WorldWideScience

Sample records for stack gas pollutants

  1. Power station stack gas emissions

    International Nuclear Information System (INIS)

    Hunwick, Richard J.

    2006-01-01

    There are increasing awareness and pressure to reduce emissions of acid rain and photochemical smog. There is a need to produce new control system and equipment to capture those emissions. The most visible form of pollutions are the chimney smoke, dust and particles of fly ash from mineral matter in the fuel. Acid gases are hard on structures and objects containing limestone. Coal fired power generation is likely to be able to sustain its competitive advantage as a clean source of electricity in comparison with nuclear power and natural gas

  2. Stack Gas Scrubber Makes the Grade

    Science.gov (United States)

    Chemical and Engineering News, 1975

    1975-01-01

    Describes a year long test of successful sulfur dioxide removal from stack gas with a calcium oxide slurry. Sludge disposal problems are discussed. Cost is estimated at 0.6 mill per kwh not including sludge removal. A flow diagram and equations are included. (GH)

  3. An industrial FT-IR process gas analyzer for stack gas cems analysis

    Energy Technology Data Exchange (ETDEWEB)

    Welch, G.M. [American instruments, Anacortes, WA (United States); Herman, B.E. [Applied Automation/Hartmann & Braun, Bartlesville, OK (United States)

    1995-12-31

    This paper describes utilizing Fourier Transform Infrared (FT-IR) technology to meet and exceed EPA requirements to Continuously Monitor Carbon Monoxide (CO) and Sulfur Dioxide (SO){sub 2} in an oil refinery. The application consists of Continuous Emission Monitoring (CEMS) of two stacks from a Fluid Catalytic Cracking unit (FCCU). The discussion will follow the project from initial specifications, installation, start-up, certification results (RATA, 7 day drift), Cylinder Gas Audit (CGA) and the required maintenance. FT-IR is a powerful analytical tool suitable for measurement of stack component gases required to meet CEMS regulations, and allows simultaneous multi-component analysis of complex stack gas streams with a continuous sample stream flow through the measurement cell. The Michelson Interferometer in a unique {open_quotes}Wishbone{close_quotes} design and with a special alignment control enables standardized configuration of the analyzer for flue gas analysis. Normal stack gas pollutants: NO{sub x}, SO{sub 2}, and CO; as well as water soluble pollutants such as NH{sub 3} and HCI may be accurately determined and reported even in the presence of 0-31 Vol % water vapor concentrations (hot and wet). This FT-IR analyzer has been operating with EPA Certification in an oil refinery environment since September 1994.

  4. Simultaneous stack-gas scrubbing and waste water treatment

    Science.gov (United States)

    Poradek, J. C.; Collins, D. D.

    1980-01-01

    Simultaneous treatment of wastewater and S02-laden stack gas make both treatments more efficient and economical. According to results of preliminary tests, solution generated by stack gas scrubbing cycle reduces bacterial content of wastewater. Both processess benefit by sharing concentrations of iron.

  5. Some important results from the air pollution distribution model STACKS (1988-1992)

    International Nuclear Information System (INIS)

    Erbrink, J.J.

    1993-01-01

    Attention is paid to the results of the study on the distribution of air pollutants by high chimney-stacks of electric power plants. An important product of the study is the integrated distribution model STACKS (Short Term Air-pollutant Concentrations Kema modelling System). The improvements and the extensions of STACKS are described in relation to the National Model, which has been used to estimate the environmental effects of individual chimney-stacks. The National Model shows unacceptable variations for high pollutant sources. Based on the results of STACKS revision of the National model has been taken into consideration. By means of the revised National Model a more realistic estimation of the environmental effects of electric power plants can be carried out

  6. Fabrication of highly porous LSM/CGO cell stacks for electrochemical flue gas purification

    DEFF Research Database (Denmark)

    Andersen, Kjeld Bøhm; Bræstrup, Frantz Radzik; Kammer Hansen, Kent

    2013-01-01

    In this study porous cell stacks for electrochemical flue gas purification were fabricated using tape casting and lamination followed by sintering. Two different mixtures of pore formers were used; either a mixture of two types of graphite or a mixture of graphite with polymethyl methacrylate micro-particles....... It was shown that the porous cell stacks fabricated with polymethyl methacrylate had a higher porosity but a similar back pressure compared to the porous cell stacks fabricated with only graphite as a pore former. This was due to a high back pressure of the electrolyte layer. The porous cell stacks fabricated...... with polymethyl methacrylate as a pore former seem to be well suited for i.e. caption of soot particles. Furthermore, the back pressure of the electrode layer was significantly reduced when using polymethyl methacrylate pore formers. However, a better interconnectivity of the pores formed by the polymethyl...

  7. Effect of Additional Structure on Effective Stack Height of Gas Dispersion in Atmosphere

    Directory of Open Access Journals (Sweden)

    Takenobu Michioka

    2016-03-01

    Full Text Available Wind-tunnel experiments were conducted to evaluate the effect of additional structure (building, sea wall and banking on the effective stack height, which is usually used in safety analyses of nuclear power facilities in Japan. The effective stack heights were estimated with and without the additional structure in addition to the reactor building while varying several conditions such as the source height, the height of additional structure and the distance between the source position and the additional structure. When the source height is equivalent to the reactor building height, the additional structure enhances both the vertical and horizontal gas dispersion widths and decreases the ground gas concentration, and it means that the additional structure does not decrease the effective stack height. When the source height is larger than the reactor height, the additional structures might affect the effective stack height. As the distance between the source and the additional structure decreases, or as the height of the additional structure increases, the structure has a larger effect on the effective stack height.

  8. Independent determination of the accuracy of the OSTR stack gas monitor and its operational application

    International Nuclear Information System (INIS)

    Pickett, B.D.; Johnson, A.G.

    1982-01-01

    This study was undertaken to determine the accuracy of the stack gas monitor, using techniques which were independent of the monitoring system itself. Samples of argon-41 to be used as the standards in this study were carefully produced in the thermal column of the OSTR and counted on a Ge(Li) detector which was connected to a multichannel analyzer (MCA). As the argon-41 standard in the gas sample flask decayed, the concentration of the argon-41 was compared to the output of the Ge(Li)/MCA system. This established a calibration curve for the counting system, whereby a sample with an unknown concentration of argon-41 could be counted and the subsequent count rate from the sample converted to a concentration expressed in mCi per milliliter. Gas samples were extracted from various points in the reactor exhaust system and the concentrations of argon-41 were determined by counting on the Ge(Li)/MCA system. Each sample concentration was then compared to the argon-41 concentration indicated by the stack gas monitor. The initial results indicated that, although possibly intermittent, the argon-41 concentrations displayed by the stack gas monitor were often approximately 50% of those predicted by analysis of individual samples from the exhaust system. Several possible sources for the discrepancy were checked, including the method of SGM calibration, uneven mixing of exhaust air and argon-41 in the reactor building exhaust stream, and dilution of the gas concentration in the SGM system by air leakage into the system. After considerable effort, the latter cause was found to be the culprit, due to an aging gasket around the stack monitor's moving particulate-filter-paper housing

  9. Effect of Gas Turbine Exhaust Temperature, Stack Temperature and Ambient Temperature on Overall Efficiency of Combine Cycle Power Plant

    OpenAIRE

    M.N.Khan; K.P.Tyagi

    2010-01-01

    The gas turbine exhaust temperature, stack temperature and ambient temperature play a very important role during the predication of the performance of combine cycle power plant. This paper covers parametric analysis of effects of gas turbine exhaust temperature, stack temperature and ambient temperature on the overall efficiency of combine cycle power plant keeping the gas turbine efficiency as well as steam turbine efficiency constant. The results shows that out of three variables i.e. turbi...

  10. CO2utilization via a novel anaerobic bioprocess configuration with simulated gas mixture and real stack gas samples.

    Science.gov (United States)

    Daglioglu, S Tugce; Karabey, Burcin; Ozdemir, Guven; Azbar, Nuri

    2017-11-28

    CO 2 , which is considered to be one of the major causes of climate change, has reached to critical levels in the atmosphere due to tremendous consumption of fossil fuels all over the world. In this study, anaerobic bioconversion of CO 2 into bio-methane using a novel bioprocess configuration (HYBRID bioreactor) was studied under mesophilic conditions. Varying ratios of H 2 /CO 2 gas mixture and volumetric feeding rates were investigated and no additional organic matter and trace element were needed throughout the study. The maximum methane production of 19 m 3 CH 4 /m 3 reactor/ d was achieved at a H 2 /CO 2 ratio of 4:1 and feeding rate of 24 m 3 gas/m 3 reactor /d. It was determined that H 2 conversion rate is about 96%. For demonstration purpose, real stack gas sample from a petrochemical industry was also tested under optimized operational conditions. No inhibitory effect from stack gas mixture was observed. This study provided an environmentally friendly and sustainable solution for industries such as petrochemical industry in order to produce extra energy while capturing their waste CO 2 . Thereby, a sustainable and environmentally friendly model solution was presented for industries with high CO 2 emissions. COV: coefficient of variation; Gt: gigatone; IEA: International Energy Agency; IPCC: International Panel on Climate Change; MBBR: moving bed biofilm reactor; MJ: Megajoule; UASB: upflow anaerobic sludge blanket; VFR: volumetric feeding rate.

  11. Gas pollutant cleaning by a membrane reactor

    Directory of Open Access Journals (Sweden)

    Kaldis Sotiris

    2006-01-01

    Full Text Available An alternative technology for the removal of gas pollutants at the integrated gasification combined cycle process for power generation is the use of a catalytic membrane reactor. In the present study, ammonia decomposition in a catalytic reactor, with a simultaneous removal of hydrogen through a ceramic membrane, was investigated. A Ni/Al2O3 catalyst was prepared by the dry and wet impregnation method and characterized by the inductively coupled plasma method, scanning electron microscopy, X-ray diffraction, and N2 adsorption before and after activation. Commercially available a-Al2O3 membranes were also characterized and the permeabilities and permselectivities of H2, N2, and CO2 were measured by the variable volume method. In parallel with the experimental analysis, the necessary mathematical models were developed to describe the operation of the catalytic membrane reactor and to compare its performance with the conventional reactor. .

  12. Tracer gas experiment to verify the dispersion from a tall stack

    International Nuclear Information System (INIS)

    Sivertsen, B.; Irwin, J.S.

    1996-01-01

    At the request of the Ministerios de Obras Publicas y Urbanismo (MOPU) in Madrid, the Norwegian Institute for Air Research (NILU) planned and carried out a comprehensive field experiment at the Andorra (Teruel) power plant in Spain. All together, eleven releases of sulfur hexafluoride (SF6) tracer were carried out at the 1,200 MW electric coal fired power plant. The tracer was emitted into the atmosphere from the 343 m high stack, stack exit diameter of 9 m. The stack gas emission characteristics were nearly constant during the period having an exit temperature of 175.1 C (1.9), exit velocity of 35.5 m/s (0.14) and sulfur dioxide (SO 2 ) emission rate of 46.1 x 10 3 kg/hr (5.15 x 10 3 ); standard deviations are listed in parentheses. Samples were taken at the surface along sampling arcs located approximately 8, 23, 43 and 75 km downwind. The releases were undertaken during typical late spring daytime conditions. The synoptic weather conditions were dominated by a large high pressure system on the Atlantic, west of Spain. Fronts were passing the area from the north and a low pressure system was developing over central Europe (Germany). Winds at the surface were generally brisk from the northwest at 7 to 12 m/s

  13. Emission and distribution of PCDD/Fs, chlorobenzenes, chlorophenols, and PAHs from stack gas of a fluidized bed and a stoker waste incinerator in China.

    Science.gov (United States)

    Wang, Tianjiao; Chen, Tong; Lin, Xiaoqing; Zhan, Mingxiu; Li, Xiaodong

    2017-02-01

    The concentrations, homologue, and congener profiles, as well as the gas/particle distribution of polychlorinated dibenzo-p-dioxins and furans (PCDD/Fs), chlorobenzenes (CBzs), chlorophenols (CPhs), and polyaromatic hydrocarbons (PAHs) from stack gas of two different municipal solid waste incinerators in China, were characterized. The incinerators were a stoker furnace incinerator equipped with the advanced air pollution control device (APCD) and a common circulating fluidized bed (CFB) furnace. The concentration of PCDD/Fs in the stack gas of the stoker incinerator ranged 0.011-0.109 ng international toxic equivalent factor (I-TEQ)/Nm 3 and was below the current limit for PCDD/F emissions from the municipal solid waste incinerators (MSWIs) in China (0.1 ng I-TEQ/Nm 3 ) in most of the cases. Moreover, the concentration of PCDD/Fs in the stack gas of the stoker incinerator was significantly lower than that of the CFB incinerator (0.734 to 24.6 ng I-TEQ/Nm 3 ). In both incinerators, the majority of the total PCDD/F emissions (above 90%) ended up in the gas phase. 2,3,4,7,8-PeCDF, which occupied 24.3-43.6 and 32.5-75.6% of I-TEQ contribution in MSWIs A and B, respectively, was the most abundant congener. However, different types of incinerators and APCDs induced different congener and homologue distributions. The total concentration of CBzs from the stoker incinerator (0.05-3.2 μg/Nm 3 ) was also much lower than that formed from the CFB incinerator (10.9-75.2 μg/Nm 3 ). The phase distribution of CBzs followed the same pattern as with the PCDD/Fs. Moreover, the emission level of CBz was 100-1000 times higher than that of the PCDD/Fs, which determines the applicability of CBzs as indicators of PCDD/F emissions. High correlations between the emission concentrations of PCDD/Fs, TeCBz, and PCBz in specific ranges were revealed. Furthermore, high concentrations of CPhs (0.6-141.0 μg/Nm 3 ) and PAHs (148.6-4986.5 μg/Nm 3 ) were detected in the stack gases of MSWI

  14. Environmental pollution due to gas flaring at Oyigbo area of Rivers State

    International Nuclear Information System (INIS)

    Avwiri, G. O.; Ebeniro, J. O.

    1996-01-01

    Environmental degradation due to oil activities in the oil rich Niger Delta of Nigeria is daily approaching a non-tolerance level. Pollutants come from various aspects of operation ranging from seismic operations through drilling to the refinery stage. Gas flared daily by Oil Companies constitute a major health hazard in this country. Environmental pollution due to gas flaring at Oyigbo area of Rivers State is hereby reported. Surface temperature-distance variations were investigated for both dry (March) and rainy (June) seasons. Physical and chemical properties of the rainwater from the areas were also measured and analysed. The results show a surface temperature elevation of about 4.1 Celsius above the mean normal diurnal temperature within a 3.00 km. radius. An average pH 4.25 was recorded thus showing the acidic nature of the environmental rainwater from the area. All other measured parameters showed serious deviations from standards. This temperature elevation and increased acidity of the rainwater have enormous influence on socio-economic lives and the activities of the populace especially on their source of income which is mainly small scale farming. It is therefore necessary that Government agencies empowered to monitor environment especially FEPA should implement all the existing legislation on gas flaring and be more involved in the design and location of gas flaring stacks. These stacks should be located at least 2 km. from towns and villages

  15. Hanford Site radionuclide national emission standards for hazardous air pollutants unregistered stack (power exhaust) source assessment

    International Nuclear Information System (INIS)

    Davis, W.E.

    1994-01-01

    On February 3, 1993, the US Department of Energy, Richland Operations Office received a Compliance Order and Information Request from the Director of the Air and Toxics Division of the US Environmental Protection Agency, Region 10. The Compliance Order requires the Richland Operations Office to evaluate all radionuclide emission points at the Hanford Site to determine which are subject to continuous emission measurement requirements in 40 Code of Federal Regulations (CFR) 61, Subpart H, and to continuously measure radionuclide emissions in accordance with 40 CFR 61.93. This evaluation provides an assessment of the 39 unregistered stacks, under Westinghouse Hanford Company's management, and their potential radionuclide emissions, i.e., emissions with no control devices in place. The evaluation also determined if the effective dose equivalent from any of these stack emissions exceeded 0.1 mrem/yr, which will require the stack to have continuous monitoring. The result of this assessment identified three stacks, 107-N, 296-P-26 and 296-P-28, as having potential emissions that would cause an effective dose equivalent greater than 0.1 mrem/yr. These stacks, as noted by 40 CFR 61.93, would require continuous monitoring

  16. Hanford Site radionuclide national emission standards for hazardous air pollutants unregistered stack (power exhaust) source assessment

    Energy Technology Data Exchange (ETDEWEB)

    Davis, W.E.

    1994-08-04

    On February 3, 1993, the US Department of Energy, Richland Operations Office received a Compliance Order and Information Request from the Director of the Air and Toxics Division of the US Environmental Protection Agency, Region 10. The Compliance Order requires the Richland Operations Office to evaluate all radionuclide emission points at the Hanford Site to determine which are subject to continuous emission measurement requirements in 40 Code of Federal Regulations (CFR) 61, Subpart H, and to continuously measure radionuclide emissions in accordance with 40 CFR 61.93. This evaluation provides an assessment of the 39 unregistered stacks, under Westinghouse Hanford Company`s management, and their potential radionuclide emissions, i.e., emissions with no control devices in place. The evaluation also determined if the effective dose equivalent from any of these stack emissions exceeded 0.1 mrem/yr, which will require the stack to have continuous monitoring. The result of this assessment identified three stacks, 107-N, 296-P-26 and 296-P-28, as having potential emissions that would cause an effective dose equivalent greater than 0.1 mrem/yr. These stacks, as noted by 40 CFR 61.93, would require continuous monitoring.

  17. Hanford Site radionuclide national emission standards for hazardous air pollutants registered stack source assessment

    International Nuclear Information System (INIS)

    Davis, W.E.; Barnett, J.M.

    1994-01-01

    On February 3, 1993, the US Department of Energy, Richland Operations Office received a Compliance Order and Information Request from the Director of the Air and Toxics Division of the US Environmental Protection Agency,, Region 10. The Compliance Order requires the Richland Operations Office to evaluate all radionuclide emission points at the Hanford Site . The evaluation also determined if the effective dose equivalent from any of these stack emissions exceeded 0.1 mrem/yr, which will require the stack to have continuous monitoring. The result of this assessment identified a total of 16 stacks as having potential emissions that,would cause an effective dose equivalent greater than 0.1 mrem/yr

  18. Hanford Site radionuclide national emission standards for hazardous air pollutants registered stack source assessment

    Energy Technology Data Exchange (ETDEWEB)

    Davis, W.E.; Barnett, J.M.

    1994-07-01

    On February 3, 1993, the US Department of Energy, Richland Operations Office received a Compliance Order and Information Request from the Director of the Air and Toxics Division of the US Environmental Protection Agency,, Region 10. The Compliance Order requires the Richland Operations Office to evaluate all radionuclide emission points at the Hanford Site . The evaluation also determined if the effective dose equivalent from any of these stack emissions exceeded 0.1 mrem/yr, which will require the stack to have continuous monitoring. The result of this assessment identified a total of 16 stacks as having potential emissions that,would cause an effective dose equivalent greater than 0.1 mrem/yr.

  19. Indoor air pollution from gas cooking and infant neurodevelopment.

    Science.gov (United States)

    Vrijheid, Martine; Martinez, David; Aguilera, Inma; Bustamante, Mariona; Ballester, Ferran; Estarlich, Marisa; Fernandez-Somoano, Ana; Guxens, Mònica; Lertxundi, Nerea; Martinez, M Dolores; Tardon, Adonina; Sunyer, Jordi

    2012-01-01

    Gas cooking is a main source of indoor air pollutants, including nitrogen dioxide and particles. Because concerns are emerging for neurodevelopmental effects of air pollutants, we examined the relationship between indoor gas cooking during pregnancy and infant neurodevelopment. Pregnant mothers were recruited between 2004 and 2008 to a prospective birth cohort study (INfancia y Medio Ambiente) in Spain during the first trimester of pregnancy. Third-trimester questionnaires collected information about the use of gas appliances at home. At age 11 to 22 months, children were assessed for mental development using the Bayley Scales of Infant Development. Linear regression models examined the association of gas cooking and standardized mental development scores (n = 1887 mother-child pairs). Gas cookers were present in 44% of homes. Gas cooking was related to a small decrease in the mental development score compared with use of other cookers (-2.5 points [95% confidence interval = -4.0 to -0.9]) independent of social class, maternal education, and other measured potential confounders. This decrease was strongest in children tested after the age of 14 months (-3.1 points [-5.1 to -1.1]) and when gas cooking was combined with less frequent use of an extractor fan. The negative association with gas cooking was relatively consistent across strata defined by social class, education, and other covariates. This study suggests a small adverse effect of indoor air pollution from gas cookers on the mental development of young children.

  20. Modelling an environmental pollutant transport from the stacks to and through the soil

    Directory of Open Access Journals (Sweden)

    Rushdi M.M. El-Kilani

    2010-07-01

    Full Text Available In this paper, a model is presented for predicting the transport of an environmental pollutant from the source to and through the soil. The model can predict the deposition of an environmental pollutant on the soil surface due to the pollutant being loaded on dust particles, which are later deposited on the soil surface. The model is a coupling of three models: a model for predicting the cumulative dust deposition from near and far field sources on a certain area; a canopy microclimate model for solving the energy partition within the canopy elements and so predicting the water convection stream for pollutant transport through the soil; and coupling the deposition of these pollutants on the soil surface to a model for its transport through the soil. The air pollution model uses the Gaussian model approach, superimposed for multiple emission sources, to elucidate the deposition of pollutant laden airborne particulates on the soil surface. A complete canopy layer model is used to calculate within the canopy energy fluxes. The retardation factor for the pollutant is calculated from an adsorption batch experiment. The model was used to predict the deposition of lead laden dust particles on the soil surface and lead's transport through the soil layers inside a metropolitan region for: (1 three large cement factories and (2 a large number of smelters. The results show that, due to the very high retardation values for lead movement through the soil, i.e. ranging from 4371 to 53,793 from previous data and 234 from the adsorption experiment in this paper, lead is immobile and all the lead added to the soil surface via deposited dust or otherwise, even if it is totally soluble, will remain mostly on the soil surface and not move downwards due to high affinity with the soil.

  1. Stability and performance improvement of a polymer electrolyte membrane fuel cell stack by laser perforation of gas diffusion layers

    Energy Technology Data Exchange (ETDEWEB)

    Gerteisen, Dietmar; Sadeler, Christian [Fraunhofer Institute for Solar Energy Systems ISE, Department of Energy Technology, Heidenhofstrasse 2, 79110 Freiburg (Germany)

    2010-08-15

    The performance and stability of a hydrogen-driven polymer electrolyte membrane fuel cell stack (6-cell PEFC stack) are investigated with regard to pore flooding within the gas diffusion layers (GDLs). Two short stacks with various GDLs (Toray TGP-H-060 untreated and laser-perforated) were characterized at different operating conditions by several characterization techniques such as constant current load, polarization curve, chronoamperometry and chronovoltammetry. The experimental results reveal that the perforation of the cathode GDLs improves the water transport in the porous media and thus the performance as well as the stability of the operating stack in medium and high current density range. A reduced pore flooding is verified when using the customized laser-perforated GDLs. The GDL perforation has a huge potential to balance the inhomogeneous in-plane saturation conditions between the inlet and outlet area of the cell and to compensate to a certain degree the effects of temperature distribution within a stack regarding the water management. (author)

  2. Stability and performance improvement of a polymer electrolyte membrane fuel cell stack by laser perforation of gas diffusion layers

    Science.gov (United States)

    Gerteisen, Dietmar; Sadeler, Christian

    The performance and stability of a hydrogen-driven polymer electrolyte membrane fuel cell stack (6-cell PEFC stack) are investigated with regard to pore flooding within the gas diffusion layers (GDLs). Two short stacks with various GDLs (Toray TGP-H-060 untreated and laser-perforated) were characterized at different operating conditions by several characterization techniques such as constant current load, polarization curve, chronoamperometry and chronovoltammetry. The experimental results reveal that the perforation of the cathode GDLs improves the water transport in the porous media and thus the performance as well as the stability of the operating stack in medium and high current density range. A reduced pore flooding is verified when using the customized laser-perforated GDLs. The GDL perforation has a huge potential to balance the inhomogeneous in-plane saturation conditions between the inlet and outlet area of the cell and to compensate to a certain degree the effects of temperature distribution within a stack regarding the water management.

  3. High-power selfshielded electron processors and their application to stack gas treatment

    International Nuclear Information System (INIS)

    Hiley, J.; Frutiger, W.A.; Nablo, S.V.

    1987-01-01

    The increasing industrial demands for large width (approximately 2 m), high dose rate (1 Mrad at 1500 m/min) electron beam machinery has led to a relatively rapid improvement in this field over the past several years. Selfshielded machinery capable of up to 1000 mA of current at 300 kV is now in commercial use, and the essential features of these designs are presented. A variety of product handling geometries for use with these accelerators has been developed for processes involving flexible web, rigid sheet, and three-dimensional objects in both the polymerization and sterilization applications. One of the major power-intensive processes to which these machines are currently applied is that of the reduction of pollutants (NO x , SO 2 , etc.) in the flue gas from fuel combustion - particularly those fossil fuels used in power production. The preferred technique utilizes the treatment of the ammoniated gas at modest dose levels (0.5-2.0 Mrads) to enhance the formation of ammonium salts which are then removed from the gas stream by conventional filtration. Some results from a 180 kWx300 kV pilot installation in Karlsruhe, Federal Republic of Germany are presented. (orig.)

  4. Durable SOC stacks for production of hydrogen and synthesis gas by high temperature electrolysis

    DEFF Research Database (Denmark)

    Ebbesen, Sune Dalgaard; Høgh, Jens Valdemar Thorvald; Nielsen, Karsten Agersted

    2011-01-01

    Electrolysis of steam and co-electrolysis of steam and carbon dioxide was studied in Solid Oxide Electrolysis Cell (SOEC) stacks composed of Ni/YSZ electrode supported SOECs. The results of this study show that long-term electrolysis is feasible without notable degradation in these SOEC stacks...

  5. Up-to-Date Materials of Gas Ducts and Smoke Stacks

    Directory of Open Access Journals (Sweden)

    V. D. Sizov

    2012-01-01

    Full Text Available The paper considers existing systems of smoke removal from heat-generating plants of various heat power. Advantages and disadvantages of every system are specified in the paper. The paper analyzes properties of fiberglass smoke stacks.

  6. Tables of formulae for calculating the mechanics of stacks in gas-graphite reactors

    International Nuclear Information System (INIS)

    1968-01-01

    This collection of formulae only gives, for nuclear graphite stacks. The mechanical effects due to the strains, thermal or not, of steel structures supporting or surrounding graphite blocks. Equations have been established by mean of experiments made at Chinon with large pile models. Thus, it is possible to calculate displacement, strain and stress in the EDF type stacks of horizontal triangular block lattice. (authors) [fr

  7. Harvesting Hydrogen Gas from Air Pollutants with an Unbiased Gas Phase Photoelectrochemical Cell.

    Science.gov (United States)

    Verbruggen, Sammy W; Van Hal, Myrthe; Bosserez, Tom; Rongé, Jan; Hauchecorne, Birger; Martens, Johan A; Lenaerts, Silvia

    2017-04-10

    The concept of an all-gas-phase photoelectrochemical (PEC) cell producing hydrogen gas from volatile organic contaminated gas and light is presented. Without applying any external bias, organic contaminants are degraded and hydrogen gas is produced in separate electrode compartments. The system works most efficiently with organic pollutants in inert carrier gas. In the presence of oxygen, the cell performs less efficiently but still significant photocurrents are generated, showing the cell can be run on organic contaminated air. The purpose of this study is to demonstrate new application opportunities of PEC technology and to encourage further advancement toward PEC remediation of air pollution with the attractive feature of simultaneous energy recovery and pollution abatement. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Experimental study and comparison of various designs of gas flow fields to PEM fuel cells and cell stack performance

    Directory of Open Access Journals (Sweden)

    Hong eLiu

    2014-01-01

    Full Text Available In this study, a significant number of experimental tests to PEM fuel cells were conducted to investigate the effect of gas flow fields on fuel cell performance. Graphite plates with various flow field or flow channel designs, from literature survey and also novel designs by the authors, were used for the PEM fuel cell assembly. The fabricated fuel cells all have an effective membrane area of 23.5 cm2. The results showed that the serpentine flow channel design is still favorable, giving the best single fuel cell performance amongst all the studied flow channel designs. A novel symmetric serpentine flow field was proposed for relatively large size fuel cell application. Four fuel cell stacks each including four cells were assembled using different designs of serpentine flow channels. The output power performances of fuel cell stacks were compared and the novel symmetric serpentine flow field design is recommended for its very good performance.

  9. Miniaturized Planar Room Temperature Ionic Liquid Electrochemical Gas Sensor for Rapid Multiple Gas Pollutants Monitoring.

    Science.gov (United States)

    Wan, Hao; Yin, Heyu; Lin, Lu; Zeng, Xiangqun; Mason, Andrew J

    2018-02-01

    The growing impact of airborne pollutants and explosive gases on human health and occupational safety has escalated the demand of sensors to monitor hazardous gases. This paper presents a new miniaturized planar electrochemical gas sensor for rapid measurement of multiple gaseous hazards. The gas sensor features a porous polytetrafluoroethylene substrate that enables fast gas diffusion and room temperature ionic liquid as the electrolyte. Metal sputtering was utilized for platinum electrodes fabrication to enhance adhesion between the electrodes and the substrate. Together with carefully selected electrochemical methods, the miniaturized gas sensor is capable of measuring multiple gases including oxygen, methane, ozone and sulfur dioxide that are important to human health and safety. Compared to its manually-assembled Clark-cell predecessor, this sensor provides better sensitivity, linearity and repeatability, as validated for oxygen monitoring. With solid performance, fast response and miniaturized size, this sensor is promising for deployment in wearable devices for real-time point-of-exposure gas pollutant monitoring.

  10. Pollution control in oil, gas and chemical plants

    CERN Document Server

    Bahadori, Alireza

    2014-01-01

    This unique book covers the fundamental requirements for air, soil, noise and water pollution control in oil and gas refineries, chemical plants, oil terminals, petrochemical plants, and related facilities. Coverage includes design and operational considerations relevant to critical systems such as monitoring of water pollution control, equipment, and engineering techniques as well as engineering/technological methods related to soil, noise and air pollution control. This book also: ·         Covers a diverse list of pollution control strategies important to practitioners, ranging from waste water gathering systems and oil/suspended solids removal to chemical flocculation units, biological treatment, and sludge handling and treatment ·         Provides numerous step-by-step tutorials that orient both entry level and veteran engineers to the essentials of pollution control methods in petroleum and chemical industries ·         Includes a comprehensive glossary providing readers with...

  11. Pollutant swapping: greenhouse gas emissions from wetland systems constructed to mitigate agricultural pollution

    Science.gov (United States)

    Freer, Adam; Quinton, John; Surridge, Ben; McNamara, Niall

    2014-05-01

    Diffuse (non-point) water pollution from agricultural land continues to challenge water quality management, requiring the adoption of new land management practices. The use of constructed agricultural wetlands is one such practice, designed to trap multiple pollutants mobilised by rainfall prior to them reaching receiving water. Through capturing and storing pollutants in bottom sediments, it could be hypothesised that the abundance of nutrients stored in the anoxic conditions commonly found in these zones may lead to pollutant swapping. Under these circumstances, trapped material may undergo biogeochemical cycling to change chemical or physical form and thereby become more problematic or mobile within the environment. Thus, constructed agricultural wetlands designed to mitigate against one form of pollution may in fact offset the created benefits by 'swapping' this pollution into other forms and pathways, such as through release to the atmosphere. Pollutant swapping to the atmosphere has been noted in analogous wetland systems designed to treat municipal and industrial wastewaters, with significant fluxes of CO2, CH4 and N2O being recorded in some cases. However the small size, low level of engineering and variable nutrient/sediment inputs which are features of constructed agricultural wetlands, means that this knowledge is not directly transferable. Therefore, more information is required when assessing whether a wetland's potential to act as hotspot for pollution swapping outweighs its potential to act as a mitigation tool for surface water pollution. Here we present results from an on-going monitoring study at a trial agricultural wetland located in small a mixed-use catchment in Cumbria, UK. Estimates were made of CH4, CO2 and N2O flux from the wetland surface using adapted floating static chambers, which were then directly compared with fluxes from an undisturbed riparian zone. Results indicate that while greenhouse gas flux from the wetland may be

  12. A methodology for handling exploration risk and constructing supply curves for oil and gas plays when resources are stacked

    International Nuclear Information System (INIS)

    Dallaire, S.M.

    1994-01-01

    The use of project economics to estimate full-cycle supply prices for undiscovered oil and gas resources is a straightforward exercise for those regions where oil and gas plays are not vertically superimposed on one another, ie. are not stacked. Exploration risk is incorporated into such an analysis by using a simple two-outcome decision tree model to include the costs of dry and abandoned wells. The decision tree model can be expanded to include multiple targets or discoveries, but this expansion requires additional drilling statistics and resource assessment data. A methodology is suggested to include exploration risk in the preparation of supply curves when stacked resources are expected and little or no information on uphole resources is available. In this method, all exploration costs for wells drilled to targets in the play being evaluated are assigned to that play, rather than prorated among the multiple targets or discoveries. Undiscovered pools are assumed to either bear all exploration costs (full cycle discoveries) or no exploration costs (half cycle discoveries). The weighted full- and half-cycle supply price is shown to be a more realistic estimate of the supply price of undiscovered pools in a play when stacked resources exist. The statistics required for this methodology are minimal, and resource estimates for prospects in other zones are not required. The equation relating the average pool finding cost to the discovery record is applicable to different scenarios regarding the presence of shallower and deeper resources. The equation derived for the two-outcome decision tree model is shown to be a special case of the general expression. 5 refs., 7 figs

  13. Emission characteristics of PCDD/Fs in stack gas from municipal solid waste incineration plants in Northern China.

    Science.gov (United States)

    Zhu, Feng; Li, Xiaofei; Lu, Jia-Wei; Hai, Jing; Zhang, Jieru; Xie, Bing; Hong, Chengyang

    2018-06-01

    Emission characteristics including congener's profile, gas emissions and toxic equivalent concentration (TEQ) indicators of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) in 57 stack gas samples from 6 municipal solid waste incinerators (MSWIs) in Northern China were investigated by gas chromatography-high resolution mass spectrometry (HRGC-HRMS). Additionally, PCDD/Fs formation mechanisms from the MSWIs were briefly discussed. Results revealed that the concentrations and equivalent concentrations of PCDD/Fs emissions in stack gas from 6 MSWIs were in the range of 0.11-2.53 ng Nm -3 and 0.007-0.059 ng TEQ Nm -3 , respectively. The emission factors of PCDD/Fs from 6 MSWIs varied from 0.027 to 0.225 μg I-TEQ tonne -1 , with a mean value of 0.17 μg I-TEQ tonne -1 waste, which was estimated to an annual emission of 234.96 mg I-TEQ of PCDD/Fs from 6 MSWIs to the atmosphere. O8CDD, O8CDF and 1,2,3,4,6,7,8-H7CDD were the indicatory compounds of PCDD/Fs to apportion the sources of PCDD/Fs in environmental medium especially in ambient environment of MSWIs. 1,2,3,7,8,9-H6CDF and 1,2,3,4,7,8-H6CDF can be used as TEQ indicators for monitoring PCDD/Fs emission. Based on the positive matrix factorization (PMF) model, eight factors were extracted by the PMF analysis. Formation of low-chlorinated PCDDs (1,2,3,7,8-P5CDD, 1,2,3,4,7,8-H6CDD, 1,2,3,6,7,8-H6CDD and 1,2,3,7,8,9-H6CDD) possessed strong correlation, and the chlorophenols maybe the important precursors of low-chlorinated PCDDs, which were generated within the low chlorinated content. Penta- and hexa-PCDFs formation in stack gas from MSWI may block catalytic sites for PCDFs formation from carbon. Meanwhile, possible formation mechanisms of high-chlorinated PCDDs (hepta- and octa-PCDDs) and high-chlorinated PCDFs (hepta- and octa-PCDFs) were respectively dependent. Copyright © 2018 Elsevier Ltd. All rights reserved.

  14. Post-test analysis of 20kW molten carbonate fuel cell stack operated on coal gas. Final report, August 1993--February 1996

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-05-01

    A 20kW carbonate fuel cell stack was operated with coal gas for the first time in the world. The stack was tested for a total of 4,000 hours, of which 3,900 hours of testing was conducted at the Louisiana Gasification Technology Incorporated, Plaquemine, Louisiana outdoor site. The operation was on either natural gas or coal gas and switched several times without any effects, demonstrating duel fuel capabilities. This test was conducted with 9142 kJ/m{sup 3} (245 Btu/cft) coal gas provided by a slipstream from Destec`s entrained flow, slagging, slurry-fed gasifier equipped with a cold gas cleanup subsystem. The stack generated up to 21 kW with this coal gas. Following completion of this test, the stack was brought to Energy Research Corporation (ERC) and a detailed post-test analysis was conducted to identify any effects of coal gas on cell components. This investigation has shown that the direct fuel cell (DFC) can be operated with properly cleaned and humidified coal-as, providing stable performance. The basic C direct fuel cell component materials are stable and display normal stability in presence of the coal gas. No effects of the coal-borne contaminants are apparent. Further cell testing at ERC 1 17, confirmed these findings.

  15. Free of pollution gas - an utopia or attainable goal? Gas radiant burner with a small capacity

    International Nuclear Information System (INIS)

    Hofbauer, P.; Bornscheuer, W.

    1993-01-01

    The firm Viessmann has developed a gas radiant burner for boiler capacities up to 100 kN combusting gas with extremely low pollutant emissions. This is possible since from the reaction zone a considerable part of the combustion heat is delivered through radiation by means of a glowing special steel structure. The theoretical fundamentals are explained by means of considerations regarding the equilibrium and a reaction kinetic numerical model. (orig.) [de

  16. Oil and Gas Production Wastewater: Soil Contamination and Pollution Prevention

    Directory of Open Access Journals (Sweden)

    John Pichtel

    2016-01-01

    Full Text Available During oil and natural gas production, so-called “produced water” comprises the largest byproduct stream. In addition, many oil and gas operations are augmented via injection of hydraulic fracturing (HF fluids into the formation. Both produced water and HF fluids may contain hundreds of individual chemicals, some known to be detrimental to public health and the environment. Oil and gas production wastewater may serve a range of beneficial purposes, particularly in arid regions, if managed correctly. Numerous treatment technologies have been developed that allow for injection, discharge to the land surface, or beneficial reuse. Although many papers have addressed the effects of oil and gas production wastewater (OGPW on groundwater and surface water quality, significantly less information is available on the effects of these fluids on the soil resource. This review paper compiles fundamental information on numerous chemicals used and produced during oil and gas development and their effects on the soil environment. Additionally, pollution prevention technologies relating to OGPW are presented. An understanding of the effects of OGPW on soil chemical, physical, and biological properties can provide a foundation for effective remediation of OGPW-affected soils; additionally, sustainable reuse of oil and gas water for irrigation and industrial purposes may be enhanced.

  17. Potential of electrical gas discharges for pollution control of large gas volumes

    International Nuclear Information System (INIS)

    Kogelschatz, U.

    1997-01-01

    Non-equilibrium gas discharges in many cases offer an innovative approach to the solution cf industrial air pollution problems. Negative corona discharges are used in electrostatic precipitators to collect dust and fly ash particles. Pulsed positive streamer coronas, dielectric-barrier discharges and possibly also flow-stabilised high pressure glow discharges are emerging technologies for the destruction of air pollutants like nitrogen oxides and sulfur dioxide in flue gases and volatile organic compounds (VOCs) in industrial effluents. The different discharge types are discussed with special emphasis on their potential for upscaling. Major applications are expected particularly in the removal of dilute concentrations of air pollutants, in odour control and in the simultaneous removal of different pollutants. Dielectric-barrier discharges exhibit disposal efficiencies similar to those of pulsed positive streamer coronas and require less sophisticated feeding circuits in large-scale industrial applications. (author)

  18. Spatial variation of PCDD/F and PCB emissions and their composition profiles in stack flue gas from the typical cement plants in China.

    Science.gov (United States)

    Zou, Lili; Ni, Yuwen; Gao, Yuan; Tang, Fengmei; Jin, Jing; Chen, Jiping

    2018-03-01

    Cement production processes are important sources of unintentionally produced persistent organic pollutants (UP-POPs), such as polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), and polychlorinated biphenyls (PCBs). The emissions of PCDD/Fs and PCBs in the stack flue gases from eight typical cement plants in China were investigated in this study, including one wet process rotary kiln, three dry process rotary kilns and four vertical shaft kilns. PCBs exhibited relatively higher mass concentrations with the dioxin-like (dl) and indicator PCBs of 0.14-17.36 and 0.42-12.90 ng/Nm 3 , respectively. However, PCDD/Fs contributed most to the total toxic equivalent concentrations, with the proportions exceeding 90%. The international toxicity equivalency (I-TEQ) concentrations of PCDD/Fs varied greatly from 0.01 to 0.46 ng I-TEQ/Nm 3 in stack gases, two of which exceeded the exhaust gas concentration limit of 0.1 ng I-TEQ/Nm 3 established by the European Union Directive. In weight units, 1,2,3,4,6,7,8-HpCDF was the most abundant congener in the stack gases from various types of cement kilns, with the factions of 17.0-27.8%. TCDFs and PeCDFs were the first two most abundant homologue groups. 2,3,4,7,8-PeCDF was the largest contributor to the total I-TEQ. The emission factors of PCDD/Fs and PCBs in the eight cement kilns were estimated to be 0.01-1.35 μg I-TEQ/t clinker and 8.20 × 10 -4 ∼8.23 × 10 -2  μg World Health Organization TEQ (W-TEQ)/t clinker, respectively. No obvious differences of the PCDD/F and PCB emission factors were found among the varied cement production technologies. Copyright © 2017. Published by Elsevier Ltd.

  19. Kinetic studies of gas mixtures and their application to gas lasers and pollutant detection

    International Nuclear Information System (INIS)

    Chen, C.H.; Judish, J.P.; Payne, M.G.

    1978-01-01

    A 2-MeV proton beam with a 10-ns pulse width was used to excite various gas mixtures. The emitted vacuum ultraviolet (500 A to 2000 A) and ultraviolet visible (2000 A to 8000 A) photons passing through separate monochromators were detected by using single photon counting techniques. Time-resolved and time-integrated fluorescent spectroscopy was used to study the detailed mechanism of excitation energy transfer, Penning ionization, charge transfer, and ion-ion recombination processes. The energy precursors of various excited species in a number of gas mixtures were identified, and the quenching rates of excited atoms and ions by numerous small molecules were measured. Relative fluorescence efficiencies and energy pathways of proton-excited gas mixtures were used to study the kinetics of high power gas lasers. An ultrasensitive method for the detection of certain pollutants utilizing energy or charge transfer processes in proton-excited gas mixtures has been developed

  20. PROJECT OF POLLUTANTS SEPARATOR FROM THE GAS STATION

    Directory of Open Access Journals (Sweden)

    Barbara Kościelnik

    2016-06-01

    Full Text Available Oily wastewater are dangerous for the environment, because they can contaminate ground water or surface, which can lead to contamination of the biosystem or poisoning of humans and animals. The treatment plant of this kind may include petroleum products or substances derived from natural gas, crude oil, asphalt or natural wax. Of course, in the wastewater oily you cannot forget about vegetable oils used in catering. Waste water of this type to be cleaned are subjected to the following processes: flotation, sedimentation, filtration, flowing out, thermal methods, biodegradation, adsorption or chemical and thermal methods to destabilize the emulsion. The aim of this study was to design a separator pollution from the gas station. We present the investment and operating costs. In designing the system chosen individual process units based on the requirements of the quality of wastewater specified in PN - EU 858.

  1. Congener-specific determination of ultratrace levels of chlorinated and brominated polycyclic aromatic hydrocarbons in atmosphere and industrial stack gas by isotopic dilution gas chromatography/high resolution mass spectrometry method.

    Science.gov (United States)

    Jin, Rong; Liu, Guorui; Zheng, Minghui; Fiedler, Heidelore; Jiang, Xiaoxu; Yang, Lili; Wu, Xiaolin; Xu, Yang

    2017-08-04

    Isotopic dilution gas chromatography combined with high resolution mass spectrometry (GC/HRMS) has overwhelming advantages with respect to the accuracy of congener-specific ultratrace analysis of complex persistent organic pollutants (POPs) in environmental matrices. However, an isotopic dilution GC/HRMS method for analysis of chlorinated and brominated polycyclic aromatic hydrocarbons (Cl-PAHs and Br-PAHs) using 13 C-labelled congeners as internal standards has not been established. In this study, a method for identification and quantification of 38 congeners of Cl-PAHs and Br-PAHs in atmosphere and stack gas samples from waste incinerators was developed using the isotopic dilution GC/HRMS technique. The instrumental detection limits of the GC/HRMS method ranged from 0.2pg to 1.8pg for Cl-PAH congeners, and 0.7pg to 2.7pg for Br-PAH congeners, which were about three orders of magnitude lower than those of the GC/quadrupole MS method. This new method developed was also the first to enable determination of Cl-PAH and Br-PAH homologs comprising congeners with the same molecular skeleton and chlorine or bromine substitution numbers. Among the detected congeners, seven Cl-PAH congeners and thirteen Br-PAH congeners that were abundant in the atmosphere and stack gases released from waste incinerators were firstly detected in real samples and reported using the established isotopic dilution GC/HRMS method. The developed isotopic dilution GC/HRMS is significant and needed for better studying the environmental behavior and health risk of Cl-PAHs and Br-PAHs. Copyright © 2017 Elsevier B.V. All rights reserved.

  2. Surface gas pollutants in Lhasa, a highland city of Tibet: current levels and pollution implications

    Science.gov (United States)

    Ran, L.; Lin, W. L.; Deji, Y. Z.; La, B.; Tsering, P. M.; Xu, X. B.; Wang, W.

    2014-05-01

    Through several years of development, the city of Lhasa has become one of the most populated and urbanized areas on the highest plateau in the world. In the process of urbanization, current and potential air quality issues have been gradually concerned. To investigate the current status of air pollution in Lhasa, various gas pollutants including NOx, CO, SO2 and O3 were continuously measured from June 2012 to May 2013 at an urban site (29.40° N, 91.08° E, 3650 m a.s.l.). The seasonal variations of primary gas pollutants exhibited a peak from November to January with a large variability. High concentrations of primary trace gases almost exclusively occurred under low wind speed and showed no distinct dependence on wind direction, implying local urban emissions to be predominant. A comparison of NO2, CO and SO2 concentrations in summer between 1998 and 2012 indicated a significant increase in emissions of these gas pollutants and a change in their intercorrelations, as a result of a substantial growth in the demand of energy consumption using fossil fuels instead of previously widely used biofuels. The pronounced diurnal double peaks of primary trace gases in all seasons suggested automobile exhaust to be a major emission source in Lhasa. The secondary gas pollutant O3 displayed an average diurnal cycle of a shallow flat peak for about 4-5 h in the afternoon and a minimum in the early morning. Nighttime O3 was sometimes completely consumed by the high level of NOx. Seasonally, the variations of O3 concentrations displayed a low valley in winter and a peak in spring. In autumn and winter, transport largely contributed to the observed O3 concentrations, given its dependence on wind speed and wind direction, while in spring and summer photochemistry played an important role. A more efficient buildup of O3 concentrations in the morning and a higher peak in the afternoon was found in summer 2012 than in 1998. An enhancement in O3 concentrations would be expected in the

  3. Surface gas pollutants in Lhasa, a highland city of Tibet - current levels and pollution implications

    Science.gov (United States)

    Ran, L.; Lin, W. L.; Deji, Y. Z.; La, B.; Tsering, P. M.; Xu, X. B.; Wang, W.

    2014-10-01

    Through several years of development, the city of Lhasa has become one of the most populated and urbanized areas on the highest plateau in the world. In the process of urbanization, current and potential air quality issues have been gradually concerned. To investigate the current status of air pollution in Lhasa, various gas pollutants including NOx, CO, SO2, and O3, were continuously measured from June 2012 to May 2013 at an urban site (29.40° N, 91.08° E, 3650 m a.s.l.). The seasonal variations of primary gas pollutants exhibited a peak from November to January with a large variability. High mixing ratios of primary trace gases almost exclusively occurred under low wind speed and showed no distinct dependence on wind direction, implying local urban emissions to be predominant. A comparison of NO2, CO, and SO2 mixing ratios in summer between 1998 and 2012 indicated a significant increase in emissions of these gas pollutants and a change in their intercorrelations, as a result of a substantial growth in the demand of energy consumption using fossil fuels instead of previously widely used biomass. The pronounced diurnal double peaks of primary trace gases in all seasons suggested automobile exhaust to be a major emission source in Lhasa. The secondary gas pollutant O3 displayed an average diurnal cycle of a shallow flat peak for about 4-5 h in the afternoon and a minimum in the early morning. Nighttime O3 was sometimes completely consumed by the high level of NOx. Seasonally, the variations of O3 mixing ratios displayed a low valley in winter and a peak in spring. In autumn and winter, transport largely contributed to the observed O3 mixing ratios, given its dependence on wind speed and wind direction, while in spring and summer photochemistry played an important role. A more efficient buildup of O3 mixing ratios in the morning and a higher peak in the afternoon was found in summer 2012 than in 1998. An enhancement in O3 mixing ratios would be expected in the

  4. Numerical evaluation of various gas and coolant channel designs for high performance liquid-cooled proton exchange membrane fuel cell stacks

    International Nuclear Information System (INIS)

    Sasmito, Agus P.; Kurnia, Jundika C.; Mujumdar, Arun S.

    2012-01-01

    A careful design of gas and coolant channel is essential to ensure high performance and durability of proton exchange membrane (PEM) fuel cell stack. The channel design should allow for good thermal, water and gas management whilst keeping low pressure drop. This study evaluates numerically the performance of various gas and coolant channel designs simultaneously, e.g. parallel, serpentine, oblique-fins, coiled, parallel-serpentine and a novel hybrid parallel-serpentine-oblique-fins designs. The stack performance and local distributions of key parameters are investigated with regards to the thermal, water and gas management. The results indicate that the novel hybrid channel design yields the best performance as it constitutes to a lower pumping power and good thermal, water and gas management as compared to conventional channels. Advantages and limitation of the designs are discussed in the light of present numerical results. Finally, potential application and further improvement of the design are highlighted. -- Highlights: ► We evaluate various gas and coolant channel designs in liquid-cooled PEM fuel cell stack. ► The model considers coupled electrochemistry, channel design and cooling effect simultaneously. ► We propose a novel hybrid channel design. ► The novel hybrid channel design yields the best thermal, water and gas management which is beneficial for long term durability. ► The novel hybrid channel design exhibits the best performance.

  5. Air Pollution Modelling to Predict Maximum Ground Level Concentration for Dust from a Palm Oil Mill Stack

    Directory of Open Access Journals (Sweden)

    Regina A. A.

    2010-12-01

    Full Text Available The study is to model emission from a stack to estimate ground level concentration from a palm oil mill. The case study is a mill located in Kuala Langat, Selangor. Emission source is from boilers stacks. The exercise determines the estimate the ground level concentrations for dust to the surrounding areas through the utilization of modelling software. The surround area is relatively flat, an industrial area surrounded by factories and with palm oil plantations in the outskirts. The model utilized in the study was to gauge the worst-case scenario. Ambient air concentrations were garnered calculate the increase to localized conditions. Keywords: emission, modelling, palm oil mill, particulate, POME

  6. Study of medical isotope production facility stack emissions and noble gas isotopic signature using automatic gamma-spectra analysis platform

    Science.gov (United States)

    Zhang, Weihua; Hoffmann, Emmy; Ungar, Kurt; Dolinar, George; Miley, Harry; Mekarski, Pawel; Schrom, Brian; Hoffman, Ian; Lawrie, Ryan; Loosz, Tom

    2013-04-01

    The nuclear industry emissions of the four CTBT (Comprehensive Nuclear-Test-Ban Treaty) relevant radioxenon isotopes are unavoidably detected by the IMS along with possible treaty violations. Another civil source of radioxenon emissions which contributes to the global background is radiopharmaceutical production companies. To better understand the source terms of these background emissions, a joint project between HC, ANSTO, PNNL and CRL was formed to install real-time detection systems to support 135Xe, 133Xe, 131mXe and 133mXe measurements at the ANSTO and CRL 99Mo production facility stacks as well as the CANDU (CANada Deuterium Uranium) primary coolant monitoring system at CRL. At each site, high resolution gamma spectra were collected every 15 minutes using a HPGe detector to continuously monitor a bypass feed from the stack or CANDU primary coolant system as it passed through a sampling cell. HC also conducted atmospheric monitoring for radioxenon at approximately 200 km distant from CRL. A program was written to transfer each spectrum into a text file format suitable for the automatic gamma-spectra analysis platform and then email the file to a server. Once the email was received by the server, it was automatically analysed with the gamma-spectrum software UniSampo/Shaman to perform radionuclide identification and activity calculation for a large number of gamma-spectra in a short period of time (less than 10 seconds per spectrum). The results of nuclide activity together with other spectrum parameters were saved into the Linssi database. This database contains a large amount of radionuclide information which is a valuable resource for the analysis of radionuclide distribution within the noble gas fission product emissions. The results could be useful to identify the specific mechanisms of the activity release. The isotopic signatures of the various radioxenon species can be determined as a function of release time. Comparison of 133mXe and 133Xe activity

  7. Energy Conservation Alternatives Study (ECAS): Conceptual Design and Implementation Assessment of a Utility Steam Plant with Conventional Furnace and Wet Lime Stack Gas Scrubbers

    Science.gov (United States)

    Brown, Dale H.

    1976-01-01

    A study was performed to estimate the technical/economic characteristics of a steam power plant (3500 pounds per square inch gauge, 1000 degrees Fahrenheit / 1000 degrees Fahrenheit) with a coal-burning radiant furnace and a wet lime stack gas scrubber to control sulfur emissions. Particulate emissions were controlled by an electrostatic precipitator operating at 300 degrees Fahrenheit. The stack gas from the scrubber was reheated from 125 degrees Fahrenheit to 250 degrees Fahrenheit as a base case, and from 125 degrees Fahrenheit to 175 degrees Fahrenheit as an alternate case. The study was performed on a basis consistent with the General Electric ECAS Phase II evaluation of advanced energy conversion systems for electric utility baseload applications using coal or coal-derived fuels. A conceptual design of the power plant was developed, including the on-site calcination of limestone to lime and the provision of sludge ponds to store the products of flue gas scrubbing. From this design, estimates were derived for power plant efficiency, capital cost, environmental intrusion characteristics, natural resource requirements, and cost of electricity at an assumed capacity factor of 65 percent. An implementation assessment was performed where factors affecting applicability of the conceptual design power plant in electric utility generation systems were appraised. At 250 degrees Fahrenheit and 175 degrees Fahrenheit stack gas temperatures respectively, the plants showed a cost of electricity of 39.8 and 37.0 mills per kilowatt-hours and overall plant efficiencies of 32 percent and 34 percent.

  8. Are greenhouse gas emissions from international shipping a type of marine pollution?

    Science.gov (United States)

    Shi, Yubing

    2016-12-15

    Whether greenhouse gas emissions from international shipping are a type of marine pollution is a controversial issue and is currently open to debate. This article examines the current treaty definitions of marine pollution, and applies them to greenhouse gas emissions from ships. Based on the legal analysis of treaty definitions and relevant international and national regulation on this issue, this article asserts that greenhouse gas emissions from international shipping are a type of 'conditional' marine pollution. Copyright © 2016 Elsevier Ltd. All rights reserved.

  9. Current situation and control measures of groundwater pollution in gas station

    Science.gov (United States)

    Wu, Qiong; Zhang, Xiaofeng; Zhang, Qianjin

    2017-11-01

    In recent years, pollution accidents caused by gas station leakage has occurred worldwide which can be persistent in groundwater. Numerous studies have demonstrated that the contaminated groundwater is threatening the ecological environment and human health. In this article, current status and sources of groundwater pollution by gas station are analyzed, and experience of how to prevent groundwater pollution from gas stations are summarized. It is demonstrated that installation of secondary containment measures for the oil storage of the oil tank system, such as installation of double-layer oil tanks or construction of impermeable ponds, is a preferable method to prevent gas stations from groundwater pollution. Regarding to the problems of groundwater pollution caused by gas station, it is proposed that it is urgent to investigate the leakage status of gas station. Relevant precise implementation regulations shall be issued and carried out, and supervision management of gas stations would need to be strengthened. Then single-layer steel oil tanks shall be replaced by double-layer tanks, and the impermeable ponds should be constructed according to the risk ranking. From the control methodology, the groundwater environment monitoring systems, supervision level, laws and regulations as well as pollution remediation should also be carried out and strengthened.

  10. Exhaust-stack nozzle area and shape for individual cylinder exhaust-gas jet-propulsion system

    Science.gov (United States)

    Pinkel, Benjamin; Turner, Richard; Voss, Fred; Humble, Leroy V

    1943-01-01

    This report presents the results of an investigation conducted on the effect of exhaust-stack nozzle area, shape, and length on engine power, jet thrust, and gain in net thrust (engine propeller plus jet). Single-cylinder engine data were obtained using three straight stacks 25, 44, and 108 inches in length; an S-shaped stack, a 90 degree bend, a 180 degree bend, and a short straight stack having a closed branch faired into it. Each stack was fitted with nozzles varying in exit area from 0.91 square inch to the unrestricted area of the stack of 4.20 square inches. The engine was generally operated over a range of engine speeds from 1300 to 2100 r.p.m, inlet-manifold pressures from 22 to 30 inches of mercury absolute, and a fuel-air ratio of 0.08. The loss in engine power, the jet thrust, and the gain in net thrust are correlated in terms of several simple parameters. An example is given for determining the optimum nozzle area and the overall net thrust.

  11. Estimates of environmental pollution from compressor stations of main gas pipelines

    International Nuclear Information System (INIS)

    Kyarges, A.A.; Ablyazina, R.R.; Petukhova, N.N.

    1997-01-01

    In natural gas transmission through main pipelines compressor stations (CS) discharge pollutants. During operation of mains and auxiliary equipment, as a rule, natural gas (having in its components odorants), products of natural gas combustion and a number of other contaminants are emitted into the atmosphere. During operation of main and auxiliary equipment of CS up to 16 pollutants are emitted into the atmosphere. Existent emissions are discussed for a number of operating CS with different gas turbine units. Estimates are made of atmosphere from mains and auxiliary units. (R.P.)

  12. Gas-phase advanced oxidation for effective, efficient in situ control of pollution

    DEFF Research Database (Denmark)

    Johnson, Matthew Stanley; Nilsson, Elna Johanna Kristina; Svensson, Erik Anders

    2014-01-01

    In this article, gas-phase advanced oxidation, a new method for pollution control building on the photo-oxidation and particle formation chemistry occurring in the atmosphere, is introduced and characterized. The process uses ozone and UV-C light to produce in situ radicals to oxidize pollution...

  13. On Stack Reconstruction Problem

    Directory of Open Access Journals (Sweden)

    V. D. Аkeliev

    2009-01-01

    Full Text Available The paper describes analytical investigations that study relation of fuel combustion regimes with concentration values of sulphur anhydride in flue gases and acid dew point. Coefficients of convective heat transfer at internal and external surfaces of stacks have been determined in the paper. The paper reveals the possibility to reconstruct stacks while using gas discharging channel made of composite material on the basis of glass-reinforced plastic which permits to reduce thermo-stressed actions on reinforced concrete and increase volume of released gases due to practically two-fold reduction of gas-dynamic pressure losses along the pipe length.

  14. Air pollution from industrial waste gas emissions is associated with cancer incidences in Shanghai, China.

    Science.gov (United States)

    Cong, Xiaowei

    2018-02-27

    Outdoor air pollution may be associated with cancer risk at different sites. This study sought to investigate outdoor air pollution from waste gas emission effects on multiple cancer incidences in a retrospective population-based study in Shanghai, China. Trends in cancer incidence for males and females and trends in waste gas emissions for the total waste gas, industrial waste gas, other waste gas, SO 2 , and soot were investigated between 1983 and 2010 in Shanghai, China. Regression models after adjusting for confounding variables were constructed to estimate associations between waste gas emissions and multiple cancer incidences in the whole group and stratified by sex, Engel coefficient, life expectancy, and number of doctors per 10,000 populations to further explore whether changes of waste gas emissions were associated with multiple cancer incidences. More than 550,000 new cancer patients were enrolled and reviewed. Upward trends in multiple cancer incidences for males and females and in waste gas emissions were observed from 1983 to 2010 in Shanghai, China. Waste gas emissions came mainly from industrial waste gas. Waste gas emissions was significantly positively associated with cancer incidence of salivary gland, small intestine, colorectal, anus, gallbladder, thoracic organs, connective and soft tissue, prostate, kidney, bladder, thyroid, non-Hodgkin's lymphoma, lymphatic leukemia, myeloid leukemia, and other unspecified sites (all p gas emissions and the esophagus cancer incidence was observed (p gas emissions was associated with multiple cancer incidences.

  15. SnO2 Nanostructure as Pollutant Gas Sensors: Synthesis, Sensing Performances, and Mechanism

    Directory of Open Access Journals (Sweden)

    Brian Yuliarto

    2015-01-01

    Full Text Available A significant amount of pollutants is produced from factories and motor vehicles in the form of gas. Their negative impact on the environment is well known; therefore detection with effective gas sensors is important as part of pollution prevention efforts. Gas sensors use a metal oxide semiconductor, specifically SnO2 nanostructures. This semiconductor is interesting and worthy of further investigation because of its many uses, for example, as lithium battery electrode, energy storage, catalyst, and transistor, and has potential as a gas sensor. In addition, there has to be a discussion of the use of SnO2 as a pollutant gas sensor especially for waste products such as CO, CO2, SO2, and NOx. In this paper, the development of the fabrication of SnO2 nanostructures synthesis will be described as it relates to the performances as pollutant gas sensors. In addition, the functionalization of SnO2 as a gas sensor is extensively discussed with respect to the theory of gas adsorption, the surface features of SnO2, the band gap theory, and electron transfer.

  16. CRITERIA POLLUTANT EMISSIONS FROM INTERNAL COMBUSTION ENGINES IN THE NATURAL GAS INDUSTRY VOLUME 1. TECHNICAL REPORT

    Science.gov (United States)

    The report summarizes emission factors for criteria pollutants (NOx, CO, CH4, C2H6, THC, NMHC, and NMEHC) from stationary internal combustion engines and gas turbines used in the natural gas industry. The emission factors were calculated from test results from five test campaigns...

  17. Natural gas and quality of fuels for the reduction of atmospheric pollution

    International Nuclear Information System (INIS)

    Riva, A.; Occhio, L.; Andreetto, B.

    1998-01-01

    The production of atmospheric pollutants in combustion processes depends on plant characteristic, combustion conditions and fuel quality. The influence of fuel quality on the emission of sulphur oxides, nitrogen oxides, carbon monoxide, dust and carbon dioxide and on the emission of some toxic pollutants, such as heavy metals and polycyclic aromatic hydrocarbons, is analysed. The comparison between the emission limits, fixed by the Italian legislation, and the uncontrolled pollutant emissions, produced by fossil fuel combustion in power plants and industrial use, shows that, in order to comply with the limits, a reduction of pollutant emissions is required through the use of abatement systems and cleaner fuels where natural gas has a primary role. The use of cleaner fuels is particularly required in heating plants and appliances for the residential sector, where the development of new gas technologies further increases the environmental advantages of natural gas in comparison with other fuels [it

  18. Water recovery and air humidification by condensing the moisture in the outlet gas of a proton exchange membrane fuel cell stack

    International Nuclear Information System (INIS)

    Wan, Z.M.; Wan, J.H.; Liu, J.; Tu, Z.K.; Pan, M.; Liu, Z.C.; Liu, W.

    2012-01-01

    Humidification is one of the most important factors for the operation of proton exchange membrane fuel cell (PEMFC). To maintain the membrane at hydrated state, plenty of water is needed for the state-of-the-art of PEMFC technology, especially in large power applications or long time operation. A condenser is introduced to separate liquid water from the air outlet for air self-sufficient in water of the stack in this study. The condensed temperature at the outlet of the condenser and water recovered amount for air self-sufficient in water are investigated theoretically and experimentally. It is shown that the condensed temperature for air self-sufficient in water is irrelevant with the working current of the stack. When the condenser outlet temperature was above the theoretical line, recovery water was not sufficient for the air humidification. On the contrary, it is sufficient while the temperature was below the theoretical line. It is also shown that when the moisture is sufficiently cooled, large amount water can be separated from the outlet gas, and it increased almost linearly with the time. With the introduction of the condenser, the recovered amount of water can easily satisfy the air self-sufficient in water by condensing the outlet gas to a proper temperature. - Highlights: ► We introduce a condenser to separate liquid water from the air outlet in the stack. ► The mechanism of air self-sufficient in water by condensing gas is presented. ► The condensed temperature and water recovered amount are investigated. ► An experiment is present to validate simplicity and feasibility of the criterion. ► The criterion for air humidification is used for choosing the condenser.

  19. Algebraic stacks

    Indian Academy of Sciences (India)

    generally, any fiber product) is not uniquely defined: it is only defined up to unique isomorphism. ..... Fiber product. Given two morphisms f1 : F1 ! G, f2 : F2 ! G, we define a new stack. F1 آG F2 (with projections to F1 and F2) as follows. The objects are triples ًX1; X2; ق ..... In fact, any Artin stack F can be defined in this fashion.

  20. Gas-phase advanced oxidation as an integrated air pollution control technique

    Directory of Open Access Journals (Sweden)

    Getachew A. Adnew

    2016-03-01

    Full Text Available Gas-phase advanced oxidation (GPAO is an emerging air cleaning technology based on the natural self-cleaning processes that occur in the Earth’s atmosphere. The technology uses ozone, UV-C lamps and water vapor to generate gas-phase hydroxyl radicals that initiate oxidation of a wide range of pollutants. In this study four types of GPAO systems are presented: a laboratory scale prototype, a shipping container prototype, a modular prototype, and commercial scale GPAO installations. The GPAO systems treat volatile organic compounds, reduced sulfur compounds, amines, ozone, nitrogen oxides, particles and odor. While the method covers a wide range of pollutants, effective treatment becomes difficult when temperature is outside the range of 0 to 80 °C, for anoxic gas streams and for pollution loads exceeding ca. 1000 ppm. Air residence time in the system and the rate of reaction of a given pollutant with hydroxyl radicals determine the removal efficiency of GPAO. For gas phase compounds and odors including VOCs (e.g. C6H6 and C3H8 and reduced sulfur compounds (e.g. H2S and CH3SH, removal efficiencies exceed 80%. The method is energy efficient relative to many established technologies and is applicable to pollutants emitted from diverse sources including food processing, foundries, water treatment, biofuel generation, and petrochemical industries.

  1. Organic Pollutants in Shale Gas Flowback and Produced Waters

    NARCIS (Netherlands)

    Butkovskyi, Andrii; Bruning, Harry; Kools, Stefan A.E.; Rijnaarts, Huub H.M.; Wezel, van Annemarie P.

    2017-01-01

    Organic contaminants in shale gas flowback and produced water (FPW) are traditionally expressed as total organic carbon (TOC) or chemical oxygen demand (COD), though these parameters do not provide information on the toxicity and environmental fate of individual components. This review addresses

  2. Gas Flaring, Environmental Pollution and Abatement Measures in ...

    African Journals Online (AJOL)

    The environmental impact of gas flaring on the oil bearing enclave of the Niger Delta, Nigeria, was examined with a view to evaluating the abatement measures put in place by the Federal government of Nigeria and the oil producing companies. Primary and secondary information and data were analyzed during the study.

  3. The impact of stack geometry and mean pressure on cold end temperature of stack in thermoacoustic refrigeration systems

    Science.gov (United States)

    Wantha, Channarong

    2018-02-01

    This paper reports on the experimental and simulation studies of the influence of stack geometries and different mean pressures on the cold end temperature of the stack in the thermoacoustic refrigeration system. The stack geometry was tested, including spiral stack, circular pore stack and pin array stack. The results of this study show that the mean pressure of the gas in the system has a significant impact on the cold end temperature of the stack. The mean pressure of the gas in the system corresponds to thermal penetration depth, which results in a better cold end temperature of the stack. The results also show that the cold end temperature of the pin array stack decreases more than that of the spiral stack and circular pore stack geometry by approximately 63% and 70%, respectively. In addition, the thermal area and viscous area of the stack are analyzed to explain the results of such temperatures of thermoacoustic stacks.

  4. Combatting urban air pollution through Natural Gas Vehicle (NGV) analysis, testing, and demonstration

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-03-01

    Deteriorating urban air quality ranks as a top concern worldwide, since air pollution adversely affects both public health and the environment. The outlook for improving air quality in the world`s megacities need not be bleak, however, The use of natural gas as a transportation fuel can measurably reduce urban pollution levels, mitigating chronic threats to health and the environment. Besides being clean burning, natural gas vehicles (NGVs) are economical to operate and maintain. The current cost of natural gas is lower than that of gasoline. Natural gas also reduces the vehicle`s engine wear and noise level, extends engine life, and decreases engine maintenance. Today, about 700,000 NGVs operate worldwide, the majority of them converted from gasoline or diesel fuel. This article discusses the economic, regulatory and technological issues of concern to the NGV industry.

  5. The Direct FuelCell™ stack engineering

    Science.gov (United States)

    Doyon, J.; Farooque, M.; Maru, H.

    FuelCell Energy (FCE) has developed power plants in the size range of 300 kW to 3 MW for distributed power generation. Field-testing of the sub-megawatt plants is underway. The FCE power plants are based on its Direct FuelCell™ (DFC) technology. This is so named because of its ability to generate electricity directly from a hydrocarbon fuel, such as natural gas, by reforming it inside the fuel cell stack itself. All FCE products use identical 8000 cm 2 cell design, approximately 350-400 cells per stack, external gas manifolds, and similar stack compression systems. The difference lies in the packaging of the stacks inside the stack module. The sub-megawatt system stack module contains a single horizontal stack whereas the MW-class stack module houses four identical vertical stacks. The commonality of the design, internal reforming features, and atmospheric operation simplify the system design, reduce cost, improve efficiency, increase reliability and maintainability. The product building-block stack design has been advanced through three full-size stack operations at company's headquarters in Danbury, CT. The initial proof-of-concept of the full-size stack design was verified in 1999, followed by a 1.5 year of endurance verification in 2000-2001, and currently a value-engineered stack version is in operation. This paper discusses the design features, important engineering solutions implemented, and test results of FCE's full-size DFC stacks.

  6. A New Empirical Model to Estimate Landfill Gas Pollution

    Directory of Open Access Journals (Sweden)

    Hamidreza Kamalan

    2016-07-01

    Full Text Available Background: Landfills are the most important producers of methane as human source. So, prediction of landfill gas generation is by far the most important concern of scientists, decision makers, and landfill owners as well as health authorities. Almost all the currently used models are based on Monod equation first order decay rate which is experimental while the main purpose of this research is to develop a numerical model. Methods: A real scale pilot landfill with 4500 tons of municipal solid waste has been designed, constructed, and operated for two years. Required measurements have been done to provide proper data on greenhouse gases emitted by the landfill and monitor its status such as internal temperature, leachate content, and its settlement during two years. Afterwards, weighted residual method has been used to develop the numerical model. Then, the newly mathematical method has been verified with data from another landfill. Results: Measurements showed that the minimum and maximum percentages of methane among landfill gas were 22.3 and 46.1%, respectively. These values for velocity of landfill gas are 0.3 and 0.48 meters per second, in that order. Conclusion: Since there is just 0.6 percent error in calculation as compared to real measurements from a landfill in California and most of the models used have ten percent error, this simple empirical numerical model is suggested to be utilized by scientists, decision makers, and landfill owners

  7. DESIGN, FABRICATION, AND TESTING OF AN ADVANCED, NON-POLLUTING TURBINE DRIVE GAS GENERATOR

    International Nuclear Information System (INIS)

    Unknown

    2002-01-01

    The objectives of this report period were to complete the development of the Gas Generator design, which was done; fabricate and test of the non-polluting unique power turbine drive gas Gas Generator, which has been postponed. Focus during this report period has been to complete the brazing and bonding necessary to fabricate the Gas Generator hardware, continue making preparations for fabricating and testing the Gas Generator, and continuing the fabrication of the Gas Generator hardware and ancillary hardware in preparation for the test program. Fabrication is more than 95% complete and is expected to conclude in early May 2002. the test schedule was affected by relocation of the testing to another test supplier. The target test date for hot fire testing is now not earlier than June 15, 2002

  8. Analysis of organic pollutants in the soils of the disused gas plants. Experimental evaluation and recommendations

    International Nuclear Information System (INIS)

    Caron, S.; Carmant, S.

    1997-01-01

    In France, environmental investigations are at the moment carried out on numerous disused gas plants sites, which soils can have been polluted by the by-products generated during the fabrication of the gas (most of the time coal tar). Within the context of those investigations, diagnosis of the pollution of soils by the analytical way is an essential operation on the basis of which the risks are evaluated and the treatments are decided. Moreover, the evolution of the pollution level during the cleaning up of the soils and the efficiency of the treatment can only be measured by the analytical way. Until today, analytical aspects, relative to the study of polluted soils can be discussed. Indeed, in consideration of the heterogeneity of the soils, there are difficulties, on the first hand on sites during the sampling of the soils, on the other hand in the laboratory during the chemical analysis of the organic pollutants. After having evoked this problematic, the paper accounts for the evaluation, done by GDF, of varied analytical methods, used and even recommended by reference oragnizations (included: preparatation of the samples, extraction of the organic pollutants, analysis of the extract and interpretation). Finally, on the basis of the accumulated experinece, some advice are given on how to optimize the number and the kind of samples as well as the combined analysis. (au)

  9. Monitoring air pollutants due to gas flaring using rain water | Rim ...

    African Journals Online (AJOL)

    The mean levels of conductivity, TDS, and SO42- were within statutory safe limits, while that of pH, CO32- and NO3- were above the safe limits specified by the Federal Ministry of Environment guidelines and standards for drinking water quality. Keywords: rainwater, gas flare, pollutants, monitoring, water quality

  10. Turbo-gas emissions and integrated pollution prevention and control (IPPC)

    International Nuclear Information System (INIS)

    Mariani, M.; Sera, B.

    2005-01-01

    The present paper considers the gas-turbine pollution and joints out that the NO, is the most important pollutant among others pollutants as well as the carbon oxide and the volatile organic compounds because the NO x , has a high mass production rate (in the combustion chamber), elevated toxicity to the ecosystem and because of being in the atmosphere a precursor of secondary ultrafine particles PM 2,5 . In with reference to the integrated pollution and control (IPPC) the job shows schemes of chain chemical reactions which are on the base of the formation of different types of NO x , thermal and organic, and it illustrates the influence of some operative parameters on the combustion's efficiency and then on the NO x , production rate. Also, the study gives the best absolvable techniques (BAT) to reduce the NO x , production rate and to demolish it before its introduction, as well as gas exhaust, in the atmosphere. At the end, the work shows that the gas-turbine are to consider thermal engines with a little environment impact index specially when they make use of the natural gas, as well as fuel [it

  11. Apparatus and method for treating pollutants in a gas using hydrogen peroxide and UV light

    Science.gov (United States)

    Cooper, Charles David (Inventor); Clausen, Christian Anthony (Inventor)

    2005-01-01

    An apparatus for treating pollutants in a gas may include a source of hydrogen peroxide, and a treatment injector for creating and injecting dissociated hydrogen peroxide into the flow of gas. The treatment injector may further include an injector housing having an inlet, an outlet, and a hollow interior extending therebetween. The inlet may be connected in fluid communication with the source of hydrogen peroxide so that hydrogen peroxide flows through the hollow interior and toward the outlet. At least one ultraviolet (UV) lamp may be positioned within the hollow interior of the injector housing. The at least one UV lamp may dissociate the hydrogen peroxide flowing through the tube. The dissociated hydrogen peroxide may be injected into the flow of gas from the outlet for treating pollutants, such as nitrogen oxides.

  12. Gaseous atmospheric pollution. Gas measurement; Pollution atmospherique gazeuse. Mesure des gaz

    Energy Technology Data Exchange (ETDEWEB)

    Toupance, G. [Paris-12 Univ., 94 - Creteil (France); Person, A. [Laboratoire d' Hygiene de la Ville de Paris, 75 (France); Le Moullec, Y.; Masclet, P.; Perros, P.E.

    2004-09-01

    This article deals with the majority of pollutants which are present in gaseous phase in the low layer of the troposphere, of the proximity of sources to the distant areas where are in weak traces persisting substances or sub-products induced by photochemical reactions. The compounds described in this article are of interest for various reasons: either they are source tracers, or they draw attention for their impact on health or/and ecosystem. Their follow-up can also be in other approaches such as the understanding of reactional mechanisms and the support to modeling of the phenomena. Thereby, the range of the covered concentrations is very large: if the preoccupations are in most of the cases to answer to detection limits of about the ppb, for some substances, the requirements can be harder and we have then to orient oneself to techniques able to quantify at the level of ppt, sometimes less. Some pollutants are qualified of 'semi-volatile', that is to say they are the property to be present in gaseous phase and in particles in suspension in air. (O.M.)

  13. Algebraic stacks

    Indian Academy of Sciences (India)

    truct the 'moduli stack', that captures all the information that we would like in a fine moduli space. ..... the fine moduli space), it has the property that for any family W of vector bundles (i.e. W is a vector bundle over B ...... the etale topology is finer: V is a 'small enough open subset' because the square root can be defined on it.

  14. Study on the Control of Polluted Odour Gas by Biological Treatment Technology

    Directory of Open Access Journals (Sweden)

    Wen Dong

    2017-07-01

    Full Text Available In order to improve the quality of the environment as well as its purification capacity, to reduce environmental costs and achieve clean and efficient management of malodorous gas pollution, on the basis of fully understanding the theory of biotechnology, this paper presents the research of biotechnology to control the pollution of malodorous pollutants. In this research, the biofiltration method was used to control the odour gas ammonia produced in waste composting, which can effectively purify gases, with a high ammonia removal rate. One week after the ammonia removal experiment, the removal rate was detected to be around 79.3 %. Twenty-four days after the experiment, the removal rate stabilized at around 98 %. Through the test of pH value of nutrient solution, it was found that the change in pH value corresponded to the increase in removal rate. There are many advantages of applying biotechnology to filter malodorous polluted gases, such as low energy consumption, high degree of purification, good environmental compatibility, simple operation and maintenance, and no secondary pollution. Therefore, it has good application prospects.

  15. High winter ozone pollution from carbonyl photolysis in an oil and gas basin

    Science.gov (United States)

    Edwards, Peter M.; Brown, Steven S.; Roberts, James M.; Ahmadov, Ravan; Banta, Robert M.; Degouw, Joost A.; Dubé, William P.; Field, Robert A.; Flynn, James H.; Gilman, Jessica B.; Graus, Martin; Helmig, Detlev; Koss, Abigail; Langford, Andrew O.; Lefer, Barry L.; Lerner, Brian M.; Li, Rui; Li, Shao-Meng; McKeen, Stuart A.; Murphy, Shane M.; Parrish, David D.; Senff, Christoph J.; Soltis, Jeffrey; Stutz, Jochen; Sweeney, Colm; Thompson, Chelsea R.; Trainer, Michael K.; Tsai, Catalina; Veres, Patrick R.; Washenfelder, Rebecca A.; Warneke, Carsten; Wild, Robert J.; Young, Cora J.; Yuan, Bin; Zamora, Robert

    2014-10-01

    The United States is now experiencing the most rapid expansion in oil and gas production in four decades, owing in large part to implementation of new extraction technologies such as horizontal drilling combined with hydraulic fracturing. The environmental impacts of this development, from its effect on water quality to the influence of increased methane leakage on climate, have been a matter of intense debate. Air quality impacts are associated with emissions of nitrogen oxides (NOx = NO + NO2) and volatile organic compounds (VOCs), whose photochemistry leads to production of ozone, a secondary pollutant with negative health effects. Recent observations in oil- and gas-producing basins in the western United States have identified ozone mixing ratios well in excess of present air quality standards, but only during winter. Understanding winter ozone production in these regions is scientifically challenging. It occurs during cold periods of snow cover when meteorological inversions concentrate air pollutants from oil and gas activities, but when solar irradiance and absolute humidity, which are both required to initiate conventional photochemistry essential for ozone production, are at a minimum. Here, using data from a remote location in the oil and gas basin of northeastern Utah and a box model, we provide a quantitative assessment of the photochemistry that leads to these extreme winter ozone pollution events, and identify key factors that control ozone production in this unique environment. We find that ozone production occurs at lower NOx and much larger VOC concentrations than does its summertime urban counterpart, leading to carbonyl (oxygenated VOCs with a C = O moiety) photolysis as a dominant oxidant source. Extreme VOC concentrations optimize the ozone production efficiency of NOx. There is considerable potential for global growth in oil and gas extraction from shale. This analysis could help inform strategies to monitor and mitigate air quality impacts

  16. SDSS IV MaNGA: Deep observations of extra-planar, diffuse ionized gas around late-type galaxies from stacked IFU spectra

    Science.gov (United States)

    Jones, A.; Kauffmann, G.; D'Souza, R.; Bizyaev, D.; Law, D.; Haffner, L.; Bahé, Y.; Andrews, B.; Bershady, M.; Brownstein, J.; Bundy, K.; Cherinka, B.; Diamond-Stanic, A.; Drory, N.; Riffel, R. A.; Sánchez, S. F.; Thomas, D.; Wake, D.; Yan, R.; Zhang, K.

    2017-03-01

    We have conducted a study of extra-planar diffuse ionized gas using the first year data from the MaNGA IFU survey. We have stacked spectra from 49 edge-on, late-type galaxies as a function of distance from the midplane of the galaxy. With this technique we can detect the bright emission lines Hα, Hβ, [O II]λλ3726, 3729, [O III]λ5007, [N II]λλ6549, 6584, and [S II]λλ6717, 6731 out to about 4 kpc above the midplane. With 16 galaxies we can extend this analysis out to about 9 kpc, I.e. a distance of 2Re, vertically from the midplane. In the halo, the surface brightnesses of the [O II] and Hα emission lines are comparable, unlike in the disk where Hα dominates. When we split the sample by specific star-formation rate, concentration index, and stellar mass, each subsample's emission line surface brightness profiles and ratios differ, indicating that extra-planar gas properties can vary. The emission line surface brightnesses of the gas around high specific star-formation rate galaxies are higher at all distances, and the line ratios are closer to ratios characteristic of H II regions compared with low specific star-formation rate galaxies. The less concentrated and lower stellar mass samples exhibit line ratios that are more like H II regions at larger distances than their more concentrated and higher stellar mass counterparts. The largest difference between different subsamples occurs when the galaxies are split by stellar mass. We additionally infer that gas far from the midplane in more massive galaxies has the highest temperatures and steepest radial temperature gradients based on their [N II]/Hα and [O II]/Hα ratios between the disk and the halo. SDSS IV.

  17. Pollutant exposures from unvented gas cooking burners: A Simulation-based Assessment for Southern California

    Energy Technology Data Exchange (ETDEWEB)

    Logue, Jennifer M. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Indoor Environment Group and Residential Building Systems Group; Klepeis, Neil E. [Stanford Univ., CA (United States). Dept. of Civil and Environmental Engineering; San Diego Univ., CA (United States). Center for Behavioral Epidemiology and Community Health; Lobscheid, Agnes B. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Indoor Environment Group; Singer, Brett C. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Indoor Environment Group and Residential Building Systems Group

    2014-01-01

    Residential natural gas cooking burners (NGCBs) can emit substantial quantities of pollutants, and they are typically used without venting range hoods. In this study, LBNL researchers quantified pollutant concentrations and occupant exposures resulting from NGCB use in California homes.The simulation model estimated that—in homes using NGCBs without coincident use of venting range hoods -- 62%, 9%, and 53% of occupants are routinely exposed to NO2, CO, and HCHO levels that exceed acute health-based standards and guidelines. NGCB use increased the sample median of the highest simulated 1-hr indoor concentrations by 100, 3,000, and 20 ppb for NO2, CO, and HCHO, respectively. The study recommends that reducing pollutant exposures from NGCBs should be a public health priority. Simulation results suggest that regular use of even moderately effective venting range hoods would dramatically reduce the percentage of homes in which concentrations exceed health-based standards.

  18. Impact of Natural Gas Appliances on Pollutant Levels in California Homes

    Energy Technology Data Exchange (ETDEWEB)

    Mullen, Nasim A.; Li, Jina; Singer, Brett C.

    2012-12-01

    This report presents results from the first year of a 2-year study, investigating associations of five air pollutants (CO, NO2, NOX, formaldehyde and acetaldehyde) with the presence of natural gas appliances in California homes. From November 2011 to March 2012, pollutant concentration and occupant activity data were collected in 155 homes for 6-day periods. The sample population included both single-family (68%) and multi-family (32%) dwellings, with 87% having at least one gas appliance and 77% having an unvented gas cooking appliance. The geometric mean (GM) NO2 levels measured in the kitchen, bedroom and outside of homes were similar at values of 15, 12 and 11 ppb, respectively. In contrast, the GM NOx levels measured in the kitchen and bedroom of homes were much higher than levels measured outdoors, at levels of 42 and 41 ppb, compared to 19 ppb, respectively. Roughly 10% of sampled homes had 6-day average NO2 levels that exceeded the outdoor annual average limit set by the California Ambient Air Quality Standards (CAAQS) (30 ppb). The GMs of the highest 1-h and 8-h CO level measured in homes were 2.5 and 1.1 ppm, respectively. Four homes had a 1-h or 8-h concentration that exceeded the outdoor limits set by the CAAQS. The GM formaldehyde and acetaldehyde concentrations measured in homes were 15 and 7 ppb, respectively. Roughly 95% of homes had average formaldehyde levels indoors that exceeded the Chronic Reference Exposure Level set by the California EPA (7 ppb). Concentrations of NO2 and NOx, and to a lesser extent CO were associated with use of gas appliances, particularly unvented gas cooking appliances. Based on first principles, it is expected that effective venting of cooking pollutant emissions at the source will lead to a reduction of pollutant concentrations. However, no statistical association was detected between kitchen exhaust fan use and pollutant concentrations in homes in this study where gas cooking occurred frequently. The lack of

  19. Pollution Monitoring System Using Gas Sensor based on Wireless Sensor Network

    Directory of Open Access Journals (Sweden)

    M. Udin Harun Al Rasyid

    2016-01-01

    Full Text Available Carbon monoxide (CO and carbon dioxide (CO2 gases are classified as colorless and odorless gas so we need special tools to monitor their concentration in the air. Concentration of air pollution of CO and CO2 that are high in the air will give serious effects for health status. CO is a poisonous gas that damages the circulation of oxygen in the blood when inhaled, while CO2 is one of the gases that causes global warming. In this paper, we developed an integrated pollution monitoring (IPOM system to monitor the concentration of air pollution. This research implemented three sensor nodes (end-device which each node contains CO and CO2 sensors on the gas sensors board to perform sensing from the environment. Furthermore, the data taken from the environment by the sensor will be sent to the meshlium gateway using IEEE 802.15.4 Zigbee communications and processed by the gateway in order to be sent to the computer server. The data is stored in meshlium gateway using MySQL database as a backup, and it will be synchronized to the MySQL database in the computer server. We provide services for public to access the information in database server through a desktop and website application.

  20. Posttranslational modification of bioaerosol protein by common gas pollutants: NO2 and O3

    Science.gov (United States)

    Abdullahi Mahmood, Marliyyah; Bloss, William; Pope, Francis

    2016-04-01

    Air pollution can exacerbate several medical conditions, for example, hay fever and asthma. The global incidence of hay fever has been rising for decades; however, the underlying reasons behind this rise remain unclear. It is hypothesized that the exposure of pollen to common gas phase pollutants, such as nitrogen dioxide (NO2) and ozone (O3), increases the allergenicity of the pollen and thus increases hay fever incidence (Reinmuth-Selzle et al., 2014, Franze, et al., 2005). Since atmospheric pollutants often have greater concentrations within urban areas (in particular NO2) the hypothesis suggests that greater allergenicity should occur in urban areas. Certainly, several studies do suggest higher hay fever incidence within urban areas compared to rural areas (Schröder et al., 2015). Previous published work suggests a link between increased allergies and changes in the chemical composition of pollen protein via posttranslational modification of the protein (Reinmuth-Selzle et al., 2014). This study investigates the posttranslational modification of two highly allergenic pollen species (Birch and Ragweed) that are common in Europe. Within the laboratory, we expose pollen grains to atmospherically relevant exposures of gas phase NO2, O3 and other common gas phase oxidants under a range of environmentally relevant conditions. The effects of the exposures on the biochemistry of the pollen grains were probed using a proteomic approach (liquid chromatography coupled ultra-high resolution spectrometer). Our findings indicate the interaction between gas phase pollutants and pollen cause protein specific modifications; in particular nitration that occurs upon tyrosine residues and nitrosylation on cysteine residues. These modifications may affect human immune response to the pollen protein, which may suggest a possible reason for increased allergies in reaction to such chemically altered protein. Quantification of the relative degree of PTMs, from a variety of

  1. Environmental assessment of phosphogypsum stacks

    International Nuclear Information System (INIS)

    Odat, M.; Al-Attar, L.; Raja, G.; Abdul Ghany, B.

    2008-03-01

    Phosphogypsum is one of the most important by-products of phosphate fertilizer industry. It is kept in large stacks to the west of Homs city. Storing Phosphogypsum as open stacks exposed to various environmental effects, wind and rain, may cause pollution of the surrounding ecosystem (soil, plant, water and air). This study was carried out in order to assess the environmental impact of Phosphogypsum stacks on the surrounding ecosystem. The obtained results show that Phosphogypsum stacks did not increase the concentration of radionuclides, i.e. Radon-222 and Radium-226, the external exposed dose of gamma rays, as well as the concentration of heavy metals in the components of the ecosystem, soil, plant, water and air, as their concentrations did not exceed the permissible limits. However, the concentration of fluorine in the upper layer of soil, located to the east of the Phosphogypsum stacks, increased sufficiently, especially in the dry period of the year. Also, the concentration of fluoride in plants growing up near-by the Phosphogypsum stacks was too high, exceeded the permissible levels. This was reflected in poising plants and animals, feeding on the plants. Consequently, increasing the concentration of fluoride in soil and plants is the main impact of Phosphogypsum stacks on the surrounding ecosystem. Minimising this effect could be achieved by establishing a 50 meter wide protection zone surrounding the Phosphogypsum stacks, which has to be planted with non palatable trees, such as pine and cypress, forming wind barriers. Increasing the concentrations of heavy metals and fluoride in infiltrated water around the stacks was high; hence cautions must be taken to prevent its usage in any application or disposal in adjacent rivers and leaks.(author)

  2. Oil and Natural Gas Production Facilities National Emissions Standards for Hazardous Air Pollutants (NESHAP) Final Rule Fact Sheet

    Science.gov (United States)

    This page contains a January 2007 fact sheet for the final National Emission Standards for Hazardous Air Pollutants (NESHAP) for Oil and Natural Gas Production Facilities. This document provides a summary of the 2007 final rule.

  3. Pollution

    NARCIS (Netherlands)

    Dürr, E.; Jaffe, R.; Nonini, D.M.

    2014-01-01

    This essay points to the role of pollution in understanding the social construction of hierarchies and urban space. Conceptualizations of pollution and approaches to waste management always reflect the Zeitgeist and tend to be politically charged. We argue that an ethnographic approach to pollution

  4. Urban traffic pollution reduction for sedan cars using petrol engines by hydro-oxide gas inclusion.

    Science.gov (United States)

    Al-Rousan, Ammar A; Alkheder, Sharaf; Musmar, Sa'ed A

    2015-12-01

    Petrol cars, in particular nonhybrid cars, contribute significantly to the pollution problem as compared with other types of cars. The originality of this article falls in the direction of using hydro-oxy gas to reduce pollution from petrol car engines. Experiments were performed in city areas at low real speeds, with constant engine speeds in the average of 2500 rpm and at variable velocity ratios (first speed was 10-20 km/hr, second speed was 20-35 km/hr, and third speed was 35-50 km/hr). Results indicated that through using hydro-oxy gas, a noticeable reduction in pollution was recorded. Oxygen (O2) percentage has increased by about 2.5%, and nitric oxide (NO) level has been reduced by about 500 ppm. Carbon monoxide (CO) has decreased by about 2.2%, and also CO2 has decreased by 2.1%. It's worth mentioning that for hybrid system in cars at speeds between 10 and 50 km/hr, the emission percentage change is zero. However, hybrid cars are less abundant than petrol cars. The originality of this paper falls in the direction of using hydro-oxy gas to reduce pollution from petrol car engines. Experiments were performed in city areas at low real speeds, with constant engine speeds in the average of 2500 rpm and at variable velocity ratios (first speed was 10-20 km/hr, second speed was 20-35 km/hr, and third speed was 35-50 km/h).

  5. Identification and quantification of mixed air pollutants based on homotopy method for gas sensor array.

    Science.gov (United States)

    Yang, Yuning; Mason, Andrew J

    2012-01-01

    Accurate recognition of air pollutants and estimation of their concentrations are critical for human health and safety monitoring and can be achieved using gas sensor arrays. In this paper, an efficient method based on a homotopy algorithm is presented for the analysis of sensor arrays responding to binary mixtures. The new method models the responses of a gas sensor array as a system of nonlinear equations and provides a globally convergent way to find the solution of the system. Real data measurement for CH4 and SO2 are used to model sensor responses. The model is applied to the method for prediction and it shows the prediction results are within 1% variation of true values for both gas models.

  6. Statistical evaluation of the impact of shale gas activities on ozone pollution in North Texas.

    Science.gov (United States)

    Ahmadi, Mahdi; John, Kuruvilla

    2015-12-01

    Over the past decade, substantial growth in shale gas exploration and production across the US has changed the country's energy outlook. Beyond its economic benefits, the negative impacts of shale gas development on air and water are less well known. In this study the relationship between shale gas activities and ground-level ozone pollution was statistically evaluated. The Dallas-Fort Worth (DFW) area in north-central Texas was selected as the study region. The Barnett Shale, which is one the most productive and fastest growing shale gas fields in the US, is located in the western half of DFW. Hourly meteorological and ozone data were acquired for fourteen years from monitoring stations established and operated by the Texas Commission on Environmental Quality (TCEQ). The area was divided into two regions, the shale gas region (SGR) and the non-shale gas (NSGR) region, according to the number of gas wells in close proximity to each monitoring site. The study period was also divided into 2000-2006 and 2007-2013 because the western half of DFW has experienced significant growth in shale gas activities since 2007. An evaluation of the raw ozone data showed that, while the overall trend in the ozone concentration was down over the entire region, the monitoring sites in the NSGR showed an additional reduction of 4% in the annual number of ozone exceedance days than those in the SGR. Directional analysis of ozone showed that the winds blowing from areas with high shale gas activities contributed to higher ozone downwind. KZ-filtering method and linear regression techniques were used to remove the effects of meteorological variations on ozone and to construct long-term and short-term meteorologically adjusted (M.A.) ozone time series. The mean value of all M.A. ozone components was 8% higher in the sites located within the SGR than in the NSGR. These findings may be useful for understanding the overall impact of shale gas activities on the local and regional ozone

  7. Stack gas desulfurization using adsorbent materials based on copper oxide; Desulfuracion de gases de combustion usando materiales adsorbentes basados en oxido de cobre

    Energy Technology Data Exchange (ETDEWEB)

    Flores Velazquez, Roberto; Rodas Grapain, Arturo [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico)

    2008-07-01

    One of main fossil fuels used to date in Mexico for power generation is the fuel oil, with a total participation of 32%. The Mexican fuel oil is constituted in average by 84% in weight of carbon, 11% hydrogen, 0.4% nitrogen, 0.2% oxygen, 4% sulfur and the remaining is assumed to be metals such as vanadium, nickel, calcium, magnesium among others. The purpose of the present paper is to show a new route of preparation of materials impregnated through the application of ultrasonic energy and to evaluate its performance in the stack gas desulfurization. [Spanish] Uno de los principales combustibles fosiles empleados actualmente en Mexico para la generacion de energia electrica es el combustoleo, con una participacion total del 32%. El combustoleo mexicano esta constituido en promedio por 84% en peso de carbono, 11% de hidrogeno, 0.4% de nitrogeno, 0.2% de oxigeno, 4% de azufre y el resto se asume a metales como vanadio, niquel, calcio, magnesio entre otros. El proposito del presente trabajo es mostrar una nueva ruta de preparacion de materiales impregnados a traves de la aplicacion de energia ultrasonica y evaluar su desempeno en la desulfuracion de gases de combustion.

  8. Multiple-pollutant cost-effectiveness of greenhouse gas mitigation measures in the UK agriculture

    International Nuclear Information System (INIS)

    Eory, Vera; Topp, Cairistiona F.E.; Moran, Dominic

    2013-01-01

    Highlights: ► Multiple-pollutant marginal abatement cost curves can inform integrated environmental policy. ► We incorporated the co-effects on NH 3 , NO 3 − , P and sediment, as monetary values, into the UK GHG MACC. ► Adding co-effects modifies the GHG MACC, though with little impact unless using high damage values. ► Further research is needed on the co-effects of GHG mitigation measures and on damage values. ► Analysis should focus on the co-effects of measures that are slightly above or below the threshold. -- Abstract: This paper develops multiple-pollutant marginal abatement cost curve analysis to identify an optimal set of greenhouse gas (GHG) mitigation measures considering the trade-offs and synergies with other environmental pollutants. The analysis is applied to UK agriculture, a sector expected to make a contribution to the national GHG mitigation effort. Previous analyses using marginal abatement cost curves (MACCs) have determined the sector's GHG abatement potential based on the cost-effectiveness of a variety of technically feasible mitigation measures. Most of these measures have external effects on other pollution loads arising from agricultural activities. Here the monetary values of four of the most important impacts to water and air (specifically ammonia, nitrate, phosphorous and sediment) are included in the cost-effectiveness analysis. The resulting multiple-pollutant marginal abatement cost curve (MP MACC) informs the design of sustainable climate change policies by showing how the MP MACC for the UK agriculture can differ from the GHG MACC. The analysis also highlights research gaps, and suggests a need to understand the wider environmental effects of GHG mitigation options and to reduce the uncertainty in pollutant damage cost estimates

  9. Pollutant Exposures from Natural Gas Cooking Burners: A Simulation-Based Assessment for Southern California

    Energy Technology Data Exchange (ETDEWEB)

    Logue, Jennifer M.; Klepeis, Neil E.; Lobscheid, Agnes B.; Singer, Brett C.

    2014-06-01

    Residential natural gas cooking burners (NGCBs) can emit substantial quantities of pollutants and they are typically used without venting. The objective of this study is to quantify pollutant concentrations and occupant exposures resulting from NGCB use in California homes. A mass balance model was applied to estimate time-dependent pollutant concentrations throughout homes and the "exposure concentrations" experienced by individual occupants. The model was applied to estimate nitrogen dioxide (NO{sub 2}), carbon monoxide (CO), and formaldehyde (HCHO) concentrations for one week each in summer and winter for a representative sample of Southern California homes. The model simulated pollutant emissions from NGCBs, NO{sub 2} and CO entry from outdoors, dilution throughout the home, and removal by ventilation and deposition. Residence characteristics and outdoor concentrations of CO and NO{sub 2} were obtained from available databases. Ventilation rates, occupancy patterns, and burner use were inferred from household characteristics. Proximity to the burner(s) and the benefits of using venting range hoods were also explored. Replicate model executions using independently generated sets of stochastic variable values yielded estimated pollutant concentration distributions with geometric means varying less than 10%. The simulation model estimates that in homes using NGCBs without coincident use of venting range hoods, 62%, 9%, and 53% of occupants are routinely exposed to NO{sub 2}, CO, and HCHO levels that exceed acute health-based standards and guidelines. NGCB use increased the sample median of the highest simulated 1-hr indoor concentrations by 100, 3000, and 20 ppb for NO{sub 2}, CO, and HCHO, respectively. Reducing pollutant exposures from NGCBs should be a public health priority. Simulation results suggest that regular use of even moderately effective venting range hoods would dramatically reduce the percentage of homes in which concentrations exceed health

  10. Comparison of Iran Power Plants Air Pollutants Before and After Shifting to Natural Gas

    Directory of Open Access Journals (Sweden)

    M Ghiasseddin

    2004-07-01

    Full Text Available In a three years period, 24 fossil fueled thermal power plants located in different parts of the country were extensively examined for discharge of pollutants into the environment and their potential effects on surrounding. During this investigation emission to air, discharge to receiving waters and land as well as electromagnetic fields were measured using relevant standard methods. This paper will focus on air pollution emissions and recent reinvestigation that was done after shifting the fuel from residual oil to natural gas. In our first studies that most of the plants were consuming residual oil, high level of SO2 emission in some areas was the main cause of losses to vegetations and fruit gardens. It was concluded that a serious problem threats the environment and health of people living near these areas. Based on the results some mitigation plans were recommended to the authorities, and after some times they started to shift to natural gas consumption. Our recent investigation that was after this action, showed a good improvement of air pollution reduction. This was almost 100% for SO2 and from 32 to 73% for NOx.

  11. Solid Oxide Fuel Cell Stack Diagnostics

    DEFF Research Database (Denmark)

    Mosbæk, Rasmus Rode; Barfod, Rasmus Gottrup

    . An operating stack is subject to compositional gradients in the gaseous reactant streams, and temperature gradients across each cell and across the stack, which complicates detailed analysis. Several experimental stacks from Topsoe Fuel Cell A/S were characterized using Electrochemical Impedance Spectroscopy...... (EIS). The stack measurement geometry was optimized for EIS by careful selection of the placement of current feeds and voltage probes in order to minimize measurement errors. It was demonstrated that with the improved placement of current feeds and voltage probes it is possible to separate the loss...... in the hydrogen fuel gas supplied to the stack. EIS was used to examine the long-term behavior and monitor the evolution of the impedance of each of the repeating units and the whole stack. The observed impedance was analyzed in detail for one of the repeating units and the whole stack and the losses reported...

  12. Urban air pollution monitoring: laser-based procedure for the detection of carbon monoxide gas.

    Science.gov (United States)

    Peng, W X; Ledingham, K W; Singhal, R P; McCanny, T

    1998-05-01

    Urban air quality is of considerable importance in many cities throughout Europe and the USA. In particular, current EU legislation has driven an expansion of monitoring of more pollutants at more sites. At present in the UK, real time readings are now available for benzene, buta-1,3-diene and other volatile organic compounds, airborne fine dust (PM10), CO, 03, SO2, and NOX. Carbon monoxide is produced to varying degrees in all combustion processes but more than 90% is caused by emissions from petrol vehicle exhausts. The World Health Ogranisation guidelines for exposure to the gas is pollutants mentioned above are monitored by different detection techniques and it has been the authors' philosophy to develop instrumentation which can monitor all the different pollutants using a single detector. To this end, a multiphoton laser based procedure, using simple ionization chambers, has been developed to detect the different pollutants with different wavelengths. For CO, a 2 + 1 resonance enhanced multiphoton ionization (REMPI) scheme at 230 nm can be used with detection limits of about 1 ppm.

  13. Factors influencing pollutant gas emissions of VOC recuperative incinerators-Large-scale parametric study

    International Nuclear Information System (INIS)

    Salvador, S.; Commandre, J.-M.; Kara, Y.

    2006-01-01

    This work establishes quantitative links between the operation parameters-plus one geometrical parameter-and the gas pollutant emissions of a recuperative incinerator (RI) of volatile organic compounds (VOCs). Using experimental design methodology, and based on a large number of experiments carried out on a half-industrial-scale pilot unit, mathematical expressions are established to calculate each of the pollutant emissions from the value of all the operation and design parameters. The gas emissions concerned are total hydrocarbons, and CO and NO x emissions, while the control parameters are the flow rate of the treated air flow, the concentration of VOCs in the air flow, the preheating temperature of the flow, and the temperature at the exit of the combustion chamber. One design parameter-the aperture of the diaphragms-is also considered. We show that the constraining emissions are only that of CO and NO x . Polynomials to predict them with a high accuracy are established. The air preheating temperature has an effect on the natural gas consumption, but not on CO and NO x emissions. There is an optimal value for the aperture of the diaphragms, and this value is quantitatively established. If the concentration of VOCs in the air flow is high, CO and NO x emissions both decrease and a high rate of efficiency in VOC destruction is attained. This demonstrates that a pre-concentration of VOCs in the air flow prior to treatment by RI is recommended. (author)

  14. Environmental and economic benefits of natural gas use for pollution control

    International Nuclear Information System (INIS)

    Dey, P.R.; Berkau, E.E.; Schnelle, K.B.

    1993-01-01

    One of the primary goals of this research effort was to document and compare the economic and environment benefits of using natural gas for pollution control in boilers, furnaces and internal combustion engines, with conventional control technologies. The study indicated that replacement of 15% of the coal used in coal-fired boilers employed in the generation of electric power in the US, with natural gas, would considerably reduce the emissions of acid rain precursors such as sulfur and nitrogen oxides, and do so in a cost-effect manner. The reductions achieved were also in concordance with the reductions in sulfur dioxide emissions mandated by the new Clean Air Act (CAA) Amendments of 1990. The combustion of natural gas would also produce less carbon dioxide as compared to the combustion of coal with an equivalent amount of heat content. Carbon dioxide is a greenhouse gas, i.e., it is believed to play a major role in global warming. Natural gas technology therefore presents a cost-effective step in the eventual mitigation of two of the main environmental problems presently facing us, acid rain, and global warming

  15. CRITERIA POLLUTANT EMISSIONS FROM INTERNAL COMBUSTION ENGINES IN THE NATURAL GAS INDUSTRY VOLUME II. APPENDICES A-I

    Science.gov (United States)

    The report summarizes emission factors for criteria pollutants (NOx, CO, CH4, C2H6, THC, NMHC, and NMEHC) from stationary internal combustion engines and gas turbines used in the natural gas industry. The emission factors were calculated from test results from five test campaigns...

  16. Integrated capture of fossil fuel gas pollutants including CO.sub.2 with energy recovery

    Science.gov (United States)

    Ochs, Thomas L [Albany, OR; Summers, Cathy A [Albany, OR; Gerdemann, Steve [Albany, OR; Oryshchyn, Danylo B [Philomath, OR; Turner, Paul [Independence, OR; Patrick, Brian R [Chicago, IL

    2011-10-18

    A method of reducing pollutants exhausted into the atmosphere from the combustion of fossil fuels. The disclosed process removes nitrogen from air for combustion, separates the solid combustion products from the gases and vapors and can capture the entire vapor/gas stream for sequestration leaving near-zero emissions. The invention produces up to three captured material streams. The first stream is contaminant-laden water containing SO.sub.x, residual NO.sub.x particulates and particulate-bound Hg and other trace contaminants. The second stream can be a low-volume flue gas stream containing N.sub.2 and O.sub.2 if CO2 purification is needed. The final product stream is a mixture comprising predominantly CO.sub.2 with smaller amounts of H.sub.2O, Ar, N.sub.2, O.sub.2, SO.sub.X, NO.sub.X, Hg, and other trace gases.

  17. Domino effect of pollution from sour gas fields : failing legume nodulation and the honey industry

    International Nuclear Information System (INIS)

    Pirker, H.J.

    1998-01-01

    The sustainability of the honey industry in Alberta's Peace Country has been threatened by pollution from sour gas fields. The region has suffered crop reductions and chlorosis in grains, grasses, and legumes. Severe die-back and die-off of aspens and poplars has also been observed. Crops per colony were reduced by as much as 75 per cent, and winter losses more than tripled. Nectar flow patterns shifted from main flow in early summer to late flows in August or September from second growth alfalfa. A sampling of 27 fields found nitrogen fixation in alfalfa and red clovers lacking in areas downwind from major oil and sour gas flaring facilities. The reduction of the early season nectar flow appears to be caused by the synergistic interaction of ozone and sulphur compounds when ozone levels are at their highest. Reduced ozone levels in the fall permit a late, but uncertain flow from alfalfa plants

  18. Optimization of manifold design for 1 kW-class flat-tubular solid oxide fuel cell stack operating on reformed natural gas

    Science.gov (United States)

    Rashid, Kashif; Dong, Sang Keun; Khan, Rashid Ali; Park, Seung Hwan

    2016-09-01

    This study focuses on optimizing the manifold design for a 1 kW-class flat-tubular solid oxide fuel cell stack by performing extensive three-dimensional numerical simulations on numerous manifold designs. The stack flow uniformity and the standard flow deviation indexes are implemented to characterize the flow distributions in the stack and among the channels of FT-SOFC's, respectively. The results of the CFD calculations demonstrate that the remodeled manifold without diffuser inlets and 6 mm diffuser front is the best among investigated designs with uniformity index of 0.996 and maximum standard flow deviation of 0.423%. To understand the effect of manifold design on the performance of stack, both generic and developed manifold designs are investigated by applying electrochemical and internal reforming reactions modeling. The simulation results of the stack with generic manifold are validated using experimental data and then validated models are adopted to simulate the stack with the developed manifold design. The results reveal that the stack with developed manifold design achieves more uniform distribution of species, temperature, and current density with comparatively lower system pressure drop. In addition, the results also showed ∼8% increase in the maximum output power due to the implementation of uniform fuel velocity distributions in the cells.

  19. Air Pollution

    Science.gov (United States)

    Air pollution is a mixture of solid particles and gases in the air. Car emissions, chemicals from factories, dust, pollen and ... Ozone, a gas, is a major part of air pollution in cities. When ozone forms air pollution, ...

  20. Curbing Air Pollution and Greenhouse Gas Emissions from Industrial Boilers in China

    Energy Technology Data Exchange (ETDEWEB)

    Shen, Bo [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Price, Lynn K [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Lu, Hongyou [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Liu, Xu [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Tsen, Katherine [Univ. of California, Berkeley, CA (United States); Xiangyang, Wei [National Energy Conservation Center (China); Yunpeng, Zhang [National Energy Conservation Center (China); Jian, Guan [China Special Equipment Inspection & Test Inst. (China); Rui, Hou [China Machinery Industry Conservation & Resource Utilization Center (China); Junfeng, Zhang [China National Offshore Oil Corp. (China); Yuqun, Zhuo [Tsinghua Univ., Beijing (China); Shumao, Xia [China Energy Conservation & Environmental Protection Group (China); Yafeng, Han [Xi' an Jiatong Univ. (China); Manzhi, Liu [China Univ. of Mining and Technology (China)

    2015-10-28

    China’s industrial boiler systems consume 700 million tons of coal annually, accounting for 18% of the nation’s total coal consumption. Together these boiler systems are one of the major sources of China’s greenhouse gas (GHG) emissions, producing approximately 1.3 gigatons (Gt) of carbon dioxide (CO2) annually. These boiler systems are also responsible for 33% and 27% of total soot and sulfur dioxide (SO2) emissions in China, respectively, making a substantial contribution to China’s local environmental degradation. The Chinese government - at both the national and local level - is taking actions to mitigate the significant greenhouse gas (GHG) emissions and air pollution related to the country’s extensive use of coal-fired industrial boilers. The United States and China are pursuing a collaborative effort under the U.S.-China Climate Change Working Group to conduct a comprehensive assessment of China’s coal-fired industrial boilers and to develop an implementation roadmap that will improve industrial boiler efficiency and maximize fuel-switching opportunities. Two Chinese cities – Ningbo and Xi’an – have been selected for the assessment. These cities represent coastal areas with access to liquefied natural gas (LNG) imports and inland regions with access to interprovincial natural gas pipelines, respectively.

  1. Indoor pollutant levels from the use of unvented natural gas fireplaces in Boulder, Colorado.

    Science.gov (United States)

    Dutton, S J; Hannigan, M P; Miller, S L

    2001-12-01

    High CO and NO2 concentrations have been documented in homes with unvented combustion appliances, such as natural gas fireplaces. In addition, polycyclic aromatic hydrocarbons (PAH) are emitted from incomplete natural gas combustion. The acute health risks of CO and NO2 exposure have been well established for the general population and for certain high-risk groups, including infants, the elderly, and people with heart disease or asthma. Health effects from PAH exposure are less well known, but may include increased risk of cancer. We monitored CO emissions during the operation of unvented natural gas fireplaces in two residences in Boulder, CO, at various times between 1997 and 2000. During 1999, we expanded our tests to include measurements of NO2 and PAH. Results show significant pollutant accumulation indoors when the fireplaces were used for extended periods of time. In one case, CO concentrations greater than 100 ppm accumulated in under 2 hr of operation; a person at rest exposed for 10 hr to this environment would get a mild case of CO poisoning with an estimated 10% carboxyhemoglobin level. Appreciable NO2 concentrations were also detected, with a 4-hr time average reaching 0.36 ppm. Similar time-average total PAH concentrations reached 35 ng/m3. The results of this study provide preliminary insights to potential indoor air quality problems in homes operating unvented natural gas fireplaces in Boulder.

  2. Modeling to Evaluate Contribution of Oil and Gas Emissions to Air Pollution.

    Science.gov (United States)

    Thompson, Tammy M; Shepherd, Donald; Stacy, Andrea; Barna, Michael G; Schichtel, Bret A

    2017-04-01

    Oil and gas production in the Western United States has increased considerably over the past 10 years. While many of the still limited oil and gas impact assessments have focused on potential human health impacts, the typically remote locations of production in the Intermountain West suggests that the impacts of oil and gas production on national parks and wilderness areas (Class I and II areas) could also be important. To evaluate this, we utilize the Comprehensive Air quality Model with Extensions (CAMx) with a year-long modeling episode representing the best available representation of 2011 meteorology and emissions for the Western United States. The model inputs for the 2011 episodes were generated as part of the Three State Air Quality Study (3SAQS). The study includes a detailed assessment of oil and gas (O&G) emissions in Western States. The year-long modeling episode was run both with and without emissions from O&G production. The difference between these two runs provides an estimate of the contribution of the O&G production to air quality. These data were used to assess the contribution of O&G to the 8 hour average ozone concentrations, daily and annual fine particulate concentrations, annual nitrogen deposition totals and visibility in the modeling domain. We present the results for the Class I and II areas in the Western United States. Modeling results suggest that emissions from O&G activity are having a negative impact on air quality and ecosystem health in our National Parks and Class I areas. In this research, we use a modeling framework developed for oil and gas evaluation in the western United States to determine the modeled impacts of emissions associated with oil and gas production on air pollution metrics. We show that oil and gas production may have a significant negative impact on air quality and ecosystem health in some national parks and other Class I areas in the western United States. Our findings are of particular interest to federal

  3. Characteristics of pollutant gas releases from swine, dairy, beef, and layer manure, and municipal wastewater.

    Science.gov (United States)

    Dai, Xiao-Rong; Saha, Chayan Kumer; Ni, Ji-Qin; Heber, Albert J; Blanes-Vidal, Victoria; Dunn, James L

    2015-06-01

    Knowledge about characteristics of gas releases from various types of organic wastes can assist in developing gas pollution reduction technologies and establishing environmental regulations. Five different organic wastes, i.e., four types of animal manure (swine, beef, dairy, and layer hen) and municipal wastewater, were studied for their characteristics of ammonia (NH3), carbon dioxide (CO2), hydrogen sulfide (H2S), and sulfur dioxide (SO2) releases for 38 or 43 days in reactors under laboratory conditions. Weekly waste additions and continuous reactor headspace ventilation were supplied to simulate waste storage conditions. Results demonstrated that among the five waste types, layer hen manure and municipal wastewater had the highest and lowest NH3 release potentials, respectively. Layer manure had the highest and dairy manure had the lowest CO2 release potentials. Dairy manure and layer manure had the highest and lowest H2S release potentials, respectively. Beef manure and layer manure had the highest and lowest SO2 releases, respectively. The physicochemical characteristics of the different types of wastes, especially the total nitrogen, total ammoniacal nitrogen, dry matter, and pH, had strong influence on the releases of the four gases. Even for the same type of waste, the variation in physicochemical characteristics affected the gas releases remarkably. Copyright © 2015 Elsevier Ltd. All rights reserved.

  4. Capacities and Limitations of Wind Tunnel Physical Experiments on Motion and Dispersion of Different Density Gas Pollutants

    Science.gov (United States)

    Zavila, Ondřej; Blejchař, Tomáš

    2017-04-01

    The article focuses on the analysis of the possibilities to model motion and dispersion of plumes of different density gas pollutants in lowspeed wind tunnels based on the application of physical similarity criteria, in this case the Froude number. The analysis of the physical nature of the modeled process by the Froude number is focused on the influence of air flow velocity, gas pollutant density and model scale. This gives an idea of limitations for this type of physical experiments in relation to the modeled real phenomena. The resulting statements and logical links are exemplified by a CFD numerical simulation of a given task calculated in ANSYS Fluent software.

  5. Evaluating the potential of CNT-supported Co catalyst used for gas pollution removal in the incineration flue gas.

    Science.gov (United States)

    Lu, Chi-Yuan; Tseng, Hui-Hsin; Wey, Ming-Yen; Chuang, Kui-Hao; Kuo, Jia-Hong

    2009-04-01

    This study investigated the use of Cu/Al(2)O(3), Co/Al(2)O(3), Fe/Al(2)O(3), and Ni/Al(2)O(3) catalysts for the growth of carbon nanotubes (CNTs). These CNTs were used as support for Co catalyst preparation and Co/CNT catalysts were applied to a catalytic reaction to remove BTEX, PAHs, SO(2), NO, and CO simultaneously in a pilot-scale incineration system. The analyzed results of EDS and XRD showed low metal content and good dispersion characteristics of the Al(2)O(3)-supported catalysts by excess-solution impregnation. FESEM analyzed results showed that the CNTs that were synthesized from Co, Fe, and Ni catalysts had a diameter of 20nm, whereas those synthesized from Cu/Al(2)O(3) had a diameter of 50nm. Pilot-scale test results demonstrated that the Co/CNT catalyst effectively removed air pollutants in the catalytic reaction and that there was no obvious deactivation by Pb, water vapor, and coke deposited in the process. The thermal stabilization at 250 degrees C and hydrophobicity properties of CNTs enhanced the application of CNT catalysts in flue gas.

  6. Reduction of gaseous pollutant emissions from gas turbine combustors using hydrogen-enriched jet fuel

    Science.gov (United States)

    Clayton, R. M.

    1976-01-01

    Recent progress in an evaluation of the applicability of the hydrogen enrichment concept to achieve ultralow gaseous pollutant emission from gas turbine combustion systems is described. The target emission indexes for the program are 1.0 for oxides of nitrogen and carbon monoxide, and 0.5 for unburned hydrocarbons. The basic concept utilizes premixed molecular hydrogen, conventional jet fuel, and air to depress the lean flammability limit of the mixed fuel. This is shown to permit very lean combustion with its low NOx production while simulataneously providing an increased flame stability margin with which to maintain low CO and HC emission. Experimental emission characteristics and selected analytical results are presented for a cylindrical research combustor designed for operation with inlet-air state conditions typical for a 30:1 compression ratio, high bypass ratio, turbofan commercial engine.

  7. Design and Performance of a Gas Chromatograph for Automatic Monitoring of Pollutants in Ambient Air

    Science.gov (United States)

    Villalobos, R.; Stevens, D.; LeBlanc, R.; Braun, L.

    1971-01-01

    In recent years, interest in air pollution constituents has focused on carbon monoxide and hydrocarbons as prime components of polluted air. Instrumental methods have been developed, and commercial instruments for continuous monitoring of these components have been available for a number of years. For the measurement of carbon monoxide, non-dispersive infrared spectroscopy has been the accepted tool, in spite of its marginal sensitivity at low parts-per-million levels. For continuously monitoring total hydrocarbons, the hydrogen flame ionization analyzer has been widely accepted as the preferred method. The inadequacy of this latter method became evident when it was concluded that methane is non-reactive and cannot be considered a contaminant even though present at over 1 ppm in the earth's atmosphere. Hence, the need for measuring methane separately became apparent as a means of measuring the reactive and potentially harmful non-methane hydrocarbons fraction. A gas chromatographic method for the measurement of methane and total hydrocarbons which met these requirements has been developed. In this technique, methane was separated on conventional gas chromatographic columns and detected by a hydrogen flame ionization detector (FID) while the total hydrocarbons were obtained by introducing a second sample directly into the FID without separating the various components. The reactive, or non-methane hydrocarbons, were determined by difference. Carbon monoxide was also measured after converting to methane over a heated catalyst to render it detectable by the FID. The development of this method made it possible to perform these measurements with a sensitivity of as much as 1 ppm full scale and a minimum detectability of 20 ppb. Incorporating this technique, criteria were developed by APCO for a second generation continuous automatic instrument for atmospheric monitoring stations.

  8. Human health cost of hydrogen sulfide air pollution from an oil and gas Field.

    Science.gov (United States)

    Kenessary, Dinara; Kenessary, Almas; Kenessariyev, Ussen Ismailovich; Juszkiewicz, Konrad; Amrin, Meiram Kazievich; Erzhanova, Aya Eralovna

    2017-06-08

    Introduction and objective. The Karachaganak oil and gas condensate field (KOGCF), one of the largest in the world, located in the Republic of Kazakhstan (RoK) in Central Asia, is surrounded by 10 settlements with a total population of 9,000 people. Approximately73% of this population constantly mention a specific odour of rotten eggs in the air, typical for hydrogen sulfide (H2S) emissions, and the occurrence of low-level concentrations of hydrogen sulfide around certain industrial installations (esp. oil refineries) is a well known fact. Therefore, this study aimed at determining the impact on human health and the economic damage to the country due to H2S emissions. Materials and method. Dose-response dependency between H2S concentrations in the air and cardiovascular morbidity using multiple regression analysis was applied. Economic damage from morbidity was derived with a newly-developed method, with Kazakhstani peculiarities taken into account. Results.Hydrogen sulfide air pollution due to the KOGCF activity costs the state almost $60,000 per year. Moreover, this is the reason for a more than 40% rise incardiovascular morbidity in the region. Conclusion. The reduction of hydrogen sulfide emissions into the air is recommended, as well as successive constant ambient air monitoring in future. Economic damage evaluation should be made mandatory, on a legal basis, whenever an industrial facility operation results in associated air pollution.

  9. Continuous-wave terahertz by photomixing: applications to gas phase pollutant detection and quantification

    Science.gov (United States)

    Hindle, Francis; Cuisset, Arnaud; Bocquet, Robin; Mouret, Gaël

    2008-03-01

    Recent advances in the development of monochromatic continuous-wave terahertz sources suitable for high resolution gas phase spectroscopy and pollution monitoring are reviewed. Details of a source using an ultra fast opto-electronic photomixing element are presented. The construction of a terahertz spectrometer using this source has allowed spectroscopic characterisation and application studies to be completed. Analysis of H 2S and OCS under laboratory conditions are used to demonstrate the spectrometer performance, and the determination of the transition line strengths and pressure self broadening coefficients for pure rotational transitions of OCS. The spectral purity 5 MHz, tunability 0.3 to 3 THz, and long wavelength ≈200 μm of this source have been exploited to identify and quantify numerous chemical species in cigarette smoke. The key advantages of this frequency domain are its high species selectivity and the possibility to make reliable measurements of gas phase samples heavily contaminated by aerosols and particles. To cite this article: F. Hindle et al., C. R. Physique 9 (2008).

  10. Water pollution risk associated with natural gas extraction from the Marcellus Shale.

    Science.gov (United States)

    Rozell, Daniel J; Reaven, Sheldon J

    2012-08-01

    In recent years, shale gas formations have become economically viable through the use of horizontal drilling and hydraulic fracturing. These techniques carry potential environmental risk due to their high water use and substantial risk for water pollution. Using probability bounds analysis, we assessed the likelihood of water contamination from natural gas extraction in the Marcellus Shale. Probability bounds analysis is well suited when data are sparse and parameters highly uncertain. The study model identified five pathways of water contamination: transportation spills, well casing leaks, leaks through fractured rock, drilling site discharge, and wastewater disposal. Probability boxes were generated for each pathway. The potential contamination risk and epistemic uncertainty associated with hydraulic fracturing wastewater disposal was several orders of magnitude larger than the other pathways. Even in a best-case scenario, it was very likely that an individual well would release at least 200 m³ of contaminated fluids. Because the total number of wells in the Marcellus Shale region could range into the tens of thousands, this substantial potential risk suggested that additional steps be taken to reduce the potential for contaminated fluid leaks. To reduce the considerable epistemic uncertainty, more data should be collected on the ability of industrial and municipal wastewater treatment facilities to remove contaminants from used hydraulic fracturing fluid. © 2012 Society for Risk Analysis.

  11. Historical and future emission of hazardous air pollutants (HAPs) from gas-fired combustion in Beijing, China.

    Science.gov (United States)

    Xue, Yifeng; Nie, Lei; Zhou, Zhen; Tian, Hezhong; Yan, Jing; Wu, Xiaoqing; Cheng, Linglong

    2017-07-01

    The consumption of natural gas in Beijing has increased in the past decade due to energy structure adjustments and air pollution abatement. In this study, an integrated emission inventory of hazardous air pollutants (HAPs) emitted from gas-fired combustion in Beijing was developed for the period from 2000 to 2014 using a technology-based approach. Future emission trends were projected through 2030 based on current energy-related and emission control policies. We found that emissions of primary HAPs exhibited an increasing trend with the rapid increase in natural gas consumption. Our estimates indicated that the total emissions of NO X , particulate matter (PM) 10 , PM 2.5 , CO, VOCs, SO 2 , black carbon, Pb, Cd, Hg, As, Cr, Cu, Ni, Zn, polychlorinated dibenzo-p-dioxins and dibenzofurans, and benzo[a]pyrene from gas-fired combustion in Beijing were approximately 22,422 t, 1042 t, 781 t, 19,097 t, 653 t, 82 t, 19 t, 0.6 kg, 0.1 kg, 43 kg, 52 kg, 0.3 kg, 0.03 kg, 4.3 kg, 0.6 kg, 216 μg, and 242 g, respectively, in 2014. To mitigate the associated air pollution and health risks caused by gas-fired combustion, stricter emission standards must be established. Additionally, combustion optimization and flue gas purification system could be used for lowering NO X emissions from gas-fired combustion, and gas-fired facilities should be continuously monitored based on emission limits. Graphical abstract Spatial distribution and typical live photos of gas-fired boiler in Beijing.

  12. Sampling of power plant stacks for air toxic emissions: Topical report for Phases 1 and 2

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-02-21

    Under contract with the US Department of Energy (DE-AC22-92PCO0367), Pittsburgh Energy Technology Center, Radian Corporation has conducted a test program to collect and analyze size-fractionated stack gas particulate samples for selected inorganic hazardous air pollutants (HAPS). Specific goals of the program are (1) the collection of one-gram quantities of size-fractionated stack gas particulate matter for bulk (total) and surface chemical charactization, and (2) the determination of the relationship between particle size, bulk and surface (leachable) composition, and unit load. The information obtained from this program identifies the effects of unit load, particle size, and wet FGD system operation on the relative toxicological effects of exposure to particulate emissions.

  13. A review on electron beam flue gas treatment (EBFGT) as a multicomponent air pollution control technology

    International Nuclear Information System (INIS)

    Basfar, A.A.; Fageeha, O.I.; Kunnummal, N.; Chmielewski, A.G.; Pawelec, A.; Zimek, Z.; Licki, J.; Warych, J.

    2010-01-01

    Implemented on an industrial scale in two thermal power plants in China and at the Electropower Station (EPS) Pomorzany in Poland. The plants in China have been designed mainly for desulfurization while the plant in Poland for a simultaneous removal of SO 2 and NO x from flue gases. The successful operation of these plants has demonstrated the advantages of using this technology for removing SO 2 and NO x from flue gas under varying conditions. At present, the plant in Poland is the only operational installation at an international level. Recent tests performed at an EBFGT industrial pilot plant in Bulgaria have demonstrated feasibility of application of this technology for treatment of high sulfur and high humidity lignite fired boilers. Further laboratory tests have been performed for model flue gases similar to those emitted from a copper smelter and flue gases originated from different types of high sulfur heavy fuel oils. In all cases, dry-scrubbing process with ammonia addition has been tested. The removal efficiency of pollutants is as high as 95% for SO 2 and 70-80% for NO x . The by-product of this process is a high quality fertilizer component. Additional laboratory studies have shown that volatile organic compounds (VOCs) emitted during combustion of fossil fuels, can be degraded as well. Therefore, EBFGT can be considered as a multicomponent air pollution control technology which can be applied to flue gases treatment from coal, lignite and heavy fuel oil-fired boilers. Other thermal processes like metallurgy and municipal waste incinerators are potential candidates for EBFGT technology application. (authors)

  14. Titania Nanotubes Grown on Carbon Fibers for Photocatalytic Decomposition of Gas-Phase Aromatic Pollutants

    Directory of Open Access Journals (Sweden)

    Wan-Kuen Jo

    2014-03-01

    Full Text Available This study aimed to prepare titania (TiO2 nanotube (TNT arrays grown on un-activated carbon fibers (UCFs, with the application of different TiO2 loadings based on the coating-hydrothermal process, and to evaluate their photocatalytic activity for the degradation of sub-ppm levels of aromatic pollutants (benzene, toluene, ethyl benzene, and o-xylene (BTEX using a plug-flow photocatalytic reactor. The characteristics of the prepared photocatalysts were determined by scanning electron microscopy (SEM, energy-dispersive X-ray (EDX, transmission electron microscopy (TEM, UV-visible absorption spectroscopy (UV-Vis and X-ray diffraction (XRD analyses. Spectral analysis showed that the prepared photocatalysts were closely associated with the characteristics of one-dimensional nanostructured TiO2 nanotubes for TNTUCFs and spherical shapes for TiO2-coated UCF (TUCF. The photocatalytic activities of BTEX obtained from TNTUCFs were higher than those obtained from a reference photocatalyst, TUCF. Specifically, the average degradation efficiencies of BTEX observed for TNTUCF-10 were 81%, 97%, 99%, and 99%, respectively, while those observed for TUCF were 14%, 42%, 52%, and 79%, respectively. Moreover, the photocatalytic activities obtained for TNTUCFs suggested that the degradation efficiencies of BTEX varied with changes in TiO2 loadings, allowing for the optimization of TiO2 loading. Another important finding was that input concentrations and air flow rates could be important parameters for the treatment of BTEX, which should be considered for the optimization of TNTUCFs application. Taken together, TNTUCFs can be applied to effectively degrade sub-ppm levels of gas-phase aromatic pollutants through the optimization of operational conditions.

  15. Real-Time Air Pollution Monitoring in Urban Environment Using In-Situ Measurements Using WO3 Gas Sensors and Satellite Imagery Through Internet GIS

    OpenAIRE

    O. Pummakarnchana; V. Phonekeo; A. Vaseashta

    2007-01-01

    Air pollution is a serious problem in densely populated and industrialized areas in some Asian countries. The area investigated for this study is Bangkok, Thailand. The air pollution in central Bangkok is significant in areas with high population density. To monitor air pollution over a large area, this research aims at developing a cost-effective and real-time air pollution monitoring system that utilizes numerical modeling in conjunction with inexpensive, state-of-the-art gas sensors, remot...

  16. Tables of formulae for calculating the mechanics of stacks in gas-graphite reactors; Formulaire pour le calcul de la mecanique des empilements des reacteurs graphite-gaz

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1968-07-01

    This collection of formulae only gives, for nuclear graphite stacks. The mechanical effects due to the strains, thermal or not, of steel structures supporting or surrounding graphite blocks. Equations have been established by mean of experiments made at Chinon with large pile models. Thus, it is possible to calculate displacement, strain and stress in the EDF type stacks of horizontal triangular block lattice. (authors) [French] Le domaine de ce formulaire est strictement limite aux effets mecaniques, pour les empilements, des deformations, thermiques ou autres, des structures metalliques de soutien (aire - support et corset). On propose un ensemble de relations qui ont ete etablies a la suite des essais de CHINON sur des maquettes de grande taille. Ces relations permettent le calcul des mouvements, des deformations et des contraintes dans les empilements du type EDF, a reseau horizontal triangulaire regulier. (auteurs)

  17. Peculiarity of radioactivity pollution of manufacturing environment gas and oil producing firms of the apsheron region

    International Nuclear Information System (INIS)

    Mamedov, A.M.; Alekperova, J.A.

    2002-01-01

    Full text: Present time protection of the biosphere from technogene pollution is the important problem, having common to all mankind value. In circuits of the technogene pollution of the environment the soil is a carrying on link for through soil the contaminants freely go to air environment, in underground waters in plants and in foodstuff of a vegetative and animal genesis. In subsequent these contaminants on the indicated chains by penetrating in an organism of the people render an ill effect on their health. In this plane the radiological contamination of soil introduces still large dangerous. As the radionuclides of soil can render as external radiation, and by getting in an organism with air, water and foodstuff can cause internal radiation. In this plane, for detection of a role of gas and oil producing firms in radiological contamination soil as object of an environment, we conduct researches by a hygienic estimation of radiological contamination of soil of territory of oil-fields OOGE 'Gum adasi' of the Apsheron region. By spectrometric method were studied a natural background radiation and radioactivity of soil of different territories of shop of complex opening-up of oil. Established, that for the raw tank the specific activity reaches 4438-9967 Bk/kg, close of the product repair shop the radioactivity reached 650- 700 micro R/hour. In territory of the region 'Gum adasi', where the waste from cleaning chisel tubes were accumulated, the radioactivity made 600 micro R/hour. These indexes the superior background level is significant. The analysis of power spectrums a gamma of radiations is model from the indicated sites has shown, that the radioactivity is conditioned by isotopes of a radium. The researches have allowed to demonstrate a radioactivity technogene of impurity of rocks to recommend urgent dumping of above-stated waste in bunkers on sites, retracted by it. Thus, was established, that gas and oil producing firms contributing to radiological

  18. Improving the accuracy of vehicle emissions profiles for urban transportation greenhouse gas and air pollution inventories.

    Science.gov (United States)

    Reyna, Janet L; Chester, Mikhail V; Ahn, Soyoung; Fraser, Andrew M

    2015-01-06

    Metropolitan greenhouse gas and air emissions inventories can better account for the variability in vehicle movement, fleet composition, and infrastructure that exists within and between regions, to develop more accurate information for environmental goals. With emerging access to high quality data, new methods are needed for informing transportation emissions assessment practitioners of the relevant vehicle and infrastructure characteristics that should be prioritized in modeling to improve the accuracy of inventories. The sensitivity of light and heavy-duty vehicle greenhouse gas (GHG) and conventional air pollutant (CAP) emissions to speed, weight, age, and roadway gradient are examined with second-by-second velocity profiles on freeway and arterial roads under free-flow and congestion scenarios. By creating upper and lower bounds for each factor, the potential variability which could exist in transportation emissions assessments is estimated. When comparing the effects of changes in these characteristics across U.S. cities against average characteristics of the U.S. fleet and infrastructure, significant variability in emissions is found to exist. GHGs from light-duty vehicles could vary by -2%-11% and CAP by -47%-228% when compared to the baseline. For heavy-duty vehicles, the variability is -21%-55% and -32%-174%, respectively. The results show that cities should more aggressively pursue the integration of emerging big data into regional transportation emissions modeling, and the integration of these data is likely to impact GHG and CAP inventories and how aggressively policies should be implemented to meet reductions. A web-tool is developed to aide cities in improving emissions uncertainty.

  19. Modeling Population Exposures to Pollutants Emitted from Natural Gas Cooking Burners

    Energy Technology Data Exchange (ETDEWEB)

    Lobscheid, Agnes; Singer, Brett C.; Klepeis, Neil E.

    2011-06-01

    We developed a physics-based data-supported model to investigate indoor pollutant exposure distributions resulting from use of natural gas cooking appliances across households in California. The model was applied to calculate time-resolved indoor concentrations of CO, NO2 and formaldehyde resulting from cooking burners and entry with outdoor air. Exposure metrics include 1-week average concentrations and frequency of exceeding ambient air quality standards. We present model results for Southern California (SoCal) using two air-exchange scenarios in winter: (1) infiltration-only, and (2) air exchange rate (AER) sampled from lognormal distributions derived from measurements. In roughly 40percent of homes in the SoCal cohort (N=6634) the 1-hour USEPA NO2 standard (190 ?g/m3) was exceeded at least once. The frequency of exceeding this standard was largely independent of AER assumption, and related primarily to building volume, emission rate and amount of burner use. As expected, AER had a more substantial impact on one-week average concentrations.

  20. Chlorine and bromine isotope fractionation of halogenated organic pollutants on gas chromatography columns.

    Science.gov (United States)

    Tang, Caiming; Tan, Jianhua; Xiong, Songsong; Liu, Jun; Fan, Yujuan; Peng, Xianzhi

    2017-09-08

    Compound-specific chlorine/bromine isotope analysis (CSIA-Cl/Br) has become a powerful approach to investigate degradation pathways and apportion sources of halogenated organic pollutants (HOPs) in the environment. CSIA-Cl/Br is usually conducted by gas chromatography-mass spectrometry (GC-MS), which could be negatively impacted by isotope fractionation on GC columns. In this study, on-column Cl/Br isotope fractionation of 31 organochlorines and 4 organobromines was explored using GC-double focus magnetic-sector high resolution MS (GC-DFS-HRMS). Twenty-nine HOPs exhibited inverse Cl/Br isotope fractionation for which the heavier isotopologues eluted faster than the lighter ones on GC columns, and two polychlorinated biphenyls (PCB-138 and PCB-153) showed normal isotope fractionation, whereas the rest four HOPs did not show observable isotope fractionation. The isotope fractionation extents varied from -13.0‰ to 73.1‰. Mechanisms of the on-column Cl/Br isotope fractionation were tentatively elucidated with a modified two-film model. The results demonstrate that integrating peak area as complete as possible for separable chromatographic peaks and integrating the middle retention-time segments for the inseparable peaks are helpful to improve precision and accuracy of the CSIA-Cl/Br data. The findings of this study will shed light on development of CSIA-Cl/Br methods with respect to improving precision and accuracy. Copyright © 2017 Elsevier B.V. All rights reserved.

  1. Measurement of atmospheric pollutants associated with oil and natural gas exploration and production activity in Pennsylvania's Allegheny National Forest.

    Science.gov (United States)

    Pekney, Natalie J; Veloski, Garret; Reeder, Matthew; Tamilia, Joseph; Rupp, Erik; Wetzel, Alan

    2014-09-01

    Oil and natural gas exploration and production (E&P) activities generate emissions from diesel engines, compressor stations, condensate tanks, leaks and venting of natural gas, construction of well pads, and well access roads that can negatively impact air quality on both local and regional scales. A mobile, autonomous air quality monitoring laboratory was constructed to collect measurements of ambient concentrations of pollutants associated with oil and natural gas E&P activities. This air-monitoring laboratory was deployed to the Allegheny National Forest (ANF) in northwestern Pennsylvania for a campaign that resulted in the collection of approximately 7 months of data split between three monitoring locations between July 2010 and June 2011. The three monitoring locations were the Kane Experimental Forest (KEF) area in Elk County, which is downwind of the Sackett oilfield; the Bradford Ranger Station (BRS) in McKean County, which is downwind of a large area of historic oil and gas productivity; and the U.S. Forest Service Hearts Content campground (HC) in Warren County, which is in an area relatively unimpacted by oil and gas development and which therefore yielded background pollutant concentrations in the ANF. Concentrations of criteria pollutants ozone and NO2 did not vary significantly from site to site; averages were below National Ambient Air Quality Standards. Concentrations of volatile organic compounds (VOCs) associated with oil and natural gas (ethane, propane, butane, pentane) were highly correlated. Applying the conditional probability function (CPF) to the ethane data yielded most probable directions of the sources that were coincident with known location of existing wells and activity. Differences between the two impacted and one background site were difficult to discern, suggesting the that the monitoring laboratory was a great enough distance downwind of active areas to allow for sufficient dispersion with background air such that the localized

  2. Determination of hexavalent chromium concentration in industrial waste incinerator stack gas by using a modified ion chromatography with post-column derivatization method.

    Science.gov (United States)

    Miyake, Yuichi; Tokumura, Masahiro; Iwazaki, Yuta; Wang, Qi; Amagai, Takashi; Horii, Yuichi; Otsuka, Hideyuki; Tanikawa, Noboru; Kobayashi, Takeshi; Oguchi, Masahiro

    2017-06-16

    An ion chromatography with post-column derivatization with 1,5-diphenylcarbazide (IC-DPC) analytical method was modified to enable measurement of trace-level hexavalent chromium (Cr(VI)) in air. One of the difficulties in determining trace levels of Cr(VI) in air with conventional IC-DPC methods is co-elution of the solvent and ion peaks due to high concentrations of ionic compounds in the extract. However, by using gradient elution rather than isocratic elution we were able to fully resolve the Cr(VI) ion peak from the solvent peak without the need for diluting the extract, which would have reduced the minimum quantifiable level of the method. With this method, we were able to detect Cr(VI) in air at concentrations of 5.3ng/m 3 (assuming a sampling volume of 1m 3 and a final solution volume of 10mL). Recovery tests at three different concentrations of Cr(VI) (50, 250, 1000ng) were performed with or without fly ash; recovery rates at all the concentrations of Cr(VI), with or without fly ash, ranged from 68% to 110% (mean±relative standard deviation, 96%±11%), and there were no differences in recovery rates with respect to the presence or absence of fly ash. Finally, we used the developed method to determine the concentration of Cr(VI) in stack gases collected from eight industrial waste incinerators located in Japan. The concentration of Cr(VI) in the stack gases ranged from below the method quantification limit to 3100ng/m 3 . The highest concentrations of Cr(VI) detected in the stack gases were two to three orders of magnitude higher than that in ambient air in Japan. Copyright © 2017 Elsevier B.V. All rights reserved.

  3. Deploying OpenStack

    CERN Document Server

    Pepple, Ken

    2011-01-01

    OpenStack was created with the audacious goal of being the ubiquitous software choice for building public and private cloud infrastructures. In just over a year, it's become the most talked-about project in open source. This concise book introduces OpenStack's general design and primary software components in detail, and shows you how to start using it to build cloud infrastructures. If you're a developer, technologist, or system administrator familiar with cloud offerings such as Rackspace Cloud or Amazon Web Services, Deploying OpenStack shows you how to obtain and deploy OpenStack softwar

  4. Determination of Organic Pollutants in Small Samples of Groundwaters by Liquid-Liquid Extraction and Capillary Gas Chromatography

    DEFF Research Database (Denmark)

    Harrison, I.; Leader, R.U.; Higgo, J.J.W.

    1994-01-01

    A method is presented for the determination of 22 organic compounds in polluted groundwaters. The method includes liquid-liquid extraction of the base/neutral organics from small, alkaline groundwater samples, followed by derivatisation and liquid-liquid extraction of phenolic compounds after...... neutralisation. The extracts were analysed by capillary gas chromatography. Dual detection by flame Ionisation and electron capture was used to reduce analysis time....

  5. Posttranslational modification of Birch and Ragweed allergen proteins by common gas phase pollutants, NO2 and O3

    Science.gov (United States)

    Mahmood, M. A.; Pope, F.; Bloss, W.

    2015-12-01

    The global incidence of hay fever has been rising for decades, however, the underlying reasons behind this rise remain unclear. It is hypothesized that exposure of pollen to common gas phase pollutants, such as nitrogen dioxide (NO2) and ozone (O3), increases the allergenicity of the pollen and thus increases hay fever incidence. Since atmospheric pollutants tend to have greater concentrations within urban areas (in particular NO2) the hypothesis suggests that greater allergenicity should occur in urban areas. Indeed, several studies do suggest higher hay fever incidence within urban areas compared to rural areas. Previous published work suggests a link between increased allergies with changes in the chemical composition of the pollen protein via posttranslational modification of the protein. This study investigates the posttranslational modification of two highly allergenic pollen species (Birch and Ragweed) that are common in Europe. Within the laboratory, we expose pollen grains to atmospherically relevant exposures of gas phase NO2, O3 and other common gas phase oxidants under a range of environmentally relevant conditions. The effects of the environmentally relevant exposures on the biochemistry of the pollen grains were probed using a proteomic approach (liquid chromatography coupled ultra-high resolution spectrometer). Our findings indicate the interaction between gas phase pollutants and pollen cause protein specific modifications; in particular, nitration occurs upon tyrosine residues and nitrosylation on cysteine residues. Possibly, these modifications may affect the immune response of the pollen protein, which may suggest a possible reason for increased allergies in reaction to such biologically altered protein. The laboratory-derived results will be supported with a time series analysis of asthma incidence rates for the London area, which take into account the pollen count, and pollutant concentrations. The implications of the results will be discussed

  6. The application of an improved gas and aerosol collector for ambient air pollutants in China

    Science.gov (United States)

    Dong, Huabin; Zeng, Limin; Zhang, Yuanhang; Hu, Min; Wu, Yusheng

    2016-04-01

    An improved Gas and Aerosol Collector (GAC) equipped with a newly designed aerosol collector and a set of dull-polished wet annular denuder (WAD) was developed by Peking University based on a Steam Jet Aerosol Collector (SJAC) sampler. Combined with Ion Chromatography (IC) the new sampler performed well in laboratory tests with high collection efficiencies for SO2 (above 98 %) and particulate sulfate (as high as 99.5 %). An inter-comparison between the GAC-IC system and the filter-pack method was performed and the results indicated that the GAC-IC system could supply reliable particulate sulfate, nitrate, chloride, and ammonium data in field measurement with a much wider range of ambient concentrations. From 2008 to 2015, dozens of big field campaigns (rural and coastal sites) were executed in different parts of China, the GAC-IC system took the chance having its field measurement performance checked repeatedly and provided high quality data in ambient conditions either under high loadings of pollutants or background area. Its measurements were highly correlated with data by other commercial instruments such as the SO2 analyzer, the HONO analyzer, a filter sampler, Aerosol Mass Spectrometer (AMS), etc. over a wide range of concentrations and proved particularly useful in future intensive campaigns or long-term monitoring stations to study various environmental issues such as secondary aerosol and haze formation. During these years of applications of GAC-IC in those field campaigns, we found some problems of several instruments running under field environment and some interesting results could also be drew from the large amount of data measured in near 20 provinces of China. Detail results will be demonstrated on the poster afterwards.

  7. OpenStack essentials

    CERN Document Server

    Radez, Dan

    2015-01-01

    If you need to get started with OpenStack or want to learn more, then this book is your perfect companion. If you're comfortable with the Linux command line, you'll gain confidence in using OpenStack.

  8. Mastering OpenStack

    CERN Document Server

    Khedher, Omar

    2015-01-01

    This book is intended for system administrators, cloud engineers, and system architects who want to deploy a cloud based on OpenStack in a mid- to large-sized IT infrastructure. If you have a fundamental understanding of cloud computing and OpenStack and want to expand your knowledge, then this book is an excellent checkpoint to move forward.

  9. Final Rule for Finding That Greenhouse Gas Emissions From Aircraft Cause or Contribute to Air Pollution That May Reasonably Be Anticipated To Endanger Public Health and Welfare

    Science.gov (United States)

    The EPA finalized findings that greenhouse gas (GHG) emissions from certain classes of engines used in aircraft contribute to the air pollution that causes climate change endangering public health and welfare under section 231(a) of the Clean Air Act.

  10. Integrated biomass gasification using the waste heat from hot slags: Control of syngas and polluting gas releases

    International Nuclear Information System (INIS)

    Sun, Yongqi; Seetharaman, Seshadri; Liu, Qianyi; Zhang, Zuotai; Liu, Lili; Wang, Xidong

    2016-01-01

    In this study, the thermodynamics of a novel strategy, i.e., biomass/CO 2 gasification integrated with heat recovery from hot slags in the steel industry, were systemically investigated. Both the target syngas yield and the polluting gas release were considered where the effect of gasifying conditions including temperature, pressure and CO 2 reacted was analyzed and then the roles of hot slags were further clarified. The results indicated that there existed an optimum temperature for the maximization of H 2 production. Compared to blast furnace slags, steel slags remarkably increased the CO yield at 600–1400 °C due to the existence of iron oxides and decreased the S-containing gas releases at 400–700 °C, indicating potential desulfurizing ability. The identification of biomass/CO 2 gasification thermodynamics in presence of slags could thus provide important clues not only for the deep understanding of biomass gasification but also for the industrial application of this emerging strategy from the viewpoint of syngas optimization and pollution control. - Highlights: • Biomass/CO 2 gasification was integrated with the heat recovery from hot slags. • Both syngas yield and polluting gas release during gasification were determined. • There existed an optimum temperature for the maximization of H 2 production. • Steel slags increased CO yield at 600–1400 °C due to the existence of iron oxides. • Steel slags remarkably decreased the releases of S-containing gas at 400–700 °C.

  11. Prediction of major pollutants emission in direct injection dual-fuel diesel and natural-gas engines

    International Nuclear Information System (INIS)

    Pirouzpanah, V.; Kashani, B.O.

    2000-01-01

    The dual-fuel diesel engine is a conventional diesel engine in which much of the energy released, hence power, comes from the combustion of gaseous fuel such as natural gas. The exhaust emission characteristics of the dual-fuel diesel engine needs further refinements, particularly in terms of reduction of Unburnt Hydrocarbons and Carbon Monoxide (CO) emission, because the concentration of these pollutants are higher than that of the baseline diesel engine. Furthermore, the combustion process in a typical dual-fuel diesel engine tends to be complex, showing combination of the problems encountered both in diesel and spark ignition engines. In this work, a computer code has been modified for simulation of dual-fuel diesel engine combustion process. This model simulates dual-fuel diesel engine combustion by using a Multi-Zone Combustion Model for diesel pilot jet combustion and a conventional spark ignition combustion model for modelling of combustion of premixed gas/air charge. Also, in this model, there are four submodels for prediction of major emission pollutants such as: Unburnt Hydrocarbons, No, Co and soot which are emitted from dual-fuel diesel engine. For prediction of formation and oxidation rates of pollutants, relevant s conventional kinetically-controlled mechanisms and mass balances are used. the model has been verified by experimental data obtained from a heavy-duty truck and bus diesel engines. The comparison shows that, there exist good agreements between the experimental and predicted results from the dual-fuel diesel engine

  12. The challenges of reducing greenhouse gas emissions and air pollution through energy sources: evidence from a panel of developed countries.

    Science.gov (United States)

    Akhmat, Ghulam; Zaman, Khalid; Shukui, Tan; Sajjad, Faiza; Khan, Muhammad Azhar; Khan, Muhammad Zahir

    2014-06-01

    The objective of the study is to investigate the long-run relationship between climatic factors (i.e., greenhouse gas emissions, agricultural methane emissions, and industrial nitrous oxide emission), air pollution (i.e., carbon dioxide emissions), and energy sources (i.e., nuclear energy; oil, gas, and coal energy; and fossil fuel energy) in the panel of 35 developed countries (including EU-15, new EU member states, G-7, and other countries) over a period of 1975-2012. In order to achieve this objective, the present study uses sophisticated panel econometric techniques including panel cointegration, panel fully modified OLS (FMOLS), and dynamic OLS (DOLS). The results show that there is a long-run relationship between the variables. Nuclear energy reduces greenhouse gases and carbon emissions; however, the other emissions, i.e., agricultural methane emissions and industrial nitrous oxide, are still to increase during the study period. Electricity production from oil, gas, and coal sources increases the greenhouse gases and carbon emissions; however, the intensity to increase emissions is far less than the intensity to increase emissions through fossil fuel. Policies that reduce emissions of greenhouse gases can simultaneously alter emissions of conventional pollutants that have deleterious effects on human health and the environment.

  13. Development of on-site PAFC stacks

    Energy Technology Data Exchange (ETDEWEB)

    Hotta, K.; Matsumoto, Y. [Kansai Electric Power Co., Amagasaki (Japan); Horiuchi, H.; Ohtani, T. [Mitsubishi Electric Corp., Kobe (Japan)

    1996-12-31

    PAFC (Phosphoric Acid Fuel Cell) has been researched for commercial use and demonstration plants have been installed in various sites. However, PAFC don`t have a enough stability yet, so more research and development must be required in the future. Especially, cell stack needs a proper state of three phases (liquid, gas and solid) interface. It is very difficult technology to keep this condition for a long time. In the small size cell with the electrode area of 100 cm{sup 2}, gas flow and temperature distributions show uniformity. But in the large size cell with the electrode area of 4000 cm{sup 2}, the temperature distributions show non-uniformity. These distributions would cause to be shorten the cell life. Because these distributions make hot-spot and gas poverty in limited parts. So we inserted thermocouples in short-stack for measuring three-dimensional temperature distributions and observed effects of current density and gas utilization on temperature.

  14. Air pollutant and greenhouse gas emissions - 'Namea-Air' - February 2017

    International Nuclear Information System (INIS)

    Baude, Manuel

    2017-02-01

    For the first time, the SOeS (Monitoring and Statistics Directorate of France's Ministry of the Environment) is publishing air pollutant emissions accounts in the National Accounting Matrix Including Environmental Accounts (NAMEA) format for the years 1990, 1995, 2000, 2005, and 2008 to 2014. Namea-Air is an inventory format breaking down emissions of greenhouse gases (GHG) and air pollutants into 64 branches of economic activity and identifying a 'direct household emissions' category. (author)

  15. Mutagenic/carcinogenic agents in indoor pollutants; the dinitropyrenes generated by kerosene heaters and fuel gas and liquefied petroleum gas burners.

    Science.gov (United States)

    Tokiwa, H; Nakagawa, R; Horikawa, K

    1985-07-01

    Incomplete combustion of kerosene heater, and fuel gas and liquefied petroleum gas-burner emissions produces indoor pollutants that may be carcinogenic. The incomplete-combustion products from each type of appliance were therefore collected by adsorption on about 3 g of XAD-2 resin, and were extracted with benzene-methanol as a solvent for determination and identification of mutagens in the Salmonella-microsome test system. Benzene-methanol extracts of the particulates generated by a heater and two burners showed extreme mutagenicity for strains TA97 and TA98 without S9 mix. Based on the results of analysis, a combination of high performance liquid chromatography (h.p.l.c.) and gas chromatography (GC), about 40-80% of the direct-acting mutagenicity in each crude extract showed the same h.p.l.c. and GC retention times as dinitropyrenes (1,3-, 1,6- and 1,8-isomers), and 1-nitropyrene. Moreover, other nitroarenes, 2-nitrofluorene, 1,5- and 1,8-dinitronaphthalene, and 4,4'-dinitrobiphenyl, were detectable in almost all samples, but their contribution to the mutagenicity of each extract was very low. Kerosene heaters were found to generate small amounts (0.2 ng/h) of dinitropyrenes, which are potential mutagens/carcinogens, only after 1 h of operation.

  16. NATURAL GAS VARIABILITY IN CALIFORNIA: ENVIRONMENTAL IMPACTS AND DEVICE PERFORMANCE EXPERIMENTAL EVALUATION OF POLLUTANT EMISSIONS FROM RESIDENTIAL APPLIANCES

    Energy Technology Data Exchange (ETDEWEB)

    Singer, Brett C.; Apte, Michael G.; Black, Douglas R.; Hotchi, Toshifumi; Lucas, Donald; Lunden, Melissa M.; Mirer, Anna G.; Spears, Michael; Sullivan, Douglas P.

    2009-12-01

    The effect of liquefied natural gas on pollutant emissions was evaluated experimentally with used and new appliances in the laboratory and with appliances installed in residences, targeting information gaps from previous studies. Burner selection targeted available technologies that are projected to comprise the majority of installed appliances over the next decade. Experiments were conducted on 13 cooktop sets, 12 ovens, 5 broiler burners, 5 storage water heaters, 4 forced air furnaces, 1 wall furnace, and 6 tankless water heaters. Air-free concentrations and fuel-based emission factors were determined for carbon monoxide, nitrogen oxides, nitrogen dioxide, and the number of (predominantly ultrafine) particles over complete burns?including transient effects (device warm-up and intermittent firing of burners) following ignition--and during more stable end-of-burn conditions. Formaldehyde was measured over multi-burn cycles. The baseline fuel was Northern California line gas with Wobbe number (a measure of fuel energy delivery rate) of 1320-1340; test fuels had Wobbe numbers of roughly 1390 and 1420, and in some cases 1360. No ignition or operational problems were observed during test fuel use. Baseline emissions varied widely across and within burner groups and with burner operational mode. Statistically significant emissions changes were observed for some pollutants on some burners.

  17. Human health cost of hydrogen sulfide air pollution from an oil and gas Field

    Directory of Open Access Journals (Sweden)

    Dinara Kenessary

    2017-06-01

    The reduction of hydrogen sulfide emissions into the air is recommended, as well as successive constant ambient air monitoring in future. Economic damage evaluation should be made mandatory, on a legal basis, whenever an industrial facility operation results in associated air pollution.

  18. Ecological assessment of oil-gas producing area in Kazakhstan zone of Caspian sea and using the bioremediation technology for cleaning of high level oil polluted sites

    International Nuclear Information System (INIS)

    Bigaliev, A.A.; Ishanova, N.E.; Bijazheva, S.M.; Novikova, A.; Bigaliev, A.B.

    2008-01-01

    A significant part of mineral raw material resources of Kazakhstan placed in the depth of the Caspian region, where more than 90% extracting of oil and natural gas, 100% balance store rare ground, 3.2% uranium, ore 0.3%, 90.5% sawn store concentrated. Last years, it takes intensive works by extraction of carbon raw materials in Kazakhstan sector of the Caspian sea. It brought to exceeding of coastal pollution at the North and middle the Caspian coastal pollution with oil products in average till 0.282 mg/l. Maximum meaning oil product pollution reaches 0.56 mg/l (which means exceeding of limited concentration on 11 times). How much money need to cover cost of remediation in real sites? Develop of assessment and monitoring procedures based on fate mechanisms for most of representative hydrocarbons in polluted soils. Step 1 - Collection of heavily polluted portions of soils, separation of hydrocarbons by cost efficient mechanical procedures and send HC rich material (HC>95%) to prepare of alternative fuel. Return of low HC content sand to project area (HC<5.0%). Step 2 - Development of low cost bioremediation procedures in areas transformed to moderately polluted site (HC<5% after removing of heavily polluted portions) with uniform HC content. We are needed to develop of coast efficiency approach for cleaning of high level oily polluted sites around urban areas in Kazakhstan new methodology to estimate polluted area and recover of pollution history, low cost bioremediation

  19. Real-Time Air Pollution Monitoring in Urban Environment Using In-Situ Measurements Using WO3 Gas Sensors and Satellite Imagery Through Internet GIS

    Directory of Open Access Journals (Sweden)

    O. Pummakarnchana

    2007-03-01

    Full Text Available Air pollution is a serious problem in densely populated and industrialized areas in some Asian countries. The area investigated for this study is Bangkok, Thailand. The air pollution in central Bangkok is significant in areas with high population density. To monitor air pollution over a large area, this research aims at developing a cost-effective and real-time air pollution monitoring system that utilizes numerical modeling in conjunction with inexpensive, state-of-the-art gas sensors, remote sensing methodologies, and Internet GIS. Conventional pollution detectors, installed by the Bangkok Pollution Control Department, as well as WO3 sensors are employed for in-situ pollution measurements. The data obtained from the satellites sensors and measurements conducted on ground are used for numerical modeling by “Multiple Regressions” to investigate air pollutants distribution. The analysis and correlation of the air pollutants data are transferred to a Personal Digital Assistant linked via Bluetooth communication tools and Global Positioning System for rapid and simultaneous dissemination of information on pollution levels at multiple sites.

  20. Stack filter classifiers

    Energy Technology Data Exchange (ETDEWEB)

    Porter, Reid B [Los Alamos National Laboratory; Hush, Don [Los Alamos National Laboratory

    2009-01-01

    Just as linear models generalize the sample mean and weighted average, weighted order statistic models generalize the sample median and weighted median. This analogy can be continued informally to generalized additive modeels in the case of the mean, and Stack Filters in the case of the median. Both of these model classes have been extensively studied for signal and image processing but it is surprising to find that for pattern classification, their treatment has been significantly one sided. Generalized additive models are now a major tool in pattern classification and many different learning algorithms have been developed to fit model parameters to finite data. However Stack Filters remain largely confined to signal and image processing and learning algorithms for classification are yet to be seen. This paper is a step towards Stack Filter Classifiers and it shows that the approach is interesting from both a theoretical and a practical perspective.

  1. A novel configuration for direct internal reforming stacks

    Science.gov (United States)

    Fellows, Richard

    This paper presents a stack concept that can be applied to both molten carbonate fuel cell (MCFC) and solid oxide fuel cell (SOFC) internal reforming stacks. It employs anode recycle and allows the design of very simple system configurations, while giving enhanced efficiencies and high specific power densities. The recycle of anode exit gas to the anode inlet has previously been proposed as a means of preventing carbon deposition in direct internal reforming (DIR) stacks. When applied to a normal stack this reduces the Nernst voltages because the recycle stream is relatively depleted in hydrogen. In the concept proposed here, known as the `Smarter' stack, there are two anode exit streams, one of which is depleted, while the other is relatively undepleted. The depleted stream passes directly to the burner, and the undepleted stream is recycled to the stack inlet. By this means high Nernst voltages are achieved in the stack. The concept has been simulated and assessed for parallel-flow and cross-flow MCFC and SOFC stacks and graphs are presented showing temperature distributions. The `Smarter' stacks employ a high recycle rate resulting in a reduced natural gas concentration at the stack inlet, and this reduces or eliminates the unfavourable temperature dip. Catalyst grading can further improve the temperature distribution. The concept allows simple system configurations in which the need for fuel pre-heat is eliminated. Efficiencies are up to 10 percentage points higher than for conventional stacks with the same cell area and maximum stack temperature. The concept presented here was devised in a project part-funded by the EU, and has been adopted by the European Advanced DIR-MCFC development programme led by BCN.

  2. Addressing Air Pollution and Greenhouse Gas Emissions in the Pan-Japan Sea Region. An Overview of Economic Instruments

    International Nuclear Information System (INIS)

    Boyle, G.; Kambu, A.

    2005-11-01

    The health and environmental impacts of fossil fuel consumption are of increasing concern to countries in the Pan-Japan Sea region, where economic growth has led to increased energy consumption in recent years. Economic instruments like green taxes and emissions-trading schemes represent important tools to help reduce air pollution and greenhouse gas (GHG) emissions in China, Japan, South Korea and Russia. Over the past several years, OECD countries have made progress in the use of economic instruments to reduce atmospheric air pollution. In Europe, new environmental taxes have been used most extensively, while in the United States market creation and emissions-trading schemes are more common. In the Pan-Japan Sea region, there has been considerable experience with pollution charge and levy systems, including the longstanding Japanese sulfur levy and the Russian and Chinese pollution charge systems. Generally, tax and emissions-trading systems are only beginning to emerge in the region although China has been experimenting with SOx emissions-trading schemes for several years now and South Korea and Japan have already begun experimenting with CO2 emissions-trading schemes. Only Japan has seriously looked at a carbon tax to curb GHG emissions among the four countries while direct subsidies for cleaner technologies have been adopted in the different Pan-Japan Sea countries. The costs and benefits of different economic instruments like taxes, charges, emissions-trading schemes and subsidies vary from case to case because they all have to be financially feasible, rest on informed and competent public institutions and perform effectively in local market and economic conditions. On top of all these is the fact that their overall success depends on their political acceptability. Given the experience of Pan-Japan Sea countries with economic instruments so far vis-a-vis the lessons learned in OECD countries and the nature of current and emerging pollution problems in Pan

  3. Laser pulse stacking method

    Science.gov (United States)

    Moses, E.I.

    1992-12-01

    A laser pulse stacking method is disclosed. A problem with the prior art has been the generation of a series of laser beam pulses where the outer and inner regions of the beams are generated so as to form radially non-synchronous pulses. Such pulses thus have a non-uniform cross-sectional area with respect to the outer and inner edges of the pulses. The present invention provides a solution by combining the temporally non-uniform pulses in a stacking effect to thus provide a more uniform temporal synchronism over the beam diameter. 2 figs.

  4. The radon gas. An air pollutant El gas radón como contaminante atmosférico

    Directory of Open Access Journals (Sweden)

    José Luis Arteche

    2010-12-01

    Full Text Available In this work different aspects about the problem of the radon in dwellings are approached. This gas of natural origin is virtually present in all the soils in the earth’s crust due to the presence of uranium and radium in the composition of them. Depending on architectural factors and of occupancy habits of the house, high concentrations of this gas can be reached indoors. In these situations, there is a quantifiable increment of the risk of developing lung cancer in the inhabitants of the housing. In the last years the methodological improvements in the realization of epidemiologic studies have led to the obtaining of scientific evidences about the relationship between the presence of indoor radon and the risk of lung cancer. This relationship, found years ago in workers of uranium mines, has been corroborated in the case of the residential radon by the light of several recent meta-analysis performed on groups of epidemiologic studies. More than 6.000 radon measurements have been carried out in Spain during the last 25 years. A summary of the results obtained from the main national radon surveys are also presented, as well as the criteria recently established by the Spanish Nuclear Safety Council concerning radon action levels in dwellings and workplaces.En este trabajo se abordan distintos aspectos acerca de la problemática del radón en viviendas. Este gas de origen natural se encuentra prácticamente en la totalidad de los suelos de la corteza terrestre debido a la presencia de uranio y radio en la composición de los mismos. En función de factores arquitectónicos y de hábitos de ocupación de la vivienda pueden alcanzarse concentraciones elevadas del gas en interiores. En estas situaciones existe un incremento cuantificable del riesgo de desarrollar cáncer de pulmón en los habitantes de la vivienda. En los últimos años, las mejoras metodológicas en la realización de estudios epidemiológicos han conducido a la obtención de

  5. Source reconciliation of atmospheric gas-phase and particle-phase pollutants during a severe photochemical smog episode.

    Science.gov (United States)

    Schauer, James J; Fraser, Matthew P; Cass, Glen R; Simoneit, Bernd R T

    2002-09-01

    A comprehensive organic compound-based receptor model is developed that can simultaneously apportion the source contributions to atmospheric gas-phase organic compounds, semivolatile organic compounds, fine particle organic compounds, and fine particle mass. The model is applied to ambient data collected at four sites in the south coast region of California during a severe summertime photochemical smog episode, where the model determines the direct primary contributions to atmospheric pollutants from 11 distinct air pollution source types. The 11 sources included in the model are gasoline-powered motor vehicle exhaust, diesel engine exhaust, whole gasoline vapors, gasoline headspace vapors, organic solvent vapors, whole diesel fuel, paved road dust, tire wear debris, meat cooking exhaust, natural gas leakage, and vegetative detritus. Gasoline engine exhaust plus whole gasoline vapors are the predominant sources of volatile organic gases, while gasoline and diesel engine exhaust plus diesel fuel vapors dominate the emissions of semivolatile organic compounds from these sources during the episode studied at all four air monitoring sites. The atmospheric fine particle organic compound mass was composed of noticeable contributions from gasoline-powered motor vehicle exhaust, diesel engine exhaust, meat cooking, and paved road dust with smaller but quantifiable contributions from vegetative detritus and tire wear debris. In addition, secondary organic aerosol, which is formed from the low-vapor pressure products of gas-phase chemical reactions, is found to be a major source of fine particle organic compound mass under the severe photochemical smog conditions studied here. The concentrations of secondary organic aerosol calculated in the present study are compared with previous fine particle source apportionment results for less intense photochemical smog conditions. It is shown that estimated secondary organic aerosol concentrations correlate fairly well with the

  6. Testing and Evaluation of an Advanced High Performance Planar SOFC Stack

    National Research Council Canada - National Science Library

    Elangovan, S

    1999-01-01

    .... SOFCo has conducted several programs which synergistically address this objective: an internally funded program focusing on stack development and system integration for pipeline natural gas (PNG...

  7. Sensitivity of global greenhouse gas budgets to tropospheric ozone pollution mediated by the biosphere

    Science.gov (United States)

    Wang, Bin; Shugart, Herman H.; Lerdau, Manuel T.

    2017-08-01

    Tropospheric ozone (O3), a harmful secondary air pollutant, can affect the climate via direct radiative forcing and by modifying the radiative forcing of aerosols through its role as an atmospheric oxidant. Moreover, O3 exerts a strong oxidative pressure on the biosphere and indirectly influences the climate by altering the materials and energy exchange between terrestrial ecosystems and the atmosphere. However, the magnitude by which O3 affects the global budgets of greenhouse gases (GHGs: CO2, CH4, and N2O) through altering the land-atmosphere exchange is largely unknown. Here we assess the sensitivity of these budgets to tropospheric O3 pollution based on a meta-analysis of experimental studies on the effects of elevated O3 on GHG exchange between terrestrial ecosystems and the atmosphere. We show that across ecosystems, elevated O3 suppresses N2O emissions and both CH4 emissions and uptake, and has little impact on stimulation of soil CO2 emissions except at relatively high concentrations. Therefore, the soil system would be transformed from a sink into a source of GHGs with O3 levels increasing. The global atmospheric budget of GHGs is sensitive to O3 pollution largely because of the carbon dioxide accumulation resulting from suppressed vegetation carbon uptake; the negative contributions from suppressed CH4 and N2O emissions can offset only ˜10% of CO2 emissions from the soil-vegetation system. Based on empirical data, this work, though with uncertainties, provides the first assessment of sensitivity of global budgets of GHGs to O3 pollution, representing a necessary step towards fully understanding and evaluating O3-climate feedbacks mediated by the biosphere.

  8. Servey of the oil and gas pollutant impacts on the human and environment

    Directory of Open Access Journals (Sweden)

    Sina Dobaradaran

    2014-04-01

    Full Text Available Oil has vital importance in many industries and is the main source of energy internationally it supplies 32% of energy in Europe and Asia and more than 53% in Middle East. The most volume of oil industry products includes fuel oil and gasoline (diesel. Oil is used as the basic material in producing chemical products such as medicines, solvents, chemical fertilizers, pesticides and etc. Considering the importance of petroleum industry in the world we should not ignore its harms to humans and the environment and should look for solutions to reduce them. Nowaday petroleum refineries emit million pounds of air pollutants that pose a serious risk of harm to human health and the environment as well as impairs the life quality of the people that living nearby these industries. These pollutants consist of volatile organic compounds, SO2, NOx, particulate matter, CO, H2S and HAPs. These pollutants have different adverse impacts on different parts of ecosystem, environment and animals. So this paper deals with some of these problems.

  9. po_stack_movie

    DEFF Research Database (Denmark)

    2009-01-01

    po_stack® er et reolsystem, hvis enkle elementer giver stor flexibilitet, variation og skulpturel virkning. Elementerne stables og forskydes frit, så reolens rum kan vendes til begge sider, være åbne eller lukkede og farvekombineres ubegrænset. Reolen kan let ombygges, udvides eller opdeles, når ...

  10. Learning SaltStack

    CERN Document Server

    Myers, Colton

    2015-01-01

    If you are a system administrator who manages multiple servers, then you know how difficult it is to keep your infrastructure in line. If you've been searching for an easier way, this book is for you. No prior experience with SaltStack is required.

  11. Description of the Process Model for the Technoeconomic Evaluation of MEA versus Mixed Amines for Carbon Dioxide Removal from Stack Gas

    Energy Technology Data Exchange (ETDEWEB)

    Jones, Dale A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2013-11-08

    This model description is supplemental to the Lawrence Livermore National Laboratory (LLNL) report LLNL-TR-642494, Technoeconomic Evaluation of MEA versus Mixed Amines for CO2 Removal at Near- Commercial Scale at Duke Energy Gibson 3 Plant. We describe the assumptions and methodology used in the Laboratory’s simulation of its understanding of Huaneng’s novel amine solvent for CO2 capture with 35% mixed amine. The results of that simulation have been described in LLNL-TR-642494. The simulation was performed using ASPEN 7.0. The composition of the Huaneng’s novel amine solvent was estimated based on information gleaned from Huaneng patents. The chemistry of the process was described using nine equations, representing reactions within the absorber and stripper columns using the ELECTNRTL property method. As a rate-based ASPEN simulation model was not available to Lawrence Livermore at the time of writing, the height of a theoretical plate was estimated using open literature for similar processes. Composition of the flue gas was estimated based on information supplied by Duke Energy for Unit 3 of the Gibson plant. The simulation was scaled at one million short tons of CO2 absorbed per year. To aid stability of the model, convergence of the main solvent recycle loop was implemented manually, as described in the Blocks section below. Automatic convergence of this loop led to instability during the model iterations. Manual convergence of the loop enabled accurate representation and maintenance of model stability.

  12. The Use of Mobile, Electrochemical Sensor Nodes for the Measurement of Personal Exposure to Gas-Phase Air Pollutants

    Science.gov (United States)

    Stewart, G.; Popoola, O. A.; Mead, M. I.; McKeating, S. J.; Calleja, M.; Hayes, M.; Baron, R. P.; Saffell, J.; Jones, R.

    2012-12-01

    , and thus also the potential insufficiency at quantifying the risks to health in the surrounding area. Recent campaigns with mobile sensor nodes have included attempts to probe the differences in personal exposure to gas-phase air pollutants at different heights of breathing zone and between different methods of transport.

  13. Ozone Pollution

    Science.gov (United States)

    Known as tropospheric or ground-level ozone, this gas is harmful to human heath and the environment. Since it forms from emissions of volatile organic compounds (VOCs) and nitrogen oxides (NOx), these pollutants are regulated under air quality standards.

  14. Livestock Production and its Impact on Nutrient Pollution and Greenhouse Gas Emissions

    International Nuclear Information System (INIS)

    Sakadevan, K.; Nguyen, M.L.

    2016-01-01

    The livestock sector provides more than one third of human protein needs and is a major provider of livelihood in almost all developing countries. While providing such immense benefits to the population, poor livestock management can potentially provide harmful environmental impacts at local, regional and national levels which have not been adequately addressed in many countries with emerging economies. Twenty six percent of global land area is used for livestock production and forest lands are continuously being lost to such production. The intensification of livestock production led to large surpluses of nitrogen and phosphorus at the farm in many parts of the world with non-point source pollution of water resources that became a national concern. The sector is one of the largest sources of greenhouse gases (GHG) contributing around 14.5% of all human induced GHG emissions, a major driver of use and pollution of freshwater (accounting 10% anthropogenic water use) and contributed to the loss of biodiversity. About 60% of global biomass harvested annually to support all human activity is consumed by livestock industry, undermining the sustainability of allocating such large resource to the industry.

  15. A contemporary landscape of air pollution and greenhouse gas emissions leads to inevitable phenomena of low birthweight.

    Science.gov (United States)

    Akhmat, Ghulam; Zaman, Khalid; Shukui, Tan; Abdul Malik, Ihtisham; Begum, Shamzana; Ahmed, Adeel

    2014-01-01

    The objective of the study is to empirically examine the air pollution, greenhouse gas (GHG) emissions and low birth weight in Pakistan through the cointegration and error correction model over a 36-year time period, i.e., between 1975 and 2012. The study employed the Johansen cointegration technique to estimate the long-run relationship between the variables, while an error correction model was used to determine the short-run dynamics of the system. The study was limited to the following variables, including carbon dioxide emissions, methane emissions, nitrous oxide emissions, GHG emissions, and low birth weight in order to manage robust data analysis. The results reveal that air pollution and GHG emissions significantly affects the low birth weight in Pakistan. In the long run, carbon dioxide emissions act as a strong contributor for low birth weight, as the coefficient value indicates there is a more elastic relationship (i.e., -1.214, pemissions have a one-to-one corresponding relationship with the low birth weight in Pakistan. Nitrous oxide emissions, both in the short and long run, have a significant and less elastic relationship (i.e., -0.517 with pemissions have no significant relationship with the low birth weight in Pakistan.

  16. Use of impedance tagging to monitor fuel cell stack performance

    Science.gov (United States)

    Silva, Gregory

    Fuel cells are electrochemical device that are traditionally assembled in stacks to perform meaningful work. Monitoring the state of the stack is vitally important to ensure that it is operating efficiently and that constituent cells are not failing for one of a several common reasons including membrane dehydration, gas diffusion layer flooding, reactant starvation, and physical damage. Current state-of-the-art monitoring systems are costly and require at least one connection per cell on the stack, which introduces reliability concerns for stacks consisting of hundreds of cells. This thesis presents a novel approach for diagnosing problems in a fuel cell stack that attempts to reduce the cost and complexity of monitoring cells in a stack. The proposed solution modifies the electrochemical impedance spectroscopy (EIS) response of each cell in the stack by connecting an electrical tag in parallel with each cell. This approach allows the EIS response of the entire stack to identify and locate problems in the stack. Capacitors were chosen as tags because they do not interfere with normal stack operation and because they can generate distinct stack EIS responses. An experiment was performed in the Center for Automation Technologies an Systems (CATS) fuel cell laboratory at Rensselaer Polytechnic Institute (RPI) to perform EIS measurements on a single cell with and without capacitor tags to investigate the proposed solution. The EIS data collected from this experiment was used to create a fuel cell model to investigate the proposed solution under ideal conditions. This thesis found that, although the concept shows some promise in simulations, significant obstacles to implementing the proposed solution. Observed EIS response when the capacitor tags were connected did not match the expected EIS response. Constraints on the capacitor tags found by the model impose significant manufacturing challenges to the proposed solution. Further development of the proposed solution is

  17. Modeling Optimized UCG Gas Qualities and Related Tar Pollutant Production Under Different Field Boundary Conditions

    OpenAIRE

    Stefan Klebingat; Rafig Azzam; Marc Schulten; T. Kempka; Ralph Schlüter; Tomás M. Fernández-Steeger

    2015-01-01

    The process of Underground Coal Gasification (UCG) bears the potential to produce medium to high calorific syngas for several industrial applications, e.g. electricity generation in the frame of the Integrated Gasification Combined Cycle (IGCC) concept; or Coal-To-Liquid (CTL) technologies as the Fischer-Tropsch synthesis. In view of preferred environmentally sound operations and stable gas qualities for these applications previous global UCG research led to considerable process experience. D...

  18. Energy Expenditure of Sport Stacking

    Science.gov (United States)

    Murray, Steven R.; Udermann, Brian E.; Reineke, David M.; Battista, Rebecca A.

    2009-01-01

    Sport stacking is an activity taught in many physical education programs. The activity, although very popular, has been studied minimally, and the energy expenditure for sport stacking is unknown. Therefore, the purposes of this study were to determine the energy expenditure of sport stacking in elementary school children and to compare that value…

  19. OpenStack cloud security

    CERN Document Server

    Locati, Fabio Alessandro

    2015-01-01

    If you are an OpenStack administrator or developer, or wish to build solutions to protect your OpenStack environment, then this book is for you. Experience of Linux administration and familiarity with different OpenStack components is assumed.

  20. Gas-particle partitioning of persistent organic pollutants in the Western Balkan countries affected by war conflicts.

    Science.gov (United States)

    Radonic, Jelena; Sekulic, Maja Turk; Miloradov, Mirjana Vojinovic; Cupr, Pavel; Klánová, Jana

    2009-01-01

    Bombing and destruction of the industrial and military targets accompanied by complete or incomplete combustion during the war conflict and NATO operation in former Yugoslavia caused the emission of persistent organic pollutants into the atmosphere, water, and soil. A total of 129 ambient air samples from 24 background, urban, and industrial sites, including hot spots, were collected to assess a gas-particle partitioning behavior of various persistent organic pollutants. High volume sampling technique was applied with quartz filters that collect the atmospheric particles and polyurethane foam filters (PUF) that retain the gaseous compounds. Three to ten samples were taken at each site. GFs and PUFs were analyzed separately for their content of polychlorinated biphenyls, organochlorine pesticides, and polyaromatic hydrocarbons. Gas phase and particle phase concentrations of selected persistent organic pollutants (POPs) in all samples were converted into the particle-bound fractions Phi. These fractions were found to be highly variable, but generally highest in Bosnia and Herzegovina due to the elevated levels of total suspended material in ambient air. Experimental values of particle-associated fraction were compared to the Junge-Pankow model. Interestingly, a model for urban/industrial environments provided a better prediction of partitioning behavior than a model for background and rural background sites. That is probably because the total amount of atmospheric particles is higher in the Balkan region than found in the previously published studies. Even though it has been stated in previous studies that less than 5% of polychlorinated biphenyls (PCBs) are bound to the particles, up to 67% of PCBs were particle associated at several sampling sites in this study. PCB-contaminated soils are probably still one of the strong sources of particles to the atmosphere. Information on the particle-bound fractions of POPs is important not only for prediction of their fate but

  1. Examination of the conditions of a broadening of the general tax for polluting activities to the intermediate energy consumptions. Incentive mechanisms for the abatement of greenhouse gas emissions

    International Nuclear Information System (INIS)

    Bureau, D.

    2000-05-01

    Among the various existing incentive mechanisms for the abatement of greenhouse gas emissions, like the pollution regulations and the financial help for energy mastery, this document analyzes the conditions of efficiency of the negotiated voluntary agreements and of the tradable emission quotas and their articulation with the fiscality. (J.S.)

  2. Hourly composition of gas and particle phase pollutants at a central urban background site in Milan, Italy

    Science.gov (United States)

    Bigi, A.; Bianchi, F.; De Gennaro, G.; Di Gilio, A.; Fermo, P.; Ghermandi, G.; Prévôt, A. S. H.; Urbani, M.; Valli, G.; Vecchi, R.; Piazzalunga, A.

    2017-04-01

    A comprehensive range of gas and particle phase pollutants were sampled at 1-hour time resolution in urban background Milan during summer 2012. Measurements include several soluble inorganic aerosols (Cl-, NO2-, NO3-, SO42-, Ca2+, K+, Mg2+, Na+, NH4+) and gases (HCl, HNO2,HNO3, NH3, NO, NO2,O3, SO2), organic, elemental and black carbon and meteorological parameters. Analysis methods used include mean diurnal pattern on weekdays and Sundays, pollution roses, bivariate polar plots and statistical models using backtrajectories. Results show how nitrous acid (HONO) was mainly formed heterogeneously at nighttime, with a dependence of its formation rate on NO2 consistent with observations during the last HONO campaign in Milan in summer 1998, although since 1998 a drop in HONO levels occurred following to the decrease of its precursors. Nitrate showed two main formation mechanisms: one occurring through N2O5 at nighttime and leading to nitrate formation onto existing particles; another occurring both daytime and nighttime following the homogeneous reaction of ammonia gas with nitric acid gas. Air masses reaching Milan influenced nitrate formation depending on their content in ammonia and the timing of arrival. Notwithstanding the low level of SO2 in Milan, its peaks were associated to point source emissions in the Po valley or shipping and power plant emissions SW of Milan, beyond the Apennines. A distinctive pattern for HCl was observed, featured by an afternoon peak and a morning minimum, and best correlated to atmospheric temperature, although it was not possible to identify any specific source. The ratio of primary-dominated organic carbon and elemental carbon on hourly PM2.5 resulted 1.7. Black carbon was highly correlated to elemental carbon and the average mass absorption coefficient resulted MAC = 13.8 ± 0.2 m2 g-1. It is noteworthy how air quality for a large metropolitan area, in a confined valley and under enduring atmospheric stability, is nonetheless

  3. Nanocrystalline SnO2-Pt Thick Film Gas Sensor for Air Pollution Applications

    Directory of Open Access Journals (Sweden)

    M. H. Shahrokh Abadi

    2011-02-01

    Full Text Available A series of xSnO2(1-xPt nanopowder (x = 1, 0.995, 0.99, 0.985, 0.98 was calcinated at 950 °C, mixed with an organic vehicle, printed on premade silver electrodes, and fired at 650 °C. Microstructural, morphological, and elemental properties of the mixed powders and films were determined by using XRD, TEM, SEM, and EDX. Samples were exposed to ethyl alcohol, xylene, methanol, isopropanol, acetone, isobutane, and truck exhaust fumes, at wide range of operating temperature, and sensitivity as well as response time of the samples were measured and compared with Taguchi Gas Sensors of TGS2602 (air contaminants, TGS3870 (CO, and TGS4160 (CO2. It was discovered that crystallite sizes of SnO2 powder and response times of samples are decreased with increasing Pt contents, whilst sensitivity is increased. Measurements are shown that 1 wt.% Pt loaded sensor, operating at 300 °C, can detect exhaust gas with high differentiating between the applied gases.

  4. New regulations, combustion, environment: responses for natural gas; Nouvelles reglementations, combustion, environnement: les reponses pour le gaz naturel

    Energy Technology Data Exchange (ETDEWEB)

    Le Peltier-Marc, A. [Gaz de France (GDF), 75 - Paris (France). Direction Commerciale

    1997-12-31

    The impacts of the new French regulations concerning low- to medium-power combustion equipment with regards to their energy sources, energy efficiency and pollution control, on natural gas fired boilers, are discussed: lower pollutant emission limits are set for SO{sub 2}, NO{sub x} and ashes. The decree gives new regulations concerning plant location, combustion control systems, plant monitoring and maintenance, and air pollution control measures such as chimney stack height and emission limits. The French national gas utility promotes environmental high performance boilers

  5. Stack Caching Using Split Data Caches

    DEFF Research Database (Denmark)

    Nielsen, Carsten; Schoeberl, Martin

    2015-01-01

    In most embedded and general purpose architectures, stack data and non-stack data is cached together, meaning that writing to or loading from the stack may expel non-stack data from the data cache. Manipulation of the stack has a different memory access pattern than that of non-stack data, showing...... higher temporal and spatial locality. We propose caching stack and non-stack data separately and develop four different stack caches that allow this separation without requiring compiler support. These are the simple, window, and prefilling with and without tag stack caches. The performance of the stack...

  6. Pollutant Emission Validation of a Heavy-Duty Gas Turbine Burner by CFD Modeling

    Directory of Open Access Journals (Sweden)

    Roberto Meloni

    2013-10-01

    Full Text Available 3D numerical combustion simulation in a can burner fed with methane was carried out in order to evaluate pollutant emissions and the temperature field. As a case study, the General Electric Frame 6001B system was considered. The numerical investigation has been performed using the CFD code named ACE+ Multiphysics (by Esi-Group. The model was validated against the experimental data provided by Cofely GDF SUEZ and related to a real power plant. To completely investigate the stability of the model, several operating conditions were taken into account, at both nominal and partial load. In particular, the influence on emissions of some important parameters, such as air temperature at compressor intake and steam to fuel mass ratio, have been evaluated. The flamelet model and Zeldovich’s mechanism were employed for combustion modeling and NOx emissions, respectively. With regard to CO estimation, an innovative approach was used to compute the Rizk and Mongia relationship through a user-defined function. Numerical results showed good agreement with experimental data in most of the cases: the best results were obtained in the NOx prediction, while unburned fuel was slightly overestimated.

  7. Contribution of Liquefied Petroleum Gas to Air Pollution in the Metropolitan Area of Mexico City.

    Science.gov (United States)

    Gamas, Erick D; Magdaleno, Moises; Diaz, Luis; Schifter, Isaac; Ontiveros, Luis; Alvarez-Cansino, G

    2000-02-01

    An estimation of hydrocarbon emissions caused by the consumption of liquefied petroleum gas (LPG) in the Metropolitan Area of Mexico City (MAMC) is presented. On the basis of experimental measurements at all points of handling, during the distribution process, and during the consumption of LPG in industrial devices and domestic appliances, an estimated 76,414 tons/year are released to the air. The most important contribution is found during the domestic consumption of LPG (70%); this makes the control initiatives available to the consumer. By developing a control program of LPG losses, a 77% reduction in emission is expected in a 5-yr period. The calculated amounts of LPG emissions when correlated with the consumption of LPG, combined with information from air samples from the MAMC, do not point to LPG emissions as the most important factor contributing to tropospheric ozone in the air in Mexico City.

  8. Pollutant Concentrations and Emission Rates from Scripted Natural Gas Cooking Burner Use in Nine Northern California Homes

    Energy Technology Data Exchange (ETDEWEB)

    Singer, Brett C. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Delp, William W. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Lorenzetti, David M. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Maddalena, Randy L. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2016-10-01

    METHODS: Combustion pollutant concentrations were measured during the scripted operation of natural gas cooking burners in nine homes. In addition to a base condition of closed windows, no forced air unit (FAU) use, and no mechanical exhaust, additional experiments were conducted while operating an FAU and/or vented range hood. Test homes included a 26m2 two-room apartment, a 134m2 first floor flat, and seven detached homes of 117–226m2. There were four single-story, four two-story and one 1.5 story homes. Cooktop use entailed boiling and simmering activities, using water as a heat sink. Oven and broiler use also were simulated. Time-resolved concentrations of carbon dioxide (CO2), nitric oxide (NO), nitrogen oxides (NOX), nitrogen dioxide (NO2), particles with diameters of 6 nm or larger (PN), carbon monoxide (CO), and fine particulate matter (PM2.5) were measured in the kitchen (K) and bedroom area (BR) of each home. CO2, NO, NO2, and PN data from sequential experiments were analyzed to quantify the contribution of burner use to the highest 1h and 4h time-integrated concentrations in each room. RESULTS: Four of the nine homes had kitchen 1h NO2 exceed the national ambient air quality standard (100 ppb). Two other homes had 1h NO2 exceed 50 ppb in the kitchen, and three had 1h NO2 above 50 ppb in the bedroom, suggesting substantial exposures to anyone at home when burners are used for a single substantial event. In all homes, the highest 1h kitchen PN exceeded 2 x105 cm-3-h, and the highest 4h PN exceeded 3 x105 cm-3-hr in all homes. The lowest 1h kitchen/bedroom ratios were 1.3–2.1 for NO in the apartment and two open floor plan homes. The largest K/BR ratios of 1h NO2 were in a two-story 1990s home retrofitted for deep energy savings: ratios in this home were 3.3 to 6.6. Kitchen 1h ratios of NO, NO2 and PN to CO2 were used to calculate fuel normalized emission factors (ng J-1). Range hood use substantially reduced cooking burner pollutant concentrations both

  9. Inventory and Policy Reduction Potential of Greenhouse Gas and Pollutant Emissions of Road Transportation Industry in China

    Directory of Open Access Journals (Sweden)

    Ye Li

    2016-11-01

    Full Text Available In recent years, emissions from the road transportation industry in China have been increasing rapidly. To evaluate the reduction potential of greenhouse gas and pollutant emissions of the industry in China, its emission inventory was calculated and scenario analysis was created for the period between 2012 and 2030 in this paper. Based on the Long-range Energy Alternatives Planning System (LEAP model, the development of China’s road transportation industry in two scenarios (the business-as-usual (BAU scenario and the comprehensive-mitigation (CM scenario was simulated. In the Comprehensive Mitigation scenario, there are nine various measures which include Fuel Economy Standards, Auto Emission Standards, Energy-saving Technology, Tax Policy, Eco-driving, Logistics Informatization, Vehicle Liquidation, Electric Vehicles, and Alternative Fuels. The cumulative energy and emission reductions of these specific measures were evaluated. Our results demonstrate that China’s road transportation produced 881 million metric tons of CO2 and emitted 1420 thousand tons of CO, 2150 thousand tons of NOx, 148 thousand tons of PM10, and 745 thousand tons of HC in 2012. The reduction potential is quite large, and road freight transportation is the key mitigation subsector, accounting for 85%–92% of the total emission. For energy conservation and carbon emission mitigation, logistics informatization is the most effective method, potentially reducing 1.80 billion tons of coal equivalent and 3.83 billion tons of CO2 from 2012 to 2030. In terms of air pollutant emission mitigation, the auto emission standards measure performs best with respect to NOx, PM10, and HC emission mitigation, and logistic informatization measure is the best in CO emission reduction. In order to maximize the mitigation potential of China’s road transportation industry, the government needs to implement various measures in a timely and strict fashion.

  10. Distributions of air pollutants associated with oil and natural gas development measured in the Upper Green River Basin of Wyoming

    Directory of Open Access Journals (Sweden)

    R.A. Field

    2015-10-01

    Full Text Available Abstract Diffusive sampler monitoring techniques were employed during wintertime studies from 2009 to 2012 to assess the spatial distribution of air pollutants associated with the Pinedale Anticline and Jonah Field oil and natural gas (O&NG developments in the Upper Green River Basin, Wyoming. Diffusive sampling identified both the extent of wintertime ozone (O3 episodes and the distributions of oxides of nitrogen (NOx, and a suite of 13 C5+ volatile organic compounds (VOC, including BTEX (benzene, toluene, ethylbenzene and xylene isomers, allowing the influence of different O&NG emission sources to be determined. Concentration isopleth mapping of both diffusive sampler and continuous O3 measurements show the importance of localized production and advective transport. As for O3, BTEX and NOx mixing ratios within O&NG development areas were elevated compared to background levels, with localized hotspots also evident. One BTEX hotspot was related to an area with intensive production activities, while a second was located in an area influenced by emissions from a water treatment and recycling facility. Contrastingly, NOx hotspots were at major road intersections with relatively high traffic flows, indicating influence from vehicular emissions. Comparisons of observed selected VOC species ratios at a roadside site in the town of Pinedale with those measured in O&NG development areas show that traffic emissions contribute minimally to VOCs in these latter areas. The spatial distributions of pollutant concentrations identified by diffusive sampling techniques have potential utility for validation of emission inventories that are combined with air quality modeling.

  11. When is stacking confusing? The impact of confusion on stacking in deep H I galaxy surveys

    Science.gov (United States)

    Jones, Michael G.; Haynes, Martha P.; Giovanelli, Riccardo; Papastergis, Emmanouil

    2016-01-01

    We present an analytic model to predict the H I mass contributed by confused sources to a stacked spectrum in a generic H I survey. Based on the ALFALFA (Arecibo Legacy Fast ALFA) correlation function, this model is in agreement with the estimates of confusion present in stacked Parkes telescope data, and was used to predict how confusion will limit stacking in the deepest Square Kilometre Array precursor H I surveys. Stacking with LADUMA (Looking At the Distant Universe with MeerKAT) and DINGO UDEEP (Deep Investigation of Neutral Gas Origins - Ultra Deep) data will only be mildly impacted by confusion if their target synthesized beam size of 10 arcsec can be achieved. Any beam size significantly above this will result in stacks that contain a mass in confused sources that is comparable to (or greater than) that which is detectable via stacking, at all redshifts. CHILES (COSMOS H I Large Extragalactic Survey) 5 arcsec resolution is more than adequate to prevent confusion influencing stacking of its data, throughout its bandpass range. FAST (Five hundred metre Aperture Spherical Telescope) will be the most impeded by confusion, with H I surveys likely becoming heavily confused much beyond z = 0.1. The largest uncertainties in our model are the redshift evolution of the H I density of the Universe and the H I correlation function. However, we argue that the two idealized cases we adopt should bracket the true evolution, and the qualitative conclusions are unchanged regardless of the model choice. The profile shape of the signal due to confusion (in the absence of any detection) was also modelled, revealing that it can take the form of a double Gaussian with a narrow and wide component.

  12. Solving widespread low-concentration VOC air pollution problems: Gas-phase photocatalytic oxidation answers the needs of many small businesses

    Energy Technology Data Exchange (ETDEWEB)

    Lyons, C; Turchi, C; Gratson, D

    1995-04-01

    Many small businesses are facing new regulations under the 1990 Amendments to the Clean Air Act. Regulators, as well as the businesses themselves, face new challenges to control small point-source air pollution emissions. An individual business-such as a dry cleaner, auto repair shop, bakery, coffee roaster, photo print shop, or chemical company-may be an insignificant source of air pollution, but collectively, the industry becomes a noticeable source. Often the businesses are not equipped to respond to new regulatory requirements because of limited resources, experience, and expertise. Also, existing control strategies may be inappropriate for these businesses, having been developed for major industries with high volumes, high pollutant concentrations, and substantial corporate resources. Gas-phase photocatalytic oxidation (PCO) is an option for eliminating low-concentration, low-flow-rate emissions of volatile organic compounds (VOCs) from small business point sources. The advantages PCO has over other treatment techniques are presented in this paper. This paper also describes how PCO can be applied to specific air pollution problems. We present our methodology for identifying pollution problems for which PCO is applicable and for reaching the technology`s potential end users. PCO is compared to other gas-phase VOC control technologies.

  13. Passive stack ventilation

    Energy Technology Data Exchange (ETDEWEB)

    Palmer, J.; Parkins, L.; Shaw, P.; Watkins, R. [Databuild, Birmingham (United Kingdom)

    1994-12-31

    The adequate ventilation of houses is essential for both the occupants and the building fabric. As air-tightness standards increase, background infiltration levels decrease and extra ventilation has to be designed into the building. Passive stack ventilation has many advantages - particularly when employed in low cost housing schemes -but it is essential that it performs satisfactorily. This paper give the results from monitoring two passive stack ventilation schemes. One scheme was a retrofit into refurbished local authority houses in which a package of energy efficiency measures had been taken and condensation had been a problem. The other series of tests were conducted on a new installation in a Housing Association development. Nine houses were monitored each of which had at least two passive vents. The results show air flow rates by the passive ducts equivalent to approximately 1 room air change per hour. The air flow in the ducts was influenced by both, internal to external temperature difference and wind speed and direction. (author)

  14. Asymmetric Flexible Supercapacitor Stack

    Directory of Open Access Journals (Sweden)

    Leela Mohana Reddy A

    2008-01-01

    Full Text Available AbstractElectrical double layer supercapacitor is very significant in the field of electrical energy storage which can be the solution for the current revolution in the electronic devices like mobile phones, camera flashes which needs flexible and miniaturized energy storage device with all non-aqueous components. The multiwalled carbon nanotubes (MWNTs have been synthesized by catalytic chemical vapor deposition technique over hydrogen decrepitated Mischmetal (Mm based AB3alloy hydride. The polymer dispersed MWNTs have been obtained by insitu polymerization and the metal oxide/MWNTs were synthesized by sol-gel method. Morphological characterizations of polymer dispersed MWNTs have been carried out using scanning electron microscopy (SEM, transmission electron microscopy (TEM and HRTEM. An assymetric double supercapacitor stack has been fabricated using polymer/MWNTs and metal oxide/MWNTs coated over flexible carbon fabric as electrodes and nafion®membrane as a solid electrolyte. Electrochemical performance of the supercapacitor stack has been investigated using cyclic voltammetry, galvanostatic charge-discharge, and electrochemical impedance spectroscopy.

  15. Sampling of power plant stacks for air toxic emissions: Final report for Phases 1 and 2

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-04-28

    A test program to collect and analyze size-fractionated stack gas particulate samples for selected inorganic hazardous air pollutants (HAPs) was conducted . Specific goals of the program are (1) the collection of one-gram quantities of size-fractionated stack gas particulate matter for bulk (total) and surface chemical characterization, and (2) the determination of the relationship between particle size, bulk and surface (leachable) composition, and unit load. The information obtained from this program identifies the effects of unit load, particle size, and wet FGD system operation on the relative toxicological effects of exposure to particulate emissions. Field testing was conducted in two phases. The Phase I field program was performed over the period of August 24 through September 20, 1992, at the Tennessee Valley Authority Widows Creek Unit 8 Power Station, located near Stevenson (Jackson County), Alabama, on the Tennessee River. Sampling activities for Phase II were conducted from September 11 through October 14, 1993. Widows Creek Unit 8 is a 575-megawatt plant that uses bituminous coal averaging 3.7% sulfur and 13% ash. Downstream of the boiler, a venture wet scrubbing system is used for control of both sulfur dioxide and particulate emissions. There is no electrostatic precipitator (ESP) in this system. This system is atypical and represents only about 5% of the US utility industry. However, this site was chosen for this study because of the lack of information available for this particulate emission control system.

  16. Instant BlueStacks

    CERN Document Server

    Judge, Gary

    2013-01-01

    Get to grips with a new technology, understand what it is and what it can do for you, and then get to work with the most important features and tasks. A fast-paced, example-based approach guide for learning BlueStacks.This book is for anyone with a Mac or PC who wants to run Android apps on their computer. Whether you want to play games that are freely available for Android but not your computer, or you want to try apps before you install them on a physical device or use it as a development tool, this book will show you how. No previous experience is needed as this is written in plain English

  17. Assessing Elementary Algebra with STACK

    Science.gov (United States)

    Sangwin, Christopher J.

    2007-01-01

    This paper concerns computer aided assessment (CAA) of mathematics in which a computer algebra system (CAS) is used to help assess students' responses to elementary algebra questions. Using a methodology of documentary analysis, we examine what is taught in elementary algebra. The STACK CAA system, http://www.stack.bham.ac.uk/, which uses the CAS…

  18. HPC Software Stack Testing Framework

    Energy Technology Data Exchange (ETDEWEB)

    2017-07-27

    The HPC Software stack testing framework (hpcswtest) is used in the INL Scientific Computing Department to test the basic sanity and integrity of the HPC Software stack (Compilers, MPI, Numerical libraries and Applications) and to quickly discover hard failures, and as a by-product it will indirectly check the HPC infrastructure (network, PBS and licensing servers).

  19. Systematic study of RPC performances in polluted or varying gas mixtures compositions: an online monitor system for the RPC gas mixture at LHC

    CERN Document Server

    Capeans, M; Mandelli, B

    2012-01-01

    The importance of the correct gas mixture for the Resistive Plate Chamber (RPC) detector systems is fundamental for their correct and safe operation. A small change in the percentages of the gas mixture components can alter the RPC performance and this will rebound on the data quality in the ALICE, ATLAS and CMS experiments at CERN. A constant monitoring of the gas mixture injected in the RPCs would avoid such kind of problems. A systematic study has been performed to understand RPC performances with several gas mixture compositions and in the presence of common gas impurities. The systematic analysis of several RPC performance parameters in different gas mixtures allows the rapid identification of any variation in the RPC gas mixture. A set-up for the online monitoring of the RPC gas mixture in the LHC gas systems is also proposed.

  20. Fuel flow distribution in SOFC stacks revealed by impedance spectroscopy

    DEFF Research Database (Denmark)

    Mosbæk, Rasmus Rode; Hjelm, Johan; Barfod, Rasmus

    2014-01-01

    . An operating stack is subject to compositional gradients in the gaseous reactant streams, and temperature gradients across each cell and across the stack, which complicates detailed analysis. An experimental stack with low ohmic resistance from Topsoe Fuel Cell A/S was characterized using Electrochemical...... Impedance Spectroscopy (EIS). The stack measurement geometry was optimized for EIS by careful selection of the placement of current feeds and voltage probes in order to minimize measurement errors. It was demonstrated that with the improved placement of current feeds and voltage probes it is possible...... to separate the loss contributions in an ohmic and a polarization part and that the low frequency response is useful in detecting mass transfer limitations. This methodology can be used to detect possible minor changes in the supply of gas to the individual cells, which is important when going to high fuel...

  1. Updated greenhouse gas and criteria air pollutant emission factors and their probability distribution functions for electricity generating units

    Energy Technology Data Exchange (ETDEWEB)

    Cai, H.; Wang, M.; Elgowainy, A.; Han, J. (Energy Systems)

    2012-07-06

    Greenhouse gas (CO{sub 2}, CH{sub 4} and N{sub 2}O, hereinafter GHG) and criteria air pollutant (CO, NO{sub x}, VOC, PM{sub 10}, PM{sub 2.5} and SO{sub x}, hereinafter CAP) emission factors for various types of power plants burning various fuels with different technologies are important upstream parameters for estimating life-cycle emissions associated with alternative vehicle/fuel systems in the transportation sector, especially electric vehicles. The emission factors are typically expressed in grams of GHG or CAP per kWh of electricity generated by a specific power generation technology. This document describes our approach for updating and expanding GHG and CAP emission factors in the GREET (Greenhouse Gases, Regulated Emissions, and Energy Use in Transportation) model developed at Argonne National Laboratory (see Wang 1999 and the GREET website at http://greet.es.anl.gov/main) for various power generation technologies. These GHG and CAP emissions are used to estimate the impact of electricity use by stationary and transportation applications on their fuel-cycle emissions. The electricity generation mixes and the fuel shares attributable to various combustion technologies at the national, regional and state levels are also updated in this document. The energy conversion efficiencies of electric generating units (EGUs) by fuel type and combustion technology are calculated on the basis of the lower heating values of each fuel, to be consistent with the basis used in GREET for transportation fuels. On the basis of the updated GHG and CAP emission factors and energy efficiencies of EGUs, the probability distribution functions (PDFs), which are functions that describe the relative likelihood for the emission factors and energy efficiencies as random variables to take on a given value by the integral of their own probability distributions, are updated using best-fit statistical curves to characterize the uncertainties associated with GHG and CAP emissions in life

  2. Relationship of atmospheric pollution characterized by gas (NO2) and particles (PM10) to microbial communities living in bryophytes at three differently polluted sites (rural, urban, and industrial).

    Science.gov (United States)

    Meyer, Caroline; Gilbert, Daniel; Gaudry, André; Franchi, Marielle; Nguyen, Hung Viet; Fabure, Juliette; Bernard, Nadine

    2010-02-01

    Atmospheric pollution has become a major problem for modern societies owing to its fatal effects on both human health and ecosystems. We studied the relationships of nitrogen dioxide atmospheric pollution and metal trace elements contained in atmospheric particles which were accumulated in bryophytes to microbial communities of bryophytes at three differently polluted sites in France (rural, urban, and industrial) over an 8-month period. The analysis of bryophytes showed an accumulation of Cr and Fe at the rural site; Cr, Fe, Zn, Cu, Al, and Pb at the urban site; and Fe, Cr, Pb, Al, Sr, Cu, and Zn at the industrial site. During this study, the structure of the microbial communities which is characterized by biomasses of microbial groups evolved differently according to the site. Microalgae, bacteria, rotifers, and testate amoebae biomasses were significantly higher in the rural site. Cyanobacteria biomass was significantly higher at the industrial site. Fungal and ciliate biomasses were significantly higher at the urban and industrial sites for the winter period and higher at the rural site for the spring period. The redundancy analysis showed that the physico-chemical variables ([NO(2)], relative humidity, temperature, and site) and the trace elements which were accumulated in bryophytes ([Cu], [Sr], [Pb]) explained 69.3% of the variance in the microbial community data. Moreover, our results suggest that microbial communities are potential biomonitors of atmospheric pollution. Further research is needed to understand the causal relationship underlined by the observed patterns.

  3. Design and application of a mobile ground-based observatory for continuous measurements of atmospheric trace gas and criteria pollutant species

    Science.gov (United States)

    Bush, S. E.; Hopkins, F. M.; Randerson, J. T.; Lai, C.-T.; Ehleringer, J. R.

    2015-08-01

    Ground-based measurements of atmospheric trace gas species and criteria pollutants are essential for understanding emissions dynamics across space and time. Gas composition in the lower 50 m of the atmosphere has the greatest direct impacts on human health as well as ecosystem processes; hence data at this level are necessary for addressing carbon-cycle- and public-health-related questions. However, such surface data are generally associated with stationary measurement towers, where spatial representation is limited due to the high cost of establishing and maintaining an extensive network of measurement stations. We describe here a compact mobile laboratory equipped to provide high-precision, high-frequency, continuous, on-road synchronous measurements of CO2, CO, CH4, H2O, NOx, O3, aerosol, meteorological, and geospatial position data. The mobile laboratory has been deployed across the western USA. In addition to describing the vehicle and its capacity, we present data that illustrate the use of the laboratory as a powerful tool for investigating the spatial structure of urban trace gas emissions and criteria pollutants at spatial scales ranging from single streets to whole ecosystem and regional scales. We assess the magnitude of known point sources of CH4 and also identify fugitive urban CH4 emissions. We illustrate how such a mobile laboratory can be used to better understand emissions dynamics and quantify emissions ratios associated with trace gas emissions from wildfire incidents. Lastly, we discuss additional mobile laboratory applications in health and urban metabolism.

  4. Design and application of a mobile ground-based observatory for continuous measurements of atmospheric trace-gas and criteria pollutant species

    Science.gov (United States)

    Bush, S. E.; Hopkins, F. M.; Randerson, J. T.; Lai, C.-T.; Ehleringer, J. R.

    2015-01-01

    Ground-based measurements of atmospheric trace gas species and criteria pollutants are essential for understanding emissions dynamics across space and time. Gas composition in the surface 50 m has the greatest direct impacts on human health as well as ecosystem processes, hence data at this level is necessary for addressing carbon cycle and public health related questions. However, such surface data are generally associated with stationary measurement towers, where spatial representation is limited due to the high cost of establishing and maintaining an extensive network of measurement stations. We describe here a compact mobile laboratory equipped to provide high-precision, high-frequency, continuous, on-road synchronous measurements of CO2, CO, CH4, H2O, NOx, O3, aerosol, meteorological, and geospatial position data. The mobile laboratory has been deployed across the western USA. In addition to describing the vehicle and its capacity, we present data that illustrate the use of the laboratory as a powerful tool for investigating the spatial structure of urban trace gas emissions and criteria pollutants at spatial scales ranging from single streets to whole ecosystem and regional scales. We identify fugitive urban CH4 emissions and assess the magnitude of CH4 emissions from known point sources. We illustrate how such a mobile laboratory can be used to better understand emissions dynamics and quantify emissions ratios associated with trace gas emissions from wildfire incidents. Lastly, we discuss additional mobile laboratory applications in health and urban metabolism.

  5. PieceStack: Toward Better Understanding of Stacked Graphs.

    Science.gov (United States)

    Wu, Tongshuang; Wu, Yingcai; Shi, Conglei; Qu, Huamin; Cui, Weiwei

    2016-02-24

    Stacked graphs have been widely adopted in various fields, because they are capable of hierarchically visualizing a set of temporal sequences as well as their aggregation. However, because of visual illusion issues, connections between overly-detailed individual layers and overly-generalized aggregation are intercepted. Consequently, information in this area has yet to be fully excavated. Thus, we present PieceStack in this paper, to reveal the relevance of stacked graphs in understanding intrinsic details of their displayed shapes. This new visual analytic design interprets the ways through which aggregations are generated with individual layers by interactively splitting and re-constructing the stacked graphs. A clustering algorithm is designed to partition stacked graphs into sub-aggregated pieces based on trend similarities of layers. We then visualize the pieces with augmented encoding to help analysts decompose and explore the graphs with respect to their interests. Case studies and a user study are conducted to demonstrate the usefulness of our technique in understanding the formation of stacked graphs.

  6. Evaluation of ground level concentration of pollutant due to gas flaring by computer simulation: A case study of Niger - Delta area of Nigeria

    Directory of Open Access Journals (Sweden)

    A. S. ABDULKAREEM

    2005-01-01

    Full Text Available The disposal of associated gases through flaring has been a major problem for the Nigerian oil and gas industries and most of theses gases are flared due to the lack of commercial out lets. The resultant effects of gas flaring are the damaging effect of the environment due to acid rain formation, green house effect, global warming and ozone depletion.This writes up is aimed at evaluating ground level concentration of CO2, SO2, NO2 and total hydrocarbon (THC, which are product of gas flared in oil producing areas. Volumes of gas flared at different flow station were collected as well as geometrical parameters. The results of simulation of model developed based on the principles of gaseous dispersion by Gaussian showed a good agreement with dispersion pattern.The results showed that the dispersion pattern of pollutants at ground level depends on the volume of gas flared, wind speed, velocity of discharge and nearness to the source of flaring. The results shows that continuous gas flaring irrespective of the quantity deposited in the immediate environment will in long run lead to change in the physicochemical properties of soil.

  7. Gas

    International Nuclear Information System (INIS)

    1996-01-01

    The French government has decided to modify the conditions of extension of local natural gas authorities to neighbouring districts. The European Union is studying the conditions of internal gas market with the objective of more open markets although considering public service requirements

  8. The Impacts of a 2-Degree Rise in Global Temperatures upon Gas-Phase Air Pollutants in Europe

    Science.gov (United States)

    Watson, Laura; Josse, Béatrice; Marecal, Virginie; Lacressonnière, Gwendoline; Vautard, Robert; Gauss, Michael; Engardt, Magnuz; Nyiri, Agnes; Siour, Guillaume

    2014-05-01

    The 15th session of the Conference of Parties (COP 15) in 2009 ratified the Copenhagen Accord, which "recognises the scientific view that" global temperature rise should be held below 2 degrees C above pre-industrial levels in order to limit the impacts of climate change. Due to the fact that a 2-degree limit has been frequently referred to by policy makers in the context of the Copenhagen Accord and many other high-level policy statements, it is important that the impacts of this 2-degree increase in temperature are adequately analysed. To this end, the European Union sponsored the project IMPACT2C, which uses a multi-disciplinary international team to assess a wide variety of impacts of a 2-degree rise in global temperatures. For example, this future increase in temperature is expected to have a significant influence upon meteorological conditions such as temperature, precipitation, and wind direction and intensity; which will in turn affect the production, deposition, and distribution of air pollutants. For the first part of the air quality analysis within the IMPACT2C project, the impact of meteorological forcings on gas phase air pollutants over Europe was studied using four offline atmospheric chemistry transport models. Two sets of meteorological forcings were used for each model: reanalysis of past observation data and global climate model output. Anthropogenic emissions of ozone precursors for the year 2005 were used for all simulations in order to isolate the impact of meteorology and assess the robustness of the results across the different models. The differences between the simulations that use reanalysis of past observation data and the simulations that use global climate model output show how global climate models modify climate hindcasts by boundary conditions inputs: information that is necessary in order to interpret simulations of future climate. The baseline results were assessed by comparison with AirBase (Version 7) measurement data, and were

  9. Effect of flow parameters on flare stack generator noise

    International Nuclear Information System (INIS)

    Dinn, T.S.

    1998-01-01

    The SoundPLAN Computer Noise Model was used to determine the general effect of flare noise in a community adjacent to a petrochemical plant. Tests were conducted to determine the effect of process flow conditions and the pulsating flame on the flare stack generator noise from both a refinery flare and process flare. Flaring under normal plant operations, the flaring of fuel gas and the flaring of hydrogen were the three conditions that were tested. It was shown that the steam flow rate was the determining factor in the flare stack generated noise. Variations in the water seal level in the flare line surge tank increased or decreased the gas flowrate, which resulted in a pulsating flame. The period and amplitude of the pulsating noise from the flare stacks was determined by measuring several parameters. Flare stack noise oscillations were found to be greater for the process flare than for the refinery flare stack. It was suggested that minimizing the amount of steam fed to the flare and improving the burner design would minimize noise. 2 tabs., 6 figs

  10. Chapter 4: Assessing the Air Pollution, Greenhouse Gas, Air Quality, and Health Benefits of Clean Energy Initiatives

    Science.gov (United States)

    Chapter 4 of Assessing the Multiple Benefits of Clean Energy helps state states understand the methods, models, opportunities, and issues associated with assessing the GHG, air pollution, air quality, and human health benefits of clean energy options.

  11. Démonstration du procédé IFP de désulfuration des fumées de centrales Demonstration of the Ifp Stack-Gas Desulfurization Process

    Directory of Open Access Journals (Sweden)

    Busson C.

    2006-11-01

    Full Text Available Les produits pétroliers et le charbon continueront à couvrir les besoins énergétiques pendant plusieurs décennies. La pollution par le SOZ, provenant de la combustion de ces combustibles fossiles, devient une préoccupation pour la population et les Pouvoirs publics. La désulfuration des fumées de combustion devrait, à plus ou moins longue échéance, se développer. L'Institut Français du Pétrole (IFP, mettant à profit ses travaux dans le domaine de la désulfuration, a développé un procédé de traitement des fumées. L'IFP, en collaboration avec Électricité de France (EDF, a effectué en 1976 une opération de démonstration à une échelle pilote (30 MW dans la Centrale de Champagne-sur-Oise. Le procédé consiste à éliminer le S02 des fumées par lavage avec une solution ammoniacale, à produire du soufre à partir de la liqueur obtenue et à recycler l'ammoniaque dans l'étape de lavage. Après quelques modifications d'ordre technologique, l'unité de démonstration a fonctionné d'une manière continue pendant une période de trois mois, correspondant à l'objectif fixé. Les résultats obtenus permettent, actuellement, d'envisager une application de cette technique à une échelle de 250 MW. Oil and coal productswill continue to fulfill energy needs for several more decades. Pollution by SO2 coming from the combustion of such fossil fuels is becoming a preoccupation for the population and the public authorities. The desulfurization of combustion fumes should continue ta develop in the more or less long run. Institut Français du Pétrole (IFP has taken advantage of its research in the fixed of desulfurization to develop a stock-gas treating process. In collaboration with Électricite de Fronce (EDF, IFP carried out a demonsiration operation in 1976 on a pilot-plant scale (30MW in a power plant at Champagne-sur-Oise. The process consists in removing S02 from stock gases by scrubbing them with an ammonia solution

  12. Environment, gas and city

    International Nuclear Information System (INIS)

    Anon.

    1994-01-01

    Here are given all the advantages of natural gas among the others energies sources to avoid air pollution in cities. Pollution, energy economy, energy control are actions of environmental policy of natural gas industry in France

  13. Sustainable passenger road transport scenarios to reduce fuel consumption, air pollutants and GHG (greenhouse gas) emissions in the Mexico City Metropolitan Area

    International Nuclear Information System (INIS)

    Chavez-Baeza, Carlos; Sheinbaum-Pardo, Claudia

    2014-01-01

    This paper presents passenger road transport scenarios that may assist the MCMA (Mexico City Metropolitan Area) in achieving lower emissions in both criteria air pollutants (CO, NO x , NMVOC (non-methane volatile organic compounds), and PM 10 ) and GHG (greenhouse gas) (CH 4 , N 2 O and CO 2 ), while also promoting better mobility and quality of life in this region. We developed a bottom-up model to estimate the historical trends of energy demand, criteria air pollutants and GHG emissions caused by passenger vehicles circulating in the Mexico City Metropolitan Area (MCMA) in order to construct a baseline scenario and two mitigation scenarios that project their impact to 2028. Mitigation scenario “eff” considers increasing fuel efficiencies and introducing new technologies for vehicle emission controls. Mitigation scenario “BRT” considers a modal shift from private car trips to a Bus Rapid Transport system. Our results show significant reductions in air pollutants and GHG emissions. Incentives and environmental regulations are needed to enable these scenarios. - Highlights: • More than 4.2 million passenger vehicles in the MCMA (Mexico City Metropolitan Area) that represent 61% of criteria pollutants and 44% of GHG (greenhouse gas) emissions. • Emissions of CO, NO x and NMVOC (non-methane volatile organic compounds) in baseline scenario decrease with respect to its 2008 value because emission standards. • Emissions of PM 10 and GHG increase in baseline scenario. • Emissions of PM 10 and GHG decrease in eff + BRT scenario from year 2020. • Additional reductions are possible with better standards for diesel vehicles and other technologies

  14. Experimental 1 kW 20 cell PEFC stack

    Energy Technology Data Exchange (ETDEWEB)

    Buechi, F.N.; Marmy, C.A.; Scherer, G.G. [Paul Scherrer Inst. (PSI), Villigen (Switzerland); Ruge, M. [Swiss Federal Inst. of Technology (ETH), Zuerich (Switzerland)

    1999-08-01

    A 20-cell PEFC stack was designed and built. Resin impregnated graphite was used as bipolar plate material. The air cooling of the stack was optimized by introducing high surface structures into the open space of the cooling plates. At {eta} (H{sub 2} LHV) = 0.5 a power of 880 W was obtained under conditions of low gas-pressures of 1.15 bar{sub a}. The auxiliary power for process air supply and cooling at 880 W power is less than 7% of the power output, indicating that the described system may be operated at a high efficiency. (author) 5 figs., 2 refs.

  15. Oxidative potential of gas phase combustion emissions - An underestimated and potentially harmful component of air pollution from combustion processes

    Science.gov (United States)

    Stevanovic, S.; Vaughan, A.; Hedayat, F.; Salimi, F.; Rahman, M. M.; Zare, A.; Brown, R. A.; Brown, R. J.; Wang, H.; Zhang, Z.; Wang, X.; Bottle, S. E.; Yang, I. A.; Ristovski, Z. D.

    2017-06-01

    The oxidative potential (OP) of the gas phase is an important and neglected aspect of environmental toxicity. Whilst prolonged exposure to particulate matter (PM) associated reactive oxygen species (ROS) have been shown to lead to negative health effects, the potential for compounds in gas phase to cause similar effects is yet to be understood. In this study we describe: the significance of the gas phase OP generated through vehicle emissions; discuss the origin and evolution of species contributing to measured OP; and report on the impact of gas phase OP on human lung cells. The model aerosol for this study was exhaust emitted from a Euro III Common-rail diesel engine fuelled with different blends of diesel and biodiesel. The gas phase of these emissions was found to be potentially as hazardous as the particle phase. Fuel oxygen content was found to negatively correlate with the gas phase OP, and positively correlate with particle phase OP. This signifies a complex interaction between reactive species present in gas and particle phase. Furthermore, this interaction has an overarching effect on the OP of both particle and gas phase, and therefore the toxicity of combustion emissions.

  16. Time-predictable Stack Caching

    DEFF Research Database (Denmark)

    Abbaspourseyedi, Sahar

    completely. Thus, in systems with hard deadlines the worst-case execution time (WCET) of the real-time software running on them needs to be bounded. Modern architectures use features such as pipelining and caches for improving the average performance. These features, however, make the WCET analysis more...... addresses, provides an opportunity to predict and tighten the WCET of accesses to data in caches. In this thesis, we introduce the time-predictable stack cache design and implementation within a time-predictable processor. We introduce several optimizations to our design for tightening the WCET while...... keeping the timepredictability of the design intact. Moreover, we provide a solution for reducing the cost of context switching in a system using the stack cache. In design of these caches, we use custom hardware and compiler support for delivering time-predictable stack data accesses. Furthermore...

  17. Glassy carbon based supercapacitor stacks

    Energy Technology Data Exchange (ETDEWEB)

    Baertsch, M.; Braun, A.; Koetz, R.; Haas, O. [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1997-06-01

    Considerable effort is being made to develop electrochemical double layer capacitors (EDLC) that store relatively large quantities of electrical energy and possess at the same time a high power density. Our previous work has shown that glassy carbon is suitable as a material for capacitor electrodes concerning low resistance and high capacity requirements. We present the development of bipolar electrochemical glassy carbon capacitor stacks of up to 3 V. Bipolar stacks are an efficient way to meet the high voltage and high power density requirements for traction applications. Impedance and cyclic voltammogram measurements are reported here and show the frequency response of a 1, 2, and 3 V stack. (author) 3 figs., 1 ref..

  18. Air pollution

    International Nuclear Information System (INIS)

    Feugier, A.

    1996-01-01

    The air pollution results from the combustion of petroleum products, natural gas, coal, wastes and transports. Some compounds are considered as particularly pollutants: the carbon monoxide, the nitrogen oxides, the tropospheric ozone and the sulfur dioxides. Their environmental and biological effects are described. The present political guide lines concerns the combustion plants, the ozone, the wastes incineration and the vehicles emissions. The aim is at some future date to control the air quality, to reduce the volatile organic compounds emissions and to limit the sulfur rate of some petroleum products. (O.L.)

  19. Multiple Segmentation of Image Stacks

    DEFF Research Database (Denmark)

    Smets, Jonathan; Jaeger, Manfred

    2014-01-01

    We propose a method for the simultaneous construction of multiple image segmentations by combining a recently proposed “convolution of mixtures of Gaussians” model with a multi-layer hidden Markov random field structure. The resulting method constructs for a single image several, alternative...... segmentations that capture different structural elements of the image. We also apply the method to collections of images with identical pixel dimensions, which we call image stacks. Here it turns out that the method is able to both identify groups of similar images in the stack, and to provide segmentations...

  20. Simulating Small-Scale Object Stacking Using Stack Stability

    DEFF Research Database (Denmark)

    Kronborg Thomsen, Kasper; Kraus, Martin

    2015-01-01

    This paper presents an extension system to a closed-source, real-time physics engine for improving structured stacking behavior with small-scale objects such as wooden toy bricks. The proposed system was implemented and evaluated. The tests showed that the system is able to simulate several common...

  1. Development of internal manifold heat exchanger (IMHEX reg-sign) molten carbonate fuel cell stacks

    International Nuclear Information System (INIS)

    Marianowski, L.G.; Ong, E.T.; Petri, R.J.; Remick, R.J.

    1991-01-01

    The Institute of Gas Technology (IGT) has been in the forefront of molten carbonate fuel cell (MCFC) development for over 25 years. Numerous cell designs have been tested and extensive tests have been performed on a variety of gas manifolding alternatives for cells and stacks. Based upon the results of these performance tests, IGT's development efforts started focusing on an internal gas manifolding concept. This work, initiated in 1988, is known today as the IMHEX reg-sign concept. MCP has developed a comprehensive commercialization program loading to the sale of commercial units in 1996. MCP's role is in the manufacture of stack components, stack assembly, MCFC subsystem testing, and the design, marketing and construction of MCFC power plants. Numerous subscale (1 ft 2 ) stacks have been operated containing between 3 and 70 cells. These tests verified and demonstrated the viability of internal manifolding from technical (no carbonate pumping), engineering (relaxed part dimensional tolerance requirements), and operational (good gas sealing) aspects. Simplified fabrication, ease of assembly, the elimination of external manifolds and all associated clamping requirements has significantly lowered anticipated stack costs. Ongoing 1 ft 2 stack testing is generating performance and endurance characteristics as a function of system specified operating conditions. Commercial-sized, full-area stacks (10 ft 2 ) are in the process of being assembled and will be tested in November. This paper will review the recent developments the MCFC scale-up and manufacture work of MCP, and the research and development efforts of IGT which support those efforts. 17 figs

  2. Pressurized electrolysis stack with thermal expansion capability

    Science.gov (United States)

    Bourgeois, Richard Scott

    2015-07-14

    The present techniques provide systems and methods for mounting an electrolyzer stack in an outer shell so as to allow for differential thermal expansion of the electrolyzer stack and shell. Generally, an electrolyzer stack may be formed from a material with a high coefficient of thermal expansion, while the shell may be formed from a material having a lower coefficient of thermal expansion. The differences between the coefficients of thermal expansion may lead to damage to the electrolyzer stack as the shell may restrain the thermal expansion of the electrolyzer stack. To allow for the differences in thermal expansion, the electrolyzer stack may be mounted within the shell leaving a space between the electrolyzer stack and shell. The space between the electrolyzer stack and the shell may be filled with a non-conductive fluid to further equalize pressure inside and outside of the electrolyzer stack.

  3. Morphological variations as nonstandard test parameters for the response to pollutant gas concentration: An application to Ruthenium Phthalocyanine sensing films

    International Nuclear Information System (INIS)

    Generosi, A.; Paci, B.; Albertini, V. Rossi; Perfetti, P.; Paoletti, A.M.; Pennesi, G.; Rossi, G.; Caminiti, R.

    2006-01-01

    A systematic time-resolved energy dispersive x-ray reflectometry study was performed in situ on Ruthenium Phthalocyanine thin fims to estimate the morphological detection limits of this material as NO 2 transducer and the influence of the gas concentration on the gas-film interaction mechanisms. The work validates the use of this unconventional method--based on the observation of the morphological parameters change--for evaluating the response of novel sensing materials in alternative to more standard procedures. Indeed, the morphological monitoring is shown to be sensitive to the gas concentration in a range comparable to the usual electroresistive measurements. Moreover, while the latter is only able to give the information on whether the gas is interacting with the sensor, the former is also able to discriminate among interaction processes of a different nature (in the present case the interaction limited to the film surface and the one involving the material bulk)

  4. Stack semantics of type theory

    DEFF Research Database (Denmark)

    Coquand, Thierry; Mannaa, Bassel; Ruch, Fabian

    2017-01-01

    We give a model of dependent type theory with one univalent universe and propositional truncation interpreting a type as a stack, generalizing the groupoid model of type theory. As an application, we show that countable choice cannot be proved in dependent type theory with one univalent universe...

  5. Multilayer Piezoelectric Stack Actuator Characterization

    Science.gov (United States)

    Sherrit, Stewart; Jones, Christopher M.; Aldrich, Jack B.; Blodget, Chad; Bao, Xioaqi; Badescu, Mircea; Bar-Cohen, Yoseph

    2008-01-01

    Future NASA missions are increasingly seeking to use actuators for precision positioning to accuracies of the order of fractions of a nanometer. For this purpose, multilayer piezoelectric stacks are being considered as actuators for driving these precision mechanisms. In this study, sets of commercial PZT stacks were tested in various AC and DC conditions at both nominal and extreme temperatures and voltages. AC signal testing included impedance, capacitance and dielectric loss factor of each actuator as a function of the small-signal driving sinusoidal frequency, and the ambient temperature. DC signal testing includes leakage current and displacement as a function of the applied DC voltage. The applied DC voltage was increased to over eight times the manufacturers' specifications to investigate the correlation between leakage current and breakdown voltage. Resonance characterization as a function of temperature was done over a temperature range of -180C to +200C which generally exceeded the manufacturers' specifications. In order to study the lifetime performance of these stacks, five actuators from one manufacturer were driven by a 60volt, 2 kHz sine-wave for ten billion cycles. The tests were performed using a Lab-View controlled automated data acquisition system that monitored the waveform of the stack electrical current and voltage. The measurements included the displacement, impedance, capacitance and leakage current and the analysis of the experimental results will be presented.

  6. Open stack thermal battery tests

    Energy Technology Data Exchange (ETDEWEB)

    Long, Kevin N. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Roberts, Christine C. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Grillet, Anne M. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Headley, Alexander J. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Fenton, Kyle [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Wong, Dennis [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Ingersoll, David [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2017-04-17

    We present selected results from a series of Open Stack thermal battery tests performed in FY14 and FY15 and discuss our findings. These tests were meant to provide validation data for the comprehensive thermal battery simulation tools currently under development in Sierra/Aria under known conditions compared with as-manufactured batteries. We are able to satisfy this original objective in the present study for some test conditions. Measurements from each test include: nominal stack pressure (axial stress) vs. time in the cold state and during battery ignition, battery voltage vs. time against a prescribed current draw with periodic pulses, and images transverse to the battery axis from which cell displacements are computed. Six battery configurations were evaluated: 3, 5, and 10 cell stacks sandwiched between 4 layers of the materials used for axial thermal insulation, either Fiberfrax Board or MinK. In addition to the results from 3, 5, and 10 cell stacks with either in-line Fiberfrax Board or MinK insulation, a series of cell-free “control” tests were performed that show the inherent settling and stress relaxation based on the interaction between the insulation and heat pellets alone.

  7. Adding large EM stack support

    KAUST Repository

    Holst, Glendon

    2016-12-01

    Serial section electron microscopy (SSEM) image stacks generated using high throughput microscopy techniques are an integral tool for investigating brain connectivity and cell morphology. FIB or 3View scanning electron microscopes easily generate gigabytes of data. In order to produce analyzable 3D dataset from the imaged volumes, efficient and reliable image segmentation is crucial. Classical manual approaches to segmentation are time consuming and labour intensive. Semiautomatic seeded watershed segmentation algorithms, such as those implemented by ilastik image processing software, are a very powerful alternative, substantially speeding up segmentation times. We have used ilastik effectively for small EM stacks – on a laptop, no less; however, ilastik was unable to carve the large EM stacks we needed to segment because its memory requirements grew too large – even for the biggest workstations we had available. For this reason, we refactored the carving module of ilastik to scale it up to large EM stacks on large workstations, and tested its efficiency. We modified the carving module, building on existing blockwise processing functionality to process data in manageable chunks that can fit within RAM (main memory). We review this refactoring work, highlighting the software architecture, design choices, modifications, and issues encountered.

  8. Manifold seal structure for fuel cell stack

    Science.gov (United States)

    Collins, William P.

    1988-01-01

    The seal between the sides of a fuel cell stack and the gas manifolds is improved by adding a mechanical interlock between the adhesive sealing strip and the abutting surface of the manifolds. The adhesive is a material which can flow to some extent when under compression, and the mechanical interlock is formed providing small openings in the portion of the manifold which abuts the adhesive strip. When the manifolds are pressed against the adhesive strips, the latter will flow into and through the manifold openings to form buttons or ribs which mechanically interlock with the manifolds. These buttons or ribs increase the bond between the manifolds and adhesive, which previously relied solely on the adhesive nature of the adhesive.

  9. Development and Applications of a Stage Stacking Procedure

    Science.gov (United States)

    Kulkarni, Sameer; Celestina, Mark L.; Adamczyk, John J.

    2012-01-01

    The preliminary design of multistage axial compressors in gas turbine engines is typically accomplished with mean-line methods. These methods, which rely on empirical correlations, estimate compressor performance well near the design point, but may become less reliable off-design. For land-based applications of gas turbine engines, off-design performance estimates are becoming increasingly important, as turbine plant operators desire peaking or load-following capabilities and hot-day operability. The current work develops a one-dimensional stage stacking procedure, including a newly defined blockage term, which is used to estimate the off-design performance and operability range of a 13-stage axial compressor used in a power generating gas turbine engine. The new blockage term is defined to give mathematical closure on static pressure, and values of blockage are shown to collapse to curves as a function of stage inlet flow coefficient and corrected shaft speed. In addition to these blockage curves, the stage stacking procedure utilizes stage characteristics of ideal work coefficient and adiabatic efficiency. These curves are constructed using flow information extracted from computational fluid dynamics (CFD) simulations of groups of stages within the compressor. Performance estimates resulting from the stage stacking procedure are shown to match the results of CFD simulations of the entire compressor to within 1.6% in overall total pressure ratio and within 0.3 points in overall adiabatic efficiency. Utility of the stage stacking procedure is demonstrated by estimation of the minimum corrected speed which allows stable operation of the compressor. Further utility of the stage stacking procedure is demonstrated with a bleed sensitivity study, which estimates a bleed schedule to expand the compressors operating range.

  10. DEVELOPMENT OF ANALYTICAL METHODS FOR THE QUANTIFICATION OF THE CHEMICAL FORMS OF MERCURY AND OTHER TARGET POLLUTANTS IN COAL-FIRED BOILER FLUE GAS

    Energy Technology Data Exchange (ETDEWEB)

    Terence J. McManus, Ph.D.

    1999-06-30

    Since approximately 55% of the electrical power produced in the U. S. is generated by coal-based power utility plants, there is serious concern about the massive amounts of coal combustion products emitted into the atmosphere annually. Furthermore, Title III of the 1990 Clean Air Act Amendments (CAAA) requires the measurement and inventory of a possible 189 hazardous air pollutants (HAPs) from any stationary source producing more than 10 tons per year of any one pollutant or more than 25 tons per year of total pollutants. Although power utilities are not presently included on the list of source categories, the CAAA requires the U. S. Environmental Protection Agency to carry out a study of emissions from electricity generation using fossil fuels. Since many of these HAPs are known to be present in coal derived flue gas, coal-fired electric power utilities may be subject to regulation following these studies if Congress considers it necessary. In a cooperative effort with the U. S. Environmental Protection Agency (EPA), the U. S. Department of Energy (DOE) through its Federal Energy Technology Center (FETC) initiated such a study in 1991. DOE-FETC commissioned five primary contractors to conduct emission studies at eight different coal-fired electric utilities. The eight sites represented a cross section of feed coal type, boiler designs, and particulate and gaseous pollutant control technologies. The major goal of these studies was to determine the sampling and analytical methodologies that could be used efficiently to perform these emission tests while producing representative and reliable emission data. The successful methodology could then be recommended to the EPA for use in compliance testing in the event the regulation of air toxic emissions from coal-fired power plants is implemented. A secondary purpose of the testing was to determine the effectiveness of the control technologies in reducing target hazardous air pollutants. Advanced Technology Systems, Inc

  11. Design and validation of a model to offer environmental consulting services to minimize oil pollution at gas stations: case study: a gas station in Costa Rica

    International Nuclear Information System (INIS)

    Calderon Hernandez, Teresita

    2016-01-01

    An environmental consulting service was designed and validated to minimize hydrocarbon contamination at gas stations, to be used by Migliore S.A. in order to strengthen and increase the number of services offered in the market niche of these companies. A matrix was synthesized with tools such as SWOT, deployment of the Quality Function Deployment (QFD) and international analysis. With the standardized protocols it will be possible to increase in a fluid way, the offer of consulting services. The final validation of the model allowed to verify the functionality of the same, through the generation of solid evaluation criteria that allowed a good knowledge of the gas station, case study, to offer a timely solution to your particular case, in a simple way and harmonious. The company providing environmental consulting services Migliore S.A. can count on a better commercial development, using the designed model [es

  12. Stack Parameters Effect on the Performance of Anharmonic Resonator Thermoacoustic Heat Engine

    KAUST Repository

    Nouh, Mostafa A.

    2014-01-01

    A thermoacoustic heat engine (TAHE) converts heat into acoustic power with no moving parts. It exhibits several advantages over traditional engines, such as simple design, stable functionality, and environment-friendly working gas. In order to further improve the performance of TAHE, stack parameters need to be optimized. Stack\\'s position, length and plate spacing are the three main parameters that have been investigated in this study. Stack\\'s position dictates both the efficiency and the maximum produced acoustic power of the heat engine. Positioning the stack closer to the pressure anti-node might ensure high efficiency on the expense of the maximum produced acoustic power. It is noticed that the TAHE efficiency can further be improved by spacing the plates of the stack at a value of 2.4 of the thermal penetration depth, δk . Changes in the stack length will not affect the efficiency much as long as the temperature gradient across the stack, as a ratio of the critical temperature gradient ψ is more than 1. Upon interpreting the effect of these variations, attempts are made towards reaching the engine\\'s most powerful operating point.

  13. Effects of a liquefied petroleum gas stove intervention on pollutant exposure and adult cardiopulmonary outcomes (CHAP): study protocol for a randomized controlled trial.

    Science.gov (United States)

    Fandiño-Del-Rio, Magdalena; Goodman, Dina; Kephart, Josiah L; Miele, Catherine H; Williams, Kendra N; Moazzami, Mitra; Fung, Elizabeth C; Koehler, Kirsten; Davila-Roman, Victor G; Lee, Kathryn A; Nangia, Saachi; Harvey, Steven A; Steenland, Kyle; Gonzales, Gustavo F; Checkley, William

    2017-11-03

    Biomass fuel smoke is a leading risk factor for the burden of disease worldwide. International campaigns are promoting the widespread adoption of liquefied petroleum gas (LPG) in resource-limited settings. However, it is unclear if the introduction and use of LPG stoves, in settings where biomass fuels are used daily, reduces pollution concentration exposure, improves health outcomes, or how cultural and social barriers influence the exclusive adoption of LPG stoves. We will conduct a randomized controlled, field intervention trial of LPG stoves and fuel distribution in rural Puno, Peru, in which we will enroll 180 female participants aged 25-64 years and follow them for 2 years. After enrollment, we will collect information on sociodemographic characteristics, household characteristics, and cooking practices. During the first year of the study, LPG stoves and fuel tanks will be delivered to the homes of 90 intervention participants. During the second year, participants in the intervention arm will keep their LPG stoves, but the gas supply will stop. Control participants will receive LPG stoves and vouchers to obtain free fuel from distributors at the beginning of the second year, but gas will not be delivered. Starting at baseline, we will collect longitudinal measurements of respiratory symptoms, pulmonary function, blood pressure, endothelial function, carotid artery intima-media thickness, 24-h dietary recalls, exhaled carbon monoxide, quality-of-life indicators, and stove-use behaviors. Environmental exposure assessments will occur six times over the 2-year follow-up period, consisting of 48-h personal exposure and kitchen concentration measurements of fine particulate matter and carbon monoxide, and 48-h kitchen concentrations of nitrogen dioxide for a subset of 100 participants. Findings from this study will allow us to better understand behavioral patterns, environmental exposures, and cardiovascular and pulmonary outcomes resulting from the adoption of

  14. Development and durability of SOFC stacks

    Energy Technology Data Exchange (ETDEWEB)

    Beeaff, D.; Dinesen, A.R.; Mikkelsen, Lars; Nielsen, Karsten A.; Solvang, M.; Hendriksen, Peter V.

    2004-12-01

    The present project is a part of the Danish SOFC programme, which has the overall aim of establishing a Danish production of SOFC - cells, stacks and systems for economical and environmentally friendly power production. The aim of the present project was to develop and demonstrate (on a small scale, few cells, few thousand hours) a durable, thermally cyclable stack with high performance at 750 deg. C. Good progress towards this target has been made and demonstrated at the level of stack-elements (one cell between two interconnects) or small stacks (3 5 cells). Three different stacks or stack-elements have been operated for periods exceeding 3000 hr. The work has covered development of stack-components (seals, interconnects, coatings, contact layers), establishment of procedures for stack assembly and initiation, and detailed electrical characterisation with the aims of identifying performance limiting factors as well as long term durability. Further, post test investigations have been carried out to identify possible degradation mechanisms. (BA)

  15. Empirical comparison of pollution generating technologies in nonparametric modelling : The case of greenhouse gas emissions in French meat sheep farming

    OpenAIRE

    Dakpo, K Hervé; Jeanneaux, Philippe; Latruffe, Laure

    2015-01-01

    In this paper we consider different models that assess eco - efficiency with production frontier estimation when both desirable outputs and undesirable outputs (or residuals) are considered. These models are confronted to livestock farm data (sheep meat farms) and greenho use gas (GHG) emissions, to discuss their suitability in eco - efficiency measurement. The application is to French sheep meat farms. Our results show t...

  16. Organic pollutants in shale gas flowback and produced waters : identification, potential ecological impact and implications for treatment strategies

    NARCIS (Netherlands)

    Butkovskyi, Andrii; Bruning, Harry; Kools, Stefan A E; Rijnaarts, Huub H M; van Wezel, Annemarie P

    2017-01-01

    Organic contaminants in shale gas flowback and produced water (FPW) are traditionally expressed as total organic carbon (TOC) or chemical oxygen demand (COD), though these parameters do not provide information on the toxicity and environmental fate of individual components. This review addresses

  17. Atmospheric pollution in our environment

    International Nuclear Information System (INIS)

    Tanvir, G.

    1986-01-01

    Air pollution is associated with all the activities of humans. It is becoming a serious problem in coming years so it is relevant to find out how seriously our atmosphere is being polluted and how this pollution affects human and plant life in our environment. Not only the human activities are the source of our pollution but nature causes more pollution. Air pollution that is due to the pressure of foreign substances in air, effects the quality and concentration of air substances. It is not only injurious to property, but also to vegetation and animal life. Air pollution is one of our most serious environmental problems. The sources vary from smoke-stacks and automobiles to noise and foreon containing aerosols. (orig./A.B.)

  18. Measurements of Short Lived Gas Phase Pollutants during AN Anthropogenic Biomass Burning Event during Winter in Manchester, UK Using a Tof-Cims

    Science.gov (United States)

    Priestley, M.; Bannan, T.; le Breton, M.; Leather, K.; Bacak, A.; Villegas, E.; Khan, A.; Allan, J. D.; Shallcross, D. E.; Coe, H.; Percival, C.

    2017-12-01

    Anthropogenic biomass burning represents a significant source of short lived harmful gases that reduces air quality and is one of the least well constrained processes in air quality and climate modelling (Andreae & Merlet 2001). Guy Fawkes Night (bonfire night) is a regular event in the UK where open fires are lit. Previous gas phase studies of bonfire night have typically used offline techniques focusing on persistent organic pollutants. Here, the first simultaneous online gas phase measurements of short lived pollutants from mixed biomass and anthropogenic fuel types were made using a chemical ionisation mass spectrometer (TOF-CIMS) with the iodide reagent ion in November 2014 in Manchester, UK. We detected a suite of compounds including isocyanates, nitrates and amides. Ambient concentrations of hydrogen cyanide (HCN), isocyanic acid and methyl isocyanate increased from maximums of 132 ppt, 144 ppt and 327 ppt to peak plume concentrations of 1.2 ppb, 1.6 ppb and 4.3 ppb respectively. We used the 6 sigma approach to define the biomass plume using HCN as a tracer and find the [HNCO]/[CO] ratio definition of burning phase is applicable (Roberts et al. 2010). Flaming emission increased the normalised excess mixing ratio (NEMR) by a factor of 2-4 relative to smouldering emission and treating burning phases separately improved the average accuracy of the NEMR by 29%. References Andreae, M.O. & Merlet, P., 2001. Emission of trace gases and aerosols from biomass burning. Global Biogeochemical Cycles, 15(4), pp.955-966. Available at: http://dx.doi.org/10.1029/2000GB001382. Roberts, J.M. et al., 2010. Measurement of HONO, HNCO, and other inorganic acids by negative-ion proton-transfer chemical-ionization mass spectrometry (NI-PT-CIMS): Application to biomass burning emissions. Atmospheric Measurement Techniques, 3, pp.981-990.

  19. Comparison of eddy covariance and modified Bowen ratio methods for measuring gas fluxes and implications for measuring fluxes of persistent organic pollutants

    Directory of Open Access Journals (Sweden)

    D. J. Bolinius

    2016-04-01

    Full Text Available Semi-volatile persistent organic pollutants (POPs cycle between the atmosphere and terrestrial surfaces; however measuring fluxes of POPs between the atmosphere and other media is challenging. Sampling times of hours to days are required to accurately measure trace concentrations of POPs in the atmosphere, which rules out the use of eddy covariance techniques that are used to measure gas fluxes of major air pollutants. An alternative, the modified Bowen ratio (MBR method, has been used instead. In this study we used data from FLUXNET for CO2 and water vapor (H2O to compare fluxes measured by eddy covariance to fluxes measured with the MBR method using vertical concentration gradients in air derived from averaged data that simulate the long sampling times typically required to measure POPs. When concentration gradients are strong and fluxes are unidirectional, the MBR method and the eddy covariance method agree within a factor of 3 for CO2, and within a factor of 10 for H2O. To remain within the range of applicability of the MBR method, field studies should be carried out under conditions such that the direction of net flux does not change during the sampling period. If that condition is met, then the performance of the MBR method is neither strongly affected by the length of sample duration nor the use of a fixed value for the transfer coefficient.

  20. Greenhouse Gas and Criteria Pollutants Emissions Derived from Different Mitigation Measures in the Management of Solid Urban Waste in the Canton of San José, Costa Rica

    Directory of Open Access Journals (Sweden)

    Jorge Herrera Murillo

    2017-12-01

    Full Text Available Greenhouse gas and criteria pollutants emissions as well as the potential for electric power generation were estimated for four different scenarios of final disposal of solid urban waste (MSW in San Jose: landfill, incineration, composting and mechanical-biological treatment. Generation and composition waste data reported by the San Jose Department of Environmental Services were used as input for a life cycle analysis as well as the respective materials and energy flows for each proposal, based on the formulation of the respective balances of mass and energy. The final disposal in landfills is the treatment that emits more emissions of greenhouse gases with 532.5 Ton CO2e / d and a potential of electricity generation of up to 73.45 MWh, followed by the incineration of MSW with 401.9 Ton CO2e / d. However, alternative scenarios such as incineration additionally generate significant emissions of air pollutants such as particulates (5.14 Ton / d, NOx (0.75 Ton / d and CO (0.13 Ton / d.

  1. Air pollution in the last 50 years - From local to global

    DEFF Research Database (Denmark)

    Fenger, Jes

    2009-01-01

    Air pollution in the industrialised world has in the last 50 years undergone drastic changes. Until after World War II the most important urban compound was sulphur dioxide combined with soot from the use of fossil fuels in heat and power production. When that problem was partly solved by cleaner...... fuels, higher stacks and flue gas cleaning in urban areas, the growing traffic gave rise to nitrogen oxides and volatile organic compounds and in some areas photochemical air pollution, which may be abated by catalytic converters. Lately the interest has centred on small particles and more exotic...... organic compounds that can be detected with new sophisticated analytical techniques. Simultaneously with the development in compounds, the time and geographical scale of interest have increased. First to transboundary air pollution, which in decades and on continents can degrade ecosystems, later...

  2. Organic Pollutants in Shale Gas Flowback and Produced Waters: Identification, Potential Ecological Impact, and Implications for Treatment Strategies

    OpenAIRE

    Butkovskyi, Andrii; Bruning, Harry; Kools, Stefan A.E.; Rijnaarts, Huub H.M.; Van Wezel, Annemarie P.

    2017-01-01

    Organic contaminants in shale gas flowback and produced water (FPW) are traditionally expressed as total organic carbon (TOC) or chemical oxygen demand (COD), though these parameters do not provide information on the toxicity and environmental fate of individual components. This review addresses identification of individual organic contaminants in FPW, and stresses the gaps in the knowledge on FPW composition that exist so far. Furthermore, the risk quotient approach was applied to predict th...

  3. Gas sensor

    Science.gov (United States)

    Schmid, Andreas K.; Mascaraque, Arantzazu; Santos, Benito; de la Figuera, Juan

    2014-09-09

    A gas sensor is described which incorporates a sensor stack comprising a first film layer of a ferromagnetic material, a spacer layer, and a second film layer of the ferromagnetic material. The first film layer is fabricated so that it exhibits a dependence of its magnetic anisotropy direction on the presence of a gas, That is, the orientation of the easy axis of magnetization will flip from out-of-plane to in-plane when the gas to be detected is present in sufficient concentration. By monitoring the change in resistance of the sensor stack when the orientation of the first layer's magnetization changes, and correlating that change with temperature one can determine both the identity and relative concentration of the detected gas. In one embodiment the stack sensor comprises a top ferromagnetic layer two mono layers thick of cobalt deposited upon a spacer layer of ruthenium, which in turn has a second layer of cobalt disposed on its other side, this second cobalt layer in contact with a programmable heater chip.

  4. Lightweight Stacks of Direct Methanol Fuel Cells

    Science.gov (United States)

    Narayanan, Sekharipuram; Valdez, Thomas

    2004-01-01

    An improved design concept for direct methanol fuel cells makes it possible to construct fuel-cell stacks that can weigh as little as one-third as much as do conventional bipolar fuel-cell stacks of equal power. The structural-support components of the improved cells and stacks can be made of relatively inexpensive plastics. Moreover, in comparison with conventional bipolar fuel-cell stacks, the improved fuel-cell stacks can be assembled, disassembled, and diagnosed for malfunctions more easily. These improvements are expected to bring portable direct methanol fuel cells and stacks closer to commercialization. In a conventional bipolar fuel-cell stack, the cells are interspersed with bipolar plates (also called biplates), which are structural components that serve to interconnect the cells and distribute the reactants (methanol and air). The cells and biplates are sandwiched between metal end plates. Usually, the stack is held together under pressure by tie rods that clamp the end plates. The bipolar stack configuration offers the advantage of very low internal electrical resistance. However, when the power output of a stack is only a few watts, the very low internal resistance of a bipolar stack is not absolutely necessary for keeping the internal power loss acceptably low.

  5. Particle Pollution

    Science.gov (United States)

    ... Your Health Particle Pollution Public Health Issues Particle Pollution Recommend on Facebook Tweet Share Compartir Particle pollution — ... see them in the air. Where does particle pollution come from? Particle pollution can come from two ...

  6. Continued SOFC cell and stack technology and improved production methods

    Energy Technology Data Exchange (ETDEWEB)

    Wandel, M.; Brodersen, K.; Phair, J. (and others)

    2009-05-15

    Within this project significant results are obtained on a number of very diverse areas ranging from development of cell production, metallic creep in interconnect to assembling and test of stacks with foot print larger than 500 cm2. Out of 38 milestones 28 have been fulfilled and 10 have been partly fulfilled. This project has focused on three main areas: 1) The continued cell development and optimization of manufacturing processes aiming at production of large foot-print cells, improving cell performance and development environmentally more benign production methods. 2) Stack technology - especially stacks with large foot print and improving the stack design with respect to flow geometry and gas leakages. 3) Development of stack components with emphasis on sealing (for 2G as well as 3G), interconnect (coat, architecture and creep) and test development. Production of cells with a foot print larger than 500 cm2 is very difficult due to the brittleness of the cells and great effort has been put into this topic. Eight cells were successfully produced making it possible to assemble and test a real stack thereby giving valuable results on the prospects of stacks with large foot print. However, the yield rate is very low and a significant development to increase this yield lies ahead. Several lessons were learned on the stack level regarding 'large foot print' stacks. Modelling studies showed that the width of the cell primarily is limited by production and handling of the cell whereas the length (in the flow direction) is limited by e.g. pressure drop and necessary manifolding. The optimal cell size in the flow direction was calculated to be between approx20 cm and < 30 cm. From an economical point of view the production yield is crucial and stacks with large foot print cell area are only feasible if the cell production yield is significantly enhanced. Co-casting has been pursued as a production technique due to the possibilities in large scale production

  7. Effective pollutant emission heights for atmospheric transport modelling based on real-world information.

    Science.gov (United States)

    Pregger, Thomas; Friedrich, Rainer

    2009-02-01

    Emission data needed as input for the operation of atmospheric models should not only be spatially and temporally resolved. Another important feature is the effective emission height which significantly influences modelled concentration values. Unfortunately this information, which is especially relevant for large point sources, is usually not available and simple assumptions are often used in atmospheric models. As a contribution to improve knowledge on emission heights this paper provides typical default values for the driving parameters stack height and flue gas temperature, velocity and flow rate for different industrial sources. The results were derived from an analysis of the probably most comprehensive database of real-world stack information existing in Europe based on German industrial data. A bottom-up calculation of effective emission heights applying equations used for Gaussian dispersion models shows significant differences depending on source and air pollutant and compared to approaches currently used for atmospheric transport modelling.

  8. Inventory of atmospheric pollutant and greenhouse gas emissions in France. Sectoral series and extended analyses - SECTEN Format, April 2011

    International Nuclear Information System (INIS)

    Chang, Jean-Pierre; Fontelle, Jean-Pierre; Serveau, Laetitia; Allemand, Nadine; Jeannot, Coralie; Andre, Jean-Marc; Joya, Romain; Deflorenne, Emmanuel; Martinet, Yann; Druart, Ariane; Mathias, Etienne; Gavel, Antoine; Nicco, Laetitia; Gueguen, Celine; Prouteau, Emilie; Jabot, Julien; Tuddenham, Mark; Jacquier, Guillaume; Vincent, Julien

    2011-04-01

    This report supplies an update of emissions into the atmosphere in mainland France under the SNIEPA in accordance with the 'SECTEN' format defined by CITEPA. This report aims to reconstitute emissions broken down in accordance with the traditional economic sectors such as industry, residential/tertiary sector, agriculture, etc. (cf. Annex 2 for the corresponding links between SECTEN sectors and sub-sectors, and the SNAP nomenclature). Unless otherwise indicated, the results cover the period 1990-2010 (estimations for 2010 are preliminary), but also go back further in time: to 1980 for certain substances covered by the different protocols adopted under the 1979 UNECE Convention on Long-Range Transboundary Air Pollution. For other substances traditionally monitored by CITEPA for many years, the results go back to 1960 (SO 2 , NO x , CO 2 , CO). Data are presented for 28 different substances in total and various indicators such as those concerning acidification or the greenhouse effect. The report shows that for most substances, emissions have been drastically reduced over the last 10 or 20 years, especially during the period 1990-2009: Very sharp decrease (over 40%) SO 2 , NMVOCs, CO, SF 6 , PFCs in CO 2 equivalent, As, Cd, Cr, Hg, Ni, Pb, Zn, dioxins and furans, PAHs, HCB, PCBs, PM 2.5 and PM 1.0 , Sharp decrease (between 20 and 40%) NO x , N 2 O, Se, TSP, PM 10 and acid equivalent index, Considerable decrease (between 5 and 20%) NH 3 , CH 4 without LULUCF, CO 2 without LULUCF, Cu and the global warming potential index without LULUCF, Stabilisation (between -5 and +5%) No substance, Very sharp increase (over 40%) HFCs in CO 2 equivalent. For more than 2/3 of substances, emission levels in 2009 were the lowest since records began (1960 to 1990 depending on the substances). For the most part of atmospheric pollutants (except the greenhouse gases), the preliminary estimations for year 2010 look rather favorable as far as the estimated level is below than observed in

  9. Effects of Local Greenhouse Gas Abatement Strategies on Air Pollutant Emissions and on Health in Kuopio, Finland

    Directory of Open Access Journals (Sweden)

    Arja Asikainen

    2017-06-01

    Full Text Available Implementation of greenhouse gas (GHG abatement strategies often ends up as the responsibility of municipal action rather than national policies. Impacts of local GHG reduction measures were investigated in the EU FP7 funded project Urban Reduction of Greenhouse Gas Emissions in China and Europe (URGENCHE. Kuopio in Finland was one of the case study cities. The assessed reduction measures were (1 increased use of biomass in local heat and power cogeneration plant, (2 energy efficiency improvements of residences, (3 increased biofuel use in traffic, and (4 increased small scale combustion of wood for residential heating. Impact assessment compared the 2010 baseline with a 2020 BAU (business as usual scenario and a 2020 CO2 interventions scenario. Changes in emissions were assessed for CO2, particulate matter (PM2.5 and PM10, NOx, and SO2, and respective impacts were assessed for PM2.5 ambient concentrations and health effects. The assessed measures would reduce the local CO2 emissions in the Kuopio urban area by over 50% and local emissions of PM2.5 would clearly decrease. However, the annual average ambient PM2.5 concentration would decrease by just 4%. Thus, only marginal population level health benefits would be achieved with these assumed local CO2 abatement actions.

  10. Synergy of air pollutants and greenhouse gas emissions of Chinese industries: A critical assessment of energy models

    International Nuclear Information System (INIS)

    Zhang, Shaohui; Worrell, Ernst; Crijns-Graus, Wina

    2015-01-01

    In China, industrial energy use accounts for two thirds of total energy consumption, and this is expected to remain the same in the medium and long-term. China has embarked on a path towards more sustainable energy use to meet domestic (e.g. air quality) and global needs (e.g. climate change), and to sustain its economic welfare. However, most energy-economy models for China have shown limitations to evaluate policy instruments and technology diffusion in industries, in relation to the multiple policy goals. In this paper, the advantages and weaknesses of 19 current energy models for China are evaluated, including important co-benefits as reduced air pollutant emissions. Results show that the co-benefits of energy use and emission policies are rarely modeled on industrial level. Based on the critical assessment of the state-of-the-art energy models, we develop recommendations for modeling industrial energy use, with an emphasis on improved incorporation of (economic, environmental and energy) policy effects, technology representation, co-benefit modeling, and uncertainty analysis. - Highlights: • This study evaluates 19 the state-of-the-art energy models on different level. • The co-benefits of different policies are rarely reported in energy models. • Technology plays a key role in models when assessing the co-benefits. • The integrated models provide a better understanding to evaluate the co-benefits. • The directions to improve the accuracy of the current energy models are presented.

  11. Greenhouse gas and air pollutant emissions from land and forest fire in Indonesia during 2015 based on satellite data

    Science.gov (United States)

    Pribadi, A.; Kurata, G.

    2017-01-01

    Land and forest fire still become a major problem in environmental management in Indonesia. In this study, we conducted quantitatively assessment of land and forest fire emissions in Indonesia during 2015. We applied methodology of emission inventory based on burned area, biomass density, combustion factor and emission factor for each land cover type using several satellite data such as MODIS burned area, Pantropical National Level Carbon Stock Dataset, as well as Vegetation Condition Index. The greenhouse gases emissions from land and forest fire in Indonesia during 2015 were (in Gg) 806,406 CO2, 8,002 CH4, 96 N2O, while pollutants emissions were (in Gg) 85,268 CO, 1,168 NOx, 340 SO2, 3,093 NMVOC, 1,041 NH3, 259 BC, 1,957 OC, 4,118 PM2.5 and 5,468 PM10. September was the peak of fire season that generate 58% (species average) of total emissions for this year. The largest contribution was from shrubland/savanna burning which account for 66% (species average) of the total emissions, while about 81% of the total emissions were generated from peatland fire. The results of this study emphasizethe importance of proper peatland management in Indonesia as land and forest fire countermeasures strategy.

  12. Organic Pollutants in Shale Gas Flowback and Produced Waters: Identification, Potential Ecological Impact, and Implications for Treatment Strategies.

    Science.gov (United States)

    Butkovskyi, Andrii; Bruning, Harry; Kools, Stefan A E; Rijnaarts, Huub H M; Van Wezel, Annemarie P

    2017-05-02

    Organic contaminants in shale gas flowback and produced water (FPW) are traditionally expressed as total organic carbon (TOC) or chemical oxygen demand (COD), though these parameters do not provide information on the toxicity and environmental fate of individual components. This review addresses identification of individual organic contaminants in FPW, and stresses the gaps in the knowledge on FPW composition that exist so far. Furthermore, the risk quotient approach was applied to predict the toxicity of the quantified organic compounds for fresh water organisms in recipient surface waters. This resulted in an identification of a number of FPW related organic compounds that are potentially harmful namely those compounds originating from shale formations (e.g., polycyclic aromatic hydrocarbons, phthalates), fracturing fluids (e.g., quaternary ammonium biocides, 2-butoxyethanol) and downhole transformations of organic compounds (e.g., carbon disulfide, halogenated organic compounds). Removal of these compounds by FPW treatment processes is reviewed and potential and efficient abatement strategies are defined.

  13. Vertically stacked nanocellulose tactile sensor.

    Science.gov (United States)

    Jung, Minhyun; Kim, Kyungkwan; Kim, Bumjin; Lee, Kwang-Jae; Kang, Jae-Wook; Jeon, Sanghun

    2017-11-16

    Paper-based electronic devices are attracting considerable attention, because the paper platform has unique attributes such as flexibility and eco-friendliness. Here we report on what is claimed to be the firstly fully integrated vertically-stacked nanocellulose-based tactile sensor, which is capable of simultaneously sensing temperature and pressure. The pressure and temperature sensors are operated using different principles and are stacked vertically, thereby minimizing the interference effect. For the pressure sensor, which utilizes the piezoresistance principle under pressure, the conducting electrode was inkjet printed on the TEMPO-oxidized-nanocellulose patterned with micro-sized pyramids, and the counter electrode was placed on the nanocellulose film. The pressure sensor has a high sensitivity over a wide range (500 Pa-3 kPa) and a high durability of 10 4 loading/unloading cycles. The temperature sensor combines various materials such as poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT:PSS), silver nanoparticles (AgNPs) and carbon nanotubes (CNTs) to form a thermocouple on the upper nanocellulose layer. The thermoelectric-based temperature sensors generate a thermoelectric voltage output of 1.7 mV for a temperature difference of 125 K. Our 5 × 5 tactile sensor arrays show a fast response, negligible interference, and durable sensing performance.

  14. 40 CFR 60.1795 - May I conduct stack testing less often?

    Science.gov (United States)

    2010-07-01

    ... Times for Small Municipal Waste Combustion Units Constructed on or Before August 30, 1999 Model Rule... or operate a Class II municipal waste combustion unit and if all stack tests for a given pollutant..., hydrogen chloride, and fugitive ash. (b) You can test less often for dioxins/furans emissions if you own or...

  15. 40 CFR 60.1305 - May I conduct stack testing less often?

    Science.gov (United States)

    2010-07-01

    ... Municipal Waste Combustion Units for Which Construction is Commenced After August 30, 1999 or for Which... combustion unit and if all stack tests for a given pollutant over 3 consecutive years show you comply with...: dioxins/furans, cadmium, lead, mercury, particulate matter, opacity, hydrogen chloride, and fugitive ash...

  16. 40 CFR 60.1300 - What test methods must I use to stack test?

    Science.gov (United States)

    2010-07-01

    ...) to calculate emission levels at 7 percent oxygen (or an equivalent carbon dioxide basis), the percent... subpart. (c) Obtain an oxygen (or carbon dioxide) measurement at the same time as your pollutant... 40 Protection of Environment 6 2010-07-01 2010-07-01 false What test methods must I use to stack...

  17. A Study of Pollutant Formation from the Lean Premixed Combustion of Gaseous Fuel Alternatives to Natural Gas

    Science.gov (United States)

    Fackler, Keith Boyd, Jr.

    The goal of this research is to identify how nitrogen oxide (NO x) emissions and flame stability (blowout) are impacted by the use of fuels that are alternatives to typical pipeline natural gas. The research focuses on lean, premixed combustors that are typically used in state-of-the-art natural gas fueled systems. An idealized laboratory lean premixed combustor, specifically the jet-stirred reactor, is used for experimental data. A series of models, including those featuring detailed fluid dynamics and those focusing on detailed chemistry, are used to interpret the data and understand the underlying chemical kinetic reasons for differences in emissions between the various fuel blends. An ultimate goal is to use these data and interpretive tools to develop a way to predict the emission and stability impacts of changing fuels within practical combustors. All experimental results are obtained from a high intensity, single-jet stirred reactor (JSR). Five fuel categories are studied: (1) pure H 2, (2) process and refinery gas, including combinations of H2, CH4, C2H6, and C3H8, (3) oxygen blown gasified coal/petcoke composed of H2, CO, and CO2, (4) landfill and digester gas composed of CH4, CO2, and N2, and (5) liquified natural gas (LNG)/shale/associated gases composed of CH4, C2H6, and C3 H8. NOx measurements are taken at a nominal combustion temperature of 1800 K, atmospheric pressure, and a reactor residence time of 3 ms. This is done to focus the results on differences caused by fuel chemistry by comparing all fuels at a common temperature, pressure, and residence time. This is one of the few studies in the literature that attempts to remove these effects when studying fuels varying in composition. Additionally, the effects of changing temperature and residence time are investigated for selected fuels. At the nominal temperature and residence time, the experimental and modeling results show the following trends for NOx emissions as a function of fuel type: 1.) NOx

  18. A novel approach to produce road-level inventories of on-road greenhouse gas and air pollutant emissions

    Science.gov (United States)

    Powell, J.; Butenhoff, C. L.

    2015-12-01

    Emissions inventories are an important tool often built by governments tomanage and assess greenhouse gases and other air pollutants. High resolutioninventories, both in space and time, are necessary to capture localcharacteristics of on-road transportation emissions in particular. Emissionsvary widely due to the local nature of the fleet, fuel, and roads and thisheterogeneity must inform effective emissions modeling on the urban level. Inaddition, widespread availability of low-cost computing now makes highresolution climate and air quality modeling feasible, but efforts to improveinventories have not kept pace. There currently is a lack of inventories atcomparable resolutions. This motivated similar work such as the VULCAN projectwhich used county-level data to estimate on-road emissions. We are motivatedto improve upon this by using site-level traffic count data where available.Here we show a new high resolution model of CO2 emissions for the Portland,OR metropolitan region. The backbone is an archive of traffic counterrecordings taken by the Portland Bureau of Transportation intermittently at9,352 sites over 21 years and continuing today (1986-2006 data are summarizedhere) and by The Portland Regional Transportation Archive Listing at 309freeway sites. We constructed a regression model to fill in traffic networkgaps using GIS data such as road class and population density. After stepwisetesting of each of eighteen road classes (from minor streets to freeway), wewere able to select ten variables that are significant (P < 0.001) predictorsof traffic; particularly freeway, unimproved road, and minor streets. Themodel was tested by holding back one-third of the data. The R2 for the linearmodel (based on road class and land use) is 0.84. The EPA MOVES model was thenused to estimate transportation CO2 emissions using local fleet, traffic, andmeteorology data.

  19. Trace gas composition in the free and upper troposphere over Asia: Examining the influence of long-range transport and convection of local pollution

    Science.gov (United States)

    Baker, A. K.; Traud, S.; Brenninkmeijer, C. A.; Hoor, P. M.; Neumaier, M.; Oram, D.; Rauthe-Schöch, A.; Schloegl, S.; Sprung, D.; Slemr, F.; van Velthoven, P.; Wernli, H.; Zahn, A.; Ziereis, H.

    2013-12-01

    Between May 2005 and March 2008 the CARIBIC observatory (Civil Aircraft for the Regular Investigation of the atmosphere Based on an Instrument Container) was deployed to make atmospheric observations during 21 round-trip flights between Frankfurt, Germany and Manila, the Philippines with a stopover in Guangzhou, China. This nearly 3 year flight series provides us with information about atmospheric composition in the free and upper troposphere over Asia during all seasons and was used to investigate seasonal and regional differences in trace gas distributions and the relative influences of long range transport and convected local air masses on composition. The flight route was separated into three different regions having unique characteristics in transport and composition; these were Western Asia (5°E to 70°E), Central Asia (70°E to 100°E) and East Asia (100°E to 125°E). The region over Western Asia was heavily influenced by long range transport of air masses from North America and had elevated levels of NOy and acetone, while the region over East Asia was mostly influenced by convected local (South East Asian) pollution, particularly from biomass/biofuel burning as indicated by high levels of acetonitrile and carbon monoxide. Air masses over Central Asia were found to be influenced by both recently convected air masses from the Indian subcontinent and mid-range transport from Eastern Europe and the Middle East. Elevated levels of propane and other non-methane hydrocarbons, both with and without concommitant elevations in other trace gases (i.e. carbon monoxide, acetonitrile) were a persisent feature of this region in all seasons except summer, and were particularly prominent in fall. Influences on composition over Central Asia were investigated more thoroughly in a case study from a series of flights in October 2006, and elevated levels of pollutants were found to be the result of convective transport of both biomass/biofuel burning and urban emissions from

  20. Generalized data stacking programming model with applications

    Directory of Open Access Journals (Sweden)

    Hala Samir Elhadidy

    2016-09-01

    Full Text Available Recent researches have shown that, everywhere in various sciences the systems are following stacked-based stored change behavior when subjected to events or varying environments “on and above” their normal situations. This paper presents a generalized data stack programming (GDSP model which is developed to describe the system changes under varying environment. These changes which are captured with different ways such as sensor reading are stored in matrices. Extraction algorithm and identification technique are proposed to extract the different layers between images and identify the stack class the object follows; respectively. The general multi-stacking network is presented including the interaction between various stack-based layering of some applications. The experiments prove that the concept of stack matrix gives average accuracy of 99.45%.

  1. Relationship between catalytic activity and gas-phase pollution fractions in the catalyst in DIR-MCFC. Reactivation method of polluted catalyst by vapor-phase carbonate; DIR-MCFC ni okeru shokubai kassei to shokubaichu no kiso osendo tono kankei. Kiso osen shokubai no saiseiho

    Energy Technology Data Exchange (ETDEWEB)

    Sugiura, K. [Osaka Prefectural College of Technology, Osaka (Japan); Naruse, I. [Toyohashi University of Technology, Aichi (Japan)

    2000-01-25

    In Direct Internal Reforming Molten Carbonate Fuel Cells (DIR-MCFC) deterioration of catalytic activity takes place in the anode channel due to both the liquid-phase pollution and vapor-phase pollution. The liquid-phase pollution meant that catalytic activity is deteriorated by the molten salt's (62 Li{sub 2}CO{sub 3}/38 K{sub 2}CO{sub 3}) adhering to the catalyst. It can be solved by installing the protective barrier in the pollutant pathway. On the other band, the vapor-phase pollution meant that that catalytic activity is deteriorated by KOH adhering to the catalyst. Because the vapor-phase pollution is caused in the entire electrode, an effective defense method has not established yet. Moreover, a reactivation method of vapor-phase polluted catalyst has not been developed yet. In order to study the reactivation method, the adhesion form of potassium compounds in the polluted catalyst under the various gas conditions was evaluated by using a thermogravimetric analyzer in which water vapor can feed. Additionally, the activity of catalyst treated demonstratively was also tested by a differential reactor. As a result, KOH changes to K{sub 2}CO{sub 3} under the condition which CO{sub 2} concentration is larger than 25%. The catalyst with K{sub 2}CO{sub 3} cannot reactive. However., the activity of polluted catalyst is revived until 80% of initial activity by controlling the gas species concentration, especially for CO{sub 2}. Based on the results obtained by these fundamental experiments, the reactivation methods of polluted catalyst are proposed as follows; (1) Catalyst should load more in the upstream in the anode. (2) In order to reactive the polluted catalyst, the ratio of H{sub 2}O to CH{sub 4} in the fuel should increase, when DIR-MCFC is under operation. (3) Gas compositions under cell maintenance mode should be applied in the case that power generation quits. (author)

  2. Flexural characteristics of a stack leg

    International Nuclear Information System (INIS)

    Cook, J.

    1979-06-01

    A 30 MV tandem Van de Graaff accelerator is at present under construction at Daresbury Laboratory. The insulating stack of the machine is of modular construction, each module being 860 mm in length. Each live section stack module contains 8 insulating legs mounted between bulkhead rings. The design, fabrication (from glass discs bonded to stainless steel discs using an epoxy film adhesive) and testing of the stack legs is described. (U.K.)

  3. Hydrogen Embrittlement And Stacking-Fault Energies

    Science.gov (United States)

    Parr, R. A.; Johnson, M. H.; Davis, J. H.; Oh, T. K.

    1988-01-01

    Embrittlement in Ni/Cu alloys appears related to stacking-fault porbabilities. Report describes attempt to show a correlation between stacking-fault energy of different Ni/Cu alloys and susceptibility to hydrogen embrittlement. Correlation could lead to more fundamental understanding and method of predicting susceptibility of given Ni/Cu alloy form stacking-fault energies calculated from X-ray diffraction measurements.

  4. An aircraft gas chromatograph-mass spectrometer System for Organic Fast Identification Analysis (SOFIA): design, performance and a case study of Asian monsoon pollution outflow

    Science.gov (United States)

    Bourtsoukidis, Efstratios; Helleis, Frank; Tomsche, Laura; Fischer, Horst; Hofmann, Rolf; Lelieveld, Jos; Williams, Jonathan

    2017-12-01

    Volatile organic compounds (VOCs) are important for global air quality and oxidation processes in the troposphere. In addition to ground-based measurements, the chemical evolution of such species during transport can be studied by performing in situ airborne measurements. Generally, aircraft instrumentation needs to be sensitive, robust and sample at higher frequency than ground-based systems while their construction must comply with rigorous mechanical and electrical safety standards. Here, we present a new System for Organic Fast Identification Analysis (SOFIA), which is a custom-built fast gas chromatography-mass spectrometry (GC-MS) system with a time resolution of 2-3 min and the ability to quantify atmospheric mixing ratios of halocarbons (e.g. chloromethanes), hydrocarbons (e.g isoprene), oxygenated VOCs (acetone, propanal, butanone) and aromatics (e.g. benzene, toluene) from sub-ppt to ppb levels. The relatively high time resolution is the result of a novel cryogenic pre-concentration unit which rapidly cools (˜ 6 °C s-1) the sample enrichment traps to -140 °C, and a new chromatographic oven designed for rapid cooling rates (˜ 30 °C s-1) and subsequent thermal stabilization. SOFIA was installed in the High Altitude and Long Range Research Aircraft (HALO) for the Oxidation Mechanism Observations (OMO) campaign in August 2015, aimed at investigating the Asian monsoon pollution outflow in the tropical upper troposphere. In addition to a comprehensive instrument characterization we present an example monsoon plume crossing flight as a case study to demonstrate the instrument capability. Hydrocarbon, halocarbon and oxygenated VOC data from SOFIA are compared with mixing ratios of carbon monoxide (CO) and methane (CH4), used to define the pollution plume. By using excess (ExMR) and normalized excess mixing ratios (NEMRs) the pollution could be attributed to two air masses of distinctly different origin, identified by back-trajectory analysis. This work

  5. Deployment Considerations for Low-cost Air Quality Sensor Networks; Examining Spatial Variability of Gas-Phase Pollutants Around a Building in Los Angeles

    Science.gov (United States)

    Collier-Oxandale, A. M.; Hannigan, M.; Casey, J. G.; Johnston, J.; Coffey, E.; Thorson, J.

    2017-12-01

    The field of low-cost air quality sensing technologies is growing rapidly through the continual development of new sensors, increased research into sensor performance, and more and more community groups utilizing sensors to investigate local issues. However, as this technology is still in an exploratory phase, there are few `best-practices' available to serve as guidelines for these projects and the standardization of some procedures could benefit the research community as a whole. For example, deployment considerations such as where and how to place a monitor at a given location are often determined by accessibility and safety, power-requirements, and what is an ideal for sampling the target pollutant. Using data from multiple gas-phase sensors, we will examine the importance of siting considerations for low-cost monitoring systems. During a sampling campaign in Los Angeles, a subset of monitors was deployed at one field site to explore the variability in air quality sensor data around a single building. The site is a three story, multi-family housing unit in a primarily residential neighborhood that is near two major roadways and other potential sources of pollution. Five low-cost monitors were co-located prior to and following the field deployment. During the approximately 2.5-month deployment, these monitors were placed at various heights above street level, on different sides of the building, and on the roof. In our analysis, we will examine how monitor placement affects a sensor's ability to detect local verses more regional trends and how this building-scale spatial variability changes over time. Additionally, examining data from VOC sensors (quantified for methane and total non-methane hydrocarbon signals) and O3 sensors will allow us to compare the variability of primary and secondary pollutants. An outcome of this analysis may include guidelines or `best practices' for siting sensors that could aid in ensuring the collection of high quality field data

  6. Comparative study of regulated and unregulated air pollutant emissions before and after conversion of automobiles from gasoline power to liquefied petroleum gas/gasoline dual-fuel retrofits.

    Science.gov (United States)

    Yang, Hsi-Hsien; Chien, Shu-Mei; Cheng, Man-Ting; Peng, Chiung-Yu

    2007-12-15

    Liquefied petroleum gas (LPG) is increasingly being examined as an alternative to gasoline use in automobiles as interest grows in reducing air pollutant emissions. In this study, emissions of regulated (CO, THC, NO(x)) and unregulated air pollutants, including CO2, particulate matter (PM), polycyclic aromatic hydrocarbons (PAHs), and BTEX (acronym for benzene, toluene, ethylbenzene, xylene), were measured before and after conversion of nine gasoline-powered automobiles to LPG/ gasoline dual-fuel retrofits. The tests were conducted on a standard chassis dynamometer in accordance with the United States Environmental Protection Agency FTP-75 test procedure, with the exception that all tests were conducted under hot-start driving conditions. The influences of LPG on air pollutant emission levels and carcinogenic potency were investigated and compared with gasoline. The results showed average emission factors of 0.14 g/km, 0.33 mg/km, 0.09 g/km, 0.44 g/km, and 197 g/km for CO, THC, NO(x), PM, and CO2, respectively, for LPG/ gasoline dual-fuel retrofits. Paired-sample t-test results indicated that the emissions of CO (p = 0.03), THC (p = 0.04), and CO2 (p = 4.6 x 10(-8)) were significantly reduced with the retrofit in comparison with gasoline-powered automobiles. The reduction percentages were 71%, 89%, and 14% for CO, THC, and CO2, respectively. The average total PAH emission factor for LPG was 217 microg/km, which is significantly lower than gasoline (863 microg/km; p = 0.05). The PAH corresponding carcinogenicities (BaP(eq)) were calculated via toxic equivalencies based on benzo(a)pyrene (BaP). Paired-sample t-test results fortotal BaP(eq) emissions showed no significant difference between gasoline (30.0 microg/km) and LPG (24.8 microg/km) at a confidence level of 95%. The discrepancy between PAH and BaP(eq) emissions resulted from the higher emission percentages of high molecular weight PAHs for LPG, which might be from lubricant oil. The average emission factors of

  7. An aircraft gas chromatograph–mass spectrometer System for Organic Fast Identification Analysis (SOFIA: design, performance and a case study of Asian monsoon pollution outflow

    Directory of Open Access Journals (Sweden)

    E. Bourtsoukidis

    2017-12-01

    Full Text Available Volatile organic compounds (VOCs are important for global air quality and oxidation processes in the troposphere. In addition to ground-based measurements, the chemical evolution of such species during transport can be studied by performing in situ airborne measurements. Generally, aircraft instrumentation needs to be sensitive, robust and sample at higher frequency than ground-based systems while their construction must comply with rigorous mechanical and electrical safety standards. Here, we present a new System for Organic Fast Identification Analysis (SOFIA, which is a custom-built fast gas chromatography–mass spectrometry (GC-MS system with a time resolution of 2–3 min and the ability to quantify atmospheric mixing ratios of halocarbons (e.g. chloromethanes, hydrocarbons (e.g isoprene, oxygenated VOCs (acetone, propanal, butanone and aromatics (e.g. benzene, toluene from sub-ppt to ppb levels. The relatively high time resolution is the result of a novel cryogenic pre-concentration unit which rapidly cools (∼ 6 °C s−1 the sample enrichment traps to −140 °C, and a new chromatographic oven designed for rapid cooling rates (∼ 30 °C s−1 and subsequent thermal stabilization. SOFIA was installed in the High Altitude and Long Range Research Aircraft (HALO for the Oxidation Mechanism Observations (OMO campaign in August 2015, aimed at investigating the Asian monsoon pollution outflow in the tropical upper troposphere. In addition to a comprehensive instrument characterization we present an example monsoon plume crossing flight as a case study to demonstrate the instrument capability. Hydrocarbon, halocarbon and oxygenated VOC data from SOFIA are compared with mixing ratios of carbon monoxide (CO and methane (CH4, used to define the pollution plume. By using excess (ExMR and normalized excess mixing ratios (NEMRs the pollution could be attributed to two air masses of distinctly different origin, identified by back

  8. Measurement of NO2 pollutant sorption of various trees, shrubs and ground cover plants using gas NO2 labelled 15N

    International Nuclear Information System (INIS)

    Nasrullah, Nizar; Wungkar, Marietje; Gunawan, Andi; Gandanegara, Soertini; Suharsono, Heny

    2000-01-01

    The objective of this study is to measure the NO 2 pollutant sorption of various trees, shrubs and ground cover plants. 32 species of trees, 64 speceis of shrubs and 13 species of ground cover plants were exposed to 3 ppm (v / v) N- 15 O 2 in a gas chamber for 60 minutes. Experiment consisted of 2 replicates. The environment conditions in the chamber were set at 30 o C, 1000 lux, and initial relative humidity 60 %. After gas treatment, plants parts were separated into leaves, stems and roots, than dried in 70 o C for 48 hours and then weighed. After weighing, those plants parts were ground to a pine powder. After kjendhal digestion, N total content of plants were analyzed by distillation method. 15 N content of plant samples were analyzed by emission spectrometer ( Yasco, N-151). The amount of N-15 absorbed by plant was the total content of 15 N in the whole plants ( leaves, stem and root ) per gram dry weight of leaves. The amount of 15 N absorbed by plants varied among investigated plants. 15 N sorption of trees are in the range 0.28 - 68.31μg/g. The sorption of shrubs and ground cover plants varied in 1.97 - 100.02 μg/g and 2.38 - 24.06μg/g, respectively. According to the amount of 15 N sorption , the plants were divided into 3 groups of sorption level, high ( > 30.0μg/g), moderate ( 15 - 30 μg/g ), and low sorption level ( 15 μg/g). Results showed that among of 32 investigated trees, 64 shrubs and 13 ground cover plant, 4 species of trees and 13 species of shrubs performed a high sorption level and no one of ground cover plants performed a high sorption level. The species of trees and 15 species of shrubs that mention above are recommended to use as an element of landscape which to be functioned to reduce NO 2 atmospheric pollutant

  9. Cu-Ni nanowire-based TiO{sub 2} hybrid for the dynamic photodegradation of acetaldehyde gas pollutant under visible light

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Shuying [Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050 (China); University of Chinese Academy of Sciences, 19 Yuquan Road, Beijing 100049 (China); Xie, Xiaofeng, E-mail: xxfshcn@163.com [Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050 (China); Chen, Sheng-Chieh [College of Science and Engineering, University of Minnesota, Minneapolis, MN 55455 (United States); Tong, Shengrui [Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190 (China); Lu, Guanhong [Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050 (China); Pui, David Y.H. [College of Science and Engineering, University of Minnesota, Minneapolis, MN 55455 (United States); Sun, Jing [Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050 (China)

    2017-06-30

    Graphical abstract: One-dimensional Cu-Ni bimetallic nanowires were introduced into TiO{sub 2}-based matrix to enhance their photocatalysis efficiency and expand their light absorption range. - Highlights: • Cu-Ni nanowire-based TiO{sub 2} hybrid photocatalyst. • One-dimensional electron pathways and surface plasmon resonance effects. • Dynamic photodegradation of acetaldehyde gas pollutant. - Abstract: One-dimensional bimetallic nanowires were introduced into TiO{sub 2}-based matrix to enhance their photocatalysis efficiency and expand their light absorption range in this work. Recently, metal nanowires have attracted many attention in photocatalyst research fields because of their favorable electronic transmission properties and especially in the aspect of surface plasmon resonance effects. Moreover, Cu-Ni bimetallic nanowires (Cu-Ni NWs) have shown better chemical stability than ordinary monometallic nanowires in our recent works. Interestingly, it has been found that Ni sleeves of the bimetallic nanowires also can modify the Schottky barrier of interface between TiO{sub 2} and metallic conductor, so that be beneficial to the separation of photogenerated carriers in the Cu-Ni/TiO{sub 2} network topology. Hence, a novel heterostructured photocatalyst composed of Cu-Ni NWs and TiO{sub 2} nanoparticles (NPs) was fabricated by one-step hydrolysis approach to explore its photocatalytic performance. TEM and EDX mapping images of this TiO{sub 2} NPs @Cu-Ni NWs (TCN) hybrid displayed that Cu-Ni NWs were wrapped by compact TiO{sub 2} layer and retained the one-dimensional structure in matrix. In experiments, the photocatalytic performance of the TCN nanocomposite was significantly enhanced comparing to pure TiO{sub 2}. Acetaldehyde, as a common gas pollutant in the environment, was employed to evaluate the photodegradation efficiency of a series of TCN nanocomposites under continuous feeding. The TCN exhibited excellent potodegradation performance, where the

  10. Atmospheric pollution; Pollution atmospherique

    Energy Technology Data Exchange (ETDEWEB)

    Lambrozo, J.; Guillossou, G. [EDF-Gas de France, Service des Etudes Medicales, 75 - Paris (France)

    2008-10-15

    The atmosphere is the reservoir of numerous pollutants (nitrogen oxides, sulfur oxides, carbon oxides, particulates, volatile organic compounds, polycyclic aromatic hydrocarbons) from natural origin or anthropogenic origin ( industry, transport, agriculture, district heating). With epidemiologic studies the atmospheric pollution is associated with an increase of respiratory and cardiovascular diseases. At the european level, the technological progress, the legislation have allowed a reduction of pollutant emissions, however these efforts have to be continued because the sanitary impact of atmospheric pollution must not be underestimated, even if the risks appear less important that these ones in relation with tobacco, inside pollution or others factors of cardiovascular risks. Indeed, on these last factors an individual action is possible for the exposure to air pollution people have no control. (N.C.)

  11. Microbes a Tool for the Remediation of Organotin Pollution Determined by Static Headspace Gas Chromatography-Mass Spectrometry

    Directory of Open Access Journals (Sweden)

    Christopher Finnegan

    2018-03-01

    Full Text Available Tributyltin (TBT is one of the most toxic anthropogenic compounds introduced into the marine environment. Despite its global ban in 2008, TBT is still a problem of great concern due to its high affinity for particulate matter, providing a direct and potentially persistent route of entry into benthic sediments. Bioremediation strategies may constitute an alternative approach to conventional physicochemical methods, benefiting from the microorganism’s potential to metabolize anthropogenic compounds. In this work, a simple, precise and accurate static headspace gas chromatography method was developed to investigate the ability of TBT degrading microbes in sedimentary microcosms over a period of 120 days. The proposed method was validated for linearity, repeatability, accuracy, specificity, limit of detection and limit of quantification. The method was subsequently successfully applied for the detection and quantification of TBT and degradation compounds in sediment samples on day 0, 30, 60, 90 and 120 of the experiment employing the principles of green chemistry. On day 120 the concentration of TBT remaining in the microcosms ranged between 91.91 ng/g wet wt for the least effective microbial inoculant to 52.73 ng/g wet wt for the most effective microbial inoculant from a starting concentration of 100 ng/g wet wt.

  12. Determining the Levels of Volatile Organic Pollutants in Urban Air Using a Gas Chromatography-Mass Spectrometry Method

    Directory of Open Access Journals (Sweden)

    Simona Nicoara

    2009-01-01

    Full Text Available The paper presents the application of a method based on coupled gas chromatography-mass spectrometry, using an isotopically labelled internal standard for the quantitative analysis of benzene (B, toluene (T, ethyl benzene (E, and o-, m-, p-xylenes (X. Their atmospheric concentrations were determined based on short-term sampling, in different sites of Cluj-Napoca, a highly populated urban centre in N-W Romania, with numerous and diversified road vehicles with internal combustion engines. The method is relatively inexpensive and simple and shows good precision and linearity in the ranges of 7–60 μg/m3 (B, 13–90 μg/m3 (T, 7–50 μg/m3 (E, 10–70 μg/m3 (X-m,p, and 20–130 μg/m3 (X-o. The limits of quantitation/detection of the method LOQ/LOD are of 10/5 μg/m3 (Xo, 5/3 μg/m3 (B, E, X-m,p, and of 3/1 μg/m3 (T, respectively.

  13. Stacks of SPS Dipole Magnets

    CERN Multimedia

    1974-01-01

    Stacks of SPS Dipole Magnets ready for installation in the tunnel. The SPS uses a separated function lattice with dipoles for bending and quadrupoles for focusing. The 6.2 m long normal conducting dipoles are of H-type with coils that are bent-up at the ends. There are two types, B1 (total of 360) and B2 (384). Both are for a maximum field of 1.8 Tesla and have the same outer dimensions (450x800 mm2 vxh) but with different gaps (B1: 39x129 mm2, B2: 52x92 mm2) tailored to the beam size. The yoke, made of 1.5 mm thick laminations, consists of an upper and a lower half joined together in the median plane once the coils have been inserted.

  14. California dreaming?[PEM stacks

    Energy Technology Data Exchange (ETDEWEB)

    Crosse, J.

    2002-06-01

    Hyundai's Santa Fe FCEV will be on sale by the end of 2002. Hyundai uses PEM stacks that are manufactured by International Fuel Cells (IFC), a division of United Technologies. Santa Fe is equipped with a 65 kW electric powertrain of Enova systems and Shell's new gasoline reformer called Hydrogen Source. Eugene Jang, Senior Engineer - Fuel Cell and Materials at Hyundai stated that the compressor related losses on IFC system are below 3%. The maximum speed offered by the vehicle is estimated as 123km/hr while the petrol equivalent fuel consumption is quoted between 5.6L/100 km and 4.8L/100 km. Santa Fe is a compact vehicle offering better steering response and a pleasant drive. (author)

  15. Stack Flow Rate Changes and the ANSI/N13.1-1999 Qualification Criteria: Application to the Hanford Canister Storage Building Stack

    Energy Technology Data Exchange (ETDEWEB)

    Flaherty, Julia E. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Glissmeyer, John A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2016-02-29

    The Canister Storage Building (CSB), located in the 200-East Area of the Hanford Site, is a 42,000 square foot facility used to store spent nuclear fuel from past activities at the Hanford Site. Because the facility has the potential to emit radionuclides into the environment, its ventilation exhaust stack has been equipped with an air monitoring system. Subpart H of the National Emissions Standards for Hazardous Air Pollutants requires that a sampling probe be located in the exhaust stack in accordance with criteria established by the American National Standards Institute/Health Physics Society Standard N13.1-1999, Sampling and Monitoring Releases of Airborne Radioactive Substances from the Stack and Ducts of Nuclear Facilities.

  16. Development of internal manifold heat exchanger (IMHEX reg sign ) molten carbonate fuel cell stacks

    Energy Technology Data Exchange (ETDEWEB)

    Marianowski, L.G.; Ong, E.T.; Petri, R.J.; Remick, R.J.

    1991-01-01

    The Institute of Gas Technology (IGT) has been in the forefront of molten carbonate fuel cell (MCFC) development for over 25 years. Numerous cell designs have been tested and extensive tests have been performed on a variety of gas manifolding alternatives for cells and stacks. Based upon the results of these performance tests, IGT's development efforts started focusing on an internal gas manifolding concept. This work, initiated in 1988, is known today as the IMHEX{reg sign} concept. MCP has developed a comprehensive commercialization program loading to the sale of commercial units in 1996. MCP's role is in the manufacture of stack components, stack assembly, MCFC subsystem testing, and the design, marketing and construction of MCFC power plants. Numerous subscale (1 ft{sup 2}) stacks have been operated containing between 3 and 70 cells. These tests verified and demonstrated the viability of internal manifolding from technical (no carbonate pumping), engineering (relaxed part dimensional tolerance requirements), and operational (good gas sealing) aspects. Simplified fabrication, ease of assembly, the elimination of external manifolds and all associated clamping requirements has significantly lowered anticipated stack costs. Ongoing 1 ft{sup 2} stack testing is generating performance and endurance characteristics as a function of system specified operating conditions. Commercial-sized, full-area stacks (10 ft{sup 2}) are in the process of being assembled and will be tested in November. This paper will review the recent developments the MCFC scale-up and manufacture work of MCP, and the research and development efforts of IGT which support those efforts. 17 figs.

  17. Study on component interface evolution of a solid oxide fuel cell stack after long term operation

    Science.gov (United States)

    Yang, Jiajun; Huang, Wei; Wang, Xiaochun; Li, Jun; Yan, Dong; Pu, Jian; Chi, Bo; Li, Jian

    2018-05-01

    A 5-cell solid oxide fuel cell (SOFC) stack with external manifold structure is assembled and underwent a durability test with an output of 250 W for nearly 4400 h when current density and operating temperature are 355 mA/cm2 and 750 °C. Cells used in the stack are anode-supported cells (ASC) with yttria-stabilized zirconia (YSZ) electrolytes, Ni/YSZ hydrogen electrodes, and YSZ based composite cathode. The dimension of the cell is 150 × 150 mm (active area: 130 × 130 mm). Ceramic-glass sealant is used in the stack to keep the gas tightness between cells, interconnects and manifolds. Pure hydrogen and dry air are used as fuel and oxidant respectively. The stack has a maximum output of 340 W at 562 mA/cm2 current density at 750 °C. The stack shows a degradation of 1.5% per 1000 h during the test with 2 thermal cycles to room temperature. After the test, the stack was dissembled and examined. The relationship between microstructure changes of interfaces and degradation in the stack are discussed. The microstructure evolution of interfaces between electrode, contact material and current collector are unveiled and their relationship with the degradation is discussed.

  18. Stacking technology for a space constrained microsystem

    DEFF Research Database (Denmark)

    Heschel, Matthias; Kuhmann, Jochen Friedrich; Bouwstra, Siebe

    1998-01-01

    In this paper we present a stacking technology for an integrated packaging of an intelligent transducer which is formed by a micromachined silicon transducer and an integrated circuit chip. Transducer and circuitry are stacked on top of each other with an intermediate chip in between. The bonding...

  19. Vector Fields and Flows on Differentiable Stacks

    DEFF Research Database (Denmark)

    A. Hepworth, Richard

    2009-01-01

    This paper introduces the notions of vector field and flow on a general differentiable stack. Our main theorem states that the flow of a vector field on a compact proper differentiable stack exists and is unique up to a uniquely determined 2-cell. This extends the usual result on the existence...... of vector fields....

  20. 40 CFR 61.44 - Stack sampling.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 8 2010-07-01 2010-07-01 false Stack sampling. 61.44 Section 61.44 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) NATIONAL... Firing § 61.44 Stack sampling. (a) Sources subject to § 61.42(b) shall be continuously sampled, during...

  1. Learning OpenStack networking (Neutron)

    CERN Document Server

    Denton, James

    2014-01-01

    If you are an OpenStack-based cloud operator with experience in OpenStack Compute and nova-network but are new to Neutron networking, then this book is for you. Some networking experience is recommended, and a physical network infrastructure is required to provide connectivity to instances and other network resources configured in the book.

  2. Project W-420 stack monitoring system upgrades

    International Nuclear Information System (INIS)

    CARPENTER, K.E.

    1999-01-01

    This project will execute the design, procurement, construction, startup, and turnover activities for upgrades to the stack monitoring system on selected Tank Waste Remediation System (TWRS) ventilation systems. In this plan, the technical, schedule, and cost baselines are identified, and the roles and responsibilities of project participants are defined for managing the Stack Monitoring System Upgrades, Project W-420

  3. On the "stacking fault" in copper

    NARCIS (Netherlands)

    Fransens, J.R.; Pleiter, F

    2003-01-01

    The results of a perturbed gamma-gamma angular correlations experiment on In-111 implanted into a properly cut single crystal of copper show that the defect known in the literature as "stacking fault" is not a planar faulted loop but a stacking fault tetrahedron with a size of 10-50 Angstrom.

  4. A method to estimate emission rates from industrial stacks based on neural networks.

    Science.gov (United States)

    Olcese, Luis E; Toselli, Beatriz M

    2004-11-01

    This paper presents a technique based on artificial neural networks (ANN) to estimate pollutant rates of emission from industrial stacks, on the basis of pollutant concentrations measured on the ground. The ANN is trained on data generated by the ISCST3 model, widely accepted for evaluation of dispersion of primary pollutants as a part of an environmental impact study. Simulations using theoretical values and comparison with field data are done, obtaining good results in both cases at predicting emission rates. The application of this technique would allow the local environment authority to control emissions from industrial plants without need of performing direct measurements inside the plant. copyright 2004 Elsevier Ltd.

  5. The importance of building downwash in assessing the need to heighten stacks of existing small and medium sized industries

    Energy Technology Data Exchange (ETDEWEB)

    Gomes, J.F.P. [Centro de Tecnologias Ambientais, ISQ - Inst. de Soldadura e Qualidade, Oeiras (Portugal); Duarte, R. [Escola Superior de Tecnologia - Inst. Politecnico de Setubal (Portugal)

    2004-07-01

    This extended abstract intends to share the authors experience on the modelling of atmospheric pollutant dispersal and on the importance of building downwash considerations when assessing the need to heighten stacks of small and medium sized industrial enterprises (SME's). In order to understand the reasons that make industrial companies, especially SME's, consider stack heightening, in section 2 the existing Portuguese legislation on air quality and the stack heightening rules are briefly commented. New legislation that ought to appear soon (new Portuguese Air Act) is also commented and compared critically with the existing one. Then, section 3 characterizes Portuguese industry in terms of the ambient quality problems related to stack height. The adequacy of the stack heightening legislation to the particularities of the Portuguese case is discussed. In section 4 the authors experience in the specific study of stack heightening is presented. The methodology considered in these studies is discussed and compared with the application of existing and soon to appear legislation on stack height calculation. Finally, section 5 presents the conclusions and the need for an increased awareness on the pollutant dispersal problem is discussed. (orig.)

  6. Status of MCFC stack technology at IHI

    Energy Technology Data Exchange (ETDEWEB)

    Hosaka, M.; Morita, T.; Matsuyama, T.; Otsubo, M. [Ishikawajima-Harima Heavy Industries Co., Ltd., Tokyo (Japan)

    1996-12-31

    The molten carbonate fuel cell (MCFC) is a promising option for highly efficient power generation possible to enlarge. IHI has been studying parallel flow MCFC stacks with internal manifolds that have a large electrode area of 1m{sup 2}. IHI will make two 250 kW stacks for MW plant, and has begun to make cell components for the plant. To improve the stability of stack, soft corrugated plate used in the separator has been developed, and a way of gathering current from stacks has been studied. The DC output potential of the plant being very high, the design of electric insulation will be very important. A 20 kW short stack test was conducted in 1995 FY to certificate some of the improvements and components of the MW plant. These activities are presented below.

  7. Oxidation behavior of metallic interconnect in solid oxide fuel cell stack

    Science.gov (United States)

    Li, Jun; Zhang, Wenying; Yang, Jiajun; Yan, Dong; Pu, Jian; Chi, Bo; Jian, Li

    2017-06-01

    Oxidation behavior of integrated interconnect with bipolar plate and corrugated sheet made by ferrite steel SUS430 is investigated and compared in simulated environment and in a realistic stack. Electrical current is found to have a direction-related impact on the thickness of the Cr2O3/MnCr2O4 composite oxide scale. Oxide scale of the interconnect aged in the stack exhibits a dual-layered structure of a complex Mn-Cr oxide layer covered by iron oxide. The oxidation rates vary greatly depending on its local environment, with different thermal, electrical density, as well as gas composition conditions. By analyzing the thickness distribution of oxide scale and comparing them with the simulated test result, the oxidation behavior of interconnect in stack is described in high definition. ASR distribution is also conducted by calculation, which could help further understanding the behavior of stack degradation.

  8. Device for equalizing molten electrolyte content in a fuel cell stack

    Science.gov (United States)

    Smith, J.L.

    1985-12-23

    A device for equalizing the molten electrolyte content throughout the height of a fuel cell stack is disclosed. The device includes a passageway for electrolyte return with electrolyte wettable wicking material in the opposite end portions of the passageway. One end portion is disposed near the upper, negative end of the stack where electrolyte flooding occurs. The second end portion is placed near the lower, positive end of the stack where electrolyte is depleted. Heating means are provided at the upper portion of the passageway to increase electrolyte vapor pressure in the upper wicking material. The vapor is condensed in the lower passageway portion and conducted as molten electrolyte in the lower wick to the positive end face of the stack. An inlet is provided to inject a modifying gas into the passageway and thereby control the rate of electrolyte return.

  9. Limestone/adipic acid FGD and stack opacity reduction pilot plant tests at Big Rivers

    Energy Technology Data Exchange (ETDEWEB)

    Laslo, D.; Bakke, E.; Chisholm, E.

    1984-01-01

    Big Rivers Electric Corporation (BREC) contracted Peabody Process Systems, Inc. (PPSI) to install a flue gas cleaning (FGC) pilot plant at the BREC R.D. Green Station Unit No. 2 located at Sebree, KY. A six month test program was completed demonstrating technology for: alternatives to using lime as an alkali; methods for improving cake dewatering; identification of the causes of high stack opacity; and methods for the reduction of high stack opacity. This paper presents highlights extracted from the reports submitted by PPSI to BREC on this test program. BREC was primarily interested in reduction of operating costs, if possible, by using an alkali less expensive than lime, and by improving the poor dewatering characteristic inherent in a dolomitic lime system. BREC was also within compliance for particulate emissions and opacity in the duct after the dry electrostatic precipitator, but not in compliance with the stack opacity regulation, and therefore wanted to investigate methods for stack opacity reduction.

  10. Health Risks Associated with Oil Pollution in the Niger Delta, Nigeria

    Directory of Open Access Journals (Sweden)

    Jerome Nriagu

    2016-03-01

    Full Text Available Background: Although there is considerable public concern about the environmental impacts of oil pollution in the Niger Delta of Nigeria, actual evidence on the pathological and psychological effects in the health of local communities is minimally known. We sought to associate the perspective measures of exposure to oil pollution with health outcomes (inventory of health symptoms and functional capacity limitations and determine how emotional reactions to environmental risks moderate these health outcomes. Method: The study was conducted with 600 participants selected from five local government areas in Akwa Ibom State where oil pollution is rampant. A structured questionnaire was used to collect the data on the respondents’ exposure to oil pollution, self-rated health and disease symptoms, perception of risk of exposure and emotional reactions to local oil pollution. Results: Most of the participants lived in areas with visible oil pollution and/or near gas flaring facilities and regularly suffered direct exposure to oil in their environment. High level of emotional distress was a part of everyone's life for the study population. Risk perception in the study area was mediated, to a large extent, by dreaded hazards (catastrophic fears of pipeline explosions and oil spill fire, visual cues (gas flares and smoke stacks and chemosensory cues (off-flavor in drinking water. The exposure metrics were found to be significant predictors of the health effects and influencing factors (emotional reactions. Multi-levels models suggest that at the individual level, the demographic variables and direct contact with oil pollution were important mediators of functional capacity limitation. At the community level, emotional distress from fear of the sources of exposure was an important mediator of the health symptoms. Conclusions: This study documents high levels of disease symptoms and environmental distress (worry, annoyance and intolerance associated with

  11. Emissions of toxic pollutants from compressed natural gas and low sulfur diesel-fueled heavy-duty transit buses tested over multiple driving cycles.

    Science.gov (United States)

    Kado, Norman Y; Okamoto, Robert A; Kuzmicky, Paul A; Kobayashi, Reiko; Ayala, Alberto; Gebel, Michael E; Rieger, Paul L; Maddox, Christine; Zafonte, Leo

    2005-10-01

    The number of heavy-duty vehicles using alternative fuels such as compressed natural gas (CNG) and new low-sulfur diesel fuel formulations and equipped with after-treatment devices are projected to increase. However, few peer-reviewed studies have characterized the emissions of particulate matter (PM) and other toxic compounds from these vehicles. In this study, chemical and biological analyses were used to characterize the identifiable toxic air pollutants emitted from both CNG and low-sulfur-diesel-fueled heavy-duty transit buses tested on a chassis dynamometer over three transient driving cycles and a steady-state cruise condition. The CNG bus had no after-treatment, and the diesel bus was tested first equipped with an oxidation catalyst (OC) and then with a catalyzed diesel particulate filter (DPF). Emissions were analyzed for PM, volatile organic compounds (VOCs; determined on-site), polycyclic aromatic hydrocarbons (PAHs), and mutagenic activity. The 2000 model year CNG-fueled vehicle had the highest emissions of 1,3-butadiene, benzene, and carbonyls (e.g., formaldehyde) of the three vehicle configurations tested in this study. The 1998 model year diesel bus equipped with an OC and fueled with low-sulfur diesel had the highest emission rates of PM and PAHs. The highest specific mutagenic activities (revertants/microg PM, or potency) and the highest mutagen emission rates (revertants/mi) were from the CNG bus in strain TA98 tested over the New York Bus (NYB) driving cycle. The 1998 model year diesel bus with DPF had the lowest VOCs, PAH, and mutagenic activity emission. In general, the NYB driving cycle had the highest emission rates (g/mi), and the Urban Dynamometer Driving Schedule (UDDS) had the lowest emission rates for all toxics tested over the three transient test cycles investigated. Also, transient emissions were, in general, higher than steady-state emissions. The emissions of toxic compounds from an in-use CNG transit bus (without an oxidation

  12. Combustion Noise and Pollutants Prediction for Injection Pattern and Exhaust Gas Recirculation Tuning in an Automotive Common-Rail Diesel Engine

    Directory of Open Access Journals (Sweden)

    Arsie Ivan

    2015-01-01

    Full Text Available In the last years, emissions standards for internal combustion engines are becoming more and more restrictive, particularly for NOx and soot emissions from Diesel engines. In order to comply with these requirements, OEMs have to face with innovative combustion concepts and/or sophisticate after-treatment devices. In both cases, the role of the Engine Management System (EMS is increasingly essential, following the large number of actuators and sensors introduced and the need to meet customer expectations on performance and comfort. On the other hand, the large number of control variables to be tuned imposes a massive recourse to the experimental testing which is poorly sustainable in terms of time and money. In order to reduce the experimental effort and the time to market, the application of simulation models for EMS calibration has become fundamental. Predictive models, validated against a limited amount of experimental data, allow performing detailed analysis on the influence of engine control variables on pollutants, comfort and performance. In this paper, a simulation analysis on the impact of injection pattern and Exhaust Gas Recirculation (EGR rate on fuel consumption, combustion noise, NO and soot emissions is presented for an automotive Common-Rail Diesel engine. Simulations are accomplished by means of a quasi-dimensional multi-zone model of in-cylinder processes. Furthermore a methodology for in-cylinder pressure processing is presented to estimate combustion noise contribution to radiated noise. Model validation is carried out by comparing simulated in-cylinder pressure traces and exhaust emissions with experimental data measured at the test bench in steady-state conditions. Effects of control variables on engine performance, noise and pollutants are analyzed by imposing significant deviation of EGR rate and injection pattern (i.e. rail pressure, start-of-injection, number of injections. The results evidence that quasi-dimensional in

  13. Refinement of pollutant gas emissions in the state of Rio de Janeiro for applications in modeling air quality on a local scale

    Science.gov (United States)

    Domínguez Chovert, Angel; Félix Alonso, Marcelo; Frassoni, Ariane; José Ferreira, Valter; Eiras, Denis; Longo, Karla; Freitas, Saulo

    2017-04-01

    Numerical modeling is a fundamental tool for studying the earth system components along with weather and climate forecast. In fact, the development of on-line models allows to simulate conditions of the atmosphere, for example, to evaluate certain chemicals in weather events with the purpose of improving a region's quality of air. For this determined purpose, the on-line models employ information from a broad range of sources in order to generate its variables forecasts. But beyond vast information sources, for a region's quality of air study, the data concerning the amount and distribution of emissions of polluting gases must be representative, as well as, it's required complete georeferenced emissions for simulations made with high resolution. Consequently, the modifications made in this work to the PREP-CHEM-SRC (Preprocessor of trace gas and aerosol emission fields for regional and a global atmospheric chemistry models) tool are presented to meliorate the initialization files for BRAMS models, 5.2 version (Brazilian Developments on the Regional Atmospheric Modeling System) and WRF (Weather Research and Forecasting Model) with vehicle emissions in the state of Rio de Janeiro, Brazil. It was determined the annual vehicle emission, until the year 2030, of the nitrogen oxides species (NOx) and carbon monoxide (CO) for each city and using different scenarios. For Rio de Janeiro city, a process of distribution by emissions of the main pollutant gases was implemented. In total, five different types of routes were used and the emission percentage for each one was calculated using the most current traffic information in them. For to check the industrial contributions to the emissions were used the global datasets RETRO (REanalysis of TROpospheric chemical composition) and EDGAR-HTAP (Emission Database for Global Atmospheric Research). On the other hand, for the biogenic contributions was used information from the MEGAN model (Model of Emissions of Gases and Aerosols

  14. Pressurized Operation of a Planar Solid Oxide Cell Stack

    DEFF Research Database (Denmark)

    Jensen, Søren Højgaard; Sun, Xiufu; Ebbesen, Sune Dalgaard

    2016-01-01

    Solid oxide cells (SOCs) can be operated either as fuel cells (SOFC) to convert fuels to electricity or as electrolyzers (SOEC) to convert electricity to fuels such as hydrogen or methane. Pressurized operation of SOCs provide several benefits on both cell and system level. If successfully matured...... (electrode performance) increases for thermodynamic and kinetic reasons, respectively. Further, the summit frequency of the gas concentration impedance arc and the pressure difference across the stack and heat exchangers is seen to decrease with increasing pressure following a power-law expression. Finally...

  15. Analytical, microbiological and eco-toxicological characterization of former polluted gas-work sites; Caracterisation analytique, microbiologique et ecotoxicologique de terres polluees d'anciennes usines a gaz

    Energy Technology Data Exchange (ETDEWEB)

    Haeseler, F.

    1999-12-17

    The present work was done on representative soil samples originating from different former gas-work sites and contaminated with poly-aromatic hydrocarbons (PAH). Because of their genotoxicity these compounds are considered as the major pollutants. A detailed analytical characterization of the polluting organic matter present in these soils shows that the 16 PAH of the US-EPA priority pollutants list (3 to 6 %) are systematically associated to other PAH (7 to 10 %) and to an organic matter extractable with organic solvents (10 to 15%), but also to a non-extractable heavy organic matter (60 to 75 %). The results show that these soils are polluted with PAH-containing coal tars generated by the industrial coal pyrolysis process of gas manufacturing. All the studied soils present a microflora able to degrade all the PAH from the US-EPA list. The main factor limiting the biodegradation rates obtained by biological soil treatment is the lack of accessibility of PAH. This is due to the presence of heavy organic matter of coal tar acting like a trap for the associated PAH. The soils which have not undergone natural attenuation present an important leaching capacity for PAH. This leaching capacity is strongly reduced after even a limited biological treatment. Bacterial tests performed on leachates of biologically treated soils show that they no longer present any detectable acute toxicity or genotoxicity. (author)

  16. Innovative direct energy conversion systems using electronic adiabatic processes of electron fluid in solid conductors: new plants of electrical power and hydrogen gas resources without environmental pollutions

    International Nuclear Information System (INIS)

    Kondoh, Y.; Kondo, M.; Shimoda, K.; Takahashi, T.

    2001-07-01

    It is shown that using a novel recycling process of the environmental thermal energy, innovative permanent auto-working direct energy converter systems (PA-DEC systems) from the environmental thermal to electrical and/or chemical potential (TE/CP) energies, abbreviated as PA-TE/CP-DEC systems, can be used for new auto-working electrical power plants and the plants of the compressible and conveyable hydrogen gas resources at various regions in the whole world, with contributions to the world peace and the economical development in the south part of the world. It is shown that the same physical mechanism by free electrons and electrical potential determined by temperature in conductors, which include semiconductors, leads to the Peltier effect and the Seebeck one. It is experimentally clarified that the long distance separation between two π type elements of the heat absorption (HAS) and the production one (HPS) of the Peltier effect circuit system or between the higher temperature side (HTS) and the lower one (LTS) of the Seebeck effect circuit one does not change in the whole for the both effects. By using present systems, we do not need to use petrified fuels such as coals, oils, and natural gases in order to decrease the greenhouse effect by the CO 2 surrounding the earth. Furthermore, we do not need plats of nuclear fissions that left radiating wastes, i.e., with no environmental pollutions. The PA-TE/CP-DEC systems can be applicable for several km scale systems to the micro ones, such as the plants of the electrical power, the compact transportable hydrogen gas resources, a large heat energy container, which can be settled at far place from thermal energy absorbing area, the refrigerators, the air conditioners, home electrical apparatuses, and further the computer elements. It is shown that the simplest PA-TE/CP-DEC system can be established by using only the Seebeck effect components and the resolving water ones. It is clarified that the externally applied

  17. Density of oxidation-induced stacking faults in damaged silicon

    NARCIS (Netherlands)

    Kuper, F.G.; Hosson, J.Th.M. De; Verwey, J.F.

    1986-01-01

    A model for the relation between density and length of oxidation-induced stacking faults on damaged silicon surfaces is proposed, based on interactions of stacking faults with dislocations and neighboring stacking faults. The model agrees with experiments.

  18. Health and exposure assessment of flare gas emissions

    International Nuclear Information System (INIS)

    Kindzierski, W.B.; Byrne-Lewis, C.; Probert, S.

    2000-01-01

    The incomplete combustion of flare gases produces pollutants such as volatile organic compounds (VOCs) and polycyclic aromatic hydrocarbons (PAHs) which are cause for concern for public health. Some of the concerns relate to potential long-term cumulative health effects from exposure to hazardous air pollutants including benzene, styrene, naphthalene, and benzopyrene. This study demonstrated that several factors should be taken into account when considering the importance of flaring and human exposure to flare gas emissions. Most flare stacks are located in rural areas, but most time-availability studies have been done on urban populations where the majority of people spend their time indoors. It was recommended that more time-activity studies are needed to emphasize the behaviour of rural populations which are most susceptible to exposure from pollutants from flaring. It was concluded that higher indoor air concentrations exist for many VOCs and PAHs compared to outdoors, but in these instances, indoor sources are the major contributors to indoor air concentrations. It was recommended that health assessments of hazardous air pollutants emitted from gas flaring has to take into account the indoor setting and other background exposures in order to provide useful information for decision makers. 49 refs., 8 tabs., 1 fig

  19. Tunable electro-optic filter stack

    Energy Technology Data Exchange (ETDEWEB)

    Fontecchio, Adam K.; Shriyan, Sameet K.; Bellingham, Alyssa

    2017-09-05

    A holographic polymer dispersed liquid crystal (HPDLC) tunable filter exhibits switching times of no more than 20 microseconds. The HPDLC tunable filter can be utilized in a variety of applications. An HPDLC tunable filter stack can be utilized in a hyperspectral imaging system capable of spectrally multiplexing hyperspectral imaging data acquired while the hyperspectral imaging system is airborne. HPDLC tunable filter stacks can be utilized in high speed switchable optical shielding systems, for example as a coating for a visor or an aircraft canopy. These HPDLC tunable filter stacks can be fabricated using a spin coating apparatus and associated fabrication methods.

  20. Dynamical stability of slip-stacking particles

    Energy Technology Data Exchange (ETDEWEB)

    Eldred, Jeffrey; Zwaska, Robert

    2014-09-01

    We study the stability of particles in slip-stacking configuration, used to nearly double proton beam intensity at Fermilab. We introduce universal area factors to calculate the available phase space area for any set of beam parameters without individual simulation. We find perturbative solutions for stable particle trajectories. We establish Booster beam quality requirements to achieve 97% slip-stacking efficiency. We show that slip-stacking dynamics directly correspond to the driven pendulum and to the system of two standing-wave traps moving with respect to each other.

  1. Modeling the Air Flow in the 3410 Building Filtered Exhaust Stack System

    Energy Technology Data Exchange (ETDEWEB)

    Recknagle, Kurtis P.; Barnett, J. Matthew; Suffield, Sarah R.

    2013-01-23

    Additional ventilation capacity has been designed for the 3410 Building filtered exhaust stack system. The updated system will increase the number of fans from two to three and will include ductwork to incorporate the new fan into the existing stack. Stack operations will involve running various two-fan combinations at any given time. The air monitoring system of the existing two-fan stack was previously found to be in compliance with the ANSI/HPS N13.1-1999 standard, however it is not known if the modified (three-fan) system will comply. Subsequently, a full-scale three-dimensional (3-D) computational fluid dynamics (CFD) model of the modified stack system has been created to examine the sampling location for compliance with the standard. The CFD modeling results show good agreement with testing data collected from the existing 3410 Building stack and suggest that velocity uniformity and flow angles will remain well within acceptance criteria when the third fan and associated ductwork is installed. This includes two-fan flow rates up to 31,840 cfm for any of the two-fan combinations. For simulation cases in which tracer gas and particles are introduced in the main duct, the model predicts that both particle and tracer gas coefficients of variance (COVs) may be larger than the acceptable 20 percent criterion of the ANSI/HPS N13.1-1999 standard for each of the two-fan, 31,840 cfm combinations. Simulations in which the tracers are introduced near the fans result in improved, though marginally acceptable, COV values for the tracers. Due to the remaining uncertainty that the stack will qualify with the addition of the third fan and high flow rates, a stationary air blender from Blender Products, Inc. is considered for inclusion in the stack system. A model of the air blender has been developed and incorporated into the CFD model. Simulation results from the CFD model that includes the air blender show striking improvements in tracer gas mixing and tracer particle

  2. Wearable solar cells by stacking textile electrodes.

    Science.gov (United States)

    Pan, Shaowu; Yang, Zhibin; Chen, Peining; Deng, Jue; Li, Houpu; Peng, Huisheng

    2014-06-10

    A new and general method to produce flexible, wearable dye-sensitized solar cell (DSC) textiles by the stacking of two textile electrodes has been developed. A metal-textile electrode that was made from micrometer-sized metal wires was used as a working electrode, while the textile counter electrode was woven from highly aligned carbon nanotube fibers with high mechanical strengths and electrical conductivities. The resulting DSC textile exhibited a high energy conversion efficiency that was well maintained under bending. Compared with the woven DSC textiles that are based on wire-shaped devices, this stacked DSC textile unexpectedly exhibited a unique deformation from a rectangle to a parallelogram, which is highly desired in portable electronics. This lightweight and wearable stacked DSC textile is superior to conventional planar DSCs because the energy conversion efficiency of the stacked DSC textile was independent of the angle of incident light. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. STACKING FAULT ENERGY IN HIGH MANGANESE ALLOYS

    Directory of Open Access Journals (Sweden)

    Eva Mazancová

    2009-04-01

    Full Text Available Stacking fault energy of high manganese alloys (marked as TWIP and TRIPLEX is an important parameter determining deformation mechanism type realized in above mentioned alloys. Stacking fault energy level can be asserted with a gliding of partial and/or full dislocations, b gliding mechanism and twinning deformation process in connection with increasing of fracture deformation level (deformation elongation and with increasing of simultaneously realized work hardening proces., c gliding mechanism and deformation induced e-martensite formation. In contribution calculated stacking fault energies are presented for various chemical compositions of high manganese alloys. Stacking fault energy dependences on manganese, carbon, iron and alluminium contents are presented. Results are confronted with some accessible papers.The aim of work is to deepen knowledge of presented data. The TWIP and TRIPLEX alloys can be held for promissing new automotive materials.

  4. Stack-Based Typed Assembly Language

    National Research Council Canada - National Science Library

    Morrisett, Greg

    1998-01-01

    .... This paper also formalizes the typing connection between CPS based compilation and stack based compilation and illustrates how STAL can formally model calling conventions by specifying them as formal translations of source function types to STAL types.

  5. Characterization of Piezoelectric Stacks for Space Applications

    Science.gov (United States)

    Sherrit, Stewart; Jones, Christopher; Aldrich, Jack; Blodget, Chad; Bao, Xiaoqi; Badescu, Mircea; Bar-Cohen, Yoseph

    2008-01-01

    Future NASA missions are increasingly seeking to actuate mechanisms to precision levels in the nanometer range and below. Co-fired multilayer piezoelectric stacks offer the required actuation precision that is needed for such mechanisms. To obtain performance statistics and determine reliability for extended use, sets of commercial PZT stacks were tested in various AC and DC conditions at both nominal and high temperatures and voltages. In order to study the lifetime performance of these stacks, five actuators were driven sinusoidally for up to ten billion cycles. An automated data acquisition system was developed and implemented to monitor each stack's electrical current and voltage waveforms over the life of the test. As part of the monitoring tests, the displacement, impedance, capacitance and leakage current were measured to assess the operation degradation. This paper presents some of the results of this effort.

  6. The stack on software and sovereignty

    CERN Document Server

    Bratton, Benjamin H

    2016-01-01

    A comprehensive political and design theory of planetary-scale computation proposing that The Stack -- an accidental megastructure -- is both a technological apparatus and a model for a new geopolitical architecture.

  7. Water Pollution

    Science.gov (United States)

    Bowen, H. J. M.

    1975-01-01

    Deals with water pollution in the following categories: a global view, self purification, local pollution, difficulties in chemical analysis, and remedies for water pollution. Emphasizes the extent to which man's activities have modified the cycles of certain elements. (GS)

  8. Air Pollution

    OpenAIRE

    Appleton, Bonnie Lee, 1948-2012; Koci, Joel; Harris, Roger; Sevebeck, Kathryn P.; Alleman, Dawn; Swanson, Lynette

    2009-01-01

    This publication reviews the major phytotoxic air pollutants, in decreasing order of severity, they include oxidants, sulfur dioxide, and particulates. Topics also include the connection between weather and air pollution and a section on diagnosing air pollution damage to trees.

  9. Stacking for Cosmic Magnetism with SKA Surveys

    OpenAIRE

    Stil, J. M.; Keller, B. W.

    2015-01-01

    Stacking polarized radio emission in SKA surveys provides statistical information on large samples that is not accessible otherwise due to limitations in sensitivity, source statistics in small fields, and averaging over frequency (including Faraday synthesis). Polarization is a special case because one obvious source of stacking targets is the Stokes I source catalog, possibly in combination with external catalogs, for example an SKA HI survey or a non-radio survey. We point out the signific...

  10. Environmental Modeling Framework using Stacked Gaussian Processes

    OpenAIRE

    Abdelfatah, Kareem; Bao, Junshu; Terejanu, Gabriel

    2016-01-01

    A network of independently trained Gaussian processes (StackedGP) is introduced to obtain predictions of quantities of interest with quantified uncertainties. The main applications of the StackedGP framework are to integrate different datasets through model composition, enhance predictions of quantities of interest through a cascade of intermediate predictions, and to propagate uncertainties through emulated dynamical systems driven by uncertain forcing variables. By using analytical first an...

  11. Generalized data stacking programming model with applications

    OpenAIRE

    Hala Samir Elhadidy; Rawya Yehia Rizk; Hassen Taher Dorrah

    2016-01-01

    Recent researches have shown that, everywhere in various sciences the systems are following stacked-based stored change behavior when subjected to events or varying environments “on and above” their normal situations. This paper presents a generalized data stack programming (GDSP) model which is developed to describe the system changes under varying environment. These changes which are captured with different ways such as sensor reading are stored in matrices. Extraction algorithm and identif...

  12. Representations of stack triangulations in the plane

    OpenAIRE

    Selig, Thomas

    2013-01-01

    Stack triangulations appear as natural objects when defining an increasing family of triangulations by successive additions of vertices. We consider two different probability distributions for such objects. We represent, or "draw" these random stack triangulations in the plane $\\R^2$ and study the asymptotic properties of these drawings, viewed as random compact metric spaces. We also look at the occupation measure of the vertices, and show that for these two distributions it converges to som...

  13. Design and experimental characterization of a 350 W High Temperature PEM fuel cell stack

    Directory of Open Access Journals (Sweden)

    Nicola Zuliani

    2011-01-01

    Full Text Available High Temperature Proton Exchange Membrane (HT PEM fuel cell based on polybenzimidazole (PBI polymer and phosphoric acid, can be operated at temperature between 120 °C and 180 °C. Reactants humidification is not required and CO content up to 2% in the fuel can be tolerated, affecting only marginally performance. This is what makes HT PEM very attractive, as low quality reformed hydrogen can be used and water management problems are avoided. Till nowadays, from experimental point of view, only few studies relate to the development and characterization of high temperature stacks. The aim of this work is to present the main design features and the performance curves of a 25 cells HT PEM stack based on PBI and phosphoric acid membranes. Performance curves refer to the stack operating with two type of fuels: pure hydrogen and a gas mixture simulating a typical steam reformer output. The stack voltage distribution analysis and the stack temperature distribution analysis suggest that cathode air could be used as coolant leading to a better thermal management. This could simplify stack design and system BOP, thus increasing system performance.

  14. Solid oxide fuel cell generator with removable modular fuel cell stack configurations

    Science.gov (United States)

    Gillett, J.E.; Dederer, J.T.; Zafred, P.R.; Collie, J.C.

    1998-04-21

    A high temperature solid oxide fuel cell generator produces electrical power from oxidation of hydrocarbon fuel gases such as natural gas, or conditioned fuel gases, such as carbon monoxide or hydrogen, with oxidant gases, such as air or oxygen. This electrochemical reaction occurs in a plurality of electrically connected solid oxide fuel cells bundled and arrayed in a unitary modular fuel cell stack disposed in a compartment in the generator container. The use of a unitary modular fuel cell stack in a generator is similar in concept to that of a removable battery. The fuel cell stack is provided in a pre-assembled self-supporting configuration where the fuel cells are mounted to a common structural base having surrounding side walls defining a chamber. Associated generator equipment may also be mounted to the fuel cell stack configuration to be integral therewith, such as a fuel and oxidant supply and distribution systems, fuel reformation systems, fuel cell support systems, combustion, exhaust and spent fuel recirculation systems, and the like. The pre-assembled self-supporting fuel cell stack arrangement allows for easier assembly, installation, maintenance, better structural support and longer life of the fuel cells contained in the fuel cell stack. 8 figs.

  15. Analyses of Large Coal-Based SOFCs for High Power Stack Block Development

    Energy Technology Data Exchange (ETDEWEB)

    Recknagle, Kurtis P; Koeppel, Brian J

    2010-10-01

    This report summarizes the numerical modeling and analytical efforts for SOFC stack development performed for the coal-based SOFC program. The stack modeling activities began in 2004, but this report focuses on the most relevant results obtained since August 2008. This includes the latter half of Phase-I and all of Phase-II activities under technical guidance of VPS and FCE. The models developed to predict the thermal-flow-electrochemical behaviors and thermal-mechanical responses of generic planar stacks and towers are described. The effects of cell geometry, fuel gas composition, on-cell reforming, operating conditions, cell performance, seal leak, voltage degradation, boundary conditions, and stack height are studied. The modeling activities to evaluate and achieve technical targets for large stack blocks are described, and results from the latest thermal-fluid-electrochemical and structural models are summarized. Modeling results for stack modifications such as scale-up and component thickness reduction to realize cost reduction are presented. Supporting modeling activities in the areas of cell fabrication and loss of contact are also described.

  16. A Time-predictable Stack Cache

    DEFF Research Database (Denmark)

    Abbaspour, Sahar; Brandner, Florian; Schoeberl, Martin

    2013-01-01

    Real-time systems need time-predictable architectures to support static worst-case execution time (WCET) analysis. One architectural feature, the data cache, is hard to analyze when different data areas (e.g., heap allocated and stack allocated data) share the same cache. This sharing leads to le...... of a cache for stack allocated data. Our port of the LLVM C++ compiler supports the management of the stack cache. The combination of stack cache instructions and the hardware implementation of the stack cache is a further step towards timepredictable architectures.......Real-time systems need time-predictable architectures to support static worst-case execution time (WCET) analysis. One architectural feature, the data cache, is hard to analyze when different data areas (e.g., heap allocated and stack allocated data) share the same cache. This sharing leads to less...... precise results of the cache analysis part of the WCET analysis. Splitting the data cache for different data areas enables composable data cache analysis. The WCET analysis tool can analyze the accesses to these different data areas independently. In this paper we present the design and implementation...

  17. Detailed Electrochemical Characterisation of Large SOFC Stacks

    DEFF Research Database (Denmark)

    Mosbæk, Rasmus Rode; Hjelm, Johan; Barfod, R.

    2012-01-01

    As solid oxide fuel cell (SOFC) technology is moving closer to a commercial break through, lifetime limiting factors, determination of the limits of safe operation and methods to measure the “state-of-health” of operating cells and stacks are becoming of increasing interest. This requires applica...... out at a range of ac perturbation amplitudes in order to investigate linearity of the response and the signal-to-noise ratio. Separation of the measured impedance into series and polarisation resistances was possible....... to analyse in detail. Today one is forced to use mathematical modelling to extract information about existing gradients and cell resistances in operating stacks, as mature techniques for local probing are not available. This type of spatially resolved information is essential for model refinement...... and validation, and helps to further the technological stack development. Further, more detailed information obtained from operating stacks is essential for developing appropriate process monitoring and control protocols for stack and system developers. An experimental stack with low ohmic resistance from Topsoe...

  18. Radioactivity and plumbum pollution

    International Nuclear Information System (INIS)

    Wu Huishan

    2006-01-01

    This paper first indicates the five aspects to understand correctly the poisoning by radioactive plumbum: milling of nonferrous metal, development of mines, production of accumulator, discharge of waste gas from vehicles and radiation from building materials, as well as 'rubbish' from manufacture of plumbiferous equipment, and analyzes the seriousness of plumbum pollution (especially for children) along with the feature and symptom to plumbism. Then a lot of cases about the radioactive plumbum pollution are expounded so as to make a deeper understanding of plumbum pollution. Finally, some needed recognitions and prevention measures are put forward in different ways. (authors)

  19. A polymer electrolyte fuel cell stack for stationary power generation from hydrogen fuel

    Energy Technology Data Exchange (ETDEWEB)

    Gottesfeld, S. [Los Alamos National Lab., NM (United States)

    1995-09-01

    The fuel cell is the most efficient device for the conversion of hydrogen fuel to electric power. As such, the fuel cell represents a key element in efforts to demonstrate and implement hydrogen fuel utilization for electric power generation. The low temperature, polymer electrolyte membrane fuel cell (PEMFC) has recently been identified as an attractive option for stationary power generation, based on the relatively simple and benign materials employed, the zero-emission character of the device, and the expected high power density, high reliability and low cost. However, a PEMFC stack fueled by hydrogen with the combined properties of low cost, high performance and high reliability has not yet been demonstrated. Demonstration of such a stack will remove a significant barrier to implementation of this advanced technology for electric power generation from hydrogen. Work done in the past at LANL on the development of components and materials, particularly on advanced membrane/electrode assemblies (MEAs), has contributed significantly to the capability to demonstrate in the foreseeable future a PEMFC stack with the combined characteristics described above. A joint effort between LANL and an industrial stack manufacturer will result in the demonstration of such a fuel cell stack for stationary power generation. The stack could operate on hydrogen fuel derived from either natural gas or from renewable sources. The technical plan includes collaboration with a stack manufacturer (CRADA). It stresses the special requirements from a PEMFC in stationary power generation, particularly maximization of the energy conversion efficiency, extension of useful life to the 10 hours time scale and tolerance to impurities from the reforming of natural gas.

  20. Monitoring system for industrial gases pollutants

    International Nuclear Information System (INIS)

    Iliescu, M.; Culcer, M.; Curuia, M.; Anghel, N.M.; Stefanescu, I.

    2003-01-01

    The system is designed for monitoring gas pollutants in air, in a chemical plant. It consists of gas detectors with transmitter and modules for environmental conditions measurement, data loggers and a central monitoring station which role is to collect data, generate alarms if pollutants concentration becomes over limit and create database. A dedicated software permits data collecting and processing in order to get solutions for minimising human and technological risks. The system role is monitoring the pollution sources and the surrounded areas that might be affected, for keeping gas pollutants concentration at an acceptable level and to minimise the pollution effects. (author)

  1. Performance evaluation of an open-cathode PEM fuel cell stack under ambient conditions: Case study of United Arab Emirates

    International Nuclear Information System (INIS)

    Al-Zeyoudi, Hend; Sasmito, Agus P.; Shamim, Tariq

    2015-01-01

    Highlights: • Performance evaluation of open-cathode PEM fuel cell stacks with forced air-convection. • Stack performance can vary up to 40% from winter to summer. • Hot and arid condition leads to membrane drying and performance deterioration. • Anode humidification improves the stack performance up to 40% during summer. - Abstract: The open-cathode polymer electrolyte membrane (PEM) fuel cell stack has been a promising candidate as a sustainable energy conversion system for replacing fossil fuel-based energy conversion devices in portable and automotive applications. As the ambient air is directly used to provide both oxidant and cooling, the complex cooling loop can be avoided which reduces the complexity and cost. However, the stack performance is highly affected by ambient conditions, i.e., ambient temperature and humidity. In this study, the effect of monthly ambient air conditions (temperature and humidity) is evaluated with respect to the stack’s power production performance as well as thermal, water and gas management by employing a validated three-dimensional open-cathode PEM fuel cell stack model. The annual climate data from the hot and arid environment of Abu Dhabi, United Arab Emirates (UAE) are used as a case study. The objective is to develop a better fundamental understanding of the interactions of physical phenomena in a fuel cell stack, which can assist in improving the performance and operation of an open-cathode PEM fuel cell-powered vehicle. The results indicate that the stack performance can vary significantly (up to 40%) from winter to summer, especially at high operating currents, with significant changes in the stack temperature and the water content at the membrane. Moreover, the anode humidification results in a significant improvement in the stack performance (up to 40%) in hot and dry conditions. However, a careful balance has to be struck between the humidifier parasitic load and the stack power.

  2. From Multi to Single Stack Automata

    Science.gov (United States)

    Atig, Mohamed Faouzi

    We investigate the issue of reducing the verification problem of multi-stack machines to the one for single-stack machines. For instance, elegant (and practically efficient) algorithms for bounded-context switch analysis of multi-pushdown systems have been recently defined based on reductions to the reachability problem of (single-stack) pushdown systems [10,18]. In this paper, we extend this view to both bounded-phase visibly pushdown automata (BVMPA) [16] and ordered multi-pushdown automata (OMPA) [1] by showing that each of their emptiness problem can be reduced to the one for a class of single-stack machines. For these reductions, we introduce effective generalized pushdown automata (EGPA) where operations on stacks are (1) pop the top symbol of the stack, and (2) push a word in some (effectively) given set of words L over the stack alphabet, assuming that L is in some class of languages for which checking whether L intersects regular languages is decidable. We show that the automata-based saturation procedure for computing the set of predecessors in standard pushdown automata can be extended to prove that for EGPA too the set of all predecessors of a regular set of configurations is an effectively constructible regular set. Our reductions from OMPA and BVMPA to EGPA, together with the reachability analysis procedure for EGPA, allow to provide conceptually simple algorithms for checking the emptiness problem for each of these models, and to significantly simplify the proofs for their 2ETIME upper bounds (matching their lower-bounds).

  3. Start-Stop Test Procedures on the PEMFC Stack Level

    DEFF Research Database (Denmark)

    Mitzel, Jens; Nygaard, Frederik; Veltzé, Sune

    The test is addressed to investigate the influence on stack durability of a long stop followed by a restart of a stack. Long stop should be defined as a stop in which the anodic compartment is fully filled by air due to stack leakages. In systems, leakage level of the stack is low and time to fil...

  4. Effective pollutant emission heights for atmospheric transport modelling based on real-world information

    International Nuclear Information System (INIS)

    Pregger, Thomas; Friedrich, Rainer

    2009-01-01

    Emission data needed as input for the operation of atmospheric models should not only be spatially and temporally resolved. Another important feature is the effective emission height which significantly influences modelled concentration values. Unfortunately this information, which is especially relevant for large point sources, is usually not available and simple assumptions are often used in atmospheric models. As a contribution to improve knowledge on emission heights this paper provides typical default values for the driving parameters stack height and flue gas temperature, velocity and flow rate for different industrial sources. The results were derived from an analysis of the probably most comprehensive database of real-world stack information existing in Europe based on German industrial data. A bottom-up calculation of effective emission heights applying equations used for Gaussian dispersion models shows significant differences depending on source and air pollutant and compared to approaches currently used for atmospheric transport modelling. - The comprehensive analysis of real-world stack data provides detailed default parameter values for improving vertical emission distribution in atmospheric modelling

  5. Pollution Probe.

    Science.gov (United States)

    Chant, Donald A.

    This book is written as a statement of concern about pollution by members of Pollution Probe, a citizens' anti-pollution group in Canada. Its purpose is to create public awareness and pressure for the eventual solution to pollution problems. The need for effective government policies to control the population explosion, conserve natural resources,…

  6. Maryland air toxics regulation applicable to a natural gas compressor station

    International Nuclear Information System (INIS)

    Weidemann, H.A.; Hoffman, P.M.

    1992-01-01

    Columbia Gas Transmission Corporation submitted an air permit application to the Maryland Department of the Environment to construct a natural gas compressor station near Rutledge, Maryland. The station consists of three natural gas-fueled internal combustion reciprocating engines, each rated at 3200 horsepower. Maximum potential pollutant emissions associated with the station operation did not trigger Prevention of Significant Deterioration review or nonattainment area New Source review. However, a minor source air permit cannot be issued without addressing Maryland's toxic air regulations. Columbia initiated a detailed investigation of toxic air pollutants, including a stack test of an identical engine. Based on this information, the proposed station was subject to the toxic air regulation for acetaldehyde, acrolein, benzene, crotonaldehyde, and formaldehyde. Compliance with the toxic air regulation for crotonaldehyde was demonstrated by having an emission rate less than the threshold emission rate, specified in the regulation. The ambient air quality impact of the other four pollutants was determined using the Industrial Source Complex dispersion model and resulted in predicted concentrations below the pollutant-specific acceptable ambient level. A carcinogenic impact analysis was performed for acetaldehyde, benzene, and formaldehyde to demonstrate compliance with the accepted risk of one in one hundred thousand

  7. A comparative study on plant morphology, gas exchange parameters, and antioxidant response of Ocimum basilicum L. and Origanum vulgare L. grown on industrially polluted soil

    OpenAIRE

    STANCHEVA, Ira; GENEVA, Maria; MARKOVSKA, Yuliana; TZVETKOVA, Nikolina

    2014-01-01

    The effects of Cd, Pb, and Zn uptake on plant morphology, photosynthetic parameters, antioxidant potential, and essential oil yield and quality in Ocimum basilicum L. and Origanum vulgare L. plants were evaluated. The plants were grown as a pot experiment in soil heavily polluted with Cd and Pb and on unpolluted soil. Both plants accumulated Cd, mainly in the roots, while Pb occurred in the oregano shoots only. The leaf blade thickness of both plants increased when grown in polluted soil. Bas...

  8. EmuStack: An OpenStack-Based DTN Network Emulation Platform (Extended Version

    Directory of Open Access Journals (Sweden)

    Haifeng Li

    2016-01-01

    Full Text Available With the advancement of computing and network virtualization technology, the networking research community shows great interest in network emulation. Compared with network simulation, network emulation can provide more relevant and comprehensive details. In this paper, EmuStack, a large-scale real-time emulation platform for Delay Tolerant Network (DTN, is proposed. EmuStack aims at empowering network emulation to become as simple as network simulation. Based on OpenStack, distributed synchronous emulation modules are developed to enable EmuStack to implement synchronous and dynamic, precise, and real-time network emulation. Meanwhile, the lightweight approach of using Docker container technology and network namespaces allows EmuStack to support a (up to hundreds of nodes large-scale topology with only several physical nodes. In addition, EmuStack integrates the Linux Traffic Control (TC tools with OpenStack for managing and emulating the virtual link characteristics which include variable bandwidth, delay, loss, jitter, reordering, and duplication. Finally, experiences with our initial implementation suggest the ability to run and debug experimental network protocol in real time. EmuStack environment would bring qualitative change in network research works.

  9. Levitation characteristics of HTS tape stacks

    Energy Technology Data Exchange (ETDEWEB)

    Pokrovskiy, S. V.; Ermolaev, Y. S.; Rudnev, I. A. [National Research Nuclear University MEPhI (Moscow Engineering Physics Institute), Moscow (Russian Federation)

    2015-03-15

    Due to the considerable development of the technology of second generation high-temperature superconductors and a significant improvement in their mechanical and transport properties in the last few years it is possible to use HTS tapes in the magnetic levitation systems. The advantages of tapes on a metal substrate as compared with bulk YBCO material primarily in the strength, and the possibility of optimizing the convenience of manufacturing elements of levitation systems. In the present report presents the results of the magnetic levitation force measurements between the stack of HTS tapes containing of tapes and NdFeB permanent magnet in the FC and ZFC regimes. It was found a non- linear dependence of the levitation force from the height of the array of stack in both modes: linear growth at small thickness gives way to flattening and constant at large number of tapes in the stack. Established that the levitation force of stacks comparable to that of bulk samples. The numerical calculations using finite element method showed that without the screening of the applied field the levitation force of the bulk superconductor and the layered superconductor stack with a critical current of tapes increased by the filling factor is exactly the same, and taking into account the screening force slightly different.

  10. Forced Air-Breathing PEMFC Stacks

    Directory of Open Access Journals (Sweden)

    K. S. Dhathathreyan

    2012-01-01

    Full Text Available Air-breathing fuel cells have a great potential as power sources for various electronic devices. They differ from conventional fuel cells in which the cells take up oxygen from ambient air by active or passive methods. The air flow occurs through the channels due to concentration and temperature gradient between the cell and the ambient conditions. However developing a stack is very difficult as the individual cell performance may not be uniform. In order to make such a system more realistic, an open-cathode forced air-breathing stacks were developed by making appropriate channel dimensions for the air flow for uniform performance in a stack. At CFCT-ARCI (Centre for Fuel Cell Technology-ARC International we have developed forced air-breathing fuel cell stacks with varying capacity ranging from 50 watts to 1500 watts. The performance of the stack was analysed based on the air flow, humidity, stability, and so forth, The major advantage of the system is the reduced number of bipolar plates and thereby reduction in volume and weight. However, the thermal management is a challenge due to the non-availability of sufficient air flow to remove the heat from the system during continuous operation. These results will be discussed in this paper.

  11. Contemporary sample stacking in analytical electrophoresis.

    Science.gov (United States)

    Malá, Zdena; Šlampová, Andrea; Křivánková, Ludmila; Gebauer, Petr; Boček, Petr

    2015-01-01

    This contribution is a methodological review of the publications about the topic from the last 2 years. Therefore, it is primarily organized according to the methods and procedures used in surveyed papers and the origin and type of sample and specification of analytes form the secondary structure. The introductory part about navigation in the architecture of stacking brings a brief characterization of the various stacking methods, with the description of mutual links to each other and important differences among them. The main body of the article brings a survey of publications organized according to main principles of stacking and then according to the origin and type of the sample. Provided that the paper cited gave explicitly the relevant data, information about the BGE(s) used, procedure, detector employed, and reached LOD and/or concentration effect is given. The papers where the procedure used is a combination of diverse fragments and parts of various stacking techniques are mentioned in a special section on combined techniques. The concluding remarks in the final part of the review evaluate present state of art and the trends of sample stacking in CE. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. Enhanced dynamical stability with harmonic slip stacking

    Directory of Open Access Journals (Sweden)

    Jeffrey Eldred

    2016-10-01

    Full Text Available We develop a configuration of radio-frequency (rf cavities to dramatically improve the performance of slip stacking. Slip stacking is an accumulation technique used at Fermilab to nearly double proton intensity by maintaining two beams of different momenta in the same storage ring. The two particle beams are longitudinally focused in the Recycler by two 53 MHz 100 kV rf cavities with a small frequency difference between them. We propose an additional 106 MHz 20 kV rf cavity with a frequency at the double the average of the upper and lower main rf frequencies. We show the harmonic rf cavity cancels out the resonances generated between the two main rf cavities and we derive the relationship between the harmonic rf voltage and the main rf voltage. We find the area factors that can be used to calculate the available phase space area for any set of beam parameters without individual simulation. We establish Booster beam quality requirements to achieve 99% slip stacking efficiency. We measure the longitudinal distribution of the Booster beam and use it to generate a realistic beam model for slip stacking simulation. We demonstrate that the harmonic rf cavity can not only reduce particle loss during slip stacking, but also reduce the final longitudinal emittance.

  13. Radiation pollution of the environment

    International Nuclear Information System (INIS)

    Benalashhar, Hanan Ali

    2006-01-01

    This paper interested in the topic of environmental pollution by radioactive materials due to several human activities. The meaning of human activities are nuclear tests and extraction of raw uranium, waste and reactor accidents, nuclear fuel and radon gas, and the peaceful uses of radiation. This paper points out the effects of environmental pollution by radiation and the means of reduction, and also illustrate the radiation pollution in the Arab region. (author)

  14. Miniaturized polymer electrolyte fuel cell (PEFC) stack using micro structured bipolar plate

    Energy Technology Data Exchange (ETDEWEB)

    Veziridis, Z.; Scherer, G.G.; Marmy, Ch.; Glaus, F. [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1999-08-01

    In Polymer Electrolyte Fuel Cell (PEFC) technology the reducing of volume and mass of the fuel cell stack and the improvement of catalyst utilization are of great interest. These parameters affect applicability and system cost. In this work we present an alternative way for reducing the stack volume by combining gas distribution and catalytic active area in one plate. Micro machined glassy carbon electrodes serve as support material for the platinum catalyst, as well as gas distributor at the same time. A comparison of these electrodes with conventional platinum-black gas diffusion electrodes under fuel cell conditions shows that the new system is a promising electrode type for enhanced power density and catalyst utilization. (author) 3 figs., 5 refs.

  15. Progress of MCFC stack technology at Toshiba

    Energy Technology Data Exchange (ETDEWEB)

    Hori, M.; Hayashi, T.; Shimizu, Y. [Toshiba Corp., Tokyo (Japan)

    1996-12-31

    Toshiba is working on the development of MCFC stack technology; improvement of cell characteristics, and establishment of separator technology. For the cell technology, Toshiba has concentrated on both the restraints of NiO cathode dissolution and electrolyte loss from cells, which are the critical issues to extend cell life in MCFC, and great progress has been made. On the other hand, recognizing that the separator is one of key elements in accomplishing reliable and cost-competitive MCFC stacks, Toshiba has been accelerating the technology establishment and verification of an advanced type separator. A sub-scale stack with such a separator was provided for an electric generating test, and has been operated for more than 10,000 hours. This paper presents several topics obtained through the technical activities in the MCFC field at Toshiba.

  16. Effects of Endwall Geometry and Stacking on Two-Stage Supersonic Turbine Performance

    Science.gov (United States)

    Dorney, Daniel J.; Griffin, Lisa W.; Huber, Frank W.; Sondak, Douglas L.; Turner, Jim (Technical Monitor)

    2002-01-01

    The drive towards high-work turbines has led to designs which can be compact, transonic, supersonic, counter rotating, or use a dense drive gas. These aggressive designs can lead to strong secondary flows and airfoil flow separation. In many cases the secondary and separated flows can be minimized by contouring the hub/shroud endwalls and/or modifying the airfoil stacking. In this study, three-dimensional unsteady Navier-Stokes simulations were performed to study three different endwall shapes between the first-stage vanes and rotors, as well as two different stackings for the first-stage vanes. The predicted results indicate that changing the stacking of the first-stage vanes can significantly impact endwall separation (and turbine performance) in regions where the endwall profile changes.

  17. Design Handbook for a Stack Foundation

    OpenAIRE

    Tuominen, Vilma

    2011-01-01

    This thesis was made for Citec Engineering Oy Ab as a handbook and as a design tool for concrete structure designers. Handbook is about the Wärtsilä Power Plant stack structure, which is a base for about 40 meters high stack pipe. The purpose is to make a calculation base to support the design work, which helps the designer to check the right dimensions of the structure. Thesis is about to be for the concrete designers and also other designers and authorities. As an example I have used an...

  18. Simple model of stacking-fault energies

    DEFF Research Database (Denmark)

    Stokbro, Kurt; Jacobsen, Lærke Wedel

    1993-01-01

    A simple model for the energetics of stacking faults in fcc metals is constructed. The model contains third-nearest-neighbor pairwise interactions and a term involving the fourth moment of the electronic density of states. The model is in excellent agreement with recently published local-density ......A simple model for the energetics of stacking faults in fcc metals is constructed. The model contains third-nearest-neighbor pairwise interactions and a term involving the fourth moment of the electronic density of states. The model is in excellent agreement with recently published local...

  19. Dispersion patterns of pollutant from smokestacks

    International Nuclear Information System (INIS)

    Tigor Nauli

    2002-01-01

    Air quality in industrial area depends on the nature of particles emitted from the plume. The particles are transported by the atmosphere away from the source and deposits at surroundings. Coverage area and pollutant concentration at contaminated areas will vary based on emission rate, plume stack, weather profile, and terrain. Forecasting of an area contaminated by industrial waste could help many parties in anticipating the effects, in improving the production process, and in imposing the policy by the authority. Such information can be created by prediction techniques. One of the models for illustrating the air pollution from a single point source is Gaussian dispersion curve. It assumed that pollutant concentration will distributed normally in vertical and downwind direction. The highest concentration of pollutants would be in centerline and lower values as the distance further away from the source. A computer application has been developed to assist modeling the pollutant dispersion. The program collects the atmospheric stability classification, computes dispersion coefficients, and maintains the corresponding mathematical equations. When data of emission rate, plume stack, average wind speed, and atmospheric condition are available, then the program will inform the concentration of pollutants in any distance from the source. By varying in inputs, the computer application produces numerous air pollution predictions as dispersion patterns. The dispersion patterns form the elliptical contour with segments of pollutant concentrations. The central segment represents the highest concentration and the outer segments in concentric manner illustrate the lower concentration. The patterns exhibit the highest contaminated point, the longest distance in a specific weather condition, the moving of the highest contaminated point as weather changing, and the variety of pollutant concentration by the effective stack height. (author)

  20. Natural gas for vehicles

    International Nuclear Information System (INIS)

    Prieur, A.

    2006-01-01

    Following a decade-long upsurge in the use of natural gas in the energy sector (heating and especially electricity), new outlets for natural gas are being developed in the transport sector. For countries endowed with substantial local resources, development in this sector can help reduce oil dependence. In addition, natural gas is often used to reduce pollution, particularly in cities

  1. Point Pollution Sources Dimensioning

    Directory of Open Access Journals (Sweden)

    Georgeta CUCULEANU

    2011-06-01

    Full Text Available In this paper a method for determining the main physical characteristics of the point pollution sources is presented. It can be used to find the main physical characteristics of them. The main physical characteristics of these sources are top inside source diameter and physical height. The top inside source diameter is calculated from gas flow-rate. For reckoning the physical height of the source one takes into account the relation given by the proportionality factor, defined as ratio between the plume rise and physical height of the source. The plume rise depends on the gas exit velocity and gas temperature. That relation is necessary for diminishing the environmental pollution when the production capacity of the plant varies, in comparison with the nominal one.

  2. Prototype particulate stack sampler with single-cut nozzle and microcomputer calculating/display system

    International Nuclear Information System (INIS)

    Eler, J.C.; Littlefield, L.G.; Tillery, M.I.

    1979-01-01

    A prototype particulate stack sampler (PPSS) has been developed to improve on the existing EPA Method 5 sampling apparatus. Its primary features are (1) higher sampling rate (56 1/min); (2) display (on demand) of all required variables and calculated values by a microcomputer-based calculating and display system; (3) continuous stack gas moisture determination; (4) a virtual impactor nozzle with 3 μm mass median diameter cutpoint which collects fine and coarse particle fractions on separate glass fiber filters; (5) a variable-area inlet to maintain isokinetic sampling conditions; and (6) conversion to stainless steel components from the glass specified by EPA Method 5. The basic sampling techniques of EPA Method 5 have been retained; however, versatility in the form of optional in-stack filters and general modernization of the stack sampler have been provided in the prototype design. Laboratory testing with monodisperse dye aerosols has shown the present variable inlet, virtual impactor nozzle to have a collection efficiency which is less than 77% and significant wall losses. This is primarily due to lack of symmetry in this rectangular jet impactor and short transition lengths dictated by physical design constraints (required passage of the nozzle through a 7.6 cm (3 in) diameter stack port). Electronic components have shown acceptable service in laboratory testing although no field testing of the prototype under a broad range of temperature, humidity, and SO 2 concentration has been undertaken

  3. Indoor air pollution

    International Nuclear Information System (INIS)

    Anwar, J.; Hussain, F.

    2005-01-01

    Indoor air pollution after being a neglected subject for a number of years, is attracting attention recently because it is a side effect of energy crisis. About 50% of world's 6 billion population, mostly in developing countries, depend on biomass and coal in the form of wood, dung and crop residues for domestic energy because of poverty. These materials are burnt in simple stoves with incomplete combustion and infants, children and women are exposed to high levels of indoor air pollution for a considerable period, approximately between 2-4 hours daily. Current worldwide trade in wood fuel is over US $7 billion and about 2 million people are employed full time in production and marketing it. One of the most annoying and common indoor pollutant in both, developing and developed countries, is cigarette smoke. Children in gas-equipped homes had higher incidences of respiratory disease. Babies' DNA can be damaged even before they are born if their mothers breathe polluted air. Exposure to indoor air pollution may be responsible for nearly 2 million excess deaths in developing countries and for 4% of the global burden of the disease. Only a few indoor pollutants have been studied in detail. Indoor air pollution is a major health threat on which further research is needed to define the extent of the problem more precisely and to determine solutions by the policy-makers instead of neglecting it because sufferers mostly belong to Third World countries. (author)

  4. Air Pollution

    Science.gov (United States)

    ... Health Lead Mercury Mold Nanomaterials Ozone Perfluorinated Chemicals Pesticides Radon Soy Infant Formula Styrene Water Pollution Weather ... government and non-government websites covering specific environmental, biological, and chemical agents that cause indoor air pollution. ...

  5. Water pollution

    OpenAIRE

    Institute, Marine

    2013-01-01

    Students will learn about what causes water pollution and how to be environmentally aware. *Note: Students should understand the concept of the water cycle before moving onto water pollution (see Lesson Plan “Oceans all Around Us”).

  6. Noise Pollution

    Science.gov (United States)

    ... Us Share Clean Air Act Title IV - Noise Pollution The 1990 Clean Air Act Amendments added a ... abatement 7642 Authorization of appropriations What is Noise Pollution? The traditional definition of noise is “unwanted or ...

  7. Contemporary sample stacking in analytical electrophoresis

    Czech Academy of Sciences Publication Activity Database

    Šlampová, Andrea; Malá, Zdeňka; Pantůčková, Pavla; Gebauer, Petr; Boček, Petr

    2013-01-01

    Roč. 34, č. 1 (2013), s. 3-18 ISSN 0173-0835 R&D Projects: GA ČR GAP206/10/1219 Institutional support: RVO:68081715 Keywords : biological samples * stacking * trace analysis * zone electrophoresis Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 3.161, year: 2013

  8. SRS reactor stack plume marking tests

    International Nuclear Information System (INIS)

    Petry, S.F.

    1992-03-01

    Tests performed in 105-K in 1987 and 1988 demonstrated that the stack plume can successfully be made visible (i.e., marked) by introducing smoke into the stack breech. The ultimate objective of these tests is to provide a means during an emergency evacuation so that an evacuee can readily identify the stack plume and evacuate in the opposite direction, thus minimizing the potential of severe radiation exposure. The EPA has also requested DOE to arrange for more tests to settle a technical question involving the correct calculation of stack downwash. New test canisters were received in 1988 designed to produce more smoke per unit time; however, these canisters have not been evaluated, because normal ventilation conditions have not been reestablished in K Area. Meanwhile, both the authorization and procedure to conduct the tests have expired. The tests can be performed during normal reactor operation. It is recommended that appropriate authorization and procedure approval be obtained to resume testing after K Area restart

  9. Testing of Electrodes, Cells and Short Stacks

    DEFF Research Database (Denmark)

    Hauch, Anne; Mogensen, Mogens Bjerg

    2017-01-01

    The present contribution describes the electrochemical testing and characterization of electrodes, cells, and short stacks. To achieve the maximum insight and results from testing of electrodes and cells, it is obviously necessary to have a good understanding of the fundamental principles...

  10. OpenStack Object Storage (Swift) essentials

    CERN Document Server

    Kapadia, Amar; Varma, Sreedhar

    2015-01-01

    If you are an IT administrator and you want to enter the world of cloud storage using OpenStack Swift, then this book is ideal for you. Basic knowledge of Linux and server technology is beneficial to get the most out of the book.

  11. Stacked spheres and lower bound theorem

    Indian Academy of Sciences (India)

    BASUDEB DATTA

    2011-11-20

    Nov 20, 2011 ... Preliminaries. Lower bound theorem. On going work. Definitions. An n-simplex is a convex hull of n + 1 affinely independent points. (called vertices) in some Euclidean space R. N . Stacked spheres and lower bound theorem. Basudeb Datta. Indian Institute of Science. 2 / 27 ...

  12. Contemporary sample stacking in analytical electrophoresis

    Czech Academy of Sciences Publication Activity Database

    Malá, Zdeňka; Šlampová, Andrea; Křivánková, Ludmila; Gebauer, Petr; Boček, Petr

    2015-01-01

    Roč. 36, č. 1 (2015), s. 15-35 ISSN 0173-0835 R&D Projects: GA ČR(CZ) GA13-05762S Institutional support: RVO:68081715 Keywords : biological samples * stacking * trace analysis * zone electrophoresis Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 2.482, year: 2015

  13. The data type variety of stack algebras

    NARCIS (Netherlands)

    Bergstra, J.A.; Tucker, J.V.

    1995-01-01

    We define and study the class of all stack algebras as the class of all minimal algebras in a variety defined by an infinite recursively enumerable set of equations. Among a number of results, we show that the initial model of the variety is computable, that its equational theory is decidable,

  14. Photoswitchable Intramolecular H-Stacking of Perylenebisimide

    NARCIS (Netherlands)

    Wang, Jiaobing; Kulago, Artem; Browne, Wesley R.; Feringa, Ben L.

    2010-01-01

    Dynamic control over the formation of H- or J-type aggregates of chromophores is of fundamental importance for developing responsive organic optoelectronic materials. In this study, the first example of photoswitching between a nonstacked and an intramolecularly H-stacked arrangement of

  15. 40 CFR 61.53 - Stack sampling.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 8 2010-07-01 2010-07-01 false Stack sampling. 61.53 Section 61.53 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) NATIONAL... sampling. (a) Mercury ore processing facility. (1) Unless a waiver of emission testing is obtained under...

  16. 40 CFR 61.33 - Stack sampling.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 8 2010-07-01 2010-07-01 false Stack sampling. 61.33 Section 61.33 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) NATIONAL... sampling. (a) Unless a waiver of emission testing is obtained under § 61.13, each owner or operator...

  17. OpenStack cloud computing cookbook

    CERN Document Server

    Jackson, Kevin

    2013-01-01

    A Cookbook full of practical and applicable recipes that will enable you to use the full capabilities of OpenStack like never before.This book is aimed at system administrators and technical architects moving from a virtualized environment to cloud environments with familiarity of cloud computing platforms. Knowledge of virtualization and managing linux environments is expected.

  18. THE DETERMINATION THE POLLUTION EMISSIONS OF SO2, NOX, CO, CO2 AND O2 FROM THE CHANNELS OF BURNT GAS ON BOILER OF 420 T/H - STEAM, IN THE SIGHT APPLICATION PROCEEDING TO REDUCE OF THESE

    Directory of Open Access Journals (Sweden)

    Valentin Nedeff

    2007-03-01

    Full Text Available The work present the results obtained after dynamic analyze the pollution emissions of SO2, NOx, CO, CO2 and O2 on evacuation channels of burnt gas on boiler of 420 t/h steam, having right the basic combustible the lignite, and auxiliary combustible the fuel oil and the natural gas. The values of pollution emission was analyze beside the admissible maxims values required by European legislation for Romania in the year 2005. The conclusion elaborated it adverted to: the values of oxides azoth, carry they frame in the limits provide in Environmental Authorization, under 60 mg/Nmc on 6% oxygen, the concentration values of SO2 which was bigger in report with one authorized comprised between 3500-3900 mg/Nmc confronted by 3400 mg/Nm. For integration in the foresee Government Decision 541/2003 aren't sufficient just proceeding of below reduce SO2, must take and another measures such as: get the fuel with quantity of sulphur 0.5% and with a content of ash below 35%.

  19. Air pollution and dry deposition of nitrogen and sulphur in the AOSR estimated using passive samplers

    Science.gov (United States)

    Yu-Mei Hsu; Andrzej Bytnerowicz

    2015-01-01

    NO2 and SO2 are the primary pollutants produced by industrial facilities of the Athabasca Oil sand Region (AOSR), Alberta, Canada. The major emission sources are the upgrader stacks for SO2 and stacks, mine fleets and vehicles for NO2. After emitting from the sources, NO

  20. Air Pollution.

    Science.gov (United States)

    Barker, K.; And Others

    Pollution of the general environment, which exposes an entire population group for an indeterminate period of time, certainly constitutes a problem in public health. Serious aid pollution episodes have resulted in increased mortality and a possible relationship between chronic exposure to a polluted atmosphere and certain diseases has been…

  1. Water Pollution

    International Nuclear Information System (INIS)

    Goni, J.

    1984-01-01

    This work is about the water pollution. The air and the water interaction cycles is the main idea of the geochemical pollution conception. In the water surface as well as in the deep aquifers we can found cough metals or minerals from the athmosferic air. The activities of mercury fluor and nitrates are important to the pollution study

  2. Oil pollution

    International Nuclear Information System (INIS)

    Mankabady, Samir.

    1994-08-01

    Oil enters the marine environment when it is discharged, or has escaped, during transport, drilling, shipping, accidents, dumping and offshore operations. This book serves as a reference both on the various complex international operational and legal matters of oil pollution using examples such as the Exxon Valdez, the Braer and Lord Donaldson's report. The chapters include the development of international rules on the marine environment, the prevention of marine pollution from shipping activities, liability for oil pollution damage, the conflict of the 1990 Oil Pollution Act and the 1992 protocols and finally the cooperation and response to pollution incidents. (UK)

  3. Experimental study on the influence of the porosity of parallel plate stack on the temperature decrease of a thermoacoustic refrigerator

    International Nuclear Information System (INIS)

    Setiawan, Ikhsan; Utomo, Agung Bambang Setio; Mitrayana; Katsuta, Masafumi; Nohtomi, Makoto

    2013-01-01

    Thermoacoustic refrigerators are cooling devices which are environmentally friendly because they don't use hazardous gases like chlorofuorocarbons (CFCs) or hydrofuorocarbons (HFCs) but rather air or inert gases as working medium. They apply sound wave with high intensity to pump heat from the cold to hot the regions through a stack in a resonator tube. One of the important parameters of thermoacoustic refrigerators is the porosity (blockage ratio) of stack which is a fraction of cross sectional area of the resonator unblocked for the gas movement by the stack. This paper describes an experimental study on how the porosity of parallel plate stack affects the temperature decrease of a thermoacoustic refrigerator. The porosity of parallel plate stack is specified by the thickness of plates and the spacing between plates. We measured the maximum temperature decreases of thermacoustic refrigerator using stacks with various porosities in the range of 0.5 – 0.85, with plate spacing from 0.5 mm to 1.5 mm and plate thicknesses 0.3 mm, 0.4 mm, and 0.5 mm. The measurements were done with two resonators with length of 0.8 m and 1.0 m, with air at atmospheric pressure and room temperature, correspond to thermal penetration depths (δ κ ) of 0.26 mm and 0.29 mm, respectively. It was found that there is an optimum porosity which gives the largest temperature decreases, and there is a tendency that the optimum porosity shifts to a larger value and the temperature decrease become larger when we used a stack with thinner plates. On the other hand, the study on the dependence of the temperature decrease on the plate thickness and the plate spacing reveals more useful information than that on the stack porosity itself. We found that stack with thinner plates tends to give larger temperature decrease, and the plate spacing of around 4δ κ leads to the largest temperature decrease.

  4. Project W-420 Stack Monitoring system upgrades conceptual design report

    Energy Technology Data Exchange (ETDEWEB)

    TUCK, J.A.

    1998-11-06

    This document describes the scope, justification, conceptual design, and performance of Project W-420 stack monitoring system upgrades on six NESHAP-designated, Hanford Tank Farms ventilation exhaust stacks.

  5. Heuristic Solution Approaches to the Double TSP with Multiple Stacks

    DEFF Research Database (Denmark)

    Petersen, Hanne Løhmann

    This paper introduces the Double Travelling Salesman Problem with Multiple Stacks and presents a three different metaheuristic approaches to its solution. The Double Travelling Salesman Problem with Multiple Stacks is concerned with finding the shortest route performing pickups and deliveries...

  6. Heuristic Solution Approaches to the Double TSP with Multiple Stacks

    DEFF Research Database (Denmark)

    Petersen, Hanne Løhmann

    2006-01-01

    This paper introduces the Double Travelling Salesman Problem with Multiple Stacks and presents a three different metaheuristic approaches to its solution. The Double Travelling Salesman Problem with Multiple Stacks is concerned with finding the shortest route performing pickups and deliveries...

  7. East Asian SO2 pollution plume over Europe – Part 1: Airborne trace gas measurements and source identification by particle dispersion model simulations

    Directory of Open Access Journals (Sweden)

    A. Stohl

    2009-07-01

    Full Text Available A large SO2-rich pollution plume of East Asian origin was detected by aircraft based CIMS (Chemical Ionization Mass Spectrometry measurements at 3–7.5 km altitude over the North Atlantic. The measurements, which took place on 3 May 2006 aboard of the German research aircraft Falcon, were part of the INTEX-B (Intercontinental Chemical Transport Experiment-B campaign. Additional trace gases (NO, NOy, CO, H2O were measured and used for comparison and source identification. The atmospheric SO2 mole fraction was markedly increased inside the plume and reached up to 900 pmol/mol. Accompanying lagrangian FLEXPART particle dispersion model simulations indicate that the probed pollution plume originated at low altitudes from densely populated and industrialized regions of East Asia, primarily China, about 8–12 days prior to the measurements.

  8. DEVS Models of Palletized Ground Stacking in Storeyed Grain Warehouse

    Directory of Open Access Journals (Sweden)

    Hou Shu-Yi

    2016-01-01

    Full Text Available Processed grain stored in storeyed warehouse is generally stacked on the ground without pallets. However, in order to improve the storing way, we developed a new stacking method, palletized ground stacking. Simulation should be used to present this new storing way. DEVS provides a formalized way to describe the system model. In this paper, DEVS models of palletized ground stacking in storeyed grain warehouse are given and a simulation model is developed by AutoMod.

  9. Air pollution in the Slovak Republic, 2001

    International Nuclear Information System (INIS)

    Mitosinkova, M.; Kozakovic, L.; Zavodsky, D.; Sajtakova, E.; Mareckova, K.; Pukancikova, K.

    2003-01-01

    A report on air quality and contribution of individual sources on its pollution in the Slovak Republic in 2001 is presented. This report consists of two parts: (1) Ambient air and (2) Emission. Ambient air part is divided into the following chapters: Regional air pollution and quality of precipitation; Local air pollution; Atmospheric ozone. Emission part is divided into the following chapters: Emission and air pollution source inventory, Greenhouse gas emissions

  10. Greenhouse gas and air pollutant emission reduction potentials of renewable energy--case studies on photovoltaic and wind power introduction considering interactions among technologies in Taiwan.

    Science.gov (United States)

    Kuo, Yu-Ming; Fukushima, Yasuhiro

    2009-03-01

    To achieve higher energy security and lower emission of greenhouse gases (GHGs) and pollutants, the development of renewable energy has attracted much attention in Taiwan. In addition to its contribution to the enhancement of reliable indigenous resources, the introduction of renewable energy such as photovoltaic (PV) and wind power systems reduces the emission of GHGs and air pollutants by substituting a part of the carbon- and pollutant-intensive power with power generated by methods that are cleaner and less carbon-intensive. To evaluate the reduction potentials, consequential changes in the operation of different types of existing power plants have to be taken into account. In this study, a linear mathematical programming model is constructed to simulate a power mix for a given power demand in a power market sharing a cost-minimization objective. By applying the model, the emission reduction potentials of capacity extension case studies, including the enhancement of PV and wind power introduction at different scales, were assessed. In particular, the consequences of power mix changes in carbon dioxide, nitrogen oxides, sulfur oxides, and particulates were discussed. Seasonally varying power demand levels, solar irradiation, and wind strength were taken into account. In this study, we have found that the synergetic reduction of carbon dioxide emission induced by PV and wind power introduction occurs under a certain level of additional installed capacity. Investigation of a greater variety of case studies on scenario development with emerging power sources becomes possible by applying the model developed in this study.

  11. Sport stacking motor intervention programme for children with ...

    African Journals Online (AJOL)

    The purpose of this study was to explore sport stacking as an alternative intervention approach with typically developing children and in addition to improve DCD. Sport stacking consists of participants stacking and unstacking 12 specially designed plastic cups in predetermined sequences in as little time as possible.

  12. Notes on G-theory of Deligne-Mumford stacks

    OpenAIRE

    Toen, B.

    1999-01-01

    Based on the methods used by the author to prove the Riemann-Roch formula for algebraic stacks, this paper contains a description of the rationnal G-theory of Deligne-Mumford stacks over general bases. We will use these results to study equivariant K-theory, and also to define new filtrations on K-theory of algebraic stacks.

  13. Learning algorithms for stack filter classifiers

    Energy Technology Data Exchange (ETDEWEB)

    Porter, Reid B [Los Alamos National Laboratory; Hush, Don [Los Alamos National Laboratory; Zimmer, Beate G [TEXAS A& M

    2009-01-01

    Stack Filters define a large class of increasing filter that is used widely in image and signal processing. The motivations for using an increasing filter instead of an unconstrained filter have been described as: (1) fast and efficient implementation, (2) the relationship to mathematical morphology and (3) more precise estimation with finite sample data. This last motivation is related to methods developed in machine learning and the relationship was explored in an earlier paper. In this paper we investigate this relationship by applying Stack Filters directly to classification problems. This provides a new perspective on how monotonicity constraints can help control estimation and approximation errors, and also suggests several new learning algorithms for Boolean function classifiers when they are applied to real-valued inputs.

  14. Industrial stacks design; Diseno de chimeneas industriales

    Energy Technology Data Exchange (ETDEWEB)

    Cacheux, Luis [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1986-12-31

    The Instituto de Investigaciones Electricas (IIE) though its Civil Works Department, develops, under contract with CFE`s Gerencia de Proyectos Termoelectricos (Management of Fossil Power Plant Projects), a series of methods for the design of stacks, which pretends to solve the a present day problem: the stack design of the fossil power plants that will go into operation during the next coming years in the country. [Espanol] El Instituto de Investigaciones Electricas (IIE), a traves del Departamento de Ingenieria Civil, desarrolla, bajo contrato con la Gerencia de Proyectos Termoelectricos, de la Comision Federal de Electricidad (CFE), un conjunto de metodos para el diseno de chimeneas, con el que se pretende resolver un problema inmediato: el diseno de las chimeneas de las centrales termoelectricas que entraran en operacion durante los proximos anos, en el pais.

  15. Annular feed air breathing fuel cell stack

    Science.gov (United States)

    Wilson, Mahlon S.

    1996-01-01

    A stack of polymer electrolyte fuel cells is formed from a plurality of unit cells where each unit cell includes fuel cell components defining a periphery and distributed along a common axis, where the fuel cell components include a polymer electrolyte membrane, an anode and a cathode contacting opposite sides of the membrane, and fuel and oxygen flow fields contacting the anode and the cathode, respectively, wherein the components define an annular region therethrough along the axis. A fuel distribution manifold within the annular region is connected to deliver fuel to the fuel flow field in each of the unit cells. In a particular embodiment, a single bolt through the annular region clamps the unit cells together. In another embodiment, separator plates between individual unit cells have an extended radial dimension to function as cooling fins for maintaining the operating temperature of the fuel cell stack.

  16. System for inspection of stacked cargo containers

    Science.gov (United States)

    Derenzo, Stephen [Pinole, CA

    2011-08-16

    The present invention relates to a system for inspection of stacked cargo containers. One embodiment of the invention generally comprises a plurality of stacked cargo containers arranged in rows or tiers, each container having a top, a bottom a first side, a second side, a front end, and a back end; a plurality of spacers arranged in rows or tiers; one or more mobile inspection devices for inspecting the cargo containers, wherein the one or more inspection devices are removeably disposed within the spacers, the inspection means configured to move through the spacers to detect radiation within the containers. The invented system can also be configured to inspect the cargo containers for a variety of other potentially hazardous materials including but not limited to explosive and chemical threats.

  17. Multistage Force Amplification of Piezoelectric Stacks

    Science.gov (United States)

    Xu, Tian-Bing (Inventor); Siochi, Emilie J. (Inventor); Zuo, Lei (Inventor); Jiang, Xiaoning (Inventor); Kang, Jin Ho (Inventor)

    2015-01-01

    Embodiments of the disclosure include an apparatus and methods for using a piezoelectric device, that includes an outer flextensional casing, a first cell and a last cell serially coupled to each other and coupled to the outer flextensional casing such that each cell having a flextensional cell structure and each cell receives an input force and provides an output force that is amplified based on the input force. The apparatus further includes a piezoelectric stack coupled to each cell such that the piezoelectric stack of each cell provides piezoelectric energy based on the output force for each cell. Further, the last cell receives an input force that is the output force from the first cell and the last cell provides an output apparatus force In addition, the piezoelectric energy harvested is based on the output apparatus force. Moreover, the apparatus provides displacement based on the output apparatus force.

  18. Radiation-Tolerant Intelligent Memory Stack - RTIMS

    Science.gov (United States)

    Ng, Tak-kwong; Herath, Jeffrey A.

    2011-01-01

    This innovation provides reconfigurable circuitry and 2-Gb of error-corrected or 1-Gb of triple-redundant digital memory in a small package. RTIMS uses circuit stacking of heterogeneous components and radiation shielding technologies. A reprogrammable field-programmable gate array (FPGA), six synchronous dynamic random access memories, linear regulator, and the radiation mitigation circuits are stacked into a module of 42.7 42.7 13 mm. Triple module redundancy, current limiting, configuration scrubbing, and single- event function interrupt detection are employed to mitigate radiation effects. The novel self-scrubbing and single event functional interrupt (SEFI) detection allows a relatively soft FPGA to become radiation tolerant without external scrubbing and monitoring hardware

  19. Absorption spectra of AA-stacked graphite

    International Nuclear Information System (INIS)

    Chiu, C W; Lee, S H; Chen, S C; Lin, M F; Shyu, F L

    2010-01-01

    AA-stacked graphite shows strong anisotropy in geometric structures and velocity matrix elements. However, the absorption spectra are isotropic for the polarization vector on the graphene plane. The spectra exhibit one prominent plateau at middle energy and one shoulder structure at lower energy. These structures directly reflect the unique geometric and band structures and provide sufficient information for experimental fitting of the intralayer and interlayer atomic interactions. On the other hand, monolayer graphene shows a sharp absorption peak but no shoulder structure; AA-stacked bilayer graphene has two absorption peaks at middle energy and abruptly vanishes at lower energy. Furthermore, the isotropic features are expected to exist in other graphene-related systems. The calculated results and the predicted atomic interactions could be verified by optical measurements.

  20. 25 CFR 226.22 - Prohibition of pollution.

    Science.gov (United States)

    2010-04-01

    ... 25 Indians 1 2010-04-01 2010-04-01 false Prohibition of pollution. 226.22 Section 226.22 Indians... LANDS FOR OIL AND GAS MINING Operations § 226.22 Prohibition of pollution. (a) All operators... holes) in a manner that will prevent pollution and the migration of oil, gas, salt water or other...

  1. CAM and stack air sampler design guide

    International Nuclear Information System (INIS)

    Phillips, T.D.

    1994-01-01

    About 128 air samplers and CAMs presently in service to detect and document potential radioactive release from 'H' and 'F' area tank farm ventilation stacks are scheduled for replacement and/or upgrade by Projects S-5764, S-2081, S-3603, and S-4516. The seven CAMs scheduled to be upgraded by Project S-4516 during 1995 are expected to provide valuable experience for the three remaining projects. The attached document provides design guidance for the standardized High Level Waste air sampling system

  2. Contemporary sample stacking in analytical electrophoresis

    Czech Academy of Sciences Publication Activity Database

    Malá, Zdeňka; Gebauer, Petr; Boček, Petr

    2011-01-01

    Roč. 32, č. 1 (2011), s. 116-126 ISSN 0173-0835 R&D Projects: GA ČR GA203/08/1536; GA ČR GAP206/10/1219; GA AV ČR IAA400310703 Institutional research plan: CEZ:AV0Z40310501 Keywords : biological samples * stacking * trace analysis * zone electrophoresis Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 3.303, year: 2011

  3. Stacked Switched Capacitor Energy Buffer Architecture

    OpenAIRE

    Chen, Minjie; Perreault, David J.; Afridi, Khurram

    2012-01-01

    Electrolytic capacitors are often used for energy buffering applications, including buffering between single-phase ac and dc. While these capacitors have high energy density compared to film and ceramic capacitors, their life is limited. This paper presents a stacked switched capacitor (SSC) energy buffer architecture and some of its topological embodiments, which when used with longer life film capacitors overcome this limitation while achieving effective energy densities comparable to elect...

  4. Thyristor stack for pulsed inductive plasma generation.

    Science.gov (United States)

    Teske, C; Jacoby, J; Schweizer, W; Wiechula, J

    2009-03-01

    A thyristor stack for pulsed inductive plasma generation has been developed and tested. The stack design includes a free wheeling diode assembly for current reversal. Triggering of the device is achieved by a high side biased, self supplied gate driver unit using gating energy derived from a local snubber network. The structure guarantees a hard firing gate pulse for the required high dI/dt application. A single fiber optic command is needed to achieve a simultaneous turn on of the thyristors. The stack assembly is used for switching a series resonant circuit with a ringing frequency of 30 kHz. In the prototype pulsed power system described here an inductive discharge has been generated with a pulse duration of 120 micros and a pulse energy of 50 J. A maximum power transfer efficiency of 84% and a peak power of 480 kW inside the discharge were achieved. System tests were performed with a purely inductive load and an inductively generated plasma acting as a load through transformer action at a voltage level of 4.1 kV, a peak current of 5 kA, and a current switching rate of 1 kA/micros.

  5. Electrochemical Detection in Stacked Paper Networks.

    Science.gov (United States)

    Liu, Xiyuan; Lillehoj, Peter B

    2015-08-01

    Paper-based electrochemical biosensors are a promising technology that enables rapid, quantitative measurements on an inexpensive platform. However, the control of liquids in paper networks is generally limited to a single sample delivery step. Here, we propose a simple method to automate the loading and delivery of liquid samples to sensing electrodes on paper networks by stacking multiple layers of paper. Using these stacked paper devices (SPDs), we demonstrate a unique strategy to fully immerse planar electrodes by aqueous liquids via capillary flow. Amperometric measurements of xanthine oxidase revealed that electrochemical sensors on four-layer SPDs generated detection signals up to 75% higher compared with those on single-layer paper devices. Furthermore, measurements could be performed with minimal user involvement and completed within 30 min. Due to its simplicity, enhanced automation, and capability for quantitative measurements, stacked paper electrochemical biosensors can be useful tools for point-of-care testing in resource-limited settings. © 2015 Society for Laboratory Automation and Screening.

  6. Mission achieved - in spite of desorption and rediffusion. Remediation of land pollution at the site of the former gas works of Biberach a.d. Riss; Trotz Desorption und Rueckdiffusion ans Ziel. Altlastensanierung des ehemaligen Gaswerks Biberach a.d. Riss

    Energy Technology Data Exchange (ETDEWEB)

    Osberghaus, T.; Zwisler, R.

    2007-07-15

    The land pollution commission of the German state of Baden-Wuerttemberg at the site of the former gas works of Biberach decided that 6500 cubic metres of soil should be exchanged. Down to a depth of 2.5 m, this was done by conventional methods. Down to 7 m, i.e. at groundwater level, the polluted soil will be removed via large-diameter boreholes. Of course, it is not the technology that is important but the goal to be achieved. The contribution therefore discusses the time required for reaching the depollution goal, i.e. how fast groundwater pollution in the discharge should be removed. (orig.)

  7. Impacts of an African Green Revolution on Greenhouse Gases and Pollution Precursors: Nonlinear Trace N Gas Emission Responses to Incremental Increases in Fertilizer Inputs in a Western Kenyan Maize Field

    Science.gov (United States)

    Hickman, J. E.; Palm, C.

    2011-12-01

    Over the last several decades, agricultural soils in many parts of sub-Saharan Africa have become depleted of nitrogen (N) and other nutrients, creating challenges to achieving food security in many countries. At only 7 kg N ha-1 yr-1, average fertilizer application rates in the region are an order of magnitude lower than typical rates in the United States, and well below optimal levels. Increased use of nutrient inputs is a centerpiece of most African Green Revolution strategies, making it important to quantify the impacts of this change in practices as farmers begin moving towards 50-80 kg N ha-1 yr-1. Increased N inputs are invariably accompanied by losses of trace N gases to the atmosphere, including the greenhouse gas nitrous oxide (N2O), and nitric oxide (NO), a precursor to tropospheric ozone pollution. Several investigations of greenhouse gas emissions and one investigation of NO emissions from sub-Saharan agricultural systems have been conducted over the last 20 years, but they are few in number and were not designed to identify potentially important thresholds in the response of trace gas emissions to fertilization rate. Here we examine the response function of NO and N2O emissions to 6 different levels of inorganic fertilizer additions in a maize field in Yala, Kenya during the 2011 long rainy season. We used a randomized complete block design incorporating inorganic fertilizer treatments of 0, 50, 75, 100, 150, and 200 kg N ha-1 in 4 blocks. After each of 2 fertilizer applications, we measured trace gas fluxes daily, and conducted weekly measurements until trace gas emissions subsided to control levels. We fit the data to linear and exponential models relating N gas emissions to N input levels, and conducted a model comparison using AIC. Preliminary analysis suggests that NO emissions do respond in a non-linear fashion over the course of 67 days, as has been found in several commercial agroecosystems for N2O. Although N2O emissions responded linearly

  8. Guanine base stacking in G-quadruplex nucleic acids

    Science.gov (United States)

    Lech, Christopher Jacques; Heddi, Brahim; Phan, Anh Tuân

    2013-01-01

    G-quadruplexes constitute a class of nucleic acid structures defined by stacked guanine tetrads (or G-tetrads) with guanine bases from neighboring tetrads stacking with one another within the G-tetrad core. Individual G-quadruplexes can also stack with one another at their G-tetrad interface leading to higher-order structures as observed in telomeric repeat-containing DNA and RNA. In this study, we investigate how guanine base stacking influences the stability of G-quadruplexes and their stacked higher-order structures. A structural survey of the Protein Data Bank is conducted to characterize experimentally observed guanine base stacking geometries within the core of G-quadruplexes and at the interface between stacked G-quadruplex structures. We couple this survey with a systematic computational examination of stacked G-tetrad energy landscapes using quantum mechanical computations. Energy calculations of stacked G-tetrads reveal large energy differences of up to 12 kcal/mol between experimentally observed geometries at the interface of stacked G-quadruplexes. Energy landscapes are also computed using an AMBER molecular mechanics description of stacking energy and are shown to agree quite well with quantum mechanical calculated landscapes. Molecular dynamics simulations provide a structural explanation for the experimentally observed preference of parallel G-quadruplexes to stack in a 5′–5′ manner based on different accessible tetrad stacking modes at the stacking interfaces of 5′–5′ and 3′–3′ stacked G-quadruplexes. PMID:23268444

  9. Final Report - MEA and Stack Durability for PEM Fuel Cells

    Energy Technology Data Exchange (ETDEWEB)

    Yandrasits, Michael A.

    2008-02-15

    Proton exchange membrane fuel cells are expected to change the landscape of power generation over the next ten years. For this to be realized one of the most significant challenges to be met for stationary systems is lifetime, where 40,000 hours of operation with less than 10% decay is desired. This project conducted fundamental studies on the durability of membrane electrode assemblies (MEAs) and fuel cell stack systems with the expectation that knowledge gained from this project will be applied toward the design and manufacture of MEAs and stack systems to meet DOE’s 2010 stationary fuel cell stack systems targets. The focus of this project was PEM fuel cell durability – understanding the issues that limit MEA and fuel cell system lifetime, developing mitigation strategies to address the lifetime issues and demonstration of the effectiveness of the mitigation strategies by system testing. To that end, several discoveries were made that contributed to the fundamental understanding of MEA degradation mechanisms. (1) The classically held belief that membrane degradation is solely due to end-group “unzipping” is incorrect; there are other functional groups present in the ionomer that are susceptible to chemical attack. (2) The rate of membrane degradation can be greatly slowed or possibly eliminated through the use of additives that scavenge peroxide or peroxyl radicals. (3) Characterization of GDL using dry gases is incorrect due to the fact that fuel cells operate utilizing humidified gases. The proper characterization method involves using wet gas streams and measuring capillary pressure as demonstrated in this project. (4) Not all Platinum on carbon catalysts are created equally – the major factor impacting catalyst durability is the type of carbon used as the support. (5) System operating conditions have a significant impact of lifetime – the lifetime was increased by an order of magnitude by changing the load profile while all other variables remain

  10. Air Pollution

    OpenAIRE

    Ababsa, Myriam

    2014-01-01

    The human costs of air pollution are considerable in Jordan. According to a report published in 2000 by the World Bank under the Mediterranean Environmental Technical Assistance Program (METAP), approximately 600 people die prematurely each year in Jordan because of urban pollution. 50-90% of air pollution in Jordanian towns is caused by road traffic. Readings taken in 2007 by Jordanian researchers showed that levels of black carbon particles in the air were higher in urban areas (caused by v...

  11. Information Pollution

    OpenAIRE

    Noruzi, Alireza

    2000-01-01

    The exponential growth of information resources creates new challenges for end-users. The correct information may be polluted by misinformation, disinformation, propaganda or incorrect information via the Internet and other media. This paper defines 'information pollution' as "the contamination of information by misinformation, disinformation, propaganda and incorrect information." The purpose of this paper is to present the methods of information pollution. It is concluded that it is sometim...

  12. Enviormental Pollution

    OpenAIRE

    Kanika Saini; Dr. Sona Malhotra

    2016-01-01

    Environment Pollution is one of the greatest problems today which is increasing with every passing year and causing crucial and severe damage to the earth. It has become a real problem since the beginning of the industrial revolution. It is the contamination of physical and biological components of the Earth / atmosphere system to such an extent that normal environmental processes are harmed. Pollution of the environment consists of five main types of pollution, namely air, water,...

  13. Environmental pollution

    International Nuclear Information System (INIS)

    Odzuck, W.

    1982-01-01

    The volume of the anthropogenic pollution of the environment (incl. radioactivity) is of great economical importance and has also a meaning to the health and happiness of people. The pocket book introduces into the whole problem by giving exact information and data. After a general survey, the pollutions of urban-industrial, and aquatic ecosystems are dealt with. The book closes with indications as to general principles, specific dangers, and the fature development of the environmental pollution. (orig.) [de

  14. Electric Engines to Gas

    International Nuclear Information System (INIS)

    Novoa, M.G.

    1996-01-01

    Environmental pollution and specially air pollution, it is produced in a wide range by exhaust gases of internal combustion engines, those which are used to generate energy. Direct use of fossil combustibles as petroleum derivatives and coal produces large quantities of harmful elements to ecology equilibrium. Whit the objective of reducing this pollutant load has been development thermoelectric plants whit turbine to gas or to steam, those which are moved by internal combustion engines. Gas engines can burn most of available gases, as both solid waste and wastewater treatment plants biogas, propane gas, oil-liquefied gas or natural gas. These gases are an alternative and clean energy source, and its efficiency in internal combustion engines is highest compared whit other combustibles as gasoline-motor or diesel

  15. Mobile Instruments Measure Atmospheric Pollutants

    Science.gov (United States)

    2009-01-01

    As a part of NASA's active research of the Earth s atmosphere, which has included missions such as the Atmospheric Laboratory of Applications and Science (ATLAS, launched in 1992) and the Total Ozone Mapping Spectrometer (TOMS, launched on the Earth Probe satellite in 1996), the Agency also performs ground-based air pollution research. The ability to measure trace amounts of airborne pollutants precisely and quickly is important for determining natural patterns and human effects on global warming and air pollution, but until recent advances in field-grade spectroscopic instrumentation, this rapid, accurate data collection was limited and extremely difficult. In order to understand causes of climate change and airborne pollution, NASA has supported the development of compact, low power, rapid response instruments operating in the mid-infrared "molecular fingerprint" portion of the electromagnetic spectrum. These instruments, which measure atmospheric trace gases and airborne particles, can be deployed in mobile laboratories - customized ground vehicles, typically - to map distributions of pollutants in real time. The instruments must be rugged enough to operate rapidly and accurately, despite frequent jostling that can misalign, damage, or disconnect sensitive components. By measuring quickly while moving through an environment, a mobile laboratory can correlate data and geographic points, revealing patterns in the environment s pollutants. Rapid pollutant measurements also enable direct determination of pollutant sources and sinks (mechanisms that remove greenhouse gases and pollutants), providing information critical to understanding and managing atmospheric greenhouse gas and air pollutant concentrations.

  16. Method of detecting stacks with leaky fuel elements in liquid-metal-cooled reactor and apparatus for effecting same

    International Nuclear Information System (INIS)

    Aristarkhov, N.N.; Efimov, I.A.; Zaistev, B.I.; Peters, I.G.; Tymosh, B.S.

    1976-01-01

    Described is a method of detecting stacks with leaky fuel elements in a liquid-metal-cooled reactor, consisting in that prior to withdrawing a coolant sample, gas is accumulated in the coolant of the stack being controlled, the reactor being shut down, separated from the sample by means of an inert carrier gas, and the radioactivity of the separated gas is measured. An apparatus for carrying out said method comprises a sampler in the form of a tube parallel to the reactor axis in the hole of a rotating plug and adapted to move along the reactor axis. Made in the top portion of the tube are holes for the introduction of the inert carrier gas and the removal thereof together with the gases evolved from the coolant, while the bottom portion of the tube is provided with a sealing member

  17. Experimental Evaluation of a Pt-based Heat Exchanger Methanol Reformer for a HTPEM Fuel Cell Stack

    DEFF Research Database (Denmark)

    Andreasen, Søren Juhl; Kær, Søren Knudsen; Nielsen, Mads Pagh

    2008-01-01

    and automotive applications. Using a liquid hydrocarbon as e.g. methanol as the hydrogen carrier and reforming it to a hydrogen rich gas can solve some of these storage issues. The work presented here examines the use of a heat exchanger methanol reformer for use with a HTPEM fuel cell stack. Initial...

  18. Development of electrochemical gas sensors for the monitoring of air pollution; Developpement de capteurs de gaz electro-chimiques pour le controle de la pollution de l'air

    Energy Technology Data Exchange (ETDEWEB)

    Billi, E.

    2003-01-15

    In this work, 2 types of ceramic gas sensors obtained by serigraphy have been considered. The first one allows to detect CO and NO{sub x} concentrations in combustion processes. An {alpha} alumina protective coating has been deposited by serigraphy to protect the sensor from the abrasive particulates of the gas flow. A precursor gel has been used instead of the inorganic binder of the serigraphy ink in order to improve the durability of the sensor and to control the porosity of the protective layer. The second type of sensor allows to detect CO{sub 2} in urban environments. It has been entirely developed in this work, from the choice of sensible materials (Nasicon and yttrium zirconia - YSZ) and of the auxiliary electrode (a mixture of Pt and Na{sub 2}CO{sub 3} ink), to the sol-gel synthesis of sensible materials, the realization of serigraphy inks, the deposition of layers and their characterization. However, because of a chemical reaction at the interface of the layers the sensor could not work. Thus, the interface has been characterized by electron microscopy and the chemical reaction is due to a diffusion of yttrium inside Nasicon where it partially substitutes to Zr and changes the structure. Therefore, another sensor has been made using {beta} alumina which does not react with YSZ. The sensor has been electrically characterized and shows a good sensitivity to CO{sub 2} concentration changes between 0.1 and 10000 ppm and a good stability. (J.S.)

  19. A study of the physical factors affecting air pollution dispersion in Helwan

    International Nuclear Information System (INIS)

    Megahed, A.A.

    1992-01-01

    Air pollution is considered as one of the most important environmental problems facing the humanity. Cement industry, usually, is responsible for building high levels of pollutants. The present research focused on the study of air pollution control of cement industry using mathematical modeling. A mathematical dispersion model was developed based on Gaussian distribution where the dispersion parameters increase with increasing atmospheric turbulence. The Gaussian equation takes in consideration the effect of emission rates. stack height, buoyant plume rise, weather and meteorological parameters. The model was tested for different stack heights, wind speeds. And atmospheric stability classes. Maximum ground level concentration of cement pollutants were measured in different locations of Helwan, south Cairo around the cement factories. Analysis of results shows that the ground level of pollutants concentrations are inversely proportional to wind speed and atmospheric stability classes. Stack height also affects the behaviour of deposition of cement particulates. The model results show satisfactory agreement with the measured concentrations. 6 figs

  20. Long-term operation of a solid oxide cell stack for coelectrolysis of steam and CO2

    DEFF Research Database (Denmark)

    Agersted, Karsten; Chen, Ming; Blennow, Peter

    2016-01-01

    High temperature electrolysis based on solid oxide electrolysis cells (SOECs) is a promising technology for production of synthetic fuels. The SOEC units can be used for co-electrolysis of steam and CO2 to produce synthesis gas (syngas, CO+H2), which can be further processed to a variety...... consists of Ni/YSZ electrode supported SOEC cells with a footprint of 12X12 cm2. The co-electrolysis operation was carried out by supplying a mixture of 45 % CO2 + 45 % H2O + 10 % H2 to the stack operating with a fixed conversion of 39 % for steam and CO2. The stack was operated at different conditions...... of synthetic fuels such as methane, methanol or DME. Previously we have reported electrolysis operation of solid oxide cell stacks for periods up to about 1000 hours. In this work, operation of a Haldor Topsoe 8-cell stack (stack design of 2014) in co-electrolysis mode for 6000 hours is reported. The stack...

  1. The impact of plug-in vehicles on greenhouse gas and criteria pollutants emissions in an urban air shed using a spatially and temporally resolved dispatch model

    Science.gov (United States)

    Razeghi, Ghazal; Brown, Tim; Samuelsen, G. Scott

    With the introduction of plug-in vehicles (PEVs) into the light-duty vehicle fleet, the tail-pipe emissions of GHGs and criteria pollutants will be partly transferred to electricity generating units. To study the impact of PEVs on well-to-wheels emissions, the U.S. Western electrical grid serving the South Coast Air Basin (SoCAB) of California is modeled with both spatial and temporal resolution at the level of individual power plants. Electricity load is calculated and projected for future years, and the temporal electricity generation of each power plant within the SoCAB is modeled based on historical data and knowledge of electricity generation and dispatch. Due to the efficiency and pollutant controls governing the performance of the Western grid, the deployment of PEVs results in a daily reduction of greenhouse gases (GHGs) and tail-pipe emissions, especially in the critical morning and afternoon commute hours. The extent of improvement depends on charging scenarios, future grid mix, and the number and type of plug-in vehicles. In addition, charging PEVs using wind energy that would otherwise be curtailed can result in a substantial emissions reduction. Smart control will be required to manage PEV charging in order to mitigate renewable intermittencies and decrease emissions associated with peaking power production.

  2. Monitoring the degradation of a solid oxide fuel cell stack during 10,000 h via electrochemical impedance spectroscopy

    International Nuclear Information System (INIS)

    Comminges, C.; Fu, Q.X.; Zahid, M.; Steiner, N. Yousfi; Bucheli, O.

    2012-01-01

    Highlights: ► Short SOFC stack tested during 10,000 h (simulated reformate gas, fuel utilization 73%). ► In situ electrochemical impedance spectroscopy (EIS) used for diagnosis. ► Stack degradation is mainly attributed to the increased ohmic resistance. ► Incidents happened with the setup accelerated the stack degradation. - Abstract: A 5-cell solid oxide fuel cell stack was tested during 10,000 h of continuous operation with simulated reformate gas as fuel (71 vol.% H 2 , 20.7 vol.% CO 2 and 8.3 vol.% steam) under high fuel utilization (73%) and constant current load (0.5 A cm −2 or 25 A) at 750 °C. In situ electrochemical impedance spectroscopy was used to monitor the evolution of ohmic and polarisation resistances of individual cells in the stack without interrupting the current load. Impedance spectra were recorded on each cell periodically (every 1000 h) or after uncontrolled incidents happened with the test setup. It has been found that the stack degradation is mainly attributed to the increased ohmic resistance, pointing to possible causes such as interconnect corrosion and reduced effective contact areas between cells and interconnects. The degradation rate during the first 5000 h was about 1% kh −1 , but increased afterwards up to 1.5% kh −1 due to the impact of incidents. Both types of incidents (fuel supply fluctuations and overloading failure of the electronic load) were complicated by inhomogeneous fuel distribution among cells, leading to most probably partial re-oxidation of the anode, accelerating the stack degradation.

  3. Air pollution

    International Nuclear Information System (INIS)

    Anon.

    2008-01-01

    Air pollution has accompanied and developed with the industrial age, since its beginnings. This very complete review furnishes the toxicological data available for the principal pollutants and assesses the epidemiologic studies thus far conducted. It also describes European regulations and international commitments for the reduction of emissions. (author)

  4. A Development of 2 kW Molten Carbonate Fuel Cell Stack

    Energy Technology Data Exchange (ETDEWEB)

    Lim, Hee Chun [Korea Electric Power Research Institute, Taejon (Korea, Republic of); Jung, Jong Soo [SAMSUNG HEAVY INDUSTRY (Korea, Republic of); Hong, Sung Ahn [Korea Institute of science and Technology, Seoul (Korea, Republic of)

    1997-12-31

    The molten carbonate fuel cell (MCFC) has been under intensive development during the last decade as the second generation fuel cell, since it has high efficiency at its operating temperature of 650 deg. C and coal gas can be utilized as the fuel. A 2 kW MCFC stack, consisted of 20 cells, was fabricated with 1,000 cm{sup 2}-area electrode and showed 16 volt at 150 A, producing stable power more than 2.4 kW. The test facility was constructed for the evaluation of the stack. The followings are included in this study : 1. Establishment of the scale-up technology of MCFC components. 2. Settling of the unit cell technology and its long term operation. 3. Manufacturing of a small scale stack and establishment of the stack operation. The feasibility study was carried out for the 100 kW class MCFC pilot plant system through the concept design. (author). 12 refs., figs. tabs.

  5. Evaluation of field emission properties from multiple-stacked Si quantum dots

    International Nuclear Information System (INIS)

    Takeuchi, Daichi; Makihara, Katsunori; Ohta, Akio; Ikeda, Mitsuhisa; Miyazaki, Seiichi

    2016-01-01

    Multiple-stacked Si quantum dots (QDs) with ultrathin SiO 2 interlayers were formed on ultrathin SiO 2 layers by repeating a process sequence consisting of the formation of Si-QDs by low pressure chemical vapor deposition using a SiH 4 gas and the surface oxidation and subsequent surface modification by remote hydrogen and oxygen plasmas, respectively. To clarify the electron emission mechanism from multiple-stacked Si-QDs covered with an ultrathin Au top electrode, the energy distribution of the emitted electrons and its electric field dependence was measured using a hemispherical electron energy analyzer in an X-ray photoelectron spectroscopy system under DC bias application to the multiple-stacked Si-QD structure. At − 6 V and over, the energy distributions reached a peak at ~ 2.5 eV with a tail toward the higher energy side. While the electron emission intensity was increased exponentially with an increase in the applied DC bias, there was no significant increase in the emission peak energy. The observed emission characteristics can be interpreted in terms of field emissions from the second and/or third topmost Si-QDs resulting from the electric concentration there. - Highlights: • Electron field emission from 6-fold stack of Si-QDs has been evaluated. • AFM measurements show the local electron emission from individual Si-QDs. • Impact of applied bias on the electron emission energy distribution was investigated.

  6. Computerized method and system for designing an aerodynamic focusing lens stack

    Science.gov (United States)

    Gard, Eric [San Francisco, CA; Riot, Vincent [Oakland, CA; Coffee, Keith [Diablo Grande, CA; Woods, Bruce [Livermore, CA; Tobias, Herbert [Kensington, CA; Birch, Jim [Albany, CA; Weisgraber, Todd [Brentwood, CA

    2011-11-22

    A computerized method and system for designing an aerodynamic focusing lens stack, using input from a designer related to, for example, particle size range to be considered, characteristics of the gas to be flowed through the system, the upstream temperature and pressure at the top of a first focusing lens, the flow rate through the aerodynamic focusing lens stack equivalent at atmosphere pressure; and a Stokes number range. Based on the design parameters, the method and system determines the total number of focusing lenses and their respective orifice diameters required to focus the particle size range to be considered, by first calculating for the orifice diameter of the first focusing lens in the Stokes formula, and then using that value to determine, in iterative fashion, intermediate flow values which are themselves used to determine the orifice diameters of each succeeding focusing lens in the stack design, with the results being output to a designer. In addition, the Reynolds numbers associated with each focusing lens as well as exit nozzle size may also be determined to enhance the stack design.

  7. Present status of coastal pollution in India and future strategies

    Digital Repository Service at National Institute of Oceanography (India)

    Satyanarayana, D.; SenGupta, R.

    environmental assessment, which would concentrate on short- or long-term monitoring of pollution resulting from human settlement, and industrial and agricultural activities. In addition, the threat of pollution associated with offshore oil and gas exploitation...

  8. Tomorrow, gas

    International Nuclear Information System (INIS)

    Icart, Laura; Jean, Pascale; Georget, Cyrille; Schmill, Rafael

    2017-01-01

    This document contains 12 articles notably addressing the importance of natural gas production and supplies in Europe. The themes of the articles are: the advantages of natural gas in the context of energy and environmental policies, energy diversification, energy supply in the local territories, etc.; the position of GrDF, one of the main French natural gas supplier; LPG (butane, propane), a solution which popularity grows in remote areas; the Gaya project (production of renewable gas from dry biomass); a panorama of gas supply routes in Europe; the situation of gas in Europe's energy supply and consumption; the promotion of LNG fuel for maritime and fluvial ships; why the small scale LNG could be the next revolution; presentation of the new 'Honfleur' ferry (using LNG fuel) that will cross the English Channel by 2019; carbon market and the role of ETS for the energy policy in Europe facing the climatic change challenge; presentation of the French 'Climate Plan' that aims to engage France into a carbon neutrality by 2050; presentation of the French policy against air pollution; economic growth, energy, climate: how to square this circle?

  9. Improved Direct Methanol Fuel Cell Stack

    Science.gov (United States)

    Wilson, Mahlon S.; Ramsey, John C.

    2005-03-08

    A stack of direct methanol fuel cells exhibiting a circular footprint. A cathode and anode manifold, tie-bolt penetrations and tie-bolts are located within the circular footprint. Each fuel cell uses two graphite-based plates. One plate includes a cathode active area that is defined by serpentine channels connecting the inlet and outlet cathode manifold. The other plate includes an anode active area defined by serpentine channels connecting the inlet and outlet of the anode manifold, where the serpentine channels of the anode are orthogonal to the serpentine channels of the cathode. Located between the two plates is the fuel cell active region.

  10. NSF tandem stack support structure deflection characteristics

    International Nuclear Information System (INIS)

    Cook, J.

    1979-12-01

    Results are reported of load tests carried out on the glass legs of the insulating stack of the 30 MV tandem Van de Graaff accelerator now under construction at Daresbury Laboratory. The tests to investigate the vulnerability of the legs when subjected to tensile stresses were designed to; establish the angle of rotation of the pads from which the stresses in the glass legs may be calculated, proof-test the structure and at the same time reveal any asymmetry in pad rotations or deflections, and to confirm the validity of the computer design analysis. (UK)

  11. Compliant Glass Seals for SOFC Stacks

    Energy Technology Data Exchange (ETDEWEB)

    Chou, Yeong -Shyung [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Choi, Jung-Pyung [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Xu, Wei [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Stephens, Elizabeth V. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Koeppel, Brian J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Stevenson, Jeffry W. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Lara-Curzio, Edgar [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2014-04-30

    This report summarizes results from experimental and modeling studies performed by participants in the Solid-State Energy Conversion Alliance (SECA) Core Technology Program, which indicate that compliant glass-based seals offer a number of potential advantages over conventional seals based on de-vitrifying glasses, including reduced stresses during stack operation and thermal cycling, and the ability to heal micro-damage induced during thermal cycling. The properties and composition of glasses developed and/or investigated in these studies are reported, along with results from long-term (up to 5,800h) evaluations of seals based on a compliant glass containing ceramic particles or ceramic fibers.

  12. Effects of combustible stacking in large compartments

    DEFF Research Database (Denmark)

    Gentili, Filippo; Giuliani, Luisa; Bontempi, Franco

    2013-01-01

    This paper focuses on the modelling of fire in case of various distributions of combustible materials in a large compartment. Large compartments often represent a challenge for structural fire safety, because of lack of prescriptive rules to follow and difficulties of taking into account the effect...... to different stacking configurations of the pallets with the avail of a CFD code. The results in term of temperatures of the hot gasses and of the steel elements composing the structural system are compared with simplified analytical model of localized and post-flashover fires, with the aim of highlighting...

  13. Displacive phase transformations and generalized stacking faults

    Czech Academy of Sciences Publication Activity Database

    Paidar, Václav; Ostapovets, Andriy; Duparc, O. H.; Khalfallah, O.

    2012-01-01

    Roč. 122, č. 3 (2012), s. 490-492 ISSN 0587-4246. [International Symposium on Physics of Materials, ISPMA /12./. Praha, 04.09.2011-08.09.2011] R&D Projects: GA AV ČR IAA100100920 Institutional research plan: CEZ:AV0Z10100520 Keywords : ab-initio calculations * close-packed structures * generalized stacking faults * homogeneous deformation * lattice deformation * many-body potentials Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 0.531, year: 2012

  14. New particle formation in the fresh flue-gas plume from a coal-fired power plant: effect of flue-gas cleaning

    Directory of Open Access Journals (Sweden)

    F. Mylläri

    2016-06-01

    Full Text Available Atmospheric emissions, including particle number and size distribution, from a 726 MWth coal-fired power plant were studied experimentally from a power plant stack and flue-gas plume dispersing in the atmosphere. Experiments were conducted under two different flue-gas cleaning conditions. The results were utilized in a plume dispersion and dilution model taking into account particle formation precursor (H2SO4 resulted from the oxidation of emitted SO2 and assessment related to nucleation rates. The experiments showed that the primary emissions of particles and SO2 were effectively reduced by flue-gas desulfurization and fabric filters, especially the emissions of particles smaller than 200 nm in diameter. Primary pollutant concentrations reached background levels in 200–300 s. However, the atmospheric measurements indicated that new particles larger than 2.5 nm are formed in the flue-gas plume, even in the very early phases of atmospheric ageing. The effective number emission of nucleated particles were several orders of magnitude higher than the primary particle emission. Modelling studies indicate that regardless of continuing dilution of the flue gas, nucleation precursor (H2SO4 from SO2 oxidation concentrations remain relatively constant. In addition, results indicate that flue-gas nucleation is more efficient than predicted by atmospheric aerosol modelling. In particular, the observation of the new particle formation with rather low flue-gas SO2 concentrations changes the current understanding of the air quality effects of coal combustion. The results can be used to evaluate optimal ways to achieve better air quality, particularly in polluted areas like India and China.

  15. The Effect of Chemical Amendments Used for Phosphorus Abatement on Greenhouse Gas and Ammonia Emissions from Dairy Cattle Slurry: Synergies and Pollution Swapping.

    Directory of Open Access Journals (Sweden)

    Raymond B Brennan

    Full Text Available Land application of cattle slurry can result in incidental and chronic phosphorus (P loss to waterbodies, leading to eutrophication. Chemical amendment of slurry has been proposed as a management practice, allowing slurry nutrients to remain available to plants whilst mitigating P losses in runoff. The effectiveness of amendments is well understood but their impacts on other loss pathways (so-called 'pollution swapping' potential and therefore the feasibility of using such amendments has not been examined to date. The aim of this laboratory scale study was to determine how the chemical amendment of slurry affects losses of NH3, CH4, N2O, and CO2. Alum, FeCl2, Polyaluminium chloride (PAC- and biochar reduced NH3 emissions by 92, 54, 65 and 77% compared to the slurry control, while lime increased emissions by 114%. Cumulative N2O emissions of cattle slurry increased when amended with alum and FeCl2 by 202% and 154% compared to the slurry only treatment. Lime, PAC and biochar resulted in a reduction of 44, 29 and 63% in cumulative N2O loss compared to the slurry only treatment. Addition of amendments to slurry did not significantly affect soil CO2 release during the study while CH4 emissions followed a similar trend for all of the amended slurries applied, with an initial increase in losses followed by a rapid decrease for the duration of the study. All of the amendments examined reduced the initial peak in CH4 emissions compared to the slurry only treatment. There was no significant effect of slurry amendments on global warming potential (GWP caused by slurry land application, with the exception of biochar. After considering pollution swapping in conjunction with amendment effectiveness, the amendments recommended for further field study are PAC, alum and lime. This study has also shown that biochar has potential to reduce GHG losses arising from slurry application.

  16. Climatic, biological, and land cover controls on the exchange of gas-phase semivolatile chemical pollutants between forest canopies and the atmosphere.

    Science.gov (United States)

    Nizzetto, Luca; Perlinger, Judith A

    2012-03-06

    An ecophysiological model of a structured broadleaved forest canopy was coupled to a chemical fate model of the air-canopy exchange of gaseous semivolatile chemicals to dynamically assess the short-term (hours) and medium term (days to season) air-canopy exchange and the influence of biological, climatic, and land cover drivers on the dynamics of the air-canopy exchange and on the canopy storage for airborne semivolatile pollutants. The chemical fate model accounts for effects of short-term variations in air temperature, wind speed, stomatal opening, and leaf energy balance, all as a function of layer in the canopy. Simulations showed the potential occurrence of intense short/medium term re-emission of pollutants having log K(OA) up to 10.7 from the canopy as a result of environmental forcing. In addition, relatively small interannual variations in seasonally averaged air temperature, canopy biomass, and precipitation can produce relevant changes in the canopy storage capacity for the chemicals. It was estimated that possible climate change related variability in environmental parameters (e.g., an increase of 2 °C in seasonally averaged air temperature in combination with a 10% reduction in canopy biomass due to, e.g., disturbance or acclimatization) may cause a reduction in canopy storage capacity of up to 15-25%, favoring re-emission and potential for long-range atmospheric transport. On the other hand, an increase of 300% in yearly precipitation can increase canopy sequestration by 2-7% for the less hydrophobic compounds.

  17. The Effect of Chemical Amendments Used for Phosphorus Abatement on Greenhouse Gas and Ammonia Emissions from Dairy Cattle Slurry: Synergies and Pollution Swapping.

    Science.gov (United States)

    Brennan, Raymond B; Healy, Mark G; Fenton, Owen; Lanigan, Gary J

    2015-01-01

    Land application of cattle slurry can result in incidental and chronic phosphorus (P) loss to waterbodies, leading to eutrophication. Chemical amendment of slurry has been proposed as a management practice, allowing slurry nutrients to remain available to plants whilst mitigating P losses in runoff. The effectiveness of amendments is well understood but their impacts on other loss pathways (so-called 'pollution swapping' potential) and therefore the feasibility of using such amendments has not been examined to date. The aim of this laboratory scale study was to determine how the chemical amendment of slurry affects losses of NH3, CH4, N2O, and CO2. Alum, FeCl2, Polyaluminium chloride (PAC)- and biochar reduced NH3 emissions by 92, 54, 65 and 77% compared to the slurry control, while lime increased emissions by 114%. Cumulative N2O emissions of cattle slurry increased when amended with alum and FeCl2 by 202% and 154% compared to the slurry only treatment. Lime, PAC and biochar resulted in a reduction of 44, 29 and 63% in cumulative N2O loss compared to the slurry only treatment. Addition of amendments to slurry did not significantly affect soil CO2 release during the study while CH4 emissions followed a similar trend for all of the amended slurries applied, with an initial increase in losses followed by a rapid decrease for the duration of the study. All of the amendments examined reduced the initial peak in CH4 emissions compared to the slurry only treatment. There was no significant effect of slurry amendments on global warming potential (GWP) caused by slurry land application, with the exception of biochar. After considering pollution swapping in conjunction with amendment effectiveness, the amendments recommended for further field study are PAC, alum and lime. This study has also shown that biochar has potential to reduce GHG losses arising from slurry application.

  18. Sampled-time control of a microbial fuel cell stack

    Science.gov (United States)

    Boghani, Hitesh C.; Dinsdale, Richard M.; Guwy, Alan J.; Premier, Giuliano C.

    2017-07-01

    Research into microbial fuel cells (MFCs) has reached the point where cubic metre-scale systems and stacks are being built and tested. Apart from performance enhancement through catalysis, materials and design, an important research area for industrial applicability is stack control, which can enhance MFCs stack power output. An MFC stack is controlled using a sampled-time digital control strategy, which has the advantage of intermittent operation with consequent power saving, and when used in a hybrid series stack connectivity, can avoid voltage reversals. A MFC stack comprising four tubular MFCs was operated hydraulically in series. Each MFC was connected to an independent controller and the stack was connected electrically in series, creating a hybrid-series connectivity. The voltage of each MFC in the stack was controlled such that the overall series stack voltage generated was the algebraic sum (1.26 V) of the individual MFC voltages (0.32, 0.32, 0.32 and 0.3). The controllers were able to control the individual voltages to the point where 2.52 mA was drawn from the stack at a load of 499.9 Ω (delivering 3.18 mW). The controllers were able to reject the disturbances and perturbations caused by electrical loading, temperature and substrate concentration.

  19. Simultaneous treatment of SO2 containing stack gases and waste water

    Science.gov (United States)

    Poradek, J. C.; Collins, D. D. (Inventor)

    1978-01-01

    A process for simultaneously removing sulfur dioxide from stack gases and the like and purifying waste water such as derived from domestic sewage is described. A portion of the gas stream and a portion of the waste water, the latter containing dissolved iron and having an acidic pH, are contacted in a closed loop gas-liquid scrubbing zone to effect absorption of the sulfur dioxide into the waste water. A second portion of the gas stream and a second portion of the waste water are controlled in an open loop gas-liquid scrubbing zone. The second portion of the waste water contains a lesser amount of iron than the first portion of the waste water. Contacting in the openloop scrubbing zone is sufficient to acidify the waste water which is then treated to remove solids originally present.

  20. Energy efficiency and pollution control for thermal units in the Egyptian industry

    International Nuclear Information System (INIS)

    Said Abdel-wahab; Ismail, W.M.

    1999-01-01

    Energy conservation and environmental protection project (ECEP) is a Usaid sponsored project. Its main objective is to promote energy conservation and pollution protection in the egyptian industry through a group of demonstrated projects. One of the implemented activities is the boilers and furnaces tune-up program, which aims to increase energy efficiency and reduce pollution. To achieve this objective. (ECEP) distributed 100 electronic portable exhaust gas analyzers to cover eight industrial sectors at six different geographical locations in egypt. These analyzers were used to measure the contents of exhaust gases to help operators tune up their equipment on regular basis. The result is that the firing thermal units operate at the highest possible combustion efficiency to reduce the amount of fuel consumption as well as pollution emissions. The analyzer used measures two types of temperature, five different stack gases, draft and smoke density. moreover it computes the efficiency of combustion as well as Co2 and excess air percentage. Thermal units that rested by these analyzers were consuming a huge amount of fossil fuel from different types. The average combustion efficiency for thermal units tested was improved by 14%, 15% and 28% for boilers, furnaces and diesel respectively

  1. Urban air pollution; La pollution de l'air dans la ville

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-07-01

    The theme of this congress concerns air pollution in urban areas. Cities are accumulation of populations and economic activities, and then pollutants activities. The first articles are devoted to pollutants and their effects on health. Then come articles relative to measurements and modeling. Finally, the traffic in city and the automobile pollution are examined. Transportation systems as well technology in matter of gas emissions are reviewed. (N.C.)

  2. Pollutant Transformations and Interactions Section

    Energy Technology Data Exchange (ETDEWEB)

    Drake, R. L.; Alkezweeny, A. J.; Laulainen, N. S.

    1976-03-01

    This section is comprised of 6 papers. It is especially important to understand the changing physical and chemical character of pollutants in the atmosphere. The biological and ecological significance can be strongly dependent on the form they assume as they are delivered to receptors. The efficiency of pollutant removal can also be strongly influenced by the pollutants physical and chemical state and the transformations that occur during transport. Investigations of atmospheric pollutant transformations have centered primarily around aircraft observations of pollutant concentrations and conversion rates, which are being interpreted with the use of numerical models of the transformation processes. The primary field experiment during the past year was conducted using the DC-3 aircraft in the St. Louis region during the final term of the METROMEX series. In this experiment, extensive trace gas and aerosol data, and solar radiation measurements were recorded in a Lagrangian reference frame downwind of the metropolitan complex. (auth)

  3. Examination of the conditions of a broadening of the general tax for polluting activities to the intermediate energy consumptions. Incentive mechanisms for the abatement of greenhouse gas emissions; Examen des conditions d'un elargissement de la TGAP aux consommations intermediaires d'energie. Mecanismes incitatifs a la reduction des emissions de gaz a effet de serre

    Energy Technology Data Exchange (ETDEWEB)

    Bureau, D

    2000-05-15

    Among the various existing incentive mechanisms for the abatement of greenhouse gas emissions, like the pollution regulations and the financial help for energy mastery, this document analyzes the conditions of efficiency of the negotiated voluntary agreements and of the tradable emission quotas and their articulation with the fiscality. (J.S.)

  4. Petition for Reconsideration from Biogenic CO2 Coalition to Gina McCarthy, U.S. EPA, for the Finding that Greenhouse Gas Emissions from Aircraft Cause or Contribute to Air Pollution that May Reasonably be Anticipated to Endanger Public Health and Welfare

    Science.gov (United States)

    This page contains a Petition for Reconsideration From Biogenic CO2 Coalition to Gina McCarthy, U.S. EPA, for the finding that greenhouse gas emissions from aircraft cause or contribute to air pollution that may reasonably be anticipated to endanger public

  5. AC impedance diagnosis of a 500 W PEM fuel cell stack . Part I: Stack impedance

    Science.gov (United States)

    Yuan, Xiaozi; Sun, Jian Colin; Blanco, Mauricio; Wang, Haijiang; Zhang, Jiujun; Wilkinson, David P.

    Diagnosis of stack performance is of importance to proton exchange membrane (PEM) fuel cell research. This paper presents the diagnostic testing results of a 500 W Ballard Mark V PEM fuel cell stack with an active area of 280 cm 2 by electrochemical impedance spectroscopy (EIS). The EIS was measured using a combination of a FuelCon test station, a TDI loadbank, and a Solartron 1260 Impedance/Gain-Phase Analyzer operating in the galvanostatic mode. The method described in this work can obtain the impedance spectra of fuel cells with a larger geometric surface area and power, which are normally difficult to measure due to the limitations on commercial load banks operating at high currents. By using this method, the effects of temperature, flow rate, and humidity on the stack impedance spectra were examined. The results of the electrochemical impedance analysis show that with increasing temperature, the charge transfer resistance decreases due to the slow oxygen reduction reaction (ORR) process at low temperature. If the stack is operated at a fixed air flow rate, a low frequency arc appears and grows with increasing current due to the shortage of air. The anode humidification cut-off does not affect the spectra compared to the cut-off for cathode humidification.

  6. Stray field interaction of stacked amorphous tapes

    International Nuclear Information System (INIS)

    Guenther, Wulf; Flohrer, Sybille

    2008-01-01

    In this study, magnetic cores made of amorphous rectangular tape layers are investigated. The quality factor Q of the tape material decreases rapidly, however, when stacking at least two tape layers. The hysteresis loop becomes non-linear, and the coercivity increases. These effects are principally independent of the frequency and occur whether tape layers are insulated or not. The Kerr-microscopy was used to monitor local hysteresis loops by varying the distance of two tape layers. The magnetization direction of each magnetic domain is influenced by the anisotropy axis, the external magnetic field and the stray field of magnetic domains of the neighboring tape layers. We found that crossed easy axes (as the extreme case for inclined axes) of congruent domains retain the remagnetization and induce a plateau of the local loop. Summarizing local loops leads to the observed increase of coercivity and non-linearity of the inductively measured loop. A high Q-factor can be preserved if the easy axes of stacked tape layers are identical within the interaction range in the order of mm

  7. Annular feed air breathing fuel cell stack

    Science.gov (United States)

    Wilson, Mahlon S.; Neutzler, Jay K.

    1997-01-01

    A stack of polymer electrolyte fuel cells is formed from a plurality of unit cells where each unit cell includes fuel cell components defining a periphery and distributed along a common axis, where the fuel cell components include a polymer electrolyte membrane, an anode and a cathode contacting opposite sides of the membrane, and fuel and oxygen flow fields contacting the anode and the cathode, respectively, wherein the components define an annular region therethrough along the axis. A fuel distribution manifold within the annular region is connected to deliver fuel to the fuel flow field in each of the unit cells. The fuel distribution manifold is formed from a hydrophilic-like material to redistribute water produced by fuel and oxygen reacting at the cathode. In a particular embodiment, a single bolt through the annular region clamps the unit cells together. In another embodiment, separator plates between individual unit cells have an extended radial dimension to function as cooling fins for maintaining the operating temperature of the fuel cell stack.

  8. Stacking Analysis of Binary Systems with HAWC

    Science.gov (United States)

    Brisbois, Chad; HAWC Collaboration

    2017-01-01

    Detecting binary systems at TeV energies is an important problem because only a handful of such systems are currently known. The nature of such systems is typically thought to be composed of a compact object and a massive star. The TeV emission from these systems does not obviously correspond to emission in GeV or X-ray, where many binary systems have previously been found. This study focuses on a stacking method to detect TeV emission from LS 5039, a known TeV binary, to test its efficacy in HAWC data. Stacking is a widely employed method for increasing signal to noise ratio in optical astronomy, but has never been attempted previously with HAWC. HAWC is an ideal instrument to search for TeV binaries, because of its wide field of view and high uptime. Applying this method to the entire sky may allow HAWC to detect binary sources of very short or very long periods not sensitive to current analyses. NSF, DOE, Los Alamos, Michigan Tech, CONACyt, UNAM, BUAP.

  9. High performance zinc air fuel cell stack

    Science.gov (United States)

    Pei, Pucheng; Ma, Ze; Wang, Keliang; Wang, Xizhong; Song, Mancun; Xu, Huachi

    2014-03-01

    A zinc air fuel cell (ZAFC) stack with inexpensive manganese dioxide (MnO2) as the catalyst is designed, in which the circulation flowing potassium hydroxide (KOH) electrolyte carries the reaction product away and acts as a coolant. Experiments are carried out to investigate the characteristics of polarization, constant current discharge and dynamic response, as well as the factors affecting the performance and uniformity of individual cells in the stack. The results reveal that the peak power density can be as high as 435 mW cm-2 according to the area of the air cathode sheet, and the influence factors on cell performance and uniformity are cell locations, filled state of zinc pellets, contact resistance, flow rates of electrolyte and air. It is also shown that the time needed for voltages to reach steady state and that for current step-up or current step-down are both in milliseconds, indicating the ZAFC can be excellently applied to vehicles with rapid dynamic response demands.

  10. Generalized stacking fault energies of alloys.

    Science.gov (United States)

    Li, Wei; Lu, Song; Hu, Qing-Miao; Kwon, Se Kyun; Johansson, Börje; Vitos, Levente

    2014-07-02

    The generalized stacking fault energy (γ surface) provides fundamental physics for understanding the plastic deformation mechanisms. Using the ab initio exact muffin-tin orbitals method in combination with the coherent potential approximation, we calculate the γ surface for the disordered Cu-Al, Cu-Zn, Cu-Ga, Cu-Ni, Pd-Ag and Pd-Au alloys. Studying the effect of segregation of the solute to the stacking fault planes shows that only the local chemical composition affects the γ surface. The calculated alloying trends are discussed using the electronic band structure of the base and distorted alloys.Based on our γ surface results, we demonstrate that the previous revealed 'universal scaling law' between the intrinsic energy barriers (IEBs) is well obeyed in random solid solutions. This greatly simplifies the calculations of the twinning measure parameters or the critical twinning stress. Adopting two twinnability measure parameters derived from the IEBs, we find that in binary Cu alloys, Al, Zn and Ga increase the twinnability, while Ni decreases it. Aluminum and gallium yield similar effects on the twinnability.

  11. Computerized plutonium laboratory-stack monitoring system

    International Nuclear Information System (INIS)

    Stafford, R.G.; DeVore, R.K.

    1977-01-01

    The Los Alamos Scientific Laboratory has recently designed and constructed a Plutonium Research and Development Facility to meet design criteria imposed by the United States Energy Research and Development Administration. A primary objective of the design criteria is to assure environmental protection and to reliably monitor plutonium effluent via the ventilation exhaust systems. A state-of-the-art facility exhaust air monitoring system is described which establishes near ideal conditions for evaluating plutonium activity in the stack effluent. Total and static pressure sensing manifolds are incorporated to measure average velocity and integrated total discharge air volume. These data are logged at a computer which receives instrument data through a multiplex scanning system. A multipoint isokinetic sampling assembly with associated instrumentation is described. Continuous air monitors have been designed to sample from the isokinetic sampling assembly and transmit both instantaneous and integrated stack effluent concentration data to the computer and various cathode ray tube displays. The continuous air monitors also serve as room air monitors in the plutonium facility with the primary objective of timely evacuation of personnel if an above tolerance airborne plutonium concentration is detected. Several continuous air monitors are incorporated in the ventilation system to assist in identification of release problem areas

  12. Pressurized reversible operation of a 30-cell solid oxide cell stack using carbonaceous gases

    DEFF Research Database (Denmark)

    Jensen, Søren Højgaard; Langnickel, Hendrik; Hintzen, N.

    2017-01-01

    Recent theoretical studies show that reversible electrochemical conversion of H2O and CO2 to CH4 inside pressurized solid oxide cells (SOCs) combined with subsurface storage of the produced gases can facilitate seasonal electricity storage with a round-trip efficiency reaching 70-80% and a storag...... in electrolysis mode. The degradation rates in both fuel cell and electrolysis mode were comparable to previously reported SOFCMAN stack degradation rates measured at ambient pressure operation with H2/H2O gas mixtures.......Recent theoretical studies show that reversible electrochemical conversion of H2O and CO2 to CH4 inside pressurized solid oxide cells (SOCs) combined with subsurface storage of the produced gases can facilitate seasonal electricity storage with a round-trip efficiency reaching 70-80% and a storage...... cost below 3 ¢/kWh. Here we show test results with a 30-cell SOFCMAN 301 stack operated with carbonaceous gases at 18.7 bar and 700 ˚C in both electrolysis and fuel cell mode. The CH4 content in the stack outlet gas increased from 0.22% at open circuit voltage (OCV) to 18% at -0.17 A cm-2...

  13. Development of Osaka gas type planar SOFC

    Energy Technology Data Exchange (ETDEWEB)

    Iha, M.; Shiratori, A.; Chikagawa, O. [Murata Mfg. Co., Ltd., Shiga (Japan)] [and others

    1996-12-31

    Osaka Gas Co. has been developing a planar type SOFC (OG type SOFC) which has a suitable structure for stacking. Murata Mfg. Co. has begun to develop the OG type SOFC stack through joint program since 1993. Figure 1 shows OG type cell structure. Because each cell is sustained by cell holders acting air manifold, the load of upper cell is not put on the lower cells. Single cell is composed of 3-layered membrane and LaCrO{sub 3} separator. 5 single cells are mounted on the cell holder, connected with Ni felt electrically, and bonded by glassy material sealant. We call the 5-cell stack a unit. Stacking 13 units, we succeeded 870 W generation in 1993. But the power density was low, 0.11 Wcm{sup -2} because of crack in the electrolyte and gas leakage at some cells.

  14. Investigation on etch characteristics of nanometer-sized magnetic tunnel junction stacks using a HBr/Ar plasma.

    Science.gov (United States)

    Kim, Eun Ho; Xiao, Yu Bin; Kong, Seon Mi; Chung, Chee Won

    2011-07-01

    The etch characteristics of CoFeB magnetic films and magnetic-tunnel-junction (MTJ) stacks masked with Ti films were investigated using an inductively coupled plasma reactive ion etching in a HBr/Ar gas mix. The etch rate, etch selectivity, and etch profile of the CoFeB films were obtained as a function of the HBr concentration. As the HBr gas was added to Ar, the etch rate of the CoFeB films, and the etch selectivity to the Ti hard mask, gradually decreased, but the etch profile of the CoFeB films was improved. The effects of the HBr concentration and etch parameters on the etch profile of the MTJ stacks with a nanometer-sized 70 x 100 nm2 pattern were explored. At 10% HBr concentration, low ICP RF power, and low DC-bias voltage, better etch profiles of the MTJ stacks were obtained without redeposition. It was confirmed that the protective layer containing hydrogen, and the surface bombardment of the Ar ions, played a key role in obtaining a steep sidewall angle in the etch profile. Fine-pattern transfer of the MTJ stacks with a high degree of anisotropy was achieved using a HBr/Ar gas chemistry.

  15. Gas, the energy for transition?

    International Nuclear Information System (INIS)

    Pigenet, Yaroslav

    2014-01-01

    The author describes gas as the less polluting fossil energy. He outlines that new gas fields have been discovered, notably non conventional gas fields. He notices that whatever conventional or not conventional, a gas field produces methane, and that there is therefore no difference for the end user. However, he notices that reserve assessments by the IAE are a matter of discussion, and that hydraulic fracturing has resulted in important environmental and human damages. Anyway, gas will be needed to face energy demand

  16. Interactions of Climate Change and Nitrogen Management for Optimizing Crop Productivity and Food Security while Minimizing Nitrogen Pollution and Greenhouse Gas Emissions

    Science.gov (United States)

    Davidson, E. A.; Suddick, E. C.

    2012-12-01

    Producing food, transportation, and energy for seven billion people has led to huge increases in use of synthetic nitrogen (N) fertilizers and fossil fuels, resulting in large releases of N as air and water pollution. In its numerous chemical forms, N plays a critical role in all aspects of climate change, including mitigation, adaptation, and impacts. Here we report on a multi-authored, interdisciplinary technical report on climate-nitrogen interactions submitted to the US National Climate Assessment as part of a Research Coordination Network activity. Management of the N cycle not only affects emissions of nitrous oxide (N2O) and nitrogen oxides (NOX), but also impacts carbon dioxide (CO2) and methane (CH4), through effects on carbon cycling processes in forests and soils and the effects on atmospheric reactions of ozone (O3) and CH4. While some of these direct and indirect N effects have a short-term cooling effect, the warming effects of N2O dominate at long time scales. The challenges of mitigating N2O emissions are substantially different from those for CO2 and CH4, because N is essential for food production, and over 80% of anthropogenic N2O emissions are from the agricultural sector. On one hand, improved agricultural nutrient management can confer some adaptive capacity of crops to climatic variability, but, on the other hand, increased climatic variability will render the task more difficult to manage nutrients for the optimization of crop productivity while minimizing N losses to the environment. Higher air temperatures will result in a "climate penalty" for air quality mitigation efforts, because larger NOX emissions reductions will be needed to achieve the same reductions of O3 pollution under higher temperatures, thus imposing further challenges to avoid harmful impacts on human health and crop productivity. Changes in river discharge, due to summer drought and to extreme precipitation events, will affect the transport of N from agricultural fields to

  17. Description of gasket failure in a 7 cell PEMFC stack

    Energy Technology Data Exchange (ETDEWEB)

    Husar, Attila; Serra, Maria [Institut de Robotica i Informatica Industrial, Parc Tecnologic de Barcelona, Edifici U, C. Llorens i Artigas, 4-6, 2a Planta, 08028 Barcelona (Spain); Kunusch, Cristian [Laboratorio de Electronica Industrial Control e Instrumentacion, Facultad de Ingenieria, UNLP (Argentina)

    2007-06-10

    This article presents the data and the description of a fuel cell stack that failed due to gasket degradation. The fuel cell under study is a 7 cell stack. The unexpected change in several variables such as temperature, pressure and voltage indicated the possible failure of the stack. The stack was monitored over a 6 h period in which data was collected and consequently analyzed to conclude that the fuel cell stack failed due to a crossover leak on the anode inlet port located on the cathode side gasket of cell 2. This stack failure analysis revealed a series of indicators that could be used by a super visional controller in order to initiate a shutdown procedure. (author)

  18. Light Pollution

    Science.gov (United States)

    Riegel, Kurt W.

    1973-01-01

    Outdoor lighting is light pollution which handicaps certain astronomical programs. Protective measures must be adopted by the government to aid observational astronomy without sacrificing legitimate outdoor lighting needs. (PS)

  19. Quadratic forms and Clifford algebras on derived stacks

    OpenAIRE

    Vezzosi, Gabriele

    2013-01-01

    In this paper we present an approach to quadratic structures in derived algebraic geometry. We define derived n-shifted quadratic complexes, over derived affine stacks and over general derived stacks, and give several examples of those. We define the associated notion of derived Clifford algebra, in all these contexts, and compare it with its classical version, when they both apply. Finally, we prove three main existence results for derived shifted quadratic forms over derived stacks, define ...

  20. Stacked Heterogeneous Neural Networks for Time Series Forecasting

    Directory of Open Access Journals (Sweden)

    Florin Leon

    2010-01-01

    Full Text Available A hybrid model for time series forecasting is proposed. It is a stacked neural network, containing one normal multilayer perceptron with bipolar sigmoid activation functions, and the other with an exponential activation function in the output layer. As shown by the case studies, the proposed stacked hybrid neural model performs well on a variety of benchmark time series. The combination of weights of the two stack components that leads to optimal performance is also studied.

  1. Status of Slip Stacking at Fermilab Main Injector

    CERN Document Server

    Seiya, Kiyomi; Chase, Brian; Dey, Joseph; Kourbanis, Ioanis; MacLachlan, James A; Meisner, Keith G; Pasquinelli, Ralph J; Reid, John; Rivetta, Claudio H; Steimel, Jim

    2005-01-01

    In order to increase proton intensity on anti proton production cycle of the Main Injector we are going to use the technique of 'slip stacking' and doing machine studies. In slip stacking, one bunch train is injected at slightly lower energy and second train is at slightly higher energy. Afterwards they are aligned longitudinally and captured with one rf bucket. This longitudinal stacking process is expected to double the bunch intensity. The required intensity for anti proton production is 8·1012

  2. A novel design for solid oxide fuel cell stacks

    Energy Technology Data Exchange (ETDEWEB)

    Al-Qattan, A.M.; Chmielewski, D.J.; Al-Hallaj, S.; Selman, J.R. [Illinois Inst. of Technology, Chicago, IL (United States). Dept. of Chemical and Environmental Engineering

    2004-01-01

    Conventional fuel cell stack designs suffer from severe spatial nonuniformity in both temperature and current density. Such variations are known to create damaging thermal stresses within the stack and thus, impact overall lifespan. In this work, we propose a novel stack design aimed at reducing spatial variations at the source. We propose a mechanism of distributed fuel feed in which the heat generation profile can be influenced directly. Simulation results are presented to illustrate the potential of the proposed scheme. (author)

  3. Development of the electric utility dispersed use PAFC stack

    Energy Technology Data Exchange (ETDEWEB)

    Horiuchi, Hiroshi; Kotani, Ikuo [Mitsubishi Electric Co., Kobe (Japan); Morotomi, Isamu [Kansai Electric Power Co., Hyogo (Japan)] [and others

    1996-12-31

    Kansai Electric Power Co. and Mitsubishi Electric Co. have been developing the electric utility dispersed use PAFC stack operated under the ambient pressure. The new cell design have been developed, so that the large scale cell (1 m{sup 2} size) was adopted for the stack. To confirm the performance and the stability of the 1 m{sup 2} scale cell design, the short stack study had been performed.

  4. Environmental pollution

    International Nuclear Information System (INIS)

    Hanif, J.; Hanif, M.I.

    1997-01-01

    The third proceedings of National Symposium on Modern Trends in Contemporary Chemistry was held in Islamabad, Pakistan from February 24-26, 1997. In this symposium more than 220 scientists, engineers and technologist were registered from 11 universities, 17 research organisations and 8 non-governmental organisation including some commercial establishments. The symposium was divided into five technical sessions on hydro spheric pollution, atmospheric pollution, bio spheric pollution, lithospheric pollution and impact assessment and environmental education. Environmental and ecology are so interdependent that any change in the balance due to natural and man made cause may result in a disaster, flood, fire, earthquake, epidemic, population explosion etc. are the natural ways of unbalancing our ecosystem. The scope of this symposium includes: 1) Review the chemistry and the chemical techniques like polarography, coulometry, HPLC, GC-MS, NAA, XRF, AAS, AES etc. involved in the assessment monitoring and control of various pollutions. 2) Propose sampling, transportation, measurement and standardization procedures. 3) Collaboration in scientific data collection. 4) Mutual consultation for management of the pollution problem in a cost effective manner. 5) sharing knowledge and experience with various environmental protection groups both in public and private sector. (A.B.)

  5. Assessment of the Revised 3410 Building Filtered Exhaust Stack Sampling Probe Location

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Xiao-Ying [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Recknagle, Kurtis P. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Glissmeyer, John A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2013-12-01

    In order to support the air emissions permit for the 3410 Building, Pacific Northwest National Laboratory performed a series of tests in the exhaust air discharge from the reconfigured 3410 Building Filtered Exhaust Stack. The objective was to determine whether the location of the air sampling probe for emissions monitoring meets the applicable regulatory criteria governing such effluent monitoring systems. In particular, the capability of the air sampling probe location to meet the acceptance criteria of ANSI/HPS N13.1-2011 , Sampling and Monitoring Releases of Airborne Radioactive Substances from the Stack and Ducts of Nuclear Facilities was determined. The qualification criteria for these types of stacks address 1) uniformity of air velocity, 2) sufficiently small flow angle with respect to the axis of the duct, 3) uniformity of tracer gas concentration, and 4) uniformity of tracer particle concentration. Testing was performed to conform to the quality requirements of NQA-1-2000. Fan configurations tested included all fan combinations of any two fans at a time. Most of the tests were conducted at the normal flow rate, while a small subset of tests was performed at a slightly higher flow rate achieved with the laboratory hood sashes fully open. The qualification criteria for an air monitoring probe location are taken from ANSI/HPS N13.1-2011 and are paraphrased as follows with key results summarized: 1. Angular Flow—The average air velocity angle must not deviate from the axis of the stack or duct by more than 20°. Our test results show that the mean angular flow angles at the center two-thirds of the ducts are smaller than 4.5% for all testing conditions. 2. Uniform Air Velocity—The acceptance criterion is that the COV of the air velocity must be ≤ 20% across the center two thirds of the area of the stack. Our results show that the COVs of the air velocity across the center two-thirds of the stack are smaller than 2.9% for all testing conditions. 3

  6. Ground Pollution Science

    International Nuclear Information System (INIS)

    Oh, Jong Min; Bae, Jae Geun

    1997-08-01

    This book deals with ground pollution science and soil science, classification of soil and fundamentals, ground pollution and human, ground pollution and organic matter, ground pollution and city environment, environmental problems of the earth and ground pollution, soil pollution and development of geological features of the ground, ground pollution and landfill of waste, case of measurement of ground pollution.

  7. Method for monitoring stack gases for uranium activity

    International Nuclear Information System (INIS)

    Beverly, C.R.; Ernstberger, H.G.

    1988-01-01

    A method for sampling stack gases emanating from the purge cascade of a gaseous diffusion cascade system utilized to enrich uranium for determining the presence and extent of uranium in the stack gases in the form of gaseous uranium hexafluoride, is described comprising the steps of removing a side stream of gases from the stack gases, contacting the side stream of the stack gases with a stream of air sufficiently saturated with moisture for reacting with and converting any gaseous uranium hexafluroide contracted thereby in the side stream of stack gases to particulate uranyl fluoride. Thereafter contacting the side stream of stack gases containing the particulate uranyl fluoride with moving filter means for continuously intercepting and conveying the intercepted particulate uranyl fluoride away from the side stream of stack gases, and continually scanning the moving filter means with radiation monitoring means for sensing the presence and extent of particulate uranyl fluoride on the moving filter means which is indicative of the extent of particulate uranyl fluoride in the side stream of stack gases which in turn is indicative of the presence and extent of uranium hexafluoride in the stack gases

  8. Design and development of an automated uranium pellet stacking system

    International Nuclear Information System (INIS)

    Reiss, B.S.; Nokleby, S.B.

    2010-01-01

    A novel design for an automated uranium pellet stacking system is presented. This system is designed as a drop-in solution to the current production line to enhance the fuel pellet stacking process. The three main goals of this system are to reduce worker exposure to radiation to as low as reasonable achievable (ALARA), improve product quality, and increase productivity. The proposed system will reduce the potential for human error. This single automated system will replace the two existing pellet stacking stations while increasing the total output, eliminating pellet stacking as a bottleneck in the fuel bundle assembly process. (author)

  9. Highly Efficient, Durable Regenerative Solid Oxide Stack, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Precision Combustion, Inc. (PCI) proposes to develop a highly efficient regenerative solid oxide stack design. Novel structural elements allow direct internal...

  10. Natural gas for vehicles (NGV)

    International Nuclear Information System (INIS)

    Prieur, A.

    2006-01-01

    Following a decade-long upsurge in the use of natural gas in the energy sector (heating and especially electricity), new outlets for natural gas are being developed in the transport sector. For countries endowed with substantial local resources, development in this sector can help reduce oil dependence. In addition, natural gas is often used to reduce pollution, particularly in cities. (author)

  11. Natural gas for vehicles (NGV)

    Energy Technology Data Exchange (ETDEWEB)

    Prieur, A

    2006-07-01

    Following a decade-long upsurge in the use of natural gas in the energy sector (heating and especially electricity), new outlets for natural gas are being developed in the transport sector. For countries endowed with substantial local resources, development in this sector can help reduce oil dependence. In addition, natural gas is often used to reduce pollution, particularly in cities. (author)

  12. Optimization of membrane stack configuration for efficient hydrogen production in microbial reverse-electrodialysis electrolysis cells coupled with thermolytic solutions

    KAUST Repository

    Luo, Xi

    2013-07-01

    Waste heat can be captured as electrical energy to drive hydrogen evolution in microbial reverse-electrodialysis electrolysis cells (MRECs) by using thermolytic solutions such as ammonium bicarbonate. To determine the optimal membrane stack configuration for efficient hydrogen production in MRECs using ammonium bicarbonate solutions, different numbers of cell pairs and stack arrangements were tested. The optimum number of cell pairs was determined to be five based on MREC performance and a desire to minimize capital costs. The stack arrangement was altered by placing an extra low concentration chamber adjacent to anode chamber to reduce ammonia crossover. This additional chamber decreased ammonia nitrogen losses into anolyte by 60%, increased the coulombic efficiency to 83%, and improved the hydrogen yield to a maximum of 3.5mol H2/mol acetate, with an overall energy efficiency of 27%. These results improve the MREC process, making it a more efficient method for renewable hydrogen gas production. © 2013 Elsevier Ltd.

  13. Experiment and numerical simulation on the performance of a kw-scale molten carbonate fuel cell stack

    Directory of Open Access Journals (Sweden)

    L. J. Yu

    2007-12-01

    Full Text Available A high-temperature molten carbonate fuel cell stack was studied experimentally and computationally. Experimental data for fuel cell temperature was obtained when the stack was running under given operational conditions. A 3-D CFD numerical model was set up and used to simulate the central fuel cell in the stack. It includes the mass, momentum and energy conservation equations, the ideal gas law and an empirical equation for cell voltage. The model was used to simulate the transient behavior of the fuel cell under the same operational conditions as those of the experiment. Simulation results show that the transient temperature and current and power densities reach their maximal values at the channel outlet. A comparison of the modeling results and the experimental data shows the good agreement.

  14. Very low emissions of airborne particulate pollutants measured from two municipal solid waste incineration plants in Switzerland

    Science.gov (United States)

    Setyan, Ari; Patrick, Michael; Wang, Jing

    2017-10-01

    A field campaign has been performed in two municipal solid waste incineration (MSWI) plants in Switzerland, at Hinwil (ZH) and Giubiasco (TI). The aim was to measure airborne pollutants at different locations of the abatement systems (including those released from the stacks into the atmosphere) and at a near-field (∼1 km) downwind site, in order to assess the efficiency of the abatement systems and the environmental impact of these plants. During this study, we measured the particle number concentration with a condensation particle counter (CPC), and the size distribution with a scanning mobility particle sizer (SMPS) and an aerodynamic particle sizer (APS). We also sampled particles on filters for subsequent analyses of the morphology, size and elemental composition with a scanning electron microscope coupled to an energy dispersive X-ray spectroscope (SEM/EDX), and of water soluble ions by ion chromatography (IC). Finally, volatile organic compounds (VOCs) were sampled on adsorbing cartridges and analyzed by thermal desorption-gas chromatography/mass spectrometry (TD-GC/MS), and a portable gas analyzer was used to monitor NO, SO2, CO, CO2, and O2. The particle concentration decreased significantly at two locations of the plants: at the electrostatic precipitator and the bag-house filter. The particle concentrations measured at the stacks were very low (efficiency of the abatement system of the two plants. At Hinwil, particles sampled at the stack were mainly constituted of NaCl and KCl, two salts known to be involved in the corrosion process in incinerators. At Giubiasco, no significant differences were observed for the morphology and chemical composition of the particles collected in the ambient background and at the downwind site, suggesting that the incineration plant released very limited amounts of particles to the surrounding areas.

  15. Directive Stacked Patch Antenna for UWB Applications

    Directory of Open Access Journals (Sweden)

    Sharif I. Mitu Sheikh

    2013-01-01

    Full Text Available Directional ultrawideband (UWB antennas are popular in wireless signal-tracking and body-area networks. This paper presents a stacked microstrip antenna with an ultrawide impedance bandwidth of 114%, implemented by introducing defects on the radiating patches and the ground plane. The compact (20×34 mm antenna exhibits a directive radiation patterns for all frequencies of the 3–10.6 GHz band. The optimized reflection response and the radiation pattern are experimentally verified. The designed UWB antenna is used to maximize the received power of a software-defined radio (SDR platform. For an ultrawideband impulse radio system, this class of antennas is essential to improve the performance of the communication channels.

  16. ATLAS software stack on ARM64

    Science.gov (United States)

    Smith, Joshua Wyatt; Stewart, Graeme A.; Seuster, Rolf; Quadt, Arnulf; ATLAS Collaboration

    2017-10-01

    This paper reports on the port of the ATLAS software stack onto new prototype ARM64 servers. This included building the “external” packages that the ATLAS software relies on. Patches were needed to introduce this new architecture into the build as well as patches that correct for platform specific code that caused failures on non-x86 architectures. These patches were applied such that porting to further platforms will need no or only very little adjustments. A few additional modifications were needed to account for the different operating system, Ubuntu instead of Scientific Linux 6 / CentOS7. Selected results from the validation of the physics outputs on these ARM 64-bit servers will be shown. CPU, memory and IO intensive benchmarks using ATLAS specific environment and infrastructure have been performed, with a particular emphasis on the performance vs. energy consumption.

  17. ATLAS software stack on ARM64

    CERN Document Server

    AUTHOR|(INSPIRE)INSPIRE-00529764; The ATLAS collaboration; Stewart, Graeme; Seuster, Rolf; Quadt, Arnulf

    2017-01-01

    This paper reports on the port of the ATLAS software stack onto new prototype ARM64 servers. This included building the “external” packages that the ATLAS software relies on. Patches were needed to introduce this new architecture into the build as well as patches that correct for platform specific code that caused failures on non-x86 architectures. These patches were applied such that porting to further platforms will need no or only very little adjustments. A few additional modifications were needed to account for the different operating system, Ubuntu instead of Scientific Linux 6 / CentOS7. Selected results from the validation of the physics outputs on these ARM 64-bit servers will be shown. CPU, memory and IO intensive benchmarks using ATLAS specific environment and infrastructure have been performed, with a particular emphasis on the performance vs. energy consumption.

  18. Stacked generalization: an introduction to super learning.

    Science.gov (United States)

    Naimi, Ashley I; Balzer, Laura B

    2018-04-10

    Stacked generalization is an ensemble method that allows researchers to combine several different prediction algorithms into one. Since its introduction in the early 1990s, the method has evolved several times into a host of methods among which is the "Super Learner". Super Learner uses V-fold cross-validation to build the optimal weighted combination of predictions from a library of candidate algorithms. Optimality is defined by a user-specified objective function, such as minimizing mean squared error or maximizing the area under the receiver operating characteristic curve. Although relatively simple in nature, use of Super Learner by epidemiologists has been hampered by limitations in understanding conceptual and technical details. We work step-by-step through two examples to illustrate concepts and address common concerns.

  19. Graphite stack corrosion of BUGEY-1 reactor (synthesis)

    International Nuclear Information System (INIS)

    Petit, A.; Brie, M.

    1996-01-01

    The definitive shutdown date for the BUGEY-1 reactor was May 27th, 1994, after 12.18 full power equivalent years and this document briefly describes some of the feedback of experience from operation of this reactor. The radiolytic corrosion of graphite stack is the major problem for BUGEY-1 reactor, despite the inhibition of the reaction by small quantities of CH 4 added to the coolant gas. The mechanical behaviour of the pile is predicted using the ''INCA'' code (stress calculation), which uses the results of graphite weight loss variation determined using the ''USURE'' code. The weight loss of graphite is determined by annually taking core samples from the channel walls. The results of the last test programme undertaken after the definitive shutdown of BUGEY-1 have enabled an experimental graph to be established showing the evolution of the compression resistance (perpendicular and parallel direction to the extrusion axis) as a function of the weight loss. The numerous analyses, made on the samples carried out in the most sensitive regions, have allowed to verify that no brutal degradation of the mechanical properties of graphite happens for the high value of weight loss up to 40% (maximum weight loss reached locally). (author). 10 refs, 3 figs, 4 tabs

  20. Actuators Using Piezoelectric Stacks and Displacement Enhancers

    Science.gov (United States)

    Bar-Cohen, Yoseph; Sherrit, Stewart; Bao, Xiaoqi; Badescu, Mircea; Lee, Hyeong Jae; Walkenmeyer, Phillip; Lih, Shyh-Shiuh

    2015-01-01

    Actuators are used to drive all active mechanisms including machines, robots, and manipulators to name a few. The actuators are responsible for moving, manipulating, displacing, pushing and executing any action that is needed by the mechanism. There are many types and principles of actuation that are responsible for these movements ranging from electromagnetic, electroactive, thermo-mechanic, piezoelectric, electrostrictive etc. Actuators are readily available from commercial producers but there is a great need for reducing their size, increasing their efficiency and reducing their weight. Studies at JPL’s Non Destructive Evaluation and Advanced Actuators (NDEAA) Laboratory have been focused on the use of piezoelectric stacks and novel designs taking advantage of piezoelectric’s potential to provide high torque/force density actuation and high electromechanical conversion efficiency. The actuators/motors that have been developed and reviewed in this paper are operated by various horn configurations as well as the use of pre-stress flexures that make them thermally stable and increases their coupling efficiency. The use of monolithic designs that pre-stress the piezoelectric stack eliminates the use of compression stress bolt. These designs enable the embedding of developed solid-state motors/actuators in any structure with the only macroscopically moving parts are the rotor or the linear translator. Finite element modeling and design tools were used to determine the requirements and operation parameters and the results were used to simulate, design and fabricate novel actuators/motors. The developed actuators and performance will be described and discussed in this paper.

  1. An innovative ultrasound assisted extraction micro-scale cell combined with gas chromatography/mass spectrometry in negative chemical ionization to determine persistent organic pollutants in air particulate matter.

    Science.gov (United States)

    Beristain-Montiel, E; Villalobos-Pietrini, R; Arias-Loaiza, G E; Gómez-Arroyo, S L; Amador-Muñoz, O

    2016-12-16

    New clean technologies are needed to determine concentration of organic pollutants without generating more pollution. A method to extract Persistent Organic Pollutants (POPs) from airborne particulate matter was developed using a novel technology recently patented called ultrasound assisted extraction micro-scale cell (UAE-MSC). This technology extracts, filters, collects the sample, and evaporates the solvent, on-line. No sample transfer is needed. The cell minimizes sample manipulation, solvent consumption, waste generation, time, and energy; fulfilling most of the analytical green chemistry protocol. The methodology was optimized applying a centred 2 3 factorial experimental design. Optimum conditions were used to validate and determine concentration of 16 organochlorine pesticides (OCls) and 6 polybrominated diphenyl ethers (PBDEs). The best conditions achieved were 2 extractions with 5mL (each) of dichloromethane over 5min (each) at 60°C and 80% ultrasound potency. POPs were determined by gas chromatography/mass spectrometry in negative chemical ionization (GC/MS-NCI). Analytical method validation was carried out on airborne particles spiked with POPs at seven concentration levels between 0.5 and 26.9pgm -3 . This procedure was done by triplicate (N=21). Recovery, ranged between 65.5±2.3% and 107.5±3.0% for OCls and between 79.1±6.5% and 105.2±3.8% for PBDEs. Linearity (r 2 ) was ≥0.94 for all compounds. Method detection limits, ranged from 0.5 to 2.7pgm -3 , while limits of quantification (LOQ), ranged from 1.7 to 9.0pgm -3 . A Bias from -18.6% to 9% for PBDEs was observed in the Standard Reference Material (SRM) 2787. SRM 2787 did not contain OCls. OCls recoveries were equivalent by UAE-MSC and Soxhlet methods UAE-MSC optimized extraction conditions reduced 30 times less solvent and decreased the extraction time from several hours to ten minutes, respect to Soxhlet. UAE-MSC was applied to 15 samples of particles less than 2.5μm (PM 2.5 ) from three

  2. The pollutants removal and bacterial community dynamics relationship within a full-scale British Gas/Lurgi coal gasification wastewater treatment using a novel system.

    Science.gov (United States)

    Jia, Shengyong; Han, Hongjun; Zhuang, Haifeng; Hou, Baolin

    2016-01-01

    The novel system of EBA (based on external circulation anaerobic (EC) process-biological enhanced (BE) process-anoxic/oxic (A/O) process) was applied to treat the British Gas/Lurgi coal gasification wastewater in Erdos, China. After a long time of commissioning, the EBA system represented a stable and highly efficient performance, particularly, the concentrations of COD, NH4(+)-N, total organic carbon, total nitrogen and volatile phenols in the final effluent reached 53, 0.3, 18, 106mg/L and not detected, respectively. Both the GC-MS and fluorescence excitation-emission matrix analyses revealed significant variations of organic compositions in the effluent of different process. The results of high-throughput sequencing represented the EBA system composed 34 main bacteria which were affiliated to 7 phyla. In addition, the canonical correspondence analysis indicated high coherence among community composition, wastewater characteristics and environmental variables, in which the pH, mixed liquid suspended solids and total phenols loading were the most three significant variables. Copyright © 2015 Elsevier Ltd. All rights reserved.

  3. Air Pollution Dispersion Modeling of Abadan oil Refinery Using SCREEN3

    International Nuclear Information System (INIS)

    Hedayati Rad, F.; Salman-Mahini, A.; Mirkarimi, H.

    2016-01-01

    Air pollution is a major problem that has been recognized throughout the world. Refineriers normally create environmental pollution through emissions of pollutants gaseous from a variety of sources. Analysing air pollution distribution and dispersion can help in reducing the negative effects. In this study NO X and SO 2 emissions and distributions were investigated for Abadan oil refinery using SCREEN3 software. In this softweare, wind speed and direction, air temperature, location and physical characteristics of chimnies and atmospheric stability were taken into consideration.The concentration of pollutants in different distances from the stacks in the range 25 km were predicted and mapped in Idrisi software. The output from software SCREEN3 for emissions from stacks were also examined and compared with the standard output of the refineries. According to our results, the concentration of pollutants in summer and autumn seasons exceeds of the environmental standards.

  4. A Software Managed Stack Cache for Real-Time Systems

    DEFF Research Database (Denmark)

    Jordan, Alexander; Abbaspourseyedi, Sahar; Schoeberl, Martin

    2016-01-01

    In a real-time system, the use of a scratchpad memory can mitigate the difficulties related to analyzing data caches, whose behavior is inherently hard to predict. We propose to use a scratchpad memory for stack allocated data. While statically allocating stack frames for individual functions to ...

  5. Calculation of AC losses in large HTS stacks and coils

    DEFF Research Database (Denmark)

    Zermeno, Victor; Abrahamsen, Asger Bech; Mijatovic, Nenad

    2012-01-01

    In this work, we present a homogenization method to model a stack of HTS tapes under AC applied transport current or magnetic field. The idea is to find an anisotropic bulk equivalent for the stack of tapes, where the internal alternating structures of insulating, metallic, superconducting and su...

  6. Efficient Context Switching for the Stack Cache: Implementation and Analysis

    DEFF Research Database (Denmark)

    Abbaspourseyedi, Sahar; Brandner, Florian; Naji, Amine

    2015-01-01

    , the analysis of the stack cache was limited to individual tasks, ignoring aspects related to multitasking. A major drawback of the original stack cache design is that, due to its simplicity, it cannot hold the data of multiple tasks at the same time. Consequently, the entire cache content needs to be saved...

  7. ENVIRONMENTAL POLLUTION

    OpenAIRE

    Reyna Ramos, julio

    2014-01-01

    The article shows the complexity of the problem of environmental pollution and what can be the possible solutions to the problem. Also, how the Industrial Engineering can contribute to the prevention and control of pollution. El artículo muestra la complejidad del problema de la contaminación ambiental y cuáles pueden ser las propuestas de solución al problema. Así mismo, cómo la Ingeniería Industrial puede contribuir a la prevención y control de la contaminación.

  8. Gas and Gas Pains

    Science.gov (United States)

    ... to produce gas. Often, relatively simple changes in eating habits can lessen bothersome gas. Certain digestive system disorders, ... such as soda and beer, increase stomach gas. Eating habits, such as eating too quickly, drinking through a ...

  9. The behaviour of stacking fault energy upon interstitial alloying.

    Science.gov (United States)

    Lee, Jee-Yong; Koo, Yang Mo; Lu, Song; Vitos, Levente; Kwon, Se Kyun

    2017-09-11

    Stacking fault energy is one of key parameters for understanding the mechanical properties of face-centered cubic materials. It is well known that the plastic deformation mechanism is closely related to the size of stacking fault energy. Although alloying is a conventional method to modify the physical parameter, the underlying microscopic mechanisms are not yet clearly established. Here, we propose a simple model for determining the effect of interstitial alloying on the stacking fault energy. We derive a volumetric behaviour of stacking fault energy from the harmonic approximation to the energy-lattice curve and relate it to the contents of interstitials. The stacking fault energy is found to change linearly with the interstitial content in the usual low concentration domain. This is in good agreement with previously reported experimental and theoretical data.

  10. Dynamic Model of High Temperature PEM Fuel Cell Stack Temperature

    DEFF Research Database (Denmark)

    Andreasen, Søren Juhl; Kær, Søren Knudsen

    2007-01-01

    The present work involves the development of a model for predicting the dynamic temperature of a high temperature PEM (HTPEM) fuel cell stack. The model is developed to test different thermal control strategies before implementing them in the actual system. The test system consists of a prototype...... parts, where also the temperatures are measured. The heat balance of the system involves a fuel cell model to describe the heat added by the fuel cells when a current is drawn. Furthermore the model also predicts the temperatures, when heating the stack with external heating elements for start-up, heat...... the stack at a high stoichiometric air flow. This is possible because of the PBI fuel cell membranes used, and the very low pressure drop in the stack. The model consists of a discrete thermal model dividing the stack into three parts: inlet, middle and end and predicting the temperatures in these three...

  11. Direct methanol fuel cell stack based on MEMS technology

    Science.gov (United States)

    Zhang, Yufeng; Tang, Xiaochuan; Yuan, Zhenyu; Liu, Xiaowei

    2008-10-01

    This paper presents a design configuration of silicon-based micro direct methanol fuel cell (DMFC) stack in a planar array. The integrated series connection is oriented in a "flip-flop" configuration with electrical interconnections made by thin-film metal layers that coat the flow channels etched in the silicon substrate. The configuration features small connection space and low contact resistance. The MEMS fabrication process was utilized to fabricate the silicon plates of DMFC stack. This DMFC stack with an active area of 64mm x 11mm was characterized at room temperature and normal atmosphere. Experimental results show that the prototype stack is able to generate an open-circuit voltage of 2.7V and a maximum power density of 2.2mW/cm2, which demonstrate the feasibility of this new DMFC stack configuration.

  12. Deformation Induced Microtwins and Stacking Faults in Aluminum Single Crystal

    Science.gov (United States)

    Han, W. Z.; Cheng, G. M.; Li, S. X.; Wu, S. D.; Zhang, Z. F.

    2008-09-01

    Microtwins and stacking faults in plastically deformed aluminum single crystal were successfully observed by high-resolution transmission electron microscope. The occurrence of these microtwins and stacking faults is directly related to the specially designed crystallographic orientation, because they were not observed in pure aluminum single crystal or polycrystal before. Based on the new finding above, we propose a universal dislocation-based model to judge the preference or not for the nucleation of deformation twins and stacking faults in various face-centered-cubic metals in terms of the critical stress for dislocation glide or twinning by considering the intrinsic factors, such as stacking fault energy, crystallographic orientation, and grain size. The new finding of deformation induced microtwins and stacking faults in aluminum single crystal and the proposed model should be of interest to a broad community.

  13. Physical Sciences Laboratory 1 Rooftop Stack Mixing Study

    Energy Technology Data Exchange (ETDEWEB)

    Flaherty, Julia E. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Antonio, Ernest J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2016-09-30

    To address concerns about worker exposures on the Physical Science Laboratory (PSL) rooftop, a tracer study was conducted to measure gaseous tracer concentrations downwind of six stacks on the southern half of the PSL building (PSL-1). These concerns were raised, in part, due to the non-standard configuration of the stacks on this building. Five of the six stacks were only about 8 feet tall, with one shorter stack that was essentially level with the roof deck. These stacks were reconfigured in August 2016, and these exhaust points on PSL-1 are now 18 feet tall. This report describes the objectives of the tracer tests performed on PSL-1, provides an overview of how the tests were executed, and presents results of the tests. The tests on the PSL rooftop were a follow-on project from a similar study performed on the LSL-II ventilation exhaust (Flaherty and Antonio, 2016).

  14. Electrochemical Impedance Spectroscopy on Industrially-Relevant Solid Oxide Electrolyzer Cell Stacks: A Powerful Tool for in-Situ Investigations of Degradation Mechanisms

    DEFF Research Database (Denmark)

    Zielke, Philipp; Høgh, Jens Valdemar Thorvald; Chen, Ming

    2016-01-01

    .g. transportation, or at high demands converted back to electricity by either conventional power plants or fuel cells. One of today’s biggest hurdles for a successful commercialization of solid oxide electrolyzers is the stack’s lifetime with current industry targets in the order of five to ten years. To identify...... that energy services can be covered in a stable and affordable manner. One promising solution is the synthetic fuel production by solid oxide electrolyzers. Electricity can be stored in a power-to-gas process during times of excess electricity production and then further converted to liquid fuels for e...... stack (Delta design) specifically optimized for EIS measurements, while the other stack was an 8-cell stack (TSP-1 design), where impedance measurements were carried out without major modifications to the stack. The individual cell voltages were monitored simultaneously by EIS during up to 2000 hours...

  15. Gas fuels and environment

    International Nuclear Information System (INIS)

    Anon.

    1996-01-01

    Environment protection is one of the major concerns for public and local authorities worldwide. Automotive transports are in a large part responsible of the daily pollution of urban areas. Gaseous fuels can notably contribute to a reduction of this pollution. This paper is divided into three parts. The first part analyses the reasons and components of pollution in the transport sector: increasing use of private cars with respect to public transport systems for short distance travels, preponderance of road transport for long distance goods delivery, increase of air traffic for passengers and freight transports. For the air pollution itself, three levels are considered: the local CO, VOC (volatile organic compounds), SO 2 , NOx and particulates concentration, the regional pollution which corresponds to spatially diluted pollutants over a wider zone (acid rain and photochemical pollution), and the worldwide pollution with the greenhouse effect and the high altitude ozone problem. The vehicles noise in another important source of urban pollution. The second part of the paper analyses the environmental advantages of gaseous fuels and compares the combustion properties and the pollutants and noise emissions from natural gas for vehicles and LPG with respect to the classical liquid fuels used for private cars and trucks. The third part of the paper is devoted to the US Clean Air Act which regroups the actions developed since 1970 to fight against the photochemical pollution and the 'smog' phenomena. Its historical evolution is summarized: the creation of the Environment Protection Agency (EPA), the norms for air quality (NAAQS) and the 1990's eleven amendments about the classification of States pollution, the pollutants emission norms and the development of clean vehicles. (J.S.)

  16. Polonium pollution

    International Nuclear Information System (INIS)

    Anon.

    1982-01-01

    In January of 1982, polonium-210 was discovered in drinking water supplies in two southwest Florida counties. Since then, the radioisotope has been found in two more counties. Samples were taken from 20-25 ft. wells, and Po-210 concentrations ranged from 50-7000 pCi/liter. Federal standards of the Nuclear Regulatory Commission limit concentrations in water supplies to 700 pCi/liter. Although Florida's phosphate rocks are rich sources of uranium, no geographical pattern has been found which would suggest an association of the contamination with phosphate mining operations. However, the ''gyp-stacks'', huge piles of waste calcium sulfate are considered by some to be a potential health hazard because they contain high levels of radium sulfate which, through decay, could eventually form polonium

  17. Ground water pollution through air pollutants

    International Nuclear Information System (INIS)

    Cichorowski, G.; Michel, B.; Versteegen, D.; Wettmann, R.

    1989-01-01

    The aim of the investigation is to determine the significance of air pollutants for ground water quality and ground water use. The report summarizes present knowledge and assesses statements with a view to potential ground water pollution from the air. In this context pollution paths, the spreading behaviour of pollutants, and 'cross points' with burden potentials from other pollutant sources are presented. (orig.) [de

  18. Domestic wastewater treatment and power generation in continuous flow air-cathode stacked microbial fuel cell: Effect of series and parallel configuration.

    Science.gov (United States)

    Estrada-Arriaga, Edson Baltazar; Hernández-Romano, Jesús; García-Sánchez, Liliana; Guillén Garcés, Rosa Angélica; Bahena-Bahena, Erick Obed; Guadarrama-Pérez, Oscar; Moeller Chavez, Gabriela Eleonora

    2018-05-15

    In this study, a continuous flow stack consisting of 40 individual air-cathode MFC units was used to determine the performance of stacked MFC during domestic wastewater treatment operated with unconnected individual MFC and in series and parallel configuration. The voltages obtained from individual MFC units were of 0.08-1.1 V at open circuit voltage, while in series connection, the maximum power and current density were 2500 mW/m 2 and 500 mA/m 2 (4.9 V), respectively. In parallel connection, the maximum power and current density was 5.8 mW/m 2 and 24 mA/m 2 , respectively. When the cells were not connected to each other MFC unit, the main bacterial species found in the anode biofilms were Bacillus and Lysinibacillus. After switching from unconnected to series and parallel connections, the most abundant species in the stacked MFC were Pseudomonas aeruginosa, followed by different Bacilli classes. This study demonstrated that when the stacked MFC was switched from unconnected to series and parallel connections, the pollutants removal, performance electricity and microbial community changed significantly. Voltages drops were observed in the stacked MFC, which was mainly limited by the cathodes. These voltages loss indicated high resistances within the stacked MFC, generating a parasitic cross current. Copyright © 2018 Elsevier Ltd. All rights reserved.

  19. Potential radionuclide emissions from stacks on the Hanford site, Part 2: Dose assessment methodology using portable low-resolution gamma spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Barnett, J.M. [Westinghouse Hanford Company, Richland, WA (United States)

    1995-02-01

    In September 1992, the Westinghouse Hanford Company began developing an in situ measurement method to assess gamma radiation emanating from high-efficiency particulate air filters using portable low-resolution gamma spectroscopy. The purpose of the new method was to assess radioactive exhaust stack air emissions from empirical data rather than from theoretical models and to determine the potential unabated dose to an offsite theoretical maximally exposed individual. In accordance with Title 40, Code of Federal Regulations, Part 61, Subpart H, {open_quotes}National Emission Standards for Hazardous Air Pollutants{close_quotes}, stacks that have the potential to emit {ge} 1 {mu}Sv y{sup {minus}1} (0.1 mrem y{sup {minus}1}) to the maximally exposed individual are considered {open_quotes}major{close_quotes} and must meet the continuous monitoring requirements. After the method was tested and verified, the U.S. Environmental Protection Agency, Region 10, approved its use in June 1993. Of the 125 stacks operated by the Westinghouse Hanford Company, 22 were targeted for evaluation by this method, and 15 were assessed. (The method could not be applied at seven stacks because of excessive background radiation or because no gamma emitting particles appear in the emission stream.) The most significant result from this study was the redesignation of the T Plant main stack. The stack was assessed as being {open_quotes}minor{close_quotes}, and it now only requires periodic confirmatory measurements and meets federally imposed sampling requirements.

  20. Water Pollution

    Science.gov (United States)

    We all need clean water. People need it to grow crops and to operate factories, and for drinking and recreation. Fish and wildlife depend on ... and phosphorus make algae grow and can turn water green. Bacteria, often from sewage spills, can pollute ...

  1. Nuclear pollution

    International Nuclear Information System (INIS)

    Ramade, Francois

    1979-01-01

    In this chapter devoted to nuclear pollution the following topics were studied: fundamentals of radiobiology (ecological importance of the various radioisotopes, biological effects of ionizing radiations); ecological effects of radioactive fallout (contamination of atmosphere, terrestrial ecosystems, oceans). The electronuclear industry and its environmental impact. PWR type reactors, fuel reprocessing plants, contamination of trophic chains by radionuclides released in the environment from nuclear installations [fr

  2. Reflector imaging by diffraction stacking with stacking velocity analysis; Jugo sokudo kaiseki wo tomonau sanran jugoho ni yoru hanshamen imaging

    Energy Technology Data Exchange (ETDEWEB)

    Matsushima, J.; Rokugawa, S.; Kato, Y. [The University of Tokyo, Tokyo (Japan). Faculty of Engineering; Yokota, T. [Japan National Oil Corp., Tokyo (Japan); Miyazaki, T. [Geological Survey of Japan, Tsukuba (Japan)

    1997-10-22

    Concerning seismic reflection survey for geometrical arrangement between pits, the scattering stacking method with stacking velocity analysis is compared with the CDP (common depth point horizontal stacking method). The advantages of the CDP supposedly include the following. Since it presumes an average velocity field, it can determine velocities having stacking effects. The method presumes stratification and, since such enables the division of huge quantities of observed data into smaller groups, more data can be calculated in a shorter time period. The method has disadvantages, attributable to its presuming an average velocity field, that accuracy in processing is lower when the velocity field contrast is higher, that accuracy in processing is low unless stratification is employed, and that velocities obtained from stacking velocity analysis are affected by dipped structures. Such shortcomings may be remedied in the scattering stacking method with stacking velocity analysis. Possibilities are that, as far as the horizontal reflection plane is concerned, it may yield stack records higher in S/N ratio than the CDP. Findings relative to dipped reflection planes will be introduced at the presentation. 6 refs., 12 figs.

  3. Electrochemical Impedance Spectroscopy (EIS) Characterization of Reformate-operated High Temperature PEM Fuel Cell Stack

    DEFF Research Database (Denmark)

    Sahlin, Simon Lennart; Simon Araya, Samuel; Andreasen, Søren Juhl

    2017-01-01

    their effects on a reformate-operated stack. Polarization curves were also recorded to complement the impedance analysis of the researched phenomena. An equivalent circuit model was used to estimate the different resistances at varying parameters. It showed a significantly higher low frequency resistance......, λanode= 1.6 for reformate operation and λcathode= 4.The work also compared dry hydrogen, steam reforming and autothermal reforming gas feeds at160 ◦Cand showed appreciably lower performance in the case of autothermal reforming at the same stoichiometry, mainly attributable to mass transport related...

  4. Development and characterisation of a portable direct methanol fuel cell stack

    Energy Technology Data Exchange (ETDEWEB)

    Oedegaard, A.

    2005-11-21

    This thesis deals with the development and characterisation of a portable direct methanol fuel cell stack. In addition, calculations of the transport of methanol and water in the membrane are compared with experimentally determined values. It also includes investigations of the behaviour of single-cells and some of its components, as the anode gas diffusion layer and the anode flow-field. For the addition of methanol to the anode feed loop, a passive concept based on a permeable tube was developed and verified by both experiments and simulations. (orig.)

  5. Single point aerosol sampling: Evaluation of mixing and probe performance in a nuclear stack

    Energy Technology Data Exchange (ETDEWEB)

    Rodgers, J.C.; Fairchild, C.I.; Wood, G.O. [Los Alamos National Laboratory, NM (United States)] [and others

    1995-02-01

    Alternative Reference Methodologies (ARMs) have been developed for sampling of radionuclides from stacks and ducts that differ from the methods required by the U.S. EPA. The EPA methods are prescriptive in selection of sampling locations and in design of sampling probes whereas the alternative methods are performance driven. Tests were conducted in a stack at Los Alamos National Laboratory to demonstrate the efficacy of the ARMs. Coefficients of variation of the velocity tracer gas, and aerosol particle profiles were determined at three sampling locations. Results showed numerical criteria placed upon the coefficients of variation by the ARMs were met at sampling stations located 9 and 14 stack diameters from flow entrance, but not at a location that is 1.5 diameters downstream from the inlet. Experiments were conducted to characterize the transmission of 10 {mu}m aerodynamic equivalent diameter liquid aerosol particles through three types of sampling probes. The transmission ratio (ratio of aerosol concentration at the probe exit plane to the concentration in the free stream) was 107% for a 113 L/min (4-cfm) anisokinetic shrouded probe, but only 20% for an isokinetic probe that follows the EPA requirements. A specially designed isokinetic probe showed a transmission ratio of 63%. The shrouded probe performance would conform to the ARM criteria; however, the isokinetic probes would not.

  6. Analysis of the effect of dissimilar welding in a high pressure flare stack

    International Nuclear Information System (INIS)

    Mahdi Ezwan Mahmoud; Mohd Harun; Zaifol Samsu; Norasiah Kasim; Zaiton Selamat; Alahuddin, K.H.

    2010-01-01

    A flare stack is an elevated vertical stack found in a natural gas processing plant, used primarily for combusting waste gases released by pressure relief valves. The materials used for our high pressure flare tip are carbon steel (CS) type A516 Gr. 55 for its lower portion, and stainless steel (SS) 310 for its upper portion. Both were combined into a single unit by arc welding (dissimilar welding), with SS310 as a base metal. After 5 years of operations, few mechanical deformations were observed on the flare stack, along with corrosion deposit on the CS portion of the flare. Detailed analysis shows the presence of toe and shrinkage cracks, along with spheroidization of pearlite in the CS. These are caused by factors such as mismatched welding and coefficient of thermal expansion (CTE) between the metals. These factors helped exacerbate crack initiation and propagation. Based on the evidence collected, it is recommended that the CS A516 be replaced with SS310. (author)

  7. Hydrogen Production Performance of a 10-Cell Planar Solid-Oxide Electrolysis Stack

    International Nuclear Information System (INIS)

    James O'Brien; Carl Stoots; Steve Herring; J. Hartvigsen

    2005-01-01

    An experimental study is under way to assess the performance of solid-oxide cells operating in the steam electrolysis mode for hydrogen production over a temperature range of 800 to 900 C. Results presented in this paper were obtained from a ten-cell planar electrolysis stack, with an active area of 64 cm2 per cell. The electrolysis cells are electrolyte supported, with scandia-stabilized zirconia electrolytes (∼140 (micro)m thick), nickel-cermet steam/hydrogen electrodes, and manganite air-side electrodes. The metallic interconnect plates are fabricated from ferritic stainless steel. The experiments were performed over a range of steam inlet mole fractions (0.1-0.6), gas flow rates (1000-4000 sccm), and current densities (0 to 0.38 A/cm2). Steam consumption rates associated with electrolysis were measured directly using inlet and outlet dewpoint instrumentation. Cell operating potentials and cell current were varied using a programmable power supply. Hydrogen production rates up to 100 Normal liters per hour were demonstrated. Values of area-specific resistance and stack internal temperatures are presented as a function of current density. Stack performance is shown to be dependent on inlet steam flow rate

  8. Porous Structures in Stacked, Crumpled and Pillared Graphene-Based 3D Materials.

    Science.gov (United States)

    Guo, Fei; Creighton, Megan; Chen, Yantao; Hurt, Robert; Külaots, Indrek

    2014-01-01

    Graphene, an atomically thin material with the theoretical surface area of 2600 m 2 g -1 , has great potential in the fields of catalysis, separation, and gas storage if properly assembled into functional 3D materials at large scale. In ideal non-interacting ensembles of non-porous multilayer graphene plates, the surface area can be adequately estimated using the simple geometric law ~ 2600 m 2 g -1 /N, where N is the number of graphene sheets per plate. Some processing operations, however, lead to secondary plate-plate stacking, folding, crumpling or pillaring, which give rise to more complex structures. Here we show that bulk samples of multilayer graphene plates stack in an irregular fashion that preserves the 2600/N surface area and creates regular slot-like pores with sizes that are multiples of the unit plate thickness. In contrast, graphene oxide deposits into films with massive area loss (2600 to 40 m 2 g -1 ) due to nearly perfect alignment and stacking during the drying process. Pillaring graphene oxide sheets by co-deposition of colloidal-phase particle-based spacers has the potential to partially restore the large monolayer surface. Surface areas as high as 1000 m 2 g -1 are demonstrated here through colloidal-phase deposition of graphene oxide with water-dispersible aryl-sulfonated ultrafine carbon black as a pillaring agent.

  9. Experimental investigation of electron cooling and stacking of lead ions in a low energy accumulation ring

    CERN Document Server

    Bosser, Jacques; Chanel, M; Hill, C; Lombardi, A M; MacCaferri, R; Maury, S; Möhl, D; Molinari, G; Rossi, S; Tanke, E; Tranquille, G; Vretenar, Maurizio

    1999-01-01

    This report gives the results of a programme of experimental investigations, which were carried out to test stacking of lead ions in a storage ring (the former Low Energy Antiproton Ring, LEAR) at 4.2 MeV per nucleon. The motivation was to demonstrate the feasibility of gaining the large factor in the phase-space density required for injection into the LHC. In the first part of the report, the layout of the experiments is described, the choice of the parameters of the electron cooling system used for stacking is reported and the multi-turn injection using horizontal- and longitudinal- (and in the final project also vertical-) phase space is discussed. In the second part the experimental results are presented. Factors of vital importance are the stacking efficiency, the beam life-time and the cooling time of the ions. The beam decay owing to charge exchange with the residual gas and to recombination by the capture of cooling electrons was intensively studied. Beam instabilities and space-charge effects in the ...

  10. Black Hole Spectroscopy with Coherent Mode Stacking.

    Science.gov (United States)

    Yang, Huan; Yagi, Kent; Blackman, Jonathan; Lehner, Luis; Paschalidis, Vasileios; Pretorius, Frans; Yunes, Nicolás

    2017-04-21

    The measurement of multiple ringdown modes in gravitational waves from binary black hole mergers will allow for testing the fundamental properties of black holes in general relativity and to constrain modified theories of gravity. To enhance the ability of Advanced LIGO/Virgo to perform such tasks, we propose a coherent mode stacking method to search for a chosen target mode within a collection of multiple merger events. We first rescale each signal so that the target mode in each of them has the same frequency and then sum the waveforms constructively. A crucial element to realize this coherent superposition is to make use of a priori information extracted from the inspiral-merger phase of each event. To illustrate the method, we perform a study with simulated events targeting the ℓ=m=3 ringdown mode of the remnant black holes. We show that this method can significantly boost the signal-to-noise ratio of the collective target mode compared to that of the single loudest event. Using current estimates of merger rates, we show that it is likely that advanced-era detectors can measure this collective ringdown mode with one year of coincident data gathered at design sensitivity.

  11. Stacking faults in austempered ductile iron

    Energy Technology Data Exchange (ETDEWEB)

    Hermida, J.D. [CNEA, San Martin (Argentina). Dept. de Materiales

    1996-06-01

    During last decade, Austempered Ductile Iron (ADI) has been successfully used as an acceptable replacement material for steel in many applications, due to the relatively high strength and reasonable ductility obtained. These properties are the result of the special microstructure exhibited by this material at the end of the upper bainite reaction: ferrite platelets surrounded by high carbon stabilized austenite. However, at the beginning of the austempering treatment, the existence of interdendritic low carbon austenite is revealed by its transformation to martensite when cooling the sample or during subsequent deformation. The completion of the upper bainite reaction is of decisive importance to mechanical properties because the remaining martensite reduces ductility. It was observed that the rate of the upper bainite reaction is governed by the carbon content difference between the low and high carbon austenites. The carbon content is obtained by the lattice parameter measurement, because there exists a known expression that relates both magnitudes. Several works have used X-ray diffraction to measure the lattice parameter and phase concentrations as a function of austempering time. In these works, the lattice parameters were obtained directly from the {l_brace}220{r_brace} and {l_brace}311{r_brace} peaks position. The purpose of this work is to show more precise lattice parameters measurement and, very closely related to this, the existence of stacking faults in austenite, even at times within the processing window.

  12. ATLAS software stack on ARM64

    CERN Document Server

    Smith, Joshua Wyatt; The ATLAS collaboration

    2016-01-01

    The ATLAS experiment explores new hardware and software platforms that, in the future, may be more suited to its data intensive workloads. One such alternative hardware platform is the ARM architecture, which is designed to be extremely power efficient and is found in most smartphones and tablets. CERN openlab recently installed a small cluster of ARM 64-bit evaluation prototype servers. Each server is based on a single-socket ARM 64-bit system on a chip, with 32 Cortex-A57 cores. In total, each server has 128 GB RAM connected with four fast memory channels. This paper reports on the port of the ATLAS software stack onto these new prototype ARM64 servers. This included building the "external" packages that the ATLAS software relies on. Patches were needed to introduce this new architecture into the build as well as patches that correct for platform specific code that caused failures on non-x86 architectures. These patches were applied such that porting to further platforms will need no or only very little adj...

  13. Long Duration Balloon Charge Controller Stack Integration

    Science.gov (United States)

    Clifford, Kyle

    NASA and the Columbia Scientific Balloon Facility are interested in updating the design of the charge controller on their long duration balloon (LDB) in order to enable the charge controllers to be directly interfaced via RS232 serial communication by a ground testing computers and the balloon's flight computer without the need to have an external electronics stack. The design involves creating a board that will interface with the existing boards in the charge controller in order to receive telemetry from and send commands to those boards, and interface with a computer through serial communication. The inputs to the board are digital status inputs indicating things like whether the photovoltaic panels are connected or disconnected; and analog inputs with information such as the battery voltage and temperature. The outputs of the board are 100ms duration command pulses that will switch relays that do things like connect the photovoltaic panels. The main component of this design is a PIC microcontroller which translates the outputs of the existing charge controller into serial data when interrogated by a ground testing or flight computer. Other components involved in the design are an AD7888 12-bit analog to digital converter, a MAX3232 serial transceiver, various other ICs, capacitors, resistors, and connectors.

  14. Lithiation-induced shuffling of atomic stacks

    KAUST Repository

    Nie, Anmin

    2014-09-10

    In rechargeable lithium-ion batteries, understanding the atomic-scale mechanism of Li-induced structural evolution occurring at the host electrode materials provides essential knowledge for design of new high performance electrodes. Here, we report a new crystalline-crystalline phase transition mechanism in single-crystal Zn-Sb intermetallic nanowires upon lithiation. Using in situ transmission electron microscopy, we observed that stacks of atomic planes in an intermediate hexagonal (h-)LiZnSb phase are "shuffled" to accommodate the geometrical confinement stress arising from lamellar nanodomains intercalated by lithium ions. Such atomic rearrangement arises from the anisotropic lithium diffusion and is accompanied by appearance of partial dislocations. This transient structure mediates further phase transition from h-LiZnSb to cubic (c-)Li2ZnSb, which is associated with a nearly "zero-strain" coherent interface viewed along the [001]h/[111]c directions. This study provides new mechanistic insights into complex electrochemically driven crystalline-crystalline phase transitions in lithium-ion battery electrodes and represents a noble example of atomic-level structural and interfacial rearrangements.

  15. Weyl magnons in noncoplanar stacked kagome antiferromagnets

    Science.gov (United States)

    Owerre, S. A.

    2018-03-01

    Weyl nodes have been experimentally realized in photonic, electronic, and phononic crystals. However, magnonic Weyl nodes are yet to be seen experimentally. In this paper, we propose Weyl magnon nodes in noncoplanar stacked frustrated kagome antiferromagnets, naturally available in various real materials. Most crucially, the Weyl nodes in the current system occur at the lowest excitation and possess a topological thermal Hall effect, therefore they are experimentally accessible at low temperatures due to the population effect of bosonic quasiparticles. In stark contrast to other magnetic systems, the current Weyl nodes do not rely on time-reversal symmetry breaking by the magnetic order. Rather, they result from explicit macroscopically broken time reversal symmetry by the scalar spin chirality of noncoplanar spin textures and can be generalized to chiral spin liquid states. Moreover, the scalar spin chirality gives a real space Berry curvature which is not available in previously studied magnetic Weyl systems. We show the existence of magnon arc surface states connecting projected Weyl magnon nodes on the surface Brillouin zone. We also uncover the first realization of triply-degenerate nodal magnon point in the noncollinear regime with zero scalar spin chirality.

  16. Air pollution with gaseous emissions and methods for their removal

    International Nuclear Information System (INIS)

    Vassilev, Venceslav; Boycheva, Sylvia; Fidancevska, Emilija

    2009-01-01

    Information concerning gaseous pollutants generated in the atmosphere, as a result of fuel incineration processes in thermal power and industrial plants, was summarized. The main methods and technologies for flue gases purification from the most ecologically hazardous pollutants are comparatively discussed. Keywords: gaseous pollutants, aerosols, flue gas purification systems and technologies, air ecology control

  17. Development of a stacked ensemble model for forecasting and analyzing daily average PM2.5 concentrations in Beijing, China.

    Science.gov (United States)

    Zhai, Binxu; Chen, Jianguo

    2018-04-18

    A stacked ensemble model is developed for forecasting and analyzing the daily average concentrations of fine particulate matter (PM 2.5 ) in Beijing, China. Special feature extraction procedures, including those of simplification, polynomial, transformation and combination, are conducted before modeling to identify potentially significant features based on an exploratory data analysis. Stability feature selection and tree-based feature selection methods are applied to select important variables and evaluate the degrees of feature importance. Single models including LASSO, Adaboost, XGBoost and multi-layer perceptron optimized by the genetic algorithm (GA-MLP) are established in the level 0 space and are then integrated by support vector regression (SVR) in the level 1 space via stacked generalization. A feature importance analysis reveals that nitrogen dioxide (NO 2 ) and carbon monoxide (CO) concentrations measured from the city of Zhangjiakou are taken as the most important elements of pollution factors for forecasting PM 2.5 concentrations. Local extreme wind speeds and maximal wind speeds are considered to extend the most effects of meteorological factors to the cross-regional transportation of contaminants. Pollutants found in the cities of Zhangjiakou and Chengde have a stronger impact on air quality in Beijing than other surrounding factors. Our model evaluation shows that the ensemble model generally performs better than a single nonlinear forecasting model when applied to new data with a coefficient of determination (R 2 ) of 0.90 and a root mean squared error (RMSE) of 23.69μg/m 3 . For single pollutant grade recognition, the proposed model performs better when applied to days characterized by good air quality than when applied to days registering high levels of pollution. The overall classification accuracy level is 73.93%, with most misclassifications made among adjacent categories. The results demonstrate the interpretability and generalizability of

  18. Efficiency of Polymer Electrolyte Membrane Fuel Cell Stack

    Directory of Open Access Journals (Sweden)

    Hans Bosma

    2011-08-01

    Full Text Available This paper applies a feedforward control of optimal oxygen excess ratio that maximize net power (improve efficiency of a NedStack P8.0-64 PEM fuel cell stack (FCS system. Net powers profile as a function of oxygen excess ratio for some points of operation are analyzed by using FCS model. The relationships between stack current and the corresponding control input voltage that gives an optimal oxygen excess ratio are used to design a feedforward control scheme. The results of this scheme are compared to the results of a feedforward control using a constant oxygen excess ratio. Simulation results show that optimal oxygen excess ratio improves fuel cell performance compared to the results of constant oxygen excess ratio. The same procedures are performed experimentally for the FCS system. The behaviour of the net power of the fuel cell stack with respect to the variation of oxygen excess ratio is analyzed to obtain optimal values. Data of stack current and the corresponding voltage input to the compressor that gives optimal values of oxygen excess ratio are used to develop a feedforward control. Feedforward control based on constant and optimal oxygen excess ratio control, are implemented in the NedStack P8.0-64 PEM fuel cell stack system by using LabVIEW. Implementation results shows that optimal oxygen excess ratio control improves the fuel cell performance compared to the constant oxygen excess ratio control.

  19. Technology for reducing aircraft engine pollution

    Science.gov (United States)

    Rudey, R. A.; Kempke, E. E., Jr.

    1975-01-01

    Programs have been initiated by NASA to develop and demonstrate advanced technology for reducing aircraft gas turbine and piston engine pollutant emissions. These programs encompass engines currently in use for a wide variety of aircraft from widebody-jets to general aviation. Emission goals for these programs are consistent with the established EPA standards. Full-scale engine demonstrations of the most promising pollutant reduction techniques are planned within the next three years. Preliminary tests of advanced technology gas turbine engine combustors indicate that significant reductions in all major pollutant emissions should be attainable in present generation aircraft engines without adverse effects on fuel consumption. Fundamental-type programs are yielding results which indicate that future generation gas turbine aircraft engines may be able to utilize extremely low pollutant emission combustion systems.

  20. Non-Thermal Removal of Gaseous Pollutants

    Science.gov (United States)

    Srivastava, S.; McGowan, J. William; Chiu, K. C. Ray

    1995-01-01

    The removal of fluorine based exhaust gases such as CFC's, PFC's, NF3, and SF6 used for plasma etching of and deposition on semi-conductors is a subject of increasing interest because of safety, air pollution, and global warming issues. Conventional treatment methods for removing exhaust gas pollutants are wet scrubbing, carbon and resin adsorption, catalytic oxidation, and thermal incineration. However, there are drawbacks associated with each of these methods which include difficulties in implementation, problems with the disposal of solid and liquid pollutant waste, large water and fuel consumption, and additional pollutants such as NOx emissions which are generated in thermal incineration processes.

  1. Hazardous Air Pollutants

    Science.gov (United States)

    ... Protection Agency Search Search Contact Us Share Hazardous Air Pollutants Hazardous air pollutants are those known to ... of industrial facilities in two phases . About Hazardous Air Pollutants What are Hazardous Air Pollutants? Health and ...

  2. Consolidity: Stack-based systems change pathway theory elaborated

    Directory of Open Access Journals (Sweden)

    Hassen Taher Dorrah

    2014-06-01

    Full Text Available This paper presents an elaborated analysis for investigating the stack-based layering processes during the systems change pathway. The system change pathway is defined as the path resulting from the combinations of all successive changes induced on the system when subjected to varying environments, activities, events, or any excessive internal or external influences and happenings “on and above” its normal stands, situations or set-points during its course of life. The analysis is essentially based on the important overall system paradigm of “Time driven-event driven-parameters change”. Based on this paradigm, it is considered that any affected activity, event or varying environment is intelligently self-recorded inside the system through an incremental consolidity-scaled change in system parameters of the stack-based layering types. Various joint stack-based mathematical and graphical approaches supported by representable case studies are suggested for the identification, extraction, and processing of various stack-based systems changes layering of different classifications and categorizations. Moreover, some selected real life illustrative applications are provided to demonstrate the (infinite stack-based identification and recognition of the change pathway process in the areas of geology, archeology, life sciences, ecology, environmental science, engineering, materials, medicine, biology, sociology, humanities, and other important fields. These case studies and selected applications revealed that there are general similarities of the stack-based layering structures and formations among all the various research fields. Such general similarities clearly demonstrate the global concept of the “fractals-general stacking behavior” of real life systems during their change pathways. Therefore, it is recommended that concentrated efforts should be expedited toward building generic modular stack-based systems or blocks for the mathematical

  3. Loop Entropy Assists Tertiary Order: Loopy Stabilization of Stacking Motifs

    Directory of Open Access Journals (Sweden)

    Daniel P. Aalberts

    2011-11-01

    Full Text Available The free energy of an RNA fold is a combination of favorable base pairing and stacking interactions competing with entropic costs of forming loops. Here we show how loop entropy, surprisingly, can promote tertiary order. A general formula for the free energy of forming multibranch and other RNA loops is derived with a polymer-physics based theory. We also derive a formula for the free energy of coaxial stacking in the context of a loop. Simulations support the analytic formulas. The effects of stacking of unpaired bases are also studied with simulations.

  4. Mixed Mechanism of Lubrication by Lipid Bilayer Stacks.

    Science.gov (United States)

    Boţan, Alexandru; Joly, Laurent; Fillot, Nicolas; Loison, Claire

    2015-11-10

    Although the key role of lipid bilayer stacks in biological lubrication is generally accepted, the mechanisms underlying their extreme efficiency remain elusive. In this article, we report molecular dynamics simulations of lipid bilayer stacks undergoing load and shear. When the hydration level is reduced, the velocity accommodation mechanism changes from viscous shear in hydration water to interlayer sliding in the bilayers. This enables stacks of hydrated lipid bilayers to act as efficient boundary lubricants for various hydration conditions, structures, and mechanical loads. We also propose an estimation for the friction coefficient; thanks to the strong hydration forces between lipid bilayers, the high local viscosity is not in contradiction with low friction coefficients.

  5. On $k$-stellated and $k$-stacked spheres

    OpenAIRE

    Bagchi, Bhaskar; Datta, Basudeb

    2012-01-01

    We introduce the class $\\Sigma_k(d)$ of $k$-stellated (combinatorial) spheres of dimension $d$ ($0 \\leq k \\leq d + 1$) and compare and contrast it with the class ${\\cal S}_k(d)$ ($0 \\leq k \\leq d$) of $k$-stacked homology $d$-spheres. We have $\\Sigma_1(d) = {\\cal S}_1(d)$, and $\\Sigma_k(d) \\subseteq {\\cal S}_k(d)$ for $d \\geq 2k - 1$. However, for each $k \\geq 2$ there are $k$-stacked spheres which are not $k$-stellated. The existence of $k$-stellated spheres which are not $k$-stacked remains...

  6. Stacking by electroinjection with discontinuous buffers in capillary zone electrophoresis.

    Science.gov (United States)

    Shihabi, Zak K

    2002-08-01

    The work presented here demonstrates that electroinjection can be performed using discontinuous buffers, which can result in better stacking than that obtained by hydrodynamic injection. The sample can be concentrated at the tip of the capillary leaving practically the whole capillary for sample separation. This results in several advantages, such as better sample concentration, higher plate number and shorter time of stacking. However, sample introduction by electromigration is suited for samples free or low in salt content. Samples, which are high in salt content, are better introduced by the hydrodynamic injection for stacking by the discontinuous buffers. Different simple methods to introduce the discontinuity in the buffer for electroinjection are discussed.

  7. Optimized stacked RADFETs for milli-rad dose measurement

    International Nuclear Information System (INIS)

    O'Connell, B.; Lane, B.; Mohammadzadeh, A.

    1999-01-01

    This paper details the improvements in the design of stacked RADFETs for increased radiation sensitivity. The issues of high read-out voltage has been shown to be a draw-back. It is the body (bulk)effect factor that is responsible for the increased overall stack Threshold voltage (V T ), which is greater than the sum of the individual devices V T . From extensive process and device simulation and resultant circuit simulation, modified stack structures have been proposed and designed. New and exciting result of lower initial (pre-irradiation) output voltage as well as increased radiation sensitivity will be presented. (author)

  8. Natural gas for vehicles

    International Nuclear Information System (INIS)

    Chauveron, S. de

    1996-01-01

    This article presents compressed natural gas for vehicles (CNG), which can provide considerable advantages both as an alternative fuel and as a clean fuel. These assets are not only economic but also technical. The first part deals with what is at stake in developing natural gas as a motor fuel. The first countries to use CNG were those with natural gas resources in their subsoil. Today, with a large number of countries having to cope with growing concern about increasing urban pollution, natural gas is also seen as a clean fuel that can help cut vehicle pollutant emissions dramatically. In the second part a brief technical descriptions is given of CNG stations and vehicles, with the aim of acquainting the reader with some of CNG's specific technical features as compared to gasoline and diesel oil. Here CNG technologies are seen to be very close to the more conventional ones. (author)

  9. Spectral Pollution

    OpenAIRE

    Davies, E B; Plum, M

    2003-01-01

    We discuss the problems arising when computing eigenvalues of self-adjoint operators which lie in a gap between two parts of the essential spectrum. Spectral pollution, i.e. the apparent existence of eigenvalues in numerical computations, when no such eigenvalues actually exist, is commonplace in problems arising in applied mathematics. We describe a geometrically inspired method which avoids this difficulty, and show that it yields the same results as an algorithm of Zimmermann and Mertins.

  10. Water Pollution. Project COMPSEP.

    Science.gov (United States)

    Lantz, H. B., Jr.

    This is an introductory program on water pollution. Examined are the cause and effect relationships of water pollution, sources of water pollution, and possible alternatives to effect solutions from our water pollution problems. Included is background information on water pollution, a glossary of pollution terminology, a script for a slide script…

  11. Air pollution control in kraft pulp mills.

    Science.gov (United States)

    Bhatia, S P; de Souza, T L; Azarniouch, M K; Prahacs, S

    1978-02-01

    A patented gas scrubbing process, whereby the emissions of malodorous reduced sulphur compounds are effectively and economically reduced, is described. Stack gases are scrubbed with an alkaline suspension of activated carbon. Reduced sulphur compounds as well as sulphur oxides are converted to sodium salts which are subsequently recovered and utilized for pulping. The process also reduces particulate emissions. It does not produce subsequent waste disposal problems and has little or, in some cases, zero net cost, on account of the simultaneous recovery of heat and chemicals. Furthermore, the paper also reviews some innovations made in gas chromatography techniques, for the measurement of trace quantities of sulphur compounds present in kraft mill emissions.

  12. Shale gas. Shale gas formation and extraction

    International Nuclear Information System (INIS)

    Renard, Francois; Artru, Philippe

    2015-10-01

    A first article recalls the origin of shale gases and technological breakthroughs which allowed their exploitation, describes the development of shale gas exploitation in the USA during the 2000's and the consequences for the gas and electricity markets, and discusses the various environmental impacts (risks of pollution of aquifers, risks of induced seismicity, use and processing of drilling and production waters). The second article describes the formation of shale gas: presence of organic matter in sediments, early evolution with the biogenic gas, burrowing, diagenesis and oil formation, thermal generation of gas (condensates and methane). The author indicates the location of gas within the rock, and the main sites of shale oils and shale gases in the World. In the next part, the author describes the various phases of shale gas extraction: exploration, oriented drillings, well preparation for hydraulic fracturing, fracturing, processing of fracturing fluids, flow-back, gas production and transport, aquifer protection. He finally gives a brief overview of technical evolution and of shale gas economy

  13. Ozone air pollution effects on tree-ring growth,{delta}{sup 13}C, visible foliar injury and leaf gas exchange in three ozone-sensitive woody plant species

    Energy Technology Data Exchange (ETDEWEB)

    Novak, K. [Swiss Federal Inst. for Forest, Snow and Landscape Research, Birmensdorf (Switzerland); Agroscope FAL Reckenholz, Swiss Federal Research Station for Agroecology and Agriculture, Zurich (Switzerland); Saurer, M. [Paul Scherrer Inst. Villigen (Switzerland); Fuhrer, J. [Agroscope FAL Reckenholz, Swiss Federal Research Station for Agroecology and Agriculture, Zurich (Switzerland); Skelly, J.M. [Pennsylvania State Univ., University Park, PA (United States). Dept. of Plant Pathology; Krauchi, N.; Schaub, M. [Swiss Federal Inst. for Forest, Snow and Landscape Research, Birmensdorf (Switzerland)

    2007-07-15

    Species specific plant responses to tropospheric ozone pollution depend on a range of morphological, biochemical and physiological characteristics as well as environmental factors. The effects of ambient tropospheric ozone on annual tree-ring growth, {delta}{sup 13} C in the rings, leaf gas exchange and ozone-induced visible foliar injury in three ozone-sensitive woody plant species in southern Switzerland were assessed during the 2001 and 2002 growing seasons. Seedlings of Populus nigra L., Viburnum lantana L. and Fraxinus excelsior L. were exposed to charcoal-filtered air and non-filtered air in open-top chambers, and to ambient air (AA) in open plots. The objective was to determine if a relationship exists between measurable ozone-induced effects at the leaf level and subsequent changes in annual tree-ring growth and {delta} {sup 13} C signatures. The visible foliar injury, early leaf senescence and premature leaf loss in all species was attributed to the ambient ozone exposures in the region. Ozone had pronounced negative effects on net photosynthesis and stomatal conductance in all species in 2002 and in V. lantana and F. excelsior in 2001. Water-use efficiency decreased and intercellular carbon dioxide concentrations increased in all species in response to ozone in 2002 only. The width and {delta}{sup 13} C of the 2001 and 2002 growth rings were measured for all species at the end of the 2002 growing season. Significant ozone-induced effects at the leaf level did not correspond to reduced tree-ring growth or increased {delta}{sup 13} C in all species, suggesting that the timing of ozone exposure and extent of leaf-level responses may be relevant in determining the sensitivity of tree productivity to ozone exposure. 48 refs., 4 tabs., 2 figs.

  14. Simulation of magnetization and levitation characteristics of HTS tape stacks

    Science.gov (United States)

    Anischenko, I. V.; Pokrovskii, S. V.; Mineev, N. A.

    2017-12-01

    In this work it is presented a computational model of a magnetic levitation system based on stacks of high-temperature second generation superconducting tapes (HTS) GdBa2Cu3O7-x. Calculated magnetic field and the current distributions in the system for different stacks geometries in the zero-field cooling mode are also presented. The magnetization curves of the stacks in the external field of a permanent NdFeB magnet and the levitation force dependence on the gap between the magnet and the HTS tapes stack were obtained. A model of the magnetic system, oriented to levitation application, is given. Results of modeling were compared with the experimental data.

  15. Fast principal component analysis for stacking seismic data

    Science.gov (United States)

    Wu, Juan; Bai, Min

    2018-04-01

    Stacking seismic data plays an indispensable role in many steps of the seismic data processing and imaging workflow. Optimal stacking of seismic data can help mitigate seismic noise and enhance the principal components to a great extent. Traditional average-based seismic stacking methods cannot obtain optimal performance when the ambient noise is extremely strong. We propose a principal component analysis (PCA) algorithm for stacking seismic data without being sensitive to noise level. Considering the computational bottleneck of the classic PCA algorithm in processing massive seismic data, we propose an efficient PCA algorithm to make the proposed method readily applicable for industrial applications. Two numerically designed examples and one real seismic data are used to demonstrate the performance of the presented method.

  16. Static analysis of worst-case stack cache behavior

    DEFF Research Database (Denmark)

    Jordan, Alexander; Brandner, Florian; Schoeberl, Martin

    2013-01-01

    Utilizing a stack cache in a real-time system can aid predictability by avoiding interference that heap memory traffic causes on the data cache. While loads and stores are guaranteed cache hits, explicit operations are responsible for managing the stack cache. The behavior of these operations can......-graph, the worst-case bounds can be efficiently yet precisely determined. Our evaluation using the MiBench benchmark suite shows that only 37% and 21% of potential stack cache operations actually store to and load from memory, respectively. Analysis times are modest, on average running between 0.46s and 1.30s per...... be analyzed statically. We present algorithms that derive worst-case bounds on the latency-inducing operations of the stack cache. Their results can be used by a static WCET tool. By breaking the analysis down into subproblems that solve intra-procedural data-flow analysis and path searches on the call...

  17. A Stack Cache for Real-Time Systems

    DEFF Research Database (Denmark)

    Schoeberl, Martin; Nielsen, Carsten

    2016-01-01

    Real-time systems need time-predictable computing platforms to allowfor static analysis of the worst-case execution time. Caches are important for good performance, but data caches arehard to analyze for the worst-case execution time. Stack allocated data has different properties related to local......Real-time systems need time-predictable computing platforms to allowfor static analysis of the worst-case execution time. Caches are important for good performance, but data caches arehard to analyze for the worst-case execution time. Stack allocated data has different properties related...... to locality, lifetime, and static analyzability of access addresses comparedto static or heap allocated data. Therefore, caching of stack allocateddata benefits from having its own cache. In this paper we present a cache architecture optimized for stack allocateddata. This cache is additional to the normal...

  18. DBaaS with OpenStack Trove

    CERN Document Server

    Giardini, Andrea

    2013-01-01

    The purpose of the project was to evaluate the Trove component for OpenStack, understand if it can be used with the CERN infrastructure and report the benefits and disadvantages of this software. Currently, databases for CERN projects are provided by a DbaaS software developed inside the IT-DB group. This solution works well with the actual infrastructure but it is not easy to maintain. With the migration of the CERN infrastructure to OpenStack the Database group started to evaluate the Trove component. Instead of mantaining an own DbaaS service it can be interesting to migrate everything to OpenStack and replace the actual DbaaS software with Trove. This way both virtual machines and databases will be managed by OpenStack itself.

  19. Stacking dependence of carrier transport properties in multilayered black phosphorous.

    Science.gov (United States)

    Sengupta, A; Audiffred, M; Heine, T; Niehaus, T A

    2016-02-24

    We present the effect of different stacking orders on carrier transport properties of multi-layer black phosphorous. We consider three different stacking orders AAA, ABA and ACA, with increasing number of layers (from 2 to 6 layers). We employ a hierarchical approach in density functional theory (DFT), with structural simulations performed with generalized gradient approximation (GGA) and the bandstructure, carrier effective masses and optical properties evaluated with the meta-generalized gradient approximation (MGGA). The carrier transmission in the various black phosphorous sheets was carried out with the non-equilibrium green's function (NEGF) approach. The results show that ACA stacking has the highest electron and hole transmission probabilities. The results show tunability for a wide range of band-gaps, carrier effective masses and transmission with a great promise for lattice engineering (stacking order and layers) in black phosphorous.

  20. SEE on Different Layers of Stacked-SRAMs

    CERN Document Server

    Gupta, V; Tsiligiannis, G; Rousselet, M; Mohammadzadeh, A; Javanainen, A; Virtanen, A; Puchner, H; Saigné, F; Wrobel, F; Dilillo, L

    2015-01-01

    This paper presents heavy-ion and proton radiation test results of a 90 nm COTS SRAM with stacked structure. Radiation tests were made using high penetration heavy-ion cocktails at the HIF (Belgium) and at RADEF (Finland) as well as low energy protons at RADEF. The heavy-ion SEU cross-section showed an unusual profile with a peak at the lowest LET (heavy-ion with the highest penetration range). The discrepancy is due to the fact that the SRAM is constituted of two vertically stacked dice. The impact of proton testing on the response of both stacked dice is presented. The results are discussed and the SEU cross-sections of the upper and lower layers are compared. The impact of the stacked structure on the proton SEE rate is investigated.