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Öğe Otomotiv fren balatalarının sürtünme performansında sic etkisi(Uludağ Üniversitesi, 2012-06) Altun, Şehmus; Öner, Cengiz; Sugözü, İlkerBu çalışmada, yüksek mukavemet, düşük aşınma, daha fazla yük ve sıcaklık dayanımı özelliklerine sahip SiC içeren balata numunelerinin sürtünme katsayısı ve aşınma dayanımına etkisi incelenmiştir. Balata bileşeni içerisine %5, %10 ve %15 SiC ilave edilmiştir. Sonuç olarak, SiC oranı arttıkça aşınma direnci artmış ve sürtünme katsayısı azalmıştırÖğe Onarımda kullanılan darbe dayanımlı iki bileşenli yapıştırıcılar(Fırat Üniversitesi, 2011) Adin, Hamit; Altun, Şehmus; Yaşar, FevziÖğe Prediction of performance and exhaust emissions of a diesel engine fueled with biodiesel by using linear regression and artificial neutral networks(University of Sarajevo, 2016) Altun, Şehmus; Ertuğrul, Ömer FarukÖğe A comparison of performance and emissions of a diesel power generator fueled with biodiesels from waste frying oils(The International University of Sarajevo, 2013) Altun, Şehmus; Yaşar, FevziÖğe Biodiesel production from raw cottonseed oil and its characterization(Energy Education Science and Technolgy Part A, 2011-07) Altun, Şehmus; Yaşar, Fevzi; Öner, CengizIn this study, raw cottonseed oil of Turkish origin was transesterified using methyl alcohol and an alkali catalyst to obtain the cottonseed oil methyl ester. The obtained cottonseed oil methyl ester was analyzed by gas chromatography (GC) for determining the fatty acid composition. The fuel-related properties of cottonseed oil methyl ester, cold filter plugging point, cloud point, kinematic viscosity, density, cetane index, flash point, distillation, sulfur content and heating value were determined and compared with those of petroleum diesel fuel and international biodiesel standards. From gas chromatograph analysis, it was found that the cottonseed oil methyl ester has the more amount of total unsaturated FA, therefore, it showed better cold-flow properties than more saturated ones, as expected. Moreover, the fuel-related properties of cottonseed oil methyl ester were within the specified standardsÖğe Hayvansal yağların dizel motor yakıtı olarak değerlendirilmesi(Taşıt Teknolojileri Elektronik Dergisi (TATED), 2010) Altun, Şehmus; Öner, CengizBiodiesel is an alternative diesel fuel, which is obtained from renewable biological sources such as vegetable oils and animal fats. When biodiesel is produced from food-grade vegetable oils, its the cost increases. To produce biodiesel an economically suitable , its cost must be lowered. The cost of biodiesel can be lowered, when it produces from low-cost feedstocks such as used frying oils and animal fats. Animal fats are highly viscous and mostly in solid form at ambient temperature that they need modifications before using them in diesel engines. The viscosity of animal fats can be reduced using transesterification process, emulsification and pyrolisis. Among these methods, the most commonly used process is transesterification reaction. In this literature review, using animal fat as a fuel for diesel engines is examined.Öğe Asfalt depolama tanklarının kızgın yağ ile ısıtılması ve sistemdeki ısı transferinin incelenmesi(Fırat Üniversitesi, 2011) Adin, Hamit; Altun, Şehmus; Yaşar, Fevzi; Işık, Mehmet Zerrakki; Işık, Süleyman KazımÖğe Fuel properties of biodiesels produced from different feedstocks(Energy Education Science and Technolgy Part A, 2011) Altun, ŞehmusBio diesel is an oxygenated diesel fuel obtained from vegetable oils or animal fats via transesterification reaction. The fuel properties such as viscosity, density, cetane number and heating value are very important for determining the suitability of bio diesel as a diesel engine fuel. These fuel properties mainly depend on the feedstock which is used in the bio diesel production. In this study, the effect of bio diesels produced from different feed stocks such as inedible animal tallow, crude canola oil and canola oil blended with animal tallow on the fuel properties were experimentally investigated. Bio diesel fuels and their blends with petroluem diesel fuel were compared with petroleum diesel (petrodiesel). The results showed that the viscosity and density of all the methyl esters were higher than that of petrodiesel, while the heating values of the methyl esters was lower. Besides, the viscosity and the density of methyl esters are within the bio diesel standards, except for animal tallow methyl ester and it was slightly out of the specification EN 14214. Animal tallow bio diesel has the highest cetane number than those of other fuels include petrodiesel. It is concluded that bio diesels and their blends with petrodiesel have suitable fuel properties, especially cetane numbers, for diesel combustion process.Öğe Effect of a mixture of biodiesel diesel ethanol as fuel on diesel engine emissions(Electronic Journal of Vehicle Technologies, 2011) Altun, Şehmus; Yaşar, Fevzi; Öner, Cengiz; Fırat, MüjdatÖğe Improved combustion of asphaltite coals in a rotating head combustor with various air supply arrangements(ACS Publications, 2014-04-16) Altun, Şehmus; Öner, CengizWhen burned in conventional stokers, coals with high swelling properties such as asphaltites make coke blocks (coking). The plastic layer formed on them prevents air from diffusing into coal; hence, the air provided for swollen coal to burn becomes insufficient. This problem can partially be resolved by shaking the flame bed automatically or by mixing the burning coals manually in order to provide continuous air for the surface of the unburned coal. Therefore, in this study, a coal combustion system with the rotating head was manufactured for burning effectively Turkish coking coals characterized by high sulfur and ash content in agitation conditions with air supply arrangements. This type of coals known as asphaltite, abundantly found in southeastern Anatolia coal basin in Turkey, were burned in the rotating head combustor in order to investigate the effect of operating parameters, such as excess air ratio, coal particle size and feeding speed, air delivery type, addition of flange, bed slope, and rotation speed on the combustion efficiency and temperature distribution on the head. Experimental results showed that both the rotating of combustion chamber and additional air supply, which was blown out with pressure from the air delivery holes, reduced the negative impact of ash on the combustion efficiency, mainly due to the coal getting in touch with air better. It was possible to increase the peak combustion efficiency over 80% by both improving the air supply and agitation of coalbed preventing coking during combustion. As a result, this system could be highly recommended to burn the coals with high swelling properties like asphaltite at a high efficiency.
