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Öğe Air Quality Issues and Settlement Suitability Analysis in Igdir Central District(Istanbul Univ, Fac Letters, Dept Geography, 2023) Coskun, Mucahit; Sahiner, Huseyin; Canbulat, Onur; Ozturk, AhmetAir pollution can be a concern during certain seasons, specifically in autumn and winter, in the city center of Igdir owing to the city's geomorphological and climatological features. This study aims to examine the spatial and vertical distribution of air pollution in the atmosphere of the city center of Igdir and identify suitable areas for urban settlement. The results revealed that areas with highest pollution levels were in the city center of Igdir and in the plain area located north of the city. The geographical conditions, specifically in winter, limit convective air movements, cause inversion, and intensify air pollution. Height of the aerosol layer expresses the upper limit that pollutants can reach in the atmosphere. In the city center of Igdir, height of the aerosol layer approximately 1000-1100 m, especially in winter. Furthermore, pollutants are trapped between 850 m, which is the average altitude of the city center of Igdir, and these altitudes causes the pollution to be felt more intensely. A change in the city's settlement plan (horizontally) cannot address this issue in the longterm as the same air pollution problem will occur again. Thus, settlements should be established at least above 1000-1100 meters, which is the upper level of the aerosol layer in winter, to prevent this issue.Öğe Experimental Investigation of an Al2O3/Distilled Water Nanofluid Used In the Heat Pipes of Heat Exchangers(Gazi Univ, 2018) Ozturk, Ahmet; Ozalp, Mehmet; Sozen, AdnanThis study investigates the thermal performance of a heat pipe heat recovery system in air-to-air heat recovery systems using a nanofluid of Al2O3 (aluminum oxide) particles and distilled water. The experimental setup used 15 wickless vacuumed copper pipes with a length of 1000 mm, a 10.5 mm inner diameter and a 12 mm outer diameter. The evaporator section consists of 450 mm of heat pipes, the condenser section is 400 mm, and the adiabatic section is 150 mm. In experimental studies, 33% of the evaporator volume of the heat pipes was filled with working fluids. Experiments were carried out at temperatures between 25 degrees C and 90 degrees C by using five different cooling air flows (40 g/s, 42 g/s, 45 g/s, 61 g/s and 84 g/s), and two different heating powers (3 kW and 6 kW) for the evaporation section, to determine the heat removed from the condensation section. Experiments were performed for distilled water and Al2O3 nanofluid, respectively, and the results were compared with each other. As a result of the experiments, it was observed that using a nanofluid as the working fluid increased the efficiency of the heat pipe. The highest efficiency (eta = 59%) was obtained in the experiments carried out using an Al2O3 nanofluid at a heating power of 3 kW and an air flow of 112 g/s.Öğe Impact of various metal-oxide based nanoparticles and biodiesel blends on the combustion, performance, emission, vibration and noise characteristics of a CI engine(Elsevier Sci Ltd, 2020) Agbulut, Umit; Karagoz, Mustafa; Saridemir, Suat; Ozturk, AhmetWith the burning of 1 L of diesel fuel, approximately 3 kg of greenhouse gas is released into the atmosphere. Therefore, it is of great importance to reduce emissions with some additives in diesel engines. This study deals with the impacts of blends of waste cooking oil methyl ester and various metal-oxide based nanoparticles on the emission, combustion, performance, vibration and noise characteristics of a single-cylinder diesel engine. The test engine was loaded at different engine loads of 2.5, 5, 7.5 and 10 Nm and a constant engine speed of 2000 rpm. In this investigation, various fuels [called as reference diesel (D100), 10 vol% of waste cooking oil methyl ester (B10), and finally the mass fractions of 100 ppm aluminium oxide (B10Al(2)O(3)), titanium oxide (B10TiO(2)) and silicon oxide (B10SiO(2)) into the B10, separately] were tested. The addition of metal-oxide based nanoparticles has firstly increased the viscosity, cetane number, and heating value of biodiesel. Higher oxygen atoms in biodiesel-nanoparticles blends have improved the quality of the combustion process. Higher peak point in CPmax and HRRmax could be reached in these nano fuels due to their lower cetane numbers than that of D100. CO, HC and NOx emissions were significantly reduced with the blending of nanoparticles and biodiesel in comparison with those of D100. The addition of nanoparticles highly improved engine performance. B10 had the lowest thermal efficiency due to its heating value, but its efficiency was converted to the highest one with the addition of nanoparticle. In conclusion, this study is suggesting that the addition of metal-oxide based nanoparticles into biodiesel blends can give better results than using biodiesel alone for diesel engines.Öğe PERFORMANCE IMPROVEMENT OF THE HEAT RECOVERY UNIT WITH SEQUENTIAL TYPE HEAT PIPES USING TiO2 NANOFLUID(Vinca Inst Nuclear Sci, 2019) Ozturk, Ahmet; Ozalp, Mehmet; Sozen, Adnan; Guru, MetinThis paper deals with the improvement of thermal performance of the heat recovery system in air-to-air unit by using a nanofluid of TiO2 particles and distilled water. The experimental set-up equipped with 15 copper pipes of a 1000 mm length, 10.5 mm inner diameter; and 12 mm outer diameter was used. The evaporator section consists of 450 mm of heat pipes, the condenser section is 400 mm, and the adiabatic section is 150 mm. In experimental studies, 33% of the evaporator volumes of heat pipes were filled with working fluids. Experiments were carried out at temperatures between 25 degrees C and 90 degrees C by usingfive different cooling air-flows (40, 42, 45, 61, and 84 g/s), and two different heating powers (3 kW and 6 kW) for the evaporation section, to determine heat removed from the condensation section. Trials were performed for distilled water and nanofluid respectively, and the results were compared with each other. Results revealed that a 50% recovery in the thermal performance of the heat pipe heat recovery system was achieved in the design using TiO2 nanofluid as the working liquid, at a heating power of 3 kW, air velocity of 2.03 m/s and air-flow of 84 g/s.Öğe Visibility Evaluation and Suitability Analysis of Fire Lookout Towers in Mediterranean Region, Southwest Anatolia/Turkiye(Mdpi, 2023) Cosgun, Ufuk; Coskun, Muecahit; Toprak, Ferhat; Yildiz, Damla; Coskun, Sevda; Tasoglu, Enes; Ozturk, AhmetThe effectiveness of fire towers in combating forest fires relies on their appropriate observation angles, enabling a swift and efficient response to fire incidents. The purpose of this study is to examine the effectiveness of 49 fire towers located within the Antalya Forestry Regional Directorate, situated in the Mediterranean basin-a region prone to frequent forest fires. The assessment encompasses the visibility of the entire study area, including forested regions, as well as the visibility of 2504 forest fires recorded by the towers between 2008 and 2021. Furthermore, the evaluation considers the objectives based on Forest Management Directorates and conducts a location suitability analysis for the six towers with the lowest visibility.We utilized the Viewshed Tool in the ArcGIS application and employed the Best-Worst approach. Two scenarios were devised, considering smoke height at 0 m or 100 m, to determine the visibility of fire lookout towers. In Scenario I, assuming a smoke height of 100 m, only three towers exhibited visibility above 70%. However, in Scenario II, assuming a smoke height of 0 m, no towers achieved visibility above 70%. Scenario I indicated that only two towers possessed a view of more than 70% of the forested region, while Scenario II suggested that no towers met this criterion. For the visibility of forest fires, Scenario I identified seven towers capable of observing more than 70%, whereas Scenario II indicated that no towers possessed such capability. In the tower suitability analysis, the visibility rates varied from 41.18% to 1016.67%. Based on the evaluation results, the current visibility capacities of the 49 fire towers proved insufficient for effective preventive measures.Öğe Wildfire Susceptibility Mapping Using Five Boosting Machine Learning Algorithms: The Case Study of the Mediterranean Region of Turkey(Hindawi Ltd, 2022) Abujayyab, Sohaib K. M.; Kassem, Moustafa Moufid; Khan, Ashfak Ahmad; Wazirali, Raniyah; Ozturk, Ahmet; Toprak, FerhatForest fires caused by different environmental and human factors are responsible for the extensive destruction of natural and economic resources. Modern machine learning techniques have become popular in developing very accurate and precise susceptibility maps of various natural disasters to help reduce the occurrence of such calamities. The present study has applied and tested multiple algorithms to map the areas susceptible to wildfire in the Mediterranean Region of Turkey. Besides, the performance of XGBoost, CatBoost, Gradient Boost, AdaBoost, and LightGBM methods for wildfire susceptibility mapping is also examined. The results have revealed the higher testing accuracy of CatBoost (95.47%) algorithm, followed by LightGBM (94.70%), XGBoost (88.8%), AdaBoost (86.0%), and GBM (84.48%) algorithms. Resultant wildfire susceptibility maps provide proper inventories for forest engineers, planners, and local governments for future policies regarding disaster management in Turkey.
