Purpose: To test the effectiveness of sitting surfaces with varied amounts of stability on muscle activity and energy expenditure.Methods: Using a within-participants repeated measures design, 11 healthy young-adult f...Purpose: To test the effectiveness of sitting surfaces with varied amounts of stability on muscle activity and energy expenditure.Methods: Using a within-participants repeated measures design, 11 healthy young-adult females(age = 20.0 ± 1.8 years) were measured using indirect calorimetry to assess energy expenditure, and electromyography to assess muscular activation in trunk and leg musculature under 3different sitting surfaces: flat-firm surface, air-filled cushion, and a stability ball. Data were analyzed using repeated measures analysis of variance with follow-up pairwise contrasts used to determine the specific effects of sitting surface on muscle activation and energy expenditure.Results: Significantly greater energy expenditure was recorded for the stability ball(p = 0.01) and the cushion(p = 0.03) over the flat surface(10.4% and 9.6% greater, respectively), with no differences between the ball and the cushion. Both the ball and the cushion produced higher tibialis anterior activation over the flat surface(1.09 and 0.63 root-mean-square millivolts(RMSmv), respectively), while the stability ball produced higher soleus activity over both cushion and flat surfaces(3.97 and 4.24 RMSmv, respectively). Additionally, the cushion elicited higher adductor longus activity over the ball and flat surfaces(1.76 and 1.81 RMSmv, respectively), but no trunk musculature differences were revealed.Conclusion: Compliant surfaces resulted in higher levels of muscular activation in the lower extremities facilitating increased caloric expenditure.Given the increasing trends in sedentary careers and the increases in obesity, this is an important finding to validate the merits of active sitting facilitating increased caloric expenditure and muscle activation.展开更多
The dissipation rate of turbulent kinetic energy ( ε ) is the key process parameters for mixing in surface aerators. At constant dynamic variables (rotational speed), ε is greatly affected by the geometric param...The dissipation rate of turbulent kinetic energy ( ε ) is the key process parameters for mixing in surface aerators. At constant dynamic variables (rotational speed), ε is greatly affected by the geometric parameters, such as impeller diameter, cross-sectional area of the tank, liquid height, rotor blade length and immersion height. By doing numerical computation by visimix, present work analyzes the effect of non-dimensional (which is non-dimensionalized through rotor diameter) geometric parameters on ε. With an increase in liquid height, there is an increase in the case of energy dissipation. In the case of tank area and blade length, it is vice versa. Energy dissipation is not affected by the variation in immersion height of the impeller.展开更多
The free-surface Green function method is widely used in solving the radiation or diffraction problems caused by a ship or ocean structure oscillating on the waves. In the context of inviscid potential flow, hydrodyna...The free-surface Green function method is widely used in solving the radiation or diffraction problems caused by a ship or ocean structure oscillating on the waves. In the context of inviscid potential flow, hydrodynamic problems such as multi-body interaction and tank side wall effect cannot be properly dealt with based on the traditional free-surface frequency domain Green function method, in which the water viscosity is omitted and the energy dissipation effect is absent. In this paper, an open-sea Green function with viscous dissipation was presented within the theory ofvisco-potential flow. Then the tank Green function with a partial reflection from the side walls in wave tanks was formulated as a formal sum of open-sea Green functions representing the infinite images between two parallel side walls of the source in the tank. The new far-field characteristics of the tank Green function is vitally important fur improving the validity of side-wall effects evaluation, which can be used in supervising the tank model tests.展开更多
This research was conducted to study the performances of the heat and multilayer reflection insulators used for buildings in South Korea to realize eco-friendly, low-energy-consumption, green construction, and to cont...This research was conducted to study the performances of the heat and multilayer reflection insulators used for buildings in South Korea to realize eco-friendly, low-energy-consumption, green construction, and to contribute to energy consumption reduction in buildings and to the nation's greenhouse gas emission reduction policy (targeting 30% reduction compared to BAUCousiness as usual) by 2020). The heat insulation performance test is about the temperatures on surfaces of test piece. The high air temperature and the low air temperature were measured to determine the overall heat transfer coefficient and thermal conductivity. The conclusions are drawn that the heat transmission coefficients for each type of existing reflection insulator are: A-1 (0.045 W/(m-K)), A-2 (0.031 W/(m.K)), A-3 (0.042 W/(m.K)), A-4 (0.078 W/(m.K)), and the average heat conductivity is 0.049 W/(m-K); The heat conductivity for each type of Styrofoam insulator are 0.030 W/(m.K) for B-l, 0.032 W/(m-K) for B-2, 0.037 W/(m'K) for B-3, 0.037 W/(m.K) for B-4, and the average heat conductivity is 0.035 W/(m'K) regardless of the thickness of the insulator; The heat conductivity values of the multilayer reflection insulators are converted based on the thickness and type C-1 (0.020 W/(m.K)), C-2 (0.018 W/(m.K)), C-3 (0.016 W/(m.K)), and C-4 (0.012 W/(m.K)); The multilayer reflection insulator keeps the indoor-side surface temperature high (during winter) or low (in summer), enhances the comfort of the building occupants, and conducts heating and moisture resistance to prevent dew condensation on the glass-outer-wall surface.展开更多
The present explanatory study was carried out to investigate the relation between diabetes mellitus and food balance in the Kingdom of Saudi Arabia during 2005-2010, using published data. This study was conducted to i...The present explanatory study was carried out to investigate the relation between diabetes mellitus and food balance in the Kingdom of Saudi Arabia during 2005-2010, using published data. This study was conducted to investigate the relationship between food balance and diabetes mellitus, using published data on food balances in the Kingdom of Saudi Arabia during 2005-2007, published by the Ministry of Agriculture in 2012 and Medical Technical papers and Scientific Reports published on Diabetes Mellitus in Saudi Arabia in an explanatory study. Food balance was calculated per capita and then its level of change was compared with changing of diabetes mellitus in the country. Results illustrated that Saudi citizen daily protein consumption (DPC) during 2005-2007 (g/capita/day) is higher than the average global consumption level of protein with 15.27%, daily fat consumption (DFC) with 24.56% and daily energy consumption (DEC) with 16.93% and increases than recommended level by International Nutrition Organizations (INO) with 56% for protein, 60.49% for fat and 27.37% for energy. On the other hand, DPC per capita in Saudi Arabia decreased during the period 2008-2010 from 88.3 g/day to 82.36 g/day. Moreover, DFC per capita in Saudi Arabia decreased during the period 2008-2010 from 3,247.90 Cal/capita/day to 3,176.43 Cal/capita/day, and daily energy consumption (DEC) of Saudi citizen increases than world consumption with 16.93%, while increases with 27.37% than INO. Despite this, DPC, DFC and DEC per capita in Saudi Arabia were still higher than world mean. On the other side, results illustrated that the number of diabetic patients in Saudi Arabia during the same period (2005-2010). The curve of diabetic patient's number in Saudi Arabia during 2005-2010 is regular ascending with increasing level ranged between 7.10% in 2005 and 12.44% in 2010. It is essential to devise Saudi National Programme to educate the public about the relation of food balances and diabetes, so it could be avoided, and provide citizens with healthy dietary balances tables.展开更多
This paper presents the investigation of energy and cost saving of microgeneration systems which consist of conventional, load sharing, renewable energy and hybrid-renewable energy systems application featuring single...This paper presents the investigation of energy and cost saving of microgeneration systems which consist of conventional, load sharing, renewable energy and hybrid-renewable energy systems application featuring single detached house and office buildings by implementing spreadsheet modeling. Microsoft excel is employed as the spreadsheet application in this study. The system performance of each case is calculated under typical weather of ottawa, canada. These cases are calculated and analyzed in terms of thermal/cooling load (building demand) and natural gas/electricity consumption (energy supply) as well as the financial part by involving several parameters which are initial cost, annual energy consumption cost, annual operational and maintenance cost, inflation rate, and return on investment. Moreover, a house and an office have the same geometry of 200 mE. Total of seven cases modeling are developed; Case-1- a house with boiler and chiller, Case-2- an office with boiler and chiller, Case-3-a simple sum of Case l and Case 2, Case-4- a load-sharing model, Case-5- a load-sharing with GSHP (ground source heat pump), Case-6- a load-sharing with ground source heat pump-fuel cell hybrid system (FC-GSHP)and Case-7- a load-sharing with GSHP--photovoltaic hybrid system (PVT-GSHP). As the results, it will be observed the efficiency of the load-sharing, renewable energy, hybrid-renewable energy implementation comparing to the conventional system.展开更多
Rolling resistance of tires is one of the most important factors influencing energy consumption of road vehicles, especially on rural roads. For practical reasons, most of rolling resistance measurements are usually p...Rolling resistance of tires is one of the most important factors influencing energy consumption of road vehicles, especially on rural roads. For practical reasons, most of rolling resistance measurements are usually performed for dry road conditions. Based on the fact that roads are wet during a considerable time over the year and as part of the projects MIR/AM, ROLRES and ROSANNE, the TUG (Technical University of Gdafisk) in Poland and VTI (Swedish National Road and Transport Research Institute) in Sweden carried out trailer rolling resistance measurements on wet road surfaces to investigate water film influence on rolling resistance on different pavements. A specially-designed trailer to measure rolling resistance has been used. The test sections were both rural roads and an abandoned airfield equipped with water film sensors mounted in the pavement. Results indicate strong influence of test speed and water film depth, as well as influence of surface texture. The increase of rolling resistance on wet surfaces is caused by both hydrodynamic phenomena and cooling effect of water that decreases tire temperature thus increasing rolling resistance.展开更多
The objective of this research is to quantify the EEC (embodied energy/CO2) of a building. The EEC represents the energy consumption and CO2 emissions at individual phases of a building's life-cycle, such as constr...The objective of this research is to quantify the EEC (embodied energy/CO2) of a building. The EEC represents the energy consumption and CO2 emissions at individual phases of a building's life-cycle, such as construction (including manufacture of materials and equipment), renewal (including repair work) and demolition. Energy and CO2 emission intensities in terms of 401 sectors were calculated, using the 2005 I-O (input-output) table in Japan. According to our case study conducted from the construction phase to demolition, the EC (embodied CO2) of an office building used for 60 years is 12,044 t-CO2 and 1,093 kg-CO2/m^2 in total. CO2 equivalent emissions (CO2e) by Freon gases, contained in building materials, equipment and devices, were also calculated. As the results, CO2e by insulators was 2% of the building's EC and CO2e by refrigerants was 9%-12% of the building's EC. It is important to keep reducing emissions of Freon gases contained in refrigerators.展开更多
文摘Purpose: To test the effectiveness of sitting surfaces with varied amounts of stability on muscle activity and energy expenditure.Methods: Using a within-participants repeated measures design, 11 healthy young-adult females(age = 20.0 ± 1.8 years) were measured using indirect calorimetry to assess energy expenditure, and electromyography to assess muscular activation in trunk and leg musculature under 3different sitting surfaces: flat-firm surface, air-filled cushion, and a stability ball. Data were analyzed using repeated measures analysis of variance with follow-up pairwise contrasts used to determine the specific effects of sitting surface on muscle activation and energy expenditure.Results: Significantly greater energy expenditure was recorded for the stability ball(p = 0.01) and the cushion(p = 0.03) over the flat surface(10.4% and 9.6% greater, respectively), with no differences between the ball and the cushion. Both the ball and the cushion produced higher tibialis anterior activation over the flat surface(1.09 and 0.63 root-mean-square millivolts(RMSmv), respectively), while the stability ball produced higher soleus activity over both cushion and flat surfaces(3.97 and 4.24 RMSmv, respectively). Additionally, the cushion elicited higher adductor longus activity over the ball and flat surfaces(1.76 and 1.81 RMSmv, respectively), but no trunk musculature differences were revealed.Conclusion: Compliant surfaces resulted in higher levels of muscular activation in the lower extremities facilitating increased caloric expenditure.Given the increasing trends in sedentary careers and the increases in obesity, this is an important finding to validate the merits of active sitting facilitating increased caloric expenditure and muscle activation.
文摘The dissipation rate of turbulent kinetic energy ( ε ) is the key process parameters for mixing in surface aerators. At constant dynamic variables (rotational speed), ε is greatly affected by the geometric parameters, such as impeller diameter, cross-sectional area of the tank, liquid height, rotor blade length and immersion height. By doing numerical computation by visimix, present work analyzes the effect of non-dimensional (which is non-dimensionalized through rotor diameter) geometric parameters on ε. With an increase in liquid height, there is an increase in the case of energy dissipation. In the case of tank area and blade length, it is vice versa. Energy dissipation is not affected by the variation in immersion height of the impeller.
基金Supported by NSFC Project(51009037)"111"Program(B07019)
文摘The free-surface Green function method is widely used in solving the radiation or diffraction problems caused by a ship or ocean structure oscillating on the waves. In the context of inviscid potential flow, hydrodynamic problems such as multi-body interaction and tank side wall effect cannot be properly dealt with based on the traditional free-surface frequency domain Green function method, in which the water viscosity is omitted and the energy dissipation effect is absent. In this paper, an open-sea Green function with viscous dissipation was presented within the theory ofvisco-potential flow. Then the tank Green function with a partial reflection from the side walls in wave tanks was formulated as a formal sum of open-sea Green functions representing the infinite images between two parallel side walls of the source in the tank. The new far-field characteristics of the tank Green function is vitally important fur improving the validity of side-wall effects evaluation, which can be used in supervising the tank model tests.
基金Project(NRF-2010-0024155) supported by the National Research Foundation of Korea
文摘This research was conducted to study the performances of the heat and multilayer reflection insulators used for buildings in South Korea to realize eco-friendly, low-energy-consumption, green construction, and to contribute to energy consumption reduction in buildings and to the nation's greenhouse gas emission reduction policy (targeting 30% reduction compared to BAUCousiness as usual) by 2020). The heat insulation performance test is about the temperatures on surfaces of test piece. The high air temperature and the low air temperature were measured to determine the overall heat transfer coefficient and thermal conductivity. The conclusions are drawn that the heat transmission coefficients for each type of existing reflection insulator are: A-1 (0.045 W/(m-K)), A-2 (0.031 W/(m.K)), A-3 (0.042 W/(m.K)), A-4 (0.078 W/(m.K)), and the average heat conductivity is 0.049 W/(m-K); The heat conductivity for each type of Styrofoam insulator are 0.030 W/(m.K) for B-l, 0.032 W/(m-K) for B-2, 0.037 W/(m'K) for B-3, 0.037 W/(m.K) for B-4, and the average heat conductivity is 0.035 W/(m'K) regardless of the thickness of the insulator; The heat conductivity values of the multilayer reflection insulators are converted based on the thickness and type C-1 (0.020 W/(m.K)), C-2 (0.018 W/(m.K)), C-3 (0.016 W/(m.K)), and C-4 (0.012 W/(m.K)); The multilayer reflection insulator keeps the indoor-side surface temperature high (during winter) or low (in summer), enhances the comfort of the building occupants, and conducts heating and moisture resistance to prevent dew condensation on the glass-outer-wall surface.
文摘The present explanatory study was carried out to investigate the relation between diabetes mellitus and food balance in the Kingdom of Saudi Arabia during 2005-2010, using published data. This study was conducted to investigate the relationship between food balance and diabetes mellitus, using published data on food balances in the Kingdom of Saudi Arabia during 2005-2007, published by the Ministry of Agriculture in 2012 and Medical Technical papers and Scientific Reports published on Diabetes Mellitus in Saudi Arabia in an explanatory study. Food balance was calculated per capita and then its level of change was compared with changing of diabetes mellitus in the country. Results illustrated that Saudi citizen daily protein consumption (DPC) during 2005-2007 (g/capita/day) is higher than the average global consumption level of protein with 15.27%, daily fat consumption (DFC) with 24.56% and daily energy consumption (DEC) with 16.93% and increases than recommended level by International Nutrition Organizations (INO) with 56% for protein, 60.49% for fat and 27.37% for energy. On the other hand, DPC per capita in Saudi Arabia decreased during the period 2008-2010 from 88.3 g/day to 82.36 g/day. Moreover, DFC per capita in Saudi Arabia decreased during the period 2008-2010 from 3,247.90 Cal/capita/day to 3,176.43 Cal/capita/day, and daily energy consumption (DEC) of Saudi citizen increases than world consumption with 16.93%, while increases with 27.37% than INO. Despite this, DPC, DFC and DEC per capita in Saudi Arabia were still higher than world mean. On the other side, results illustrated that the number of diabetic patients in Saudi Arabia during the same period (2005-2010). The curve of diabetic patient's number in Saudi Arabia during 2005-2010 is regular ascending with increasing level ranged between 7.10% in 2005 and 12.44% in 2010. It is essential to devise Saudi National Programme to educate the public about the relation of food balances and diabetes, so it could be avoided, and provide citizens with healthy dietary balances tables.
文摘This paper presents the investigation of energy and cost saving of microgeneration systems which consist of conventional, load sharing, renewable energy and hybrid-renewable energy systems application featuring single detached house and office buildings by implementing spreadsheet modeling. Microsoft excel is employed as the spreadsheet application in this study. The system performance of each case is calculated under typical weather of ottawa, canada. These cases are calculated and analyzed in terms of thermal/cooling load (building demand) and natural gas/electricity consumption (energy supply) as well as the financial part by involving several parameters which are initial cost, annual energy consumption cost, annual operational and maintenance cost, inflation rate, and return on investment. Moreover, a house and an office have the same geometry of 200 mE. Total of seven cases modeling are developed; Case-1- a house with boiler and chiller, Case-2- an office with boiler and chiller, Case-3-a simple sum of Case l and Case 2, Case-4- a load-sharing model, Case-5- a load-sharing with GSHP (ground source heat pump), Case-6- a load-sharing with ground source heat pump-fuel cell hybrid system (FC-GSHP)and Case-7- a load-sharing with GSHP--photovoltaic hybrid system (PVT-GSHP). As the results, it will be observed the efficiency of the load-sharing, renewable energy, hybrid-renewable energy implementation comparing to the conventional system.
文摘Rolling resistance of tires is one of the most important factors influencing energy consumption of road vehicles, especially on rural roads. For practical reasons, most of rolling resistance measurements are usually performed for dry road conditions. Based on the fact that roads are wet during a considerable time over the year and as part of the projects MIR/AM, ROLRES and ROSANNE, the TUG (Technical University of Gdafisk) in Poland and VTI (Swedish National Road and Transport Research Institute) in Sweden carried out trailer rolling resistance measurements on wet road surfaces to investigate water film influence on rolling resistance on different pavements. A specially-designed trailer to measure rolling resistance has been used. The test sections were both rural roads and an abandoned airfield equipped with water film sensors mounted in the pavement. Results indicate strong influence of test speed and water film depth, as well as influence of surface texture. The increase of rolling resistance on wet surfaces is caused by both hydrodynamic phenomena and cooling effect of water that decreases tire temperature thus increasing rolling resistance.
文摘The objective of this research is to quantify the EEC (embodied energy/CO2) of a building. The EEC represents the energy consumption and CO2 emissions at individual phases of a building's life-cycle, such as construction (including manufacture of materials and equipment), renewal (including repair work) and demolition. Energy and CO2 emission intensities in terms of 401 sectors were calculated, using the 2005 I-O (input-output) table in Japan. According to our case study conducted from the construction phase to demolition, the EC (embodied CO2) of an office building used for 60 years is 12,044 t-CO2 and 1,093 kg-CO2/m^2 in total. CO2 equivalent emissions (CO2e) by Freon gases, contained in building materials, equipment and devices, were also calculated. As the results, CO2e by insulators was 2% of the building's EC and CO2e by refrigerants was 9%-12% of the building's EC. It is important to keep reducing emissions of Freon gases contained in refrigerators.