Krklareli University

Turkey

Krklareli University

Turkey
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Sola O.C.,Istanbul University | Ozyazgan C.,Krklareli University
Indian Journal of Engineering and Materials Sciences | Year: 2016

In this study, waste tire powder groups from the same waste tire material but with different particle sizes are added in cement mixtures that are intended for the production of cement composites as a replacement for certain proportions of the cement content. Four different waste tire group particle size ranges of 0-0.075 mm, 0.075-0.18 mm, 0.18-0.425 mm and 0.425-2 mm are added in cement mixtures by mass of 5%, 10% and 15%. After physical and chemical properties and particle size distributions of the prepared mixtures are determined, mortar specimens of 4×4×16 cm are taken, which are then subjected to compressive strength, weight change, microstructure (SEM-EDS) and mineralogical (XRD) analyses. When the results are evaluated, it is found that compressive strength values of cement mortars including 10% of waste tire powder are higher in thaw freezing-series when compared to the water-curing series. The SEM-EDS and XRD analyses also provided results coherent with compressive strength values. On the other hand, the wetting-drying series are found to be the series with the lowest weight change results. © 2016, National Institute of Science Communication and Information Resources (NISCAIR). All rights reserved.


Magden A.,Atatürk University | Ylmaz S.,Dokuz Eylül University | Unluturk Y.,Krklareli University
International Journal of Geometric Methods in Modern Physics | Year: 2017

In this paper, we first obtain the differential equation characterizing position vector of time-like curve in Lorentzian plane (Formula presented.) Then we study the special curves such as Smarandache curves, circular indicatrices, and curves of constant breadth in Lorentzian plane (Formula presented.) We give some characterizations of these special curves in (Formula presented.) © 2017 World Scientific Publishing Company


Water quality assessment has always been a major part of environmental management plans. In this study, the groundwater quality and spatial distribution in the eastern Thrace region was assessed and mapped for agricultural and drinking purposes. Groundwater samples (n = 18) were collected from deep wells in the study area and analyzed for hydrochemical properties for the water quality assessment. The Water Quality Index (WQI) was calculated for the quantification of water quality for human consumption. The WQI values showed that 52 % of the groundwater samples fall in the “poor” and “very poor” category due to agricultural impact. Nevertheless, the majority of the groundwater were suitable for irrigation in terms of sodium absorption ratio (SAR), residual sodium carbonate (RSC), sodium ratio (Na%) and magnesium hazard (MH). © 2016, TMMOB - Jeoloji Muhendisleri Odasi. All rights reserved.


Kibaroglu A.,Istanbul Science University | Gursoy S.I.,Krklareli University
Water International | Year: 2015

The interlinkage between water, energy and food security and its transboundary relevance is becoming increasingly important. The paper analyses the evolution of transboundary water resources management in the Euphrates–Tigris basin with specific reference to interlinkages between water, food and energy policies at national and transboundary levels, and it explores how the policy shifts at the highest decision-making level have served to produce synergies for cooperation among the riparians or vice versa. © 2015 International Water Resources Association.


Atav R.,Namik Kemal University | Baris B.,Krklareli University
AATCC Journal of Research | Year: 2016

The aim of this study was to determine whether dendrimer-based products can replace classic fluorocarbon-based products in water repellent, woven cotton fabrics. Furthermore, the effect of adding a dendrimer to a fluorocarbon product on the resulting water and oil repellency was studied. For that purpose, fluorocarbon, dendrimer, and dendrimer-fluorocarbon mixture-based commercial products were applied to cotton fabrics using the pad-dry-cure method. Repellency performance and wash resistance of these chemicals were investigated. It was found that the same water repellency values could be obtained in lower concentrations or under milder curing conditions using the dendrimer-fluorocarbon mixture-based product compared to that of the fluorocarbon-based product. © 2016, American Association of Textile Chemists and Colorists. All rights reserved.


Korpinar T.,Mus Alparslan University | Unluturk Y.,Krklareli University
General Relativity and Gravitation | Year: 2015

Anisotropic Bianchi type-I magnetized string cosmological models are obtained in decaying vacuum energy density proposed by Pradhan (Commun Theor Phys 55:931–941, 2011). In this study, we obtain some physical and geometrical properties of biharmonic particles of a new spacetime using Bianchi type-I (B-I) cosmological model. We use solution of the Einstein’s field equations for biharmonic particles. Some important features of the model have been discussed. Established the existence of string cosmological models for biharmonic particles, unlike the earlier authors, in this theory and studied some physical and geometrical properties. © 2015, Springer Science+Business Media New York.


Can E.,Krklareli University
International Journal of Environmental and Science Education | Year: 2016

The purpose of this study is to develop, and test the validity and reliability of a scale for the use of researchers to determine the accreditation standards of open and distance education based on the views of administrators, teachers, staff and students. This research was designed according to general descriptive survey model since it aims to develop a scale to measure the accreditation standards in open and distance education. The sample of the research comprises 196 students and 19 teachers, administrators and staff studying or working in Private Open education courses in Kadıköy district of İstanbul during 2011-2012 school year. The research data were collected using a scale developed to measure the level of accreditation standards in open and distance education based on the views of stakeholders in open and distance education institutions. The five-point Likert type scale “Acreditation Standards Scale for Open and Distance Education” developed in this research is consist of 47 items under eight factor including Organizational Structure, Students Services, Quality Assurance/Accreditation, Measurement and Assessment, Organization Mission, Distance Education Management, Distance Education Program, Openness/Credibility/Transparency. The Cronbach Alpha internal consistency coefficient was estimated.9683. It was concluded that Open and Distance Education Standards Scale is a valid and reliable instrument developed to measure the open and distance education quality at post-secondary education stages in Turkey. © 2016 The Author(s).


Korkmaz G.G.,Krklareli University | Konukoglu D.,Istanbul University | Kurtulus E.M.,Istanbul University | Irmak H.,Istanbul University | And 2 more authors.
Scandinavian Journal of Clinical and Laboratory Investigation | Year: 2013

Background. We investigated the ischemia-modified albumin (IMA), advanced oxidation protein products (AOPPs), prooxidants-antioxidants balance (PAB), and ferric reducing antioxidant power (FRAP) concentrations in patients with impaired fasting glucose (IFG), impaired glucose tolerance (IGT) and diabetes mellitus (DM) and compared the results to those of normoglycemic individuals at baseline and 2 hours after glucose loading. Methods. An oral glucose tolerance test was performed on age-matched subjects (n = 110) with a body mass index (BMI) < 27 kg/m. Subjects were categorized as normoglycemic (n = 35), IFG (n = 25), IGT (n = 30) and DM (n = 20) according to the WHO criteria. The IMA, AOPP, PAB, FRAP concentrations were determined by colorimetric methods. Results. At baseline, the AOPP concentrations were significantly higher in subjects with IFG and DM compared to normoglycemic subjects (p < 0.01 for all cases). The IFG, IGT and DM patients had a significantly higher IMA at baseline when compared with the normoglycemic individuals (p < 0.001 for all cases). The IMA in IFG subjects was significantly elevated (p < 0.05), while in DM patients, the IMA was significantly decreased (p < 0.001) after glucose loading with respect to baseline concentrations. Following glucose loading, the PAB was significantly decreased from baseline concentrations in normoglycemic individuals (p < 0.001) and in the IFG (p < 0.001) and IGT (p < 0.001) patients. Conclusion. In subjects with impaired glucose metabolism, the hyperglycemia is associated with increased IMA, AOPP and PAB concentrations. Increased IMA in subjects with IFG and decreased FRAP concentrations in subjects with IGT after glucose loading suggests that an increase in glucose concentrations can lead to tissue damage by increasing oxidative stress. © 2013 Informa Healthcare.


Esenpnar A.A.,Krklareli University | Ozkaya A.R.,Marmara University | Bulut M.,Marmara University
Journal of Organometallic Chemistry | Year: 2011

The synthesis of novel 6,7-[15-crown-5]-3-[p-(3,4-dicyanophenoxy)phenyl] coumarin (1)/6,7-[15-crown-5]-3-[p-(2,3-dicyanophenoxy)phenyl]coumarin (2) and their peripherally/non-peripherally cobalt and copper phthalocyanine complexes (3-6) have been prepared and characterized by elementel analysis, 1H-NMR, MALDI-TOF, FT-IR and UV-Vis spectral data. Fluorescence intensity changes of compound 1 and 2 have been determined by addition of Na + or K + ions at 25 °C in THF. The effect of substitution type on the redox and aggregation behaviour of the compounds was investigated by voltammetry and in situ spectroelectrochemistry. © 2011 Elsevier B.V. All rights reserved.


Amur M.,Krklareli University | Esenpnar A.A.,Krklareli University | Ozkaya A.R.,Marmara University | Bulut M.,Marmara University
Journal of Organometallic Chemistry | Year: 2011

The synthesis, spectroscopic and electrochemical properties of the tetra-(3-ferrocenyl-7-oxycoumarin)-substituted zinc (II) and cobalt (II) phthalocyanines (3 and 4) are reported for the first time. The synthesis of novel 3-ferrocenyl-7-hydroxycoumarin (1) was performed according to Perkin reaction, and the ligand, 7-(3,4-dicyanophenoxy)-3-ferrocenylcoumarin (2), was synthesized by the reaction of 3-ferrocenyl-7-hydroxycoumarin with 4-nitrophthalonitrile in the presence of K 2CO 3 as the base in dry dimethylformamide. The preparation of the corresponding zinc (II) and cobalt (II) metallo phthalocyanines (3 and 4) substituted with 3-ferrocenyl-7-oxycoumarin moieties at β-positions of the phthalocyanine ring was achieved by the cyclotetramerization of the coumarin ligand (2) with relevant metal(II) acetates in dry 2-dimethylaminoethanol. The new compounds have been characterized by elemental analyses, FT-IR, 1H NMR, Mass and electronic spectroscopy. The fluorescence property of the zinc metallo phthalocyanine (3) is strongly affected by the presence of ferrocenyl moiety. The ferrocenyl moieties were very efficient in quenching the excited state of 3, which show very poor fluorescent intensity. The electrochemical properties of the complexes were also investigated by cyclic and differential pulse voltammetry techniques in non-aqueous medium. It was found that the redox-active ferrocene substituents are reduced concurrently at one potential. © 2010 Elsevier B.V. All rights reserved.

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