An investigation on airflow simulation study on urban scale for passive ventilation strategies

International Symposium on Urbanization and Environmental Problems: Transition/Transformation/Authenticity (2018 : Eskişehir, Turkey)Energy efficient building design has emerged by an active contribution of simulation and analysis tools on design stages. Especially in recent years, the concept of Building Information Modelling (BIM) has introduced a platform that incorporates the entire building lifecycle into the designers during the design phase. The program delivers an opportunity to acquire and manage the building in different design scenarios that have more efficient and more optimized solutions. The oil embargo imposed by OPEC countries in the 1970s emphasized the importance of going for energy consumption, and after these dates, the buildings were forced to be more conservative regarding both heating and cooling costs. To reduce energy consumption reduction of cooling and heating needs and to design more efficient HVAC devices has become a priority. The use of passive ventilation systems is also one of the essential inputs to energy expenditure in structure. In this respect, the obstruction of air flow is considered a critical factor as much as the design of the structure. The condition of surroundings and relations of prevailing wind in a layout of neighboring buildings are curial factors in passive ventilation design. The aim of the research presented here is that passive ventilation must initiate at the urban scale and then be introduced to building scale. Therefore, to be able to use passive ventilation in a building, it is first necessary to layout a city that respects the prevailing wind directions, and speeds then consider the calculation for a structure that can efficiently utilize the winds as natural ventilation element. As a case study, two different textured neighborhoods of Antalya that is a hot and humid city is selected for analyses on building height and the solid-void ratio of city context. The methodology of the research is first, created the mass models in the existing buildings and then, airflow simulation utilized to study the prevailing wind directions and speed derived from national meteorology database. The result of air circulation simulation maps in two neighborhoods in different urban contexts are evaluated and discussed in the paper. The study argue that running any passive design or a green design on only a building scale will underestimate the situation; it needs to be handled on the urban scale. The research aims to contribute to the work that will be done in this direction.No sponso

Evaluate and measure performance of the building design to reduce energy consumption

Recent Advances in Energy Conservatıon Techniques for Buildings Workshop: From Micro Scale to Urban Level (2017 : İstanbul, Turkey)Understanding a construction site and the impacts associated with building on it has been for a long time a primary concern of green professionals (Emarald Architecture 2008). Traditional design results in adverse effects on the environmental and therefore concerned architects are attempting to minimize the problems of the past and create a new path to follow for the future. Therefore, Green Buildings can be proposed as a solution that reduces energy consumption while maintaining occupant comfort. The technics of the Green Design collected over the years by concerned professionals to eliminate the negative impact on the environment. These technics are not always requiring high-technology solutions; even low- technology solutions can make measurable differences such as using energy simulation programs to evaluate design alternatives to provides more factual data to identify improvements and confidently suggest building design alternatives that will reduce energy consumption. In this study some basic passive design strategies are applied and represented in scenarios. The results, impact percentages of each parameter changes in each scenario were given credit rather than focusing on quantitative results. The methodology of this research consisted of numerous simulations to provide energy efficient design alternatives that properly apply to a structure.No sponso

Morbid obezitede gastrik histopatolojik bulgular ve Ghrelin ekspresyonu

Objective: The role of Ghrelin, also known as the appetite hormone, is not fully explained in the development of morbid obesity. Plasma Ghrelin level is low in obese and high in slim subjects. Ghrelin-expressing cells were investigated histopathologically in the stomach of morbid obese patients in this study. Tissue Ghrelin expression was also compared with various parameters such as the distribution of endocrine cells, age, gender, body mass index, preoperative plasma Ghrelin level and presence of accompanying diseases. Material and Method: The study included 33 morbidly obese patients, and 8 non-obese control patients. Plasma Ghrelin levels were measured preoperatively. Sleeve gastrectomy resection materials of 33 cases were evaluated with histopathological and immunohistochemical (Ghrelin and Chromogranin-A) techniques. The results were statistically evaluated by nonparametric tests. Results: Histopathological findings observed in sleeve gastrectomy resection materials were interstitial lymphocytic infiltration (63.6%), hyperplasia of lymphoid follicles in the lamina propria (60.7%) and microvesiculation / dilatation of parietal cells (57.6%). The number of Ghrelin immunopositive cells in the gastric mucosa in females was significantly higher compared to males (p=0,007). Additionally, the number of Ghrelin immunopositive cells was significantly higher at the fundus-proximal corpus compared to the distal corpus of the stomach (p=0.0001). No significant correlation was found between Ghrelin-chromogranin immunopositive endocrine cell distribution and preoperative plasma Ghrelin levels and endocrine cell hyperplasia. Conclusion: Our study confirms that Ghrelin producing cells are most dense in the proximal stomach. Increased number of Ghrelin expressing cells in the gastric mucosa in females compared to males suggests that gender may also be a factor in determining the method for treatment of morbid obesity

The renoprotective effects of mannitol and udenafil in renal ischemia-reperfusion injury model

Purpose: The aim of this study was to investigate and compare the effects of udenafil and mannitol in an experimental renal ischemia-reperfusion (I/R) injury model.Materials and Methods: A total of 64 female Wister Albino rats were used. Right nephrectomy was performed in all groups. In the control group; I/R injury was not performed. In the I/R group; left renal pedicle was clamped for 45 minutes and then underwent 60 minutes and 24 hours of reperfusion. In the mannitol group; 1 mL 20% mannitol was given intravenously 15 minutes before clamping. In the udenafil group; 10-mg/kg udenafil was given orally 1 hour before clamping. Creatinine (Cr), blood urea nitrogen (BUN), Cr clearance, malondialdehyde, neutrophil gelatinase associated lipocalin (NGAL), histological examination and DNA damage (Comet Assay method) levels were compared in tissue, serum and urine samples.Results: Udenafil had a better protective effect than mannitol according to biochemical parameters (Cr, BUN, Cr clearance, and NGAL levels) and histopathological findings when compared with the I/R group. In the Comet sampling analysis no significant difference was detected.Conclusions: Udenafil has a better renoprotective effect than mannitol against I/R injury and this effect supports more functional improvements. Further clinical trials are needed to demonstrate those effects and clinical utility of udenafil for that purpose in humans

An investigation on airflow simulation study on urban scale for passive ventilation strategies

International Symposium on Urbanization and Environmental Problems: Transition/Transformation/Authenticity (2018 : Eskişehir, Turkey)Energy efficient building design has emerged by an active contribution of simulation and analysis tools on design stages. Especially in recent years, the concept of Building Information Modelling (BIM) has introduced a platform that incorporates the entire building lifecycle into the designers during the design phase. The program delivers an opportunity to acquire and manage the building in different design scenarios that have more efficient and more optimized solutions. The oil embargo imposed by OPEC countries in the 1970s emphasized the importance of going for energy consumption, and after these dates, the buildings were forced to be more conservative regarding both heating and cooling costs. To reduce energy consumption reduction of cooling and heating needs and to design more efficient HVAC devices has become a priority. The use of passive ventilation systems is also one of the essential inputs to energy expenditure in structure. In this respect, the obstruction of air flow is considered a critical factor as much as the design of the structure. The condition of surroundings and relations of prevailing wind in a layout of neighboring buildings are curial factors in passive ventilation design. The aim of the research presented here is that passive ventilation must initiate at the urban scale and then be introduced to building scale. Therefore, to be able to use passive ventilation in a building, it is first necessary to layout a city that respects the prevailing wind directions, and speeds then consider the calculation for a structure that can efficiently utilize the winds as natural ventilation element. As a case study, two different textured neighborhoods of Antalya that is a hot and humid city is selected for analyses on building height and the solid-void ratio of city context. The methodology of the research is first, created the mass models in the existing buildings and then, airflow simulation utilized to study the prevailing wind directions and speed derived from national meteorology database. The result of air circulation simulation maps in two neighborhoods in different urban contexts are evaluated and discussed in the paper. The study argue that running any passive design or a green design on only a building scale will underestimate the situation; it needs to be handled on the urban scale. The research aims to contribute to the work that will be done in this direction.No sponso

Evaluate and measure performance of the building design to reduce energy consumption

Recent Advances in Energy Conservatıon Techniques for Buildings Workshop: From Micro Scale to Urban Level (2017 : İstanbul, Turkey)Understanding a construction site and the impacts associated with building on it has been for a long time a primary concern of green professionals (Emarald Architecture 2008). Traditional design results in adverse effects on the environmental and therefore concerned architects are attempting to minimize the problems of the past and create a new path to follow for the future. Therefore, Green Buildings can be proposed as a solution that reduces energy consumption while maintaining occupant comfort. The technics of the Green Design collected over the years by concerned professionals to eliminate the negative impact on the environment. These technics are not always requiring high-technology solutions; even low- technology solutions can make measurable differences such as using energy simulation programs to evaluate design alternatives to provides more factual data to identify improvements and confidently suggest building design alternatives that will reduce energy consumption. In this study some basic passive design strategies are applied and represented in scenarios. The results, impact percentages of each parameter changes in each scenario were given credit rather than focusing on quantitative results. The methodology of this research consisted of numerous simulations to provide energy efficient design alternatives that properly apply to a structure.No sponso

Performance analysis of a hybrid system under quality impact of returns

In this paper we analyze a hybrid system that meets the demand with remanufactured or new products. In the remanufacturing stage there are uncertainties in the quality of remanufactured products, return rates and return times of returned products. These uncertainties affect raw material order quantities, processing times and material recovery rates. In the study returned products are classified by considering quality uncertainties. According to this classification remanufacturing processing times. material recovery rates, remanufacturing costs and disposal costs are determined. In order to analyze the effect of uncertainties in return quality a simulation model is constructed by using the ARENA simulation program. Our analysis denotes that under different cost scenarios quality based classification of returned products brings significant cost savings. The numerical analysis indicates that a cost improvement of more than 8% is achieved when return rates are high. (C) 2007 Elsevier Ltd. All rights reserved

Effect of Different Doses of Vitamin E with Selenium on Renal Damage Caused by Unilateral Ureteral Obstruction Model?

Objective: Chronic kidney disease (CKD) is still common worldwide. We investigated the effect of two different doses of vitamin E with selenium (Se) administration to prevent CKD leads to renal damage via unilateral ureteral obstruction (UUO).Material and Methods: Thirty-two female Wistar Albino rats were divided into four groups; a sham group (left UUO+no medication); left UUO with no treatment, left UUO treated with 100 mg/kg dose Vitamin E+Se (RPVE+Se) and left UUO treated with 1000 mg/kg Vitamin E+Se (HDVE+Se) mixture. All rats subjected during 14 days and killed humanely. Malondialdehyde (MDA), superoxide dismutase (SOD), glutathione (GSH), levels were determined in kidney tissue, whereas total antioxidant status ( TAS), total oxidant status (TOS) and DNA damage marker 8-hydroxy-2-deoxyguanosine (8-OHdG) in serum. Histologic examination were also done.Results: The unilateral ureteral obstruction model increased MDA (p<0.05), TOS (p<0.001) and 8-OHdG levels (p<0.001) via oxidative mechanisms. In the treatment groups increased TAS, SOD (p< 0.001), and GSH (p<0.001) levels were determined, but in RPVE+Se group, TAS levels were slightly higher than the HDVE+Se group (p=0,039). In terms of histological findings, tubular necrosis (p=0.003) and lymphocyte infiltration (p=0.002) were observed renal tissue images. RPVE+Se group findings were similar to the sham group, while in HDVE group these images similar to the UUO group.Conclusions: It was observed that UUO caused oxidative stress resulting in renal damage, and controlled vitamin E application with Selenium administration, which is considered to be an effective antioxidant couple, inhibited oxidative stress