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Giresun, Turkey

Giresun University is a public university in Giresun, Turkey, founded in 2006. Wikipedia.

Kacal M.R.,Giresun University
Radiation Physics and Chemistry | Year: 2014

Energy dispersive X-ray fluorescence technique (EDXRF) has been employed for measuring L3-subshell absorption jump ratios, rL3 and jump factors, JL3 for high Z elements. Jump factors and jump ratios for these elements have been determined by measuring L3 subshell fluorescence parameters such as L3 subshell X-ray production cross section σL3, L3 subshell fluorescence yield, ωL3, total L3 subshell and higher subshells photoionization cross section σLT. Measurements were performed using a Cd-109 radioactive point source and an Si(Li) detector in direct excitation experimental geometry. Measured values for jump factors and jump ratios have been compared with theoretically calculated and other experimental values. © 2014 Elsevier Ltd. Source

Ultay N.,Giresun University | Calik M.,Karadeniz Technical University
Journal of Science Education and Technology | Year: 2012

Context-based chemistry education aims at making connections between real life and the scientific content of chemistry courses. The purpose of this study was to evaluate context-based chemistry studies. In looking for the context-based chemistry studies, the authors entered the keywords 'context-based', 'contextual learning' and 'chemistry education' in well-known databases (i. e. Academic Search Complete, Education Research Complete, ERIC, Springer LINK Contemporary). Further, in case the computer search by key words may have missed a rather substantial part of the important literature in the area, the authors also conducted a hand search of the related journals. To present a detailed thematic review of context-based chemistry studies, a matrix was used to summarize the findings by focusing on insights derived from the related studies. The matrix incorporates the following themes: needs, aims,methodologies, general knowledge claims, andimplications for teaching and learning, implications for curriculum development and suggestions for future research. The general knowledge claims investigated in this paper were: (a) positive effects of the context-based chemistry studies; (b) caveats, both are examined in terms of students' attitudes and students' understanding/cognition. Implications were investigated for practice in context-based chemistry studies, for future research in context-based chemistry studies, and for curriculum developers in context-based chemistry studies. Teachers of context-based courses claimed that the application of the context-based learning approach in chemistry education improved students' motivation and interest in the subject. This seems to have generated an increase in the number of the students who wish to continue chemistry education at higher levels. However, despite the fact that the majority of the studies have reported advantages of context-based chemistry studies, some of them have also referred to pitfalls, i. e. dominant structure of out-of-school learning, tough nature of some chemistry topics, and teacher anxiety of lower-ability students. © 2011 Springer Science+Business Media, LLC. Source

Pseudomonas putida RW-II isolated from petroleum refinery wastewater was tested for hydrocarbon degradation potential in the presence of polycationic surfactant, cetyl trimethylammonium bromide (CTAB). The effects of CTAB on growth profile, cell surface hydrophobicity, cell adhesion, zeta potential and hydrocarbon biodegradation were investigated. The addition of CTAB had a significant effect on the growth profile of RW-II and the growth was increased 1.11 times in hexadecane containing medium. In the presence of CTAB, the growth of Pseudomonas putida RW-II increased about 14.4%. The zeta potential of Pseudomonas putida RW-II decreased significantly when CTAB was added to the medium. The addition of CTAB not only decreased the zeta potential of surface, but also significantly increased the hydrophobicity of the cell surface. The degradation rate of hexadecane, anthracene and naphthalene was observed as 64.8%, 46% and 56% at the end of 120 h, respectively. Biodegradation of hexadecane, anthracene and naphthalene was enhanced 1.16, 1.15 and 1.08 times at 40 mg/L CTAB addition, respectively. The increase in biodegradation resulted from improved interaction between the hydrocarbon and microorganism derived from the increased adhesion. Thus, the use of CTAB has been proposed to be a valuable effect to enhance the biodegradation of hydrocarbons. Source

Guney M.S.,Giresun University
Renewable and Sustainable Energy Reviews | Year: 2016

Solar energy conversion and its application methods varies in wide range from passive solar to heat building to complex concentrated form to generate electricity. It is crucial to know these structures in detail and to classify them in methodical order. The constituent mechanism of primary energy sources have been briefly mentioned. Hereafter the classification of renewable energies, various application methods of solar power, the amount of solar energy falling on the earth, the main effects created by solar energy, and energy conversion methods, inclusively concentrated solar power, have been discussed. © 2015 Elsevier Ltd. All rights reserved. Source

Baris B.,Giresun University
Physica E: Low-Dimensional Systems and Nanostructures | Year: 2013

Al/rubrene/p-Si Schottky diode has been fabricated by forming a rubrene layer on p type Si by using the spin coating method. The frequency and voltage dependent dielectric constant (ε'), dielectric loss (ε''), tangent loss (tanδ), electrical modulus (M′ and M″), and ac electrical conductivity (σac) properties of Al/rubrene/p-Si Schottky diodes have been investigated in the frequency range of 1 kHz-1 MHz at room temperature. It is found that the values of the ε', ε'' and tanδ decrease with increasing frequency while an increase is observed in σac and the real component (M') of the electrical modulus. The values of ε', ε'', and tanδ were found as 5.01, 2.55, and 0.51 for 1 kHz and 2.46, 0.069, and 0.028 for 1 MHz at zero bias, respectively. Furthermore, the imaginary component (M') of the electric modulus showed a peak that shifts to a higher voltage with decreasing frequency. © 2013 Elsevier B.V. All rights reserved. Source

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