Kucukozer H.,Balikesir University
Computers and Education | Year: 2013
Abstract The purpose of this study was to investigate the long-term effectiveness of a three-dimensional (3D) computer modeling supported predict-observe-explain (POE) strategy on pre-service science teachers' understanding of lunar concepts. Thirty-three preservice teachers participated in the study. A questionnaire was used to assess participants' understanding of the phases of the Moon and eclipses before, after, and 22 months after the instruction. Semi-structured interviews were conducted with six participants before and after the instruction. The results demonstrated that few participants had a scientific understanding about the targeted lunar concepts before the instruction. However, the majority of the participants had a scientific understanding after the instruction indicating that the instructional intervention was quite effective in facilitating conceptual change. The results also demonstrated that twenty-two months after the instruction most participants maintained their scientific conceptual understanding suggesting that the powerful learning environment designed for this study was effective in promoting a durable conceptual change. © 2013 Elsevier Ltd. All rights reserved.
Demirtas M.,Balikesir University
Energy Conversion and Management | Year: 2011
In this paper, a new method of tuning Proportional Integral (PI) coefficients for a permanent magnet brushless DC (PMBLDC) motor drives is proposed. Artificial neural network is used to identify the whole system using maximum overshoot and settling time obtained from the application circuit for different Kp-Ki pairs. Optimal values of PI controller coefficients are obtained using genetic algorithm. Motion Control Kit (MCK243) is used to carry out digital motion control applications. The MCK243 kit includes a power module and a three-phase brushless motor. TMS320F243 programs are used for PMBLDC motor speed control. Experimental results are given to show the validity of this method. © 2010 Published by Elsevier Ltd.
Coskun C.,Balikesir University
Energy | Year: 2010
This paper presents a novel approach to temperature probability density distribution and function. Probability density functions and frequency are successfully used in wind speed and solar energy analyses in literature. This study applies these data to temperature data analysis. The present model is developed using the indoor and outdoor temperature as a parameter. Outdoor temperature distribution is crucial for the calculation of monthly and total degree-hour. In this paper, using past weather data, the outdoor temperature probability density functions are modeled for four cities in different regions in Turkey via a new computer program. The main advantage of this approach is to allow us to determine heating and cooling loads with respect to different indoor and outdoor temperatures. © 2010 Elsevier Ltd. All rights reserved.
Koc E.,Balikesir University
Journal of Travel and Tourism Marketing | Year: 2013
This study aims to explore gluttony as a liminoidal and inversionary form of behavior on all-inclusive holidays and its possible relationship with obesity. The study particularly looks at tourists' attitudes toward food and drinks on all-inclusive holidays, that is, whether they consume food and drinks excessively on holidays; and if they do, whether their excessive eating and drinking habits are continued after their all-inclusive holidays. The findings suggest that people who go on all-inclusive holidays consume more food and drinks (both in terms quantity and variety) and a significant proportion of them, though to a varying extent, continue their excessive consumption habits after their holidays. © 2013 Copyright Taylor and Francis Group, LLC.
Karadas C.,Balikesir University
Water, Air, and Soil Pollution | Year: 2014
A simple, rapid, sensitive, and inexpensive dispersive liquid-liquid microextraction method was developed for the determination of trace amounts of copper by flame atomic absorption spectrometry (FAAS). N,N-bis-(2-hydroxy-5-bromobenzyl)-2-hydroxy-1,3-diiminopropane was used as the chelating ligand. Several analytical parameters affecting the microextraction efficiency such as, sample pH, volume of extraction solvent (carbon tetrachloride), concentrations of the chelating ligand and NaCl, and sample volume were investigated and optimized. The effect of the interfering ions on the recovery of copper was also examined. Under the optimum conditions, the detection limit (3σ) was 0.75 μg L-1 for copper with a sample volume of 10 mL, and a preconcentration factor of 20 was achieved. The relative standard deviation (R.S.D) for ten independent determinations of a 10 μg L-1 solution of Cu(II) was 2.3 %. In order to verify the accuracy of the developed method, different certified reference materials (SLRS-5, QCS-19, Rice flour unpolished high level of Cd NIES 10c) were analyzed and the results obtained were in good agreement with the certified values. The proposed method was applied to tap water, river water, seawater, rice flour, and wheat flour samples. The percentage recovery values for spiked water samples were between 95.4 and 108.4. © 2014 Springer International Publishing Switzerland.
Kara D.,Balikesir University
Analytical Letters | Year: 2011
Flow injection analyses facilitate faster, inexpensive, and more environmentally friendly sample-preparation techniques than many traditional "wet chemistry" methods, and the use of flow injection has, therefore, expanded significantly in recent years. This review focuses on chelating solid phase materials, which have been used in flow injection analyses and also describes important information, such as type of chelating groups, the type of stationary phases, and their efficiency at pre-concentrating metal ions. Discussions of the improvement of the sensitivity and of improving limit of detection, as well as the efficiency with which concomitant ions are removed for the flow injection methods using chelating solid phase materials, are also made. © Taylor & Francis Group, LLC.
Ugulu I.,Balikesir University
Studies on Ethno-Medicine | Year: 2012
The value and importance of indigenous knowledge are now being increasingly acknowledged all over the world. For this reason, the aims of this study is not only to identify the medicinal plants used for Therapeutic Turkish Baths by local people of various areas in Turkey, but also to draw attention to the traditional knowledge that is in danger of being lost. In this study, a total of 105 people from twenty-one provinces (N=5) were interviewed. Information was gathered through scientifically guided questionnaires, interviews and general conversations and fidelity level (FL) of species were determined. According to the results of the identification, 42 plants are being used to make Therapeutic Turkish Baths for medicinal purposes in Turkey. Among them 29 plants are wild and 13 plants are cultivated plants. Most used families were Lamiaceae, Asteraceae, Fabaceae, Malvaceae and Poaceae. The category that has the highest FL value is Cucumis sativus (100%) followed by Rosmarinus officinalis (93%). The lowest is Thymus vulgaris (32%). The data obtained from our informants and analyses in the present paper clearly show that folk knowledge on medicinal plants and plant uses is still alive in the studied region. © Kamla-Raj 2012.
Celik V.,Balikesir University |
Mete E.,Balikesir University
Physical Review B - Condensed Matter and Materials Physics | Year: 2012
The electronic properties and atomic structures of W, N, S, W/N, and W/S dopings of anatase TiO 2 have been systematically investigated using the density functional theory. The exchange and correlation effects have been treated with the Heyd, Scuseria, and Ernzerhof (HSE) hybrid functional. Mixing traditional semilocal and nonlocal screened Hartree-Fock exchange energies, the HSE method corrects the band gap and also improves the description of anion/cation-derived gap states. Enhanced charge-carrier dynamics, observed for W/N codoped titania, can partly be explained by mutually passivating modifications of N 2p and W 5d states on its electronic structure. Following this trend, we have found an apparent band gap narrowing of 1.03 eV for W/S codoping. This is due to the large dispersion of S 3p states at the valance band top extending its edge to higher energies and Ti-S-W hybridization appearing at the bottom of the conduction band. W/S-TiO 2 might show a strong visible-light response comparable to W/N codoped anatase catalysts. © 2012 American Physical Society.
Aydin S.,Balikesir University
Computer Assisted Language Learning | Year: 2013
While research mainly focuses on the effectiveness of computer use and its contribution to the teaching of English as a foreign language (EFL), EFL teachers have received scant attention. Only a limited number of studies have been conducted regarding Turkish EFL teachers' perceptions of computer use for teaching EFL. Therefore, in the context of Turkish EFL teachers' perceptions of computer usage in learning and teaching, the current study aims to examine Turkish EFL teachers' knowledge of software and their reasons for personal computer use, including the attitudes and perceptions of self-confidence among teachers in integrating computers and the school climate and support with respect to the use of computers for teaching EFL. The sample group in the study consisted of 157 EFL teachers. Before descriptives were computed, a background questionnaire and survey that assessed the degree of knowledge about the computer software, the frequency of software use for personal purposes, the teachers' attitudes toward and perceived self-confidence in integrating computers, and finally, the school climate and support were used to collect quantitative data. The results indicated that Turkish EFL teachers have little knowledge about certain software and experience difficulties using the software programs and that they suffer from a lack of technical and instructional support, although they have positive perceptions of computer integration and attitudes toward computer use. © 2013 Copyright Taylor and Francis Group, LLC.
Karadas C.,Balikesir University |
Kara D.,Balikesir University
Food Chemistry | Year: 2012
Herbs (mint, thyme and rosemary) and spices (black pepper, chili pepper, cinnamon, cumin, sweet red pepper and turmeric) were analysed using atomic spectrometry and then subjected to chemometric evaluation in an attempt to classify them using their trace metallic analyte concentrations (As, Ba, Ca, Cd, Co, Cr, Cu, Fe, Mg, Mn, Ni, Sr and Zn). Trace metals in acid digests of these materials were determined using both inductively coupled plasma-atomic emission spectrometry and inductively coupled plasma-mass spectrometry. The chemometric techniques of principal component analysis (PCA), linear discriminant analysis (LDA) and cluster analysis (CA) were used for the classification studies. These herbs and spices were classified into five groups by PCA and CA. When the results of these techniques were compared with those from LDA, it was found that all group members determined by PCA and CA are in the predicted group that 100.0% of original grouped cases correctly classified by LDA. © 2011 Elsevier Ltd. All rights reserved.