Betul Sarac - Academia.edu (original) (raw)
Papers by Betul Sarac
Journal of Thermal Analysis and Calorimetry, Dec 19, 2023
Journal of Advanced Research in Natural and Applied Sciences, Jul 9, 2023
Makale Tarihçesi Öz − Bu çalışmada, deniz suyunun kondensere giriş sıcaklığı araştırma parametres... more Makale Tarihçesi Öz − Bu çalışmada, deniz suyunun kondensere giriş sıcaklığı araştırma parametresi olarak alınan buhar sıkıştırmalı bir gemi soğutma sisteminin performansı eksergoekonomik analiz yöntemiyle belirlenerek soğutma sistem süreçlerinin ekserji maliyetleri hesaplanmıştır. Deniz suyunun kondensere giriş sıcaklıkları 20.5 o C, 24.5 o C ve 29.5 o C olarak ölçülmüş ve soğutucu akışkan olarak R22 kullanılmıştır. Buhar sıkıştırmalı soğutma sisteminin her bir elemanında oluşan ekserji tahribatlarının maliyeti eksergoekonomik analiz metodu ile hesaplanmıştır. Eksergoekonomik analiz sonuçları, kondenserdeki R22 soğutucu akışkanın yoğuşma sürecinde ekserji tahribatı maliyetinin en yüksek seviyede olduğunu göstermiştir. Çalışmanın yapıldığı gemiye ait soğutma sisteminde bulunan kondenserin ekonomiklik kriterinin kondensere giren deniz suyu sıcaklığı arttıkça iyileştiği gözlemlenmiştir. Parasal giderler açısından sistem bileşenleri değerlendirildiğinde, en yüksek maliyetli bileşenin kompresör olduğu bulunmuştur. Ekserji tahribatı maliyetleri açısından sistem bileşenleri değerlendirildiğinde, kondenser, kompresör, LT evaporatörü ve MT evaporatöründe sırasıyla 0.2552
Journal of thermal analysis and calorimetry, Apr 9, 2024
The use of renewable energy sources to maintain appropriate thermal humidity and temperature cond... more The use of renewable energy sources to maintain appropriate thermal humidity and temperature conditions in food drying technologies, especially in humid climate zones, is a current area of research. In the Eastern Black Sea Region, the high relative and specific humidity of the atmospheric air lead to a low drying rate of the products. Therefore, in this study, to enhance the drying rate of the products, three models and their psychometric cycles were studied on decreasing the specific humidity of the drying air and increasing the moisture saturation degree of the drying air. The innovative hazelnut drying models proposed for the climatic conditions of the Eastern Black Sea region incorporate several components, including thermoelectric modules (TEM), photovoltaic thermal (PV/T) systems, desiccant wheels (DW), heat pipes (HP) and heat exchangers (HX). The thermodynamic analysis was conducted on the theoretical cycles belonging proposed models. Emphasis was given to the development of Model-C, taking into account the drying conditions specific to hazelnuts in the Eastern Black Sea region, among the cycles named Model-A, Model-B and Model-C. The energy efficiencies and SEMER values of Model-A, Model-B and Model-C were presented based on selected atmospheric conditions. Each model is valid under its characteristic operating conditions, and the energy efficiencies, SEMER values and the exergetic efficiencies for Model-A, Model-B and Model-C were determined as (4.66%-0.271 kg-H 2 O kWh −1-62%), (9.87%-0.1542 kg-H 2 O kWh −1-22%) and (9.13%-0.1381 kg-H 2 O kWh −1-10%), respectively. Also, presented models of hazelnut drying supported by renewable energy have achieved high sustainable index (SI) values. Consequently, these models ensure the sustainability of energy in the drying sector and facilitate the assessment of their environmental, economic and social impacts. The utilization of renewable energy in the models will lead to a reduction in CO 2 emissions during the drying process. These results indicate that TEM systems are a viable option for food drying in the future.
This study treats the production process at the Çamlı Tea Factory as a continuous flow open syste... more This study treats the production process at the Çamlı Tea Factory as a continuous flow open system and analyses it according to the second law of thermodynamics, using the values for the years 2014-2015. Thermodynamic models of the component processes are constructed and each step is examined in terms of exergetic parameters. Tables are presented of the values of exergy input and exergy destruction for each component in the thermodynamic model. The study reports numerical values for important exergy losses in the system and identifies the zones where energy saving should be made.
Fen-mühendislik dergisi, Sep 20, 2019
This study presents the results of the thermodynamic analysis of the new desiccant-evaporativeair... more This study presents the results of the thermodynamic analysis of the new desiccant-evaporativeair-cooling cycles can be applied in ships. The desiccant-evaporative-cooling system is characterized by energy efficiency and low environmental impact. In this work, thermodynamic possibility to install desiccant cooling system (DCS) has been studied for a M/V ASSTAR Trabzon Ro-Ro cargo vessel, by using fraction of the heat rejected by existing on-board engine. The baseline system is incorporated a desiccant dehumidifier, a heat exchanger, an indirect evaporative cooler, and a direct evaporative cooler. The system offered sufficient sensible and latent cooling capacities for a wide range of climatic, while allowing in flux of outside air in excess of what is typically required for Ro-Ro cargo vessel. The present work aims at identifying the parameters of the system cycle and investigates their effect on the performance of the waste-heat driven cooling systems. And, the effect of different return air flow rates usage on the system performance is another aspect of the study. Two ways are considered for mixing process of the return and outside air streams; one is consists of two recirculation cycles, other one is a ventilation cycle, all of them have been examined and demonstrated. The maximum coefficient of thermal performance (COP) of a waste-heat driven cooling cycles were determined by assuming that the cycles are totally reversible.
Journal of Thermal Analysis and Calorimetry, 2020
The effects of the seawater-intake temperature on the performance of the refrigeration system whi... more The effects of the seawater-intake temperature on the performance of the refrigeration system which exists on a cargo vessel were introduced in this study. The performance of the real refrigeration system was analysed by using both conventional and advanced exergy analyses and exergoeconomic evaluation. First, a parametric study with different seawater-intake temperatures was carried out by applying conventional exergy and advanced exergy analyses to the refrigeration system considered to identify the pinch point components and processes with high irreversibilities. Then, advanced exergy analyses were applied to overcome technological and physical limitations to increase the knowledge about the refrigeration system. The exergetic efficiency of the refrigeration system was calculated based on varying seawater-intake temperature which enters the condenser while other operating parameters are kept constant. Seawater-intake temperatures were selected in terms of regional seawater temperatures which are assumed to be in the vessel route. As a result of the study, it was determined that the hot entry of the seawater into the condenser causes a reduction in the exergetic efficiency of the refrigeration system. The gap between real system exergetic efficiency and the unavoidable cycle exergetic efficiency increased as the pinch point temperature differences increased in the condenser by approximately 16%. Some of the exergy destruction in the refrigeration system components was unavoidable and constrained by technological and physical limitations. Based on the findings in this study, it has been shown that the greatest improvement in the exergetic efficiency of the cooling system can be achieved by improving the condenser and compressor.
Deu Muhendislik Fakultesi Fen ve Muhendislik, 2019
This study presents the results of the thermodynamic analysis of the new desiccant-evaporativeair... more This study presents the results of the thermodynamic analysis of the new desiccant-evaporativeair-cooling cycles can be applied in ships. The desiccant-evaporative-cooling system is characterized by energy efficiency and low environmental impact. In this work, thermodynamic possibility to install desiccant cooling system (DCS) has been studied for a M/V ASSTAR Trabzon Ro-Ro cargo vessel, by using fraction of the heat rejected by existing on-board engine. The baseline system is incorporated a desiccant dehumidifier, a heat exchanger, an indirect evaporative cooler, and a direct evaporative cooler. The system offered sufficient sensible and latent cooling capacities for a wide range of climatic, while allowing in flux of outside air in excess of what is typically required for Ro-Ro cargo vessel. The present work aims at identifying the parameters of the system cycle and investigates their effect on the performance of the waste-heat driven cooling systems. And, the effect of different return air flow rates usage on the system performance is another aspect of the study. Two ways are considered for mixing process of the return and outside air streams; one is consists of two recirculation cycles, other one is a ventilation cycle, all of them have been examined and demonstrated. The maximum coefficient of thermal performance (COP) of a waste-heat driven cooling cycles were determined by assuming that the cycles are totally reversible.
Atmospheric Pollution Research, 2018
Turkey has an important role in maritime transport because it is surrounded on three sides by the... more Turkey has an important role in maritime transport because it is surrounded on three sides by the sea and is strategically located between Asia and Europe. Therefore, air pollution due to ships is an important issue for Turkey. This study was carried out in Samsun, which is an important port on the Black Sea coast. Between 2010 and 2015, emissions of nitrogen oxides (NO 2), sulphur dioxide (SO 2), hydrocarbons (HC) and particulate matter less than 10 μm size (PM 10) from six different ship types were calculated for different operating modes. The estimated values for NOx, SO 2 , HC and PM 10 were 728 tons, 574 tons, 32 tons and 64 tons, respectively. The highest emission values were generated by general cargo ships. The highest percentage of total pollutants (71.6% for NOx, 65.9% for SO 2 , 54.9% for HC and 62.9% for PM 10) were generated in cruising mode by Ro-Ro (Roll-on/ Roll-off) ships. Additionally, the maneuvering emissions were from 12.6% to 42.4% and the hoteling emissions were from 6.0% to 51.1% in total for all pollutants. In Ro-Ro ships, 80% of the total emissions are generated while the main engine is operational.
Isı Bilimi ve Tekniği Dergisi, 2021
Özet: Termodinamiğin Birinci Kanunu ile yapılan hesaplamalarda her bir ünitede oluşan sıcaklık fa... more Özet: Termodinamiğin Birinci Kanunu ile yapılan hesaplamalarda her bir ünitede oluşan sıcaklık farkından ve basınç kayıpları nedeniyle oluşan tersinmezliklerin sistem performansı üzerindeki etkileri belirlenememektedir. Bu nedenle Termodinamiğin ikinci kanunu ve ileri ekserji analizi metodu kullanılarak, seçilen termal sistemde her bir ünitede oluşan ekserji tahribatının büyüklükleri ve ekserji tahribatı tipleri hesaplanmalıdır. Bu çalışmada, buhar sıkıştırmalı soğutma sistemi ile çalışan bir test ünitesinin performansı ekserji ve ileri ekserji analiz metodu ile incelenmiştir. İleri ekserji analizi sonucunda buhar sıkıştırmalı soğutma test ünitesindeki her bir bileşenin günümüz de ulaşılabilen en son teknolojiyi içeren ürünlerin kullanıldığını göstermektedir. Yapılan çalışmada evaparatörün diğer bileşenler arasında en yüksek termal performans ile çalıştığı bulunmuştur.
Nephrology Dialysis Transplantation
Background and Aims Fabry disease is a rare metabolic disorder, lifelong enzyme replacement thera... more Background and Aims Fabry disease is a rare metabolic disorder, lifelong enzyme replacement therapy with recombinant human alpha-galactosidase A (agalsidase) constituted the cornerstone of disease-specific therapy. COVID-19 pandemic and epidemic control measures including lockdowns impaired access to health care services. We examined the effect of COVID-19 pandemic and lockdown measures on mood status and management of Fabry disease patients. Method We conducted a cross-sectional study between October 2020 and December 2020. We used the Hospital Anxiety and Depression Scale (HADS) to evaluate the mood statuses of FD patients and the Morisky Medication Adherence Scale (MMAS-4) to assess patient adherence. We also examined age and sex-matched control group to compare mood status. Results A total of 68 (Male 48.5 %, mean age 37.0) FD patients were under regular follow-up in our institution, 59 of those patients were taking ERT every other week. Two of our patients had reported having a...
Deu Muhendislik Fakultesi Fen ve Muhendislik
Nem-alıcılı ve buharlaşma-soğutmalı (NABS) hava şartlandırma sistemleri ülkelerin coğrafik ve ikl... more Nem-alıcılı ve buharlaşma-soğutmalı (NABS) hava şartlandırma sistemleri ülkelerin coğrafik ve iklim şartlarına bağlı olarak değişik şekillerde yaygınca kullanıldığı görülmektedir. Bu sistemlerde nem alma işlemleri katı veya sıvı higroskopik malzemelerin üzerine işlem havasının üflenmesiyle gerçekleştirilmektedir. Soğutma işlemi ise işletme havasının doğrudan ve dolaylı buharlaşma soğutulmasıyla sağlanmaktadır. Bu çalışmada Doğu Karadeniz'de (Rize) mevcut çay endüstrilerindeki atık ısıların veya değişik şekillerdeki enerjinin bu tip soğutma sistemlerinde kullanılmasıyla yaz aylarında ortam ve yaşam mahallerinin iklimlendirmesinde kullanılmasının, termodinamik kullanılabilirliliğinin alt ve üst limitleri belirlenmiştir. Çay fabrikalarından atılan atık havanın doğrudan rejenerasyon havası olarak kullanılması dış havanın neminin konfor şartlarına getirilmesinde büyük katkı sağladığı görülmüştür.
Journal of Thermophysics and Heat Transfer, 2017
This study investigated the characteristics of convective heat transfer and fluid flow for a heat... more This study investigated the characteristics of convective heat transfer and fluid flow for a heated plate surrounded by unheated plates aligned at angles to the flow direction inside a rectangular ...
Özet –Bir ortam havasının yaz şartlarına göre soğutulmasında, hava karışım bağlantısı, evaparatör... more Özet –Bir ortam havasının yaz şartlarına göre soğutulmasında, hava karışım bağlantısı, evaparatör, ısıtıcı ve bir fandan oluşan iklimlendirme ünitesini içeren model göz önüne alınmıştır. Bu uygulamayla bilinen ekserji analizi ile birlikte ileri ekserji analizi metotlarının iklimlendirme konularındaki uygulanabilirliğinin gösterilmesi amaçlanmıştır. Tasarlanan modelde iklimlendirme ünitesini oluşturan her bir bileşende oluşan ekserji kaybı ve ekserji tahribatı hesaplanmaktadır. Bu amaçla, ele alınan model, üfleme havası, taze hava ve geri dönüş havasının %20’lik kısmıyla karışımından oluştuğu düşünülmüştür. İklimlendirme ünitesindeki ekserji tahribatı kullanılamaz-endojen, kaçınılma-eksojen, kaçınılmaz-endojen ve önlenebilir-eksojen olarak parçalara ayrılmıştır. Üfleme havasının ekserji değerleri atmosferik hava şartlarına göre belirlenmiştir
Atmospheric Pollution Research
Abstract Turkey has an important role in maritime transport because it is surrounded on three sid... more Abstract Turkey has an important role in maritime transport because it is surrounded on three sides by the sea and is strategically located between Asia and Europe. Therefore, air pollution due to ships is an important issue for Turkey. This study was carried out in Samsun, which is an important port on the Black Sea coast. Between 2010 and 2015, emissions of nitrogen oxides (NO2), sulphur dioxide (SO2), hydrocarbons (HC) and particulate matter less than 10 μm size (PM10) from six different ship types were calculated for different operating modes. The estimated values for NOx, SO2, HC and PM10 were 728 tons, 574 tons, 32 tons and 64 tons, respectively. The highest emission values were generated by general cargo ships. The highest percentage of total pollutants (71.6% for NOx, 65.9% for SO2, 54.9% for HC and 62.9% for PM10) were generated in cruising mode by Ro-Ro (Roll-on/Roll-off) ships. Additionally, the maneuvering emissions were from 12.6% to 42.4% and the hoteling emissions were from 6.0% to 51.1% in total for all pollutants. In Ro-Ro ships, 80% of the total emissions are generated while the main engine is operational.
Hittite Journal of Science & Engineering, Mar 1, 2020
T he contribution of energy in ensuring the sustainability of modern life is a primary requiremen... more T he contribution of energy in ensuring the sustainability of modern life is a primary requirement. Today, energy technologies are advancing towards the use of clean energy resources. However, it is observed that it would take long years to develop the technologies that could be adequate for global energy requirements [1]. Today, energy conversion technologies based on fossil fuels are used in power generation and to fulfill power requirements. Due to the development of energy conversion technologies based on fossil fuels, the importance of composite cycles in the reduction of exhaust emissions released to the environment per unit of generated electrical energy and the thermal efficiency of the system has increased. The combined power cycles for high efficiency and reduction of negative effects on the environment have led to the consideration of combined power cycles as ideal conventional power systems [2,3].
International Journal of Heat and Technology
The humidification chamber is a vital component of the humidification-dehumidification cycle that... more The humidification chamber is a vital component of the humidification-dehumidification cycle that plays an essential role in determining the effectiveness of this system. In this study, the combined effect of heating and humidifying processes in the plate type humidification chamber, the so-called solar air humidifier is investigated experimentally and using computational fluid dynamics (CFD) modeling. A lab-scale experimental setup was built consisting of a parabolic reflector coupled by a radiant heating coil, a glass plate and water tray with an insulation cover. Two parameters were investigated in the experimental phase of the study, namely, heat flux and inlet air flow rate. The mathematical model was validated against the experimental findings, and the results were in a close agreement. In addition to the heat flux and air flow rate, the effect of the height of the humidification channel was investigated theoretically. For the different heat fluxes, it has been found that the maximum evaporation rate is achieved at the smallest channel height and flow velocity. Also, the effectiveness of the humidification chamber depended strongly on the inlet conditions, and it decreased by increasing the input heat flux.
International Journal of Exergy
Journal of Thermal Analysis and Calorimetry, Dec 19, 2023
Journal of Advanced Research in Natural and Applied Sciences, Jul 9, 2023
Makale Tarihçesi Öz − Bu çalışmada, deniz suyunun kondensere giriş sıcaklığı araştırma parametres... more Makale Tarihçesi Öz − Bu çalışmada, deniz suyunun kondensere giriş sıcaklığı araştırma parametresi olarak alınan buhar sıkıştırmalı bir gemi soğutma sisteminin performansı eksergoekonomik analiz yöntemiyle belirlenerek soğutma sistem süreçlerinin ekserji maliyetleri hesaplanmıştır. Deniz suyunun kondensere giriş sıcaklıkları 20.5 o C, 24.5 o C ve 29.5 o C olarak ölçülmüş ve soğutucu akışkan olarak R22 kullanılmıştır. Buhar sıkıştırmalı soğutma sisteminin her bir elemanında oluşan ekserji tahribatlarının maliyeti eksergoekonomik analiz metodu ile hesaplanmıştır. Eksergoekonomik analiz sonuçları, kondenserdeki R22 soğutucu akışkanın yoğuşma sürecinde ekserji tahribatı maliyetinin en yüksek seviyede olduğunu göstermiştir. Çalışmanın yapıldığı gemiye ait soğutma sisteminde bulunan kondenserin ekonomiklik kriterinin kondensere giren deniz suyu sıcaklığı arttıkça iyileştiği gözlemlenmiştir. Parasal giderler açısından sistem bileşenleri değerlendirildiğinde, en yüksek maliyetli bileşenin kompresör olduğu bulunmuştur. Ekserji tahribatı maliyetleri açısından sistem bileşenleri değerlendirildiğinde, kondenser, kompresör, LT evaporatörü ve MT evaporatöründe sırasıyla 0.2552
Journal of thermal analysis and calorimetry, Apr 9, 2024
The use of renewable energy sources to maintain appropriate thermal humidity and temperature cond... more The use of renewable energy sources to maintain appropriate thermal humidity and temperature conditions in food drying technologies, especially in humid climate zones, is a current area of research. In the Eastern Black Sea Region, the high relative and specific humidity of the atmospheric air lead to a low drying rate of the products. Therefore, in this study, to enhance the drying rate of the products, three models and their psychometric cycles were studied on decreasing the specific humidity of the drying air and increasing the moisture saturation degree of the drying air. The innovative hazelnut drying models proposed for the climatic conditions of the Eastern Black Sea region incorporate several components, including thermoelectric modules (TEM), photovoltaic thermal (PV/T) systems, desiccant wheels (DW), heat pipes (HP) and heat exchangers (HX). The thermodynamic analysis was conducted on the theoretical cycles belonging proposed models. Emphasis was given to the development of Model-C, taking into account the drying conditions specific to hazelnuts in the Eastern Black Sea region, among the cycles named Model-A, Model-B and Model-C. The energy efficiencies and SEMER values of Model-A, Model-B and Model-C were presented based on selected atmospheric conditions. Each model is valid under its characteristic operating conditions, and the energy efficiencies, SEMER values and the exergetic efficiencies for Model-A, Model-B and Model-C were determined as (4.66%-0.271 kg-H 2 O kWh −1-62%), (9.87%-0.1542 kg-H 2 O kWh −1-22%) and (9.13%-0.1381 kg-H 2 O kWh −1-10%), respectively. Also, presented models of hazelnut drying supported by renewable energy have achieved high sustainable index (SI) values. Consequently, these models ensure the sustainability of energy in the drying sector and facilitate the assessment of their environmental, economic and social impacts. The utilization of renewable energy in the models will lead to a reduction in CO 2 emissions during the drying process. These results indicate that TEM systems are a viable option for food drying in the future.
This study treats the production process at the Çamlı Tea Factory as a continuous flow open syste... more This study treats the production process at the Çamlı Tea Factory as a continuous flow open system and analyses it according to the second law of thermodynamics, using the values for the years 2014-2015. Thermodynamic models of the component processes are constructed and each step is examined in terms of exergetic parameters. Tables are presented of the values of exergy input and exergy destruction for each component in the thermodynamic model. The study reports numerical values for important exergy losses in the system and identifies the zones where energy saving should be made.
Fen-mühendislik dergisi, Sep 20, 2019
This study presents the results of the thermodynamic analysis of the new desiccant-evaporativeair... more This study presents the results of the thermodynamic analysis of the new desiccant-evaporativeair-cooling cycles can be applied in ships. The desiccant-evaporative-cooling system is characterized by energy efficiency and low environmental impact. In this work, thermodynamic possibility to install desiccant cooling system (DCS) has been studied for a M/V ASSTAR Trabzon Ro-Ro cargo vessel, by using fraction of the heat rejected by existing on-board engine. The baseline system is incorporated a desiccant dehumidifier, a heat exchanger, an indirect evaporative cooler, and a direct evaporative cooler. The system offered sufficient sensible and latent cooling capacities for a wide range of climatic, while allowing in flux of outside air in excess of what is typically required for Ro-Ro cargo vessel. The present work aims at identifying the parameters of the system cycle and investigates their effect on the performance of the waste-heat driven cooling systems. And, the effect of different return air flow rates usage on the system performance is another aspect of the study. Two ways are considered for mixing process of the return and outside air streams; one is consists of two recirculation cycles, other one is a ventilation cycle, all of them have been examined and demonstrated. The maximum coefficient of thermal performance (COP) of a waste-heat driven cooling cycles were determined by assuming that the cycles are totally reversible.
Journal of Thermal Analysis and Calorimetry, 2020
The effects of the seawater-intake temperature on the performance of the refrigeration system whi... more The effects of the seawater-intake temperature on the performance of the refrigeration system which exists on a cargo vessel were introduced in this study. The performance of the real refrigeration system was analysed by using both conventional and advanced exergy analyses and exergoeconomic evaluation. First, a parametric study with different seawater-intake temperatures was carried out by applying conventional exergy and advanced exergy analyses to the refrigeration system considered to identify the pinch point components and processes with high irreversibilities. Then, advanced exergy analyses were applied to overcome technological and physical limitations to increase the knowledge about the refrigeration system. The exergetic efficiency of the refrigeration system was calculated based on varying seawater-intake temperature which enters the condenser while other operating parameters are kept constant. Seawater-intake temperatures were selected in terms of regional seawater temperatures which are assumed to be in the vessel route. As a result of the study, it was determined that the hot entry of the seawater into the condenser causes a reduction in the exergetic efficiency of the refrigeration system. The gap between real system exergetic efficiency and the unavoidable cycle exergetic efficiency increased as the pinch point temperature differences increased in the condenser by approximately 16%. Some of the exergy destruction in the refrigeration system components was unavoidable and constrained by technological and physical limitations. Based on the findings in this study, it has been shown that the greatest improvement in the exergetic efficiency of the cooling system can be achieved by improving the condenser and compressor.
Deu Muhendislik Fakultesi Fen ve Muhendislik, 2019
This study presents the results of the thermodynamic analysis of the new desiccant-evaporativeair... more This study presents the results of the thermodynamic analysis of the new desiccant-evaporativeair-cooling cycles can be applied in ships. The desiccant-evaporative-cooling system is characterized by energy efficiency and low environmental impact. In this work, thermodynamic possibility to install desiccant cooling system (DCS) has been studied for a M/V ASSTAR Trabzon Ro-Ro cargo vessel, by using fraction of the heat rejected by existing on-board engine. The baseline system is incorporated a desiccant dehumidifier, a heat exchanger, an indirect evaporative cooler, and a direct evaporative cooler. The system offered sufficient sensible and latent cooling capacities for a wide range of climatic, while allowing in flux of outside air in excess of what is typically required for Ro-Ro cargo vessel. The present work aims at identifying the parameters of the system cycle and investigates their effect on the performance of the waste-heat driven cooling systems. And, the effect of different return air flow rates usage on the system performance is another aspect of the study. Two ways are considered for mixing process of the return and outside air streams; one is consists of two recirculation cycles, other one is a ventilation cycle, all of them have been examined and demonstrated. The maximum coefficient of thermal performance (COP) of a waste-heat driven cooling cycles were determined by assuming that the cycles are totally reversible.
Atmospheric Pollution Research, 2018
Turkey has an important role in maritime transport because it is surrounded on three sides by the... more Turkey has an important role in maritime transport because it is surrounded on three sides by the sea and is strategically located between Asia and Europe. Therefore, air pollution due to ships is an important issue for Turkey. This study was carried out in Samsun, which is an important port on the Black Sea coast. Between 2010 and 2015, emissions of nitrogen oxides (NO 2), sulphur dioxide (SO 2), hydrocarbons (HC) and particulate matter less than 10 μm size (PM 10) from six different ship types were calculated for different operating modes. The estimated values for NOx, SO 2 , HC and PM 10 were 728 tons, 574 tons, 32 tons and 64 tons, respectively. The highest emission values were generated by general cargo ships. The highest percentage of total pollutants (71.6% for NOx, 65.9% for SO 2 , 54.9% for HC and 62.9% for PM 10) were generated in cruising mode by Ro-Ro (Roll-on/ Roll-off) ships. Additionally, the maneuvering emissions were from 12.6% to 42.4% and the hoteling emissions were from 6.0% to 51.1% in total for all pollutants. In Ro-Ro ships, 80% of the total emissions are generated while the main engine is operational.
Isı Bilimi ve Tekniği Dergisi, 2021
Özet: Termodinamiğin Birinci Kanunu ile yapılan hesaplamalarda her bir ünitede oluşan sıcaklık fa... more Özet: Termodinamiğin Birinci Kanunu ile yapılan hesaplamalarda her bir ünitede oluşan sıcaklık farkından ve basınç kayıpları nedeniyle oluşan tersinmezliklerin sistem performansı üzerindeki etkileri belirlenememektedir. Bu nedenle Termodinamiğin ikinci kanunu ve ileri ekserji analizi metodu kullanılarak, seçilen termal sistemde her bir ünitede oluşan ekserji tahribatının büyüklükleri ve ekserji tahribatı tipleri hesaplanmalıdır. Bu çalışmada, buhar sıkıştırmalı soğutma sistemi ile çalışan bir test ünitesinin performansı ekserji ve ileri ekserji analiz metodu ile incelenmiştir. İleri ekserji analizi sonucunda buhar sıkıştırmalı soğutma test ünitesindeki her bir bileşenin günümüz de ulaşılabilen en son teknolojiyi içeren ürünlerin kullanıldığını göstermektedir. Yapılan çalışmada evaparatörün diğer bileşenler arasında en yüksek termal performans ile çalıştığı bulunmuştur.
Nephrology Dialysis Transplantation
Background and Aims Fabry disease is a rare metabolic disorder, lifelong enzyme replacement thera... more Background and Aims Fabry disease is a rare metabolic disorder, lifelong enzyme replacement therapy with recombinant human alpha-galactosidase A (agalsidase) constituted the cornerstone of disease-specific therapy. COVID-19 pandemic and epidemic control measures including lockdowns impaired access to health care services. We examined the effect of COVID-19 pandemic and lockdown measures on mood status and management of Fabry disease patients. Method We conducted a cross-sectional study between October 2020 and December 2020. We used the Hospital Anxiety and Depression Scale (HADS) to evaluate the mood statuses of FD patients and the Morisky Medication Adherence Scale (MMAS-4) to assess patient adherence. We also examined age and sex-matched control group to compare mood status. Results A total of 68 (Male 48.5 %, mean age 37.0) FD patients were under regular follow-up in our institution, 59 of those patients were taking ERT every other week. Two of our patients had reported having a...
Deu Muhendislik Fakultesi Fen ve Muhendislik
Nem-alıcılı ve buharlaşma-soğutmalı (NABS) hava şartlandırma sistemleri ülkelerin coğrafik ve ikl... more Nem-alıcılı ve buharlaşma-soğutmalı (NABS) hava şartlandırma sistemleri ülkelerin coğrafik ve iklim şartlarına bağlı olarak değişik şekillerde yaygınca kullanıldığı görülmektedir. Bu sistemlerde nem alma işlemleri katı veya sıvı higroskopik malzemelerin üzerine işlem havasının üflenmesiyle gerçekleştirilmektedir. Soğutma işlemi ise işletme havasının doğrudan ve dolaylı buharlaşma soğutulmasıyla sağlanmaktadır. Bu çalışmada Doğu Karadeniz'de (Rize) mevcut çay endüstrilerindeki atık ısıların veya değişik şekillerdeki enerjinin bu tip soğutma sistemlerinde kullanılmasıyla yaz aylarında ortam ve yaşam mahallerinin iklimlendirmesinde kullanılmasının, termodinamik kullanılabilirliliğinin alt ve üst limitleri belirlenmiştir. Çay fabrikalarından atılan atık havanın doğrudan rejenerasyon havası olarak kullanılması dış havanın neminin konfor şartlarına getirilmesinde büyük katkı sağladığı görülmüştür.
Journal of Thermophysics and Heat Transfer, 2017
This study investigated the characteristics of convective heat transfer and fluid flow for a heat... more This study investigated the characteristics of convective heat transfer and fluid flow for a heated plate surrounded by unheated plates aligned at angles to the flow direction inside a rectangular ...
Özet –Bir ortam havasının yaz şartlarına göre soğutulmasında, hava karışım bağlantısı, evaparatör... more Özet –Bir ortam havasının yaz şartlarına göre soğutulmasında, hava karışım bağlantısı, evaparatör, ısıtıcı ve bir fandan oluşan iklimlendirme ünitesini içeren model göz önüne alınmıştır. Bu uygulamayla bilinen ekserji analizi ile birlikte ileri ekserji analizi metotlarının iklimlendirme konularındaki uygulanabilirliğinin gösterilmesi amaçlanmıştır. Tasarlanan modelde iklimlendirme ünitesini oluşturan her bir bileşende oluşan ekserji kaybı ve ekserji tahribatı hesaplanmaktadır. Bu amaçla, ele alınan model, üfleme havası, taze hava ve geri dönüş havasının %20’lik kısmıyla karışımından oluştuğu düşünülmüştür. İklimlendirme ünitesindeki ekserji tahribatı kullanılamaz-endojen, kaçınılma-eksojen, kaçınılmaz-endojen ve önlenebilir-eksojen olarak parçalara ayrılmıştır. Üfleme havasının ekserji değerleri atmosferik hava şartlarına göre belirlenmiştir
Atmospheric Pollution Research
Abstract Turkey has an important role in maritime transport because it is surrounded on three sid... more Abstract Turkey has an important role in maritime transport because it is surrounded on three sides by the sea and is strategically located between Asia and Europe. Therefore, air pollution due to ships is an important issue for Turkey. This study was carried out in Samsun, which is an important port on the Black Sea coast. Between 2010 and 2015, emissions of nitrogen oxides (NO2), sulphur dioxide (SO2), hydrocarbons (HC) and particulate matter less than 10 μm size (PM10) from six different ship types were calculated for different operating modes. The estimated values for NOx, SO2, HC and PM10 were 728 tons, 574 tons, 32 tons and 64 tons, respectively. The highest emission values were generated by general cargo ships. The highest percentage of total pollutants (71.6% for NOx, 65.9% for SO2, 54.9% for HC and 62.9% for PM10) were generated in cruising mode by Ro-Ro (Roll-on/Roll-off) ships. Additionally, the maneuvering emissions were from 12.6% to 42.4% and the hoteling emissions were from 6.0% to 51.1% in total for all pollutants. In Ro-Ro ships, 80% of the total emissions are generated while the main engine is operational.
Hittite Journal of Science & Engineering, Mar 1, 2020
T he contribution of energy in ensuring the sustainability of modern life is a primary requiremen... more T he contribution of energy in ensuring the sustainability of modern life is a primary requirement. Today, energy technologies are advancing towards the use of clean energy resources. However, it is observed that it would take long years to develop the technologies that could be adequate for global energy requirements [1]. Today, energy conversion technologies based on fossil fuels are used in power generation and to fulfill power requirements. Due to the development of energy conversion technologies based on fossil fuels, the importance of composite cycles in the reduction of exhaust emissions released to the environment per unit of generated electrical energy and the thermal efficiency of the system has increased. The combined power cycles for high efficiency and reduction of negative effects on the environment have led to the consideration of combined power cycles as ideal conventional power systems [2,3].
International Journal of Heat and Technology
The humidification chamber is a vital component of the humidification-dehumidification cycle that... more The humidification chamber is a vital component of the humidification-dehumidification cycle that plays an essential role in determining the effectiveness of this system. In this study, the combined effect of heating and humidifying processes in the plate type humidification chamber, the so-called solar air humidifier is investigated experimentally and using computational fluid dynamics (CFD) modeling. A lab-scale experimental setup was built consisting of a parabolic reflector coupled by a radiant heating coil, a glass plate and water tray with an insulation cover. Two parameters were investigated in the experimental phase of the study, namely, heat flux and inlet air flow rate. The mathematical model was validated against the experimental findings, and the results were in a close agreement. In addition to the heat flux and air flow rate, the effect of the height of the humidification channel was investigated theoretically. For the different heat fluxes, it has been found that the maximum evaporation rate is achieved at the smallest channel height and flow velocity. Also, the effectiveness of the humidification chamber depended strongly on the inlet conditions, and it decreased by increasing the input heat flux.
International Journal of Exergy