Kütahya, Turkey
Kütahya, Turkey

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Aydin H.,Yuzuncu Yil University | Karakus H.,Dumlupnar University
Environmental Earth Sciences | Year: 2016

An evaporation study was conducted at Van Lake, one of the largest soda lakes on Earth, which is located on a high plateau in the Eastern Anatolia region of Turkey. Evaporation on a daily basis for the Gevaş station located at the southeastern shore of the lake was calculated using the Bowen ratio energy budget (BREB), Priestley–Taylor, deBruin–Keijman, Penman, and deBruin methods. The calculated evaporation values were then compared and tested with previously calculated and measured evaporation rates. Compared with available measured evaporation data, the best evaporation estimations (within ±0.5 mm/day) were made by the BREB method. The BREB calculations made in this study were statistically significant at the confidence level of 99.9 % for estimation of evaporation at the Gevaş station. Relationships between the calculated BREB evaporations and historical climatic records were also examined to propose a new empirical equation for evaporation estimation for the case of Lake Van. The best regression equation with a coefficient of determination (R2) of 0.9399 was found between BREB evaporation values and incoming solar radiation (Qs) values. A power regression model proposed to estimate daily evaporation rates from Qs values was statistically significant at the confidence level of 99.9 %. Additionally, a few regression models were also examined to predict the surface water temperature of Lake Van from recorded air temperature. The highest coefficient of determination (0.974) and moderate standard error (3.12 °C) values were obtained from a polynomial air–water temperature model. Estimated lake water temperatures using the polynomial model were within ±10 % of observed lake water temperatures. © 2016, Springer-Verlag Berlin Heidelberg.

Gok A.,Amasya University | Gok K.,Dumlupnar University
Transactions of the Indian Institute of Metals | Year: 2014

Austempered ductile irons (ADI) have been developed for an increasing number of the engineering applications such as crankshaft, gears, and other mechanic equipments because of its combination of strength and toughness. Therefore, austempering process has important effects on the mechanical properties of ADI. In this study, we have investigated the effect of austempering process on the cutting tool stresses. The cutting forces (main cutting force, feed force and thrust force) obtained from experimental studies have been applied to rake face, main cutting edge, auxiliary cutting edge on the cutting tool, and then the stresses (von-Mises, shear stress, normal stresses in the X, Y and Z directions) occurred on the cutting tool has been analyzed based on finite element method using ANSYS Workbench commercial software. It is also observed that analytical process of Frocht for the stresses on cutting tool tip. The results obtained show that the austempering process is the significant factor affecting cutting tool stresses. © 2014, Indian Institute of Metals.

Ekinci D.,Ondokuz Mayis University | Avdar H.,Dumlupnar University | Durdagi S.,University of Calgary | Talaz O.,University of Art | And 2 more authors.
European Journal of Medicinal Chemistry | Year: 2012

Several 5,10-dihydroindeno[1,2-b]indole derivatives incorporating methoxy, hydroxyl, and halogen (F, Cl, and Br) moieties on the indene fragment of the molecule were prepared and tested against five carbonic anhydrase (CA, EC isoforms. The inhibitory potencies of these compounds against the human (h) isoforms hCA I, II, IV, VI and bovine (b) isoform bCA III were assessed. Most of them exhibited low micromolar inhibition of these enzymes. K I values of these compounds against hCA I and hCA II were in the range of 2.14-16.32 μM, and 0.34-2.52 μM, respectively. Isozyme hCA IV was inhibited with K I-s in the range of 0.435-5.726 μM, while hCA VI with K I-s of 1.92-12.84 μM bCA III was inhibited with K I-s in the range of 2.13-17.83 μM. The structurally related compounds, 1,2-dimethoxybenzene, catechol and indole were also tested in order to understand the structure activity relationship. In silico docking studies of some derivatives within the active site of hCA I and II were also carried out in order to rationalize the inhibitory properties of these compounds and understand their inhibition mechanism. © 2012 Elsevier Masson SAS. All rights reserved.

Ustun O.,Dumlupnar University
The Scientific World Journal | Year: 2014

In multiobjective optimization methods, multiple conflicting objectives are typically converted into a single objective optimization problem with the help of scalarizing functions. The conic scalarizing function is a general characterization of Benson proper efficient solutions of non-convex multiobjective problems in terms of saddle points of scalar Lagrangian functions. This approach preserves convexity. The conic scalarizing function, as a part of a posteriori or a priori methods, has successfully been applied to several real-life problems. In this paper, we propose a conic scalarizing function based interactive reference point procedure where the decision maker actively takes part in the solution process and directs the search according to her or his preferences. An algorithmic framework for the interactive solution of multiple objective optimization problems is presented and is utilized for solving some illustrative examples. © 2014 Ozden Ustun.

Aksoy A.N.,Nenehatun Hospital | Gozukara I.,Nenehatun Hospital | Kucur S.K.,Dumlupnar University
Journal of Obstetrics and Gynaecology Research | Year: 2014

Aim: The aim of this casecontrol study was to compare the efficacy of ethinyl estradiol/drospirenone and Fructus agni casti in women with severe primary dysmenorrhea measuring uterine artery blood flow via Doppler ultrasonography. Methods: A total of 60 women with severe primary dysmenorrhea and 30 healthy women (control) were included in this study. Thirty patients were treated with ethinyl estradiol 0.03 mg/drospirenone (group 1) and another 30 were treated with Fructus agni casti (group 2) during three menstrual cycles. Before and at the end of third month of therapy visual analog scale (VAS) scores, pulsatility index (PI), resistance index (RI) of uterine artery were recorded before and after receiving therapy on the first day of the menstrual cycle. Results: Mean PI and RI values in patients with severe primary dysmenorrhea were significantly higher than in the control groups on the first day of the menstrual cycle (P < 0.0001). Mean PI and RI values were significantly lower after the treatment in both groups compared to before values (P < 0.001 for both). After using the drugs for three menstrual cycles, VAS scores were significantly dropped in both groups compared to before treatment values (P < 0.0001 for both); however, there were no significant differences in terms of Doppler findings between group 1 and 2. Conclusion: The effectiveness of Fructus agni casti was similar to that of ethinyl estradiol/drospirenone in patients with primary dysmenorrhea. © 2013 Japan Society of Obstetrics and Gynecology.

Ozkul C.,Dumlupnar University
Environmental Monitoring and Assessment | Year: 2016

Tunçbilek, one of the major thermal power plants (TTPP) in Turkey running on coal, has capacity to generate 365 MW (per year) electricity. Fifty top soil samples were collected from a depth about 0–20 cm in the close vicinity of the TTPP from random points and at different distances. The samples were analyzed using ICP-MS for heavy metals. Heavy metal contents in soils around TTPP varied from 4.4 to 317.5 mg/kg for As, 0.03 to 0.26 mg/kg for Cd, 20.3 to 1028 mg/kg for Cr, 4.8 to 76.8 mg/kg for Cu, 0.09 to 9.3 mg/kg for Hg, 16.6 to 2385 mg/kg for Ni, 4.8 to 58.6 mg/kg for Pb, and 14.5 to 249.5 mg/kg for Zn. Geoaccumulation index (Igeo) and enrichment factor (EF) have been calculated in order to evaluate heavy metal pollution in the soils. According to the Igeo calculations, the surface soils around TTPP are contaminated by As, Hg, and Ni from uncontaminated to extremely contaminated. Igeo values for Cr show practically uncontaminated to be heavily contaminated. The contamination of soil samples changes from practically uncontaminated to moderately contaminated degree for Pb and Zn. The soil samples were uncontaminated for Cd and Cu metals. The enrichment factors of As, Cr, Hg, and Ni in most of the sampling locations indicate significant to extremely high enrichment. The EF for Pb is also high and indicates moderate to very high enrichment of chromium in the soils. The average EF values for Cd, Cu, and Zn are showing moderate enrichment. © 2016, Springer International Publishing Switzerland.

Acaravci A.,Mustafa Kemal University | Erdogan S.,Mustafa Kemal University | Akalin G.,Dumlupnar University
International Journal of Energy Economics and Policy | Year: 2015

This study aims to explore both the long-run and causal relationships between electricity consumption per capita, real gross domestic product (GDP) per capita, trade openness and foreign direct investment inflows per capita in Turkey during the time period 1974-2013. The study employs the autoregressive distributed lag model and the augmented Granger causality model. The bounds F-test for cointegration test yields evidence of a longrun relationship between variables. The overall results from the three error-correction based Granger causality models show that there is an evidence of unidirectional short-run, long-run and strong causalities running from the electricity consumption per capita to real GDP per capita. But, there is no causal evidence from the real GDP per capita to electricity consumption per capita. This result also support that, “growth hypothesis” is confirmed in Turkey. As a policy implication, the energy growth policies regarding electricity consumption should be adapted in such a way that the development of this sector stimulates economic growth. © 2015, Econjournals. All rights reserved.

Zortuk M.,Dumlupnar University
Economic Computation and Economic Cybernetics Studies and Research | Year: 2015

In real life because of various reasons, data that are used in efficiency analysis may be imprecise or uncertain, whereas, data are measured with certainty in conventional Data Envelopment Analysis (DEA). In the other hand, sometimes outlier data may also take part in dataset. Therefore, we can use Fuzzy DEA (FDEA) method that is more responsive in situations as mentioned above for measuring efficiency. In FDEA, fuzzy data can be transformed in to interval data by using some techniques such as α-cut level sets. The interval DEA model is used for measuring the relative efficiency of decision maker units (DMUs). In this paper, FDEA method will be used for measuring efficiency of foreign direct investment in 12 transition economies that separated from USSR. Additionally, mini-max regret method (MRM) will be used to compare and rank efficiency intervals of DMUs. © 2015, Academy of Economic Studies. All rights reserved.

Kunt H.,Dumlupnar University
International Journal of Environmental and Science Education | Year: 2016

The purpose of this research was to determine science student teachers’ level of knowledge about the anatomical structure of two sensory organs, the eye and the ear, in addition to vision and hearing processes. Conducted with 86 science student teachers, research utilized drawing methods and open-ended questions as data collection instruments. The results showed that when science student teachers’ answers with regard to vision and its structures compared with their answers concerning hearing and its structures, their success rate was higher for hearing and its structures. Even though students were sufficiently informed about the anatomical structures constituting eyes and ears, it was observed that a significant percentage of the students were incompetent with regard to their understanding of how seeing and hearing takes place and correctly showing the anatomical structures constituting both eyes and ears on a schema. Human organ/organ system education may contribute to an increase in teaching capacity. © 2016 by author/s.

Gultepe N.,Dumlupnar University
International Journal of Environmental and Science Education | Year: 2016

The current research is a descriptive study in which a survey model was used. The research involved chemistry (n=26), physics (n=27), and biology (n=29) teachers working in Science High Schools and Anatolian High Schools in Turkey. An inventory that consisted of seven questions was designed to ascertain teachers’ think about the importance of science process skills in teaching science, to identify the frequency of these skills and the problems teachers encounter during their practice in class, and to specify their identification levels on these skills. The results of the study showed that these skills in general have a positive effect on teaching science and that the in-class activities promote conceptual learning. Most of the teachers participated in the study argued that these skills can only be gained effectively through laboratory activities in which both teachers and students engage; and almost all of them thought that central-examination-based teaching poses a great obstacle. Teachers are more successful in identifying skills of observing, predicting, experimenting, and inferencing than other skills. © 2016 Author(s).

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