The application of in situ air sparging as an innovative soils and ground water remediation technology

International Nuclear Information System (INIS)

Marley, M.C.; Hazebrouck, D.J.; Walsh, M.T.

1992-01-01

Vapor extraction (soil venting) has been demonstrated to be a successful and cost-effective remediation technology for removing VOCs from the vadose (unsaturated) zone. However, in many cases, seasonal water table fluctuations, drawdown associated with pump-and-treat remediation techniques, and spills involving dense, non-aqueous phase liquids (DNAPLS) create contaminated soil below the water table. Vapor extraction alone is not considered to be an optimal remediation technology to address this type of contamination. An innovative approach to saturated zone remediation is the use of sparging (injection) wells to inject a hydrocarbon-free gaseous medium (typically air) into the saturated zone below the areas of contamination. The contaminants dissolved in the ground water and sorbed onto soil particles partition into the advective air phase, effectively simulating an in situ air-stripping system. The stripped contaminants are transported in the gas phase to the vadose zone, within the radius of influence of a vapor extraction and vapor treatment system. In situ air sparging is a complex multifluid phase process, which has been applied successfully in Europe since the mid-1980s. To date, site-specific pilot tests have been used to design air-sparging systems. Research is currently underway to develop better engineering design methodologies for the process. Major design parameters to be considered include contaminant type, gas injection pressures and flow rates, site geology, bubble size, injection interval (areal and vertical) and the equipment specifications. Correct design and operation of this technology has been demonstrated to achieve ground water cleanup of VOC contamination to low part-per-billion levels

A field-scale demonstration of air sparging to remediate tritiated fluids

International Nuclear Information System (INIS)

Russell, C.E.; Gillespie, D.R.; Hokett, S.L.; Donithan, J.D.

1996-09-01

Two pilot field-scale studies were conducted during the period of May 24 to July 22, 1996, to evaluate the potential of air sparging to remediate tritiated fluids. Previous analytical solutions to the rate of tritium removal were evaluated and compared to the experimental results. The analytical solution of Craig and Gordon that describes isotopic fractionation of an evaporating body of water appears to most accurately describe the process, versus the more limited isotopic exchange equation of Slattery and Ingraham and the mass transfer equation of Wilson and Fordham, which are accurate only at moderate to high humidities and do not describe the tritium enrichment process that would occur at low humidities. The results of the two experiments demonstrated that air sparging of tritium is a viable process in the field. Tritium removal rates of 60 percent were reported during the first experiment and 66 percent for the second experiment. Comparison to previous laboratory work revealed that rates could have been improved by starting with higher concentrations, utilizing smaller bubbles, and longer bubble path lengths. Risks associated with the pilot study were greater the closer one worked to the experiment with a maximum increase in the Lifetime Excess Total Risk per Unit Uptake of 2.4 x 10 -5 . Conduct of this experiment at locations with much higher activities of tritium would significantly increase the associated risk

Optimization of air-sparged plutonium oxalate/hydroxide precipitators

International Nuclear Information System (INIS)

VanderHeyden, W.B.; Yarbro, S.L.; Fife, K.W.

1997-04-01

The high cost of waste management and experimental work makes numerical modeling an inexpensive and attractive tool for optimizing and understanding complex chemical processes. Multiphase open-quotes bubbleclose quotes columns are used extensively at the Los Alamos Plutonium Facility for a variety of different applications. No moving parts and efficient mixing characteristics allow them to be used in glovebox operations. Initially, a bubble column for oxalate precipitations is being modeled to identify the effect of various design parameters such as, draft tube location, air sparge rate and vessel geometry. Two-dimensional planar and axisymmetric models have been completed and successfully compared to literature data. Also, a preliminary three-dimensional model has been completed. These results are discussed in this report along with future work

Field Application of Modified In Situ Soil Flushing in Combination with Air Sparging at a Military Site Polluted by Diesel and Gasoline in Korea

Science.gov (United States)

Lee, Hwan; Lee, Yoonjin; Kim, Jaeyoung; Kim, Choltae

2014-01-01

In this study the full-scale operation of soil flushing with air sparging to improve the removal efficiency of petroleum at depths of less than 7 m at a military site in Korea was evaluated. The target area was polluted by multiple gasoline and diesel fuel sources. The soil was composed of heterogeneous layers of granules, sand, silt and clay. The operation factors were systemically assessed using a column test and a pilot study before running the full-scale process at the site. The discharged TPH and BTEX (benzene, toluene, ethylbenzene, and xylenes) concentrations in the water were highest at 20 min and at a rate of 350 L/min, which was selected as the volume of air for the full-scale operation in the pilot air sparging test. The surfactant-aid condition was 1.4 times more efficient than the non-surfactant condition in the serial operations of modified soil flushing followed by air sparging. The hydraulic conductivity (3.13 × 10−3 cm/s) increased 4.7 times after the serial operation of both processes relative to the existing condition (6.61 × 10−4 cm/s). The removal efficiencies of TPH were 52.8%, 57.4%, and 61.8% for the soil layers at 6 to 7, 7 to 8 and 8 to 9 m, respectively. Therefore, the TPH removal was improved at depth of less than 7 m by using this modified remediation system. The removal efficiencies for the areas with TPH and BTEX concentrations of more than 500 and 80 mg/kg, were 55.5% and 92.9%, respectively, at a pore volume of 2.9. The total TPH and BTEX mass removed during the full-scale operation was 5109 and 752 kg, respectively. PMID:25166919

Demonstrating practical application of soil and groundwater clean-up and recovery technologies at natural gas processing facilities: Bioventing, air sparging and wetlands remediation

International Nuclear Information System (INIS)

Moore, B.

1996-01-01

This issue of the project newsletter described the nature of bioventing, air sparging and wetland remediation. It reviewed their effectiveness in remediating hydrocarbon contaminated soil above the groundwater surface. Bioventing was described as an effective, low cost treatment in which air is pumped below ground to stimulate indigenous bacteria. The bacteria then use the oxygen to consume the hydrocarbons, converting them to CO 2 and water. Air sparging involves the injection of air below the groundwater surface. As the air rises, hydrocarbons are stripped from the contaminated soil and water. The advantage of air sparging is that it cleans contaminated soil and water from below the groundwater surface. Hydrocarbon contamination of wetlands was described as fairly common. Conventional remediation methods of excavation, trenching, and bellholes to remove contamination often cause extreme harm to the ecosystem. Recent experimental evidence suggests that wetlands may be capable of attenuating contaminated water through natural processes. Four hydrocarbon contaminated wetlands in Alberta are currently under study. Results to date show that peat's high organic content promotes sorption and biodegradation and that some crude oil spills can been resolved by natural processes. It was suggested that assuming peat is present, a good clean-up approach may be to contain the contaminant source, monitor the lateral and vertical extent of contamination, and wait for natural processes to resolve the problem. 3 figs

Enhancement of the microbial community biomass and diversity during air sparging bioremediation of a soil highly contaminated with kerosene and BTEX

Czech Academy of Sciences Publication Activity Database

Kabelitz, N.; Macháčková, I.; Imfeld, G.; Brennerová, Mária; Pieper, D. H.; Heipieper, H. J.; Junca, H.

2009-01-01

Roč. 82, - (2009), s. 565-577 ISSN 0175-7598 Institutional research plan: CEZ:AV0Z50200510 Keywords : btex * air sparging * bioremediation Subject RIV: EE - Microbiology, Virology Impact factor: 2.896, year: 2009

Structure of two-phase adiabatic flow in air sparging regime in vertical cylindrical channel with water

Directory of Open Access Journals (Sweden)

V. I. Solonin

2014-01-01

Full Text Available The article presents a research of two-phase adiabatic flow in air sparging regime in vertical cylindrical channel filled with water. A purpose of the work is to obtain experimental data for further analysis of a character of the moving phases. Research activities used the optic methods PIV (Particle Image Visualization because of their noninvasiveness to obtain data without disturbing effect on the flow. A laser sheet illuminated the fluorescence particles, which were admixed in water along the channel length. A digital camera recorded their motion for a certain time interval that allowed building the velocity vector fields. As a result, gas phase velocity components typical for a steady area of the channel and their relations for various intensity of volume air rate were obtained. A character of motion both for an air bubble and for its surrounding liquid has been conducted. The most probable direction of phases moving in the channel under sparging regime is obtained by building the statistic scalar fields. The use of image processing enabled an analysis of the initial area of the air inlet into liquid. A characteristic curve of the bubbles offset from the axis for various intensity of volume gas rate and channel diameter is defined. A character of moving phases is obtained by building the statistic scalar fields. The values of vertical components of liquid velocity in the inlet part of channel are calculated. Using the obtained data of the gas phase velocities a true void fraction was calculated. It was compared with the values of void fraction, calculated according to the liquid level change in the channel. Obtained velocities were compared with those of the other researchers, and a small difference in their values was explained by experimental conditions. The article is one of the works to research the two-phase flows with no disturbing effect on them. Obtained data allow us to understand a character of moving the two-phase flows in

Aerosol entrainment from a sparged non-Newtonian slurry.

Science.gov (United States)

Fritz, Brad G

2006-08-01

Previous bench-scale experiments have provided data necessary for the development of empirical models that describe aerosol entrainment from bubble bursting. However, previous work has not been extended to non-Newtonian liquid slurries. Design of a waste treatment plant on the Hanford Site in Washington required an evaluation of the applicability of these models outside of their intended range. For this evaluation, aerosol measurements were conducted above an air-sparged mixing tank filled with simulated waste slurry possessing Bingham plastic rheological properties. Three aerosol-size fractions were measured at three sampling heights and for three different sparging rates. The measured entrainment was compared with entrainment models. One model developed based on bench-scale air-water experiments agreed well with measured entrainment. Another model did not agree well with the measured entrainment. It appeared that the source of discrepancy between measured and modeled entrainment stemmed from application beyond the range of data used to develop the model. A possible separation in entrainment coefficients between air-water and steam-water systems was identified. A third entrainment model was adapted to match experimental conditions and fit a posteri to the experimental data, resulting in a modified version that resulted in estimated entrainment rates similar to the first model.

The use of sparge curtains for contaminant plume control

International Nuclear Information System (INIS)

Molnaa, B.; Dablow, J.

1994-01-01

Contamination by petroleum hydrocarbons and organic solvents represents a major impact to soil and groundwater. Following recent research and development, several technologies have evolved to treat saturated zone adsorbed- and dissolved-phase contaminants in situ. These technologies include bioremediation and air sparging. Funnel and gate approaches have been developed at the Waterloo Center for Groundwater Research to control contaminant plume migration and treat dissolved-phase contaminants before allowing migration downgradient and off site. The process consists of using low hydraulic conductivity cutoff walls to funnel groundwater flow through gates that contain in situ bioreactors. These systems can maintain hydraulic control and treat dissolved-phase contaminants at the downgradient margins of plumes, while minimizing, or in some cases eliminating, the need for groundwater pumping. Sparge curtains can be applied to treat dissolved-phase contaminants and prevent downgradient, off-site migration of contaminated groundwater

Remedial Process Optimization and Green In-Situ Ozone Sparging for Treatment of Groundwater Impacted with Petroleum Hydrocarbons

Science.gov (United States)

Leu, J.

2012-12-01

A former natural gas processing station is impacted with TPH and BTEX in groundwater. Air sparging and soil vapor extraction (AS/AVE) remediation systems had previously been operated at the site. Currently, a groundwater extraction and treatment system is operated to remove the chemicals of concern (COC) and contain the groundwater plume from migrating offsite. A remedial process optimization (RPO) was conducted to evaluate the effectiveness of historic and current remedial activities and recommend an approach to optimize the remedial activities. The RPO concluded that both the AS/SVE system and the groundwater extraction system have reached the practical limits of COC mass removal and COC concentration reduction. The RPO recommended an in-situ chemical oxidation (ISCO) study to evaluate the best ISCO oxidant and approach. An ISCO bench test was conducted to evaluate COC removal efficiency and secondary impacts to recommend an application dosage. Ozone was selected among four oxidants based on implementability, effectiveness, safety, and media impacts. The bench test concluded that ozone demand was 8 to 12 mg ozone/mg TPH and secondary groundwater by-products of ISCO include hexavalent chromium and bromate. The pH also increased moderately during ozone sparging and the TDS increased by approximately 20% after 48 hours of ozone treatment. Prior to the ISCO pilot study, a capture zone analysis (CZA) was conducted to ensure containment of the injected oxidant within the existing groundwater extraction system. The CZA was conducted through a groundwater flow modeling using MODFLOW. The model indicated that 85%, 90%, and 95% of an injected oxidant could be captured when a well pair is injecting and extracting at 2, 5, and 10 gallons per minute, respectively. An ISCO pilot test using ozone was conducted to evaluate operation parameters for ozone delivery. The ozone sparging system consisted of an ozone generator capable of delivering 6 lbs/day ozone through two ozone

Optimisation and design of nitrogen-sparged fermentative hydrogen production bioreactors

Energy Technology Data Exchange (ETDEWEB)

Kraemer, Jeremy T. [CH2M HILL, 255 Consumers Road, Suite 300, Toronto, Ontario, M2J 5B6 (Canada); Bagley, David M. [Department of Civil and Architectural Engineering, University of Wyoming, 1000 E. University Avenue, Department 3295, Laramie, Wyoming 82071 (United States)

2008-11-15

The optimisation of nitrogen sparging during fermentative hydrogen production was investigated. A N{sub 2} sparging rate of 12 mL/min/L-liquid was observed to maximise the H{sub 2} yield at approximately 2 mol H{sub 2}/mol glucose converted, compared to an H{sub 2} yield of approximately 1 mol H{sub 2}/mol glucose converted without any sparging. There was no significant increase in H{sub 2} yield at sparging rates of 12-80 mL/min/L-liquid. The optimum sparging rate was lower than N{sub 2} sparging rates examined in the past (>20 mL/min/L-liquid). To facilitate improved scale-up, the overall volumetric mass-transfer coefficients (K{sub L}a) for H{sub 2} and CO{sub 2} were measured and the relationship between the dimensionless Sherwood and Froude numbers was determined. The optimal sparging rate occurred at a K{sub L}a value of 5.0 h{sup -1} for H{sub 2}, corresponding to a Sherwood number of 4800. By holding the Sherwood number constant upon scale-up, the full-scale K{sub L}a can be determined and the appropriate sparging rate can be determined from the corresponding Froude number. The benefits of operating at the optimum sparging rate, including minimising product hydrogen gas dilution and energy use, can thus be achieved in larger-scale systems. (author)

TREATMENT OF CYANIDE SOLUTIONS AND SLURRIES USING AIR-SPARGED HYDROCYCLONE (ASH) TECHNOLOGY

Energy Technology Data Exchange (ETDEWEB)

Jan D. Miller; Terrence Chatwin; Jan Hupka; Doug Halbe; Tao Jiang; Bartosz Dabrowski; Lukasz Hupka

2003-03-31

The two-year Department of Energy (DOE) project ''Treatment of Cyanide Solutions and Slurries Using Air-Sparged Hydrocyclone (ASH) Technology'' (ASH/CN) has been completed. This project was also sponsored by industrial partners, ZPM Inc., Elbow Creek Engineering, Solvay Minerals, EIMCO-Baker Process, Newmont Mining Corporation, Cherokee Chemical Co., Placer Dome Inc., Earthworks Technology, Dawson Laboratories and Kennecott Minerals. Development of a new technology using the air-sparged hydrocyclone (ASH) as a reactor for either cyanide recovery or destruction was the research objective. It was expected that the ASH could potentially replace the conventional stripping tower presently used for HCN stripping and absorption with reduced power costs. The project was carried out in two phases. The first phase included calculation of basic processing parameters for ASH technology, development of the flowsheet, and design/adaptation of the ASH mobile system for hydrogen cyanide (HCN) recovery from cyanide solutions. This was necessary because the ASH was previously used for volatile organics removal from contaminated water. The design and modification of the ASH were performed with the help from ZPM Inc. personnel. Among the modifications, the system was adapted for operation under negative pressure to assure safe operating conditions. The research staff was trained in the safe use of cyanide and in hazardous material regulations. Cyanide chemistry was reviewed resulting in identification of proper chemical dosages for cyanide destruction, after completion of each pilot plant run. The second phase of the research consisted of three field tests that were performed at the Newmont Mining Corporation gold cyanidation plant near Midas, Nevada. The first field test was run between July 26 and August 2, 2002, and the objective was to demonstrate continuous operation of the modified ASH mobile system. ASH units were applied for both stripping and absorption

Liquid entrainment through orifices by sparging gas

International Nuclear Information System (INIS)

Bonnet, J.M.; Malara, M.; Amblard, M.; Seiler, J.M.

2001-01-01

Corium Coolability by water flood during an MCCI (Molten Corium Concrete Interaction) is still an open problem. Several physical mechanisms have been identified which may reduce significantly and finally stop the ablation of concrete. Among these mechanisms, corium ejection by sparging gas into the overlying water may represent an important contribution. This mechanism was at the origin of a large and coolable debris bed and volcano formation in the MACE M3B test. This mechanism has also been observed in simulant material tests performed at UCSB and at FZK. The objective of the work, which is described in the present paper, is to model this mechanism and to quantify the liquid entrainment rate by sparging gas. (author)

Sustainable operation of submerged Anammox membrane bioreactor with recycling biogas sparging for alleviating membrane fouling.

Science.gov (United States)

Li, Ziyin; Xu, Xindi; Xu, Xiaochen; Yang, FengLin; Zhang, ShuShen

2015-12-01

A submerged anaerobic ammonium oxidizing (Anammox) membrane bioreactor with recycling biogas sparging for alleviating membrane fouling has been successfully operated for 100d. Based on the batch tests, a recycling biogas sparging rate at 0.2m(3)h(-1) was fixed as an ultimate value for the sustainable operation. The mixed liquor volatile suspended solid (VSS) of the inoculum for the long operation was around 3000mgL(-1). With recycling biogas sparging rate increasing stepwise from 0 to 0.2m(3)h(-1), the reactor reached an influent total nitrogen (TN) up to 1.7gL(-1), a stable TN removal efficiency of 83% and a maximum specific Anammox activity (SAA) of 0.56kg TNkg(-1) VSSd(-1). With recycling biogas sparging rate at 0.2 m(3) h(-1) (corresponding to an aeration intensity of 118m(3)m(-2)h(-1)), the membrane operation circle could prolong by around 20 times compared to that without gas sparging. Furthermore, mechanism of membrane fouling was proposed. And with recycling biogas sparging, the VSS and EPS content increasing rate in cake layer were far less than the ones without biogas sparging. The TN removal performance and sustainable membrane operation of this system showed the appealing potential of the submerged Anammox MBR with recycling biogas sparging in treating high-strength nitrogen-containing wastewaters. Copyright © 2014 Elsevier Ltd. All rights reserved.

Supersaturation of dissolved H(2) and CO (2) during fermentative hydrogen production with N(2) sparging.

Science.gov (United States)

Kraemer, Jeremy T; Bagley, David M

2006-09-01

Dissolved H(2) and CO(2) were measured by an improved manual headspace-gas chromatographic method during fermentative H(2) production with N(2) sparging. Sparging increased the yield from 1.3 to 1.8 mol H(2)/mol glucose converted, although H(2) and CO(2) were still supersaturated regardless of sparging. The common assumption that sparging increases the H(2) yield because of lower dissolved H(2) concentrations may be incorrect, because H(2) was not lowered into the range necessary to affect the relevant enzymes. More likely, N(2) sparging decreased the rate of H(2) consumption via lower substrate concentrations.

Effect of biogas sparging on the performance of bio-hydrogen reactor over a long-term operation

Science.gov (United States)

Nualsri, Chatchawin; Kongjan, Prawit; Imai, Tsuyoshi

2017-01-01

This study aimed to enhance hydrogen production from sugarcane syrup by biogas sparging. Two-stage continuous stirred tank reactor (CSTR) and upflow anaerobic sludge blanket (UASB) reactor were used to produce hydrogen and methane, respectively. Biogas produced from the UASB was used to sparge into the CSTR. Results indicated that sparging with biogas increased the hydrogen production rate (HPR) by 35% (from 17.1 to 23.1 L/L.d) resulted from a reduction in the hydrogen partial pressure. A fluctuation of HPR was observed during a long term monitoring because CO2 in the sparging gas and carbon source in the feedstock were consumed by Enterobacter sp. to produce succinic acid without hydrogen production. Mixed gas released from the CSTR after the sparging can be considered as bio-hythane (H2+CH4). In addition, a continuous sparging biogas into CSTR release a partial pressure in the headspace of the methane reactor. In consequent, the methane production rate is increased. PMID:28207755

In situ air stripping using horizontal wells. Innovative technology summary report

International Nuclear Information System (INIS)

1995-04-01

In-situ air stripping employs horizontal wells to inject or sparge air into the ground water and vacuum extract VOC'S from vadose zone soils. The horizontal wells provide better access to the subsurface contamination, and the air sparging eliminates the need for surface ground water treatment systems and treats the subsurface in-situ. A full-scale demonstration was conducted at the Savannah River Plant in an area polluted with trichloroethylene and tetrachloroethylene. Results are described

Increase in volatilization of organic compounds using air sparging through addition in alcohol in a soil-water system.

Science.gov (United States)

Chao, Huan-Ping; Hsieh, Lin-Han Chiang; Tran, Hai Nguyen

2018-02-15

This study developed a novel method to promote the remediation efficiency of air sparging. According to the enhanced-volatilization theory presented in this study, selected alcohols added to groundwater can highly enhance the volatilization amounts of organic compounds with high Henry's law constants. In this study, the target organic compounds consisted of n-hexane, n-heptane, benzene, toluene, 1,1,2-trichloroethane, and tetrachloroethene. n-pentanol, n-hexanol, and n-heptanol were used to examine the changes in the volatilization amounts of organic compounds in the given period. Two types of soils with high and low organic matter were applied to evaluate the transport of organic compounds in the soil-water system. The volatilization amounts of the organic compounds increased with increasing alcohol concentrations. The volatilization amounts of the test organic compounds exhibited a decreasing order: n-heptanol>n-hexanol>n-pentanol. When 10mg/L n-heptanol was added to the system, the maximum volatilization enhancement rate was 18-fold higher than that in distilled water. Samples of soil with high organic matter might reduce the volatilization amounts by a factor of 5-10. In the present study, the optimal removal efficiency for aromatic compounds was approximately 98%. Copyright © 2017 Elsevier B.V. All rights reserved.

Effect of gas sparging on flux enhancement and phytochemical properties of clarified pineapple juice by microfiltration

KAUST Repository

Laorko, Aporn

2011-08-01

Membrane fouling is a major obstacle in the application of microfiltration. Several techniques have been proposed to enhance the permeate flux during microfiltration. Gas sparging is a hydrodynamic method for improving the performance of the membrane process. In this study, a 0.2 μm hollow fiber microfiltration membrane was used to study the effect of cross flow velocity (CFV) and gas injection factor () on the critical and limiting flux during microfiltration of pineapple juice. In addition, the phytochemical properties of clarified juice were investigated. In the absence of gas sparging, the critical and limiting flux increased as the CFV or shear stress number increased. The use of gas sparging led to a remarkable improvement in both the critical and limiting flux but it was more effective at the lower CFV (1.5 m s-1), compared to those at higher CFV (2.0 and 2.5 m s-1). When the gas injection factor was applied at 0.15, 0.25 and 0.35 with a CFV of 1.5 m s -1, the enhancement of 55.6%, 75.5% and 128.2% was achieved for critical flux, while 65.8%, 69.7% and 95.2% was achieved for limiting flux, respectively. The results also indicated that the use of gas sparging was an effective method to reduce reversible fouling and external irreversible fouling rather than internal irreversible fouling. In addition, the CFV and gas sparging did not affect pH, total soluble solids, colour, total phenolic content and the antioxidant property of the clarified juice. The l-ascorbic acid and total vitamin C were significantly decreased when the higher CFV and high gas injection factor were applied. The results also indicated that the use of gas sparging with low CFV was beneficial for flux enhancement while most of the phytochemical properties of the clarified juice was preserved. © 2011 Elsevier B.V. All rights reserved.

Remediation of Chlorinated Solvent Plumes Using In-Situ Air Sparging—A 2-D Laboratory Study

Directory of Open Access Journals (Sweden)

Jeffrey A. Adams

2011-06-01

Full Text Available In-situ air sparging has evolved as an innovative technique for soil and groundwater remediation impacted with volatile organic compounds (VOCs, including chlorinated solvents. These may exist as non-aqueous phase liquid (NAPL or dissolved in groundwater. This study assessed: (1 how air injection rate affects the mass removal of dissolved phase contamination, (2 the effect of induced groundwater flow on mass removal and air distribution during air injection, and (3 the effect of initial contaminant concentration on mass removal. Dissolved-phase chlorinated solvents can be effectively removed through the use of air sparging; however, rapid initial rates of contaminant removal are followed by a protracted period of lower removal rates, or a tailing effect. As the air flow rate increases, the rate of contaminant removal also increases, especially during the initial stages of air injection. Increased air injection rates will increase the density of air channel formation, resulting in a larger interfacial mass transfer area through which the dissolved contaminant can partition into the vapor phase. In cases of groundwater flow, increased rates of air injection lessened observed downward contaminant migration effect. The air channel network and increased air saturation reduced relative hydraulic conductivity, resulting in reduced groundwater flow and subsequent downgradient contaminant migration. Finally, when a higher initial TCE concentration was present, a slightly higher mass removal rate was observed due to higher volatilization-induced concentration gradients and subsequent diffusive flux. Once concentrations are reduced, a similar tailing effect occurs.

CO2 Sparging Phase 3 Full Scale Implementation and Monitoring Report

Science.gov (United States)

In-situ carbon dioxide (CO2) sparging was designed and implemented to treat a subsurface causticbrine pool (CBP) formed as a result of releases from historical production of industrial chemicals at theLCP Chemicals Site, Brunswick, GA (Site).

Foaming/antifoaming in WTP Tanks Equipped with Pulse Jet Mixer and Air Spargers

International Nuclear Information System (INIS)

HASSAN, NEGUIB

2004-01-01

The River Protection Project-Waste Treatment Plant (RPP-WTP) requested Savannah River National Laboratory (SRNL) to conduct small-scale foaming and antifoam testing using actual Hanford waste and simulants subjected to air sparging. The foaminess of Hanford tank waste solutions was previously demonstrated in SRNL during WTP evaporator foaming and ultrafiltration studies and commercial antifoam DOW Q2-3183A was recommended to mitigate the foam in the evaporators. Currently, WTP is planning to use air spargers in the HLW Lag Storage Vessels, HLW Concentrate Receipt Vessel, and the Ultrafiltration Vessels to assist the performance of the Jet Pulse Mixers (JPM). Sparging of air into WTP tanks will induce a foam layer within the process vessels. The air dispersion in the waste slurries and generated foams could present problems during plant operation. Foam in the tanks could also adversely impact hydrogen removal and mitigation. Antifoam (DOW Q2-3183A) will be used to control foaming in Hanford sparged waste processing tanks. These tanks will be mixed by a combination of pulse-jet mixers and air spargers. The percent allowable foaminess or freeboard in WTP tanks are shown in tables

Radioactive Air Emissions Notice of Construction for the 105-KW Basin integrated water treatment system filter vessel sparging vent

Energy Technology Data Exchange (ETDEWEB)

Kamberg, L.D.

1998-02-23

This document serves as a notice of construction (NOC), pursuant to the requirements of Washington Administrative Code (WAC) 246-247-060, and as a request for approval to construct, pursuant to 40 Code of Federal Regulations (CFR) 61.07, for the Integrated Water Treatment System (IWTS) Filter Vessel Sparging Vent at 105-KW Basin. Additionally, the following description, and references are provided as the notices of startup, pursuant to 40 CFR 61.09(a)(1) and (2) in accordance with Title 40 Code of Federal Regulations, Part 61, National Emission Standards for Hazardous Air Pollutants. The 105-K West Reactor and its associated spent nuclear fuel (SNF) storage basin were constructed in the early 1950s and are located on the Hanford Site in the 100-K Area about 1,400 feet from the Columbia River. The 105-KW Basin contains 964 Metric Tons of SNF stored under water in approximately 3,800 closed canisters. This SNF has been stored for varying periods of time ranging from 8 to 17 years. The 105-KW Basin is constructed of concrete with an epoxy coating and contains approximately 1.3 million gallons of water with an asphaltic membrane beneath the pool. The IWTS, which has been described in the Radioactive Air Emissions NOC for Fuel Removal for 105-KW Basin (DOE/RL-97-28 and page changes per US Department of Energy, Richland Operations Office letter 97-EAP-814) will be used to remove radionuclides from the basin water during fuel removal operations. The purpose of the modification described herein is to provide operational flexibility for the IWTS at the 105-KW basin. The proposed modification is scheduled to begin in calendar year 1998.

Ultralow Level Mercury Treatment Using Chemical Reduction and Air Stripping: Scoping Report

International Nuclear Information System (INIS)

Looney, B.B.

2000-01-01

Data collected during the first stage of a Savannah River Technology Center (SRTC) Strategic Research and Development Project confirmed the efficacy of chemical reduction and air stripping/sparging as an ultralow level mercury treatment concept for waters containing Hg(II). The process consists of dosing the water with low levels of stannous chloride to convert the mercury to Hg. This form of mercury can easily be removed from the water by air stripping or sparging. Samples of Savannah River Site (SRS) groundwater containing approximately 130 ng/L of total mercury (as Hg(II)) were used for the study. In undosed samples, sparging removed 0 percent of the initial mercury. In the dosed samples, all of the removals were greater than 94 percent, except in one water type at one dose. This sample, which was saturated with dissolved oxygen, showed a 63 percent reduction in mercury following treatment at the lowest dose. Following dosing at minimally effective levels and sparging, treated water contained less than 10 ng/L total mercury. In general, the data indicate that the reduction of mercury is highly favored and that stannous chloride reagent efficiently targets the Hg(II) contaminant in the presence of competing reactions. Based on the results, the authors estimated that the costs of implementing and operating an ultralow level mercury treatment process based on chemical reduction and stripping/sparging are 10 percent to 20 percent of traditional treatment technologies

CO2 Sparging Proof of Concept Test Report, Revision 1, LCP Chemicals Site, Brunswick, Georgia

Science.gov (United States)

April 2013 report to evaluate the feasibility of CO2 sparging to remediate a sub-surface caustic brine pool (CBP) at the LCP Chemicals Superfund Site, GA. Region ID : 04, DocID: 10940639 , DocDate: 2013-04-01

Modeling of permeate flux and mass transfer resistances in the reclamation of molasses wastewater by a novel gas-sparged nanofiltration

International Nuclear Information System (INIS)

Patel, Tejal Manish; Nath, Kaushik

2014-01-01

A semi-empirical model has been applied to predict the permeate flux and mass transfer resistances during the cross flow nanofiltration of molasses wastewater in flat-sheet module. The model includes laminar flow regime as well as flow in presence of gas sparging at two different gas velocities. Membrane hydraulic resistance (R m ), osmotic pressure resistance (R osm ) and the concentration polarization resistance (R cp ) were considered in series. The concentration polarization resistance was correlated to the operating conditions, namely, the feed concentration, the trans-membrane pressure difference and the cross flow velocity for a selected range of experiments. There was an appreciable reduction of concentration polarization resistance R cp spar in presence of gas sparging. Both the concentration polarization resistance R cp lam and osmotic pressure resistance R osm decreased with cross-flow velocity, but increased with feed concentration and the operating pressure. Experimental and theoretical permeate flux values as a function of cross flow velocity for both the cases, in the presence and absence of gas sparging, were also compared

Modeling of permeate flux and mass transfer resistances in the reclamation of molasses wastewater by a novel gas-sparged nanofiltration

Energy Technology Data Exchange (ETDEWEB)

Patel, Tejal Manish; Nath, Kaushik [G H Patel College of Engineering and Technology, Gujarat (India)

2014-10-15

A semi-empirical model has been applied to predict the permeate flux and mass transfer resistances during the cross flow nanofiltration of molasses wastewater in flat-sheet module. The model includes laminar flow regime as well as flow in presence of gas sparging at two different gas velocities. Membrane hydraulic resistance (R{sub m}), osmotic pressure resistance (R{sub osm}) and the concentration polarization resistance (R{sub cp}) were considered in series. The concentration polarization resistance was correlated to the operating conditions, namely, the feed concentration, the trans-membrane pressure difference and the cross flow velocity for a selected range of experiments. There was an appreciable reduction of concentration polarization resistance R{sub cp}{sup spar} in presence of gas sparging. Both the concentration polarization resistance R{sub cp}{sup lam} and osmotic pressure resistance R{sub osm} decreased with cross-flow velocity, but increased with feed concentration and the operating pressure. Experimental and theoretical permeate flux values as a function of cross flow velocity for both the cases, in the presence and absence of gas sparging, were also compared.

In-situ biogas sparging enhances the performance of an anaerobic membrane bioreactor (AnMBR) with mesh filter in low-strength wastewater treatment.

Science.gov (United States)

Li, Na; Hu, Yi; Lu, Yong-Ze; Zeng, Raymond J; Sheng, Guo-Ping

2016-07-01

In the recent years, anaerobic membrane bioreactor (AnMBR) technology is being considered as a very attractive alternative for wastewater treatment due to the striking advantages such as upgraded effluent quality. However, fouling control is still a problem for the application of AnMBR. This study investigated the performance of an AnMBR using mesh filter as support material to treat low-strength wastewater via in-situ biogas sparging. It was found that mesh AnMBR exhibited high and stable chemical oxygen demand (COD) removal efficiencies with values of 95 ± 5 % and an average methane yield of 0.24 L CH4/g CODremoved. Variation of transmembrane pressure (TMP) during operation indicated that mesh fouling was mitigated by in-situ biogas sparging and the fouling rate was comparable to that of aerobic membrane bioreactor with mesh filter reported in previous researches. The fouling layer formed on the mesh exhibited non-uniform structure; the porosity became larger from bottom layer to top layer. Biogas sparging could not change the composition but make thinner thickness of cake layer, which might be benefit for reducing membrane fouling rate. It was also found that ultrasonic cleaning of fouled mesh was able to remove most foulants on the surface or pores. This study demonstrated that in-situ biogas sparging enhanced the performance of AnMBRs with mesh filter in low-strength wastewater treatment. Apparently, AnMBRs with mesh filter can be used as a promising and sustainable technology for wastewater treatment.

Three-dimensional calculation of pollutant migration via compressible two-phase flow, for analysis of the methods of in situ air sparging and soil vapor extraction; Raeumliche Berechnung des Schadstofftransportes mit einer kompressiblen Zweiphasenstroemung zur Untersuchung der Drucklufteinblasung und Bodenluftabsaugung

Energy Technology Data Exchange (ETDEWEB)

Kuepper, S.

1997-12-01

In this study an analysis method is presented which allows numerical simulation of in situ air sparging coupled with soil vapor extraction. The improved FE-program takes the following phenomena into account: - Two-phase flow of compressible air and incompressible water - convective-dispersive contamination migration with air and water - transfer of volatile components from liquid phase to gas and water phase - sorption of contaminants onto soil - transfer of contaminants between air and water phase - biological processes. By means of back calculations of the results of laboratory experiments made by Eisele (1989) it was shown that with the developed program GWLCOND some of the necessary parameters for the numerical simulation of remedial systems can be determined. (orig./SR) [Deutsch] In dieser Arbeit wird ein Verfahren vorgestellt, mit dem eine numerische Simulation der Drucklufteinblasung und Bodenluftabsaugung durchgefuehrt werden kann. Das weiterentwickelte FE-Programmsystem beinhaltet folgende Ablaeufe: - Zweiphasenstroemung der kompressiblen Luft- und der inkompressiblen Wasserphase - Konvektiv-dispersiver Schadstofftransport mit der Gas- und der Wasserphase - Uebergang fluessiger Schadstoffe in die Gas- und in die Wasserphase - Sorption der Schadstoffe an der Feststoffphase - Uebergang der Schadstoffe zwischen der Gas- und der Wasserphase - Biologischer Abbau. Anhand der Nachrechnung eines Laborversuches von Eisele (1989) wird gezeigt, wie mit dem entwickelten Transportprogramm GWLCOND ein Teil der fuer die numerische Simulation des Sanierungsverfahrens benoetigten Kennwerte ermittelt werden kann. (orig./SR)

Full-scale testing and early production results from horizontal air sparging and soil vapor extraction wells remediating jet fuel in soil and groundwater at JFK International Airport, New York

International Nuclear Information System (INIS)

Roth, R.J.; Bianco, P.; Pressly, N.C.

1996-01-01

Jet fuel contaminated soil and groundwater contaminated at the International Arrivals Building (IAB) of the JFK International Airport in Jamaica, New York, are being remediated using soil vapor extraction (SVE) and air sparging (AS). The areal extent of the contaminated soil is estimated to be 70 acres and the volume of contaminated groundwater is estimated to be 2.3 million gallons. The remediation uses approximately 13,000 feet of horizontal SVE (HSVE) wells and 7,000 feet of horizontal AS (HAS) wells. The design of the HSVE and HAS wells was based on a pilot study followed by a full-scale test. In addition to the horizontal wells, 28 vertical AS wells and 15 vertical SVE wells are used. Three areas are being remediated, thus, three separate treatment systems have been installed. The SVE and AS wells are operated continuously while groundwater will be intermittently extracted at each HAS well, treated by liquid phase activated carbon and discharged into stormwater collection sewerage. Vapors extracted by the SVE wells are treated by vapor phase activated carbon and discharged into ambient air. The duration of the remediation is anticipated to be between two and three years before soil and groundwater are remediated to New York State cleanup criteria for the site. Based on the monitoring data for the first two months of operation, approximately 14,600 lbs. of vapor phase VOCs have been extracted. Analyses show that the majority of the VOCs are branched alkanes, branched alkenes, cyclohexane and methylated cyclohexanes

CaBr2 hydrolysis for HBr production using a direct sparging contactor

International Nuclear Information System (INIS)

Doctor, R.D.; Yang, J.; Panchal, Ch.B.; Lottes, St.A.; Lyczkowski, R.W.

2010-01-01

We investigated a novel, continuous hybrid cycle for hydrogen production employing both heat and electricity. Calcium bromide (CaBr 2 ) hydrolysis, which is endothermic, generates hydrogen bromide (HBr), and this is electrolysed to produce hydrogen. CaBr 2 hydrolysis at 1050 K is endothermic with a 181.5 KJ/mol heat of reaction and the free energy change is positive at 99.6 kJ/mol. What makes this hydrolysis reaction attractive is both its rate and the fact that well over half the thermodynamic requirements for water-splitting free energy of ΔG T = 285.8 KJ/mol are supplied at this stage using heat rather than electricity. These experiments provide support for a second order hydrolysis reaction in CaBr 2 forming a complex involving CaBr 2 and CaO and the system appears to be: 3CaBr 2 + H 2 O → (CaBr 2 ) 2 .CaO + 2HBr. This reaction is highly endothermic and the complex also includes some water of hydration. COMSOL TM multi-physics modelling of sparging steam into a calcium bromide melt guided the design of an experiment using a mullite tube (ID 70 mm) capable of holding 0.3-0.5 kg (1.5-2.5 10 -3 kmol) CaBr 2 forming a melt with a maximum 0.08 m depth. Half of the experiments employed packings. Sparging steam at a steam rate of 0.02-0.04 mol/mol of CaBr 2 per minute into this molten bath promptly yielded HBr in a stable operation that converted up to 19 mol% of the calcium bromide. The kinetic constant derived from the experimental data was kinetic constant was 2.17 10 -12 kmol s -1 m -2 MPa -1 for the hydrolysis reaction. (authors)

Alternative for Summer Use of Solar Air Heaters in Existing Buildings

Directory of Open Access Journals (Sweden)

Sergio L. González-González

2017-07-01

Full Text Available Among solar thermal technologies for indoor heating, solar air heaters (SAH are appealing for implementation on existing buildings due to their simplicity, fewer risks related to the working fluid, and possible independence from the building structure. However, existing research work mainly focuses on winter use and still fails in providing effective solutions for yearly operation, which would enhance their interest. With the aim of analysing an alternative summer use, this work firstly characterises a double channel-single pass solar air collector through experimentation. From the obtained results, modelling and simulation tasks have been conducted to evaluate the possibilities of using hot air, provided by the SAH, while operating under summer conditions within a closed loop, to feed an air-to-water heat exchanger for domestic hot water (DHW production. The system is studied through simulation under two different configurations for a case study in Valladolid (Spain, during the period from May to September for different airflows in the closed loop. Results show that daily savings can vary from 27% to 85% among the different operating conditions; a configuration where make-up water is fed to the heat exchanger being preferable, with a dedicated water tank for the solar heated water storage of the minimum possible volume. The more favourable results for the harshest months highlight the interest of extending the use of the solar air heaters to the summer period.

A feasibility study on the bioconversion of CO2 and H2 to biomethane by gas sparging through polymeric membranes.

Science.gov (United States)

Díaz, I; Pérez, C; Alfaro, N; Fdz-Polanco, F

2015-06-01

In this study, the potential of a pilot hollow-fiber membrane bioreactor for the conversion of H2 and CO2 to CH4 was evaluated. The system transformed 95% of H2 and CO2 fed at a maximum loading rate of 40.2 [Formula: see text] and produced 0.22m(3) of CH4 per m(3) of H2 fed at thermophilic conditions. H2 mass transfer to the liquid phase was identified as the limiting step for the conversion, and kLa values of 430h(-1) were reached in the bioreactor by sparging gas through the membrane module. A simulation showed that the bioreactor could upgrade biogas at a rate of 25m(3)/mR(3)d, increasing the CH4 concentration from 60 to 95%v. This proof-of-concept study verified that gas sparging through a membrane module can efficiently transfer H2 from gas to liquid phase and that the conversion of H2 and CO2 to biomethane is feasible on a pilot scale at noteworthy load rates. Copyright © 2015 Elsevier Ltd. All rights reserved.

Treatment of waste salts by oxygen sparging and vacuum distillation

International Nuclear Information System (INIS)

Cho, Y.J.; Yang, H.C.; Kim, E.H.; Kin, I.T.; Eun, H.C.

2007-01-01

Full text of publication follows. During the electrorefining process of the oxide spent fuel from LWR, amounts of waste salts containing some metal chloride species such as rare earths and actinide chlorides are generated, where the reuse of the waste salts is very important from the standpoint of an economical as well as an environmental aspect. In order to reuse the waste salts, a salt vacuum distillation method can be used. For the best separation by a vacuum distillation, the metal chloride species involved in the waste salts must be converted into their oxide(or oxychloride) forms due to the their low volatility compared to that of LiCl-KCl. In this study, an oxygen sparging process was adopted for the oxidation (or precipitation) of rare earth chlorides. The effects of oxygen flow rate and molten salt temperature on the conversion of rare earth chlorides to the precipitate phase (i.e. oxide or oxychloride) were investigated. In addition, distillation characteristics of LiCl-KCl molten salt with system pressure and temperature were studied. (authors)

Analysis of heat and mass transfer to determine heat loss and the rate of condensation of the MVSTs off-gas ducts

International Nuclear Information System (INIS)

Ebadian, M.A.; Yang, G.; Bigzadeh, E.; Walker, J.F.; Abraham, T.J.

1992-01-01

Reduction of the existing nuclear waste in the Melton Valley Storage Tanks (MVSTs) at the Oak Ridge National Laboratory (ORNL) is of utmost concern to the scientists at this facility. This paper provides proof that a combination of vault heating, sparged air heating, and prevention of condensation is the best alternative to achieve this goal. Therefore, in this study a general system of mathematical equations has been developed taking into account all of the parameters affecting evaporation and condensation. This evaporation process has been analyzed by the careful modeling of a bubble chain through the extremely viscous, radioactive liquid contained in the storage tanks. This paper discusses in detail the evaporation procedure using bubble formation, air velocity, and determining the rate at which this liquid waste can be removed from the MVSTs by evaporation under different conditons of the sparging air. An additional objective is to study the heating/cooling of the condensation process of the off-gas piping inside the vault. A laboratory scale model has also been assembled for this purpose at ORNL to verify the accuracy of the mathematical modeling. A comparison of the experimental findings with the mathematical modeling shows excellent agreement. (orig.)

Improving the yield from fermentative hydrogen production.

Science.gov (United States)

Kraemer, Jeremy T; Bagley, David M

2007-05-01

Efforts to increase H(2) yields from fermentative H(2) production include heat treatment of the inoculum, dissolved gas removal, and varying the organic loading rate. Although heat treatment kills methanogens and selects for spore-forming bacteria, the available evidence indicates H(2) yields are not maximized compared to bromoethanesulfonate, iodopropane, or perchloric acid pre-treatments and spore-forming acetogens are not killed. Operational controls (low pH, short solids retention time) can replace heat treatment. Gas sparging increases H(2) yields compared to un-sparged reactors, but no relationship exists between the sparging rate and H(2) yield. Lower sparging rates may improve the H(2) yield with less energy input and product dilution. The reasons why sparging improves H(2) yields are unknown, but recent measurements of dissolved H(2) concentrations during sparging suggest the assumption of decreased inhibition of the H(2)-producing enzymes is unlikely. Significant disagreement exists over the effect of organic loading rate (OLR); some studies show relatively higher OLRs improve H(2) yield while others show the opposite. Discovering the reasons for higher H(2) yields during dissolved gas removal and changes in OLR will help improve H(2) yields.

Phosphate interference during in situ treatment for arsenic in groundwater.

Science.gov (United States)

Brunsting, Joseph H; McBean, Edward A

2014-01-01

Contamination of groundwater by arsenic is a problem in many areas of the world, particularly in West Bengal (India) and Bangladesh, where reducing conditions in groundwater are the cause. In situ treatment is a novel approach wherein, by introduction of dissolved oxygen (DO), advantages over other treatment methods can be achieved through simplicity, not using chemicals, and not requiring disposal of arsenic-rich wastes. A lab-scale test of in situ treatment by air sparging, using a solution with approximately 5.3 mg L(-1) ferrous iron and 200 μg L(-1) arsenate, showed removal of arsenate in the range of 59%. A significant obstacle exists, however, due to the interference of phosphate since phosphate competes for adsorption sites on oxidized iron precipitates. A lab-scale test including 0.5 mg L(-1) phosphate showed negligible removal of arsenate. In situ treatment by air sparging demonstrates considerable promise for removal of arsenic from groundwater where iron is present in considerable quantities and phosphates are low.

Indoor air quality in mechanically ventilated residential dwellings/low-rise buildings: A review of existing information

DEFF Research Database (Denmark)

Aganovic, Amar; Hamon, Mathieu; Kolarik, Jakub

Mechanical ventilation has become a mandatory requirement in multiple European standards addressing indoor air quality (IAQ) and ventilation in residential dwellings (single family houses and low-rise apartment buildings). This article presents the state of the art study through a review...... of the existing literature, to establish a link between ventilation rate and key indoor air pollutants. Design characteristics of a mechanical ventilation system such as supply/exhaustairflow, system and design of supply and exhaust outlets were considered. The performance of various ventilation solutionswas......-house ventilation rate was reported below 0.5h-1 or 14 l/s·person in bedrooms, the concentrations of the pollutants elevated above minimum threshold limits (CO2>1350 ppm; TVOC >3000 μg/m3) defined by the standard. Insufficient or non-existent supply of air was related to significantly higher pollutant...

Uranium (III) precipitation in molten chloride by wet argon sparging

Energy Technology Data Exchange (ETDEWEB)

Vigier, Jean-François, E-mail: jean-francois.vigier@ec.europa.eu [CEA, Nuclear Energy Division, Radiochemistry & Processes Department, F-30207 Bagnols sur Cèze (France); Unité de Catalyse et de Chimie du Solide, UCCS UMR CNRS 8181, Univ. Lille Nord de France, ENSCL-USTL, B.P. 90108, 59652 Villeneuve d' Ascq Cedex (France); Laplace, Annabelle [CEA, Nuclear Energy Division, Radiochemistry & Processes Department, F-30207 Bagnols sur Cèze (France); Renard, Catherine [Unité de Catalyse et de Chimie du Solide, UCCS UMR CNRS 8181, Univ. Lille Nord de France, ENSCL-USTL, B.P. 90108, 59652 Villeneuve d' Ascq Cedex (France); Miguirditchian, Manuel [CEA, Nuclear Energy Division, Radiochemistry & Processes Department, F-30207 Bagnols sur Cèze (France); Abraham, Francis [Unité de Catalyse et de Chimie du Solide, UCCS UMR CNRS 8181, Univ. Lille Nord de France, ENSCL-USTL, B.P. 90108, 59652 Villeneuve d' Ascq Cedex (France)

2016-06-15

In the context of pyrochemical processes for nuclear fuel treatment, the precipitation of uranium (III) in molten salt LiCl-CaCl{sub 2} (30–70 mol%) at 705 °C is studied. First, this molten chloride is characterized with the determination of the water dissociation constant. With a value of 10{sup −4.0}, the salt has oxoacid properties. Then, the uranium (III) precipitation using wet argon sparging is studied. The salt is prepared using UCl{sub 3} precursor. At the end of the precipitation, the salt is totally free of solubilized uranium. The main part is converted into UO{sub 2} powder but some uranium is lost during the process due to the volatility of uranium chloride. The main impurity of the resulting powder is calcium. The consequences of oxidative and reductive conditions on precipitation are studied. Finally, coprecipitation of uranium (III) and neodymium (III) is studied, showing a higher sensitivity of uranium (III) than neodymium (III) to precipitation. - Highlights: • Precipitation of Uranium (III) is quantitative in molten salt LiCl-CaCl{sub 2} (30–70 mol%). • The salt is oxoacid with a water dissociation constant of 10{sup −4.0} at 705 °C. • Volatility of uranium chloride is strongly reduced in reductive conditions. • Coprecipitation of U(III) and Nd(III) leads to a consecutive precipitation of the two elements.

Planar air-bearing microgravity simulators: Review of applications, existing solutions and design parameters

Science.gov (United States)

Rybus, Tomasz; Seweryn, Karol

2016-03-01

All devices designed to be used in space must be thoroughly tested in relevant conditions. For several classes of devices the reduced gravity conditions are the key factor. In early stages of development and later due to financial reasons, the tests need to be done on Earth. However, in Earth conditions it is impossible to obtain a different gravity field independent on all linear and rotational spatial coordinates. Therefore, various test-bed systems are used, with their design driven by the device's specific needs. One of such test-beds are planar air-bearing microgravity simulators. In such an approach, the tested objects (e.g., manipulators intended for on-orbit operations or vehicles simulating satellites in a close formation flight) are mounted on planar air-bearings that allow almost frictionless motion on a flat surface, thus simulating microgravity conditions in two dimensions. In this paper we present a comprehensive review of research activities related to planar air-bearing microgravity simulators, demonstrating achievements of the most active research groups and describing newest trends and ideas, such as tests of landing gears for low-g bodies. Major design parameters of air-bearing test-beds are also reviewed and a list of notable existing test-beds is presented.

Pulsed-Plasma Disinfection of Water Containing Escherichia coli

Science.gov (United States)

Satoh, Kohki; MacGregor, Scott J.; Anderson, John G.; Woolsey, Gerry A.; Fouracre, R. Anthony

2007-03-01

The disinfection of water containing the microorganism, Escherichia coli (E. coli) by exposure to a pulsed-discharge plasma generated above the water using a multineedle electrode (plasma-exposure treatment), and by sparging the off-gas of the pulsed plasma into the water (off-gas-sparging treatment), is performed in the ambient gases of air, oxygen, and nitrogen. For the off-gas-sparging treatment, bactericidal action is observed only when oxygen is used as the ambient gas, and ozone is found to generate the bactericidal action. For the plasma-exposure treatment, the density of E. coli bacteria decreases exponentially with plasma-exposure time for all the ambient gases. It may be concluded that the main contributors to E. coli inactivation are particle species produced by the pulsed plasma. For the ambient gases of air and nitrogen, the influence of acidification of the water in the system, as a result of pulsed-plasma exposure, may also contribute to the decay of E. coli density.

Extended Aquifer Air Sparging/Soil Vapor Extraction Treatability Study for Site SS59 (WP-21) Dover Air Force Base, Dover, Delaware

National Research Council Canada - National Science Library

1995-01-01

Site 5559 at Dover Air Force Base, Delaware is under investigation for the remediation of ground water which was contaminated by a system of industrial waste basins operated to the north of this area...

Measurement of air and VOC vapor fluxes during gas-driven soil remediation: bench-scale experiments.

Science.gov (United States)

Kim, Heonki; Kim, Taeyun; Shin, Seungyeop; Annable, Michael D

2012-09-04

In this laboratory study, an experimental method was developed for the quantitative analyses of gas fluxes in soil during advective air flow. One-dimensional column and two- and three-dimensional flow chamber models were used in this study. For the air flux measurement, n-octane vapor was used as a tracer, and it was introduced in the air flow entering the physical models. The tracer (n-octane) in the gas effluent from the models was captured for a finite period of time using a pack of activated carbon, which then was analyzed for the mass of n-octane. The air flux was calculated based on the mass of n-octane captured by the activated carbon and the inflow concentration. The measured air fluxes are in good agreement with the actual values for one- and two-dimensional model experiments. Using both the two- and three-dimensional models, the distribution of the air flux at the soil surface was measured. The distribution of the air flux was found to be affected by the depth of the saturated zone. The flux and flux distribution of a volatile contaminant (perchloroethene) was also measured by using the two-dimensional model. Quantitative information of both air and contaminant flux may be very beneficial for analyzing the performance of gas-driven subsurface remediation processes including soil vapor extraction and air sparging.

Recovery of Extracellular Lipolytic Enzymes from Macrophomina phaseolina by Foam Fractionation with Air

Directory of Open Access Journals (Sweden)

Claudia Schinke

2013-01-01

Full Text Available Macrophomina phaseolina was cultivated in complex and simple media for the production of extracellular lipolytic enzymes. Culture supernatants were batch foam fractionated for the recovery of these enzymes, and column design and operation included the use of P 2 frit (porosity 40 to 100 μm, air as sparging gas at variable flow rates, and Triton X-100 added at the beginning or gradually in aliquots. Samples taken at intervals showed the progress of the kinetic and the efficiency parameters. Best results were obtained with the simple medium supernatant by combining the stepwise addition of small amounts of the surfactant with the variation of the air flow rates along the separation. Inert proteins were foamed out first, and the subsequent foamate was enriched in the enzymes, showing estimated activity recovery (R, enrichment ratio (E, and purification factor (P of 45%, 34.7, and 2.9, respectively. Lipases were present in the enriched foamate.

Thermal environmental case study of an existing underfloor air distribution (UFAD) system in a high-rise building in the tropics

Science.gov (United States)

Ya, Y. H.; Poh, K. S.

2015-09-01

The performance of an existing underfloor air distribution (UFAD) system in a renowned high-rise office tower in Malaysia was studied to identify the root cause issues behind the poor indoor air quality. Occupants are the best thermal sensor. The building was detected with the sick building syndrome (SBS) that causes runny noses, flu-like symptoms, irritated skin, and etc. Long period of exposure to indoor air pollutants may increase the occupant's health risk. The parameters such as the space temperature, relative humidity, air movement, air change, fresh air flow rate, chilled water supply and return are evaluated at three stories that consist of five open offices. A full traverse study was carried out at one of the fresh air duct. A simplified duct flow measurement method using pitot-tubes was developed. The results showed that the diffusers were not effective in creating the swirl effect to the space. Internal heat gain from human and office electrical equipment were not drawn out effectively. Besides, relative humidity has exceeded the recommended level. These issues were caused by the poor maintenance of the building. The energy efficiency strategy of the UFAD system comes from the higher supply air temperature. It may leads to insufficient cooling load for the latent heat gained under improper system performance. Special care and considerations in design, construction and maintenance are needed to ensure the indoor air quality to be maintained. Several improvements were recommended to tackle the existing indoor air quality issues. Solar system was studied as one of the innovative method for retrofitting.

CO2 saturated water as two-phase flow for fouling control in reverse electrodialysis.

Science.gov (United States)

Moreno, J; de Hart, N; Saakes, M; Nijmeijer, K

2017-11-15

When natural feed waters are used in the operation of a reverse electrodialysis (RED) stack, severe fouling on the ion exchange membranes and spacers occurs. Fouling of the RED stack has a strong influence on the gross power density output; which can decrease up to 50%. Moreover, an increase in the pressure loss occurs between the feed water inlet and outlet, increasing the pumping energy and thus decreasing the net power density that can be obtained. In this work, we extensively investigated the use of CO 2 saturated water as two-phase flow cleaning for fouling mitigation in RED using natural feed waters. Experiments were performed in the REDstack research facility located at the Afsluitdijk (the Netherlands) using natural feed waters for a period of 60 days. Two different gas combinations were experimentally investigated, water/air sparging and water/CO 2 (saturated) injection. Air is an inert gas mixture and induces air sparging in the stack. In the case of CO 2 , nucleation, i.e. the spontaneous formation of bubbles, occurs at the spacer filaments due to depressurization of CO 2 saturated water, inducing cleaning. Results showed that stacks equipped with CO 2 saturated water can produce an average net power density of 0.18 W/m 2 under real fouling conditions with minimal pre-treatment and at a low outside temperature of only 8 °C, whereas the stacks equipped with air sparging could only produce an average net power density of 0.04 W/m 2 . Electrochemical impedance spectroscopy measurements showed that the stacks equipped with air sparging increased in stack resistance due to the presence of stagnant bubbles remaining in the stack after every air injection. Furthermore, the introduction of CO 2 gas in the feed water introduces a pH decrease in the system (carbonated solution) adding an additional cleaning effect in the system, thus avoiding the use of environmentally unwanted cleaning chemicals. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All

Purification and characterization of an H2O-forming NADH oxidase from Clostridium aminovalericum: existence of an oxygen-detoxifying enzyme in an obligate anaerobic bacteria.

Science.gov (United States)

Kawasaki, Shinji; Ishikura, Jun; Chiba, Daisuke; Nishino, Tomoko; Niimura, Youichi

2004-04-01

Clostridium aminovalericum, an obligate anaerobe, is unable to form colonies on PYD agar plates in the presence of 1% O(2). When grown anaerobically in PYD liquid medium, the strain can continue normal growth after the shift from anoxic (sparged with O(2)-free N(2) carrier-gas) to microoxic (sparged with 3% O(2)/97% N(2) mixed carrier-gas) growth conditions in the mid exponential phase (OD(660)=1.0). When the strain grew under 3% O(2)/97% N(2), the medium remains anoxic. Thirty minutes after beginning aeration with 3% O(2), the activity of NADH oxidase in cell-free extracts increased more than five-fold from the level before aeration. We purified NADH oxidase to determine the characteristics of this enzyme in an obligate anaerobe. The purified NADH oxidase dominated the NADH oxidase activity detected in cell-free extracts. The enzyme is a homotetramer composed of a subunit with a molecular mass of 45 kDa. The enzyme shows a spectrum typical of a flavoprotein, and flavin adenine dinucleotide (FAD) was identified as a cofactor. The final product of NADH oxidation was H(2)O, and the estimated K(m) for oxygen was 61.9 microM. These data demonstrate that an O(2)-response enzyme that is capable of detoxifying oxygen to water exists in C. aminovalericum.

Managing the Drivers of Air Flow and Water Vapor Transport in Existing Single-Family Homes

Energy Technology Data Exchange (ETDEWEB)

Cummings, James [Building America Partnership for Improved Residential Construction (BA-PIRC), Cocoa, FL (United States); Withers, Charles [Building America Partnership for Improved Residential Construction (BA-PIRC), Cocoa, FL (United States); Martin, Eric [Building America Partnership for Improved Residential Construction (BA-PIRC), Cocoa, FL (United States); Moyer, Neil [Building America Partnership for Improved Residential Construction (BA-PIRC), Cocoa, FL (United States)

2012-10-01

This report is a revision of an earlier report titled: Measure Guideline: Managing the Drivers of Air Flow and Water Vapor Transport in Existing Single-Family Homes. Revisions include: Information in the text box on page 1 was revised to reflect the most accurate information regarding classifications as referenced in the 2012 International Residential Code. “Measure Guideline” was dropped from the title of the report. An addition was made to the reference list.

Improved glycerol production from cane molasses by the sulfite process with vacuum or continuous carbon dioxide sparging during fermentation

Energy Technology Data Exchange (ETDEWEB)

Kalle, G.P.; Naik, S.C.; Lashkari, B.Z.

1985-01-01

The conventional sulfite process for glycerol production from molasses using Saccharomyces cerevisiae var. Hansen was modified to obtain product concentrations of up to 230 g/l and productivity of 15 g/l.d by fermenting under vacuum (80 mm) or with continuous sparging of CO2 (0.4 vvm). Under these conditions the requirement of sulfite for optimum production of glycerol was reduced by two thirds (20 g/l), the ethanol concentration in the medium was kept below 30 g/l and the competence of yeast cells to ferment was conserved throughout the fermentation period for up to 20 days. In addition to the above, the rate of incorporation of sulfite had a significant effect on glucose fermentation and glycerol yields. There was an optimal relationship between glycerol yields and the molar ratio of sulfite to glucose consumed, which for cane molasses was 0.67. This ratio was characteristic of the medium composition.

Improved glycerol production from cane molasses by the sulfite process with vacuum or continuous carbon dioxide sparging during fermentation

Energy Technology Data Exchange (ETDEWEB)

Kalle, G.P.; Naik, S.C.; Lashkari, B.Z.

1985-01-01

The conventional sulfite process for glycerol production from molasses using Saccharomyces cerevisiae var. Hansen was modified to obtain product concentrations of up to 230 g/l and productivity of 15 g/l x d by fermenting under vacuum (80 mm) or with continuous sparging of CO/sub 2/ (0.4 vvm). Under these conditions the requirement of sulfite for optimum production of glycerol was reduced by two thirds (20 g/l), the ethanol concentration in the medium was kept below 30 g/l and the competence of yeast cells to ferment was conserved throughout the fermentation period for up to 20 days. In addition to the above, the rate of incorporation of sulfite had a significant effect on glucose fermentation and glycerol yields. There was an optimal relationship between glycerol yields and the molar ratio of sulfite to glucose consumed, which for cane molasses was 0.67. This ratio was characteristic of the medium composition. 10 references, 4 figures, 3 tables.

Localized electrochemical corrosion of nickel-based alloys. Final report

International Nuclear Information System (INIS)

Isaacs, H.S.; Oyeleye, O.; Davidson, M.; Dudek, D.; Hatton, T.A.; Tester, J.W.; Helling, R.K.; Erickson, J.C.

1986-09-01

The technique of monitoring open-circuit potential over time to study pitting corrosion of Alloy 600 was demonstrated at 95 0 C. Chloride ion and oxygen levels were varied to determine the conditions required for pit initiation and propagation at 25 0 C and 95 0 C. Without applied potential pitting was not observed at 25 0 C in solutions of up to 2.6 M NaCl. At 95 0 C pit initiation occurred above 0.22 M NaCl for a nitrogen sparged system, 0.042 M NaCl for a contaminated air sparged system and 0.059 M for an O 2 sparged system. At 95 0 C initiation followed by propagation was observed at 0.22 M, 0.12 M and 0.11 M NaCl for the N 2 , air and O 2 sparged systems, respectively. A theoretical model, using a hemispherical pit geometry and transport based on the Nernst-Einstein equation, was developed to predict changes in ion concentration, current and pit size. For a pit with an initial radius of 100 A, a fixed potential difference of 0.5 V and constant ionic diffusivities on the order of 10 -5 , cm 2 /sec, the model predicts that the solution within the pit will become saturated with metal chloride within 2 x 10 -7 seconds. The current density increases exponentially with time and reaches a maximum value of 7.2 x 10 4 A/cm 2 at the point of saturation

Measuring Outdoor Air Intake Rates into Existing Building

Energy Technology Data Exchange (ETDEWEB)

Fisk, William; Sullivan, Douglas; Cohen, Sebastian; Han, Hwataik

2009-04-16

Practical and accurate technologies are needed for continuously measuring and controlling outdoor air (OA) intake rates in commercial building heating, ventilating, and air conditioning (HVAC) systems. This project evaluated two new measurement approaches. Laboratory experiments determined that OA flow rates were measurable with errors generally less than 10 percent using electronic air velocity probes installed between OA intake louver blades or at the outlet face of louvers. High accuracy was maintained with OA flow rates as low as 15 percent of the maximum for the louvers. Thus, with this measurement approach HVAC systems do not need separate OA intakes for minimum OA supply. System calibration parameters are required for each unique combination of louver type and velocity sensor location but calibrations are not necessary for each system installation. The research also determined that the accuracy of measuring OA flow rates with velocity probes located in the duct downstream of the intake louver was not improved by installing honeycomb airflow straighteners upstream of the probes. Errors varied with type of upstream louver, were as high as 100 percent, and were often greater than 25 percent. In conclusion, use of electronic air velocity probes between the blades of OA intake louvers or at the outlet face of louvers is a highly promising means of accurately measuring rates of OA flow into HVAC systems. The use of electronic velocity probes downstream of airflow straighteners is less promising, at least with the relatively small OA HVAC inlet systems employed in this research.

Evaluation of air cleaning technologies existing in the Danish market

DEFF Research Database (Denmark)

Ardkapan, Siamak Rahimi; Afshari, Alireza; Bergsøe, Niels Christian

2014-01-01

Five portable air cleaning technologies including one new technology were evaluated to find their effectiveness in removing ultrafine particles. Measurements were carried out both in a duct and in a test room. The results showed that the technologies that use/create ozone to clean air can increase...... the ozone level significantly in the room. Moreover, they can cause generation of ultrafine particles and consequently increase ultrafine particle concentration in the room. The study suggests using a mechanical filter with low pressure drop as a recommended air cleaning technology in order to remove...

Design, Construction, and Validation of an Internally Lit Air-Lift Photobioreactor for Growing Algae

International Nuclear Information System (INIS)

Hincapie, Esteban; Stuart, Ben J.

2015-01-01

A novel 28 L photobioreactor for growing algae was developed using fiber optics for internal illumination. The proposed design uses the air-lift principle to enhance the culture circulation and induce light/dark cycles to the microorganisms. Optical fibers were used to distribute photons inside the culture media providing an opportunity to control both light cycle and intensity. The fibers were coupled to an artificial light source; however, the development of this approach aims for the future use of natural light collected through parabolic solar collectors. This idea could also allow the use of opaque materials for photobioreactor construction significantly reducing costs and increasing durability. Internal light levels were determined in dry conditions and were maintained above 80 μmol/(s·m 2 ). The hydrodynamic equations of the air-lift phenomena were explored and used to define the geometric characteristics of the unit. The reactor was inoculated with the algae strain Chlorella sp. and sparged with air. The reactor was operated under batch mode and daily monitored for biomass concentration. The specific growth rate constant of the novel device was determined to be 0.011 h −1 . The proposed design can be effectively and economically used in carbon dioxide mitigation technologies and in the production of algal biomass for biofuel and other bioproducts.

Micropropagation of an endangered medicinal herb Chlorophytum ...

African Journals Online (AJOL)

SAM

2014-04-23

Apr 23, 2014 ... improved agro technological practices have also limited its commercial ... volume of 5 L. The impeller in this air sparged top driven system provided .... plants were covered with transparent polythene bags with small holes for ...

Assessment of the Natural Attenuation of NAPL Source Zones and Post-Treatment NAPL Source Zone Residuals

Science.gov (United States)

2013-11-15

and Rhodes, S., 2000, Natural bioremediation of NZAS diesel spill: Rio Tinto Technical Services Report. Guilbeault, M., Parker, B., and Cherry...situ chemical oxidation (ISCO), electrical resistive heating (ERH), bioremediation , air sparging, soil vapor extraction) often involves short- term

DEMONSTRATION BULLETIN: SUBSURFACE VOLATILIZATION AND VENTILATION SYSTEM - BROWN & ROOT ENVIRONMENTAL

Science.gov (United States)

The Subsurface Volatilization and Ventilation System (SVVS*) is an in-situ vacuum extraction/air sparging and bioremediation technology for the treatment of subsurface organic contamination in soil and groundwater. The technology, developed by Billings and Associates, Inc., and o...

Air pollution and the school air environment

OpenAIRE

Fsadni, Peter; Montefort, Stephen

2015-01-01

There is growing concern about the association of school indoor air quality (SIAQ) with asthma, rhinitis, and rhinoconjunctivitis. Students and school staff deserve the highest standards of school air quality to ensure a safe and productive environment for our children’s education. Existing studies highlight the presence of several air pollutants present within school classrooms that have a direct association with poor health and poor student performance. Very little data exist ab...

Design, Construction, and Validation of an Internally Lit Air-Lift Photobioreactor for Growing Algae

Energy Technology Data Exchange (ETDEWEB)

Hincapie, Esteban [Department of Mechanical Engineering, Russ College of Engineering and Technology, Ohio University, Athens, OH (United States); Stuart, Ben J., E-mail: stuart@ohio.edu [Department of Civil Engineering, Russ College of Engineering and Technology, Ohio University, Athens, OH (United States)

2015-01-23

A novel 28 L photobioreactor for growing algae was developed using fiber optics for internal illumination. The proposed design uses the air-lift principle to enhance the culture circulation and induce light/dark cycles to the microorganisms. Optical fibers were used to distribute photons inside the culture media providing an opportunity to control both light cycle and intensity. The fibers were coupled to an artificial light source; however, the development of this approach aims for the future use of natural light collected through parabolic solar collectors. This idea could also allow the use of opaque materials for photobioreactor construction significantly reducing costs and increasing durability. Internal light levels were determined in dry conditions and were maintained above 80 μmol/(s·m{sup 2}). The hydrodynamic equations of the air-lift phenomena were explored and used to define the geometric characteristics of the unit. The reactor was inoculated with the algae strain Chlorella sp. and sparged with air. The reactor was operated under batch mode and daily monitored for biomass concentration. The specific growth rate constant of the novel device was determined to be 0.011 h{sup −1}. The proposed design can be effectively and economically used in carbon dioxide mitigation technologies and in the production of algal biomass for biofuel and other bioproducts.

In Situ Biodegradation of MTBE and TBA

Science.gov (United States)

Ground water at most UST spills sites in Kansas contains both MTBE and benzene, and both contaminants must be effectively treated to close the sites. Soil vacuum extraction, and air sparging are common treatment technologies in Kansas. The technologies supply oxygen to support ...

Performance assessment of the In-Well Vapor-Stripping System

Energy Technology Data Exchange (ETDEWEB)

Gilmore, T.J.; White, M.D.; Spane, F.A. Jr. [and others

1996-10-01

In-well vapor stripping is a remediation technology designed to preferentially extract volatile organic compounds dissolved in groundwater by converting them to a vapor phase and then treating the vapor. This vapor-stripping system is distinctly different from the more traditional in situ air-sparging concept. In situ sparging takes place in the aquifer formation; in-well vapor stripping takes place within the well casing. The system was field demonstrated at Edwards Air Force Base, California; the first-time demonstration of this technology in the United States. Installation and testing of the system were completed in late 1995, and the demonstration was operated nearly continuously for 6 months (191 days) between January 16 and July 25, 1996. Postdemonstration hydrochemical sampling continued until September 1996. The demonstration was conducted by collaborating researchers from Pacific Northwest National Laboratory (a) and Stanford University as part of an interim cleanup action at the base. Edwards Air Force Base and its environmental subcontractor, Earth Technology Corporation, as well as EG&G Environmental, holders of the commercial rights to the technology, were also significant contributors to the demonstration.

MASS TRANSFER COEFFICIENTS FOR A NON-NEWTONIAN FLUID AND WATER WITH AND WITHOUT ANTI-FOAM AGENTS

Energy Technology Data Exchange (ETDEWEB)

Leishear, R.

2009-09-09

Mass transfer rates were measured in a large scale system, which consisted of an 8.4 meter tall by 0.76 meter diameter column containing one of three fluids: water with an anti-foam agent, water without an anti-foam agent, and AZ101 simulant, which simulated a non-Newtonian nuclear waste. The testing contributed to the evaluation of large scale mass transfer of hydrogen in nuclear waste tanks. Due to its radioactivity, the waste was chemically simulated, and due to flammability concerns oxygen was used in lieu of hydrogen. Different liquids were used to better understand the mass transfer processes, where each of the fluids was saturated with oxygen, and the oxygen was then removed from solution as air bubbled up, or sparged, through the solution from the bottom of the column. Air sparging was supplied by a single tube which was co-axial to the column, the decrease in oxygen concentration was recorded, and oxygen measurements were then used to determine the mass transfer coefficients to describe the rate of oxygen transfer from solution. Superficial, average, sparging velocities of 2, 5, and 10 mm/second were applied to each of the liquids at three different column fill levels, and mass transfer coefficient test results are presented here for combinations of superficial velocities and fluid levels.

MASS TRANSFER COEFFICIENTS FOR A NON-NEWTONIAN FLUID AND WATER WITH AND WITHOUT ANTI-FOAM AGENTS

International Nuclear Information System (INIS)

Leishear, R.

2009-01-01

Mass transfer rates were measured in a large scale system, which consisted of an 8.4 meter tall by 0.76 meter diameter column containing one of three fluids: water with an anti-foam agent, water without an anti-foam agent, and AZ101 simulant, which simulated a non-Newtonian nuclear waste. The testing contributed to the evaluation of large scale mass transfer of hydrogen in nuclear waste tanks. Due to its radioactivity, the waste was chemically simulated, and due to flammability concerns oxygen was used in lieu of hydrogen. Different liquids were used to better understand the mass transfer processes, where each of the fluids was saturated with oxygen, and the oxygen was then removed from solution as air bubbled up, or sparged, through the solution from the bottom of the column. Air sparging was supplied by a single tube which was co-axial to the column, the decrease in oxygen concentration was recorded, and oxygen measurements were then used to determine the mass transfer coefficients to describe the rate of oxygen transfer from solution. Superficial, average, sparging velocities of 2, 5, and 10 mm/second were applied to each of the liquids at three different column fill levels, and mass transfer coefficient test results are presented here for combinations of superficial velocities and fluid levels

TECHNOLOGIES TO ENHANCE THE OPERATION OF EXISTING NATURAL GAS COMPRESSION INFRASTRUCTURE - MANIFOLD DESIGN FOR CONTROLLING ENGINE AIR BALANCE

Energy Technology Data Exchange (ETDEWEB)

Gary D. Bourn; Ford A. Phillips; Ralph E. Harris

2005-12-01

This document provides results and conclusions for Task 15.0--Detailed Analysis of Air Balance & Conceptual Design of Improved Air Manifolds in the ''Technologies to Enhance the Operation of Existing Natural Gas Compression Infrastructure'' project. SwRI{reg_sign} is conducting this project for DOE in conjunction with Pipeline Research Council International, Gas Machinery Research Council, El Paso Pipeline, Cooper Compression, and Southern Star, under DOE contract number DE-FC26-02NT41646. The objective of Task 15.0 was to investigate the perceived imbalance in airflow between power cylinders in two-stroke integral compressor engines and develop solutions via manifold redesign. The overall project objective is to develop and substantiate methods for operating integral engine/compressors in gas pipeline service, which reduce fuel consumption, increase capacity, and enhance mechanical integrity.

A case study on the application of air sparging with vapor extraction at a gasoline spill site

International Nuclear Information System (INIS)

Marley, M.C.; Walsh, M.T.; Nangeroni, T.E.

1991-01-01

This paper reports that in 1985, remedial activities were implemented at a gasoline spill site in Pawtucket, Rhode Island. The engineering company that contracted to perform the remedial activities designed, installed, and operated a free gasoline product recovery system and a groundwater pump and treat system. An air striping tower was utilized to remove volatile organic hydrocarbons (VOCs) dissolved in the groundwater. Gasoline hydrocarbon vapor migration into nearby basements was controlled through the operation of a soil gas venting system (SGVS), also installed in 1985. The groundwater treatment and free product recovery systems were shut off in may 1987; however, the soil venting system remained in operation and additional vacuum wells were installed to remediate gasoline contaminated vadose zone soils and to recover hydrocarbon vapors in the vicinity of the spill location

In situ bioremediation under high saline conditions

International Nuclear Information System (INIS)

Bosshard, B.; Raumin, J.; Saurohan, B.

1995-01-01

An in situ bioremediation treatability study is in progress at the Salton Sea Test Base (SSTB) under the NAVY CLEAN 2 contract. The site is located in the vicinity of the Salon Sea with expected groundwater saline levels of up to 50,000 ppm. The site is contaminated with diesel, gasoline and fuel oils. The treatability study is assessing the use of indigenous heterotrophic bacteria to remediate petroleum hydrocarbons. Low levels of significant macro nutrients indicate that nutrient addition of metabolic nitrogen and Orthophosphate are necessary to promote the process, requiring unique nutrient addition schemes. Groundwater major ion chemistry indicates that precipitation of calcium phosphorus compounds may be stimulated by air-sparging operations and nutrient addition, which has mandated the remedial system to include pneumatic fracturing as an option. This presentation is tailored at an introductory level to in situ bioremediation technologies, with some emphasize on innovations in sparge air delivery, dissolved oxygen uptake rates, nutrient delivery, and pneumatic fracturing that should keep the expert's interest

Measurements of the radiolytic oxidation of aqueous CsI using a sparging apparatus

Energy Technology Data Exchange (ETDEWEB)

Ashmore, C B; Brown, D; Sims, H E [AEA Technology, Harwell (United Kingdom); Gwyther, J R [NE plc Berkeley Technology Centre, Berkeley (United Kingdom)

1996-12-01

Radiolytic oxidation is considered to be the main mechanism for the formation of I{sub 2} from aqueous CsI in containment of a water cooled reactor after a LOCA. Despite the amount of study over the last 60 years on the radiation chemistry of iodine there has been no consistent set of experiments spanning a wide enough range of conditions to verify models with confidence. This paper describes results from a set of experiments carried out in order to remedy this deficiency. In this work the rate of evolution of I{sub 2} from sparged irradiated CsI solution labeled with {sup 131}I was measured on-line over a range of conditions. This work involved the measurement of the effects of pH, temperature, O{sub 2} concentration, I{sup -} concentration, phosphate concentration, dose-rate and impurities on the rate of evolution of I{sub 2}. The range of conditions was chosen in order to span as closely as possible conditions expected in a LOCA but also to help to elucidate some of the mechanisms especially at high pH. pH was found to be a very important factor influencing iodine volatility, over the temperature range studied the extent of oxidation reduced with temperature but this was compensated for by the decrease in partition coefficient. Oxygen concentration was more important in solutions not containing phosphate. The fractional oxidation was not particularly dependent on iodide concentration but G{sub I2} was very dependent on [I{sup -}]. There was no effect of added impurities, Fe, Mn, Mo or organics although in separate work silver was found to have a very important effect. During attempts to interpret the data it was found that it was necessary to include the iodine atom as a volatile species with a partition coefficient of 1.9 taken from thermodynamic data. The modelling work is described in a separate paper. (author) 15 figs., 1 tab., 19 refs.

Measurements of the radiolytic oxidation of aqueous CsI using a sparging apparatus

International Nuclear Information System (INIS)

Ashmore, C.B.; Brown, D.; Sims, H.E.; Gwyther, J.R.

1996-01-01

Radiolytic oxidation is considered to be the main mechanism for the formation of I 2 from aqueous CsI in containment of a water cooled reactor after a LOCA. Despite the amount of study over the last 60 years on the radiation chemistry of iodine there has been no consistent set of experiments spanning a wide enough range of conditions to verify models with confidence. This paper describes results from a set of experiments carried out in order to remedy this deficiency. In this work the rate of evolution of I 2 from sparged irradiated CsI solution labeled with 131 I was measured on-line over a range of conditions. This work involved the measurement of the effects of pH, temperature, O 2 concentration, I - concentration, phosphate concentration, dose-rate and impurities on the rate of evolution of I 2 . The range of conditions was chosen in order to span as closely as possible conditions expected in a LOCA but also to help to elucidate some of the mechanisms especially at high pH. pH was found to be a very important factor influencing iodine volatility, over the temperature range studied the extent of oxidation reduced with temperature but this was compensated for by the decrease in partition coefficient. Oxygen concentration was more important in solutions not containing phosphate. The fractional oxidation was not particularly dependent on iodide concentration but G I2 was very dependent on [I - ]. There was no effect of added impurities, Fe, Mn, Mo or organics although in separate work silver was found to have a very important effect. During attempts to interpret the data it was found that it was necessary to include the iodine atom as a volatile species with a partition coefficient of 1.9 taken from thermodynamic data. The modelling work is described in a separate paper. (author) 15 figs., 1 tab., 19 refs

Degradation of chlorinated compounds in an anaerobic-aerobic process

Energy Technology Data Exchange (ETDEWEB)

Alfan-Guzman, R.; Guerrero-Barajas, C.; Garcia-Pena, I.

2009-07-01

Remediation technologies that involves gas transport (e.g., soil vapor extraction and air sparging of groundwater) cause the emission of gases contaminated with chlorinated solvents. Under anaerobic conditions, reductive dechlorination of trichloroethylene (TCE) proceeds via the formation of cis and trans dichloroethene (DCEs) and vinyl chloride (VC) as intermediates. (Author)

Mitigation of trichloroethylene contaminated air streams through biofiltration: a pilot-scale study

International Nuclear Information System (INIS)

Lackey, L.W.; Gamble, J.R.; Boles, J.L.

2002-01-01

As a result of abundant usage and improper disposal practices, trichloroethylene (TCE) is one of the most prevalent groundwater contaminants. Traditional cleanup methods of aquifers contaminated with TCE include pumping the water to the surface and treating with stripper technology, soil vapor extraction, and air sparging. As a result of each of these mitigation schemes, TCE is transferred from the aqueous to the gas phase. As regulations associated with air emission tighten, development of technologies both technically feasible and cost effective for remediating TCE laden gas streams becomes imperative. This project demonstrated the use of biofiltration technology to mitigate TCE contaminated air streams. A pilot-scale biofilter system was designed, constructed, and subsequently installed at the Anniston Army Depot (ANAD), Anniston, AL. The system was inoculated with a propane-oxidizing microbial consortium that had previously been shown to degrade TCE as well as other short-chained chlorinated aliphatics and a variety of one-and two-ring aromatic compounds. Critical process variables were identified and their effects on system performance analyzed. Results indicated that the process scheme used to introduce propane into the biofiltration system had a significant impact on the observed TCE removal efficiency. The inlet contaminant concentration as well as the loading rate also had an impact on observed TCE degradation rates. Results suggest that biofilter performance and economics are generally improved by manipulating a specific waste stream so as to increase the TCE concentration and decrease the volumetric flow rate of the contaminated air fed to the biofilter. Through manipulation of process variables, including the empty bed contact time, TCE degradation efficiencies greater than 99.9 percent were sustained. No microbial inhibition was observed at inlet TCE concentrations as high as 87 parts per million on a volume basis (ppmv). (author)

EFFECTS OF OXYGEN AND AIR MIXING ON VOID FRACTIONS IN A LARGE SCALE SYSTEM

International Nuclear Information System (INIS)

Leishear, R; Hector Guerrero, H; Michael Restivo, M

2008-01-01

Oxygen and air mixing with spargers was performed in a 30 foot tall by 30 inch diameter column, to investigate mass transfer as air sparged up through the column and removed saturated oxygen from solution. The mixing techniques required to support this research are the focus of this paper. The fluids tested included water, water with an antifoam agent (AFA), and a high, solids content, Bingham plastic, nuclear waste simulant with AFA, referred to as AZ01 simulant, which is non-radioactive. Mixing of fluids in the column was performed using a recirculation system and an air sparger. The re-circulation system consisted of the column, a re-circulating pump, and associated piping. The air sparger was fabricated from a two inch diameter pipe concentrically installed in the column and open near the bottom of the column. The column contents were slowly re-circulated while fluids were mixed with the air sparger. Samples were rheologically tested to ensure effective mixing, as required. Once the fluids were adequately mixed, oxygen was homogeneously added through the re-circulation loop using a sintered metal oxygen sparger followed by a static mixer. Then the air sparger was re-actuated to remove oxygen from solution as air bubbled up through solution. To monitor mixing effectiveness several variables were monitored, which included flow rates, oxygen concentration, differential pressures along the column height, fluid levels, and void fractions, which are defined as the percent of dissolved gas divided by the total volume of gas and liquid. Research showed that mixing was uniform for water and water with AFA, but mixing for the AZ101 fluid was far more complex. Although mixing of AZ101 was uniform throughout most of the column, gas entrapment and settling of solids significantly affected test results. The detailed test results presented here provide some insight into the complexities of mixing and void fractions for different fluids and how the mixing process itself

EFFECTS OF OXYGEN AND AIR MIXING ON VOID FRACTIONS IN A LARGE SCALE SYSTEM

Energy Technology Data Exchange (ETDEWEB)

Leishear, R; Hector Guerrero, H; Michael Restivo, M

2008-09-11

Oxygen and air mixing with spargers was performed in a 30 foot tall by 30 inch diameter column, to investigate mass transfer as air sparged up through the column and removed saturated oxygen from solution. The mixing techniques required to support this research are the focus of this paper. The fluids tested included water, water with an antifoam agent (AFA), and a high, solids content, Bingham plastic, nuclear waste simulant with AFA, referred to as AZ01 simulant, which is non-radioactive. Mixing of fluids in the column was performed using a recirculation system and an air sparger. The re-circulation system consisted of the column, a re-circulating pump, and associated piping. The air sparger was fabricated from a two inch diameter pipe concentrically installed in the column and open near the bottom of the column. The column contents were slowly re-circulated while fluids were mixed with the air sparger. Samples were rheologically tested to ensure effective mixing, as required. Once the fluids were adequately mixed, oxygen was homogeneously added through the re-circulation loop using a sintered metal oxygen sparger followed by a static mixer. Then the air sparger was re-actuated to remove oxygen from solution as air bubbled up through solution. To monitor mixing effectiveness several variables were monitored, which included flow rates, oxygen concentration, differential pressures along the column height, fluid levels, and void fractions, which are defined as the percent of dissolved gas divided by the total volume of gas and liquid. Research showed that mixing was uniform for water and water with AFA, but mixing for the AZ101 fluid was far more complex. Although mixing of AZ101 was uniform throughout most of the column, gas entrapment and settling of solids significantly affected test results. The detailed test results presented here provide some insight into the complexities of mixing and void fractions for different fluids and how the mixing process itself

Air Quality in Lanzhou, a Major Industrial City in China: Characteristics of Air Pollution and Review of Existing Evidence from Air Pollution and Health Studies

Science.gov (United States)

Zhang, Yaqun; Li, Min; Bravo, Mercedes A.; Jin, Lan; Nori-Sarma, Amruta; Xu, Yanwen; Guan, Donghong; Wang, Chengyuan; Chen, Mingxia; Wang, Xiao; Tao, Wei; Qiu, Weitao; Zhang, Yawei

2015-01-01

Air pollution contributes substantially to global health burdens; however, less is known about pollution patterns in China and whether they differ from those elsewhere. We evaluated temporal and spatial heterogeneity of air pollution in Lanzhou, an urban Chinese city (April 2009–December 2012), and conducted a systematic review of literature on air pollution and health in Lanzhou. Average levels were 141.5, 42.3, and 47.2 µg/m3 for particulate matter with an aerodynamic diameter ≤10 µm (PM10), NO2, and SO2, respectively. Findings suggest some seasonality, particularly for SO2, with higher concentrations during colder months relative to warmer months, although a longer time frame of data is needed to evaluate seasonality fully. Correlation coefficients generally declined with distance between monitors, while coefficients of divergence increased with distance. However, these trends were not statistically significant. PM10 levels exceeded Chinese and other health-based standards and guidelines. The review identified 13 studies on outdoor air pollution and health. Although limited, the studies indicate that air pollution is associated with increased risk of health outcomes in Lanzhou. These studies and the high air pollution levels suggest potentially serious health consequences. Findings can provide guidance to future epidemiological studies, monitor placement programs, and air quality policies. PMID:25838615

40 CFR 63.312 - Existing regulations and requirements.

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 9 2010-07-01 2010-07-01 false Existing regulations and requirements. 63.312 Section 63.312 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... National Emission Standards for Coke Oven Batteries § 63.312 Existing regulations and requirements. (a) The...

Field test for treatment verification of an in-situ enhanced bioremediation study

International Nuclear Information System (INIS)

Taur, C.K.; Chang, S.C.

1995-01-01

Due to a leakage from a 12-inch pressurized diesel steel pipe four years ago, an area of approximately 30,000 square meters was contaminated. A pilot study applying the technology of in-situ enhanced bioremediation was conducted. In the study, a field test kit and on-site monitoring equipment were applied for site characterization and treatment verification. Physically, the enhanced bioremediation study consisted of an air extraction and air supply system, and a nutrition supply network. Certain consistent sampling methodology was employed. Progress was verified by daily monitoring and monthly verification. The objective of this study was to evaluate the capabilities of indigenous microorganisms to biodegrade the petroleum hydrocarbons with provision of oxygen and nutrients. Nine extraction wells and eight air sparging wells were installed. The air sparging wells injected the air into geoformation and the extraction wells provided the underground air circulation. The soil samples were obtained monthly for treatment verification by a Minuteman drilling machine with 2.5-foot-long hollow-stem augers. The samples were analyzed on site for TPH-diesel concentration by a field test kit manufactured by HNU-Hanby, Houston, Texas. The analytical results from the field test kit were compared with the results from an environmental laboratory. The TVPH concentrations of the air extracted from the vadose zone by a vacuum blower and the extraction wells were routinely monitored by a Foxboro FID and Cosmos XP-311A combustible air detector. The daily monitoring of TVPH concentrations provided the reliable data for assessing the remedial progress

In situ diesel fuel bioremediation: A case history

International Nuclear Information System (INIS)

Rhodes, D.K.; Burke, G.K.; Smith, N.; Clark, D.

1995-01-01

As a result of a ruptured fuel line, the study site had diesel fuel soil contamination and free product more than 2 ft (0.75 m) thick on the groundwater surface. Diesel fuel, which is composed of a high percentage of nonvolatile compounds, has proven difficult to remediate using conventional extraction remediation techniques. A number of remedial alternatives were reviewed, and the patented in situ biodegradation BioSparge SM technology was selected for the site and performed under license by a specialty contractor. BioSparge SM is a field-proven closed-loop (no vapor emissions) system that supplies a continuous, steady supply of oxygen, moisture, and additional heat to enhance microorganism activity. The system injects an enriched airstream beneath the groundwater surface elevation and/or within the contaminant plume and removes residual vapors from vadose zone soil within and above the contaminant plume. The technology has no air discharge, which is critical in areas where strict air discharge regulations apply. The focus of this paper is the viability of in situ biodegradation as an effective remediation alternative for reducing nonvolatile petroleum products

Modeling and validation of existing VAV system components

Energy Technology Data Exchange (ETDEWEB)

Nassif, N.; Kajl, S.; Sabourin, R. [Ecole de Technologie Superieure, Montreal, PQ (Canada)

2004-07-01

The optimization of supervisory control strategies and local-loop controllers can improve the performance of HVAC (heating, ventilating, air-conditioning) systems. In this study, the component model of the fan, the damper and the cooling coil were developed and validated against monitored data of an existing variable air volume (VAV) system installed at Montreal's Ecole de Technologie Superieure. The measured variables that influence energy use in individual HVAC models included: (1) outdoor and return air temperature and relative humidity, (2) supply air and water temperatures, (3) zone airflow rates, (4) supply duct, outlet fan, mixing plenum static pressures, (5) fan speed, and (6) minimum and principal damper and cooling and heating coil valve positions. The additional variables that were considered, but not measured were: (1) fan and outdoor airflow rate, (2) inlet and outlet cooling coil relative humidity, and (3) liquid flow rate through the heating or cooling coils. The paper demonstrates the challenges of the validation process when monitored data of existing VAV systems are used. 7 refs., 11 figs.

Modular head assembly and method of retrofitting existing nuclear reactor facilities

International Nuclear Information System (INIS)

Malandra, L.J.; Ledue, R.J.; Hankinson, M.F.; Kowalski, E.F.

1987-01-01

A method is described of retrofitting existing nuclear reactor facilities so as to form a modular closure head assembly for a nuclear reactor pressure vessel, where the existing nuclear reactor facilities comprise control rod drive mechanism cooling systems which include vertically extending elbow air ducts inter-connecting vertically spaced upper and lower air manifolds. The elbow air ducts extend radially beyond the peripheral envelope of the closure head, comprising the steps of: removing the upper air manifold; removing the vertically extending elbow air ducts; capping the air ports of the lower air manifold which ports were previously fluidically connecting the lower air manifold to the vertically extending elbow air ducts; disposing vertically upwardly extending air exhaust ducts above the lower air manifold in such an manner that the air exhaust ducts are disposed within the peripheral envelope of the closure head; fluidically connecting exhaust fans to the upper regions of the air exhaust ducts; fluidically connecting the lower regions of the air exhaust ducts the lower air manifold; permanently securing lift rods to the closure head at positions disposed radially outwardly of the lower air manifold; attaching a seismic support platform to the lift rods; proving fluidic passage of the vertically extending air exhaust ducts through the seismic support platform; attaching a missile shield plate to the lift rods; and proving fluidic passage of the vertically extending air exhaust ducts through the missile shield plate

Green Remediation Best Management Practices: Soil Vapor Extraction & Air Sparging

Science.gov (United States)

Historically, approximately one-quarter of Superfund source control projects have involved soil vapor extraction (SVE) to remove volatile organic compounds (VOCs) sorbed to soil in the unsaturated (vadose) zone.

In situ iron activated persulfate oxidative fluid sparging treatment of TCE contamination--a proof of concept study.

Science.gov (United States)

Liang, Chenju; Lee, I-Ling

2008-09-10

In situ chemical oxidation (ISCO) is considered a reliable technology to treat groundwater contaminated with high concentrations of organic contaminants. An ISCO oxidant, persulfate anion (S(2)O(8)(2-)) can be activated by ferrous ion (Fe(2+)) to generate sulfate radicals (E(o)=2.6 V), which are capable of destroying trichloroethylene (TCE). The property of polarity inhibits S(2)O(8)(2-) or sulfate radical (SO(4)(-)) from effectively oxidizing separate phase TCE, a dense non-aqueous phase liquid (DNAPL). Thus the oxidation primarily takes place in the aqueous phase where TCE is dissolved. A bench column study was conducted to demonstrate a conceptual remediation method by flushing either S(2)O(8)(2-) or Fe(2+) through a soil column, where the TCE DNAPL was present, and passing the dissolved mixture through either a Fe(2+) or S(2)O(8)(2-) fluid sparging curtain. Also, the effect of a solubility enhancing chemical, hydroxypropyl-beta-cyclodextrin (HPCD), was tested to evaluate its ability to increase the aqueous TCE concentration. Both flushing arrangements may result in similar TCE degradation efficiencies of 35% to 42% estimated by the ratio of TCE degraded/(TCE degraded+TCE remained in effluent) and degradation byproduct chloride generation rates of 4.9 to 7.6 mg Cl(-) per soil column pore volume. The addition of HPCD did greatly increase the aqueous TCE concentration. However, the TCE degradation efficiency decreased because the TCE degradation was a lower percentage of the relatively greater amount of dissolved TCE by HPCD. This conceptual treatment may serve as a reference for potential on-site application.

Expanding AirSTAR Capability for Flight Research in an Existing Avionics Design

Science.gov (United States)

Laughter, Sean A.

2012-01-01

The NASA Airborne Subscale Transport Aircraft Research (AirSTAR) project is an Unmanned Aerial Systems (UAS) test bed for experimental flight control laws and vehicle dynamics research. During its development, the test bed has gone through a number of system permutations, each meant to add functionality to the concept of operations of the system. This enabled the build-up of not only the system itself, but also the support infrastructure and processes necessary to support flight operations. These permutations were grouped into project phases and the move from Phase-III to Phase-IV was marked by a significant increase in research capability and necessary safety systems due to the integration of an Internal Pilot into the control system chain already established for the External Pilot. The major system changes in Phase-IV operations necessitated a new safety and failsafe system to properly integrate both the Internal and External Pilots and to meet acceptable project safety margins. This work involved retrofitting an existing data system into the evolved concept of operations. Moving from the first Phase-IV aircraft to the dynamically scaled aircraft further involved restructuring the system to better guard against electromagnetic interference (EMI), and the entire avionics wiring harness was redesigned in order to facilitate better maintenance and access to onboard electronics. This retrofit and harness re-design will be explored and how it integrates with the evolved Phase-IV operations.

Indoor Air Quality in Chemistry Laboratories.

Science.gov (United States)

Hays, Steve M.

This paper presents air quality and ventilation data from an existing chemical laboratory facility and discusses the work practice changes implemented in response to deficiencies in ventilation. General methods for improving air quality in existing laboratories are presented and investigation techniques for characterizing air quality are…

Impact of wood burning on outdoor air quality: existing French data and current studies

International Nuclear Information System (INIS)

Leoz-Garziandia, E.; Mandin, C.; Collet, S.; Besombes, J.L.; Pissot, N.; Allemand, N.; Riberon, J.; Jaffrezo, J.L.

2009-01-01

French source apportionment studies of air quality including the wood combustion source become widespread. Quantify a single source contribution to air quality requires to be provided with a specific measurable data to this source. For that reason, numerous studies have focused on the determination, in the atmospheric samples, of the source-specific compounds, usually called molecular tracers. Since 2000, trend works focused on the 'wood combustion' contribution to air quality have been based on the use of some tracers such as levoglucosan and metoxyphenols. Obtained results have been compared to atmospheric particles global characteristics: organic carbon (OC), elementary carbon (EC), PM 10 , PM 2.5 and polycyclic aromatic hydrocarbons (PAH). The results presented in this article show not only the interest but also the limits of such an approach, as well as the need to develop and complete the current studies in order to quantify the different sources contribution to air quality. (author)

Comparison of residual NAPL source removal techniques in 3D metric scale experiments

Science.gov (United States)

Atteia, O.; Jousse, F.; Cohen, G.; Höhener, P.

2017-07-01

This study compared four treatment techniques for the removal of a toluene/n-decane as NAPL (Non Aqueous Phase Liquid) phase mixture in identical 1 cubic meter tanks filled with different kind of sand. These four treatment techniques were: oxidation with persulfate, surfactant washing with Tween80®, sparging with air followed by ozone, and thermal treatment at 80 °C. The sources were made with three lenses of 26 × 26 × 6.5 cm, one having a hydraulic conductivity similar to the whole tank and the two others a value 10 times smaller. The four techniques were studied after conditioning the tanks with tap water during approximately 80 days. The persulfate treatment tests showed average removal of the contaminants but significant flux decrease if density effects are considered. Surfactant flushing did not show a highly significant increase of the flux of toluene but allowed an increased removal rate that could lead to an almost complete removal with longer treatment time. Sparging removed a significant amount but suggests that air was passing through localized gas channels and that the removal was stagnating after removing half of the contamination. Thermal treatment reached 100% removal after the target temperature of 80 °C was kept during more than 10 d. The experiments emphasized the generation of a high-spatial heterogeneity in NAPL content. For all the treatments the overall removal was similar for both n-decane and toluene, suggesting that toluene was removed rapidly and n-decane more slowly in some zones, while no removal existed in other zones. The oxidation and surfactant results were also analyzed for the relation between contaminant fluxes at the outlet and mass removal. For the first time, this approach clearly allowed the differentiation of the treatments. As a conclusion, experiments showed that the most important differences between the tested treatment techniques were not the global mass removal rates but the time required to reach 99% decrease in

Air filtration in HVAC systems

CERN Document Server

Ginestet, Alain; Tronville, Paolo; Hyttinen, Marko

2010-01-01

Air filtration Guidebook will help the designer and user to understand the background and criteria for air filtration, how to select air filters and avoid problems associated with hygienic and other conditions at operation of air filters. The selection of air filters is based on external conditions such as levels of existing pollutants, indoor air quality and energy efficiency requirements.

Remediation of the Wells G & H Superfund Site, Woburn, Massachusetts.

Science.gov (United States)

Bair, E Scott; Metheny, Maura A

2002-01-01

Remediation of ground water and soil contamination at the Wells G & H Superfund Site, Woburn, Massachusetts, uses technologies that reflect differences in hydrogeologic settings, concentrations of volatile organic compounds (VOCs), and costs of treatment. The poorly permeable glacial materials that overlie fractured bedrock at the W.R. Grace property necessitate use of closely spaced recovery wells. Contaminated ground water is treated with hydrogen peroxide and ultraviolet (UV) oxidation. At UniFirst, a deep well completed in fractured bedrock removes contaminated ground water, which is treated by hydrogen peroxide, UV oxidation, and granular activated carbon (GAC). The remediation system at Wildwood integrates air sparging, soil-vapor extraction, and ground water pumping. Air stripping and GAC are used to treat contaminated water; GAC is used to treat contaminated air. New England Plastics (NEP) uses air sparging and soil-vapor extraction to remove VOCs from the unsaturated zone and shallow ground water. Contaminated air and water are treated using separate GAC systems. After nine years of operation at W.R. Grace and UniFirst, 30 and 786 kg, respectively, of VOCs have been removed. In three years of operation, 866 kg of VOCs have been removed at Wildwood. In 15 months of operation, 36 kg of VOCs were removed at NEP. Characterization work continues at the Olympia Nominee Trust, Whitney Barrel, Murphy Waste Oil, and Aberjona Auto Parts properties. Risk assessments are being finalized that address heavy metals in the floodplain sediments along the Aberjona River that are mobilized from the Industri-Plex Superfund Site located a few miles upstream.

Managing the Drivers of Air Flow and Water Vapor Transport in Existing Single Family Homes (Revised)

Energy Technology Data Exchange (ETDEWEB)

Cummings, J.; Withers, C.; Martin, E.; Moyer, N.

2012-10-01

This document focuses on managing the driving forces which move air and moisture across the building envelope. While other previously published Measure Guidelines focus on elimination of air pathways, the ultimate goal of this Measure Guideline is to manage drivers which cause air flow and water vapor transport across the building envelope (and also within the home), control air infiltration, keep relative humidity (RH) within acceptable limits, avoid combustion safety problems, improve occupant comfort, and reduce house energy use.

Machine & electrical double control air dryer for vehicle air braking system

Science.gov (United States)

Zhang, Xuan; Yang, Liu; Wang, Xian Yan; Tan, Xiao Yan; Wang, Wei

2017-09-01

As is known to all, a vehicle air brake system, in which usually contains moisture. To solve the problem, it is common to use air dryer to dry compressed air effectively and completely remove the moisture and oil of braking system. However, the existing air dryer is not suitable for all commercial vehicles. According to the operational status of the new energy vehicles in the initial operating period, the structure design principle of the machine & electric control air dryer is expounded from the aspects of the structure and operating principle, research & development process.

Air Conditioner/Dehumidifier

Science.gov (United States)

1986-01-01

An ordinary air conditioner in a very humid environment must overcool the room air, then reheat it. Mr. Dinh, a former STAC associate, devised a heat pipe based humidifier under a NASA Contract. The system used heat pipes to precool the air; the air conditioner's cooling coil removes heat and humidity, then the heat pipes restore the overcooled air to a comfortable temperature. The heat pipes use no energy, and typical savings are from 15-20%. The Dinh Company also manufactures a "Z" coil, a retrofit cooling coil which may be installed on an existing heater/air conditioner. It will also provide free hot water. The company has also developed a photovoltaic air conditioner and solar powered water pump.

Use of Cometabolic Air Sparging to Remediate Chloroethene-Contaminated Groundwater Aquifers

National Research Council Canada - National Science Library

Magar, Victor

2001-01-01

...) process at the McClellan National Test Site, California. The purpose of the demonstration was to evaluate the effectiveness of and costs associated with CAS for removal of chlorinated aromatic hydrocarbons (CAHs) from groundwater...

Does evaporation paradox exist in China?

Directory of Open Access Journals (Sweden)

Z. T. Cong

2009-03-01

Full Text Available One expected consequence of global warming is the increase in evaporation. However, lots of observations show that the rate of evaporation from open pans of water has been steadily decreasing all over the world in the past 50 years. The contrast between expectation and observation is called "evaporation paradox". Based on data from 317 weather stations in China from 1956 to 2005, the trends of pan evaporation and air temperature were obtained and evaporation paradox was analyzed. The conclusions include: (1 From 1956 to 2005, pan evaporation paradox existed in China as a whole while pan evaporation kept decreasing and air temperature became warmer and warmer, but it does not apply to Northeast and Southeast China; (2 From 1956 to 1985, pan evaporation paradox existed narrowly as a whole with unobvious climate warming trend, but it does not apply to Northeast China; (3 From 1986 to 2005, in the past 20 years, pan evaporation paradox did not exist for the whole period while pan evaporation kept increasing, although it existed in South China. Furthermore, the trend of other weather factors including sunshine duration, windspeed, humidity and vapor pressure deficit, and their relations with pan evaporation are discussed. As a result, it can be concluded that pan evaporation decreasing is caused by the decreasing in radiation and wind speed before 1985 and pan evaporation increasing is caused by the decreasing in vapor pressure deficit due to strong warming after 1986. With the Budyko curve, it can be concluded that the actual evaporation decreased in the former 30 years and increased in the latter 20 year for the whole China.

Unlocking Chain Exchange in Highly Amphiphilic Block Polymer Micellar Systems: Influence of Agitation.

Science.gov (United States)

Murphy, Ryan P; Kelley, Elizabeth G; Rogers, Simon A; Sullivan, Millicent O; Epps, Thomas H

2014-11-18

Chain exchange between block polymer micelles in highly selective solvents, such as water, is well-known to be arrested under quiescent conditions, yet this work demonstrates that simple agitation methods can induce rapid chain exchange in these solvents. Aqueous solutions containing either pure poly(butadiene- b -ethylene oxide) or pure poly(butadiene- b -ethylene oxide- d 4 ) micelles were combined and then subjected to agitation by vortex mixing, concentric cylinder Couette flow, or nitrogen gas sparging. Subsequently, the extent of chain exchange between micelles was quantified using small angle neutron scattering. Rapid vortex mixing induced chain exchange within minutes, as evidenced by a monotonic decrease in scattered intensity, whereas Couette flow and sparging did not lead to measurable chain exchange over the examined time scale of hours. The linear kinetics with respect to agitation time suggested a surface-limited exchange process at the air-water interface. These findings demonstrate the strong influence of processing conditions on block polymer solution assemblies.

A review of treatment technologies for MTBE

International Nuclear Information System (INIS)

Bass, D.

1995-01-01

Available treatment technologies for methyl tertiary butyl ether (MTBE) contamination in soil, groundwater, and recovered groundwater are reviewed and assessed. MTBE contamination is becoming an important issue due to the increasing prevalence and regulation of this gasoline additive. In addition, MTBE is more soluble and more mobile in groundwater than most hydrocarbons, so it is usually the first gasoline constituent to reach sensitive receptors. Treatment of MTBE is complicated by its Henry's constant, which is lower than most other gasoline constituents. Furthermore, evidence of biodegradability of MTBE is mixed, and MTBE does not degrade rapidly abiotically. Groundwater pumping is usually employed to contain and collect MTBE-contaminated groundwater, often successfully because of its high aqueous solubility. Air sparging/soil vapor extraction is also successfully employed to treat MTBE, but its effectiveness is reduced by the low Henry's constant of MTBE. Sparging and other aerobic bioremediation approaches are hampered by the poor biodegradability of MTBE. Oxidation technologies, such as ozone injection, hold promise for rapid in situ remediation of MTBE. Treatment of recovered groundwater contaminated with MTBE is also problematic. MTBE adsorbs poorly to granular activated carbon; advanced oxidation processes are effective on MTBE, but entail high capital and operating costs; bioreactors are of questionable effectiveness on MTBE. Air stripping is usually the most cost-effective treatment technology for MTBE so long as the off gas from the air stripper can be discharged without treatment. However, off gas treatment is expensive, so groundwater is sometimes heated to reduce the requirement for stripping air

Advances in Understanding Air Pollution and Cardiovascular Diseases: The Multi-Ethnic Study of Atherosclerosis and Air Pollution (MESA Air)

Science.gov (United States)

Kaufman, Joel D.; Spalt, Elizabeth W.; Curl, Cynthia L.; Hajat, Anjum; Jones, Miranda R.; Kim, Sun-Young; Vedal, Sverre; Szpiro, Adam A.; Gassett, Amanda; Sheppard, Lianne; Daviglus, Martha L.; Adar, Sara D.

2016-01-01

The Multi-Ethnic Study of Atherosclerosis and Air Pollution (MESA Air) leveraged the platform of the MESA cohort into a prospective longitudinal study of relationships between air pollution and cardiovascular health. MESA Air researchers developed fine-scale, state-of-the-art air pollution exposure models for the MESA Air communities, creating individual exposure estimates for each participant. These models combine cohort-specific exposure monitoring, existing monitoring systems, and an extensive database of geographic and meteorological information. Together with extensive phenotyping in MESA—and adding participants and health measurements to the cohort—MESA Air investigated environmental exposures on a wide range of outcomes. Advances by the MESA Air team included not only a new approach to exposure modeling but also biostatistical advances in addressing exposure measurement error and temporal confounding. The MESA Air study advanced our understanding of the impact of air pollutants on cardiovascular disease and provided a research platform for advances in environmental epidemiology. PMID:27741981

Treatment of gaseous and airborne radioactive waste

International Nuclear Information System (INIS)

Leichsenring, C.H.

1982-01-01

Gaseous and airborne radionuclides in the fuel cycle are retained in vessel off-gas filter systems and in the dissolver off-gas cleaning system. Those systems have to meet the regulatory requirements for both normal and accident conditions. From the solutions liquid aerosols are formed during liquid transfer (air lifts, steam jets) or by air sparging or by evaporation processes. During dissolution the volatile radionuclides i.e. 85 Kr, 129 I and 14 C are liberated and enter into the dissolver off-gas cleaning system. Flow sheets of different cleaning systems and their stage of development are described. (orig./RW)

Analysis of energy efficiency retrofit schemes for heating, ventilating and air-conditioning systems in existing office buildings based on the modified bin method

International Nuclear Information System (INIS)

Wang, Zhaoxia; Ding, Yan; Geng, Geng; Zhu, Neng

2014-01-01

Highlights: • A modified bin method is adopted to propose and optimize the EER schemes. • A case study is presented to demonstrate the analysis procedures of EER schemes. • Pertinent EER schemes for HVAC systems are proposed for the object building. - Abstract: Poor thermal performance of building envelop and low efficiencies of heating, ventilating and air-conditioning (HVAC) systems can always be found in the existing office buildings with large energy consumption. This paper adopted a modified bin method to propose and optimize the energy efficiency retrofit (EER) schemes. An existing office building in Tianjin was selected as an example to demonstrate the procedures of formulating the design scheme. Pertinent retrofit schemes for HVAC system were proposed after the retrofit of building envelop. With comprehensive consideration of energy efficiency and economic benefits, the recommended scheme that could improve the overall energy efficiency by 71.20% was determined

Sitewide Monitoring at Agra, Kansas, in 2015

Energy Technology Data Exchange (ETDEWEB)

LaFreniere, Lorraine M. [Argonne National Lab. (ANL), Argonne, IL (United States)

2016-05-01

The CCC/USDA is currently implementing a KDHE-approved interim measure (IM) to address the contamination identified on its former property. This source control IM consists of large-diameter boreholes coupled with soil vapor extraction (SVE) and air sparging (AS). The CCC/USDA completed installation of the IM in May 2009. Assessment of the performance and effectiveness of the IM is being reported separately. Pro-Ag is conducting its own site investigation (KDHE 2011c).

Human preference for air movement

DEFF Research Database (Denmark)

Toftum, Jørn; Melikov, Arsen Krikor; Tynel, A.

2002-01-01

Human preference for air movement was studied at slightly cool, neutral, and slightly warm overall thermal sensations and at temperatures ranging from 18 deg.C to 28 deg.C. Air movement preference depended on both thermal sensation and temperature, but large inter-individual differences existed...... between subjects. Preference for less air movement was linearly correlated with draught discomfort, but the percentage of subjects who felt draught was lower than the percentage who preferred less air movement....

Measure Guideline: Wall Air Sealing and Insulation Methods in Existing Homes; An Overview of Opportunity and Process

Energy Technology Data Exchange (ETDEWEB)

Roberts, S.; Stephenson, R.

2012-09-01

This guide provides renovators and retrofit contractors an overview of considerations when including wall air sealing and insulation in an energy retrofit project. It also outlines the potential project risks, various materials for insulating, possible field inspections needed, installation procedures, as well as the benefits and drawbacks. The purpose of this document is to provide the outline of the overview and process of insulating and air sealing walls so that home retrofit professionals can identify approaches to air sealing and insulation measures.

Periodic feedwater reversal and air sparging as antifouling strategies in reverse electrodialysis

NARCIS (Netherlands)

Vermaas, D.A.; Kunteng, D.; Veerman, J.; Saakes, M.; Nijmeijer, K.

2014-01-01

Renewable energy can be generated using natural streams of seawater and river water in reverse electrodialysis (RED). The potential for electricity production of this technology is huge, but fouling of the membranes and the membrane stack reduces the potential for large scale applications. This

Performance improvement of air-cooled refrigeration system by using evaporatively cooled air condenser

Energy Technology Data Exchange (ETDEWEB)

Hajidavalloo, E.; Eghtedari, H. [Mechanical Engineering Department, Shahid Chamran University, Golestan St., Ahvaz (Iran)

2010-08-15

Increasing the coefficient of performance of air conditioner with air-cooled condenser is a challenging problem especially in area with very hot weather conditions. Application of evaporatively cooled air condenser instead of air-cooled condenser is proposed in this paper as an efficient way to solve the problem. An evaporative cooler was built and coupled to the existing air-cooled condenser of a split-air-conditioner in order to measure its effect on the cycle performance under various ambient air temperatures up to 49 C. Experimental results show that application of evaporatively cooled air condenser has significant effect on the performance improvement of the cycle and the rate of improvement is increased as ambient air temperature increases. It is also found that by using evaporatively cooled air condenser in hot weather conditions, the power consumption can be reduced up to 20% and the coefficient of performance can be improved around 50%. More improvements can be expected if a more efficient evaporative cooler is used. (author)

INDOOR AIR POLLUTION

OpenAIRE

Ahmet Soysal; Yucel Demiral

2007-01-01

The existance of hazardious materials including biological, chemical, and physical agents such as carbon dioxide, carbon monoxide, sulphur dioxide, nitrogen oxides, radon, volotile organic compounds, microorganisms in houses and the other non-industrilized buildings have been defined as “indoor air pollution”. Indoor air pollutants could possible arised from inside or outside environment and categorized into six subgroups. Almost 80% Turkish population have living in the urban areas...

Paradoxical cerebral air embolism

International Nuclear Information System (INIS)

Lopez-Negrete, L.; Garcia-Lozano, J.; Sanchez, J. L.; Sala, J.

2000-01-01

We present a fatal case of intracranial air embolism produced by the passage of intravenous air to the arteries owing to the existence of a patent foremen ovale associated with pulmonary hypertension, which permitted a right-left shunt (paradoxical embolism). The pathophysiological mechanisms of pneumcephalus and paradoxical embolism are discussed and the pertinent literature is reviewed. (Author) 6 refs

Improvement Design of an Existing Atomized Kerosene Stove for ...

African Journals Online (AJOL)

The existing atomized kerosene stove being used in some households in Nigeria does not give room for primary air fuel mixture but secondary one before combustion. This in turn leads to higher specific fuel consumption and ultimately lower thermal efficiency (resulting from low combustion efficiency) of the stove. In order ...

Determination of osmium concentrations and (187)Os/(188)Os of crude oils and source rocks by coupling high-pressure, high-temperature digestion with sparging OsO(4) into a multicollector inductively coupled plasma mass spectrometer.

Science.gov (United States)

Sen, Indra S; Peucker-Ehrenbrink, Bernhard

2014-03-18

The (187)Os/(188)Os ratio that is based on the β(-)-decay of (187)Re to (187)Os (t1/2 = 41.6 billion years) is widely used to investigate petroleum system processes. Despite its broad applicability to studies of hydrocarbon deposits worldwide, a suitable matrix-matched reference material for Os analysis does not exist. In this study, a method that enables Os isotope measurement of crude oil with in-line Os separation and purification from the sample matrix is proposed. The method to analyze Os concentration and (187)Os/(187)Os involves sample digestion under high pressure and high temperature using a high pressure asher (HPA-S, Anton Paar), sparging of volatile osmium tetroxide from the sample solution, and measurements using multicollector inductively coupled plasma mass spectrometry (MC-ICPMS). This methods significantly reduced the total procedural time compared to conventional Carius tube digestion followed by Os separation and purification using solvent extraction, microdistillation and N-TIMS analysis. The method yields Os concentration (28 ± 4 pg g(-1)) and (187)Os/(188)Os (1.62 ± 0.15) of commercially available crude oil reference material NIST 8505 (1 S.D., n = 6). The reference material NIST 8505 is homogeneous with respect to Os concentration at a test portion size of 0.2 g. Therefore, (187)Os/(188)Os composition and Os concentration of NIST 8505 can serve as a matrix-matched reference material for Os analysis. Data quality was assessed by repeated measurements of the USGS shale reference material SCo-1 (sample matrix similar to petroleum source rock) and the widely used Liquid Os Standard solution (LOsSt). The within-laboratory reproducibility of (187)Os/(188)Os for a 5 pg of LOsSt solution, analyzed with this method over a period of 12 months was ∼1.4% (1 S.D., n = 26), respectively.

Mass transfer model for two-layer TBP oxidation reactions

International Nuclear Information System (INIS)

Laurinat, J.E.

1994-01-01

To prove that two-layer, TBP-nitric acid mixtures can be safely stored in the canyon evaporators, it must be demonstrated that a runaway reaction between TBP and nitric acid will not occur. Previous bench-scale experiments showed that, at typical evaporator temperatures, this reaction is endothermic and therefore cannot run away, due to the loss of heat from evaporation of water in the organic layer. However, the reaction would be exothermic and could run away if the small amount of water in the organic layer evaporates before the nitric acid in this layer is consumed by the reaction. Provided that there is enough water in the aqueous layer, this would occur if the organic layer is sufficiently thick so that the rate of loss of water by evaporation exceeds the rate of replenishment due to mixing with the aqueous layer. This report presents measurements of mass transfer rates for the mixing of water and butanol in two-layer, TBP-aqueous mixtures, where the top layer is primarily TBP and the bottom layer is comprised of water or aqueous salt solution. Mass transfer coefficients are derived for use in the modeling of two-layer TBP-nitric acid oxidation experiments. Three cases were investigated: (1) transfer of water into the TBP layer with sparging of both the aqueous and TBP layers, (2) transfer of water into the TBP layer with sparging of just the TBP layer, and (3) transfer of butanol into the aqueous layer with sparging of both layers. The TBP layer was comprised of 99% pure TBP (spiked with butanol for the butanol transfer experiments), and the aqueous layer was comprised of either water or an aluminum nitrate solution. The liquid layers were air sparged to simulate the mixing due to the evolution of gases generated by oxidation reactions. A plastic tube and a glass frit sparger were used to provide different size bubbles. Rates of mass transfer were measured using infrared spectrophotometers provided by SRTC/Analytical Development

Reduced energy reqirement for air conditioning by using air diffusion with air flow from floor to ceiling

Energy Technology Data Exchange (ETDEWEB)

Bach, H; Dittes, W; Mangelsdorf, R; Detzer, R; Jungbaeck, E; Fitzner, K; Radtke, W; Soethout, F

1982-02-01

The condition of the air in the occupied zone in airconditioned rooms is influenced by the mixing of supply air with room air. When supplying air from the ceiling there is a mixing all over the room, when supplying from the floor or from desks there is a mixing region only in the lower area. Above this their is warm air from which the return air is drawn. For air supply from below the cooling load can be decreased. In combination with the possible enthalpy difference between room air and supply air this decrease of the cooling load influences the necessary air rate. The interdependence of various air conditioning systems and various air temperatures is shown with a computer program. The load factor for various air distribution system at various cooling loads have been measured in a room of (8 x 5)m/sup 2/ x 3m. Experiments in a smaller model room (scale 1:3) showed how the heat was transported from the mixing region to the stratification region. The theoretically gained influence of the supply air jets of the height of the mixing region and on the load rate could be verified by the experiments. For the design of the fresh air rate, experience has been gained by measurements with tracegas (N/sub 2/O) in a third room. In comparing calculations the annual energy consumption has been computed for a building assuming various air conditioning systems and typical operation data. From experience with the existing systems the conclusions have been drawn how air distribution from floor to ceiling can be installed and operated.

Functional genes reveal the intrinsic PAH biodegradation potential in creosote-contaminated groundwater following in situ biostimulation.

Science.gov (United States)

Nyyssönen, Mari; Kapanen, Anu; Piskonen, Reetta; Lukkari, Tuomas; Itävaara, Merja

2009-08-01

A small-scale functional gene array containing 15 functional gene probes targeting aliphatic and aromatic hydrocarbon biodegradation pathways was used to investigate the effect of a pilot-scale air sparging and nutrient infiltration treatment on hydrocarbon biodegradation in creosote-contaminated groundwater. Genes involved in the different phases of polycyclic aromatic hydrocarbon (PAH) biodegradation were detected with the functional gene array in the contaminant plume, thus indicating the presence of intrinsic biodegradation potential. However, the low aerobic fluorescein diacetate hydrolysis, the polymerase chain reaction (PCR) amplification of 16S rRNA genes closely similar to sulphate-reducing and denitrifying bacteria and the negligible decrease in contaminant concentrations showed that aerobic PAH biodegradation was limited in the anoxic groundwater. Increased abundance of PAH biodegradation genes was detected by functional gene array in the monitoring well located at the rear end of the biostimulated area, which indicated that air sparging and nutrient infiltration enhanced the intrinsic, aerobic PAH biodegradation. Furthermore, ten times higher naphthalene dioxygenase gene copy numbers were detected by real-time PCR in the biostimulated area, which was in good agreement with the functional gene array data. As a result, functional gene array analysis was demonstrated to provide a potential tool for evaluating the efficiency of the bioremediation treatment for enhancing hydrocarbon biodegradation in field-scale applications.

Comparative analysis of top-lit bubble column and gas-lift bioreactors for microalgae-sourced biodiesel production

International Nuclear Information System (INIS)

Seyed Hosseini, Nekoo; Shang, Helen; Ross, Gregory M.; Scott, John Ashley

2016-01-01

Highlights: • Top-lit gas-lift and bubble columns were studied as deep algal cultivation tank. • A theoretical energy requirement analysis and a hydrodynamic model were developed. • Areal productivities of both bioreactors were notably higher than traditional raceways. • A gas-lift reactor sparged with 6% carbon dioxide achieved the highest lipid production. • Hydrodynamic and light stresses increased the lipid content suitable for biodiesel. - Abstract: The development of top-lit one-meter deep bioreactors operated as either a gas-lift or bubble column system using air and carbon dioxide enriched air was studied. The goal was high productivity cultivation of algae with elevated lipid levels suitable for conversion into biodiesel. A theoretical energy requirement analysis and a hydrodynamic model were developed to predict liquid circulation velocities in the gas-lift bioreactor, which agreed well with experimental measurements. The influence of operational parameters such as design of bioreactor, gas flow rates and carbon dioxide concentration on the growth and lipid volumetric production of Scenedesmus dimorphus was evaluated using factorial design. While biomass productivity was 12% higher in the bubble column bioreactor (68.2 g_d_w m"−"2 day"−"1), maximum lipid volumetric production (0.19 g_L_i_p_i_d L"−"1) was found in a gas-lift bioreactor sparged with 6% carbon dioxide due to hydrodynamic and light stresses.

A dense cell retention culture system using stirred ceramic membrane reactor.

Science.gov (United States)

Suzuki, T; Sato, T; Kominami, M

1994-11-20

A novel reactor design incorporating porous ceramic tubes into a stirred jar fermentor was developed. The stirred ceramic membrane reactor has two ceramic tubular membrane units inside the vessel and maintains high filtration flux by alternating use for filtering and recovering from clogging. Each filter unit was linked for both extraction of culture broth and gas sparging. High permeability was maintained for long periods by applying the periodical control between filtering and air sparging during the stirred retention culture of Saccharomyces cerevisiae. The ceramic filter aeration system increased the k(L)a to about five times that of ordinary gas sparing. Using the automatic feeding and filtering system, cell mass concentration reached 207 g/L in a short time, while it was 64 g/L in a fed-batch culture. More than 99% of the growing cells were retained in the fermentor by the filtering culture. Both yield and productivity of cells were also increased by controlling the feeding of fresh medium and filtering the supernatant of the dense cells culture. (c) 1994 John Wiley & Sons, Inc.

Performance Analysis of an Integrated Heat Pump with Air-Conditioning System for the Existing Hospital Building Application

Directory of Open Access Journals (Sweden)

Chen-Yu Chiang

2017-03-01

Full Text Available In this study, a complete evaluation procedure of energy-saving and efficiency improvement for a large-scale hospital retrofit project has been established and successfully validated in Taiwan. The retrofit scheme, in integrating the alternative hot water system, namely, a water source heat pump (WSHP, with the existing HVAC (Heating, Ventilating, and Air-Conditioning system, enables the capability to meet the cooling and hot water demand simultaneously with a larger safety margin as well as saving energy. In addition, it has been found that the integrated system provides a new source for cooling which can be utilized as a system redundancy in avoiding system shutdown. This is very useful when considering in specific areas in the hospital, such as intensive care unit, or operation rooms, where cooling should not be interrupted on any occasion. In this study, it is validated that the coefficient of performance (COP of the newly added WSHP system, under heating and cooling mode, is 3.62 and 2.62, respectively. The recorded annual cost reduction by this integrated system is $102,564, with a payback of 1.2 years. The hospital after retrofit has been operating safer, with more redundancy, and more energy-efficient which warrants tremendous potential for implementation in the industry.

Case studies illustrating in-situ remediation methods for soil and groundwater contaminated with petrochemicals

Energy Technology Data Exchange (ETDEWEB)

Dixon, Robert A; Lance, P E; Downs, A; Kier, Brian P [EMCON Northwest Inc., Portland, OR (United States)

1994-12-31

Four case studies of successful in-situ remediation are summarized illustrating cost-effective methods to remediate soil and groundwater contaminated with volatile and non-volatile petrochemicals. Each site is in a different geologic environment with varying soil types and with and without groundwater impact. The methods described include vadose zone vapor extraction, high-vacuum vapor extraction combined with groundwater tab.le depression, air sparging with groundwater recovery and vapor extraction, and bio remediation of saturated zone soils using inorganic nutrient and oxygen addition

Case studies illustrating in-situ remediation methods for soil and groundwater contaminated with petrochemicals

Energy Technology Data Exchange (ETDEWEB)

Dixon, Robert A.; Lance, P.E.; Downs, A.; Kier, Brian P. [EMCON Northwest Inc., Portland, OR (United States)

1993-12-31

Four case studies of successful in-situ remediation are summarized illustrating cost-effective methods to remediate soil and groundwater contaminated with volatile and non-volatile petrochemicals. Each site is in a different geologic environment with varying soil types and with and without groundwater impact. The methods described include vadose zone vapor extraction, high-vacuum vapor extraction combined with groundwater tab.le depression, air sparging with groundwater recovery and vapor extraction, and bio remediation of saturated zone soils using inorganic nutrient and oxygen addition

KDHE Project Code: C6-074-00002: Progress and Monitoring Report for the LDB/SVE/AS System at the Former CCC/USDA Grain Storage Facility, Agra, Kansas, in January-June 2013

Energy Technology Data Exchange (ETDEWEB)

LaFreniere, Lorraine [Argonne National Lab. (ANL), Argonne, IL (United States)

2014-04-01

In 2008-2009, to address the carbon tetrachloride contamination detected on its former property, the CCC/USDA implemented a source area cleanup in accord with the document Interim Measure Work Plan/Design for Agra, Kansas (IMWP/D; Argonne 2008). The cleanup involves five large-diameter boreholes (LDBs) coupled with soil vapor extraction (SVE) and air sparging (AS). The work plan was approved by the Kansas Department of Health and Environment (KDHE) in November 2008 (KDHE 2008b), and operation began in May 2009.

Air Traffic Control Tools Assessment

Directory of Open Access Journals (Sweden)

Tomáš Noskievič

2017-04-01

Full Text Available Undoubtedly air transport in today’s world wouldn’t be able to exist without any air traffic control service. As the air transport has been coming through major changes and it has been expanding, it is assumed that its volume will be doubled in the next 15 years. Air traffic control uses strictly organised procedures to ensure safe course of air operations. With the skies covered with more airplanes every year, new tools must be introduced to allow the controllers to manage this rising amount of flying aircraft and to keep the air transport safe. This paper provides a comprehensive and organized material, which describes the newest tools and systems used by air traffic control officers. It proposes improvements for further research and development of ATC tools.

Air pollution meteorology

Energy Technology Data Exchange (ETDEWEB)

Shirvaikar, V V; Daoo, V J [Environmental Assessment Div., Bhabha Atomic Research Centre, Mumbai (India)

2002-06-01

This report is intended as a training cum reference document for scientists posted at the Environmental Laboratories at the Nuclear Power Station Sites and other sites of the Department of Atomic Energy with installations emitting air pollutants, radioactive or otherwise. Since a manual already exists for the computation of doses from radioactive air pollutants, a general approach is take here i.e. air pollutants in general are considered. The first chapter presents a brief introduction to the need and scope of air pollution dispersion modelling. The second chapter is a very important chapter discussing the aspects of meteorology relevant to air pollution and dispersion modelling. This chapter is important because without this information one really does not understand the phenomena affecting dispersion, the scope and applicability of various models or their limitations under various weather and site conditions. The third chapter discusses the air pollution models in detail. These models are applicable to distances of a few tens of kilometres. The fourth chapter discusses the various aspects of meteorological measurements relevant to air pollution. The chapters are followed by two appendices. Apendix A discusses the reliability of air pollution estimates. Apendix B gives some practical examples relevant to general air pollution. It is hoped that the document will prove very useful to the users. (author)

Evaluating natural radiation level by existing airborne radioactive data

International Nuclear Information System (INIS)

Mingkao, Hu; Changqing, Han; Jiangqi, Fang; Zhengxin, Shen

2002-01-01

Airborne Survey and Remote Sensing Center of Nuclear Industry, founded in the middle of 1950s, is a unique unit specialized in uranium exploration by airborne radioactive survey in China. Large numbers of airborne data of radioactivity and abundant experience have been accumulated for more than 40 years. All-round detailed investigation of environmental radiation levels in our country will not be completed in the near future. Thus, at present it is considered to evaluate natural radiation levels using the existing radioactive data. This paper introduces the results of analysis and study comparing airborne radioactive data for radiation environmental evaluation obtained from survey area in Gansu, China, in the 2001 with the measurement results by ground gamma ray radiation dose-rate instrument for environment. The air-earth inter-comparison error does not exceed 30% at radiation fields with a definite area, and the air-earth inter-comparison error does not exceed 60% at outcrop of granite. In 6km long profile that has various circumstances, such as desert, Gobi, farmland and residential area, minimum of air absorbed dose rate is 47nGy/h at an altitude of 1 meter above the soil plane, maximum is 68nGy/h. The inter-comparison errors are usually less than 20%, and maximum is 25.38%. This shows that it is feasible to obtain natural radiation levels rapidly if we could use the existing radioactive data adequately and make some correction, such as geology factor

Reevaluation of air surveillance station siting

International Nuclear Information System (INIS)

Abbott, K.; Jannik, T.

2016-01-01

DOE Technical Standard HDBK-1216-2015 (DOE 2015) recommends evaluating air-monitoring station placement using the analytical method developed by Waite. The technique utilizes wind rose and population distribution data in order to determine a weighting factor for each directional sector surrounding a nuclear facility. Based on the available resources (number of stations) and a scaling factor, this weighting factor is used to determine the number of stations recommended to be placed in each sector considered. An assessment utilizing this method was performed in 2003 to evaluate the effectiveness of the existing SRS air-monitoring program. The resulting recommended distribution of air-monitoring stations was then compared to that of the existing site perimeter surveillance program. The assessment demonstrated that the distribution of air-monitoring stations at the time generally agreed with the results obtained using the Waite method; however, at the time new stations were established in Barnwell and in Williston in order to meet requirements of DOE guidance document EH-0173T.

Reevaluation of air surveillance station siting

Energy Technology Data Exchange (ETDEWEB)

Abbott, K. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Jannik, T. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

2016-07-06

DOE Technical Standard HDBK-1216-2015 (DOE 2015) recommends evaluating air-monitoring station placement using the analytical method developed by Waite. The technique utilizes wind rose and population distribution data in order to determine a weighting factor for each directional sector surrounding a nuclear facility. Based on the available resources (number of stations) and a scaling factor, this weighting factor is used to determine the number of stations recommended to be placed in each sector considered. An assessment utilizing this method was performed in 2003 to evaluate the effectiveness of the existing SRS air-monitoring program. The resulting recommended distribution of air-monitoring stations was then compared to that of the existing site perimeter surveillance program. The assessment demonstrated that the distribution of air-monitoring stations at the time generally agreed with the results obtained using the Waite method; however, at the time new stations were established in Barnwell and in Williston in order to meet requirements of DOE guidance document EH-0173T.

Uncertainties in emission estimates of greenhouse gases and air pollutants in China and India and their impacts on regional air quality

Science.gov (United States)

Saikawa, E.; Trail, M.; Young, C. L.; Zhong, M.; Avramov, A.; Kim, H.; Wu, Q.; Janssens-Maenhout, G. G. A.; Kurokawa, J. I.; Klimont, Z.; Wagner, F.; Naik, V.; Horowitz, L. W.; Zhao, Y.; Nagpure, A.; Gurjar, B.; Zhang, Q.

2017-12-01

Greenhouse gas and air pollutant precursor emissions have been increasing rapidly in both China and India, resulting in local to regional scale effects on air quality. Modelers use emission inventories to represent the temporal and spatial distribution of impacts of air pollutant emissions on regional and global air quality. However, large uncertainties exist in emission inventories. Quantification of uncertainties in emission estimates is essential to better understand the linkages among emissions, air quality, climate, and health. We use Monte Carlo methods to assess the uncertainties of the existing carbon dioxide (CO2), carbon monoxide (CO), sulfur dioxide (SO2), nitrogen oxides (NOx), and particulate matter (PM) emission estimates for both China and India. We focus on the period between 2000 and 2008. In addition to national totals, we also analyze emissions from four source sectors, including industry, transport, power, and residential. We also assess differences in the existing emission estimates within each of the subnational regions. We find large disagreements among the existing inventories at disaggregated levels. We further assess the impact of these differences in emissions on air quality using a chemical transport model. More efforts are needed to constrain emissions, especially in the Indo-Gangetic Plains and in the East and Central regions of China, where large differences across emission inventories result in concomitant large differences in the simulated concentrations of PM and ozone. Our study also highlights the importance of constraining SO2, NOx, and NH3 emissions for secondary PM concentrations over China and India.

The results of air treatment process modeling at the location of the air curtain in the air suppliers and ventilation shafts

Directory of Open Access Journals (Sweden)

Nikolaev Aleksandr

2017-01-01

Full Text Available In the existing shaft air heater installations (AHI, that heat the air for air suppliers in cold seasons, a heater channel is used. Some parts of the air from the heater go to the channel, other parts are sucked through a pithead by the general shaft pressure drawdown formed by the main ventilation installation (MVI. When this happens, a mix of two air flows leads to a shaft heat regime violation that can break pressurization of intertubular sealers. The problem of energy saving while airing underground mining enterprises is also very important. The proposed solution of both tasks due to the application of an air curtain is described in the article. In cold seasons the air treatment process should be used and it is offered to place an air curtain in the air suppliers shaft above the place of interface of the calorifer channel to a trunk in order to avoid an infiltration (suction of air through the pithead. It’s recommended to use an air curtain in a ventilation shaft because it reduces external air leaks thereby improving energy efficiency of the MVI work. During the mathematical modeling of ventilation and air preparation process (in SolidWorks Flowsimulation software package it was found out that the use of the air curtain in the air supply shaft can increase the efficiency of the AHI, and reduce the electricity consumption for ventilation in the ventilation shaft.

INDOOR AIR POLLUTION

Directory of Open Access Journals (Sweden)

Ahmet Soysal

2007-06-01

Full Text Available The existance of hazardious materials including biological, chemical, and physical agents such as carbon dioxide, carbon monoxide, sulphur dioxide, nitrogen oxides, radon, volotile organic compounds, microorganisms in houses and the other non-industrilized buildings have been defined as “indoor air pollution”. Indoor air pollutants could possible arised from inside or outside environment and categorized into six subgroups. Almost 80% Turkish population have living in the urban areas and people in the cities have spending approximetely 90% of their time in the closed enviroments, health problems could increased due to indoor air pollution. Moreover, currently there is no specific regulation on this area. [TAF Prev Med Bull 2007; 6(3.000: 221-226

INDOOR AIR POLLUTION

Directory of Open Access Journals (Sweden)

Ahmet Soysal

2007-06-01

Full Text Available The existance of hazardious materials including biological, chemical, and physical agents such as carbon dioxide, carbon monoxide, sulphur dioxide, nitrogen oxides, radon, volotile organic compounds, microorganisms in houses and the other non-industrilized buildings have been defined as “indoor air pollution”. Indoor air pollutants could possible arised from inside or outside environment and categorized into six subgroups. Almost 80% Turkish population have living in the urban areas and people in the cities have spending approximetely 90% of their time in the closed enviroments, health problems could increased due to indoor air pollution. Moreover, currently there is no specific regulation on this area. [TAF Prev Med Bull. 2007; 6(3: 221-226

Correlation of Air Quality Data to Ultrafine Particles (UFP Concentration and Size Distribution in Ambient Air

Directory of Open Access Journals (Sweden)

Werner Hofmann

2010-07-01

Full Text Available This study monitored ultrafine particles (UFP concurrent with environmental air quality data, investigating whether already existing instrumentation used by environmental authorities can provide reference values for estimating UFP concentrations. Of particular interest was the relation of UFP to PM10 (particulate matter and nitrogen oxides (NOx, NO2 in ambient air. Existing PM measurement methods alone did not correspond exactly enough with the actual particle number, but we observed a link between NOx and NO2 to UFP concentration. The combined data could act as proxy-indicator for authorities in estimating particle number concentrations, but cannot replace UFP monitoring.

Anaerobic dynamic membrane bioreactors for high strength wastewater treatment

NARCIS (Netherlands)

Ersahin, M.E.; Gimenez Garcia, J.B.; Ozgun, H.; Tao, Y.; Van Lier, J.B.

2013-01-01

A laboratory scale external anaerobic dynamic membrane bioreactor (AnDMBR) treating high strength wastewater was operated to assess the effect of gas sparging velocity and organic loading rate on removal efficiency and dynamic membrane (DM) filtration characteristics. An increase in gas sparging

KDHE POroject Code: C6-074-00002: Progress and Monitoring Report for the LBD/SVE/AS System at the Former CCC/USDA Grain Storage Facility, Agra, Kansas, in January-June 2016

Energy Technology Data Exchange (ETDEWEB)

LaFreniere, Lorraine M. [Argonne National Lab. (ANL), Argonne, IL (United States)

2016-09-01

In 2008-2009, to address the carbon tetrachloride contamination detected on its former property, the CCC/USDA implemented a source area cleanup in accord with the document Interim Measure Work Plan/Design for Agra, Kansas (IMWP/D; Argonne 2008). The cleanup involves five large-diameter boreholes (LDBs) coupled with soil vapor extraction (SVE) and air sparge (AS) systems. The work plan was approved by the Kansas Department of Health and Environment (KDHE) in November 2008 (KDHE 2008b), and operation began in May 2009.

KDHE Project Code: C6-074-00002: Progress and Monitoring Report for the LDB/SVE/AS System at the Former CCC/USDA Grain Storage Facility, Agra, Kansas, in January-June 2015

Energy Technology Data Exchange (ETDEWEB)

LaFreniere, Lorraine M. [Argonne National Lab. (ANL), Argonne, IL (United States)

2015-09-01

In 2008-2009, to address the carbon tetrachloride contamination detected on its former property, the CCC/USDA implemented a source area cleanup in accord with the document Interim Measure Work Plan/Design for Agra, Kansas (IMWP/D; Argonne 2008). The cleanup involves five large-diameter boreholes (LDBs) coupled with soil vapor extraction (SVE) and air sparge (AS) systems. The work plan was approved by the Kansas Department of Health and Environment (KDHE) in November 2008 (KDHE 2008b), and operation began in May 2009.

Management of industrial sulfur dioxide and nitrogen oxides emissions in Alberta - description of the existing system

International Nuclear Information System (INIS)

Macdonald, W.S.; Bietz, B.F.

1999-01-01

In addition to being key primary air contaminants, sulfur dioxide and nitrogen oxides are also major contributors to acidic deposition. The current management system for controlling industrial sources of SO(2) and NO(x) emissions in Alberta was developed in the late 1960s/early 1970s. The focus is on control of point source emissions through the use of appropriate technology. The approach taken for managing SO(2) and NO(x) emissions is similar to the approach taken to other industrial air and wastewater pollutants in Alberta. It is a command and control regulatory system. There are three main industry categories in Alberta which emit SO(2): sour gas processing, oil sand plants and thermal power plants. For NO(x) emissions, the two main categories with emissions: are natural gas production and thermal power plants. The two main goals of the existing industrial air quality management systems are to ensire that: (1) emissions from industrial facilities are minimized through the use of best available demonstrated technology, and (2) ambient levels of air contaminants in the vicinity of industrial facilities do not exceed Alberta guidelines. The four main policies which support these two goals of the existing management system are described. There are a number of key components of the existing management system including: ambient guideline levels, source emission standards, plume dispersion modelling, ambient air and source emission monitoring, environmental reporting, emission inventories, and approvals. 32 refs., 13 figs

Air Pollution Potential from Electroplating Operations.

Science.gov (United States)

Diamond, Philip

Measurements were made of emission rates from electroplating operations considered to have maximum air pollution potential. Sampling was performed at McClellan and additional data from a previous survey at Hill Air Force Base was used. Values obtained were extremely low. Based on existing Federal standards, no collectors are specifically required…

[Establishment of Assessment Method for Air Bacteria and Fungi Contamination].

Science.gov (United States)

Zhang, Hua-ling; Yao, Da-jun; Zhang, Yu; Fang, Zi-liang

2016-03-15

In this paper, in order to settle existing problems in the assessment of air bacteria and fungi contamination, the indoor and outdoor air bacteria and fungi filed concentrations by impact method and settlement method in existing documents were collected and analyzed, then the goodness of chi square was used to test whether these concentration data obeyed normal distribution at the significant level of α = 0.05, and combined with the 3σ principle of normal distribution and the current assessment standards, the suggested concentrations ranges of air microbial concentrations were determined. The research results could provide a reference for developing air bacteria and fungi contamination assessment standards in the future.

Growth of the obligate anaerobe Desulfovibrio vulgaris Hildenborough under continuous low oxygen concentration sparging: impact of the membrane-bound oxygen reductases.

Science.gov (United States)

Ramel, Fanny; Brasseur, Gael; Pieulle, Laetitia; Valette, Odile; Hirschler-Réa, Agnès; Fardeau, Marie Laure; Dolla, Alain

2015-01-01

Although obligate anaerobe, the sulfate-reducing bacterium Desulfovibrio vulgaris Hildenborough (DvH) exhibits high aerotolerance that involves several enzymatic systems, including two membrane-bound oxygen reductases, a bd-quinol oxidase and a cc(b/o)o3 cytochrome oxidase. Effect of constant low oxygen concentration on growth and morphology of the wild-type, single (Δbd, Δcox) and double deletion (Δcoxbd) mutant strains of the genes encoding these oxygen reductases was studied. When both wild-type and deletion mutant strains were cultured in lactate/sulfate medium under constant 0.02% O2 sparging, they were able to grow but the final biomasses and the growth yield were lower than that obtained under anaerobic conditions. At the end of the growth, lactate was not completely consumed and when conditions were then switched to anaerobic, growth resumed. Time-lapse microscopy revealed that a large majority of the cells were then able to divide (over 97%) but the time to recover a complete division event was longer for single deletion mutant Δbd than for the three other strains. Determination of the molar growth yields on lactate suggested that a part of the energy gained from lactate oxidation was derived toward cells protection/repairing against oxidative conditions rather than biosynthesis, and that this part was higher in the single deletion mutant Δbd and, to a lesser extent, Δcox strains. Our data show that when DvH encounters oxidative conditions, it is able to stop growing and to rapidly resume growing when conditions are switched to anaerobic, suggesting that it enters active dormancy sate under oxidative conditions. We propose that the pyruvate-ferredoxin oxidoreductase (PFOR) plays a central role in this phenomenon by reversibly switching from an oxidative-sensitive fully active state to an oxidative-insensitive inactive state. The oxygen reductases, and especially the bd-quinol oxidase, would have a crucial function by maintaining reducing conditions

Growth of the obligate anaerobe Desulfovibrio vulgaris Hildenborough under continuous low oxygen concentration sparging: impact of the membrane-bound oxygen reductases.

Directory of Open Access Journals (Sweden)

Fanny Ramel

Full Text Available Although obligate anaerobe, the sulfate-reducing bacterium Desulfovibrio vulgaris Hildenborough (DvH exhibits high aerotolerance that involves several enzymatic systems, including two membrane-bound oxygen reductases, a bd-quinol oxidase and a cc(b/oo3 cytochrome oxidase. Effect of constant low oxygen concentration on growth and morphology of the wild-type, single (Δbd, Δcox and double deletion (Δcoxbd mutant strains of the genes encoding these oxygen reductases was studied. When both wild-type and deletion mutant strains were cultured in lactate/sulfate medium under constant 0.02% O2 sparging, they were able to grow but the final biomasses and the growth yield were lower than that obtained under anaerobic conditions. At the end of the growth, lactate was not completely consumed and when conditions were then switched to anaerobic, growth resumed. Time-lapse microscopy revealed that a large majority of the cells were then able to divide (over 97% but the time to recover a complete division event was longer for single deletion mutant Δbd than for the three other strains. Determination of the molar growth yields on lactate suggested that a part of the energy gained from lactate oxidation was derived toward cells protection/repairing against oxidative conditions rather than biosynthesis, and that this part was higher in the single deletion mutant Δbd and, to a lesser extent, Δcox strains. Our data show that when DvH encounters oxidative conditions, it is able to stop growing and to rapidly resume growing when conditions are switched to anaerobic, suggesting that it enters active dormancy sate under oxidative conditions. We propose that the pyruvate-ferredoxin oxidoreductase (PFOR plays a central role in this phenomenon by reversibly switching from an oxidative-sensitive fully active state to an oxidative-insensitive inactive state. The oxygen reductases, and especially the bd-quinol oxidase, would have a crucial function by maintaining

Air congestion delay: a review

Directory of Open Access Journals (Sweden)

Daniel Alberto Pamplona

2016-04-01

Full Text Available This article is a literature review of the air congestion delay and its costs. Air congestion is a worldwide problem. Its existence brings costs for airlines and discomfort for passengers. With the increasing demand for air transport, the study of air congestion has attracted the attention of many researchers around the world. The cause for the delays is erroneously attributed only to the lack of infrastructure investments. The literature review shows that other factors such as population growth, increasing standards of living, lack of operational planning and environmental issues exercise decisive influence. Several studies have been conducted in order to analyze and propose solutions to this problem that affects society as a whole.

Indoor air quality

International Nuclear Information System (INIS)

Hollowell, C.D.

1981-06-01

Rising energy prices, among other factors, have generated an incentive to reduce ventilation rates and thereby reduce the cost of heating and cooling buildings. Reduced ventilation in buildings may significantly increase exposure to indoor air pollution and perhaps have adverse effects on occupant health and comfort. Preliminary findings suggest that reduced ventilation may adversely affect indoor air quality unless appropriate control strategies are undertaken. The strategies used to control indoor air pollution depend on the specific pollutant or class of pollutants encountered, and differ somewhat depending on whether the application is to an existing building or a new building under design and construction. Whenever possible, the first course of action is prevention or reduction of pollutant emissions at the source. In most buildings, control measures involve a combination of prevention, removal, and suppression. Common sources of indoor air pollution in buildings, the specific pollutants emitted by each source, the potential health effects, and possible control techniques are discussed

Baltimore Air Toxics Study (BATS)

Energy Technology Data Exchange (ETDEWEB)

Sullivan, D.A. [Sullivan Environmental Consulting, Inc., Alexandria, VA (United States)

1996-12-31

The Baltimore Air Toxics Study is one of the three urban air toxics initiatives funded by EPA to support the development of the national air toxics strategy. As part of this project, the Air Quality Integrated Management System (AIMS) is under development. AIMS is designed to bring together the key components of urban air quality management into an integrated system, including emissions assessment, air quality modeling, and air quality monitoring. Urban area source emissions are computed for a wide range of pollutants and source categories, and are joined with existing point source emissions data. Measured air quality data are used to evaluate the adequacy of the emissions data and model treatments as a function of season, meteorological parameters, and daytime/nighttime conditions. Based on tested model performance, AIMS provides the potential to improve the ability to predict air quality benefits of alternative control options for criteria and toxic air pollutants. This paper describes the methods used to develop AIMS, and provides examples from its application in the Baltimore metropolitan area. The use of AIMS in the future to enhance environmental management of major industrial facilities also will be addressed in the paper.

Experimental study of air distribution and ventilation effectiveness in a room heated by warm air and/or floor heating

DEFF Research Database (Denmark)

Simone, Angela; Olesen, Bjarne W.; Krajčík, Michal

2010-01-01

The levels of required ventilation depend on the criteria for indoor air quality in existing standards and guidelines. On top of that, the resulting ventilation in air changes per hour is depending on the ventilation effectiveness. In the standard CR 1752 the recommended values for ventilation ef...

Site remediation using biological processes

International Nuclear Information System (INIS)

Lei, J.; Sansregret, J.L.; Cyr, B.; Pouliot, Y.

1995-01-01

The main process used in the bioremediation of contaminated sites is the microbial degradation and mineralization of pollutants. The bioengineering processes developed and applied by the company to optimize the microbial degradation are described and full scale case studies are reviewed. In each case, the site characteristics (type of contaminants, nature of soil, geographic location, etc.) and the results obtained are presented. The selected projects cover different bioremediation techniques (biopile, bioventing and air sparging), different contaminants (PAH, PCP, hydrocarbons) and different types of industrial sites (former gas work plant, petroleum depot, refinery, etc.)

Setting priorities for ambient air quality objectives

International Nuclear Information System (INIS)

2004-10-01

Alberta has ambient air quality objectives in place for several pollutants, toxic substances and other air quality parameters. A process is in place to determine if additional air quality objectives are required or if existing objectives should be changed. In order to identify the highest priority substances that may require an ambient air quality objective to protect ecosystems and public health, a rigorous, transparent and cost effective priority setting methodology is required. This study reviewed, analyzed and assessed successful priority setting techniques used by other jurisdictions. It proposed an approach for setting ambient air quality objective priorities that integrates the concerns of stakeholders with Alberta Environment requirements. A literature and expert review were used to examine existing priority-setting techniques used by other jurisdictions. An analysis process was developed to identify the strengths and weaknesses of various techniques and their ability to take into account the complete pathway between chemical emissions and damage to human health or the environment. The key strengths and weaknesses of each technique were identified. Based on the analysis, the most promising technique was the tool for the reduction and assessment of chemical and other environmental impacts (TRACI). Several considerations for using TRACI to help set priorities for ambient air quality objectives were also presented. 26 refs, 8 tabs., 4 appendices

The Improvement of the Ventilation System in the Existing Terraced Houses in Malaysia

Directory of Open Access Journals (Sweden)

Arab Yasser

2016-01-01

Full Text Available This study aims to find a sustainable solution in order to reduce the indoor temperature in hot and humid climate such as Malaysia. The focus of this study is to create a new device (Air Tube which is considered to be a remedial device for the indoor spaces, and can be installed for the existed houses. The method of this study is to design the Air Tube device and install is in the rooms of second floor in semi-detached and terrace house in order to reduce the temperature few degrees. The study will depend on taking manual measurements in the site and making simulation using computer software Ecotect on 14th of February (which considered to be the hottest day in the year and trying to find the best solution to reduce the temperature in such hot and humid weather, the case study is a semi-detach house with post-modern architectural style, which is located in Sungai Petani, Kedah, Malaysia. The research finds that AirTubeis a good solution for the existed houses to decrease the temperature and reach the thermal comfortable atmosphere.

The user's influence on air change

International Nuclear Information System (INIS)

Kvisgaard, B.; Collet, P.F.

1990-01-01

Of the various parameters deciding the air change in a building, the influence of wind and the stack effect have in particular been focused on. Concurrently, with the increase in quality of buildings and the tightening of existing buildings, the influence of the climatic parameters is reduced, and other parameters gain a greater influence on the air change. One of the parameters having a great influence on the air change in tight buildings are the users. The air change rate is greatly influenced by the users not only in naturally ventilated buildings, but also in mechanically ventilated buildings. On the basis of continuous measurement of the air change in 28 dwellings, the proportion between the total air change (air change in house with occupants) and the basic air change (air change in a sealed house) is discussed. The air change in each of the dwellings has been measured for a period of about one week during occupancy. The measuring principle applied is the method with constant concentration of tracer gas

Transient Air-Water Flow and Air Demand following an Opening Outlet Gate

Directory of Open Access Journals (Sweden)

James Yang

2018-01-01

Full Text Available In Sweden, the dam-safety guidelines call for an overhaul of many existing bottom outlets. During the opening of an outlet gate, understanding the transient air-water flow is essential for its safe operation, especially under submerged tailwater conditions. Three-dimensional CFD simulations are undertaken to examine air-water flow behaviors at both free and submerged outflows. The gate, hoisted by wire ropes and powered by AC, opens at a constant speed. A mesh is adapted to follow the gate movement. At the free outflow, the CFD simulations and model tests agree well in terms of outlet discharge capacity. Larger air vents lead to more air supply; the increment becomes, however, limited if the vent area is larger than 10 m2. At the submerged outflow, a hydraulic jump builds up in the conduit when the gate reaches approximately 45% of its full opening. The discharge is affected by the tailwater and slightly by the flow with the hydraulic jump. The flow features strong turbulent mixing of air and water, with build-up and break-up of air pockets and collisions of defragmented water bodies. The air demand rate is several times as much as required by steady-state hydraulic jump with free surface.

Improving the angular resolution of existing air shower arrays by adding a thin layer of lead

International Nuclear Information System (INIS)

Poirier, J.; Mikocki, S.

1987-01-01

Calculations show that placing a thin sheet of lead above conventional extensive air shower counters yields an additional signal which is earlier in time. This will improve the array's angular resolution. (orig.)

Applications Using AIRS Data

Science.gov (United States)

Ray, S. E.; Pagano, T. S.; Fetzer, E. J.; Lambrigtsen, B.; Olsen, E. T.; Teixeira, J.; Licata, S. J.; Hall, J. R.; Thompson, C. K.

2015-12-01

The Atmospheric Infrared Sounder (AIRS) on NASA's Aqua spacecraft has been returning daily global observations of Earth's atmospheric constituents and properties since 2002. With a 12-year data record and daily, global observations in near real-time, AIRS data can play a role in applications that fall under many of the NASA Applied Sciences focus areas. For vector-borne disease, research is underway using AIRS near surface retrievals to assess outbreak risk, mosquito incubation periods and epidemic potential for dengue fever, malaria, and West Nile virus. For drought applications, AIRS temperature and humidity data are being used in the development of new drought indicators and improvement in the understanding of drought development. For volcanic hazards, new algorithms using AIRS data are in development to improve the reporting of sulfur dioxide concentration, the burden and height of volcanic ash and dust, all of which pose a safety threat to aircraft. In addition, anomaly maps of many of AIRS standard products are being produced to help highlight "hot spots" and illustrate trends. To distribute it's applications imagery, AIRS is leveraging existing NASA data frameworks and organizations to facilitate archiving, distribution and participation in the BEDI. This poster will communicate the status of the applications effort for the AIRS Project and provide examples of new maps designed to best communicate the AIRS data.

Acceptance test report for 241-AW process air system

International Nuclear Information System (INIS)

Kostelnik, A.J.

1994-01-01

The acceptance test procedure (ATP) for the compressed air system at building 241-AW-273 was completed on March 11, 1993. The system was upgraded to provide a reliable source of compressed air to the tank farm. The upgrade included the demolition of the existing air compressor and associated piping, as well as the installation of a new air compressor with a closed loop cooling system. A compressed air cross-tie was added to allow the process air compressor to function as a back-up to the existing instrument air compressor. The purpose of the ATP was to achieve three primary objectives: verify system upgrade in accordance with the design media; provide functional test of system components and controls; and prepare the system for the Operational Test. The ATP was successfully completed with thirteen exceptions, which were resolved prior to completing the acceptance test. The repaired exceptions had no impact to safety or the environment and are briefly summarized. Testing ensured that the system was installed per design, that its components function as required and that it is ready for operational testing and subsequent turnover to operations

Biomonitoring of air quality using plants

Energy Technology Data Exchange (ETDEWEB)

Mulgrew, A.; Williams, P. [King' s Coll., London (United Kingdom). Monitoring and Assessment Research Centre - WHO Collaborating Centre for Monitoring and Assessment

2000-02-01

This report is an update of the MARC Report No. 32 'Biological Monitoring' and a first volume referring to a WHO project on biological monitoring. The monograph reviews comprehensively the existing literature on biological monitoring of air quality with plants. This review includes consideration of all plant species that are currently, or have a potential of, being used as bioindicators of air pollution. This review is intended to serve as a background paper for the derivation of guidelines for the use of biological monitors in air pollution control. (orig.)

Biomonitoring of air quality using plants

Energy Technology Data Exchange (ETDEWEB)

Mulgrew, A; Williams, P [King' s Coll., London (United Kingdom). Monitoring and Assessment Research Centre - WHO Collaborating Centre for Monitoring and Assessment

2000-02-01

This report is an update of the MARC Report No. 32 'Biological Monitoring' and a first volume referring to a WHO project on biological monitoring. The monograph reviews comprehensively the existing literature on biological monitoring of air quality with plants. This review includes consideration of all plant species that are currently, or have a potential of, being used as bioindicators of air pollution. This review is intended to serve as a background paper for the derivation of guidelines for the use of biological monitors in air pollution control. (orig.)

The landscape of existing models for high-throughput exposure assessment

DEFF Research Database (Denmark)

Jolliet, O.; Fantke, Peter; Huang, L.

2017-01-01

and ability to easily handle large datasets. For building materials a series of diffusion-based models have been developed to predict the chemicals emissions from building materials to indoor air, but existing models require complex analytical or numerical solutions, which are not suitable for LCA or HTS...... applications. Thus, existing model solutions needed to be simplified for application in LCA and HTS, and a parsimonious model has been developed by Huang et al. (2017) to address this need. For SVOCs, simplified solutions do exist, assuming constant SVOC concentrations in building materials and steadystate...... for skin permeation and volatilization as competing processes and that requires a limited number of readily available physiochemical properties would be suitable for LCA and HTS purposes. Thus, the multi-pathway exposure model for chemicals in cosmetics developed by Ernstoff et al.constitutes a suitable...

Indoor Air Quality: A Guide for Educators.

Science.gov (United States)

California State Dept. of Education, Sacramento.

Indoor air quality is a major concern for educators involved in the development of new school facilities, or the remodeling and maintenance of existing ones. This guide addresses the issue of air quality, the health concerns involved, and procedures for minimizing the impact of pollutants in the school environment. It defines common indoor air…

Overview of ambient air quality monitoring in South Africa

CSIR Research Space (South Africa)

Naidoo, M

2006-10-01

Full Text Available Air quality data is currently collected, processed and archived by a number of independent institutes. No collaboration exists between these organisations and there is no provincial or national air quality data information system or archive...

Air ventilation/controlling facility

Energy Technology Data Exchange (ETDEWEB)

Yoshikawa, Kazuhiro; Kinoshita, Shoichiro

1997-12-12

When all electricity supply from the outside of a power plant are lost, a power generator directly connected to an emergency steam turbine which is driven by steams introduced from a nuclear reactor is driven to supply electricity required in the power plant. Cool water prepared by a refrigerator is used as cooling water in an air ventilation/controlling facility of a room equipped with the power generating facility. As the refrigerator, a refrigerator of an existent emergency air cooling water system for an auxiliary air ventilation/controlling equipment is used. This can extend the period of time till the temperature of the room where the power generator is disposed exceeds the temperature range capable of keeping the integrity of the power generator even when all the AC power supply are lost to inactivate the function of the air ventilation/controlling system. (I.S.)

Climate Strategy with CO2 Capture from the Air

Energy Technology Data Exchange (ETDEWEB)

Keith, D.W. [Department of Chemical and Petroleum Engineering, University of Calgary, 2500 University Drive NW, Calgary, AB (Canada); Ha-Duong, M. [CNRS-CIRED, Campus du Jardin Tropical, 45 bis, av. de la Belle Gabrielle, 94736 Nogent sur Marne CEDEX (France); Stolaroff, J.K. [Department of Engineering and Public Policy, Carnegie Mellon University, 5000 Forbes Ave, Pittsburgh, PA 15213 (United States)

2006-01-15

It is physically possible to capture CO2 directly from the air and immobilize it in geological structures. Air capture differs from conventional mitigation in three key aspects. First, it removes emissions from any part of the economy with equal ease or difficulty, so its cost provides an absolute cap on the cost of mitigation. Second, it permits reduction in concentrations faster than the natural carbon cycle: the effects of irreversibility are thus partly alleviated. Third, because it is weakly coupled to existing energy infrastructure, air capture may offer stronger economies of scale and smaller adjustment costs than the more conventional mitigation technologies. We assess the ultimate physical limits on the amount of energy and land required for air capture and describe two systems that might achieve air capture at prices under 200 and 500 $/tC using current technology. Like geoengineering, air capture limits the cost of a worst-case climate scenario. In an optimal sequential decision framework with uncertainty, existence of air capture decreases the need for near-term precautionary abatement. The long-term effect is the opposite; assuming that marginal costs of mitigation decrease with time while marginal climate change damages increase, then air capture increases long-run abatement. Air capture produces an environmental Kuznets curve, in which concentrations are returned to preindustrial levels.

The Air Force and Diversity: The Awkward Embrace

Science.gov (United States)

2014-06-01

diversity across the force. Table. Reasons for leaving the Air Force (2002 data) Reasons for Leaving the Air Force % Critical/Significant Factor % Not a... source in which members pro- vide reasons that women officers leave as well as possible solutions. May–June 2014 Air & Space Power Journal | 122...response, including the time for reviewing instructions, searching existing data sources , gathering and maintaining the data needed, and completing and

Air Layer Drag Reduction

Science.gov (United States)

Ceccio, Steven; Elbing, Brian; Winkel, Eric; Dowling, David; Perlin, Marc

2008-11-01

A set of experiments have been conducted at the US Navy's Large Cavitation Channel to investigate skin-friction drag reduction with the injection of air into a high Reynolds number turbulent boundary layer. Testing was performed on a 12.9 m long flat-plate test model with the surface hydraulically smooth and fully rough at downstream-distance-based Reynolds numbers to 220 million and at speeds to 20 m/s. Local skin-friction, near-wall bulk void fraction, and near-wall bubble imaging were monitored along the length of the model. The instrument suite was used to access the requirements necessary to achieve air layer drag reduction (ALDR). Injection of air over a wide range of air fluxes showed that three drag reduction regimes exist when injecting air; (1) bubble drag reduction that has poor downstream persistence, (2) a transitional regime with a steep rise in drag reduction, and (3) ALDR regime where the drag reduction plateaus at 90% ± 10% over the entire model length with large void fractions in the near-wall region. These investigations revealed several requirements for ALDR including; sufficient volumetric air fluxes that increase approximately with the square of the free-stream speed, slightly higher air fluxes are needed when the surface tension is reduced, higher air fluxes are required for rough surfaces, and the formation of ALDR is sensitive to the inlet condition.

''Z'' Facility Dielectric Oil Clean-Up

International Nuclear Information System (INIS)

Alessandri, Daniel; Bloomquist, Doug; Donovan, Guy; Feltz, Greg; Grelle, Nibby; Guthrie, Doug; Harris, Mark; Horry, Mike; Lockas, Mike; Potter, Jimmy; Pritchard, Chuck; Steedly, Jim.

1999-01-01

In August of 1998 the Z facility leaked approximately 150 gallons of deionized water into the dielectric oil of the Energy Storage Section (ESS). After processing the oil to remove existing particulate and free water the dielectric breakdown strength increased from the mid 20kV range to values in excess of 40 kV. 40 kV is above historical operating levels of about 35 kV. This, however, was not enough to allow 90 kV charging of the Marx Generators in the ESS. Further analysis of the oil showed dissolved water at a saturated level (70 - 80 ppm) and some residual particulate contamination smaller than 3 microns. The dissolved water and particulate combination was preventing the 90 kV charging of the Marx Generators in the ESS. After consulting with the oil industry it was determined that nitrogen sparging could be used to remove the dissolved water. Further particulate filtering was also conducted. After approximately 20 hours of sparging the water content in the ESS was reduced to 42 ppm which enabled Marx charging to 90 kV

INDOOR AIR QUALITY AND INHALATION EXPOSURE - SIMULATION TOOL KIT

Science.gov (United States)

A Microsoft Windows-based indoor air quality (IAQ) simulation software package is presented. Named Simulation Tool Kit for Indoor Air Quality and Inhalation Exposure, or IAQX for short, this package complements and supplements existing IAQ simulation programs and is desi...

Air Pollution Manual, Part 1--Evaluation. Second Edition.

Science.gov (United States)

Giever, Paul M., Ed.

Due to the great increase in technical knowledge and improvement in procedures, this second edition has been prepared to update existing information. Air pollution legislation is reviewed. Sources of air pollution are examined extensively. They are treated in terms of natural sources, man-made sources, metropolitan regional emissions, emission…

Complying with Clean Air Act acid rain provisions: A case history of required air quality analyses

International Nuclear Information System (INIS)

McComb, G.G. Jr.; Naperkoski, G.J.; Rogers, F.A.

1990-01-01

Clean Air Act Amendments being considered by Congress require SO 2 emissions reductions from numerous large power generation sources nationwide. As currently written, these amendments also require that the affected sources must continue to comply with all provisions of the existing Clean Air Act while achieving the required reductions. United Engineers and Constructors is presently assisting utilities in the evaluation of compliance options for units totaling over 18,000 MW. The methods of achieving compliance with the probable requirements of the Act most often include the retrofit installation of SO 2 scrubbers. A study designed to determine permitting issues and the scope of air quality analyses required to demonstrate the regulatory acceptability of installation of wet scrubbing systems has been completed for units totaling a portion of the above-referenced 18,000 MW. The study results show that, under certain commonly occurring circumstances, there is a risk of creating National Ambient Air Quality Standards contraventions for SO 2 and NO 2 when scrubbers are installed at an existing facility. Any such contraventions subject the plant to state and/or federal enforcement actions. In addition, installation of materials handling equipment for lime stone can trigger Prevention of Significant Deterioration requirements as a major modification. This paper is divided into two major areas. The first deals with the air quality regulatory requirements imposed upon installation of pollution control equipment. The first section is further sub-divided into two sections: one covering requirements emanating from the 1977 Clean Air Act Amendments and its implementing regulations and the other the regulatory requirements of the new Clean Air Act Amendments. This section on regulatory requirements provides background information for the understanding of the second major section of the paper which gives the results of the hypothetical case study

Indoor air quality/air infiltration in selected low-energy houses

International Nuclear Information System (INIS)

Shohl Wagner, B.; Phillips, T.J.

1984-01-01

Indoor air quality and air infiltration were measured in 16 low-energy California houses. Eleven has gas stoves; all had average infiltration rates of 0.5 h -1 of less, recent construction dates, low natural ventilation, and no mechanical ventilation. HCHO levels in 12 houses and radon-222 and NO 2 levels in all houses were measured using passive monitors. Blower door measurements and local weather data were used to calculate average infiltration rates during the monitoring period. Correlation of pollutant concentrations with infiltration rates and building characteristics indicate that new houses with average heating season infiltration rates less than 0.5 h -1 do not necessarily experience poor indoor air quality, HCHO and radon-222 levels in new houses exceeded the lowest currently proposed standards or guidelines, and much higher levels probably exist elsewhere. Therefore, some strategy for identifying 'problem' houses is needed. We recommend an approach for future research in this area. (Author)

Measure Guideline. Air Sealing Attics in Multifamily Buildings

Energy Technology Data Exchange (ETDEWEB)

Otis, Casey [Consortium for Advanced Residential Buildings (CARB), Norwalk, CT (United States); Maxwell, Sean [Consortium for Advanced Residential Buildings (CARB), Norwalk, CT (United States)

2012-06-01

This Building America Measure Guideline is intended for owners, builders, contractors, homeowners, and other stakeholders in the multifamily building industry, and focuses on challenges found in existing buildings for a variety of housing types. It explains why air sealing is desirable, explores related health and safety issues, and identifies common air leakage points in multifamily building attics. In addition, it also gives an overview of materials and techniques typically used to perform air sealing work.

Air pollution monitoring - a methodological approach

International Nuclear Information System (INIS)

Trajkovska Trpevska, Magdalena

2002-01-01

Methodology for monitoring the emission of polluters in the air is a complex concept that in general embraces following fazes: sampling, laboratory treatment, and interpretation of results. In Company for technological and laboratory investigation and environmental protection - Mining Institute Skopje, the control of emission of polluters in the air is performing according methodology based in general on the recommendation of standard VDI 2.066 prescribe from Ministry of Ecology in Germany, because adequate legislation in our country does not exist. In this article the basic treatment of methodology for the air polluters emission control is presented. (Original)

Existing Whole-House Solutions Case Study: Retrofitting a 1960s Split-Level Cold-Climate Home

Energy Technology Data Exchange (ETDEWEB)

Puttagunta, S.

2015-08-01

National programs such as Home Performance with ENERGY STAR® and numerous other utility air sealing programs have brought awareness to homeowners of the benefits of energy efficiency retrofits. Yet, these programs tend to focus on the low-hanging fruit: air-sealing the thermal envelope and ductwork where accessible, switch to efficient lighting, and low-flow fixtures. At the other end of the spectrum, deep-energy retrofit programs are also being encouraged by various utilities across the country. While deep energy retrofits typically seek 50% energy savings, they are often quite costly and most applicable to gut-rehab projects. A significant potential for lowering energy usage in existing homes lies between the low hanging fruit and deep energy retrofit approaches - retrofits that save approximately 30% in energy over the existing conditions.

Air pollution control. 3. ed.

International Nuclear Information System (INIS)

Baumbach, G.; Baumann, K.; Droescher, F.; Gross, H.; Steisslinger, B.

1994-01-01

Controlling the pollution of the air is an interdisciplinary problem. This introduction reaches from the origin of hazardous substances via their extension and conversion in the atmosphere, their effects of men, animals, plants and goods up to reduction methods for the various sources. Measuring techniques are one of the main points of interest, as it plays a key role in detecting hazardous substances and monitoring reduction measures. A survey of the history shows the historical dimension of the subject. The prescriptions relating to air pollution control give an impression of the present situation of air pollution control. Currently existing problems such as waste gases from motor vehicles, SO 2 transports, ozone in the ambient air, newly detected sorts of damage to the forests, emission reduction in the burning of fossile fuels, polychloried dibenzodioxins and furanes are dealt with. (orig.). 232 figs [de

Indoor air humidity, air quality, and health - An overview.

Science.gov (United States)

Wolkoff, Peder

2018-04-01

There is a long-standing dispute about indoor air humidity and perceived indoor air quality (IAQ) and associated health effects. Complaints about sensory irritation in eyes and upper airways are generally among top-two symptoms together with the perception "dry air" in office environments. This calls for an integrated analysis of indoor air humidity and eye and airway health effects. This overview has reviewed the literature about the effects of extended exposure to low humidity on perceived IAQ, sensory irritation symptoms in eyes and airways, work performance, sleep quality, virus survival, and voice disruption. Elevation of the indoor air humidity may positively impact perceived IAQ, eye symptomatology, and possibly work performance in the office environment; however, mice inhalation studies do not show exacerbation of sensory irritation in the airways by low humidity. Elevated humidified indoor air appears to reduce nasal symptoms in patients suffering from obstructive apnea syndrome, while no clear improvement on voice production has been identified, except for those with vocal fatigue. Both low and high RH, and perhaps even better absolute humidity (water vapor), favors transmission and survival of influenza virus in many studies, but the relationship between temperature, humidity, and the virus and aerosol dynamics is complex, which in the end depends on the individual virus type and its physical/chemical properties. Dry and humid air perception continues to be reported in offices and in residential areas, despite the IAQ parameter "dry air" (or "wet/humid air") is semantically misleading, because a sensory organ for humidity is non-existing in humans. This IAQ parameter appears to reflect different perceptions among other odor, dustiness, and possibly exacerbated by desiccation effect of low air humidity. It is salient to distinguish between indoor air humidity (relative or absolute) near the breathing and ocular zone and phenomena caused by moisture

Modeling the Environmental Impact of Air Traffic Operations

Science.gov (United States)

Chen, Neil

2011-01-01

There is increased interest to understand and mitigate the impacts of air traffic on the climate, since greenhouse gases, nitrogen oxides, and contrails generated by air traffic can have adverse impacts on the climate. The models described in this presentation are useful for quantifying these impacts and for studying alternative environmentally aware operational concepts. These models have been developed by leveraging and building upon existing simulation and optimization techniques developed for the design of efficient traffic flow management strategies. Specific enhancements to the existing simulation and optimization techniques include new models that simulate aircraft fuel flow, emissions and contrails. To ensure that these new models are beneficial to the larger climate research community, the outputs of these new models are compatible with existing global climate modeling tools like the FAA's Aviation Environmental Design Tool.

Healthy Buildings and Air Distribution in Rooms

DEFF Research Database (Denmark)

Nielsen, Peter V.

Healthy buildings are to a great extent a question of indoor air quality. The processes involved in air quality can be looked upon as a number of links in a chain. Typical links will be emission from building materials, convection and diffusion in the room, local airflow around a person, personal...... exposure and at last the effect of the air quality on the occupant. The best results will obviously be obtained by using building materials with low emission. However, there will always exist some emission and the ventilation will consequently be an important link....

Life cycle analysis of retrofitting with high energy efficiency air-conditioner and fluorescent lamp in existing buildings

International Nuclear Information System (INIS)

Techato, Kua-anan; Watts, Daniel J.; Chaiprapat, Sumate

2009-01-01

Life cycle analysis of mercury in discarded low energy efficiency fluorescent lamps (36 W) and of HCFC in air-conditioners (12,000 Btu) removed from service has been conducted in this study. The objective was to find out the environmental impact (EDIP 1997 category, waste evaluation) of the products that appear in the waste stream as a result of facility upgrades. The scope of the study starts from retrofitting of the lamps and air-conditioners through recycling and disposal. For a 36 W fluorescent lamp, the bulk waste 1.64E-5 kg, hazardous waste 1.11E-4 kg, radioactive waste 1.09E-9 kg, and slag-ash 6.02E-7 kg occurred at the end of life of the retrofitting cycle. For a 12,000 Btu air-conditioner, the bulk waste 0.58 kg, hazardous waste 0.11 kg, radioactive waste 0.0002 kg, and slag-ash 0.01 kg also occurred at the end of life of the retrofitting cycle. These small amounts become important when viewed at the country level. These quantities imply that the policy makers who deal with hazardous waste should be aware of this waste-generating characteristic before issuing any pertinent policy. Consideration of this characteristic and planning for appropriate waste management methods at the beginning stage will reduce any future problem of contamination by the hazardous waste

Life cycle analysis of retrofitting with high energy efficiency air-conditioner and fluorescent lamp in existing buildings

Energy Technology Data Exchange (ETDEWEB)

Techato, Kua-anan [International Postgraduate Programs in Environmental Management (Hazardous Waste Management) and ERI (Energy Research Institute), Chulalongkorn University, Bangkok 10330 (Thailand); Watts, Daniel J. [Otto H. York Center for Environmental Engineering and Science, New Jersey Institute of Technology, Newark, NJ 07102 (United States); Chaiprapat, Sumate [Department of Civil Engineering, Faculty of Engineering, Prince of Songkla University, Hat Yai Campus, Hat Yai, Songkhla 90112 (Thailand); National Center of Excellence for Environmental and Hazardous Waste Management-Satellite Center at Prince of Songkla University (Thailand)

2009-01-15

Life cycle analysis of mercury in discarded low energy efficiency fluorescent lamps (36 W) and of HCFC in air-conditioners (12,000 Btu) removed from service has been conducted in this study. The objective was to find out the environmental impact (EDIP 1997 category, waste evaluation) of the products that appear in the waste stream as a result of facility upgrades. The scope of the study starts from retrofitting of the lamps and air-conditioners through recycling and disposal. For a 36 W fluorescent lamp, the bulk waste 1.64E-5 kg, hazardous waste 1.11E-4 kg, radioactive waste 1.09E-9 kg, and slag-ash 6.02E-7 kg occurred at the end of life of the retrofitting cycle. For a 12,000 Btu air-conditioner, the bulk waste 0.58 kg, hazardous waste 0.11 kg, radioactive waste 0.0002 kg, and slag-ash 0.01 kg also occurred at the end of life of the retrofitting cycle. These small amounts become important when viewed at the country level. These quantities imply that the policy makers who deal with hazardous waste should be aware of this waste-generating characteristic before issuing any pertinent policy. Consideration of this characteristic and planning for appropriate waste management methods at the beginning stage will reduce any future problem of contamination by the hazardous waste. (author)

A Survey of Wireless Sensor Network Based Air Pollution Monitoring Systems.

Science.gov (United States)

Yi, Wei Ying; Lo, Kin Ming; Mak, Terrence; Leung, Kwong Sak; Leung, Yee; Meng, Mei Ling

2015-12-12

The air quality in urban areas is a major concern in modern cities due to significant impacts of air pollution on public health, global environment, and worldwide economy. Recent studies reveal the importance of micro-level pollution information, including human personal exposure and acute exposure to air pollutants. A real-time system with high spatio-temporal resolution is essential because of the limited data availability and non-scalability of conventional air pollution monitoring systems. Currently, researchers focus on the concept of The Next Generation Air Pollution Monitoring System (TNGAPMS) and have achieved significant breakthroughs by utilizing the advance sensing technologies, MicroElectroMechanical Systems (MEMS) and Wireless Sensor Network (WSN). However, there exist potential problems of these newly proposed systems, namely the lack of 3D data acquisition ability and the flexibility of the sensor network. In this paper, we classify the existing works into three categories as Static Sensor Network (SSN), Community Sensor Network (CSN) and Vehicle Sensor Network (VSN) based on the carriers of the sensors. Comprehensive reviews and comparisons among these three types of sensor networks were also performed. Last but not least, we discuss the limitations of the existing works and conclude the objectives that we want to achieve in future systems.

Growth of plant root cultures in liquid- and gas-dispersed reactor environments.

Science.gov (United States)

McKelvey, S A; Gehrig, J A; Hollar, K A; Curtis, W R

1993-01-01

The growth of Agrobacterium transformed "hairy root" cultures of Hyoscyamus muticus was examined in various liquid- and gas-dispersed bioreactor configurations. Reactor runs were replicated to provide statistical comparisons of nutrient availability on culture performance. Accumulated tissue mass in submerged air-sparged reactors was 31% of gyratory shake-flask controls. Experiments demonstrate that poor performance of sparged reactors is not due to bubble shear damage, carbon dioxide stripping, settling, or flotation of roots. Impaired oxygen transfer due to channeling and stagnation of the liquid phase are the apparent causes of poor growth. Roots grown on a medium-perfused inclined plane grew at 48% of gyratory controls. This demonstrates the ability of cultures to partially compensate for poor liquid distribution through vascular transport of nutrients. A reactor configuration in which the medium is sprayed over the roots and permitted to drain down through the root tissue was able to provide growth rates which are statistically indistinguishable (95% T-test) from gyratory shake-flask controls. In this type of spray/trickle-bed configuration, it is shown that distribution of the roots becomes a key factor in controlling the rate of growth. Implications of these results regarding design and scale-up of bioreactors to produce fine chemicals from root cultures are discussed.

Air Pollution Forecasts: An Overview.

Science.gov (United States)

Bai, Lu; Wang, Jianzhou; Ma, Xuejiao; Lu, Haiyan

2018-04-17

Air pollution is defined as a phenomenon harmful to the ecological system and the normal conditions of human existence and development when some substances in the atmosphere exceed a certain concentration. In the face of increasingly serious environmental pollution problems, scholars have conducted a significant quantity of related research, and in those studies, the forecasting of air pollution has been of paramount importance. As a precaution, the air pollution forecast is the basis for taking effective pollution control measures, and accurate forecasting of air pollution has become an important task. Extensive research indicates that the methods of air pollution forecasting can be broadly divided into three classical categories: statistical forecasting methods, artificial intelligence methods, and numerical forecasting methods. More recently, some hybrid models have been proposed, which can improve the forecast accuracy. To provide a clear perspective on air pollution forecasting, this study reviews the theory and application of those forecasting models. In addition, based on a comparison of different forecasting methods, the advantages and disadvantages of some methods of forecasting are also provided. This study aims to provide an overview of air pollution forecasting methods for easy access and reference by researchers, which will be helpful in further studies.

Air Pollution Forecasts: An Overview

Directory of Open Access Journals (Sweden)

Lu Bai

2018-04-01

Full Text Available Air pollution is defined as a phenomenon harmful to the ecological system and the normal conditions of human existence and development when some substances in the atmosphere exceed a certain concentration. In the face of increasingly serious environmental pollution problems, scholars have conducted a significant quantity of related research, and in those studies, the forecasting of air pollution has been of paramount importance. As a precaution, the air pollution forecast is the basis for taking effective pollution control measures, and accurate forecasting of air pollution has become an important task. Extensive research indicates that the methods of air pollution forecasting can be broadly divided into three classical categories: statistical forecasting methods, artificial intelligence methods, and numerical forecasting methods. More recently, some hybrid models have been proposed, which can improve the forecast accuracy. To provide a clear perspective on air pollution forecasting, this study reviews the theory and application of those forecasting models. In addition, based on a comparison of different forecasting methods, the advantages and disadvantages of some methods of forecasting are also provided. This study aims to provide an overview of air pollution forecasting methods for easy access and reference by researchers, which will be helpful in further studies.

Air Pollution Forecasts: An Overview

Science.gov (United States)

Bai, Lu; Wang, Jianzhou; Lu, Haiyan

2018-01-01

Air pollution is defined as a phenomenon harmful to the ecological system and the normal conditions of human existence and development when some substances in the atmosphere exceed a certain concentration. In the face of increasingly serious environmental pollution problems, scholars have conducted a significant quantity of related research, and in those studies, the forecasting of air pollution has been of paramount importance. As a precaution, the air pollution forecast is the basis for taking effective pollution control measures, and accurate forecasting of air pollution has become an important task. Extensive research indicates that the methods of air pollution forecasting can be broadly divided into three classical categories: statistical forecasting methods, artificial intelligence methods, and numerical forecasting methods. More recently, some hybrid models have been proposed, which can improve the forecast accuracy. To provide a clear perspective on air pollution forecasting, this study reviews the theory and application of those forecasting models. In addition, based on a comparison of different forecasting methods, the advantages and disadvantages of some methods of forecasting are also provided. This study aims to provide an overview of air pollution forecasting methods for easy access and reference by researchers, which will be helpful in further studies. PMID:29673227

Healthier Schools: A Review of State Policies for Improving Indoor Air Quality. Research Report.

Science.gov (United States)

Bernstein, Tobie

Existing indoor air quality (IAQ) policies for schools reflect the variety of institutional, political, social, and economic contexts that exist within individual states. The purpose of this report is to provide a better understanding of the types of policy strategies used by states in addressing general indoor air quality problems. The policies…

Liquid air cycle engines

Science.gov (United States)

Rosevear, Jerry

1992-01-01

Given here is a definition of Liquid Air Cycle Engines (LACE) and existing relevant technologies. Heat exchanger design and fabrication techniques, the handling of liquid hydrogen to achieve the greatest heat sink capabilities, and air decontamination to prevent heat exchanger fouling are discussed. It was concluded that technology needs to be extended in the areas of design and fabrication of heat exchangers to improve reliability along with weight and volume reductions. Catalysts need to be improved so that conversion can be achieved with lower quantities and lower volumes. Packaging studies need to be investigated both analytically and experimentally. Recycling with slush hydrogen needs further evaluation with experimental testing.

Dispersion of radioactive materials in air and water

International Nuclear Information System (INIS)

Tolksdorf, P.; Meurin, G.

1976-01-01

A review of current analytical methods for treating the dispersion of radioactive material in air and water is given. It is shown that suitable calculational models, based on experiments, exist for the dispersion in air. By contrast, the analysis of the dispersion of radioactive material in water still depends on the evaluation of experiments with site-specific models. (orig.) [de

77 FR 28519 - Test Procedure Guidance for Room Air Conditioners, Residential Dishwashers, and Residential...

Science.gov (United States)

2012-05-15

... Guidance for Room Air Conditioners, Residential Dishwashers, and Residential Clothes Washers: Public... procedures for room air conditioners, residential dishwashers, and residential clothes washers. DATES: DOE...'s existing test procedures for residential room air conditioners, residential dishwashers, and...

75 FR 51569 - National Emission Standards for Hazardous Air Pollutants for Reciprocating Internal Combustion...

Science.gov (United States)

2010-08-20

... Air Pollutants for Reciprocating Internal Combustion Engines; Final Rule #0;#0;Federal Register / Vol... for Hazardous Air Pollutants for Reciprocating Internal Combustion Engines AGENCY: Environmental... hazardous air pollutants for existing stationary spark ignition reciprocating internal combustion engines...

Health Effects of Air Pollution.

Science.gov (United States)

Environmental Education Report and Newsletter, 1985

1985-01-01

Summarizes health hazards associated with air pollution, highlighting the difficulty in establishing acceptable thresholds of exposure. Respiratory disease, asthma, cancer, cardiovascular disease, and other problems are addressed. Indicates that a wide range of effects from any one chemical exists and that there are differences in sensitivity to…

An adaptive maneuvering logic computer program for the simulation of one-on-one air-to-air combat. Volume 1: General description

Science.gov (United States)

Burgin, G. H.; Fogel, L. J.; Phelps, J. P.

1975-01-01

A technique for computer simulation of air combat is described. Volume 1 decribes the computer program and its development in general terms. Two versions of the program exist. Both incorporate a logic for selecting and executing air combat maneuvers with performance models of specific fighter aircraft. In the batch processing version the flight paths of two aircraft engaged in interactive aerial combat and controlled by the same logic are computed. The realtime version permits human pilots to fly air-to-air combat against the adaptive maneuvering logic (AML) in Langley Differential Maneuvering Simulator (DMS). Volume 2 consists of a detailed description of the computer programs.

On air-chemistry reduction for hypersonic external flow applications

International Nuclear Information System (INIS)

Ibrahim, Ashraf; Suman, Sawan; Girimaji, Sharath S.

2015-01-01

Highlights: • The existence of the slow manifold for the air-mixture system is shown. • The QSSA estimate of the slow manifold is fairly accurate. • For mid-temperature range the reduction mechanisms could be useful. - Abstract: In external hypersonic flows, viscous and compressibility effects generate very high temperatures leading to significant chemical reactions among air constituents. Therefore, hypersonic flow computations require coupled calculations of flow and chemistry. Accurate and efficient computations of air-chemistry kinetics are of much importance for many practical applications but calculations accounting for detailed chemical kinetics can be prohibitively expensive. In this paper, we investigate the possibility of applying chemical kinetics reduction schemes for hypersonic air-chemistry. We consider two chemical kinetics sets appropriate for three different temperature ranges: 2500 K to 4500 K; 4500 K to 9000 K; and above 9000 K. By demonstrating the existence of the so-called the slow manifold in each of the chemistry sets, we show that judicious chemical kinetics reduction leading to significant computational savings is possible without much loss in accuracy

Existence of a sex pheromone in Triatoma infestans (Hemiptera: Reduvidae: II. Electrophysiological correlates

Directory of Open Access Journals (Sweden)

Maria G. de Brito Sanchez

1995-10-01

Full Text Available The stimulus provided by a copulating pair of Triatoma infestans significantly affects the electrical activity of the nervous system of Triatoma infestans. Electrophysiological recordings were perfomed on stationary adult males presented with stimuli of an air current carrying odors from males, females, non-copulating pairs and mating pairs. The electrophysiological response was characterized by the low frequency occurrence of biphasic compound impulses. A significant increase in the frequency of the impulses occurred in stationary males when exposed to air currents of mating pairs, when compared to that evoked by a clean air stream. Analysis of the time course of the assays, showed that the electrophisiological activity during the copula was higher than prior to or after copula. The electrophysiological evidence presented here strongly supports the existence of pheromone(s released by one or both sexes during mating and which is perceived by male chemoreceptors located on the antennae.

Cost-benefit analysis of improved air quality in an office building

DEFF Research Database (Denmark)

Djukanovic, R.; Wargocki, Pawel; Fanger, Povl Ole

2002-01-01

A cost-benefit analysis of measures to improve air quality in an existing air-conditoned office building (11581 m2, 864 employees) was carried out for hot, temperate and cold climates and for two operating modes: Variable Air Volume (VAV) with economizer; and Constant Air Volume (CAV) with heat...... recovery. The annual energy cost and first cost of the HVAC system were calculat4ed using DOE 2.1E for different levels of air quality (10-50% dissatisfied). This was achieved by changing the outdoor air supply rate and the pollution loads. Previous studies have documented a 1.1% increase in office...

New calculation method for thermodynamic properties of humid air in humid air turbine cycle – The general model and solutions for saturated humid air

International Nuclear Information System (INIS)

Wang, Zidong; Chen, Hanping; Weng, Shilie

2013-01-01

The article proposes a new calculation method for thermodynamic properties (i.e. specific enthalpy, specific entropy and specific volume) of humid air in humid air turbine cycle. The research pressure range is from 0.1 MPa to 5 MPa. The fundamental behaviors of dry air and water vapor in saturated humid air are explored in depth. The new model proposes and verifies the relationship between total gas mixture pressure and gas component pressures. This provides a good explanation of the fundamental behaviors of gas components in gas mixture from a new perspective. Another discovery is that the water vapor component pressure of saturated humid air equals P S , always smaller than its partial pressure (f·P S ) which was believed in the past researches. In the new model, “Local Gas Constant” describes the interaction between similar molecules. “Improvement Factor” is proposed for the first time by this article, and it quantitatively describes the magnitude of interaction between dissimilar molecules. They are combined to fully describe the real thermodynamic properties of humid air. The average error of Revised Dalton's Method is within 0.1% compared to experimentally-based data. - Highlights: • Our new model is suitable to calculate thermodynamic properties of humid air in HAT cycle. • Fundamental behaviors of dry air and water vapor in saturated humid air are explored in depth. • Local-Gas-Constant describes existing alone component and Improvement Factor describes interaction between different components. • The new model proposes and verifies the relationship between total gas mixture pressure and component pressures. • It solves saturated humid air thoroughly and deviates from experimental data less than 0.1%

Measure Guideline. Wall Air Sealing and Insulation Methods in Existing Homes; An Overview of Opportunity and Process

Energy Technology Data Exchange (ETDEWEB)

Roberts, S. [NAHB Research Center Industry Partnership, Upper Marlboro, MD (United States); Stephenson, R. [NAHB Research Center Industry Partnership, Upper Marlboro, MD (United States)

2012-09-01

This guide provides renovators and retrofit contractors an overview of considerations when including wall air sealing and insulation in an energy retrofit project. It also outlines the potential project risks, various materials for insulating, possible field inspections needed, installation procedures, as well as the benefits and drawbacks.

Air Quality and Heart Health: An Emerging Topic for Heart Month

Science.gov (United States)

Air Quality and Heart Health: An Emerging Topic for Heart Month: Ambient air particle pollution increases short- and long-term cardiovascular morbidity and mortality. Older-people, those with pre-existing heart disease and lung disease and diabetes are at higher risk. Mechanism...

Compressed air noise reductions from using advanced air gun nozzles in research and development environments.

Science.gov (United States)

Prieve, Kurt; Rice, Amanda; Raynor, Peter C

2017-08-01

The aims of this study were to evaluate sound levels produced by compressed air guns in research and development (R&D) environments, replace conventional air gun models with advanced noise-reducing air nozzles, and measure changes in sound levels to assess the effectiveness of the advanced nozzles as engineering controls for noise. Ten different R&D manufacturing areas that used compressed air guns were identified and included in the study. A-weighted sound level and Z-weighted octave band measurements were taken simultaneously using a single instrument. In each area, three sets of measurements, each lasting for 20 sec, were taken 1 m away and perpendicular to the air stream of the conventional air gun while a worker simulated typical air gun work use. Two different advanced noise-reducing air nozzles were then installed. Sound level and octave band data were collected for each of these nozzles using the same methods as for the original air guns. Both of the advanced nozzles provided sound level reductions of about 7 dBA, on average. The highest noise reductions measured were 17.2 dBA for one model and 17.7 dBA for the other. In two areas, the advanced nozzles yielded no sound level reduction, or they produced small increases in sound level. The octave band data showed strong similarities in sound level among all air gun nozzles within the 10-1,000 Hz frequency range. However, the advanced air nozzles generally had lower noise contributions in the 1,000-20,000 Hz range. The observed decreases at these higher frequencies caused the overall sound level reductions that were measured. Installing new advanced noise-reducing air nozzles can provide large sound level reductions in comparison to existing conventional nozzles, which has direct benefit for hearing conservation efforts.

Need Analysis for Air Conditioners in Public Sector of Surabaya City Government

Directory of Open Access Journals (Sweden)

Dwiarti Larasputri

2017-01-01

Full Text Available In typical buildings, air conditioners have the biggest percentage in energy consumption among all sectors. It makes a good management for air conditioners is needed and important in order to use the energy efficiently. Having a very hot and humid weather, it gives impact that most of buildings in Surabaya installed air conditioners, including Surabaya City Government office buildings. However, there is no regulation nor guidance how to manage air conditioners in Surabaya City Government, while Surabaya itself has a goal to become a green-eco city. Then, the existing condition of air conditioners usage in Surabaya Government units (SKPDs is evaluated. The evaluation resulted that most of air conditioners were over capacity and not all of them were efficient in energy consumption. Therefore, a need analysis is required to help Surabaya City Government managing its air conditioners better. By applying two different concepts, one is based on the architectural view and another one is based on green building criteria, the existing condition is analyzed and two procedures of need analysis are produced. The procedures can be implemented for two different conditions of office building rooms in Surabaya City Government.

Ontological Proofs of Existence and Non-Existence

Czech Academy of Sciences Publication Activity Database

Hájek, Petr

2008-01-01

Roč. 90, č. 2 (2008), s. 257-262 ISSN 0039-3215 R&D Projects: GA AV ČR IAA100300503 Institutional research plan: CEZ:AV0Z10300504 Keywords : ontological proofs * existence * non-existence * Gödel * Caramuel Subject RIV: BA - General Mathematics

Enershield : energy saving air barriers

Energy Technology Data Exchange (ETDEWEB)

Hallihan, D. [Enershield Industries Ltd., Edmonton, AB (Canada)

2008-07-01

Enershield Industries is a leader in air barrier technology and provides solution for the Canadian climate. This presentation described the advantages of air barriers and the impact of rising energy costs. An air barrier is used to separate areas of differing environments and makes existing building systems more efficient. This presentation discussed how an air barrier works. It also identified how Enershield Industries calculates energy savings. It described air barrier applications and those who use barrier technology. These include the commercial and industrial sector as well as the personnel and retail sector. Barrier technology can be used for cold storage; vehicle and equipment washes; food processing; and environmental separation. Features and benefits such as the ability to create seal, acoustic insulation, and long term durability were also discussed. Last, the presentation addressed model selection and design criteria issues. Design criteria that were presented included a discussion of acoustic installation, articulating nozzles, scroll cased fans, and structural frame. Other design criteria presented were galvanized frames, telescopic sliders, and off the shelf parts. It was concluded that the ability to reduce energy consumption and enhance employee/client comfort is beneficial to the employer as well as to the employee. figs.

Air Quality Awareness Among U.S. Adults With Respiratory and Heart Disease.

Science.gov (United States)

Mirabelli, Maria C; Boehmer, Tegan K; Damon, Scott A; Sircar, Kanta D; Wall, Hilary K; Yip, Fuyuen Y; Zahran, Hatice S; Garbe, Paul L

2018-05-01

Poor air quality affects respiratory and cardiovascular health. Information about health risks associated with outdoor air quality is communicated to the public using air quality alerts. This study was conducted to assess associations of existing respiratory and heart disease with three aspects of air quality awareness: awareness of air quality alerts, discussing with a health professional strategies to reduce air pollution exposure, and avoiding busy roads to reduce air pollution exposure when walking, biking, or exercising outdoors. During 2014-2016, a total of 12,599 U.S. adults participated in summer waves of the ConsumerStyles surveys and self-reported asthma, emphysema/chronic obstructive pulmonary disease, heart disease, and each aspect of air quality awareness. In 2017, associations between each health condition and air quality awareness were estimated using log binomial and multinomial regression. Overall, 49% of respondents were aware of air quality alerts, 3% discussed with a health professional strategies to reduce air pollution exposure, and 27% always/usually avoided busy roads to reduce air pollution exposure. Asthma was associated with increased prevalence of awareness of air quality alerts (prevalence ratio=1.11, 95% CI=1.04, 1.20), discussing with a health professional (prevalence ratio=4.88, 95% CI=3.74, 6.37), and always/usually avoiding busy roads to reduce air pollution exposure (prevalence ratio=1.13, 95% CI=1.01, 1.27). Heart disease was not associated with air quality awareness. Existing respiratory disease, but not heart disease, was associated with increased air quality awareness. These findings reveal important opportunities to raise awareness of air quality alerts and behavior changes aimed at reducing air pollution exposure among adults at risk of exacerbating respiratory and heart diseases. Published by Elsevier Inc.

Air radioactivity: to assess risks. Tools answer citizen questions. The Opera-Air network: the journey of a filter

International Nuclear Information System (INIS)

Didier, Damien; Gariel, Jean-Christophe; Bruno, Valerie; Debayle, Christophe

2017-01-01

Very highly efficient filters containing a porous glass fibre fabric are used in industrial installations to trap radioactive or toxic particles in order to limit their release, notably in accidental situations. Thus this set of articles discusses various issues related to the use of such filters. A first one describes how air radioactivity is continuously monitored by two coexisting networks: Opera-Air and Teleray. It indicates where air radioactivity comes from, and how the origin of a release can be determined, and outlines the importance of modelling tools. Air monitoring about the Gravelines nuclear power plant is briefly presented with a drawing. A second article comments the existence of numerous tools which are used as information channels about the monitoring of air radioactivity: web sites, mobile application, and so on. The last article briefly describes the journey of a filter from its removal on a Monday to a complete and validated analysis which lasts between two and four weeks

Maximizing economic and environmental performance of existing coal-fired assets

Energy Technology Data Exchange (ETDEWEB)

Bartley, Pat; Foucher, Jean-Claude; Hestermann, Rolf; Hilton, Bob; Keegan, Bill; Stephen, Don

2007-07-01

In recent years, Plant Owners and innovative suppliers such as ALSTOM have come to realize that existing coal-fired assets have in many cases hidden capacity. This largely results from the conservative nature of their original design, but also from the possibility of integrating the latest advances in technology without the need to buy complete power plant components. ALSTOM's Optimized Plant Retrofit (OPR) process is a proven method to identify the full potential of existing equipment, taking a systemic and holistic approach to achieve full optimisation. OPRs are supported by ALSTOM's comprehensive portfolio of available technologies and a proven capability to integrate retrofit opportunities encompassing innovative solutions for a variety of plant components such as coal mills, boiler, air pollution control equipment, turbogenerator, feedheating and condensing plant. By teaming utility representatives with ALSTOM's technical experts we can collectively identify solutions for enhancing both heat rate and net output, to maximise the value of existing assets. This often gives a return on investment significantly better than greenfield construction for supply margin improvement. This paper introduces the OPR concept in detail and presents case studies and insights into future developments, in particular retrofitting existing assets in an emissions constrained environment. (auth)

Development Of Chemical Reduction And Air Stripping Processes To Remove Mercury From Wastewater

Energy Technology Data Exchange (ETDEWEB)

Jackson, Dennis G.; Looney, Brian B.; Craig, Robert R.; Thompson, Martha C.; Kmetz, Thomas F.

2013-07-10

This study evaluates the removal of mercury from wastewater using chemical reduction and air stripping using a full-scale treatment system at the Savannah River Site. The existing water treatment system utilizes air stripping as the unit operation to remove organic compounds from groundwater that also contains mercury (C ~ 250 ng/L). The baseline air stripping process was ineffective in removing mercury and the water exceeded a proposed limit of 51 ng/L. To test an enhancement to the existing treatment modality a continuous dose of reducing agent was injected for 6-hours at the inlet of the air stripper. This action resulted in the chemical reduction of mercury to Hg(0), a species that is removable with the existing unit operation. During the injection period a 94% decrease in concentration was observed and the effluent satisfied proposed limits. The process was optimized over a 2-day period by sequentially evaluating dose rates ranging from 0.64X to 297X stoichiometry. A minimum dose of 16X stoichiometry was necessary to initiate the reduction reaction that facilitated the mercury removal. Competing electron acceptors likely inhibited the reaction at the lower 1 doses, which prevented removal by air stripping. These results indicate that chemical reduction coupled with air stripping can effectively treat large-volumes of water to emerging part per trillion regulatory standards for mercury.

The Air Campaign: Planning for Combat

Science.gov (United States)

1988-01-01

Outcomes of this kind have been common in land war, but so far only a few exam - ples exist of the same thing in air war. TWO EXAMPLES OF AIR DEFENSE...the com- poser decides how best to reach that objective. Should it be a piano concerto, a violin concerto, or a flute con- certo? Only one will get...him to the objective he has chosen; clearly, a piano cannot say what a violin can say, and vice versa. That he has chosen an instrument to be his kev

Air pollution control policy in Switzerland

Energy Technology Data Exchange (ETDEWEB)

Leutert, G. [Forests and Landscape, Berne (Switzerland). Federal Office of Environment

1995-12-31

The legal basis of the Swiss air pollution control policy is set by the Federal Law on the Protection of the Environment, which came into force in 1985. It aims to protect human beings, animals and plants, their biological communities and habitats against harmful effects or nuisances and to maintain the fertility of the soil. The law is source-oriented (by emission standards) as well as effect-oriented (by ambient air quality standards). To link both elements a two-stage approach is applied. In the first stage preventive measures are taken at the emitting sources, irrespective of existing air pollution levels. Emissions have to be limited by early preventive measures as much as technical and operational conditions allow and as far as economically acceptable (prevention principle). By this, air pollution shall be kept as low as possible as a matter of principle, without the environment having to be in danger first. In a second stage the measures are strengthened or backed up by additional measures if ambient air quality standards laid down in the Ordinance on Air Pollution Control are exceeded. At this second stage, protection of man and his environment has priority over economic considerations. (author)

Air pollution control policy in Switzerland

Energy Technology Data Exchange (ETDEWEB)

Leutert, G [Forests and Landscape, Berne (Switzerland). Federal Office of Environment

1996-12-31

The legal basis of the Swiss air pollution control policy is set by the Federal Law on the Protection of the Environment, which came into force in 1985. It aims to protect human beings, animals and plants, their biological communities and habitats against harmful effects or nuisances and to maintain the fertility of the soil. The law is source-oriented (by emission standards) as well as effect-oriented (by ambient air quality standards). To link both elements a two-stage approach is applied. In the first stage preventive measures are taken at the emitting sources, irrespective of existing air pollution levels. Emissions have to be limited by early preventive measures as much as technical and operational conditions allow and as far as economically acceptable (prevention principle). By this, air pollution shall be kept as low as possible as a matter of principle, without the environment having to be in danger first. In a second stage the measures are strengthened or backed up by additional measures if ambient air quality standards laid down in the Ordinance on Air Pollution Control are exceeded. At this second stage, protection of man and his environment has priority over economic considerations. (author)

Air quality: how to assess air quality management policies on a short and on a long term? The integration of the climate factor

International Nuclear Information System (INIS)

Prevot, Aurelie

2014-01-01

This document presents the activities and works performed by the INERIS Institute in the development of tools for the assessment of air quality management policies including the climate factor. This comprises the development of simulations within the frame of the SALUT'AIR project, and also within the frame of the reviewing of the European policy on air quality (directives 2008/50/CE on ambient air quality and 2001/81/CE on national limits of emissions of some pollutants). The CHIMERE model of chemistry and transport is one of these tools. Simulations are performed to analyse the impact of scenarios of air quality management on a short term, in terms of pollutant emissions, pollutant concentration, and particle concentrations. The integration of a climate factor is justified by the existence of interactions between climate and air quality

REVIEW OF CONCENTRATION STANDARDS AND GUIDELINES FOR FUNGI IN INDOOR AIR

Science.gov (United States)

The paper reviews and compares existing guidelines for indoor airborne fungi, discusses limitations of existing guidelines, and identifies research needs that should contribute to the development of realistic and useful guidelines for these important air pollutants. (NOTE: Exposu...

Measurement Methods to Determine Air Leakage Between Adjacent Zones

Energy Technology Data Exchange (ETDEWEB)

Hult, Erin L. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Dickerhoff, Darryl J. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Price, Phillip N. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

2012-09-01

Air leakage between adjacent zones of a building can lead to indoor air quality and energy efficiency concerns, however there is no existing standard for measuring inter-zonal leakage. In this study, synthesized data and field measurements are analyzed in order to explore the uncertainty associated with different methods for collecting and analyzing fan pressurization measurements to calculate interzone leakage.

Measure Guideline: Selecting Ventilation Systems for Existing Homes

Energy Technology Data Exchange (ETDEWEB)

Aldrich, R. [Consortium for Advanced Residential Buildings (CARB), Norwalk, CT (United States)

2014-02-01

This report, developed by Building America research team CARB, addresses adding or improving mechanical ventilation systems to existing homes. The goal of this report is to assist decision makers and contractors in making informed decisions when selecting ventilation systems for homes. With more air-sealed envelopes, a mechanical means of removing contaminants is critical for indoor environmental quality and building durability. The purpose of ventilation is to remove contaminants from homes, and this report discusses where, when, and how much ventilation is appropriate in a home, including examination of relevant codes and standards. Choosing the "best" system is not always straightforward; selecting a system involves balancing performance, efficiency, cost, required maintenance, and several other factors.

Control in indoor radon decay products by air treatment devices

International Nuclear Information System (INIS)

Hinds, W.C.; Rudnick, S.N.; Maher, E.F.; First, M.W.

1983-01-01

An evaluation of the efficacy of household air cleaning devices as a means to control radon decay products in existing buildings is presented. Previous research on air cleaning methods for airborne radon decay products has been directed primarily to the control of radon decay products in mines and has only limited application to control in residences where dust concentration, air change rate, and humidity are lower than in mines. Results show that room size air cleaners can achieve substantial reductions in working levels in residences. Reductions observed at air infiltration rates of 0.52 air changes per hour ranged from 58 to 89%. Although the two air cleaners tested produced the greatest reductions, the low cost, simplicity, and other benefits of air circulating fans, particularly the ceiling fan, appear to make them most suitable for residences

Effects of air pollution on human health

Energy Technology Data Exchange (ETDEWEB)

Heimann, H

1961-01-01

An appreciable amount of knowledge exists about the effects of community air pollution upon human health. This knowledge comes in part from direct studies of the air pollution health problem and in part from investigations done for other purposes. It is equally apparent that there are many aspects of the subject of the health effects of air pollution on which sound information is lacking. Many years undoubtedly will pass before we have the answers to all the questions involved. Man-made air pollution could be entirely eliminated, but the price that civilization would be required to pay for this would be exorbitant by any standards, whether monetary or otherwise. It is unreasonable to contemplate that we could put a stop to all combustion, the chief source of man-made air pollution. It is logical, however, to consider that the clarification of the air on a qualitatively and quantitatively selective basis is feasible, and in some cases, highly desirable. This can be done, for example, by selectively arresting the contaminants at their source. 404 references.

Experimental investigation of a super performance dew point air cooler

International Nuclear Information System (INIS)

Xu, Peng; Ma, Xiaoli; Zhao, Xudong; Fancey, Kevin

2017-01-01

Highlights: •The cooler had a complex heat & mass exchanger with an advanced wet material layer. •Intermittent water supply scheme was implemented. •The cooler achieved 100–160% higher COP compared to the existing dew point coolers. •Electricity use of the cooler was reduced by 50–70% compared to existing dew coolers. •This optimal working air ratio was 0.364 that enabled maximised cooling effectiveness. -- Abstract: This paper presents an experimental investigation of a super performance dew point air cooler which, by employing a super performance wet material layer, innovative heat and mass exchanger and intermittent water supply scheme, has achieved a significantly higher energy efficiency (i.e. Coefficient of Performance, COP) and a much lower electrical energy use compared to the existing air coolers of the same type. This involves the dedicated system design & construction, fully planned experimental testing under various simulated climatic conditions representing the climate of hot & dry, warm & dry, moderate, warm & humid and standard lab testing condition, testing results analysis and discussion, as well as the parallel comparison against the commercial dew point air cooler. Under the standard test condition, i.e. dry bulb temperature of 37.8 °C and coincident wet bulb temperature of 21.1 °C, the prototype cooler achieved the wet-bulb cooling effectiveness of 114% and dew-point cooling effectiveness of 75%, yielding a significantly high COP value of 52.5 at the optimal working air ratio of 0.364. The testing also indicated that the lower inlet air relative humidity led to a higher cooling efficiency, while the lower cooling output helped increase COP and cooling effectiveness (including the wet-bulb effectiveness and dew-point effectiveness) of the cooler.

Ontario Hydro's integrated air management plan

International Nuclear Information System (INIS)

Kalvins, A.K.; Brown, D.; Camacho, F.; Howes, H.; Jantzi, B.; Lin, X.; Lui, P.; Melo, O.T.; Mortimer, W.P.; Reuber, B.

1992-01-01

Ontario Hydro is developing an integrated air management plan as a tool for comparing the environmental impacts of fossil-fuel power generation options. The goal is to relate equipment, location, emissions, and impacts and to identify the optimum way to manage the utility's fossil generation system in view of upcoming environmental regulations and public expectations. The eight steps of the plan are briefly described: definition of power generation scenarios (upgrading, conversion to natural gas, non-utility generation, alternative technologies); estimation of emissions for each generation and fuel option studied; identification of impact of air emissions on building materials, agriculture, forests, lakes, and fisheries; modelling of air emissions dispersion; quantification of damage to pollution receptors; quantification of full fuel cycle effects; and comparison of the scenarios. The scenario having the lowest overall environmental impact involved upgrading the existing fossil-fuel system with additional air emissions controls and two integrated gasification combined cycle plants. 9 refs., 3 figs., 3 tabs

Technology of Measuring equipment for Air Pollution. Development of Mobile Air Pollution monitoring system (LIDAR)

International Nuclear Information System (INIS)

Cha, Hyung Ki; Song, Ky Seok; Rhee, Young Joo; Kim, Duck Hyun; Yang, Ki Ho; Lee, Jong Min; Cha, Byung Heon; Lee, Kang Soo

1999-01-01

Most air pollution monitoring technologies accompany a time-consuming sample treatment process and provides pollution information only for a local area. Thus, they have a critical restriction in monitoring time-dependent pollution variation effectively over the wide range of area both in height and in width. LIDAR (Light detection and ranging) is a new technology to overcome such drawbacks of the existing pollution monitoring technologies and has long been investigated in the advanced countries. The goal of this project is to develop the mobile air pollution monitoring system and to apply the system to the detection of various pollutants, such as ozone, nitrogen dioxide, sulfur dioxide and aerosols

Technology of Measuring equipment for Air Pollution. Development of Mobile Air Pollution monitoring system (LIDAR)

Energy Technology Data Exchange (ETDEWEB)

Cha, Hyung Ki; Song, Ky Seok; Rhee, Young Joo; Kim, Duck Hyun; Yang, Ki Ho; Lee, Jong Min; Cha, Byung Heon; Lee, Kang Soo

1999-01-01

Most air pollution monitoring technologies accompany a time-consuming sample treatment process and provides pollution information only for a local area. Thus, they have a critical restriction in monitoring time-dependent pollution variation effectively over the wide range of area both in height and in width. LIDAR (Light detection and ranging) is a new technology to overcome such drawbacks of the existing pollution monitoring technologies and has long been investigated in the advanced countries. The goal of this project is to develop the mobile air pollution monitoring system and to apply the system to the detection of various pollutants, such as ozone, nitrogen dioxide, sulfur dioxide and aerosols.

Development and Application of a Next Generation Air Sensor Network for the Hong Kong Marathon 2015 Air Quality Monitoring.

Science.gov (United States)

Sun, Li; Wong, Ka Chun; Wei, Peng; Ye, Sheng; Huang, Hao; Yang, Fenhuan; Westerdahl, Dane; Louie, Peter K K; Luk, Connie W Y; Ning, Zhi

2016-02-05

This study presents the development and evaluation of a next generation air monitoring system with both laboratory and field tests. A multi-parameter algorithm was used to correct for the impact of environmental conditions on the electrochemical sensors for carbon monoxide (CO) and nitrogen dioxide (NO2) pollutants. The field evaluation in an urban roadside environment in comparison to designated monitors showed good agreement with measurement error within 5% of the pollutant concentrations. Multiple sets of the developed system were then deployed in the Hong Kong Marathon 2015 forming a sensor-based network along the marathon route. Real-time air pollution concentration data were wirelessly transmitted and the Air Quality Health Index (AQHI) for the Green Marathon was calculated, which were broadcast to the public on an hourly basis. The route-specific sensor network showed somewhat different pollutant patterns than routine air monitoring, indicating the immediate impact of traffic control during the marathon on the roadside air quality. The study is one of the first applications of a next generation sensor network in international sport events, and it demonstrated the usefulness of the emerging sensor-based air monitoring technology in rapid network deployment to supplement existing air monitoring.

Determination of velocity correction factors for real-time air velocity monitoring in underground mines

OpenAIRE

Zhou, Lihong; Yuan, Liming; Thomas, Rick; Iannacchione, Anthony

2017-01-01

When there are installations of air velocity sensors in the mining industry for real-time airflow monitoring, a problem exists with how the monitored air velocity at a fixed location corresponds to the average air velocity, which is used to determine the volume flow rate of air in an entry with the cross-sectional area. Correction factors have been practically employed to convert a measured centerline air velocity to the average air velocity. However, studies on the recommended correction fac...

Direct measurement of homogeneously distributed radioactive air contamination with germanium detectors

International Nuclear Information System (INIS)

Sowa, W.

1990-01-01

Air contamination by γ emitting radionuclides was measured with a vertically arranged germanium detector, laterally shielded by a lead ring, and calibration factors and detection limits of a number of fission products determined. The possibility of measuring simultaneously existing air and soil contamination by measurements with and without lead shield is described. The change of detection limit of air contamination is presented for different soil contamination levels by the same radionuclide. Calibration factors are given to determine the dose rate on the ground due to air contamination by different radionuclides. (author)

Performance analysis of air conditioning system and airflow simulation in an operating theater

Science.gov (United States)

Alhamid, Muhammad Idrus; Budihardjo, Rahmat

2018-02-01

The importance of maintaining performance of a hospital operating theater is to establish an adequate circulation of clean air within the room. The parameter of air distribution in a space should be based on Air Changes per Hour (ACH) to maintain a positive room pressure. The dispersion of airborne particles in the operating theater was governed by regulating the air distribution so that the operating theater meets clean room standards ie ISO 14664 and ASHRAE 170. Here, we introduced several input parameters in a simulation environment to observe the pressure distribution in the room. Input parameters were air temperature, air velocity and volumetric flow rate entering and leaving room for existing and designed condition. In the existing operating theatre, several observations were found. It was found that the outlet air velocity at the HEPA filter above the operating table was too high thus causing a turbulent airflow pattern. Moreover, the setting temperature at 19°C was found to be too low. The supply of air into the room was observed at lower than 20 ACH which is under the standard requirement. Our simulation using FloVent 8.2™ program showed that not only airflow turbulence could be reduced but also the amount of particle contamination could also be minimized.

Assessment methodology for air defence control systems

CSIR Research Space (South Africa)

Oosthuizen, R

2013-09-01

Full Text Available In Command and Control, humans have to make sense of the situation to support decision making on the required action. Development of an Air Defence Control system through a Systems Engineering process starts with assessment of existing systems...

Particulate air pollution and impaired lung function [version 1; referees: 3 approved

Directory of Open Access Journals (Sweden)

Laura Paulin

2016-02-01

Full Text Available Air pollution is a leading cause of morbidity and mortality throughout the world, particularly in individuals with existing lung disease. Of the most common air pollutants, particulate matter (PM is associated with an increased risk of exacerbations and respiratory symptoms in individuals with existing lung disease, and to a lesser extent, in those without known respiratory issues. The majority of published research has focused on the effects of PM exposures on symptoms and health care utilization. Fewer studies focus on the impact of PM on objective measurements of pulmonary function. This review will focus on the effects of PM exposure on objective measurements of lung function in both healthy individuals and those with existing lung disease.

Cost and Performance Report - Use of Cometabolic Air Sparging to Remediate Chloroethene-Contaminated Groundwater Aquifers

National Research Council Canada - National Science Library

Magar, Victor

2001-01-01

...) process at the McClellan National Test Site, California. The purpose of the demonstration was to evaluate the effectiveness of and costs associated with CAS for removal of chlorinated aromatic hydrocarbons (CAHs) from groundwater...

Geothermally Coupled Well-Based Compressed Air Energy Storage

Energy Technology Data Exchange (ETDEWEB)

Davidson, C L [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Bearden, Mark D [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Horner, Jacob A [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Appriou, Delphine [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); McGrail, B Peter [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

2015-12-01

Previous work by McGrail et al. (2013, 2015) has evaluated the possibility of pairing compressed air energy storage with geothermal resources in lieu of a fossil-fired power generation component, and suggests that such applications may be cost competitive where geology is favorable to siting both the geothermal and CAES components of such a system. Those studies also note that the collocation of subsurface resources that meet both sets of requirements are difficult to find in areas that also offer infrastructure and near- to mid-term market demand for energy storage. This study examines a novel application for the compressed air storage portion of the project by evaluating the potential to store compressed air in disused wells by amending well casings to serve as subsurface pressure vessels. Because the wells themselves would function in lieu of a geologic storage reservoir for the CAES element of the project, siting could focus on locations with suitable geothermal resources, as long as there was also existing wellfield infrastructure that could be repurposed for air storage. Existing wellfields abound in the United States, and with current low energy prices, many recently productive fields are now shut in. Should energy prices remain stagnant, these idle fields will be prime candidates for decommissioning unless they can be transitioned to other uses, such as redevelopment for energy storage. In addition to the nation’s ubiquitous oil and gas fields, geothermal fields, because of their phased production lifetimes, also may offer many abandoned wellbores that could be used for other purposes, often near currently productive geothermal resources. These existing fields offer an opportunity to decrease exploration and development uncertainty by leveraging data developed during prior field characterization, drilling, and production. They may also offer lower-cost deployment options for hybrid geothermal systems via redevelopment of existing well-field infrastructure

Geothermally Coupled Well-Based Compressed Air Energy Storage

Energy Technology Data Exchange (ETDEWEB)

Davidson, Casie L. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Bearden, Mark D. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Horner, Jacob A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Cabe, James E. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Appriou, Delphine [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); McGrail, B. Peter [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

2015-12-20

Previous work by McGrail et al. (2013, 2015) has evaluated the possibility of pairing compressed air energy storage with geothermal resources in lieu of a fossil-fired power generation component, and suggests that such applications may be cost competitive where geology is favorable to siting both the geothermal and CAES components of such a system. Those studies also note that the collocation of subsurface resources that meet both sets of requirements are difficult to find in areas that also offer infrastructure and near- to mid-term market demand for energy storage. This study examines a novel application for the compressed air storage portion of the project by evaluating the potential to store compressed air in disused wells by amending well casings to serve as subsurface pressure vessels. Because the wells themselves would function in lieu of a geologic storage reservoir for the CAES element of the project, siting could focus on locations with suitable geothermal resources, as long as there was also existing wellfield infrastructure that could be repurposed for air storage. Existing wellfields abound in the United States, and with current low energy prices, many recently productive fields are now shut in. Should energy prices remain stagnant, these idle fields will be prime candidates for decommissioning unless they can be transitioned to other uses, such as redevelopment for energy storage. In addition to the nation’s ubiquitous oil and gas fields, geothermal fields, because of their phased production lifetimes, also may offer many abandoned wellbores that could be used for other purposes, often near currently productive geothermal resources. These existing fields offer an opportunity to decrease exploration and development uncertainty by leveraging data developed during prior field characterization, drilling, and production. They may also offer lower-cost deployment options for hybrid geothermal systems via redevelopment of existing well-field infrastructure

77 FR 46911 - Approval and Promulgation of Air Quality Implementation Plans; Michigan; Regional Haze State...

Science.gov (United States)

2012-08-06

...-air quality environmental impacts of compliance; (3) any existing pollution control technology in use... relying on EPA's Cross-State Air Pollution Rule (CSAPR) to address these requirements. EPA is also taking...) monitoring network, show that visibility impairment caused by air pollution occurs virtually all the time at...

40 CFR Table 1 to Subpart Oooo of... - Emission Limits for New or Reconstructed and Existing Affected Sources in the Printing, Coating...

Science.gov (United States)

2010-07-01

... Reconstructed and Existing Affected Sources in the Printing, Coating and Dyeing of Fabrics and Other Textiles... SOURCE CATEGORIES National Emission Standards for Hazardous Air Pollutants: Printing, Coating, and Dyeing...—Emission Limits for New or Reconstructed and Existing Affected Sources in the Printing, Coating and Dyeing...

Public Perception of Urban Air Pollution: An Exploratory Study

International Nuclear Information System (INIS)

Sala, R.; Oltra, C.; Goncalves, L.

2014-01-01

This report presents the results of a qualitative study using focus groups aimed at understanding the beliefs and attitudes of the population towards air pollution, its levels, causes, health impacts and possible mitigation and protection actions. The study sample consisted of members of the general population, between 18 and 65 years living in Barcelona. The analysis of the group discussion indicates that there is little awareness among participants about air pollution risks. The causes of air pollution are relatively known but there is little knowledge about pollution levels and types of pollutants. We found a low level of perceived personal risk associated to air pollution that coexists with a general awareness of the health impacts of air pollution, a low level of concern about the problem and a low level of personal involvement in mitigation and self protection measures. Participants reported no use of existing information services about air pollution. (Author)

Local evaluation of air pollution by remote sensing

Energy Technology Data Exchange (ETDEWEB)

1975-02-01

Air pollution in Kanagawa Prefecture was studied by examining the relationship between tree vitality (on the ground) and the density distribution of trees as remotely measured with an aerial multiband camera. There was a close relationship between tree vitality and air pollution; a positive significant correlation existed between the density determination of trees obtained by remote sensing and the vitality of trees. The best time for photographing the trees by multiband camera was August. 4 figures, 24 tables.

Volatile organic compounds in indoor air: A review ofconcentrations measured in North America since 1990

Energy Technology Data Exchange (ETDEWEB)

ATHodgson@lbl.gov

2003-04-01

Central tendency and upper limit concentrations of volatile organic compounds (VOCs) measured in indoor air are summarized and reviewed. Data were obtained from published cross-sectional studies of residential and office buildings conducted in North America from 1990through the present. VOC concentrations in existing residences reported in 12 studies comprise the majority of the data set. Central tendency and maximum concentrations are compared between new and existing residences and between existing residences and office buildings. Historical changes in indoor VOC concentrations since the Clean Air Act Amendments of 1990 are explored by comparing the current data set with two published reviews of previous data obtained primarily in the 1980s. These historical comparisons suggest average indoor concentrations of some toxic air contaminants, such as 1,1,1-trichloroethane have decreased.

Proposal for the award of a contract for the design, supply, installation and commissioning of a ventilation and air conditioning system for the ECN3 experimental area and the TCC8 and GHN300 service tunnels and for the dismantling of the existing system

CERN Document Server

2014-01-01

Proposal for the award of a contract for the design, supply, installation and commissioning of a ventilation and air conditioning system for the ECN3 experimental area and the TCC8 and GHN300 service tunnels and for the dismantling of the existing system

Radionuclide characterization of environmental air around nuclear facilities

International Nuclear Information System (INIS)

Gede Sutresna Wijaya; Anung Muharini

2015-01-01

Air is an important environmental component in human life. Presence of air pollutants or contaminants will have a negative impact on human health. According to the existence of a nuclear facility in Yogyakarta, the characterization of radionuclides in the air is absolutely necessary to ensure the safety of people and the environment and also to supervise the safe operation of the facility. In this research the characterization of radionuclides in the air was carried through the air sampling by using High Volume Air Sampler equipped with filter TFA 2133, followed by analysis using combination of a gamma and alpha spectrometers. The concentration of radioactivity in the air fluctuates depending on the time and duration of sampling. Characterization of gamma emitting radionuclides in the air is dominated by radon progeny radionuclides such as 214 Pb, 214 Bi with activity 20.09 ± 1.23 until 32.91 ± 4.87 Bq/m 3 and 31.22 ± 1.76 until 44.25 ± 4.91 Bq/m 3 . Alpha emitter radionuclide was dominated by 214 Po (7.69 MeV) which is also radon progeny and a primordial radionuclides. It can be concluded that the presence of radionuclides in the environmental air not as a product resulting from the operation of nuclear facilities in Yogyakarta. (author)

Effects of political institutions on air quality

International Nuclear Information System (INIS)

Bernauer, Thomas; Koubi, Vally

2009-01-01

We empirically test existing theories on the provision of public goods, in particular air quality, using data on sulfur dioxide (SO 2 ) concentrations from the Global Environment Monitoring Projects for 107 cities in 42 countries from 1971 to 1996. The results are as follows: First, we provide additional support for the claim that the degree of democracy has an independent positive effect on air quality. Second, we find that among democracies, presidential systems are more conducive to air quality than parliamentary ones. Third, in testing competing claims about the effect of interest groups on public goods provision in democracies we establish that labor union strength contributes to lower environmental quality, whereas the strength of green parties has the opposite effect. (author)

Towards development of a deposition monitoring network for air pollution of Europe

NARCIS (Netherlands)

Erisman JW; Mennen MG; Fowler D; Flechard CR; Spindler G; Gruner A; Duyzer JH; Ruigrok W; Wyers GP; LLO; TNO; ECN; ITE (Engeland); IFT (Duitsland)

1996-01-01

In January 1993 within the framework of the LIFE programme a project was financed which aim was to develop a deposition monitoring method for air pollution of Europe. This method should be used to extend existing European monitoring networks of air concentrations to provide deposition inputs on an

The Relationship of Land Use and Transportation Planning to Air Quality Management.

Science.gov (United States)

Hagevik, George, Ed.

Due to a lack of communication between urban, regional, and transportation planning agencies and air pollution control agencies, cooperative efforts in environmental planning have been nearly non-existent. This traditional lack of communication and understanding serves to obscure the fact that air pollution control agencies and planning agencies…

Trace Contaminant Monitor for Air in Spacecraft, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — A need exists for analyzers that can measure trace contaminants in air on board spacecraft. Toxic gas buildup can endanger the crew particularly during long...

Measurement of polyurethane foam - air partition coefficients for semivolatile organic compounds as a function of temperature: Application to passive air sampler monitoring.

Science.gov (United States)

Francisco, Ana Paula; Harner, Tom; Eng, Anita

2017-05-01

Polyurethane foam - air partition coefficients (K PUF-air ) for 9 polycyclic aromatic hydrocarbons (PAHs), 10 alkyl-substituted PAHs, 4 organochlorine pesticides (OCPs) and dibenzothiophene were measured as a function of temperature over the range 5 °C-35 °C, using a generator column approach. Enthalpies of PUF-to-air transfer (ΔH PUF-air , kJ/mol) were determined from the slopes of log K PUF-air versus 1000/T (K), and have an average value of 81.2 ± 7.03 kJ/mol. The log K PUF-air values at 22 °C ranged from 4.99 to 7.25. A relationship for log K PUF-air versus log K OA was shown to agree with a previous relationship based on only polychlorinated biphenyls (PCBs) and derived from long-term indoor uptake study experiments. The results also confirm that the existing K OA -based model for predicting log K PUF-air values is accurate. This new information is important in the derivation of uptake profiles and effective air sampling volumes for PUF disk samplers so that results can be reported in units of concentration in air. Crown Copyright © 2017. Published by Elsevier Ltd. All rights reserved.

77 FR 24793 - Approval and Promulgation of Air Quality Implementation Plans; State of New York; Regional Haze...

Science.gov (United States)

2012-04-25

...- air quality environmental impacts of compliance, (3) any existing pollution control technology in use.... Implication of Clean Air Interstate Rule and Cross State Air Pollution Rule II. What is the background for EPA... CAIR rule, on July 6, 2011 EPA finalized the Cross- State Air Pollution Rule (CSAPR); a rule intended...

Indoor air quality in the 21st century: search for excellence

DEFF Research Database (Denmark)

Fanger, Povl Ole

2000-01-01

as elements behind a new philosophy of excellence: 1) better indoor air quality increases productivity and decreases SBS symptoms; 2) unnecessary indoor pollution sources should be avoided; 3) the air should be served cool and dry to the occupants; 4) "personalized air", i.e. a small amount of clean air...... are rather low, allowing a substantial group of people to become dissatisfied and to be adversely affected. A paradigm shift from rather mediocre to excellent indoor environments is foreseen in the 21st century. Based on existing information and on new research results, five principles are suggested...

Development and Application of a Next Generation Air Sensor Network for the Hong Kong Marathon 2015 Air Quality Monitoring

Directory of Open Access Journals (Sweden)

Li Sun

2016-02-01

Full Text Available This study presents the development and evaluation of a next generation air monitoring system with both laboratory and field tests. A multi-parameter algorithm was used to correct for the impact of environmental conditions on the electrochemical sensors for carbon monoxide (CO and nitrogen dioxide (NO2 pollutants. The field evaluation in an urban roadside environment in comparison to designated monitors showed good agreement with measurement error within 5% of the pollutant concentrations. Multiple sets of the developed system were then deployed in the Hong Kong Marathon 2015 forming a sensor-based network along the marathon route. Real-time air pollution concentration data were wirelessly transmitted and the Air Quality Health Index (AQHI for the Green Marathon was calculated, which were broadcast to the public on an hourly basis. The route-specific sensor network showed somewhat different pollutant patterns than routine air monitoring, indicating the immediate impact of traffic control during the marathon on the roadside air quality. The study is one of the first applications of a next generation sensor network in international sport events, and it demonstrated the usefulness of the emerging sensor-based air monitoring technology in rapid network deployment to supplement existing air monitoring.

Development and Application of a Next Generation Air Sensor Network for the Hong Kong Marathon 2015 Air Quality Monitoring

Science.gov (United States)

Sun, Li; Wong, Ka Chun; Wei, Peng; Ye, Sheng; Huang, Hao; Yang, Fenhuan; Westerdahl, Dane; Louie, Peter K.K.; Luk, Connie W.Y.; Ning, Zhi

2016-01-01

This study presents the development and evaluation of a next generation air monitoring system with both laboratory and field tests. A multi-parameter algorithm was used to correct for the impact of environmental conditions on the electrochemical sensors for carbon monoxide (CO) and nitrogen dioxide (NO2) pollutants. The field evaluation in an urban roadside environment in comparison to designated monitors showed good agreement with measurement error within 5% of the pollutant concentrations. Multiple sets of the developed system were then deployed in the Hong Kong Marathon 2015 forming a sensor-based network along the marathon route. Real-time air pollution concentration data were wirelessly transmitted and the Air Quality Health Index (AQHI) for the Green Marathon was calculated, which were broadcast to the public on an hourly basis. The route-specific sensor network showed somewhat different pollutant patterns than routine air monitoring, indicating the immediate impact of traffic control during the marathon on the roadside air quality. The study is one of the first applications of a next generation sensor network in international sport events, and it demonstrated the usefulness of the emerging sensor-based air monitoring technology in rapid network deployment to supplement existing air monitoring. PMID:26861336

Spatial variability of POPs in European background air

Directory of Open Access Journals (Sweden)

A. K. Halse

2011-02-01

Full Text Available Passive air samplers (PAS were deployed at 86 European background sites during summer 2006 in order (i to gain further insight into spatial patterns of persistent organic pollutants (POPs in European background air and, (ii to evaluate PAS as an alternative sampling technique under EMEP (Co-operative programme for monitoring and evaluation of the long-range transmissions of air pollutants in Europe. The samples were analyzed for selected PCBs, HCHs, DDTs, HCB, PAHs and chlordanes, and air concentrations were calculated on the basis of losses of performance reference compounds. Air concentrations of PCBs were generally lowest in more remote areas of northern Europe with elevated levels in more densely populated areas. γ-HCH was found at elevated levels in more central parts of Europe, whereas α-HCH, β-HCH and DDTs showed higher concentrations in the south-eastern part. There was no clear spatial pattern in the concentrations for PAHs, indicative of influence by local sources, rather than long range atmospheric transport (LRAT. HCB was evenly distributed across Europe, while the concentrations of chlordanes were typically low or non-detectable. A comparison of results obtained on the basis of PAS and active air sampling (AAS illustrated that coordinated PAS campaigns have the potential serve as useful inter-comparison exercises within and across existing monitoring networks. The results also highlighted limitations of the current EMEP measurement network with respect to spatial coverage. We finally adopted an existing Lagrangian transport model (FLEXPART as recently modified to incorporate key processes relevant for POPs to evaluate potential source regions affecting observed concentrations at selected sites. Using PCB-28 as an example, the model predicted concentrations which agreed within a factor of 3 with PAS measurements for all except 1 out of the 17 sites selected for this analysis.

Hydrodynamic behaviour and comparison of technologies for the removal of excess biomass in gas-phase biofilters.

Science.gov (United States)

Mendoza, J A; Prado, O J; Veiga, M C; Kennes, C

2004-01-01

The hydrodynamic behaviour of a biofilter fed toluene and packed with an inert carrier was evaluated on start-up and after long-term operation, using both methane and styrene as tracers in Residence Time Distribution experiments. Results indicated some deviation from ideal plug flow behaviour after 2-year operation. It was also observed that the retention time of VOCs gradually increased with time and was significantly longer than the average residence time of the bulk gas phase. Non-ideal hydrodynamic behaviour in packed beds may be due to excess biomass accumulation and affects both reactor modeling and performance. Therefore, several methods were studied for the removal of biomass after long-term biofilter operation: filling with water and draining, backwashing, and air sparging. Several flow rates and temperatures (20-60 degrees C) were applied using either water or different chemicals (NaOH, NaOCl, HTAB) in aqueous solution. Usually, higher flow rates and higher temperatures allowed the removal of more biomass, but the efficiency of biomass removal was highly dependent on the pressure drop reached before the treatment. The filling/draining method was the least efficient for biomass removal, although the treatment did basically not generate any biological inhibition. The efficiency of backwashing and air sparging was relatively similar and was more effective when adding chemicals. However, treatments with chemicals resulted in a significant decrease of the biofilter's performance immediately after applying the treatment, needing periods of several days to recover the original performance. The effect of manually mixing the packing material was also evaluated in duplicate experiments. Quite large amounts of biomass were removed but disruption of the filter bed was observed. Batch assays were performed simultaneously in order to support and quantify the observed inhibitory effects of the different chemicals and temperatures used during the treatments.

A Comparative Study of Physical and Chemical Processes for Removal of Biomass in Biofilters

Directory of Open Access Journals (Sweden)

Jorge Alberto Mendoza-Pérez

2011-08-01

Full Text Available After 6 months of operation a long-term biofilter was stopped for two weeks and then it was started up again for a second experimental period of almost 1.3 years, with high toluene loads and submitted to several physical and chemical treatments in order to remove excess biomass that could affect the reactor’s performance due to clogging, whose main effect is a high pressure drop. Elimination capacity and removal efficiency were determined after each treatment. The methods applied were: filling with water and draining, backwashing, and air sparging. Different flows and temperatures (20, 30, 45 and 60 °C were applied, either with distilled water or with different chemicals in aqueous solutions. Treatments with chemicals caused a decrease of the biofilter performance, requiring periods of 1 to 2 weeks to recover previous values. The results indicate that air sparging with pure distilled water as well as with solutions of NaOH (0.01% w/v and NaOCl (0.01% w/v were the treatments that removed more biomass, working either at 20, 30 or 45 °C and at relatively low flow rates (below 320 L h−1, but with a high biodegradation inhibition after the treatments. Dry biomass (g VS content was determined at three different heights of the biofilter in order to carry out each experiment under the same conditions. The same amount of dry biomass when applying a treatment was established so it could be considered that the biofilm conditions were identical. Wet biomass was used as a control of the biofilter’s water content during treatments. Several batch assays were performed to support and quantify the observed inhibitory effects of the different chemicals and temperatures applied.

78 FR 46552 - Approval and Promulgation of Air Quality Implementation Plans; Massachusetts; Regulations...

Science.gov (United States)

2013-08-01

... by the Commonwealth of Massachusetts. These are revisions to existing air pollution control... facilitate interpretation and understanding, and enhance enforceability, of the state's air pollution control... emission limits, was added to the following sections: of 310 CMR 7.18: (21), Surface Coating of Plastic...

Trading emissions improve air quality

International Nuclear Information System (INIS)

Lents, J.M.

1993-01-01

While admitting sharply contrasting views exist, James M. Lents of the South Coast Air Quality Management District in southern California sees emissions trading open-quotes as a lifesaver for our troubled planet.close quotes He explains: open-quotes If political support for the environment is to be maintained, we must seek the most economical and flexible means of pursuing cleanup. At present, market incentives and emissions trading represent our best hope.close quotes Lents is putting his money where his pen is. The air quality management district he heads plans to use market incentives, including emissions trading, to reduce air pollution in the notoriously dirty southern California area. When the system goes into operation in 1994, he estimates it will save southern California businesses more than $400 million a year in compliance costs, while also making major improvements in the region's air quality. If the idea works there, why won't it work elsewhere, even on a global scale, Lents asks? He believes it will. But open-quotes the ultimate success of emissions-trading programs, whether regional, national, or international in scope, lies in the proof that they're actually achieving reductions in harmful emissions,close quotes he emphasizes. open-quotes These reductions must be real and verifiable to satisfy the Clean Air Act and a skeptical public.close quotes

75 FR 37732 - National Emission Standards for Hazardous Air Pollutants for Reciprocating Internal Combustion...

Science.gov (United States)

2010-06-30

... National Emission Standards for Hazardous Air Pollutants for Reciprocating Internal Combustion Engines... hazardous air pollutants for existing stationary compression ignition reciprocating internal combustion... combustion engines. 40 CFR 63.6590 was amended by revising paragraphs (b)(1) and (3). Inadvertently...

Air travellers' awareness of the preventability of otic barotrauma.

Science.gov (United States)

Mitchell-Innes, A; Young, E; Vasiljevic, A; Rashid, M

2014-06-01

Otic barotrauma is common among air travellers and can cause severe otalgia, perforation of the tympanic membrane and hearing loss. Many prevention measures exist, with varying evidence to support their use. There are no data to establish if air travellers are aware of them or indeed use them. We aimed to establish air travellers' knowledge of such prevention measures. We surveyed air travellers at two UK airports by means of a questionnaire. Answers to the questionnaire were collected over a two-week period. Overall, 179 air travellers with a mean age of 28 years (range: 15-72 years) completed the questionnaire. There were 66 female and 113 male air travellers. The majority (84 per cent) complained of symptoms while flying and 30 per cent were not aware of any prevention measures. Barotrauma-related symptoms were reported in 25 per cent of air travellers who were unaware of any prevention measures. Nearly all air travellers (86 per cent) indicated that more information regarding prevention measures would be useful. Air travellers are often not aware of prevention measures to avoid otic barotrauma, and the majority suffer as a result. Increasing public awareness of simple prevention measures would have a significant impact on air travellers.

Secondary Aluminum Production: National Emission Standards for Hazardous Air Pollutants

Science.gov (United States)

National emission standards for hazardous air pollutants (NESHAP) for new and existing sources at secondary aluminum production facilities. Includes rule history, summary, federal register citations and implementation information.

Merging Air Quality and Public Health Decision Support Systems

Science.gov (United States)

Hudspeth, W. B.; Bales, C. L.

2003-12-01

The New Mexico Air Quality Mapper (NMAQM) is a Web-based, open source GIS prototype application that Earth Data Analysis Center is developing under a NASA Cooperative Agreement. NMAQM enhances and extends existing data and imagery delivery systems with an existing Public Health system called the Rapid Syndrome Validation Project (RSVP). RSVP is a decision support system operating in several medical and public health arenas. It is evolving to ingest remote sensing data as input to provide early warning of human health threats, especially those related to anthropogenic atmospheric pollutants and airborne pathogens. The NMAQM project applies measurements of these atmospheric pollutants, derived from both remotely sensed data as well as from in-situ air quality networks, to both forecasting and retrospective analyses that influence human respiratory health. NMAQM provides a user-friendly interface for visualizing and interpreting environmentally-linked epidemiological phenomena. The results, and the systems made to provide the information, will be applicable not only to decision-makers in the public health realm, but also to air quality organizations, demographers, community planners, and other professionals in information technology, and social and engineering sciences. As an accessible and interactive mapping and analysis application, it allows environment and health personnel to study historic data for hypothesis generation and trend analysis, and then, potentially, to predict air quality conditions from daily data acquisitions. Additional spin off benefits to such users include the identification of gaps in the distribution of in-situ monitoring stations, the dissemination of air quality data to the public, and the discrimination of local vs. more regional sources of air pollutants that may bear on decisions relating to public health and public policy.

In situ bioremediation using horizontal wells. Innovative technology summary report

International Nuclear Information System (INIS)

1995-04-01

In Situ Bioremediation (ISB) is the term used in this report for Gaseous Nutrient Injection for In Situ Bioremediation. This process (ISB) involves injection of air and nutrients (sparging and biostimulation) into the ground water and vacuum extraction to remove Volatile Organic Compounds (VOCs) from the vadose zone concomitant with biodegradation of the VOCs. This process is effective for remediation of soils and ground water contaminated with VOCs both above and below the water table. A full-scale demonstration of ISB was conducted as part of the Savannah River Integrated Demonstration: VOCs in Soils and Ground Water at Nonarid Sites. This demonstration was performed at the Savannah River Site from February 1992 to April 1993

Public concern for air quality: explaining change in Toronto, Canada, 1967-1978

Energy Technology Data Exchange (ETDEWEB)

Dworkin, J M [Univ of Arizona, Tucson; Pijawka, K D

1982-01-01

The paper presents the results of an empirical study of the change in perception of air quality in Toronto, Canada from 1968-1978. The data show a shift in public concern with and awareness of air quality. Despite the fact that the 1978 population regarded air quality as degraded, air pollution declined as a public concern, requiring a less serious response by government than other societal problems. The results of the study were reviewed in the context of existing perception studies. In explaining change, the study found: (1) perception of ambient air quality was not related to air pollution levels; (2) air pollution declines as a public concern as other socioeconomic problems surface; and (3) the mass media has an important role in affecting public attitudes and behavior over environmental quality issues.

Workplace air monitoring and sampling practices at DOE facilities

International Nuclear Information System (INIS)

Swinth, K.L.; Kenoyer, J.L.; Selby, J.M.

1987-01-01

The Pacific Northwest Laboratory (PNL) surveyed the current air monitoring and sampling practices at U.S. Department of Energy (DOE) facilities as a part of an air monitoring upgrade task. A comprehensive questionnaire was developed and distributed to DOE contractors through the DOE field offices. Twenty-six facilities returned a completed questionnaire. Questionnaire replies indicate a large diversity in air sampling and monitoring practices among DOE facilities. The differences among the facilities exist in monitoring and sampling instrumentation, procedures, calibration, analytical methods, detection levels, and action levels. Many of these differences could be attributed to different operational needs. 5 references, 2 figures, 2 tables

New challenges to air/gas cleaning systems

Energy Technology Data Exchange (ETDEWEB)

Kovach, J.L. [NUCON International, Inc., Columbus, OH (United States)

1997-08-01

This paper discusses the need for changes in the design and manufacturing of air and gas cleaning systems to meet waste management and site remediation requirements. Current design and manufacturing practices are primarily directed toward evaluating operational problems with existing systems in nuclear reactor facilities. However, nuclear waste management needs have developed which are much broader in scope and have different processing conditions. Numerous examples of air cleaning needs for waste management activities are provided; the major differences from operating facility needs are the requirement for continuous effluent treatment under widely different processing conditions. Related regulatory issues are also discussed briefly. 1 ref.

State of the air in British Columbia

International Nuclear Information System (INIS)

McDonald, S.; Furberg, M.; Rother, P.

2005-08-01

Scientific evidence is rising regarding the danger of air pollution. Poor air quality can pose a problem in British Columbia, particularly in interior communities when temperature inversions, during certain times of the year, trap pollutants in mountain valleys. This document described where pollutants come from, ambient levels in the atmosphere and how they affect human health. Particular focus was on fine particulate matter, ozone and oxides of nitrogen, as these 3 pollutants have been linked to health impacts. The cost of air pollution through increased health care costs and the economic impact of lost productivity from missed work days was also discussed along with the influence of poor air quality on crop damage and forestry production losses. The document also outlined government and community initiatives to protect public health and listed some measures that individuals can do to keep air clean. Air pollution stems from activities such as land development, burning fossil fuels for energy and transportation, industrial operations, residential wood burning and backyard burning of debris and burning from forestry and agricultural operations. The health impacts range from irritation, to coughing and worsening of existing heart and lung conditions. The document states that despite all measures being taken to reduce emissions and to maintain levels of air pollutants at current low levels, health effects are still observed and still pose a burden to health care cost. Scientific evidence indicates that a further reduction in air pollution will result in health benefits. refs., figs

State of the air in British Columbia

Energy Technology Data Exchange (ETDEWEB)

McDonald, S.; Furberg, M.; Rother, P. [British Columbia Lung Association, Vancouver, BC (Canada)

2005-08-15

Scientific evidence is rising regarding the danger of air pollution. Poor air quality can pose a problem in British Columbia, particularly in interior communities when temperature inversions, during certain times of the year, trap pollutants in mountain valleys. This document described where pollutants come from, ambient levels in the atmosphere and how they affect human health. Particular focus was on fine particulate matter, ozone and oxides of nitrogen, as these 3 pollutants have been linked to health impacts. The cost of air pollution through increased health care costs and the economic impact of lost productivity from missed work days was also discussed along with the influence of poor air quality on crop damage and forestry production losses. The document also outlined government and community initiatives to protect public health and listed some measures that individuals can do to keep air clean. Air pollution stems from activities such as land development, burning fossil fuels for energy and transportation, industrial operations, residential wood burning and backyard burning of debris and burning from forestry and agricultural operations. The health impacts range from irritation, to coughing and worsening of existing heart and lung conditions. The document states that despite all measures being taken to reduce emissions and to maintain levels of air pollutants at current low levels, health effects are still observed and still pose a burden to health care cost. Scientific evidence indicates that a further reduction in air pollution will result in health benefits. refs., figs.

TECHNOLOGIES TO ENHANCE OPERATION OF THE EXISTING NATURAL GAS COMPRESSION INFRASTRUCTURE

Energy Technology Data Exchange (ETDEWEB)

Anthony J. Smalley; Ralph E. Harris; Gary D. Bourn; Danny M. Deffenbaugh

2005-01-01

This quarterly report documents work performed under Tasks 10 through 14 of the project entitled: ''Technologies to Enhance Operation of the Existing Natural Gas Compression Infrastructure''. The project objective is to develop and substantiate methods for operating integral engine/compressors in gas pipeline service, which reduce fuel consumption, increase capacity, and enhance mechanical integrity. The report first documents tests performed on a KVG103 engine/compressor installed at Duke's Thomaston Compressor Station. This is the first series of tests performed on a four-stroke engine under this program. Additionally, this report presents results, which complete a comparison of performance before and after modification to install High Pressure Fuel Injection and a Turbocharger on a GMW10 at Williams Station 60. Quarterly Reports 7 and 8 already presented detailed data from tests before and after this modification, but the final quantitative comparison required some further analysis, which is presented in Section 5 of this report. The report further presents results of detailed geometrical measurements and flow bench testing performed on the cylinders and manifolds of the Laboratory Cooper GMVH6 engine being employed for two-stroke engine air balance investigations. These measurements are required to enhance the detailed accuracy in modeling the dynamic interaction of air manifold, exhaust manifold, and in-cylinder fuel-air balance.

Grandfather regulations, new source bias, and state air toxics regulations

International Nuclear Information System (INIS)

Levinson, Arik

1999-01-01

This paper uses plant-level data from the Census of Manufactures and the variation in toxic air pollution regulations across states to measure the effects of laws that are more stringent for new sources of pollution than for existing sources (so-called 'grandfather' regulations). Of particular interest is the resulting 'new source bias' and its effects on capital vintage and investment. Two industries are examined: commercial printing, which has a local product market; and paint manufacturing, which has a more national market. In general, there seem to be no statistically significant differences in capital vintage or investment between plants in states that grandfather new sources of pollution, plants in states that have no air toxics regulations, and plants in states that regulate both new and existing sources

Measurements of environmental policy for air pollution abatement

International Nuclear Information System (INIS)

Friedrich, R.

1993-01-01

The first part of the study goes into the determination of efficient strategies for the reduction of air pollutants. The developed method is not only derived theoretically but is tested with the concrete example of emissions sources of a German state. The second part goes into the question what the government can do in order to attain that air pollution abatement measures recognized as being efficient will be put into practice. As market economy mechanisms have advantages over central state planning in the allocation of economic resources the question arises if not also for environmental protection market economy tools may contribute to an improvement of the efficiency of air pollution abatement. Therefore the suitability of different tools of environmental policy for the realization of efficient air pollution abatement is investigated and evaluated. This is again not done abstractly but with existing emission sources. (orig./HSCH). 32 figs., 12 tabs [de

European Private Law: Up in the Air?

NARCIS (Netherlands)

Luzak, J.; Bobek, M.; Prassl, J.

2016-01-01

This paper compares the existing rights granted to consumers when they purchase services in the EU, whether in a shop or within a distance selling scheme, with the provisions of Regulation 261/2004. While the works on the new European rules on air passengers’ rights are still ongoing it is important

New sensor for measurement of low air flow velocity. Phase I final report

International Nuclear Information System (INIS)

Hashemian, H.M.; Hashemian, M.; Riggsbee, E.T.

1995-08-01

The project described here is the Phase I feasibility study of a two-phase program to integrate existing technologies to provide a system for determining air flow velocity and direction in radiation work areas. Basically, a low air flow sensor referred to as a thermocouple flow sensor has been developed. The sensor uses a thermocouple as its sensing element. The response time of the thermocouple is measured using an existing in-situ method called the Loop Current Step Response (LCSR) test. The response time results are then converted to a flow signal using a response time-versus-flow correlation. The Phase I effort has shown that a strong correlation exists between the response time of small diameter thermocouples and the ambient flow rate. As such, it has been demonstrated that thermocouple flow sensors can be used successfully to measure low air flow rates that can not be measured with conventional flow sensors. While the thermocouple flow sensor developed in this project was very successful in determining air flow velocity, determining air flow direction was beyond the scope of the Phase I project. Nevertheless, work was performed during Phase I to determine how the new flow sensor can be used to determine the direction, as well as the velocity, of ambient air movements. Basically, it is necessary to use either multiple flow sensors or move a single sensor in the monitoring area and make flow measurements at various locations sweeping the area from top to bottom and from left to right. The results can then be used with empirical or physical models, or in terms of directional vectors to estimate air flow patterns. The measurements can be made continuously or periodically to update the flow patterns as they change when people and objects are moved in the monitoring area. The potential for using multiple thermocouple flow sensors for determining air flow patterns will be examined in Phase II

Providing cleaner air to Canadians

International Nuclear Information System (INIS)

2001-02-01

This booklet is designed to explain salient aspects of the Ozone Annex, negotiated and signed recently by Canada and the United States, in a joint effort to improve air quality in North America. By significantly reducing the transboundary flows of air pollutants that cause smog, the Ozone Annex will benefit some 16 million people in central and eastern Canada and provide an example for a future round of negotiations to address concerns of the millions of Canadians and Americans who live in the border area between British Columbia and Washington State. The brochure provide summaries of the Canadian and American commitments, focusing on transportation, monitoring and reporting. The Ozone Annex complements other air quality initiatives by the Government of Canada enacted under the Environmental Protection Act, 1999. These measures include regulations to reduce sulphur content to 30 parts per million by Jan 1, 2005; proposing to restrict toxic particulate matter (PM) to less than 10 microns; establishing daily smog forecasts in the Maritimes and committing to a national program built upon existing smog advisories and forecasts in Quebec, Ontario and British Columbia; and investing in more clean air research through the newly created Canadian Foundation for Climate and Atmospheric Sciences

OPERATIONAL RESTRICTIONS FOR REDUCING NOISE AND THE SAFETY OF AIR OPERATIONS

Directory of Open Access Journals (Sweden)

Anna KWASIBORSKA

2017-03-01

Full Text Available Many European airports are located in close proximity to residential or protected areas. Aircraft noise emissions caused by the landing and taking off of aircraft are a big problem in these areas. From an operational point of view, the method for reducing noise is to reduce traffic volume or change its organization, especially during the night. Some procedures and tools have been developed to support air traffic management in the implementation of operational constraints necessary to maintain noise at an acceptable level. The objective of this paper is to analyse the effectiveness of these tools. For this purpose, we have analysed existing methods of operational noise reduction, taking into account their influence on the structure, smoothness, punctuality and, especially, the safety of air traffic. As a result, existing risks have been identified, while methods have been proposed to combine two important air traffic service tasks: ensuring safety, while taking into account the environmental constraints, especially in relation to the acoustic climate.

Compressed air system audit in a chemical company

Energy Technology Data Exchange (ETDEWEB)

Radgen, P. [Fraunhofer ISI, Karlsruhe (Germany)

2005-07-01

This paper describes the results achieved during a compressed air system audit at a chemical company in Switzerland. The aim of the audit conducted in Muttenz at the site of Clariant Schweiz AG was to analyse the installed compressed air system and its operation in order to identify energy and cost saving potentials. Because there was measurement equipment already installed, it was not necessary to install a new meter. Instead the existing data had to be extracted from the controlled system and regrouped for the analysis. Aggregated data for 2003 and 2004 and a set of detailed data acquired in the course of one week were used for the analysis. The audit identified a number of measures to improve the compressed air system, but had to conclude that the saving potentials at this site are below average. The audit included the compressors, the air treatment and air distribution up to production or storage buildings. The saving potential identified was quantified as about 300 000 kWh/a, or 13.3% of the compressed air energy demand. The cost savings were calculated to be around 41 852 Swiss Franks. (orig.)

Proposal for an Environmental Ship Index. Air pollutants and CO2

Energy Technology Data Exchange (ETDEWEB)

Den Boer, E.; Faber, J.; Nelissen, D.

2009-02-15

This report develops an environmental index for the air emissions of seagoing ships. The ports of Le Havre (France), Antwerp (Belgium), Rotterdam (Netherlands), Bremen and Hamburg (both Germany) want to develop a uniform Environmental Ship Index (ESI) that identifies ships that go beyond the current average technology in reducing air emissions. The index should be transparent, easy to determine and easy to verify. It should build on current legislation on air pollutant emissions. Therefore, the report reviews current legislation, existing indices in the maritime sector and in other modes of transport.

Effects of air jet duration and timing on the combustion characteristics of high-pressure air jet controlled compression ignition combustion mode in a hybrid pneumatic engine

International Nuclear Information System (INIS)

Long, Wuqiang; Meng, Xiangyu; Tian, Jiangping; Tian, Hua; Cui, Jingchen; Feng, Liyan

2016-01-01

Highlights: • A 3-D CFD model of the power cylinder in HPE was developed. • High-pressure air JCCI combustion mode includes two-stage high-temperature reaction. • The combustion phasing of the pre-mixture is controllable via the SOJ timing. • There exists an optimum SOJ timing for obtaining the highest combustion efficiency and shortest burning duration. - Abstract: The high-pressure air jet controlled compression ignition (JCCI) combustion mode was employed to control the premixed diesel compression ignition combustion phasing by using the compound thermodynamic cycle under all operating conditions, which is accomplished in a hybrid pneumatic engine (HPE). A three-dimensional computational fluid dynamics (CFD) numerical simulation coupled with reduced n-heptane chemical kinetics mechanism has been applied to investigate the effects of high-pressure air jet duration and the start of jet (SOJ) timing on the combustion characteristics in the power cylinder of HPE. By sweeping the high-pressure air jet durations from 6 to 14 °CA and SOJ timings from −12 °CA ATDC to the top dead center (TDC) under the air jet temperatures of 400 and 500 K, respectively, the low- and high-temperature reactions, combustion efficiency, as well as the combustion phasing and burning duration have been analyzed in detail. The results illustrated that a longer air jet duration results in a higher peak in the first-stage high-temperature reaction, and the short air jet duration of 6 °CA can lead to a higher combustion efficiency. The SOJ timing sweep results showed that there exists an optimum timing for obtaining the highest combustion efficiency and shortest burning duration.

Monitoring-based HVAC commissioning of an existing office building for energy efficiency

International Nuclear Information System (INIS)

Wang, Liping; Greenberg, Steve; Fiegel, John; Rubalcava, Alma; Earni, Shankar; Pang, Xiufeng; Yin, Rongxin; Woodworth, Spencer; Hernandez-Maldonado, Jorge

2013-01-01

Highlights: ► Demonstrated monitoring-based HVAC commissioning using an existing office building. ► Diagnosed various types of faulty operation in the HVAC system by trend data analyses. ► Identified a list of energy saving measures for the HVAC system. ► Quantified energy saving potential for each commissioning measure using calibrated energy simulation model. ► Achieved an actual energy saving of 10% after the implementations of cost-effective measures. -- Abstract: The performance of Heating, Ventilation and Air Conditioning (HVAC) systems may fail to satisfy design expectations due to improper equipment installation, equipment degradation, sensor failures, or incorrect control sequences. Commissioning identifies and implements cost-effective operational and maintenance measures in buildings to bring them up to the design intent or optimum operation. An existing office building is used as a case study to demonstrate the process of commissioning. Building energy benchmarking tools are applied to evaluate the energy performance for screening opportunities at the whole building level. A large natural gas saving potential was indicated by the building benchmarking results. Faulty operations in the HVAC systems, such as improper operations of air-side economizers, simultaneous heating and cooling, and ineffective optimal start, were identified through trend data analyses and functional testing. The energy saving potential for each commissioning measure is quantified with a calibrated building simulation model. An actual energy saving of 10% was realized after the implementations of cost-effective measures.

A flexible well-mixed milliliter-scale reactor with high oxygen transfer rate for microbial cultivations

DEFF Research Database (Denmark)

Bolic, Andrijana; Larsson, Hilde Kristina; Hugelier, Siewert

2016-01-01

solution and replacement for existing microtiter plates, shaken flasks and bench scale bioreactors. In this work, a new design of a milliliter-scale bioreactor system is presented and characterized. The entire system consists of a platform with gas connections, heater, temperature sensor and optical fibers...... on the one side and a bioreactor with special designed magnetic stirrer and non-invasive optical sensors for measurement of pH, dissolved oxygen and optical density on the other side. The system has a high level of flexibility in terms of volume (0.5–2 mL), aeration (sparging and surface aeration) and mixing...

Assessment of Air Quality Status in Wuhan, China

Directory of Open Access Journals (Sweden)

Jiabei Song

2016-04-01

Full Text Available In this study, air quality characteristics in Wuhan were assessed through descriptive statistics and Hierarchical Cluster Analysis (HCA. Results show that air quality has slightly improved over the recent years. While the NO2 concentration is still increasing, the PM10 concentration shows a clearly downward trend with some small fluctuations. In addition, the SO2 concentration has steadily decreased since 2008. Nevertheless, the current level of air pollutants is still quite high, with the PM10 and NO2 levels exceeding the air quality standard. Seasonal variation exists consistently for all the pollutants, with the highest concentration in winter and the lowest in summer. Cluster analysis evidenced that nine urban monitoring sites could be classified into three clusters. Cluster I consists of only the LY site, which is located in the famous East Lake scenic area with the best air quality. Cluster II corresponds to three monitoring sites with heavily trafficked roads nearby, where relatively severe NO2 pollution occurred. Cluster III is comprised of the remaining five sites, characterized by PM10 and SO2 pollution.

Air filtration and indoor air quality

DEFF Research Database (Denmark)

Bekö, Gabriel

2006-01-01

Demands for better indoor air quality are increasing, since we spend most of our time indoors and we are more and more aware of indoor air pollution. Field studies in different parts of the world have documented that high percentage of occupants in many offices and buildings find the indoor air...... decent ventilation and air cleaning/air filtration, high indoor air quality cannot be accomplished. The need for effective air filtration has increased with increasing evidence on the hazardous effects of fine particles. Moreover, the air contains gaseous pollutants, removal of which requires various air...... cleaning techniques. Supply air filter is one of the key components in the ventilation system. Studies have shown that used ventilation filters themselves can be a significant source of indoor air pollution with consequent impact on perceived air quality, sick building syndrome symptoms and performance...

Air humidity requirements for human comfort

DEFF Research Database (Denmark)

Toftum, Jørn; Fanger, Povl Ole

1999-01-01

level near 100% rh. For respiratory comfort are the requirements much more stringent and results in lower permissible indoor air humidities. Compared with the upper humidity limit specified in existing thermal comfort standards, e.g. ASHRAE Addendum 55a, the humidity limit based on skin humidity......Upper humidity limits for the comfort zone determined from two recently presented models for predicting discomfort due to skin humidity and insufficient respiratory cooling are proposed. The proposed limits are compared with the maximum permissible humidity level prescribed in existing standards...... for the thermal indoor environment. The skin humidity model predicts discomfort as a function of the relative humidity of the skin, which is determined by existing models for human heat and moisture transfer based on environmental parameters, clothing characteristics and activity level. The respiratory model...

Quantifying the impact of traffic-related air pollution on the indoor air quality of a naturally ventilated building.

Science.gov (United States)

Tong, Zheming; Chen, Yujiao; Malkawi, Ali; Adamkiewicz, Gary; Spengler, John D

2016-01-01

Improper natural ventilation practices may deteriorate indoor air quality when in close proximity to roadways, although the intention is often to reduce energy consumption. In this study, we employed a CFD-based air quality model to quantify the impact of traffic-related air pollution on the indoor air quality of a naturally ventilated building. Our study found that the building envelope restricts dispersion and dilution of particulate matter. The indoor concentration in the baseline condition located 10m away from the roadway is roughly 16-21% greater than that at the edge of the roadway. The indoor flow recirculation creates a well-mixed zone with little variation in fine particle concentration (i.e., 253nm). For ultrafine particles (building, particle size, wind condition, and window size and location. A break-even point is observed at D'~2.1 (normalized distance from the roadway by the width of the road). The indoor particle concentration is greater than that at the highway where D'building planning, the distance from the roadway and the ambient wind condition need to be considered at the early design stage whereas the size and location of the window openings, the interior layout, and the placement of fresh air intakes are important to the indoor air quality of existing buildings adjacent to roadways. Copyright © 2016 Elsevier Ltd. All rights reserved.

76 FR 53633 - Airworthiness Directives; Viking Air Limited (Type Certificate No. A-815 Formerly Held by...

Science.gov (United States)

2011-08-29

... Airworthiness Directives; Viking Air Limited (Type Certificate No. A-815 Formerly Held by Bombardier Inc. and de... superseding an existing airworthiness directive (AD) for all Viking Air Limited (type certificate No. A-815..., contact Viking Air Ltd., 9574 Hampden Road, Sidney, BC Canada V8L 5V5; telephone: (800) 663-8444; Internet...

Policy of air protection in Poland

International Nuclear Information System (INIS)

Karaczun, Z.M.

1995-01-01

The changed political situation and recognition of the acute destruction of the natural environment in Poland have caused a series of actions aimed at preventing further deterioration of Polish environment. One of the most important events which took place in the last few years was the enactment by the Polish Parliament in May 1991 of the Act on the National Ecological Policy. The basic assumption of the new environmental policy is a declaration that sustainable development will in future direct economic development in Poland. The aim of the presented paper is to introduce existing policy of air protection and instruments which have been implemented to protect the air. Special attention is paid to legislation instruments, introduction and enforcement of proper economic mechanisms strengthening air protection and foreign policy aiming at increasing foreign assistance for this objective. Pollutants involved include sulfur dioxide, nitrogen oxides, carbon dioxide and particulates from industry and coal-fired power plants. 9 refs

A Risk-based Assessment And Management Framework For Multipollutant Air Quality

Science.gov (United States)

Frey, H. Christopher; Hubbell, Bryan

2010-01-01

The National Research Council recommended both a risk- and performance-based multipollutant approach to air quality management. Specifically, management decisions should be based on minimizing the exposure to, and risk of adverse effects from, multiple sources of air pollution and that the success of these decisions should be measured by how well they achieved this objective. We briefly describe risk analysis and its application within the current approach to air quality management. Recommendations are made as to how current practice could evolve to support a fully risk- and performance-based multipollutant air quality management system. The ability to implement a risk assessment framework in a credible and policy-relevant manner depends on the availability of component models and data which are scientifically sound and developed with an understanding of their application in integrated assessments. The same can be said about accountability assessments used to evaluate the outcomes of decisions made using such frameworks. The existing risk analysis framework, although typically applied to individual pollutants, is conceptually well suited for analyzing multipollutant management actions. Many elements of this framework, such as emissions and air quality modeling, already exist with multipollutant characteristics. However, the framework needs to be supported with information on exposure and concentration response relationships that result from multipollutant health studies. Because the causal chain that links management actions to emission reductions, air quality improvements, exposure reductions and health outcomes is parallel between prospective risk analyses and retrospective accountability assessments, both types of assessment should be placed within a single framework with common metrics and indicators where possible. Improvements in risk reductions can be obtained by adopting a multipollutant risk analysis framework within the current air quality management

Indoor air quality and the law in Singapore.

Science.gov (United States)

Chan, P

1999-12-01

With the greater use of air-conditioned offices in Singapore, achieving good indoor air quality has become an important issue. The laws that impose duties upon designers and contractors with respect to the design and construction of air-conditioning and mechanical ventilation (ACMV) systems are set out in the Building Control Regulations and the Singapore Standard Code of Practice for Mechanical Ventilation and Air-conditioning in Buildings (hereinafter "SS CP 13:1980"). ACMV maintenance is governed by the Environmental Public Health Act, the Building and Common Property (Maintenance and Management) Act, and the Land Titles (Strata) Act, as well as by lease or tenancy agreements. Designers, contractors, developers, building owners and management corporations may also be liable to the workers, occupants and other premises users for indoor air quality (IAQ)-related injuries under the general principles of contract and tort. Recently, the Guidelines for Good Indoor Air Quality in Office Premises was issued by the Ministry of Environment to complement SS CP 13:1980 toward improving the indoor air quality of air-conditioned office premises. Although the Guidelines have no statutory effect, they may be adopted as contractual requirements in construction, lease and maintenance contracts. They may also be used to determine the relevant standard of duty of care required to discharge tortious liability. This paper looks at the existing laws and rules affecting the design, construction and maintenance of air-conditioned offices in light of Part III of the Ministry's Guidelines.

Energy analysis of under-floor air distribution (UFAD) system: An office building case study

International Nuclear Information System (INIS)

Alajmi, Ali F.; Abou-Ziyan, Hosny Z.; El-Amer, Wid

2013-01-01

Highlights: • The key issue for efficient performance of UFAD system is to ensure the thermal stratification establishment. • The unnecessarily excess air supplied to the room deteriorates the thermal stratification. • Improper UFAD operation increases the fan power and HVAC electric demand. • The proper UFAD system is typically more efficient than the existed UFAD system with energy savings of about 23–37%. • UFAD system shows over the CBAD system saving by about 37–39% during the peak months and 51% during October. - Abstract: This paper presents the results of an experimental and theoretical investigation to evaluate an under-floor air distribution (UFAD) system existed in an office building working on hot climate. Air temperature a distribution and supply air velocity are measured in two measuring stations; each consists of eight temperature sensors which were installed to measure room air temperatures along zone height. The obtained data shows an inefficient operation of the UFAD system which deteriorates the advantages of energy saving that presumed by UFAD system. The building energy simulation program, EnergyPlus, was used to identify the best setting of UFAD system and compare it with the existed UFAD and the conventional ceiling based air distribution (CBAD) system. The simulation results show that setting of room thermostat at 26 °C and supply air temperature at 18 °C provides the best efficient UFAD system. Due to improper operation of the tested UFAD system, its actual consumption is found to be higher than the best simulated UFAD by 23–37% during July to October. Also, the simulation results show that the HVAC demand of UFAD is lower than CBAD by 37–39% during July–September and 51% in October

Development of fuzzy air quality index using soft computing approach.

Science.gov (United States)

Mandal, T; Gorai, A K; Pathak, G

2012-10-01

Proper assessment of air quality status in an atmosphere based on limited observations is an essential task for meeting the goals of environmental management. A number of classification methods are available for estimating the changing status of air quality. However, a discrepancy frequently arises from the quality criteria of air employed and vagueness or fuzziness embedded in the decision making output values. Owing to inherent imprecision, difficulties always exist in some conventional methodologies like air quality index when describing integrated air quality conditions with respect to various pollutants parameters and time of exposure. In recent years, the fuzzy logic-based methods have demonstrated to be appropriated to address uncertainty and subjectivity in environmental issues. In the present study, a methodology based on fuzzy inference systems (FIS) to assess air quality is proposed. This paper presents a comparative study to assess status of air quality using fuzzy logic technique and that of conventional technique. The findings clearly indicate that the FIS may successfully harmonize inherent discrepancies and interpret complex conditions.

Data Quality Objectives Summary Report Supporting Radiological Air Surveillance Monitoring for the INL Site

Energy Technology Data Exchange (ETDEWEB)

Haney, Thomas Jay [Idaho National Lab. (INL), Idaho Falls, ID (United States)

2015-05-01

This report documents the Data Quality Objectives (DQOs) developed for the Idaho National Laboratory (INL) Site ambient air surveillance program. The development of the DQOs was based on the seven-step process recommended “for systematic planning to generate performance and acceptance criteria for collecting environmental data” (EPA 2006). The process helped to determine the type, quantity, and quality of data needed to meet current regulatory requirements and to follow U.S. Department of Energy guidance for environmental surveillance air monitoring design. It also considered the current air monitoring program that has existed at INL Site since the 1950s. The development of the DQOs involved the application of the atmospheric dispersion model CALPUFF to identify likely contamination dispersion patterns at and around the INL Site using site-specific meteorological data. Model simulations were used to quantitatively assess the probable frequency of detection of airborne radionuclides released by INL Site facilities using existing and proposed air monitors.

Public Perception of Urban Air Pollution in Four Spanish Cities

International Nuclear Information System (INIS)

Oltra, C.; Jorcano, A.; Sala, R.

2015-01-01

This report presents the results of a study on public reactions to urban air pollution. An on-line survey was implemented in four Spanish cities. Various psychosocial dimensions were assessed: perception of local air quality; attention, understanding and public awareness of the problem of air pollution; perceived impacts on health and quality of life; beliefs of severity, susceptibility and controllability associated with the risk; emotional responses and related self-protection and involvement behaviors. Results show that residents in the four cities pay little attention to the quality of air in their daily life. They perceive air quality in their city as regular. Nevertheless, significant differences exist among cities that could be explained by air pollution levels. Participants believe that air pollution has significant impacts on their health and quality of life; however the degree of information and knowledge about air quality effects seems to be low. Fatalistic beliefs and low controllability regarding the possibility to protect from air pollution were found. Participants declare performing very few self-protection or involvement behaviors. Differences between cities were also found in this dimension. Those findings could be useful for risk communication programs and public involvement strategies in the field of urban air pollution.

Consequences of air around an ionization chamber : Are existing solid phantoms suitable for reference dosimetry on an MR-linac?

NARCIS (Netherlands)

Hackett, S. L.; Van Asselen, B.; Wolthaus, J. W H; Kok, J. G M; Woodings, S. J.; Lagendijk, J. J W; Raaymakers, B. W.

2016-01-01

Purpose: A protocol for reference dosimetry for the MR-linac is under development. The 1.5 T magnetic field changes the mean path length of electrons in an air-filled ionization chamber but has little effect on the electron trajectories in a surrounding phantom. It is therefore necessary to correct

Adiabatic liquid piston compressed air energy storage

Energy Technology Data Exchange (ETDEWEB)

Petersen, Tage [Danish Technological Institute, Aarhus (Denmark); Elmegaard, B. [Technical Univ. of Denmark. DTU Mechanical Engineering, Kgs. Lyngby (Denmark); Schroeder Pedersen, A. [Technical Univ. of Denmark. DTU Energy Conversion, Risoe Campus, Roskilde (Denmark)

2013-01-15

;'Adiabatic Liquid Piston Compressed Air Energy Storage'' (ALP-CAES). The compression ratio of the gas in the vessel (ratio between maximum and minimum pressure) is relatively low; typical values would be < 1,5, whereas the compression ratio in existing CAES systems can be higher than 100, because the air is compressed from atmospheric pressure to the storage pressure. This investigation leads to the conclusion that: 1) The mechanical/electrical efficiency of the ALP-CAES system is significantly higher than existing CAES systems due to a low or nearly absent compression heat loss. Furthermore, pumps/turbines, which use a liquid as a medium, are more efficient than air/gas compressors/turbines. In addition, the demand for fuel during expansion does not occur. 2) The energy density of the ALP-CAES system is much lower than that of existing CAES systems (by a factor of 15-30) leading to a similar increase in investment in pressure vessel volume per stored MWh. Since the pressure vessel constitutes a relatively large fraction of the overall cost of a CAES system, an increase of 15-30 times renders the system economically unfeasible unless the operating conditions and the system design are very carefully selected to compensate the low energy density. Future electricity prices may increase to the extent that the efficiency benefit of ALP-CAES partly compensates the added investment. 3) When comparing ALP-CAES to an adiabatic CAES system, where compression heat is stored in thermal oil, the ALP-CAES system is found only to be competitive under a very specific set of operating/design conditions, including very high operation pressure and the use of very large caverns. 4) New systems are under development, which show an interesting trend in that they use near-isothermal compression and expansion of air (compression/expansion at almost constant temperature), eliminate compression heat loss and still maintain nearly the same level of energy density as existing CAES systems. This

The Performance of a Desiccant-Based air Conditioner on a Florida School

Energy Technology Data Exchange (ETDEWEB)

Miller, J.

2001-08-22

Indoor air quality has become a major public health issue in recent years. ASHRAE standard 62-1989-which is an attempt to improve indoor air quality by increasing building ventilation rates-greatly increases the latent loads on many buildings. In more humid climates, the Sensible Heat Ratio (SHR) of a building's air conditioner (which is the fraction of total delivered cooling that is sensible) is too high to meet the existing latent loads. The implementation of ASHRAE 62-1989 will only exacerbate this problem.

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.)

Solutions Network Formulation Report. NASA's Potential Contributions for Using Solar Ultraviolet Radiation in Conjunction with Photocatalysis for Urban Air Pollution Mitigation and Increasing Air Quality

Science.gov (United States)

Underwood, Lauren; Ryan, Robert E.

2007-01-01

This Candidate Solution is based on using NASA Earth science research on atmospheric ozone and aerosols data as a means to predict and evaluate the effectiveness of photocatalytically created surfaces (building materials like glass, tile and cement) for air pollution mitigation purposes. When these surfaces are exposed to near UV light, organic molecules, like air pollutants and smog precursors, will degrade into environmentally friendly compounds. U.S. EPA (Environmental Protection Agency) is responsible for forecasting daily air quality by using the Air Quality Index (AQI) that is provided by AIRNow. EPA is partnered with AIRNow and is responsible for calculating the AQI for five major air pollutants that are regulated by the Clean Air Act. In this Solution, UV irradiance data acquired from the satellite mission Aura and the OMI Surface UV algorithm will be used to help understand both the efficacy and efficiency of the photocatalytic decomposition process these surfaces facilitate, and their ability to reduce air pollutants. Prediction models that estimate photocatalytic function do not exist. NASA UV irradiance data will enable this capability, so that air quality agencies that are run by state and local officials can develop and implement programs that utilize photocatalysis for urban air pollution control and, enable them to make effective decisions about air pollution protection programs.

Formation of inorganic nitrogenous byproducts in aqueous solution under ultrasound irradiation.

Science.gov (United States)

Yao, Juanjuan; Chen, Longfu; Chen, Xiangyu; Zhou, Lingxi; Liu, Wei; Zhang, Zhi

2018-04-01

The effects of ultrasonic frequency, power intensity, temperature and sparged gas on the generation of nitrogenous by-products NO 2 - and NO 3 - have been investigated, and the new kinetics model of NO 2 - and NO 3 - generation was also explored. The results show that the highest primary generation rate of NO 2 - and NO 3 - by direct sonolysis in the cavitation bubbles (represented by k 1 ' and k 2 ', respectively) was obtained at 600 kHz and 200 kHz, respectively, in the applied ultrasonic frequency range of 200 to 800 kHz. The primary generation rate of NO 2 - (represented by k 1 ') increased with the increasing ultrasonic intensity while the primary generation rate of NO 3 - (represented by k 2 ') decreased. The lower temperature is beneficial to the primary generation of both NO 2 - and NO 3 - in the cavitation bubbles. The optimal overall yields of both NO 2 - and NO 3 - were obtained at the N 2 /O 2 volume (in the sparged gas) ratio of 3:1 which is near to the ratio of N 2 /O 2 in air. The dissolved O 2 is the dominant oxygen element source for both NO and NO 2 , compared with water vapor. Ultrasonic irradiation can significant enhance the recovery rates of dissolved N 2 and O 2 and thus keep the N 2 fixation reaction going even without aeration. Copyright © 2017 Elsevier B.V. All rights reserved.

78 FR 4800 - Approval and Promulgation of Air Quality Implementation Plans; Connecticut; Reasonably Available...

Science.gov (United States)

2013-01-23

... outdoors and individuals with a pre-existing respiratory disease such as asthma. On November 29, 2005, EPA... the District of Columbia issued on August 21, 2012 which vacated the Cross State Air Pollution Rule... that the state has adopted air pollution control strategies that represent RACT for purposes of...

Operation of a soil vapor extraction and air sparging system at a former gasoline service station

International Nuclear Information System (INIS)

Gromicko, G.J.; Klingensmith, R.C.; Simpson, D.K.

1995-01-01

Closure activities for three underground storage tanks (USTs) were conducted at Quaker State Corporation's (QSC) former service station in Conneaut, Pennsylvania as part of a property transfer during July, 1991. The facility, formerly owned by QSC, was operated from construction (early 1960's) through the sale of the property (early 1980's). Subsequent to sale of the facility, the property has been resold and the building reconfigured several times. The facility is located on a comer lot located along state highway Route 322 in the business district of Conneaut Lake as shown in Figure 1. Across the highway to the north, is Conneaut lake. The site is bordered by a residential property to the south and commercial properties on the east and west. A Pennsylvania State Game Commission Game Lands, is located approximately 150 feet southeast of the property Quaker State again became involved with the property in 1991 when the cur-rent owner attempted to sell the property and the lender for the prospective purchaser identified the presence of USTs. Subsequent to the confirmation of the USTS, UST closure activities were initiated. Subsurface investigations were conducted to delineate the extent of potential petroleum impacts and corrective actions were initiated which are on-going today

Indoor air quality, ventilation and respiratory health in elderly residents living in nursing homes in Europe

DEFF Research Database (Denmark)

Bentayeb, Malek; Norback, Dan; Bednarek, Micha

2015-01-01

cough. Elderly subjects aged ≥80 years were at higher risk. Pollutant effects were more pronounced in the case of poor ventilation. Even at low levels, indoor air quality affected respiratory health in elderly people permanently living in nursing homes, with frailty increasing with age. The effects were......Few data exist on respiratory effects of indoor air quality and comfort parameters in the elderly. In the context of the GERIE study, we investigated for the first time the relationships of these factors to respiratory morbidity among elderly people permanently living in nursing homes in seven...... European countries. 600 elderly people from 50 nursing homes underwent a medical examination and completed a standardised questionnaire. Air quality and comfort parameters were objectively assessed in situ in the nursing home. Mean concentrations of air pollutants did not exceed the existing standards...

EER, COP, and the Second Law Efficiency for Air Conditioners

Science.gov (United States)

Leff, Harvey S.; Teeters, William D.

1978-01-01

Describes the relationship existing between coefficient of performance (COP) and energy efficiency ratio (EER) in air conditioning units and introduces new efficiency parameters measured relative to the energy extracted from the primary energy source. (SL)

Simplified model-based optimal control of VAV air-conditioning system

Energy Technology Data Exchange (ETDEWEB)

Nassif, N.; Kajl, S.; Sabourin, R. [Ecole de Technologie Superieure, Montreal, PQ (Canada). Dept. of Construction Engineering

2005-07-01

The improvement of Variable Air Volume (VAV) system performance is one of several attempts being made to minimize the high energy use associated with the operation of heating, ventilation and air conditioning (HVAC) systems. A Simplified Optimization Process (SOP) comprised of controller set point strategies and a simplified VAV model was presented in this paper. The aim of the SOP was to determine supply set points. The advantage of the SOP over previous methods was that it did not require a detailed VAV model and optimization program. In addition, the monitored data for representative local-loop control can be checked on-line, after which controller set points can be updated in order to ensure proper operation by opting for real situations with minimum energy use. The SOP was validated using existing monitoring data and a model of an existing VAV system. Energy use simulations were compared to that of the existing VAV system. At each simulation step, 3 controller set point values were proposed and studied using the VAV model in order to select a value for each point which corresponded to the best performance of the VAV system. Simplified VAV component models were presented. Strategies for controller set points were described, including zone air temperature, duct static pressure set points; chilled water supply set points and supply air temperature set points. Simplified optimization process calculations were presented. Results indicated that the SOP provided significant energy savings when applied to specific AHU systems. In a comparison with a Detailed Optimization Process (DOP), the SOP was capable of determining set points close to those obtained by the DOP. However, it was noted that the controller set points determined by the SOP need a certain amount of time to reach optimal values when outdoor conditions or thermal loads are significantly changed. It was suggested that this disadvantage could be overcome by the use of a dynamic incremental value, which

Contaminación del aire por parque automotor en la ciudad de Puno

OpenAIRE

Marin Paucara, Esteban

2007-01-01

En el presente trabajo de tesis, denominado "Contaminación del aire por parque automotor en la ciudad de Puno", cuyo problema esta formulado mediante el siguiente enunciado: ¿Cuál es la relación que existe entre emisiones de gases (CO y HC) y opacidad, producidas a través del tubo de escape por el parque automotor y el nivel de contaminación del aire por este rubro en la ciudad de Puno?, siendo el objetivo general: Evaluar el nivel de contaminación del aire (calidad del aire) en relación a la...

Model-generated air quality statistics for application in vegetation response models in Alberta

International Nuclear Information System (INIS)

McVehil, G.E.; Nosal, M.

1990-01-01

To test and apply vegetation response models in Alberta, air pollution statistics representative of various parts of the Province are required. At this time, air quality monitoring data of the requisite accuracy and time resolution are not available for most parts of Alberta. Therefore, there exists a need to develop appropriate air quality statistics. The objectives of the work reported here were to determine the applicability of model generated air quality statistics and to develop by modelling, realistic and representative time series of hourly SO 2 concentrations that could be used to generate the statistics demanded by vegetation response models

Impact of U.S. Smoke-free Air Laws on Restaurant and Bar Employment, 1990-2015.

Science.gov (United States)

Shafer, Paul

2017-12-23

Secondhand smoke exposure is responsible for an estimated 50,000 deaths per year among nonsmokers in the U.S. Smoke-free air laws reduce secondhand smoke exposure but often encounter opposition over concerns about their economic impact. Expansion of these laws has stagnated and efforts to weaken existing laws may exacerbate existing disparities in exposure. Studies at the state and local levels have found that smoke-free air laws do not generally have an adverse effect, but there are no recent estimates of the impact of these laws nationally. Employment and sales are two measures commonly used to estimate the economic impact of smoke-free air laws. Sales data are gathered by state and local taxing authorities but not uniformly across jurisdictions. Dynamic panel models are used to estimate a population-weighted national average treatment effect of smoke-free air laws on restaurant and bar employment using data from the Quarterly Census of Employment and Wages for 1990 to 2015. A one-percentage point increase in population covered by a restaurant smoke-free air law is associated with a small increase (approximately 0.01%) in restaurant employment (b=0.0001, Plaw was not associated with bar employment. Smoke-free air laws are a powerful tool for protecting hospitality workers and patrons from the dangers of secondhand smoke. Using data over more than two decades, these results suggest that smoke-free air laws in the U.S. do not generally have any meaningful effect on restaurant and bar employment. Smoke-free air laws are associated with reductions in negative health outcomes and decreased smoking prevalence. Despite this clear public health argument and strong public support, passage of new laws has stagnated and exemptions are being used to weaken existing laws. The ability to make both a health and business case in support of existing laws may also bolster the case for expansion. This study provides an updated look at the economic impact of smoke-free air laws

78 FR 37118 - Approval and Promulgation of Air Quality Implementation Plans; Charlotte, Raleigh/Durham and...

Science.gov (United States)

2013-06-20

... the core maintenance area exists; c. alternative fuel vehicle programs to include compressed natural... Promulgation of Air Quality Implementation Plans; Charlotte, Raleigh/Durham and Winston-Salem Carbon Monoxide... (CO), showing continued attainment of the 8-hour CO national ambient air quality standard for the...

Design of workshops in air quality management for senior managers in Mexico (Taller de la calidad del aire para mandos superiores)

Energy Technology Data Exchange (ETDEWEB)

Auberle, W.M.; Alvarez, V.M.; Leary, J.; Paramo, V.H.

1999-07-01

A collaborative program among agencies and professionals in Mexico and the US is designing, developing and delivering specialized workshops for Mexican officials responsible for air quality management. The initial project is development and pilot delivery (Spring 1999) of a workshop for senior officials of SEMARNAP plus selected state and municipal officials. This paper describes the process for design of professional development programs in air quality management for Mexican officials. Key issues include optimum learning styles and delivery techniques; available time of senior managers for education; need for new materials versus adaptation of existing air quality management information; and utilization of the Internet and asynchronous methods to supplement the traditional workshop format. The paper describes the results of this analysis and design features and content of the initial workshop.

Effects of air pollution on general practitioner consultations for upper respiratory diseases in London

OpenAIRE

Hajat, S; Anderson, H; Atkinson, R; Haines, A; Seaton, A.

2002-01-01

Objectives: Few published studies have examined the effect of air pollution on upper respiratory conditions. Furthermore, most epidemiological studies on air pollution focus on mortality or hospital admissions as the main health outcomes, but very rarely consider the effect in primary care. If pollution effects do exist then the public health impact could be considerable because of the many patient contacts involved. We investigated the relation between air pollution and upper respiratory dis...

Impact of wood burning on outdoor air quality: existing French data and current studies; Contribution du chauffage au bois a la qualite de l'air exterieur: donnees existantes et etudes en cours en France

Energy Technology Data Exchange (ETDEWEB)

Leoz-Garziandia, E.; Mandin, C.; Collet, S. [Institut National de l' Environnement Industriel et des Risques, 60 - Verneuil en Halatte (INERIS) (France); Besombes, J.L.; Pissot, N. [Universite de Savoie, Lab. de Chimie Moleculaire et Environnemental (LCME), 73 - Le Bourget du Lac (France); Allemand, N. [Centre Interprofessionnel Technique d' Etudes de la Pollution Atmospherique, CITEPA, 75 - Paris (France); Riberon, J. [Centre Scientifique et Technique du Batiment (CSTB), 75 - Paris (France); Jaffrezo, J.L. [Laboratoire de Glaciologie et Geophysique de l' Environnement (LGGE UMR CNRS), 38 - Grenoble (France)

2009-03-15

French source apportionment studies of air quality including the wood combustion source become widespread. Quantify a single source contribution to air quality requires to be provided with a specific measurable data to this source. For that reason, numerous studies have focused on the determination, in the atmospheric samples, of the source-specific compounds, usually called molecular tracers. Since 2000, trend works focused on the 'wood combustion' contribution to air quality have been based on the use of some tracers such as levoglucosan and metoxyphenols. Obtained results have been compared to atmospheric particles global characteristics: organic carbon (OC), elementary carbon (EC), PM{sub 10}, PM{sub 2.5} and polycyclic aromatic hydrocarbons (PAH). The results presented in this article show not only the interest but also the limits of such an approach, as well as the need to develop and complete the current studies in order to quantify the different sources contribution to air quality. (author)

33 CFR 334.1280 - Bristol Bay, Alaska; air-to-air weapon range, Alaskan Air Command, U.S. Air Force.

Science.gov (United States)

2010-07-01

... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Bristol Bay, Alaska; air-to-air weapon range, Alaskan Air Command, U.S. Air Force. 334.1280 Section 334.1280 Navigation and Navigable... REGULATIONS § 334.1280 Bristol Bay, Alaska; air-to-air weapon range, Alaskan Air Command, U.S. Air Force. (a...

Quantifying the health impacts of air pollution under a changing climate-a review of approaches and methodology.

Science.gov (United States)

Sujaritpong, Sarunya; Dear, Keith; Cope, Martin; Walsh, Sean; Kjellstrom, Tord

2014-03-01

Climate change has been predicted to affect future air quality, with inevitable consequences for health. Quantifying the health effects of air pollution under a changing climate is crucial to provide evidence for actions to safeguard future populations. In this paper, we review published methods for quantifying health impacts to identify optimal approaches and ways in which existing challenges facing this line of research can be addressed. Most studies have employed a simplified methodology, while only a few have reported sensitivity analyses to assess sources of uncertainty. The limited investigations that do exist suggest that examining the health risk estimates should particularly take into account the uncertainty associated with future air pollution emissions scenarios, concentration-response functions, and future population growth and age structures. Knowledge gaps identified for future research include future health impacts from extreme air pollution events, interactions between temperature and air pollution effects on public health under a changing climate, and how population adaptation and behavioural changes in a warmer climate may modify exposure to air pollution and health consequences.

Modem Communications Systems Development Guidelines in Function of Air Traffic Safety ...

Directory of Open Access Journals (Sweden)

Petar Obradović

2007-05-01

Full Text Available The communications requirements in air traffic control areincreasing in complexity. From the middle 90s, huge progress inairport infrastructure, especially in air traffic control systems,has been made in Bosnia and Herzegovina in damage rehabilitation,caused by war conflicts, owing, first of all, to the EuropeanUnion aid that contributed to the re-establishment of regularinternational air traffic. The current air traffic control systemhas matured in its functionality. Therefore, the phase of advancementand preparation for the technological improvementis the next logical step. However, before establishing a new communicationsstrategy, the current application trends have to beanalyzed in details according to the existing communicationsenvironment interfaces. The goal of this work is to find theguidelines of technological development that will result in moreefficiency, safety and economic benefit in the near future, butthe air traffic safety must not be compromised by economicbenefit.

Royal Danish Air Force. Air Operations Doctrine

DEFF Research Database (Denmark)

Nørby, Søren

This brief examines the development of the first Danish Air Force Air Operations Doctrine, which was officially commissioned in October 1997 and remained in effect until 2010. The development of a Danish air power doctrine was heavily influenced by the work of Colonel John Warden (USAF), both...... through his book ”The Air Campaign” and his subsequent planning of the air campaign against Iraq in 1990-1991. Warden’s ideas came to Denmark and the Danish Air Force by way of Danish Air Force students attending the United States Air Force Air University in Alabama, USA. Back in Denmark, graduates from...... the Air University inspired a small number of passionate airmen, who then wrote the Danish Air Operations Doctrine. The process was supported by the Air Force Tactical Command, which found that the work dovetailed perfectly with the transformation process that the Danish Air Force was in the midst...

The Satellite based Monitoring Initiative for Regional Air quality (SAMIRA): Project summary and first results

Science.gov (United States)

Schneider, Philipp; Stebel, Kerstin; Ajtai, Nicolae; Diamandi, Andrei; Horalek, Jan; Nemuc, Anca; Stachlewska, Iwona; Zehner, Claus

2017-04-01

We present a summary and some first results of a new ESA-funded project entitled Satellite based Monitoring Initiative for Regional Air quality (SAMIRA), which aims at improving regional and local air quality monitoring through synergetic use of data from present and upcoming satellite instruments, traditionally used in situ air quality monitoring networks and output from chemical transport models. Through collaborative efforts in four countries, namely Romania, Poland, the Czech Republic and Norway, all with existing air quality problems, SAMIRA intends to support the involved institutions and associated users in their national monitoring and reporting mandates as well as to generate novel research in this area. The primary goal of SAMIRA is to demonstrate the usefulness of existing and future satellite products of air quality for improving monitoring and mapping of air pollution at the regional scale. A total of six core activities are being carried out in order to achieve this goal: Firstly, the project is developing and optimizing algorithms for the retrieval of hourly aerosol optical depth (AOD) maps from the Spinning Enhanced Visible and InfraRed Imager (SEVIRI) onboard of Meteosat Second Generation. As a second activity, SAMIRA aims to derive particulate matter (PM2.5) estimates from AOD data by developing robust algorithms for AOD-to-PM conversion with the support from model- and Lidar data. In a third activity, we evaluate the added value of satellite products of atmospheric composition for operational European-scale air quality mapping using geostatistics and auxiliary datasets. The additional benefit of satellite-based monitoring over existing monitoring techniques (in situ, models) is tested by combining these datasets using geostatistical methods and demonstrated for nitrogen dioxide (NO2), sulphur dioxide (SO2), and aerosol optical depth/particulate matter. As a fourth activity, the project is developing novel algorithms for downscaling coarse

Exacerbation of pneumomediastinum after air travel in a patient with dermatomyositis.

Science.gov (United States)

Ye, Qiuyue; Zhang, Lu; Tian, Xinlun; Shi, Juhong

2011-07-01

Although the presence of pneumothorax is generally considered an absolute contraindication to air travel, reports on pneumomediastinum after air travel are extremely rare. Moreover, to the best of our knowledge, exacerbation of existing pneumomediastinum after commercial air travel has never been reported. We report on a case of a patient (the first case that we are aware of) who suffered exacerbation of pneumomediastinum after commercial air travel. This patient, with confirmed pneumomediastinum before air travel, flew to our city for medical care without being warned about exacerbation by the local hospital or airlines. Obvious exacerbation of pneumomediastinum and subcutaneous emphysema was noticed after the travel. Subsequently, a diagnosis of amyopathic dermatomyositis with interstitial lung disease and pneumomediastinum was made. The patient died despite treatment with corticosteroid, cyclophosphamide and intravenous immunoglobulin. This report discusses this rare condition and offers suggestions regarding air travel for patients with presence of pneumomediastinum at the time of flight.

Health benefits from improved outdoor air quality and intervention in China.

Science.gov (United States)

Li, Shanshan; Williams, Gail; Guo, Yuming

2016-07-01

China is at its most critical stage of outdoor air quality management. In order to prevent further deterioration of air quality and to protect human health, the Chinese government has made a series of attempts to reduce ambient air pollution. Unlike previous literature reviews on the widespread hazards of air pollution on health, this review article firstly summarized the existing evidence of human health benefits from intermittently improved outdoor air quality and intervention in China. Contents of this paper provide concrete and direct clue that improvement in outdoor air quality generates various health benefits in China, and confirm from a new perspective that it is worthwhile for China to shift its development strategy from economic growth to environmental economic sustainability. Greater emphasis on sustainable environment design, consistently strict regulatory enforcement, and specific monitoring actions should be regarded in China to decrease the health risks and to avoid long-term environmental threats. Copyright © 2016 Elsevier Ltd. All rights reserved.

Ventilation System Effectiveness and Tested Indoor Air Quality Impacts

Energy Technology Data Exchange (ETDEWEB)

Rudd, Armin [National Renewable Energy Lab. (NREL), Golden, CO (United States); Bergey, Daniel [National Renewable Energy Lab. (NREL), Golden, CO (United States)

2014-02-01

Ventilation system effectiveness testing was conducted at two unoccupied, single-family, detached lab homes at the University of Texas - Tyler. Five ventilation system tests were conducted with various whole-building ventilation systems. Multizone fan pressurization testing characterized building and zone enclosure leakage. PFT testing showed multizone air change rates and interzonal airflow. Cumulative particle counts for six particle sizes, and formaldehyde and other Top 20 VOC concentrations were measured in multiple zones. The testing showed that single-point exhaust ventilation was inferior as a whole-house ventilation strategy. It was inferior because the source of outside air was not direct from outside, the ventilation air was not distributed, and no provision existed for air filtration. Indoor air recirculation by a central air distribution system can help improve the exhaust ventilation system by way of air mixing and filtration. In contrast, the supply and balanced ventilation systems showed that there is a significant benefit to drawing outside air from a known outside location, and filtering and distributing that air. Compared to the Exhaust systems, the CFIS and ERV systems showed better ventilation air distribution and lower concentrations of particulates, formaldehyde and other VOCs. System improvement percentages were estimated based on four System Factor Categories: Balance, Distribution, Outside Air Source, and Recirculation Filtration. Recommended System Factors could be applied to reduce ventilation fan airflow rates relative to ASHRAE Standard 62.2 to save energy and reduce moisture control risk in humid climates. HVAC energy savings were predicted to be 8-10%, or $50-$75/year.

Ventilation System Effectiveness and Tested Indoor Air Quality Impacts

Energy Technology Data Exchange (ETDEWEB)

Rudd, Armin [Building Science Corporation, Somerville, MA (United States); Bergey, Daniel [Building Science Corporation, Somerville, MA (United States)

2014-02-01

In this project, Building America research team Building Science Corporation tested the effectiveness of ventilation systems at two unoccupied, single-family, detached lab homes at the University of Texas - Tyler. Five ventilation system tests were conducted with various whole-building ventilation systems. Multizone fan pressurization testing characterized building and zone enclosure leakage. PFT testing showed multizone air change rates and interzonal airflow. Cumulative particle counts for six particle sizes, and formaldehyde and other Top 20 VOC concentrations were measured in multiple zones. The testing showed that single-point exhaust ventilation was inferior as a whole-house ventilation strategy. This was because the source of outside air was not direct from outside, the ventilation air was not distributed, and no provision existed for air filtration. Indoor air recirculation by a central air distribution system can help improve the exhaust ventilation system by way of air mixing and filtration. In contrast, the supply and balanced ventilation systems showed that there is a significant benefit to drawing outside air from a known outside location, and filtering and distributing that air. Compared to the exhaust systems, the CFIS and ERV systems showed better ventilation air distribution and lower concentrations of particulates, formaldehyde and other VOCs. System improvement percentages were estimated based on four system factor categories: balance, distribution, outside air source, and recirculation filtration. Recommended system factors could be applied to reduce ventilation fan airflow rates relative to ASHRAE Standard 62.2 to save energy and reduce moisture control risk in humid climates. HVAC energy savings were predicted to be 8-10%, or $50-$75/year.

Annular Air Leaks in a liquid hydrogen storage tank

Science.gov (United States)

Krenn, AG; Youngquist, RC; Starr, SO

2017-12-01

Large liquid hydrogen (LH2) storage tanks are vital infrastructure for NASA, the DOD, and industrial users. Over time, air may leak into the evacuated, perlite filled annular region of these tanks. Once inside, the extremely low temperatures will cause most of the air to freeze. If a significant mass of air is allowed to accumulate, severe damage can result from nominal draining operations. Collection of liquid air on the outer shell may chill it below its ductility range, resulting in fracture. Testing and analysis to quantify the thermal conductivity of perlite that has nitrogen frozen into its interstitial spaces and to determine the void fraction of frozen nitrogen within a perlite/frozen nitrogen mixture is presented. General equations to evaluate methods for removing frozen air, while avoiding fracture, are developed. A hypothetical leak is imposed on an existing tank geometry and a full analysis of that leak is detailed. This analysis includes a thermal model of the tank and a time-to-failure calculation. Approaches to safely remove the frozen air are analyzed, leading to the conclusion that the most feasible approach is to allow the frozen air to melt and to use a water stream to prevent the outer shell from chilling.

Ambient air pollution and thrombosis.

Science.gov (United States)

Robertson, Sarah; Miller, Mark R

2018-01-03

Air pollution is a growing public health concern of global significance. Acute and chronic exposure is known to impair cardiovascular function, exacerbate disease and increase cardiovascular mortality. Several plausible biological mechanisms have been proposed for these associations, however, at present, the pathways are incomplete. A seminal review by the American Heart Association (2010) concluded that the thrombotic effects of particulate air pollution likely contributed to their effects on cardiovascular mortality and morbidity. The aim of the current review is to appraise the newly accumulated scientific evidence (2009-2016) on contribution of haemostasis and thrombosis towards cardiovascular disease induced by exposure to both particulate and gaseous pollutants.Seventy four publications were reviewed in-depth. The weight of evidence suggests that acute exposure to fine particulate matter (PM 2.5 ) induces a shift in the haemostatic balance towards a pro-thrombotic/pro-coagulative state. Insufficient data was available to ascertain if a similar relationship exists for gaseous pollutants, and very few studies have addressed long-term exposure to ambient air pollution. Platelet activation, oxidative stress, interplay between interleukin-6 and tissue factor, all appear to be potentially important mechanisms in pollution-mediated thrombosis, together with an emerging role for circulating microvesicles and epigenetic changes.Overall, the recent literature supports, and arguably strengthens, the contention that air pollution contributes to cardiovascular morbidity by promoting haemostasis. The volume and diversity of the evidence highlights the complexity of the pathophysiologic mechanisms by which air pollution promotes thrombosis; multiple pathways are plausible and it is most likely they act in concert. Future research should address the role gaseous pollutants play in the cardiovascular effects of air pollution mixture and direct comparison of potentially

Application of nuclear air cleaning and treatment codes

International Nuclear Information System (INIS)

Kriskovich, J.R.

1995-01-01

All modifications to existing ventilation systems, as well as any new ventilation systems used on the Hanford Site are required to meet both American Society of Mechanical Engineers (ASME) codes N509 and N510. Difficulties encountered when applying code N509 at the Hanford Site include the composition of the ventilation air stream and requirements related to ventilation equipment procurement. Also, the existing ventilation systems for the waste tanks at the Hanford Site cannot be tested in accordance with code N510 because of the current configuration of these systems

Application of nuclear air cleaning and treatment codes

Energy Technology Data Exchange (ETDEWEB)

Kriskovich, J.R. [Westinghouse Hanford Company, Richland, WA (United States)

1995-02-01

All modifications to existing ventilation systems, as well as any new ventilation systems used on the Hanford Site are required to meet both American Society of Mechanical Engineers (ASME) codes N509 and N510. Difficulties encountered when applying code N509 at the Hanford Site include the composition of the ventilation air stream and requirements related to ventilation equipment procurement. Also, the existing ventilation systems for the waste tanks at the Hanford Site cannot be tested in accordance with code N510 because of the current configuration of these systems.

Retrofitting existing chemical scrubbers to biotrickling filters for H2S emission control.

Science.gov (United States)

Gabriel, David; Deshusses, Marc A

2003-05-27

Biological treatment is a promising alternative to conventional air-pollution control methods, but thus far biotreatment processes for odor control have always required much larger reactor volumes than chemical scrubbers. We converted an existing full-scale chemical scrubber to a biological trickling filter and showed that effective treatment of hydrogen sulfide (H2S) in the converted scrubber was possible even at gas contact times as low as 1.6 s. That is 8-20 times shorter than previous biotrickling filtration reports and comparable to usual contact times in chemical scrubbers. Significant removal of reduced sulfur compounds, ammonia, and volatile organic compounds present in traces in the air was also observed. Continuous operation for >8 months showed stable performance and robust behavior for H2S treatment, with pollutant-removal performance comparable to that achieved by using a chemical scrubber. Our study demonstrates that biotrickling filters can replace chemical scrubbers and be a safer, more economical technique for odor control.

An energy impact assessment of indoor air quality acceptance for air-conditioned offices

International Nuclear Information System (INIS)

Wong, L.T.; Mui, K.W.; Shi, K.L.; Hui, P.S.

2008-01-01

Treatment of fresh air in ventilation systems for the air-conditioning consumes a considerable amount of energy and affects the indoor air quality (IAQ). The ventilation demand is primarily related to the occupant load. In this study, the ventilation demands due to occupant load variations and occupant acceptability were examined against certain IAQ objectives using the mass balance of carbon dioxide (CO 2 ) concentrations in an air-conditioned office. In particular, this study proposed a ventilation model for the consideration of the occupant load variations and occupant acceptability based on the regional survey of typical offices (422 samples) in Hong Kong. The model was applied to evaluate the relative energy performance of different IAQ objectives in ventilation systems for typical office buildings in Hong Kong. The results showed that the energy consumption of a ventilation system would be correlated with the occupant load and acceptability in the air-conditioned office. Indicative CO 2 levels of 800 ppmv, 1000 ppmv and 1200 ppmv corresponding to 83%, 97% and 99.7% survey samples were shown, corresponding to the thermal energy consumptions of 1500 MJ m -2 yr -1 , 960 MJ m -2 yr -1 and 670 MJ m -2 yr -1 , respectively. In regards to the monetary issue, an annual value of HK$ 762 million per year in electrical consumption could be saved in all office buildings in Hong Kong when the indoor target CO 2 concentration is increased from 1000 ppmv to 1200 ppmv. To achieve an excellent IAQ following the existing design standard, i.e. to decrease the CO 2 level from 1000 ppmv to 800 ppmv, 56% additional energy would be consumed, corresponding to an annual value of HK$ 1,419 million, even though the occupant acceptability is only improved from 81% to 86%. The development of the models in this study would be useful for the energy performance evaluation of ventilation systems in air-conditioned offices

Section 112 hazardous air pollutants Clean Air Act Amendments of 1990; potential impact of fossil/NUC

International Nuclear Information System (INIS)

Cronmiller, R.E.

1990-01-01

Control of hazardous air pollutants under the Clean Air Act (CAA) goes back several decades. Section 112 of the 1970 CAA as amended in 1977 served as the national statutory basis for controlling hazardous air pollutants until the most recent 1990 Amendments. Following severe criticism of the effectiveness of the Act to address hazardous air pollutant issues and a pile of seemingly never ending lawsuits challenging the regulatory process, the U.S. Congress has substantially rewritten Section 112 in the 1990 CAA Amendments. Many provisions heretofore requiring findings or regulatory decisions by the Environmental Protection Agency (EPA) Administrator are now automatic in the sense that the decisions have already been made by the US Congress legislatively. Thus, the new Section 112 has eliminated many of the existing regulatory obstacles, or safeguards; this will likely result in sweeping new regulatory programs mandating extensive controls on many industrial activities. A much needed study program to address fossil fuel fired steam electric generating units' hazardous air emissions and to identify control alternatives to regulate these emissions, if regulation is required, was incorporated into new Section 112. Because of this study, the regulatory fate of these units under the new Section 112 remains highly uncertain. An extensive regulatory program addressing hazardous air pollutants of these utility units under Section 112 would dwarf electric utility costs associated with the new acid rain control program. First, this paper identifies major provisions of the old law and the resulting regulatory status for both coal and nuclear power facilities before addressing the new Section 112 under the 1990 CAA Amendments and potential implications for electric utilities specifically

Effect of air gap on uniformity of large-scale surface-wave plasma

International Nuclear Information System (INIS)

Lan Chaohui; Hu Xiwei; Jiang Zhonghe; Liu Minghai

2009-01-01

The effect of air gap on the uniformity of large-scale surface-wave plasma (SWP) in a rectangular chamber device is studied by using three-dimensional numerical analyses based on the finite difference time-domain (FDTD) approximation to Maxwell's equations and plasma fluid model. The spatial distributions of surface wave excited by slot-antenna array and the plasma parameters such as electron density and temperature are presented. For different air gap thicknesses, the results show that the existence of air gap would severely weaken the excitations of the surface wave and thereby the SWP. Thus the air gap should be eliminated completely in the design of the SWP source, which is opposite to the former research results. (authors)

Evaluation of the Magnesium Hydroxide Treatment Process for Stabilizing PFP Plutonium/Nitric Acid Solutions

Energy Technology Data Exchange (ETDEWEB)

Gerber, Mark A.; Schmidt, Andrew J.; Delegard, Calvin H.; Silvers, Kurt L.; Baker, Aaron B.; Gano, Susan R.; Thornton, Brenda M.

2000-09-28

This document summarizes an evaluation of the magnesium hydroxide [Mg(OH)2] process to be used at the Hanford Plutonium Finishing Plant (PFP) for stabilizing plutonium/nitric acid solutions to meet the goal of stabilizing the plutonium in an oxide form suitable for storage under DOE-STD-3013-99. During the treatment process, nitric acid solutions bearing plutonium nitrate are neutralized with Mg(OH)2 in an air sparge reactor. The resulting slurry, containing plutonium hydroxide, is filtered and calcined. The process evaluation included a literature review and extensive laboratory- and bench-scale testing. The testing was conducted using cerium as a surrogate for plutonium to identify and quantify the effects of key processing variables on processing time (primarily neutralization and filtration time) and calcined product properties.

Innovative approaches to remediation for VOC sites using recirculating wells

International Nuclear Information System (INIS)

Dawson, G.W.

1996-01-01

In-well air stripping with approaches such as the patented NoVOCs system offer both cost and operational advantages over pump and treat, and in situ air sparging technologies. With in-well stripping, the water is treated in the well and discharged without being brought to the surface. Discharged water is circulated through the saturated zone acting as a carrier to continually flush contaminants from the aquifer matrix and transport them to the well for treatment. With pumping rates up to four times those of comparable extraction wells, large radii of influence can be maintained and remediation is achieved faster and more efficiently. In-well stripping is applicable to any strippable contaminant including chlorinated solvents (i.e., TCE and PCE) and hydrocarbons such as the aromatic components in petroleum fuels. Growing costs associated with water discharge, NPDES permits, water rights and, in some areas, salt water intrusion have provided economic incentives to retrofit existing pump and treat systems with NoVOCs units. A large number of wells are amenable to retrofitting depending on their diameter, location and length of screens, and back fill. Even with the new initiatives for intrinsic remediation for petroleum fuel releases, there is a role for the NoVOCs technology. Free product removal wells based on the NoVOCs design eliminate the need to treat and permit water discharges produced when generating a cone of depression for collecting the floating fuel. Additionally, the stripping action and introduction of dissolved oxygen reduce soluble hydrocarbon concentrations to risk levels that can be easily addressed through intrinsic bioremediation

Determination of velocity correction factors for real-time air velocity monitoring in underground mines.

Science.gov (United States)

Zhou, Lihong; Yuan, Liming; Thomas, Rick; Iannacchione, Anthony

2017-12-01

When there are installations of air velocity sensors in the mining industry for real-time airflow monitoring, a problem exists with how the monitored air velocity at a fixed location corresponds to the average air velocity, which is used to determine the volume flow rate of air in an entry with the cross-sectional area. Correction factors have been practically employed to convert a measured centerline air velocity to the average air velocity. However, studies on the recommended correction factors of the sensor-measured air velocity to the average air velocity at cross sections are still lacking. A comprehensive airflow measurement was made at the Safety Research Coal Mine, Bruceton, PA, using three measuring methods including single-point reading, moving traverse, and fixed-point traverse. The air velocity distribution at each measuring station was analyzed using an air velocity contour map generated with Surfer ® . The correction factors at each measuring station for both the centerline and the sensor location were calculated and are discussed.

Human health effects of air pollution

International Nuclear Information System (INIS)

Kampa, Marilena; Castanas, Elias

2008-01-01

Hazardous chemicals escape to the environment by a number of natural and/or anthropogenic activities and may cause adverse effects on human health and the environment. Increased combustion of fossil fuels in the last century is responsible for the progressive change in the atmospheric composition. Air pollutants, such as carbon monoxide (CO), sulfur dioxide (SO 2 ), nitrogen oxides (NOx), volatile organic compounds (VOCs), ozone (O 3 ), heavy metals, and respirable particulate matter (PM2.5 and PM10), differ in their chemical composition, reaction properties, emission, time of disintegration and ability to diffuse in long or short distances. Air pollution has both acute and chronic effects on human health, affecting a number of different systems and organs. It ranges from minor upper respiratory irritation to chronic respiratory and heart disease, lung cancer, acute respiratory infections in children and chronic bronchitis in adults, aggravating pre-existing heart and lung disease, or asthmatic attacks. In addition, short- and long-term exposures have also been linked with premature mortality and reduced life expectancy. These effects of air pollutants on human health and their mechanism of action are briefly discussed. - The effect of air pollutants on human health and underlying mechanisms of cellular action are discussed

The changing face of urban air pollution

Science.gov (United States)

Lewis, Alastair C.

2018-02-01

The atmospheric chemistry that leads to photochemical smog and climate-active aerosols requires the presence of volatile organic compounds (VOCs) (1, 2). The VOCs in urban air typically derive from the prevailing energy and transport technologies as well as the use of petrochemical-derived products. On page 760 of this issue, McDonald et al. (3) report that a notable change in emissions may be underway in U.S. cities, with effects on secondary pollutants such as organic aerosols. Shifting from an urban atmosphere dominated by transport-related VOCs to one dominated by VOCs from coatings, adhesives, and consumer products would alter predictions of urban air quality and challenge the existing policy framework for emissions control.

Preventing freezing of condensate inside tubes of air cooled condenser

International Nuclear Information System (INIS)

Joo, Jeong A; Hwang, In Hwan; Lee, Dong Hwan; Cho, Young Il

2012-01-01

An air cooled condenser is a device that is used for converting steam into condensate by using ambient air. The air cooled condenser is prone to suffer from a serious explosion when the condensate inside the tubes of a heat exchanger is frozen; in particular, tubes can break during winter. This is primarily due to the structural problem of the tube outlet of an existing conventional air cooled condenser system, which causes the backflow of residual steam and noncondensable gases. To solve the backflow problem in such condensers, such a system was simulated and a new system was designed and evaluated in this study. The experimental results using the simulated condenser showed the occurrence of freezing because of the backflow inside the tube. On the other hand, no backflow and freezing occurred in the advanced new condenser, and efficient heat exchange occurred

Air pollution and mortality: A history

Science.gov (United States)

Anderson, H. R.

Mortality is the most important health effect of ambient air pollution and has been studied the longest. The earliest evidence relates to fog episodes but with the development of more precise methods of investigation it is still possible to discern short-term temporal associations with daily mortality at the historically low levels of air pollution that now exist in most developed countries. Another early observation was that mortality was higher in more polluted areas. This has been confirmed by modern cohort studies that account for other potential explanations for such associations. There does not appear to be a threshold of effect within the ambient range of concentrations. Advances in the understanding of air pollution and mortality have been driven by the combined development of methods and biomedical concepts. The most influential methodological developments have been in time-series techniques and the establishment of large cohort studies, both of which are underpinned by advances in data processing and statistical analysis. On the biomedical side two important developments can be identified. One has been the application of the concept of multifactorial disease causation to explaining how air pollution may affect mortality at low levels and why thresholds are not obvious at the population level. The other has been an increasing understanding of how air pollution may plausibly have pathophysiological effects that are remote from the lung interface with ambient air. Together, these advances have had a profound influence on policies to protect public health. Throughout the history of air pollution epidemiology, mortality studies have been central and this will continue because of the widespread availability of mortality data on a large population scale and the weight that mortality carries in estimating impacts for policy development.

Investigation concerning the existence of quarks near the nuclei of great air showers with the help of a cloud chamber

International Nuclear Information System (INIS)

Wiemken, U.

1974-01-01

In order to compare the results of McCusker's (1969) experiment, this paper presents an experiment with improved technical details. For this purpose, a large cloud chamber in connection with the Kiel air shower set-up was available. First, the expected quark induced ionisation has been determined by a calibration measurement on minimum ionising muons. These data are in extremely good agreement with values from the literature. Then, measurements in air showers with a mean primary energy of 10 16 eV have been performed during an effective measuring time of 66 days. The mean distance from the nucleus amounts to about 9 m. In contradiction to the quark abundance of McCusker, which predicts six quarks for the Kiel set-up, no track was found with 'quark suspicion'. Some tracks with low droplet densities could be explained already in a preliminary stage of the evaluation by normal cloud chamber effects. (orig.) [de

Assessment of an air pollution monitoring network to generate urban air pollution maps using Shannon information index, fuzzy overlay, and Dempster-Shafer theory, A case study: Tehran, Iran

Science.gov (United States)

Pahlavani, Parham; Sheikhian, Hossein; Bigdeli, Behnaz

2017-10-01

Air pollution assessment is an imperative part of megacities planning and control. Hence, a new comprehensive approach for air pollution monitoring and assessment was introduced in this research. It comprises of three main sections: optimizing the existing air pollutant monitoring network, locating new stations to complete the coverage of the existing network, and finally, generating an air pollution map. In the first section, Shannon information index was used to find less informative stations to be candidate for removal. Then, a methodology was proposed to determine the areas which are not sufficiently covered by the current network. These areas are candidates for establishing new monitoring stations. The current air pollution monitoring network of Tehran was used as a case study, where the air pollution issue has been worsened due to the huge population, considerable commuters' absorption and topographic barriers. In this regard, O3, NO, NO2, NOx, CO, PM10, and PM2.5 were considered as the main pollutants of Tehran. Optimization step concluded that all the 16 active monitoring stations should be preserved. Analysis showed that about 35% of the Tehran's area is not properly covered by monitoring stations and about 30% of the area needs additional stations. The winter period in Tehran always faces the most severe air pollution in the year. Hence, to produce the air pollution map of Tehran, three-month of winter measurements of the mentioned pollutants, repeated for five years in the same period, were selected and extended to the entire area using the kriging method. Experts specified the contribution of each pollutant in overall air pollution. Experts' rankings aggregated by a fuzzy-overlay process. Resulted maps characterized the study area with crucial air pollution situation. According to the maps, more than 45% of the city area faced high pollution in the study period, while only less than 10% of the area showed low pollution. This situation confirms the need

High Performance Cathodes for Li-Air Batteries

Energy Technology Data Exchange (ETDEWEB)

Xing, Yangchuan

2013-08-22

The overall objective of this project was to develop and fabricate a multifunctional cathode with high activities in acidic electrolytes for the oxygen reduction and evolution reactions for Li-air batteries. It should enable the development of Li-air batteries that operate on hybrid electrolytes, with acidic catholytes in particular. The use of hybrid electrolytes eliminates the problems of lithium reaction with water and of lithium oxide deposition in the cathode with sole organic electrolytes. The use of acid electrolytes can eliminate carbonate formation inside the cathode, making air breathing Li-air batteries viable. The tasks of the project were focused on developing hierarchical cathode structures and bifunctional catalysts. Development and testing of a prototype hybrid Li-air battery were also conducted. We succeeded in developing a hierarchical cathode structure and an effective bifunctional catalyst. We accomplished integrating the cathode with existing anode technologies and made a pouch prototype Li-air battery using sulfuric acid as catholyte. The battery cathodes contain a nanoscale multilayer structure made with carbon nanotubes and nanofibers. The structure was demonstrated to improve battery performance substantially. The bifunctional catalyst developed contains a conductive oxide support with ultra-low loading of platinum and iridium oxides. The work performed in this project has been documented in seven peer reviewed journal publications, five conference presentations, and filing of two U.S. patents. Technical details have been documented in the quarterly reports to DOE during the course of the project.

Adiabatic Liquid Piston Compressed Air Energy Storage

DEFF Research Database (Denmark)

Petersen, Tage; Elmegaard, Brian; Pedersen, Allan Schrøder

the system. The compression leads to a significant increase in temperature, and the heat generated is dumped into the ambient. This energy loss results in a low efficiency of the system, and when expanding the air, the expansion leads to a temperature drop reducing the mechanical output of the expansion......), but no such units are in operation at present. The CAES system investigated in this project uses a different approach to avoid compression heat loss. The system uses a pre-compressed pressure vessel full of air. A liquid is pumped into the bottom of the vessel when charging and the same liquid is withdrawn through......-CAES system is significantly higher than existing CAES systems due to a low or nearly absent compression heat loss. Furthermore, pumps/turbines, which use a liquid as a medium, are more efficient than air/gas compressors/turbines. In addition, the demand for fuel during expansion does not occur. •The energy...

Revenue management of air cargo service in theory and practice

Science.gov (United States)

Budiarto, S.; Putro, H. P.; Pradono, P.; Yudoko, G.

2018-05-01

This study examines the air cargo service by comparing existing theories from previous research with the conditions on the ground. The object of the study is focused on the freight forwarder and the airport management. This study reviews the models and results of previous research that will be summarized and used to identify any issues related to the characteristics of air cargo operational services, as well as observing and monitoring literature with airlines, shipping companies, and airport management to explore and see the gap between prior research and implementation of its process in the air cargo service. The first phase in this study is to provide an overview of the air cargo industry. The second phase analyzes the characteristic differences between air cargo services and air passenger operating services. And the third phase is a literary bibliography study of air cargo operations, where the focus is on the studies using quantitative models from the perspective of the object of the study, which is the optimization of revenue management on air cargo services. From the results of the study, which is based on the gap between theory and practice, new research opportunities which are related to management of air cargo service revenue in the form of model development are found by adding booking timelines aspects of cargo that can affect the revenue of cargo airline companies and airports.

Measure Guideline: Selecting Ventilation Systems for Existing Homes

Energy Technology Data Exchange (ETDEWEB)

Aldrich, Robb [National Renewable Energy Lab. (NREL), Golden, CO (United States)

2014-02-01

This document addresses adding -or improving - mechanical ventilation systems to existing homes. The purpose of ventilation is to remove contaminants from homes, and this report discusses where, when, and how much ventilation is appropriate in a home, including some discussion of relevant codes and standards. Advantages, disadvantages, and approximate costs of various system types are presented along with general guidelines for implementing the systems in homes. CARB intends for this document to be useful to decision makers and contractors implementing ventilation systems in homes. Choosing the "best" system is not always straightforward; selecting a system involves balancing performance, efficiency, cost, required maintenance, and several other factors. It is the intent of this document to assist contractors in making more informed decisions when selecting systems. Ventilation is an integral part of a high-performance home. With more air-sealed envelopes, a mechanical means of removing contaminants is critical for indoor environmental quality and building durability.

Characterization of Oxy-combustion Impacts in Existing Coal-fired Boilers

Energy Technology Data Exchange (ETDEWEB)

Adams, Bradley [Univ. of Utah, Salt Lake City, UT (United States); Davis, Kevin [Univ. of Utah, Salt Lake City, UT (United States); Senior, Constance [Univ. of Utah, Salt Lake City, UT (United States); Shim, Hong Shim [Univ. of Utah, Salt Lake City, UT (United States); Otten, Brydger Van [Univ. of Utah, Salt Lake City, UT (United States); Fry, Andrew [Univ. of Utah, Salt Lake City, UT (United States); Wendt, Jost [Univ. of Utah, Salt Lake City, UT (United States); Eddings, Eric [Univ. of Utah, Salt Lake City, UT (United States); Paschedag, Alan [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Shaddix, Christopher [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Cox, William [Brigham Young Univ., Provo, UT (United States); Tree, Dale [Brigham Young Univ., Provo, UT (United States)

2013-09-30

Reaction Engineering International (REI) managed a team of experts from University of Utah, Siemens Energy, Praxair, Vattenfall AB, Sandia National Laboratories, Brigham Young University (BYU) and Corrosion Management Ltd. to perform multi-scale experiments, coupled with mechanism development, process modeling and CFD modeling, for both applied and fundamental investigations. The primary objective of this program was to acquire data and develop tools to characterize and predict impacts of CO{sub 2} flue gas recycle and burner feed design on flame characteristics (burnout, NO{sub x}, SO{sub x}, mercury and fine particle emissions, heat transfer) and operational concerns (fouling, slagging and corrosion) inherent in the retrofit of existing coal-fired boilers for oxy-coal combustion. Experimental work was conducted at Sandia National Laboratories’ Entrained Flow Reactor, the University of Utah Industrial Combustion Research Facility, and Brigham Young University. Process modeling and computational fluid dynamics (CFD) modeling was performed at REI. Successful completion of the project objectives resulted in the following key deliverables: 1) Multi-scale test data from 0.1 kW bench-scale, 100 kW and 200 kW laboratory-scale, and 1 MW semi-industrial scale combustors that describe differences in flame characteristics, fouling, slagging and corrosion for coal combustion under air-firing and oxygen-firing conditions, including sensitivity to oxy-burner design and flue gas recycle composition. 2) Validated mechanisms developed from test data that describe fouling, slagging, waterwall corrosion, heat transfer, char burnout and sooting under coal oxy-combustion conditions. The mechanisms were presented in a form suitable for inclusion in CFD models or process models. 3) Principles to guide design of pilot-scale and full-scale coal oxy-firing systems and flue gas recycle configurations, such that boiler operational impacts from oxy-combustion retrofits are minimized. 4

Development of mobile air pollution monitoring system (LIDAR)

Energy Technology Data Exchange (ETDEWEB)

Cha, Hyung Ki; Song, Kyu Seok; Kim, Dukh Yeon; Yang, Ki Ho; Lee, Jong Min; Yoon, S.; Rostov, A

2001-01-01

Most air pollution monitoring technologies accompany a time-consuming sample treatment and provide pollution information only for a local area. Thus, they have a critical restriction in monitoring time-dependent pollution variation effectively over the wide range of area both in height and in width. LIDAR(Light Detection And Ranging) is a new technology to overcome such drawbacks of the existing pollution monitoring technologies and has long been investigated in the advanced countries. The coal of this project is to develop the mobile air pollution monitoring system and to apply the system to the detection of various pollutants, such as ozone, nitrogen dioxide, sulfur dioxide and aerosols.

Development of mobile air pollution monitoring system (LIDAR)

International Nuclear Information System (INIS)

Cha, Hyung Ki; Song, Kyu Seok; Kim, Dukh Yeon; Yang, Ki Ho; Lee, Jong Min; Yoon, S.; Rostov, A.

2001-01-01

Most air pollution monitoring technologies accompany a time-consuming sample treatment and provide pollution information only for a local area. Thus, they have a critical restriction in monitoring time-dependent pollution variation effectively over the wide range of area both in height and in width. LIDAR(Light Detection And Ranging) is a new technology to overcome such drawbacks of the existing pollution monitoring technologies and has long been investigated in the advanced countries. The coal of this project is to develop the mobile air pollution monitoring system and to apply the system to the detection of various pollutants, such as ozone, nitrogen dioxide, sulfur dioxide and aerosols

Theme and variations: amphibious air-breathing intertidal fishes.

Science.gov (United States)

Martin, K L

2014-03-01

Over 70 species of intertidal fishes from 12 families breathe air while emerging from water. Amphibious intertidal fishes generally have no specialized air-breathing organ but rely on vascularized mucosae and cutaneous surfaces in air to exchange both oxygen and carbon dioxide. They differ from air-breathing freshwater fishes in morphology, physiology, ecology and behaviour. Air breathing and terrestrial activity are present to varying degrees in intertidal fish species, correlated with the tidal height of their habitat. The gradient of amphibious lifestyle includes passive remainers that stay in the intertidal zone as tides ebb, active emergers that deliberately leave water in response to poor aquatic conditions and highly mobile amphibious skipper fishes that may spend more time out of water than in it. Normal terrestrial activity is usually aerobic and metabolic rates in air and water are similar. Anaerobic metabolism may be employed during forced exercise or when exposed to aquatic hypoxia. Adaptations for amphibious life include reductions in gill surface area, increased reliance on the skin for respiration and ion exchange, high affinity of haemoglobin for oxygen and adjustments to ventilation and metabolism while in air. Intertidal fishes remain close to water and do not travel far terrestrially, and are unlikely to migrate or colonize new habitats at present, although in the past this may have happened. Many fish species spawn in the intertidal zone, including some that do not breathe air, as eggs and embryos that develop in the intertidal zone benefit from tidal air emergence. With air breathing, amphibious intertidal fishes survive in a variable habitat with minimal adjustments to existing structures. Closely related species in different microhabitats provide unique opportunities for comparative studies. © 2013 The Fisheries Society of the British Isles.

Monitoring and analysis of an absorption air-conditioning system

Energy Technology Data Exchange (ETDEWEB)

Perez de Vinaspre, M.; Bourouis, M.; Coronas, A. [Centro de Innovacion Tecnologica en Revalorizacion Energetica y Refrigeracion, Tarragona (Spain); Garcia, A.; Soto, V.; Pinazo, J.M. [E.T.S. Ingenieros Industriales, Valencia (Spain)

2004-09-01

In the last few years, high-energy consumption due to air-conditioning has led to a growing interest in the efficient use of energy in buildings. Although simulation programs have always been the main tools for analyzing energy in buildings, the reliability of their results is often compromised by a lack of certainty to reflect real conditions. The aim of this work is to monitorize and analyze the thermal behavior of an absorption-based air-conditioning installation of a university building in Tarragona, Spain. The existing monitoring system of the installation has been improved by implementing additional sensors and flow meters. The data has been stored during summer 2002 and used to assess the energy balance of the air-conditioning installation and the operational regime of the absorption chiller. [Author].

Hydroxyl radical reactivity at the air-ice interface

Directory of Open Access Journals (Sweden)

T. F. Kahan

2010-01-01

Full Text Available Hydroxyl radicals are important oxidants in the atmosphere and in natural waters. They are also expected to be important in snow and ice, but their reactivity has not been widely studied in frozen aqueous solution. We have developed a spectroscopic probe to monitor the formation and reactions of hydroxyl radicals in situ. Hydroxyl radicals are produced in aqueous solution via the photolysis of nitrite, nitrate, and hydrogen peroxide, and react rapidly with benzene to form phenol. Similar phenol formation rates were observed in aqueous solution and bulk ice. However, no reaction was observed at air-ice interfaces, or when bulk ice samples were crushed prior to photolysis to increase their surface area. We also monitored the heterogeneous reaction between benzene present at air-water and air-ice interfaces with gas-phase OH produced from HONO photolysis. Rapid phenol formation was observed on water surfaces, but no reaction was observed at the surface of ice. Under the same conditions, we observed rapid loss of the polycyclic aromatic hydrocarbon (PAH anthracene at air-water interfaces, but no loss was observed at air-ice interfaces. Our results suggest that the reactivity of hydroxyl radicals toward aromatic organics is similar in bulk ice samples and in aqueous solution, but is significantly suppressed in the quasi-liquid layer (QLL that exists at air-ice interfaces.

AirPEx. Air Pollution Exposure Model

Energy Technology Data Exchange (ETDEWEB)

Freijer, J.I.; Bloemen, H.J.Th.; De Loos, S.; Marra, M.; Rombout, P.J.A.; Steentjes, G.M.; Van Veen, M.P.

1997-12-01

Analysis of inhalatory exposure to air pollution is an important area of investigation when assessing the risks of air pollution for human health. Inhalatory exposure research focuses on the exposure of humans to air pollutants and the entry of these pollutants into the human respiratory tract. The principal grounds for studying the inhalatory exposure of humans to air pollutants are formed by the need for realistic exposure/dose estimates to evaluate the health effects of these pollutants. The AirPEx (Air Pollution Exposure) model, developed to assess the time- and space-dependence of inhalatory exposure of humans to air pollution, has been implemented for use as a Windows 3.1 computer program. The program is suited to estimating various exposure and dose quantities for individuals, as well as for populations and subpopulations. This report describes the fundamentals of the AirPEx model and provides a user manual for the computer program. Several examples included in the report illustrate the possibilities of the AirPEx model in exposure assessment. The model will be used at the National Institute of Public Health and the Environment as a tool in analysing the current exposure of the Dutch population to air pollutants. 57 refs.

TECHNOLOGIES TO ENHANCE THE OPERATION OF EXISTING NATURAL GAS COMPESSION INFRASTRUCTURE

Energy Technology Data Exchange (ETDEWEB)

Anthony J. Smalley; Ralph E. Harris; Gary D. Bourn; Danny M. Deffenbaugh

2006-01-24

This quarterly report documents work performed under Tasks 15, 16, and 18 through 23 of the project entitled: ''Technologies to Enhance the Operation of Existing Natural Gas Compression Infrastructure''. The project objective is to develop and substantiate methods for operating integral engine/compressors in gas pipeline service, which reduce fuel consumption, increase capacity, and enhance mechanical integrity. The report presents results of design analysis performed on the TCVC10 engine/compressor installed at Dominion's Groveport Compressor Station to develop options and guide decisions for reducing pulsations and enhancing compressor system efficiency and capacity. The report further presents progress on modifying and testing the laboratory GMVH6 at SwRI for correcting air imbalance.

Step response and frequency response of an air conditioning system

NARCIS (Netherlands)

Crommelin, R.D.; Jackman, P.J.

1978-01-01

A system of induction units of an existing air conditioning system has been analyzed with respect to its dynamic properties. Time constants were calculated and measured by analogue models. Comparison with measurements at the installation itself showed a reasonable agreement. Frequency responses were

Air movement and perceived air quality

DEFF Research Database (Denmark)

Melikov, Arsen Krikor; Kaczmarczyk, J.

2012-01-01

The impact of air movement on perceived air quality (PAQ) and sick building syndrome (SBS) symptoms was studied. In total, 124 human subjects participated in four series of experiments performed in climate chambers at different combinations of room air temperature (20, 23, 26 and 28 °C), relative...... and the humidity of the room air. At a low humidity level of 30% an increased velocity could compensate for the decrease in perceived air quality due to an elevated temperature ranging from 20 °C to 26 °C. In a room with 26 °C, increased air movement was also able to compensate for an increase in humidity from 30...... humidity (30, 40 and 70%) and pollution level (low and high). Most of the experiments were performed with and without facially applied airflow at elevated velocity. The importance of the use of recirculated room air and clean, cool and dry outdoor air was studied. The exposures ranged from 60. min to 235...

Pressure ulcer incidence and progression in critically ill subjects: influence of low air loss mattress versus a powered air pressure redistribution mattress.

Science.gov (United States)

Black, Joyce; Berke, Christine; Urzendowski, Gail

2012-01-01

The primary objective of this study was to compare facility-acquired pressure ulcer incidence and progression of pressure ulcers present on admission in critically ill patients, using 2 different support surfaces. We completed a comparison cohort study in a surgical intensive care unit (ICU). The study setting was a 12-bed cardiovascular ICU in a university-based hospital in the Midwestern United States. The sample comprised 52 critically ill patients; 31 were placed on low air loss weight-based pressure redistribution-microclimate management system beds and 21 were placed on integrated powered air pressure redistribution beds. Prior to the start of the study, 5 low airloss beds were placed in open rooms in the cardiovascular surgical ICU. Inclusion criteria were anticipated ICU stay of 3 days, and patients did not receive a speciality bed for pulmonary or wound issues. Initial assessment of the patients included risk assessment and prior events that would increase risk for pressure ulcer development such as extended time in operating room, along with skin assessment for existing pressure ulcers. Subjects in both groups had ongoing skin assessment every 3 to 4 days and a subjective evaluation of heel elevation and turning or repositioning by the researcher. Data were collected until the subjects were dismissed from the ICU. Patients admitted to the unit were assigned to open rooms following the usual protocols. The mean length of stay was 7.0 days, with an 8.1-day length of stay for subjects on "low air loss with microclimate management" beds (LAL-MCM) and 6.6 days on the integrated power pressure air redistribution (IP-AR) beds (P = NS). The incidence of pressure ulcers on the buttocks, sacrum, or coccyx was 0% (0/31) on the low air loss bed and 18% (4/21) on the IP-AR bed (P = .046). Five subjects had 6 pressure ulcers on admission. Two pressure ulcers on 2 patients worsened on the integrated power air redistribution beds, which required specialty bed rental

Low-head air stripper treats oil tanker ballast water

International Nuclear Information System (INIS)

Goldman, M.

1992-01-01

Prototype tests conducted during the winter of 1989/90 have successfully demonstrated an economical design for air stripping volatile hydrocarbons from oily tanker ballast water. The prototype air stripper, developed for Alyeska's Ballast Water Treatment (BWT) facility in Valdez, Alaska, ran continuously for three months with an average removal of 88% of the incoming volatile organics. Initially designed to remove oil and grease compounds from tanker ballast water, the BWT system has been upgraded to a three-step process to comply with new, stringent regulations. The BWT biological oxidation process enhances the growth of bacteria present in the incoming ballast water through nutrient addition, aeration, and recirculation within a complete-mixed bioreactor. The average removal of BETX is over 95%, however, occassional upsets required the placement of a polishing air stripper downstream of the aeration tanks. Packed-tower air stripping was investigated but deemed economically unfeasible for a facility that would only occasionally be used. Twelve feet of excess gravity head in the existing BWT hydraulic gradeline were employed to drive the air stripper feed. This limited the stripper packing depth to 8 feet and imposed constraints on the design of the inlet water and air distributors. Water distribution, air flow, temperature effects, and fouling from constituents in the ballast water were investigated. The prototype was operated under water and air flow conditions similar to those specified for the full-scale unit, and at a range of test conditions above and below the normal design conditions

Numerical Analysis and Geometry Optimisation of Vertical Vane of Room Air-conditioner

Directory of Open Access Journals (Sweden)

Al-Obaidi Abdulkareem Sh. Mahdi

2018-01-01

Full Text Available Vertical vanes of room air-conditioners are used to control and direct cold air. This paper aims to study vertical vane as one of the parameters that affect the efficiency of dissipating cold air to a given space. The vertical vane geometry is analysed and optimised for lower production cost using CFD. The optimised geometry of the vertical vane should have the same or increased efficiency of dissipating cold air and have lesser mass compared to the existing original design. The existing original design of vertical vane is simplified and analysed by using ANSYS Fluent. Efficiency of wind direction is define as how accurate the direction of airflow coming out from vertical vane. In order to calculate the efficiency of wind direction, 15° and 30° rotation of vertical vane inside room air-conditioner are simulated. The efficiency of wind direction for 15° rotation of vertical vane is 57.81% while efficiency of wind direction for 30° rotation of vertical vane is 47.54%. The results of the efficiency of wind direction are used as base reference for parametric study. The parameters investigated for optimisation of vertical vane are focused at length of long span, tip chord and short span. The design of 15% decreased in vane surface area at tip chord is the best optimised design of vertical vane because the efficiency of wind direction is the highest as 60.32%.

Storage of compressed air - Optimisation and measurement of an existing project example; Druckluftspeicherung: Optimierung / Ausmessung bestehendes Projektmuster

Energy Technology Data Exchange (ETDEWEB)

Brueckmann, P. [Brueckmann Elektronik, Davos Dorf (Switzerland); Cyphelly, I. [Cyphelly and Cie, Les Brenets (Switzerland)

2007-06-15

This short final report for the Swiss Federal Office of Energy (SFOE) deals with an additional project that augmented an earlier report on a compressed-air energy storage system. First tests are reported on that revealed that the chosen heat exchanger fulfils the thermal expectations with substantial reserves. Certain effects concerning the liquid piston system are described which showed that further development of the test infrastructure were required. This project was launched to further examine these problems. Difficulties with the liquids available which prohibited the intended exact series of measurements are commented on. The authors note that independent investigations by the Austrian company LINDE came to the same conclusions, thus confirming the function of the heat exchanger.

High-energy air shock study in steel and grout pipes

International Nuclear Information System (INIS)

Glenn, H.D.; Kratz, H.R.; Keough, D.D.; Duganne, D.A.; Ruffner, D.J.; Swift, R.P.; Baum, D.

1979-01-01

Voitenko compressors are used to generate 43 mm/μs air shocks in both a steel and a grout outlet pipe containing ambient atmospheric air. Fiber-optic ports provide diaphragm burst times, time-of-arrival (TOA) data, and velocities for the shock front along the 20-mm-ID exit pipes. Pressure profiles are obtained at higher enthalpy shock propagation than ever before and at many locations along the exit pipes. Numerous other electronic sensors and postshot observations are described, as well as experimental results. The primary objectives of the experiments are as follows: (1) provide a data base for normalization/improvement of existing finite-difference codes that describe high-energy air shocks and gas propagation; (2) obtain quantitative results on the relative attenuation effects of two very different wall materials for high-energy air shocks and gas flows. The extensive experimental results satisfy both objectives

Demand modelling of passenger air travel: An analysis and extension. Volume 1: Background and summary

Science.gov (United States)

Jacobson, I. D.

1978-01-01

The framework for a model of travel demand which will be useful in predicting the total market for air travel between two cities is discussed. Variables to be used in determining the need for air transportation where none currently exists and the effect of changes in system characteristics on attracting latent demand are identified. Existing models are examined in order to provide insight into their strong points and shortcomings. Much of the existing behavioral research in travel demand is incorporated to allow the inclusion of non-economic factors, such as convenience. The model developed is characterized as a market segmentation model. This is a consequence of the strengths of disaggregation and its natural evolution to a usable aggregate formulation. The need for this approach both pedagogically and mathematically is discussed.

Methodological issues in studies of air pollution and reproductive health.

Science.gov (United States)

Woodruff, Tracey J; Parker, Jennifer D; Darrow, Lyndsey A; Slama, Rémy; Bell, Michelle L; Choi, Hyunok; Glinianaia, Svetlana; Hoggatt, Katherine J; Karr, Catherine J; Lobdell, Danelle T; Wilhelm, Michelle

2009-04-01

In the past decade there have been an increasing number of scientific studies describing possible effects of air pollution on perinatal health. These papers have mostly focused on commonly monitored air pollutants, primarily ozone (O(3)), particulate matter (PM), sulfur dioxide (SO(2)), carbon monoxide (CO), and nitrogen dioxide (NO(2)), and various indices of perinatal health, including fetal growth, pregnancy duration, and infant mortality. While most published studies have found some marker of air pollution related to some types of perinatal outcomes, variability exists in the nature of the pollutants and outcomes associated. Synthesis of the findings has been difficult for various reasons, including differences in study design and analysis. A workshop was held in September 2007 to discuss methodological differences in the published studies as a basis for understanding differences in study findings and to identify priorities for future research, including novel approaches for existing data. Four broad topic areas were considered: confounding and effect modification, spatial and temporal exposure variations, vulnerable windows of exposure, and multiple pollutants. Here we present a synopsis of the methodological issues and challenges in each area and make recommendations for future study. Two key recommendations include: (1) parallel analyses of existing data sets using a standardized methodological approach to disentangle true differences in associations from methodological differences among studies; and (2) identification of animal studies to inform important mechanistic research gaps. This work is of critical public health importance because of widespread exposure and because perinatal outcomes are important markers of future child and adult health.

Health benefits from improved outdoor air quality and intervention in China

International Nuclear Information System (INIS)

Li, Shanshan; Williams, Gail; Guo, Yuming

2016-01-01

China is at its most critical stage of outdoor air quality management. In order to prevent further deterioration of air quality and to protect human health, the Chinese government has made a series of attempts to reduce ambient air pollution. Unlike previous literature reviews on the widespread hazards of air pollution on health, this review article firstly summarized the existing evidence of human health benefits from intermittently improved outdoor air quality and intervention in China. Contents of this paper provide concrete and direct clue that improvement in outdoor air quality generates various health benefits in China, and confirm from a new perspective that it is worthwhile for China to shift its development strategy from economic growth to environmental economic sustainability. Greater emphasis on sustainable environment design, consistently strict regulatory enforcement, and specific monitoring actions should be regarded in China to decrease the health risks and to avoid long-term environmental threats. - Highlights: • Firstly reviews the health benefits of improvement in outdoor air quality in China. • Reduction in air pollution generates various health benefits in China. • Chinese government should consider environmental economic sustainability. • Future research on health benefits of air quality improvement is proposed. - Improvement in outdoor air quality generates various health benefits in China. It is worthwhile for China to consider environmental economic sustainability.

Review on urban vegetation and particle air pollution - Deposition and dispersion

Science.gov (United States)

Janhäll, Sara

2015-03-01

Urban vegetation affects air quality through influencing pollutant deposition and dispersion. Both processes are described by many existing models and experiments, on-site and in wind tunnels, focussing e.g. on urban street canyons and crossings or vegetation barriers adjacent to traffic sources. There is an urgent need for well-structured experimental data, including detailed empirical descriptions of parameters that are not the explicit focus of the study. This review revealed that design and choice of urban vegetation is crucial when using vegetation as an ecosystem service for air quality improvements. The reduced mixing in trafficked street canyons on adding large trees increases local air pollution levels, while low vegetation close to sources can improve air quality by increasing deposition. Filtration vegetation barriers have to be dense enough to offer large deposition surface area and porous enough to allow penetration, instead of deflection of the air stream above the barrier. The choice between tall or short and dense or sparse vegetation determines the effect on air pollution from different sources and different particle sizes.

Droplet Impacting on Liquid Film: Evolution of Entrapped Air Layer

Science.gov (United States)

Tang, Xiaoyu; Saha, Abhishek; Law, Chung K.

2014-11-01

In this work we experimentally studied the dynamics of droplet impacting films of various thicknesses within a range of h / R <= 1 (h: film thickness; R: droplet radius). High speed imaging and color interferometry enabled the investigation of the evolution of the air layer trapped between two surfaces, which plays a critical role in determining the collision outcome. Globally, two distinct regimes of impaction outcome, namely bouncing and merging, are observed at low and high impact inertia, respectively. Impaction with high inertia depletes the air layer before the droplet significantly deforms, resulting in permanent merging. At low impact inertia, however, color interferometry shows the existence of three phases prior to bouncing. Upon impaction, droplet endures significant deformation trapping the air layer between the interfaces, hence increasing the resistance force. This phase is characterized by fast deformation of the air film, followed by a period of pseudo equilibrium, with minimal changes in the interfacial air-film profile. The droplet also lacks kinetic energy to penetrate further into the film, resulting in a temporary balance between the droplet weight and air-film pressure. The deformed droplet eventually relaxes towards spherical shape to destroy the equilibrium. Fast change occurs in air-layer and pressure distribution favoring the droplet bouncing.

Air Quality and Heart Health: An Emerging Topic for Heart ...

Science.gov (United States)

Air Quality and Heart Health: An Emerging Topic for Heart Month: Ambient air particle pollution increases short- and long-term cardiovascular morbidity and mortality. Older-people, those with pre-existing heart disease and lung disease and diabetes are at higher risk. Mechanisms are under investigation and are likely related to oxidative stress, inflammation and effects on autonomic control. Improvements in air pollution levels reduce health impacts and increase life expectancy. Reductions of short-term exposure in those at highest risk are predicted to mitigate adverse health effects. EPA regularly evaluates the standards, health risks and issues improved standards when needed. Public health action is needed along with EPA standards to reduce the public health burden of short- and long-term adverse health effects of air pollution. Health risks remain and need to be addressed through integrated efforts of public health, health care, environmental health, individuals and communities. Presented at Webinar for the National Association of Clean Air Agencies, February 2, 2017, Chapel Hill, NC- This webinar provided an update of environmental health information related to the effects of air pollution and heart and blood vessel disease. Such information is critically important for the Clean Air Agencies to understand as it provides the justification of their actions.

Phase 1 remediation of jet fuel contaminated soil and groundwater at JFK International Airport using dual phase extraction and bioventing

International Nuclear Information System (INIS)

Roth, R.; Bianco, P. Rizzo, M.

1995-01-01

Soil and groundwater contaminated with jet fuel at Terminal One of the JFK International Airport in New York have been remediated using dual phase extraction (DPE) and bioventing. Two areas were remediated using 51 DPE wells and 20 air sparging/air injection wells. The total area remediated by the DPE wells is estimated to be 4.8 acres. Groundwater was extracted to recover nonaqueous phase and aqueous phase jet fuel from the shallow aquifer and treated above ground by the following processes; oil/water separation, iron-oxidation, flocculation, sedimentation, filtration, air stripping and liquid-phase granular activated carbon (LPGAC) adsorption. The extracted vapors were treated by vapor-phase granular activated carbon (VPGAC) adsorption in one area, and catalytic oxidation and VPGAC adsorption in another area. After 6 months of remediation, approximately 5,490 lbs. of volatile organic compounds (VOCs) were removed by soil vapor extraction (SVE), 109,650 lbs. of petroleum hydrocarbons were removed from the extracted groundwater, and 60,550 lbs. of petroleum hydrocarbons were biologically oxidized by subsurface microorganisms. Of these three mechanisms, the rate of petroleum hydrocarbon removal was the highest for biological oxidation in one area and by groundwater extraction in another area

Conflict Resolution: The Relationship Between Air Force Public Affairs and Legal Functions

National Research Council Canada - National Science Library

Law, James

1998-01-01

.... This research examines the relationship between Air Force public affairs and legal functions to find out what conflict exists, how often it occurs, how it is resolved, what the results are for the...

Nondestructive natural gas hydrate recovery driven by air and carbon dioxide.

Science.gov (United States)

Kang, Hyery; Koh, Dong-Yeun; Lee, Huen

2014-10-14

Current technologies for production of natural gas hydrates (NGH), which include thermal stimulation, depressurization and inhibitor injection, have raised concerns over unintended consequences. The possibility of catastrophic slope failure and marine ecosystem damage remain serious challenges to safe NGH production. As a potential approach, this paper presents air-driven NGH recovery from permeable marine sediments induced by simultaneous mechanisms for methane liberation (NGH decomposition) and CH₄-air or CH₄-CO₂/air replacement. Air is diffused into and penetrates NGH and, on its surface, forms a boundary between the gas and solid phases. Then spontaneous melting proceeds until the chemical potentials become equal in both phases as NGH depletion continues and self-regulated CH4-air replacement occurs over an arbitrary point. We observed the existence of critical methane concentration forming the boundary between decomposition and replacement mechanisms in the NGH reservoirs. Furthermore, when CO₂ was added, we observed a very strong, stable, self-regulating process of exchange (CH₄ replaced by CO₂/air; hereafter CH₄-CO₂/air) occurring in the NGH. The proposed process will work well for most global gas hydrate reservoirs, regardless of the injection conditions or geothermal gradient.

Electrodialytic remediation of air pollution control residues in bench scale

DEFF Research Database (Denmark)

Jensen, Pernille Erland; Ferreira, Celia; Hansen, Henrik K.

2008-01-01

Air pollution control (APC) residue from municipal solid waste incineration (MSWI) is considered a hazardous waste due to its alkalinity and high content of salts and mobile heavy metals. Various solutions for the handling of APC-residue exist in different regions; however, most commercial soluti...

78 FR 63937 - Approval and Promulgation of Implementation Plans; Approval and Promulgation of State Air Quality...

Science.gov (United States)

2013-10-25

... Quality Plans for Designated Facilities and Pollutants, State of Iowa; Control of Emissions From Existing Hospital/ Medical/Infectious Waste Incinerator Units, Negative Declaration and 111(d) Plan Rescission... existing state air quality rules, approve an exemption from constructing permitting for engines used in...

Control of air toxics

International Nuclear Information System (INIS)

Livengood, C.D.

1995-01-01

For more than 10 years, Argonne National Laboratory has supported the US DOE's Flue Gas Cleanup Program objective by developing new or improved environmental controls for industries that use fossil fuels. Argonne's pollutant emissions research has ranged from experiments in the basic chemistry of pollution-control systems, through laboratory-scale process development and testing, to pilot-scale field tests of several technologies. The work on air toxics is currently divided into two components: Investigating measures to improve the removal of mercury in existing pollution-control systems applied to coal combustion; and, Developing sensors and control techniques for emissions found in the textile industry

New Brunswick air quality monitoring results for the year 2000

International Nuclear Information System (INIS)

Hughes, R.

2002-01-01

Monitoring data for air quality in New Brunswick in 2000 is presented in this document. Designed for the general public, it summarizes the air quality results for 2000 and focuses on air quality assessment as it relates to existing air quality standards and objectives. The report also contains the long term trend data for representative sites. The New Brunswick Air Quality Regulation of the Clean Air Act specifies the air quality standards applicable for carbon monoxide, sulphur dioxide, hydrogen sulphide, nitrogen dioxide and total suspended particulate. The monitoring was conducted at 58 sites in 8 regional monitoring networks throughout the province. Thirteen additional sites were selected for the measurement of acid rain. Despite the fact that no standards were in effect in 2000 in New Brunswick for several substances, including inhalable particulate matter, ground-level ozone, volatile organic compounds, selected semi-volatile organic compounds, trace elements in particulate matter and mercury in air and precipitation, their levels were measured at some locations. The results indicate that emissions trends, variations in industrial output, changing process or emission control technologies, and weather conditions throughout the year explain most of the variations in results between regions. As a rule, compliance with standards is good. Acid rain continued to impact, especially in the southwestern districts of the province. Since 1996, the levels of mercury in precipitation has slightly declined. 39 refs., 43 figs

Assessment of SRS ambient air monitoring network

Energy Technology Data Exchange (ETDEWEB)

Abbott, K. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Jannik, T. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

2016-08-03

Three methodologies have been used to assess the effectiveness of the existing ambient air monitoring system in place at the Savannah River Site in Aiken, SC. Effectiveness was measured using two metrics that have been utilized in previous quantification of air-monitoring network performance; frequency of detection (a measurement of how frequently a minimum number of samplers within the network detect an event), and network intensity (a measurement of how consistent each sampler within the network is at detecting events). In addition to determining the effectiveness of the current system, the objective of performing this assessment was to determine what, if any, changes could make the system more effective. Methodologies included 1) the Waite method of determining sampler distribution, 2) the CAP88- PC annual dose model, and 3) a puff/plume transport model used to predict air concentrations at sampler locations. Data collected from air samplers at SRS in 2015 compared with predicted data resulting from the methodologies determined that the frequency of detection for the current system is 79.2% with sampler efficiencies ranging from 5% to 45%, and a mean network intensity of 21.5%. One of the air monitoring stations had an efficiency of less than 10%, and detected releases during just one sampling period of the entire year, adding little to the overall network intensity. By moving or removing this sampler, the mean network intensity increased to about 23%. Further work in increasing the network intensity and simulating accident scenarios to further test the ambient air system at SRS is planned

[Air pollution and cardiovascular toxicity: known risks].

Science.gov (United States)

Kostrzewa, A; Filleul, L; Eilstein, D; Harrabi, I; Tessier, J F

2004-03-01

Review of studies about epidemiological and physiopathological knowledge of ambient air particles short-term cardio-vascular effects. CURRENTS AND STRONG POINTS: Many studies, in contrasted countries for pollution's sources, meteorological conditions or socio-demographical characteristics, have shown health effects due to ambient air particles. After having studied mainly the respiratory effects of particulate air pollution, epidemiologists are now interested in the cardio-vascular effects of ambient air particles. In fact, serious effects seem to exist in fragile people which can get to emergency department visits, hospitalisation and even death. In addition, studies have shown less serious effects, but likely to be frequent (cardiac symptoms, and stoppages for cardio-vascular causes, notably). The exact mechanism by which particles have cardio-vascular adverse health effects is unknown, but experimental and epidemiological studies have led to several hypotheses: local pulmonary effects seem to be followed by systemic effects, which would be responsible for effects on the electrical activity of the heart through cardiac autonomic dysfunction and effects on the blood supply to the heart. The objective of this work is to summarise epidemiological and physiopathological knowledge about the cardio-vascular effects of ambient air particles. To evaluate the real importance of cardio-vascular effects due to particulate air pollution and to identify their exact mechanism, a more precise knowledge of detailed causes of deaths and hospitalisations and a better knowledge of less serious effects, but likely to be frequent, is necessary. Equally, a detailed identification of fragile people is essential for developing preventive actions.

Air dose rate in Aichi Prefecture

International Nuclear Information System (INIS)

Ohnuma, Shoko; Chaya, Kunio; Tomita, Banichi; Aoyama, Kan; Yamada, Naoki; Yamada, Masuo; Hamamura, Norikatsu

1985-01-01

We have carried out the observations of air dose rate during 1964--1983 at the fixed points of Aichi Prefecture and investigated the distribution of air dose rate in this prefecture during 1979--1983. The results of these researches are as follows. 1) The apparent half time of radiation dose from the earth and the atmosphere during the last 20 years was about 9.7 years and it was longer than the apparent half time of fallout total β radioactivity in every rainfall that was about 3.2 years. 2) The influence of nuclear explosion test in China on the measurements of air does rate did not existed directly during the latter half of 20 years, not so as during the former and it was keeping decreasing. It was expected that the air dose rate would begin to indicate the natural radiation dose from the earth and the atmosphere in the near future. 3) The distribution of air dose rate in this prefecture depended strongly on the geology. The maximum value was 5.6 μR/hr (except cosmic rays) in Fujioka Cho, the minimum value was 1.9 μR/hr (except cosmic rays) in Tahara Cho and the average in the whole prefecture was 3.5+-0.7 μR/hr (except cosmic rays). 4) It was estimated that the radiation dose which the inhabitants received from the earth and the atmosphere was 17--52 m rem a year and the average was 31 m rem a year. (author)

Air dose rate in Aichi Prefecture

Energy Technology Data Exchange (ETDEWEB)

Ohnuma, Shoko; Chaya, Kunio; Tomita, Banichi; Aoyama, Kan; Yamada, Naoki; Yamada, Masuo; Hamamura, Norikatsu

1985-03-01

We have carried out the observations of air dose rate during 1964-1983 at the fixed points of Aichi Prefecture and investigated the distribution of air dose rate in this prefecture during 1979-1983. The results of these researches are as follows. 1) The apparent half time of radiation dose from the earth and the atmosphere during the last 20 years was about 9.7 years and it was longer than the apparent half time of fallout total ..beta.. radioactivity in every rainfall that was about 3.2 years. 2) The influence of nuclear explosion test in China on the measurements of air does rate did not existed directly during the latter half of 20 years, not so as during the former and it was keeping decreasing. It was expected that the air dose rate would begin to indicate the natural radiation dose from the earth and the atmosphere in the near future. 3) The distribution of air dose rate in this prefecture depended strongly on the geology. The maximum value was 5.6 ..mu..R/hr (except cosmic rays) in Fujioka Cho, the minimum value was 1.9 ..mu..R/hr (except cosmic rays) in Tahara Cho and the average in the whole prefecture was 3.5 +- 0.7 ..mu..R/hr (except cosmic rays). 4) It was estimated that the radiation dose which the inhabitants received from the earth and the atmosphere was 17-52 m rem a year and the average was 31 m rem a year.

Evaluation of modified boehm titration methods for use with biochars.

Science.gov (United States)

Fidel, Rivka B; Laird, David A; Thompson, Michael L

2013-11-01

The Boehm titration, originally developed to quantify organic functional groups of carbon blacks and activated carbons in discrete pK ranges, has received growing attention for analyzing biochar. However, properties that distinguish biochar from carbon black and activated carbon, including greater carbon solubility and higher ash content, may render the original Boehm titration method unreliable for use with biochars. Here we use seven biochars and one reference carbon black to evaluate three Boehm titration methods that use (i) acidification followed by sparging (sparge method), (ii) centrifugation after treatment with BaCl (barium method), and (iii) a solid-phase extraction cartridge followed by acidification and sparging (cartridge method) to remove carbonates and dissolved organic compounds (DOC) from the Boehm extracts before titration. Our results for the various combinations of Boehm reactants and methods indicate that no one method was free of bias for all three Boehm reactants and that the cartridge method showed evidence of bias for all pK ranges. By process of elimination, we found that a combination of the sparge method for quantifying functional groups in the lowest pK range (∼5 to 6.4), and the barium method for quantifying functional groups in the higher pK ranges (∼6.4 to 10.3 and ∼10.3 to 13) to be free of evidence for bias. We caution, however, that further testing is needed and that all Boehm titration results for biochars should be considered suspect unless efforts were undertaken to remove ash and prevent interference from DOC. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

X-rays spectrum and air Kerma during a mammography study; Espectro de los rayos X y Kerma en aire durante un estudio mamografico

Energy Technology Data Exchange (ETDEWEB)

Ramirez G, J. [Instituto Nacional de Estadistica Geografia e Informatica, Av. Heroes de Nacozari Sur 2301, Fracc. Jardines del Parque, 20276 Aguascalientes (Mexico); Hernandez V, R.; Hernandez D, V. M.; Vega C, H. R. [Unidad Academica de Estudios Nucleares, Universidad Autonoma de Zacatecas, Cipres 10, Fracc. La Penuela, 98068 Zacatecas (Mexico)], e-mail: fermineutron@yahoo.com

2009-10-15

In this calculation series was modeled the source of electrons, the target and the filter. Using thermoluminescent dosemeters of ZrO{sub 2}+PTFE the air Kerma was measured in five points located on a phantom made with acrylic and water when it was exposed to a X-rays beam produced by electrons of 24 KeV and 10 m A of current that produces a mammography. The air Kerma values at the entrance surface of the phantom were compared with values calculated by Monte Carlo methods. The air Kerma values measured indicate that approximately the five points receive the same air Kerma, what means that the beam is homogeneous, of the Monte Carlo calculations we find that the center receives a greater dose what implies that the beam is not uniform, the explanation of this fact is attributed to was used a simple model in the calculations, nevertheless, the air Kerma average measured at the entrance surface of the phantom was of 0.96 +{sub -} 0.03 m G, while the other obtained by the calculations was of 0.96 +{sub -} 0.06 mGy, to compare both do not exist significant differences. (author)

A mixed air/air and air/water heat pump system ensures the air-conditioning of a cinema; Un systeme mixte PAC air/air et air/eau climatise un cinema

Energy Technology Data Exchange (ETDEWEB)

Anon.

2001-03-01

This article presents the air conditioning system of a new cinema complex of Boulogne (92, France) which comprises a double-flux air processing plant and two heat pumps. Each heat pump has two independent refrigerating loops: one with a air condenser and the other with a water condenser. This system allows to limit the power of the loop and to reduce the size of the cooling tower and of the vertical ducts. This article describes the technical characteristics of the installation: thermodynamic units, smoke clearing, temperature control, air renewing. (J.S.)

Analysis of flame shapes in turbulent hydrogen jet flames with coaxial air

International Nuclear Information System (INIS)

Moon, Hee Jang

2009-01-01

This paper addresses the characteristics of flame shapes and flame length in three types of coaxial air flames realizable by varying coaxial air and/or fuel velocity. Forcing coaxial air into turbulent jet flames induces substantial changes in flame shapes and NOx emissions through the complex flow interferences that exist within the mixing region. Mixing enhancement driven by coaxial air results in flame volume decrease, and such a diminished flame volume finally reduces NOx emissions significantly by decreasing NOx formation zone where a fuel/air mixture burns. It is found that mixing in the vicinity of high temperature zone mainly results from the increase of diffusive flux than the convective flux, and that the increase of mass diffusion is amplified as coaxial air is increased. Besides, it is reaffirmed that nonequilibrium chemistry including HO 2 /H 2 O 2 should be taken into account for NOx prediction and scaling analysis by comparing turbulent combustion models. In addition, it is found that coaxial air can break down the self-similarity law of flames by changing mixing mechanism, and that EINOx scaling parameters based on the self-similarity law of simple jet flames may not be eligible in coaxial air flames

Distribution and Room Air Mixing Risks to Retrofitted Homes

Energy Technology Data Exchange (ETDEWEB)

Burdick, A. [IBACOS, Inc., Pittsburgh, PA (United States)

2014-12-01

Energy efficiency upgrades reduce heating and cooling loads on a house. With enough load reduction and if the HVAC system warrants replacement, the HVAC system is often upgraded with a more efficient, lower capacity system that meets the loads of the upgraded house. For a single-story house with ceiling supply air diffusers, ducts are often removed and upgraded. For houses with ducts that are embedded in walls, the cost of demolition precludes the replacement of ducts. The challenge with the use of existing ducts is that the reduced airflow creates a decreased throw at the supply registers, and the supply air and room air do not mix well, leading to potential thermal comfort complaints. This project investigates this retrofit scenario. The issues and solutions discussed here are relevant to all climate zones, with emphasis on climates that require cooling.

A simple method to determine Tr concentrations in the moisture of the exhaust air of nuclear facilities and in the ambient air

International Nuclear Information System (INIS)

Weber, H.W.; Schuettelkopf, H.

1983-04-01

In the course of nuclear power plant operation radioactive tritium is generated which is released to the environment as HTO via the exhaust air and the liquid effluents. Measurement and balancing of the tritium emissions are required in order to be able to evaluate the resulting radiation exposure of the population. For determination of the HTO emission the humidity of the measured air is absorbed at a rod shaped molecular sieve of 1/16'' mesh size. The desiccant is contacted with T-free water and the T activity concentration of the water is determined after 3 H/ 1 H isotope exchange. The rod shaped molecular sieves are suited for use under this method on account of their drying capacity largely independent of temperature and air humidity and the good handling capability. The detection limit is at 19 Bq HTO/m 3 air. The exhaust air from several 3 H-emitters of the Karlsruhe Nuclear Research Center was monitored by this method for its HTO content and the results were compared with the values measured at existing points of measurement. The good results have been the reason for the application of such collectors in the routine T-measurement performed within the framework of exhaust air monitoring on the site of the Karlsruhe Nuclear Research Center. (orig./HP) [de

Air quality management planning (AQMP

Directory of Open Access Journals (Sweden)

Sivertsen Bjarne

2012-01-01

Full Text Available In most urban areas of the world, particulate matter (PM levels pose severe problems, addressed in several policy areas (air quality, climate change, and human health. PM presents multiple challenges due to the multitude of its sources, spanning many sectors of economic activity as well as nature, and due to the complexity of atmospheric processes involved in its transport and secondary formation. For the authorities, the goal is to assure minimal impacts of atmospheric PM levels, in practice represented by compliance with existing regulations and standards. This may be achieved through an air quality management plan (AQMP. In Northern America and in parts of Europe, comprehensive research programs have guided development of AQMP over the last forty years. This cumulated experience can be utilized by others who face the same problems, but have yet to develop their own substantial research base. The main purpose of the AQMP development process is to establish an effective and sound basis for planning and management of air quality in a selected area. This type of planning will ensure that significant sources of impacts are identified and controlled in a most cost-effective manner. The choice of tools, methods and input information is often dictated by their availability, and should be evaluated against current best practices. Important elements of the AQMP are the identification of sources and development of a complete emission inventory, the development and operation of an air quality monitoring programme, and the development and application of atmospheric dispersion models. Major task is to collect the necessary input data. The development of the AQMP will take into account: - Air Quality Management System (AQMS requirements; - Operational and functional structure requirements; - Source identification through emission inventories; - Source reduction alternatives, which may be implemented; - Mechanisms for facilitating interdepartmental

Federal-state partnership: An overview of the Clean Air Act through the 1980s

International Nuclear Information System (INIS)

Anon.

1991-01-01

This chapter examines the experience with Clean Air Act regulation over the past two decades as a means of understanding the multiple layers of regulatory requirements that now exist since the enactment of the 1990 Amendments to the Act. The efforts of Congress and the EPA to deal with the complexities of clean air regulation suggest several themes for the 1990s: more federal oversight, more complex regulatory issues, an emphasis on alternatives to traditional rulemaking proceedings, and a search for innovative ways to control the escalating costs of clean air regulation

Fate of corrosion products released from stainless steel in marine sediments and seawater. Part 4: Hatteras abyssal red clay

International Nuclear Information System (INIS)

Schmidt, R.L.

1982-07-01

A study in which neutron-activated 347 stainless steel was exposed to surficial sediment from a site in the Hatteras Abyssal Plain of the Northwest Atlantic Ocean is described. This sediment consists of approx. 20% CaCO 3 , which could lead to the formation of calcareous scale on the metal surface and reduce the corrosion rate. The distribution of indigenous metals among different chemical fractions shows that extractable Cr, Mn, Fe, Co, and Zn were associated with amorphous Mn and Fe oxides. Most of the remaining extractable Cr, and about a third of the extractable Cu appear to have been weakly complexed. Major fractions (25 to 36%) of extractable Mn, Co and Ni were present as adsorbed cations. Organic complexation appears to account for a large amount of extractable Fe, Ni, Cu and Zn. Neutron-activated 347 stainless steel specimens were exposed to sediment slurry under aerobic and non-oxygenated conditions for a period of 94 days. The redox potential measurements for air-sparged and N 2 , CO 2 -sparged sediment slurries were +410 and +60 mv, respectively. The presence of 0 2 produced increased amounts of corrosion products. Chemical extraction showed that relatively labile substances constituted about 84% of the 60 Co activity released in aerated sediment. Relatively labile substances constitute about 82% of the total 60 Co activity released under non-oxygenated conditions. A large fraction of 60 Co which was in the soluble or easily dissolved forms under non-oxygenated conditions appears to have been more strongly adsorbed to the sediment under aerated conditions

An analysis of severe air transport accidents

International Nuclear Information System (INIS)

McClure, J.D.; Luna, R.E.

1989-01-01

The objective of this paper is to analyze the severity of aircraft accidents that may involve the air transport of radioactive materials (RAM). One of the basic aims of this paper is to provide a numerical description of the severity of aircraft transport accidents so that the accident severity can be compared with the accident performance standards that are specified in IAEA Safety Series 6, the international packaging standards for the safe movement of RAM. The existing packaging regulations in most countries embrace the packaging standards developed by the IAEA. Historically, the packaging standards for Type B packages have been independent of the transport mode. That is, if the shipment occurs in a certified packaging, then the shipment can take place by any transport mode. In 1975, a legislative action occurred in the US Congress which led to the development of a package designed specifically for the air transport of plutonium. Changes were subsequently made to the US packaging regulations in 10CFR71 to incorporate the plutonium air transport performance standards. These standards were used to certify the air transport package for plutonium which is commonly referred to as PAT-1 (US NRC). The PAT-1 was certified by the US Nuclear Regulatory Commission in September 1978

Air-breathing fishes in aquaculture. What can we learn from physiology?

Science.gov (United States)

Lefevre, S; Wang, T; Jensen, A; Cong, N V; Huong, D T T; Phuong, N T; Bayley, M

2014-03-01

During the past decade, the culture of air-breathing fish species has increased dramatically and is now a significant global source of protein for human consumption. This development has generated a need for specific information on how to maximize growth and minimize the environmental effect of culture systems. Here, the existing data on metabolism in air-breathing fishes are reviewed, with the aim of shedding new light on the oxygen requirements of air-breathing fishes in aquaculture, reaching the conclusion that aquatic oxygenation is much more important than previously assumed. In addition, the possible effects on growth of the recurrent exposure to deep hypoxia and associated elevated concentrations of carbon dioxide, ammonia and nitrite, that occurs in the culture ponds used for air-breathing fishes, are discussed. Where data on air-breathing fishes are simply lacking, data for a few water-breathing species will be reviewed, to put the physiological effects into a growth perspective. It is argued that an understanding of air-breathing fishes' respiratory physiology, including metabolic rate, partitioning of oxygen uptake from air and water in facultative air breathers, the critical oxygen tension, can provide important input for the optimization of culture practices. Given the growing importance of air breathers in aquaculture production, there is an urgent need for further data on these issues. © 2014 The Fisheries Society of the British Isles.

Kajian Analitik Perencanaan Pintu Air Pembangkit Listrik Tenaga Air

OpenAIRE

Pradoto, Pradoto

1993-01-01

Pada pintu air pembangkit listrik tenaga air umumnya dipasang pengauat-penguat (girder). Tujuannya agar pintu air kuat dalam menahan tekanan air. Tekanan air yang diderita oleh pintu air cukup besar karena dipasang pada kedalaman + 50 meter di bawah permukaan air. Permasalahan yang timbul adalah menentukan posisi atau letak girder pada pintu air.

Accelerated Air-coupled Ultrasound Imaging of Wood Using Compressed Sensing

Directory of Open Access Journals (Sweden)

Yiming Fang

2015-12-01

Full Text Available Air-coupled ultrasound has shown excellent sensitivity and specificity for the nondestructive imaging of wood-based material. However, it is time-consuming, due to the high scanning density limited by the Nyquist law. This study investigated the feasibility of applying compressed sensing techniques to air-coupled ultrasound imaging, aiming to reduce the number of scanning lines and then accelerate the imaging. Firstly, an undersampled scanning strategy specified by a random binary matrix was proposed to address the limitation of the compressed sensing framework. The undersampled scanning can be easily implemented, while only minor modification was required for the existing imaging system. Then, discrete cosine transform was selected experimentally as the representation basis. Finally, orthogonal matching pursuit algorithm was utilized to reconstruct the wood images. Experiments on three real air-coupled ultrasound images indicated the potential of the present method to accelerate air-coupled ultrasound imaging of wood. The same quality of ACU images can be obtained with scanning time cut in half.

Optimisation of key performance measures in air cargo demand management

Directory of Open Access Journals (Sweden)

Alexander May

2014-04-01

Full Text Available This article sought to facilitate the optimisation of key performance measures utilised for demand management in air cargo operations. The focus was on the Revenue Management team at Virgin Atlantic Cargo and a fuzzy group decision-making method was used. Utilising intelligent fuzzy multi-criteria methods, the authors generated a ranking order of ten key outcome-based performance indicators for Virgin Atlantic air cargo Revenue Management. The result of this industry-driven study showed that for Air Cargo Revenue Management, ‘Network Optimisation’ represents a critical outcome-based performance indicator. This collaborative study contributes to existing logistics management literature, especially in the area of Revenue Management, and it seeks to enhance Revenue Management practice. It also provides a platform for Air Cargo operators seeking to improve reliability values for their key performance indicators as a means of enhancing operational monitoring power.

Recent trends in air transport sustainibility

Energy Technology Data Exchange (ETDEWEB)

Benito, A.; Alonso, G.

2016-07-01

The target of this paper is to analyse the main elements of Air Transport sustainability, studying their evolution during the last years and establishing the future prevalent trends, which might be modified by the application of the adequate policies. Air Transport sustainability is considered as integrated by five basic characteristics: physical accessibility, economic affordability, safety, security and environmental impact. Each one of them has its own influence on the development of this transportation mode and all of them are required in order to achieve a sustainable development. After defining the structural elements of the five characteristics and the corresponding quantitative indicators, the paper studies the recent evolution of such indicators and extrapolates the most likely future trends, having taken into account the most relevant limitations presently existent or potentially appearing in the near future. The most important policies being presently studied (future aircraft designs, infrastructure developments, potential safety and security new rules and tentative environmental action programs) are evaluated, considering the potential repercussions on sustainability progress. Some combinations of them are suggested as the most efficient alternatives for preserving the sustainable development of XXI century air transport. (Author)

Promoting Sound Ethical Decisions in the Air Force: CGO Solutions to Air Force Moral and Ethical Lapses

Science.gov (United States)

2014-07-01

The second step is to create a Cross Check program—essentially franchising the Think Tank process in smaller groups across the Air Force as a forum...the Think Tank process as it now exists considering the shortening of SOS to five weeks. An evolution of the Think Tank—Think Tank Next—however, could...accessed 20 July 2014). 32  Cross Check Think Tank 14D proposes the implementation of “Cross Check” programs—essentially franchising the Think Tank

Results of Large-Scale Testing on Effects of Anti-Foam Agent on Gas Retention and Release

Energy Technology Data Exchange (ETDEWEB)

Stewart, Charles W.; Guzman-Leong, Consuelo E.; Arm, Stuart T.; Butcher, Mark G.; Golovich, Elizabeth C.; Jagoda, Lynette K.; Park, Walter R.; Slaugh, Ryan W.; Su, Yin-Fong; Wend, Christopher F.; Mahoney, Lenna A.; Alzheimer, James M.; Bailey, Jeffrey A.; Cooley, Scott K.; Hurley, David E.; Johnson, Christian D.; Reid, Larry D.; Smith, Harry D.; Wells, Beric E.; Yokuda, Satoru T.

2008-01-03

The U.S. Department of Energy (DOE) Office of River Protection’s Waste Treatment Plant (WTP) will process and treat radioactive waste that is stored in tanks at the Hanford Site. The waste treatment process in the pretreatment facility will mix both Newtonian and non-Newtonian slurries in large process tanks. Process vessels mixing non-Newtonian slurries will use pulse jet mixers (PJMs), air sparging, and recirculation pumps. An anti-foam agent (AFA) will be added to the process streams to prevent surface foaming, but may also increase gas holdup and retention within the slurry. The work described in this report addresses gas retention and release in simulants with AFA through testing and analytical studies. Gas holdup and release tests were conducted in a 1/4-scale replica of the lag storage vessel operated in the Pacific Northwest National Laboratory (PNNL) Applied Process Engineering Laboratory using a kaolin/bentonite clay and AZ-101 HLW chemical simulant with non-Newtonian rheological properties representative of actual waste slurries. Additional tests were performed in a small-scale mixing vessel in the PNNL Physical Sciences Building using liquids and slurries representing major components of typical WTP waste streams. Analytical studies were directed at discovering how the effect of AFA might depend on gas composition and predicting the effect of AFA on gas retention and release in the full-scale plant, including the effects of mass transfer to the sparge air. The work at PNNL was part of a larger program that included tests conducted at Savannah River National Laboratory (SRNL) that is being reported separately. SRNL conducted gas holdup tests in a small-scale mixing vessel using the AZ-101 high-level waste (HLW) chemical simulant to investigate the effects of different AFAs, their components, and of adding noble metals. Full-scale, single-sparger mass transfer tests were also conducted at SRNL in water and AZ-101 HLW simulant to provide data for PNNL�

Dry storage systems with free convection air cooling

International Nuclear Information System (INIS)

Kioes, S.R.

1980-01-01

Several design principles to remove heat from the spent fuel by free air convection are illustrated and described. The key safety considerations were felt to be: loss of coolant is impossible as the passive system uses air as a coolant; overheating is precluded because as the temperatures of the containers rises the coolant flow rate increases; mass of the storage building provides a large heat sink and therefore a rapid temperature rise is impossible; and lack of any active external support requirements makes the cooling process less likely to equipment or operator failures. An example of this type of storage already exists. The German HTGR is operated with spherical graphite fuel elements which are stored in canister and in storage cells. The concept is a double cooling system with free convection inside the cells and heat exchange via two side walls of the cell to the ambient air in the cooling ducts. Technical description of the TN 1300 cask is also presented

Annoyance due to noise and air pollution to the residents of heavily frequented streets

Science.gov (United States)

Wanner, H. U.; Wehrli, B.; Nemecek, J.; Turrian, V.

1980-01-01

The residents of different streets with varying traffic density and building density were questioned about annoyance due to traffic noise and air pollution. Results show that annoyance felt is dependent not only on the measured noise levels and/or air pollution concentrations, but that there do exist interactions between the residential quarters and annoyance. These interactions should be considered when fixing the limits and standards.

The ultimate air shower observatory

International Nuclear Information System (INIS)

Jones, L.W.

1981-01-01

The possibility of constructing an international air shower observatory in the Himalayas is explored. A site at about 6500 m elevation (450 g/cm 2 ) would provide more definitive measurements of composition and early interaction properties of primaries above 10 16 eV than can be achieved with existing arrays. By supplementing a surface array with a Fly's Eye and muon detectors, information on the highest energy cosmic rays may be gained which is not possible in any other way. Potential sites, technical aspects, and logistical problems are explored

Estimation of air quality by air pollution indices

International Nuclear Information System (INIS)

Liblik, Valdo; Kundel, Helmut

1999-01-01

A novel system for estimating the quality of atmospheric air in the over-ground air layer with the help of air pollution indices was developed. The method is based on a comparison of measured or calculated maximum short-term concentrations and average annual concentrations of pollutants with maximum permissible concentrations (with regard to human beings and vegetation). Special air quality estimation scales for residential areas and natural systems are presented. On the basis of the concentration of the substance under study zones of very high, high, rather high, moderate, low and very low air pollution were distinguished in the over-ground layer of the atmosphere. These are projected to land surface for landscape zonation. The application of the system of indices is demonstrated in the analysis of air quality for the towns of Kohtla-Jarve, Johvi and Kivioli (in 1997-1998). A comparative analysis of the air pollution zones distinguished on the basis of emissions and data from bio monitoring yielded satisfactory results. The system of air pollution indices developed enables to process the results of air monitoring in case of pollution fields of complicated composition so that the result for estimating the quality of ambient air in a residential area is easily understood by inhabitants and interpretable with the help of a special scale; analyse temporal changes in the quality of the air in towns, villages and other residential areas and use the results as basis for developing measures for reducing the pollution of ambient air; carry out zonation of large territories on the basis of air pollution levels (spatial air pollution zones are projected on the ground surface) and estimate air quality in places where air monitoring is lacking to forecast the possible effect of air pollution on natural systems (author)

[Effects of air pollution on human health and their importance in Mexico City].

Science.gov (United States)

Vallejo, Maite; Jáuregui-Renaud, Kathrine; Hermosillo, Antonio G; Márquez, Manlio F; Cárdenas, Manuel

2003-01-01

The impact of air pollution on human health is a complicated problem. In this review, we describe the main health effects of exposure to ozone, carbon monoxide, sulfur dioxide, nitrogen dioxide, lead and particulate matter. Geographical characteristics of the metropolitan area of Mexico City that favor pollutant persistence with adverse effects on the population are described; the use of the Indice Metropolitano de la Calidad del Aire (IMECA), current norms, and present programs to diminish this problem are discussed. Evidence shows that through these actions, air quality has improved. However, some pollutants such as ozone and particulate matter, still exceed the standard. To further improve air quality in the city, existing programs should continue and multidisciplinary research, both basic and applied, is required.

An assessment of hopanes in settled dust and air as indicators of exposure to traffic-related air pollution in Windsor, Ontario

Science.gov (United States)

Curran, Jason

Traffic-related air pollution (TRAP) has been linked with several adverse health effects. We investigated hopanes, markers of primary particle emissions from gasoline and diesel engines, in house dust as an alternative approach for assessing exposure to TRAP in Windsor, Ontario. Settled house dust was collected from the homes of 28 study participants (10 -- 13 yrs). The dust was then analyzed for a suite of hopanes by gas chromatography-mass spectrometry. We calculated correlations between dust hopane concentrations and estimates of annual average NO2 concentrations derived from an existing LUR model. Hopanes were consistently present in detectable quantities in house dust. Annual average outdoor NO2 estimated was moderately correlated with hopanes in house dust (r = 0.46; pefficiency or the presence of an attached garage. Hopanes measured in settled house dust show promise as an indicator of long-term exposure to traffic-related air pollution. Keywords: hopane; air pollution; traffic; dust; exposure; TRAP.

A Novel Hybrid-Fuel Storage System of Compressed Air Energy for China

Directory of Open Access Journals (Sweden)

Wenyi Liu

2014-08-01

Full Text Available Compressed air energy storage (CAES is a large-scale technology that provides long-duration energy storage. It is promising for balancing the large-scale penetration of intermittent and dispersed sources of power, such as wind and solar power, into electric grids. The existing CAES plants utilize natural gas (NG as fuel. However, China is rich in coal but is deficient in NG; therefore, a hybrid-fuel CAES is proposed and analyzed in this study. Based on the existing CAES plants, the hybrid-fuel CAES incorporates an external combustion heater into the power generation subsystem to heat the air from the recuperator and the air from the high-pressure air turbine. Coal is the fuel for the external combustion heater. The overall efficiency and exergy efficiency of the hybrid-fuel CAES are 61.18% and 59.84%, respectively. Given the same parameters, the cost of electricity (COE of the hybrid-fuel CAES, which requires less NG, is $5.48/MW∙h less than that of the gas-fuel CAES. Although the proposed CAES requires a relatively high investment in the current electricity system in North China, the proposed CAES will be likely to become competitive in the market, provided that the energy supplies are improved and the large scale grid-connection of wind power is realized.

Air extraction in gas turbines burning coal-derived gas

Energy Technology Data Exchange (ETDEWEB)

Yang, Tah-teh; Agrawal, A.K.; Kapat, J.S.

1993-11-01

In the first phase of this contracted research, a comprehensive investigation was performed. Principally, the effort was directed to identify the technical barriers which might exist in integrating the air-blown coal gasification process with a hot gas cleanup scheme and the state-of-the-art, US made, heavy-frame gas turbine. The guiding rule of the integration is to keep the compressor and the expander unchanged if possible. Because of the low-heat content of coal gas and of the need to accommodate air extraction, the combustor and perhaps, the flow region between the compressor exit and the expander inlet might need to be modified. In selecting a compressed air extraction scheme, one must consider how the scheme affects the air supply to the hot section of the turbine and the total pressure loss in the flow region. Air extraction must preserve effective cooling of the hot components, such as the transition pieces. It must also ensure proper air/fuel mixing in the combustor, hence the combustor exit pattern factor. The overall thermal efficiency of the power plant can be increased by minimizing the total pressure loss in the diffusers associated with the air extraction. Therefore, a study of airflow in the pre- and dump-diffusers with and without air extraction would provide information crucial to attaining high-thermal efficiency and to preventing hot spots. The research group at Clemson University suggested using a Griffith diffuser for the prediffuser and extracting air from the diffuser inlet. The present research establishes that the analytically identified problems in the impingement cooling flow are factual. This phase of the contracted research substantiates experimentally the advantage of using the Griffith diffuser with air extraction at the diffuser inlet.

Air ejector augmented compressed air energy storage system

Science.gov (United States)

Ahrens, F.W.; Kartsounes, G.T.

Energy is stored in slack demand periods by charging a plurality of underground reservoirs with air to the same peak storage pressure, during peak demand periods throttling the air from one storage reservoir into a gas turbine system at a constant inlet pressure until the air presure in the reservoir falls to said constant inlet pressure, thereupon permitting air in a second reservoir to flow into said gas turbine system while drawing air from the first reservoir through a variable geometry air ejector and adjusting said variable geometry air ejector, said air flow being essentially at the constant inlet pressure of the gas turbine system.

Human requirements in future air-conditioned environments: a search for excellence

DEFF Research Database (Denmark)

Fanger, Povl Ole

2000-01-01

Although air-conditioning has played a positive role for economic development in warm climates, its image is globally mixed. Field studies demonstrate that there are substantial numbers of dissatisfied people in many buildings, among them those suffering from SBS symptoms, even though existing...

Spontaneous pneumocephalus after commercial air travel complicated by meningitis.

Science.gov (United States)

Javan, Ramin; Duszak, Richard; Eisenberg, Alan D; Eggers, Frank M

2011-12-01

Pneumocephalus usually results from trauma, infection, neoplasm, or iatrogenic causes. Barotrauma-induced spontaneous pneumocephalus is extremely rare, usually seen in divers or occassionally with air travel. We report a case of a 61-yr-old female presenting with confusion, fever, and respiratory failure one day after developing sudden nausea, vomiting, and headache during descent on a commercial airliner. Pneumocephalus and meningitis were present on admission. Sinus computed tomography (CT) showed pansinusitis and a tiny bone defect in the posterior wall of the right sphenoid sinus, through which a cisternogram later showed free communication with the prepontine cistern. An orbital CT 2 yr earlier after a fall showed the bone defect, with no other areas of abnormality or fracture. After repair of defects by otolaryngology and appropriate antibiotics, she did well and was eventually discharged. Changes in aircraft cabin pressure likely resulted in rupture of dura and arachnoid layers beneath the pre-existing bony defect, predisposed by existing sinus disease. The pathophysiology, implications, and potential sources of spontaneous pneumocephalus, as well as risks of postcraniotomy and post-trauma air-travel, are discussed.

Thermal reservoir sizing for adiabatic compressed air energy storage

Energy Technology Data Exchange (ETDEWEB)

Kere, Amelie; Goetz, Vincent; Py, Xavier; Olives, Regis; Sadiki, Najim [Perpignan Univ. (France). PROMES CNRS UPR 8521; Mercier-Allart, Eric [EDF R et D, Chatou (France)

2012-07-01

Despite the operation of the two existing industrial facilities to McIntosh (Alabama), and for more than thirty years, Huntorf (Germany), electricity storage in the form of compressed air in underground cavern (CAES) has not seen the development that was expected in the 80s. The efficiency of this form of storage was with the first generation CAES, less than 50%. The evolving context technique can significantly alter this situation. The new generation so-called Adiabatic CAES (A-CAES) is to retrieve the heat produced by the compression via thermal storage, thus eliminating the necessity of gas to burn and would allow consideration efficiency overall energy of the order of 70%. To date, there is no existing installation of A-CAES. Many studies describe the principal and the general working mode of storage systems by adiabatic compression of air. So, efficiencies of different configurations of adiabatic compression process were analyzed. The aim of this paper is to simulate and analyze the performances of a thermal storage reservoir integrated in the system and adapted to the working conditions of a CAES.

Air pollution and respiratory health in Africa: A review | Tanmowo ...

African Journals Online (AJOL)

Objective: To bring into focus the existence of respiratory hazards due to air pollution as a result of industrialisation, tobacco smoking (personal pollution), domestic pollution and vehicular fuel combustion on the African continent; and to stimulate health workers, and the various governments in Africa, to devote more ...

Enhancing indoor air quality -The air filter advantage.

Science.gov (United States)

Vijayan, Vannan Kandi; Paramesh, Haralappa; Salvi, Sundeep Santosh; Dalal, Alpa Anil Kumar

2015-01-01

Air pollution has become the world's single biggest environmental health risk, linked to around 7 million deaths in 2012 according to a recent World Health Organisation (WHO) report. The new data further reveals a stronger link between, indoor and outdoor air pollution exposure and cardiovascular diseases, such as strokes and ischemic heart disease, as well as between air pollution and cancer. The role of air pollution in the development of respiratory diseases, including acute respiratory infections and chronic obstructive pulmonary diseases, is well known. While both indoor and outdoor pollution affect health, recent statistics on the impact of household indoor pollutants (HAP) is alarming. The WHO factsheet on HAP and health states that 3.8 million premature deaths annually - including stroke, ischemic heart disease, chronic obstructive pulmonary disease (COPD) and lung cancer are attributed to exposure to household air pollution. Use of air cleaners and filters are one of the suggested strategies to improve indoor air quality. This review discusses the impact of air pollutants with special focus on indoor air pollutants and the benefits of air filters in improving indoor air quality.

Modeling skin temperature to assess the effect of air velocity to mitigate heat stress among growing pigs

DEFF Research Database (Denmark)

Bjerg, Bjarne; Pedersen, Poul; Morsing, Svend

2017-01-01

It is generally accepted that increased air velocity can help to mitigate heat stress in livestock housing, however, it is not fully clear how much it helps and significant uncertainties exists when the air temperature approaches the animal body temperature. This study aims to develop a skin...... temperature model to generated data for determining the potential effect of air velocity to mitigate heat stress among growing pigs housed in warm environment. The model calculates the skin temperature as function of body temperature, air temperature and the resistances for heat transfer from the body...

Air Consumption Analysis of Air-Jet Weaving

Directory of Open Access Journals (Sweden)

RAJ KUMAR KHIANI

2016-07-01

Full Text Available In Textile industry, production is mostly key concern for Industry owner. This always has attracted researchers and machines manufacturers to make new developments in process and machines. Air-jet is one of the leading and successful highest productive weaving machines. However, it is now well established that due to add of charges of compressed air, manufacturing cost of air-jet weaving machine is higher as compared with rapier and projectile weaving machines. This is why countries having energy issues do not prefer air-jet weaving machines comparing projectile weaving machines. In this regard, several researchers and machine manufacturers have continuously been working to improve the efficiency of air-jet weft insertion. However, industry practice is as important as design made by researchers. The aim of this research is to investigate the air consumption of air-jet weaving on industrial scale practice. In this study, five weaving machine of same manufacturer and model were selected. It was observed that despite of manufacturing same quality of fabric, air consumption was varying almost in all weaving machines. Conventionally, mill workers adopt hit and trial practice in weaving industry including airpressure setting which leads to variation of nozzle pressure. Main reason of disparity of air consumption in air-jet weaving machines may be variation of distance from compressor to weaving machines, number of joints, un-necessary valve opening and pipes leakages cause an increase of compressed air consumption.

Analysis of air quality in Dire Dawa, Ethiopia.

Science.gov (United States)

Kasim, Oluwasinaayomi Faith; Woldetisadik Abshare, Muluneh; Agbola, Samuel Babatunde

2017-12-07

Ambient air quality was monitored and analyzed to develop air quality index and its implications for livability and climate change in Dire Dawa, Ethiopia. Using survey research design, 16 georeferenced locations, representing different land uses, were randomly selected and assessed for sulfur dioxide (SO 2 ), nitrogen dioxide (NO 2 ), carbon dioxide (CO 2 ), carbon monoxide (CO),volatile organic compounds (VOCs), and meteorological parameters (temperature and relative humidity). The study found mean concentrations across all land uses for SO 2 of 0.37 ± 0.08 ppm, NO 2 of 0.13 ± 0.17 ppm, CO 2 of 465.65 ± 28.63 ppm, CO of 3.35 ± 2.04 ppm, and VOCs of 1850.67 ± 402 ppm. An air quality index indicated that ambient air quality for SO 2 was very poor, NO 2 ranged from moderate to very poor, whereas CO rating was moderate. Significant positive correlations existed between temperature and NO 2 , CO 2 , and CO and between humidity and VOCs. Significant relationships were also recorded between CO 2 and NO 2 and between CO and CO 2 . Poor urban planning, inadequate pollution control measure, and weak capacity to monitor air quality have implications for energy usage, air quality, and local meteorological parameters, with subsequent feedback into global climate change. Implementation of programs to monitor and control emissions in order to reduce air pollution will provide health, economic, and environmental benefits to the city. The need to develop and implement emission control programs to reduce air pollution in Dire Dawa City is urgent. This will provide enormous economic, health, and environmental benefits. It is expected that economic effects of air quality improvement will offset the expenditures for pollution control. Also, strategies that focus on air quality and climate change present a unique opportunity to engage different stakeholders in providing inclusive and sustainable development agenda for Dire Dawa.

EPA's Response to the February 2014 Release of Radioactive Material from the Waste Isolation Pilot Plant (WIPP): EPA's WIPP Air Sampling Data from April 2014

Science.gov (United States)

In April 2014, U.S. Environmental Protection Agency (EPA) environmental monitoring and assessment team members reviewed DOE's air sampling plan, visited DOE's air samplers and placed air samplers onsite near existing DOE samplers to corroborate results.

Manual for THOR-AirPAS - air pollution assessment system

DEFF Research Database (Denmark)

Jensen, Steen Solvang; Ketzel, Matthias; Brandt, Jørgen

The report provides an outline of the THOR-AirPAS - air pollution assessment system and a brief manual for getting started with the air quality models and input data included in THOR-AirPAS.......The report provides an outline of the THOR-AirPAS - air pollution assessment system and a brief manual for getting started with the air quality models and input data included in THOR-AirPAS....

Experimental Air-Tightness Analysis in Mediterranean Buildings after Windows Retrofit

Directory of Open Access Journals (Sweden)

Francesca Romana d’Ambrosio Alfano

2016-09-01

Full Text Available Energy saving and Indoor Air Quality (IAQ in buildings are strongly affected by air leakages. Several studies reveal that the energy loss owing to leaky windows can account for up to 40% of the total building energy demand. Furthermore, at the design stage, the possible infiltration of outdoor air through windows is not taken into account when determining the nominal outdoor airflow rate of the ventilation system. This practice may result in an oversizing of the ventilation system and consequent energy waste. Thus, the air-tightness class of a wall assembly should be assessed for each window component considering the type of material, the presence of the seal, the type of closure, the sealing and the maintenance condition. In this paper, the authors present the experimental results of air-tightness measurements carried out using the fan pressurization method in three residential buildings located in the Mediterranean region before and after a window retrofit. Two different window retrofits were investigated: the application of rubber seals on window frames and the substitution of existing windows with new certified high performance windows. The effectiveness of such retrofits was estimated also in terms of energy saving. Test results demonstrated a high variability of the building air tightness after window retrofits, despite the fact that air tight–certified windows were used.

Operational, cost, and technical study of large windpower systems integrated with an existing electric utility. Final report

Energy Technology Data Exchange (ETDEWEB)

Ligon, C.; Kirby, G.; Jordan, D.; Lawrence, J.H.; Wiesner, W.; Kosovec, A.; Swanson, R.K.; Smith, R.T.; Johnson, C.C.; Hodson, H.O.

1976-04-01

Detailed wind energy assessment from the available wind records, and evaluation of the application of wind energy systems to an existing electric utility were performed in an area known as the Texas Panhandle, on the Great Plains. The study area includes parts of Texas, eastern New Mexico, the Oklahoma Panhandle and southern Kansas. The region is shown to have uniformly distributed winds of relatively high velocity, with average wind power density of 0.53 kW/m/sup 2/ at 30 m height at Amarillo, Texas, a representative location. The annual period of calm is extremely low. Three separate compressed air storage systems with good potential were analyzed in detail, and two potential pumped-hydro facilities were identified and given preliminary consideration. Aquifer storage of compressed air is a promising possibility in the region.

Testing and evaluation of existing techniques for identifying uptakes and measuring retention of uranium in mill workers

International Nuclear Information System (INIS)

1983-03-01

Preliminary tests and evaluations of existing bio-analytical techniques for identifying uptakes and measuring retention of uranium in mill workers were made at two uranium mills. Urinalysis tests were found to be more reliable indicators of uranium uptakes than personal air sampling. Static air samples were not found to be good indicators of personal uptakes. In vivo measurements of uranium in lung were successfully carried out in the presence of high and fluctuating background radiation. Interference from external contamination was common during end of shift measurements. A full scale study to evaluate model parameters for the uptake, retention and elimination of uranium should include, in addition to the above techniques, particle size determination of airborne uranium, solubility in simulated lung fluid, uranium analysis in faeces and bone and minute volume measurements for each subject

PRECOMBUSTION REMOVAL OF HAZARDOUS AIR POLLUTANT PRECURSORS

Energy Technology Data Exchange (ETDEWEB)

Unknown

2000-10-09

In response to growing environmental concerns reflected in the 1990 Clean Air Act Amendment (CAAA), the United States Department of Energy (DOE) sponsored several research and development projects in late 1995 as part of an initiative entitled Advanced Environmental Control Technologies for Coal-Based Power Systems. The program provided cost-shared support for research and development projects that could accelerate the commercialization of affordable, high-efficiency, low-emission, coal-fueled electric generating technologies. Clean coal technologies developed under this program would serve as prototypes for later generations of technologies to be implemented in the industrial sector. In order to identify technologies with the greatest potential for commercial implementation, projects funded under Phase I of this program were subject to competitive review by DOE before being considered for continuation funding under Phase II. One of the primary topical areas identified under the DOE initiative relates to the development of improved technologies for reducing the emissions of air toxics. Previous studies have suggested that many of the potentially hazardous air pollutant precursors (HAPPs) occur as trace elements in the mineral matter of run-of-mine coals. As a result, these elements have the potential to be removed prior to combustion at the mine site by physical coal cleaning processes (i.e., coal preparation). Unfortunately, existing coal preparation plants are generally limited in their ability to remove HAPPs due to incomplete liberation of the mineral matter and high organic associations of some trace elements. In addition, existing physical coal cleaning plants are not specifically designed or optimized to ensure that high trace element rejections may be achieved.

Developing a Clinical Approach to Air Pollution and Cardiovascular Health.

Science.gov (United States)

Hadley, Michael B; Baumgartner, Jill; Vedanthan, Rajesh

2018-02-13

Nearly 3 billion people are exposed to household air pollution emitted from inefficient cooking and heating stoves, and almost the entire global population is exposed to detectable levels of outdoor air pollution from traffic, industry, and other sources. Over 3 million people die annually of ischemic heart disease or stroke attributed to air pollution, more than from traditional cardiac risk factors such as obesity, diabetes mellitus, or smoking. Clinicians have a role to play in reducing the burden of pollution-attributable cardiovascular disease. However, there currently exists no clear clinical approach to this problem. Here, we provide a blueprint for an evidence-based clinical approach to assessing and mitigating cardiovascular risk from exposure to air pollution. We begin with a discussion of the global burden of pollution-attributable cardiovascular disease, including a review of the mechanisms by which particulate matter air pollution leads to cardiovascular outcomes. Next, we offer a simple patient-screening tool using known risk factors for pollution exposure. We then discuss approaches to quantifying air pollution exposures and cardiovascular risk, including the development of risk maps for clinical catchment areas. We review a collection of interventions for household and outdoor air pollution, which clinicians can tailor to patients and populations at risk. Finally, we identify future research needed to quantify pollution exposures and validate clinical interventions. Overall, we demonstrate that clinicians can be empowered to mitigate the global burden of cardiovascular disease attributable to air pollution. © 2018 American Heart Association, Inc.

Measuring the value of air quality: application of the spatial hedonic model.

Science.gov (United States)

Kim, Seung Gyu; Cho, Seong-Hoon; Lambert, Dayton M; Roberts, Roland K

2010-03-01

This study applies a hedonic model to assess the economic benefits of air quality improvement following the 1990 Clean Air Act Amendment at the county level in the lower 48 United States. An instrumental variable approach that combines geographically weighted regression and spatial autoregression methods (GWR-SEM) is adopted to simultaneously account for spatial heterogeneity and spatial autocorrelation. SEM mitigates spatial dependency while GWR addresses spatial heterogeneity by allowing response coefficients to vary across observations. Positive amenity values of improved air quality are found in four major clusters: (1) in East Kentucky and most of Georgia around the Southern Appalachian area; (2) in a few counties in Illinois; (3) on the border of Oklahoma and Kansas, on the border of Kansas and Nebraska, and in east Texas; and (4) in a few counties in Montana. Clusters of significant positive amenity values may exist because of a combination of intense air pollution and consumer awareness of diminishing air quality.

SIMULATION OF AIR-CONDITIONNED OPERATING THEATRES

OpenAIRE

El Gharbi , N.; Benzaoui , A ,

2006-01-01

International audience; A hospital is a place where we find simultaneously people whose health state is weakened, or vulnerable, and pathogenic microorganisms able to worsen their health. The quality of the air in a hospital must be in conformity with precise criteria in such buildings in everyday usage, and in particular in the areas of the buildings where some risks of specific pollution exist such as in operating rooms. In this paper, we present a modelisation and three dimensional numeric...

40 CFR Table 3 to Subpart Dd of... - Tank Control Levels for Tanks at Existing Affected Sources as Required by 40 CFR 63.685(b)(1)

Science.gov (United States)

2010-07-01

... Existing Affected Sources as Required by 40 CFR 63.685(b)(1) 3 Table 3 to Subpart DD of Part 63 Protection... Hazardous Air Pollutants from Off-Site Waste and Recovery Operations Pt. 63, Subpt. DD, Table 3 Table 3 to Subpart DD of Part 63—Tank Control Levels for Tanks at Existing Affected Sources as Required by 40 CFR 63...

Analysis of MINIE2013 Explosion Air-Blast Data

Energy Technology Data Exchange (ETDEWEB)

Schnurr, Julie M. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Univ. of Hawaii, Manoa, HI (United States); Rodgers, Arthur J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Kim, Keehoon [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Ford, Sean R. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Ramirez, Abelardo L. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

2016-10-14

We report analysis of air-blast overpressure measurements from the MINIE2013 explosive experiments. The MINIE2013 experiment involved a series of nearly 70 near-surface (height-ofburst, HOB, ranging from -1 to +4 m) low-yield (W=2-20 kg TNT equivalent) chemical highexplosives tests that were recorded at local distances (230 m – 28.5 km). Many of the W and HOB combinations were repeated, allowing for quantification of the variability in air-blast features and corresponding yield estimates. We measured canonical signal features (peak overpressure, impulse per unit area, and positive pulse duration) from the air-blast data and compared these to existing air-blast models. Peak overpressure measurements showed good agreement with the models at close ranges but tended to attenuate more rapidly at longer range (~ 1 km), which is likely caused by upward refraction of acoustic waves due to a negative vertical gradient of sound speed. We estimated yields of the MINIE2013 explosions using the Integrated Yield Determination Tool (IYDT). Errors of the estimated yields were on average within 30% of the reported yields, and there were no significant differences in the accuracy of the IYDT predictions grouped by yield. IYDT estimates tend to be lower than ground truth yields, possibly because of reduced overpressure amplitudes by upward refraction. Finally, we report preliminary results on a development of a new parameterized air-blast waveform.

SAMIRA - SAtellite based Monitoring Initiative for Regional Air quality

Science.gov (United States)

Schneider, Philipp; Stebel, Kerstin; Ajtai, Nicolae; Diamandi, Andrei; Horalek, Jan; Nicolae, Doina; Stachlewska, Iwona; Zehner, Claus

2016-04-01

Here, we present a new ESA-funded project entitled Satellite based Monitoring Initiative for Regional Air quality (SAMIRA), which aims at improving regional and local air quality monitoring through synergetic use of data from present and upcoming satellites, traditionally used in situ air quality monitoring networks and output from chemical transport models. Through collaborative efforts in four countries, namely Romania, Poland, the Czech Republic and Norway, all with existing air quality problems, SAMIRA intends to support the involved institutions and associated users in their national monitoring and reporting mandates as well as to generate novel research in this area. Despite considerable improvements in the past decades, Europe is still far from achieving levels of air quality that do not pose unacceptable hazards to humans and the environment. Main concerns in Europe are exceedances of particulate matter (PM), ground-level ozone, benzo(a)pyrene (BaP) and nitrogen dioxide (NO2). While overall sulfur dioxide (SO2) emissions have decreased in recent years, regional concentrations can still be high in some areas. The objectives of SAMIRA are to improve algorithms for the retrieval of hourly aerosol optical depth (AOD) maps from SEVIRI, and to develop robust methods for deriving column- and near-surface PM maps for the study area by combining satellite AOD with information from regional models. The benefit to existing monitoring networks (in situ, models, satellite) by combining these datasets using data fusion methods will be tested for satellite-based NO2, SO2, and PM/AOD. Furthermore, SAMIRA will test and apply techniques for downscaling air quality-related EO products to a spatial resolution that is more in line with what is generally required for studying urban and regional scale air quality. This will be demonstrated for a set of study sites that include the capitals of the four countries and the highly polluted areas along the border of Poland and the

Columbia River final environmental impact statement. Appendix B: Air quality

International Nuclear Information System (INIS)

1995-11-01

The System Operation Review (SOR) is a study and environmental compliance process being used by the three Federal agencies to analyze future operations of the system and river use issues. The goal of the SOR is to achieve a coordinated system operation strategy for the river that better meets the needs of all river users. This technical appendix addresses only the effects of alternative system operating strategies for managing the Columbia River system. This appendix consists of eight chapters. Chapter 1 describes the air quality issues that were raised in the SOR scoping process and provides an overview of the study process used to evaluate air quality effects from various system operation alternatives. Chapter 2 describes the Federal, state, and local programs that regulate air quality and discusses the air quality standards that are relevant to the analysis. It also gives an overview of the limatology of the region and the existing air quality in the Columbia River Basin, including areas of non-attainment for relevant air quality standards. Chapter 3 presents the methods this study uses for the analysis of air quality and for the evaluation of human health effects from air pollutants. Chapter 4 provides the study results for the System Operating Strategy (SOS) alternatives and potential mitigation measures. Chapter 5 compares impacts on air quality and human health across alternatives, and discusses mitigation measures and cumulative effects. Chapters 6, 7, and 8 contain the list of preparers, glossary, and references, respectively. Technical exhibits supporting the analysis are also included

Thermodynamic analysis of the two-phase ejector air-conditioning system for buses

International Nuclear Information System (INIS)

Ünal, Şaban; Yilmaz, Tuncay

2015-01-01

Air-conditioning compressors of the buses are usually operated with the power taken from the engine of the buses. Therefore, an improvement in the air-conditioning system will reduce the fuel consumption of the buses. The improvement in the coefficient of performance (COP) of the air-conditioning system can be provided by using the two-phase ejector as an expansion valve in the air-conditioning system. In this study, the thermodynamic analysis of bus air-conditioning system enhanced with a two-phase ejector and two evaporators is performed. Thermodynamic analysis is made assuming that the mixing process in ejector occurs at constant cross-sectional area and constant pressure. The increase rate in the COP with respect to conventional system is analyzed in terms of the subcooling, condenser and evaporator temperatures. The analysis shows that COP improvement of the system by using the two phase ejector as an expansion device is 15% depending on design parameters of the existing bus air-conditioning system. - Highlights: • Thermodynamic analysis of the two-phase ejector refrigeration system. • Analysis of the COP increase rate of bus air-conditioning system. • Analysis of the entrainment ratio of the two-phase ejector refrigeration system

Electricity supply. Older plants' impact on reliability and air quality

International Nuclear Information System (INIS)

England-Joseph, Judy A.; Adams, Charles M.; Wood, David G.; Feehan, Daniel J.; Veal, Howard F.; Skeen, John H. III; Koenigs, Melvin J.; Lichtenfeld, David I.; Seretakis, Pauline J.

1990-09-01

Life extension of fossil fuel plants is a relatively recent phenomenon; thus, utilities have little experience to demonstrate the longer-term operating reliability of plants with an extended service life. While utility industry officials and government and industry studies express optimism that these plants will continue to operate reliably, the officials and the studies also caution that it is too soon to determine how pursuing life extension will affect the reliability of the nation's electricity supply. According to DOE, the number of fossil fuel generating units' 30 years old or older is expected to increase from about 2,500 in 1989 to roughly 3,700 in 1998, increasing such plants' share of overall generating capacity from 13 percent in 1989 to 27 percent in 1998. EPA estimates that with existing air quality requirements, fossil fuel plant emissions will increase steadily during the coming decade. Proposed acid rain control legislation, which would affect many plants that may have their service life extended, would require utilities to significantly reduce emissions by the year 2000 but would allow utilities flexibility in deciding how and where to achieve the reductions. If such legislation is enacted, utilities generally are expected to find reducing emissions from existing plants more cost-effective than replacing them and to continue extending plants' service life. Officials of DOE and utility organizations expressed concern, however, that EPA could decide, as it did for one plant in 1988, that alterations made in extending the service life of plants exempted from the Clean Air Act would result in increased emissions and thus cause the altered plants to lose their exemption. According to the officials, the additional costs of achieving the Clean Air Act's standards could discourage some life extension projects. However, such decisions by EPA could also reduce the nation's total power plant emissions by eliminating an existing incentive to retain exempt

Indoor air pollution and respiratory health in the elderly.

Science.gov (United States)

Bentayeb, Malek; Simoni, Marzia; Norback, Dan; Baldacci, Sandra; Maio, Sara; Viegi, Giovanni; Annesi-Maesano, Isabella

2013-01-01

Data on respiratory effects of indoor air pollution in elderly are scanty. The purpose of this review is to summarize current knowledge on adverse respiratory effects of indoor air pollution in individuals aged over 65 years, by presenting existing epidemiological evidence. Using MEDLINE database through PubMed, we identified relevant publications published between 1991 and 2011 in English on respiratory health effects of indoor air pollution in elderly (>65 years). A total of 61 studies were found and after application of the inclusion criteria: (i) epidemiologic studies published in English in peer-reviewed journals between January 1991 and December 2011, (ii) study population with age over or equal 65 years, and (iii) outcome of respiratory symptoms and disease with the exclusion of lung cancer, 33 relevant publications were selected. Most of them showed significant relationships between exposure to major indoor air pollutants and various short-term and long-term respiratory health outcomes such as wheezing, breathlessness, cough, phlegm, asthma, COPD, lung cancer and more rarely lung function decline. The most consistent relationship is found between chronic obstructive pulmonary disease (COPD) and environmental tobacco smoke (ETS). Further studies in the elderly population are needed in order to define causal relationships between exposures to indoor air pollution and underlying mechanisms in this sub-population.

Headquarters Air Force Material Command Customer Relationship Management

Science.gov (United States)

2006-06-01

The concept of CRM is new to the Air Force, but customer relationship management has existed as long as there have been buyer and sellers of goods... people that call their customer service centers, which constitute their external customers . This approach does not incorporate inputs and insights...indicator, the ACSI tracks trends in customer satisfaction and provides valuable benchmarking insights of the consumer economy for companies, industry

X-rays spectrum and air Kerma during a mammography study

International Nuclear Information System (INIS)

Ramirez G, J.; Hernandez V, R.; Hernandez D, V. M.; Vega C, H. R.

2009-10-01

In this calculation series was modeled the source of electrons, the target and the filter. Using thermoluminescent dosemeters of ZrO 2 +PTFE the air Kerma was measured in five points located on a phantom made with acrylic and water when it was exposed to a X-rays beam produced by electrons of 24 KeV and 10 m A of current that produces a mammography. The air Kerma values at the entrance surface of the phantom were compared with values calculated by Monte Carlo methods. The air Kerma values measured indicate that approximately the five points receive the same air Kerma, what means that the beam is homogeneous, of the Monte Carlo calculations we find that the center receives a greater dose what implies that the beam is not uniform, the explanation of this fact is attributed to was used a simple model in the calculations, nevertheless, the air Kerma average measured at the entrance surface of the phantom was of 0.96 + - 0.03 m G, while the other obtained by the calculations was of 0.96 + - 0.06 mGy, to compare both do not exist significant differences. (author)

Analysis of flame shapes in turbulent hydrogen jet flames with coaxial air

Energy Technology Data Exchange (ETDEWEB)

Moon, Hee Jang [Korea Aerospace University, Goyang (Korea, Republic of)

2009-06-15

This paper addresses the characteristics of flame shapes and flame length in three types of coaxial air flames realizable by varying coaxial air and/or fuel velocity. Forcing coaxial air into turbulent jet flames induces substantial changes in flame shapes and NOx emissions through the complex flow interferences that exist within the mixing region. Mixing enhancement driven by coaxial air results in flame volume decrease, and such a diminished flame volume finally reduces NOx emissions significantly by decreasing NOx formation zone where a fuel/air mixture burns. It is found that mixing in the vicinity of high temperature zone mainly results from the increase of diffusive flux than the convective flux, and that the increase of mass diffusion is amplified as coaxial air is increased. Besides, it is reaffirmed that nonequilibrium chemistry including HO{sub 2}/H{sub 2}O{sub 2} should be taken into account for NOx prediction and scaling analysis by comparing turbulent combustion models. In addition, it is found that coaxial air can break down the self-similarity law of flames by changing mixing mechanism, and that EINOx scaling parameters based on the self-similarity law of simple jet flames may not be eligible in coaxial air flames

AirPEx: Air Pollution Exposure Model

NARCIS (Netherlands)

Freijer JI; Bloemen HJTh; Loos S de; Marra M; Rombout PJA; Steentjes GM; Veen MP van; LBO

1997-01-01

Analysis of inhalatory exposure to air pollution is an important area of investigation when assessing the risks of air pollution for human health. Inhalatory exposure research focuses on the exposure of humans to air pollutants and the entry of these pollutants into the human respiratory tract. The

An under-aisle air distribution system facilitating humidification of commercial aircraft cabins

Energy Technology Data Exchange (ETDEWEB)

Zhang, Tengfei; Yin, Shi; Wang, Shugang [School of Civil and Hydraulic Engineering, Dalian University of Technology (DUT), 2 Linggong Road, Dalian 116024 (China)

2010-04-15

Air environment in aircraft cabins has long been criticized especially for the dryness of the air within. Low moisture content in cabins is known to be responsible for headache, tiredness and many other non-specific symptoms. In addition, current widely used air distribution systems on airplanes dilute internally generated pollutants by promoting air mixing and thus impose risks of infectious airborne disease transmission. To boost air humidity level while simultaneously restricting air mixing, this investigation uses a validated computational fluid dynamics (CFD) program to design a new under-aisle air distribution system for wide-body aircraft cabins. The new system supplies fully outside, dry air at low momentum through a narrow channel passage along both side cabin walls to middle height of the cabin just beneath the stowage bins, while simultaneously humidified air is supplied through both perforated under aisles. By comparing with the current mixing air distribution system in terms of distribution of relative humidity, CO{sub 2} concentration, velocity, temperature and draught risk, the new system is found being able to improve the relative humidity from the existent 10% to the new level of 20% and lessen the inhaled CO{sub 2} concentration by 30%, without causing moisture condensation on cabin interior and inducing draught risks for passengers. The water consumption rate in air humidification is only around 0.05 kg/h per person, which should be affordable by airliners. (author)

Air quality and future energy system planning

Science.gov (United States)

Sobral Mourao, Zenaida; Konadu, Dennis; Lupton, Rick

2016-04-01

energy system planning. Some example applications of this work are: (1) to discover conflicts and synergies between air quality regulations and future developments in the energy system and land use change; (2) to show the drivers of air quality in a given spatial context; (3) to explore effective ways to visualize impacts of different energy, land use and emissions control policies on air quality. An initial test case for the Bay Area in California will be presented, extending the scope of the existing California ForeseerTM tool to identify impacts of different policies within the water-energy-land nexus on local air quality.

The influence of polymeric membrane gas spargers on hydrodynamics and mass transfer in bubble column bioreactors.

Science.gov (United States)

Tirunehe, Gossaye; Norddahl, B

2016-04-01

Gas sparging performances of a flat sheet and tubular polymeric membranes were investigated in 3.1 m bubble column bioreactor operated in a semi batch mode. Air-water and air-CMC (Carboxymethyl cellulose) solutions of 0.5, 0.75 and 1.0 % w/w were used as interacting gas-liquid mediums. CMC solutions were employed in the study to simulate rheological properties of bioreactor broth. Gas holdup, bubble size distribution, interfacial area and gas-liquid mass transfer were studied in the homogeneous bubbly flow hydrodynamic regime with superficial gas velocity (U(G)) range of 0.0004-0.0025 m/s. The study indicated that the tubular membrane sparger produced the highest gas holdup and densely populated fine bubbles with narrow size distribution. An increase in liquid viscosity promoted a shift in bubble size distribution to large stable bubbles and smaller specific interfacial area. The tubular membrane sparger achieved greater interfacial area and an enhanced overall mass transfer coefficient (K(L)a) by a factor of 1.2-1.9 compared to the flat sheet membrane.

Training of U.S. Air Traffic Controllers. (IDA Report No. R-206).

Science.gov (United States)

Henry, James H.; And Others

The report reviews the evolution of existing national programs for air traffic controller training, estimates the number of persons requiring developmental and supplementary training, examines present controller selection and training programs, investigates performance measurement methods, considers standardization and quality control, discusses…

The introduction of local air quality management in the United Kingdom: A review and theoretical framework

Science.gov (United States)

Longhurst, J. W. S.; Lindley, S. J.; Watson, A. F. R.; Conlan, D. E.

In the light of recent episodes of poor air quality in many of the U.K.'s major urban areas, concern has been expressed regarding the apparent inability of existing air quality control procedures to effectively tackle contemporary scenarios. As a result of this, a new philosophy for air quality control has been sought which can provide a solid basis for the preservation and future improvement of air quality. It is proposed that a suitable mechanism for this would be found through the adoption of an integrated and holistic local air quality management approach. This paper will present and discuss a theoretical framework for the application of local air quality management in the U.K. and investigate the potential of the Environment Act (1995) to provide such a framework.

Air Research

Science.gov (United States)

EPA's air research provides the critical science to develop and implement outdoor air regulations under the Clean Air Act and puts new tools and information in the hands of air quality managers and regulators to protect the air we breathe.

Satellite observations of air quality of megacities in China

Science.gov (United States)

Hao, N.; Valks, P.; Smedt, I. D.; Loyola, D.; Roozendael, M. V.; Zhou, B.; Zimmer, W.

2012-04-01

In the last three decades, air pollution has become a major environmental issue in metropolitan areas of China as a consequence of fast industrialization and urbanization, and the rapid increase of the vehicle ownership. Now in China there are 3 megacities (Beijing, Shanghai and Guangzhou) in existence. A recent study of Asian megacities showed that they cover less than 2% of the land area, hold more than 30% of the population and produce about 10% of the anthropogenic gas and aerosol emissions. Therefore, it is important to qualify and understand current air pollution distribution and development in and around the megacities of China. Satellite observations provide unique insight into the regional air quality around megacities and air pollution transport from surrounding areas. In this work, we present an investigation of air quality over Beijing, Shanghai and Guangzhou combining satellite and ground-based measurements. Aerosol optical thickness (AOT), precursors of ozone (notably NO2 and CH2O), and SO2 are observed from space. The operational GOME-2 trace gases products developed at German Aerospace Center and MODIS AOT products will be used. Moreover, near surface concentrations of particular matter (PM), NO2 and SO2 in Beijing, Shanghai and Guangzhou are investigated. The effect of air pollution transport from neighboring areas to megacities will be researched using satellite measurements. Initial comparison between satellite and ground-based measurements of air pollutants in Beijing, Shanghai and Guangzhou will be shown. We will present the relationship between AOT and PM concentrations in megacities. The use of AOT, tropospheric NO2 and CH2O columns for air quality applications will also be shown.

Greening Existing Tribal Buildings

Science.gov (United States)

Guidance about improving sustainability in existing tribal casinos and manufactured homes. Many steps can be taken to make existing buildings greener and healthier. They may also reduce utility and medical costs.

Assessment of indoor air quality in office buildings across Europe - The OFFICAIR study.

Science.gov (United States)

Mandin, Corinne; Trantallidi, Marilena; Cattaneo, Andrea; Canha, Nuno; Mihucz, Victor G; Szigeti, Tamás; Mabilia, Rosanna; Perreca, Erica; Spinazzè, Andrea; Fossati, Serena; De Kluizenaar, Yvonne; Cornelissen, Eric; Sakellaris, Ioannis; Saraga, Dikaia; Hänninen, Otto; De Oliveira Fernandes, Eduardo; Ventura, Gabriela; Wolkoff, Peder; Carrer, Paolo; Bartzis, John

2017-02-01

The European project OFFICAIR aimed to broaden the existing knowledge regarding indoor air quality (IAQ) in modern office buildings, i.e., recently built or refurbished buildings. Thirty-seven office buildings participated in the summer campaign (2012), and thirty-five participated in the winter campaign (2012-2013). Four rooms were investigated per building. The target pollutants were twelve volatile organic compounds, seven aldehydes, ozone, nitrogen dioxide and particulate matter with aerodynamic diameter indoor air concentrations of formaldehyde and ozone did not exceed their respective WHO air quality guidelines, and those of acrolein, α-pinene, and d-limonene were lower than their estimated thresholds for irritative and respiratory effects. PM 2.5 indoor concentrations were higher than the 24-h and annual WHO ambient air quality guidelines. Copyright © 2016 Elsevier B.V. All rights reserved.

A portfolio evaluation framework for air transportation improvement projects

Science.gov (United States)

Baik, Hyeoncheol

This thesis explores the application of portfolio theory to the Air Transportation System (ATS) improvement. The ATS relies on complexly related resources and different stakeholder groups. Moreover, demand for air travel is significantly increasing relative to capacity of air transportation. In this environment, improving the ATS is challenging. Many projects, which are defined as technologies or initiatives, for improvement have been proposed and some have been demonstrated in practice. However, there is no clear understanding of how well these projects work in different conditions nor of how they interact with each other or with existing systems. These limitations make it difficult to develop good project combinations, or portfolios that maximize improvement. To help address this gap, a framework for identifying good portfolios is proposed. The framework can be applied to individual projects or portfolios of projects. Projects or portfolios are evaluated using four different groups of factors (effectiveness, time-to-implement, scope of applicability, and stakeholder impacts). Portfolios are also evaluated in terms of interaction-determining factors (prerequisites, co-requisites, limiting factors, and amplifying factors) because, while a given project might work well in isolation, interdependencies between projects or with existing systems could result in lower overall performance in combination. Ways to communicate a portfolio to decision makers are also introduced. The framework is unique because (1) it allows using a variety of available data, and (2) it covers diverse benefit metrics. For demonstrating the framework, an application to ground delay management projects serves as a case study. The portfolio evaluation approach introduced in this thesis can aid decision makers and researchers at universities and aviation agencies such as Federal Aviation Administration (FAA), National Aeronautics and Space Administration (NASA), and Department of Defense (DoD), in

MAXIMUM AIR SUCTION INTO HORIZONTAL OPEN ENDED CYLINDRICAL LOUVERED PIPE

Directory of Open Access Journals (Sweden)

SAMEER RANJAN SAHU

2017-02-01

Full Text Available The main approach behind the present numerical investigation is to estimate the mass flow rate of air sucked into a horizontal open-ended louvered pipe from the surrounding atmosphere. The present numerical investigation has been performed by solving the conservation equations for mass, momentum and energy along with two equation based k-ɛ model for a louvered horizontal cylindrical pipe by finite volume method. It has been found from the numerical investigation that mass suction rate of air into the pipe increases with increase in louvered opening area and the number of nozzles used. Keeping other parameters fixed, for a given mass flow rate there exists an optimum protrusion of nozzle for highest mass suction into the pipe. It was also found from the numerical investigation that increasing the pipe diameter the suction mass flow rate of air was increased.

Requirements for existing buildings

DEFF Research Database (Denmark)

Thomsen, Kirsten Engelund; Wittchen, Kim Bjarne

This report collects energy performance requirements for existing buildings in European member states by June 2012.......This report collects energy performance requirements for existing buildings in European member states by June 2012....

Urban land use, air toxics and public health: Assessing hazardous exposures at the neighborhood scale

International Nuclear Information System (INIS)

Corburn, Jason

2007-01-01

Land use data are increasingly understood as important indicators of potential environmental health risk in urban areas where micro-scale or neighborhood level hazard exposure data are not routinely collected. This paper aims to offer a method for estimating the distribution of air toxics in urban neighborhoods using land use information because actual air monitoring data rarely exist at this scale. Using Geographic Information System spatial modeling tools, we estimate air toxics concentrations across neighborhoods in New York City and statistically compare our model with the US Environmental Protection Agency's National Air Toxic Assessment and air monitoring data across three NYC neighborhoods. We conclude that land use data can act as a good proxy for estimating neighborhood scale air toxics, particularly in the absence of monitoring data. In addition, the paper suggests that land use data can expand the reach of environmental impact assessments that routinely exclude analyses of potential exposures to urban air toxics at the neighborhood scale

Physico-chemical characterization of grain dust in storage air of Bangalore.

Science.gov (United States)

Mukherjee, A K; Nag, D P; Kakde, Y; Babu, K R; Prdkash, M N; Rao, S R

1998-06-01

An Anderson personal cascade impactor was used to study the particle mass size distribution in the storage air of two major grain storage centers in Bangalore. Dust levels in storage air as well as the personal exposures of workers were determined along with a detailed study on the particle size distribution. Protein and carbohydrate content of the dust were also determined respectively in the phosphate buffer saline (PBS) and water extracts by using the standard analytical techniques. Personal exposures in both of the grain storage centers have been found to be much above the limit prescribed by ACGIH (1995-96). But the results of particle size analysis showed a higher particle mass distribution in the non-respirable size range. The mass median diameters (MMD) of the storage air particulate of both the centers were found to be beyond the respirable range. Presence of protein and carbohydrate in the storage air dust is indicative of the existence of glyco-proteins, mostly of membrane origin.

TECHNOLOGIES TO ENHANCE THE OPERATION OF EXISTING NATURAL GAS COMPRESSION INFRASTRUCTURE

Energy Technology Data Exchange (ETDEWEB)

Anthony J. Smalley; Ralph E. Harris; Gary D. Bourn; Danny M. Deffenbaugh

2005-07-27

This quarterly report documents work performed under Tasks 15, 16, and 18 through 23 of the project entitled: ''Technologies to Enhance the Operation of Existing Natural Gas Compression Infrastructure''. The project objective is to develop and substantiate methods for operating integral engine/compressors in gas pipeline service, which reduce fuel consumption, increase capacity, and enhance mechanical integrity. The report first documents a survey site test performed on a TCVC10 engine/compressor installed at Dominion's Groveport Compressor Station. This test completes planned screening efforts designed to guide selection of one or more units for design analysis and testing with emphasis on identification and reduction of compressor losses. The report further presents the validation of the simulation model for the Air Balance tasks and outline of conceptual manifold designs.

Existing contradictions and problems in China's current economic and social development

Institute of Scientific and Technical Information of China (English)

Wang Tongsan

2014-01-01

Since the 18th National Congress of Communist Party of China (CPC),China has made important achievements and headway in economic and social development.However,now more than ever the focus should be on the conflicts and problems that continue to exist in China's economy.This paper examines six of them:(1) lack of a firm foundation for sustaining steady economic growth;(2) risks and hidden dangers in the financial,banking,and real estate sectors and massive overcapacity in some industries;(3) increasing difficulty in increasing agricultural production and raising rural incomes;(4) severe air,water,and soil pollution in certain regions and the arduous task of energy conservation and emissions reduction;(5) major structural problems constraining employment;and (6) issues of people's livelihood that have been the source of dissatisfaction for many Chinese citizens.

Dosimetric Effects of Air Pockets Around High-Dose Rate Brachytherapy Vaginal Cylinders

International Nuclear Information System (INIS)

Richardson, Susan; Palaniswaamy, Geethpriya; Grigsby, Perry W.

2010-01-01

Purpose: Most physicians use a single-channel vaginal cylinder for postoperative endometrial cancer brachytherapy. Recent published data have identified air pockets between the vaginal cylinders and the vaginal mucosa. The purpose of this research was to evaluate the incidence, size, and dosimetric effects of these air pockets. Methods and Materials: 25 patients receiving postoperative vaginal cuff brachytherapy with a high-dose rate vaginal cylinders were enrolled in this prospective data collection study. Patients were treated with 6 fractions of 200 to 400 cGy per fraction prescribed at 5 mm depth. Computed tomography simulation for brachytherapy treatment planning was performed for each fraction. The quantity, volume, and dosimetric impact of the air pockets surrounding the cylinder were quantified. Results: In 25 patients, a total of 90 air pockets were present in 150 procedures (60%). Five patients had no air pockets present during any of their treatments. The average number of air pockets per patient was 3.6, with the average total air pocket volume being 0.34 cm 3 (range, 0.01-1.32 cm 3 ). The average dose reduction to the vaginal mucosa at the air pocket was 27% (range, 9-58%). Ten patients had no air pockets on their first fraction but air pockets occurred in subsequent fractions. Conclusion: Air pockets between high-dose rate vaginal cylinder applicators and the vaginal mucosa are present in the majority of fractions of therapy, and their presence varies from patient to patient and fraction to fraction. The existence of air pockets results in reduced radiation dose to the vaginal mucosa.

Air quality plans unveiled at Toronto's first Smog Summit

Energy Technology Data Exchange (ETDEWEB)

Anon.

2000-06-23

New federal and provincial initiatives to improve air quality were announced at the recent first-ever Toronto Smog Summit. An initial one million dollars have been pledged by the federal Minister of the Environment to support a framework for extending daily air quality forecasting across Canada, to begin within the next year. The funding will be used to increase the information base of existing air quality advisory programs in Ontario, and to create a daily air quality index immediately in other areas of the country most affected by smog. Existing air quality assessment programs will be expanded to include air quality models incorporating measurement and reporting of particulate matter levels. A second federal initiative also announced at the is meeting will be a corporate smog action plan, led by the Ontario regional offices of the federal departments of the Environment, Health Canada, and Public Works and Government Services. This program will include rapid response by federal government departments during Smog Alerts Days and measures to reduce the federal government's contribution to causing smog through encouragement of low or no emission options for employees, educational programs on best practices at home and at the office, reduction of employee travel through flextime and telecommuting, conversion of government vehicles to natural gas and other alternatives, and retrofitting government buildings for greater energy and water efficiency. A federal commitment of at least $200,000 was also announced by the Minister of Transport to support six sustainable transportation projects. The provincial Minister of the Environment announced the membership of the province's Anti-Smog Action Plan, which involves some 50 partners from industry associations, companies, government agencies and non-government organizations to help Ontario to meet its commitment to reduces nitrogen oxides and volatile organic compounds emissions by 45 per cent by 2015. A strategy for

Temporary air-raid shelters

International Nuclear Information System (INIS)

Jokela, J.; Olin, J.; Koukkari, H.

1983-05-01

This report deals with materials and structures of temporary air-raid shelters. At first, the weapon effects against which the temporary shelters can protect are described. These are, primarily, the fragmentation and blast pressure caused by conventional weapons and those effects of the nuclear weapons which exist outside the total disaster and fire areas. Temporary shelters built into existing buildings can give protection either from radioactive fallout or from fallout and collapse of the building above. For fallout protection heavy materials are needed, which simultaneously protect from fragmentation. In the research report, the methods and materials used for the contruction of a fallout shelter into an apartment house and a small house are introduced. The collapse loads acting on a basement ceiling and the design of additional timber supports are also presented. The use of various materials in the construction of shelters outside the buildings are introduced. Separate shelters can be built either under the ground or on the ground. The same materials can be used in both cases, but the underground shelters have a better level of protection. (author)

Air-cooled, hydrogen-air fuel cell

Science.gov (United States)

Shelekhin, Alexander B. (Inventor); Bushnell, Calvin L. (Inventor); Pien, Michael S. (Inventor)

1999-01-01

An air-cooled, hydrogen-air solid polymer electrolyte (SPE) fuel cell with a membrane electrode assembly operatively associated with a fluid flow plate having at least one plate cooling channel extending through the plate and at least one air distribution hole extending from a surface of the cathode flow field into the plate cooling channel.

Organic compounds as indicators of air pollution

DEFF Research Database (Denmark)

Mølhave, Lars

2003-01-01

The most important indoor air pollutants have already been addressedwith individual national guidelines or recommendations. However, an interna-tional set of guidelines or recommendations for indoor air quality (IAQ) isneeded for these pollutants based on general and uniform rules for setting...... suchstandards. A major research need exist on the less adverse pollutants beforerecommendations or guidelines can be established. In the interim period a pre-caution principle should lead to an ALARA principle for these secondary cau-salities. It should be noted that volatile organic compound (VOC......) is an indicatorfor the presence of VOC indoors. The TVOC indicator can be used in relation toexposure characterization and source identification but for VOCs only, not as anindictor of other pollutants and their health effects. In risk assessment the TVOCindicator can only be used as a screening tool and only...

New Brunswick air quality monitoring results for the year 2007 : executive summary

International Nuclear Information System (INIS)

2009-01-01

Air quality has been monitored in New Brunswick since the 1960s. This report summarized air quality results for general public information, with emphasis on air quality assessment in relation to existing air quality standards and objectives. Long-term trend data were also presented for representative sites. Air contaminants currently covered by provincial objectives were measured at 59 sites across the province during 2007. Acid rain was measured at 13 additional sites. Some locations were monitored for volatile organic compounds and mercury in air. Quality assurance procedures used in the provincial air quality system were also described. The report revealed that there were no exceedances of New Brunswick air quality objectives for nitrogen dioxide or carbon monoxide at any of the provincial monitoring sites in 2007. In many instances, exceedances for ozone, total reduced sulphur, fine particulate matter and total volatile organic compound concentrations were lower in 2007 than in 2006. Air quality trends indicate that since the late 1970s and 1980s, air quality has improved for all pollutants currently being measured, with the possible exception of ground level ozone. Annual average levels of sulphur dioxide have decreased significantly over the past 15-20 years. The long term levels of carbon monoxide and nitrogen dioxide have also decreased. Acid deposition has declined since the early 1990s, but its effects continue to be of concern in the province. In 2007, sulphate in precipitation was moderately lower than in 2006.

Effects of forest fires on visibility and air quality

Science.gov (United States)

Douglas G. Fox; Allen R. Riebau

2009-01-01

The U.S. Clean Air Act establishes the goal of preventing future and remedying existing visibility impairment in 156 Class I areas (national parks, wilderness areas, and wildlife refuges). A key element in implementing this goal is the Regional Haze Regulation (RHR). RHR is based on relating impaired visibility, using metrics of extinction (inverse megameters and/or ‘‘...

San Antonio Creek Restoration, Vandenberg Air Force Base, California

Science.gov (United States)

2008-06-27

Vandenberg Air Force Base Scientific Name Common Name Scientific Name Common Name Sambucus mexicana Blue elderberry Sonchus oleraceus * Common sow... Sonchus oleraceus Common sow-thistle exotic NI Spergularia bocconii Sand-spurry exotic FAC Spergularia marina Sand-spurry native FACW...border the existing roads within the project area. Both weedy non-native species adapted to frequent disturbance, such as sow thistle ( Sonchus

HOCl and Cl2 observations in marine air

Directory of Open Access Journals (Sweden)

R. Sommariva

2011-08-01

Full Text Available Cl atoms in the marine atmosphere may significantly impact the lifetimes of methane and other hydrocarbons. However, the existing estimates of Cl atom levels in marine air are based on indirect evidence. Here we present measurements of the Cl precursors HOCl and Cl2 in the marine boundary layer during June of 2009 at the Cape Verde Atmospheric Observatory in the eastern tropical Atlantic. These are the first measurements of tropospheric HOCl. HOCl and Cl2 levels were low in air with open ocean back trajectories, with maximum levels always below 60 and 10 ppt (pmol/mol, respectively. In air with trajectories originating over Europe, HOCl and Cl2 levels were higher, with HOCl maxima exceeding 100 ppt each day and Cl2 reaching up to 35 ppt. The increased Cl cycling associated with long distance pollutant transport over the oceans likely impacts a wide geographic area and represents a mechanism by which human activities have increased the reactivity of the marine atmosphere. Data-constrained model simulations indicate that Cl atoms account for approximately 15 % of methane destruction on days when aged polluted air arrives at the site. A photochemical model does not adequately simulate the observed abundances of HOCl and Cl2, raising the possibility of an unknown HOCl source.

Constructal design of finned tubes used in air-cooled heat exchangers

Energy Technology Data Exchange (ETDEWEB)

Shokouhmand, Hossein; Mahjoub, Shoeib [University of Tehran, Tehran (Iran, Islamic Republic of); Salimpour, Mohammad Reza [Isfahan University of Technology, Isfahan (Iran, Islamic Republic of)

2014-06-15

The present study documents the constructal design and optimization of finned tubes used in air-cooled heat exchangers. The considered tubes are equipped with annular fins. The aim is to minimize the overall thermal resistance by morphing the geometry. The geometrical and thermo-physical parameters considered are the number of fins, ratio of fin height to tube diameter, Stanton number, ratio of fin conductivity to air conductivity, ratio of in-tube fluid conductivity to air conductivity and dimensionless pressure drop. Two constraints are applied in the optimization process: fixed overall volume of heat exchanger and fixed volume fraction of fin material. It is found that there exist optimal values for the number and the height of fins. Moreover, the optimal heat transfer has an extremum in a special volume fraction of fin material.

Constructal design of finned tubes used in air-cooled heat exchangers

International Nuclear Information System (INIS)

Shokouhmand, Hossein; Mahjoub, Shoeib; Salimpour, Mohammad Reza

2014-01-01

The present study documents the constructal design and optimization of finned tubes used in air-cooled heat exchangers. The considered tubes are equipped with annular fins. The aim is to minimize the overall thermal resistance by morphing the geometry. The geometrical and thermo-physical parameters considered are the number of fins, ratio of fin height to tube diameter, Stanton number, ratio of fin conductivity to air conductivity, ratio of in-tube fluid conductivity to air conductivity and dimensionless pressure drop. Two constraints are applied in the optimization process: fixed overall volume of heat exchanger and fixed volume fraction of fin material. It is found that there exist optimal values for the number and the height of fins. Moreover, the optimal heat transfer has an extremum in a special volume fraction of fin material.

Mixed deterministic statistical modelling of regional ozone air pollution

KAUST Repository

Kalenderski, Stoitchko

2011-03-17

We develop a physically motivated statistical model for regional ozone air pollution by separating the ground-level pollutant concentration field into three components, namely: transport, local production and large-scale mean trend mostly dominated by emission rates. The model is novel in the field of environmental spatial statistics in that it is a combined deterministic-statistical model, which gives a new perspective to the modelling of air pollution. The model is presented in a Bayesian hierarchical formalism, and explicitly accounts for advection of pollutants, using the advection equation. We apply the model to a specific case of regional ozone pollution-the Lower Fraser valley of British Columbia, Canada. As a predictive tool, we demonstrate that the model vastly outperforms existing, simpler modelling approaches. Our study highlights the importance of simultaneously considering different aspects of an air pollution problem as well as taking into account the physical bases that govern the processes of interest. © 2011 John Wiley & Sons, Ltd..

Recirculating electric air filter for use in confined spaces

International Nuclear Information System (INIS)

Bergman, W.; Biermann, A.; Kuhl, W.

1985-01-01

We have developed recirculating electric air filters for use in confined spaces where the existing ventilation system is not adequate for removing suspended particles. Two experimental filters were built and evaluated, both of which consisted of a cylindrical cartridge filter fitted over an air blower. In one design the cylindrical cartridge is a disposable unit with the electrodes and filter medium built as an integrated unit. The second design has a cylindrical cartridge that can be easily disassembled to allow replacement of the filter medium. Both designs were evaluated in a 354-ft 3 test cell using NaCl aerosols. The second design was installed and evaluated in a chamber where highly radioactive 238 PuO 2 powder is formed into pellets. We have derived equations that describe the theory of recirculating air filters. The predicted performance compares well with experimental measurements under controlled conditions. 2 refs., 7 figs., 1 tab. (DT)