Browsing by Author "Solmaz, H"

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    Production of waste tyre oil and experimental investigation on combustion, engine performance and exhaust emissions
    Uyumaz, A; Aydogan, B; Solmaz, H; Yilmaz, E; Hopa, DY; Bahtli, TA; Solmaz, Ö; Aksoy, F
    In this study, waste tyre was pyrolyzed at different conditions such as temperature, heating rate and inert purging gas (N-2) flow rate. Pyrolysis parameters were optimized. Optimum parameters were determined. The main objective of this study was to investigate combustion, performance and emissions of diesel and waste tyre oil fuel blend. Experimental investigation was performed in a single cylinder, direct injection, air cooled diesel engine at maximum engine torque speed of 2200 rpm and four different engine load including 3.75, 7.5, 11.25 and 15 Nm. The effects of waste tyre oil on combustion characteristics such as cylinder pressure, heat release rate, ignition delay (ID), combustion duration, engine performance were investigated. In-cylinder pressure and heat release rate increased with waste tyre oil fuel blend (W10) with the increase of engine load. In addition, ID was shortened with the increase of engine load for test fuels but it increased with the addition of waste tyre oil. Lower imep values were obtained because of the lower calorific value of waste tyre oil fuels. Maximum thermal efficiencies were determined as 28.27% and %25.12 with diesel and W10 respectively at 11.25 Nm engine load. When test results were examined, it was seen that waste tyre oil highly affected combustion characteristics, performance and emissions. (C) 2018 Energy Institute. Published by Elsevier Ltd. All rights reserved.
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    Evaluation of the prevalence of coronary artery disease in patients with valvular heart disease
    Emren, ZY; Emren, SV; Kiliçaslan, B; Solmaz, H; Susam, I; Sayin, A; Abud, B; Aydin, M; Bayturan, Ö
    Objectives: The aim of the present study was to retrospectively evaluate the prevalence of concurrent coronary artery disease in patients who underwent surgery due to severe valvular heart disease. The study also investigated the association of coronary artery disease with the type of valvular heart disease. Materials and methods: A total of 241 patients (123 females [51%]), who had underwent single valvular heart surgery, were included in the study. The patients who underwent valve replacement surgery were divided into four groups: patients with severe mitral stenosis (MS), patients with severe mitral regurgitation (MR), patients with severe aortic regurgitation (AR), and patients with severe aortic stenosis (AS). Age, DM, HT, history of smoking, and LDL values were recorded as the risk factors for CAD. Results: Coronary artery disease was detected in 26.4% of patients with mitral stenosis and 57.7% of patients with aortic stenosis. Of the patients with mitral insufficiency, 41.9% had CAD, and 44.4% of the patients with aortic insufficiency had CAD. Conclusion: The comparison of MS and AS groups revealed significantly higher prevalence of CAD in the AS group. There was no statistically significant difference between the MR and AR groups in terms of the prevalence of CAD. The comparison of MS and MR groups revealed significantly higher prevalence of CAD in the MR group. Furthermore, the comparison of these groups in terms of the extensiveness of the coronary artery disease revealed significantly higher Gensini score in the MR group.