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Karabuk, Turkey

Karabük University is located in Karabuk on the Western Black Sea Region of Turkey and near Safranbolu, a district and 8 KMs away from Karabuk, which is famous for its ancient historical wooden Ottoman Houses, many of which are under legal protection and used as lodging-houses, and it is thus in “the List of World Heritage Cities” by the UNESCO.Supported mainly by state funds, the University offers both undergraduate and graduate programmes with 14 faculties, 4 institutes, 4 higher school, and 7 vocational higher schools, where approximately 42.000 students take education at both undergraduate and graduate levels during the 2013-2014 academic year with around 1200 academic staff, 400 administrative and technical staff. Through highly qualify studies in these educational programmes, the University moves forward not only to achieve its target of being one of the world’s best leading universities in the near future but also to serve our country and humanity at large. By means of the advantage of the opportunities of international cooperation and solidarity, which is of vital importance in the international education, Karabuk University continues to have its voice heard serving the nation in the fields of science and technology, while taking its proper place in the world with its contribution to education and research with all of its academic units and academic staff in the local, national, and international arena.At Karabuk University, one academic year is divided into two semesters, Fall and Spring. The undergraduate degrees are conducted for 8 semesters, while associate degrees consist of 4 semesters at vocational schools. The graduate institutes, Natural and Applied science and Social science, offer graduate courses and degrees that lead to master's or doctorate degrees. All the degree programmes, undergraduate and graduate, are intended to be compatible with requirements stipulated by the Bologna Process. Hence the University has afforded much to organize its programmes and education in line with the Bologna Process and the Framework of European Qualifications, and as a result of this strenuous effort, now it holds a valid Erasmus Extended Charter and has currently been awarded ECTS Label in December 2013. In addition, Karabuk University has also been awarded Diploma Supplement Label 2011-2018 by European Commission. Wikipedia.

In this study, nitrogen and argon were used as the sintering atmosphere for AISI 316L stainless steel compacts. The effects of sintering atmosphere on sintered density, grain morphology and mechanical properties were investigated. The mechanical and microstructural characteristics of the sintered compacts were evaluated using optical microscopy, and scanning electron microscope. Tensile strength and hardness of the compacts sintered in nitrogen atmosphere are 290MPa and 355.2HV0.1, respectively. When argon was used as the sintering atmosphere, the tensile strength and hardness of the 316L stainless steel sintered compacts have become 226MPa and 181.8HV0.1 respectively. The results of this study indicate that the compacts sintered in nitrogen atmosphere exhibits higher strength and hardness than that of the steels sintered in argon atmosphere. © 2013 Elsevier Ltd.

Turen Y.,Karabuk University
Materials and Design | Year: 2013

In this study, effect of Sn addition on microstructure, mechanical and the casting properties of AZ91 magnesium alloy have been studied. Results from the microstructural analysis showed that refinement of Mg17Al12 phase took place and new Mg2Sn phase was formed as Sn was added into the AZ91 alloy. Fluidity increased with 0.5wt.% Sn content then decreases rapidly as the Sn content exceeded above 0.5wt.%. Hot tear susceptibility (HTS) decreased with 0.5wt.% Sn addition to AZ91 magnesium alloy above which it increased considerably. Tensile strength and elongation increased by addition of up to 0.5wt.% Sn above which it decreased with increasing Sn content. The increase of mechanical properties was attributed to transformation of lamellar to fully divorced eutectic β phases by 0.5wt.% Sn addition existed in grain boundaries of the magnesium matrix. The reduction in the mechanical properties above 0.5wt.% Sn was attributed to formation of clustered Mg2Sn phase. © 2013 Elsevier Ltd.

Investigating the joining capability of magnesium AZ31 alloy sheets and aluminium 1350 alloy sheets with the application of resistance spot welding was the objective of this study. The weld current values used in the welding process of Al-Mg sheets were 22, 23, 25, 27, 29, 31, and 33. kA. The studies examined the nugget geometries of joined specimens, recorded the scanning electron microscopy (SEM) images of the welded zone and the fracture surface, and recorded the energy-dispersive spectroscopy (EDS, semi-quantitative) analyses. The results of the experiment confirmed that nugget geometry was different for the Al and Mg sides. Tensile shear tests carried out on the welded joints determined their strength and failure mode. The increase in the weld current and duration resulted in an increase in the nugget size and the weld strength. According to observations, the tensile load bearing capacity (TLBC) increased up to 29. kA of the weld current value. It was also found that tearing during fracture occurred in two different ways. © 2010 Elsevier Ltd.

Gokolu G.,Karabuk University
Solid State Sciences | Year: 2012

In this study, ab initio calculation results of electronic structure and elastic properties of NiCoCrGa quaternary Heusler compound are presented. Plane wave pseudopotential method is used with spin-polarized Generalized Gradient Approximation (σ-GGA) scheme of the Density Functional Theory (DFT). Static elastic constants of the cubic system satisfy mechanical stability criteria. The cubic phase of the system remains stable under tetragonal distortion. The spin-polarized electronic band structures and density of electronic states indicate a metallic band structure for majority spins, while minority spin structure has semiconducting character. This situation displays a slightly disturbed half-metallic behavior with high-spin polarization ratio (P = 0.961) at Fermi level E F. Two electronic bands of minority spins resulting from d-states of cobalt atom cross Fermi level at Γ-point. This situation gives a finite but very low density of states at E F. The material can be classified as a new half-metallic ferromagnet for spintronic applications. © 2012 Elsevier Masson SAS. All rights reserved.

In this study, the microstructure and mechanical properties of sintered AISI 316L stainless steel implant materials produced by powder metallurgy (P/M) method were investigated as a function of porosity amount. AISI 316L stainless steel powders were cold-pressed with 800. MPa pressure and sintered at 1200. °C, 1250. °C and 1300. °C for 30. min in a nitrogen atmosphere. The mechanical properties of the 316L implant samples were determined by tensile, fatigue and microhardness tests. Metallographic studies such as pore formation, and fractured surface analyses were performed by Scanning Electron Microscopy (SEM) and Light Optical Microscopy (LOM). The results of this study indicate that, irregular pore formation tendencies increase with an increase in porosity (%). Furthermore, an increase in porosity was shown to decrease the mechanical properties of sintered AISI 316L stainless steel. Sintering temperature is important parameter in decreasing the porosity of P/M materials. © 2013 Elsevier Ltd.

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