The waste tire rubber that had been grounded in room temperature was devulcanized by using the microwave method. As the devulcanizing agent, diphenyldisulfide (DPDS), the efficiency of which in the breaking off of sulfur bonds (S-S) had been proven in various studies, was employed. By maintaining the microwave power at a fixed value, the effects of time and the DPDS amount on the process were investigated. The untreated waste tire rubber powder was characterized physically and thermally. Composite materials were prepared with 20 phr untreated waste tire rubber powder and devulcanized rubber (DVR) with the styrene butadiene rubber (SBR) matrix. These composites were compared with a control sample that was prepared from virgin SBR. The sol content (soluble part) and Fourier Transform Infrared Spectrophotometer (FTIR) analyses of the devulcanized samples have been examined to define the efficiency of devulcanization. The mechanical properties of the SBR composites were researched. In this study, it was found that using devulcanized rubber produced much better properties than using waste tire rubber powder, thereby showing the significant benefits of microwave devulcanization. At the DPDS content of 1 g, the elongation at break of the DVR 4 min/SBR composites increased to 578% from 481% for the untreated waste tire rubber powder and SBR composites, the elongation at break was enhanced by 20% by the devulcanization of waste tire rubber powder.

Heat shields are vehicle components that prevent transferring overheating that occurs in vehicle components at high temperatures to neighboring elements and vehicle body. Embossing is a sheet metal forming process for producing bulged designs by means of matched male and female roller rigid dies. After embossing process, embossed sheets are formed with the helping of molds according to the shape of vehicle component that will be kept away from overheating and in this forming process, some bulged designs are compressed. In this paper, for researching this compressed process, the embossed sheets are compressed with upper and lower rigid platens and this process entitled as restoration process. The purpose of this study is to investigate the effects of restoration process on the yield, tensile and bending strengths.

In modern market conditions, sustainable and effective management of main manufacturers, suppliers and customer relationship is a necessity for competitiveness. Suppliers must satisfy customers’ expectations such as cost minimization, quality maximization, improved flexibility and achieved deadlines; which is also required for systematic management of products, work and environmental safety. The supplier selection process is consistently getting more complicated by the effect of increasing amount of suppliers and supplier selection criteria. Supplier selection decisions which take an important role in efficient supplier management will be more consistent by the application of decision making models which integrate the quantitative and qualitative evaluation factors. In this study, a dynamic process is designed and modeled for supplier selection. For this purpose, evaluation criteria are established according to the Balanced Scorecard perspectives, system sustainability and safety requirements. Fuzzy Analytic Hierarchy Process method is used for evaluating the importance of supplier selection criteria. A utility range-based interactive group decision making method is used for the selection of the best supplier. In order to test the proposed model, a representative from airport operation sector is selected. Finally, it is revealed that the application of the proposed model generates consistent results for supplier selection decisions.

The traffic problem which gets worse with the increasing population and mobility in Istanbul, one of the biggest metropolises of the world, has been an attractive subject for the transportation experts. It is obvious that Bus-lane, which is one of the oldest methods to solve traffic jam and promote public transportation, brings advantages. In this study it is aimed to measure, quantify, and analyze the benefit of the Bus-lane application. The study contains 25 lines and their data that are serving on bus-lane of Millet Street, Istanbul. The data includes the morning and evening pick hours. During the cross of the buses on the street in the pick hours, the location data, speed data, service duration data, and number of passengers in the busses are provided by passenger information system. By comparing the speed, volume and service duration data of before and after application, it is reached to a conclusion on how much time saved by the passengers in the buses using bus-lane, the amount of fuel saved by buses and how much CO2 emission is reduced. It is seen that the bus-lane application provides advantages on time, fuel, and CO2 emission.

There is limited number of papers which consider setup times in assembly line balancing literature. Additionally, in these studies setup times are assumed as deterministic. Nevertheless, task and setup times can include variation due to human factors, machine breakdowns, lack of equipment and environmental factors in real life applications. Therefore, in this study assembly line balancing problem with stochastic sequence-dependent setup time is studied. A mathematical model is proposed for solving the problem and computational analysis is made on certain test problems.