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Liu Dong - One of the best experts on this subject based on the ideXlab platform.
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application of the grey system theory for forecasting the content of 238 u in soil near a uranium mine Exhaust Outlet
Uranium Mining and Metallurgy, 2008Co-Authors: Liu DongAbstract:In order to forecast the content of 238U in soil near a uranium mine Exhaust Outlet,a general GM(1,1) forecasting model was established based on grey system theory,analyzing association degree and residual error distinction.According to the measuring datum of the content of 238U in soil near a uranium mine Exhaust Outlet from 2001 to 2006,used the model to forecast the content of 238U in soil,The results show that the forecasting value agrees with the measuring results and the forecasting precision is higher;at the same time the content of 238U in soil in 2007 is also forecasted based on the model,the relative error was 4.8%,which shows the GM(1,1) forecasting model has higher practical value,and is a effective method for forecasting the content of 238U in soil near a uranium mine Exhaust Outlet.
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Application of the grey system theory for forecasting the content of ~(238)U in soil near a uranium mine Exhaust Outlet
Uranium Mining and Metallurgy, 2008Co-Authors: Liu DongAbstract:In order to forecast the content of 238U in soil near a uranium mine Exhaust Outlet,a general GM(1,1) forecasting model was established based on grey system theory,analyzing association degree and residual error distinction.According to the measuring datum of the content of 238U in soil near a uranium mine Exhaust Outlet from 2001 to 2006,used the model to forecast the content of 238U in soil,The results show that the forecasting value agrees with the measuring results and the forecasting precision is higher;at the same time the content of 238U in soil in 2007 is also forecasted based on the model,the relative error was 4.8%,which shows the GM(1,1) forecasting model has higher practical value,and is a effective method for forecasting the content of 238U in soil near a uranium mine Exhaust Outlet.
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Application of the index of geo-accumulation in safety assessment of radioactive pollution in soil near uranium mine Exhaust Outlet
Uranium Mining and Metallurgy, 2008Co-Authors: Liu DongAbstract:Data survey and analysis on the character of radioactive pollution in soil near uranium mine Exhaust Outlet were made.The results are obtained as follows:(1)the content of 238U and 226Ra in soil decreases with the distance between the sample spot and uranium mine Exhaust Outlet increasing;(2)in the period of exploiting uranium,the content of 238U in the same sample spot grows with the accumulated time increasing.Next, the radioactive pollution in soil was assessed based on the index of geo-accumulation.The following are our conclusion:(1)the radioactive pollution range of 238U is a circular area whose center is the Exhaust Outlet and radius is 1 000 m,and the 226Ra is a circular area of 1 500 m;(2)the radioactive pollution degree of 226Ra is higher than that of 238U in the same place;(3) in the period of exploiting uranium,the radioactive pollution degree of 238U increases with the accumulated time increasing.The safety assessment result of radioactive pollution is of great important reference to the radioactive protection design in uranium mines.
J Lacey - One of the best experts on this subject based on the ideXlab platform.
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Silencing urban exhalations: A case study of student-led soundscape design interventions
2017Co-Authors: J LaceyAbstract:This paper describes a practice-led soundscape studies studio, in which students created sound interventions to transform the 'voice of the city'. A loud Exhaust fan Outlet dominated the intervention site, in which students were asked to create a soundscape intervention in response to an imaginative-artistic question: the Exhaust Outlet is the voice of the city, speaking; can this voice be deciphered, transformed, augmented? Students responded with live sound-art, musical and electroacoustic performances played through loudspeakers placed adjacently to the Exhaust Outlet, and physical changes to the environment with interactive sound-making artifacts. The intervention was informed by the acoustic ecology movement's maxim that acoustic design and the 'retrieval of a significant aural culture' is a 'task for everyone' (Schafer 1977: 206); as such students were encouraged to listen and creatively respond to the dominant sound. Students were introduced to a mixture of acoustic ecology listening exercises, and structural approaches derived from the Research Centre on Sonic Space and the Urban Environment (CRESSON). The project aimed to demonstrate that with the assistance of educational resources, city dwellers, given the opportunity to creatively interact with city sounds, might revitalise their city-relationship through participatory soundscape design.
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Revoicing the urban soundscape: a case study of soundscape design interventions at RMIT University
2012Co-Authors: J LaceyAbstract:Soundscape Studies students in the School of Architecture & Design at RMIT University, Melbourne, Australia were asked to create a soundscape intervention to transform the acoustic space of a campus site. The site is a social space activated by markets, student activities and conversation; however, a loud Exhaust fan Outlet creating a lo-fi environment dominates the acoustic space of the site. Students were asked to create a soundscape intervention in the space, in response to an imaginative-artistic approach to acoustic ecology: the Exhaust Outlet is the voice of the city, speaking; can this voice be deciphered, transformed, augmented? Students responded with live sound-art, musical and electroacoustic performances played through loudspeakers placed adjacently to the Exhaust Outlet, and transformations of the environment with interactive sound-making artifacts. The intervention project was informed by the acoustic ecology movement's maxim that anyone who cares to listen is a soundscape designer; as such students were encouraged to listen, apropos, creatively respond to the dominant sound of the space. The project aimed to demonstrate that city dwellers given the opportunity to creatively interact with their city soundscape, with the assistance of education and resources, could revitalise their city-relationship through soundscape design.
Ahmed Qasim Ahmed - One of the best experts on this subject based on the ideXlab platform.
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Modelling Thermal Comfort and Energy Saving Enhancements in an Office Room Served by Stratified Air Distribution Systems
2017Co-Authors: Ahmed Qasim AhmedAbstract:A numerical study is performed into the effects of the location of Exhaust diffusers in relation to the room heat sources on thermal comfort and energy saving. A new concept of the combination of indoor heat sources and the Exhaust Outlet was also employed in this investigation. The results showed that the indoor thermal environment and energy saving were greatly improved by combining the Exhaust Outlets with some of the room’s heat sources. For further improvement, this concept was also used along with a novel local Exhaust ventilation system in the modelled office room. This system was adopted and developed for use in office spaces, where the Exhaust opening was combined with the office workstation into a single unit. The main aim was to help extract the warmed and contaminated air locally before it could disperse across the room. Three different amounts of recirculated air and three different heights of the combined system were analysed. The results showed a significant improvement in energy savings and inhaled air quality in the room using the new ventilation system. It was also found that the performance of this system was greatly influenced by the height factor. In addition, in this research, the LES method was employed to investigate the complex characteristics of airflow and temperature distribution in the office room which used the concept of combining the Exhaust Outlet with room heat sources. The results revealed that the airflow and temperature distribution were highly unsteady and unstable, particularly in the regions where buoyancy works effectively to cause a high number of perturbations. The developed CFD models were thoroughly validated
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a numerical study on the effects of Exhaust locations on energy consumption and thermal environment in an office room served by displacement ventilation
Energy Conversion and Management, 2016Co-Authors: Ahmed Qasim Ahmed, Shian Gao, Ali Khaleel KareemAbstract:Abstract In an office room, many factors affect the pattern of airflow, thermal comfort, indoor air quality and energy saving. In this study, the effects of the location of Exhaust diffusers where the warm and contaminant air is extracted and their relation to room heat sources on thermal comfort and energy saving were investigated numerically for an office served by a displacement ventilation system. The indoor air quality in the breathing level and the inhaled zone were also evaluated. The contaminants were released from window and door frames in order to simulate the contaminants coming from outside. The amount of energy consumption and the indoor thermal environment for various Exhaust locations were investigated numerically using the computational fluid dynamics techniques. The results showed that the thermal indoor environment, thermal comfort, quality of indoor air and energy saving were greatly improved by combining the Exhaust Outlets with some of the room’s heat sources such as ceiling lamps and external walls. In particular, a 25.0% of energy saving was achieved by combining the Exhaust diffuser with room’s ceiling lamps. In addition, locating the Exhaust diffuser near the heat sources also reduced the cooling coil load by 13.8%. The risk of a large difference in temperature between the head and foot levels, increased particle concentration in the occupied zone, as well as increased energy consumption was also clearly demonstrated when the Exhaust and recirculated air Outlet (return opening) were combined in one unit in the occupied boundary area that is located at 2 m away from the occupants. Thus, for the optimum energy saving and better indoor environment, the combination of the indoor heat sources with the Exhaust Outlet is necessary.
B. Rmili - One of the best experts on this subject based on the ideXlab platform.
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Ultrafine particulate matter emissions from a gasoline direct injection engine
2013Co-Authors: B. Rmili, A. Boreave, M. Tsampas, N. Charbonnel, L. Retailleau-mevel, B. Danna, P. Vernoux, W.y. Hernandez, M. Leblanc, S. RauxAbstract:Epidemiological studies have linked exposure to particles matter less than 2.5 microns in diameter (PM2.5) with adverse health (cardiovascular or pulmonary diseases that would cause premature death). The contribution of the transport sector to the total concentration of PM2.5 in the ambient air is 12% [1]. This value represents an average which likely is higher in areas near emission sources (i.e. urban area). PM abatement in Exhausts of gasoline direct injection (GDI) engines, which aims to improve fuel efficiency, will be necessary due to the strengthening of the European legislations. GDI engines offer a number of opportunities for improving fuel efficiency, such as reducing pumping losses, charge air cooling, and downsizing when turbocharged [2]. However, direct injection of fuel into the engine cylinder is susceptible to incomplete fuel evaporation and to fuel impingement on piston and cylinder walls, both of which lead to combusti on of liquid fuel and, consequently, to PM emissions increase [3]. Gasoline Particulate Filters (GPF) are currently developed to mechanically filter the soot particles emitted by GDI engines. The particle sizes in this case are typically smaller in comparison with diesel engines [4]. Ultrafine particulate (UFP) matter (1-40 nm) emissions from a GDI engine (model PSA EP6CD) were characterized as a function of the engine operating regime in terms of particle numbers and size distributions. Exhaust gas samples were analyzed upstream and downstream a three-way converter (TWC), as well as downstream a GPF, i.e. at the Exhaust Outlet. UFPs were analyzed with a Scanning Mobility Particle Sizer equipped with a dielectric barrier discharge, a differential mobility analyzer (176 channels) to classify the PM size range that enters into a Faraday-Cup Electrometer (FCE) to count the charged particulates (SMPS+E, Grimm). After a two stage dilution (realized by FPS4000, DEKATI), the sampled aerosol was analyzed in the range 1 to 38 nm. SMPS+E data were compared with those of a SMPS (TSI, model 3080, PM size range 3-150 nm) and a DMS (Differential Mobility Spectrometer, Cambustion, PM size range analysis 5-1000 nm). In addition, the fraction of the elemental carbon in PM was estimated with a Multi-Angle Absorption Photometer (MAAP, Thermo Scientific, model 5012). UFPs with diameters lower than 20 nm was detected upstream the TWC. UFPs total concentrations were high, in the range 2 20 1014 part/m3 depending on the engine load. UFPs size distributions were found to be bimodal with mean diameters around 2-3 nm and 10 nm, respectively. The impact of TWC on UFP concentration and size was significant since a large part of UFPs, lower than 10 nm, was removed. Furthermore, the overall UFPs number was divided by one order of magnitude. The filtering efficiency for UFPs of the GPF was found to be high since no UFPs was detectable using the SMPS+E downstream the GPF. These results will be discussed in relation with PM analysis in the range 5 200 nm, carbon elemental concentration as well as gas pollutant emissions.
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Ultrafine particulate matter emissions from a gasoline direct injection engine
2013Co-Authors: B. Rmili, A. Boreave, M. Tsampas, N. Charbonnel, L. Retailleau-mevel, B. Danna, P. Vernoux, W.y. Hernandez, S. Raux, M. LeblancAbstract:Epidemiological studies have linked exposure to particles matter less than 2.5 microns in diameter (PM2.5) with adverse health (cardiovascular or pulmonary diseases that would cause premature death). The contribution of the transport sector to the total concentration of PM2.5 in the ambient air is 12%. This value represents an average which likely is higher in areas near emission sources (i.e. urban area). PM abatement in Exhausts of gasoline direct injection (GDI) engines, which aims to improve fuel efficiency, will be necessary due to the strengthening of the European legislations. GDI engines offer a number of opportunities for improving fuel efficiency, such as reducing pumping losses, charge air cooling, and downsizing when turbocharged [2]. However, direct injection of fuel into the engine cylinder is susceptible to incomplete fuel evaporation and to fuel impingement on piston and cylinder walls, both of which lead to combustion o f liquid fuel and, consequently, to PM emissions increase [3]. Gasoline Particulate Filters (GPF) are currently developed to mechanically filter the soot particles emitted by GDI engines. The particle sizes in this case are typically smaller in comparison with diesel engines. Ultrafine particulate (UFP) matter (1-40 nm) emissions from a GDI engine (1.6 L) were characterized as a function of the engine operating regime in terms of particle numbers and size distributions. Exhaust gas samples were analyzed upstream and downstream a three-way converter (TWC), as well as downstream a GPF, i.e. at the Exhaust Outlet. UFPs were analyzed with a Scanning Mobility Particle Sizer equipped with a dielectric barrier discharge, a differential mobility analyzer (176 channels) to classify the PM size range that enters into a Faraday-Cup Electrometer (FCE) to count the charged particulates (SMPS+E, Grimm). After a two stage dilution (realized by FPS4000, DEKATI), the sampled aerosol was analyzed in the range 1 to 38 nm. SMPS+E data were compared with those of a SMPS (TSI, model 3080, PM size range 3-150 nm) and a DMS (Differential Mobility Spectrometer, Cambustion, PM size range analysis 5-1000 nm). In addition, the fraction of the elemental carbon in PM was estim ated with a Multi-Angle Absorption Photometer (MAAP, Thermo Scientific, model 5012). UFPs with diameters lower than 20 nm was detected upstream the TWC. UFPs total concentrations were high, in the range 2 20 1014 part/m3 depending on the engine load. UFPs size distributions were found to be bimodal with mean diameters around 2-3 nm and 10 nm, respectively. The impact of TWC on UFP concentration and size was significant since a large part of UFPs, lower than 10 nm, was removed. Furthermore, the overall UFPs number was divided by one order of magnitude. The filtering efficiency for UFPs of the GPF was found to be high since no UFPs was detectable using the SMPS+E downstream the GPF.. These results will be discussed in relation with PM analysis in the range 5 200 nm, carbon elemental concentration as well as gas pollutant emissions.
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Ultrafine particulate matter emissions from a gasoline direct injection engine
2013Co-Authors: B. Rmili, A. Boreave, M. Tsampas, N. Charbonnel, L. Retailleau-mevel, B. Danna, P. Vernoux, ? Hernandez, ? Leblanc, ? ZinolaAbstract:Epidemiological studies have linked exposure to particles matter less than 2.5 microns in diameter (PM2.5) with adverse health (cardiovascular or pulmonary diseases that would cause premature death). The contribution of the transport sector to the total concentration of PM2.5 in the ambient air is 12% [1]. This value represents an average which likely is higher in areas near emission sources (i.e. urban area). PM abatement in Exhausts of gasoline direct injection (GDI) engines, which aims to improve fuel efficiency, will be necessary due to the strengthening of the European legislations. GDI engines offer a number of opportunities for improving fuel efficiency, such as reducing pumping losses, charge air cooling, and downsizing when turbocharged [2]. However, direct injection of fuel into the engine cylinder is susceptible to incomplete fuel evaporation and to fuel impingement on piston and cylinder walls, both of which lead to combusti on of liquid fuel and, consequently, to PM emissions increase [3]. Gasoline Particulate Filters (GPF) are currently developed to mechanically filter the soot particles emitted by GDI engines. The particle sizes in this case are typically smaller in comparison with diesel engines [4]. Ultrafine particulate (UFP) matter (1-40 nm) emissions from a GDI engine (1.6 L) were characterized as a function of the engine operating regime in terms of particle numbers and size distributions. Exhaust gas samples were analyzed upstream and downstream a three-way converter (TWC), as well as downstream a GPF, i.e. at the Exhaust Outlet. UFPs were analyzed with a Scanning Mobility Particle Sizer equipped with a dielectric barrier discharge, a differential mobility analyzer (176 channels) to classify the PM size range that enters into a Faraday-Cup Electrometer (FCE) to count the charged particulates (SMPS+E, Grimm). After a two stage dilution (realized by FPS4000, DEKATI), the sampled aerosol was analyzed in the range 1 to 38 nm. SMPS+E data were compared with those of a SMPS (TSI, model 3080, PM size range 3-150 nm) and a DMS (Differential Mobility Spectrometer, Cambustion, PM size range analysis 5-1000 nm). In addition, the fraction of the elemental carbon in PM was estim ated with a Multi-Angle Absorption Photometer (MAAP, Thermo Scientific, model 5012). UFPs with diameters lower than 20 nm was detected upstream the TWC. UFPs total concentrations were high, in the range 2 20 1014 part/m3 depending on the engine load. UFPs size distributions were found to be bimodal with mean diameters around 2-3 nm and 10 nm, respectively. The impact of TWC on UFP concentration and size was significant since a large part of UFPs, lower than 10 nm, was removed. Furthermore, the overall UFPs number was divided by one order of magnitude. The filtering efficiency for UFPs of the GPF was found to be high since no UFPs was detectable using the SMPS+E downstream the GPF (Fig. 1). These results will be discussed in relation with PM analysis in the range 5 200 nm, carbon elemental concentration as well as gas pollutant emissions. Figure 1: UFPs size distributions at 2500 rpm/ 13 bar. Dilution ratio= 6. Acknowledgements The authors would like to thank the Agence National de la Recherche (ANR) for the financial support of the TRIPTIC-H project (N°ANR-11-VPTT-003-05). References [1] WHO, 2006a: Health risks of particulate matter from long-range transboundary air pollution. WHO report E88189, WHO Regional Office for Europe, Copenhagen, Denmark. [2] J. Yi, S. Wooldridge, G. Coulson, J. Hilditch, C.O. Lyer, P. Moilanen, G. Papaioannou, D. Reich, M. Shelby, B. VanDer-Wege, C. Weaver, Z. Xu, G. Davis, B. Hinds, A. Schamel, SAE Technical Paper. 2009-01-1494 (2009). [3] S. J. Harris, M. M. Maricq, Aerosol Science 32 (2001) 749. [4] M.M. Maricq, Combustion and Flame. 159 (2012) 170.
Ali Khaleel Kareem - One of the best experts on this subject based on the ideXlab platform.
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a numerical study on the effects of Exhaust locations on energy consumption and thermal environment in an office room served by displacement ventilation
Energy Conversion and Management, 2016Co-Authors: Ahmed Qasim Ahmed, Shian Gao, Ali Khaleel KareemAbstract:Abstract In an office room, many factors affect the pattern of airflow, thermal comfort, indoor air quality and energy saving. In this study, the effects of the location of Exhaust diffusers where the warm and contaminant air is extracted and their relation to room heat sources on thermal comfort and energy saving were investigated numerically for an office served by a displacement ventilation system. The indoor air quality in the breathing level and the inhaled zone were also evaluated. The contaminants were released from window and door frames in order to simulate the contaminants coming from outside. The amount of energy consumption and the indoor thermal environment for various Exhaust locations were investigated numerically using the computational fluid dynamics techniques. The results showed that the thermal indoor environment, thermal comfort, quality of indoor air and energy saving were greatly improved by combining the Exhaust Outlets with some of the room’s heat sources such as ceiling lamps and external walls. In particular, a 25.0% of energy saving was achieved by combining the Exhaust diffuser with room’s ceiling lamps. In addition, locating the Exhaust diffuser near the heat sources also reduced the cooling coil load by 13.8%. The risk of a large difference in temperature between the head and foot levels, increased particle concentration in the occupied zone, as well as increased energy consumption was also clearly demonstrated when the Exhaust and recirculated air Outlet (return opening) were combined in one unit in the occupied boundary area that is located at 2 m away from the occupants. Thus, for the optimum energy saving and better indoor environment, the combination of the indoor heat sources with the Exhaust Outlet is necessary.