhaust gasses temperature were clarified by the performance tests. The influences of blends on CO, NOx, SO2 and smoke opacity were investigated by emission tests. The experimental results showed that the use of the lower blends (B5) slightly increases the engine torque at medium and higher speeds in compression ignition engines. However, there were no significant differences in performance values of B5, B20 and diesel fuel. Also with the increase of the biodiesel in blends, the exhaust emissions were reduced. The experimental results showed that the lower contents of CSOME in the blends can partially be substituted for the diesel fuel without any modifications in diesel engines.
