Browsing by Author "Akgün, S"

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    STRENGTH OF WHEAT AND BARLEY STEMS AND DESIGN OF NEW BEAM/COLUMNS
    Deger, G; Pakdemirli, M; Candan, F; Akgün, S; Boyaci, H
    In this study, physical and mechanical properties of wheat and barley stems are examined. Transverse sections of the stems are magnified by a microscope and the material structure in the transverse sections are analysed with image processing programs. Geometric properties such as inner, outer radius, stern wall thickness and density variation of the material along the radius are measured and density variations are approximated by a mathematical model. Moment of inertia of the cross-sectional area which plays a vital role in resistance against bending and buckling is calculated approximately. Using the material density variations of the wheat (Triticum sativum L.) stems, new beam/columns are designed. Stress distributions in this new design and conventional designs of equivalent weight are compared using ANSYS program. It is found that stresses are more uniformly distributed in the new design with maximum stresses being lower than the conventional designs.
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    Tribological and mechanical properties of Al alloyed bearings
    Ünlü, BS; Durmus, H; Akgün, S
    Aluminum based alloys are widely used as journal bearing materials in tribological applications. Duralumines, AlMgSi are widely used as journal bearing materials for aluminum based alloys. These alloys provide properties expected from journal bearings. In this study, tribological and mechanical properties of these journal bearings manufactured from aluminum alloys were investigated. SAE 1050 steel shaft was used as counter abrader. Experiments were carried out in every 30 min for the total of 150 min by using radial journal bearing wear test rig. Wear resistance of AI alloyed bearings increased about 2-3 times and journal wear resistance increased about 2-8 times. The highest bearing wear rate occurred in pure AI bearings while the lowest bearing wear rate occurred in AlMgsi bearing. (C) 2009 Elsevier B.V. All rights reserved.
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    Evaluation of 2015-2016 MOTAKK HBV DNA and HCV RNA External Quality Assessment National Program Results
    Karatayli, E; Soydemir, E; Aksoy, ZB; Kizilpinar, M; Altay Koçak, A; Karatayli, SC; Yurdcu, E; Yildirim, U; Güriz, H; Bozdayi, G; Yurdaydin, C; Ilhan, O; Yildirim, Y; Bozdayi, AM; Oguz, AY; Baris, A; Alp, A; Aksözek, A; Sayiner, A; Karagul, A; Ordu, A; Istanbullu, A; Otlu, B; Aridogan, B; Aksu, B; Buruk, CK; Karahan, C; Güney, Ç; Toksöz, D; Yildirim, D; Çolak, D; Daglar, DE; Findik, D; Kas, E; Çaliskan, E; Zeyrek, FY; Arslan, F; Demir, F; Milletli, F; Kibar, F; Özdinçer, F; Dündar, G; Arslan, H; Agca, H; Aliskan, HE; Güdücüoglu, H; Fidan, I; Akyar, I; Afsar, I; Kaleli, I; Dönmez, I; Yanik, K; Midilli, K; Çubukçu, K; Özdemir, M; Acar, M; Yalinay, M; Kuskucu, MA; Bakici, MZ; Aydin, N; Yilmaz, N; Çeken, N; Ziyade, N; Yilmaz, N; Özgümüs, OB; Gitmisoglu, Ö; Demirgan, R; Kesli, R; Güçkan, R; Sertöz, R; Akgün, S; Aksaray, S; Tezcan, S; Kaygusuz, S; Gökahmetoglu, S; Mese, S; Bayik, SA; Akçali, S; Gürcan, S; Karsligil, T; Us, T; Özekinci, T; Pilgir, T; Aslan, U; Dinç, U; Coskun, USS; Çetinkol, Y; Keskin, Y; Ayaydin, Z; Toraman, ZA
    MOTAKK, as a national external quality control program has been launched to evaluate the molecular detection of viral infections including HBV DNA and HCV RNA in molecular microbiology diagnostic laboratories in Turkey. This program is prepared in compliance with ISO 17043:2010 (Conformity assessment general requirements for proficiency testing) standards, and aims to take the place of external quality control programs from abroad, contributing to standardization and accuracy of molecular diagnostic tests in our country. The aim of this study was to evaluate 2015 and 2016 results of the MOTAKK External Quality Control Program for HBV DNA and HCV RNA viral load. The calls were announced on the web page of MOTAKK (www.motakk.org). The quality control samples were sent to participating laboratories in 2015 and 2016. Main stocks were prepared from patients with chronic hepatitis B and C who had viral load detection with reference methods according to WHO reference materials for viral load studies to improve quality control sera. From these main stocks, samples with different viral loads were prepared from dilutions of plasma with HBV, HCV, HAV, HIV, Parvovirus B19 and CMV negative serologic markers. Quality control samples were sent to the participating laboratories along with the negative samples in the cold chain. The laboratories accomplished the related tests within 2-3 weeks and entered their results on the MOTAKK web page. These results were analysed according to ISO 13528 (Statistical methods for use in proficiency testing by interlaboratory comparison) and scoring reports were created by a software developed by MOTAKK and sent to participating labs. Each laboratory evaluated their own results in comparison with the other laboratory results, reassessed the tests via observing the distance from the mean result and the reference values. The number of laboratories participating in the HBV DNA and HCV RNA external quality control program was 70-73 in 2015-2016. Participants were able to comply with the program tools, registering, entering results and receiving the results reports problem. In HBV panel, 72.6-89.1% and 84.7-90.3% of the participant laboratories were in 1 standard deviation (SD) in 2015-2016, respectively. In HCV panel, 70.8-89.1% and 84.7-90.3% of the participant laboratories were in 1 SD in 2015-2016, respectively. A national external quality control program for HBV DNA and HCV RNA in Turkey has been prepared for the first time with this project and implemented successfully. All the data provided in the MOTAKK external quality control program final report, compensate all the data provided by the quality control program final reports from abroad; additionally, the report allows comparison of used technologies and commercial products.