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Isparta, Turkey

Süleyman Demirel University is a public university located in Isparta, Turkey. Established in 1992, the university, with around 70.000 students, is the second largest academic institution in Turkey. SDU is known for its programs in agricultural research, medicine, engineering, and business science. The university is approved by the Erasmus programme for participation and funding. SDU is a member of European University Association. Wikipedia.

Sofiyev A.H.,Suleyman Demirel University of Turkey
Composite Structures | Year: 2012

In this study, the non-linear vibration of truncated conical shells made of functionally graded materials (FGMs) has been investigated using the large deformation theory with von Karman-Donnell-type of kinematic non-linearity. The material properties of FGMs are assumed to vary continuously through the thickness of the shell. The fundamental relations, the non-linear motion and compatibility equations of the FGM truncated conical shell are derived. By using Superposition method, Galerkin method and Harmonic balance method, the non-linear vibration of an FGM truncated conical shell is analyzed. Finally, the influences of compositional profiles and variation of shell geometry on the dimensionless non-linear frequency parameter and the variation of ratio of the non-linear frequency to the linear frequency are investigated. The present results are compared with the available data for a special case. © 2012 Elsevier Ltd. Source

Koc M.,Suleyman Demirel University of Turkey
Computers and Education | Year: 2013

This research applied metaphor analysis to investigate student teachers' conceptions of technology. The sample included 237 students enrolled in technical pre-service teacher education in Turkey. Participants were given a questionnaire consisting of demographic questions and the prompt "Technology is like. because." to articulate their conceptualizations of technology. Data were analyzed both qualitatively and quantitatively. Participants produced 58 distinct mental images clustered into five conceptual categories that characterize technology as development, facilitation, vital necessity, power, and threat. Gender and major had no significant effect on their conceptions. Overall, the results suggest that student teachers' conception of technology is restricted and mostly focuses on artifact and technical dimensions. The implications and potential ways for constructing balanced and broader conceptualization of technology were discussed within the context of teacher education curriculum. © 2013 Elsevier Ltd. All rights reserved. Source

Naziroglu M.,Suleyman Demirel University of Turkey
Neurochemical Research | Year: 2011

The Na+ and Ca 2+-permeable melastatin related transient receptor potential 2 (TRPM2) channels can be gated either by ADP-ribose (ADPR) in concert with Ca 2+ or by hydrogen peroxide (H 2O 2), an experimental model for oxidative stress, binding to the channel's enzymatic Nudix domain. Since the mechanisms that lead to TRPM2 gating in response to ADPR and H 2O 2 are not understood in neuronal cells, I summarized previous findings and important recent advances in the understanding of Ca 2+ influx via TRPM2 channels in different neuronal cell types and disease processes. Considering that TRPM2 is activated by oxidative stress, mediated cell death and inflammation, and is highly expressed in brain, the channel has been investigated in the context of central nervous system. TRPM2 plays a role in H 2O 2 and amyloid β-peptide induced striatal cell death. Genetic variants of the TRPM2 gene confer a risk of developing Western Pacific amyotropic lateral sclerosis and parkinsonism-dementia complex and bipolar disorders. TRPM2 also contributes to traumatic brain injury processes such as oxidative stress, inflammation and neuronal death. There are a limited number of TRPM2 channel blockers and they seem to be cell specific. For example, ADPR-induced Ca 2+ influx in rat hippocampal cells was not blocked by N-(p-amylcinnomoyl) anthralic acid (ACA), the IP3 receptor inhibitor 2-aminoethoxydiphenyl borate or PLC inhibitor flufenamic acid (FFA). However, the Ca 2+ entry in rat primary striatal cells was blocked by ACA and FFA. In conclusion TRPM2 channels in neuronal cells can be gated by either ADPR or H 2O 2. It seems to that the exact relationship between TRPM2 channels activation and neuronal cell death still remains to be determined. © Springer Science+Business Media, LLC 2010. Source

Kizilkan O.,Suleyman Demirel University of Turkey
Energy Education Science and Technology Part A: Energy Science and Research | Year: 2011

This study presents performance modeling of an experimental refrigeration system driven by variable speed compressor using artificial neural networks (ANNs) with small data sets. Controlling the rotational speed of compressor with a frequency inverter is one of the best methods to vary the capacity of refrigeration system. For this aim, an experimental refrigeration system was designed with a frequency inverter mounted on compressor electric motor. The experiments were made for different compressor electric motor frequencies. Instead of several experiments, the use of ANNs had been proposed to determine the system performance parameters based on various compressor frequencies and cooling loads using results of experimental analysis. The backpropagation learning algorithm with two different variants was used in the network. In order to train the neural network, limited experimental measurements were used as training and test data. The best fitting training data set was obtained with eight neurons in the hidden layer. The results showed that the statistical error values of training were obviously within acceptable uncertainties. Also the predicted values were very close to actual values. © Sila Science. Source

Sofiyev A.H.,Suleyman Demirel University of Turkey
Composites Part B: Engineering | Year: 2014

In this study, the large-amplitude vibration of non-homogenous orthotropic composite truncated conical shell is investigated. It is assumed that the Young's moduli and density of orthotropic materials vary exponentially through the thickness direction. The basic equations of non-homogenous orthotropic truncated conical shell are derived using the finite deflection theory with von Karman-Donnell-type of kinematic non-linearity. Then, foregoing equations are solved using the Superposition principle, Galerkin and Semi-inverse methods and the frequency- amplitude relationship is found. Finally, carrying out some computations, the effects of non-homogeneity, orthotropy and conical shell characteristics on the nonlinear vibration characteristics have been studied. © 2013 Elsevier Ltd. All rights reserved. Source

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