Sürdürülebilir Kalkınma Amaçları

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• MakaleYalnız künye2024/r/gumushane/16054
  Investigation of Corrosion Properties of LA-91 Alloy Coated with MAO Method

  Sukuroglu, Suleyman; Totik, Yasar; Sukuroglu, Ebru Emine; Avci, Selcuk

  LA91 magnesium alloy is a super lightweight magnesium -lithium alloy proposed for next generation materials. In addition to the advantages of these alloys such as low density, high strength-to -weight ratio, specific stiffness and brittleness, these alloys also have disadvantages such as low corrosion resistance and the oxide -carbonate film formed on the surfaces of the alloys cannot provide sufficient corrosion protection even in non-corrosive environments. In this study, micro arc oxidation, one of the coating methods, was applied to LA91 alloy. The surface morphologies of the coatings were characterized and it was aimed to increase the corrosion resistance of LA91 alloy. For this purpose, potentiodynamic polarization tests were carried out in 3.5% NaCl solution at room temperature to draw attention to the protection of the coating. As a result of the tests, it was determined that the oxide coatings raised on the surface

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• MakaleYalnız künye2023/r/gumushane/16770
  Wear Behavior of Dental Restorative Materials

  Sen, Sadri; Zamanlou, Hamid; Karabudak, Filiz; Süküroglu, Ebru Emine

  Gradual wear of opposing teeth is a normal phenomenon in human dentition. There is a need for quality dental restorative materials to repair or replace natural teeth to ensure a higher quality of life through dental health. One of the main physiological mechanism that exists in dental materials during normal muscle function is called abrasion. There are two types of that in teeth which are common; Two-body and three-body. If the teeth are contacted directly, it is referred to as two-body abrasion. However, when there is abrasive slurry-like food between the teeth, this abrasive is called to be three-body abrasive. Several types of materials are available in current dentistry for teeth restoration and replacement, and new materials are being promoted every year. Dental specialists need to understand the wear mechanisms of these new types of dental restorative materials, alone or in combination with either enamel or other dental restorative material. The present study evaluates the abrasive resistance of three restorative materials groups: direct composites, indirect composites, and ceramics. To define the resistance of the wear, the authors then perform a micro-wear test on chosen materials. The results show that the wear mechanism is abrasive due to its low hardness compared to zirconia ball. The wear path in the nanohybrid (Grandio (R), 87s% w/w (71s% volume) inorganic nanohybrid filler, BisGMA, UDMA, TEGDMA) sample was smooth and without particles. In this study wear FEM analysis calculated for all models and the answers compared with experimental data.

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• Derleme MakaleAçık Erişim2019/r/gumushane/13393
  A Review Study on the Using of Diethyl Ether in Diesel Engines: Effects on CO2 Emissions

  Sezer, İsmet

  Vehicle and other fuel combustion emissions can change the composition of the atmosphere, increasing its ability to trap heat. Gases that are effective in trapping heat are called greenhouse gases and include all of the gases in vehicle emissions. The major component of greenhouse gases emissions is carbon dioxide (CO2). Reduction of CO2 emissions has become a concern worldwide. Introduction of biofuels to fueling of automotive engines is the one method to decrease emissions of greenhouse gases. The CO2 from biofuels, is emitted during combustion and absorbed during growth of tree end plants. These biofuels can be applied as blends or sole fuels. The most researches declare that the best way to reduce greenhouse emissions is the use of various biofuels. Therefore, it is very important that the results of various studies on alternative fuels or fuel additives are evaluated together to practice applications. On the other hand, diesel cars are also helping to reduce CO2 emissions. For these reasons, this study especially focuses on the use diethyl ether in diesel engines as fuel or fuel additive in various diesel engine fuels. This review study investigates the effects of diethyl ether addition on the CO2 emissions.

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• MakaleYalnız künye2019/r/gumushane/11394
  3Bio-Based Additives to Improve Diesel Engine Performance and Emissions

  Sezer, İsmet

  This study investigates addition of ethanol and diethyl ether into diesel fuel. Base fuel and three different blends were used in the tests. The experiments were performed at engine speed of 1500 rpm and under various loads by single cylinder diesel engine. Injection, combustion, performance and emissions parameters were evaluated for base fuel and blends. Results show that injection pressure decreases for all blends, and DEE addition causes delay in injection timing. Burnt mass fraction is lower for ethanol and DEE blends during early combustion phase, while it increases with DEE blends during progressive combustion phase. Ethanol and DEE blends also give reductions in cylinder pressure and temperature. Generally, air excess coefficients increase but exhaust gas temperature decreases when using ethanol and DEE blends. Although ethanol blend causes decrements in engine power and torque, DEE blends give closer values to diesel fuel. Both ethanol and DEE blends yield improvement in brake thermal efficiency and reduction in brake specific fuel consumption. When using fuel blends, generally, decrements in NOx and CO2 emissions and increments in HC emission occur, while CO emission shows fluctuations depending on engine load.

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