Development of the automotive industry not only facilitated our daily lives, but also introduced environmental stress. The automotive industry consists of both the original equipment manufacturers (OEMs), and a great variety of suppliers that support this industry. Most of the published studies focus on the environmental impacts of the OEMs; the impacts of suppliers were generally neglected. The objective of this study was to evaluate the types and amounts of solid and hazardous wastes generated by the automotive industry especially in relation to the supplier companies supporting the automotive manufacturers in Turkey. A survey was conducted with representative numbers of automotive manufacturers and suppliers located in Bursa, Turkey to obtain data on resource usage, waste types, and waste amounts generated. One hundred and five different parts of an automobile were examined in the framework of the study. Interviews were also conducted with the suppliers about the details on each item produced. Resource usage, solid and hazardous waste generation during the production of each component of an automobile were calculated. The environmental burden of the automotive industry in Turkey was roughly calculated in terms of waste generation and resource usage based on energy and water. It was seen that of the items constituting an automobile, which are provided by the suppliers, 47% is made of plastics, 31% is made of textile, and 21% is made of metals. The amounts of water and electricity used for all the items by the suppliers were found as 0.60 m3/vehicle and 190 kWh/vehicle, respectively. Water and electricity usage by OEMs were 3.47 m3/vehicle and 1763 kWh/vehicle, respectively. Solid and hazardous waste generated by OEMs were found as 48.97 kg/vehicle and 7.04 kg/vehicle, respectively, and by suppliers were 5.71 kg/vehicle and 0.6 kg/vehicle, respectively.
{"title":"Evaluation of the Solid and Hazardous Wastes Generated by the Automotive Industry in Turkey","authors":"G. Salihoglu, B. Erdogan, G. Salihoğlu","doi":"10.5383/IJTEE.16.02.003","DOIUrl":"https://doi.org/10.5383/IJTEE.16.02.003","url":null,"abstract":"Development of the automotive industry not only facilitated our daily lives, but also introduced environmental stress. The automotive industry consists of both the original equipment manufacturers (OEMs), and a great variety of suppliers that support this industry. Most of the published studies focus on the environmental impacts of the OEMs; the impacts of suppliers were generally neglected. The objective of this study was to evaluate the types and amounts of solid and hazardous wastes generated by the automotive industry especially in relation to the supplier companies supporting the automotive manufacturers in Turkey. A survey was conducted with representative numbers of automotive manufacturers and suppliers located in Bursa, Turkey to obtain data on resource usage, waste types, and waste amounts generated. One hundred and five different parts of an automobile were examined in the framework of the study. Interviews were also conducted with the suppliers about the details on each item produced. Resource usage, solid and hazardous waste generation during the production of each component of an automobile were calculated. The environmental burden of the automotive industry in Turkey was roughly calculated in terms of waste generation and resource usage based on energy and water. It was seen that of the items constituting an automobile, which are provided by the suppliers, 47% is made of plastics, 31% is made of textile, and 21% is made of metals. The amounts of water and electricity used for all the items by the suppliers were found as 0.60 m3/vehicle and 190 kWh/vehicle, respectively. Water and electricity usage by OEMs were 3.47 m3/vehicle and 1763 kWh/vehicle, respectively. Solid and hazardous waste generated by OEMs were found as 48.97 kg/vehicle and 7.04 kg/vehicle, respectively, and by suppliers were 5.71 kg/vehicle and 0.6 kg/vehicle, respectively.","PeriodicalId":429709,"journal":{"name":"International Journal of Thermal and Environmental Engineering","volume":"83 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123337067","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In Poland, the biogas obtained from municipal solid waste landfills is most frequently used in biogas systems. In combustion of biogas contaminated with siloxanes, they transform and decompose to silica and silicate deposits, which affect the proper operation of power supply devices, i.e. electric generation systems or boilers. The study aimed to determine the optimal methods for the collection of representative biogas sample for gas chromatography (GC) analysis. The main tasks included the selection of the most favourable sampling conditions for siloxane sorption in a given sorbent, i.e. sampling time, gas flow speed and sorbent volume. The study regarded the landfill gas from the Municipal Landfill located in the city of Opole in Poland. Research showed the presence of organosilicon compounds in the tested biogas but their concentration was low. That’s way the landfill gas can be successfully used for energy purposes without compromising the equipment caused by the presence of siloxanes
{"title":"Development of Measurement Techniques for Siloxanes in Landfill Gas","authors":"M. Wzorek, Mirosława Kaszubska","doi":"10.5383/IJTEE.16.02.004","DOIUrl":"https://doi.org/10.5383/IJTEE.16.02.004","url":null,"abstract":"In Poland, the biogas obtained from municipal solid waste landfills is most frequently used in biogas systems. In combustion of biogas contaminated with siloxanes, they transform and decompose to silica and silicate deposits, which affect the proper operation of power supply devices, i.e. electric generation systems or boilers. The study aimed to determine the optimal methods for the collection of representative biogas sample for gas chromatography (GC) analysis. The main tasks included the selection of the most favourable sampling conditions for siloxane sorption in a given sorbent, i.e. sampling time, gas flow speed and sorbent volume. The study regarded the landfill gas from the Municipal Landfill located in the city of Opole in Poland. Research showed the presence of organosilicon compounds in the tested biogas but their concentration was low. That’s way the landfill gas can be successfully used for energy purposes without compromising the equipment caused by the presence of siloxanes","PeriodicalId":429709,"journal":{"name":"International Journal of Thermal and Environmental Engineering","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115232727","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This study surveyed the plastic packaging waste segregation behavior of residents of Kobe, Japan, especially aged residents. It discusses the possible environmental effects on the municipal solid waste management system that could occur due to the projected increase in the number of senior citizens in the population and the consequent changes in garbage segregation behavior. Two questionnaire surveys of 1,653 people aged 20 to 99 years old residing in Kobe, Japan, were conducted. The results revealed that younger age groups have a low level of plastic waste segregation behavior despite a high level of recognition that plastic packaging waste is recyclable. We also found that the level of segregation increases among older age groups but that the level decreases among residents of 85 years and older because of diminished physical mobility. Based on the result, we discuss education about the existing rules pertaining to garbage segregation by using a quantification of the CO2 emissions avoided and not avoided by waste segregation.
{"title":"Plastic Packaging Waste Segregation Behavior of Residents and its Environmental Effect on Municipal Solid Waste Management","authors":"T. Tabata, M. Oda, P. Tsai, K. Katagiri","doi":"10.5383/IJTEE.16.02.002","DOIUrl":"https://doi.org/10.5383/IJTEE.16.02.002","url":null,"abstract":"This study surveyed the plastic packaging waste segregation behavior of residents of Kobe, Japan, especially aged residents. It discusses the possible environmental effects on the municipal solid waste management system that could occur due to the projected increase in the number of senior citizens in the population and the consequent changes in garbage segregation behavior. Two questionnaire surveys of 1,653 people aged 20 to 99 years old residing in Kobe, Japan, were conducted. The results revealed that younger age groups have a low level of plastic waste segregation behavior despite a high level of recognition that plastic packaging waste is recyclable. We also found that the level of segregation increases among older age groups but that the level decreases among residents of 85 years and older because of diminished physical mobility. Based on the result, we discuss education about the existing rules pertaining to garbage segregation by using a quantification of the CO2 emissions avoided and not avoided by waste segregation.","PeriodicalId":429709,"journal":{"name":"International Journal of Thermal and Environmental Engineering","volume":"21 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128657141","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The TiO2 production by the sulphate route uses ilmenite as raw material, which is initially milled and dissolved by adding concentrated sulphuric acid (98%). A significant fraction of the original raw material (about 10-15 %) cannot be dissolved in the digestion step. In order to recovery the titanium (rutile form) and other economic minerals during the digestion stay, was carried out a deep characterization of the used raw material in relation to several parameters, such as the elemental composition (major and trace elements), mineralogy, microscopic morphology and physical composition. Therefore, the main goal of this work has been to separate and to analyse the minerals contained in the raw material in order to isolate the potentially dangerous and economics minerals prior to the industrial process. The main conclusion the study was that the raw material is mainly composed of ilmenite and its alteration products (ilmenite unchanged, leached ilmenite, pseudorutile, leached pseudorutile and rutile), produced by weathering of the original ilmenite, and containing small amounts of other minerals (monazite, spinel, quartz and zircon). According to this, a near total isolation of each mineral is very complex, but a high percent of them can be recovery by optimizing the industrial process. In addition, the economical impurities isolated can be commercial. Likewise, this fact could be reduced the potential environmental impact of the TiO2 industries via sulphate by reducing the waste production.
{"title":"Mineral Separation and Characterization of the Ilmenite Ore Phases: Optimization of the TiO2 Pigment Process","authors":"M. Contreras, M. Gázquez, J. Bolívar","doi":"10.5383/IJTEE.16.02.006","DOIUrl":"https://doi.org/10.5383/IJTEE.16.02.006","url":null,"abstract":"The TiO2 production by the sulphate route uses ilmenite as raw material, which is initially milled and dissolved by adding concentrated sulphuric acid (98%). A significant fraction of the original raw material (about 10-15 %) cannot be dissolved in the digestion step. In order to recovery the titanium (rutile form) and other economic minerals during the digestion stay, was carried out a deep characterization of the used raw material in relation to several parameters, such as the elemental composition (major and trace elements), mineralogy, microscopic morphology and physical composition. Therefore, the main goal of this work has been to separate and to analyse the minerals contained in the raw material in order to isolate the potentially dangerous and economics minerals prior to the industrial process. The main conclusion the study was that the raw material is mainly composed of ilmenite and its alteration products (ilmenite unchanged, leached ilmenite, pseudorutile, leached pseudorutile and rutile), produced by weathering of the original ilmenite, and containing small amounts of other minerals (monazite, spinel, quartz and zircon). According to this, a near total isolation of each mineral is very complex, but a high percent of them can be recovery by optimizing the industrial process. In addition, the economical impurities isolated can be commercial. Likewise, this fact could be reduced the potential environmental impact of the TiO2 industries via sulphate by reducing the waste production.","PeriodicalId":429709,"journal":{"name":"International Journal of Thermal and Environmental Engineering","volume":"442 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115610776","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The performance of PV (photovoltaic) module is strongly dependent on its operating temperature. Most of the energy absorbed by the panel is converted to heat which is normally lost and provides no value. This work investigated experimentally the PV performance through using three separated PV panels. Three identical photovoltaic (PV) panels have been installed side by side to investigate the effect of cooling on the PV panels performance, one of them is used as a baseline ; the second is cooled using pure water; while the third is cooled using nanofluids. Aluminum Oxide (Al2O3) and Copper Oxide (CuO ) nanoparticles were added to the pure water to form the nanofluid, each one with different concentration in order to find the optimum concentration of Al2O3 and CuO. Meteorological data was measured using a weather station. Also, the temperature of the cooling fluids together with the backside temperature of the PV Panels was recorded. It was found that an increase in the efficiency of the panel of 2% was obtained when 0.4 % Al2O3 by weight was mixed with the pure water. This increase in efficiency was 2.34% when 0.6 % CuO
{"title":"Improvement of Photovoltaic Panel Efficiency using Nanofluid","authors":"","doi":"10.5383/ijtee.14.02.008","DOIUrl":"https://doi.org/10.5383/ijtee.14.02.008","url":null,"abstract":"The performance of PV (photovoltaic) module is strongly dependent on its operating temperature. Most of the energy absorbed by the panel is converted to heat which is normally lost and provides no value. This work investigated experimentally the PV performance through using three separated PV panels. Three identical photovoltaic (PV) panels have been installed side by side to investigate the effect of cooling on the PV panels performance, one of them is used as a baseline ; the second is cooled using pure water; while the third is cooled using nanofluids. Aluminum Oxide (Al2O3) and Copper Oxide (CuO ) nanoparticles were added to the pure water to form the nanofluid, each one with different concentration in order to find the optimum concentration of Al2O3 and CuO. Meteorological data was measured using a weather station. Also, the temperature of the cooling fluids together with the backside temperature of the PV Panels was recorded. It was found that an increase in the efficiency of the panel of 2% was obtained when 0.4 % Al2O3 by weight was mixed with the pure water. This increase in efficiency was 2.34% when 0.6 % CuO","PeriodicalId":429709,"journal":{"name":"International Journal of Thermal and Environmental Engineering","volume":"59 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130238183","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A shell type helical tube countercurrent flow heat exchanger was designed, fabricated and tested using CO2 refrigerant material. Helical copper tube was immersed in bulk water tank. Hot CO2 was piped to upper coil baffle and cold CO2 was circulated into collector loop through lower baffle. Cold water was made to enter through lower tap and hot water was taken out from upper tap. Both in/out pipes were inserted from the top and coil tubes from upper and lower sides of water tank. Supercritical thermosyphon operation was achieved by evacuated glass tube solar heat collector using CO2 refrigerant. U shaped copper pipes enveloped in aluminum foil were inserted in evacuated glass tubes to transfer heat under thermosiphon principle to upper header connected to inlet baffle of shell type helical coil heat exchanger. Lower header was connected to heat exchanger helical coil outlet baffle. Solar collector heat raised CO2 refrigerant temperature from 35 to 78C giving temperature difference of 43C. Temperature of CO2 refrigerant at exit from heat exchanger was found to be 40C at surrounding ambient temperature of 36C. Heat exchanger raised the inlet water temperature from 26 to 55C under off water tap condition in about 3 hours. Inlet and outlet temperature difference of heat exchanger was measured to be 27C. We believe system efficiency can further increase if we use the system in mild sunshine cold weather regions duplicating geothermal loop.
{"title":"Theory and Design of Counter Flow Shell-and-Coil Heat Exchanger for CO2Based Solar Water Heater","authors":"","doi":"10.5383/ijtee.10.02.001","DOIUrl":"https://doi.org/10.5383/ijtee.10.02.001","url":null,"abstract":"A shell type helical tube countercurrent flow heat exchanger was designed, fabricated and tested using CO2 refrigerant material. Helical copper tube was immersed in bulk water tank. Hot CO2 was piped to upper coil baffle and cold CO2 was circulated into collector loop through lower baffle. Cold water was made to enter through lower tap and hot water was taken out from upper tap. Both in/out pipes were inserted from the top and coil tubes from upper and lower sides of water tank. Supercritical thermosyphon operation was achieved by evacuated glass tube solar heat collector using CO2 refrigerant. U shaped copper pipes enveloped in aluminum foil were inserted in evacuated glass tubes to transfer heat under thermosiphon principle to upper header connected to inlet baffle of shell type helical coil heat exchanger. Lower header was connected to heat exchanger helical coil outlet baffle. Solar collector heat raised CO2 refrigerant temperature from 35 to 78C giving temperature difference of 43C. Temperature of CO2 refrigerant at exit from heat exchanger was found to be 40C at surrounding ambient temperature of 36C. Heat exchanger raised the inlet water temperature from 26 to 55C under off water tap condition in about 3 hours. Inlet and outlet temperature difference of heat exchanger was measured to be 27C. We believe system efficiency can further increase if we use the system in mild sunshine cold weather regions duplicating geothermal loop.","PeriodicalId":429709,"journal":{"name":"International Journal of Thermal and Environmental Engineering","volume":"98 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123983585","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Depletion of fossil, their associated thermal emission, and fear of global warming, have been exerting unparallel momentum to tap on natural energy resources. At the current state however some of these resources are associated with large capital, low capacity, large overall carbon footprint that we need to be aware off to make a judicial decision. A comparison study between renewable, fossil fuel and nuclear PowerSystems is presented in this work. The comparison includes the resource intensity, operational parameters and current status. The results show that the renewable power systems such as hydro power, tidal power (barrage), offshore wind power, and wave power utilize more materials during the construction than the conventional (coal, natural gas) and nuclear power systems the renewable energy systems require greater surface area reaches 50 to 150 times the conventional and nuclear power systems except geothermal power plant the renewable hydro-power system has the highest energy and CO2 intensities during the construction of the power plant solar power system has the highest capital intensity compared to all power systems as it requires more capital and energy to construct the same nominal generating capacity the system efficiency of solar power is only 10% to 18% compared to 30-50 % for conventional and nuclear power systems and the capacity factor for solar power is as low as 10% compared to 80% for conventional power system. Still, - most of the renewable power systems have low-capacity factor except the geothermal power that offers up to 95%.
{"title":"Comparison of Resource Intensities and Operational Parameters of Renewable, Fossil Fuel, and Nuclear Power Systems","authors":"C. Ghenai, I. Janajreh","doi":"10.5383/ijtee.05.02.001","DOIUrl":"https://doi.org/10.5383/ijtee.05.02.001","url":null,"abstract":"Depletion of fossil, their associated thermal emission, and fear of global warming, have been exerting unparallel momentum to tap on natural energy resources. At the current state however some of these resources are associated with large capital, low capacity, large overall carbon footprint that we need to be aware off to make a judicial decision. A comparison study between renewable, fossil fuel and nuclear PowerSystems is presented in this work. The comparison includes the resource intensity, operational parameters and current status. The results show that the renewable power systems such as hydro power, tidal power (barrage), offshore wind power, and wave power utilize more materials during the construction than the conventional (coal, natural gas) and nuclear power systems the renewable energy systems require greater surface area reaches 50 to 150 times the conventional and nuclear power systems except geothermal power plant the renewable hydro-power system has the highest energy and CO2 intensities during the construction of the power plant solar power system has the highest capital intensity compared to all power systems as it requires more capital and energy to construct the same nominal generating capacity the system efficiency of solar power is only 10% to 18% compared to 30-50 % for conventional and nuclear power systems and the capacity factor for solar power is as low as 10% compared to 80% for conventional power system. Still, - most of the renewable power systems have low-capacity factor except the geothermal power that offers up to 95%.","PeriodicalId":429709,"journal":{"name":"International Journal of Thermal and Environmental Engineering","volume":"19 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122752797","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A. Mohammad, S. Mat, M. Sulaiman, K. Sopian, Abduljalil A. Al-abidi
The present work presents an experimental investigation on the performance of a direct evaporative cooler in hot and humid regions. The experimental study is based on weather data from Kuala Lumpur, Malaysia. The direct evaporative cooler consists of a cellulose pad with a surface area per unit volume ratio of 100 m2 /m3 . The performance of the evaporative cooler is evaluated using the output temperature, saturation efficiency, and cooling capacity. The output temperature of the air varies between 27.5°C and 29.4° C, while the cooling capacity is between 1.384 kW and 5.358 kW.
{"title":"Experimental Performance of a Direct Evaporative Cooler Operating in Kuala Lumpur","authors":"A. Mohammad, S. Mat, M. Sulaiman, K. Sopian, Abduljalil A. Al-abidi","doi":"10.5383/ijtee.06.01.003","DOIUrl":"https://doi.org/10.5383/ijtee.06.01.003","url":null,"abstract":"The present work presents an experimental investigation on the performance of a direct evaporative cooler in hot and humid regions. The experimental study is based on weather data from Kuala Lumpur, Malaysia. The direct evaporative cooler consists of a cellulose pad with a surface area per unit volume ratio of 100 m2 /m3 . The performance of the evaporative cooler is evaluated using the output temperature, saturation efficiency, and cooling capacity. The output temperature of the air varies between 27.5°C and 29.4° C, while the cooling capacity is between 1.384 kW and 5.358 kW.","PeriodicalId":429709,"journal":{"name":"International Journal of Thermal and Environmental Engineering","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128229170","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
According to the World Health Organization (WHO), hearing loss (HL) is one of the six key contributors to worldwide disease rates. It is becoming a critical issue in society, not just affecting the aging population, but also negatively impacting young people who are spending more of their spare time performing activities that expose them to excessive noise levels. In this research, we intend to design a filter as a signal processing system in a hearing aid (HA). MATLAB is used to model the digital filter structure, while Simulink is used to capture the entire design. This study examines current critical concerns in hearing aid research from the perspectives of a variety of disciplines. The study proposes a filter and signal processor model based on hearing aid experience, but first, it provides an audiogram for numerous examples to determine if the suggested model would suit or not. The work thus provides an effective compensation of missed high-frequency sounds response in patient hearing by the digital signal processor.
{"title":"Modelling of Hearing Aid’s Digital Signal Processor","authors":"","doi":"10.5383/ijtee.17.02.005","DOIUrl":"https://doi.org/10.5383/ijtee.17.02.005","url":null,"abstract":"According to the World Health Organization (WHO), hearing loss (HL) is one of the six key contributors to worldwide disease rates. It is becoming a critical issue in society, not just affecting the aging population, but also negatively impacting young people who are spending more of their spare time performing activities that expose them to excessive noise levels. In this research, we intend to design a filter as a signal processing system in a hearing aid (HA). MATLAB is used to model the digital filter structure, while Simulink is used to capture the entire design. This study examines current critical concerns in hearing aid research from the perspectives of a variety of disciplines. The study proposes a filter and signal processor model based on hearing aid experience, but first, it provides an audiogram for numerous examples to determine if the suggested model would suit or not. The work thus provides an effective compensation of missed high-frequency sounds response in patient hearing by the digital signal processor.","PeriodicalId":429709,"journal":{"name":"International Journal of Thermal and Environmental Engineering","volume":"43 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121404619","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This work focuses on the rib-turbulated cooling which is a category of impingement cooling and aims at optimizing the geometry of rib-roughened cooling passage of a gas turbine blade. CFD analysis is carried out using Ansys/Fluent to solve the steady RANS equations. Computational domain consists of a long rectangular channel with the length of the channel being 9 times its height. Ratios of rib width, rib height and rib pitch to hydraulic diameter of the channel are taken as 0.1, 0.1 and 1.2, respectively. Numerical simulations are performed to analyze the performance of various rib shapes for Reynolds number, based upon the hydraulic diameter, in a range of 5000 to 50,000. Uniform heat flux of 800 W/m2 is applied to the ribbed wall. Incompressible air is used as the cooling fluid. Turbulent flow conditions are applied to the channel geometry with k-ω turbulence model. The effect of rib cross-section and rib pitch to rib width ratio on the heat transfer and friction factor is observed. The 2D CFD analysis revealed that the presence of ribs has significant effect on thermo-hydraulic performance of the cooling channel. Introducing square ribs in a smooth channel caused the Nusselt number to increase by two-folds. The highest value of Nusselt number was achieved by incorporating right-angle triangular ribs which caused the Nusselt number to increase by further 8%, as compared to the square ribs, and an increase in friction factor of 2.5%. The lowest value of friction factor was observed in semicircular ribs (2.95% less than the square ribs), however, the Nusselt number also decreased by 1.5%, as compared to square ribs. Decreasing rib pitch to rib width ratio increased both the Nusselt number and friction factor for all the cases. For square ribs, decreasing this ratio from 15 to 9 resulted in the rise of Nusselt number by 50% and increase in friction factor by 54%.
{"title":"Geometric Optimization of a Gas Turbine Blade Cooling Passage using CFD","authors":"","doi":"10.5383/ijtee.17.02.004","DOIUrl":"https://doi.org/10.5383/ijtee.17.02.004","url":null,"abstract":"This work focuses on the rib-turbulated cooling which is a category of impingement cooling and aims at optimizing the geometry of rib-roughened cooling passage of a gas turbine blade. CFD analysis is carried out using Ansys/Fluent to solve the steady RANS equations. Computational domain consists of a long rectangular channel with the length of the channel being 9 times its height. Ratios of rib width, rib height and rib pitch to hydraulic diameter of the channel are taken as 0.1, 0.1 and 1.2, respectively. Numerical simulations are performed to analyze the performance of various rib shapes for Reynolds number, based upon the hydraulic diameter, in a range of 5000 to 50,000. Uniform heat flux of 800 W/m2 is applied to the ribbed wall. Incompressible air is used as the cooling fluid. Turbulent flow conditions are applied to the channel geometry with k-ω turbulence model. The effect of rib cross-section and rib pitch to rib width ratio on the heat transfer and friction factor is observed. The 2D CFD analysis revealed that the presence of ribs has significant effect on thermo-hydraulic performance of the cooling channel. Introducing square ribs in a smooth channel caused the Nusselt number to increase by two-folds. The highest value of Nusselt number was achieved by incorporating right-angle triangular ribs which caused the Nusselt number to increase by further 8%, as compared to the square ribs, and an increase in friction factor of 2.5%. The lowest value of friction factor was observed in semicircular ribs (2.95% less than the square ribs), however, the Nusselt number also decreased by 1.5%, as compared to square ribs. Decreasing rib pitch to rib width ratio increased both the Nusselt number and friction factor for all the cases. For square ribs, decreasing this ratio from 15 to 9 resulted in the rise of Nusselt number by 50% and increase in friction factor by 54%.","PeriodicalId":429709,"journal":{"name":"International Journal of Thermal and Environmental Engineering","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126414636","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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