Yuzuncu Yll University

Van, Turkey

Yuzuncu Yll University

Van, Turkey

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Guler C.,Yuzuncu Yll University
Journal of Educational Computing Research | Year: 2017

The aim of this study is to investigate the use of WhatsApp application in anonymous peer assessment in higher education. The mobile phone application WhatsApp was used as both an anonymous and nonanonymous peer assessment tool in a classroom environment. The participants of the study were the students of two classes (sophomores and juniors), half of which were assigned to the anonymous peer assessment group and the other half to the nonanonymous peer assessment group for each class. The members of the anonymous groups used the personal messaging function of WhatsApp for assessment, whereas the nonanonymous groups used the group chat function of the application. WhatsApp was confirmed to be a valid tool for peer assessment, and it was shown that the required anonymity of the method was appropriate for the task. The students' perceived attitudes toward the procedure were found to be rather high, with no significant difference identified between the sophomores and junior groups related to the procedure. © SAGE Publications.

Bulut A.,Yuzuncu Yll University | Yurderi M.,Yuzuncu Yll University | Karatas Y.,Yuzuncu Yll University | Say Z.,Bilkent University | And 5 more authors.
ACS Catalysis | Year: 2015

Formic acid (HCOOH) has a great potential as a safe and a convenient hydrogen carrier for fuel cell applications. However, efficient and CO-free hydrogen production through the decomposition of formic acid at low temperatures (<363 K) in the absence of additives constitutes a major challenge. Herein, we present a new heterogeneous catalyst system composed of bimetallic PdAg alloy and MnOx nanoparticles supported on amine-grafted silica facilitating the liberation of hydrogen at room temperature through the dehydrogenation of formic acid in the absence of any additives with remarkable activity (330 mol H2·mol catalyst-1·h-1) and selectivity (>99%) at complete conversion (>99%). Moreover this new catalytic system enables facile catalyst recovery and very high stability against agglomeration, leaching, and CO poisoning. Through a comprehensive set of structural and functional characterization experiments, mechanistic origins of the unusually high catalytic activity, selectivity, and stability of this unique catalytic system are elucidated. Current heterogeneous catalytic architecture presents itself as an excellent contender for clean hydrogen production via room-temperature additive-free dehydrogenation of formic acid for on-board hydrogen fuel cell applications. © 2015 American Chemical Society.

Balkan F.,Aksaray State Hospital | Usluogullar A.,Dr Ersin Arslan State Hospital | Ucler R.,Yuzuncu Yll University
Turkish Journal of Endocrinology and Metabolism | Year: 2015

Purpose: Our objective in this study was to investigate the prevalence of metabolic syndrome in two different group of patients who had a thyroid-stimulating hormone (TSH) level within normal limits. Material and Method: Three hundred and ffty patients, who presented to Aksaray Public Hospital, Endocrinology and Metabolism Diseases Outpatient clinic and who had no thyroid disease, were included in the study. The patients were divided into two groups according to TSH levels. Group 1 had a TSH level of <2.5 mIU/L and group 2 had a TSH level of >2.5 mIU/L. The prevalence of metabolic syndrome, insulin resistance and lipid parameters were investigated in both groups. Results: A total of 350 patients were included in the study. Group 1 included 229 (65.5%) patients and group 2 included 121 (34.5%) patients. The prevalence of metabolic syndrome was found to be 112/229 (48%) in group 1 and 55/121 (45%) in group 2. There was no statistically signifcant difference between the two groups (p>0.05). FT3 level was found to be positively correlated with hip circumference (r=0.10, p=0.04), weight (r=0.12; p=0.016) and waist circumference (r=0.13; p=0.014). FT4 level was found to be positively correlated with height (r=0.12, p=0.02). Discussion: TSH level was not found to be correlated with the prevalence of metabolic syndrome (p>0.05). The prevalence of metabolic syndrome was found to be similar in both groups. © 2015 Galenos Yayincilik, All rights reserved.

Bayraktar A.,Karadeniz Technical University | Altunlslk A.C.,Karadeniz Technical University | Muvaflk M.,Yuzuncu Yll University
Journal of Performance of Constructed Facilities | Year: 2016

This paper addresses field investigations of the performance of masonry buildings during the October 23 (Ercis) and November 9 (Edremit), 2011, Van earthquakes in Turkey. Ercis and Edremit are villages respectively located 90 km and 18 km from the city of Van in Turkey. Ground accelerations and response spectra for these earthquakes are discussed. A total of 28,000 buildings were damaged or collapsed in the city center and surrounding villages after the Ercis earthquake. This number increased to 35,000 after the Edremit earthquake. Almost all masonry buildings were affected in the region. Most of them in the area were constructed of random or coursed stone walls with no reinforcement to support heavy clay tile roofing over wooden logs. A large number of such buildings were heavily damaged or collapsed. Cracking and failure patterns are examined and interpreted according to current provisions for earthquake resistance of masonry structures. From the field investigations, it is shown that damages had several causes, among them site effect, location and length of the fault, and poor construction quality. In addition, the two earthquakes hit the masonry buildings within 17 days, causing progressive damage. A large number of nonengineered masonry buildings completely collapsed or were heavily damaged. Most of those in the affected area were not designed and constructed in accordance with the Turkish Earthquake Resistant Design Code. © 2014 American Society of Civil Engineers.

Isci B.,Ege University | Gokbayrak Z.,Canakkale Onsekiz Mart University | Keskin N.,Yuzuncu Yll University
South African Journal of Enology and Viticulture | Year: 2015

The total phenolic and vitamin C contents of organic table grapes were determined by spectrophotometry and HPLC, respectively, after several quality-increasing treatments were applied at veraison for two growing seasons. Cane girdling and cluster-berry thinning resulted in different responses in the cultivars. 'Red Globe' generally was found to produce the lowest quantity of total phenolics in the berries, while 'Trakya llkeren' was the cultivar that accumulated the highest phenolics. Vitamin C accumulation in the berries was also affected by the treatments. The effect of the treatments was inconclusive in 'Buca Razakls1'. The application of both girdling and thinning caused more accumulation of vitamin C in the 'Alphonse L.' and 'Trakya Ilkeren' berries.

Arabaci M.,Yuzuncu Yll University | Snalan S.,Yuzuncu Yll University
AIP Conference Proceedings | Year: 2016

Lactococcosis, yersiniosis, listenollosis and cold water disease agents are frequently observed in Turkey as bacterial fish pathogens. Bacterial fish pathogens have high mortality prognosis, causing significant economic losses for the businesses. Use of molecular methods in substantiation of disease factors became prevalent in recent years. These methods have a significant role in fast diagnosis and early treatment of fish diseases. In the present study, 8 rainbow trout samples were obtained from each of 19 rainbow trout farms located in Van province, Turkey and registered with Food, Agriculture and Livestock Ministry. Total genomic DNAs were isolated from kidney tissues of sampled rainbow trout. Obtained DNAs were analyzed with real-time PCR there is/not (+/-) analysis using disease specific primer pairs for each disease. Molecular diagnosis of lactococcosis pathogen in 4 farms out of 19 rainbow trout farms active in Van province, and yersiniosis pathogen in 1 farm were made as a result real-time PCR analysis. Listenollosis and cold water pathogens were not molecularly observed. Results of the present study demonstrated that the region was safe for bacterial fish pathogens of cold water disease and listenollosis, which are observed frequently in Turkey, and there were deficiencies in preventive measures against lactococcosis and yersiniosis and fish transfer was a significant reason for the prevalence these diseases. © 2016 Author(s).

Kanberoglu G.S.,Yuzuncu Yll University | Coldur F.,Erzincan University | Topcu C.,Erzincan University | Cubuk O.,Erzincan University
IEEE Sensors Journal | Year: 2015

Novel tamoxifen-selective potentiometric electrodes based on various ion associations of tamoxifen were developed. The most suitable membrane composition, which has the best potentiometric characteristics, was examined under steady-state conditions. The membrane composed of (w/w) 3% tamoxifen-phosphomolibdate ion pair, 32% poly(vinylchloride), and 65% 2-nitrophenyloctylether was determined as the membrane with the best analytical properties. On the condition of pH=2-6, the fabricated electrode exhibited linear responses over the concentration range of 9.1 × 10-6- 1 × 10-3 M tamoxifen solutions (R2 =0.9989) with a sensitivity of 42.9 ± 0.3 mV/decade, detection limit of 7.3 ± 0.4 × 10-6 M and short response time of ≈25 s. The influences of some alkaline, alkaline earth metals, biologically significant molecules, and some pharmaceutical species over electrode responses were studied. The proposed electrode was applied for the determination of tamoxifen contents of some pharmaceutical formulations by using standard addition method. The potentiometric analysis results obtained for the pharmaceutical formulations were in good harmony with the results obtained by high performance liquid chromatography at 95% confidence level. © 2001-2012 IEEE.

Yigit A.,Yuzuncu Yll University | Yardim Y.,Yuzuncu Yll University | Senturk Z.,Yuzuncu Yll University
IEEE Sensors Journal | Year: 2016

In this paper, a method was developed for the individual and simultaneous determination of paracetamol (PAR), caffeine (CAF), and aspirin (ASA), based on the oxidation of these compounds at a cathodically pretreated boron-doped diamond electrode without any chemical modification. The electrochemical behavior of these three molecules was investigated employing cyclic voltammetry and square-wave adsorptive stripping voltammetry. Using stripping voltammetry in phosphate buffer at pH 2.5, the three compounds can well separate from each other with the potential differences of 0.71, 1.27, and 0.56 V among PAR-CAF, PAR-ASA, and CAF-ASA, respectively, which are large enough to determine PAR, CAF, and ASA individually and simultaneously. After the optimization of analytical conditions employing this electrode in phosphate buffer (pH 2.5), the adsorptive stripping peak currents for the three molecules were found to be linearly with their concentrations in the range of 5-125 μg mL-1 with the detection limits of 0.597, 0.277, and 1.310 μg mL-1 for PAR, CAF, and ASA, respectively. The presented method was provided a fast, sensitive, and simple approach to the determination of PAR, CAF, and ASA in the pharmaceutical formulations. The results obtained were statistically analyzed and compared with those obtained by applying the high-performance liquid chromatographic method with diode-array detection. © 2015 IEEE.

Ozdag R.,Yuzuncu Yll University
2016 24th Signal Processing and Communication Application Conference, SIU 2016 - Proceedings | Year: 2016

The establishment of wireless connection area and the continuation of it have been a significant problem in Wireless Sensor Networks (WSN) up to now because WSNs enable us to watch various environments with military and civil applications and at the same time, they give the opportunity of evaluating the information gained from such environments through the transmission of it to a certain control point. Thus, k-coverage problem in dynamic deployment of sensor nodes in WSNs is one of the reasons that affetcs the performance and the continuity of the network. For this reason; the algorithm Maximum Target Detection Algorithm based on Electromagnetism-Like (MTDA-EM), which enables us to detect all the targets in the related area at maximum level and additionally provides the dynamic deployment of the sensors with overlap of the minimum number of nodes, has been proposed. MTDA-EM has been improved based on Electromagnetism-Like (EM) algorithm which is metaheuristic. The aim in proposed MTDA-EM; is to decrease the energy consumption of the nodes and increase the lifetime of the network by optimizing the k-coverage degrees of the sensors while the dynamic deployment of the nodes in the related area is being made. Simulation results; it has been observed that the improved MTDA-EM has provided optimum results in terms of solving the problems of k-coverage. © 2016 IEEE.

Ozdemir O.F.,Yuzuncu Yll University | Arasoglu A.,Yuzuncu Yll University
EPJ Web of Conferences | Year: 2015

Oxygen is one of the elements which interacts with emitted neutrons after fission reactions. Oxygen exists abundantly both in nuclear fuel (UO2) and moderators (H2O). Nuclear reactions of oxygen with neutrons are important in terms of stability of nuclear fuel and neutron economy. In this study, equilibrium and pre-equilibrium models have been used to calculate (n,p), (n,d), (n,2n) and (n,α) nuclear reaction cross-sections of 16O. In these calculations, neutron incident energy has been taken up to 40 MeV. Hybrid and Standard Weisskopf-Ewing Models in ALICE-2011 program, Weisskopf-Ewing and Full Exciton Models in PCROSS program, and Cascade Exciton Model in CEM03.01 program have been utilized. The calculated results have been compared with experimental and theroretical cross-section data which are obtained from libraries of EXFOR and ENDF/B VII.1. © 2015 Owned by the authors, published by EDP Sciences.

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