Cam shafts used in automobiles are produced by cast iron (grey cast iron, nodular cast iron) or steel. In this study, effect of chill formation on the surface of grey and nodular cast irons is investigated on the wear behavior, hardness, impact toughness and microstructure of grey and nodular cast irons. For this purpose, four types cam shaft made of grey cast iron with and without chill on the surfaces and nodular cast iron with and without chill on the surfaces, were casted. Mechanical tests were conducted after the camshafts have been produced by casting method. Surface hardness and wear resistance of grey and nodular cast irons have been improved by chill formation on the surfaces and it is concluded that the amount of wear on the surfaces of grey cast iron with chill and nodular cast iron with chill is almost the same. Maximum hardness value was obtained on the surface of grey cast iron with chill. The impact toughness has been found to decrease by chill formation. Maximum impact toughness value was obtained on nodular cast iron. Microstructures of grey cast iron with and without chill and nodular cast iron with and without chill were examined under optical microscope and worn surfaces of cast irons were examined by scanning electron microscopy (SEM). Wear mechanisms of the four types of cast iron were evaluated by SEM examination.

Nowadays, effect of global warming is increasing drastically so it leads to increased interest on energy efficiency and sustainable production methods. As a result of adverse conditions, national and international project platforms, OEMs (Original Equipment Manufacturers), SMEs (Small and Mid-size Manufacturers) perform many studies or improve existing methodologies in scope of advanced manufacturing techniques. In this study, advanced manufacturing and sustainable production method "Incremental Sheet Metal Forming (ISF)" was used for sheet metal forming process. A vehicle fender was manufactured with or without die by using different toolpath strategies and die sets. At the end of the study, Results have been investigated under the influence of method and parameters used.

In recent years, the welding of materials of new and complex structure constitutes a problem for the industry. The solid state welding method for joining of these materials were effective. Sheets produced from aluminum and aluminum alloys, especially in areas such as automotive, railway and defense industry have revealed the requirement of the application of solid state welding methods. The friction stir spot welding is one of the solid state welding method. Welding parameters is very important FSSW in order to obtain the maximum welding strength in FSSW. SKNK as parameters (tool rotational speed, depth, dive team, team and team inclination angle of standby time) is selected. In this study has investigated the joining of AA2024-T3 and AA5754-H22 aluminum alloy sheets with FSSW technique by Taguchi analysis. “The highest -the better” quality control characteristic using the Analysis of Variance (ANOVA) method were obtained the optimum welding parameters. The results have been analyzed both the graphical methods and numerical data. The most important parameters affecting the weld tensile strength were detected as tool rotation speed (44.74%) and the team of waiting time (31.60%). Weld tensile strength by Taguchi analysis result conducted for comparing experiments the increased by 42% compared to the initial parameters.

An analytical model is developed to estimate the mechanical response of nonisothermal, orthotropic, variable thickness disks under a variety of boundary conditions. Combining basic mechanical equations of disk geometry with the equations of orthotropic material, the elastic equation of the disk is obtained. This equation is transformed into a standard hypergeometric differential equation by means of a suitable transformation. An analytical solution is then obtained in terms of hypergeometric functions. The boundary conditions used to complete the solutions simulate rotating annular disks with two free surfaces, stationary annular disks with pressurized inner and free outer surfaces, and free inner and pressurized outer surfaces. The results of the solutions to each of these cases are presented in graphical forms. It is observed that, for the three cases investigated the elastic orthotropy parameter turns out to be an important parameter affecting the elastic behavior

In order to obtain a proper powder injection molding the rheological behavior of feedstocks should be known. To determine the binder effect on the rheological behavior of 316L stainless steel powders feedstock two different feedstock were prepared. In the current experiments water atomized 316L stainless steel powders (-20 µm) were used. Two types of binders, one of which is mainly paraffin wax can be dissolved in heptane and the other Polietilenglikol (PEG) based and can be dissolved in water, were used. Polypropylene was used as binder and steric acid was used as lubricant for both binder systems as skeleton binder. Dry binder system were mixed for 30 min in a three dimensional Turbola. Capillary rheometer was used to characterize the rheological properties of feed stocks at 150-200 °C and a pressures of 0.165-2.069 MPa. Powder loading capacity of PEG and PW based feed stocks were found to be %55 and %61 respectively. The lowest viscosity of PEG and PW based feed stocks were found to be 304.707 Pa.s and 48.857 Pa.s respectively.

Transportation has a great role in logistics. Many researchers have studied on transportation and vehicle routing problems. Transportation of hazardous materials (hazmat) is a special subject for logistics. Causalities due to the accidents caused by trucks carrying hazardous materials will be intolerable. Many researchers have studied on risk assessment of hazmat transportation to find ways for reducing hazardous material transportation risks. Some researchers have studied routing of hazmat trucks. The emergency response models and network design problems for hazmat transportation were also studied by some researchers. The transportation of hazmats can also be classified according to the mode of transport. Mainly roads are used for hazmat transportation but some shipments are intermodal. There has been a great amount of effort spent to find convenient ways for hazmat transportation. In this study, a literature survey for the articles about hazmat transportation is prepared. After pointing out the importance of hazmat transportation by the example of US hazmat transportation data, the studies on hazmat transportation since 2005 have been examined. Totally 88 articles are classified as risk, routing, routing and scheduling, emergency response, network design and accident analysis. What can be studied in future researches is pointed out.

In the world and in our country, most of urban transportation is performed by public transportation. Public transportation is a system which provides transportation easiness and opportunity to people, not to vehicles. Therefore, giving priority to public transportation system is necessary in organizing urban transportation. In this study, in order to reduce traffic intensity and to facilitate passenger transportation in Izmit urban transportation, It is tried to determine appropriate public transportation system. For this, firstly, alternatives which could be used for public transportation were determined. These alternatives are metro, metrobus, tram, light rail system and monorail. Afterwards, the variables affecting decision making about public transportation were determined. These variables are cost, transportation line features, vehicle characteristics, sensitivity to environment and customer satisfaction. Lastly, most appropriate public transportation system is proposed by using the axiomatic design method. As a result, light trail system and metrobus are determined as the most appropriate alternatives for Izmit public transportation system.

Traveling Salesman Problem (TSP) is the problem of finding a minimum distance tour of cities beginning and ending at the same city and that each city are visited only once. As the number of cities increases, it is difficult to find an optimal solution by exact methods in a reasonable duration. Therefore, in recent five decades many heuristic solution methods inspired of nature and biology have been developed. In this paper, a new metaheuristic method inspired of the by-passing the obstacle strategy of blind mole rats living in their individual tunnel systems under the soil is designed for solving TSP. The method is called as Blind Mole-rat Algorithm. The proposed algorithm is tested on different size of symmetric TSP problems and the results are compared to the best known results. Initial test results are promising although proposed metaheuristic is not yet competitive enough among other algorithms in the literature.

In this study, modelling and thermodynamic analysis of solar assisted trigeneration system was carried out. The required thermal energy for gas and vapor cycles were supplied from solar tower which is a new concept for gas cycle applications. Additionally, an absorption refrigeration cycle, vapor production process, drying process and water heating process were integrated to the system. Energy and exergy efficiencies of the trigeneration system were determined by the application of first and second law analyses. The results showed that the gas cycle efficiency was found to be 31%, vapor cycle efficiency was found to be 28% and coefficient of performance (COP) values of the refrigeration system was found to be 0.77. Also the highest exergy destruction rate was found to be 4154 kW in solar tower.