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Sample records for air riopa study

  1. Analysis of Personal and Home Characteristics Associated with the Elemental Composition of PM2.5 in Indoor, Outdoor, and Personal Air in the RIOPA Study.

    PubMed

    Ryan, Patrick H; Brokamp, Cole; Fan, Zhi-Hua; Rao, M B

    2015-12-01

    The complex mixture of chemicals and elements that constitute particulate matter (PM*) varies by season and geographic location because source contributors differ over time and place. The composition of PM having an aerodynamic diameter < 2.5 μm (PM2.5) is hypothesized to be responsible, in part, for its toxicity. Epidemiologic studies have identified specific components and sources of PM2.5 that are associated with adverse health outcomes. The majority of these studies use measures of outdoor concentrations obtained from one or a few central monitoring sites as a surrogate for measures of personal exposure. Personal PM2.5 (and its elemental composition), however, may be different from the PM2.5 measured at stationary outdoor sites. The objectives of this study were (1) to describe the relationships between the concentrations of various elements in indoor, outdoor, and personal PM2.5 samples, (2) to identify groups of individuals with similar exposures to mixtures of elements in personal PM2.5 and to examine personal and home characteristics of these groups, and (3) to evaluate whether concentrations of elements from outdoor PM2.5 samples are appropriate surrogates for personal exposure to PM2.5 and its elements and whether indoor PM2.5 concentrations and information about home characteristics improve the prediction of personal exposure. The objectives of the study were addressed using data collected as part of the Relationships of Indoor, Outdoor, and Personal Air (RIOPA) study. The RIOPA study has previously measured the mass concentrations of PM2.5 and its elemental constituents during 48-hour concurrent indoor, outdoor (directly outside the home), and personal samplings in three urban areas (Los Angeles, California; Houston, Texas; and Elizabeth, New Jersey). The resulting data and information about personal and home characteristics (including air-conditioning use, nearby emission sources, time spent indoors, census-tract geography, air-exchange rates, and

  2. Identifying Housing and Meteorological Conditions Influencing Residential Air Exchange Rates in the DEARS and RIOPA Studies: Development of Distributions for Human Exposure Modeling

    EPA Science Inventory

    Appropriate prediction of residential air exchange rate (AER) is important for estimating human exposures in the residential microenvironment, as AER drives the infiltration of outdoor-generated air pollutants indoors. AER differences among homes may result from a number of fact...

  3. Aldehydes in passenger vehicles: An analysis of data from the RIOPA Study 1999-2001

    NASA Astrophysics Data System (ADS)

    Mapou, Ashley E. M.; Shendell, Derek G.; Therkorn, Jennifer H.; Xiong, Youyou; Meng, Qingyu; Zhang, Junfeng

    2013-11-01

    In-vehicle air quality (IVAQ) can be a major health concern due to factors such as urban sprawl and increased commuting time spent by individuals in vehicles. Few studies, particularly in the U.S., have considered in-vehicle toxic air contaminants, and none to date collected/analyzed field data in multiple communities across multiple climate zones. This study presents analyses of field data collected during the RIOPA Study from participating non-smoking adults for communities in Los Angeles County, CA, Elizabeth, NJ and Houston, TX. A significant difference (p < 0.001) in in-vehicle formaldehyde concentrations was observed, with the median concentration of in-vehicle formaldehyde in the CA communities about twice as high as in the NJ and TX communities. The highest median concentration of in-vehicle acetaldehyde was observed among the TX participants, over 40% higher than the overall study median. Given small sample sizes, the community (state) differences may be driven independently by differences in individual vehicle conditions and driving habits. Positive correlations were found between average community outdoor relative humidity in CA and NJ and in-vehicle formaldehyde and acetaldehyde concentrations. The amount of time car windows were reported as closed was inversely correlated with in-vehicle formaldehyde across study locations, and for in-vehicle acetaldehyde in CA and TX. Average wind speed and varying sky conditions also had suggested associations to in-vehicle formaldehyde and acetaldehyde. In CA and TX, 88% (7/8) of participants with a diagnosis of bronchitis reported at study baseline had in-vehicle formaldehyde concentrations greater than the overall study median. Every participant with diagnoses of both asthma and bronchitis (n = 3) reported at study baseline had in-vehicle formaldehyde and acetaldehyde concentrations above the overall study median; one participant in TX with two seasonal in-vehicle samplings had in-vehicle concentrations > 75th

  4. Extreme value analyses of VOC exposures and risks: A comparison of RIOPA and NHANES datasets

    NASA Astrophysics Data System (ADS)

    Su, Feng-Chiao; Jia, Chunrong; Batterman, Stuart

    2012-12-01

    Extreme value theory, which characterizes the behavior of tails of distributions, is potentially well-suited to model exposures and risks of pollutants. In this application, it emphasizes the highest exposures, particularly those that may be high enough to present acute or chronic health risks. The present study examines extreme value distributions of exposures and risks to volatile organic compounds (VOCs).Exposures of 15 different VOCs were measured in the Relationship between Indoor, Outdoor and Personal Air (RIOPA) study, and ten of the same VOCs were measured in the nationally representative National Health and Nutrition Examination Survey (NHANES). Both studies used similar sampling methods and study periods. Using the highest 5 and 10% of measurements, generalized extreme value (GEV), Gumbel and lognormal distributions were fit to each VOC in these two large studies. Health risks were estimated for individual VOCs and three VOC mixtures. Simulated data that matched the three types of distributions were generated and compared to observations to evaluate goodness-of-fit. The tail behavior of exposures, which clearly neither fit normal nor lognormal distributions for most VOCs in RIOPA, was usually best fit by the 3-parameter GEV distribution, and often by the 2-parameter Gumbel distribution. In contrast, lognormal distributions significantly underestimated both the level and likelihood of extrema. Among the RIOPA VOCs, 1,4-dichlorobenzene (1,4-DCB) caused the greatest risks, e.g., for the top 10% extrema, all individuals had risk levels above 10-4, and 13% of them exceeded 10-2. NHANES had considerably higher concentrations of all VOCs with two exceptions, methyl tertiary-butyl ether and 1,4-DCB. Differences between these studies can be explained by sampling design, staging, sample demographics, smoking and occupation.This analysis shows that extreme value distributions can represent peak exposures of VOCs, which clearly are neither normally nor lognormally

  5. Determinants of personal, indoor and outdoor VOC concentrations: An analysis of the RIOPA data

    PubMed Central

    Su, Feng-Chiao; Mukherjee, Bhramar; Batterman, Stuart

    2014-01-01

    Community and environmental exposure to volatile organic compounds (VOCs) has been associated with a number of emission sources and activities, e.g., environmental tobacco smoke and pumping gasoline. Such factors have been identified from mostly small studies with relatively limited information regarding influences on VOC levels. This study uses data from the Relationship of Indoor Outdoor and Personal Air (RIOPA) study to investigate environmental, individual and social determinants of VOC concentrations. RIOPA included outdoor, indoor and personal measurements of 18 VOCs from 310 non-smoking households and adults in three cities and two seasons, and collected a wide range of information pertaining to participants, family members, households, and neighborhoods. Exposure determinants were identified using stepwise regressions and linear mixed-effect models. Most VOC exposure (66 to 78% of the total exposure, depending on VOC) occurred indoors, and outdoor VOC sources accounted for 5 (d-limonene) to 81% (carbon tetrachloride) of the total exposure. Personal exposure and indoor measurements had similar determinants, which depended on the VOC. Gasoline-related VOCs (e.g., benzene, methyl tertiary butyl ether) were associated with city, residences with attached garages, self-pumping of gas, wind speed, and house air exchange rate (AER). Odorant and cleaning-related VOCs (e.g., 1,4-dichlorobenzene and chloroform) also were associated with city and AER, and with house size and family members showering. Dry-cleaning and industry-related VOCs (e.g., tetrachloroethylene and trichloroethylene) were associated with city, residence water supply type, and dry-cleaner visits. These and other relationships were significant, explained from 10 to 40% of the variation, and are consistent with known emission sources and the literature. Outdoor concentrations had only two common determinants: city and wind speed. Overall, personal exposure was dominated by the home setting, although a

  6. Personal Exposure to Mixtures of Volatile Organic Compounds: Modeling and Further Analysis of the RIOPA Data

    PubMed Central

    Batterman, Stuart; Su, Feng-Chiao; Li, Shi; Mukherjee, Bhramar; Jia, Chunrong

    2015-01-01

    known to affect VOC exposures, many personal, environmental, and socioeconomic determinants remain to be identified, and the significance and applicability of the determinants reported in the literature are uncertain. To help answer these unresolved questions and overcome limitations of previous analyses, this project used several novel and powerful statistical modeling and analysis techniques and two large data sets. The overall objectives of this project were (1) to identify and characterize exposure distributions (including extreme values), (2) evaluate mixtures (including dependencies), and (3) identify determinants of VOC exposure. METHODS VOC data were drawn from two large data sets: the Relationships of Indoor, Outdoor, and Personal Air (RIOPA) study (1999–2001) and the National Health and Nutrition Examination Survey (NHANES; 1999–2000). The RIOPA study used a convenience sample to collect outdoor, indoor, and personal exposure measurements in three cities (Elizabeth, NJ; Houston, TX; Los Angeles, CA). In each city, approximately 100 households with adults and children who did not smoke were sampled twice for 18 VOCs. In addition, information about 500 variables associated with exposure was collected. The NHANES used a nationally representative sample and included personal VOC measurements for 851 participants. NHANES sampled 10 VOCs in common with RIOPA. Both studies used similar sampling methods and study periods. Specific Aim 1 To estimate and model extreme value exposures, extreme value distribution models were fitted to the top 10% and 5% of VOC exposures. Health risks were estimated for individual VOCs and for three VOC mixtures. Simulated extreme value data sets, generated for each VOC and for fitted extreme value and lognormal distributions, were compared with measured concentrations (RIOPA observations) to evaluate each model’s goodness of fit. Mixture distributions were fitted with the conventional finite mixture of normal distributions and the

  7. Determinants of Indoor and Personal Exposure to PM2.5 of Indoor and Outdoor Origin during the RIOPA Study

    PubMed Central

    Meng, Qing Yu; Spector, Dalia; Colome, Steven; Turpin, Barbara

    2010-01-01

    Effects of physical/environmental factors on fine particle (PM2.5) exposure, outdoor-to-indoor transport and air exchange rate (AER) were examined. The fraction of ambient PM2.5 found indoors (FINF) and the fraction to which people are exposed (α) modify personal exposure to ambient PM2.5. Because FINF, α, and AER are infrequently measured, some have used air conditioning (AC) as a modifier of ambient PM2.5 exposure. We found no single variable that was a good predictor of AER. About 50% and 40% of the variation in FINF and α, respectively, was explained by AER and other activity variables. AER alone explained 36% and 24% of the variations in FINF and α, respectively. Each other predictor, including Central AC Operation, accounted for less than 4% of the variation. This highlights the importance of AER measurements to predict FINF and α. Evidence presented suggests that outdoor temperature and home ventilation features affect particle losses as well as AER, and the effects differ. Total personal exposures to PM2.5 mass/species were reconstructed using personal activity and microenvironmental methods, and compared to direct personal measurement. Outdoor concentration was the dominant predictor of (partial R2 = 30–70%) and the largest contributor to (20–90%) indoor and personal exposures for PM2.5 mass and most species. Several activities had a dramatic impact on personal PM2.5 mass/species exposures for the few study participants exposed to or engaged in them, including smoking and woodworking. Incorporating personal activities (in addition to outdoor PM2.5) improved the predictive power of the personal activity model for PM2.5 mass/species; more detailed information about personal activities and indoor sources is needed for further improvement (especially for Ca, K, OC). Adequate accounting for particle penetration and persistence indoors and for exposure to non-ambient sources could potentially increase the power of epidemiological analyses linking health

  8. Assessing exposure to air toxics relative to asthma.

    PubMed Central

    Weisel, Clifford P

    2002-01-01

    Asthma is a respiratory disease whose prevalence has been increasing since the mid 1970s and that affects more than 14.6 million residents of the United States. Environmental triggers of asthma include air pollutants that are respiratory irritants. Air toxics emitted into the ambient air are listed in the 1990 Clean Air Act Amendments as hazardous air pollutants (HAPs) if they can adversely affect human health, including the respiratory tract. HAPs include particulate and gaseous-phase pollutants, individual organic compounds and metals, and mixtures. Associations between asthma exacerbation and both particles and indoor volatile organic compounds (VOCs), often referred to as indoor air quality, have been reported. Studies conducted in the United States, Canada, and Europe over the past two decades have shown that most people living in the developed countries spend the majority of their time indoors and that the air concentrations of many air toxics or HAPs are higher indoors than in the ambient air in urban, suburban, and rural settings. Elevated indoor air concentrations result from emissions of air toxics from consumer products, household furnishings, and personal activities. The Relationship of Indoor, Outdoor and Personal Air (RIOPA) study was designed to oversample homes in close proximity to ambient sources, excluding residences where smokers lived, to determine the contribution of ambient emissions to air toxics exposure. The ratios of indoor to outdoor air concentrations of some VOCs in homes measured during RIOPA were much greater than one, and for most other VOCs that had indoor-to-outdoor ratios close to unity in the majority of homes, elevated ratios were found in the paired samples with the highest concentration. Thus, although ambient emissions contribute to exposure of some air toxics indoors as well as outdoors, this was not true for all of the air toxics and especially for the higher end of exposures to most volatile organic air toxics examined

  9. RELATIONSHIPS OF INDOOR, OUTDOOR, AND PERSONAL AIR (RIOPA). PART I. COLLECTION METHODS AND DESCRIPTIVE ANALYSES

    EPA Science Inventory

    The homes and subjects selected did not proportionally represent the greater population. Rather, homes close to sources were preferentially sampled in order to examine the impact of possibly high exposures. In addition, the characteristics of the subjects and the homes diff...

  10. A FUNCTIONAL GROUP CHARACTERIZATION OF ORGANIC PM 2.5 EXPOSURE: RESULTS FROM THE RIOPA STUDY

    EPA Science Inventory

    The functional group (FG) composition of urban residential outdoor, indoor, and personal fine particle (PM2.5) samples is presented and used to provide insights relevant to organic PM2.5 exposure. PM2.5 samples (48 h) were collected during the Rel...

  11. Baltimore Air Toxics Study (BATS)

    SciTech Connect

    Sullivan, D.A.

    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.

  12. Airborne rotary air separator study

    NASA Technical Reports Server (NTRS)

    Acharya, A.; Gottzmann, C. F.; Nowobilski, J. J.

    1990-01-01

    Several air breathing propulsion concepts for future earth-to-orbit transport vehicles utilize air collection and enrichment, and subsequent storage of liquid oxygen for later use in the vehicle emission. Work performed during the 1960's established the feasibility of substantially reducing weight and volume of a distillation type air separator system by operating the distillation elements in high 'g' fields obtained by rotating the separator assembly. This contract studied the capability test and hydraulic behavior of a novel structured or ordered distillation packing in a rotating device using air and water. Pressure drop and flood points were measured for different air and water flow rates in gravitational fields of up to 700 g. Behavior of the packing follows the correlations previously derived from tests at normal gravity. The novel ordered packing can take the place of trays in a rotating air separation column with the promise of substantial reduction in pressure drop, volume, and system weight. The results obtained in the program are used to predict design and performance of rotary separators for air collection and enrichment systems of interest for past and present concepts of air breathing propulsion (single or two-stage to orbit) systems.

  13. Study of air pollutant detectors

    NASA Technical Reports Server (NTRS)

    Gutshall, P. L.; Bowles, C. Q.

    1974-01-01

    The application of field ionization mass spectrometry (FIMS) to the detection of air pollutants was investigated. Current methods are reviewed for measuring contaminants of fixed gases, sulfur compounds, nitrogen oxides, hydrocarbons, and particulates. Two enriching devices: the dimethyl silicone rubber membrane separator, and the selective adsorber of polyethylene foam were studied along with FIMS. It is concluded that the membrane enricher system is not a suitable method for removing air pollutants. However, the FIMS shows promise as a useable system for air pollution detection.

  14. Infants Can Study Air Science.

    ERIC Educational Resources Information Center

    Ward, Alan

    1983-01-01

    Provided are activities and demonstrations which can be used to teach infants about the nature of air, uses of air, and objects that fly in the air. The latter include airships, hot-air balloons, kites, parachutes, airplanes, and Hovercraft. (JN)

  15. REGIONAL AIR POLLUTION STUDY, EMISSION INVENTORY SUMMARIZATION

    EPA Science Inventory

    As part of the Regional Air Pollution Study (RAPS), data for an air pollution emission inventory are summarized for point and area sources in the St. Louis Air Quality Control Region. Data for point sources were collected for criteria and noncriteria pollutants, hydrocarbons, sul...

  16. Air travel in pregnancy: the 'air-born' study.

    PubMed

    Breathnach, F; Geoghegan, T; Daly, S; Turner, M J

    2004-06-01

    An increasingly common question posed by patients antenatally is whether air travel can be considered safe in pregnancy. The aim of this study was to assess whether any agreed standards or policies exist between airlines with respect to flying in pregnancy. Sixty-eight international airlines were surveyed, of whom seventeen (25%) replied. Three of seventeen (17.5%) airlines applied no restrictions at all to pregnant passengers; the remainder applied restrictions to air travel with varying gestations (28 to 36 weeks). A full delivery kit was carried by 5/17 airlines (29%), and some form of training in the management of a delivery was provided to the cabin crew in 12/17 airlines (70%). Experience of in-flight obstetric emergencies was reported by 11/17 airlines (65%). This study highlights a lack of consensus regarding restrictions on air travel in pregnancy. The low response rate also suggests an unwillingness on the part of the airline industry to openly declare their policy on this issue. PMID:15305617

  17. Visual air quality assessment: Denver case study

    NASA Astrophysics Data System (ADS)

    Mumpower, Jeryl; Middleton, Paulette; Dennis, Robin L.; Stewart, Thomas R.; Veirs, Val

    Studies of visual air quality in the Denver metropolitan region during summer 1979 and winter 1979-1980 are described and results reported. The major objective of the studies was to investigate relationships among four types of variables important to urban visual air quality: (1) individuals' judgements of overall visual air quality; (2) perceptual cues used in making judgments of visual air quality; (3) measurable physical characteristics of the visual environment and (4) concentrations of visibility-reducing pollutants and their precursors. During August 1979 and mid-December 1979 to January 1980, simultaneous measurements of observational and environmental data were made daily at various locations throughout the metropolitan area. Observational data included ratings of overall air quality and related perceptual cues (e.g., distance, clarity, color, border) by multiple observers. Environmental data included routine hourly pollutant and meteorological measurements from several fixed locations within the city, as well as aerosol light scattering and absorption measures from one location. Statistical analyses indicated that (1) multiple perceptual cues are required to explain variation in judgments of overall visual air quality and (2) routine measurements of the physical environment appear to be inadequate predictors of either judgments of overall visual air quality or related perceptual cues.

  18. Experimental studies on an air-air jet exhaust pump

    SciTech Connect

    Chou, S.K.

    1986-01-01

    Industrial ventilation employing an air-air jet exhaust pump connected to a compressed-air line was investigated. The motive air supply pressure was maintained between 2 and 3 bar. A unique ejector housing was constructed to receive both the convergent-divergent primary nozzle and the mixing chamber. The entire unit adapts readily to any existing compressed-air system. The mixing chamber was so constructed that the length of its cylindrical section may be changed. Pressure variations along the mixing chamber were recorded, and this offered a valuable appreciation of the effects of the length-to-diameter ratios. Results indicate the influence of the supply air pressure and pressure ratio on the jet entrainment capacity and efficiency. It has also been shown that the present design is capable of achieving the maximum reported jet-pump efficiency of around 25% corresponding to a nozzle-to-mixing chamber area ratio of 0.15.

  19. LAKE MICHIGAN URBAN AIR TOXICS STUDY

    EPA Science Inventory

    During the summer of 1991, an air toxics monitoring program wa conducted in the lower Lake Michigan area. his study was designed to take advantage of the intensive meteorological and oxidant data base being generated concurrently by the Lake Michigan Ozone Study (LMOS stations). ...

  20. Controlled air incinerator conceptual design study

    SciTech Connect

    Not Available

    1982-01-01

    This report presents a conceptual design study for a controlled air incinerator facility for incineration of low level combustible waste at Three Mile Island Unit 2 (TMI-2). The facility design is based on the use of a Helix Process Systems controlled air incinerator. Cost estimates and associated engineering, procurement, and construction schedules are also provided. The cost estimates and schedules are presented for two incinerator facility designs, one with provisions for waste ash solidification, the other with provisions for packaging the waste ash for transport to an undefined location.

  1. Experimental Studies on High Speed Air Intakes

    NASA Astrophysics Data System (ADS)

    Panigrahy, Amit Kumar; Muruganandam, T. M.

    All high speed air breathing engines require an inlet to decelerate air from free stream velocity to a lower velocity conducive to combustion. The inlet is designed to capture and deliver the required mass flow to combustion chamber with minimum pressure loss, along with minimum flow distortion. Inlet buzz can occur due to several reasons, such as large internal area contraction ratio, serious shock-boundary layer interactions, and high back pressure. Inlet buzz is detrimental to thrust and can even cause structural damage. Thus a detailed back pressure and over contraction based study of inlet behavior is needed.

  2. HARVARD'S INDOOR AIR POLLUTION/HEALTH STUDY

    EPA Science Inventory

    An indoor air pollution/acute respiratory health study is being conducted by researchers at the Harvard University School of Public Health. Upper and lower respiratory symptoms of 300 children living in Watertown, Massachusetts, have been recorded on a daily diary by a parent. Ev...

  3. REGIONAL AIR POLLUTION STUDY: HEAT EMISSION INVENTORY

    EPA Science Inventory

    As part of the St. Louis Regional Air Pollution Study (RAPS), a heat emission inventory has been assembled. Heat emissions to the atmosphere originate, directly or indirectly, from the combustion of fossil fuels (there are no nuclear plants in the St. Louis AQCR). With the except...

  4. Classification Studies in an Advanced Air Classifier

    NASA Astrophysics Data System (ADS)

    Routray, Sunita; Bhima Rao, R.

    2016-01-01

    In the present paper, experiments are carried out using VSK separator which is an advanced air classifier to recover heavy minerals from beach sand. In classification experiments the cage wheel speed and the feed rate are set and the material is fed to the air cyclone and split into fine and coarse particles which are collected in separate bags. The size distribution of each fraction was measured by sieve analysis. A model is developed to predict the performance of the air classifier. The objective of the present model is to predict the grade efficiency curve for a given set of operating parameters such as cage wheel speed and feed rate. The overall experimental data with all variables studied in this investigation is fitted to several models. It is found that the present model is fitting good to the logistic model.

  5. Baseline air quality study at Fermilab

    SciTech Connect

    Dave, M.J.; Charboneau, R.

    1980-10-01

    Air quality and meteorological data collected at Fermi National Accelerator Laboratory are presented. The data represent baseline values for the pre-construction phase of a proposed coal-gasification test facility. Air quality data were characterized through continuous monitoring of gaseous pollutants, collection of meteorological data, data acquisition and reduction, and collection and analysis of discrete atmospheric samples. Seven air quality parameters were monitored and recorded on a continuous real-time basis: sulfur dioxide, ozone, total hydrocarbons, nonreactive hydrocarbons, nitric oxide, nitrogen oxides, and carbon monoxide. A 20.9-m tower was erected near Argonne's mobile air monitoring laboratory, which was located immediately downwind of the proposed facility. The tower was instrumented at three levels to collect continuous meteorological data. Wind speed was monitored at three levels; wind direction, horizontal and vertical, at the top level; ambient temperature at the top level; and differential temperature between all three levels. All continuously-monitored parameters were digitized and recorded on magnetic tape. Appropriate software was prepared to reduce the data. Statistical summaries, grphical displays, and correlation studies also are presented.

  6. Air

    MedlinePlus

    ... do to protect yourself from dirty air . Indoor air pollution and outdoor air pollution Air can be polluted indoors and it can ... this chart to see what things cause indoor air pollution and what things cause outdoor air pollution! Indoor ...

  7. Study of low density air transportation concepts

    NASA Technical Reports Server (NTRS)

    Webb, H. M.

    1972-01-01

    Low density air transport refers to air service to sparsely populated regions. There are two major objectives. The first is to examine those characteristics of sparsely populated areas which pertain to air transportation. This involves determination of geographical, commercial and population trends, as well as those traveler characteristics which affect the viability of air transport in the region. The second objective is to analyze the technical, economic and operational characteristics of low density air service. Two representative, but diverse arenas, West Virginia and Arizona, were selected for analysis: The results indicate that Arizona can support air service under certain assumptions whereas West Virginia cannot.

  8. Air Pollution Exposure Model for Individuals (EMI) in Health Studies

    EPA Science Inventory

    In health studies, traffic-related air pollution is associated with adverse respiratory effects. Due to cost and participant burden of personal measurements, health studies often estimate exposures using local ambient air monitors. Since outdoor levels do not necessarily reflect ...

  9. A Study on the Air flow outside Ambient Vaporizer Fin

    NASA Astrophysics Data System (ADS)

    Oh, G.; Lee, T.; Jeong, H.; Chung, H.

    2015-09-01

    In this study, we interpreted Fog's Fluid that appear in the Ambient Vaporizer and predict the point of change Air to Fog. We interpreted using Analysis working fluid was applied to LNG and Air. We predict air flow when there is chill of LNG in the air Temperature and that makes fog. Also, we interpreted based on Summer and Winter criteria in the air temperature respectively. Finally, we can check the speed of the fog when fog excreted.

  10. Air cushion landing gear applications study

    NASA Technical Reports Server (NTRS)

    Earl, T. D.

    1979-01-01

    A series of air cushion landing gear (ACLG) applications was studied and potential benefits analyzed in order to identify the most attractive of these. The selected applications are new integrated designs (not retrofits) and employ a modified design approach with improved characteristics and performance. To aid the study, a survey of potential users was made. Applications were evaluated in the light of comments received. A technology scenario is developed, with discussion of problem areas, current technology level and future needs. Feasible development timetables are suggested. It is concluded that near-term development of small-size ACLG trunks, exploration of flight effects and braking are key items. The most attractive applications are amphibious with very large cargo aircraft and small general aviation having the greatest potential.

  11. Air quality: from observation to applied studies

    NASA Astrophysics Data System (ADS)

    Weber, Christiane H.; Wania, Annett; Hirsch, Jacky; Bruse, Michael

    2004-10-01

    Air qualities studies in urban areas embrace several directions that are strongly associated with urban complexity. In the last centuries cities evolution implied changes in urbanization trends: urban sprawl has modified the relationship between cities and surroundings settlements. The existence and protection of urban green and open areas is promoted as a mean to improve the quality of life of their citizens and increase the satisfactory level of the inhabitants against pollution and noise adverse effects. This paper outlines the methods and approaches used in the EU research project Benefits of Urban Green Space (BUGS). The main target of BUGS is to assess the role of urban green spaces in alleviating the adverse effects of urbanization trends by developing an integrative methodology, ranging from participatory planning tools to numerical simulation models. The influence of urban structures on atmospheric pollutants distribution is investigated as a multi-scale problem ranging from micro to macro/regional scale. Traditionally, air quality models are applied on a single scale, seldom considering the joint effects of traffic network and urban development together. In BUGS, several numerical models are applied to cope with urban complexity and to provide quantitative and qualitative results. The differing input data requirements for the various models demanded a methodology which ensures a coherent data extraction and application procedure. In this paper, the stepwise procedure used for BUGS is presented after a general presentation of the research project and the models implied. A discussion part will highlight the statements induced by the choices made and a conclusive part bring to the stage some insights for future investigations.

  12. Residential air conditioner cycling: A case study

    SciTech Connect

    Strickler, G.F.; Noell, S.K.

    1988-02-01

    Southern California Edison currently operates its Residential Air Conditioner Cycling Program as a production program on a systemwide basis. Air conditioner cycling enables Edison to cycle, or switch off, at predetermined intervals, approximately 100,000 air conditioners throughout the Edison service areas. Activation of this system reduces peak demands for load shaping capability. Benefits of this method of peak reduction include the potential for system load factor improvement and/or for deferral of construction of new generation facilities. Edison began testing hardware for direct load control in 1976. Experimental test programs were implemented from 1978 through 1980. These successful test programs resulted in the decision to implement the Residential Air Conditioner Cycling Program on a systemwide basis in 1983.

  13. Urban air quality estimation study, phase 1

    NASA Technical Reports Server (NTRS)

    Diamante, J. M.; Englar, T. S., Jr.; Jazwinski, A. H.

    1976-01-01

    Possibilities are explored for applying estimation theory to the analysis, interpretation, and use of air quality measurements in conjunction with simulation models to provide a cost effective method of obtaining reliable air quality estimates for wide urban areas. The physical phenomenology of real atmospheric plumes from elevated localized sources is discussed. A fluctuating plume dispersion model is derived. Individual plume parameter formulations are developed along with associated a priori information. Individual measurement models are developed.

  14. STATISTICAL COMPARISON OF RESULTS OF TWO INDOOR AIR PILOT STUDIES

    EPA Science Inventory

    The objective of this study was to compare the results between two previous indoor air PAH monitoring studies conducted by EPA in 1984 and 1987. Both of the previous studies were pilot studies involving ambient and indoor air monitoring at a small number of residences in Columbus...

  15. ORIMULSION(R) RESEARCH STUDY (AIR POLLUTION TECHNOLOGY BRANCH, AIR POLLUTION PREVENTION AND CONTROL DIVISION, NRMRL)

    EPA Science Inventory

    In response to a 1998 Congressional request, the Air Pollution Technology Branch (APTB) of NRMRL's Air Pollution Prevention and Control Division began research as part of a study to evaluate the environmental impacts of Orimulsion(R). Orimulsion(R)is a fossil fuel composed of 70%...

  16. WEST LOUISVILLE AIR TOXICS STUDY (WLATS)

    EPA Science Inventory

    WLATS was a cooperative effort among the Louisville Metro Air Pollution Control District, the Commonwealth of Kentucky, the West Jefferson County Community Task Force, the University of Louisville, and EPA Region 4 whose purpose was to determine whether residents of the Rubbertow...

  17. Air pollution exposure prediction approaches used in air pollution epidemiology studies

    EPA Science Inventory

    Epidemiological studies of the health effects of air pollution have traditionally relied upon surrogates of personal exposures, most commonly ambient concentration measurements from central-site monitors. However, this approach may introduce exposure prediction errors and miscla...

  18. Summary of selected compressed air energy storage studies

    SciTech Connect

    Allen, R.D.; Doherty, T.J.; Kannberg, L.D.

    1985-01-01

    A descriptive summarily of research and development in compressed air energy storage technology is presented. Research funded primarily by the Department of Energy is described. Results of studies by other groups and experience at the Huntorf plant in West Germany are included. Feasibility studies performed by General Electric are summarized. The feasibility of air storage in dissolved salt cavities is also demonstrated. (BCS)

  19. A study of commuter air service

    NASA Technical Reports Server (NTRS)

    Belina, F. W.; Bush, L. R.

    1977-01-01

    A regionally oriented overview of the commuter air service industry is provided. A framework for an eventual assessment of potential technology directions that may be of benefit to the industry is presented. Data are provided on the industry's market characteristics, service patterns, patronage characteristics, aircraft and airport needs, economic characteristics and institutional issues. Using personal interview and literature survey methods, investigation of a considerable cross-section of the industry was made.

  20. Performance of underfloor air distribution: Results of a field study

    SciTech Connect

    Fisk, William; Faulkner, David; Sullivan, Douglas

    2004-09-02

    Underfloor air distribution (UFAD) is a new method of supplying heated or cooled air throughout a building. Reported advantages of UFAD include easy relocation of air supply diffusers, energy savings, and improved indoor air quality (IAQ). We measured several aspects of the performance of an UFAD system installed in a medium-size office building. The measured air change effectiveness was very close to unity, which is comparable to that measured in buildings with typical overhead air distribution. The pollutant removal efficiency for carbon dioxide was 13 percent higher than expected in a space with well-mixed air, suggesting a 13 percent reduction in exposures to occupant generated pollutants. The increase in indoor air temperatures with height above the floor was only 1 to 2 C (2-4 F). This amount of thermal stratification could reduce the sensible energy requirements for cooling of outdoor air by approximately 10 percent. The occupants level of satisfaction with thermal conditions w as well above average and this high satisfaction rating could possibly be due, in all or part, to the use of a UFAD system. The results of this study provide some evidence of moderate energy and IAQ-related benefits of UFAD. Before general conclusions are drawn, the benefits need to be confirmed in other studies.

  1. Study of Extended Air Defence Post 2000

    NASA Astrophysics Data System (ADS)

    Mantle, Peter J.

    1995-01-01

    This invited paper, which was the second oral presentation at the conference, covered the conclusions found by NIAG SG-37 during a one year research of the issues and solutions to furnishing extended air defense capability to NATO and its forces. Key issues diagnosed included: (1) the requirement of a multi-layered defense system that includes space-based defense, aircraft, missiles, and other hardware; (2) the electronics needed for this support; and (3) the materials, propulsion devices, and lethality of the systems. A technological forecast of funding recommendations is included.

  2. REGIONAL AIR POLLUTION STUDY, NON-CRITERIA POLLUTANT INVENTORY

    EPA Science Inventory

    In conjunction with the Regional Air Pollution Study (RAPS) being conducted in the St. Louis Air Quality Control Region (AQCR), an inventory of non-criteria pollutants was assembled for point sources. The inventory was based on the following data: (1) The National Emissions Data ...

  3. Methodological issues in studies of air pollution and reproductive health

    EPA Science Inventory

    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 (O3), particulate matter (PM), sulfur dioxide (S...

  4. Indoor Air Quality and Student Performance [and Case Studies].

    ERIC Educational Resources Information Center

    Environmental Protection Agency, Washington, DC. Office of Radiation and Indoor Air.

    This report examines how indoor air quality (IAQ) affects a child's ability to learn and provides several case studies of schools that have successfully addressed their indoor air problems, the lessons learned from that experience, and what long-term practices and policies emerged from the effort. The report covers the effects from…

  5. Air pollution exposure prediction approaches used in air pollution epidemiology studies.

    PubMed

    Özkaynak, Halûk; Baxter, Lisa K; Dionisio, Kathie L; Burke, Janet

    2013-01-01

    Epidemiological studies of the health effects of outdoor air pollution have traditionally relied upon surrogates of personal exposures, most commonly ambient concentration measurements from central-site monitors. However, this approach may introduce exposure prediction errors and misclassification of exposures for pollutants that are spatially heterogeneous, such as those associated with traffic emissions (e.g., carbon monoxide, elemental carbon, nitrogen oxides, and particulate matter). We review alternative air quality and human exposure metrics applied in recent air pollution health effect studies discussed during the International Society of Exposure Science 2011 conference in Baltimore, MD. Symposium presenters considered various alternative exposure metrics, including: central site or interpolated monitoring data, regional pollution levels predicted using the national scale Community Multiscale Air Quality model or from measurements combined with local-scale (AERMOD) air quality models, hybrid models that include satellite data, statistically blended modeling and measurement data, concentrations adjusted by home infiltration rates, and population-based human exposure model (Stochastic Human Exposure and Dose Simulation, and Air Pollutants Exposure models) predictions. These alternative exposure metrics were applied in epidemiological applications to health outcomes, including daily mortality and respiratory hospital admissions, daily hospital emergency department visits, daily myocardial infarctions, and daily adverse birth outcomes. This paper summarizes the research projects presented during the symposium, with full details of the work presented in individual papers in this journal issue. PMID:23632992

  6. Analytical and experimental study on complex compressed air pipe network

    NASA Astrophysics Data System (ADS)

    Gai, Yushou; Cai, Maolin; Shi, Yan

    2015-09-01

    To analyze the working characteristics of complex compressed air networks, numerical methods are widely used which are based on finite element technology or intelligent algorithms. However, the effectiveness of the numerical methods is limited. In this paper, to provide a new method to optimize the design and the air supply strategy of the complex compressed air pipe network, firstly, a novel method to analyze the topology structure of the compressed air flow in the pipe network is initially proposed. A matrix is used to describe the topology structure of the compressed air flow. Moreover, based on the analysis of the pressure loss of the pipe network, the relationship between the pressure and the flow of the compressed air is derived, and a prediction method of pressure fluctuation and air flow in a segment in a complex pipe network is proposed. Finally, to inspect the effectiveness of the method, an experiment with a complex network is designed. The pressure and the flow of airflow in the network are measured and studied. The results of the study show that, the predicted results with the proposed method have a good consistency with the experimental results, and that verifies the air flow prediction method of the complex pipe network. This research proposes a new method to analyze the compressed air network and a prediction method of pressure fluctuation and air flow in a segment, which can predicate the fluctuation of the pressure according to the flow of compressed air, and predicate the fluctuation of the flow according to the pressure in a segment of a complex pipe network.

  7. Residential air exchange rates for use in indoor air and exposure modeling studies.

    PubMed

    Pandian, M D; Ott, W R; Behar, J V

    1993-01-01

    Data on air exchange rates are important inputs to indoor air quality models. Indoor air models, in turn, are incorporated into the structure of total human exposure models. Fragmentary data on residential ventilation rates are available in various governmental reports, journal articles, and contractor reports. Most of the published papers present data on only a few homes to answer very specialized questions, and none of these publications summarize the ventilation rates of a large population of homes across the United States. Brookhaven National Laboratory (BNL) has conducted more than 4000 residential perfluorocarbon tracer (PFT) measurements and brought them together into a large data base from about 100 studies in the United States and elsewhere. This paper analyzes the BNL PFT data base to generate frequency distributions and summary statistics for different regions of the United States, different seasons, and different levels within the homes. The data analyses suggest that residential ventilation rates are similar in the northeastern and northwestern states but higher in the southwestern states. Winter and fall ventilation rates are similar, but the rates are slightly higher in spring, and much higher in summer. Multi-level residences have higher air exchange rates than single-level residences. Although the BNL data are not a representative sample of homes in the United States, these analyses give insight into the range of air exchange rates found in the United States under a great variety of conditions and are intended for use by developers of models of indoor air quality and total human exposure. PMID:8173341

  8. A reliability study of instrument air system design options

    SciTech Connect

    Guey, C.; Skelley, W. ); Gilbert, L.; Anoba, R.; Stutzke, M. )

    1992-01-01

    The existing instrument air system at Turkey Point station uses mobile diesel-driven air compressors. Although these diesel compressors have performed their function well, they represent a maintenance and financial burden requiring engineering review. An engineering evaluation is ongoing to develop several feasible conceptual design options to upgrade the instrument air systems. This phase-1 study was performed to assess the reliability of the various proposed design options. A phase-2 study will be conducted later to determine the core damage frequency for a selected option.

  9. PILOT STUDY OF AMBIENT AIR POLLUTION AND SURVIVAL FROM CANCER

    EPA Science Inventory

    The study was concerned with investigating the potential influence exerted by ambient concentrations of particulate and sulfur dioxide air pollutants upon the length of survival for diagnosed cancer patients. Monitoring data from the National Aerometric Data Bank for particulates...

  10. Air Quality Modeling of Traffic-related Air Pollutants for the NEXUS Study

    EPA Science Inventory

    The paper presents the results of the model applications to estimate exposure metrics in support of an epidemiologic study in Detroit, Michigan. A major challenge in traffic-related air pollution exposure studies is the lack of information regarding pollutant exposure characteriz...

  11. Air Pollution Studies in Metromanila and Catalysis Technology Towards Clean Air Philippines

    NASA Astrophysics Data System (ADS)

    Gallardo, S. M.

    - Considerable air quality and emission data gathered in Metropolitan Manila (MM) led to the development of automobile exhaust treatment catalysts as well as their continued improvement. Findings of a 5-year (1993-1998) collaborative work on the development of base metal oxide catalysts for automobile exhaust are summarized here. One study in 1991 reveals an average 16% increase in the number of motor vehicles in MM where 16% are new and the rest are old ones. Another study in 1992 shows the CO and hydrocarbon emission levels from different types of motor vehicles in MM as a function of the age of the vehicle, type of fuel, and the operating condition. Reports of the Department of Environment and Natural Resources (DENR) and other related studies also provided data showing the quality of air in MM. Currently, there are several requirements to further improve the catalyst performance towards the reduction of NOX and to develop catalyst-sorbent for simultaneous NOX-SOX removal. This is so because of the present condition of rain acidification that is found in certain places in MM. These air quality and emission data are needed not only to establish practical emission standards for motor vehicles and the stationary industries and power plants but also in the development of technologies for air pollution control and other clean technologies for cleaner air in the country.

  12. Characterization of air quality data for the southern California air quality study. Final report

    SciTech Connect

    Underwood, K.; Seinfeld, J.H.; Hopke, P.K.; Grosjean, D.

    1995-12-01

    This report presents research based on data acquired during the Southern California Air Quality Study (SCAQS). Various techniques were applied to identify the sources of acidity in the South Coast Air Basin of California. These Techniques included graphical analysis, box modeling, deterministic modeling, and receptor modeling. A fog model was developed to study the contribution of fog to acidic species formation and removal. A trajectory model was also used to examine the vertical distribution of acidity and the implications with respect to fog acidity. Receptor models with different complexity were used: principal component analysis, stepwise multiple regression, target transformation factor analysis, and potential source contribution function analysis.

  13. Epidemiological study air disaster in Amsterdam (ESADA): study design

    PubMed Central

    Slottje, Pauline; Huizink, Anja C; Twisk, Jos WR; Witteveen, Anke B; van der Ploeg, Henk M; Bramsen, Inge; Smidt, Nynke; Bijlsma, Joost A; Bouter, Lex M; van Mechelen, Willem; Smid, Tjabe

    2005-01-01

    Background In 1992, a cargo aircraft crashed into apartment buildings in Amsterdam, killing 43 victims and destroying 266 apartments. In the aftermath there were speculations about the cause of the crash, potential exposures to hazardous materials due to the disaster and the health consequences. Starting in 2000, the Epidemiological Study Air Disaster in Amsterdam (ESADA) aimed to assess the long-term health effects of occupational exposure to this disaster on professional assistance workers. Methods/Design Epidemiological study among all the exposed professional fire-fighters and police officers who performed disaster-related task(s), and hangar workers who sorted the wreckage of the aircraft, as well as reference groups of their non-exposed colleagues who did not perform any disaster-related tasks. The study took place, on average, 8.5 years after the disaster. Questionnaires were used to assess details on occupational exposure to the disaster. Health measures comprised laboratory assessments in urine, blood and saliva, as well as self-reported current health measures, including health-related quality of life, and various physical and psychological symptoms. Discussion In this paper we describe and discuss the design of the ESADA. The ESADA will provide additional scientific knowledge on the long-term health effects of technological disasters on professional workers. PMID:15921536

  14. A pilot study of energy efficient air cleaning for ozone

    SciTech Connect

    Gundel, Lara A.; Sullivan, Douglas P.; Katsapov, Gregory Y.; Fisk, William J.

    2002-11-01

    A laboratory pilot study has been undertaken with the material that showed the most promise (high capacity and low pressure drop) based on the literature review and associated calculations. The best-performing air cleaner was a commercially available pleated filter that contained a thin layer of small activated carbon particles between two sheets of non-woven fibrous webbing. We will refer to this unit as the ''ozone filter'' although it is marketed for removal of volatile organic compounds (VOCs) from automobile passenger compartments. This pilot study strongly suggests that ozone air cleaning can be practical in commercial air handling systems; however, further tests are needed to assess air cleaner performance under a wider range of conditions.

  15. Air Quality Modeling in Support of the Near-Road Exposures and Effects of Urban Air Pollutants Study (NEXUS)

    EPA Science Inventory

    A major challenge in traffic-related air pollution exposure studies is the lack of information regarding pollutant exposure characterization. Air quality modeling can provide spatially and temporally varying exposure estimates for examining relationships between traffic-related a...

  16. Studies of urban climates and air pollution in Switzerland

    SciTech Connect

    Wanner, H.; Hertig, J.

    1984-12-01

    In addition to an assessment of the factors that are responsible for urban climate change, this paper describes climatological studies and peculiarities of some Swiss cities. Although these cities are small, urban air pollution presents a real problem for urban planning. This is a result of the narow street canyons, the high traffic concentration and the complex topography, which favors air stagnation during anticyclonic weather conditions.

  17. The Air Force health study: an epidemiologic retrospective.

    PubMed

    Buffler, Patricia A; Ginevan, Michael E; Mandel, Jack S; Watkins, Deborah K

    2011-09-01

    In 1979, the U.S. Air Force announced that an epidemiologic study would be undertaken to determine whether the Air Force personnel involved in Operation Ranch Hand-the program responsible for herbicide spraying in Vietnam-had experienced adverse health effects as a result of that service. In January 1982 the Air Force Health Study (AFHS) protocol was approved and the 20 year matched cohort study consisting of independent mortality, morbidity and reproductive health components was initiated. This controversial study has been criticized regarding the study's potential scientific limitations as well as some of the administrative aspects of its conduct. Now, almost 30 years since the implementation of the AFHS and nearly a decade since the final follow up examinations, an appraisal of the study indicates that the results of the AFHS do not provide evidence of disease in the Ranch Hand veterans caused by their elevated levels of exposure to Agent Orange. PMID:21441038

  18. Mobile Air Quality Studies (MAQS)-an international project

    PubMed Central

    2010-01-01

    Due to an increasing awareness of the potential hazardousness of air pollutants, new laws, rules and guidelines have recently been implemented globally. In this respect, numerous studies have addressed traffic-related exposure to particulate matter using stationary technology so far. By contrast, only few studies used the advanced technology of mobile exposure analysis. The Mobile Air Quality Study (MAQS) addresses the issue of air pollutant exposure by combining advanced high-granularity spatial-temporal analysis with vehicle-mounted, person-mounted and roadside sensors. The MAQS-platform will be used by international collaborators in order 1) to assess air pollutant exposure in relation to road structure, 2) to assess air pollutant exposure in relation to traffic density, 3) to assess air pollutant exposure in relation to weather conditions, 4) to compare exposure within vehicles between front and back seat (children) positions, and 5) to evaluate "traffic zone"-exposure in relation to non-"traffic zone"-exposure. Primarily, the MAQS-platform will focus on particulate matter. With the establishment of advanced mobile analysis tools, it is planed to extend the analysis to other pollutants including NO2, SO2, nanoparticles and ozone. PMID:20380704

  19. Conceptual Study on Air Ingress Mitigation for VHTRs

    SciTech Connect

    Chang H. Oh; Eung S. Kim

    2012-09-01

    An air-ingress accident followed by a pipe break is considered as a critical event for a very high temperature gas-cooled reactor (VHTR) safety. Following helium depressurization, it is anticipated that unless countermeasures are taken, air will enter the core through the break leading to oxidation of the in-core graphite structure. Thus, without mitigation features, this accident might lead to severe exothermic chemical reactions of graphite and oxygen depending on the accident scenario and the design. Under extreme circumstances, a loss of core structural integrity may occur and lead to a detrimental situation for the VHTR safety. This paper discusses various air-ingress mitigation concepts applicable for the VHTRs. The study begins with identifying important factors (or phenomena) associated with the air-ingress accident using a root-cause analysis. By preventing main causes of the important events identified in the root-cause diagram, the basic air-ingress mitigation ideas were conceptually developed. Among them, two concepts were finally evaluated as effective candidates. One concept is to inject helium into the lower plenum which is a direct in-vessel helium injection. The other concept is to enclose the reactor with a non-pressure boundary consisting of an opening at the bottom, which is an ex-vessel enclosure boundary. Computational fluid dynamics (CFD) methods were used to validate these concepts. As a result, it was shown that both concepts can effectively mitigate the air-ingress process. In the first concept, the injected helium replaces the air in the core and the lower plenum upper part by buoyancy force because of its low density. It prevented air from moving into the reactor core showing great potential for mitigating graphite oxidation in the core. In the second concept, the air-ingress rate is controlled by molecular diffusion through the opening at the enclosure bottom after depressurization. Some modified reactor cavity design is expected to

  20. Ozone Lidar Observations for Air Quality Studies

    NASA Technical Reports Server (NTRS)

    Wang, Lihua; Newchurch, Mike; Kuang, Shi; Burris, John F.; Huang, Guanyu; Pour-Biazar, Arastoo; Koshak, William; Follette-Cook, Melanie B.; Pickering, Kenneth E.; McGee, Thomas J.; Sullivan, John T.; Langford, Andrew O.; Senff, Christoph J.; Alvarez, Raul; Eloranta, Edwin

    2015-01-01

    Tropospheric ozone lidars are well suited to measuring the high spatio-temporal variability of this important trace gas. Furthermore, lidar measurements in conjunction with balloon soundings, aircraft, and satellite observations provide substantial information about a variety of atmospheric chemical and physical processes. Examples of processes elucidated by ozone-lidar measurements are presented, and modeling studies using WRF-Chem, RAQMS, and DALES/LES models illustrate our current understanding and shortcomings of these processes.

  1. A case study of air enrichment in rotary kiln incineration

    SciTech Connect

    Melo, G.F.; Lacava, P.T.; Carvalho, J.A. Jr.

    1998-07-01

    This paper presents a case study of air enrichment in an industrial rotary kiln type incineration unit. The study is based on mass and energy balances, considering the combustion reaction of a mixture composed by the residue and the auxiliary fuel with air enriched with oxygen. The steps are shown for the primary chamber (rotary kiln) and secondary chamber (afterburner). The residence times in the primary and secondary chamber are 2.0 and 3.2 sec, respectively. The pressure is atmospheric in both chambers. Based on constant chamber gas residence time and gas temperature, it is shown that the residue input rates can be increased by one order of magnitude as air is substituted by pure oxygen. As the residue consumption rate in the rotary kiln is also dependent on residue physical characteristics (mainly size), the study was also carried out for different percentages of oxygen in the oxidizer gas.

  2. LAKE MICHIGAN URBAN AIR TOXICS STUDY DESIGN AND OVERVIEW

    EPA Science Inventory

    During the summer of 1991, an air toxics monitoring program was conducted in the lower Lake Michigan area. his study was designed to take advantage of the extensive meteorological and oxidant database being generated concurrently by the Lake Michigan Ozone Study (LMOS). ntegrated...

  3. A diagnostic model for studying daytime urban air quality trends

    NASA Technical Reports Server (NTRS)

    Brewer, D. A.; Remsberg, E. E.; Woodbury, G. E.

    1981-01-01

    A single cell Eulerian photochemical air quality simulation model was developed and validated for selected days of the 1976 St. Louis Regional Air Pollution Study (RAPS) data sets; parameterizations of variables in the model and validation studies using the model are discussed. Good agreement was obtained between measured and modeled concentrations of NO, CO, and NO2 for all days simulated. The maximum concentration of O3 was also predicted well. Predicted species concentrations were relatively insensitive to small variations in CO and NOx emissions and to the concentrations of species which are entrained as the mixed layer rises.

  4. Evaluation and Application of Alternative Air Pollution Exposure Metrics in Air Pollution Epidemiology Studies

    EPA Science Inventory

    ABSTRACT: Periodic review, revision and subsequent implementation of the National Ambient Air Quality Standards for criteria air pollutants rely upon various types of scientific air quality, exposure, toxicological dose-response and epidemiological information. Exposure assessmen...

  5. Designing and managing the San Joaquin Valley Air Quality Study

    SciTech Connect

    Lagarias, J.S.; Sylte, W.W. )

    1991-09-01

    The field measurement phase of the San Joaquin Valley Air Quality Study, which was conducted in the summer of 1990, was the largest and most sophisticated study of its kind ever conducted in this country. The San Joaquin Valley has the nation's second worst overall air quality problem and is using the study results to conduct regional modeling to refine its control strategies. The study began in 1985 and will continue into the mid-1990s. The origins of the study, and the manner in which it is being funded and administered, reflect a unique and highly successful collaboration among several levels of government and the private sector. The temporary organizational structure formed to manage the study sets an interesting precedent for how political-level leaders can work effectively with the scientific community to conduct a long term technical study.

  6. Compressed Air System Optimization: Case Study Food Industry in Indonesia

    NASA Astrophysics Data System (ADS)

    Widayati, Endang; Nuzahar, Hasril

    2016-01-01

    Compressors and compressed air systems was one of the most important utilities in industries or factories. Approximately 10% of the cost of electricity in the industry was used to produce compressed air. Therefore the potential for energy savings in the compressors and compressed air systems had a big challenge. This field was conducted especially in Indonesia food industry or factory. Compressed air system optimization was a technique approach to determine the optimal conditions for the operation of compressors and compressed air systems that included evaluation of the energy needs, supply adjustment, eliminating or reconfiguring the use and operation of inefficient, changing and complementing some equipment and improving operating efficiencies. This technique gave the significant impact for energy saving and costs. The potential savings based on this study through measurement and optimization e.g. system that lowers the pressure of 7.5 barg to 6.8 barg would reduce energy consumption and running costs approximately 4.2%, switch off the compressor GA110 and GA75 was obtained annual savings of USD 52,947 ≈ 455 714 kWh, running GA75 light load or unloaded then obtained annual savings of USD 31,841≈ 270,685 kWh, install new compressor 2x132 kW and 1x 132 kW VSD obtained annual savings of USD 108,325≈ 928,500 kWh. Furthermore it was needed to conduct study of technical aspect of energy saving potential (Investment Grade Audit) and performed Cost Benefit Analysis. This study was one of best practice solutions how to save energy and improve energy performance in compressors and compressed air system.

  7. Studies defining interactions between hypertension and air pollutants

    SciTech Connect

    Drew, R T; Costa, D L; Haber, S; Iwai, J

    1980-01-01

    An animal model of hypertension was developed by breeding two lines of rats. The model was used to investigate interactions between commonly encountered air pollutants and the development of hypertension. This paper summarizes studies of the interaction of sulfur dioxide and ozone with the models. (ACR)

  8. Simulation study of plane motion of air cushion vehicle

    NASA Astrophysics Data System (ADS)

    Zhao, Shu-Qin; Shi, Xiao-Cheng; Shi, Yi-Long; Bian, Xin-Qian

    2003-12-01

    This research is on horizontal plane motion equations of Air Cushion Vehicle (ACV) and its simulation. To investigate this, a lot of simulation study including ACV’s voyage and turning performance has been done. It was found that the voyage simulation results were accorded with ACV own characteristic and turning simulation results were accorded with USA ACV’s movement characteristic basically.

  9. Air Quality Scoping Study for Rachel, Nevada (EMSI April 2007)

    SciTech Connect

    Engelbrecht, Johann; Kavouras, Ilias; Campbell, Dave; Campbell, Scott; Kohl, Steven; Shafer, David

    2007-04-01

    The Desert Research Institute (DRI) is performing a scoping study as part of the U.S. Department of Energy’s Yucca Mountain Environmental Monitoring Systems Initiative (EMSI). The main objective is to obtain baseline air quality information for Yucca Mountain and an area surrounding the Nevada Test Site (NTS). Air quality and meteorological monitoring and sampling equipment housed in a mobile trailer (shelter) is collecting data at seven sites outside the NTS, including Ash Meadows National Wildlife Refuge, Sarcobatus Flat, Beatty, Rachel, Caliente, Pahranagat National Wildlife Refuge, and Crater Flat, and at four sites on the NTS. The trailer is stationed at any one site for approximately eight weeks at a time. Letter reports provide summaries of air quality and meteorological data, on completion of each site’s sampling program.

  10. Air Quality Scoping Study for Beatty, Nevada (EMSI April 2007)

    SciTech Connect

    Engelbrecht, Johann; Kav, Ilias; Campbell, Dave; Campbell, Scott; Kohl, Steven; Shafer, David

    2007-04-01

    The Desert Research Institute (DRI) is performing a scoping study as part of the U.S. Department of Energy’s Yucca Mountain Environmental Monitoring Systems Initiative (EMSI). The main objective is to obtain baseline air quality information for Yucca Mountain and an area surrounding the Nevada Test Site (NTS). Air quality and meteorological monitoring and sampling equipment housed in a mobile trailer (shelter) is collecting data at seven sites outside the NTS, including Ash Meadows National Wildlife Refuge, Sarcobatus Flat, Beatty, Rachel, Caliente, Pahranagat National Wildlife Refuge, and Crater Flat, and at four sites on the NTS. The trailer is stationed at any one site for approximately eight weeks at a time. Letter reports provide summaries of air quality and meteorological data, on completion of each site’s sampling program.

  11. Empirical study of air quality in Barreiro city

    NASA Astrophysics Data System (ADS)

    Garcia, J. N.; Teodoroa, M. F.; Coelho, L. M.; Carvalho, M. G.

    2014-10-01

    The main objective of the work is to study the impact of air pollution on children's health in Portugal and more specifically in the city of Barreiro. We use the suitability of general linear methods (GLM) as a tool to estimate a model which relates air qualityand health. With detail, this relationship is investigated for the case of the effects of small particles on health. It was difficult to find clear and unambiguous correlations in particle dispersion, air quality and health. After a previous treatment of data, the models are estimated and validated by GLM. At the end of this process, the best models are selected using validation tests and residual analysis. The results are promising but some work using different statistical methods is ongoing.

  12. Urban compaction or dispersion? An air quality modelling study

    NASA Astrophysics Data System (ADS)

    Martins, Helena

    2012-07-01

    Urban sprawl is altering the landscape, with current trends pointing to further changes in land use that will, in turn, lead to changes in population, energy consumption, atmospheric emissions and air quality. Urban planners have debated on the most sustainable urban structure, with arguments in favour and against urban compaction and dispersion. However, it is clear that other areas of expertise have to be involved. Urban air quality and human exposure to atmospheric pollutants as indicators of urban sustainability can contribute to the discussion, namely through the study of the relation between urban structure and air quality. This paper addresses the issue by analysing the impacts of alternative urban growth patterns on the air quality of Porto urban region in Portugal, through a 1-year simulation with the MM5-CAMx modelling system. This region has been experiencing one of the highest European rates of urban sprawl, and at the same time presents a poor air quality. As part of the modelling system setup, a sensitivity study was conducted regarding different land use datasets and spatial distribution of emissions. Two urban development scenarios were defined, SPRAWL and COMPACT, together with their new land use and emission datasets; then meteorological and air quality simulations were performed. Results reveal that SPRAWL land use changes resulted in an average temperature increase of 0.4 °C, with local increases reaching as high as 1.5 °C. SPRAWL results also show an aggravation of PM10 annual average values and an increase in the exceedances to the daily limit value. For ozone, differences between scenarios were smaller, with SPRAWL presenting larger concentration differences than COMPACT. Finally, despite the higher concentrations found in SPRAWL, population exposure to the pollutants is higher for COMPACT because more inhabitants are found in areas of highest concentration levels.

  13. Experimental study on the evaporative cooling of an air-cooled condenser with humidifying air

    NASA Astrophysics Data System (ADS)

    Wen, Mao-Yu; Ho, Ching-Yen; Jang, Kuang-Jang; Yeh, Cheng-Hsiung

    2014-02-01

    Using six different materials to construct a water curtain, this study aims to determine the most effective spray cooling of an air cooled heat exchanger under wet conditions. The experiments were carried out at a mass flow rate of 0.005-0.01 kg/s (spraying water), an airspeed of 0.6-2.4 m/s and a run time of 0-72 h for the material degradation tests. The experimental results indicate that the cooling efficiency, the heat rejection, and the sprinkling density increase as the amount of spraying water increases, but, the air-flow of the condenser is reduced at the same time. In addition, the cooling efficiency of the pads decreases with an increase of the inlet air velocity. In terms of experimental range, the natural wood pulp fiberscan can reach 42.7-66 % for cooling efficiency and 17.17-24.48 % for increases of heat rejection. This means that the natural wood pulp fiberscan pad most effectively enhances cooling performance, followed in terms of cooling effectiveness by the special non-woven rayon pad, the woollen blanket, biochemistry cotton and kapok, non-woven cloth of rayon cotton and kapok, and white cotton pad, respectively. However, the natural wood pulp fiberscan and special non-woven rayon display a relatively greater degradation of the cooling efficiency than the other test pads used in the material degradation tests.

  14. Parametric Studies of Flow Separation using Air Injection

    NASA Technical Reports Server (NTRS)

    Zhang, Wei

    2004-01-01

    Boundary Layer separation causes the airfoil to stall and therefore imposes dramatic performance degradation on the airfoil. In recent years, flow separation control has been one of the active research areas in the field of aerodynamics due to its promising performance improvements on the lifting device. These active flow separation control techniques include steady and unsteady air injection as well as suction on the airfoil surface etc. This paper will be focusing on the steady and unsteady air injection on the airfoil. Although wind tunnel experiments revealed that the performance improvements on the airfoil using injection techniques, the details of how the key variables such as air injection slot geometry and air injection angle etc impact the effectiveness of flow separation control via air injection has not been studied. A parametric study of both steady and unsteady air injection active flow control will be the main objective for this summer. For steady injection, the key variables include the slot geometry, orientation, spacing, air injection velocity as well as the injection angle. For unsteady injection, the injection frequency will also be investigated. Key metrics such as lift coefficient, drag coefficient, total pressure loss and total injection mass will be used to measure the effectiveness of the control technique. A design of experiments using the Box-Behnken Design is set up in order to determine how each of the variables affects each of the key metrics. Design of experiment is used so that the number of experimental runs will be at minimum and still be able to predict which variables are the key contributors to the responses. The experiments will then be conducted in the 1ft by 1ft wind tunnel according to the design of experiment settings. The data obtained from the experiments will be imported into JMP, statistical software, to generate sets of response surface equations which represent the statistical empirical model for each of the metrics as

  15. ECAIM : Air Quality Studies and its Impact in Central Mexico.

    NASA Astrophysics Data System (ADS)

    Ruiz-Suárez, L. G.; Torres, R.; Garcia-Reynoso, J. A.; Zavala-Hidalgo, J.; Grutter, M.; Delgado-Campos, J.; Molina, L. T.

    2014-12-01

    Mexico City Metropolitan Area has been the object of several well know intensive campaigns. Since MARI (1991) , IMADA (1997), MCMA 2003 and MILAGRO (2006). The spatial scope of these studies have gone from urban to regional to continental, with the focus on MCMA as an emissions source. During MILAGRO, the influence on MCMA of wildfires and agricultural biomass burning around the megacity was considered. However, around Mexico City a crown of metropolis and middle size cities make a region known as the Central Mexico Regional Crow (CRCM for its acronym in Spanish language) or Central Mexico City Belt. It contains 32 million inhabitants and produces 40% of national gross product. The region undergoes an uncontrolled urban sprawl. Evidence is building-up on complex air pollution transport processes between the air basins within CRCM. However, only MCMA counts with reliable long-term records of criteria pollutants monitoring. Only few intensive campaigns have been done in the air basins surrounding MCMA. ECAIM project has several goals: a) To use ground and satellite observations to assess emissions inventories; b) To use ground and satellite observations to assess the performance of air quality models for the whole region; c) to produce critical levels exceedence maps; d) To produce a preliminary diagnostic of air quality for the CRCM; e) to produce a preliminary estimate of the cost of air pollution within the CRCM. In this work we show the method approach to use the best available information from local AQM networks, field campaigns, satellite observations and modeling to achieve those goals. We show some preliminary results.

  16. Prefeasibility study on compressed air energy storage systems

    NASA Astrophysics Data System (ADS)

    Elmahgary, Y.; Peltola, E.; Sipilae, K.; Vaeaetaeinen, A.

    1991-08-01

    A prefeasibility study on compressed air energy storage (CALS) systems was launched in VTT in the course of the year 1990. The study was undertaken partly in the Laboratory of Electrical and Automation Engineering and partly in the Road, Traffic and Geotechnical Laboratory. Information on existing mines in Finland which could be used as storage caverns were collected (part 2). The costs of excavating rock caverns for compressed air storage and those for forming suitable storage caverns in existing mines were also estimated. This information was used in the first (and present) part of the report to calculate the economics of CAES. In the present part (part 1) of the study, an analysis of the different possible systems was given following a review of literature on CAES. This was followed by an economic analysis which comprised two separate systems. The first consisted of conventional oil fueled gas turbine plants provided with the CALS system. In the second system, wind turbines were used to run the compressors which are used in charging the compressed air storage cavern. The results of the current prefeasibility study confirmed the economic attractiveness of the CAES in the first system. Wind turbines still seem, however, to be too expensive to compete with coal power plants. More accurate and straight-forward results could be obtained only in a more comprehensive study.

  17. Technology Solutions Case Study: Sealed Air-Return Plenum Retrofit

    SciTech Connect

    none,

    2012-08-01

    In this project, Pacific Northwest National Laboratory researchers greatly improved indoor air quality and HVAC performance by replacing an old, leaky air handler with a new air handler with an air-sealed return plenum with filter; they also sealed the ducts, and added a fresh air intake.

  18. Biomass production chamber air analysis of wheat study (BWT931)

    NASA Technical Reports Server (NTRS)

    Batten, J. H.; Peterson, B. V.; Berdis, E.; Wheeler, E. M.

    1993-01-01

    NASA's Controlled Ecological Life Support System (CELSS) biomass production chamber at John F. Kennedy Space Center provides a test bed for bioregenerative studies using plants to provide food, oxygen, carbon dioxide removal, and potable water to humans during long term space travel. Growing plants in enclosed environments has brought about concerns regarding the level of volatile organic compounds (VOC's) emitted from plants and the construction materials that make up the plant growth chambers. In such closed systems, the potential exists for some VOC's to reach toxic levels and lead to poor plant growth, plant death, or health problems for human inhabitants. This study characterized the air in an enclosed environment in which wheat cv. Yocora Rojo was grown. Ninty-four whole air samples were analyzed by gas chromatography/mass spectrometry throughout the eighty-four day planting. VOC emissions from plants and materials were characterized and quantified.

  19. RESIDENTIAL AIR EXCHANGE RATES FOR USE IN INDOOR AIR AND EXPOSURE MODELING STUDIES

    EPA Science Inventory

    Data on air exchange rates are important inputs to indoor air quality models. ndoor air models, in turn, are incorporated into the structure of total human exposure models. ragmentary data on residential ventilation rates are available in various governmental reports, journal art...

  20. Recent design and cost studies for air blown gasification

    SciTech Connect

    Dawes, S.G.; Mordecai, M.; Welford, G.B.; Otter, N.R.

    1997-12-31

    The Air Blown Gasification Cycle (ABGC) (formerly known as the British Coal Topping Cycle) is a high efficiency low cost system for producing power with excellent environmental performance. High efficiency is achieved without the complexity associated with other advanced cycles and the technology can be introduced in a modular fashion. Being a simple air blown fluid bed gasifier and combustor combination it is capable of using a wide range of fuels and is particularly suited for dealing with high ash melting point fuels found in areas of the world short of natural gas. An extensive program of pilot plant testing of a variety of fuels is now being completed on the test facility at the Coal Technology Development Division (CTDD) of British Coal as part of a UK program to develop the Air Blown Gasification Cycle. This program is supplying data to produce a design specification for a Prototype Integrated Plant (PIP) of around 90 MWe, and is managed by a consortium, the Clean Coal Power Generation Group. The paper summarizes recent results and operating experience for the pilot plant including fuel behavior studies, research in hot gas cleaning (particulate and gaseous contaminants), and gas combustion experience. The various cost studies undertaken on the ABGC are outlined and compared, including recent studies by EPRI.

  1. Multiple Air-Toxics Exposure Study Working Paper Number 3. Urban air-toxics exposure model: development and application

    SciTech Connect

    Not Available

    1988-11-01

    The South Coast Air Quality Management District of California completed a Multiple Air Toxics Exposure Study (MATES) that examines the additive risk from a number of air toxics on an urban area. The project, though partially funded by EPA, is an example of how a State or local agency may approach assessing their local air-toxics risks as is encouraged by EPA's Urban Air Toxics Program which results from EPA's Air Toxic Strategy. The report is a summary of the methods used by the California agency. Though not intended as an endorsement of the entire contents of the report, EPA is reproducing their report (Working Paper Number 3) to benefit and encourage other agencies that may be contemplating such an assessment.

  2. Hybrid Air Quality Modeling Approach For Use in the Near-Road Exposures to Urban Air Pollutant Study (NEXUS)

    EPA Science Inventory

    The Near-road EXposures to Urban air pollutant Study (NEXUS) investigated whether children with asthma living in close proximity to major roadways in Detroit, MI, (particularly near roadways with high diesel traffic) have greater health impacts associated with exposure to air pol...

  3. Corrosion study in the chemical air separation (MOLTOX trademark ) process

    SciTech Connect

    Kang, Doohee; Wong, Kai P.; Archer, R.A.; Cassano, A.A.

    1988-12-01

    This report presents the results of studies aimed at solving the corrosion problems encountered during operation of the MOLTOX{trademark} pilot plant. These studies concentrated on the screening of commercial and developmental alloys under conditions simulating operation conditions in this high temperature molten salt process. Process economic studies were preformed in parallel with the laboratory testing to ensure that an economically feasible solution would be achieved. In addition to the above DOE co-funded studies, Air Products and Chemicals pursued proprietary studies aimed at developing a less corrosive salt mixture which would potentially allow the use of chemurgically available alloys such as stainless steels throughout the system. These studies will not be reported here; however, the results of corrosion tests in the new less corrosive salt mixtures are reported. Because our own studies on salt chemistry impacts heavily on the overall process and thereby has an influence on the experimental work conducted under this contract, some of the studies discussed here were impacted by our own proprietary data. Therefore, the reasons behind some of the experiments presented herein will not be explained because that information is proprietary to Air Products. 14 refs., 42 figs., 21 tabs.

  4. Formaldehyde--study of indoor air pollution in Austria.

    PubMed

    Koeck, M; Pichler-Semmelrock, F P; Schlacher, R

    1997-09-01

    As part of a long-term study of indoor air pollution, formaldehyde concentrations were determined in 792 apartments following complaints by inhabitants. Measurements were carried out using Draeger tubes as well as the acetyl acetone method. In 157 apartments, HCHO concentrations of more than 0.1 ppm, exceeding the recommended standard values for indoor air concentrations, were determined. The concentrations determined tended to decrease over time. As far as they were caused by furnishings, they were limited to the spaces where these furnishings were installed. In older-style prefabricated houses with foam-filled particle-board wall systems, concentrations of more than 1.0 ppm were determined. In spite of legal regulations governing the release of formaldehyde from substances, preparations and products containing formaldehyde which have been in existence in Austria since 1990, this substance must still be considered as a possible factor of indoor pollution in causing feelings of ill-health. PMID:9386898

  5. Air traffic control surveillance accuracy and update rate study

    NASA Technical Reports Server (NTRS)

    Craigie, J. H.; Morrison, D. D.; Zipper, I.

    1973-01-01

    The results of an air traffic control surveillance accuracy and update rate study are presented. The objective of the study was to establish quantitative relationships between the surveillance accuracies, update rates, and the communication load associated with the tactical control of aircraft for conflict resolution. The relationships are established for typical types of aircraft, phases of flight, and types of airspace. Specific cases are analyzed to determine the surveillance accuracies and update rates required to prevent two aircraft from approaching each other too closely.

  6. Observational Buoy Studies of Coastal Air-Sea Fluxes.

    NASA Astrophysics Data System (ADS)

    Frederickson, Paul A.; Davidson, Kenneth L.

    2003-02-01

    Recent advancements in measurement and analysis techniques have allowed air-sea fluxes to be measured directly from moving platforms at sea relatively easily. These advances should lead to improved surface flux parameterizations, and thus to improved coupled atmosphere-ocean modeling. The Naval Postgraduate School has developed a `flux buoy' (FB) that directly measures air-sea fluxes, mean meteorological parameters, and one-dimensional and directional wave spectra. In this study, the FB instrumentation and data analysis techniques are described, and the data collected during two U.S. east coast buoy deployments are used to examine the impact of atmospheric and surface wave properties on air-sea momentum transfer in coastal ocean regions. Data obtained off Duck, North Carolina, clearly show that, for a given wind speed, neutral drag coefficients in offshore winds are higher than those in onshore winds. Offshore wind drag coefficients observed over the wind speed range from 5 to 21 m s1 were modeled equally well by a linear regression on wind speed, and a Charnock model with a constant of 0.016. Measurements from an FB deployment off Wallops Island, Virginia, show that neutral drag coefficients in onshore winds increase as the wind-wave direction differences increase, especially beyond ±60°.

  7. Southern California air quality study: A search for methyl nitrate

    NASA Astrophysics Data System (ADS)

    Grosjean, Daniel; Parmar, Sucha S.; Williams, Edwin L.

    Methyl nitrate, CH 3ONO 2, was measured by electron capture gas chromatography (EC-GC) under conditions which allowed resolution of methyl nitrate, PAN, and several chlorinated hydrocarbons. Calibrations involved both EC-GC andNO x chemiluminescence and were in agreement with independent calibrations involving i.r. spectroscopy. The rate constant for photolysis of methyl nitrate in sunlight was< 2.3 × 10 -6s -1. Detection limits of field instruments were 0.1-0.4 ppb. Some 3000 EC-GC chromatograms grams of ambient air recorded between June and December 1987, during the Southern California Air Quality Study (SCAQS) at up to nine Southern California locations yielded only seven possible, but unlikely observations of methyl nitrate. Thus, methyl nitrate was only a minor component among nitrogenous air pollutants during SCAQS. The measured CH 3ONO 2/PAN ratios of<0.003-0.2 during SCAQS are discussed in terms of available kinetic data for PAN unimolecular decomposition (a major source of methyl nitrate), PAN thermal decomposition and CH 3ONO 2 photolysis.

  8. 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

    PubMed Central

    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

  9. Indoor air quality study of forty east Tennessee homes

    SciTech Connect

    Hawthorne, A.R.; Gammage, R.B.; Dudney, C.S.; Hingerty, B.E.; Schuresko, D.D.; Parzyck, D.C.; Womack, D.R.; Morris, S.A.; Westley, R.R.; White, D.A.

    1984-12-01

    Over a one-year period, measurements of indoor air pollutants (CO/sub x/, NO/sub x/, formaldehyde, volatile organics, particulates, and radon) were made in 40 homes in East Tennessee. The houses were of various ages with different types of insulation and heating. Over one-half of the houses exceeded the ASHRAE indoor ceiling guideline of 0.1 ppM for formaldehyde on at least one occasion. Over the duration of the study, older houses averaged 0.04 ppM of formaldehyde while houses less than 5 years old averaged 0.08 ppM (P < 0.01). The highest concentration of formaldehyde measured was 0.4 ppM in a new home. Diurnal and seasonal fluctuations in levels of formaldehyde in some homes were as much as twofold and tenfold, respectively. The highest levels of formaldehyde were usually recorded during summer months. The concentration in indoor air of various organics was at least tenfold higher than in outdoor air. Carbon monoxide and nitrgen oxides were usually <2 and <0.02 ppM, respectively, except when gas stoves or kerosene space heaters were operating, or when a car was running in the garage. In 30% of the houses, the annual indoor guideline for radon, 4 pCi/L, was exceeded. The mean radon level in houses built on the ridgelines was 4.4 pCi/L, while houses located in the valleys had a mean level of 1.7 pCi/L (P < 0.01). The factor having the most impact on infiltration was operation of the central duct fan of the heating, ventilation, and air conditioning system. The mean rate of air exchange increased from 0.39 to 0.74 h/sup -1/ when the duct fan was operated (measurements prior to December 1982). This report presents the study design and implementation, describes the monitoring protocols, and provides a complete set of the data collected during the project. 25 references, 29 figures, 42 tables.

  10. Air Quality Study Using Satellites - Current Capability and Future Plans

    NASA Technical Reports Server (NTRS)

    Bhartia, Pawan K.; Joiner, Joanna; Gleason, James; Liu, Xiong; Torres, Omar; Krotkov, Nickolay; Ziemke, Jerry; Chandra, Sushil

    2008-01-01

    Satellite instruments have had great success in monitoring the stratospheric ozone and in understanding the processes that control its daily to decadal scale variations. This field is now reaching its zenith with a number of satellite instruments from the US, Europe and Canada capping several decades of active research in this field. The primary public policy imperative of this research was to make reliable prediction of increases in biologically active surface UV radiation due to human activity. By contrast retrieval from satellite data of atmospheric constituents and photo-chemically active radiation that affect air quality is a new and growing field that is presenting us with unique challenges in measurement and data interpretation. A key distinction compared to stratospheric sensors is the greatly enhanced role of clouds, aerosols, and surfaces (CAS) in determining the quality and quantity of useful data that is available for air quality research. In our presentation we will use data from several sensors that are currently flying on the A-train satellite constellation, including OMI, MODIS, CLOUDSAT, and CALIPSO, to highlight that CAS can have both positive and negative effects on the information content of satellite measurements. This is in sharp contrast to other fields of remote sensing where CAS are usually considered an interference except in those cases when they are the primary subject of study. Our analysis has revealed that in the reflected wavelengths one often sees much further down into the atmosphere, through most cirrus, than one does in the emitted wavelengths. The lower level clouds provide a nice background against which one can track long-range transport of trace gases and aerosols. In addition, differences in trace gas columns estimated over cloudy and adjacent clear pixels can be used to measure boundary layer trace gases. However, in order to take full advantage of these features it will be necessary to greatly advance our understanding of

  11. Technology Solutions Case Study: Air Leakage and Air Transfer Between Garage and Living Space, Waldorf, Maryland

    SciTech Connect

    2014-11-01

    In this project, Building Science Corporation worked with production homebuilder K. Hovnanian to evaluate air transfer between the garage and living space in a single-family detached home constructed by a production homebuilder in compliance with the 2009 International Residential Code and the 2009 International Energy Conservation Code. The project gathered important information about the performance of whole-building ventilation systems and garage ventilation systems as they relate to minimizing flow of contaminated air from garage to living space. A series of 25 multipoint fan pressurization tests and additional zone pressure diagnostic testing measured the garage and house air leakage, the garage-to-house air leakage, and garage and house pressure relationships to each other and to outdoors using automated fan pressurization and pressure monitoring techniques. While the relative characteristics of this house may not represent the entire population of new construction configurations and air tightness levels (house and garage) throughout the country, the technical approach was conservative and should reasonably extend the usefulness of the results to a large spectrum of house configurations from this set of parametric tests in this one house. Based on the results of this testing, the two-step garage-to-house air leakage test protocol described above is recommended where whole-house exhaust ventilation is employed. For houses employing whole-house supply ventilation (positive pressure) or balanced ventilation (same pressure effect as the baseline condition), adherence to the EPA Indoor airPLUS house-to-garage air sealing requirements should be sufficient to expect little to no garage-to-house air transfer.

  12. Experimental and numerical study of open-air active cooling

    NASA Astrophysics Data System (ADS)

    Al-Fifi, Salman Amsari

    The topic of my thesis is Experimental and Numerical Study of Open Air Active Cooling. The present research is intended to investigate experimentally and Numerically the effectiveness of cooling large open areas like stadiums, shopping malls, national gardens, amusement parks, zoos, transportation facilities and government facilities or even in buildings outdoor gardens and patios. Our cooling systems are simple cooling fans with different diameters and a mist system. This type of cooling systems has been chosen among the others to guarantee less energy consumption, which will make it the most favorable and applicable for cooling such places mentioned above. In the experiments, the main focus is to study the temperature domain as a function of different fan diameters aerodynamically similar in different heights till we come up with an empirical relationship that can determine the temperature domain for different fan diameters and for different heights of these fans. The experimental part has two stages. The first stage is devoted to investigate the maximum range of airspeed and profile for three different fan diameters and for different heights without mist, while the second stage is devoted to investigate the maximum range of temperature and profile for the three different diameter fans and for different heights with mist. The computational study is devoted to built an experimentally verified mathematical model to be used in the design and optimization of water mist cooling systems, and to compare the mathematical results to the experimental results and to get an insight of how to apply such evaporative mist cooling for different places for different conditions. In this study, numerical solution is presented based on experimental conditions, such dry bulb temperature, wet bulb temperature, relative humidity, operating pressure and fan airspeed. In the computational study, all experimental conditions are kept the same for the three fans except the fan airspeed

  13. Observational Studies of Parameters Influencing Air-sea Gas Exchange

    NASA Astrophysics Data System (ADS)

    Schimpf, U.; Frew, N. M.; Bock, E. J.; Hara, T.; Garbe, C. S.; Jaehne, B.

    A physically-based modeling of the air-sea gas transfer that can be used to predict the gas transfer rates with sufficient accuracy as a function of micrometeorological parameters is still lacking. State of the art are still simple gas transfer rate/wind speed relationships. Previous measurements from Coastal Ocean Experiment in the Atlantic revealed positive correlations between mean square slope, near surface turbulent dis- sipation, and wind stress. It also demonstrated a strong negative correlation between mean square slope and the fluorescence of surface-enriched colored dissolved organic matter. Using heat as a proxy tracer for gases the exchange process at the air/water interface and the micro turbulence at the water surface can be investigated. The anal- ysis of infrared image sequences allow the determination of the net heat flux at the ocean surface, the temperature gradient across the air/sea interface and thus the heat transfer velocity and gas transfer velocity respectively. Laboratory studies were carried out in the new Heidelberg wind-wave facility AELOTRON. Direct measurements of the Schmidt number exponent were done in conjunction with classical mass balance methods to estimate the transfer velocity. The laboratory results allowed to validate the basic assumptions of the so called controlled flux technique by applying differ- ent tracers for the gas exchange in a large Schmidt number regime. Thus a modeling of the Schmidt number exponent is able to fill the gap between laboratory and field measurements field. Both, the results from the laboratory and the field measurements should be able to give a further understanding of the mechanisms controlling the trans- port processes across the aqueous boundary layer and to relate the forcing functions to parameters measured by remote sensing.

  14. Surface-catalyzed air oxidation of hydrazines: Environmental chamber studies

    NASA Technical Reports Server (NTRS)

    Kilduff, Jan E.; Davis, Dennis D.; Koontz, Steven L.

    1988-01-01

    The surface-catalyzed air oxidation reactions of fuel hydrazines were studied in a 6500-liter fluorocarbon-film chamber at 80 to 100 ppm concentrations. First-order rate constants for the reactions catalyzed by aluminum, water-damaged aluminum (Al/Al2O3), stainless steel 304L, galvanized steel and titanium plates with surface areas of 2 to 24 sq m were determined. With 23.8 sq m of Al/Al2O3 the surface-catalyzed air oxidation of hydrazine had a half-life of 2 hours, diimide (N2H2) was observed as an intermediate and traces of ammonia were present in the final product mixture. The Al/Al2O3 catalyzed oxidation of monomethylhydrazine yielded methyldiazine (HN = NCH3) as an intermediate and traces of methanol. Unsymmetrical dimethylhydrazine gave no detectable products. The relative reactivities of hydrazine, MMH and UDMH were 130 : 7.3 : 1.0, respectively. The rate constants for Al/Al2O3-catalyzed oxidation of hydrazine and MMH were proportional to the square of the surface area of the plates. Mechanisms for the surface-catalyzed oxidation of hydrazine and diimide and the formation of ammonia are proposed.

  15. Air Quality Modeling in Support of the Near-Road Exposures and Effects of Urban Air Pollutants Study (NEXUS)

    PubMed Central

    Isakov, Vlad; Arunachalam, Saravanan; Batterman, Stuart; Bereznicki, Sarah; Burke, Janet; Dionisio, Kathie; Garcia, Val; Heist, David; Perry, Steve; Snyder, Michelle; Vette, Alan

    2014-01-01

    A major challenge in traffic-related air pollution exposure studies is the lack of information regarding pollutant exposure characterization. Air quality modeling can provide spatially and temporally varying exposure estimates for examining relationships between traffic-related air pollutants and adverse health outcomes. A hybrid air quality modeling approach was used to estimate exposure to traffic-related air pollutants in support of the Near-Road Exposures and Effects of Urban Air Pollutants Study (NEXUS) conducted in Detroit (Michigan, USA). Model-based exposure metrics, associated with local variations of emissions and meteorology, were estimated using a combination of the American Meteorological Society/Environmental Protection Agency Regulatory Model (AERMOD) and Research LINE-source dispersion model for near-surface releases (RLINE) dispersion models, local emission source information from the National Emissions Inventory, detailed road network locations and traffic activity, and meteorological data from the Detroit City Airport. The regional background contribution was estimated using a combination of the Community Multi-scale Air Quality (CMAQ) and the Space-Time Ordinary Kriging (STOK) models. To capture the near-road pollutant gradients, refined “mini-grids” of model receptors were placed around participant homes. Exposure metrics for CO, NOx, PM2.5 and its components (elemental and organic carbon) were predicted at each home location for multiple time periods including daily and rush hours. The exposure metrics were evaluated for their ability to characterize the spatial and temporal variations of multiple ambient air pollutants compared to measurements across the study area. PMID:25166917

  16. Air quality modeling in support of the Near-Road Exposures and Effects of Urban Air Pollutants Study (NEXUS).

    PubMed

    Isakov, Vlad; Arunachalam, Saravanan; Batterman, Stuart; Bereznicki, Sarah; Burke, Janet; Dionisio, Kathie; Garcia, Val; Heist, David; Perry, Steve; Snyder, Michelle; Vette, Alan

    2014-09-01

    A major challenge in traffic-related air pollution exposure studies is the lack of information regarding pollutant exposure characterization. Air quality modeling can provide spatially and temporally varying exposure estimates for examining relationships between traffic-related air pollutants and adverse health outcomes. A hybrid air quality modeling approach was used to estimate exposure to traffic-related air pollutants in support of the Near-Road Exposures and Effects of Urban Air Pollutants Study (NEXUS) conducted in Detroit (Michigan, USA). Model-based exposure metrics, associated with local variations of emissions and meteorology, were estimated using a combination of the American Meteorological Society/Environmental Protection Agency Regulatory Model (AERMOD) and Research LINE-source dispersion model for near-surface releases (RLINE) dispersion models, local emission source information from the National Emissions Inventory, detailed road network locations and traffic activity, and meteorological data from the Detroit City Airport. The regional background contribution was estimated using a combination of the Community Multi-scale Air Quality (CMAQ) and the Space-Time Ordinary Kriging (STOK) models. To capture the near-road pollutant gradients, refined "mini-grids" of model receptors were placed around participant homes. Exposure metrics for CO, NOx, PM2.5 and its components (elemental and organic carbon) were predicted at each home location for multiple time periods including daily and rush hours. The exposure metrics were evaluated for their ability to characterize the spatial and temporal variations of multiple ambient air pollutants compared to measurements across the study area. PMID:25166917

  17. Development and Evaluation of Alternative Metrics of Ambient Air Pollution Exposure for Use in Epidemiologic Studies

    EPA Science Inventory

    Population-based epidemiologic studies of air pollution have traditionally relied upon imperfect surrogates of personal exposures, such as area-wide ambient air pollution levels based on readily available outdoor concentrations from central monitoring sites. This practice may in...

  18. Exergy parametric study of carbon monoxide oxidation in moist air

    NASA Astrophysics Data System (ADS)

    Souidi, Ferhat; Benmalek, Toufik; Yesaad, Billel; Baik, Mouloud

    2015-12-01

    This study aims to analyze the oxidation of carbon monoxide in moist air from the second thermodynamic law aspect. A mathematical model of laminar premixed flame in a stagnation point flow has been achieved by numerical solution of the boundary layer equation using a self-made code. The chemical kinetic mechanism for flameless combustion of fuel, which is a mixture of carbon monoxide, oxygen, and water vapor, is modeled by 34 elementary reactions that incorporate (09) nine chemical species: CO, O, CO2, O2, H2O, H, H2, HO2, and OH. The salient point is that for all the parameters we considered, the exergy of the process is completely destroyed by irreversibilities. From the chemical viewpoint, the OH radical plays an essential role in CO oxidation. This latter point has already been mentioned by previous investigators.

  19. Vegetation studies on Vandenberg Air Force Base, California

    NASA Technical Reports Server (NTRS)

    Schmalzer, Paul A.; Hickson, Diana E.; Hinkle, C. Ross

    1988-01-01

    Vandenburg Air Force Base, located in coastal central California with an area of 98,400 ac, contains resources of considerable biological significance. Available information on the vegetation and flora of Vandenburg is summarized and new data collected in this project are presented. A bibliography of 621 references dealing with vegetation and related topics related to Vanderburg was compiled from computer and manual literature searches and a review of past studies of the base. A preliminary floristic list of 642 taxa representing 311 genera and 80 families was compiled from past studies and plants identified in the vegetation sampling conducted in this project. Fifty-two special interest plant species are known to occur or were suggested to occur. Vegetation was sampled using permanent plots and transects in all major plant communities including chaparral, Bishop pine forest, tanbark oak forest, annual grassland, oak woodland, coastal sage scrub, purple sage scrub, coastal dune scrub, coastal dunes, box elder riparian woodland, will riparian woodland, freshwater marsh, salt marsh, and seasonal wetlands. Comparison of the new vegetation data to the compostie San Diego State University data does not indicate major changes in most communities since the original study. Recommendations are made for additional studies needed to maintain and extend the environmental data base and for management actions to improve resource protection.

  20. The National Near-Road Mobile Source Air Toxics Study

    EPA Science Inventory

    Recently, much attention has been directed at understanding the impact of mobile sources on near-road air quality, especially PM and its components, NOx and CO, but little information exists for mobile source air toxics (MSATs). MSATs of interest to this project are 1,3-butadiene...

  1. Overview and Evaluation of Alternative Air Quality ExposureMetrics Used in Recent Air Pollution Epidemiological Studies

    EPA Science Inventory

    This poster presents selected results from a few of these studies conducted and provides a summary of key findings and lessons learned and recommendations, in order to improve the use of enhanced exposure metrics during future epidemiological studies of air pollution.

  2. Air Quality Modeling in Support of the Near-road EXposures and effects of Urban air pollutants Study (NEXUS)

    EPA Science Inventory

    The paper presents the results of the model applications to estimate exposure metrics in support of an epidemiologic study in Detroit, Michigan. The Near-road Exposures to Urban air pollutant Study (NEXUS) design includes determining if children in Detroit, MI with asthma living ...

  3. Aerosol analysis for the regional air pollution study. Final report

    SciTech Connect

    Jaklevic, J.M.; Gatti, R.C.; Goulding, F.S.; Loo, B.W.; Thompson, A.C.

    1980-05-01

    The design and operation of an aerosol sampling and analysis program implemented during the 1975 to 1977 St. Louis Regional Air Pollution Study is described. A network of ten samplers were operated at selected sites in the St. Louis area and the total mass and elemental composition of the collected particulates were determined. Sampling periods of 2 to 24 hours were employed. The samplers were capable of collecting aerosol particles in two distinct size ranges corresponding to fine (< 2.4 ..mu..m diameter) and coarse (> 2.4 ..mu..m diameter) particles. This unique feature allowed the separation of the particulate samples into two distinct fractions with differing chemical origins and health effects. The analysis methods were also newly developed for use in the St. Louis RAPS study. Total particulate mass was measured by a beta-particle attenuation method in which a precision of +- 5 ..mu..m/cm/sup 2/ could be obtained in a one minute measurement time. Elemental compositions of the samples were determined using an energy dispersive x-ray fluorescence method in which detectable limits of 5 ng/cm/sup 2/ or less were routinely achieved for elements ranging in atomic number from Al to Pb. The advantages of these analytical methods over more conventional techniques arise from the ability to automate the measurements. During the course of the two year study, a total of more than 35,000 individual samples were processed and a total of 28 concentrations measured for each sample.

  4. Preliminary results from the Pittsburgh Air Quality Study

    NASA Astrophysics Data System (ADS)

    Pandis, S. N.; Davidson, C. I.; Robinson, A. L.; Khlystov, A. Y.

    2002-12-01

    The Pittsburgh Air Quality Study (PAQS) is a collaborative effort among 20 research groups, and is part of the EPA Supersite Program. In collaboration with several other Supersites around the country, PAQS is also one component of an intensive experiment conducted in July 2001. The PAQS study includes monitoring for aerosol number, surface, and volume distributions, PM mass in several size ranges, single particle chemical composition, continuous aerosol sulfate, nitrate, and carbon mass, bioaerosols, hygroscopic aerosol growth, and filter-based aerosol chemical composition including trace metals, anions/cations, elemental and organic carbon, and various organic compounds. Meteorological data and concentrations of several trace gases are obtained simultaneously. The results will be used to test a variety of hypothesis on atmospheric aerosols. Examples include our ability to account for aerosol mass by summing contributions of individual chemical species, the extent to which single particle chemical composition data can be used to determine bulk chemical concentrations, our ability to predict natural and anthropogenic sources of aerosols, and the extent to which aerosols contribute to increased morbidity and mortality in Pittsburgh. This paper summarizes a few of the interesting results obtained during the study, such as closure of the aerosol mass balance, frequent new particle formation, aerosol water content and artifacts when sampling carbonaceous aerosol.

  5. Southern California air quality study (SCAQS) begins; major effort to examine smog causes, chemistry

    SciTech Connect

    Not Available

    1987-07-01

    More than 50 teams of research scientists from around the world, including Canada and Europe, will swarm over Southern California this summer in the most extensive study of air pollution makeup in 15 years. Known as the Southern California Air Quality Study (SCAQS), the $10 million project will give smog researchers the most up-to-date information about what is in the air, where it comes from, and the complex chemistry in the atmosphere that produces some of the world's worst air quality. Major pollutants to be studied will include: ozone; carbon compounds; nitrogen oxides; particulates; acid rain; and toxics. Information from the study will help the California Air Resources Board and others refine programs that reduce emissions, making them more effective in improving air quality, and will set the technical foundation for air pollution clean-up efforts well into the next century.

  6. NEXAFS Study of Air Oxidation for Mg Nanoparticle Thin Film

    NASA Astrophysics Data System (ADS)

    Ogawa, S.; Murakami, S.; Shirai, K.; Nakanishi, K.; Ohta, T.; Yagi, S.

    2013-03-01

    The air oxidation reaction of Mg nanoparticle thin film has been investigated by Mg K-edge NEXAFS technique. It is revealed that MgO is formed on the Mg nanoparticle surfaces at the early stage of the air oxidation for Mg nanoparticle thin film. The simulation of NEXAFS spectrum using standard spectra indicates the existence of complex magnesium carbonates (x(MgCO3).yMg(OH2).z(H2O)) in addition to MgO at the early stage of the air oxidation.

  7. Studying Air Quality with Data from the Internet.

    ERIC Educational Resources Information Center

    Salter, Leo; Parsons, Barbara

    2000-01-01

    Explains how the internet can be used between institutions for parallel research opportunities. Uses air quality data to examine the relationship between traffic flow and atmospheric particulate matter (PM) values. (Author/YDS)

  8. Studies in the demand for short haul air transportation

    NASA Technical Reports Server (NTRS)

    Kanafani, A.; Gosling, G.; Taghavi, S.

    1975-01-01

    Demand is analyzed in a short haul air transportation corridor. Emphasis is placed on traveler selection from available routes. Model formulations, estimation techniques, and traffic data handling are included.

  9. Coleman Highlands subsurface air utilization study. Final report

    SciTech Connect

    Shapiro, M.D.

    1982-11-15

    An investigation was conducted into the feasibility of using a 1 million square foot developed cave within the Downtown Industrial Park as a heating and cooling source for a proposed residential subdivision on an adjacent vacant tract of land. Both sites are located near the Coleman Highlands neighborhood in the Westport Community of Kansas City, Missouri. Characteristics of the cave and surface sites were studied, as well as potential heating and cooling sources and transfer media. BTU capacity of the cave and demand for the prototype houses was calculated. The preferred system included a water source in the cave, water transfer medium, and water-to-air heat pumps in the individual homes. Analysis of that system showed it would be marginally effective due to the limited heat valve available in the cave and substantial shortfalls of cooling capacity for summertime operation. Estimated system costs appeared to be in an affordable range, but it was felt that those capital costs could be better applied to other energy-conserving measures.

  10. Sitewide feasibility study Eielson Air Force Base, Alaska

    SciTech Connect

    Last, G.V.; Lanigan, D.C.; Josephson, G.B.; Bagaasen, L.M.

    1995-09-01

    The Sitewide Feasibility Study (FS) is required under the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA), the National Contingency Plan (NCP), and the Federal Facility Agreement (FFA) for Eielson Air Force Base (AFB). It is based on findings presented in the Sitewide Remedial Investigation (RI) Report (USAF 1995a), and the Sitewide Baseline Risk Assessment (BLRA) Report (USAF 1995b). Under the FFA, 64 potential source areas were placed in one of six operable units, based on similar contaminant and environmental characteristics, or were included for evaluation under a Source Evaluation Report (SER). The sitewide RI was directed at contamination that was not confined to an operable unit (OU) or SER source area. The objectives of the sitewide RI were to: Provide information about site characteristics to support individual OU RI/FS efforts and the sitewide RI/FS, including site hydrogeology and determination of background soil and groundwater characteristics; identify and characterize contamination that is not confined or attributable to a specific source area through sitewide monitoring of groundwater and surface water; evaluate cumulative risks to human health and the environment from contamination on a sitewide basis; and provide a mechanism for continued cohesive sitewide monitoring.

  11. Improving urban air quality in China: Beijing case study

    SciTech Connect

    Jiming Hao; Litao Wang

    2005-09-01

    China is undergoing rapid urbanization because of unprecedented economic growth. As a result, many cities suffer from air pollution. Two-thirds of China's cities have not attained the ambient air quality standards applicable to urban residential areas (Grade II). Particulate matter (PM), rather than sulfur dioxide (SO{sub 2}), is the major pollutant reflecting the shift from coal burning to mixed source pollution. In 2002, 63.2 and 22.4% of the monitored cities have PM and SO{sub 2} concentrations exceeding the Grade II standard, respectively. Nitrogen oxides (NOx) concentration kept a relatively stable level near the Grade II standard in the last decade and had an increasing potential in recent years because of the rapid motorization. In general, the air pollutants emission did not increase as quickly as the economic growth and energy consumption, and air quality in Chinese cities has improved to some extent. Beijing, a typical representative of rapidly developing cities, is an example to illustrate the possible options for urban air pollution control. Beijing's case provides hope that the challenges associated with improving air quality can be met during a period of explosive development and motorization. 21 refs., 19 figs., 6 tabs.

  12. Field Study of Exhaust Fans for Mitigating Indoor Air Quality Problems & Indoor Air Quality - Exhaust Fan Mitigation.

    SciTech Connect

    United States. Bonneville Power Administration.

    1987-07-01

    Overall, the findings show that exhaust fans basically provide small amounts of ventilation compensation. By monitoring the common indoor air pollutants (radon, formaldehyde, carbon monoxide, nitrogen dioxide, and water vapor), it was found that the quality of the indoor air was not adversely affected by the use of exhaust fans. Nor did their use provide any measurable or significant benefits since no improvement in air quality was ascertained. While exhaust fans of this small size did not increase radon, which is the contaminant of most concern, the researchers caution that operation of a larger fan or installation in a very tight home could result in higher levels because depressurization is greater. The daily energy consumption for use of these appliances during the heating season was calculated to be 1.5 kilowatt hours or approximately 3% of the energy consumption in the study homes. The information collected in this collaborative field study indicates that the use of these particular ventilation systems has no significant effect on indoor air quality.

  13. Using GIS to study the health impact of air emissions

    SciTech Connect

    Dent, A.L.; Fowler, D.A.; Kaplan, B.M.; Zarus, G.M.

    1999-07-01

    Geographical Information Systems (GIS) is a fast-developing technology with an ever-increasing number of applications. Air dispersion modeling is a well-established discipline that can produce results in a spatial context. The marriage of these two application is optimal because it leverages the predictive capacity of modeling with the data management, analysis, and display capabilities of GIS. In the public health arena, exposure estimation techniques are invaluable. The utilization of air emission data, such as US EPA Toxic Release Inventory (TRI) data, and air dispersion modeling with GIS enable public health professionals to identify and define the potentially exposed population, estimate the health risk burden of that population, and determine correlations between point-based health outcome results with estimated health risk.

  14. Optimization study on a single-cylinder compressed air engine

    NASA Astrophysics Data System (ADS)

    Yu, Qihui; Cai, Maolin; Shi, Yan; Xu, Qiyue

    2015-11-01

    The current research of compressed air engine (CAE) mainly focused on simulations and system integrations. However, energy efficiency and output torque of the CAE is limited, which restricts its application and popularization. In this paper, the working principles of CAE are briefly introduced. To set a foundation for the study on the optimization of the CAE, the basic mathematical model of working processes is set up. A pressure-compensated valve which can reduce the inertia force of the valve is proposed. To verify the mathematical model, the prototype with the newly designed pressure-compensated intake valve is built and the experiment is carried out, simulation and experimental results of the CAE are conducted, and pressures inside the cylinder and output torque of the CAE are obtained. Orthogonal design and grey relation analysis are utilized to optimize structural parameters. The experimental and optimized results show that, first of all, pressure inside the cylinder has the same changing tendency in both simulation curve and experimental curve. Secondly, the highest average output torque is obtained at the highest intake pressure and the lowest rotate speed. Thirdly, the optimization of the single-cylinder CAE can improve the working efficiency from an original 21.95% to 50.1%, an overall increase of 28.15%, and the average output torque increases also increases from 22.047 5 N • m to 22.439 N • m. This research designs a single-cylinder CAE with pressure-compensated intake valve, and proposes a structural parameters design method which improves the single-cylinder CAE performance.

  15. Study of long term options for electric vehicle air conditioning

    SciTech Connect

    Dieckmann, J.; Mallory, D. , Inc., Cambridge, MA )

    1991-07-01

    There are strong incentives in terms of national energy and environmental policy to encourage the commercialization of electrically powered vehicles in the U.S. Among these incentives are reduced petroleum consumption, improved electric generation capacity utilization, reduced IC engine emissions, and, depending on the primary fuel used for electric power generation, reduced emissions of carbon dioxide. A basic requirement for successfully commercializing any motor vehicle in the US is provision of adequate passenger comfort heating and air conditioning (cooling). Although air conditioning is generally sold as optional equipment, in excess of 80% of the automobiles and small trucks sold in the US have air conditioning systems. In current, pre-commercial electric vehicles, comfort heating is provided by a liquid fuel fired heater that heats water which is circulated through the standard heater core in the conventional interior air handling unit. Air conditioning is provided by electric motor driven compressors, installed in a system having, perhaps, an [open quotes]upsized[close quotes] condenser and a standard evaporator (front and rear evaporators in some instances) installed in the conventional interior air handler. Although this approach is adequate in the near term for initial commercialization efforts, a number of shortcomings of this arrangement, as well as longer range concerns need to be addressed. In this project, the long term alternatives for cooling and heating electric vehicles effectively, efficiently (with minimum range penalties), and without adverse environmental impacts have been examined. Identification of options that can provide both heating and cooling is important, in view of the disadvantages of carrying separate heating and cooling systems in the vehicle.

  16. Study of long term options for electric vehicle air conditioning

    SciTech Connect

    Dieckmann, J.; Mallory, D.

    1991-07-01

    There are strong incentives in terms of national energy and environmental policy to encourage the commercialization of electrically powered vehicles in the U.S. Among these incentives are reduced petroleum consumption, improved electric generation capacity utilization, reduced IC engine emissions, and, depending on the primary fuel used for electric power generation, reduced emissions of carbon dioxide. A basic requirement for successfully commercializing any motor vehicle in the US is provision of adequate passenger comfort heating and air conditioning (cooling). Although air conditioning is generally sold as optional equipment, in excess of 80% of the automobiles and small trucks sold in the US have air conditioning systems. In current, pre-commercial electric vehicles, comfort heating is provided by a liquid fuel fired heater that heats water which is circulated through the standard heater core in the conventional interior air handling unit. Air conditioning is provided by electric motor driven compressors, installed in a system having, perhaps, an {open_quotes}upsized{close_quotes} condenser and a standard evaporator (front and rear evaporators in some instances) installed in the conventional interior air handler. Although this approach is adequate in the near term for initial commercialization efforts, a number of shortcomings of this arrangement, as well as longer range concerns need to be addressed. In this project, the long term alternatives for cooling and heating electric vehicles effectively, efficiently (with minimum range penalties), and without adverse environmental impacts have been examined. Identification of options that can provide both heating and cooling is important, in view of the disadvantages of carrying separate heating and cooling systems in the vehicle.

  17. A Comparison of Exposure Metrics for Traffic-Related Air Pollutants: Application to Epidemiology Studies in Detroit, Michigan

    EPA Science Inventory

    Vehicles are major sources of air pollutant emissions, and individuals living near large roads endure high exposures and health risks associated with traffic-related air pollutants. Air pollution epidemiology, health risk, environmental justice, and transportation planning studi...

  18. An experimental study of air-assist atomizer spray flames

    NASA Technical Reports Server (NTRS)

    Mao, Chien-Pei; Wang, Geng; Chigier, Norman

    1988-01-01

    It is noted that air-assisted atomizer spray flames encountered in furnaces, boilers, and gas turbine combustors possess a more complex structure than homogeneous turbulent diffusion flames, due to the swirling motion introduced into the fuel and air flows for the control of flame stability, length, combustion intensity, and efficiency. Detailed comparisons are presented between burning and nonburning condition measurements of these flames obtained by nonintrusive light scattering phase/Doppler detection. Spray structure is found to be drastically changed within the flame reaction zone, with changes in the magnitude and shape of drop number density, liquid flux, mean drop size diameter, and drop mean axial velocity radial distributions.

  19. Winter season air pollution in El Paso-Ciudad Juarez. A review of air pollution studies in an international airshed

    SciTech Connect

    Einfeld, W.; Church, H.W.

    1995-03-01

    This report summarizes a number of research efforts completed over the past 20 years in the El Paso del Norte region to characterize pollution sources and air quality trends. The El Paso del Norte region encompasses the cities of El Paso, Texas and Ciudad Juarez, Chihuahua and is representative of many US-Mexico border communities that are facing important air quality issues as population growth and industrialization of Mexican border communities continue. Special attention is given to a group of studies carried out under special US Congressional funding and administered by the US Environmental Protection Agency. Many of these studies were fielded within the last several years to develop a better understanding of air pollution sources and trends in this typical border community. Summary findings from a wide range of studies dealing with such issues as the temporal and spatial distribution of pollutants and pollution potential from both stationary and mobile sources in both cities are presented. Particular emphasis is given to a recent study in El Paso-Ciudad Juarez that focussed on winter season PM{sub 10} pollution in El Paso-Ciudad Juarez. Preliminary estimates from this short-term study reveal that biomass combustion products and crustal material are significant components of winter season PM{sub 10} in this international border community.

  20. Energy Conservation in Air Cooled Condenser: A Case Study

    NASA Astrophysics Data System (ADS)

    Mallick, D. S.; Paul, S.

    2014-01-01

    Air cooled condensers were first introduced in the US power industry in the early 1970s, but only during the last few decades has the number of installations greatly increased, largely to mitigate the problem of available water supply. Air may be used as a cooling medium in condensers where, primarily, there is scarcity of water, or where the ambient remains significantly cold for major parts of the year. Air cooled condensers are designed considering the design ambient conditions of summer. During winter months, if the air flow rate over the heat transfer surfaces is kept constant, it leads to improved condenser vacuum, and consequently, improved heat rate. Alternatively, the fans may be run at lower speeds, by using variable frequency drives (VFD), so as to keep the condenser vacuum constant, resulting uniform heat rate. This paper compares the economics between the power saved by the use of VFD in the condenser fans, keeping constant heat rate throughout the year, vis-à-vis, the saving in fuel, effected when the fans are operated at constant speed throughout the year and thus achieving improved heat rate during colder ambient.

  1. Computational and experimental study of spin coater air flow

    NASA Astrophysics Data System (ADS)

    Zhu, Xiaoguang; Liang, Faqiu; Haji-Sheikh, A.; Ghariban, N.

    1998-06-01

    An extensive 2- and 3-D analysis of air flow in a POLARISTM 2200 Microlithography Cluster spin coater was conducted using FLUENTTM Computational Fluid Dynamics (CFD) software. To supplement this analysis, direct measurement of air flow velocity was also performed using a DantecTM Hot Wire Anemometer. Velocity measurements were made along two major planes across the entire flow field in the spin coater at various operating conditions. It was found that the flow velocity at the spin coater inlet is much lower than previously assumed and quite nonuniform. Based on this observation, a pressure boundary condition rather than a velocity boundary condition was used for subsequent CFD analysis. A comparison between calculated results and experimental data shows that the 3D model accurately predicts the air flow field in the spin coater. An added advantage of this approach is that the CFD model can be easily generated from the mechanical design database and used to analyze the effect of design changes. The modeled and measured results show that the flow pattern in the spin bowl is affected by interactions between the spinning wafer, exhaust flow, and the gap between the spin head and surrounding baffle. Different operating conditions such as spin speed, inlet pressure, and exhaust pressure were found to generate substantially different flow patterns. It was also found that backflow of air could be generated under certain conditions.

  2. A Study of the Effects of Air Pollution on Children

    ERIC Educational Resources Information Center

    Bury, Irene B.

    1970-01-01

    An investigation of the possible effects of air pollution on the absenteeism of elementary school children showed that a greater percent of absences occurred in the test group than in a comparable group. There is little question as to the importance that such information should have for educators, informed parents, and other adults in community…

  3. Biomarkers: New breakthroughs in the world of air pollution studies

    EPA Science Inventory

    This session aims are to show the use of biomarkers in better understanding health effects derived from air pollution and to provide updates on the utility of new biomarker techniques including “omics”-type of analyses. Presentations that focus on improved use of biomarkers of...

  4. A STUDY OF WINTER AIR POLLUTANTS AT FAIRBANKS, ALASKA

    EPA Science Inventory

    An air pollution monitoring program was initiated by the Arctic Environmental Research Station (AERS). Ambient monitoring was done throughout the winters of 76-77 and 77-78 at the Fairbanks Post Office and on the AERS roof. Indoor-outdoor monitoring was done at the new State Buil...

  5. Environmental Perception and Citizen Response: a Denver, Colorado Air Pollution Case Study.

    NASA Astrophysics Data System (ADS)

    Naomi, Leaura M.

    Denver, a high altitude city, suffers from air pollution. Automobile emissions, as well as wood and coal burning contribute to Denver's air pollution. In order to reduce its air pollution, Denver hosted a no-drive campaign, The Better Air Campaign. This study examined how Denver -area citizens perceived their air pollution, responded to their air pollution, and responded to their no-drive campaign. First, I conducted personal interviews of twenty Denver air pollution decision-makers to ascertain their perceptions and definitions of Denver's air pollution problem. Second, I created a theoretical model of environmental perception and behavioral response to air pollution. Third, I conducted a telephone survey of 500 Denver-area residents to examine the usefulness of the model. By segmenting a sample of 500 Denver-area residents via a modified values and lifestyles (VALS) technique included in a telephone survey, the perceptions and behaviors of residents fell into a clear pattern. This values and lifestyles pattern coincided with a conventional innovation-adoption pattern, including innovators, the bandwagon, and laggards. Thus, the research determined the population's perceptions and behavioral responses to their air pollution. The research also pointed a direction for Denver's air pollution decision-makers to follow in order to reduce use of the gasoline-powered automobile. And, for those interested in encouraging public acceptance of ecological sustainability, it suggested application of the VALS technique for reaching the public.

  6. Electric air filtration: theory, laboratory studies, hardware development, and field evaluations

    SciTech Connect

    Bergman, W.; Biermann, A.; Kuhl, W.; Lum, B.; Bogdanoff, A.; Hebard, H.; Hall, M.; Banks, D.; Mazumder, M.; Johnson, J.

    1983-09-01

    We summarize the results of a seven-year research project for the US Department of Energy (DOE) to develop electric air filters that extend the service life of high-efficiency particulate air (HEPA) filters used in the nuclear industry. This project was unique to Lawrence Livermore National Laboratory (LLNL), and it entailed comprehensive theory, laboratory studies, and hardware development. We present our work in three major areas: (1) theory of and instrumentation for filter test methods, (2) theoretical and laboratory studies of electric air filters, and (3) development and evaluation of eight experimental electric air filters.

  7. A new study of muons in air showers by NBU air shower array

    NASA Technical Reports Server (NTRS)

    Chaudhuri, N.; Mukherjee, N.; Sarkar, S.; Basak, D. K.; Ghosh, B.

    1985-01-01

    The North Bengal University (NBU) air shower array has been in operation in conjunction with two muon magnetic spectrographs. The array incorporates 21 particle density sampling detectors around the magnetic spectrographs covering an area of 900 sq m. The layout of the array is based on the arrangement of detectors in a square symmetry. The array set up on the ground level is around a 10 m high magnetic spectrograph housing. This magnetic spectrograph housing limits the zenith angular acceptance of the incident showers to a few degrees. Three hundred muons in the fitted showers of size range 10 to the 4th power to 10 to the 5th power particles have so far been scanned and the momenta determined in the momentum range 2 - 440 GeV/c. More than 1500 recorded showers are now in the process of scanning and fitting. A lateral distribution of muons of energy greater than 300 MeV in the shower size range 10 to the 5th power to 7 x 10 to the 5th power has been obtained.

  8. *A participant-based approach to indoor/outdoor air monitoring in Community Health Studies

    EPA Science Inventory

    Community health studies of traffic-related air pollution have been hampered by the cost and participant burden associated with collecting household-level exposure data. The current study utilized a participant-based approach to collect indoor and outdoor air monitoring data from...

  9. CASE STUDIES IN THE APPLICATION OF AIR QUALITY MODELING IN ENVIRONMENTAL DECISION MAKING: SUMMARY AND RECOMMENDATIONS

    EPA Science Inventory

    Eleven case studies of the application of air quality models were undertaken in order to examine the problems encountered when trying to use these models in making environmental policy decisions. The case studies of air pollution control decisions describe the decision process, t...

  10. Ships, ports and particulate air pollution - an analysis of recent studies.

    PubMed

    Mueller, Daniel; Uibel, Stefanie; Takemura, Masaya; Klingelhoefer, Doris; Groneberg, David A

    2011-01-01

    The duration of use is usually significantly longer for marine vessels than for roadside vehicles. Therefore, these vessels are often powered by relatively old engines which may propagate air pollution. Also, the quality of fuel used for marine vessels is usually not comparable to the quality of fuels used in the automotive sector and therefore, port areas may exhibit a high degree of air pollution. In contrast to the multitude of studies that addressed outdoor air pollution due to road traffic, only little is known about ship-related air pollution. Therefore the present article aims to summarize recent studies that address air pollution, i.e. particulate matter exposure, due to marine vessels. It can be stated that the data in this area of research is still largely limited. Especially, knowledge on the different air pollutions in different sea areas is needed. PMID:22141925

  11. How smoke-free laws improve air quality: A global study of Irish pubs

    PubMed Central

    Carpenter, Carrie M.; Travers, Mark J.; Cummings, K. Michael; Hyland, Andrew; Mulcahy, Maurice; Clancy, Luke

    2009-01-01

    Introduction The present study examined indoor air quality in a global sample of smoke-free and smoking-permitted Irish pubs. We hypothesized that levels of respirable suspended particles, an important marker of secondhand smoke, would be significantly lower in smoke-free Irish pubs than in pubs that allowed smoking. Methods Indoor air quality was assessed in 128 Irish pubs in 15 countries between 21 January 2004 and 10 March 2006. Air quality was evaluated using an aerosol monitor, which measures the level of fine particle (PM2.5) pollution in the air. A standard measurement protocol was used by data collectors across study sites. Results Overall, the level of air pollution inside smoke-free Irish pubs was 93% lower than the level found in pubs where smoking was permitted. Discussion Levels of indoor air pollution can be massively reduced by enacting and enforcing smoke-free policies. PMID:19380381

  12. Ships, ports and particulate air pollution - an analysis of recent studies

    PubMed Central

    2011-01-01

    The duration of use is usually significantly longer for marine vessels than for roadside vehicles. Therefore, these vessels are often powered by relatively old engines which may propagate air pollution. Also, the quality of fuel used for marine vessels is usually not comparable to the quality of fuels used in the automotive sector and therefore, port areas may exhibit a high degree of air pollution. In contrast to the multitude of studies that addressed outdoor air pollution due to road traffic, only little is known about ship-related air pollution. Therefore the present article aims to summarize recent studies that address air pollution, i.e. particulate matter exposure, due to marine vessels. It can be stated that the data in this area of research is still largely limited. Especially, knowledge on the different air pollutions in different sea areas is needed. PMID:22141925

  13. Field Studies for Secondary Organic Aerosol in the Transboundary Air

    NASA Astrophysics Data System (ADS)

    Irei, S.; Takami, A.; Sadanaga, Y.; Nozoe, S.; Hayashi, M.; Hara, K.; Arakaki, T.; Hatakeyama, S.; Miyoshi, T.; Yokouchi, Y.; Bandow, H.

    2014-12-01

    To study formation of secondary organic aerosol (SOA) in the air outflowed from the Chinese continent and its fraction in an urban city located in downwind, we have conducted field studies at two background sites and one urban site in the western Japan: the Cape Hedo Aerosol and Atmospheric Monitoring Station (26.9˚N, 128.3˚E), the Fukue Atmospheric Monitoring Station (32.8˚N, 128.7˚E), and Fukuoka University (33.6˚N, 130.4˚E), respectively. During the studies, stable carbon isotope ratio (δ13C) of low-volatile water-soluble organic carbon (LV-WSOC) was measured in 24 h collected filter samples of total suspended particulate matter. Concentration of fine organic aerosol and the proportion of the signal at m/z 44 (ions from the carboxyl group) in the organic mass spectra (f44) were also measured by Aerodyne aerosol mass spectrometers. Limited to the Fukue site only, mixing ratios of trace gas species, such as aromatic hydrocarbons, NOx, and NOy, were also measured using GC-FID and NOx and NOyanalyzers for estimation of photochemical age (t[OH]). A case study in December 2010 showed that plots of δ13C versus f44 showed systematic variations at Hedo and Fukue. However, their trends were opposite. At Fukue the trend was consistent in the plot of δ13C of LV-WSOC versus t[OH] estimated by the NOx/NOy or the hydrocarbon ratios, indicating influence of SOA. The systematic trends aforementioned qualitatively agreed with a binary mixture model of SOA with background LV-WSOC having the f44 of ~0.06 and the δ13C of -17‰ or higher, implication of some influence of primary emission associated with C4plants. Given that the LV-WSOC at the urban Fukuoka site was a binary mixture, a mass balance for δ13C was constructed below. In the equation, δ13CMix, δ13CLocal, δ13CTrans, and FLocal are δ13C of binary LV-WSOC mixture, δ13C of LV-WSOC from local emission origin, δ13C of LV-WSOC from transboundary pollution origin, and a fraction of LV-WSOC from local emission

  14. WIPP air-intake shaft disturbed-rock zone study

    SciTech Connect

    Dale, T.; Hurtado, L.D.

    1996-12-01

    The disturbed-rock zone surrounding the air-intake shaft at the Waste Isolation Pilot Plant (WIPP) site was investigated to determine the extent and the permeability of the disturbed-rock zone as a function of radial distance from the 6.1 m diameter shaft, at different elevations within the Salado. Gas- and brine-permeability tests were performed in the bedded halite of the Salado formation at two levels within the air-intake shaft. The gas- and brine-permeability test results demonstrated that the radial distance to an undisturbed formation permeability of 1 {times} 10{sup {minus}21} m{sup 2} was less than 3.0 m.

  15. Air-water analogy and the study of hydraulic models

    NASA Technical Reports Server (NTRS)

    Supino, Giulio

    1953-01-01

    The author first sets forth some observations about the theory of models. Then he established certain general criteria for the construction of dynamically similar models in water and in air, through reference to the perfect fluid equations and to the ones pertaining to viscous flow. It is, in addition, pointed out that there are more cases in which the analogy is possible than is commonly supposed.

  16. An environmental study of mercury speciation in ambient air

    SciTech Connect

    Gottfried, T.; Koenig, M.; Koprivcia, V.; Lover, A.; Stephens, O.

    1996-10-01

    Mercury is a highly toxic environmental pollutant that is emitted to the atmosphere primarily from power plants and is then deposited to the earth as a water soluble species in rain and snow. One of the important unanswered questions in the atmospheric chemistry of mercury is whether gas-phase ionic Hg{sup 2+} species exist and under what conditions they are formed. This paper will describe a novel technique for measuring atmospheric Hg{sup 2+} using a high-flow refluxing mist chamber to trap water-soluble Hg(II) from ambient air, coupled with an ultra-sensitive atomic fluorescence method for mercury quantitation. Various tests and refinement of the technique will be described, along with representative measurements in ambient air. The data show a strong diurnal trend in Hg(II) concentrations. Evidence suggests that some Hg(II) is formed within the mist chamber, most probably by aqueous-phase reaction of ozone with the Hg{sup O} present in ambient air.

  17. Air quality measurements in urban green areas - a case study

    NASA Astrophysics Data System (ADS)

    Kuttler, W.; Strassburger, A.

    The influence of traffic-induced pollutants (e.g. CO, NO, NO 2 and O 3) on the air quality of urban areas was investigated in the city of Essen, North Rhine-Westphalia (NRW), Germany. Twelve air hygiene profile measuring trips were made to analyse the trace gas distribution in the urban area with high spatial resolution and to compare the air hygiene situation of urban green areas with the overall situation of urban pollution. Seventeen measurements were made to determine the diurnal concentration courses within urban parks (summer conditions: 13 measurements, 530 30 min mean values, winter conditions: 4 measurements, 128 30 min mean values). The measurements were carried out during mainly calm wind and cloudless conditions between February 1995 and March 1996. It was possible to establish highly differentiated spatial concentration patterns within the urban area. These patterns were correlated with five general types of land use (motorway, main road, secondary road, residential area, green area) which were influenced to varying degrees by traffic emissions. Urban parks downwind from the main emission sources show the following typical temporal concentration courses: In summer rush-hour-dependent CO, NO and NO 2 maxima only occurred in the morning. A high NO 2/NO ratio was established during weather conditions with high global radiation intensities ( K>800 W m -2), which may result in a high O 3 formation potential. Some of the values measured found in one of the parks investigated (Gruga Park, Essen, area: 0.7 km 2), which were as high as 275 μg m -3 O 3 (30-min mean value) were significantly higher than the German air quality standard of 120 μg m -3 (30-min mean value, VDI Guideline 2310, 1996) which currently applies in Germany and about 20% above the maximum values measured on the same day by the network of the North Rhine-Westphalian State Environment Agency. In winter high CO and NO concentrations occur in the morning and during the afternoon rush-hour. The

  18. Laboratory study of air sparging of TCE-contaminated saturated soils and ground water

    SciTech Connect

    Adams, J.A.; Reddy, K.R.

    1999-06-30

    Air sparging has proven to be an effective remediation technique for treating saturated soils and ground water contaminated by volatile organic compounds (VOCs). Since little is known about the system variables and mass transfer mechanisms important to air sparging, several researchers have recently performed laboratory investigations to study such issues. This paper presents the results of column experiments performed to investigate the behavior of dense nonaqueous phase liquids (DNAPLs), specifically trichloroethylene (TCE), during air sparging. The specific objectives of the study were (1) to compare the removal of dissolved TCE with the removal of dissolved light nonaqueous phase liquids (LNAPLs), such as benzene or toluene; (2) to determine the effect of injected air-flow rate on dissolved TCE removal; (3) to determine the effect of initial dissolved TCE concentration on removal efficiency; and (4) to determine the differences in removal between dissolved and pure-chase TCE. The test results showed that (1) the removal of dissolved TCE was similar to that of dissolved LNAPL; (2) increased air-injection rates led to increased TCE removal at lower ranges of air injection, but further increases at higher ranges of air injection did not increase the rate of removal, indicating a threshold removal rate had been reached; (3) increased initial concentration of dissolved TCE resulted in similar rates of removal; and (4) the removal pf pure-phase TCE was difficult using a low air-injection rate, but higher air-injection rates led to easier removal.

  19. Theoretical and Experimental study on multiple filaments in air

    SciTech Connect

    Zhang Jie; Lu Xin; Hao Zuoqiang; Xi Tingting; Zhang Zhe; Jin Zhan

    2007-07-11

    The physics of filaments formed by femtosecond laser pulses propagating in air is revealed both in theory and in experiment. An analytical method is used to investigate the interaction of two filaments. The interaction Hamiltonian of two filaments with different phase shifts is obtained and used to judge the properly of filaments interaction. The analytical results are in good agreement with simulation results. The influence of energy background on propagation of filaments is investigated in experiment. It is found that the characteristics of filaments can be changed by spatial and temporal control of laser pulses.

  20. Vandenberg Air Force Base Pressure Gradient Wind Study

    NASA Technical Reports Server (NTRS)

    Shafer, Jaclyn A.

    2013-01-01

    Warning category winds can adversely impact day-to-day space lift operations at Vandenberg Air Force Base (VAFB) in California. NASA's Launch Services Program and other programs at VAFB use wind forecasts issued by the 30 Operational Support Squadron Weather Flight (30 OSSWF) to determine if they need to limit activities or protect property such as a launch vehicle. The 30 OSSWF tasked the AMU to develop an automated Excel graphical user interface that includes pressure gradient thresholds between specific observing stations under different synoptic regimes to aid forecasters when issuing wind warnings. This required the AMU to determine if relationships between the variables existed.

  1. Use of air quality modeling results as exposure estimates in health studies

    NASA Astrophysics Data System (ADS)

    Holmes, H. A.; Ivey, C.; Friberg, M.; Zhai, X.; Balachandran, S.; Hu, Y.; Russell, A. G.; Mulholland, J. A.; Tolbert, P. E.; Sarnat, S. E.

    2013-12-01

    Air pollutant measurements from regulatory monitoring networks are commonly utilized in combination with spatial averaging techniques to develop air quality metrics for use in epidemiologic studies. While these data provide useful indicators for air pollution in a region, their temporal and spatial information are limited. The growing availability of spatially resolved health data sets (i.e., resident and county level patient records) provides an opportunity to develop and apply corresponding spatially resolved air quality metrics as enhanced exposure estimates when investigating the impact of air pollution on health outcomes. Additionally, the measured species concentrations from monitoring networks cannot directly identify specific emission sources or characterize pollutant mixtures. However, these observations in combination with chemical transport models (e.g., CMAQ) and source apportionment methods (e.g., CMB and PMF) can be used to characterize pollutant mixtures, sources and species impacting both individual locations and wider areas. Extensive analysis using a combination of air quality modeling approaches and observations may be beneficial for health studies whose goal is to assess the health impacts of pollutant mixtures, in both spatially resolved and time-series health analyses. As part of the Southeastern Center for Air Pollution and Epidemiology (SCAPE) unique methods have been developed to effectively analyze air pollution and air quality modeling data to better understand how emission sources combine to impact air quality and to provide air quality metrics for use in health assessments. This presentation will discuss the air quality modeling techniques being utilized in SCAPE investigations that are aimed at providing enhanced exposure metrics for use in spatially resolved (state of Georgia) and time-series epidemiologic analyses (St. Louis and Atlanta). To generate spatially resolved daily air quality estimates of species concentrations and source

  2. Air and Life. A Learning Experience for Coastal and Oceanic Awareness Studies, No. 223. [Project COAST].

    ERIC Educational Resources Information Center

    Delaware Univ., Newark. Coll. of Education.

    The purpose of these activities is to offer the secondary school student an opportunity to review what he/she has learned about air by moving quickly through a series of "Do-it-yourself" experiments. Emphasis is placed on the study of the composition of air and relating this information to life in aquatic and marine environments. Included are…

  3. Studying the Proteomic Composition of Expired Air Condensate in Newborns on Breathing Support.

    PubMed

    Kononikhin, A S; Ryndin, A Yu; Starodubtseva, N L; Chagovets, V V; Burov, A A; Bugrova, A E; Kostyukevich, Yu I; Popov, I A; Frankevich, V E; Ionov, O V; Zubkov, V V; Nikolaev, E N

    2016-04-01

    This study was designed to collect and perform a proteomic analysis of expired air condensate in newborns receiving respiratory support at the Department of Resuscitation and Intensive Care. The proteomic composition of expired air condensate was evaluated in newborns at various stages of development and with different abnormalities. PMID:27165072

  4. Extra-Curricular Social Studies in an Open Air History Museum

    ERIC Educational Resources Information Center

    Morris, Ronald Vaughan

    2008-01-01

    This article discusses extra-curricular social studies in an Open Air History Museum. Open Air History Museum, Conner Prairie Interpretive Park in Fishers, Indiana, is a cultural institution that encourages and supports talented students as they participate in an extra-curricular program. Ten-to sixteen-year-old youths "apply for jobs" as youth…

  5. DEVELOPMENT OF MODEL-BASED AIR POLLUTION EXPOSURE METRICS FOR USE IN EPIDEMIOLOGIC STUDIES

    EPA Science Inventory

    Population-based epidemiological studies of air pollution have traditionally relied upon imperfect surrogates of personal exposures, such as area-wide ambient air pollution levels based on readily available concentrations from central monitoring sites. U.S. EPA in collaboration w...

  6. REGIONAL AIR POLLUTION STUDY: OFF-HIGHWAY MOBILE SOURCE EMISSION INVENTORY

    EPA Science Inventory

    An emission inventory of mobile off-highway sources of air pollution has been determined for the Regional Air Pollution Study (RAPS) in St. Louis, Missouri. Emissions of HC, CO, NOx, SOx and particulate matter have been calculated with the aid of a computer for the 1,989 grid squ...

  7. THE UNIVERSITY OF AKRON URBAN AIR POLLUTION AND HUMAN HEALTH STUDY

    EPA Science Inventory

    Approximately 350 volunteers from East Cleveland, Ohio and 320 counterparts from Elyria, Ohio were studied for the chronic effects of air pollution. The East Cleveland area was chosen for its proximity to heavy industrial air pollution, and Elyria, because it is an urban area wit...

  8. "Development of Model-Based Air Pollution Exposure Metrics for use in Epidemiologic Studies"

    EPA Science Inventory

    Population-based epidemiological studies of air pollution have traditionally relied upon imperfect surrogates of personal exposures, such as area-wide ambient air pollution levels based on readily available concentrations from central monitoring sites. U.S. EPA in collaboration w...

  9. Laser optoacoustic tomography for the study of femtosecond laser filaments in air

    NASA Astrophysics Data System (ADS)

    Bychkov, A. S.; Cherepetskaya, E. B.; Karabutov, A. A.; Makarov, V. A.

    2016-08-01

    We propose to use optoacoustic tomography to study the characteristics of femtosecond laser filamentation in air and condensed matter. The high spatial resolution of the proposed system, which consists of an array of broadband megahertz piezoelectric elements, ensures its effectiveness, despite the attenuation of ultrasonic waves in air.

  10. Air Conditioning, Heating, and Ventilating: Construction, Supervision, and Inspection. Course of Study.

    ERIC Educational Resources Information Center

    Messer, John D.

    This course of study on air conditioning, heating, and ventilating is part of a construction, supervision, and inspection series, which provides instructional materials for community or junior college technical courses in the inspection program. Material covered pertains to: piping and piping systems; air movers; boilers; heat exchangers; cooling…

  11. Introducing the scanning air puff tonometer for biological studies

    NASA Astrophysics Data System (ADS)

    Fleury, Vincent; Al-Kilani, Alia; Boryskina, Olena P.; Cornelissen, Annemiek J. M.; Nguyen, Thi-Hanh; Unbekandt, Mathieu; Leroy, Loïc; Baffet, Georges; Le Noble, Ferdinand; Sire, Olivier; Lahaye, Elodie; Burgaud, Vincent

    2010-02-01

    It is getting increasingly evident that physical properties such as elastoviscoplastic properties of living materials are quite important for the process of tissue development, including regulation of genetic pathways. Measuring such properties in vivo is a complicated and challenging task. In this paper, we present an instrument, a scanning air puff tonometer, which is able to map point by point the viscoelastic properties of flat or gently curved soft materials. This instrument is an improved version of the air puff tonometer used by optometrists, with important modifications. The instrument allows one to obtain a direct insight into gradients of material properties in vivo. The instrument capabilities are demonstrated on substances with known elastoviscoplastic properties and several biological objects. On the basis of the results obtained, the role of the gradients of elastoviscoplastic properties is outlined for the process of angiogenesis, limb development, bacterial colonies expansion, etc. which is important for bridging the gaps in the theory of the tissue development and highlighting new possibilities for tissue engineering, based on a clarification of the role of physical features in developing biological material.

  12. Exploratory study of air quality in elementary schools, Coimbra, Portugal

    PubMed Central

    Ferreira, Ana Maria Conceição; Cardoso, Salvador Massano

    2013-01-01

    OBJECTIVE To analyze the air quality in elementary schools and their structural and functional conditions. METHODS Air quality in 51 elementary schools (81 classrooms) in the city of Coimbra, Portugal, both inside and outside of the rooms was evaluated during the four seasons, from 2010 to 2011. Temperature (T°), relative humidity (Hr), concentrations of carbon monoxide (CO), carbon dioxide (CO2), ozone (O3), nitrogen dioxide (NO2), sulfur dioxide (SO2), compounds were evaluated, as were volatile organics (VOC), formaldehyde and particulate matter (PM10), from November 2010 to February 2011 (autumn/winter) and March 2011 to June 2011 (spring/summer). A grid characterizing the structural and functional conditions of the schools was created. The statistical Student t test for paired samples and the Wilcoxon t test were applied. RESULTS In 47 schools, the average CO2concentrations were above the maximum reference concentration (984 ppm) mentioned in Portuguese legislation. The maximum concentration values found inside the rooms were critical, especially in the fall/winter (5,320 ppm). In some schools the average concentrations of VOC and PM10within the maximum concentration exceeded the reference legislated. The values (risk) of CO, formaldehyde, NO2, SO2and O3detected were not relevant. CONCLUSIONS There was a higher concentration of pollutants inside the rooms compared with outside. Inadequate ventilation is associated with high CO2concentration in the classroom. PMID:24626544

  13. Sensitivity Studies of Air Ingress Acidents in Modular HTGRs

    SciTech Connect

    Ball, Sydney J; Richards, Matt; Shepelev, Sergey

    2008-01-01

    Postulated air ingress accidents, while of very low probability in a modular high-temperature gas-cooled reactor (HTGR), are of considerable interest to the plant designer, operator, and regulator because of the possibility that the core could sustain significant damage under some circumstances. Sensitivity analyses are described that cover a wide spectrum of conditions affecting outcomes of the postulated accident sequences, for both prismatic and pebble-bed core designs. The major factors affecting potential core damage are the size and location of primary system leaks, flow path resistances, the core temperature distribution, and the long-term availability of oxygen in the incoming gas from a confinement building. Typically, all the incoming oxygen entering the core area is consumed within the reactor vessel, so it is more a matter of where, not whether, oxidation occurs. An air ingress model with example scenarios and means for mitigating damage are described. Representative designs of modular HTGRs included here are a 400-MW(th) pebble-bed reactor (PBR), and a 600-MW(th) prismatic-core modular reactor (PMR) design such as the gas-turbine modular helium reactor (GT-MHR).

  14. Study of PCBs and PBDEs in King George Island, Antarctica, using PUF passive air sampling

    NASA Astrophysics Data System (ADS)

    Li, Yingming; Geng, Dawei; Liu, Fubin; Wang, Thanh; Wang, Pu; Zhang, Qinghua; Jiang, Guibin

    2012-05-01

    Polyurethane foam (PUF)-disk based passive air samplers were deployed in King George Island, Antarctica, during the austral summer of 2009-2010, to investigate levels, distributions and potential sources of polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) in Antarctic air. The atmospheric levels of ∑ indicator PCBs and ∑14 PBDEs ranged from 1.66 to 6.50 pg m-3 and from 0.67 to 2.98 pg m-3, respectively. PCBs homologue profiles were dominated by di-PCBs, tri-PCBs and tetra-PCBs, whereas BDE-17 and BDE-28 were the predominant congeners of PBDEs, which could be explained by long-range atmospheric transport processes. However, the sampling sites close to the Antarctic research stations showed higher atmospheric concentrations of PCBs and PBDEs than the other sites, reflecting potential local sources from the Antarctic research stations. The non-Aroclor congener PCB-11 was found in all the air samples, with air concentrations of 3.60-31.4 pg m-3 (average 15.2 pg m-3). Comparison between the results derived from PUF-disk passive air sampling and high-volume air sampling validates the feasibility of using the passive air samplers in Antarctic air. To our knowledge, this study is the first employment of PUF-disk based passive air samplers in Antarctic atmosphere.

  15. Regional air quality in the four corners studys region: modeling approach

    SciTech Connect

    Nochumson, D.

    1982-01-01

    A two-dimensional Eulerian air pollutant transport model was used in an air quality study of the Four Corners region conducted for the National Commission on Air Quality. The regional modeling methodology and some sample results from the regional air quality analysis are presented. One major advantage of the regional transport model that was employed is that its solution involves the calculation of transfer coefficients that relate emissions to ambient concentrations and deposition and which can be used repeatedly to evaluate alternative scenarios and regulatory policies which represent different emission source configurations. The regional transport model was used in the calculation of the concentration and deposition of SO/sub 2/, SO/sub 4/, and primary fine particulates; and these estimates were used as inputs to regional atmospheric visibility and mass budget calculations. Previous studies have shown that the methods used in the regional air quality analysis give good agreement when comparing observed and estimated values.

  16. Acute effects of air pollution changes in schoolchildren: the Gardanne coal basin study

    NASA Astrophysics Data System (ADS)

    Charpin, D.; Kleisbauer, J. P.; Fondarai, A.; Francheterre, A.; Fondarai, J.; Graland, B.; Viala, A.

    1988-12-01

    In the literature, studies devoted to shortterm effects of air pollution episodes in children have provided controversial results. To evaluate if acute air pollution changes in the Gardanne coal basin (France) could have deleterious effects on children's pulmonary function, we studied 160 children on two different days. Each in-school examination consisted of a short questionnaire and a spirometric assessment. The area included districts of high and low pollution levels. In the former, the two examinations took place at different air pollution levels whereas, in the latter, the air pollution levels were comparable. We obtained higher spirometric values during the second examination, regardless of air pollution changes and suggesting a learning effect, which vanished when we used FEV1/FVC ratio. The difference in FEV1/FVC between days of low and high pollution was significant but merely equal to 2%. There was no change of clinical symptom score.

  17. Air pollution studies using PIXE and ICP methods

    NASA Astrophysics Data System (ADS)

    Stihi, Claudia; Bancuta, Anca; Popescu, I. V.; Virgolici, M.; Cimpoca, V.; Gugiu, M.; Vlaicu, Gh

    2006-05-01

    In the present work the moss biomonitoring technique and the combination of two analytical techniques - Particle Induced X-ray Emission (PIXE) [3] and Inductively Coupled Plasma (ICP) [4] - were applied for assessing environmental situation from the point of view of air polluting along the transect from north to south of the Dambovita County. PIXE analysis at the Tandem Accelerator FN-8 of the National Institute of Nuclear Physics - Horia Hulubei of Magurele, Bucharest, allowed determination of P, S, Cl, K, Ca, Mn, Fe, Ni, Cu, Zn, As, Sr, Cd and Pb in samples. ICP analyses were made using a Baird ICP2070 - Sequential Plasma Spectrometer in Targoviste and we determined in samples the concentration of Li, B, Na, and Mg together with Cd and Pb. The obtained results will permit to determine the regional extent of heavy metals and toxic elements atmospheric pollution and to identify specially affected areas and local sources of

  18. Studies of uncontrolled air traffic patterns, phase 1

    NASA Technical Reports Server (NTRS)

    Baxa, E. G., Jr.; Scharf, L. L.; Ruedger, W. H.; Modi, J. A.; Wheelock, S. L.; Davis, C. M.

    1975-01-01

    The general aviation air traffic flow patterns at uncontrolled airports are investigated and analyzed and traffic pattern concepts are developed to minimize the midair collision hazard in uncontrolled airspace. An analytical approach to evaluate midair collision hazard probability as a function of traffic densities is established which is basically independent of path structure. Two methods of generating space-time interrelationships between terminal area aircraft are presented; one is a deterministic model to generate pseudorandom aircraft tracks, the other is a statistical model in preliminary form. Some hazard measures are presented for selected traffic densities. It is concluded that the probability of encountering a hazard should be minimized independently of any other considerations and that the number of encounters involving visible-avoidable aircraft should be maximized at the expense of encounters in other categories.

  19. The RTL-46: A simulated commercial air transportation study

    NASA Technical Reports Server (NTRS)

    Dunbar, Christian; Prette, John; Andersen, Gerald; Sprunck, Martin; Vogel, Christine; Rivera, Francisco

    1993-01-01

    The RTL-46 provides an aircraft which utilizes advanced technology within the fictional Aeroworld market to better service the air travel customers and airlines of Aeroworld. The RTL-46 is designed to serve the portion of the travel market which flies less than 10,000 feet per flight. The design cruise velocity for the aircraft is 35 ft/sec, which rapidly expedites travel through Aeroworld. The major focus of the endeavor was to design an aircraft which would serve the Aeroworld market better than the existing aircraft, the HB-40. This could have been done through targeting another portion of the Aeroworld market or through serving the current HB-40 market more effectively. Due to the fact that approximately 70 percent of the potential Aeroworld passengers desired flights of 10,000 ft or less, this range became the target market for the RTL-46.

  20. Atmospheric Modelling for Air Quality Study over the complex Himalayas

    NASA Astrophysics Data System (ADS)

    Surapipith, Vanisa; Panday, Arnico; Mukherji, Aditi; Banmali Pradhan, Bidya; Blumer, Sandro

    2014-05-01

    An Atmospheric Modelling System has been set up at International Centre for Integrated Mountain Development (ICIMOD) for the assessment of Air Quality across the Himalaya mountain ranges. The Weather Research and Forecasting (WRF) model version 3.5 has been implemented over the regional domain, stretching across 4995 x 4455 km2 centred at Ichhyakamana , the ICIMOD newly setting-up mountain-peak station (1860 m) in central Nepal, and covering terrains from sea-level to the Everest (8848 m). Simulation is carried out for the winter time period, i.e. December 2012 to February 2013, when there was an intensive field campaign SusKat, where at least 7 super stations were collecting meteorology and chemical parameters on various sites. The very complex terrain requires a high horizontal resolution (1 × 1 km2), which is achieved by nesting the domain of interest, e.g. Kathmandu Valley, into 3 coarser ones (27, 9, 3 km resolution). Model validation is performed against the field data as well as satellite data, and the challenge of capturing the necessary atmospheric processes is discussed, before moving forward with the fully coupled chemistry module (WRF-Chem), having local and regional emission databases as input. The effort aims at finding a better understanding of the atmospheric processes and air quality impact on the mountain population, as well as the impact of the long-range transport, particularly of Black Carbon aerosol deposition, to the radiative budget over the Himalayan glaciers. The higher rate of snowcap melting, and shrinkage of permafrost as noticed by glaciologists is a concern. Better prediction will supply crucial information to form the proper mitigation and adaptation strategies for saving people lives across the Himalayas in the changing climate.

  1. Controller evaluation of initial data link en route air traffic control services: Mini study 3

    NASA Astrophysics Data System (ADS)

    Marek, Hank; Shochet, Ephraim; Darby, Evan; Buck, Frank; Sweeney, David; Cratch, Preston

    1991-06-01

    The results of Mini Study 3 conducted November 5-9, 1990 are presented. This Mini Study was conducted at the Federal Aviation Administration (FAA) Technical Center utilizing the Washington Air Route Traffic Control Center (ARTCC) airspace in the Data Link test bed. Initial Data Link en route services were evaluated in order to identify service delivery methods which optimize the human computer interface. Controllers from the Air Traffic Data Link Validation Team participated in this study.

  2. Linking stroke mortality with air pollution, income, and greenness in northwest Florida: an ecological geographical study

    PubMed Central

    Hu, Zhiyong; Liebens, Johan; Rao, K Ranga

    2008-01-01

    Background Relatively few studies have examined the association between air pollution and stroke mortality. Inconsistent and inclusive results from existing studies on air pollution and stroke justify the need to continue to investigate the linkage between stroke and air pollution. No studies have been done to investigate the association between stroke and greenness. The objective of this study was to examine if there is association of stroke with air pollution, income and greenness in northwest Florida. Results Our study used an ecological geographical approach and dasymetric mapping technique. We adopted a Bayesian hierarchical model with a convolution prior considering five census tract specific covariates. A 95% credible set which defines an interval having a 0.95 posterior probability of containing the parameter for each covariate was calculated from Markov Chain Monte Carlo simulations. The 95% credible sets are (-0.286, -0.097) for household income, (0.034, 0.144) for traffic air pollution effect, (0.419, 1.495) for emission density of monitored point source polluters, (0.413, 1.522) for simple point density of point source polluters without emission data, and (-0.289,-0.031) for greenness. Household income and greenness show negative effects (the posterior densities primarily cover negative values). Air pollution covariates have positive effects (the 95% credible sets cover positive values). Conclusion High risk of stroke mortality was found in areas with low income level, high air pollution level, and low level of exposure to green space. PMID:18452609

  3. Indoor air quality study in Agency Building Two, Empire State Plaza, Albany, New York

    SciTech Connect

    Not Available

    1992-04-01

    The quality of the indoor environment and potential health conquences have become major concerns for occupants of office buildings. Increasing ventilation rates are often recommended as a potential solution for indoor air quality (IAQ) problems, whether real or perceived as real by occupants. To date, limited quantitative data have been collected to relate increased outdoor-air intake to commonly measured IAQ or comfort parameters. The purpose of this study, conducted by GEOMET Technologies, Inc. for the New York State Energy Research and Development Authority, was to quantitatively assess the effect of ventilation rate on indoor air quality and associated parameters in an occupied office building, and occupant perceptions of air quality and comfort in the building. The building studied, a 20-story office tower located at the Empire State Plaza in Albany, New York, has a total floor area of approximately 100,000 ft. The building is operated by the New York State Office of General Services (OGS). The air-distribution component of the heating, ventilating, and air-conditioning (HVAC) system for the building consists of two air-handling units that serve the perimeter of the building through induction supply-air units and two other units that serve the core area of the building through ceiling diffusers. The perimeter system has separate zones that serve the north and south sides of the building, and the core system is zoned to individually serve the upper and lower halves of the building.

  4. A critical review of studies of the association between demands for hospital services and air pollution.

    PubMed Central

    Lipfert, F W

    1993-01-01

    Studies of the associations between air pollution and hospital admissions and emergency room use are reviewed, including studies of air pollution episodes, time-series analyses, and cross-sectional analyses. These studies encompass a variety of methods of analysis and levels of air quality. Findings from all three types of studies were generally consistent in that almost all of the studies reviewed found statistically significant associations between hospital use and air pollution; this unanimity may have resulted in part from publication bias. These associations were characterized by elasticities of the order of 0.20; i.e., a 100% change in air pollution was associated with a change in hospital use of about 20%, for specific diagnoses. Respiratory diagnoses were emphasized by most studies; cardiac diagnoses were included in five of them. The air pollutants most often associated with changes in hospital use were particulate matter, sulfur oxides, and oxidants. Apart from the major air pollution episodes, there was no obvious link between air pollution level and the significance or magnitudes of the associations. Long-term indicators of hospitalization appeared to also be influenced by medical care supply factors, including the numbers of beds and physicians per capita. These nonpathological causal factors could also have influenced the findings of the time-series studies by introducing extraneous factors in the patterns of admissions. Although consistent associations have been shown between hospital use and air pollution, further research is required to distinguish among potentially responsible pollutants and to deduce specific dose-response relationships of general utility. PMID:8243395

  5. A critical review of studies of the association between demands for hospital services and air pollution.

    PubMed

    Lipfert, F W

    1993-07-01

    Studies of the associations between air pollution and hospital admissions and emergency room use are reviewed, including studies of air pollution episodes, time-series analyses, and cross-sectional analyses. These studies encompass a variety of methods of analysis and levels of air quality. Findings from all three types of studies were generally consistent in that almost all of the studies reviewed found statistically significant associations between hospital use and air pollution; this unanimity may have resulted in part from publication bias. These associations were characterized by elasticities of the order of 0.20; i.e., a 100% change in air pollution was associated with a change in hospital use of about 20%, for specific diagnoses. Respiratory diagnoses were emphasized by most studies; cardiac diagnoses were included in five of them. The air pollutants most often associated with changes in hospital use were particulate matter, sulfur oxides, and oxidants. Apart from the major air pollution episodes, there was no obvious link between air pollution level and the significance or magnitudes of the associations. Long-term indicators of hospitalization appeared to also be influenced by medical care supply factors, including the numbers of beds and physicians per capita. These nonpathological causal factors could also have influenced the findings of the time-series studies by introducing extraneous factors in the patterns of admissions. Although consistent associations have been shown between hospital use and air pollution, further research is required to distinguish among potentially responsible pollutants and to deduce specific dose-response relationships of general utility. PMID:8243395

  6. United States Air Force 611th Air Support Group/Civil Engineering Squadron Elmendorf AFB, Alaska. Remedial investigation and feasibility study. Bullen Point Radar Installation, Alaska. Final report

    SciTech Connect

    Karmi, S.

    1996-03-18

    The United States Air Force (Air Force) has prepared this Remedial investigation/Feasibility Study (RI/FS) report as part of the Installation Restoration Program (IRP) to present results of RI/FS activities at five sites at the Bullen Point radar installation. The IRP provides for investigating, quantifying, and remediating environmental contamination from past waste management activities at Air Force installations throughout the United States.

  7. The Near-Road Exposures and Effects of Urban Air Pollutants Study (NEXUS): Study Design and Methods

    EPA Science Inventory

    The Near-road EXposures and effects of urban air pollutants Study (NEXUS) was designed to examine the relationship between near-roadway exposures to air pollutants and respiratory outcomes in a cohort of asthmatic children who live close to major roadways in Detroit, Michigan USA...

  8. Study of short atmospheric pressure dc glow microdischarge in air

    NASA Astrophysics Data System (ADS)

    Kudryavtsev, Anatoly; Bogdanov, Eugene; Chirtsov, Alexander; Emelin, Sergey

    2011-10-01

    The results of experiments and simulations of short (without positive column) atmospheric pressure dc glow discharge in air are presented. We used metal steel electrodes with a gap of 5-100 microns. The experimental voltage-current characteristic's (VAC) have a constant or slightly increasing form at low gap. The most stable microdischarges were burning with a flat cathode and rounded anode, when the length of the discharge is automatically established near the minimum of the Paschen curve by changing their binding on the anode. In this case microdischarge was stable and it had growing VAC. For simulations we used 2D fluid model with kinetic description of electrons. We solved the balance equations for the vibrationally- and the electronically-excited states of a nitrogen and oxygen molecules; nitrogen and oxygen atoms; ozone molecule; and different nitrogen and oxygen ions with different plasmochemical reactions between them. Simulations predicted the main regions of the dc glow discharges including cathode and anode sheath and plasma of negative glow, Faraday dark space and transition region. Gas heating plays an important role in shaping the discharge profiles. The results of experiments and simulations of short (without positive column) atmospheric pressure dc glow discharge in air are presented. We used metal steel electrodes with a gap of 5-100 microns. The experimental voltage-current characteristic's (VAC) have a constant or slightly increasing form at low gap. The most stable microdischarges were burning with a flat cathode and rounded anode, when the length of the discharge is automatically established near the minimum of the Paschen curve by changing their binding on the anode. In this case microdischarge was stable and it had growing VAC. For simulations we used 2D fluid model with kinetic description of electrons. We solved the balance equations for the vibrationally- and the electronically-excited states of a nitrogen and oxygen molecules; nitrogen

  9. MEASUREMENT OF HYDROPEROXIDES DURING THE TEXAS 2000 AIR QUALITY STUDY.

    SciTech Connect

    ZHENG,J.; ALAOUIE,A.; WEINSTEIN-LLOYD,J.B.; SPRINGSTON,S.R.; NUNNERMACKER,L.J.; LEE,Y.N.; BRECHTEL,F.; KLEINMAN,L.; DAUM,P.

    2002-01-17

    Hydroperoxides are important atmospheric oxidants. They are responsible for most of the oxidation of aqueous-phase SO{sub 2} to sulfate in the northeastern United States, resulting in the formation of acid precipitation and visibility-reducing sulfate aerosol (Penkett et al., 1979; Lind et al., 1987; Madronich and Calvert, 1990; Tanner and Schorran, 1995). Atmospheric hydrogen peroxide (H{sub 2}O{sub 2} or HP) is produced by the self-reaction of hydroperoxyl radicals (HO{sub 2}); higher organic peroxides are produced by reaction of HO{sub 2} with alkylperoxyl radicals (RO{sub 2}). Peroxyl radicals, along with OH, are chain carriers in the complex photochemical process that produces tropospheric ozone. Thus, concentrations of peroxides and their free radical precursors depend on solar intensity and ambient concentrations of water vapor, ozone, NO{sub x} (NO + NO{sub 2}), and VOCs (volatile organic compounds). Several investigators have demonstrated that HP and hydroxymethyl hydroperoxide (HOCH2 OOH or HMHP) also may be formed when ozone reacts with alkenes in moist air (Becker et al., 1990; Hewitt and Kok, 1991; Gaeb et al., 1995). Peroxides are the expected sink for peroxyl radicals when concentrations of NO are low. Otherwise, these radicals react with NO to form NO{sub 2}. Under high NO{sub x} conditions, NO{sub z} (oxidation products of NO and NO{sub 2}) becomes the principal radical sink. Therefore, formation rates of peroxides relative to NO{sub z} provide information about the history of an air mass and the expected sensitivity of ozone production to reduced emissions (Kleinman et al., 1997; Sillman, 1995; 1997). Through photolysis and reaction with OH, peroxides also act as a radical source; thus, reliable peroxide measurements are necessary for calculating ozone production rates. In this paper, we will summarize peroxide observations at the Williams Tower, and aboard the U.S. Department of Energy G-1 research aircraft in Houston, TX, during August and

  10. Beryllium concentrations in ambient air and its source identification. A case study.

    PubMed

    Thorat, D D; Mahadevan, T N; Ghosh, D K; Narayan, S

    2001-06-01

    Beryllium concentrations in atmospheric particulate and soil samples in and around a Beryllium Processing Facility (BPF) have been measured. The mean air concentration level of beryllium in and around the fence line of the BPF is 0.48 +/- 0.43 ng m(-3) (n = 397) and is mostly influenced by diurnal and seasonal changes. The observed air concentration levels were well below the prescribed ambient air quality (AAQ) standard of 10 ng m(-3). The soil concentration levels of beryllium in the study area were found to be in the range of 1.42-2.75 microg g(-1). The mass median aerodynamic diameter (MMAD) of beryllium aerosols in ambient air was found to be 6.9 microm. Source identification using the Enrichment Factor (EF) approach indicates soil as the predominant contributory source for air concentrations at the site. PMID:11393544

  11. MODEL FOR MEASURING THE HEALTH IMPACT FROM CHANGING LEVELS OF AMBIENT AIR POLLUTION: MORBIDITY STUDY

    EPA Science Inventory

    The study quantitatively examines the relationship between human health and ambient air concentrations of the major pollutants in the city of Chicago. This report describes the morbidity analysis in which linear regression models have been developed to quantitatively estimate the...

  12. AIR QUALITY AND SELECTED BIRTH DEFECTS, SEVEN COUNTY STUDY, TEXAS, 1997-2000

    EPA Science Inventory

    Introduction: A number of epidemiologic investigations have shown adverse effects of ambient air pollution on reproductive outcomes including spontaneous abortion, fetal growth, preterm delivery, and infant mortality. A southern California study found associations between carbon ...

  13. HP-25 PROGRAMMABLE POCKET CALCULATOR APPLIED TO AIR POLLUTION MEASUREMENT STUDIES: STATIONARY SOURCES

    EPA Science Inventory

    The report should be useful to persons concerned with Air Pollution Measurement Studies of Stationary Industrial Sources. It gives detailed descriptions of 22 separate programs, written specifically for the Hewlett Packard Model HP-25 manually programmable pocket calculator. Each...

  14. MICA-AIR: A PARTICIPANT-BASED APPROACH TO EXPOSURE ASSESSMENT IN EPIDEMIOLOGIC AND COMMUNITY HEALTH STUDIES

    EPA Science Inventory

    Objective. Epidemiologic and community health studies of traffic-related air pollution and childhood asthma have been limited by resource intensive exposure assessment techniques. The current study utilized a novel participant-based approach to collect air monitoring data f...

  15. Pathologic Analysis of Control Plans for Air Pollution Management in Tehran Metropolis: A Qualitative Study

    PubMed Central

    Shahrabi, Narges Salehi; Pourezzat, Aliasghar; Fayaz-Bakhsh, Ahmad; Mafimoradi, Shiva; Poursafa, Parinaz

    2013-01-01

    Background: Regarding the importance of air pollution issue for large cities, as Tehran metropolis, many plans, programs, projects and regulations have been developed to manage urban air pollution. However, most of them failed to decline the pollution. The purpose of this study is to pathologically analyze air-pollution control plans in order to offer effective solutions for Tehran metropolis. Methods: A qualitative content analysis and a semi-structured interview with 14 practicing professionals were used to identify key causes and sources of Tehran's air pollution, to recognize challenges and obstacles towards effective performance of air-pollution control plans in this metropolitan area, and to suggest the most effective controlling solutions. Results: Challenges related to air-pollution control plans can be divided into two major categories: Firstly lack of integrated and organized stewardship and secondly those related to political, economical, social and technical environmental abbreviated as PEST, challenges. For effective control of the Tehran air pollution, the following eight controlling alternatives were identified: Systematization of plan preparation process, organizing the stewardship, standardization and utilization of new technologies and professional experts, cultural and infrastructural development, realization of social justice, developing coordination and controlling mechanisms, improving citizen's participatory capacity, and focusing on effective management of fuel and energy. Conclusions: Controlling air pollution in Tehran should be considered as a priority for policymakers to make enforcements through applying a systemic cycle of preparation effective and comprehensive plans. Further, implement the enforcements and evaluate the environmental impact of the plans through involving all stakeholders. PMID:24130939

  16. Magnetic signature of indoor air pollution: Household dust study

    NASA Astrophysics Data System (ADS)

    Górka-Kostrubiec, Beata; Jeleńska, Maria; Król, Elżbieta

    2014-12-01

    The combination of magnetic and geochemical methods was used to determine the mineralogy, grain size and domain structure of magnetic particles in indoor dust collected in 195 sites in Warsaw, Poland. Data show an asymmetric distribution of magnetic susceptibility (χ) in the wide range of 20-1514 × 10-8 m3 kg-1. Comparison of magnetic parameters shows that the internal dust contains outside pollution characteristic for air and soil. More than 90% of indoor dust samples were characterized by roughly uniform magnetic mineralogy, typical for fine grained magnetite (diameter of 0.2-5 μm), and grain size between pseudo-single-domain and small multi-domain with small contribution of superpara-magnetic particles (˜10%). Samples with χ larger than 220 × 10-8 m3 kg-1 contain mainly magnetite and an anthropogenic metallic Fe with T C > 700°C. The indoor dust contains, characteristic for the urban areas, spherical magnetic particles originated from fossil fuel combustion processes and mixture of irregular angular iron-oxides grains containing other elements, including Na, Ca, Al, Si, K, S, Mn, Cl, and Mg.

  17. Study of noise transmission from an air compressor

    NASA Astrophysics Data System (ADS)

    Nathak, Subhro; Puranik, Anand; Schut, Jeffrey; Wells, Lee; Rao, M. D.

    2005-09-01

    The paper discusses the reduction of noise from a Porter Cable 4-gal, 135-psi air compressor. The objectives were to identify the major sources of noise, implement possible noise control measures, and evaluate their effectiveness. Sound measurements were taken according to a procedure that was developed and based on the standards for power tools. Broadband analysis (1/12 octave band) was done to determine the main sources of noise. Ranking of noise sources was done accordingly. The major source of noise was determined to be the piston cylinder assembly and efforts were taken to reduce this main source of noise. The noise control treatments included manufacturing of new parts, use of gasket made of cork between the housing and the cylinder sleeve to isolate the vibrations, implementing a silencer at the exhaust side of the piston and finally, an enclosure encircling the piston/cylinder assembly. The sound-pressure level measurements of the prototype were compared to the baseline measurements to test the effectiveness of the treatments. The overall sound pressure level was reduced from 101.5 to 94.3 dB with the implementation of enclosure around the piston/cylinder assembly and the silencer at the exhaust side of the piston.

  18. Experimental and analytical studies of advanced air cushion landing systems

    NASA Technical Reports Server (NTRS)

    Lee, E. G. S.; Boghani, A. B.; Captain, K. M.; Rutishauser, H. J.; Farley, H. L.; Fish, R. B.; Jeffcoat, R. L.

    1981-01-01

    Several concepts are developed for air cushion landing systems (ACLS) which have the potential for improving performance characteristics (roll stiffness, heave damping, and trunk flutter), and reducing fabrication cost and complexity. After an initial screening, the following five concepts were evaluated in detail: damped trunk, filled trunk, compartmented trunk, segmented trunk, and roll feedback control. The evaluation was based on tests performed on scale models. An ACLS dynamic simulation developed earlier is updated so that it can be used to predict the performance of full-scale ACLS incorporating these refinements. The simulation was validated through scale-model tests. A full-scale ACLS based on the segmented trunk concept was fabricated and installed on the NASA ACLS test vehicle, where it is used to support advanced system development. A geometrically-scaled model (one third full scale) of the NASA test vehicle was fabricated and tested. This model, evaluated by means of a series of static and dynamic tests, is used to investigate scaling relationships between reduced and full-scale models. The analytical model developed earlier is applied to simulate both the one third scale and the full scale response.

  19. A Study of Interior Landscape Plants for Indoor Air Pollution Abatement

    NASA Technical Reports Server (NTRS)

    Wolverton, B. C.; Douglas, Willard L.; Bounds, Keith

    1989-01-01

    Previously, preliminary data on the ability of a group of common indoor plants to remove organic chemical from indoor air was presented. The group of plants chosen for this study was determined by joint agreement between NASA and the Associated Landscape Contractors of America. The chemicals chosen for study were benzene, trichloroethylene, and formaldehyde. The results show that plants can play a major role in removal of organic chemicals from indoor air.

  20. Experimental study of the effects of secondary air on the emissions and stability of a lean premixed combustor

    NASA Technical Reports Server (NTRS)

    Roffe, G.; Raman, R. S. V.; Marek, C. J.

    1982-01-01

    A study of the effects of secondary air addition on the stability and emissions of a gas turbine combustor has been performed. Tests were conducted with two types of flameholders and varying amounts of dilution air addition. Results indicate that NO(x) decreases with increasing dilution air injection, whereas CO is independent of the amount of dilution air and is related to the gas temperature near the walls. The axial location of the dilution air addition has no effect on the performance or stability. Results also indicate that the amount of secondary air entrained by the flameholder recirculation zone is dependent on the amount of dilution air and flameholder geometry.

  1. A diagnostic study of baroclinic disturbances in polar air streams

    NASA Technical Reports Server (NTRS)

    Sinclair, Mark R.; Elsberry, Russell L.

    1986-01-01

    Quasi-Lagrangian budgets of mass, vorticity and heat are calculated following disturbances that form within polar air streams. Observed cases are extracted from the European Centre for Medium-range Weather Forecasts analyses during the First GARP Global Experiment. Model-generated cases are extracted from the simulations of extratropical cyclogenesis by Sandgathe. These polar lows grow primarily through basic baroclinic instability processes and exhibit many features of larger maritime extratropical cyclones. Polar lows that originate on the poleward (or Cyclonic - Type C) side of the jet and have considerable midtropospheric positive vorticity advection at formation time are contrasted with lows that form on the equatorward (or Anticyclonic - Type A) side of a nearly straight upper-level jet. The midtropospheric positive vorticity advection must be present to enhance the vertical circulation when the large surface fluxes that are associated with strong outbreaks act to damp the thermal wave amplification. Although latent heat release is an important factor in both types, it is an essential energy source for the Type A low developments on the equatorward side. Although the vorticity balance is initially different for the two types of polar lows, the vorticity budgets during later stages are similar. The heat budget and the thickness tendency equation demonstrated that the self-development process that is present in larger maritime cyclones is also important for polar low intensification. The absence of favorable coupling to a jet stream is the missing factor in a model-generated Type A polar low that failed to develop. Consequently, the mid- and upper-tropospheric wind fields determine which polar lows will intensify to significant amplitudes.

  2. Development Study on a Precooler for the HypersonicAir-Breathing Engine

    NASA Astrophysics Data System (ADS)

    Sato, Tetsuya; Tanatsugu, Nobuhiro; Harada, Kenya; Kobayashi, Hiroaki; Tomike, Jun'Ichiro

    Here is presented an experimental and analytical study on a precooler for hypersonic air-breathing engines. Precooling of the incoming air breathed by an air-inlet gives extension of the flight envelope and improvement of the thrust and specific impulse. Three precooler models were installed into an air-turbo ramjet engine and tested under the sea level static condition. When the fan inlet temperature was down to 180K, the engine thrust and specific impulse increased by 2.0 and 1.2 times respectively. Thick frost formed on the tube surfaces at the entrance part of the precooler blocked the air-flow passage. On the other hand, very thin frost formed at the exit part because the water vapor included in the air was changed to mist particles due to the low temperature of the air in this part. Parametric studies on the precooler design values and a sizing analysis were also performed. Decrease of tube outer diameters on the precooler is only way to increase heat exchange rates without increase of its weight and pressure loss.

  3. Effects of air cavity on fly-ear inspired directional microphones: a numerical study

    NASA Astrophysics Data System (ADS)

    Liu, Haijun; Yu, Miao

    2011-04-01

    The superacute ear of the parasitoid fly Ormia ochracea has inspired the development of a variety of novel miniature directional microphones for sound source localization, in which the effects of air cavity backing the eardrums are often neglected without validation. In the original testing on the fly ear, the integrity of the air space is shown not to be the key to the intertympnal coupling. However, it does not necessarily mean that the tympanum can be treated as in vacuo, and the effects of the air cavity backing the eardrums have yet to be fully understood. In this article, a normalized version of our previous model of air-backed circular membranes is derived to study the conditions under which the air cavity can be indeed neglected. This model is then used to study a fly-ear inspired directional microphone design with two clamped circular membranes mechanically coupled by a bridge. The performance of the directional microphone with air cavity is evaluated in comparison to its counterpart in vacuo. This article not only provides more insights into the fly ear phenomena, but builds a theoretical foundation on whether and how to take the air cavity into account in the design of pressure sensors and directional microphones in general.

  4. ESTIMATION OF PERSONAL EXPOSURES TO AIR POLLUTANTS FOR A COMMUNITY-BASED STUDY OF HEALTH EFFECTS IN ASTHMATICS: DESIGN AND RESULTS OF AIR MONITORING

    EPA Science Inventory

    In order to provide reliable pollutant and meteorological exposure estimates for an epidemiological study of asthmatics residing in two Houston neighborhoods, a dedicated three-tier air monitoring system was established. This consisted of fixed site ambient air monitoring at the ...

  5. STATISTICAL ISSUES FOR SEEDLING STUDIES IN AIR POLLUTION RESEARCH

    EPA Science Inventory

    By the very nature that seedlings represent the future forests, they are an important population for exposure studies. he experimental conditions for seedling studies cover a wide range of treatment combinations, facilities, and exposure regimes. he experimental utilization of ex...

  6. High pressure flame system for pollution studies with results for methane-air diffusion flames

    NASA Technical Reports Server (NTRS)

    Miller, I. M.; Maahs, H. G.

    1977-01-01

    A high pressure flame system was designed and constructed for studying nitrogen oxide formation in fuel air combustion. Its advantages and limitations were demonstrated by tests with a confined laminar methane air diffusion flame over the pressure range from 1 to 50 atm. The methane issued from a 3.06 mm diameter port concentrically into a stream of air contained within a 20.5 mm diameter chimney. As the combustion pressure is increased, the flame changes in shape from wide and convex to slender and concave, and there is a marked increase in the amount of luminous carbon. The height of the flame changes only moderately with pressure.

  7. A numerical study of a vertical solar air collector with obstacle

    NASA Astrophysics Data System (ADS)

    Moumeni, A.; Bouchekima, B.; Lati, M.

    2016-07-01

    Because of the lack of heat exchange obtained by a solar air between the fluid and the absorber, the introduction of obstacles arranged in rows overlapping in the ducts of these systems improves heat transfer. In this work, a numerical study using the finite volume methods is made to model the dynamic and thermal behavior of air flow in a vertical solar collector with baffles destined for integration in building. We search essentially to compare between three air collectors models with different inclined obstacles angle. The first kind with 90° shows a good performance energetic and turbulent.

  8. Control strategies for sub-micrometer particles indoors: model study of air filtration and ventilation.

    PubMed

    Jamriska, M; Morawska, L; Ensor, D S

    2003-06-01

    The effects of air filtration and ventilation on indoor particles were investigated using a single-zone mathematical model. Particle concentration indoors was predicted for several I/O conditions representing scenarios likely to occur in naturally and mechanically ventilated buildings. The effects were studied for static and dynamic conditions in a hypothetical office building. The input parameters were based on real-world data. For conditions with high particle concentrations outdoors, it is recommended to reduce the amount of outdoor air delivered indoors and the necessary reduction level can be quantified by the model simulation. Consideration should also be given to the thermal comfort and minimum outdoor air required for occupants. For conditions dominated by an indoor source, it is recommended to increase the amount of outdoor air delivered indoors and to reduce the amount of return air. Air filtration and ventilation reduce particle concentrations indoors, with the overall effect depending on efficiency, location and the number of filters applied. The assessment of indoor air quality for specific conditions could be easily calculated by the model using user-defined input parameters. PMID:12756003

  9. Exposure to Air Ions in Indoor Environments: Experimental Study with Healthy Adults

    PubMed Central

    Wallner, Peter; Kundi, Michael; Panny, Michael; Tappler, Peter; Hutter, Hans-Peter

    2015-01-01

    Since the beginning of the 20th century there has been a scientific debate about the potential effects of air ions on biological tissues, wellbeing and health. Effects on the cardiovascular and respiratory system as well as on mental health have been described. In recent years, there has been a renewed interest in this topic. In an experimental indoor setting we conducted a double-blind cross-over trial to determine if higher levels of air ions, generated by a special wall paint, affect cognitive performance, wellbeing, lung function, and cardiovascular function. Twenty healthy non-smoking volunteers (10 female, 10 male) participated in the study. Levels of air ions, volatile organic compounds and indoor climate factors were determined by standardized measurement procedures. Air ions affected the autonomous nervous system (in terms of an increase of sympathetic activity accompanied by a small decrease of vagal efferent activity): In the test room with higher levels of air ions (2194/cm3 vs. 1038/cm3) a significantly higher low to high frequency ratio of the electrocardiography (ECG) beat-to-beat interval spectrogram was found. Furthermore, six of nine subtests of a cognitive performance test were solved better, three of them statistically significant (verbal factor, reasoning, and perceptual speed), in the room with higher ion concentration. There was no influence of air ions on lung function and on wellbeing. Our results indicate slightly activating and cognitive performance enhancing effects of a short-term exposure to higher indoor air ion concentrations. PMID:26569277

  10. Exposure to Air Ions in Indoor Environments: Experimental Study with Healthy Adults.

    PubMed

    Wallner, Peter; Kundi, Michael; Panny, Michael; Tappler, Peter; Hutter, Hans-Peter

    2015-11-01

    Since the beginning of the 20th century there has been a scientific debate about the potential effects of air ions on biological tissues, wellbeing and health. Effects on the cardiovascular and respiratory system as well as on mental health have been described. In recent years, there has been a renewed interest in this topic. In an experimental indoor setting we conducted a double-blind cross-over trial to determine if higher levels of air ions, generated by a special wall paint, affect cognitive performance, wellbeing, lung function, and cardiovascular function. Twenty healthy non-smoking volunteers (10 female, 10 male) participated in the study. Levels of air ions, volatile organic compounds and indoor climate factors were determined by standardized measurement procedures. Air ions affected the autonomous nervous system (in terms of an increase of sympathetic activity accompanied by a small decrease of vagal efferent activity): In the test room with higher levels of air ions (2194/cm³ vs. 1038/cm³) a significantly higher low to high frequency ratio of the electrocardiography (ECG) beat-to-beat interval spectrogram was found. Furthermore, six of nine subtests of a cognitive performance test were solved better, three of them statistically significant (verbal factor, reasoning, and perceptual speed), in the room with higher ion concentration. There was no influence of air ions on lung function and on wellbeing. Our results indicate slightly activating and cognitive performance enhancing effects of a short-term exposure to higher indoor air ion concentrations. PMID:26569277

  11. Study of Ram-air Heat Exchangers for Reducing Turbine Cooling-air Temperature of a Supersonic Aircraft Turbojet Engine

    NASA Technical Reports Server (NTRS)

    Diaguila, Anthony J; Livingood, John N B; Eckert, Ernst R G

    1956-01-01

    The sizes and weights of the cores of heat exchangers were determined analytically for possible application for reducing turbine cooling-air temperatures of an engine designed for a Mach number of 2.5 and an altitude The sizes and weights of the cores of heat exchangers were determined analytically for possible application for reducing turbine cooling-air temperatures of an engine designed for a Mach number of 2.5 and an altitude of 70,000 feet. A compressor-bleed-air weight flow of 2.7 pounds per second was assumed for the coolant; ram air was considered as the other fluid. Pressure drops and inlet states of both fluids were prescribed, and ranges of compressor-bleed-air temperature reductions and of the ratio of compressor-bleed to ram-air weight flows were considered.

  12. Retrospective studies of operating problems in air transport

    NASA Technical Reports Server (NTRS)

    Billings, C. E.; Lauber, J. K.; Cooper, G. E.; Ruffell-Smith, H. P.

    1976-01-01

    An epidemiological model for the study of human errors in aviation is presented. In this approach, retrospective data are used as the basis for formulation of hypotheses as to system factors which may have contributed to such errors. Prospective experimental studies of aviation operations are also required in order to prove or disprove the hypotheses, and to evaluate the effectiveness of intervention techniques designed to solve operational problems in the aviation system.

  13. Linking Meteorology, Air Quality Models and Observations to Characterize Human Exposures in Support of the Environmental Health Studies

    EPA Science Inventory

    Epidemiologic studies are critical in establishing the association between exposure to air pollutants and adverse health effects. Results of epidemiologic studies are used by U.S. EPA in developing air quality standards to protect the public from the health effects of air polluta...

  14. Association of driver air bags with driver fatality: a matched cohort study

    PubMed Central

    Cummings, Peter; McKnight, Barbara; Rivara, Frederick P; Grossman, David C

    2002-01-01

    Objective To estimate the association of driver air bag presence with driver fatality in road traffic crashes. Design Matched pair cohort study. Setting All passenger vehicle crashes in the United States during 1990-2000 inclusive. Subjects 51 031 driver-passenger pairs in the same vehicle. Main outcome measures Relative risk of death within 30 days of a crash. Results Drivers with an air bag were less likely to die than drivers without an air bag (adjusted relative risk 0.92 (95% confidence interval 0.88 to 0.96)). This estimate was nearly the same whether drivers wore a seat belt (adjusted relative risk 0.93) or not (0.91). Air bags were associated with more protection for women (0.88 (0.82 to 0.93)), than for men (0.94 (0.90 to 0.99)). Drivers wearing a seat belt were less likely to die than unbelted drivers (0.35 (0.33 to 0.36)). Belted drivers with an air bag were less likely to die than unbelted drivers without an air bag (0.32 (0.30 to 0.34)). Conclusions If the associations are causal the average risk of driver death was reduced 8% (95% confidence interval 4% to 12%) by an air bag. Benefit was similar for belted and unbelted drivers and was slightly greater for women. However, seat belts offered much more protection than air bags. What is already known on this topicStudies have estimated that driver air bags reduce the risk of death in a road vehicle crash by 10-14%These studies disagree as to whether benefit is greater for drivers wearing a seat belt or for unbelted driversWhat this study addsHaving an air bag was associated with an 8% reduction in the risk of death, whether the driver was belted or notThe reduction in risk was greater for women (12%) than for men (6%)Seat belts provided much greater protection, with seat belt use reducing the risk of death by 65% (or by 68% in combination with an air bag) PMID:12003882

  15. Windsor, Ontario Exposure Assessment Study: Design and Methods Validation of Personal, Indoor and Outdoor Air Pollution Monitoring

    EPA Science Inventory

    The Windsor, Ontario Exposure Assessment Study evaluated the contribution of ambient air pollutants to personal and indoor exposures of adults and asthmatic children living in Windsor, Ontario, Canada. In addition, the role of personal, indoor, and outdoor air pollution exposures...

  16. Air-Q intubating laryngeal airway: A study of the second generation supraglottic airway device

    PubMed Central

    Attarde, Viren Bhaskar; Kotekar, Nalini; Shetty, Sarika M

    2016-01-01

    Background and Aims: Air-Q intubating laryngeal mask airway (ILA) is used as a supraglottic airway device and as a conduit for endotracheal intubation. This study aims to assess the efficacy of the Air-Q ILA regarding ease of insertion, adequacy of ventilation, rate of successful intubation, haemodynamic response and airway morbidity. Methods: Sixty patients presenting for elective surgery at our Medical College Hospital were selected. Following adequate premedication, baseline vital parameters, pulse rate and blood pressure were recorded. Air-Q size 3.5 for patients 50-70 kg and size 4.5 for 70-100 kg was selected. After achieving adequate intubating conditions, Air-Q ILA was introduced. Confirming adequate ventilation, appropriate sized endotracheal tube was advanced through the Air-Q blindly to intubate the trachea. Placement of the endotracheal tube in trachea was confirmed. Results: Air-Q ILA was successfully inserted in 88.3% of patients in first attempt and 11.7% patients in second attempt. Ventilation was adequate in 100% of patients. Intubation was successful in 76.7% of patients with Air-Q ILA. 23.3% of patients were intubated by direct laryngoscopy following failure with two attempts using Air-Q ILA. Post-intubation the change in heart rate was statistically significant (P < 0.0001). 10% of patients were noted to have a sore throat and 5% of patients had mild airway trauma. Conclusion: Air-Q ILA is a reliable device as a supraglottic airway ensuring adequate ventilation as well as a conduit for endotracheal intubation. It benefits the patient by avoiding the stress of direct laryngoscopy and is also superior alternative device for use in a difficult airway. PMID:27212722

  17. A study of the air movement in two aircraft-engine cylinders

    NASA Technical Reports Server (NTRS)

    Lee, Dana W

    1940-01-01

    Studies were made of the air movements in the NACA glass-cylinder apparatus using cylinder heads similar to those on the Wright R-1820-G engine and the Pratt & Whitney Wasp engine as modified by the Eclipse Aviation Corporation to use fuel-injection equipment. The air movements were made visible by mixing small feathers with the air; high-speed motion pictures were than taken of the feathers as they swirled about the inside the glass cylinder. The test engine speeds were 350, 500, and 1,000 r.p.m. Motion pictures were also taken of gasoline sprays injected into the cylinder during the intake stroke. The air flow produced by each cylinder head is described and some results of the velocity measurements of feathers are presented. The apparent time intervals required for vaporization of the gasoline sprays are also given.

  18. Flow visualization study of grooved surface/surfactant/air sheet interaction

    NASA Astrophysics Data System (ADS)

    Reed, Jason C.; Weinstein, Leonard M.

    1989-03-01

    The effects of groove geometry, surfactants, and airflow rate have been ascertained by a flow-visualization study of grooved-surface models which addresses the possible conditions for skin friction-reduction in marine vehicles. It is found that the grooved surface geometry holds the injected bubble stream near the wall and, in some cases, results in a 'tube' of air which remains attached to the wall. It is noted that groove dimension and the use of surfactants can substantially affect the stability of this air tube; deeper grooves, surfactants with high contact angles, and angled air injection, are all found to increase the stability of the attached air tube, while convected disturbances and high shear increase interfacial instability.

  19. Experimental study on bi-phase flow Air-Oil in Water Emulsion

    NASA Astrophysics Data System (ADS)

    Arnone, Davide; Poesio, Pietro

    2015-11-01

    Bi-phase slug flow oil-in-water emulsion [5%-20%] and air through a horizontal pipe (inner diameter 22mm) is experimentally studied. A test with water and air has been performed as comparison. First we create and analyze the flow pattern map to identify slug flow liquid and air inlet conditions. Flow maps are similar for all the used liquid. A video analysis procedure using an high speed camera has been created to obtain all the characteristics of unit slugs: slug velocity, slug length, bubble velocity, bubbles length and slug frequency. We compare translational velocity and frequency with models finding a good agreement. We calculate the pdfs of the lengths to find the correlations between mean values and STD on different air and liquid superficial velocities. We also perform pressure measurements along the pipe. We conclude that the percentage of oil-in- water has no influence on results in terms of velocity, lengths, frequency and pressure drop.

  20. Comparative study of the effects of air or saline to identify the extradural space.

    PubMed

    Valentine, S J; Jarvis, A P; Shutt, L E

    1991-02-01

    Fifty women in labour were allocated randomly to receive either air or saline to assist in the identification of the extradural space by the loss of resistance technique. A study volume of 4 ml of air or saline was used before 0.5% bupivacaine 8 ml and the spread of analgesia was followed for 30 min. The first segment blocked, time of onset, number of blocked segments and height of block were comparable in the two groups. At 30 min, there were eight patients with an unblocked segment in the air group, compared with two in the saline group (P less than 0.01). All unblocked segments were blocked subsequently by further doses of bupivacaine. We conclude that air is more likely than saline to produce unblocked segments in the initiation of extradural analgesia in labour. PMID:1817625

  1. The Precision and Accuracy of AIRS Level 1B Radiances for Climate Studies

    NASA Technical Reports Server (NTRS)

    Hearty, Thomas J.; Gaiser, Steve; Pagano, Tom; Aumann, Hartmut

    2004-01-01

    We investigate uncertainties in the Atmospheric Infrared Sounder (AIRS) radiances based on in-flight and preflight calibration algorithms and observations. The global coverage and spectra1 resolution ((lamda)/(Delta)(lamda) 1200) of AIRS enable it to produce a data set that can be used as a climate data record over the lifetime of the instrument. Therefore, we examine the effects of the uncertainties in the calibration and the detector stability on future climate studies. The uncertainties of the parameters that go into the AIRS radiometric calibration are propagated to estimate the accuracy of the radiances and any climate data record created from AIRS measurements. The calculated radiance uncertainties are consistent with observations. Algorithm enhancements may be able to reduce the radiance uncertainties by as much as 7%. We find that the orbital variation of the gain contributes a brightness temperature bias of < 0.01 K.

  2. STUDY ON AIR INGRESS MITIGATION METHODS IN THE VERY HIGH TEMPERATURE GAS COOLED REACTOR (VHTR)

    SciTech Connect

    Chang H. Oh

    2011-03-01

    An air-ingress accident followed by a pipe break is considered as a critical event for a very high temperature gas-cooled reactor (VHTR). Following helium depressurization, it is anticipated that unless countermeasures are taken, air will enter the core through the break leading to oxidation of the in-core graphite structure. Thus, without mitigation features, this accident might lead to severe exothermic chemical reactions of graphite and oxygen. Under extreme circumstances, a loss of core structural integrity may occur along with excessive release of radiological inventory. Idaho National Laboratory under the auspices of the U.S. Department of Energy is performing research and development (R&D) that focuses on key phenomena important during challenging scenarios that may occur in the VHTR. Phenomena Identification and Ranking Table (PIRT) studies to date have identified the air ingress event, following on the heels of a VHTR depressurization, as very important (Oh et al. 2006, Schultz et al. 2006). Consequently, the development of advanced air ingress-related models and verification and validation (V&V) requirements are part of the experimental validation plan. This paper discusses about various air-ingress mitigation concepts applicable for the VHTRs. The study begins with identifying important factors (or phenomena) associated with the air-ingress accident by using a root-cause analysis. By preventing main causes of the important events identified in the root-cause diagram, the basic air-ingress mitigation ideas can be conceptually derived. The main concepts include (1) preventing structural degradation of graphite supporters; (2) preventing local stress concentration in the supporter; (3) preventing graphite oxidation; (4) preventing air ingress; (5) preventing density gradient driven flow; (4) preventing fluid density gradient; (5) preventing fluid temperature gradient; (6) preventing high temperature. Based on the basic concepts listed above, various air

  3. Flow visualization study of grooved surface/surfactant/air sheet interaction

    NASA Technical Reports Server (NTRS)

    Reed, Jason C.; Weinstein, Leonard M.

    1989-01-01

    The effects of groove geometry, surfactants, and airflow rate have been ascertained by a flow-visualization study of grooved-surface models which addresses the possible conditions for skin friction-reduction in marine vehicles. It is found that the grooved surface geometry holds the injected bubble stream near the wall and, in some cases, results in a 'tube' of air which remains attached to the wall. It is noted that groove dimension and the use of surfactants can substantially affect the stability of this air tube; deeper grooves, surfactants with high contact angles, and angled air injection, are all found to increase the stability of the attached air tube, while convected disturbances and high shear increase interfacial instability.

  4. SCHOOL AIR CONDITIONING/CASE STUDY, MCPHERSON HIGH SCHOOL.

    ERIC Educational Resources Information Center

    OSTENBERG, JOE W.

    THE STANFORD UNIVERSITY SCHOOL PLANNING LABORATORIES CONDUCTED AN EDUCATIONAL SURVEY OF THE EDUCATIONAL NEEDS OF THE MCPHERSON CITY SCHOOLS BY STUDYING THE EXISTING CONDITIONS, LOCAL ECONOMIES, AND POTENTIAL POPULATION GROWTH. IT WAS RECOMMENDED THAT A NEW SENIOR HIGH BE BUILT TO HOUSE 700-750 STUDENTS, THE ANTICIPATED ENROLLMENT 10 YEARS AFTER…

  5. STUDY OF REMOVAL PROCESSES FOR HALOGENATED AIR POLLUTANTS

    EPA Science Inventory

    The fate of halocarbons released into the atmosphere from anthropogenic sources and their potential impact on the stratospheric ozone layer has been studied. Experimental kinetic data have been obtained for the reaction of OH radicals with CH3Cl, CH2Cl2, CHCl3, C2H5Cl, C2H4Cl2, C...

  6. SOURCES OF ORGANIC ACIDS IN INDOOR AIR: A FIELD STUDY

    EPA Science Inventory

    Simultaneous indoor and outdoor measurements of organic acids were made at six residential houses located in suburban New Jersey area during the summer of 1992. ach house was measured for six days and controlled for ventilation and gas combustion conditions. he study presents the...

  7. Hamilton study: distribution of factors confounding the relationship between air quality and respiratory health

    SciTech Connect

    Pengelly, L.D.; Kerigan, A.T.; Goldsmith, C.H.; Inman, E.M.

    1984-10-01

    Hamilton, Ontario is an industrial city with a population of 300,000 which is situated at the western end of Lake Ontario. Canada's two largest iron and steel mills are located here; the city historically has had relatively poor air quality, which has improved markedly in the last 25 years. Concern about the health effects of current air quality recently led us to carry out an epidemiological study of the effects of air pollution on the respiratory health of over 3500 school children. Respiratory health was measured by pulmonary function testing of each child, and by an assessment of each child's respiratory symptoms via a questionnaire administered to the parents. Previous studies had shown that other environmental factors (e.g. parental smoking, parental cough, socioeconomic level, housing, and gas cooking) might also affect respiratory health, and thus confound any potential relationships between health and air pollution. The questionnaire also collected information on many of these confounding factors. For the purposes of initial analysis, the city was divided into five areas in which differences in air quality were expected. In general, factors which have been associated with poor respiratory health were observed to be more prevalent in areas of poorer air quality.

  8. An experimental study of geyser-like flows induced by a pressurized air pocket

    NASA Astrophysics Data System (ADS)

    Elayeb, I. S.; Leon, A.; Choi, Y.; Alnahit, A. O.

    2015-12-01

    Previous studies argues that the entrapment of pressurized air pockets within combined sewer systems can produce geyser flows, which is an oscillating jetting of a mixture of gas-liquid flows. To verify that pressurized air pockets can effectively produce geysers, laboratory experiments were conducted. However, past experiments were conducted in relatively small-scale apparatus (i.e. maximum φ2" vertical shaft). This study conducted a set of experiments in a larger apparatus. The experimental setup consists of an upstream head tank, a downstream head tank, a horizontal pipe (46.5ft long, φ6") and a vertical pipe (10ft long, φ6"). The initial condition for the experiments is constant flow discharge through the horizontal pipe. The experiments are initiated by injecting an air pocket with pre-determined volume and pressure at the upstream end of the horizontal pipe. The air pocket propagates through the horizontal pipe until it arrives to the vertical shaft, where it is released producing a geyser-like flow. Three flow rates in the horizontal pipe and three injected air pressures were tested. The variables measured were pressure at two locations in the horizontal pipe and two locations in the vertical pipe. High resolution videos at two regions in the vertical shaft were also recorded. To gain further insights in the physics of air-water interaction, the laboratory experiments were complemented with numerical simulations conducted using a commercial 3D CFD model, previously validated with experiments.

  9. Acute symptoms related to air pollution in urban areas: a study protocol

    PubMed Central

    Yunesian, Masud; Asghari, Fariba; Vash, Javad Homayoun; Forouzanfar, Mohammad Hossein; Farhud, Dariush

    2006-01-01

    Background The harmful effects of urban air pollution on general population in terms of annoying symptoms are not adequately evaluated. This is in contrast to the hospital admissions and short term mortality. The present study protocol is designed to assess the association between the level of exposure to certain ambient air pollutants and a wide range of relevant symptoms. Awareness of the impact of pollution on the population at large will make our estimates of the pertinent covert burden imposed on the society more accurate. Methods/design A cross sectional study with spatial analysis for the addresses of the participants was conducted. Data were collected via telephone interviews administered to a representative sample of civilians over age four in the city. Households were selected using random digit dialling procedures and randomization within each household was also performed to select the person to be interviewed. Levels of exposure are quantified by extrapolating the addresses of the study population over the air pollution matrix of the city at the time of the interview and also for different lag times. This information system uses the data from multiple air pollution monitoring stations in conjunction with meteorological data. General linear models are applied for statistical analysis. Discussion The important limitations of cross-sectional studies on acute effects of air pollution are personal confounders and measurement error for exposure. A wide range of confounders in this study are controlled for in the statistical analysis. Exposure error may be minimised by employing a validated geographical information system that provides accurate estimates and getting detailed information on locations of individual participants during the day. The widespread operation of open air conditioning systems in the target urban area which brings about excellent mixing of the outdoor and indoor air increases the validity of outdoor pollutants levels that are taken as

  10. Rise velocity of an air bubble in porous media: Theoretical studies

    NASA Astrophysics Data System (ADS)

    Corapcioglu, M. Yavuz; Cihan, Abdullah; Drazenovic, Mirna

    2004-04-01

    The rise velocity of injected air phase from the injection point toward the vadose zone is a critical factor in in-situ air sparging operations. It has been reported in the literature that air injected into saturated gravel rises as discrete air bubbles in bubbly flow of air phase. The objective of this study is to develop a quantitative technique to estimate the rise velocity of an air bubble in coarse porous media. The model is based on the macroscopic balance equation for forces acting on a bubble rising in a porous medium. The governing equation incorporates inertial force, added mass force, buoyant force, surface tension and drag force that results from the momentum transfer between the phases. The momentum transfer terms take into account the viscous as well as the kinetic energy losses at high velocities. Analytical solutions are obtained for steady, quasi-steady, and accelerated bubble rise velocities. Results show that air bubbles moving up through a porous medium equilibrate after a short travel time and very short distances of rise. It is determined that the terminal rise velocity of a single air bubble in an otherwise water saturated porous medium cannot exceed 18.5 cm/s. The theoretical model results compared favorably with the experimental data reported in the literature. A dimensional analysis conducted to study the effect of individual forces indicates that the buoyant force is largely balanced by the drag force for bubbles with an equivalent radius of 0.2-0.5 cm. With increasing bubble radius, the dimensionless number representing the effect of the surface tension force decreases rapidly. Since the total inertial force is quite small, the accelerated bubble rise velocity can be approximated by the terminal velocity.

  11. Duration study for heating and air-conditioning design temperatures

    SciTech Connect

    Snelling, H.J.

    1985-01-01

    Recently, abnormally cold winters and hot summers have generated interest in the duration of time that design temperature values have been equaled or exceeded. ETAC's Engineering Meteorology Section did a pilot study to examine temperature records for several military installations and give some insight into durations that may occur. The authors chose sites to represent different climatic regimes. For each site, the authors generated statistics on the number of occurrences of durations of one, two, three ... up to eight hours for each of the design temperature values (1%, 2 1/2%, and 5% temperatures for the summer months; 99% and 97 1/2% for winter months). The authors also made a study of the longest duration of each design value. The authors used the latest available 15 consecutive years of temperature data for all sites. The authors also made a comparison of data for the 15-year period of record (POR) versus data for the total available POR for some of the sites. Results were inconclusive and indicate that more study is needed.

  12. Modeling Spatial and Temporal Variability of Residential Air Exchange Rates for the Near-Road Exposures and Effects of Urban Air Pollutants Study (NEXUS)

    EPA Science Inventory

    Air pollution health studies often use outdoor concentrations as exposure surrogates. Failure to account for variability of residential infiltration of outdoor pollutants can induce exposure errors and lead to bias and incorrect confidence intervals in health effect estimates. Th...

  13. Determinants of perceived air pollution annoyance and association between annoyance scores and air pollution (PM 2.5, NO 2) concentrations in the European EXPOLIS study

    NASA Astrophysics Data System (ADS)

    Rotko, Tuulia; Oglesby, Lucy; Künzli, Nino; Carrer, Paolo; Nieuwenhuijsen, Mark J.; Jantunen, Matti

    Apart from its traditionally considered objective impacts on health, air pollution can also have perceived effects, such as annoyance. The psychological effects of air pollution may often be more important to well-being than the biophysical effects. Health effects of perceived annoyance from air pollution are so far unknown. More knowledge of air pollution annoyance levels, determinants and also associations with different air pollution components is needed. In the European air pollution exposure study, EXPOLIS, the air pollution annoyance as perceived at home, workplace and in traffic were surveyed among other study objectives. Overall 1736 randomly drawn 25-55-yr-old subjects participated in six cities (Athens, Basel, Milan, Oxford, Prague and Helsinki). Levels and predictors of individual perceived annoyances from air pollution were assessed. Instead of the usual air pollution concentrations at fixed monitoring sites, this paper compares the measured microenvironment concentrations and personal exposures of PM 2.5 and NO 2 to the perceived annoyance levels. A considerable proportion of the adults surveyed was annoyed by air pollution. Female gender, self-reported respiratory symptoms, downtown living and self-reported sensitivity to air pollution were directly associated with high air pollution annoyance score while in traffic, but smoking status, age or education level were not significantly associated. Population level annoyance averages correlated with the city average exposure levels of PM 2.5 and NO 2. A high correlation was observed between the personal 48-h PM 2.5 exposure and perceived annoyance at home as well as between the mean annoyance at work and both the average work indoor PM 2.5 and the personal work time PM 2.5 exposure. With the other significant determinants (gender, city code, home location) and home outdoor levels the model explained 14% (PM 2.5) and 19% (NO 2) of the variation in perceived air pollution annoyance in traffic. Compared to

  14. Study of air emissions related to aircraft deicing

    SciTech Connect

    Zarubiak, D.C.Z.; DeToro, J.A.; Menon, R.P.

    1997-12-31

    This paper outlines the results of a study that was conducted by Trinity Consultants Incorporated (Trinity) to estimate the airborne emissions of glycol from Type 1 Deicer fluid and potential exposure of ground personnel during routine deicing of aircraft. The study involved the experimental measurement of Type 1 Deicer fluid vapor emissions by Southern Research Institute (SRI, Research Triangle Park, NC). An open path Fourier Transform Infrared (FTIR) spectroscopic technique developed by SRI was used during a simulated airplane deicing event. The emissions measurement data are analyzed to obtain appropriate emission rates for an atmospheric dispersion modeling analysis. The modeled gaseous Type 1 Deicer fluid concentrations are determined from calculated emission rates and selected meteorological conditions. A propylene glycol (PG)-based Type 1 Deicer fluid was used. In order to examine the effects of the assumptions that are made for the development of the emission quantification and dispersion modeling methodologies, various scenarios are evaluated. A parametric analysis evaluates the effect of variations in the following parameters on the results of the study: glycol concentrations in deicing fluids, error limits of emission measurements, emission source heights, evaporation rate for various wind speeds, wind directions over typical physical layouts, and background (ambient) Type 1 Deicer fluid concentrations. The emissions for an EG based Type 1 Deicing fluid are expected to be between 80 and 85% of the reported data. In general, the model shows the region of maximum concentrations is located between 20 and 50 meters downwind from the trailing edge of the wing. This range is consistent with experimental findings. Depending on the specific modeled scenarios, maximum glycol concentrations are found to generally range between 50 and 500 milligrams per cubic meter.

  15. Air resources

    SciTech Connect

    1995-10-01

    This section describes the ambient (surrounding) air quality of the TVA region, discusses TVA emission contributions to ambient air quality, and identifies air quality impacts to human health and welfare. Volume 2 Technical Document 2, Environmental Consequences, describes how changes in TVA emissions could affect regional air quality, human health, environmental resources, and materials. The primary region of the affected environment is broadly defined as the state of Tennessee, as well as southern Kentucky, western Virginia, southern West Virginia, western North Carolina, and northern Georgia, Alabama, and Mississippi. This area represents the watershed of the Tennessee River and the 201 counties of the greater TVA service area. Emissions from outside the Tennessee Valley region contribute to air quality in the Valley. Also, TVA emissions are transported outside the Valley and have some impact on air quality beyond the primary study area. Although the study area experiences a number of air quality problems, overall air quality is good.

  16. An observation tool to study air traffic control and flightdeck collaboration.

    PubMed

    Cox, Gemma; Sharples, Sarah; Stedmon, Alex; Wilson, John

    2007-07-01

    The complex systems of the flightdeck (FD) and the Air Traffic Control Centre (ATC) are characterised by numerous concurrently operating and interacting communication channels between people and between people and machines/computer systems. This paper describes work in support of investigating the impact of changes to technologies and responsibilities within this system with respect to human factors. It focuses primarily on the introduction of datalink (text-based communication rather than traditional radio communication) and the move towards freeflight (pilot-mediated air traffic control). Air traffic management investigations have outlined these specific changes as strategies to enable further increases in the volume of air traffic. A systems approach was taken and field studies were conducted. Small numbers of domain experts such as air traffic controllers (ATCOs) were involved in the field-based observations of how people interact with systems and each other. This paper summarises the overall research approach taken and then specifically reports on the field-based observations including the justification, development, and findings of the observation tool used. The observation tool examined information propagation through the air traffic control-flightdeck (ATC-FD) system, and resulted in models of possible information trajectories through the system. PMID:17498641

  17. A study of mercuric oxide and zinc-air battery life in hearing aids.

    PubMed

    Sparkes, C; Lacey, N K

    1997-09-01

    The requirement to phase out mercuric oxide (mercury) batteries on environmental grounds has led to the widespread introduction of zinc-air technology. The possibility arises that high drain hearing aids may not be adequately catered for by zinc-air cells, leading to poor performance. This study investigated the hearing aid user's ability to perceive differences between zinc-air and mercury cells in normal everyday usage. The data was collected for 100 experienced hearing aid users in field trials. Users report 50 per cent greater life for zinc-air cells in high power aids and 28 per cent in low power aids. The average life of the zinc-air cells range from 15 days in high power to 34 days in low power aids. Users are able to perceive a difference in sound quality in favour of zinc-air cells for low and medium power aids. The hearing aid population is not disadvantaged by phasing out mercury cells. PMID:9373545

  18. Study of Air Ingress Across the Duct During the Accident Conditions

    SciTech Connect

    Hassan, Yassin

    2013-05-06

    The goal of this project is to study the fundamental physical phenomena associated with air ingress in very high temperature reactors (VHTRs). Air ingress may occur due to a rupture of primary piping and a subsequent breach in the primary pressure boundary in helium-cooled and graphite-moderated VHTRs. Significant air ingress is a concern because it introduces potential to expose the fuel, graphite support rods, and core to a risk of severe graphite oxidation. Two of the most probable air ingress scenarios involve rupture of a control rod or fuel access standpipe, and rupture in the main coolant pipe on the lower part of the reactor pressure vessel. Therefore, establishing a fundamental understanding of air ingress phenomena is critical in order to rationally evaluate safety of existing VHTRs and develop new designs that minimize these risks. But despite this importance, progress toward development these predictive capabilities has been slowed by the complex nature of the underlying phenomena. The combination of inter-diffusion among multiple species, molecular diffusion, natural convection, and complex geometries, as well as the multiple chemical reactions involved, impose significant roadblocks to both modeling and experiment design. The project team will employ a coordinated experimental and computational effort that will help gain a deeper understanding of multiphased air ingress phenomena. This project will enhance advanced modeling and simulation methods, enabling calculation of nuclear power plant transients and accident scenarios with a high degree of confidence. The following are the project tasks: Perform particle image velocimetry measurement of multiphase air ingresses; and, Perform computational fluid dynamics analysis of air ingress phenomena.

  19. A photochemical box model for urban air quality study

    SciTech Connect

    Jin, Shengxin.

    1991-01-01

    The photochemical box model (PBM) is based on the principle of mass conservation. The concentration of any pollutant is determined by horizontal advection, vertical entrainment, source emissions, and chemical reactions. A one dimensional high resolution boundary layer model by Blackadar has been further developed by considering the effect of urban heat islands to simulate the variation of the mixed layer height and incorporated in the PBM. The model predicted mixed layer height is a significant improvement over the characteristic mixed layer growth curve used in the original PBM by Schere and Demerjian. The gas phase chemical kinetic mechanism used in the Regional Acid Deposition Study II (RADM2) and Demerjian chemical mechanism have been used to calculate the contributions of chemical reactions to the changes of pollutant concentrations. Detailed analysis and comparisons of the two chemical mechanisms have been made. The simulated pollutant concentration using both chemical mechanisms are in very good agreement with observations. A radiative transfer model developed by Madronich has been incorporated in the PBM for the calculation of actinic flux and photolytic rate constants. Height averaged and radiation corrected photolytic rate constant are used for the photochemical reactions. The simulated pollutant concentrations for CO, NO, NO[sub 2] and O[sub s] are in very good agreement with observations. Sensitivities of model results to the variation of photolytic rate constants, boundary conditions, hydrocarbon speciation factors, and thermal rate constant have been tested.

  20. Investigation of Nucleation Bursts During the Pittsburgh Air Quality Study

    NASA Astrophysics Data System (ADS)

    Stanier, C. O.; Khlystov, A. Y.; Wittig, B.; Pandis, S. N.; Zhou, Y.; Bein, K.; Wexler, A. S.; Misra, C.; Sioutas, C.

    2002-12-01

    Homogeneous nucleation is one of the major sources of atmospheric particles on a global scale. Understanding nucleation is important for quantifying its role in shaping the ambient aerosol distribution and its effects on cloud properties and the planetary energy balance. Over 100 days with nucleation events were investigated during a sampling campaign sampling continental aerosols in Pittsburgh, Pennsylvania. Over 90,000 size distributions were collected over 12 months using Scanning Mobility Particle Sizers (SMPS) at three locations, including both urban and rural sites. Particle size distributions were measured down to 3 nm at the main site and to 10 nm at the other sites. The frequency of nucleation events was surprising. Approximately 50% of the study days were characterized by nucleation events. These events appear to occur over a large area and are not directly related to the emissions from the urban area. Some nucleation events occurred near simultaneously at samplers 500 km apart. Theories under investigation for the nucleation mechanism include sulfuric acid-water, sulfuric acid-water-ammonia, and secondary organic nucleation. The chemistry of the freshly nucleated and growing particles was investigated by collecting over 20,000 single particle mass spectra using Laser Ablation Aerosol Mass Spectrometry on particles as small as 20 nm. Results of TDMA and hygroscopic growth measurements of nuclei mode particles will also be presented. A large number of high-frequency gas, particle, and meteorological measurements were taken with collocated instruments. Data will be analyzed to elucidate possible cause-effect relationships and the dataset will be compared to theoretical estimates of nucleation rates for a number of mechanisms.

  1. Building America Case Study: Air Leakage and Air Transfer Between Garage and Living Space, Waldorf, Maryland (Fact Sheet)

    SciTech Connect

    Not Available

    2014-11-01

    This research project focused on evaluation of air transfer between the garage and living space in a single-family detached home constructed by a production homebuilder in compliance with the 2009 International Residential Code and the 2009 International Energy Conservation Code. The project gathered important information about the performance of whole-building ventilation systems and garage ventilation systems as they relate to minimizing flow of contaminated air from garage to living space. A series of 25 multi-point fan pressurization tests and additional zone pressure diagnostic testing characterized the garage and house air leakage, the garage-to-house air leakage, and garage and house pressure relationships to each other and to outdoors using automated fan pressurization and pressure monitoring techniques. While the relative characteristics of this house may not represent the entire population of new construction configurations and air tightness levels (house and garage) throughout the country, the technical approach was conservative and should reasonably extend the usefulness of the results to a large spectrum of house configurations from this set of parametric tests in this one house. Based on the results of this testing, the two-step garage-to-house air leakage test protocol described above is recommended where whole-house exhaust ventilation is employed. For houses employing whole-house supply ventilation (positive pressure) or balanced ventilation (same pressure effect as the Baseline condition), adherence to the EPA Indoor airPLUS house-to-garage air sealing requirements should be sufficient to expect little to no garage-to-house air transfer.

  2. CORRELATIONS OF PERSONAL EXPOSURE TO PARTICLES WITH OUTDOOR AIR MEASUREMENT: A REVIEW OF RECENT STUDIES

    EPA Science Inventory

    Epidemiological studies have found a correlation between daily mortality and particle concentrations in outdoor air as measured at a central monitoring station. These studies have been the central reason for the U.S. EPA to propose new tighter particle standards. However, perso...

  3. Operationally efficient propulsion system study (OEPSS) data book. Volume 10; Air Augmented Rocket Afterburning

    NASA Technical Reports Server (NTRS)

    Farhangi, Shahram; Trent, Donnie (Editor)

    1992-01-01

    A study was directed towards assessing viability and effectiveness of an air augmented ejector/rocket. Successful thrust augmentation could potentially reduce a multi-stage vehicle to a single stage-to-orbit vehicle (SSTO) and, thereby, eliminate the associated ground support facility infrastructure and ground processing required by the eliminated stage. The results of this preliminary study indicate that an air augmented ejector/rocket propulsion system is viable. However, uncertainties resulting from simplified approach and assumptions must be resolved by further investigations.

  4. Study of Air Pollution from Space Using TOMS: Challenges and Promises for Future Missions

    NASA Technical Reports Server (NTRS)

    Bhartia, Pawan K.

    2002-01-01

    A series of TOMS instruments built by NASA has flown on US, Russian, and Japanese satellites in the last 24 years. These instruments are well known for producing spectacular maps of the ozone hole that forms over Antarctica each spring. However, it is less well known that these instruments also provided first evidence that space-based measurements in UV of sufficiently high precision and accuracy can provide valuable information to study global air quality. We will use the TOMS experience to highlight the promises and challenges of future space-based missions designed specifically for air quality studies.

  5. Study on an air quality evaluation model for Beijing City under haze-fog pollution based on new ambient air quality standards.

    PubMed

    Li, Li; Liu, Dong-Jun

    2014-09-01

    Since 2012, China has been facing haze-fog weather conditions, and haze-fog pollution and PM2.5 have become hot topics. It is very necessary to evaluate and analyze the ecological status of the air environment of China, which is of great significance for environmental protection measures. In this study the current situation of haze-fog pollution in China was analyzed first, and the new Ambient Air Quality Standards were introduced. For the issue of air quality evaluation, a comprehensive evaluation model based on an entropy weighting method and nearest neighbor method was developed. The entropy weighting method was used to determine the weights of indicators, and the nearest neighbor method was utilized to evaluate the air quality levels. Then the comprehensive evaluation model was applied into the practical evaluation problems of air quality in Beijing to analyze the haze-fog pollution. Two simulation experiments were implemented in this study. One experiment included the indicator of PM2.5 and was carried out based on the new Ambient Air Quality Standards (GB 3095-2012); the other experiment excluded PM2.5 and was carried out based on the old Ambient Air Quality Standards (GB 3095-1996). Their results were compared, and the simulation results showed that PM2.5 was an important indicator for air quality and the evaluation results of the new Air Quality Standards were more scientific than the old ones. The haze-fog pollution situation in Beijing City was also analyzed based on these results, and the corresponding management measures were suggested. PMID:25170682

  6. Study on an Air Quality Evaluation Model for Beijing City Under Haze-Fog Pollution Based on New Ambient Air Quality Standards

    PubMed Central

    Li, Li; Liu, Dong-Jun

    2014-01-01

    Since 2012, China has been facing haze-fog weather conditions, and haze-fog pollution and PM2.5 have become hot topics. It is very necessary to evaluate and analyze the ecological status of the air environment of China, which is of great significance for environmental protection measures. In this study the current situation of haze-fog pollution in China was analyzed first, and the new Ambient Air Quality Standards were introduced. For the issue of air quality evaluation, a comprehensive evaluation model based on an entropy weighting method and nearest neighbor method was developed. The entropy weighting method was used to determine the weights of indicators, and the nearest neighbor method was utilized to evaluate the air quality levels. Then the comprehensive evaluation model was applied into the practical evaluation problems of air quality in Beijing to analyze the haze-fog pollution. Two simulation experiments were implemented in this study. One experiment included the indicator of PM2.5 and was carried out based on the new Ambient Air Quality Standards (GB 3095-2012); the other experiment excluded PM2.5 and was carried out based on the old Ambient Air Quality Standards (GB 3095-1996). Their results were compared, and the simulation results showed that PM2.5 was an important indicator for air quality and the evaluation results of the new Air Quality Standards were more scientific than the old ones. The haze-fog pollution situation in Beijing City was also analyzed based on these results, and the corresponding management measures were suggested. PMID:25170682

  7. [Prevention and control of air pollution needs to strengthen further study on health damage caused by air pollution].

    PubMed

    Wu, T C

    2016-08-01

    Heath issues caused by air pollution such as particulate matter (PM) are much concerned and focused among air, water and soil pollutions because human breathe air for whole life span. Present comments will review physical and chemical characteristics of PM2.5 and PM10; Dose-response associations of PM10, PM2.5 and their components with mortality and risk of cardiopulmonary diseases, early health damages such as the decrease of lung functions and heart rate variability, DNA damage; And the roles of genetic variations and epigenetic changes in lung functions and heart rate variability, DNA damage related to PMs and their components. This comments list some limitations and perspectives about the associations of air pollution with health. PMID:27539517

  8. Experimental study on corrugated cross-flow air-cooled plate heat exchangers

    SciTech Connect

    Kim, Minsung; Baik, Young-Jin; Park, Seong-Ryong; Ra, Ho-Sang; Lim, Hyug

    2010-11-15

    Experimental study on cross-flow air-cooled plate heat exchangers (PHEs) was performed. The two prototype PHEs were manufactured in a stack of single-wave plates and double-wave plates in parallel. Cooling air flows through the PHEs in a crosswise direction against internal cooling water. The heat exchanger aims to substitute open-loop cooling towers with closed-loop water circulation, which guarantees cleanliness and compactness. In this study, the prototype PHEs were tested in a laboratory scale experiments. From the tests, double-wave PHE shows approximately 50% enhanced heat transfer performance compared to single-wave PHE. However, double-wave PHE costs 30% additional pressure drop. For commercialization, a wide channel design for air flow would be essential for reliable performance. (author)

  9. Numerical Simulation and Experimental Study of a Dental Handpiece Air Turbine

    NASA Astrophysics Data System (ADS)

    Hsu, Chih-Neng; Chiang, Hsiao-Wei D.; Chang, Ya-Yi

    2011-06-01

    Dental air turbine handpieces have been widely used in clinical dentistry for over 30 years, however, little work has been reported on their performance. In dental air turbine handpieces, the types of flow channel and turbine blade shape can have very different designs. These different designs can have major influence on the torque, rotating speed, and power performance. This research is focused on the turbine blade and the flow channel designs. Using numerical simulation and experiments, the key design parameters which influence the performance of dental hand pieces can be studied. Three types of dental air turbine designs with different turbine blades, nozzle angles, nozzle flow channels, and shroud clearances were tested and analyzed. Very good agreement was demonstrated between the numerical simulation analyses and the experiments. Using the analytical model, parametric studies were performed to identify key design parameters.

  10. Roadside air quality and implications for control measures: A case study of Hong Kong

    NASA Astrophysics Data System (ADS)

    Ai, Z. T.; Mak, C. M.; Lee, H. C.

    2016-07-01

    Traffic related air pollution is one of major environmental issues in densely populated urban areas including Hong Kong. A series of control measures has been implemented by Hong Kong government to cut traffic related air pollutants, including retrofitting the Euro II and Euro III buses with selective catalytic reduction (SCR) devices to lower nitrogen dioxide (NO2) emissions. In order to reveal the real-life roadside air quality and evaluate the effectiveness of the control measures, this study first analyzed the recent six-year data regarding concentrations of pollutants typically associated with traffic recorded in two governmental roadside monitoring stations and second conducted on-site measurements of concentration of pollutants at pedestrian level near five selected roads. Given that there is a possibility of ammonia leakage as a secondary pollutant from SCR devices, a special attention was paid to the measurements of ammonia level in bus stations and along roadsides. Important influencing factors, such as traffic intensity, street configuration and season, were analyzed. Control measures implemented by the government are effective to decrease the traffic emissions. In 2014, only NO2 cannot achieve the annual air quality objective of Hong Kong. However, it is important to find that particulate matters, rather than NO2, post potentially a short-term exposure risk to passengers and pedestrians. Based on the findings of this study, specific control measures are suggested, which are intended to further improve the roadside air quality.

  11. AIR STUDIES

    EPA Science Inventory

    MOBILE SOURCE AMMONIA EMISSIONS CHARACTERIZATION: Multiple vehicles and different types of catalyst will be evaluated for ammonia emissions while these vehicles are operated on a dynamometer. The results will provide a relationship between the rate of ammonia production and the ...

  12. Western Pacific Air-Sea Interaction Study (W-PASS), Introduction and Highlights (Invited)

    NASA Astrophysics Data System (ADS)

    Tsuda, A.

    2010-12-01

    Western Pacific Air-Sea Interaction Study (W-PASS), Introduction and Highlights Atsushi Tsuda Atmosphere and Ocean Research Institute, The University of Tokyo In the western Pacific (WESTPAC) region, dust originating from Asian and Australian arid regions to the North and South Pacific, biomass burning emissions from the Southeast Asia to sub-tropical Pacific, and other anthropogenic substances are transported regionally and globally to affect cloud and rainfall patterns, air quality, and radiative budgets downwind. Deposition of these compounds into the Asian marginal seas and onto the Pacific Ocean influence surface primary productivity and species composition. In the WESTPAC region, subarctic, subtropical oceans and marginal seas are located relatively narrow latitudinal range and these areas are influenced by the dust and anthropogenic inputs. Moreover, anthropogenic emission areas are located between the arid region and the oceans. The W-PASS (Western Pacific Air-Sea interaction Study) project has been funded for 5 years as a part of SOLAS-Japan activity in the summer of 2006. We aim to resolve air-sea interaction through field observation studies mainly using research vessels and island observatories over the western Pacific. We have carried out 5 cruises to the western North Pacific focusing on air-sea interactions. Also, an intensive marine atmospheric observation including direct atmospheric deposition measurement was accomplished by a dozen W-PASS research groups at the NIES Atmospheric and Aerosol Monitoring Station of Cape Hedo in the northernmost tip of the Okinawa main Island facing the East China Sea in the spring 2008. A few weak Kosa (dust) events, anthropogenic air outflows, typical local air and occupation of marine background air were identified during the campaign period. The W-PASS has four research groups mainly focusing on VOC emissions, air-sea gas exchange processes, biogeochemical responses to dust depositions and its modeling. We also

  13. Design and analysis of multilevel analytic studies with applications to a study of air pollution.

    PubMed Central

    Navidi, W; Thomas, D; Stram, D; Peters, J

    1994-01-01

    We discuss a hybrid epidemiologic design that aims to combine two approaches to studying exposure-disease associations. The analytic approach is based on comparisons between individuals, e.g., case-control and cohort studies, and the ecologic approach is based on comparisons between groups. The analytic approach generally provides a stronger basis for inference, in part because of freedom from between-group confounding and better quality data, but the ecologic approach is less susceptible to attenuation bias from measurement error and may provide greater variability in exposure. The design we propose entails selection of a number of groups and enrollment of individuals within each group. Exposures, outcomes, confounders, and modifiers would be assessed on each individual; but additional exposure data might be available on the groups. The analysis would then combine the individual-level and the group-level comparisons, with appropriate adjustments for exposure measurement errors, and would test for compatibility between the two levels of analysis, e.g., to determine whether the associations at the individual level can account for the differences in disease rates between groups. Trade-offs between numbers of groups, numbers of individuals, and the extent of the individual and group measurement protocols are discussed in terms of design efficiency. These issues are illustrated in the context of an on-going study of the health effects of air pollution in southern California, in which 12 communities with different levels and types of pollution have been selected and 3500 school children are being enrolled in a ten-year cohort study.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7851327

  14. Effect of body repositioning after venous air embolism. An echocardiographic study

    NASA Technical Reports Server (NTRS)

    Geissler, H. J.; Allen, S. J.; Mehlhorn, U.; Davis, K. L.; Morris, W. P.; Butler, B. D.

    1997-01-01

    BACKGROUND: Current therapy for massive venous air embolism (VAE) may include the use of the left lateral recumbent (LLR) position, although its effectiveness has been questioned. This study used transesophageal echocardiography to evaluate the effect of body repositioning on intracardiac air and acute cardiac dimension changes. METHODS: Eighteen anesthetized dogs in the supine position received a venous air injection of 2.5 ml/kg at a rate of 5 ml/ s. After 1 min the dogs were repositioned into either the LLR, LLR 10 degrees head down (LLR-10 degrees), right lateral recumbence, or remained in the supine position. RESULTS: Repositioning after VAE resulted in relocation of intracardiac air to nondependent areas of the right heart. Peak right ventricular (RV) diameter increase and mean arterial pressure decrease were greater in the repositioned animals compared with those in the supine position (P < 0.05). Right ventricular diameter and mean arterial pressure showed an inverse correlation (r = 0.81). Peak left atrial diameter decrease was greater in the LLR and LLR-10 degrees positions compared with the supine position (P < 0.05). Repositioning did not influence peak pulmonary artery pressure increase, and no correlation was found between RV diameter and pulmonary artery pressure. All animals showed electrocardiogram and echocardiographic changes reconcilable with myocardial ischemia. CONCLUSIONS: In dogs, body repositioning after VAE provided no benefit in hemodynamic performance or cardiac dimension changes, although relocation of intracardiac air was demonstrated. Right ventricular air did not appear to result in significant RV outflow obstruction, as pulmonary artery pressure increased uniformly in all groups and was not influenced by the relocation of intracardiac air. The combination of increased RV afterload and arterial hypotension, possibly with subsequent RV ischemia rather than RV outflow obstruction by an airlock appeared to be the primary mechanism for

  15. An experimental study on the effect of air bubble injection on the flow induced rotational hub

    SciTech Connect

    Nouri, N.M.; Sarreshtehdari, A.

    2009-01-15

    Modification of shear stress due to air bubbles injection in a rotary device was investigated experimentally. Air bubbles inject to the water flow crosses the neighbor of the hub which can rotate just by water flow shear stresses, in this device. Increasing air void fraction leads to decrease of shear stresses exerted on the hub surface until in high void fractions, the hub motion stopped as observed. Amount of skin friction decrease has been estimated by counting central hub rotations. Wall shear stress was decreased by bubble injection in all range of tested Reynolds number, changing from 50,378 to 71,238, and also by increasing air void fraction from zero to 3.06%. Skin friction reduction more than 85% was achieved in this study as maximum measured volume of air fraction injected to fluid flow while bubbles are distinct and they do not make a gas layer. Significant skin friction reduction obtained in this special case indicate that using small amount of bubble injection causes large amount of skin friction reduction in some rotary parts in the liquid phases like as water. (author)

  16. Experimental study on sulfur removal from ladle furnace refining slag in hot state by blowing air

    NASA Astrophysics Data System (ADS)

    Zhao, Li-hua; Lin, Lu; Wu, Qi-fan

    2016-01-01

    In view of the present problem of sulfur enrichment in the metallurgical recycling process of ladle furnace (LF) refining slag, a simple and efficient method of removing sulfur from this slag was proposed. The proposed method is compatible with current steelmaking processes. Sulfur removal from LF refining slag for SPHC steel (manufactured at a certain steel plant in China) by blowing air in the hot state was studied by using hot-state experiments in a laboratory. The FactSage software, a carbon/sulfur analyzer, and scanning electron microscopy in conjunction with energy-dispersive X-ray spectroscopy were used to test and analyze the sulfur removal effect and to investigate factors influencing sulfur removal rate. The results show that sulfur ions in LF refining slag can be oxidized into SO2 by O2 at high temperature by blowing air into molten slag; SO2 production was observed to reach a maximum with a small amount of blown O2 when the temperature exceeded 1350°C. At 1370°C and 1400°C, experimental LF refining slag is in the liquid state and exhibits good fluidity; under these conditions, the sulfur removal effect by blowing air is greater than 90wt% after 60 min. High temperature and large air flow rate are beneficial for removing sulfur from LF refining slag; compared with air flow rate, temperature has a greater strongly influences on the sulfur removal.

  17. Air pollution and fasting blood glucose: A longitudinal study in China.

    PubMed

    Chen, Linping; Zhou, Yong; Li, Shanshan; Williams, Gail; Kan, Haidong; Marks, Guy B; Morawska, Lidia; Abramson, Michael J; Chen, Shuohua; Yao, Taicheng; Qin, Tianbang; Wu, Shouling; Guo, Yuming

    2016-01-15

    Limited studies have examined the associations between air pollutants [particles with diameters of 10 μm or less (PM10), sulphur dioxide (SO2), and nitrogen dioxide (NO2)] and fasting blood glucose (FBG). We collected data for 27,685 participants who were followed during 2006 and 2008. Generalized Estimating Equation models were used to examine the effects of air pollutants on FBG while controlling for potential confounders. We found that increased exposure to NO2, SO2 and PM10 was significantly associated with increased FBG levels in single pollutant models (p<0.001). For exposure to 4 days' average of concentrations, a 100 μg/m(3) increase in SO2, NO2, and PM10 was associated with 0.17 mmol/L (95% CI: 0.15-0.19), 0.53 mmol/L (95% CI: 0.42-0.65), and 0.11 mmol/L (95% CI: 0.07-0.15) increase in FBG, respectively. In the multi-pollutant models, the effects of SO2 were enhanced, while the effects of NO2 and PM10 were alleviated. The effects of air pollutants on FBG were stronger in female, elderly, and overweight people than in male, young and underweight people. In conclusion, the findings suggest that air pollution increases the levels of FBG. Vulnerable people should pay more attention on highly polluted days to prevent air pollution-related health issues. PMID:26433332

  18. Study of using oxygen-enriched combustion air for locomotive diesel engines

    SciTech Connect

    Poola, R.B.; Sekar, R.; Assanis, D.N.; Cataldi, G.R.

    1996-10-01

    A thermodynamic simulation is used to study effects of O2-enriched intake air on performance and NO emissions of a locomotive diesel engine. Parasitic power of the air separation membrane required to supply the O2-enriched air is also estimated. For a given constraint on peak cylinder pressure, gross and net power output of an engine operating under different levels of O2 enrichment are compared with those obtained when a high-boost turbocharged engine is used. A 4% increase in peak cylinder pressure can result in 13% increase in net engine power when intake air with 28 vol% O2 is used and fuel injection timing retarded by 4 degrees. When the engine is turbocharged to a higher inlet boost, the same increase in peak cylinder pressure can result in only 4% improvement in power. If part of the higher exhaust enthalpies from the O2 enrichment is recovered, the power requirements of the air separator membrane can be met. O2 enrichment with its higher combustion temperatures reduces emissions of particulates and visible smoke but increases NO emissions (by up to 3 times at 26% O2 content). Therefore, exhaust gas after-treatment and heat recovery would be required if the full potential of O2 enrichment for improving the performance of locomotive diesel engines is to be realized.

  19. Study on the characteristic decomposition components of air-insulated switchgear cabinet under partial discharge

    NASA Astrophysics Data System (ADS)

    Gui, Yingang; Zhang, Xiaoxing; Zhang, Ying; Qiu, Yinjun; Chen, Lincong

    2016-07-01

    Air-insulated switchgear cabinet plays a critical role in entire power transmission and distribution system. Its stability directly affects the operational reliability of the power system. And the on-line gas detection method, which evaluates the insulation status of insulation equipment by detecting the decomposition components of filled air in cabinet, becomes an innovative way to ensure the running stability of air-insulated switchgear cabinet. In order to study the characteristic gas types and production regularity of decomposition components under partial discharge, three insulation defects: needle-plate, air-gap and impurity defect are proposed to simulate the insulation defects under partial discharge in air-insulated switchgear cabinet. Firstly, the generation pathways and mechanism of composition components are discussed. Then CO and NO2 are selected as the characteristic decomposition components to characterize the partial discharge due to their high concentration and chemical stability. Based on the different change regularity of CO and NO2 concentration under different insulation defect, it provides an effective way to evaluate and predict the insulation defect type and severity in the field.

  20. A new study of shower age distribution in near vertical showers by EAS air shower array

    NASA Technical Reports Server (NTRS)

    Chaudhuri, N.; Goswami, G. C.; Basak, D. K.; Ghosh, B.

    1984-01-01

    The air shower array has been developed since it started operation in 1931. The array covering an area of 900 sq m now incorporates 21 particle density sampling detectors around two muon magnetic spectrographs. The air showers are detected in the size range 10 to the 4th power to 10 to the 6th power particles. A total of 11000 showers has so far been detected. Average values of shower age have been obtained in various shower size ranges to study the dependence of shower age on shower size. The core distance dependence of shower age parameter has also been analyzed for presentation.

  1. Technology Solutions Case Study: Overcoming Comfort Issues Due to Reduced Flow Room Air Mixing

    SciTech Connect

    2015-03-01

    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. In this project, IBACOS studied when HVAC equipment is downsized and ducts are unaltered to determine conditions that could cause a supply air delivery problem and to evaluate the feasibility of modifying the duct systems using minimally invasive strategies to improve air distribution.

  2. Central California coastal air-quality model validation study: Data analysis and model evaluation

    SciTech Connect

    Dabberdt, W.F.; Johnson, W.B.; Brodzinsky, R.; Ruff, R.E.

    1984-08-01

    The objectives of the study were: to obtain a comprehensive experimental data base of overwater and inland dispersion along the central California coast; to evaluate air-quality models presently being used by MMS for determining air-quality impacts from offshore emission sources; to evaluate various schemes for determining atmospheric stability and methods of determining atmospheric stability and methods of determining dispersion parameters (sigma-y and sigma-z) overwater; and to provide data needed for an overwater dispersion model presently under development by MMS.

  3. Performance studies of energy consumption for single and multiple nozzle systems under impinging air jets

    NASA Astrophysics Data System (ADS)

    Etemoglu, Akin Burak; Can, Muhiddin

    2013-08-01

    Impinging air jets of various shapes, sizes and configurations are commonly used in heating, cooling and drying industrial processes. An analytical study has been carried out to optimise the thermal performance of single and multiple nozzle systems using impinging air jets. The optimisation of the nozzle array was given for practical purposes. The results show that within practical limits, a narrower nozzle size results in a greater heat and mass transfer coefficient. An economical analysis of the drying processes is also given for slot nozzles.

  4. Benefits of using enhanced air quality information in human health studies

    EPA Science Inventory

    The ability of four (4) enhancements of gridded PM2.5 concentrations derived from observations and air quality models to detect the relative risk of long-term exposure to PM2.5 are evaluated with a simulation study. The four enhancements include nearest-nei...

  5. Temporal aspects of air pollutant measures in epidemiologic analysis: a simulation study

    PubMed Central

    White, Laura F; Yu, Jeffrey; Jerrett, Michael; Coogan, Patricia

    2016-01-01

    Numerous observational studies have assessed the association between ambient air pollution and chronic disease incidence, but there is no uniform approach to create an exposure metric that captures the variability in air pollution through time and determines the most relevant exposure window. The purpose of the present study was to assess ways of modeling exposure to air pollution in relation to incident hypertension. We simulated data on incident hypertension to assess the performance of six air pollution exposure metrics, using characteristics from the Black Women’s Health Study. Each metric made different assumptions about how to incorporate time trends in pollutant data, and the most relevant window of exposure. We use observed values for particulate matter ≤2.5 microns (PM2.5) for this cohort to create the six exposure metrics and fit Cox proportional hazards models to the simulated data using the six metrics. The optimal exposure metric depends on the underlying association between PM2.5 and disease, which is unknown. Metrics that incorporate exposure information from multiple years tend to be more robust and suffer from less bias. This study provides insight into factors that influence the metric used to quantifying exposure to PM2.5 and suggests the need for careful sensitivity analyses. PMID:26791428

  6. A Novice-Expert Study of Modeling Skills and Knowledge Structures about Air Quality

    ERIC Educational Resources Information Center

    Hsu, Ying-Shao; Lin, Li-Fen; Wu, Hsin-Kai; Lee, Dai-Ying; Hwang, Fu-Kwun

    2012-01-01

    This study compared modeling skills and knowledge structures of four groups as seen in their understanding of air quality. The four groups were: experts (atmospheric scientists), intermediates (upper-level graduate students in a different field), advanced novices (talented 11th and 12th graders), and novices (10th graders). It was found that when…

  7. Air Pollution, Cognitive Deficits and Brain Abnormalities: A Pilot Study with Children and Dogs

    ERIC Educational Resources Information Center

    Calderon-Garciduenas, Lilian; Mora-Tiscareno, Antonieta; Ontiveros, Esperanza; Gomez-Garza, Gilberto; Barragan-Mejia, Gerardo; Broadway, James; Chapman, Susan; Valencia-Salazar, Gildardo; Jewells, Valerie; Maronpot, Robert R.; Henriquez-Roldan, Carlos; Perez-Guille, Beatriz; Torres-Jardon, Ricardo; Herrit, Lou; Brooks, Diane; Osnaya-Brizuela, Norma; Monroy, Maria E.; Gonzalez-Maciel, Angelica; Reynoso-Robles, Rafael; Villarreal-Calderon, Rafael; Solt, Anna C.; Engle, Randall W.

    2008-01-01

    Exposure to air pollution is associated with neuroinflammation in healthy children and dogs in Mexico City. Comparative studies were carried out in healthy children and young dogs similarly exposed to ambient pollution in Mexico City. Children from Mexico City (n:55) and a low polluted city (n:18) underwent psychometric testing and brain magnetic…

  8. LONGITUDINAL STUDY OF SEMEN QUALITY AFTER INTERMITTENT EXPOSURE TO AIR POLLUTION

    EPA Science Inventory

    LONGITUDINAL STUDY OF SEMEN QUALITY AFTER INTERMITTENT EXPOSURE TO AIR POLLUTION. J. Rubes*, D. Zudova*, Veterinary Research Institute, Brno, CR, S.G. Selevan*, US EPA/ORD/NCEA, Washington, DC, D.P. Evenson, South Dakota State University, Brookings, SD, and S.D. Perreault, US ...

  9. ATMOSPHERIC ACIDITY MEASUREMENTS DURING THE LAKE MICHIGAN URBAN AIR TOXICS STUDY

    EPA Science Inventory

    During the summer of 1991, as part of the Lake Michigan Urban Air Toxics Study (LMUATS), measurements of reactive gases and fine fraction and size-fractionated acidic aerosols were taken at two sites (South Haven, MI and aboard the research vessel, R/V Laurentian). he fine fracti...

  10. DEVELOPMENT AND APPLICATIONS OF CFD SIMULATIONS IN SUPPORT OF AIR QUALITY STUDIES INVOLVING BUILDINGS

    EPA Science Inventory

    There is a need to properly develop the application of Computational Fluid Dynamics (CFD) methods in support of air quality studies involving pollution sources near buildings at industrial sites. CFD models are emerging as a promising technology for such assessments, in part due ...

  11. MECHANISMS OF PHOTOCHEMICAL REACTIONS IN URBAN AIR. VOLUME II. CHAMBER STUDIES

    EPA Science Inventory

    The smog chamber facility of the Statewide Air Pollution Research Center has been employed in a study designed to provide experimental data required for the validation of kinetic computer models of chemical transformations in polluted atmospheres. A 5800-l, Teflon-coated, evacuab...

  12. DYNAMIC ENERGY SAVING IN BUILDINGS WITH UNDERFLOOR AIR DISTRIBUTION SYSTEM – EXPERIMENTAL AND SIMULATION STUDIES

    EPA Science Inventory

    The present study is aimed at seeking a better understanding of the thermodynamics involved with the air distribution strategies associated with UFAD systems and its impact on the energy saving dynamics.
    Thus objectives are:

  1. RELATIONAHIP BETWEEN AMBIENT AIR QUALITY AND SELECTED BIRTH DEFECTS, SEVEN COUNTY STUDY, TEXAS, 1997-2000

    EPA Science Inventory

    A population-based case-control study investigated the association between maternal exposure to criteria air pollutants, CO, NO2, O3, SO2, and PM10 during weeks three through eight of pregnancy, and the risk of selected cardiac birth defects and oral clefts among live births and ...

  2. Assessing the Feasibility of Performing an Air Accountability Study in New Haven, CT

    EPA Science Inventory

    The main objective of this EPA study was to examine the feasibility of conducting a local (e.g., city level) assessment of the public health impacts of cumulative air pollution reduction activities (a.k.a. accountability) from the federal, state, local and voluntary actions in t...

  3. HP-65 PROGRAMMABLE POCKET CALCULATOR APPLIED TO AIR POLLUTION MEASUREMENT STUDIES: STATIONARY SOURCES

    EPA Science Inventory

    The handbook is intended for persons concerned with air pollution measurement studies of stationary industrial sources. It gives detailed descriptions of 22 different programs written specifically for the Hewlett Packard Model HP-65 card-programmable pocket calculator. For each p...

  4. ENVIRONMENTAL PROTECTION AGENCY INDOOR AIR QUALITY AND WORKENVIRONMENT STUDY: HEALTH SYMPTOMS AND COMFORT CONCERNS

    EPA Science Inventory

    In recent years, employees at the three headquarters buildings ofthe U.S. Environmental Protection Agency (EPA) in the Washington,DC, area have expressed concerns about air quality and workenvironment discomforts. n February 1989, a two-stage study ofhealth and comfort concerns a...

  5. AN OBJECTIVE ANALYSIS TECHNIQUE FOR THE REGIONAL AIR POLLUTION STUDY. PART I

    EPA Science Inventory

    This report documents the development of an objective analysis program for the mesoscale gridding of wind and temperature for the Regional Air Pollution Study being conducted in St. Louis by the Environmental Protection Agency. The program is designed to produce a 5-km spaced hor...

  6. AN OBJECTIVE ANALYSIS TECHNIQUE FOR THE REGIONAL AIR POLLUTION STUDY. PART II

    EPA Science Inventory

    This report discusses the application of objective analysis techniques to the computation of trajectories from surface wind observations of the Regional Air Pollution Study in St. Louis. Trajectories were computed over a 100-kilometer square grid centered on St. Louis for two 5-h...

  7. Air Quality Scoping Study for Ash Meadows National Wildlife Refuge, Nevada (EMSI April 2007)

    SciTech Connect

    Engelbrecht, Johann; Kavouras, Ilias; Campbell, Dave; Campbell, Scott; Kohl, Steven; Shafer, David

    2007-04-01

    The Desert Research Institute (DRI) is performing a scoping study as part of the U.S.Department of Energy’s Yucca Mountain Environmental Monitoring Systems Initiative (EMSI). The main objective is to obtain baseline air quality information for Yucca Mountain and an area surrounding the Nevada Test Site (NTS). Air quality and meteorological monitoring and sampling equipment housed in a mobile trailer (shelter) is collecting data at seven sites outside the NTS, including Ash Meadows National Wildlife Refuge, Sarcobatus Flat, Beatty, Rachel, Caliente, Pahranagat National Wildlife Refuge, and Crater Flat, and at four sites on the NTS. The trailer is stationed at any one site for approximately eight weeks at a time. Letter reports provide summaries of air quality and meteorological data, on completion of each site’s sampling program.

  8. Air Quality Scoping Study for Sarcobatus Flat, Nevada (EMSI April 2007)

    SciTech Connect

    Engelbrecht, Johann; Kavouras, Ilias; Campbell, Dave; Campbell, Scott; Kohl, Steven; Shafer, David

    2007-04-01

    The Desert Research Institute (DRI) is performing a scoping study as part of the U.S. Department of Energy’s Yucca Mountain Environmental Monitoring Systems Initiative (EMSI). The main objective is to obtain baseline air quality information for Yucca Mountain and an area surrounding the Nevada Test Site (NTS). Air quality and meteorological monitoring and sampling equipment housed in a mobile trailer (shelter) is collecting data at seven sites outside the NTS, including Ash Meadows National Wildlife Refuge, Sarcobatus Flat, Beatty, Rachel, Caliente, Pahranagat National Wildlife Refuge, and Crater Flat, and at four sites on the NTS. The trailer is stationed at any one site for approximately eight weeks at a time. Letter reports provide summaries of air quality and meteorological data, on completion of each site’s sampling program.

  9. Theoretical study of vibrational energy transfer of free OH groups at the water-air interface

    NASA Astrophysics Data System (ADS)

    Zheng, Renhui; Wei, Wenmei; Sun, Yuanyuan; Song, Kai; Shi, Qiang

    2016-04-01

    Recent experimental studies have shown that the vibrational dynamics of free OH groups at the water-air interface is significantly different from that in bulk water. In this work, by performing molecular dynamics simulations and mixed quantum/classical calculations, we investigate different vibrational energy transfer pathways of free OH groups at the water-air interface. The calculated intramolecular vibrational energy transfer rate constant and the free OH bond reorientation time scale agree well with the experiment. It is also found that, due to the small intermolecular vibrational couplings, the intermolecular vibrational energy transfer pathway that is very important in bulk water plays a much less significant role in the vibrational energy relaxation of the free OH groups at the water-air interface.

  10. Comparative studies of metal air pollution by atomic spectrometry techniques and biomonitoring with moss and lichens.

    PubMed

    State, Gabriel; Popescu, Ion V; Radulescu, Cristiana; Macris, Cristina; Stihi, Claudia; Gheboianu, Anca; Dulama, Ioana; Niţescu, Ovidiu

    2012-09-01

    Our study was dedicated to the analysis of air pollution level with metals in Dambovita County, Romania; maps of the concentration distributions for air pollutants were drawn; statistical analysis includes calculation of the background concentrations and the contamination factors. The highest values of the contamination factor CF is 63.1 ± 6.63 for mosses samples and 33.12 ± 3.96 for lichens and it indicates extreme contaminations in the surroundings of steel works and an electric plant. The comparison of the distribution maps for Cr, Cu, Fe, Ni, Pb and Zn concentrations enables the identification of the pollution sources, the limits of areas with very high levels of pollution, the comparison of the concentration gradients in some areas and the influence of woodlands on the spread of pollutants through the air. PMID:22760846

  11. Theoretical study of vibrational energy transfer of free OH groups at the water-air interface.

    PubMed

    Zheng, Renhui; Wei, Wenmei; Sun, Yuanyuan; Song, Kai; Shi, Qiang

    2016-04-14

    Recent experimental studies have shown that the vibrational dynamics of free OH groups at the water-air interface is significantly different from that in bulk water. In this work, by performing molecular dynamics simulations and mixed quantum/classical calculations, we investigate different vibrational energy transfer pathways of free OH groups at the water-air interface. The calculated intramolecular vibrational energy transfer rate constant and the free OH bond reorientation time scale agree well with the experiment. It is also found that, due to the small intermolecular vibrational couplings, the intermolecular vibrational energy transfer pathway that is very important in bulk water plays a much less significant role in the vibrational energy relaxation of the free OH groups at the water-air interface. PMID:27083739

  12. An experimental study on high temperature and low oxygen air combustion

    NASA Astrophysics Data System (ADS)

    Kim, W. B.; Chung, D. H.; Yang, J. B.; Noh, D. S.

    2000-06-01

    High temperature preheated and diluted air combustion has been confirmed as the technology, mainly applied to industrial furnaces and kilns, to realize higher thermal efficiency and lower emissions. The purpose of this study was to investigate fundamental aspects of the above-mentioned combustion experimentally and to compare with those in ordinary hydrocarbon combustion with room temperature air. The test items were exhaust gas components of CO, NOx, flame shape and radical components of CH, OH and C2, which were measured with gas analyser, camera and ICCD(Intensified Charged - Coupled Device) camera. Many phenomena as results appeared in combustion with the oxidizer, low oxygen concentration and extremely high temperature air, such as expansion of the flammable limits, increased flame propagation speed, it looked so strange as compared with those in existing combustion technology. We confirmed that such extraordinary phenomena were believable through the hot-test experiment.

  13. Microorganism levels in air near spray irrigation of municipal waste water: The Lubbock Infection Surveillance Study

    SciTech Connect

    Camann, D.E.; Moore, B.E.; Harding, H.J.; Sorber, C.A.

    1988-01-01

    The Lubbock Infection Surveillance Study (LISS) investigated possible adverse effects on human health from slow-rate land application of municipal wastewater. Extensive air sampling was conducted to characterize the irrigation site as a source of infectious microbial aerosols. Spray irrigation of poor-quality waste water received directly from the treatment plant significantly elevated air densities of fecal coliforms, fecal streptococci, mycobacteria, and coliphage above ambient background levels for at least 200 m downwind. Enteroviruses were repeatedly recovered at 44 to 60 m downwind at a higher level (geometric mean = 0.05 pfu/m3) than observed at other waste water aerosol sites in the U.S. and in Israel. Waste water storage in reservoirs reduced downwind air densities of indicator organisms by two orders of magnitude.

  14. Experimental study of heat transfer and thermal performance with longitudinal fins of solar air heater

    PubMed Central

    Chabane, Foued; Moummi, Noureddine; Benramache, Said

    2013-01-01

    The thermal performance of a single pass solar air heater with five fins attached was investigated experimentally. Longitudinal fins were used inferior the absorber plate to increase the heat exchange and render the flow fluid in the channel uniform. The effect of mass flow rate of air on the outlet temperature, the heat transfer in the thickness of the solar collector, and the thermal efficiency were studied. Experiments were performed for two air mass flow rates of 0.012 and 0.016 kg s−1. Moreover, the maximum efficiency values obtained for the 0.012 and 0.016 kg s−1 with and without fins were 40.02%, 51.50% and 34.92%, 43.94%, respectively. A comparison of the results of the mass flow rates by solar collector with and without fins shows a substantial enhancement in the thermal efficiency. PMID:25685486

  15. Summarising climate and air quality (ozone) data on self-organising maps: a Sydney case study.

    PubMed

    Jiang, Ningbo; Betts, Alan; Riley, Matt

    2016-02-01

    This paper explores the classification and visualisation utility of the self-organising map (SOM) method in the context of New South Wales (NSW), Australia, using gridded NCEP/NCAR geopotential height reanalysis for east Australia, together with multi-site meteorological and air quality data for Sydney from the NSW Office of Environment and Heritage Air Quality Monitoring Network. A twice-daily synoptic classification has been derived for east Australia for the period of 1958-2012. The classification has not only reproduced the typical synoptic patterns previously identified in the literature but also provided an opportunity to visualise the subtle, non-linear change in the eastward-migrating synoptic systems influencing NSW (including Sydney). The summarisation of long-term, multi-site air quality/meteorological data from the Sydney basin on the SOM plane has identified a set of typical air pollution/meteorological spatial patterns in the region. Importantly, the examination of these patterns in relation to synoptic weather types has provided important visual insights into how local and synoptic meteorological conditions interact with each other and affect the variability of air quality in tandem. The study illustrates that while synoptic circulation types are influential, the within-type variability in mesoscale flows plays a critical role in determining local ozone levels in Sydney. These results indicate that the SOM can be a useful tool for assessing the impact of weather and climatic conditions on air quality in the regional airshed. This study further promotes the use of the SOM method in environmental research. PMID:26787272

  16. Laboratory scale studies on mitigation of high 222Rn concentrations in air and water

    NASA Astrophysics Data System (ADS)

    Mamoon, A.; Gomma, M. A.; Sohsah, M.

    2004-01-01

    In view of the occasional occurrence of high 222Rn concentrations in air and water under certain circumstances, and in view of the potential health hazards of increased levels of 222Rn in respirable air and in potable water, mitigation of such high 222Rn concentration has become of primary concern. To facilitate the study of the efficiency of the various 222Rn mitigating factors simple laboratory systems were used. Altered alkali granite was used as radon source to enrich air and a piece of pitchblende was used as radon source to enrich water samples. Both enriched media will then be subjected to the mitigation treatments. Charcoal canister technique along with gamma spectrometry were used to measure 222Rn concentrations in air before and after the different mitigating treatments. These were: use of ventilation, radon barriers such as geo-membranes and aluminum sheet, and sealant such as epoxy and vinyl tape. Regarding high levels of 222Rn in air ventilation was the most efficient mitigating factor. Standard liquid scintillation counting was used to measure 222Rn concentrations in water before and after the different mitigation treatments. These were: use of aeration, activated charcoal and heating. Regarding high levels of 222Rn in water, aeration using bubblers and large volume of air was most effective in removing radon from water in a short time. However all the mitigating factors proved effective, in different degrees in decreasing 222Rn concentrations in the respective media. The result from these studies are in general agreement with reports in the literature. It can be concluded then that the different 222Rn mitigating factors can be tested and compared effectively under controlled conditions using simple laboratory scale systems.

  17. Chemical characterization of particulate air pollutants Case studies on indoor air quality, cultural heritage and the marine environment

    NASA Astrophysics Data System (ADS)

    Horemans, Benjamin

    When attempting to discuss the effects of airborne particulate matter (PM), it is important to address both physical and chemical aspects of this pollutant. This work reports on the results of three separate case studies, each approaching a specific problem of air pollution by evaluating the chemical composition of PM. 1. In the US and Europe, office workers often complain about work-related health symptoms. These symptoms are collectively referred as the 'sick building syndrome'. This work could be considered as one of the largest data collections on particulate pollutants in Belgian offices. It helps to understand the sources as well as the behavior and fate of PM at our workplace environments. Especially the chemical information on PM makes the results unique, since it enables a better evaluation of the health risks connected to office dust. 2. The Alhambra and Generalife bring every year more than 3 million people to Granada in Southern Spain. Recently, the increasing urbanization of Granada and the immense pressure of mass tourism form a threat for this heritage. Despite the fact that atmospheric pollutants are known to he potentially aggressive for our cultural patrimony. this case study is the first to assess the effects of environmental aerosols on the Alhambra monument. The results of this study could help decision-makers at the Alhambra and the city of Granada with the formulation of preventive conservation measures. They show how local vehicular traffic is the main source for atmospheric pollution in and around the Alhambra monument. Targeted strategies are necessary in order to maximally preserve these monuments and their UNESCO world cultural heritage label. 3. Excessive input of nitrogen-containing atmospheric nutrients via dry and wet deposition can cause entrophication of marine regions, which is also a common, seasonal phenomenon along the coasts of the North Sea. This study is the first to give a complete quantitative description of the

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

    PubMed Central

    Adams, Jeffrey A.; Reddy, Krishna R.; Tekola, Lue

    2011-01-01

    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. PMID:21776228

  19. Baseline Studies of Selected Polybrominated Diphenyl Ethers in the Air of the Nandamojo Watershed, Costa Rica

    NASA Astrophysics Data System (ADS)

    Geesey, Mary Sophia

    Polybrominated diphenyl ethers (PBDEs) have been used as flame retardants in a number of common household and commercial products around the world. PBDEs enter the environment in a variety of ways, such as through emissions, leaching from end-of-life electronics in landfills, and incineration. While many countries have phased out the manufacturing of penta-, octa-, and deca-PBDEs or have banned the manufacture and use of these congeners altogether, these persistent organic pollutants (POPs) continue to be detected in humans and the environment. This study investigates spatial and temporal variations of selected PBDEs in the air of the Nandamojo watershed area in Costa Rica by comparing air concentrations of PBDEs in the dry winter vs. wet summer seasons and rural vs. urban areas and also investigates the impact of anthropogenic activities on air concentration of PBDEs. This study is significant to the field, because there are no baseline studies nor are there currently any monitoring programs to assess the environmental levels of PBDEs or other POPs for this region of the Guanacaste province. Baseline information is needed to track spatial and temporal trends as well as evaluate the effectiveness of control measures employed nationally and internationally. Samples obtained from passive air sampling devices were analyzed via GC/MS for a number of congeners. PBDE-47 and -99 were found to be the congeners present in greatest concentration in air samples from the Nandamojo watershed area. Air concentrations were estimated assuming an average sampler uptake rate of 3.5 m3/day and ranged as follows: SigmaPBDE5 35.20-1549.25 pg/m3 over the entire study. The presence of PBDEs in remote and pristine environments indicates that PBDEs are now a global concern. This study suggests that the spatial and temporal distribution patterns observed are strongly related to anthropogenic activities and presence of a population similar to that observed in other studies. The presence of

  20. Extreme Air Pollution Conditions Adversely Affect Blood Pressure and Insulin Resistance: The Air Pollution and Cardiometabolic Disease Study.

    PubMed

    Brook, Robert D; Sun, Zhichao; Brook, Jeffrey R; Zhao, Xiaoyi; Ruan, Yanping; Yan, Jianhua; Mukherjee, Bhramar; Rao, Xiaoquan; Duan, Fengkui; Sun, Lixian; Liang, Ruijuan; Lian, Hui; Zhang, Shuyang; Fang, Quan; Gu, Dongfeng; Sun, Qinghua; Fan, Zhongjie; Rajagopalan, Sanjay

    2016-01-01

    Mounting evidence supports that fine particulate matter adversely affects cardiometabolic diseases particularly in susceptible individuals; however, health effects induced by the extreme concentrations within megacities in Asia are not well described. We enrolled 65 nonsmoking adults with metabolic syndrome and insulin resistance in the Beijing metropolitan area into a panel study of 4 repeated visits across 4 seasons since 2012. Daily ambient fine particulate matter and personal black carbon levels ranged from 9.0 to 552.5 µg/m(3) and 0.2 to 24.5 µg/m(3), respectively, with extreme levels observed during January 2013. Cumulative fine particulate matter exposure windows across the prior 1 to 7 days were significantly associated with systolic blood pressure elevations ranging from 2.0 (95% confidence interval, 0.3-3.7) to 2.7 (0.6-4.8) mm Hg per SD increase (67.2 µg/m(3)), whereas cumulative black carbon exposure during the previous 2 to 5 days were significantly associated with ranges in elevations in diastolic blood pressure from 1.3 (0.0-2.5) to 1.7 (0.3-3.2) mm Hg per SD increase (3.6 µg/m(3)). Both black carbon and fine particulate matter were significantly associated with worsening insulin resistance (0.18 [0.01-0.36] and 0.22 [0.04-0.39] unit increase per SD increase of personal-level black carbon and 0.18 [0.02-0.34] and 0.22 [0.08-0.36] unit increase per SD increase of ambient fine particulate matter on lag days 4 and 5). These results provide important global public health warnings that air pollution may pose a risk to cardiometabolic health even at the extremely high concentrations faced by billions of people in the developing world today. PMID:26573709

  1. The effects of outdoor air pollution on the respiratory health of Canadian children: A systematic review of epidemiological studies

    PubMed Central

    Rodriguez-Villamizar, Laura A; Magico, Adam; Osornio-Vargas, Alvaro; Rowe, Brian H

    2015-01-01

    BACKGROUND: Outdoor air pollution is a global problem with serious effects on human health, and children are considered to be highly susceptible to the effects of air pollution. OBJECTIVE: To conduct a comprehensive and updated systematic review of the literature reporting the effects of outdoor air pollution on the respiratory health of children in Canada. METHODS: Searches of four electronic databases between January 2004 and November 2014 were conducted to identify epidemiological studies evaluating the effect of exposure to outdoor air pollutants on respiratory symptoms, lung function measurements and the use of health services due to respiratory conditions in Canadian children. The selection process and quality assessment, using the Newcastle-Ottawa Scale, were conducted independently by two reviewers. RESULTS: Twenty-seven studies that were heterogeneous with regard to study design, population, respiratory outcome and air pollution exposure were identified. Overall, the included studies reported adverse effects of outdoor air pollution at concentrations that were below Canadian and United States standards. Heterogeneous effects of air pollutants were reported according to city, sex, socioeconomic status and seasonality. The present review also describes trends in research related to the effect of air pollution on Canadian children over the past 25 years. CONCLUSION: The present study reconfirms the adverse effects of outdoor air pollution on the respiratory health of children in Canada. It will help researchers, clinicians and environmental health authorities identify the available evidence of the adverse effect of outdoor air pollution, research gaps and the limitations for further research. PMID:25961280

  2. Outdoor Air Pollution and Cardiovascular Diseases in Lebanon: A Case-Control Study

    PubMed Central

    Nasser, Zeina; Salameh, Pascale; Dakik, Habib; Elias, Elias; Abou Abbas, Linda; Levêque, Alain

    2015-01-01

    Outdoor air pollution is increasingly considered as a serious threat for cardiovascular diseases (CVD). The aim of this study is to investigate the association between outdoor pollutants and cardiovascular diseases among adults in Lebanon and to examine the possible moderator effect of cigarette smoking status on this association. A multicenter case-control study was conducted between October 2011 and October 2012. Cases were hospitalized patients diagnosed with CVD by a cardiologist while the control group subjects were free of any cardiac diseases. Information on sociodemographic characteristics, tobacco consumption, self-rated global health, pollution exposure, and other risk factors was collected using a questionnaire. The results of the logistic regression revealed that living near busy highway (OR 5.04, 95% CI (4.44–12.85), P < 0.001) and close to local diesel generator (OR 4.76, 95% CI (2.07–10.91), P < 0.001) was significantly associated with CVD. The association between the CVD and exposure to outside pollutants differed by cigarette smoking status. A clear difference was noted between nonsmokers and current smokers OR 4.6, 95% CI (1.10–19.25) and OR 10.11, 95% CI (7.33–20.23), respectively. Forthcoming studies are needed to clarify the potential link between outdoor air pollution and cardiovascular diseases in Lebanon. Public health interventions must be implemented to reduce air pollution and to improve air quality. PMID:25653681

  3. Outdoor air pollution and cardiovascular diseases in Lebanon: a case-control study.

    PubMed

    Nasser, Zeina; Salameh, Pascale; Dakik, Habib; Elias, Elias; Abou Abbas, Linda; Levêque, Alain

    2015-01-01

    Outdoor air pollution is increasingly considered as a serious threat for cardiovascular diseases (CVD). The aim of this study is to investigate the association between outdoor pollutants and cardiovascular diseases among adults in Lebanon and to examine the possible moderator effect of cigarette smoking status on this association. A multicenter case-control study was conducted between October 2011 and October 2012. Cases were hospitalized patients diagnosed with CVD by a cardiologist while the control group subjects were free of any cardiac diseases. Information on sociodemographic characteristics, tobacco consumption, self-rated global health, pollution exposure, and other risk factors was collected using a questionnaire. The results of the logistic regression revealed that living near busy highway (OR 5.04, 95% CI (4.44-12.85), P < 0.001) and close to local diesel generator (OR 4.76, 95% CI (2.07-10.91), P < 0.001) was significantly associated with CVD. The association between the CVD and exposure to outside pollutants differed by cigarette smoking status. A clear difference was noted between nonsmokers and current smokers OR 4.6, 95% CI (1.10-19.25) and OR 10.11, 95% CI (7.33-20.23), respectively. Forthcoming studies are needed to clarify the potential link between outdoor air pollution and cardiovascular diseases in Lebanon. Public health interventions must be implemented to reduce air pollution and to improve air quality. PMID:25653681

  4. Numerical study on air-structure coupling dynamic characteristics of the axial fan blade

    NASA Astrophysics Data System (ADS)

    Chen, Q. G.; Xie, B.; Li, F.; Gu, W. G.

    2013-12-01

    In order to understand the dynamic characteristics of the axial-flow fan blade due to the effect of rotating stress and the action of unsteady aerodynamic forces caused by the airflow, a numerical simulation method for air-structure coupling in an axial-flow fan with fixed rear guide blades was performed. The dynamic characteristics of an axial-flow fan rotating blade were studied by using the two-way air-structure coupling method. Based on the standard k-ε turbulence model, and using weak coupling method, the preceding six orders modal parameters of the rotating blade were obtained, and the distributions of stress and strain on the rotating blade were presented. The results show that the modal frequency from the first to the sixth order is 3Hz higher than the modal frequency without considering air-structure coupling interaction; the maximum stress and the maximum strain are all occurred in the vicinity of root area of the blade no matter the air-structure coupling is considered or not, thus, the blade root is the dangerous location subjected to fatigue break; the position of maximum deformation is at the blade tip, so the vibration of the blade tip is significant. This study can provide theoretical references for the further study on the strength analysis and mechanical optimal design.

  5. Loose-coupling an air dispersion model and a geographic information system (GIS) for studying air pollution and asthma in the Bronx, New York City.

    PubMed

    Maantay, Juliana A; Tu, Jun; Maroko, Andrew R

    2009-02-01

    This study developed new procedures to loosely integrate an air dispersion model, AERMOD, and a geographic information system (GIS) package, ArcGIS, to simulate air dispersion from stationary sources in the Bronx, New York City, for five pollutants: PM(10), PM(2.5), NO(x), CO, and SO(2). Plume buffers created from the model results were used as proxies of human exposure to the pollution from the sources and they modified the commonly used fixed-distance proximity buffers by considering the realities of air dispersion. The application of the plume buffers confirmed that the higher asthma hospitalization rates were associated with the higher potential exposure to local air pollution. The air dispersion modeling exhibited advantages over proximity analysis and geostatistical methods for environmental health research. The loose integration provides a relatively simple and feasible method for health scientists to take advantage of both air dispersion modeling and GIS by avoiding the need for intensive programming and substantial GIS expertise. PMID:19241247

  6. Study of indoor radon levels in high-rise air-conditioned office buildings.

    PubMed

    Chao, C Y

    1999-12-01

    A series of measurements were conducted to study the indoor radon pollution in air-conditioned high-rise office buildings. Continuous monitoring of indoor radon levels in nine air-conditioned premises located in six office buildings in Hong Kong was conducted from August 1996 to February 1998. Each of the tests lasted for at least 48 hours. The measurement covered both day time monitoring while the air-conditioning was on and night time monitoring while the air-conditioning was off. The indoor radon level followed inversely the operation pattern of the mechanical ventilation systems in the buildings. During office hours when the mechanical ventilation was on, the indoor radon level decayed and after the mechanical ventilation was off during non-office hours, the radon level increased. The average indoor radon level during office hours on the nine premises varied from 87 Bq/m3 to 296 Bq/m3, and the indoor averaged radon levels over both day time and night time periods without mechanical ventilation were about 25 percent higher. The air infiltration rate and the radon emission characteristics from the building materials were estimated from the radon build-up curves which were observed after the mechanical ventilation was off. The radon decay curve observed after the mechanical ventilation system was turned on was used to calculate the total fresh air intake rate. Average radon emanation rates of the building materials in the six buildings varied from 0.0019 to 0.0033 Bq/m2s. It has been found that building infiltration rate accounted for about 10-30 percent of the total building ventilation rate in the buildings depending on building tightness. PMID:10633952

  7. Hybrid Air Quality Modeling Approach for use in the Hear-road Exposures to Urban air pollutant Study(NEXUS)

    EPA Science Inventory

    The paper presents a hybrid air quality modeling approach and its application in NEXUS in order to provide spatial and temporally varying exposure estimates and identification of the mobile source contribution to the total pollutant exposure. Model-based exposure metrics, associa...

  8. THE USE OF AIR QUALITY FORECASTS TO ASSESS IMPACTS OF AIR POLLUTION ON CROPS: METHODOLOGY AND CASE STUDY

    EPA Science Inventory

    It has been reported that ambient ozone (O3), either alone or in concurrence with acid rain precursors, accounts for up to 90% of U.S. crop losses resulting from exposure to all major air pollutants. Crop damage due to O3 exposure is of particular concern as...

  9. Household air pollution and lung cancer in China: a review of studies in Xuanwei.

    PubMed

    Seow, Wei Jie; Hu, Wei; Vermeulen, Roel; Hosgood Iii, H Dean; Downward, George S; Chapman, Robert S; He, Xingzhou; Bassig, Bryan A; Kim, Christopher; Wen, Cuiju; Rothman, Nathaniel; Lan, Qing

    2014-10-01

    Over half of the world's population is exposed to household air pollution from the burning of solid fuels at home. Household air pollution from solid fuel use is a leading risk factor for global disease and remains a major public health problem, especially in low- and mid-income countries. This is a particularly serious problem in China, where many people in rural areas still use coal for household heating and cooking. This review focuses on several decades of research carried out in Xuanwei County, Yunnan Province, where household coal use is a major source of household air pollution and where studies have linked household air pollution exposure to high rates of lung cancer. We conducted a series of case-control and cohort studies in Xuanwei to characterize the lung cancer risk in this population and the factors associated with it. We found lung cancer risk to vary substantially between different coal types, with a higher risk associated with smoky (i.e., bituminous) coal use compared to smokeless (i.e., anthracite) coal use. The installation of a chimney in homes resulted in a substantial reduction in lung cancer incidence and mortality. Overall, our research underscores the need among existing coal users to improve ventilation, use the least toxic fuel, and eventually move toward the use of cleaner fuels, such as gas and electricity. PMID:25223911

  10. Household air pollution and lung cancer in China: a review of studies in Xuanwei

    PubMed Central

    Seow, Wei Jie; Hu, Wei; Vermeulen, Roel; Hosgood, H. Dean; Downward, George S.; Chapman, Robert S.; He, Xingzhou; Bassig, Bryan A.; Kim, Christopher; Wen, Cuiju; Rothman, Nathaniel; Lan, Qing

    2014-01-01

    Over half of the world's population is exposed to household air pollution from the burning of solid fuels at home. Household air pollution from solid fuel use is a leading risk factor for global disease and remains a major public health problem, especially in low- and mid-income countries. This is a particularly serious problem in China, where many people in rural areas still use coal for household heating and cooking. This review focuses on several decades of research carried out in Xuanwei County, Yunnan Province, where household coal use is a major source of household air pollution and where studies have linked household air pollution exposure to high rates of lung cancer. We conducted a series of case-control and cohort studies in Xuanwei to characterize the lung cancer risk in this population and the factors associated with it. We found lung cancer risk to vary substantially between different coal types, with a higher risk associated with smoky (i.e., bituminous) coal use compared to smokeless (i.e., anthracite) coal use. The installation of a chimney in homes resulted in a substantial reduction in lung cancer incidence and mortality. Overall, our research underscores the need among existing coal users to improve ventilation, use the least toxic fuel, and eventually move toward the use of cleaner fuels, such as gas and electricity. PMID:25223911

  11. A pilot study of indoor air quality in screen golf courses.

    PubMed

    Goung, Sun-Ju Nam; Yang, Jinho; Kim, Yoon Shin; Lee, Cheol Min

    2015-05-01

    The aims of this study were to provide basic data for determining policies on air quality for multi-user facilities, including the legal enrollment of the indoor air quality regulation as designated by the Ministry of Environment, and to establish control plans. To this end, concentrations of ten pollutants (PM10, carbon monoxide (CO), carbon dioxide (CO2), nitrogen dioxide (NO2), formaldehyde (HCHO), total volatile organic compounds (TVOCs), radon (Rn), oxone (O3), total bacteria counts (TBC), and asbestos) in addition to nicotine, a smoking index material used to determine the impact of smoking on the air quality, were investigated in indoor game rooms and lobbies of 64 screen golf courses. The average concentration of none of the ten pollutants in the game rooms and lobbies of screen golf courses was found to exceed the limit set by the law. There were, however, pollutant concentrations exceeding limits in some screen golf courses, in order to establish a control plan for the indoor air quality of screen golf courses, a study on the emission sources of each pollutant was conducted. The major emission sources were found to be facility users' activities such as smoking and the use of combustion appliances, building materials, and finishing materials. PMID:25510613

  12. Study on the gas-explosion soot remover and its application to powerplant air-preheaters

    SciTech Connect

    Fan, W.; He, W.; Sun, W.; Wu, C.

    1997-12-31

    Chinese power plants burn a large amount of high-ash coal without washing, so the fouling problems are often serious, especially in the rear portion of the flue gas passage. For instance, the rotary air preheaters are often fouled up so badly that the furnace has to be stopped for mechanical cleaning of the gas passages. The ash deposits cause lowering of heat transfer capacity and a rise in flow resistance, resulting in reduction of output and boiler efficiency. Ordinary steam jet blowers and ultra-sonic or infra-sonic devices are not too effective against the hard deposits. The gas-explosion soot remover has been used in some Ukrainian power plants. The authors have developed similar apparatus and applied it to the air preheaters of 200--300 MWe power plants with good results. The combustion process in such devices has been studied in the laboratory. The device consists of a combustion chamber for premixed fuel and air and output tube with openings for the gas jet pulse. The pressure rise and turbulent flame propagation in the prototype and a scaled-down model have been measured with various fuel/air ratios, outlet area ratios and turbulence-generating setups as experimental parameters. It was found that all these parameters had important effects on the pressure pulse shape. This paper mainly gives results of the laboratory study, but also briefly describes the results of practical application.

  13. Modeling study on the factors affecting regional air quality during the Beijing 2008 Olympic Games

    NASA Astrophysics Data System (ADS)

    Wei, C.; Carmichael, G. R.; Adhikary, B.; D'Allura, A.; Cheng, Y.; Tang, Y.; Zhang, Q.; Streets, D. G.; Pierce, R.; Al-Saadi, J. A.; Flowers, B. A.; Dubey, M. K.; Krotkov, N. A.; Pickering, K. E.; Ramanathan, V.

    2009-12-01

    Chinese government took measures to control emissions of pollutants before and during the Beijing 2008 Olympic Games in order to get better air quality for the event. A 3-dimensional regional chemical transport model, the University of Iowa’s Sulfur Transport and dEposition Model (STEM), is used to evaluate the effects of emission reductions on regional air quality by this event. The emission inventories with and without the consideration of emission reductions are used in case studies. Impacts of the emissions from different regions and sectors on Beijing and regional air quality are discussed in this study. Meteorological factor on the improvement of air quality during this event is also assessed by using the meteorological conditions from different years to drive the model. Model performance is evaluated by comparing the modeled trace gases and aerosols with the surface measurements from Beijing, the field observations from the Cheju ABC Plume-Asian Monsoon Experiment (CAPMEX) during this summer, and satellite data from NASA.

  14. Experimental feasibility study of radial injection cooling of three-pad radial air foil bearings

    NASA Astrophysics Data System (ADS)

    Shrestha, Suman K.

    Air foil bearings use ambient air as a lubricant allowing environment-friendly operation. When they are designed, installed, and operated properly, air foil bearings are very cost effective and reliable solution to oil-free turbomachinery. Because air is used as a lubricant, there are no mechanical contacts between the rotor and bearings and when the rotor is lifted off the bearing, near frictionless quiet operation is possible. However, due to the high speed operation, thermal management is one of the very important design factors to consider. Most widely accepted practice of the cooling method is axial cooling, which uses cooling air passing through heat exchange channels formed underneath the bearing pad. Advantage is no hardware modification to implement the axial cooling because elastic foundation structure of foil bearing serves as a heat exchange channels. Disadvantage is axial temperature gradient on the journal shaft and bearing. This work presents the experimental feasibility study of alternative cooling method using radial injection of cooling air directly on the rotor shaft. The injection speeds, number of nozzles, location of nozzles, total air flow rate are important factors determining the effectiveness of the radial injection cooling method. Effectiveness of the radial injection cooling was compared with traditional axial cooling method. A previously constructed test rig was modified to accommodate a new motor with higher torque and radial injection cooling. The radial injection cooling utilizes the direct air injection to the inlet region of air film from three locations at 120° from one another with each location having three axially separated holes. In axial cooling, a certain axial pressure gradient is applied across the bearing to induce axial cooling air through bump foil channels. For the comparison of the two methods, the same amount of cooling air flow rate was used for both axial cooling and radial injection. Cooling air flow rate was

  15. Exploring the concept of compressed air energy storage (CAES) in lined rock caverns at shallow depth: A modeling study of air tightness and energy balance

    SciTech Connect

    Kim, H.-M.; Rutqvist, J.; Ryu, D.-W.; Choi, B.-H.; Sunwoo, C.; Song, W.-K.

    2011-07-15

    This paper presents a numerical modeling study of coupled thermodynamic, multiphase fluid flow and heat transport associated with underground compressed air energy storage (CAES) in lined rock caverns. Specifically, we explored the concept of using concrete lined caverns at a relatively shallow depth for which constructing and operational costs may be reduced if air tightness and stability can be assured. Our analysis showed that the key parameter to assure long-term air tightness in such a system was the permeability of both the concrete lining and the surrounding rock. The analysis also indicated that a concrete lining with a permeability of less than 1×10{sup -18} m{sup 2} would result in an acceptable air leakage rate of less than 1%, with the operational pressure range between 5 and 8 MPa at a depth of 100 m. It was further noted that capillary retention properties and the initial liquid saturation of the lining were very important. Indeed, air leakage could be effectively prevented when the air-entry pressure of the concrete lining is higher than the operational air pressure and when the lining is kept moist at a relatively high liquid saturation. Our subsequent energy-balance analysis demonstrated that the energy loss for a daily compression and decompression cycle is governed by the air-pressure loss, as well as heat loss by conduction to the concrete liner and surrounding rock. For a sufficiently tight system, i.e., for a concrete permeability off less than 1×10{sup -18} m{sup 2}, heat loss by heat conduction tends to become proportionally more important. However, the energy loss by heat conduction can be minimized by keeping the air-injection temperature of compressed air closer to the ambient temperature of the underground storage cavern. In such a case, almost all the heat loss during compression is gained back during subsequent decompression. Finally, our numerical simulation study showed that CAES in shallow rock caverns is feasible from a leakage

  16. Consistent pattern of elevated symptoms in air-conditioned office buildings: a reanalysis of epidemiologic studies.

    PubMed Central

    Mendell, M J; Smith, A H

    1990-01-01

    Published studies of the relation between type of building ventilation system and work-related symptom prevalence in office workers have been contradictory. A reanalysis was performed of six studies meeting specific eligibility criteria, combining published data with unpublished information obtained from study authors. Five eligible studies were from the United Kingdom, and one was from Denmark. Standardized categories of building ventilation type were created to allow comparison of effects across studies. Within each study, prevalence odds ratios (PORs) were calculated for symptoms in each ventilation category relative to a baseline category of naturally ventilated buildings. Air-conditioned buildings were consistently associated with increased prevalence of work-related headache (POR = 1.3-3.1), lethargy (POR = 1.4-5.1), and upper respiratory/mucus membrane symptoms (POR = 1.3-4.8). Humidification was not a necessary factor for the higher symptom prevalence associated with air-conditioning. Mechanical ventilation without air-conditioning was not associated with higher symptom prevalence. The consistent associations found between type of building ventilation and reported symptom prevalence have potentially important public health and economic implications. PMID:2400029

  17. Traffic-Related Air Pollution and Dementia Incidence in Northern Sweden: A Longitudinal Study

    PubMed Central

    Oudin, Anna; Forsberg, Bertil; Adolfsson, Annelie Nordin; Lind, Nina; Modig, Lars; Nordin, Maria; Nordin, Steven; Adolfsson, Rolf; Nilsson, Lars-Göran

    2015-01-01

    Background Exposure to ambient air pollution is suspected to cause cognitive effects, but a prospective cohort is needed to study exposure to air pollution at the home address and the incidence of dementia. Objectives We aimed to assess the association between long-term exposure to traffic-related air pollution and dementia incidence in a major city in northern Sweden. Methods Data on dementia incidence over a 15-year period were obtained from the longitudinal Betula study. Traffic air pollution exposure was assessed using a land-use regression model with a spatial resolution of 50 m × 50 m. Annual mean nitrogen oxide levels at the residential address of the participants at baseline (the start of follow-up) were used as markers for long-term exposure to air pollution. Results Out of 1,806 participants at baseline, 191 were diagnosed with Alzheimer’s disease during follow-up, and 111 were diagnosed with vascular dementia. Participants in the group with the highest exposure were more likely than those in the group with the lowest exposure to be diagnosed with dementia (Alzheimer’s disease or vascular dementia), with a hazard ratio (HR) of 1.43 (95% CI: 0.998, 2.05 for the highest vs. the lowest quartile). The estimates were similar for Alzheimer’s disease (HR 1.38) and vascular dementia (HR 1.47). The HR for dementia associated with the third quartile versus the lowest quartile was 1.48 (95% CI: 1.03, 2.11). A subanalysis that excluded a younger sample that had been retested after only 5 years of follow-up suggested stronger associations with exposure than were present in the full cohort (HR = 1.71; 95% CI: 1.08, 2.73 for the highest vs. the lowest quartile). Conclusions If the associations we observed are causal, then air pollution from traffic might be an important risk factor for vascular dementia and Alzheimer’s disease. Citation Oudin A, Forsberg B, Nordin Adolfsson A, Lind N, Modig L, Nordin M, Nordin S, Adolfsson R, Nilsson LG. 2016. Traffic

  18. The Near-Road Exposures and Effects of Urban Air Pollutants Study (NEXUS): Study design and methods

    PubMed Central

    Vette, Alan; Burke, Janet; Norris, Gary; Landis, Matthew; Batterman, Stuart; Breen, Michael; Isakov, Vlad; Lewis, Toby; Gilmour, M. Ian; Kamal, Ali; Hammond, Davyda; Vedantham, Ram; Bereznicki, Sarah; Tian, Nancy; Croghan, Carry

    2014-01-01

    The Near-Road Exposures and Effects of Urban Air Pollutants Study (NEXUS) was designed to examine the relationship between near-roadway exposures to air pollutants and respiratory outcomes in a cohort of asthmatic children who live close to major roadways in Detroit, Michigan USA. From September 2010 to December 2012 a total of 139 children with asthma, ages 6–14, were enrolled in the study on the basis of the proximity of their home to major roadways that carried different amounts of diesel traffic. The goal of the study was to investigate the effects of traffic-associated exposures on adverse respiratory outcomes, biomolecular markers of inflammatory and oxidative stress, and how these exposures affect the frequency and severity of respiratory viral infections in a cohort of children with asthma. An integrated measurement and modeling approach was used to quantitatively estimate the contribution of traffic sources to near-roadway air pollution and evaluate predictive models for assessing the impact of near-roadway pollution on children’s exposures. Two intensive field campaigns were conducted in Fall 2010 and Spring 2011 to measure a suite of air pollutants including PM2.5 mass and composition, oxides of nitrogen (NO and NO2), carbon monoxide, and black carbon indoors and outdoors of 25 participants’ homes, at two area schools, and along a spatial transect adjacent to I-96, a major highway in Detroit. These data were used to evaluate and refine models to estimate air quality and exposures for each child on a daily basis for the health analyses. The study design and methods are described, and selected measurement results from the Fall 2010 field intensive are presented to illustrate the design and successful implementation of the study. These data provide evidence of roadway impacts and exposure variability between study participants that will be further explored for associations with the health measures. PMID:23149275

  19. Study of Stable Cathodes and Electrolytes for High Specific Density Lithium-Air Battery

    NASA Technical Reports Server (NTRS)

    Hernandez-Lugo, Dionne M.; Wu, James; Bennett, William; Ming, Yu; Zhu, Yu

    2015-01-01

    Future NASA missions require high specific energy battery technologies, greater than 400 Wh/kg. Current NASA missions are using "state-of-the-art" (SOA) Li-ion batteries (LIB), which consist of a metal oxide cathode, a graphite anode and an organic electrolyte. NASA Glenn Research Center is currently studying the physical and electrochemical properties of the anode-electrolyte interface for ionic liquid based Li-air batteries. The voltage-time profiles for Pyr13FSI and Pyr14TFSI ionic liquids electrolytes studies on symmetric cells show low over-potentials and no dendritic lithium morphology. Cyclic voltammetry measurements indicate that these ionic liquids have a wide electrochemical window. As a continuation of this work, sp2 carbon cathode and these low flammability electrolytes were paired and the physical and electrochemical properties were studied in a Li-air battery system under an oxygen environment.

  20. Acute exposure to Buenos Aires air particles (UAP-BA) induces local and systemic inflammatory response in middle-aged mice: A time course study.

    PubMed

    Orona, Nadia S; Ferraro, Sebastián A; Astort, Francisco; Morales, Celina; Brites, Fernando; Boero, Laura; Tiscornia, Gisela; Maglione, Guillermo A; Saldiva, Paulo H N; Yakisich, Sebastian; Tasat, Deborah R

    2016-01-01

    Exposure to air particulate matter (PM) is associated with increased cardiovascular morbimortality. However, PM doesn't affect equally to all people, being the old cohort the most susceptible and studied. We hypothesized that another specific life phase, the middle-aged subpopulation, may be negatively affected. Therefore, the aim of this study was to analyze in vivo the acute biological impact of two environmental particles, Urban Air Particles from Buenos Aires and Residual Oil Fly Ash, on the cardiorespiratory system of middle-aged mice, evaluating oxidative metabolism and inflammation. Both PM provoked a local and systemic inflammatory response, leading to a reduced alveolar area in the lung, an epicard inflammation in the heart, an increment of IL-6, and a reduction on PON 1 activity in serum of middle-aged animals. The positive correlation of local parameters with systemic markers of oxidative stress and inflammation could be responsible for associations of cardiovascular morbimortality in this subpopulation. PMID:26255684

  1. Rodent models of cardiopulmonary disease: their potential applicability in studies of air pollutant susceptibility.

    PubMed Central

    Kodavanti, U P; Costa, D L; Bromberg, P A

    1998-01-01

    The mechanisms by which increased mortality and morbidity occur in individuals with preexistent cardiopulmonary disease following acute episodes of air pollution are unknown. Studies involving air pollution effects on animal models of human cardiopulmonary diseases are both infrequent and difficult to interpret. Such models are, however, extensively used in studies of disease pathogenesis. Primarily they comprise those developed by genetic, pharmacologic, or surgical manipulations of the cardiopulmonary system. This review attempts a comprehensive description of rodent cardiopulmonary disease models in the context of their potential application to susceptibility studies of air pollutants regardless of whether the models have been previously used for such studies. The pulmonary disease models include bronchitis, emphysema, asthma/allergy, chronic obstructive pulmonary disease, interstitial fibrosis, and infection. The models of systemic hypertension and congestive heart failure include: those derived by genetics (spontaneously hypertensive, Dahl S. renin transgenic, and other rodent models); congestive heart failure models derived by surgical manipulations; viral myocarditis; and cardiomyopathy induced by adriamycin. The characteristic pathogenic features critical to understanding the susceptibility to inhaled toxicants are described. It is anticipated that this review will provide a ready reference for the selection of appropriate rodent models of cardiopulmonary diseases and identify not only their pathobiologic similarities and/or differences to humans but also their potential usefulness in susceptibility studies. Images Figure 2 PMID:9539009

  2. Comparison of residential geocoding methods in population-based study of air quality and birth defects.

    PubMed

    Gilboa, Suzanne M; Mendola, Pauline; Olshan, Andrew F; Harness, Catherine; Loomis, Dana; Langlois, Peter H; Savitz, David A; Herring, Amy H

    2006-06-01

    Our population-based case-control study of air quality and birth defects in Texas relied on the geocoding of maternal residence from vital records for the assignment of air pollution exposures during early pregnancy. We attempted to geocode the maternal addresses for 5,338 birth defect cases and 4,574 frequency-matched controls using an automated procedure with standard matching criteria in ArcGIS 8.2 and 8.3. Initially, we matched 7,266 observations (73%). To increase the proportion of successful matches, we used an interactive procedure for the 2,646 addresses that were initially not geocoded by the software. This yielded an additional 985 matches (37%). Using the same 2,646 initially unmatched addresses, we compared the results of this interactive procedure to those of an automated procedure using lower standards. The automated procedure with lower standards yielded more matches (n=1,559, 59%) but with questionable accuracy. We included the interactively geocoded observations in our final data set. Their inclusion did not affect the estimates of air pollution exposure but increased our statistical power to detect associations between air quality and risk of selected birth defects. The geocoded and not geocoded populations differed in the distribution of Latino ethnicity (51% vs 59%) and ethnicity was independently associated with air pollution exposures (P<0.05). Geocoding status also appeared to modify the association between ethnicity and risk of birth defects; Latina women appeared to have a slightly lower risk of birth defects than non-Latina women in the geocoded population and to have a slightly higher risk in the not geocoded population. Incomplete geocoding may have resulted in a selection bias because of the under-representation of Latinas in our study population. PMID:16483563

  3. Air pollution and gene-specific methylation in the Normative Aging Study

    PubMed Central

    Bind, Marie-Abele; Lepeule, Johanna; Zanobetti, Antonella; Gasparrini, Antonio; Baccarelli, Andrea A; Coull, Brent A; Tarantini, Letizia; Vokonas, Pantel S; Koutrakis, Petros; Schwartz, Joel

    2014-01-01

    The mechanisms by which air pollution has multiple systemic effects in humans are not fully elucidated, but appear to include inflammation and thrombosis. This study examines whether concentrations of ozone and components of fine particle mass are associated with changes in methylation on tissue factor (F3), interferon gamma (IFN-γ), interleukin 6 (IL-6), toll-like receptor 2 (TLR-2), and intercellular adhesion molecule 1 (ICAM-1). We investigated associations between air pollution exposure and gene-specific methylation in 777 elderly men participating in the Normative Aging Study (1999–2009). We repeatedly measured methylation at multiple CpG sites within each gene’s promoter region and calculated the mean of the position-specific measurements. We examined intermediate-term associations between primary and secondary air pollutants and mean methylation and methylation at each position with distributed-lag models. Increase in air pollutants concentrations was significantly associated with F3, ICAM-1, and TLR-2 hypomethylation, and IFN-γ and IL-6 hypermethylation. An interquartile range increase in black carbon concentration averaged over the four weeks prior to assessment was associated with a 12% reduction in F3 methylation (95% CI: -17% to -6%). For some genes, the change in methylation was observed only at specific locations within the promoter region. DNA methylation may reflect biological impact of air pollution. We found some significant mediated effects of black carbon on fibrinogen through a decrease in F3 methylation, and of sulfate and ozone on ICAM-1 protein through a decrease in ICAM-1 methylation. PMID:24385016

  4. Laboratory study of asthmatic volunteers exposed to nitrogen dioxide and to ambient air pollution

    SciTech Connect

    Avol, E.L.; Linn, W.S.; Peng, R.C.; Valencia, G.; Little, D.; Hackney, J.D.

    1988-04-01

    Adult volunteers with moderate to severe asthma (N = 59) underwent dose-response studies to assess their reactivity to nitrogen dioxide (NO/sub 2/) in otherwise clean air. Exposure concentrations were 0.0 (control), 0.3 and 0.6 ppm. A subgroup (N = 36) also underwent exposures to Los Angeles area ambient air at times when NO/sub 2/ pollution was expected. Concentrations of NO/sub 2/ during ambient exposures were 0.086 +/- 0.024 ppm (mean +/- s.d.). All exposures took place in a movable chamber/laboratory facility. Each study lasted 2 hr, with alternating 10 min periods of exercise (mean ventilation rate 40 L/min) and rest. Lung function was measured prior to exposure and after 10 min, 1 hr and 2 hr of exposure. Symptoms were recorded prior to exposure, during exposure and for 1 week afterward. In some subjects bronchial reactivity to cold air was measured 1 hr after the end of exposure and again 24 hr later. Different exposure conditions were presented in randomized order, 1 week apart. No pollutant exposure produced statistically significant changes in lung function, symptoms, or bronchial reactivity, relative to clean air. Ambient air exposures produced the largest (still nonsignificant) mean changes in some lung function tests. Given the physiological and atmospheric variability, negative statistical results do not rule out a small unfavorable effect of ambient pollution on lung function. If any such effect occurred, it was not likely caused by NO/sub 2/. Statistical results remained negative when the analysis was restricted to the 20 subjects with most severe lung dysfunction. In conclusion at least in the Los Angeles area, sensitivity to ambient concentrations of NO/sub 2/ is not common, even among adult asthmatics with moderate to severe disease.

  5. Numerical Study on a Detailed Air Flows in an Urban Area Using a CFD model

    NASA Astrophysics Data System (ADS)

    Kwon, A.

    2014-12-01

    In this study, detailed air flows in an urban area were analyzed using a computational fluid dynamics (CFD) model. For this model buildings used as the surface boundary in the model were constructed using Los Angeles Region Imagery Acquisition Consortium 2 Geographic Information System (LARIAC2 GIS) data. Three target areas centered at the cross roads of Broadway & 7th St., Olive & 12th St., and Wilshire blvd. & Carondelet, Los Angeles, California were considered. The size of each numerical domain is 400 m, 400 m, and 200 m in the x‒, y‒, and z‒directions, respectively. The grid sizes in the x‒, y‒, and z‒directions are 2 m, 2 m, and 2 m, respectively. Based on the inflow wind data provided by California Air Resources Board, detailed flow characteristics were investigated for each target area. Descending air flow were developed at the leeward area of tall building and ascending air current were occurred on the windward area of tall building. Vertically rotating vortices were formed in spaces between buildings, so-called, street canyons and horizontally rotating vortices appeared near cross roads. When flows came into narrow street canyon from wide street canyon, channeling effects appeared and flow speed increased for satisfying mass continuity.

  6. Effect of Air-Polishing on Titanium Surfaces, Biofilm Removal, and Biocompatibility: A Pilot Study

    PubMed Central

    Bennani, Vincent; Hwang, Linda; Tawse-Smith, Andrew; Dias, George J.; Cannon, Richard D.

    2015-01-01

    Purpose. The aims of this in vitro study were to evaluate morphological changes induced by glycine powder air-polishing on titanium surfaces, biofilm removal, and biocompatibility. Material and Methods. Titanium grade IV discs were allocated into two groups: (1) discs without biofilm and (2) discs for Streptococcus mutans biofilm formation. Discs in each group were further subdivided into (a) no treatment and (b) air-polishing treatment with glycine powder. Discs were characterized by scanning electron microscopy (SEM), electron-dispersive spectroscopy (EDS), and confocal microscopy. Bacterial biofilms were quantified using a crystal violet dye-binding assay. Biocompatibility was evaluated by measuring the coverage and viability of L929 fibroblast cells cultured on the discs. Results. Air-polishing increased the roughness of treated discs (P < 0.05). EDS analysis did not show significant differences in the chemical composition of treated and nontreated discs. The amount of residual biofilm on treated discs was 8.6-fold lower than untreated controls (P < 0.05). Coverage of treated discs by fibroblasts was half that of untreated discs (P < 0.05) although both groups had the same cell viability. Conclusions. Air-polishing removed a significant amount of biofilm from titanium surfaces. The “polishing” was accompanied by increased surface roughness, but there were no changes in chemical and elemental compositions, nor the biocompatibility. PMID:26881198

  7. Study on an Efficient Dehumidifying Air-conditioning System utilizing Phase Change of Intermediate Pressure Refrigerant

    NASA Astrophysics Data System (ADS)

    Maeda, Kensaku; Inaba, Hideo

    The present study has proven a new dehumidifying system that aimed to reduce the sensible heat factor(SHF) of cooling process without using additional heat to relieve the internationally indicated conflict between energy saving and dehumidification necessary for keeping adequate indoor air quality (IAQ). In this system, we used intermediate pressure refrigerant in a vapor compression refrigerating cycle as heat transfer medium of a characteristic heat exchanger to precool the process air entering into an evaporator as well as to reheat the process air leaving from the evaporator. By this system, the present results achieved higher moisture removal and consequently higher efficiency of dehumidifying process. In addition to this fact, since this system has capability of integration into air-conditioning apparatus(HVAC system), it will be able to work for wide range of cooling load by variable SHF function. In the present paper, technical information, experimental results, and simulation results which assumed to apply this system into HVAC system are reported.

  8. Ambient particulate matter air pollution in Mpererwe District, Kampala, Uganda: a pilot study.

    PubMed

    Schwander, Stephan; Okello, Clement D; Freers, Juergen; Chow, Judith C; Watson, John G; Corry, Melody; Meng, Qingyu

    2014-01-01

    Air quality in Kampala, the capital of Uganda, has deteriorated significantly in the past two decades. We made spot measurements in Mpererwe district for airborne particulate matter PM2.5 (fine particles) and coarse particles. PM was collected on Teflon-membrane filters and analyzed for mass, 51 elements, 3 anions, and 5 cations. Both fine and coarse particle concentrations were above 100 µg/m(3) in all the samples collected. Markers for crustal/soil (e.g., Si and Al) were the most abundant in the PM2.5 fraction, followed by primary combustion products from biomass burning and incinerator emissions (e.g., K and Cl). Over 90% of the measured PM2.5 mass can be explained by crustal species (41% and 59%) and carbonaceous aerosol (33%-55%). Crustal elements dominated the coarse particles collected from Kampala. The results of this pilot study are indicative of unhealthy air and suggest that exposure to ambient air in Kampala may increase the burden of environmentally induced cardiovascular, metabolic, and respiratory diseases including infections. Greater awareness and more extensive research are required to confirm our findings, to identify personal exposure and pollution sources, and to develop air quality management plans and policies to protect public health. PMID:24693293

  9. An experimental study on the airlift pump with air jet nozzle and booster pump.

    PubMed

    Cho, Nam-Cheol; Hwang, In-Ju; Lee, Chae-Moon; Park, Jung-Won

    2009-01-01

    The experiments for high head airlifting performance with vertical tube were examined for wastewater treatment. Comparing with the centrifugal pump and other pumps, the airlift pump has some problems and limited applications. However, an advantage of an airlift pump is in its geometrical simplicity, not having any moving parts, so it is suitable in lifting fluids including tiny pieces of metal or grit. In this study, for the purpose of high lifting head, an air jet nozzle was used. We have performed experimentally according to various characteristics of the airlift pump system such as the change of submerged depth, lifting head of liquid-air mixture (total head) and air flow rate. This work has verified through experiments that airlift pump shows lifting ability for 3 m (Sr = 0.3) in comparison with conventional height, 2 m (Sr = 0.4). Also, we suggested that the new airlift pump system with the air booster pump be used to improve the higher lifting head performance. PMID:25084423

  10. Product lifetime, energy efficiency and climate change: A case study of air conditioners in Japan.

    PubMed

    Nishijima, Daisuke

    2016-10-01

    This study proposed a modelling technique for estimating life-cycle CO2 emissions of durable goods by considering changes in product lifetime and energy efficiency. The stock and flow of durable goods was modelled by Weibull lifetime distributions and the trend in annual energy efficiency (i.e., annual electricity consumption) of an "average" durable good was formulated as a reverse logistic curve including a technologically critical value (i.e., limit energy efficiency) with respect to time. I found that when the average product lifetime is reduced, there is a trade-off between the reduction in emissions during product use (use phase), due to the additional purchases of new, more energy-efficient air conditioners, and the increase in emissions arising from the additional production of new air conditioners stimulated by the reduction of the average product lifetime. A scenario analysis focused on residential air conditioners in Japan during 1972-2013 showed that for a reduction of average lifetime of 1 year, if the air conditioner energy efficiency limit can be improved by 1.4% from the estimated current efficiency level, then CO2 emissions can be reduced by approximately the same amount as for an extension of average product lifetime of 1 year. PMID:27423771

  11. Using global aerosol models and satellite data for air quality studies: Challenges and data needs

    NASA Technical Reports Server (NTRS)

    Chin, Mian

    2006-01-01

    Aerosol particles, also known as PM2.5 (particle diameter less than 2.5 pm) and PM10 (particle diameter less than 10 pm), are one of the key atmospheric components that determines air quality. Yet, air quality forecasts for PM are still in their infancy and remain a challenging task. It is difficult to simply relate PM levels to local meteorological conditions, and large uncertainties exist in regional air quality model emission inventories and initial and boundary conditions. Especially challenging are periods when a significant amount of aerosol comes from outside the regional modeling domain through long-range transport. In the past few years, NASA has launched several satellites with global aerosol measurement capabilities, providing large-scale chemical weather pictures. NASA has also supported development of global models which simulate atmospheric transport and transformation processes of important atmospheric gas and aerosol species. I will present the current modeling and satellite capabilities for PM2.5 studies, the possibilities and challenges in using satellite data for PM2.5 forecasts, and the needs of future remote sensing data for improving air quality monitoring and modeling.

  12. Air Pollutant Characterization in Tula Industrial Corridor, Central Mexico, during the MILAGRO Study

    PubMed Central

    Sosa, G.; Vega, E.; González-Avalos, E.; Mora, V.; López-Veneroni, D.

    2013-01-01

    Pollutant emissions and their contribution to local and regional air quality at the industrial area of Tula were studied during a four-week period as part of the MILAGRO initiative. A recurrent shallow stable layer was observed in the morning favoring air pollutants accumulation in the lower 100 m atmospheric layer. In the afternoon the mixing layer height reached 3000 m, along with a featuring low level jet which was responsible of transporting air pollutants at regional scales. Average PM10 at Jasso (JAS) and Tepeji (TEP) was 75.1 and 36.8 μg/m3, respectively while average PM2.5 was 31.0 and 25.7 μg/m3. JAS was highly impacted by local limestone dust, while TEP was a receptor of major sources of combustion emissions with 70% of the PM10 constituted by PM2.5. Average hourly aerosol light absorption was 22 Mm−1, while aerosol scattering (76 Mm−1) was higher compared to a rural site but much lower than at Mexico City. δ13C values in the epiphyte Tillandsia recurvata show that the emission plume directly affects the SW sector of Mezquital Valley and is then constrained by a mountain range preventing its dispersion. Air pollutants may exacerbate acute and chronic adverse health effects in this region. PMID:23484131

  13. Air pollutant characterization in Tula industrial corridor, Central Mexico, during the MILAGRO study.

    PubMed

    Sosa, G; Vega, E; González-Avalos, E; Mora, V; López-Veneroni, D

    2013-01-01

    Pollutant emissions and their contribution to local and regional air quality at the industrial area of Tula were studied during a four-week period as part of the MILAGRO initiative. A recurrent shallow stable layer was observed in the morning favoring air pollutants accumulation in the lower 100 m atmospheric layer. In the afternoon the mixing layer height reached 3000 m, along with a featuring low level jet which was responsible of transporting air pollutants at regional scales. Average PM10 at Jasso (JAS) and Tepeji (TEP) was 75.1 and 36.8 μ g/m(3), respectively while average PM2.5 was 31.0 and 25.7 μ g/m(3). JAS was highly impacted by local limestone dust, while TEP was a receptor of major sources of combustion emissions with 70% of the PM10 constituted by PM2.5. Average hourly aerosol light absorption was 22 Mm(-1), while aerosol scattering (76 Mm(-1)) was higher compared to a rural site but much lower than at Mexico City. δ(13)C values in the epiphyte Tillandsia recurvata show that the emission plume directly affects the SW sector of Mezquital Valley and is then constrained by a mountain range preventing its dispersion. Air pollutants may exacerbate acute and chronic adverse health effects in this region. PMID:23484131

  14. Effect of green roofs on air temperature; measurement study of well-watered and dry conditions

    NASA Astrophysics Data System (ADS)

    Solcerova, Anna; van de Ven, Frans; Wang, Mengyu; van de Giesen, Nick

    2016-04-01

    Rapid urbanization and increasing number and duration of heat waves poses a need for understanding urban climate and ways to mitigate extremely high temperatures. One of repeatedly suggested and often investigated methods to moderate the so called urban heat island are green roofs. This study investigates several extensive green roofs in Utrecht (NL) and their effect on air temperature right above the roof surface. Air temperature was measured 15 and 30 cm above the roof surface and also in the substrate. We show that under normal condition is air above green roof, compared to white gravel roof, colder at night and warmer during day. This suggest that green roofs might help decrease air temperatures at night, when the urban heat island is strongest, but possibly contribute to high temperatures during daytime. We also measured situation when the green roofs wilted and dried out. Under such conditions green roof exhibits more similar behavior to conventional white gravel roof. Interestingly, pattern of soil temperature remains almost the same for both dry and well-prospering green roof, colder during day and warmer at night. As such, green roof works as a buffer of diurnal temperature changes.

  15. Megacity and Air Pollution in the Eastern Mediterranean: Istanbul Case Study

    NASA Astrophysics Data System (ADS)

    Unal, Alper; Kindap, Tayfun; Im, Ulas; Markakis, Kostas; Mihalopoulos, Nikos; Gerasopoulos, Evangelos; Kocak, Mustafa; Mangir, Nizamettin; Kubilay, Nilgun; Kanakidou, Maria

    2010-05-01

    Turkey, with a population of 75 million, is located at the confluence of Europe and Asia. Istanbul is at the hearth of Turkey's fast economic growth. The city has an annual growth of 3.7% and, according to a study conducted by OECD, is ranked 12th among 45 OECD metro-regions. Istanbul generates 27% of Turkey's Gross Domestic Product (GDP); 40% of tax revenues; and 38% of total industrial output (OECD, 2008). As a result, Istanbul is facing a variety of challenging environmental problems affecting more than 15 million people. Observations show that the number of days exceeding the 24-hour limit value of 50 μgm-3 reached 157 in 2008, with a significant increase from previous years. The city is also a hot spot of pollutant emissions for the surrounding Eastern Mediterranean area. As part of the CityZEN project, in order to quantify the contribution of this megacity as a source of air pollution in the Eastern Mediterranean, a climatological trajectory analysis using a regional climate model output (RegCM3) and a high resolution regional modeling study were performed using the Models-3 WRF meteorological and CMAQ air quality models. Trajectory approach was used to identify the effects of Istanbul emissions on other cities in regional scale. A 30-year (1961-1990) period RegCM3 simulations were used to get a meaningful evaluation. The trajectories were computed according to a method described by Pettersen (1956) as a forward trajectory approach in a 27-km grid resolution. An air parcel was released once every 6h and a total of 42,368 air parcels (trajectories) were released during these 30 years. Long-term meteorological observations in Istanbul show northeasterly and southwesterly prevailing winds over the city. According to these prevailing winds, the distributions of trajectories were mainly observed from the north and south directions of the city. In order to run an air quality model, anthropogenic emission inventory was compiled from a number of different sources

  16. Testing flow-through air samplers for use in near-field vapour drift studies by measuring pyrimethanil in air after spraying.

    PubMed

    Geoghegan, Trudyanne S; Hageman, Kimberly J; Hewitt, Andrew J

    2014-03-01

    Pesticide volatilisation and subsequent vapour drift reduce a pesticide's efficiency and contribute to environmental contamination. High-volume air samplers (HVSs) are often used to measure pesticide concentrations in air but these samplers are expensive to purchase and require network electricity, limiting the number and type of sites where they can be deployed. The flow-through sampler (FTS) presents an opportunity to overcome these limitations. The FTS is a wind-driven passive sampler that has been developed to quantify organic contaminants in remote ecosystems. FTSs differ from other passive samplers in that they turn into the wind and use the wind to draw air through the sampling media. The main objective of this work was to evaluate the FTS in a near-field pesticide vapour drift study by comparing the concentrations of pyrimethanil in air measured using one HVS and three FTSs placed in the same location. Pyrimethanil was sprayed onto a vineyard as part of normal pest management procedures. Air samples were collected every eight hours for 48 h. The volume of air sampled by the FTSs was calculated using the measured relationship between ambient wind speed and the wind speed inside the sampler as determined with a separate wind tunnel study. The FTSs sampled 1.7 to 40.6 m(3) of air during each 8 h sampling period, depending on wind speed, whereas the mean volume sampled by the HVS was 128.7 m(3). Mean pyrimethanil concentrations ranged from 0.4 to 3.2 μg m(-3) of air. Inter-sampler reproducibility, as represented by percent relative standard deviation, for the three FTSs was ∼20%. The largest difference in FTS-derived versus HVS-derived pyrimethanil concentrations occurred during the lowest wind-speed period. During this period, it is likely that the FTS predominately acted like a traditional diffusion-based passive sampler. As indicated by both types of sampler, pyrimethanil concentrations in air changed by a factor of ∼2 during the two days after spaying

  17. Modeling spatial and temporal variability of residential air exchange rates for the Near-Road Exposures and Effects of Urban Air Pollutants Study (NEXUS).

    PubMed

    Breen, Michael S; Burke, Janet M; Batterman, Stuart A; Vette, Alan F; Godwin, Christopher; Croghan, Carry W; Schultz, Bradley D; Long, Thomas C

    2014-11-01

    Air pollution health studies often use outdoor concentrations as exposure surrogates. Failure to account for variability of residential infiltration of outdoor pollutants can induce exposure errors and lead to bias and incorrect confidence intervals in health effect estimates. The residential air exchange rate (AER), which is the rate of exchange of indoor air with outdoor air, is an important determinant for house-to-house (spatial) and temporal variations of air pollution infiltration. Our goal was to evaluate and apply mechanistic models to predict AERs for 213 homes in the Near-Road Exposures and Effects of Urban Air Pollutants Study (NEXUS), a cohort study of traffic-related air pollution exposures and respiratory effects in asthmatic children living near major roads in Detroit, Michigan. We used a previously developed model (LBL), which predicts AER from meteorology and questionnaire data on building characteristics related to air leakage, and an extended version of this model (LBLX) that includes natural ventilation from open windows. As a critical and novel aspect of our AER modeling approach, we performed a cross validation, which included both parameter estimation (i.e., model calibration) and model evaluation, based on daily AER measurements from a subset of 24 study homes on five consecutive days during two seasons. The measured AER varied between 0.09 and 3.48 h(-1) with a median of 0.64 h(-1). For the individual model-predicted and measured AER, the median absolute difference was 29% (0.19 h‑1) for both the LBL and LBLX models. The LBL and LBLX models predicted 59% and 61% of the variance in the AER, respectively. Daily AER predictions for all 213 homes during the three year study (2010-2012) showed considerable house-to-house variations from building leakage differences, and temporal variations from outdoor temperature and wind speed fluctuations. Using this novel approach, NEXUS will be one of the first epidemiology studies to apply calibrated and

  18. Modeling Spatial and Temporal Variability of Residential Air Exchange Rates for the Near-Road Exposures and Effects of Urban Air Pollutants Study (NEXUS)

    PubMed Central

    Breen, Michael S.; Burke, Janet M.; Batterman, Stuart A.; Vette, Alan F.; Godwin, Christopher; Croghan, Carry W.; Schultz, Bradley D.; Long, Thomas C.

    2014-01-01

    Air pollution health studies often use outdoor concentrations as exposure surrogates. Failure to account for variability of residential infiltration of outdoor pollutants can induce exposure errors and lead to bias and incorrect confidence intervals in health effect estimates. The residential air exchange rate (AER), which is the rate of exchange of indoor air with outdoor air, is an important determinant for house-to-house (spatial) and temporal variations of air pollution infiltration. Our goal was to evaluate and apply mechanistic models to predict AERs for 213 homes in the Near-Road Exposures and Effects of Urban Air Pollutants Study (NEXUS), a cohort study of traffic-related air pollution exposures and respiratory effects in asthmatic children living near major roads in Detroit, Michigan. We used a previously developed model (LBL), which predicts AER from meteorology and questionnaire data on building characteristics related to air leakage, and an extended version of this model (LBLX) that includes natural ventilation from open windows. As a critical and novel aspect of our AER modeling approach, we performed a cross validation, which included both parameter estimation (i.e., model calibration) and model evaluation, based on daily AER measurements from a subset of 24 study homes on five consecutive days during two seasons. The measured AER varied between 0.09 and 3.48 h−1 with a median of 0.64 h−1. For the individual model-predicted and measured AER, the median absolute difference was 29% (0.19 h‑1) for both the LBL and LBLX models. The LBL and LBLX models predicted 59% and 61% of the variance in the AER, respectively. Daily AER predictions for all 213 homes during the three year study (2010–2012) showed considerable house-to-house variations from building leakage differences, and temporal variations from outdoor temperature and wind speed fluctuations. Using this novel approach, NEXUS will be one of the first epidemiology studies to apply calibrated

  19. Do waste incinerators induce adverse respiratory effects? An air quality and epidemiological study of six communities.

    PubMed

    Shy, C M; Degnan, D; Fox, D L; Mukerjee, S; Hazucha, M J; Boehlecke, B A; Rothenbacher, D; Briggs, P M; Devlin, R B; Wallace, D D

    1995-01-01

    The purpose of the study presented here was to simultaneously measure air quality and respiratory function and symptoms in populations living in the neighborhood of waste incinerators and to estimate the contribution of incinerator emissions to the particulate air mass in these neighborhoods. We studied the residents of three communities having, respectively, a biomedical and a municipal incinerator, and a liquid hazardous waste-burning industrial furnace. We compared results with three matched-comparison communities. We did not detect differences in concentrations of particulate matter among any of the three pairs of study communities. Average fine particulate (PM2.5) concentrations measured for 35 days varied across study communities from 16 to 32 micrograms/m3. Within the same community, daily concentrations of fine particulates varied by as much as eightfold, from 10 to 80 micrograms/m3, and were nearly identical within each pair of communities. Direct measurements of air quality and estimates based on a chemical mass balance receptor model showed that incinerator emissions did not have a major or even a modest impact on routinely monitored air pollutants. A onetime baseline descriptive survey (n = 6963) did not reveal consistent community differences in the prevalence of chronic or acute respiratory symptoms between incinerator and comparison communities, nor did we see a difference in baseline lung function tests or in the average peak expiratory flow rate measured over a period of 35 days. Based on this analysis of the first year of our study, we conclude that we have no evidence to reject the null hypothesis of no acute or chronic respiratory effects associated with residence in any of the three incinerator communities. PMID:7588484

  20. Do Waste Incinerators Induce Adverse Respiratory Effects? An Air Quality and Epidemiological Study of Six Communities

    PubMed Central

    Shy, Carl M.; Degnan, Darrah; Fox, Donald L.; Mukerjee, Shaibal; Hazucha, Milan J.; Boehlecke, Brian A.; Rothenbacher, Dietrich; Briggs, Patsy M.; Devlin, Robert B.; Wallace, Dennis D.; Stevens, Robert K.; Bromberg, Philip A.

    1995-01-01

    The purpose of the study presented here was to simultaneously measure air quality and respiratory function and symptoms in populations living in the neighborhood of waste incinerators and to estimate the contribution of incinerator emissions to the particulate air mass in these neighborhoods. We studied the residents of three communities having, respectively, a biomedical and a municipal incinerator, and a liquid hazardous waste-burning industrial furnace. We compared results with three matched-comparison communities. We did not detect differences in concentrations of particulate matter among any of the three pairs of study communities. Average fine particulate (PM2.5) concentrations measured for 35 days varied across study communities from 16 to 32 μg/m3. Within the same community, daily concentrations of fine particulates varied by as much as eightfold, from 10 to 80 μg/m3, and were nearly identical within each pair of communities. Direct measurements of air quality and estimates based on a chemical mass balance receptor model showed that incinerator emissions did not have a major or even a modest impact on routinely monitored air pollutants. A one-time baseline descriptive survey (n = 6963) did not reveal consistent community differences in the prevalence of chronic or acute respiratory symptoms between incinerator and comparison communities, nor did we see a difference in baseline lung function tests or in the average peak expiratory flow rate measured over a period of 35 days. Based on this analysis of the first year of our study, we conclude that we have no evidence to reject the null hypothesis of no acute or chronic respiratory effects associated with residence in any of the three incinerator communities. ImagesFigure 1.Figure 2.Figure 3.Figure 4.Figure 4.Figure 4.Figure 5.Figure 5.Figure 5.Figure 6.Figure 7. PMID:7588484

  1. Chamber bioaerosol study: outdoor air and human occupants as sources of indoor airborne microbes.

    PubMed

    Adams, Rachel I; Bhangar, Seema; Pasut, Wilmer; Arens, Edward A; Taylor, John W; Lindow, Steven E; Nazaroff, William W; Bruns, Thomas D

    2015-01-01

    Human occupants are an important source of microbes in indoor environments. In this study, we used DNA sequencing of filter samples to assess the fungal and bacterial composition of air in an environmental chamber under different levels of occupancy, activity, and exposed or covered carpeting. In this office-like, mechanically ventilated environment, results showed a strong influence of outdoor-derived particles, with the indoor microbial composition tracking that of outdoor air for the 2-hour sampling periods. The number of occupants and their activity played a significant but smaller role influencing the composition of indoor bioaerosols. Human-associated taxa were observed but were not particularly abundant, except in the case of one fungus that appeared to be transported into the chamber on the clothing of a study participant. Overall, this study revealed a smaller signature of human body-associated taxa than had been expected based on recent studies of indoor microbiomes, suggesting that occupants may not exert a strong influence on bioaerosol microbial composition in a space that, like many offices, is well ventilated with air that is moderately filtered and moderately occupied. PMID:26024222

  2. Chamber Bioaerosol Study: Outdoor Air and Human Occupants as Sources of Indoor Airborne Microbes

    PubMed Central

    Adams, Rachel I.; Bhangar, Seema; Pasut, Wilmer; Arens, Edward A.; Taylor, John W.; Lindow, Steven E.; Nazaroff, William W.; Bruns, Thomas D.

    2015-01-01

    Human occupants are an important source of microbes in indoor environments. In this study, we used DNA sequencing of filter samples to assess the fungal and bacterial composition of air in an environmental chamber under different levels of occupancy, activity, and exposed or covered carpeting. In this office-like, mechanically ventilated environment, results showed a strong influence of outdoor-derived particles, with the indoor microbial composition tracking that of outdoor air for the 2-hour sampling periods. The number of occupants and their activity played a significant but smaller role influencing the composition of indoor bioaerosols. Human-associated taxa were observed but were not particularly abundant, except in the case of one fungus that appeared to be transported into the chamber on the clothing of a study participant. Overall, this study revealed a smaller signature of human body-associated taxa than had been expected based on recent studies of indoor microbiomes, suggesting that occupants may not exert a strong influence on bioaerosol microbial composition in a space that, like many offices, is well ventilated with air that is moderately filtered and moderately occupied. PMID:26024222

  3. An Integrative Study of Photochemical Air Pollution in Hong Kong: an Overview

    NASA Astrophysics Data System (ADS)

    Wang, T.

    2014-12-01

    Hong Kong is situated in the Pearl River delta of Southern China. This region has experienced phenomenal economic growth in the past 30 years. Emissions of large amount of pollutants from urban areas and various industries coupled with subtropical climate have led to frequent occurrences of severe photochemical air pollution. Despite the long-term control efforts of the Hong Kong government, the atmospheric levels of ozone have been increasing in the past decade. To obtain an updated and more complete understanding of photochemical smog, an integrative study has been conducted during 2010-2014. Several intensive measurement campaigns were carried out at urban, suburban and rural sites in addition to the routine observations at fourteen air quality monitoring stations in Hong Kong. Meteorological, photochemical, and chemical-transport modeling studies were conducted to investigate the causes/processes of elevated photochemical pollution . The main activities of this study were to (1) examine the situation and trends of photochemical air pollution in Hong Kong, (2) understand some underlying chemical processes in particular the poorly-understood heterogeneous processes of reactive nitrogen oxides, (3) quantify the local, regional, and super-regional contributions to the ozone pollution in Hong Kong, and (4) review the control policy and make further recommendations based on the science. This paper will give an overview of this study and present some key results on the trends and chemistry of the photochemical pollution in this polluted subtropical region.

  4. A Unified Spatiotemporal Modeling Approach for Predicting Concentrations of Multiple Air Pollutants in the Multi-Ethnic Study of Atherosclerosis and Air Pollution

    PubMed Central

    Olives, Casey; Kim, Sun-Young; Sheppard, Lianne; Sampson, Paul D.; Szpiro, Adam A.; Oron, Assaf P.; Lindström, Johan; Vedal, Sverre; Kaufman, Joel D.

    2014-01-01

    Background: Cohort studies of the relationship between air pollution exposure and chronic health effects require predictions of exposure over long periods of time. Objectives: We developed a unified modeling approach for predicting fine particulate matter, nitrogen dioxide, oxides of nitrogen, and black carbon (as measured by light absorption coefficient) in six U.S. metropolitan regions from 1999 through early 2012 as part of the Multi-Ethnic Study of Atherosclerosis and Air Pollution (MESA Air). Methods: We obtained monitoring data from regulatory networks and supplemented those data with study-specific measurements collected from MESA Air community locations and participants’ homes. In each region, we applied a spatiotemporal model that included a long-term spatial mean, time trends with spatially varying coefficients, and a spatiotemporal residual. The mean structure was derived from a large set of geographic covariates that was reduced using partial least-squares regression. We estimated time trends from observed time series and used spatial smoothing methods to borrow strength between observations. Results: Prediction accuracy was high for most models, with cross-validation R2 (R2CV) > 0.80 at regulatory and fixed sites for most regions and pollutants. At home sites, overall R2CV ranged from 0.45 to 0.92, and temporally adjusted R2CV ranged from 0.23 to 0.92. Conclusions: This novel spatiotemporal modeling approach provides accurate fine-scale predictions in multiple regions for four pollutants. We have generated participant-specific predictions for MESA Air to investigate health effects of long-term air pollution exposures. These successes highlight modeling advances that can be adopted more widely in modern cohort studies. Citation: Keller JP, Olives C, Kim SY, Sheppard L, Sampson PD, Szpiro AA, Oron AP, Lindström J, Vedal S, Kaufman JD. 2015. A unified spatiotemporal modeling approach for predicting concentrations of multiple air pollutants in the Multi

  5. Treatment of high-strength industrial wastewater by wet air oxidation--A case study

    SciTech Connect

    Lin, S.H.; Ho, S.J.

    1997-12-31

    Treatment of high concentration chemical wastewater obtained from a petrochemical company by wet air oxidation (WAO) is studied. Experiments were conducted to investigate the effects of the mixer speed, operating pressure, initial pH of wastewater and temperature on the pollutant (chemical oxygen demand or COD) removal. Both air and oxygen were tested to determine their respective effect on the COD removal. Results showed that over 50% of COD removal can be easily realized in an hour of WAO treatment. Also considered in the present study was the catalytic WAO treatment of the high concentration wastewater. Copper sulfate (CuSO{sub 4}), cobalt oxide (Co{sub 2}O{sub 3}) and zinc oxide (ZnO) were employed as the catalysts. The COD removal efficiency of the catalytic WAO process was found to vary significantly with the catalyst utilized with CuSO{sub 4} being the most effective.

  6. Biocatalytic coatings for air pollution control: a proof of concept study on VOC biodegradation.

    PubMed

    Estrada, José M; Bernal, Oscar I; Flickinger, Michael C; Muñoz, Raúl; Deshusses, Marc A

    2015-02-01

    Although biofilm-based biotechnologies exhibit a large potential as solutions for off-gas treatment, the high water content of biofilms often causes pollutant mass transfer limitations, which ultimately limit their widespread application. The present study reports on the proof of concept of the applicability of bioactive latex coatings for air pollution control. Toluene vapors served as a model volatile organic compound (VOC). The results showed that Pseudomonas putida F1 cells could be successfully entrapped in nanoporous latex coatings while preserving their toluene degradation activity. Bioactive latex coatings exhibited toluene specific biodegradation rates 10 times higher than agarose-based biofilms, because the thin coatings were less subject to diffusional mass transfer limitations. Drying and pollutant starvation were identified as key factors inducing a gradual deterioration of the biodegradation capacity in these innovative coatings. This study constitutes the first application of bioactive latex coatings for VOC abatement. These coatings could become promising means for air pollution control. PMID:25115963

  7. Mortality, length of life, and physical examination attendance in participants of the Air Force Health Study.

    PubMed

    Ketchum, Norma S; Michalek, Joel E; Pavuk, Marian

    2007-01-01

    Begun in 1982, the Air Force Health Study (AFHS) has assessed the mortality of veterans of Operation Ranch Hand, the unit responsible for aerially spraying herbicides in Vietnam. A comparison group of other Air Force veterans involved with aircraft missions in Southeast Asia during the same period, but not involved with spraying herbicides, was included in the study. Among 18,082 veterans, this report examined whether attendance at AFHS physical examinations from 1982 to 1999 played a role in mortality experience and potential lengthening of life relative to veterans who did not attend. The years of potential life lost for 1173 veterans who died before age 65 was calculated. No statistically significant difference in risk of death was found from all causes, cancer, or circulatory disease between attendees and nonattendees. No evidence was found to suggest that attending physical examinations decreased mortality or substantially lengthened life in AFHS participants. PMID:17274267

  8. Air pollution epidemiologic studies in South Africa--need for freshening up.

    PubMed

    Wichmann, Janine; Voyi, Kuku V V

    2005-01-01

    The results of epidemiologic studies obtained in developed countries cannot be extrapolated with complete confidence to developing countries. The objectives of this review were to examine the evidence from local studies for associations between air pollution and adverse health along with a critical review for methodologic limitations. The literature search strategy and selection criteria involved a MEDLINE search up to June 2005. Of 267 journal articles found, 14 focused on air pollution epidemiology (excluding active smoking and internal dose as a proxy for health outcomes). Two studies were also located by word of mouth or through the references from the selected studies. The local studies provide some evidence of an association with a range of serious and common health problems. No study established an exposure-response curve for the criteria pollutants carbon monoxide, sulfur dioxide, nitrogen oxides, lead, and ozone. Therefore, using the results of such studies in risk-assessment is impossible. The studies were fraught with systematic and random errors, which limit their validity and precision. We recommend conducting a quantitative intervention study with an analytical study design in all major cities in the countries where residents are still using dirty fuels for cooking, lighting, and space heating. Future studies must involve national and international multidisciplinary stakeholders and must be planned well in advance. PMID:16422348

  9. Feasibility of Measuring Tobacco Smoke Air Pollution in Homes: Report from a Pilot Study

    PubMed Central

    Rosen, Laura; Zucker, David; Hovell, Melbourne; Brown, Nili; Ram, Amit; Myers, Vicki

    2015-01-01

    Tobacco smoke air pollution (TSAP) measurement may persuade parents to adopt smoke-free homes and thereby reduce harm to children from tobacco smoke in the home. In a pilot study involving 29 smoking families, a Sidepak was used to continuously monitor home PM2.5 during an 8-h period, Sidepak and/or Dylos monitors provided real-time feedback, and passive nicotine monitors were used to measure home air nicotine for one week. Feedback was provided to participants in the context of motivational interviews. Home PM2.5 levels recorded by continuous monitoring were not well-accepted by participants because of the noise level. Also, graphs from continuous monitoring showed unexplained peaks, often associated with sources unrelated to indoor smoking, such as cooking, construction, or outdoor sources. This hampered delivery of a persuasive message about the relationship between home smoking and TSAP. By contrast, immediate real-time PM2.5 feedback (with Sidepak or Dylos monitor) was feasible and provided unambiguous information; the Dylos had the additional advantages of being more economical and quieter. Air nicotine sampling was complicated by the time-lag for feedback and questions regarding shelf-life. Improvement in the science of TSAP measurement in the home environment is needed to encourage and help maintain smoke-free homes and protect vulnerable children. Recent advances in the use of mobile devices for real-time feedback are promising and warrant further development, as do accurate methods for real-time air nicotine air monitoring. PMID:26633440

  10. A modelling study of air pollution in Beirut city for the summer of 2011.

    NASA Astrophysics Data System (ADS)

    Waked, A.; Afif, C.; Seigneur, C.

    2012-04-01

    Beirut, the capital city of Lebanon which is located on the eastern shore of the Mediterranean basin experiences high pollution episodes. Annual average concentrations of coarse and fine particulate matter (PM) as well as nitrogen dioxide (NO2) often exceed the World Health Organisation (WHO) recommended values. Therefore, improving air quality in this region is essential. In this work, the Polyphemus/Polair3D modelling system was used to investigate air pollution episodes in Beirut during 2-17 July 2011 to develop better understanding of air pollution in the city and its suburbs. This work will help in developing optimal emission reduction strategies for decreasing air pollution levels. The modeling domain covered two nested grids of 1 and 5 km resolution, respectively. The emission inventory was developed in a previous step of this work with a resolution of 1 km for Beirut and 5 km for the rest of the country (Waked et al., Atmos.Environ, in press). The Weather and Research Forecast (WRF) model was used to generate the meteorological fields and the Model of Emissions of Gases and Aerosols from Nature (MEGAN) was used for biogenic emissions. The results of the study are compared to measurements from a field campaign conducted in the suburb of Beirut during 2-17 July as a part of the Emission and Chemistry of Organic Carbon in East Mediterranean Beirut (ECOCEM-Beirut) project. The model reproduces well the concentrations of carbon monoxide (CO), PM10 and PM2.5 particulate matter but tends to overpredict the concentrations of nitrogen dioxide (NO2) and ozone (O3). The relative influence of chemistry and transport on air quality at the site is discussed.

  11. Development of a multicopter-carried whole air sampling apparatus and its applications in environmental studies.

    PubMed

    Chang, Chih-Chung; Wang, Jia-Lin; Chang, Chih-Yuan; Liang, Mao-Chang; Lin, Ming-Ren

    2016-02-01

    To advance the capabilities of probing chemical composition aloft, we designed a lightweight remote-controlled whole air sampling component (WASC) and integrated it into a multicopter drone with agile maneuverability to perform aerial whole air sampling. A field mission hovering over an exhaust shaft of a roadway tunnel to collect air samples was performed to demonstrate the applicability of the multicopter-carried WASC apparatus. Ten aerial air samples surrounding the shaft vent were collected by the multicopter-carried WASC. Additional five samples were collected manually inside the shaft for comparison. These samples were then analyzed in the laboratory for the chemical composition of 109 volatile organic compounds (VOCs), CH4, CO, CO2, or CO2 isotopologues. Most of the VOCs in the upwind samples (the least affected by shaft exhaust) were low in concentrations (5.9 ppbv for total 109 VOCs), posting a strong contrast to those in the shaft exhaust (235.8 ppbv for total 109 VOCs). By comparing the aerial samples with the in-shaft samples for chemical compositions, the influence of the shaft exhaust on the surrounding natural air was estimated. Through the aerial measurements, three major advantages of the multicopter-carried WASC were demonstrated: 1. The highly maneuverable multicopter-carried WASC can be readily deployed for three-dimensional environmental studies at a local scale (0-1.5 km); 2. Aerial sampling with superior sample integrity and preservation conditions can now be performed with ease; and 3. Data with spatial resolution for a large array of gaseous species with high precision can be easily obtained. PMID:26386435

  12. Feasibility of Measuring Tobacco Smoke Air Pollution in Homes: Report from a Pilot Study.

    PubMed

    Rosen, Laura; Zucker, David; Hovell, Melbourne; Brown, Nili; Ram, Amit; Myers, Vicki

    2015-12-01

    Tobacco smoke air pollution (TSAP) measurement may persuade parents to adopt smoke-free homes and thereby reduce harm to children from tobacco smoke in the home. In a pilot study involving 29 smoking families, a Sidepak was used to continuously monitor home PM(2.5) during an 8-h period, Sidepak and/or Dylos monitors provided real-time feedback, and passive nicotine monitors were used to measure home air nicotine for one week. Feedback was provided to participants in the context of motivational interviews. Home PM(2.5) levels recorded by continuous monitoring were not well-accepted by participants because of the noise level. Also, graphs from continuous monitoring showed unexplained peaks, often associated with sources unrelated to indoor smoking, such as cooking, construction, or outdoor sources. This hampered delivery of a persuasive message about the relationship between home smoking and TSAP. By contrast, immediate real-time PM(2.5) feedback (with Sidepak or Dylos monitor) was feasible and provided unambiguous information; the Dylos had the additional advantages of being more economical and quieter. Air nicotine sampling was complicated by the time-lag for feedback and questions regarding shelf-life. Improvement in the science of TSAP measurement in the home environment is needed to encourage and help maintain smoke-free homes and protect vulnerable children. Recent advances in the use of mobile devices for real-time feedback are promising and warrant further development, as do accurate methods for real-time air nicotine air monitoring. PMID:26633440

  13. Love Canal Emergency Declaration Area habitability study. Volume 2. Air assessment: indicator chemicals. Final report

    SciTech Connect

    Not Available

    1988-02-01

    Environmental studies were conducted to provide data that could be used by the Commissioner of Health for the State of New York in determining whether the Emergency Declaration Area (EDA) surrounding the Love Canal hazardous-waste site is habitable. An air assessment was conducted for Love Canal Indicator Chemicals. Homes throughout the EDA were sampled using the Trace Atmospheric Gas Analyzer Model 6000E.

  14. The use of ERTS-1 imagery in air pollution and mesometeorological studies around the Great Lakes

    NASA Technical Reports Server (NTRS)

    Lyons, W. A.; Northouse, R. A.

    1974-01-01

    ERTS-1 images continue to be highly useful in studies of: (1) long range transport of air pollutants over the Great Lakes; (2) the mesoscale atmospheric dynamics associated with episodic levels of photochemical smog along the western shore of Lake Michigan; and (3) inadvertant weather modification by large industrial complexes. Also unusual wave patterns in fogs and low stratus over the Great Lakes are being detected for the first time due to the satellites high resolution.

  15. Experimental study of wood downdraft gasification for an improved producer gas quality through an innovative two-stage air and premixed air/gas supply approach.

    PubMed

    Jaojaruek, Kitipong; Jarungthammachote, Sompop; Gratuito, Maria Kathrina B; Wongsuwan, Hataitep; Homhual, Suwan

    2011-04-01

    This study conducted experiments on three different downdraft gasification approaches: single stage, conventional two-stage, and an innovative two-stage air and premixed air/gas supply approach. The innovative two-stage approach has two nozzle locations, one for air supply at combustion zone and the other located at the pyrolysis zone for supplying the premixed gas (air and producer gas). The producer gas is partially bypassed to mix with air and supplied to burn at the pyrolysis zone. The result shows that producer gas quality generated by the innovative two-stage approach improved as compared to conventional two-stage. The higher heating value (HHV) increased from 5.4 to 6.5 MJ/Nm(3). Tar content in producer gas reduced to less than 45 mg/Nm(3). With this approach, gas can be fed directly to an internal combustion engine. Furthermore, the gasification thermal efficiency also improved by approximately 14%. The approach gave double benefits on gas qualities and energy savings. PMID:21292477

  16. United States Air Force 611th Air Support Group Civil Engineering Squadron, Elmendorf AFB, Alaska. Remedial investigation and feasibility study Point Lay Radar Installation, Alaska. Final report

    SciTech Connect

    Karmi, S.

    1996-03-04

    The United States Air Force (Air Force) has prepared this Remedial Investigation/Feasibility Study (RI/FS) report to present the results of RI/FS activities at four sites located at the Point Lay radar installation. The remedial investigation (RI) field activities were conducted at the Point Lay radar installation during the summer of 1993. The four sites at Point Lay were investigated because they were suspected of being contaminated with hazardous substances. RI activities were conducted using methods and procedures specified in the RI/FS Work Plan, Sampling and Analysis Plan (SAP), and Health and Safety Plan.

  17. CFD based aerodynamic modeling to study flight dynamics of a flapping wing micro air vehicle

    NASA Astrophysics Data System (ADS)

    Rege, Alok Ashok

    The demand for small unmanned air vehicles, commonly termed micro air vehicles or MAV's, is rapidly increasing. Driven by applications ranging from civil search-and-rescue missions to military surveillance missions, there is a rising level of interest and investment in better vehicle designs, and miniaturized components are enabling many rapid advances. The need to better understand fundamental aspects of flight for small vehicles has spawned a surge in high quality research in the area of micro air vehicles. These aircraft have a set of constraints which are, in many ways, considerably different from that of traditional aircraft and are often best addressed by a multidisciplinary approach. Fast-response non-linear controls, nano-structures, integrated propulsion and lift mechanisms, highly flexible structures, and low Reynolds aerodynamics are just a few of the important considerations which may be combined in the execution of MAV research. The main objective of this thesis is to derive a consistent nonlinear dynamic model to study the flight dynamics of micro air vehicles with a reasonably accurate representation of aerodynamic forces and moments. The research is divided into two sections. In the first section, derivation of the nonlinear dynamics of flapping wing micro air vehicles is presented. The flapping wing micro air vehicle (MAV) used in this research is modeled as a system of three rigid bodies: a body and two wings. The design is based on an insect called Drosophila Melanogaster, commonly known as fruit-fly. The mass and inertial effects of the wing on the body are neglected for the present work. The nonlinear dynamics is simulated with the aerodynamic data published in the open literature. The flapping frequency is used as the control input. Simulations are run for different cases of wing positions and the chosen parameters are studied for boundedness. Results show a qualitative inconsistency in boundedness for some cases, and demand a better

  18. Air pollution and lung function among susceptible adult subjects: a panel study

    PubMed Central

    Lagorio, Susanna; Forastiere, Francesco; Pistelli, Riccardo; Iavarone, Ivano; Michelozzi, Paola; Fano, Valeria; Marconi, Achille; Ziemacki, Giovanni; Ostro, Bart D

    2006-01-01

    Background Adverse health effects at relatively low levels of ambient air pollution have consistently been reported in the last years. We conducted a time-series panel study of subjects with chronic obstructive pulmonary disease (COPD), asthma, and ischemic heart disease (IHD) to evaluate whether daily levels of air pollutants have a measurable impact on the lung function of adult subjects with pre-existing lung or heart diseases. Methods Twenty-nine patients with COPD, asthma, or IHD underwent repeated lung function tests by supervised spirometry in two one-month surveys. Daily samples of coarse (PM10–2.5) and fine (PM2.5) particulate matter were collected by means of dichotomous samplers, and the dust was gravimetrically analyzed. The particulate content of selected metals (cadmium, chrome, iron, nickel, lead, platinum, vanadium, and zinc) was determined by atomic absorption spectrometry. Ambient concentrations of nitrogen dioxide (NO2), carbon monoxide (CO), ozone (O3), and sulphur dioxide (SO2) were obtained from the regional air-quality monitoring network. The relationships between concentrations of air pollutants and lung function parameters were analyzed by generalized estimating equations (GEE) for panel data. Results Decrements in lung function indices (FVC and/or FEV1) associated with increasing concentrations of PM2.5, NO2 and some metals (especially zinc and iron) were observed in COPD cases. Among the asthmatics, NO2 was associated with a decrease in FEV1. No association between average ambient concentrations of any air pollutant and lung function was observed among IHD cases. Conclusion This study suggests that the short-term negative impact of exposure to air pollutants on respiratory volume and flow is limited to individuals with already impaired respiratory function. The fine fraction of ambient PM seems responsible for the observed effects among COPD cases, with zinc and iron having a potential role via oxidative stress. The respiratory function

  19. OHIO RIVER BASIN ENERGY STUDY: AIR QUALITY AND RELATED IMPACTS. VOLUME I. DOCUMENTATION IN SUPPORT OF KEY ORBES AIR QUALITY FINDINGS

    EPA Science Inventory

    This report was prepared as part of the Ohio River Basin Energy Study (ORBES), a multi-disciplinary research program supported by the Environmental Protection Agency. The extensive air quality analysis undertaken for the ORBES included examination of pollutant emissions and resul...

  20. EPA'S INDOOR AIR QUALITY AND WORK ENVIRONMENT STUDY: RELATIONSHIPS OF EMPLOYEE'S SELF-REPORTED HEALTHY SYMPTOMS WITH DIRECT INDOOR AIR QUALITY MEASUREMENTS

    EPA Science Inventory

    In recent years, employees at the three headquarters buildings of the U.S. Environmental Protection Agency (EPA) in the Washington, D.C. area have expressed concerns about air quality and work environment discomforts. s part of a large-scale study of health and comfort concerns, ...

  1. Impact of emission control on regional air quality: an observational study of air pollutants before, during and after the Beijing Olympic Games.

    PubMed

    Wang, Shulan; Gao, Jian; Zhang, Yuechong; Zhang, Jingqiao; Cha, Fahe; Wang, Tao; Ren, Chun; Wang, Wenxing

    2014-01-01

    An observational study on trace gases and PM2.5 was conducted at three sites in and around Beijing, during the Olympic season from 2007 to 2009. Air quality improved significantly during the Olympic Games due to the special emission control measures. However, concentrations of the primary pollutants and PM were found to have risen significantly after the Games. Although the major O3 precursors (NO(x) and VOCs) were well controlled during the Olympic season, O3 was still found to be the highest in 2008, based on the data of ground-based observation. All this information suggests that while control of regional emissions for the Beijing Olympic Games did improved the air quality in Beijing, more efforts will be needed for the continuous improvement of regional air quality, especially for significant reductions of O3 and fine particulate pollution, and not only in Beijing, but also in the Beijing-Tianjin-Hebei region. PMID:24649704

  2. Traffic-Related Air Pollution and Perinatal Mortality: A Case–Control Study

    PubMed Central

    de Medeiros, Andréa Paula Peneluppi; Gouveia, Nelson; Machado, Reinaldo Paul Pérez; de Souza, Miriam Regina; Alencar, Gizelton Pereira; Novaes, Hillegonda Maria Dutilh; de Almeida, Márcia Furquim

    2009-01-01

    Background Ambient levels of air pollution may affect the health of children, as indicated by studies of infant and perinatal mortality. Scientific evidence has also correlated low birth weight and preterm birth, which are important determinants of perinatal death, with air pollution. However, most of these studies used ambient concentrations measured at monitoring sites, which may not consider differential exposure to pollutants found at elevated concentrations near heavy-traffic roadways. Objectives Our goal was to examine the association between traffic-related pollution and perinatal mortality. Methods We used the information collected for a case–control study conducted in 14 districts in the City of São Paulo, Brazil, regarding risk factors for perinatal deaths. We geocoded the residential addresses of cases (fetal and early neonatal deaths) and controls (children who survived the 28th day of life) and calculated a distance-weighted traffic density (DWTD) measure considering all roads contained in a buffer surrounding these homes. Results Logistic regression revealed a gradient of increasing risk of early neonatal death with higher exposure to traffic-related air pollution. Mothers exposed to the highest quartile of the DWTD compared with those less exposed exhibited approximately 50% increased risk (adjusted odds ratio = 1.47; 95% confidence interval, 0.67–3.19). Associations for fetal mortality were less consistent. Conclusions These results suggest that motor vehicle exhaust exposures may be a risk factor for perinatal mortality. PMID:19165399

  3. Controlling for localised spatio-temporal autocorrelation in long-term air pollution and health studies

    PubMed Central

    Mitchell, Richard

    2014-01-01

    Estimating the long-term health impact of air pollution using an ecological spatio-temporal study design is a challenging task, due to the presence of residual spatio-temporal autocorrelation in the health counts after adjusting for the covariate effects. This autocorrelation is commonly modelled by a set of random effects represented by a Gaussian Markov random field (GMRF) prior distribution, as part of a hierarchical Bayesian model. However, GMRF models typically assume the random effects are globally smooth in space and time, and thus are likely to be collinear to any spatially and temporally smooth covariates such as air pollution. Such collinearity leads to poor estimation performance of the estimated fixed effects, and motivated by this epidemiological problem, this paper proposes new GMRF methodology to allow for localised spatio-temporal smoothing. This means random effects that are either geographically or temporally adjacent are allowed to be autocorrelated or conditionally independent, which allows more flexible autocorrelation structures to be represented. This increased flexibility results in improved fixed effects estimation compared with global smoothing models, which is evidenced by our simulation study. The methodology is then applied to the motivating study investigating the long-term effects of air pollution on respiratory ill health in Greater Glasgow, Scotland between 2007 and 2011. PMID:24648100

  4. Air pollution, climate and pollen comparisons in urban, rural and alpine regions in Switzerland (SAPALDIA study)

    NASA Astrophysics Data System (ADS)

    Monn, Christian; Alean-Kirkpatrick, Pamela; Künzli, Nino; Defila, Claudio; Peeters, Annie; Ackermann-Liebrich, Ursula; Leuenberger, Philippe; Sapaldia Team

    The aim of this paper is to show spatial differences and correlations in long- term air pollution measurements in the eight SAPALDIA sites (Swiss Study on Air Pollution and Lung Diseases in Adults, SAPALDIA). In addition, a comparison with climatic parameters and pollen counts are presented in a descriptive way. SAPALDIA investigated health effects from air pollutants and climate in a cross-sectional study (1991) and in a follow-up longitudinal study (1992-1993). Over the period 1991-1993, urban-rural-Alpine concentration gradients were found for SO 2, NO 2, PM 10 and HNO 3. For O 3, average levels were higher in the Alps but peak levels were higher at sites on the Swiss Plateau. Levels of sulphuric acid were negligibly small; acidity was mainly determined by the content of HNO 3. A statistical analysis of long-term data for SO 2, NO 2, TSP, PM 10, HNO 3 and size-fractions of suspended particulate matter (SPM) indicated strong correlations.

  5. The AirView Study: Comparison of Intubation Conditions and Ease between the Airtraq-AirView and the King Vision

    PubMed Central

    Schoettker, Patrick; Corniche, Jocelyn

    2015-01-01

    We conducted a study assessing the quality and speed of intubation between the Airtraq with its new iPhone AirView app and the King Vision in a manikin. The primary endpoint was reduction of time needed for intubation. Secondary endpoints included times necessary for intubation. 30 anaesthetists randomly performed 3 intubations with each device on a difficult airway manikin. Participants had a professional experience of 12 years: 60.0% possessed the Airtraq in their hospital, 46.7% the King Vision, and 20.0% both. Median time difference [IQR] to identify glottis (1.1 [−1.3; 3.9] P = 0.019), for tube insertion (2.1 [−2.6; 9.4] P = 0.002) and lung ventilation (2.8 [−2.4; 11.5] P = 0.001), was shorter with the Airtraq-AirView. Median time for glottis visualization was significantly shorter with the Airtraq-AirView (5.3 [4.0; 8.4] versus 6.4 [4.6; 9.1]). Cormack Lehane before intubation was better with the King Vision (P = 0.03); no difference was noted during intubation, for subjective device insertion or quality of epiglottis visualisation. Assessment of tracheal tube insertion was better with the Airtraq-AirView. The Airtraq-AirView allows faster identification of the landmarks and intubation in a difficult airway manikin, while clinical relevance remains to be studied. Anaesthetists assessed the intubation better with the Airtraq-AirView. PMID:26161393

  6. The AirView Study: Comparison of Intubation Conditions and Ease between the Airtraq-AirView and the King Vision.

    PubMed

    Schoettker, Patrick; Corniche, Jocelyn

    2015-01-01

    We conducted a study assessing the quality and speed of intubation between the Airtraq with its new iPhone AirView app and the King Vision in a manikin. The primary endpoint was reduction of time needed for intubation. Secondary endpoints included times necessary for intubation. 30 anaesthetists randomly performed 3 intubations with each device on a difficult airway manikin. Participants had a professional experience of 12 years: 60.0% possessed the Airtraq in their hospital, 46.7% the King Vision, and 20.0% both. Median time difference [IQR] to identify glottis (1.1 [-1.3; 3.9] P = 0.019), for tube insertion (2.1 [-2.6; 9.4] P = 0.002) and lung ventilation (2.8 [-2.4; 11.5] P = 0.001), was shorter with the Airtraq-AirView. Median time for glottis visualization was significantly shorter with the Airtraq-AirView (5.3 [4.0; 8.4] versus 6.4 [4.6; 9.1]). Cormack Lehane before intubation was better with the King Vision (P = 0.03); no difference was noted during intubation, for subjective device insertion or quality of epiglottis visualisation. Assessment of tracheal tube insertion was better with the Airtraq-AirView. The Airtraq-AirView allows faster identification of the landmarks and intubation in a difficult airway manikin, while clinical relevance remains to be studied. Anaesthetists assessed the intubation better with the Airtraq-AirView. PMID:26161393

  7. Long-term ambient air pollution and lung function impairment in Chinese children from a high air pollution range area: The Seven Northeastern Cities (SNEC) study

    NASA Astrophysics Data System (ADS)

    Zeng, Xiao-Wen; Vivian, Elaina; Mohammed, Kahee A.; Jakhar, Shailja; Vaughn, Michael; Huang, Jin; Zelicoff, Alan; Xaverius, Pamela; Bai, Zhipeng; Lin, Shao; Hao, Yuan-Tao; Paul, Gunther; Morawska, Lidia; Wang, Si-Quan; Qian, Zhengmin; Dong, Guang-Hui

    2016-08-01

    Epidemiological studies have reported inconsistent and inconclusive associations between long-term exposure to ambient air pollution and lung function in children from Europe and America, where air pollution levels were typically low. The aim of the present study is to examine the relationship between air pollutants and lung function in children selected from heavily industrialized and polluted cities in northeastern China. During 2012, 6740 boys and girls aged 7-14 years were recruited in 24 districts of seven northeastern cities. Portable electronic spirometers were used to measure lung function. Four-year average concentrations of particulate matter with an aerodynamic diameter ≤10 μm (PM10), sulfur dioxide (SO2), nitrogen dioxide (NO2), and ozone (O3) were measured at monitoring stations in the 24 districts. Two-staged regression models were used in the data analysis, controlling for covariates. Overall, for all subjects, the increased odds of lung function impairment associated with exposure to air pollutants, ranged from 5% (adjusted odds ratio [aOR] = 1.05; 95% confidence interval [CI] = 1.01, 1.10) for FVC < 85% predicted per 46.3 μg/m3 for O3 to 81% (aOR = 1.81; 95%CI = 1.44, 2.28) for FEV1 < 85% predicted per 30.6 μg/m3 for PM10. The linear regression models consistently showed a negative relationship between all air pollutants and lung function measures across subjects. There were significant interaction terms indicating gender differences for lung function impairment and pulmonary function from exposure to some pollutants (P < 0.10). In conclusion, long term exposure to high concentrations of ambient air pollution is associated with decreased pulmonary function and lung function impairment, and females appear to be more susceptible than males.

  8. Long-Term Air Pollution Exposure and Blood Pressure in the Sister Study

    PubMed Central

    Chan, Stephanie H.; Van Hee, Victor C.; Bergen, Silas; Szpiro, Adam A.; DeRoo, Lisa A.; London, Stephanie J.; Marshall, Julian D.; Sandler, Dale P.

    2015-01-01

    Background Exposure to air pollution has been consistently associated with cardiovascular morbidity and mortality, but mechanisms remain uncertain. Associations with blood pressure (BP) may help to explain the cardiovascular effects of air pollution. Objective We examined the cross-sectional relationship between long-term (annual average) residential air pollution exposure and BP in the National Institute of Environmental Health Sciences’ Sister Study, a large U.S. cohort study investigating risk factors for breast cancer and other outcomes. Methods This analysis included 43,629 women 35–76 years of age, enrolled 2003–2009, who had a sister with breast cancer. Geographic information systems contributed to satellite-based nitrogen dioxide (NO2) and fine particulate matter (≤ 2.5 μm; PM2.5) predictions at participant residences at study entry. Generalized additive models were used to examine the relationship between pollutants and measured BP at study entry, adjusting for cardiovascular disease risk factors and including thin plate splines for potential spatial confounding. Results A 10-μg/m3 increase in PM2.5 was associated with 1.4-mmHg higher systolic BP (95% CI: 0.6, 2.3; p < 0.001), 1.0-mmHg higher pulse pressure (95% CI: 0.4, 1.7; p = 0.001), 0.8-mmHg higher mean arterial pressure (95% CI: 0.2, 1.4; p = 0.01), and no significant association with diastolic BP. A 10-ppb increase in NO2 was associated with a 0.4-mmHg (95% CI: 0.2, 0.6; p < 0.001) higher pulse pressure. Conclusions Long-term PM2.5 and NO2 exposures were associated with higher blood pressure. On a population scale, such air pollution–related increases in blood pressure could, in part, account for the increases in cardiovascular disease morbidity and mortality seen in prior studies. Citation Chan SH, Van Hee VC, Bergen S, Szpiro AA, DeRoo LA, London SJ, Marshall JD, Kaufman JD, Sandler DP. 2015. Long-term air pollution exposure and blood pressure in the Sister Study. Environ Health

  9. Simulation studies of STOL airplane operations in metropolitan downtown and airport air traffic control environments

    NASA Technical Reports Server (NTRS)

    Sawyer, R. H.; Mclaughlin, M. D.

    1974-01-01

    The operating problems and equipment requirements for STOL airplanes in terminal area operations in simulated air traffic control (ATC) environments were studied. These studies consisted of Instrument Flight Rules (IFR) arrivals and departures in the New York area to and from a downtown STOL port, STOL runways at John F. Kennedy International Airport, or STOL runways at a hypothetical international airport. The studies were accomplished in real time by using a STOL airplane flight simulator. An experimental powered lift STOL airplane and two in-service airplanes having high aerodynamic lift (i.e., STOL) capability were used in the simulations.

  10. Evolution of soot size distribution in premixed ethylene/air and ethylene/benzene/air flames: Experimental and modeling study

    SciTech Connect

    Echavarria, Carlos A.; Sarofim, Adel F.; Lighty, JoAnn S.; D'Anna, Andrea

    2011-01-15

    The effect of benzene concentration in the initial fuel on the evolution of soot size distribution in ethylene/air and ethylene/benzene/air flat flames was characterized by experimental measurements and model predictions of size and number concentration within the flames. Experimentally, a scanning mobility particle sizer was used to allow spatially resolved and online measurements of particle concentration and sizes in the nanometer-size range. The model couples a detailed kinetic scheme with a discrete-sectional approach to follow the transition from gas-phase to nascent particles and their coagulation to larger soot particles. The evolution of soot size distribution (experimental and modeled) in pure ethylene and ethylene flames doped with benzene showed a typical nucleation-sized (since particles do not actually nucleate in the classical sense particle inception is often used in place of nucleation) mode close to the burner surface, and a bimodal behavior at greater height above burner (HAB). However, major features were distinguished between the data sets. The growth of nucleation and agglomeration-sized particles was faster for ethylene/benzene/air flames, evidenced by the earlier presence of bimodality in these flames. The most significant changes in size distribution were attributed to an increase in benzene concentration in the initial fuel. However, these changes were more evident for high temperature flames. In agreement with the experimental data, the model also predicted the decrease of nucleation-sized particles in the postflame region for ethylene flames doped with benzene. This behavior was associated with the decrease of soot precursors after the main oxidation zone of the flames. (author)

  11. Serum 2,3,7,8-tetrachlorodibenzo-p-dioxin levels in Air Force health study participants - preliminary report

    SciTech Connect

    Not Available

    1988-06-24

    In 1978, the US Air Force responded to a congressional mandate to initiate an epidemiologic study of the possible health effects of exposure to herbicides and their 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) contaminants in Air Force veterans who served in the Ranch Hand defoliation operation during the Vietnam conflict. Accordingly, the Air Force conducted a nonconcurrent prospective study, the Air Force Health Study, of all 1267 members of the Ranch Hand unit and a series of matched controls. This phase of the Air Force study focused on measuring serum TCDD levels in 150 Ranch Hand veterans and 50 controls. All participants were enlisted men; the Ranch Hand veterans had been either herbicide loaders or herbicide specialists in Vietnam. The demographic and health characteristics of Ranch Hand personnel and controls were similar; however, their serum TCDD levels differed markedly.

  12. Air Pollution and Cardiovascular Health in Mandi-Gobindgarh, Punjab, India - A Pilot Study

    PubMed Central

    Nautiyal, Jyoti; Garg, ML.; Kumar, Manoj Sharma; Khan, Asif Ali; Thakur, Jarnail S.; Kumar, Rajesh

    2007-01-01

    Large number of epidemiological studies to know the effect of air pollution on the general mortality and morbidity, and the cardiopulmonary morbidity and mortality are concentrated in USA and Europe. Regional differences in air pollution necessitate regional level health effects studies. Present study is a cross sectional pilot study from India, an Asian country. A sample of population from an industrial town ‘Mandi Gobindgarh’ and a non-industrial town ‘Morinda’ were selected. A cross-sectional household survey was done in both the towns. One hundred subjects were selected from each of the towns. Ambient air quality data was collected for both towns over a period of 10-months to assess seasonal variations. In the present study the average PM10 (particulate matter with ≤ 10μm aerodynamic diameter) levels in Morinda were 99.54 μg/m3 and in Mandi Gobindgarh 161.20 μg/m3. As per NAAQS the permitted levels of PM10 is 50 μg/m3 taken as annual average (arithmetic mean). Elemental analysis of the aerosol samples found the concentration levels to be higher in Mandi- Gobindgarh than Morinda. The population in Gobindgarh shows a higher prevalence of symptoms of angina and cardiovascular disease considered in the study as compared to Morinda. When the same data is viewed in terms of male and female population, the female population is found to show these symptoms marginally higher than their counterparts. Considering the results of present study it can be stated that the increased levels of different pollutants and the higher prevalence of cardiovascular symptoms in Mandi-Gobindgarh (Industrial town) than the Morinda (Non-Industrial town) is because of the association of PM pollution with cardiovascular diseases. Keeping in view the current status of literature, further studies in this direction are needed in a country like India. Such data will also be globally relevant. PMID:18180537

  13. Time-location patterns of a diverse population of older adults: the Multi-Ethnic Study of Atherosclerosis and Air Pollution (MESA Air).

    PubMed

    Spalt, Elizabeth W; Curl, Cynthia L; Allen, Ryan W; Cohen, Martin; Adar, Sara D; Stukovsky, Karen H; Avol, Ed; Castro-Diehl, Cecilia; Nunn, Cathy; Mancera-Cuevas, Karen; Kaufman, Joel D

    2016-06-01

    The primary aim of this analysis was to present and describe questionnaire data characterizing time-location patterns of an older, multiethnic population from six American cities. We evaluated the consistency of results from repeated administration of this questionnaire and between this questionnaire and other questionnaires collected from participants of the Multi-Ethnic Study of Atherosclerosis and Air Pollution (MESA Air). Participants reported spending most of their time inside their homes (average: 121 h/week or 72%). More than 50% of the participants reported spending no time in several of the location options, including at home outdoors, at work/volunteer/school locations indoors or outdoors, or in "other" locations outdoors. We observed consistency between self-reported time-location patterns from repeated administration of the time-location questionnaire and compared with other survey instruments. Comparisons with national cohorts demonstrated the differences in time-location patterns in the MESA Air cohort due to differences in demographics, but the data showed similar trends in patterns by age, gender, season, and employment status. This study was the first to explicitly examine the time-location patterns in an older, multiethnic population and the first to add data on Chinese participants. These data can be used to inform future epidemiological research of MESA Air and other studies that include diverse populations. PMID:25921083

  14. A Further Study of High Air Pollution Episodes in Taiwan Using the Microwave Temperature Profiler (MTP-5HE)

    NASA Astrophysics Data System (ADS)

    Chang, Che-Ming; Chang, Long-Nan; Hsiao, Hui-Chuan; Lu, Fang-Chuan; Shieh, Ping-Fei; Chen, Chi-Nan; Lu, Shish-Chong

    In the metropolitan areas of Taiwan with high population density, heavy traffic, and/or zones of heavy industries, serious air pollution episodes may occur during stable weather conditions. The information of mixing height is therefore essential to the air pollution control in this area. In this study, diurnal variation of the mixing height derived using the newly established EPA-Taiwan microwave temperature profiler (MTP-5HE) and that obtained through the CWB soundings are compared. The relationships between the air quality and the diurnal variation of the mixing height is discussed during different air pollution episodes.

  15. Air Quality Impacts of Atmospheric Particles & Trace Gases: Field Studies in Diverse Environments

    NASA Astrophysics Data System (ADS)

    Mwaniki, George R.

    Air pollution impacts occur at all scales, meaning that policies and air quality management practices must be implemented and coordinated at the local, regional, national, and global scales. This dissertation is part of a continuing effort to improve our understanding of various air quality related issues in different environments. The dissertation consists of four studies. In the first study, wintertime chemical composition of water-soluble particulate matter with aerodynamic diameter less than 2.5 microm (PM2.5) was monitored in the Treasure Valley region near Boise, Idaho. This study was aimed at understanding the major drivers of wintertime PM2.5 within the locality of Boise and its suburbs. From this study, organics and particulate nitrate were the dominant contributors to the PM2.5 mass during wintertime. In the second study, particle size distribution, light scattering coefficient, speciated water soluble PM2.5, and cloud condensation nuclei (CCN) concentration were monitored in a mixed deciduous forest in Northern Michigan during the Community Atmosphere-Biosphere Interactions Experiment (CABINEX-2009). The overall goal of this study was to understand on how emissions of biogenic volatile organic compounds (BVOC) affect the gas-phase and particle-phase chemistry in the near-canopy environment, and the implications on local and regional air quality. From this study aerosol derived from the oxidation of BVOCs exhibited reduced hygroscopicity and CCN activation potential compared to aerosols derived from anthropogenic activities. The third study employed the eddy covariance (EC) technique to understand source-sink interactions of carbon dioxide (CO2), methane (CH 4), carbon monoxide (CO) and nitrous oxide (N2O) in Xi'an, China. In this study urban vegetation were found to play a major role in regulating CO2 emissions within the city while vehicular activities were a major driver for CO and CH4 fluxes. In the fourth study, visibility degradation effects of

  16. Air pollution and mortality in Valencia, Spain: a study using the APHEA methodology.

    PubMed Central

    Ballester, F; Corella, D; Pérez-Hoyos, S; Hervás, A

    1996-01-01

    STUDY OBJECTIVE: To assess the short term relationship between daily air pollution indicators (black smoke and sulphur dioxide (SO2)) and mortality in Valencia. DESIGN: This was an ecological study using time series data with application of Poisson regression. Daily variations in four selected outcome variables (total mortality, mortality in those over 70 years of age, and cardiovascular and respiratory mortality) were considered in relation to daily variations in air pollution levels for the period 1991-93. SETTING: The city of Valencia, Spain. MAIN RESULTS: The mean daily mortality was 17.5, and the average daily levels of air pollutants from the three monitoring stations included in the study were, 67.7 micrograms/m3 for black smoke, and 39.9 micrograms/ m3 for SO2. A significant positive association between black smoke and three of the four outcomes in the study was found. The estimated relative risk (RR) of dying corresponding to a 10 micrograms/m3 increase in mean daily black smoke over the whole period was 1.009 (95% confidence interval (95% CI): 1.003, 1.015). For mortality in the group aged more than 70 years and for cardiovascular mortality, the RRs were 1.008 (95% CI: 1.001, 1.016) and 1.012 (95% CI: 1.003, 1.022) respectively. The association with SO2 was less clear: it was only evident during the warm season. The estimated RRs in this case were 1.007 (95% CI: 0.999, 1.015) for total mortality, 1.009 (95% CI: 1.00, 1.21) for total mortality in those older than 70, and 1.012 (95% CI: 0.995, 1.026) for cardiovascular deaths. No significant association was found between mortality from respiratory diseases and either of the two pollutants. CONCLUSIONS: A positive relationship between air pollution and mortality was found in the short term, as has been shown in an important number of studies carried out elsewhere. Although the current levels of particulate air pollution in Valencia are not very high, they could have an effect on the number of premature

  17. The Novel Relationship between Urban Air Pollution and Epilepsy: A Time Series Study

    PubMed Central

    Xu, Chen; Fan, Yan-Ni; Kan, Hai-Dong; Chen, Ren-Jie; Liu, Jiang-Hong; Li, Ya-Fei; Zhang, Yao; Ji, Ai-Ling

    2016-01-01

    Background and purpose The data concerning the association between environmental pollution and epilepsy attacks are limited. The aim of this study was to explore the association between acute air pollution exposure and epilepsy attack. Methods A hospital record-based study was carried out in Xi’an, a heavily-polluted metropolis in China. Daily baseline data were obtained. Time-series Poisson regression models were applied to analyze the association between air pollution and epilepsy. Results A 10 μg/m3 increase of NO2, SO2, and O3 concentrations corresponded to 3.17% (95%Cl: 1.41%, 4.93%), 3.55% (95%Cl: 1.93%, 5.18%), and -0.84% (95%Cl: -1.58%, 0.09%) increase in outpatient-visits for epilepsy on the concurrent days, which were significantly influenced by sex and age. The effects of NO2 and SO2 would be stronger when adjusted for PM2.5. As for O3, a -1.14% (95%Cl: -1.90%, -0.39%) decrease was evidenced when adjusted for NO2. The lag models showed that the most significant effects were evidenced on concurrent days. Conclusions We discovered previously undocumented relationships between short-term air pollution exposure and epilepsy: while NO2 and SO2 were positively associated with outpatient-visits of epilepsy, O3 might be associated with reduced risk. PMID:27571507

  18. Studies on diversity of lichen, Pyxine cocoes to air pollution in Bhadravathi town, Karnataka, India.

    PubMed

    Danesh, Naveen; Puttaiah, E T; Basavarajappa, B E

    2013-05-01

    Air pollution induced climate change affecting the pigmentation and diversity of lichen, Pyxine cocoes were monitored around the industrial area and traffic area of Bhadravthi using European guidelines. The obtained data has been discussed and results compared with data from that of Kuvempu University campus (control). From the present study, it was evident that the air pollutants emitted from the two major industries and other small scale industries affected the total chlorophyll (0.16 mg g(-1)) and carotene pigments (0.11 mg g(-1)) in Pyxine cocoes, as well as their diversity (approx 13) on two plants (M. indica and P. pinnata) in the vicinity of the industrial area. Further, as a result of vehicular pollution at traffic area resulted in the deterioration of total chlorophyll (0.11 mg g(-1)), carotene pigments (0.07 mg g(-1)) and diversity (approx. 17) of Pyxine cocoes compared to control site. The present study has thrown light on lichens sensitivity to the air pollution. PMID:24617145

  19. Association of stillbirth with ambient air pollution in a California cohort study.

    PubMed

    Green, Rochelle; Sarovar, Varada; Malig, Brian; Basu, Rupa

    2015-06-01

    Recent studies have suggested an association between air pollution and stillbirth. In this California study, we examined the records of 13,999 stillbirths and 3,012,270 livebirths occurring between 1999 and 2009. Using a retrospective cohort design and logistic regression models, we calculated the odds of stillbirth associated with each pollutant exposure by trimester and throughout the entire pregnancy. Covariates considered in the model included infant sex, maternal demographic characteristics, season of last menstrual period, apparent temperature, air basin of mother's residence, and year of conception. In single-pollutant models, we found that a 10-µg/m(3) increase in particulate matter with an aerodynamic diameter less than or equal to 2.5 µm (odds ratio (OR) = 1.06, 95% confidence interval (CI): 0.99, 1.13) and a 10-ppb increase in nitrogen dioxide (OR = 1.08, 95% CI: 1.03, 1.13) during the entire pregnancy were associated with stillbirth. A 10-ppb increase in ozone exposure during the third trimester was also associated with a slightly elevated risk (OR = 1.03, 95% CI: 1.01, 1.05). These ozone and nitrogen dioxide findings were fairly stable after adjustment in 2-pollutant models. However, adjustment for nitrogen dioxide attenuated the full-pregnancy-particulate matter relationship. No significant associations were found for sulfur dioxide or carbon monoxide. These findings support growing evidence of an association between air pollution and adverse birth outcomes. PMID:25861815

  20. A statistical study of the macroepidemiology of air pollution and total mortality

    SciTech Connect

    Lipfert, F.W.; Malone, R.G.; Daum, M.L.; Mendell, N.R.; Yang, Chin-Chun

    1988-04-01

    A statistical analysis of spatial patterns of 1980 US urban total mortality (all causes) was performed, evaluating demographic, socioeconomic and air pollution factors as predictors. Specific mortality predictors included cigarette smoking, drinking water hardness, heating fuel use, and 1978-1982 annual concentrations of the following air pollutants: ozone, carbon monoxide, sulfate aerosol, particulate concentrations of lead, iron, cadmium, manganese, vanadium, as well as total and fine particle mass concentrations from the inhalable particulate network (dichotomous samplers). In addition, estimates of sulfur dioxide, oxides of nitrogen, and sulfate aerosol were made for each city using the ASTRAP long-range transport diffusion model, and entered into the analysis as independent variables. Because the number of cities with valid air quality and water hardness data varied considerably by pollutant, it was necessary to consider several different data sets, ranging from 48 to 952 cities. The relatively strong associations (ca. 5--10%) shown for 1980 pollution with 1980 total mortality are generally not confirmed by independent studies, for example, in Europe. In addition, the US studies did not find those pollutants with known adverse health effects at the concentrations in question (such as ozone or CO) to be associated with mortality. The question of causality vs. circumstantial association must therefore be regarded as still unresolved. 59 refs., 20 figs., 40 tabs.

  1. A study of the glow discharge characteristics of contact electrodes at atmospheric pressure in air

    SciTech Connect

    Liu, Wenzheng Sun, Guangliang Li, Chuanhui; Zhang, Rongrong

    2014-04-15

    Electric field distributions and discharge properties of rod-rod contact electrodes were studied under the condition of DBD for the steady generation of atmospheric pressure glow discharge plasma (APGD) in air. We found that under the effect of the initial electrons generated in a nanometer-scale gap, the rod-rod cross-contact electrodes yielded APGD plasma in air. Regarding the rod-rod cross-contact electrodes, increasing the working voltage expanded the strong electric field area of the gas gap so that both discharge area and discharge power increased, and the increase in the number of contact points kept the initial discharge voltage unchanged and caused an increase in the plasma discharge area and discharge power. A mesh-like structure of cross-contact electrodes was designed and used to generate more APGD plasma, suggesting high applicability.

  2. Studies of Cosmic Ray Composition and Air Shower Structure with the Pierre Auger Observatory

    SciTech Connect

    Abraham, : J.; Abreu, P.; Aglietta, M.; Aguirre, C.; Ahn, E.J.; Allard, D.; Allekotte, I.; Allen, J.; Alvarez-Muniz, J.; Ambrosio, M.; Anchordoqui, L.

    2009-06-01

    These are presentations to be presented at the 31st International Cosmic Ray Conference, in Lodz, Poland during July 2009. It consists of the following presentations: (1) Measurement of the average depth of shower maximum and its fluctuations with the Pierre Auger Observatory; (2) Study of the nuclear mass composition of UHECR with the surface detectors of the Pierre Auger Observatory; (3) Comparison of data from the Pierre Auger Observatory with predictions from air shower simulations: testing models of hadronic interactions; (4) A Monte Carlo exploration of methods to determine the UHECR composition with the Pierre Auger Observatory; (5) The delay of the start-time measured with the Pierre Auger Observatory for inclined showers and a comparison of its variance with models; (6) UHE neutrino signatures in the surface detector of the Pierre Auger Observatory; and (7) The electromagnetic component of inclined air showers at the Pierre Auger Observatory.

  3. The semi-individual study in air pollution epidemiology: a valid design as compared to ecologic studies.

    PubMed Central

    Künzli, N; Tager, I B

    1997-01-01

    The assessment of long-term effects of air pollution in humans relies on epidemiologic studies. A widely used design consists of cross-sectional or cohort studies in which ecologic assignment of exposure, based on a fixed-site ambient monitor, is employed. Although health outcome and usually a large number of covariates are measured in individuals, these studies are often called ecological. We will introduce the term semi-individual design for these studies. We review the major properties and limitations with regard to causal inference of truly ecologic studies, in which outcome, exposure, and covariates are available on an aggregate level only. Misclassification problems and issues related to confounding and model specification in truly ecologic studies limit etiologic inference to individuals. In contrast, the semi-individual study shares its methodological and inferential properties with typical individual-level study designs. The major caveat relates to the case where too few study areas, e.g., two or three, are used, which render control of aggregate level confounding impossible. The issue of exposure misclassification is of general concern in epidemiology and not an exclusive problem of the semi-individual design. In a multicenter setting, the semi-individual study is a valuable tool to approach long-term effects of air pollution. Knowledge about the error structure of the ecologically assigned exposure allows consideration of the impact of ecologically assigned exposure on effect estimation. Semi-individual studies, i.e., individual level air pollution studies with ecologic exposure assignment, more readily permit valid inference to individuals and should not be labeled as ecologic studies. PMID:9349825

  4. Air leak seal for lung dissection plane with diode laser irradiation: an ex vivo study

    NASA Astrophysics Data System (ADS)

    Gotoh, Maya; Tokunaga, Hisako; Kaneko, Kenji; Arai, Tsunenori

    2007-02-01

    In order to seal air leak from lung dissection plane in thoracotomy, we studied diode laser irradiation (wavelength: 810nm) with surface stain of indocyanine green (ICG, peak absorption wavelength: 805nm) ex vivo. In general, this air leak is sealed by suturing with weak tension and large margin of parenchyma. This suturing requires surgeon's skill and takes long time. Moreover, lung ventilatory performance is significantly impaired. Since laser tissue welding is novel method to adhere living tissue with thin thermally denatured attachment layer, we propose to seal the lung dissection plane with laser irradiation. Our aim of this study is to investigate the sealing mechanism as well as optimum condition to develop reliable laser sealing method for dissected lung plane in surgery, using practical laser-dye combination. Compartment of extracted porcine lung was prepared as a lung model, which volume was approximately 60cm^3. ICG solution (2.5mg/ml) was applied to the dissection plane of this lung model with 1minute. The diode laser (power density: 8-40W/cm^2) irradiated to the plane, moving the laser spot with constant speed (v=1mm/s). The heat degeneration depth and smoothness of the laser irradiated surface were observed by a microscope. When power density was over 24W/cm^2, heat degeneration depth was over 1.5E-4 m. There were no pin holes on the surface and the air leak seemed to be sealed completely. We also evaluated the air leak by endotracheal pressure. In the case of above condition, the heat degeneration depth was the same that of previous reported result with CO2 laser.

  5. Geriatric study in Europe on health effects of air quality in nursing homes (GERIE study) profile: objectives, study protocol and descriptive data

    PubMed Central

    2013-01-01

    Background Indoor air pollution (IAP) constitutes a major global public health problem requiring increasing efforts in research and policymaking that may have special significance for elderly that are likely to spend most of their day indoors and appear to be particularly susceptible to adverse effects of chemical pollutants and bio-contaminants. Yet, evidence existing on the effects of IAP in elderly is scanty. The Geriatric study in Europe on health effects of air quality in nursing homes (GERIE) study aimed to assess health effects of major indoor air pollutants and thermal conditions in elderly (> 70 years) living stably in nursing homes (NH) across Europe. Respiratory effects were particularly considered as airways and lung constitute the first target of air pollutants. Objectives We describe here the rationale and the methods of the GERIE Study. Methods 8 nursing homes were randomly selected in 7 European countries. Twenty individuals were randomly selected in each nursing home. Major indoor and outdoor air chemical pollutants (PM10, PM2.5, PM0.1, formaldehyde, NO2; O3, VOC, CO2) and bio-contaminants (moulds, allergens) were assessed objectively with standardized procedures. Major health status indicators were assessed through a standardized questionnaire, non-invasive clinical tests and blood and urine biomarkers as well as saliva for ADN. Results The GERIE study has given the opportunity to publish two reviews on respiratory health effects of indoor and outdoor air pollution in elderly. In addition it has provided the inventory of air quality and thermal conditions in 50 nursing homes across Europe and data on respiratory health status in 600 elderly aged 82 years in mean. Major future results will include the relationships between NH environment and health in elderly. Conclusions The main long-term purpose of the GERIE study is to improve the health of elderly who permanently reside in nursing homes or of those who are exposed to indoor air pollution

  6. A Method for Estimating Urban Background Concentrations in Support of Hybrid Air Pollution Modeling for Environmental Health Studies

    EPA Science Inventory

    Exposure studies rely on detailed characterization of air quality, either from sparsely located routine ambient monitors or from central monitoring sites that may lack spatial representativeness. Alternatively, some studies use models of various complexities to characterize local...

  7. Plasma test on industrial diamond powder in hydrogen and air for fracture strength study

    NASA Astrophysics Data System (ADS)

    Chary, Rohit Asuri Sudharshana

    Diamonds are the most precious material all over the world. Ever since their discovery, the desire for natural diamonds has been great; recently, the demand has steeply increased, leading to scarcity. For example, in 2010, diamonds worth $50 billion were marketed. This increased demand has led to discovering alternative sources to replace diamonds. The diamond, being the hardest material on earth, could be replaced with no other material except another diamond. Thus, the industrial or synthetic diamond was invented. Because of extreme hardness is one of diamond's properties, diamonds are used in cutting operations. The fracture strength of diamond is one of the crucial factors that determine its life time as a cutting tool. Glow discharge is one of the techniques used for plasma formation. The glow discharge process is conducted in a vacuum chamber by ionizing gas atoms. Ions penetrate into the atomic structure, ejecting a secondary electron. The objective of this study is to determine the change in fracture strength of industrial diamond powder before and after plasma treatment. This study focuses mainly on the change in crystal defects and crushing strength (CS) of industrial diamond powder after the penetration of hydrogen gas, air and hydrogen-air mixture ions into the sample powder. For this study, an industrial diamond powder sample of 100 carats weight, along with its average fracture strength value was received from Engis Corporation, Illinois. The sample was divided into parts, each weighing 10-12 carats. At the University of Nevada, Las Vegas (UNLV), a plasma test was conducted on six sample parts for a total of 16 hours on each part. The three gas types mentioned above were used during plasma tests, with the pressure in vacuum chamber between 200 mTorr and 2 Torr. The plasma test on four sample parts was in the presence of hydrogen-air mixture. The first sample had chamber pressures between 200 mTorr and 400 mTorr. The remaining three samples had chamber

  8. Feasibility study of porous media compressed air energy storage in South Carolina, United States of America

    NASA Astrophysics Data System (ADS)

    Jarvis, Alexandra-Selene

    Renewable Energy Systems (RES) such as solar and wind, are expected to play a progressively significant role in electricity production as the world begins to move away from an almost total reliance on nonrenewable sources of power. In the US there is increasing investment in RES as the Department of Energy (DOE) expands its wind power network to encompass the use of offshore wind resources in places such as the South Carolina (SC) Atlantic Coastal Plain. Because of their unstable nature, RES cannot be used as reliable grid-scale power sources unless power is somehow stored during excess production and recovered at times of insufficiency. Only two technologies have been cited as capable of storing renewable energy at this scale: Pumped Hydro Storage and Compressed Air Energy Storage (CAES). Both CAES power plants in existence today use solution-mined caverns as their storage spaces. This project focuses on exploring the feasibility of employing the CAES method to store excess wind energy in sand aquifers. The numerical multiphase flow code, TOUGH2, was used to build models that approximate subsurface sand formations similar to those found in SC. Although the aquifers of SC have very low dips, less than 10, the aquifers in this study were modeled as flat, or having dips of 00. Cycle efficiency is defined here as the amount of energy recovered compared to the amount of energy injected. Both 2D and 3D simulations have shown that the greatest control on cycle efficiency is the volume of air that can be recovered from the aquifer after injection. Results from 2D simulations showed that using a dual daily peak load schedule instead of a single daily peak load schedule increased cycle efficiency as do the following parameters: increased anisotropy, screening the well in the upper portions of the aquifer, reduced aquifer thickness, and an initial water displacement by the continuous injection of air for at least 60 days. Aquifer permeability of 1x10-12 m2 produced a cycle

  9. Modeling exposures to traffic-related air pollutants for the NEXUS respiratory health study of asthmatic children in Detroit, MI

    EPA Science Inventory

    The Near-Road EXposures and Effects of Urban Air Pollutants Study (NEXUS) was designed to investigate associations between exposure to traffic-related air pollution and the respiratory health of asthmatic children living near major roadways in Detroit, MI. A combination of modeli...

  10. RADIOMETRIC METHOD FOR THE DETERMINATION OF URANIUM IN SOIL AND AIR: SINGLE-LABORATORY EVALUATION AND INTERLABORATORY COLLABORATIVE STUDY

    EPA Science Inventory

    Results of a single-laboratory evaluation and an interlaboratory collaborative study of a method for determining uranium isotopes in soil and air samples are presented. The method is applicable to 10-gram soil samples and to both glass fiber and polystyrene air filter samples. Sa...

  11. Application of the Gestalt Theory of Learning in Teaching a Unit of Study Dealing with Air Pollution in Polk County.

    ERIC Educational Resources Information Center

    Nelson, Hershel H.

    This practicum was designed to demonstrate the value of Gestalt learning theory in teaching a unit of study on air pollution in Polk County, Florida. Students researched specific viewpoints based upon assigned positions in regard to air pollution (Cattlemen's Association, Florida Phosphate Council, Florida Citrus Mutual, Mid-State Lung…

  12. Applicability of the Environmental Relative Moldiness Index for Quantification of Residential Mold Contamination in an Air Pollution Health Effects Study

    EPA Science Inventory

    As part of the Near-Road Exposures and Effects of Urban Air Pollutants Study (NEXUS) investigating the respiratory health impacts of traffic-related air pollutants on asthmatic children in Detroit, Michigan, residential dust samples were collected to quantify mold exposure. Sett...

  13. THE UNIVERSITY OF AKRON STUDY ON AIR POLLUTION AND HUMAN HEALTH EFFECTS II. EFFECTS ON ACUTE RESPIRATORY ILLNESS

    EPA Science Inventory

    The purpose of this study was to determine the effects of air pollution on acute respiratory illness (ARI). Levels of air pollutants were monitored on a daily 24-hour basis at two schools in Akron, Ohio. The children at each school completed daily diaries which served as a screen...

  14. U.S.-MEXICO BORDER PROGRAM ARIZONA BORDER STUDY--PAHS IN AIR--REAL TIME SENSOR ANALYTICAL RESULTS

    EPA Science Inventory

    This PAHs in Air data set contains 516 readings detecting the presence of polynuclear aromatic hydrocarbons (PAHs) in 86 households in the Arizona Border Study using a photo ionization device (PID). Keywords: air; PAHs, real time.

    The U.S.-Mexico Border Program is sponsored by...

  15. Characterizing exposure in community health studies: A participant-based approach to indoor/outdoor air monitoring

    EPA Science Inventory

    Introduction: Traffic-related air pollution has been associated with numerous adverse outcomes. However, community health studies of traffic-related air pollution have been hampered by the cost and participant burden associated with estimating household-level exposure through te...

  16. POPULATION EXPOSURE AND DOSE MODEL FOR AIR TOXICS: A BENZENE CASE STUDY

    EPA Science Inventory

    The EPA's National Exposure Research Laboratory (NERL) is developing a human exposure and dose model called the Stochastic Human Exposure and Dose Simulation model for Air Toxics (SHEDS-AirToxics) to characterize population exposure to air toxics in support of the National Air ...

  17. NHEXAS PHASE I REGION 5 STUDY--METALS IN AIR ANALYTICAL RESULTS

    EPA Science Inventory

    This data set includes analytical results for measurements of metals in 534 air samples. Samples of personal air, indoor air, and outdoor air were collected using a pump and interval timer over a period of approximately 144 hours to measure inhalation exposure to metals. Most of ...

  18. NHEXAS PHASE I REGION 5 STUDY--PARTICLES IN AIR ANALYTICAL RESULTS

    EPA Science Inventory

    This data set includes analytical results for measurements of particles (aerosol mass) in 538 air samples. Samples of personal air, indoor air, and outdoor air were collected using a pump and interval timer over a period of approximately 144 hours to measure inhalation exposure t...

  19. NHEXAS PHASE I REGION 5 STUDY--VOCS IN AIR ANALYTICAL RESULTS

    EPA Science Inventory

    This data set includes analytical results for measurements of VOCs (volatile organic compounds) in 998 air samples. Samples of personal air, indoor air, and outdoor air were collected using two-stage passive badges (3-M, 3520, Minneapolis, MN) over a period of approximately 144 h...

  20. Indoor air sampling and mutagenicity studies related to emissions from unvented coal combustion

    SciTech Connect

    Mumford, J.L.; Harris, D.B.; Williams, K.; Chuang, J.C.; Cooke, M.

    1986-07-01

    The purpose of the study is to develop sampling strategies and bioassay methods for indoor air in homes. The work reported here was conducted to prepare for a joint U.S.-China field study in Xuan Wei County, Yunnan Province, southern China, where the residents traditionally burn coal or wood for domestic cooking and heating without flue ventilation. These residents are exposed daily to high levels of combustion smoke and have unusually high lung cancer mortality rates, the women's rate the highest in China, and the men's rate among the highest. The paper reports the chemical and biological characterization of coal emissions from a simulated combustion laboratory.

  1. The effect of ambient air pollution on respiratory health of school children: a panel study

    PubMed Central

    Epton, Michael J; Dawson, Robin D; Brooks, Wendy M; Kingham, Simon; Aberkane, Teresa; Cavanagh, Jo-Anne E; Frampton, Christopher M; Hewitt, Tracey; Cook, Julie M; McLeod, Susan; McCartin, Fiona; Trought, Katherine; Brown, Leslie

    2008-01-01

    Background Adverse respiratory effects of particulate air pollution have been identified by epidemiological studies. We aimed to examine the health effects of ambient particulate air pollution from wood burning on school-age students in Christchurch, New Zealand, and to explore the utility of urine and exhaled breath condensate biomarkers of exposure in this population. Methods A panel study of 93 male students (26 with asthma) living in the boarding house of a metropolitan school was undertaken in the winter of 2004. Indoor and outdoor pollution data was continuously monitored. Longitudinal assessment of lung function (FEV1 and peak flow) and symptoms were undertaken, with event studies of high pollution on biomarkers of exposure (urinary 1-hydroxypyrene) and effect (exhaled breath condensate (EBC) pH and hydrogen peroxide concentration). Results Peak levels of air pollution were associated with small but statistically significant effects on lung function in the asthmatic students, but not healthy students. No significant effect of pollution could be seen either on airway inflammation and oxidative stress either in healthy students or students with asthma. Minor increases in respiratory symptoms were associated with high pollution exposure. Urinary 1-hydroxypyrene levels were raised in association with pollution events by comparison with low pollution control days. Conclusion There is no significant effect of ambient wood-smoke particulate air pollution on lung function of healthy school-aged students, but a small effect on respiratory symptoms. Asthmatic students show small effects of peak pollution levels on lung function. Urinary 1-hydroxypyrene shows potential as a biomarker of exposure to wood smoke in this population; however measurement of EBC pH and hydrogen peroxide appears not to be useful for assessment of population health effects of air pollution. Some of the data presented in this paper has previously been published in Kingham and co

  2. Effects of air pollution on the respiratory health of children: a cross-sectional study

    SciTech Connect

    Spinaci, S.; Arossa, W.; Bugiani, M.; Natale, P.; Bucca, C.; de Candussio, G.

    1985-09-01

    To investigate the effects of air pollution on the respiratory health of children, a subject of some controversy, a comparative study was undertaken of 2,385 school children who lived in central urban, peripheral urban, and suburban areas. Daily monitoring of sulfur dioxide and total suspended particle concentrations in all areas showed that pollutant concentrations in central and peripheral urban areas were above commonly accepted safety levels for respiratory health, while concentrations in the suburban area were within acceptable limits. A questionnaire administered to each mother assessed environmental exposure to pollutants in the household, the occurrence of respiratory symptoms as well as lung diseases as diagnosed by a physician, and general information. Children were interviewed about smoking habits and any acute respiratory symptoms. Children also performed standard lung function tests. Results showed that children from both urban areas had lessened pulmonary function and a higher prevalence of bronchial secretion with common colds than did those from the suburban area. These differences persisted after corrections for exposure to indoor pollutants, active or passive smoking, socioeconomic status, and sex. Parental cigarette smoking was related to a fall in forced expiratory volume in 1 second and an increased incidence of acute respiratory illnesses and chronic cough in children. Although boys had higher lung volumes and lower air flow, regression analysis showed no significant influence of the interactions sex-geographic area and sex-smoking on lung function. It was concluded that air pollution has a significant effect on the respiratory health of children.

  3. Assessment of environmental impact on air quality by cement industry and mitigating measures: a case study.

    PubMed

    Kabir, G; Madugu, A I

    2010-01-01

    In this study, environmental impact on air quality was evaluated for a typical Cement Industry in Nigeria. The air pollutants in the atmosphere around the cement plant and neighbouring settlements were determined using appropriate sampling techniques. Atmospheric dust and CO2 were prevalent pollutants during the sampling period; their concentrations were recorded to be in the range of 249-3,745 mg/m3 and 2,440-2,600 mg/m3, respectively. Besides atmospheric dust and CO2, the air pollutants such as NOx, SOx and CO were in trace concentrations, below the safe limits approved by FEPA that are 0.0062-0.093 mg/m3 NOx, 0.026 mg/m3 SOx and 114.3 mg/m3 CO, respectively. Some cost-effective mitigating measures were recommended that include the utilisation of readily available and low-cost pozzolans material to produce blended cement, not only could energy efficiency be improved, but carbon dioxide emission could also be minimised during clinker production; and the installation of an advance high-pressure grinding rolls (clinker-roller-press process) to maximise energy efficiency to above what is obtainable from the traditional ball mills and to minimise CO2 emission from the power plant. PMID:19067202

  4. Experimental performance study of a proposed desiccant based air conditioning system.

    PubMed

    Bassuoni, M M

    2014-01-01

    An experimental investigation on the performance of a proposed hybrid desiccant based air conditioning system referred as HDBAC is introduced in this paper. HDBAC is mainly consisted of a liquid desiccant dehumidification unit integrated with a vapor compression system (VCS). The VCS unit has a cooling capacity of 5.27 kW and uses 134a as refrigerant. Calcium chloride (CaCl2) solution is used as the working desiccant material. HDBAC system is used to serve low sensible heat factor applications. The effect of different parameters such as, process air flow rate, desiccant solution flow rate, evaporator box and condenser box solution temperatures, strong solution concentration and regeneration temperature on the performance of the system is studied. The performance of the system is evaluated using some parameters such as: the coefficient of performance (COPa), specific moisture removal and energy saving percentage. A remarkable increase of about 54% in the coefficient of performance of the proposed system over VCS with reheat is achieved. A maximum overall energy saving of about 46% is observed which emphasizes the use of the proposed system as an energy efficient air conditioning system. PMID:25685475

  5. Improved Satellite-based Photosysnthetically Active Radiation (PAR) for Air Quality Studies

    NASA Astrophysics Data System (ADS)

    Pour Biazar, A.; McNider, R. T.; Cohan, D. S.; White, A.; Zhang, R.; Dornblaser, B.; Doty, K.; Wu, Y.; Estes, M. J.

    2015-12-01

    One of the challenges in understanding the air quality over forested regions has been the uncertainties in estimating the biogenic hydrocarbon emissions. Biogenic volatile organic compounds, BVOCs, play a critical role in atmospheric chemistry, particularly in ozone and particulate matter (PM) formation. In southeastern United States, BVOCs (mostly as isoprene) are the dominant summertime source of reactive hydrocarbon. Despite significant efforts in improving BVOC estimates, the errors in emission inventories remain a concern. Since BVOC emissions are particularly sensitive to the available photosynthetically active radiation (PAR), model errors in PAR result in large errors in emission estimates. Thus, utilization of satellite observations to estimate PAR can help in reducing emission uncertainties. Satellite-based PAR estimates rely on the technique used to derive insolation from satellite visible brightness measurements. In this study we evaluate several insolation products against surface pyranometer observations and offer a bias correction to generate a more accurate PAR product. The improved PAR product is then used in biogenic emission estimates. The improved biogenic emission estimates are compared to the emission inventories over Texas and used in air quality simulation over the period of August-September 2013 (NASA's Discover-AQ field campaign). A series of sensitivity simulations will be performed and evaluated against Discover-AQ observations to test the impact of satellite-derived PAR on air quality simulations.

  6. Experimental performance study of a proposed desiccant based air conditioning system

    PubMed Central

    Bassuoni, M.M.

    2013-01-01

    An experimental investigation on the performance of a proposed hybrid desiccant based air conditioning system referred as HDBAC is introduced in this paper. HDBAC is mainly consisted of a liquid desiccant dehumidification unit integrated with a vapor compression system (VCS). The VCS unit has a cooling capacity of 5.27 kW and uses 134a as refrigerant. Calcium chloride (CaCl2) solution is used as the working desiccant material. HDBAC system is used to serve low sensible heat factor applications. The effect of different parameters such as, process air flow rate, desiccant solution flow rate, evaporator box and condenser box solution temperatures, strong solution concentration and regeneration temperature on the performance of the system is studied. The performance of the system is evaluated using some parameters such as: the coefficient of performance (COPa), specific moisture removal and energy saving percentage. A remarkable increase of about 54% in the coefficient of performance of the proposed system over VCS with reheat is achieved. A maximum overall energy saving of about 46% is observed which emphasizes the use of the proposed system as an energy efficient air conditioning system. PMID:25685475

  7. Experimental and computational studies on Coanda nozzle flow for the air knife application

    NASA Astrophysics Data System (ADS)

    Kwon, Soon-Bum; Lee, Dong-Won; Kwon, Young-Doo

    2007-05-01

    To control the film thickness of zinc in the process of continuous hot-dip galvanizing, it is known from the early days that the gas wiping through an air knife is the most effective one. The gas wiping using in galvanizing process brings about a problem of splashing from the strip edge for a certain high speed of coating. So, in the present study, the effects of the deflection angle of Coanda nozzle on jet structure and the distribution of impinging pressure at the plate surface are investigated numerically and experimentally. In numerical analysis, the governing equations consisted of three-dimensional time dependent full Navier-Stokes equations, standard k-ɛ turbulence model to solve turbulent stress and so on are employed. In experiment, 16 channel pressure scanning valve and 3-axis auto traversing unit are used to measure the impinging pressure at the strip surface. As a result, it is found that the smaller the deflection angle for the same nozzle slit of air knife is, the larger the impinging pressure is. To reduce the size of separation bubble and to enhance the cutting ability, it is recommendable to use an air knife with the Coanda nozzle.

  8. Technology Solutions Case Study: Combustion Safety for Appliances Using Indoor Air

    SciTech Connect

    2014-05-01

    This case study describes how to assess and carry out the combustion safety procedures for appliances and heating equipment that uses indoor air for combustion in low-rise residential buildings. Only appliances installed in the living space, or in an area freely communicating with the living space, vented alone or in tandem with another appliance are considered here. This document is for inspectors, auditors, and technicians working in homes where energy upgrades are being conducted whether or not air infiltration control is included in the package of measures being applied. In the indoor combustion air case, guidelines summarized here are based on language provided in several of the codes to establish minimum requirements for the space using simplified prescriptive measures. In addition, building performance testing procedures are provided by testing agencies. The codes in combination with the test procedures offer comprehensive combustion safety coverage to address safety concerns, allowing inexperienced residential energy retrofit inspectors to effectively address combustion safety issues and allow energy retrofits to proceed.

  9. Indoor air pollution by organic emissions from textile floor coverings. Climate chamber studies under dynamic conditions

    NASA Astrophysics Data System (ADS)

    Sollinger, S.; Levsen, K.; Wünsch, G.

    The time dependence of the emission of organic compounds from a polyamide floor covering with styrene-butadiene-rubber (SBR) backing was studied in three climate chambers (0.03, 1.0 and 38 m 3) at 23°C 5nd 45% RH. While volatile compounds such as toluene reach a maximum concentration in the gas phase within 1 h and decrease in concentration to less than 2% within 60 h, the concentration of less volatile compounds, such as 4-phenylcyclohexene, decreases slowly over a period of months. If the chamber is well mixed and a defined chamber loading is maintained the observed concentrations do not depend on the chamber size, the wall material and air velocity. The concentration of the observed emissions is roughly proportional to the chamber loading. Surprisingly it is not inversely proportional to the air exchange rate. Rather, at high air exchange rates mass transfer from the carpet to the gas phase is enhanced. The "decreasing source models" of Dunn and Tichenor ( Atmospheric Environment22, 885-894, 1988) have been applied to the data. They allow the extrapolation of experimental data beyond the time available for measurement. The model calculations reveal the presence of sink effects. The role of the chamber walls as sinks can be determined more reliably if constant sources of an organic compound are placed into the chamber and their increase in concentration with time is compared with the theoretical predictions neglecting sink effects.

  10. Exposure prediction approaches used in air pollution epidemiology studies: Key findings and future recommendations

    PubMed Central

    Baxter, Lisa K.; Dionisio, Kathie L.; Burke, Janet; Sarnat, Stefanie Ebelt; Sarnat, Jeremy A.; Hodas, Natasha; Rich, David Q.; Turpin, Barbara J.; Jones, Rena R.; Mannshardt, Elizabeth; Kumar, Naresh; Beevers, Sean D.; Özkaynak, Halûk

    2014-01-01

    Many epidemiologic studies of the health effects of exposure to ambient air pollution use measurements from central-site monitors as their exposure estimate. However, measurements from central-site monitors may lack the spatial and temporal resolution required to capture exposure variability in a study population, thus resulting in exposure error and biased estimates. Articles in this dedicated issue examine various approaches to predict or assign exposures to ambient pollutants. These methods include: combining existing central-site pollution measurements with local- and/or regional-scale air quality models to create new or “hybrid” models for pollutant exposure estimates, and using exposure models to account for factors such as infiltration of pollutants indoors and human activity patterns. Key findings from these articles are summarized to provide lessons learned and recommendations for additional research on improving exposure estimation approaches for future epidemiological studies. In summary, when compared to use of central-site monitoring data, the enhanced spatial resolution of air quality or exposure models can have an impact on resultant health effect estimates, especially for pollutants derived from local sources such as traffic (e.g. EC, CO, and NOx). In addition, the optimal exposure estimation approach also depends upon the epidemiological study design. We recommend that future research develop pollutant-specific infiltration data (including for PM species), and improve existing data on human time-activity patterns, and exposure to local source (e.g. traffic), in order to enhance human exposure modeling estimates. We also recommend comparing how various approaches to exposure estimation characterize relationships between multiple pollutants in time and space, and investigating the impact of improved exposure estimates in chronic health studies. PMID:24084756

  11. Estimated long-term outdoor air pollution concentrations in a cohort study

    NASA Astrophysics Data System (ADS)

    Beelen, Rob; Hoek, Gerard; Fischer, Paul; Brandt, Piet A. van den; Brunekreef, Bert

    Several recent studies associated long-term exposure to air pollution with increased mortality. An ongoing cohort study, the Netherlands Cohort Study on Diet and Cancer (NLCS), was used to study the association between long-term exposure to traffic-related air pollution and mortality. Following on a previous exposure assessment study in the NLCS, we improved the exposure assessment methods. Long-term exposure to nitrogen dioxide (NO 2), nitrogen oxide (NO), black smoke (BS), and sulphur dioxide (SO 2) was estimated. Exposure at each home address ( N=21 868) was considered as a function of a regional, an urban and a local component. The regional component was estimated using inverse distance weighed interpolation of measurement data from regional background sites in a national monitoring network. Regression models with urban concentrations as dependent variables, and number of inhabitants in different buffers and land use variables, derived with a Geographic Information System (GIS), as predictor variables were used to estimate the urban component. The local component was assessed using a GIS and a digital road network with linked traffic intensities. Traffic intensity on the nearest road and on the nearest major road, and the sum of traffic intensity in a buffer of 100 m around each home address were assessed. Further, a quantitative estimate of the local component was estimated. The regression models to estimate the urban component explained 67%, 46%, 49% and 35% of the variances of NO 2, NO, BS, and SO 2 concentrations, respectively. Overall regression models which incorporated the regional, urban and local component explained 84%, 44%, 59% and 56% of the variability in concentrations for NO 2, NO, BS and SO 2, respectively. We were able to develop an exposure assessment model using GIS methods and traffic intensities that explained a large part of the variations in outdoor air pollution concentrations.

  12. The South Karelia Air Pollution Study: acute health effects of malodorous sulfur air pollutants released by a pulp mill

    SciTech Connect

    Haahtela, T.; Marttila, O.; Vilkka, V.; Jaeppinen, P.J.; Jaakkola, J.J. )

    1992-04-01

    We evaluated the acute health effects of a strong emission of malodorous sulfur compounds released from a pulp mill in South Karelia, Finland. The 24-hour ambient air concentrations of hydrogen sulfide for the two emission days were 35 and 43 micrograms/m3 (maximum 4-hour 135 micrograms/m3). A questionnaire was distributed after the high exposure and later after a low exposure period to 29 households with 75 subjects living in the nearby community. During the high exposure, 63% of the respondents reported experience of at least one symptom compared to 26% during the reference period. Every third participant reported difficulties in breathing. In the 45 subjects responding to both questionnaires more eye, respiratory and neuropsychological symptoms occurred during the exposure compared to the reference period. The strong malodorous emission from a pulp mill caused an alarming amount of adverse effects in the exposed population.

  13. Study of flow fields induced by surface dielectric barrier discharge actuator in low-pressure air

    SciTech Connect

    Che, Xueke E-mail: st@mail.iee.ac.cn; Nie, Wansheng; Tian, Xihui; Hou, Zhiyong; He, Haobo; Zhou, Penghui; Zhou, Siyin; Yang, Chao; Shao, Tao E-mail: st@mail.iee.ac.cn

    2014-04-15

    Surface dielectric barrier discharge (SDBD) is a promising method for a flow control. Flow fields induced by a SDBD actuator driven by the ac voltage in static air at low pressures varying from 1.0 to 27.7 kPa are measured by the particle image velocimetry method. The influence of the applied ac voltage frequency and magnitude on the induced flow fields is studied. The results show that three different classes of flow fields (wall jet flow field, complex flow field, and vortex-shape flow field) can be induced by the SDBD actuator in the low-pressure air. Among them, the wall jet flow field is the same as the tangential jet at atmospheric pressure, which is, together with the vertical jet, the complex flow field. The vortex-shape flow field is composed of one vertical jet which points towards the wall and two opposite tangential jets. The complex and the vortex-shape flow fields can be transformed to the wall jet flow field when the applied ac voltage frequency and magnitude are changed. It is found that the discharge power consumption increases initially, decreases, and then increases again at the same applied ac voltage magnitude when the air pressure decreases. The tangential velocity of the wall jet flow field increases when the air pressure decreases. It is however opposite for the complex flow field. The variation of the applied ac voltage frequency influences differently three different flow fields. When the applied ac voltage magnitude increases at the same applied ac voltage frequency, the maximal jet velocity increases, while the power efficiency increases only initially and then decreases again. The discharge power shows either linear or exponential dependences on the applied ac voltage magnitude.

  14. Epidemiological study of air filtration systems for preventing PRRSV infection in large sow herds.

    PubMed

    Alonso, Carmen; Murtaugh, Michael P; Dee, Scott A; Davies, Peter R

    2013-10-01

    Porcine reproductive and respiratory syndrome virus (PRRSV) is the most economically significant pathogen in the US swine industry. Aerosol transmission among herds is a major concern in pig dense regions and filtration of incoming air, in combination with standard biosecurity procedures, has been demonstrated to prevent transmission of PRRSV into susceptible herds. To quantify the impact of air filtration on reducing risk of PRRSV outbreaks, we compared the incidence rate of new PRRSV introductions in 20 filtered and 17 non-filtered control sow herds in a swine dense region of North America during a 7 year study period. Events of novel virus introduction were ascertained by phylogenetic analysis of PRRSV ORF5 gene sequences. Putative new viruses were defined as exogenous (introduced) based on ORF5 nucleotide sequence differences compared to previous farm isolates. The influence of sequence difference cut-off values ranging from 2 to 10% on case definition and relative risk were evaluated. Non-filtered farms incurred about 0.5 outbreaks per year, with a seasonal increase in risk in cooler periods. Baseline risk, prior to filtration, in treatment farms was approximately 0.75 per year, approximately 50% higher than in control farms. Air filtration significantly reduced risk of PRRSV introduction events to 0.06-0.22 outbreaks per year, depending on the cut-off values used to classify a virus isolate as new to the herd. Overall, air filtration led to an approximately 80% reduction in risk of introduction of novel PRRSV, indicating that on large sow farms with good biosecurity in swine-dense regions, approximately four-fifths of PRRSV outbreaks may be attributable to aerosol transmission. PMID:23870693

  15. Urban Heat Island Versus Air Quality - a Numerical Modelling Study for a European City

    NASA Astrophysics Data System (ADS)

    Fallmann, J.; Forkel, R.; Emeis, S.

    2014-12-01

    In 2050 70% of the global population is expected to live in urban areas. Climate change will render these areas more vulnerable to heat waves, which often are accompanied by severe air pollution problems. The Urban Heat Island (UHI) is a feature that adds to the general temperature increase that is expected. Decreasing the UHI can impact air quality as well, because heat influences atmospheric dynamics and accelerates air chemical processes and often also increases the emission of primary pollutants due to increased demand of energy. The goal of this study is to investigate the effect of, e.g., high reflective surfaces and urban greening on mitigating the UHI and the related impact on air quality. A multi-layer urban canopy model is coupled to the mesoscale model WRF-Chem and the urban area of Stuttgart (South-West Germany) is taken as one example. Different scenario runs are executed for short time periods and are compared to a control run. The results show that the UHI effect can be substantially reduced when changing the albedo of roof surfaces, whereas the effect of urban greening is minor. Both scenarios have in common, that they evoke changes in secondary circulation patterns. The effects of these mitigation strategies on chemical composition of the urban atmosphere are complex, attributed to both chemical and dynamical features. Increasing the reflectivity of roof surfaces in the model results in a net decrease of the surface ozone concentration, because ozone formation is highly correlated to temperature. With regard to primary pollutants, e.g. NO, CO and PM10 concentrations are increased when increasing reflectivity. This effect primarily can be ascribed to a reduction of turbulent motion, convection and a decrease of the boundary layer height, coming along with lower temperatures in the urban canopy layer due to increased reflectivity. The table below shows the effect on grid cell mean concentrations for different chemical species and scenarios.

  16. Air pollution and newly diagnostic autism spectrum disorders: a population-based cohort study in Taiwan.

    PubMed

    Jung, Chau-Ren; Lin, Yu-Ting; Hwang, Bing-Fang

    2013-01-01

    There is limited evidence that long-term exposure to ambient air pollution increases the risk of childhood autism spectrum disorder (ASD). The objective of the study was to investigate the associations between long-term exposure to air pollution and newly diagnostic ASD in Taiwan. We conducted a population-based cohort of 49,073 children age less than 3 years in 2000 that were retrieved from Taiwan National Insurance Research Database and followed up from 2000 through 2010. Inverse distance weighting method was used to form exposure parameter for ozone (O3), carbon monoxide (CO), nitrogen dioxide (NO2), sulfur dioxide (SO2), and particles with aerodynamic diameter less than 10 µm (PM10). Time-dependent Cox proportional hazards (PH) model was performed to evaluate the relationship between yearly average exposure air pollutants of preceding years and newly diagnostic ASD. The risk of newly diagnostic ASD increased according to increasing O3, CO, NO2, and SO2 levels. The effect estimate indicating an approximately 59% risk increase per 10 ppb increase in O3 level (95% CI 1.42-1.79), 37% risk increase per 10 ppb in CO (95% CI 1.31-1.44), 340% risk increase per 10 ppb increase in NO2 level (95% CI 3.31-5.85), and 17% risk increase per 1 ppb in SO2 level (95% CI 1.09-1.27) was stable with different combinations of air pollutants in the multi-pollutant models. Our results provide evident that children exposure to O3, CO, NO2, and SO2 in the preceding 1 year to 4 years may increase the risk of ASD diagnosis. PMID:24086549

  17. A numerical study of a persistent cold air pool episode in the Salt Lake Valley, Utah

    NASA Astrophysics Data System (ADS)

    Lu, Wei; Zhong, Shiyuan

    2014-02-01

    The Weather Research and Forecasting (WRF) model is used to simulate a persistent cold air pool (CAP) episode observed in December 2010 during the Persistent Cold Air Pool Study (PCAPS) field campaign in Salt Lake Valley, Utah. The availability of intensive observations from PCAPS, especially the added vertical profiles, allows for an in-depth analysis of CAP structure and evolution and model evaluation beyond what was done in similar work before. Comparisons of the WRF simulation with surface observations and upper air soundings indicate that WRF is capable of simulating the observed spatial and temporal variation of the valley atmosphere during the CAP episode. The model also successfully captures the formation and removal of the persistent temperature inversion. Process analysis helps quantify the contribution of various physical processes to the buildup and breakup of the inversion. The inversion developed due primarily to a rapid warming above the valley by synoptic subsidence and warm advection and to strong radiative cooling within the valley under clear sky conditions. The inversion was lifted when strong southerly winds entered the valley from the gap mixing out the cold air in the valley. Synoptic-scale cold advection above the valley contributed to the inversion removal by weakening the inversion from aloft. Sensitivity experiments suggested that the WRF simulation of the CAP episode is more sensitive to large-scale initialization fields with North American Mesoscale Model outperforming North American Regional Reanalysis and National Centers for Environmental Prediction (NCEP) Eta analysis than to the choice of boundary layer parameterizations and land surface models.

  18. Study of single and combined mass-sensitive observables of cosmic ray induced extensive air showers

    NASA Astrophysics Data System (ADS)

    Rastegarzadeh, G.; Nemati, M.

    2016-03-01

    In this study, combinations of the global arrival time, (Δτ_{global}), pseudorapidity, and lateral density distribution (ρ_{μ}) of muons, which are three mass-sensitive observables of cosmic ray induced extensive air showers, have been used as new parameters to study the primary mass discrimination around the knee energies (100 TeV-10 PeV). This is a simulation-based study and the simulations have been performed for the KASCADE array at Karlsruhe and the Alborz-I array at Tehran to study the effect of the altitude on the quality of the primary mass discrimination. The merit factors of the single and combined three mass-sensitive observables have been calculated to compare the discrimination power of combined and single observables. We have used the CORSIKA 7.4 code to simulate the extensive air showers (EASs) sample sets. Considering all aspects of our study, it is found that the ratio of the global time to the lateral density distribution of the muons gives better results than other ratios; also in the case of single observables, the muon density gives better results compared with the other observables. Also it is shown that below 1 PeV primary energies, the ratio of the muon global time to the muon density (Δτ_{global}/ρ_{μ}) results in a better mass discrimination relative to the muon density only.

  19. Comparison of emergency department and hospital admissions data for air pollution time-series studies

    PubMed Central

    2012-01-01

    Background Emergency department (ED) visit and hospital admissions (HA) data have been an indispensible resource for assessing acute morbidity impacts of air pollution. ED visits and HAs are types of health care visits with similarities, but also potentially important differences. Little previous information is available regarding the impact of health care visit type on observed acute air pollution-health associations from studies conducted for the same location, time period, outcome definitions and model specifications. Methods As part of a broader study of air pollution and health in St. Louis, individual-level ED and HA data were obtained for a 6.5 year period for acute care hospitals in the eight Missouri counties of the St. Louis metropolitan area. Patient demographic characteristics and diagnostic code distributions were compared for four visit types including ED visits, HAs, HAs that came through the ED, and non-elective HAs. Time-series analyses of the relationship between daily ambient ozone and PM2.5 and selected cardiorespiratory outcomes were conducted for each visit type. Results Our results indicate that, compared with ED patients, HA patients tended to be older, had evidence of greater severity for some outcomes, and had a different mix of specific outcomes. Consideration of ‘HA through ED’ appeared to more effectively select acute visits than consideration of ‘non-elective HA’. While outcomes with the strongest observed temporal associations with air pollutants tended to show strong associations for all visit types, we found some differences in observed associations for ED visits and HAs. For example, risk ratios for the respiratory disease-ozone association were 1.020 for ED visits and 1.004 for ‘HA through ED’; risk ratios for the asthma/wheeze-ozone association were 1.069 for ED visits and 1.106 for ‘HA through ED’. Several factors (e.g. age) were identified that may be responsible, in part, for the differences in observed

  20. Traffic-related Air Pollution and the Right Ventricle. The Multi-ethnic Study of Atherosclerosis

    PubMed Central

    Kaufman, Joel D.; Barr, R. Graham; Bluemke, David A.; Curl, Cynthia L.; Hough, Catherine L.; Lima, Joao A.; Szpiro, Adam A.; Van Hee, Victor C.; Kawut, Steven M.

    2014-01-01

    Rationale: Right heart failure is a cause of morbidity and mortality in common and rare heart and lung diseases. Exposure to traffic-related air pollution is linked to left ventricular hypertrophy, heart failure, and death. Relationships between traffic-related air pollution and right ventricular (RV) structure and function have not been studied. Objectives: To characterize the relationship between traffic-related air pollutants and RV structure and function. Methods: We included men and women with magnetic resonance imaging assessment of RV structure and function and estimated residential outdoor nitrogen dioxide (NO2) concentrations from the Multi-ethnic Study of Atherosclerosis, a study of individuals free of clinical cardiovascular disease at baseline. Multivariable linear regression estimated associations between NO2 exposure (averaged over the year prior to magnetic resonance imaging) and measures of RV structure and function after adjusting for demographics, anthropometrics, smoking status, diabetes mellitus, and hypertension. Adjustment for corresponding left ventricular parameters, traffic-related noise, markers of inflammation, and lung disease were considered in separate models. Secondary analyses considered oxides of nitrogen (NOx) as the exposure. Measurements and Main Results: The study sample included 3,896 participants. In fully adjusted models, higher NO2 was associated with greater RV mass and larger RV end-diastolic volume with or without further adjustment for corresponding left ventricular parameters, traffic-related noise, inflammatory markers, or lung disease (all P < 0.05). There was no association between NO2 and RV ejection fraction. Relationships between NOx and RV morphology were similar. Conclusions: Higher levels of NO2 exposure were associated with greater RV mass and larger RV end-diastolic volume. PMID:24593877

  1. IMPACT OF HEATING AND AIR CONDITIONING SYSTEM OPERATION AND LEAKAGE ON VENTILATION AND INTERCOMPARTMENT TRANSPORT: STUDIES IN UNOCCUPIED AND OCCUPIED TENNESSEE VALLEY HOMES

    EPA Science Inventory

    Forced-air heating and air conditioning (HAC) systems caused an average and maximum increase in air infiltration rates of 1.8- and 4.3-fold, respectively, during brief whole-house studies of tracer gas decay In 39 occupied houses. An average Increase in air infiltration rate of 0...

  2. Study on the Efficient Drive of a Desiccant Air Conditioning System

    NASA Astrophysics Data System (ADS)

    Jeong, Jong-Soo; Saito, Kiyoshi; Kawai, Sunao

    This paper constructs the static simulation model of a desiccant air conditioning system and gives the guidelines for the efficient drive of the desiccant air conditioning system. The desiccant air conditioning system is composed of a desiccant wheel, a heat exchanger, two evaporative coolers and a heater. The process air and regeneration air are supplied to this system. The desiccant is Silica gel. In the simulation model, two-dimensional model in space is adopted for the desiccant wheel. As the simulation result, it is clarified that optimum outlet temperature of the regeneration air in the heater, rotational speed of the desiccant wheel, the rejected air flow rate of the regeneration air, the process and regeneration air flow rate that maximize COP exist. For example, in case that the regeneration temperature is 63°C and relative humidity is 55% maximum COP is about 0.62.

  3. Study of muon bundles from extensive air showers with the ALICE detector at CERN LHC

    NASA Astrophysics Data System (ADS)

    Shtejer, K.

    2016-05-01

    ALICE is one of four large experiments at the CERN Large Hadron Collider, specially designed to study particle production in ultra-relativistic heavy-ion collisions. Located 52 meters underground with 28 meters of overburden rock, it has also been used to detect muons produced by cosmic-ray interactions in the upper atmosphere. The large size and excellent tracking capability of the ALICE Time Projection Chamber are exploited to study the muonic component of extensive air showers. We present the multiplicity distribution of these atmospheric muons and its comparison with Monte Carlo simulations. The latest version of the QGSJET hadronic interaction model was used to simulate the development of the resulting air showers. High multiplicity events containing more than 100 reconstructed muons were also studied. Similar events have been studied in previous underground experiments such as ALEPH and DELPHI at LEP without satisfactory explanations for the frequency of the highest multiplicity events. We demonstrate that the high muon-multiplicity events observed in ALICE stem from primary cosmic rays with energies above 1016 eV and that the frequency of these events can be successfully described by assuming a heavy mass composition of primary cosmic rays in this energy range.

  4. Oil and gas impacts on air quality in federal lands in the Bakken region: an overview of the Bakken Air Quality Study and first results

    NASA Astrophysics Data System (ADS)

    Prenni, A. J.; Day, D. E.; Evanoski-Cole, A. R.; Sive, B. C.; Hecobian, A.; Zhou, Y.; Gebhart, K. A.; Hand, J. L.; Sullivan, A. P.; Li, Y.; Schurman, M. I.; Desyaterik, Y.; Malm, W. C.; Collett, J. L., Jr.; Schichtel, B. A.

    2016-02-01

    The Bakken formation contains billions of barrels of oil and gas trapped in rock and shale. Horizontal drilling and hydraulic fracturing methods have allowed for extraction of these resources, leading to exponential growth of oil production in the region over the past decade. Along with this development has come an increase in associated emissions to the atmosphere. Concern about potential impacts of these emissions on federal lands in the region prompted the National Park Service to sponsor the Bakken Air Quality Study over two winters in 2013-2014. Here we provide an overview of the study and present some initial results aimed at better understanding the impact of local oil and gas emissions on regional air quality. Data from the study, along with long-term monitoring data, suggest that while power plants are still an important emissions source in the region, emissions from oil and gas activities are impacting ambient concentrations of nitrogen oxides and black carbon and may dominate recent observed trends in pollutant concentrations at some of the study sites. Measurements of volatile organic compounds also definitively show that oil and gas emissions were present in almost every air mass sampled over a period of more than 4 months.

  5. Oil and gas impacts on air quality in federal lands in the Bakken region: an overview of the Bakken Air Quality Study and first results

    NASA Astrophysics Data System (ADS)

    Prenni, A. J.; Day, D. E.; Evanoski-Cole, A. R.; Sive, B. C.; Hecobian, A.; Zhou, Y.; Gebhart, K. A.; Hand, J. L.; Sullivan, A. P.; Li, Y.; Schurman, M. I.; Desyaterik, Y.; Malm, W. C.; Schichtel, B. A.; Collett, J. L., Jr.

    2015-10-01

    The Bakken formation contains billions of barrels of oil and gas trapped in rock and shale. Horizontal drilling and hydraulic fracturing methods have allowed for extraction of these resources, leading to exponential growth of oil production in the region over the past decade. Along with this development has come an increase in associated emissions to the atmosphere. Concern about potential impacts of these emissions on federal lands in the region prompted the National Park Service to sponsor the Bakken Air Quality Study over two winters in 2013-2014. Here we provide an overview of the study and present some initial results aimed at better understanding the impact of local oil and gas emissions on regional air quality. Data from the study, along with long term monitoring data, suggest that while power plants are still an important emissions source in the region, emissions from oil and gas activities are impacting ambient concentrations of nitrogen oxides and black carbon and may dominate recent observed trends in pollutant concentrations at some of the study sites. Measurements of volatile organic compounds also definitively show that oil and gas emissions were present in almost every air mass sampled over a period of more than four months.

  6. Air Pollution and the Risk of Cardiac Defects: A Population-Based Case-Control Study.

    PubMed

    Hwang, Bing-Fang; Lee, Yungling Leo; Jaakkola, Jouni J K

    2015-11-01

    Previous epidemiologic studies have assessed the role of the exposure to ambient air pollution in the development of cardiac birth defects, but they have provided somewhat inconsistent results. To assess the associations between exposure to ambient air pollutants and the risk of cardiac defects, a population-based case-control study was conducted using 1087 cases of cardiac defects and a random sample of 10,870 controls from 1,533,748 Taiwanese newborns in 2001 to 2007.Logistic regression was performed to calculate odds ratios for 10 ppb increases in O3 and 10 μg/m increases in PM10. In addition, we compared the risk of cardiac defects in 4 categories-high exposure (>75th percentile); medium exposure (75th to 50th percentile); low exposure (<50th-25th percentile); reference (<25th percentile) based on the distribution of each pollutant. The risks of ventricular septal defects (VSD), atrial septal defects (ASD), and patent ductus arteriosus (PDA) were associated with 10 ppb increases in O3 exposure during the first 3 gestational months among term and preterm babies. In comparison between high PM10 exposure and reference category, there were statistically significant elevations in the effect estimates of ASD for all and terms births. In addition, there was a negative or weak association between SO2, NO2, CO, and cardiac defects.The study proved that exposure to outdoor air O3 and PM10 during the first trimester of gestation may increase the risk of VSD, ASD, and PDA. PMID:26554783

  7. Status of Air Quality in Central California and Needs for Further Study

    NASA Astrophysics Data System (ADS)

    Tanrikulu, S.; Beaver, S.; Soong, S.; Tran, C.; Jia, Y.; Matsuoka, J.; McNider, R. T.; Biazar, A. P.; Palazoglu, A.; Lee, P.; Wang, J.; Kang, D.; Aneja, V. P.

    2012-12-01

    Ozone and PM2.5 levels frequently exceed NAAQS in central California (CC). Additional emission reductions are needed to attain and maintain the standards there. Agencies are developing cost-effective emission control strategies along with complementary incentive programs to reduce emissions when exceedances are forecasted. These approaches require accurate modeling and forecasting capabilities. A variety of models have been rigorously applied (MM5, WRF, CMAQ, CAMx) over CC. Despite the vast amount of land-based measurements from special field programs and significant effort, models have historically exhibited marginal performance. Satellite data may improve model performance by: establishing IC/BC over outlying areas of the modeling domain having unknown conditions; enabling FDDA over the Pacific Ocean to characterize important marine inflows and pollutant outflows; and filling in the gaps of the land-based monitoring network. BAAQMD, in collaboration with the NASA AQAST, plans to conduct four studies that include satellite-based data in CC air quality analysis and modeling: The first project enhances and refines weather patterns, especially aloft, impacting summer ozone formation. Surface analyses were unable to characterize the strong attenuating effect of the complex terrain to steer marine winds impinging on the continent. The dense summer clouds and fog over the Pacific Ocean form spatial patterns that can be related to the downstream air flows through polluted areas. The goal of this project is to explore, characterize, and quantify these relationships using cloud cover data. Specifically, cloud agreement statistics will be developed using satellite data and model clouds. Model skin temperature predictions will be compared to both MODIS and GOES skin temperatures. The second project evaluates and improves the initial and simulated fields of meteorological models that provide inputs to air quality models. The study will attempt to determine whether a cloud

  8. Study on law of negative corona discharge in microparticle-air two-phase flow media

    NASA Astrophysics Data System (ADS)

    He, Bo; Li, Tianwei; Xiu, Yaping; Zhao, Heng; Peng, Zongren; Meng, Yongpeng

    2016-03-01

    To study the basic law of negative corona discharge in solid particle-air two-phase flow, corona discharge experiments in a needle-plate electrode system at different voltage levels and different wind speed were carried out in the wind tunnel. In this paper, the change law of average current and current waveform were analyzed, and the observed phenomena were systematically explained from the perspectives of airflow, particle charging, and particle motion with the help of PIV (particle image velocity) measurements and ultraviolet observations.

  9. Study of effects of injector geometry on fuel-air mixing and combustion

    NASA Technical Reports Server (NTRS)

    Bangert, L. H.; Roach, R. L.

    1977-01-01

    An implicit finite-difference method has been developed for computing the flow in the near field of a fuel injector as part of a broader study of the effects of fuel injector geometry on fuel-air mixing and combustion. Detailed numerical results have been obtained for cases of laminar and turbulent flow without base injection, corresponding to the supersonic base flow problem. These numerical results indicated that the method is stable and convergent, and that significant savings in computer time can be achieved, compared with explicit methods.

  10. Comparison of Profiling Microwave Radiometer, Aircraft, and Radiosonde Measurements From the Alliance Icing Research Study (AIRS)

    NASA Technical Reports Server (NTRS)

    Reehorst, Andrew L.

    2001-01-01

    Measurements from a profiling microwave radiometer are compared to measurements from a research aircraft and radiosondes. Data compared is temperature, water vapor, and liquid water profiles. Data was gathered at the Alliance Icing Research Study (AIRS) at Mirabel Airport outside Montreal, Canada during December 1999 and January 2000. All radiometer measurements were found to lose accuracy when the radome was wet. When the radome was not wetted, the radiometer was seen to indicate an inverted distribution of liquid water within a cloud. When the radiometer measurements were made at 15 deg. instead of the standard zenith, the measurements were less accurate.

  11. Study of a very low cost air combat maneuvering trainer aircraft

    NASA Technical Reports Server (NTRS)

    Hill, G. C.; Bowles, J. V.

    1976-01-01

    A very low cost aircraft for performing Air Combat Maneuvering (ACM) training was studied using the BD-5J sport plane as a point of departure. The installation of a larger engine and increased fuel capacity were required to meet the performance and mission objectives. Reduced wing area increased the simulation of the ACM engagement, and a comparison with current tactical aircraft is presented. Other factors affecting the training transfer are considered analytically, but a flight evaluation is recommended to determine the concept utility.

  12. Tracer study of oxygen and hydrogen uptake by Mg alloys in air with water vapor

    DOE PAGESBeta

    Brady, M. P.; Fayek, M.; Meyer, H. M.; Leonard, D. N.; Elsentriecy, H. H.; Unocic, K. A.; Anovitz, L. M.; Cakmak, E.; Keiser, J. R.; Song, G. L.; et al

    2015-05-15

    We studied the pure oxidation of Mg, Mg–3Al–1Zn (AZ31B), and Mg–1Zn–0.25Zr–<0.5Nd (ZE10A) at 85 °C in humid air using sequential exposures with H218O and D216O for water vapor. Incorporation of 18O in the hydroxide/oxide films indicated that oxygen from water vapor participated in the reaction. Moreover, penetration of hydrogen into the underlying metal was observed, particularly for the Zr- and Nd-containing ZE10A. Isotopic tracer profiles suggested a complex mixed inward/outward film growth mechanism.

  13. Health risks and air pollution--error analysis for a cross-sectional mortality study

    SciTech Connect

    Pickles, J.H.

    1986-06-01

    An attempt is made to analyze in quantitative terms the uncertainties in multiple regression estimates of the effects of air pollution on death rates. A range of factors--statistical fluctuations in numbers of deaths, differences in local age distribution, differences in smoking habits, errors in estimated pollution levels, migration, and variability of the characterization of socioeconomic effects--are assessed as potential sources of error. Both the precision and the robustness of the regression calculation are shown to be poor. Examples and illustrative calculations are given based on a study of U. K. death rates around the 1971 Census.

  14. Air Pollution and Mortality in Seven Million Adults: The Dutch Environmental Longitudinal Study (DUELS)

    PubMed Central

    Marra, Marten; Ameling, Caroline B.; Hoek, Gerard; Beelen, Rob; de Hoogh, Kees; Breugelmans, Oscar; Kruize, Hanneke; Janssen, Nicole A.H.; Houthuijs, Danny

    2015-01-01

    Background Long-term exposure to air pollution has been associated with mortality in urban cohort studies. Few studies have investigated this association in large-scale population registries, including non-urban populations. Objectives The aim of the study was to evaluate the associations between long-term exposure to air pollution and nonaccidental and cause-specific mortality in the Netherlands based on existing national databases. Methods We used existing Dutch national databases on mortality, individual characteristics, residence history, neighborhood characteristics, and national air pollution maps based on land use regression (LUR) techniques for particulates with an aerodynamic diameter ≤ 10 μm (PM10) and nitrogen dioxide (NO2). Using these databases, we established a cohort of 7.1 million individuals ≥ 30 years of age. We followed the cohort for 7 years (2004–2011). We applied Cox proportional hazard models adjusting for potential individual and area-specific confounders. Results After adjustment for individual and area-specific confounders, for each 10-μg/m3 increase, PM10 and NO2 were associated with nonaccidental mortality [hazard ratio (HR) = 1.08; 95% CI: 1.07, 1.09 and HR = 1.03; 95% CI: 1.02, 1.03, respectively], respiratory mortality (HR = 1.13; 95% CI: 1.10, 1.17 and HR = 1.02; 95% CI: 1.01, 1.03, respectively), and lung cancer mortality (HR = 1.26; 95% CI: 1.21, 1.30 and HR = 1.10 95% CI: 1.09, 1.11, respectively). Furthermore, PM10 was associated with circulatory disease mortality (HR = 1.06; 95% CI: 1.04, 1.08), but NO2 was not (HR = 1.00; 95% CI: 0.99, 1.01). PM10 associations were robust to adjustment for NO2; NO2 associations remained for nonaccidental mortality and lung cancer mortality after adjustment for PM10. Conclusions Long-term exposure to PM10 and NO2 was associated with nonaccidental and cause-specific mortality in the Dutch population of ≥ 30 years of age. Citation Fischer PH, Marra M, Ameling CB, Hoek G, Beelen R, de

  15. Configuration Studies of Personal Air Vehicles. Personal Air Vehicle and Flying Jeep Concepts: A Commentary on Promising Approaches or What Goes Around Comes Around (About Every Twenty Years)

    NASA Technical Reports Server (NTRS)

    Hall, David W.

    2001-01-01

    The NASA/Langley Personal Air Vehicle (PAV) Exploration (PAVE) and the DARPA (Defense Advanced Research Projects Agency) Dual Air/Road Transportation System (DARTS) projects were established to investigate the feasibility of creating vehicles which could replace, or at the very least augment, personal ground and air transportation schemes. This overall goal implies integrating several technology areas with practical everyday transportation requirements to design a class of vehicles which will achieve the following goals: (1) Vertical, Extremely Short, or Short Takeoff and Landing (VTOL, ESTOL, STOL) capability; (2) Operation at block speeds markedly faster than current combinations of land and air transportation, particularly in critical market areas; (3) Unit cost comparable to current luxury cars and small general aviation aircraft; (4) Excellent reliability; (5) Excellent safety; (6) Ability to integrate with existing land and air transportation systems. The conclusions of these configuration studies are summarized as follows: (1) Creation of the five assigned configurations prompted added explorations, some of which were dead-ends; (2) Some components could be common to all configurations such as avionics and dual-mode suspension schemes; (3) Single-Mode PAVs can be created by removing dual-mode-specific items; (4) Aviation history provided some intriguing starting points, as in what goes around comes around; (5) CTOL (Conventional Take-off and Landing) and STOL dual-mode PAVs look feasible with single-mode PAVs being simplifications of the dual-mode approach; (6) VTOL PAVs will require development; (7) More exotic collapsing mechanisms mechanisms need development; (8) As a teaching tool, PAVs are not yet a well-enough bounded design problem.

  16. Ambient air metallic pollutant study at HAF areas during 2013-2014

    NASA Astrophysics Data System (ADS)

    Fang, Guor-Cheng; Kuo, Yu-Chen; Zhuang, Yuan-Jie

    2015-05-01

    This study characterized diurnal variations of the total suspended particulate (TSP) concentrations, dry deposition flux and dry deposition velocity of metallic elements at Taichung Harbor (Harbor), Gong Ming Junior High School (Airport) and Sha lu Farmland (Farmland) sampling sites in central Taiwan between August, 2013 and July, 2014 in this study. The result indicated that: 1) the ambient air particulate concentrations, dry depositions were displayed as Harbor > Farmland > Airport during the day time sampling period. However, dry deposition velocities were shown as Airport > Harbor > Farmland for this study. 2) The ambient air particulate concentrations, dry depositions were displayed as Airport > Harbor > Farmland during the night time sampling period. However, dry deposition velocities were shown as Farmland > Harbor > Airport for this study. 3) The metallic element Zn has the average highest concentrations at Airport, Harbor and Farmland among all the metallic elements during the day time sampling period in this study. 4) There were significant differences for the metallic elements (Cr, Cu, Zn and Pb) in dry depositions at these three characteristic sampling sites (HAF) for the night time sampling period. The only exception is metallic element Cd. It displayed that there were no significant differences for the metallic element Cd at the Airport and Farmland sampling sites during the night time sampling period. 5) The average highest values for the metallic element Cu in TSP among the three characteristic sampling sites occurred during the fall and winter seasons for this study. As for the dry depositions, the average highest values in dry deposition among the three characteristic sampling sites occurred during the spring and summer seasons for this study. 6) The average highest values for the metallic element Cd in TSP among the three characteristic sampling sites occurred during the spring and summer seasons for this study. As for the dry depositions, the

  17. Identification of potential inhibitors for AIRS from de novo purine biosynthesis pathway through molecular modeling studies - a computational approach.

    PubMed

    Rao, R Guru Raj; Biswal, Jayashree; Dhamodharan, Prabhu; Kanagarajan, Surekha; Jeyaraman, Jeyakanthan

    2016-10-01

    In cancer, de novo pathway plays an important role in cell proliferation by supplying huge demand of purine nucleotides. Aminoimidazole ribonucleotide synthetase (AIRS) catalyzes the fifth step of de novo purine biosynthesis facilitating in the conversion of formylglycinamidine ribonucleotide to aminoimidazole ribonucleotide. Hence, inhibiting AIRS is crucial due to its involvement in the regulation of uncontrollable cancer cell proliferation. In this study, the three-dimensional structure of AIRS from P. horikoshii OT3 was constructed based on the crystal structure from E. coli and the modeled protein is verified for stability using molecular dynamics for a time frame of 100 ns. Virtual screening and induced fit docking were performed to identify the best antagonists based on their binding mode and affinity. Through mutational studies, the residues necessary for catalytic activity of AIRS were identified and among which the following residues Lys35, Asp103, Glu137, and Thr138 are important in determination of AIRS function. The mutational studies help to understand the structural and energetic characteristics of the specified residues. In addition to Molecular Dynamics, ADME properties, binding free-energy, and density functional theory calculations of the compounds were carried out to find the best lead molecule. Based on these analyses, the compound from the NCI database, NCI_121957 was adjudged as the best molecule and could be suggested as the suitable inhibitor of AIRS. In future studies, experimental validation of these ligands as AIRS inhibitors will be carried out. PMID:26524231

  18. Utilization of data from human population studies for setting air quality standards: evaluation of important issues.

    PubMed Central

    Lebowitz, M D

    1983-01-01

    Epidemiological studies of community populations are highly relevant to the process of setting national ambient air quality primary standards, as criteria for those standards are the protection of human populations against adverse effects on health. Nevertheless, because of the difficulties of performing adequate community population studies of a quality commensurate with the needs of standard setting, the use of data derived from studies is problematic. This paper addresses the important issues of appropriate exposure assessment and health assessment, and discusses the problems of multiplex variables and colinearity as they are critical in assessments of exposure-effect relationships. It is concluded that a major problem in the use of data from such studies for standard setting is not necessarily one of scientific reliability or validity, but arises from the attempt of translating adequate science into policy decisions. PMID:6653523

  19. Venous and paradoxical air embolism in the sitting position. A prospective study with transoesophageal echocardiography.

    PubMed

    Papadopoulos, G; Kuhly, P; Brock, M; Rudolph, K H; Link, J; Eyrich, K

    1994-01-01

    This prospective study investigates the frequency of patent foramen ovale (PFO), venous air embolism (VAE) and paradoxical air embolism (PAE) by transoesophageal echocardiography (TOE) in neurosurgical patients operated on in the sitting position. The risk of PAE after exclusion of PFO is assessed. A PFO was identified by pre-operative TOE and VAE and PAE by continuous intraoperative TOE. Sixty-two patients were divided into two groups, 22 patients were studied in group 1 (posterior fossa surgery) and group 2 (cervical surgery) contained 40 patients. Pre-operative TOE demonstrated a PFO in 5 of the 22 patients in group 1 (23%). Patients with proven PFO were excluded from the sitting position. Two further patients of this group (12% of 17 patients), in whom a PFO had been excluded pre-operatively, nevertheless had PAE, air occurring in all cavities of the heart. In group 2 the incidence of PFO was 4 out of 40 patients (10%). No PAE was observed in this group. Three morphological types of VAE with different haemodynamic and ventilation changes were demonstrated. VAE was observed in 76% of all posterior fossa operations and in 25% of cervical laminectomies. We conclude that a pre-operative search for PFO is mandatory considering its incidence of 23% in group 1 and of 10% in group 2, and the risk of PAE. If a PFO is detected, the sitting position should be avoided. A residual risk for PAE remains despite exclusion of PFO because the reliability of TOE is limited. TOE is the method of choice for detecting VAE and PAE. PMID:8042546

  20. Source apportionment and air quality impact assessment studies in Beijing/China

    NASA Astrophysics Data System (ADS)

    Suppan, P.; Schrader, S.; Shen, R.; Ling, H.; Schäfer, K.; Norra, S.; Vogel, B.; Wang, Y.

    2012-04-01

    More than 15 million people in the greater area of Beijing are still suffering from severe air pollution levels caused by sources within the city itself but also from external impacts like severe dust storms and long range advection from the southern and central part of China. Within this context particulate matter (PM) is the major air pollutant in the greater area of Beijing (Garland et al., 2009). PM did not serve only as lead substance for air quality levels and therefore for adverse health impact effects but also for a strong influence on the climate system by changing e.g. the radiative balance. Investigations on emission reductions during the Olympic Summer Games in 2008 have caused a strong reduction on coarser particles (PM10) but not on smaller particles (PM2.5). In order to discriminate the composition of the particulate matter levels, the different behavior of coarser and smaller particles investigations on source attribution, particle characteristics and external impacts on the PM levels of the city of Beijing by measurements and modeling are performed: Examples of long term measurements of PM2.5 filter sampling in 2005 with the objectives of detailed chemical (source attribution, carbon fraction, organic speciation and inorganic composition) and isotopic analyses as well as toxicological assessment in cooperation with several institutions (Karlsruhe Institute of Technology (IfGG/IMG), Helmholtz Zentrum München (HMGU), University Rostock (UR), Chinese University of Mining and Technology Beijing, CUMTB) will be discussed. Further experimental studies include the operation of remote sensing systems to determine continuously the MLH (by a ceilometer) and gaseous air pollutants near the ground (by DOAS systems) as well as at the 320 m measurement tower (adhesive plates at different heights for passive particle collection) in cooperation with the Institute of Atmospheric Physics (IAP) of the Chinese Academy of Sciences (CAS). The influence of the MLH on

  1. A systematic study of Rayleigh-Brillouin scattering in air, N₂, and O₂ gases.

    PubMed

    Gu, Ziyu; Ubachs, Wim

    2014-09-14

    Spontaneous Rayleigh-Brillouin scattering experiments in air, N2, and O2 have been performed for a wide range of temperatures and pressures at a wavelength of 403 nm and at a 90° scattering angle. Measurements of the Rayleigh-Brillouin spectral scattering profile were conducted at high signal-to-noise ratio for all three species, yielding high-quality spectra unambiguously showing the small differences between scattering in air, and its constituents N2 and O2. Comparison of the experimental spectra with calculations using the Tenti S6 model, developed in the 1970s based on linearized kinetic equations for molecular gases, demonstrates that this model is valid to high accuracy for N2 and O2, as well as for air. After previous measurements performed at 366 nm, the Tenti S6 model is here verified for a second wavelength of 403 nm, and for the pressure-temperature parameter space covered in the present study (250-340 K and 0.6-3 bars). In the application of the Tenti S6 model, based on the transport coefficients of the gases, such as thermal conductivity κ, internal specific heat capacity c(int) and shear viscosity η, as well as their temperature dependencies taken as inputs, values for the more elusive bulk viscosity η(b) for the gases are derived by optimizing the model to the measurements. It is verified that the bulk viscosity parameters obtained from previous experiments at 366 nm are valid for wavelengths of 403 nm. Also for air, which is treated as a single-component gas with effective gas transport coefficients, the Tenti S6 treatment is validated for 403 nm as for the previously used wavelength of 366 nm, yielding an accurate model description of the scattering profiles for a range of temperatures and pressures, including those of relevance for atmospheric studies. It is concluded that the Tenti S6 model, further verified in the present study, is applicable to LIDAR applications for exploring the wind velocity and the temperature profile distributions of

  2. A systematic study of Rayleigh-Brillouin scattering in air, N2, and O2 gases

    NASA Astrophysics Data System (ADS)

    Gu, Ziyu; Ubachs, Wim

    2014-09-01

    Spontaneous Rayleigh-Brillouin scattering experiments in air, N2, and O2 have been performed for a wide range of temperatures and pressures at a wavelength of 403 nm and at a 90° scattering angle. Measurements of the Rayleigh-Brillouin spectral scattering profile were conducted at high signal-to-noise ratio for all three species, yielding high-quality spectra unambiguously showing the small differences between scattering in air, and its constituents N2 and O2. Comparison of the experimental spectra with calculations using the Tenti S6 model, developed in the 1970s based on linearized kinetic equations for molecular gases, demonstrates that this model is valid to high accuracy for N2 and O2, as well as for air. After previous measurements performed at 366 nm, the Tenti S6 model is here verified for a second wavelength of 403 nm, and for the pressure-temperature parameter space covered in the present study (250-340 K and 0.6-3 bars). In the application of the Tenti S6 model, based on the transport coefficients of the gases, such as thermal conductivity κ, internal specific heat capacity cint and shear viscosity η, as well as their temperature dependencies taken as inputs, values for the more elusive bulk viscosity ηb for the gases are derived by optimizing the model to the measurements. It is verified that the bulk viscosity parameters obtained from previous experiments at 366 nm are valid for wavelengths of 403 nm. Also for air, which is treated as a single-component gas with effective gas transport coefficients, the Tenti S6 treatment is validated for 403 nm as for the previously used wavelength of 366 nm, yielding an accurate model description of the scattering profiles for a range of temperatures and pressures, including those of relevance for atmospheric studies. It is concluded that the Tenti S6 model, further verified in the present study, is applicable to LIDAR applications for exploring the wind velocity and the temperature profile distributions of the

  3. Assessment of the impact on the air environment due to opencast coal mining — an Indian case study

    NASA Astrophysics Data System (ADS)

    Ghose, M. K.; Majee, S. R.

    The Indian reserve of coking coal is mainly located in the Jharia Coalfield (JCF) of Bharat Coking Coal Ltd. (BCCL). The reserves which are 19 339 Mt, have been exploited intensely over the last 80 yr. Resulting air pollution is increasing in the area due to large-scale opencast (O/C) mining. But no well-defined method of estimating the generation of air pollutants is used due to different mining activities. An investigation has been conducted to evaluate the air pollution due to a large O/C coal project. The mining project under study is one of the largest opencast projects (OCP) of BCCL and the details have been described. Ambient air monitoring stations were chosen considering the dominant wind directions (upwind and downwind) and covering industrial, residential and sensitive zones. The air quality survey was carried out for four seasons and the methodology adopted has been described. The data revealed a high air pollution potential and are in respect of suspended particulate matter (SPM) and respirable particulate matter (RPM) in the project area as well as in the surrounding locations. Impacts on the air quality have been assessed on the basis of upwind and downwind concentration of air pollutants.

  4. Acute Effects of Fine Particulate Air Pollution on ST Segment Height: A Longitudinal Study

    EPA Science Inventory

    Background: The mechanisms for the relationship between particulate air pollution and cardiac disease are not fully understood. Air pollution-induced myocardial ischemia is one of the potentially important mechanisms. Methods: We investigate the acute effects and the time cours...

  5. HEALTH COSTS OF AIR POLLUTION DAMAGES: A STUDY OF HOSPITALIZATION COSTS

    EPA Science Inventory

    An investigation of the hospitalization costs of exposure to air pollution in Allegheny County, Pennsylvania was conducted to determine whether persons exposed to air pollution incurred higher incidences of hospitalization or additional costs for treatment. A hospitalization data...

  6. New Whole-House Solutions Case Study: Evaluating Through-Wall Air Transfer Fans, Pittsburgh, Pennsylvania

    SciTech Connect

    2014-10-01

    In this project, Building America team IBACOS performed field testing in a new construction unoccupied test house in Pittsburgh, Pennsylvania, to evaluate heating, ventilating, and air conditioning (HVAC) distribution systems during heating, cooling, and midseason conditions. The team evaluated a market-available through-wall air transfer fan system that provides air to the bedrooms.The relative ability of this system was considered with respect to relevant Air Conditioning Contractors of America and ASHRAE standards for house temperature uniformity and stability.

  7. Fine Particulate Air Pollution and the Progression of Carotid Intima-Medial Thickness: A Prospective Cohort Study from the Multi-Ethnic Study of Atherosclerosis and Air Pollution

    PubMed Central

    Adar, Sara D.; Sheppard, Lianne; Vedal, Sverre; Polak, Joseph F.; Sampson, Paul D.; Diez Roux, Ana V.; Budoff, Matthew; Jacobs, David R.; Barr, R. Graham; Watson, Karol; Kaufman, Joel D.

    2013-01-01

    Background Fine particulate matter (PM2.5) has been linked to cardiovascular disease, possibly via accelerated atherosclerosis. We examined associations between the progression of the intima-medial thickness (IMT) of the common carotid artery, as an indicator of atherosclerosis, and long-term PM2.5 concentrations in participants from the Multi-Ethnic Study of Atherosclerosis (MESA). Methods and Results MESA, a prospective cohort study, enrolled 6,814 participants at the baseline exam (2000–2002), with 5,660 (83%) of those participants completing two ultrasound examinations between 2000 and 2005 (mean follow-up: 2.5 years). PM2.5 was estimated over the year preceding baseline and between ultrasounds using a spatio-temporal model. Cross-sectional and longitudinal associations were examined using mixed models adjusted for confounders including age, sex, race/ethnicity, smoking, and socio-economic indicators. Among 5,362 participants (5% of participants had missing data) with a mean annual progression of 14 µm/y, 2.5 µg/m3 higher levels of residential PM2.5 during the follow-up period were associated with 5.0 µm/y (95% CI 2.6 to 7.4 µm/y) greater IMT progressions among persons in the same metropolitan area. Although significant associations were not found with IMT progression without adjustment for metropolitan area (0.4 µm/y [95% CI −0.4 to 1.2 µm/y] per 2.5 µg/m3), all of the six areas showed positive associations. Greater reductions in PM2.5 over follow-up for a fixed baseline PM2.5 were also associated with slowed IMT progression (−2.8 µm/y [95% CI −1.6 to −3.9 µm/y] per 1 µg/m3 reduction). Study limitations include the use of a surrogate measure of atherosclerosis, some loss to follow-up, and the lack of estimates for air pollution concentrations prior to 1999. Conclusions This early analysis from MESA suggests that higher long-term PM2.5 concentrations are associated with increased IMT progression and that greater reductions in PM2.5 are

  8. Short-Term Exposure to Air Pollution and Lung Function in the Framingham Heart Study

    PubMed Central

    Ljungman, Petter L.; Wilker, Elissa H.; Gold, Diane R.; Schwartz, Joel D.; Koutrakis, Petros; Washko, George R.; O’Connor, George T.; Mittleman, Murray A.

    2013-01-01

    Rationale: Short-term exposure to ambient air pollution has been associated with lower lung function. Few studies have examined whether these associations are detectable at relatively low levels of pollution within current U.S. Environmental Protection Agency (EPA) standards. Objectives: To examine exposure to ambient air pollutants within EPA standards and lung function in a large cohort study. Methods: We included 3,262 participants of the Framingham Offspring and Third Generation cohorts living within 40 km of the Harvard Supersite monitor in Boston, Massachusetts (5,358 examinations, 1995–2011) who were not current smokers, with previous-day pollutant levels in compliance with EPA standards. We compared lung function (FEV1 and FVC) after previous-day exposure to particulate matter less than 2.5 μm in diameter (PM2.5), nitrogen dioxide (NO2), and ozone (O3) in the “moderate” range of the EPA Air Quality Index to exposure in the “good” range. We also examined linear relationships between moving averages of pollutant concentrations 1, 2, 3, 5, and 7 days before spirometry and lung function. Measurements and Main Results: Exposure to pollutant concentrations in the “moderate” range of the EPA Air Quality Index was associated with a 20.1-ml lower FEV1 for PM2.5 (95% confidence interval [CI], −33.4, −6.9), a 30.6-ml lower FEV1 for NO2 (95% CI, −60.9, −0.2), and a 55.7-ml lower FEV1 for O3 (95% CI, −100.7, −10.8) compared with the “good” range. The 1- and 2-day moving averages of PM2.5, NO2, and O3 before testing were negatively associated with FEV1 and FVC. Conclusions: Short-term exposure to PM2.5, NO2, and O3 within current EPA standards was associated with lower lung function in this cohort of adults. PMID:24200465

  9. Cyclist route choice, traffic-related air pollution, and lung function: a scripted exposure study

    PubMed Central

    2013-01-01

    Background A travel mode shift to active transportation such as bicycling would help reduce traffic volume and related air pollution emissions as well as promote increased physical activity level. Cyclists, however, are at risk for exposure to vehicle-related air pollutants due to their proximity to vehicle traffic and elevated respiratory rates. To promote safe bicycle commuting, the City of Berkeley, California, has designated a network of residential streets as “Bicycle Boulevards.” We hypothesized that cyclist exposure to air pollution would be lower on these Bicycle Boulevards when compared to busier roads and this elevated exposure may result in reduced lung function. Methods We recruited 15 healthy adults to cycle on two routes – a low-traffic Bicycle Boulevard route and a high-traffic route. Each participant cycled on the low-traffic route once and the high-traffic route once. We mounted pollutant monitors and a global positioning system (GPS) on the bicycles. The monitors were all synced to GPS time so pollutant measurements could be spatially plotted. We measured lung function using spirometry before and after each bike ride. Results We found that fine and ultrafine particulate matter, carbon monoxide, and black carbon were all elevated on the high-traffic route compared to the low-traffic route. There were no corresponding changes in the lung function of healthy non-asthmatic study subjects. We also found that wind-speed affected pollution concentrations. Conclusions These results suggest that by selecting low-traffic Bicycle Boulevards instead of heavily trafficked roads, cyclists can reduce their exposure to vehicle-related air pollution. The lung function results indicate that elevated pollutant exposure may not have acute negative effects on healthy cyclists, but further research is necessary to determine long-term effects on a more diverse population. This study and broader field of research have the potential to encourage policy-makers and

  10. Air Pollution and DNA Methylation: Interaction by Psychological Factors in the VA Normative Aging Study

    PubMed Central

    Madrigano, Jaime; Baccarelli, Andrea; Mittleman, Murray A.; Sparrow, David; Spiro, Avron; Vokonas, Pantel S.; Cantone, Laura; Kubzansky, Laura; Schwartz, Joel

    2012-01-01

    DNA methylation is a potential pathway linking air pollution to disease. Studies indicate that psychological functioning modifies the association between pollution and morbidity. The authors estimated the association of DNA methylation with ambient particulate matter less than 2.5 µm in diameter (PM2.5) and black carbon, using mixed models. DNA methylation of the inducible nitric oxide synthase gene, iNOS, and the glucocorticoid receptor gene, GCR, was measured by quantitative polymerase chain reaction pyrosequencing of 1,377 blood samples from 699 elderly male participants in the VA Normative Aging Study (1999–2009). The authors also investigated whether this association was modified by psychological factors including optimism or pessimism, anxiety, and depression. iNOS methylation was decreased after acute exposure to both black carbon and PM2.5. A 1-μg/m3 increase in exposure to black carbon in the 4 hours preceding the clinical examination was associated with a 0.9% decrease in 5-methylcytosine (95% CI: 0.4, 1.4) in iNOS, and a 10-μg/m3 increase in exposure to PM2.5 was associated with a 0.6% decrease in 5-methylcytosine (95% CI: 0.03, 1.1) in iNOS. Participants with low optimism and high anxiety had associations that were 3–4 times larger than those with high optimism or low anxiety. GCR methylation was not associated with particulate air pollution exposure. PMID:22798479

  11. Air Pollution and Emergency Department Visits for Depression: A Multicity Case-Crossover Study

    PubMed Central

    Szyszkowicz, Mieczysław; Kousha, Termeh; Kingsbury, Mila; Colman, Ian

    2016-01-01

    BACKGROUND The aim of this study was to investigate the associations between ambient air pollution and emergency department (ED) visits for depression. METHODS Health data were retrieved from the National Ambulatory Care Reporting System. ED visits for depression were retrieved from the National Ambulatory Care Reporting System using the International Classification of Diseases (ICD-10), Tenth revision codes; ICD-10: F32 (mild depressive episode) and ICD-10: F33 (recurrent depressive disorder). A case-crossover design was employed for this study. Conditional logistic regression models were used to estimate odds ratios. RESULTS For females, exposure to ozone was associated with increased risk of an ED visit for depression between 1 and 7 days after exposure, for males, between 1 and 5, and 8 days after exposure, with odds ratios ranging between 1.02 and 1.03. CONCLUSIONS These findings suggest that, as hypothesized, there is a positive association between exposure to air pollution and ED visits for depression. PMID:27597809

  12. A method for optimizing waste collection using mathematical programming: a Buenos Aires case study.

    PubMed

    Bonomo, Flavio; Durán, Guillermo; Larumbe, Frederico; Marenco, Javier

    2012-03-01

    A method is proposed that uses operations research techniques to optimize the routes of waste collection vehicles servicing dumpster or skip-type containers. The waste collection problem is reduced to the classic travelling salesman problem, which is then solved using the Concorde solver program. A case study applying the method to the collection system in the southern zone of Buenos Aires is also presented. In addition to the typical minimum distance criterion, the optimization problem incorporates the objective of reducing vehicle wear and tear as measured by the physics concept of mechanical work. The solution approach, employing graph theory and mathematical programming tools, is fully described and the data correction process is also discussed. The application of the proposed method minimized the distance travelled by each collection vehicle in the areas studied, with actual reductions ranging from 10 to 40% of the existing routes. The shortened distances led in turn to substantial decreases in work done and therefore in vehicle wear and tear. Extrapolation of the results to the entire southern zone of Buenos Aires indicates potential savings for the civic authorities of more than US $200,000 per year in addition to the qualitative impacts of less traffic disruption, less vehicle driver fatigue and less pollution. PMID:21460074

  13. A Proposal for the Time Domain Modeling of Split Air Conditioners for Consumer Reimbursement Studies

    NASA Astrophysics Data System (ADS)

    Rezende, Paulo Henrique Oliveira; Almeida Junior, Afonso Bernardino; Gondim, Isaque Nogueira; Oliveira, José Carlos

    2015-04-01

    This paper deals with computer application procedures for the evaluation of the causal consistency between anomalous phenomena manifested in electrical networks, along with the physical damage associated with electrical equipment and possible reimbursement requests. The focus is on the development of an air conditioner appliance model of the type known as split founded upon a representation, in the time domain, in accordance with the Alternative Transients Program (ATP) simulator requirements. This approach permits investigations concerning the performance of the product when submitted to ideal and non-ideal supply conditions. Once the equipment model is implemented in the program, a set of investigative studies are carried out to show the device performance under specific energy quality disturbance conditions. In addition, there are still the results for the validation of the process established through the correlation between computational performance of the air conditioner with corresponding studies carried out experimentally, which are presented herein. Moreover, once the effectiveness of the developed model is verified, it is implemented into the Requests for Reimbursement Software. Investigations related to the correlation between disturbances and the levels of thermal and dielectric tolerance are then performed aiming at illustrating the use of the research results for the reimbursement analyzes purposes.

  14. NHEXAS PHASE I MARYLAND STUDY--PESTICIDES IN AIR ANALYTICAL RESULTS

    EPA Science Inventory

    The Pesticides in Air data set contains analytical results for measurements of up to 9 pesticides in 127 air samples over 51 households. Samples were taken by pumping standardized air volumes through URG impactors with a 10 um cutpoint and polyurethane foam (PUF) filters at indo...

  15. NHEXAS PHASE I MARYLAND STUDY--PAHS IN AIR ANALYTICAL RESULTS

    EPA Science Inventory

    The PAHs in Air data set contains analytical results for measurements of up to 11 PAHs in 127 air samples over 51 households. Twenty-four-hour samples were taken over a one-week period using a continuous pump and solenoid apparatus pumping a standardized air volume through an UR...

  16. NHEXAS PHASE I ARIZONA STUDY--METALS IN AIR ANALYTICAL RESULTS

    EPA Science Inventory

    The Metals in Air data set contains analytical results for measurements of up to 11 metals in 369 air samples over 175 households. Samples were taken by pumping standardized air volumes through filters at indoor and outdoor sites around each household being sampled. The primary...

  17. U.S.-MEXICO BORDER PROGRAM ARIZONA BORDER STUDY--METALS IN AIR ANALYTICAL RESULTS

    EPA Science Inventory

    The Metals in Air data set contains analytical results for measurements of up to 11 metals in 344 air samples over 86 households. Samples were taken by pumping standardized air volumes through filters at indoor and outdoor sites around each household being sampled. The primary ...

  18. U.S.-MEXICO BORDER PROGRAM ARIZONA BORDER STUDY--PARTICULATE MATTER IN AIR ANALYTICAL RESULTS

    EPA Science Inventory

    The Particulate Matter in Air data set contains analytical results for measurements of 2 particle sizes in 344 air samples over 86 households. Samples were taken by pumping standardized air volumes through filters using impactors with a 10-um outpoint or with a 2.5-um outpoint. ...

  19. U.S.-MEXICO BORDER PROGRAM ARIZONA BORDER STUDY--PAHS IN AIR ANALYTICAL RESULTS

    EPA Science Inventory

    The PAHs in Air data set contains the analytical results for measurements of up to 22 polynuclear aromatic hydrocarbons (PAHs) in air samples taken indoors and outdoors. The information is for 172 samples for 86 households. Active samples were taken by pumping standardized air ...

  20. NHEXAS PHASE I MARYLAND STUDY--METALS IN AIR ANALYTICAL RESULTS

    EPA Science Inventory

    The Metals in Air data set contains analytical results for measurements of up to 4 metals in 458 air samples over 79 households. Twenty-four-hour samples were taken over a one-week period using a continuous pump and solenoid apparatus by pumping a standardized air volume through...

  1. Urban and Rural Air Pollution: A Cross-Age Study of School Students' Ideas.

    ERIC Educational Resources Information Center

    Myers, George; Boyes, Edward; Stanisstreet, Martin

    2000-01-01

    Explores ideas about the causes and consequences of urban and rural air pollution of secondary school students aged 11-16 years (n=786) using a questionnaire. Students thought the air in towns and cities was more polluted than the air in the countryside. (Author/SAH)

  2. CMAQ MODELING FOR AIR TOXICS AT FINE SCALES: A PROTOTYPE STUDY

    EPA Science Inventory

    Toxic air pollutants (TAPs) or hazardous air pollutants (HAPs) exhibit considerable spatial and temporal variability across urban areas. Therefore, the ability of chemical transport models (CTMs), e.g. Community Multi-scale Air Quality (CMAQ), to reproduce the spatial and tempor...

  3. NHEXAS PHASE I ARIZONA STUDY--METALS-XRF IN AIR ANALYTICAL RESULTS

    EPA Science Inventory

    The Metals-XRF in Air data set contains X-ray fluorescence (XRF) analytical results for measurements of up to 27 metals in 432 air samples over 236 households. Samples were taken by pumping standardized air volumes through filters at indoor and outdoor sites around each househol...

  4. U.S.-MEXICO BORDER PROGRAM ARIZONA BORDER STUDY--METALS/XRF IN AIR ANALYTICAL RESULTS

    EPA Science Inventory

    The Metals-XRF in Air data set contains X-ray fluorescence (XRF) analytical results for measurements of up to 27 metals in 344 air samples over 86 households. Samples were taken by pumping standardized air volumes through filters at indoor and outdoor sites around each household...

  5. Overview of the Frontal Air-Sea Interaction Experiment (FASINEX) - A study of air-sea interaction in a region of strong oceanic gradients

    NASA Technical Reports Server (NTRS)

    Weller, Robert A.

    1991-01-01

    From 1984 to 1986 the cooperative Frontal Air-Sea Interaction Experiment (FASINEX) was conducted in the subtropical convergence zone southwest of Bermuda. The overall objective of the experiment was to study air-sea interaction on 1- to 100-km horizontal scales in a region of the open ocean characterized by strong horizontal gradients in upper ocean and sea surface properties. Ocean fronts provided both large spatial gradients in sea surface temperature and strong jetlike flows in the upper ocean. The motivation for and detailed objectives of FASINEX are reviewed. Then the components of the field program are summarized. Finally, selected results are presented in order to provide an overview of the outcome of FASINEX.

  6. Modeling of Personal Exposures to Ambient Air Toxics in Camden, New Jersey: An Evaluation Study

    PubMed Central

    Wang, Sheng-Wei; Tang, Xiaogang; Fan, Zhi-Hua (Tina); Wu, Xiangmei; Lioy, Paul J.; Georgopoulos, Panos G.

    2011-01-01

    This study presents the Individual Based Exposure Modeling (IBEM) application of MENTOR (Modeling ENvironment for TOtal Risk studies) in a hot spot area, where there are concentrated local sources on the scale of tens to hundreds of meters, and an urban reference area in Camden, NJ, to characterize the ambient concentrations and personal exposures to benzene and toluene from local ambient sources. The emission-based ambient concentrations in the two neighborhoods were first estimated through atmospheric dispersion modeling. Subsequently, the calculated and measured ambient concentrations of benzene and toluene were separately combined with the time-activity diaries completed by the subjects as inputs to MENTOR/IBEM for estimating personal exposures resulting from ambient sources. The modeling results were then compared with the actual personal measurements collected from over 100 individuals in the field study to identify the gaps in modeling personal exposures in a hot spot. The modeled ambient concentrations of benzene and toluene were generally in agreement with the neighborhood measurements within a factor of 2, but were underestimated at the high-end percentiles. The major local contributors to the benzene ambient levels are from mobile sources, whereas mobile and stationary (point and area) sources contribute to the toluene ambient levels in the study area. This finding can be used as guidance for developing better air toxic emission inventories for characterizing, through modeling, the ambient concentrations of air toxics in the study area. The estimated percentage contributions of personal exposures from ambient sources were generally higher in the hot spot area than the urban reference area in Camden, NJ, for benzene and toluene. This finding demonstrates the hot spot characteristics of stronger local ambient source impacts on personal exposures. Non-ambient sources were also found as significant contributors to personal exposures to benzene and toluene

  7. Air pollution, asthma attacks, and socioeconomic deprivation: a small-area case-crossover study.

    PubMed

    Laurent, Olivier; Pedrono, Gaëlle; Segala, Claire; Filleul, Laurent; Havard, Sabrina; Deguen, Séverine; Schillinger, Charles; Rivière, Emmanuel; Bard, Denis

    2008-07-01

    With few exceptions, studies of short-term health effects of air pollution use pollutant concentrations that are averaged citywide as exposure indicators. They are thus prone to exposure misclassification and consequently to bias. Measurement of the relations between air pollution and health, generally and in specific populations, could be improved by employing more geographically precise exposure estimates. The authors investigated short-term relations between ambient air pollution estimated in small geographic areas (French census blocks) and asthma attacks in Strasbourg, France, in 2000-2005--in the general population and in populations with contrasting levels of socioeconomic deprivation. Emergency health-care networks provided data on 4,683 telephone calls made for asthma attacks. Deprivation was estimated using a block-level index constructed from census data. Hourly concentrations of particulate matter less than 10 microm in aerodynamic diameter (PM(10)), sulfur dioxide, nitrogen dioxide, and ozone were modeled by block with ADMS-Urban software. Adjusted case-crossover analyses showed that asthma calls were positively but not significantly associated with PM(10) (for a 10-microg x m(-3) increase, odds ratio (OR) = 1.035, 95% confidence interval (CI): 0.997, 1.075), sulfur dioxide (OR = 1.056, 95% CI: 0.979, 1.139), and nitrogen dioxide (OR = 1.025, 95% CI: 0.990, 1.062). No association was observed for ozone (OR = 0.998, 95% CI: 0.965, 1.032). Socioeconomic deprivation had no significant influence on these relations. PMID:18467319

  8. Spatial and Temporal Distribution of Ozone Over Houston in the 2006 Texas Air Quality Study

    NASA Astrophysics Data System (ADS)

    Tytell, J.; Johnson, R.; Porter, J.; Businger, S.; Talbot, R.; Troop, D.; Mao, H.

    2006-12-01

    The second Texas Air Quality Study (TexAQS II), which took place during the summer of 2006, combined the efforts of a large number of universities as well as local and federal air quality programs to gather technical information to help policy makers design plans that will improve the air quality over Texas. Contributing to this campaign was a collaborative effort by NOAA, the University of New Hampshire, and the University of Hawaii to gather Lagrangian data on the circulation of ozone and its precursors in the vicinity of Houston. Six smart balloons with buoyancy control were deployed from the La Porte airport in the industrialized sector of Houston. The smart balloon deployments occurred over a three-week period as part of a larger effort to monitor the regional distribution of ozone under specific circulation episodes around Houston. The Lagrangian balloon observations included measurements of ozone concentrations and basic meteorological variables as they moved with and tracked the flow. A team on the ground followed the balloons and collected supplemental data, using a MICROTOPS II ozone monitor and a portable ozone sensor designed by the University of New Hampshire. Our synthesis also includes data from surface monitoring stations, research aircraft, and NOAA's ship, the Ron Brown. The resulting comprehensive analysis aims to provide additional insight into the complex interaction of synoptic-scale flows with local sea-breeze and urban circulations on the pollution distribution over the greater Houston region. A preliminary examination of the ozone measurements suggests that the ozone level in the near-coastal region reached >200 ppbv aloft. However, values dropped to near zero in the outflow from the Greater Houston area, possibly as a result of being titrated by high concentrations of NO.

  9. A Case Study of the Impact of AIRS Temperature Retrievals on Numerical Weather Prediction

    NASA Technical Reports Server (NTRS)

    Reale, O.; Atlas, R.; Jusem, J. C.

    2004-01-01

    Large errors in numerical weather prediction are often associated with explosive cyclogenesis. Most studes focus on the under-forecasting error, i.e. cases of rapidly developing cyclones which are poorly predicted in numerical models. However, the over-forecasting error (i.e., to predict an explosively developing cyclone which does not occur in reality) is a very common error that severely impacts the forecasting skill of all models and may also present economic costs if associated with operational forecasting. Unnecessary precautions taken by marine activities can result in severe economic loss. Moreover, frequent occurrence of over-forecasting can undermine the reliance on operational weather forecasting. Therefore, it is important to understand and reduce the prdctions of extreme weather associated with explosive cyclones which do not actually develop. In this study we choose a very prominent case of over-forecasting error in the northwestern Pacific. A 960 hPa cyclone develops in less than 24 hour in the 5-day forecast, with a deepening rate of about 30 hPa in one day. The cyclone is not versed in the analyses and is thus a case of severe over-forecasting. By assimilating AIRS data, the error is largely eliminated. By following the propagation of the anomaly that generates the spurious cyclone, it is found that a small mid-tropospheric geopotential height negative anomaly over the northern part of the Indian subcontinent in the initial conditions, propagates westward, is amplified by orography, and generates a very intense jet streak in the subtropical jet stream, with consequent explosive cyclogenesis over the Pacific. The AIRS assimilation eliminates this anomaly that may have been caused by erroneous upper-air data, and represents the jet stream more correctly. The energy associated with the jet is distributed over a much broader area and as a consequence a multiple, but much more moderate cyclogenesis is observed.

  10. A case study of deep convective transport of tropospheric air into the lowermost stratosphere

    NASA Astrophysics Data System (ADS)

    Hegglin, M. I.; Brunner, D.; Wernli, H.; Hoor, P.; Fischer, H.; Schiller, C.; Weers, U.; Peter, Th.

    2003-04-01

    In the framework of SPURT seasonal conducted high-resolution airborne measurements of NO, NOy and O3 besides other long-lived tracers are performed in order to investigate the role of dynamical and chemical processes shaping the structure of the tropopause region. NO, NOy, and O3 are measured by chemiluminescence reaction of NO and O3, NOy after beeing reduced by an externally mounted catalytic converter into NO.[0.3cm] First evaluations of the measurements show that in winter and spring tracer-correlations in the lowermost stratosphere between NOy/O3 and NOy/N2O are controlled by downward transport of aged stratospheric air, whereas summer and autumn measurements show characteristics of tropospheric air composition. In a case study of a flight from Hohn 52oN to Faro 37oN we analyzed the results of a flight through a spectacularly deep stratospheric intrusion associated with a large convective system over the Mediterranean using the reverse-domain-filling technique (RDF) based on three-dimensional ECMWF analyses. Unexpectedly high NOy and H2O concentrations were observed above the tropopause but could not be explained by troposphere to stratosphere transport in the past 20 days based on trajectory calculations. However, nearby convective clouds with cloud top temperatures as low as -50oC suggest a high potential for convective injection of tropospheric air into the stratosphere. Simulations with cloud resolving models confirm the possibility of TST up to about 40 K above the tropopause.

  11. Study of biomass burning emissions with Aqua/AIRS and MetOp-A/IASI

    NASA Astrophysics Data System (ADS)

    Thonat, T.; Crevoisier, C.; Chédin, A.; Armante, R.; Crépeau, L.; Scott, N. A.

    2012-04-01

    Biomass burning is an important source of CO2 and CO to the atmosphere, and plays a key role in the global carbon budget. However, there are still large discrepancies between existing emission inventories, stressing the need of diverse approaches to improve our knowledge of biomass burning emissions. Hyperspectral infrared sounders such as AIRS and IASI provide information on several gases emitted by fires, with the spatial and temporal coverage needed to improve our knowledge of the biomass burning issue. From IASI, we derive monthly mid-tropospheric integrated content of CO2 and CO by night and day (09:30/21:30 LT) in clear sky conditions, for the period July 2007-present (4.5 years will be available in April 2012). Retrieving simultaneously the two gases from the same instrument allows studying the correlations between their atmospheric distributions and provides important information on the role of fires on the evolution of these gases. For the same period, we also derive mid-tropospheric integrated content of CO from AIRS at 01:30/13:30 LT. Focusing our analysis on Africa and Amazonia, where most of tropical fire emissions are located, and following Chédin et al. (2005, 2008) who revealed the existence of a daily tropospheric excess of CO2 quantitatively related to fire emissions in the tropics, we will show that both daily CO and CO2 are in good agreement with the location and seasonal variations of fires, with fires playing a key role in the interannual variations of these gases. We will also show that combining AIRS (01:30/13:30 LT) and IASI (09:30/21:30 LT) improves the characterisation of the diurnal cycle of CO and its relation with fire emissions, either in the flaming or smoldering phases, and with the vertical transport of fire plumes.

  12. Computational Study of the Hydrodynamic Behavior during Air Discharge through a Sparger Submerged in the Condensation Pool

    SciTech Connect

    Ahn, Hyung-Joon; Bang, Young-Seok; Kim, In-Goo; Kim, Hho-Jung; Lee, Byeong-Eun; Kwon, Soon-Bum

    2002-07-01

    The In-containment Refueling Water Storage Tank (IRWST) has the function of heat sink when steam is released from the pressurizer. The hydrodynamic behaviors occurring at the sparger are very complex because of the wide variety of operating conditions and the complex geometry. Hydrodynamic behavior when air is discharged through a sparger in a condensation pool is investigated using CFD techniques in the present study. The effect of pressure acting on the sparger header during both water and air discharge through the sparger is studied. In addition, pressure oscillation occurring during air discharge through the sparger is studied for a better understanding of mechanisms of air discharge and a better design of the IRWST, including sparger. (authors)

  13. A study of energy use for ventilation and air-conditioning systems in Hong Kong

    NASA Astrophysics Data System (ADS)

    Yu, Chung Hoi Philip

    Most of the local modern buildings are high-rise with enclosed structure. Mechanical ventilation and air conditioning (MVAC) systems are installed for thermal comfort. Various types of MVAC systems found in Hong Kong were critically reviewed with comments on their characteristics in energy efficiency as well as application. The major design considerations were also discussed. Besides MVAC, other energy-consuming components in commercial buildings were also identified, such as lighting, lifts and escalators, office equipment, information technology facilities, etc. A practical approach has been adopted throughout this study in order that the end results will have pragmatic value to the heating, ventilating and air-conditioning (HVAC) industry in Hong Kong. Indoor Air Quality (IAQ) has become a major issue in commercial buildings worldwide including Hong Kong. Ventilation rate is no doubt a critical element in the design of HVAC systems, which can be realized more obviously in railway train compartments where the carbon dioxide level will be built up quickly when the compartments are crowded during rush hours. A study was carried out based on a simplified model using a train compartment that is equipped with an MVAC system. Overall Thermal Transfer Value (OTTV) is a single-value parameter for controlling building energy use and is relatively simple to implement legislatively. The local government has taken a first step in reacting to the worldwide concern of energy conservation and environmental protection since 1995. Different methods of OTTV calculation were studied and the computation results were compared. It gives a clear picture of the advantages and limitations for each method to the building designers. However, due to the limitations of using OTTV as the only parameter for building energy control, some new approaches to a total control of building energy use were discussed and they might be considered for future revision of the building energy codes in Hong

  14. Experimental study of the water-to-air stopping power ratio of monoenergetic carbon ion beams for particle therapy.

    PubMed

    Sánchez-Parcerisa, D; Gemmel, A; Jäkel, O; Parodi, K; Rietzel, E

    2012-06-01

    Reference dosimetry with ionization chambers requires a number of chamber-specific and beam-specific calibration factors. For carbon ion beams, IAEA report TRS-398 yields a total uncertainty of 3% in the determination of the absorbed dose to water, for which the biggest contribution arises from the water-to-air stopping power ratio (s(w, air)), with an uncertainty of 2%. The variation of (s(w, air)) along the treatment field has been studied in several Monte Carlo works presented over the last few years. Their results were, in all cases, strongly dependent on the choice of mean ionization potentials (I-values) for air and water. A smaller dependence of (s(w, air)) with penetration depth was observed. Since a consensus on I(w, air) and I(air) has not yet been reached, the validity of such studies for clinical use cannot be assessed independently. Our approach is based on a direct experimental measurement of water-equivalent thicknesses of different air gaps at different beam energies. A theoretical expression describing the variation of the stopping power ratio with kinetic energy, s(w,air)(E), was derived from the Bethe-Bloch formula and fit to the measured data, yielding a coherent pair of I(w) and I(air) values with I(air)/I(w) = 1.157 ± 0.023. Additionally, the data from five different beam energies were combined in an average value of s(w,air) = 1.132 ± 0.003 (statistical) ± 0.003 (variation over energy range), valid for monoenergetic carbon ion beams at the plateau area of the depth dose distribution. A detailed uncertainty analysis was performed on the data, in order to assess the limitations of the method, yielding an overall standard uncertainty below 1% in s(w,air)(E). Therefore, when properly combined with the appropriate models for the fragment spectra, our experimental work can contribute to narrow the uncertainty margins currently in use in absorbed dose to water determination for dosimetry of carbon ion beam radiotherapy. PMID:22596046

  15. Technology Solutions Case Study: Ventilation System Effectiveness and Tested Indoor Air Quality Impacts

    SciTech Connect

    A. Rudd and D. Bergey

    2015-08-01

    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 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.

  16. Southern california offshore air quality model validation study. Volume I: executive summary. Final report

    SciTech Connect

    Zannetti, P.; Wilbur, D.M.; Baxter, R.A.

    1981-11-01

    This volume summarizes the significant results of a BLM-funded study conducted jointly by AeroVironment Inc. and the Naval Postgraduate School to validate and/or modify screening models commonly used to predict onshore air quality impacts from outer continental shelf (OCS) emission sources. The study involved both field experiments and computer modeling analysis to give a better understanding of dispersion over water and at the land/sea interface. Two field experiments were performed releasing SF6 tracer gas from a research vessel offshore the Ventura-Oxnard, California coastal area in September, 1980 and January, 1981. Modifications are discussed for standard Gaussian models to predict peak plume concentration values, the horizontal and vertical shape of the plume, and peak ground-level impacts from OCS emission sources.

  17. Southern california offshore air quality model validation study. Volume II: synthesis of findings. Final report

    SciTech Connect

    Zannetti, P.; Wilbur, D.M.; Baxter, R.A.

    1981-11-01

    This volume describes the significant results of a BLM-funded study conducted jointly by AeroVironment Inc. and the Naval Postgraduate School to validate and/or modify screening models commonly used to predict onshore air quality impacts from outer continental shelf (OCS) emission sources. The study involved both field experiments and computer modeling analysis to give a better understanding of dispersion over water and at the land/sea interface. Two field experiments were performed releasing SF tracer gas from a research vessel offshore the Ventura-Oxnard, California coastal area in September, 1980 and January, 1981. Modifications are discussed for standard Gaussian models to predict peak plume concentration values, the horizontal and vertical shape of the plume, and peak ground-level impacts from OCS emission sources.

  18. Brewster Angle Microscopy Study of Model Stratum Corneum Lipid Monolayers at the Air-Water Interface

    NASA Astrophysics Data System (ADS)

    Adams, Ellen; Champagne, Alex; William, Joseph; Allen, Heather

    2012-04-01

    As the first and last barrier in the body, the stratum corneum (SC) is essential to life. Understanding the interactions and organization of lipids within the SC provides insight into essential physiological processes, including water loss prevention and the adsorption of substances from the environment. Langmuir monolayers have long been used to study complex systems, such as biological membranes and marine aerosols, due to their ability to shed light on intermolecular interactions. In this study, lipid mixtures with varying cholesterol and cerebroside ratios were investigated at the air/water interface. Surface tension measurements along with Brewster angle microscopy (BAM) images were used to examine the lipid phase transitions. Results indicate that cholesterol and cerebrosides form miscible monolayers, exhibiting ideal behavior. BAM images of a singular, uniform collapse phase also suggest formation of a miscible monolayer.

  19. Application of a three-dimensional, prognostic model to Mexico City air quality studies

    SciTech Connect

    Williams, M.D.; Porch, W.M.

    1991-01-01

    Los Alamos National Laboratory and Instituto Mexicano del Petroleo have embarked on a joint study of options for improving air quality in Mexico City. One of the first steps in the process is to develop an understanding of the existing air quality situation. In this context we have begun by modifying a three-dimensional, prognostic, higher order turbulence model for atmospheric circulation (HOTMAC) to threat domains which include an urbanized area. This sophisticated meteorological model is required because of the complexity of the terrain and the relative paucity of meteorological data. The basic model (HOTMAC) was modified to include an urban canopy and urban heat sources. HOTMAC has been used to drive a Monte-Carlo kernel dispersion code (RAPTAD). RAPTAD was used to model the flow of carbon monoxide and sulfur dioxide, and the results have been compared to measurements. In addition the modeled wind fields which are based on upper-level winds from the airport are compared to the measured low-level winds. Also, a four year history of temperature structure obtained from the rawinsode at the airport has been related to mixing parameters and less reactive pollutant measurements (such as carbon monoxide). 10 refs., 15 figs.

  20. Classroom ventilation and indoor air quality-results from the FRESH intervention study.

    PubMed

    Rosbach, J; Krop, E; Vonk, M; van Ginkel, J; Meliefste, C; de Wind, S; Gehring, U; Brunekreef, B

    2016-08-01

    Inadequate ventilation of classrooms may lead to increased concentrations of pollutants generated indoors in schools. The FRESH study, on the effects of increased classroom ventilation on indoor air quality, was performed in 18 naturally ventilated classrooms of 17 primary schools in the Netherlands during the heating seasons of 2010-2012. In 12 classrooms, ventilation was increased to targeted CO2 concentrations of 800 or 1200 ppm, using a temporary CO2 controlled mechanical ventilation system. Six classrooms were included as controls. In each classroom, data on endotoxin, β(1,3)-glucans, and particles with diameters of <10 μm (PM10 ) and <2.5 μm (PM2.5 ) and nitrogen dioxide (NO2 ) were collected during three consecutive weeks. Associations between the intervention and these measured indoor air pollution levels were assessed using mixed models, with random classroom effects. The intervention lowered endotoxin and β(1,3)-glucan levels and PM10 concentrations significantly. PM10 for instance was reduced by 25 μg/m³ (95% confidence interval 13-38 μg/m³) from 54 μg/m³ at maximum ventilation rate. No significant differences were found between the two ventilation settings. Concentrations of PM2.5 and NO2 were not affected by the intervention. Our results provide evidence that increasing classroom ventilation is effective in decreasing the concentrations of some indoor-generated pollutants. PMID:26171647

  1. Energy Impacts of Oversized Residential Air Conditioners -- Simulation Study of Retrofit Sequence Impacts

    SciTech Connect

    Booten, C.; Christensen, C.; Winkler, J.

    2014-11-01

    This research addresses the question of what are the energy consequences for oversizing of an air conditioner in a home. Conventional wisdom holds that oversizing the AC results in significant energy penalties. However, the reason for this was shown to be due to crankcase heaters and not due to cycling performance of the AC, and is only valid for a particular set of assumptions. Adding or removing individual characteristics, such as ducts or crankcase heaters, can have measurable impacts on energy use. However, with all other home characteristics held constant, oversizing the AC generally has a small effect on cooling energy use, even if the cycling performance of the unit is poor. The relevant aspects of air conditioner modeling are discussed to illustrate the effects of the cycling loss coefficient, Cd, capacity, climate, ducts and parasitic losses such as crankcase heaters. A case study of a typical 1960's vintage home demonstrates results in the context of whole building simulations using EnergyPlus.

  2. Modeling the effects of ship emissions on coastal air quality: A case study of southern California

    NASA Astrophysics Data System (ADS)

    Vutukuru, Satish; Dabdub, Donald

    2008-05-01

    Impact of emissions from ocean-going ships on ozone and particulate matter concentrations is quantified using UCI-CIT model for the South Coast Air Basin of California (SoCAB). The modeling domain encompasses Los Angeles and Long Beach ports and part of the Pacific Ocean that is traversed by ships to visit these ports. Impacts are assessed for a base year (2002) and a future year (2020) by analyzing results from simulations of a three-day summer episode. Contribution of ship emissions to peak 1-h and 8-h ozone concentrations is predicted to be up to 29 and 24 ppb, respectively, for the year 2002. Similarly, particulate nitrate and sulfate concentrations increase up to 12.8 and 1.7 μg m-3, respectively, in the basin when ship emissions are included. Maximum impacts are predicted to occur along the coasts of Ventura and Los Angeles and also at inland locations near Simi Valley. Future year simulations show substantial increase in impacts from ships due to expected growth in ship emissions. Ozone increases are as high as 59 ppb for land-based locations when estimates of ship emissions for 2020 are included. Similarly, particulate nitrate and sulfate increase up to 14 and 2.5 μg m-3. The results of this study show that control of ship emissions is important to mitigate air pollution.

  3. Experimental study on gas-liquid flow characteristics of submerged air jets

    NASA Astrophysics Data System (ADS)

    Qin, S. J.; Liu, J. T.; Miao, T. C.; Wu, D. Z.

    2016-05-01

    The gas-liquid flow structure and interfacial behavior of submerged air jets were investigated experimentally using high speed digital video camera and image processing techniques. The jet pressure ratio varied from 1.8 to 4.8 in the experiment. And results from different jet nozzles were processed and compared. Statistical characteristics of the jet diameters along the axial distance were obtained and analyzed. Time series analysis was implemented to study the interface unsteadiness by calculating the gas-liquid interface deviation. The results showed that the jet diameters increase first linearly then nonlinearly and its growth rate decreases along the axial distance. The reason for the divergence between the result of this experiment and those done by other researchers was analyzed. Comparing the results of different pressure ratios and nozzle diameters, we found that larger jet pressure ratios have larger jet diameters and nozzle diameters nearly have no bearing on the distribution of dimensionless jet diameters. The interface unsteadiness in low and high pressure ratios exhibited totally distinct properties. And a minimum unsteady value was found along the axis of the air jets.

  4. Spatial misalignment in time series studies of air pollution and health data

    PubMed Central

    Peng, Roger D.; Bell, Michelle L.

    2010-01-01

    Time series studies of environmental exposures often involve comparing daily changes in a toxicant measured at a point in space with daily changes in an aggregate measure of health. Spatial misalignment of the exposure and response variables can bias the estimation of health risk, and the magnitude of this bias depends on the spatial variation of the exposure of interest. In air pollution epidemiology, there is an increasing focus on estimating the health effects of the chemical components of particulate matter (PM). One issue that is raised by this new focus is the spatial misalignment error introduced by the lack of spatial homogeneity in many of the PM components. Current approaches to estimating short-term health risks via time series modeling do not take into account the spatial properties of the chemical components and therefore could result in biased estimation of those risks. We present a spatial–temporal statistical model for quantifying spatial misalignment error and show how adjusted health risk estimates can be obtained using a regression calibration approach and a 2-stage Bayesian model. We apply our methods to a database containing information on hospital admissions, air pollution, and weather for 20 large urban counties in the United States. PMID:20392805

  5. Air pollution, cognitive deficits and brain abnormalities: a pilot study with children and dogs.

    PubMed

    Calderón-Garcidueñas, Lilian; Mora-Tiscareño, Antonieta; Ontiveros, Esperanza; Gómez-Garza, Gilberto; Barragán-Mejía, Gerardo; Broadway, James; Chapman, Susan; Valencia-Salazar, Gildardo; Jewells, Valerie; Maronpot, Robert R; Henríquez-Roldán, Carlos; Pérez-Guillé, Beatriz; Torres-Jardón, Ricardo; Herrit, Lou; Brooks, Diane; Osnaya-Brizuela, Norma; Monroy, Maria E; González-Maciel, Angelica; Reynoso-Robles, Rafael; Villarreal-Calderon, Rafael; Solt, Anna C; Engle, Randall W

    2008-11-01

    Exposure to air pollution is associated with neuroinflammation in healthy children and dogs in Mexico City. Comparative studies were carried out in healthy children and young dogs similarly exposed to ambient pollution in Mexico City. Children from Mexico City (n: 55) and a low polluted city (n:18) underwent psychometric testing and brain magnetic resonance imaging MRI. Seven healthy young dogs with similar exposure to Mexico City air pollution had brain MRI, measurement of mRNA abundance of two inflammatory genes cyclooxygenase-2, and interleukin 1 beta in target brain areas, and histopathological evaluation of brain tissue. Children with no known risk factors for neurological or cognitive disorders residing in a polluted urban environment exhibited significant deficits in a combination of fluid and crystallized cognition tasks. Fifty-six percent of Mexico City children tested showed prefrontal white matter hyperintense lesions and similar lesions were observed in dogs (57%). Exposed dogs had frontal lesions with vascular subcortical pathology associated with neuroinflammation, enlarged Virchow-Robin spaces, gliosis, and ultrafine particulate matter deposition. Based on the MRI findings, the prefrontal cortex was a target anatomical region in Mexico City children and its damage could have contributed to their cognitive dysfunction. The present work presents a groundbreaking, interdisciplinary methodology for addressing relationships between environmental pollution, structural brain alterations by MRI, and cognitive deficits/delays in healthy children. PMID:18550243

  6. A new dynamical atmospheric ionizing radiation (AIR) model for epidemiological studies

    NASA Technical Reports Server (NTRS)

    De Angelis, G.; Clem, J. M.; Goldhagen, P. E.; Wilson, J. W.

    2003-01-01

    A new Atmospheric Ionizing Radiation (AIR) model is currently being developed for use in radiation dose evaluation in epidemiological studies targeted to atmospheric flight personnel such as civilian airlines crewmembers. The model will allow computing values for biologically relevant parameters, e.g. dose equivalent and effective dose, for individual flights from 1945. Each flight is described by its actual three dimensional flight profile, i.e. geographic coordinates and altitudes varying with time. Solar modulated primary particles are filtered with a new analytical fully angular dependent geomagnetic cut off rigidity model, as a function of latitude, longitude, arrival direction, altitude and time. The particle transport results have been obtained with a technique based on the three-dimensional Monte Carlo transport code FLUKA, with a special procedure to deal with HZE particles. Particle fluxes are transformed into dose-related quantities and then integrated all along the flight path to obtain the overall flight dose. Preliminary validations of the particle transport technique using data from the AIR Project ER-2 flight campaign of measurements are encouraging. Future efforts will deal with modeling of the effects of the aircraft structure as well as inclusion of solar particle events. Published by Elsevier Ltd on behalf of COSPAR.

  7. Lichens of wilderness areas in California: Baseline studies for monitoring air pollution. [Letharia; Melanelia; Pseudophebe minuscula

    SciTech Connect

    Ryan, B.D.; Nash, T.H. III )

    1990-01-01

    The lichen floras of selected wilderness areas in California are being surveyed to provide baseline data for monitoring air pollution. A small number of permanent transects on trees and quadrats on rock were established, and Letharia spp. were collected for element analyses. In the San Gabriel Wilderness (immediately north of Los Angeles), a diverse lichen flora was found on rocks and (in some areas) on soil or hardwood trees, but not on conifers, and the thalli of several taxa (e.g., Melanelia spp. and Pseudephebe minuscula) showed clear signs of distortion or discoloration. No obvious signs of damaged thalli or depauperate floras have been found in the other wildernesses studied so far, except in the Agua Tibia Wilderness (near San Diego), which was largely destroyed by fire in the summer of 1989. The two wildernesses examined in the Sierra Nevada Mountains had very few corticolous lichen taxa and few taxa known to be pollution-sensitive, but this probably reflects climatic conditions more than pollution. Re-examination of the wildernesses in the future should provide information on any changes in the lichen vegetation due to changes in air quality.

  8. Experimental study of the behavior of two laser produced plasmas in air

    SciTech Connect

    Yang, Zefeng; Wei, Wenfu; Han, Jiaxun; Wu, Jian Li, Xingwen; Jia, Shenli

    2015-07-15

    The interactions among two laser ablated Al plasmas and their shock wave fronts (SWFs) induced by double laser pulses in air were studied experimentally. The evolution processes, including the expansion and interaction of the two plasmas and their shocks, were investigated by laser shadowgraphs, schlieren images, and interferograms. Remarkably, the distribution of the compressed air and the laser plasmas during the colliding process was clearly obtained using the Mach-Zehnder interferometer. From the refractive index profiles, typical plasmas density and gas density behind the shock front were estimated as ∼5.2 × 10{sup 18 }cm{sup −3} and ∼2.4 × 10{sup 20 }cm{sup −3}. A stagnation layer formed by the collision of gas behind the shock front is observed. The SWFs propagated, collided, and reflected with a higher velocity than plasmas. The results indicated that the slower plasma collided at middle, leading to the formation of the soft stagnation.

  9. NASA/Air Force/Environmental Protection Agency Interagency Depainting Study

    NASA Technical Reports Server (NTRS)

    Clark-Ingram, Marceia

    1998-01-01

    Many popular and widely used paint stripping products have traditionally contained methylene chloride as their main active ingredient. However, the Environmental Protection Agency (EPA) has critically curved the allowable use of methylene chloride under the National Emission Standard for Hazardous Air Pollutants regulating Aerospace Manufacturing and Rework Facilities . Compliance with this rule was mandatory by September 1998 for affected facilities. An effort is underway to identify and evaluate alternative depainting technologies emphasizing those believed both effective and environmentally benign. On behalf of the EPA and in cooperation with the United States Air Force, the National Aeronautics and Space Administration is conducting a technical assessment of several alternative technologies ( i.e. : chemical stripping, two CO2 blasting processes, CO2 xenon lamp coating removal, CO2 Laser stripping, plastic media blasting, sodium bicarbonate wet stripping, high pressure water stripping, and wheat starch blasting). These depainting processes represent five removal method categories, namely abrasive, impact, cryogenic, thermal, and/or molecular bonding dissociation. This paper discusses the test plan and parameters for this interagency study. Several thicknesses of clad and non-clad aluminum substrates were used to prepare test specimens. Each depainting process has been assigned a specimen lot, all of which have completed three to five stripping cycles. Numerous metallurgical evaluations are underway to assess the impact of these alternative depainting processes upon the structural integrity of the substrate.

  10. Experimental Study on a Standing Wave Thermoacoustic Prime Mover with Air Working Gas at Various Pressures

    NASA Astrophysics Data System (ADS)

    Setiawan, Ikhsan; Achmadin, Wahyu N.; Murti, Prastowo; Nohtomi, Makoto

    2016-04-01

    Thermoacoustic prime mover is an energy conversion device which converts thermal energy into acoustic work (sound wave). The advantages of this machine are that it can work with air as the working gas and does not produce any exhaust gases, so that it is environmentally friendly. This paper describes an experimental study on a standing wave thermoacoustic prime mover with air as the working gas at various pressures from 0.05 MPa to 0.6 MPa. We found that 0.2 MPa is the optimum pressure which gives the lowest onset temperature difference of 355 °C. This pressure value would be more preferable in harnessing low grade heat sources to power the thermoacoustic prime mover. In addition, we find that the lowest onset temperature difference is obtained when rh /δ k ratio is 2.85, where r h is the hydraulic radius of the stack and δ k is the thermal penetration depth of the gas. Moreover, the pressure amplitude of the sound wave is significantly getting larger from 2.0 kPa to 9.0 kPa as the charged pressure increases from 0.05 MPa up to 0.6 MPa.

  11. Controlling Air Traffic (Simulated) in the Presence of Automation (CATS PAu) 1995: A Study of Measurement Techniques for Situation Awareness in Air Traffic Control

    NASA Technical Reports Server (NTRS)

    French, Jennifer R.

    1995-01-01

    As automated systems proliferate in aviation systems, human operators are taking on less and less of an active role in the jobs they once performed, often reducing what should be important jobs to tasks barely more complex than monitoring machines. When operators are forced into these roles, they risk slipping into hazardous states of awareness, which can lead to reduced skills, lack of vigilance, and the inability to react quickly and competently when there is a machine failure. Using Air Traffic Control (ATC) as a model, the present study developed tools for conducting tests focusing on levels of automation as they relate to situation awareness. Subjects participated in a two-and-a-half hour experiment that consisted of a training period followed by a simulation of air traffic control similar to the system presently used by the FAA, then an additional simulation employing automated assistance. Through an iterative design process utilizing numerous revisions and three experimental sessions, several measures for situational awareness in a simulated Air Traffic Control System were developed and are prepared for use in future experiments.

  12. An Evaluation of Real-time Air Quality Forecasts and their Urban Emissions over Eastern Texas During the Summer of 2006 Second Texas Air Quality Study Field Study

    EPA Science Inventory

    Forecasts of ozone (O3) and particulate matter (diameter less than 2.5 µm, PM2.5) from seven air quality forecast models (AQFMs) are statistically evaluated against observations collected during August and September of 2006 (49 days) through the AIRNow netwo...

  13. Case study of odor and indoor air quality assessment in the dewatering building at the Stickney Water Reclamation Plant.

    PubMed

    Sharma, Manju; O'Connell, Susan; Garelli, Brett; Sattayatewa, Chakkrid; Moschandreas, Demetrios; Pagilla, Krishna

    2012-01-01

    Indoor air quality (IAQ) and odors were determined using sampling/monitoring, measurement, and modeling methods in a large dewatering building at a very large water reclamation plant. The ultimate goal was to determine control strategies to reduce the sensory impacts on the workforce and achieve odor reduction within the building. Study approaches included: (1) investigation of air mixing by using CO(2) as an indicator, (2) measurement of airflow capacity of ventilation fans, (3) measurement of odors and odorants, (4) development of statistical and IAQ models, and (5) recommendation of control strategies. The results showed that air quality in the building complies with occupational safety and health guidelines; however, nuisance odors that can increase stress and productivity loss still persist. Excess roof fan capacity induced odor dispersion to the upper levels. Lack of a local air exhaust system of sufficient capacity and optimum design was found to be the contributor to occasional less than adequate indoor air quality and odors. Overall, air ventilation rate in the building has less effect on persistence of odors in the building. Odor/odorant emission rates from centrifuge drops were approximately 100 times higher than those from the open conveyors. Based on measurements and modeling, the key control strategies recommended include increasing local air exhaust system capacity and relocation of exhaust hoods closer to the centrifuge drops. PMID:22277239

  14. Controlled Exposure Study of Air Pollution and T-Wave Alternans in Volunteers without Cardiovascular Disease

    PubMed Central

    Kusha, Marjan; Masse, Stephane; Farid, Talha; Urch, Bruce; Silverman, Frances; Brook, Robert D; Gold, Diane R; Mangat, Iqwal; Speck, Mary; Nair, Krishnakumar; Poku, Kwaku; Meyer, Chris; Mittleman, Murray A; Wellenius, Gregory A

    2012-01-01

    Background: Epidemiological studies have assessed T-wave alternans (TWA) as a possible mechanism of cardiac arrhythmias related to air pollution in high-risk subjects and have reported associations with increased TWA magnitude. Objective: In this controlled human exposure study, we assessed the impact of exposure to concentrated ambient particulate matter (CAP) and ozone (O3) on T-wave alternans in resting volunteers without preexisting cardiovascular disease. Methods: Seventeen participants without preexisting cardiovascular disease were randomized to filtered air (FA), CAP (150 μg/m3), O3 (120 ppb), or combined CAP + O3 exposures for 2 hr. Continuous electrocardiograms (ECGs) were recorded at rest and T-wave alternans (TWA) was computed by modified moving average analysis with QRS alignment for the artifact-free intervals of 20 beats along the V2 and V5 leads. Exposure-induced changes in the highest TWA magnitude (TWAMax) were estimated for the first and last 5 min of each exposure (TWAMax_Early and TWAMax_Late respectively). ΔTWAMax (Late–Early) were compared among exposure groups using analysis of variance. Results: Mean ± SD values for ΔTWAMax were –2.1 ± 0.4, –2.7 ± 1.1, –1.9 ± 1.5, and –1.2 ± 1.5 in FA, CAP, O3, and CAP + O3 exposure groups, respectively. No significant differences were observed between pollutant exposures and FA. Conclusion: In our study of 17 volunteers who had no preexisting cardiovascular disease, we did not observe significant changes in T-wave alternans after 2-hr exposures to CAP, O3, or combined CAP + O3. This finding, however, does not preclude the possibility of pollution-related effects on TWA at elevated heart rates, such as during exercise, or the possibility of delayed responses. PMID:22552907

  15. Road, rail, and air transportation noise in residential and workplace neighborhoods and blood pressure (RECORD Study).

    PubMed

    Méline, Julie; Van Hulst, Andraea; Thomas, Frederique; Chaix, Basile

    2015-01-01

    Associations between road traffic noise and hypertension have been repeatedly documented, whereas associations with rail or total road, rail, and air (RRA) traffic noise have rarely been investigated. Moreover, most studies of noise in the environment have only taken into account the residential neighborhood. Finally, few studies have taken into account individual/neighborhood confounders in the relationship between noise and hypertension. We performed adjusted multilevel regression analyses using data from the 7,290 participants of the RECORD Study to investigate the associations of outdoor road, rail, air, and RRA traffic noise estimated at the place of residence, at the workplace, and in the neighborhoods around the residence and workplace with systolic blood pressure (SBP), diastolic blood pressure (DBP), and hypertension. Associations were documented between higher outdoor RRA and road traffic noise estimated at the workplace and a higher SBP [+1.36 mm of mercury, 95% confidence interval (CI): +0.12, +2.60 for 65-80 dB(A) vs 30-45 dB(A)] and DBP [+1.07 (95% CI: +0.28, +1.86)], after adjustment for individual/neighborhood confounders. These associations remained after adjustment for risk factors of hypertension. Associations were documented neither with rail traffic noise nor for hypertension. Associations between transportation noise at the workplace and blood pressure (BP) may be attributable to the higher levels of road traffic noise at the workplace than at the residence. To better understand why only noise estimated at the workplace was associated with BP, our future work will combine Global Positioning System (GPS) tracking, assessment of noise levels with sensors, and ambulatory monitoring of BP. PMID:26356373

  16. Road, rail, and air transportation noise in residential and workplace neighborhoods and blood pressure (RECORD Study)

    PubMed Central

    Méline, Julie; Van Hulst, Andraea; Thomas, Frederique; Chaix, Basile

    2015-01-01

    Associations between road traffic noise and hypertension have been repeatedly documented, whereas associations with rail or total road, rail, and air (RRA) traffic noise have rarely been investigated. Moreover, most studies of noise in the environment have only taken into account the residential neighborhood. Finally, few studies have taken into account individual/neighborhood confounders in the relationship between noise and hypertension. We performed adjusted multilevel regression analyses using data from the 7,290 participants of the RECORD Study to investigate the associations of outdoor road, rail, air, and RRA traffic noise estimated at the place of residence, at the workplace, and in the neighborhoods around the residence and workplace with systolic blood pressure (SBP), diastolic blood pressure (DBP), and hypertension. Associations were documented between higher outdoor RRA and road traffic noise estimated at the workplace and a higher SBP [+1.36 mm of mercury, 95% confidence interval (CI): +0.12, +2.60 for 65-80 dB(A) vs 30-45 dB(A)] and DBP [+1.07 (95% CI: +0.28, +1.86)], after adjustment for individual/neighborhood confounders. These associations remained after adjustment for risk factors of hypertension. Associations were documented neither with rail traffic noise nor for hypertension. Associations between transportation noise at the workplace and blood pressure (BP) may be attributable to the higher levels of road traffic noise at the workplace than at the residence. To better understand why only noise estimated at the workplace was associated with BP, our future work will combine Global Positioning System (GPS) tracking, assessment of noise levels with sensors, and ambulatory monitoring of BP. PMID:26356373

  17. Air pollution and respiratory symptoms: results from three panel studies in Bangkok, Thailand.

    PubMed Central

    Vichit-Vadakan, N; Ostro, B D; Chestnut, L G; Mills, D M; Aekplakorn, W; Wangwongwatana, S; Panich, N

    2001-01-01

    Several studies in North American cities have reported associations between air pollution and respiratory symptoms. Replicating these studies in cities with very different population and weather characteristics is a useful way of addressing uncertainties and strengthening inferences of causality. To this end we examined the responses of three different panels to particulate matter (PM) air pollution in Bangkok, Thailand, a tropical city characterized by a very warm and humid climate. Panels of schoolchildren, nurses, and adults were asked to report daily upper and lower respiratory symptoms for 3 months. Concentrations of daily PM(10) (PM with a mass median aerodynamic diameter less than 10 microm) and PM(2.5) (airborne particles with aerodynamic diameters less than 2.5 microm) were collected at two sites. Generally, associations were found between these pollution metrics and the daily occurrence of both upper and lower respiratory symptoms in each of the panels. For example, an interquartile increase of 45 microg/m(3) in PM(10) was associated with about a 50% increase in lower respiratory symptoms in the panel of highly exposed adults, about 30% in the children, and about 15% in the nurses. These estimates were not appreciably altered by changes in the specification of weather variables, stratification by temperature, or inclusion of individual characteristics in the models; however, time trends in the data cause some uncertainty about the magnitude of the effect of PM on respiratory symptoms. These pollutants were also associated with the first day of a symptom episode in both adult panels but not in children. The estimated odds ratios are generally consistent with and slightly higher than the findings of previous studies conducted in the United States. PMID:11427387

  18. Methods for bias reduction in time-series studies of particulate matter air pollution and mortality.

    PubMed

    Roberts, Steven; Martin, Michael A

    2007-04-15

    In many cities of the United States, measurements of ambient particulate matter air pollution (PM) are available only every sixth day. Time-series studies conducted in these cities that investigate the relationship between mortality and PM are restricted to using a single day's PM as the measure of PM exposure, rather than using measurements taken over several consecutive days. Studies showed that using a single-day PM as the measure of PM exposure can result in estimates that have a negative bias, sometimes in the order of over half of the value being estimated. In this article two methods are introduced that can be used to obtain estimates that can in some situations reduce the bias to negligible proportions when only every-sixth-day PM concentrations are available. Using one of these methods, the national average PM mortality effect estimates obtained for total mortality and cardiovascular and respiratory mortality, respectively, correspond to 0.27% and 0.39% increases in mortality per 10-microg/m3 increment in PM. The corresponding effect estimates obtained using the single-day lag-1 PM concentration are 0.18% and 0.23%. The estimates obtained using the lag-1 PM concentration were the most widely reported results from the recent multicity National Morbidity, Mortality, and Air Pollution Study (NMMAPS) analyses. The more accurate estimates obtained from the methods introduced in this article will enable more accurate quantification of the increased incidence in mortality due to elevation in PM levels and the benefit of current or more stringent regulatory standards. PMID:17365620

  19. Conceptual design and engineering studies of adiabatic compressed air energy storage (CAES) with thermal energy storage

    SciTech Connect

    Hobson, M. J.

    1981-11-01

    The objective of this study was to perform a conceptual engineering design and evaluation study and to develop a design for an adiabatic CAES system using water-compensated hard rock caverns for compressed air storage. The conceptual plant design was to feature underground containment for thermal energy storage and water-compensated hard rock caverns for high pressure air storage. Other design constraints included the selection of turbomachinery designs that would require little development and would therefore be available for near-term plant construction and demonstration. The design was to be based upon the DOE/EPRI/PEPCO-funded 231 MW/unit conventional CAES plant design prepared for a site in Maryland. This report summarizes the project, its findings, and the recommendations of the study team; presents the development and optimization of the plant heat cycle and the selection and thermal design of the thermal energy storage system; discusses the selection of turbomachinery and estimated plant performance and operational capability; describes the control system concept; and presents the conceptual design of the adiabatic CAES plant, the cost estimates and economic evaluation, and an assessment of technical and economic feasibility. Particular areas in the plant design requiring further development or investigation are discussed. It is concluded that the adiabatic concept appears to be the most attractive candidate for utility application in the near future. It is operationally viable, economically attractive compared with competing concerns, and will require relatively little development before the construction of a plant can be undertaken. It is estimated that a utility could start the design of a demonstration plant in 2 to 3 years if research regarding TES system design is undertaken in a timely manner. (LCL)

  20. A Study on the Potential Applications of Satellite Data in Air Quality Monitoring and Forecasting

    NASA Technical Reports Server (NTRS)

    Li, Can; Hsu, N. Christina; Tsay, Si-Chee

    2011-01-01

    In this study we explore the potential applications of MODIS (Moderate Resolution Imaging Spectroradiometer) -like satellite sensors in air quality research for some Asian regions. The MODIS aerosol optical thickness (AOT), NCEP global reanalysis meteorological data, and daily surface PM(sub 10) concentrations over China and Thailand from 2001 to 2009 were analyzed using simple and multiple regression models. The AOT-PM(sub 10) correlation demonstrates substantial seasonal and regional difference, likely reflecting variations in aerosol composition and atmospheric conditions, Meteorological factors, particularly relative humidity, were found to influence the AOT-PM(sub 10) relationship. Their inclusion in regression models leads to more accurate assessment of PM(sub 10) from space borne observations. We further introduced a simple method for employing the satellite data to empirically forecast surface particulate pollution, In general, AOT from the previous day (day 0) is used as a predicator variable, along with the forecasted meteorology for the following day (day 1), to predict the PM(sub 10) level for day 1. The contribution of regional transport is represented by backward trajectories combined with AOT. This method was evaluated through PM(sub 10) hindcasts for 2008-2009, using ohservations from 2005 to 2007 as a training data set to obtain model coefficients. For five big Chinese cities, over 50% of the hindcasts have percentage error less than or equal to 30%. Similar performance was achieved for cities in northern Thailand. The MODIS AOT data are responsible for at least part of the demonstrated forecasting skill. This method can be easily adapted for other regions, but is probably most useful for those having sparse ground monitoring networks or no access to sophisticated deterministic models. We also highlight several existing issues, including some inherent to a regression-based approach as exemplified by a case study for Beijing, Further studies will be

  1. Efficient control of air pollution through plants, a cost-effective alternative: studies on Dalbergia sissoo Roxb.

    PubMed

    Kapoor, C S; Bamniya, B R; Kapoor, K

    2013-09-01

    Plants can be used as both passive biomonitors and biomitigators in urban and industrial environments to indicate the environmental quality and to ameliorate pollution level in a locality. Many studies reveal that plants are negatively affected by the ambient levels of air pollutants. The present study was conducted to evaluate the impact of air pollution on comparative basis with reference to changes in photosynthetic pigments, plant height, leaves, as well as, biochemical parameters of plants of different sites around Udaipur city receiving varying levels of pollution load. The investigated tree species Dalbergia sissoo Roxb. (Family: Fabaceae) exhibited a reduction in various physiological and biochemical growth parameters that correspond with air pollution levels at different sites. The tree species growing in polluted and control areas were compared with respect to foliar dust load, leaf area, and chlorophyll and total carbohydrate and total protein concentration in the leaves. Our studies suggest that D. sissoo Roxb. can successfully be grown in an area for monitoring air pollution, where it is mild and droughts are common. It will prove as an ideal tree species to control pollution effectively beside acting as a shade tree and being a source of food for birds and animals. By plantation of D. sissoo Roxb., mitigative measure at the polluted sites to control generation of particulate matter and the air quality required can be ensured. Our results also confirm that industrial and vehicular air pollution level in Udaipur city is shifting beyond limits. PMID:23423551

  2. Effects of long-term exposure to traffic-related air pollution on respiratory and cardiovascular mortality in the Netherlands: the NLCS-AIR study.

    PubMed

    Brunekreef, Bert; Beelen, Rob; Hoek, Gerard; Schouten, Leo; Bausch-Goldbohm, Sandra; Fischer, Paul; Armstrong, Ben; Hughes, Edward; Jerrett, Michael; van den Brandt, Piet

    2009-03-01

    Evidence is increasing that long-term exposure to ambient air pollution is associated with deaths from cardiopulmonary diseases. In a 2002 pilot study, we reported clear indications that traffic-related air pollution, especially at the local scale, was related to cardiopulmonary mortality in a randomly selected subcohort of 5000 older adults participating in the ongoing Netherlands Cohort Study (NLCS) on diet and cancer. In the current study, referred to as NLCS-AIR, our objective was to obtain more precise estimates of the effects of traffic-related air pollution by analyzing associations with cause-specific mortality, as well as lung cancer incidence, in the full cohort of approximately 120,000 subjects. Cohort members were 55 to 69 years of age at enrollment in 1986. Follow-up was from 1987 through 1996 for mortality (17,674 deaths) and from late 1986 through 1997 for lung cancer incidence (2234 cases). Information about potential confounding variables and effect modifiers was available from the questionnaire that subjects completed at enrollment and from publicly available data (including neighborhood-scale information such as income distributions). The NLCS was designed for a case-cohort approach, which makes use of all the cases in the full cohort, while data for the random subcohort are used to estimate person-time experience in the study. Full information on confounders was available for the subjects in the random subcohort and for the emerging cases of mortality and lung cancer incidence during the follow-up period, and in NLCS-AIR we used the case-cohort approach to examine the relation between exposure to air pollution and cause-specific mortality and lung cancer. We also specified a standard Cox proportional hazards model within the full cohort, for which information on potential confounding variables was much more limited. Exposure to air pollution was estimated for the subjects' home addresses at baseline in 1986. Concentrations were estimated for

  3. The ORNL Indoor Air Quality Study: Re-cap, Context, and Assessment on Radon

    SciTech Connect

    Tonn, Bruce Edward; Rose, Erin M.; Ternes, Mark P.

    2015-10-01

    As part of the retrospective evaluation of the U.S. Department of Energy s low-income Weatherization Assistance Program that was led by Oak Ridge National Laboratory (ORNL), an assessment of the impacts of weatherization on indoor air quality (IAQ) was conducted. This assessment included nearly 500 treatment and control homes across the country. Homes were monitored for carbon monoxide, radon, formaldehyde, temperature and humidity pre- and post-weatherization. This report focuses on the topic of radon and addresses issues not thoroughly discussed in the original IAQ report. The size, scope and rigor of the radon component of the IAQ study are compared to previous studies that assessed the impacts of weatherization on indoor radon levels. It is found that the ORNL study is by far the most extensive study conducted to date, though the ORNL results are consistent with the findings of the other studies. However, the study does have limitations related to its reliance on short-term measurements of radon and inability to attribute changes in radon levels in homes post-weatherization to specific weatherization measures individually or in combination.

  4. Monitoring air pollution effects on children for supporting public health policy: the protocol of the prospective cohort MAPEC study

    PubMed Central

    Feretti, D; Ceretti, E; De Donno, A; Moretti, M; Carducci, A; Bonetta, S; Marrese, M R; Bonetti, A; Covolo, L; Bagordo, F; Villarini, M; Verani, M; Schilirò, T; Limina, R M; Grassi, T; Monarca, S; Casini, B; Carraro, E; Zani, C; Mazzoleni, G; Levaggi, R; Gelatti, U

    2014-01-01

    Introduction Genotoxic biomarkers have been studied largely in adult population, but few studies so far have investigated them in children exposed to air pollution. Children are a high-risk group as regards the health effects of air pollution and some studies suggest that early exposure during childhood can play an important role in the development of chronic diseases in adulthood. The objective of the project is to evaluate the associations between the concentration of urban air pollutants and biomarkers of early biological effect in children, and to propose a model for estimating the global risk of early biological effects due to air pollutants and other factors in children. Methods and analysis Two biomarkers of early biological effects, DNA damage by the comet assay and the micronuclei (MN) test, will be investigated in oral mucosa cells of 6–8-year-old children. Concurrently, some toxic airborne pollutants (polycyclic aromatic hydrocarbon (PAH) and nitro-PAH) and in vitro air mutagenicity and toxicity in ultra-fine air particulates (PM0.5) will be evaluated. Furthermore, demographic and socioeconomic variables, other sources of exposures to air pollutants and lifestyle variables will be assessed by a structured questionnaire. The associations between sociodemographic, environmental and other exposure variables and biomarkers of early biological effect using univariate and multivariate models will be analysed. A tentative model for calculating the global absolute risk of having early biological effects caused by air pollution and other variables will be proposed. Ethics and dissemination The project has been approved by the Ethics Committees of the local Health Authorities. The results will be communicated to local Public Health Agencies, for supporting educational programmes and health policy strategies. LIFE+2012 Environment Policy and Governance. LIFE12 ENV/IT/000614. PMID:25227631

  5. Mechanism Study of Carbon Dioxide Capture from Ambient Air by Hydration Energy Variation

    NASA Astrophysics Data System (ADS)

    Shi, X.; Lackner, K. S.

    2014-12-01

    Hydration of neutral and ionic species on solid interfaces plays an important role in a wide range of natural and engineered processes within energy systems as well as biological and environmental systems. Various chemical reactions are significantly enhanced, both in the rate and the extent of the reaction, because of water molecules present or absent at the interface. A novel technology for carbon dioxide capture, driven by the free energy difference between more or less hydrated states of an anionic exchange resin is studied for a new approach to absorb CO2 from ambient air. For these materials the affinity to CO2 is dramatically lowered as the availability of water is increased. This makes it possible to absorb CO2 from air in a dry environment and release it at two orders of magnitude larger partial pressures in a wet environment. While the absorption process and the thermodynamic properties of air capture via ion exchange resins have been demonstrated, the underlying physical mechanisms remain to be understood. In order to rationally design better sorbent materials, the present work elucidates through molecular dynamics and quantum mechanical modeling the energy changes in the carbonate, bicarbonate and hydroxide ions that are induced by hydration, and how these changes affect sorbent properties. A methodology is developed to determine the free energy change during carbonate ion hydrolysis changes with different numbers of water molecules present. This makes it possible to calculate the equilibrium in the reaction CO3--•nH2O ↔ HCO3- • m1H2O + OH- • m2H2O + (n - 1 - m1 - m2)H2O Molecular dynamics models are used to calculate free energies of hydration for the CO32- ion, the HCO3- ion, and the OH- ion as function of the amount of water that is present. A quantum mechanical model is employed to study the equilibrium of the reaction Na2CO3 + H2O ↔ NaHCO3 + NaOHin a vacuum and at room temperature. The computational analysis of the free energy of

  6. Using Satellite-Based Spatiotemporal Resolved Air Temperature Exposure to Study the Association between Ambient Air Temperature and Birth Outcomes in Massachusetts

    PubMed Central

    Melly, Steven J.; Coull, Brent A.; Nordio, Francesco; Schwartz, Joel D.

    2015-01-01

    Background Studies looking at air temperature (Ta) and birth outcomes are rare. Objectives We investigated the association between birth outcomes and daily Ta during various prenatal exposure periods in Massachusetts (USA) using both traditional Ta stations and modeled addresses. Methods We evaluated birth outcomes and average daily Ta during various prenatal exposure periods in Massachusetts (USA) using both traditional Ta stations and modeled address Ta. We used linear and logistic mixed models and accelerated failure time models to estimate associations between Ta and the following outcomes among live births > 22 weeks: term birth weight (≥ 37 weeks), low birth weight (LBW; < 2,500 g at term), gestational age, and preterm delivery (PT; < 37 weeks). Models were adjusted for individual-level socioeconomic status, traffic density, particulate matter ≤ 2.5 μm (PM2.5), random intercept for census tract, and mother’s health. Results Predicted Ta during multiple time windows before birth was negatively associated with birth weight: Average birth weight was 16.7 g lower (95% CI: –29.7, –3.7) in association with an interquartile range increase (8.4°C) in Ta during the last trimester. Ta over the entire pregnancy was positively associated with PT [odds ratio (OR) = 1.02; 95% CI: 1.00, 1.05] and LBW (OR = 1.04; 95% CI: 0.96, 1.13). Conclusions Ta during pregnancy was associated with lower birth weight and shorter gestational age in our study population. Citation Kloog I, Melly SJ, Coull BA, Nordio F, Schwartz JD. 2015. Using satellite-based spatiotemporal resolved air temperature exposure to study the association between ambient air temperature and birth outcomes in Massachusetts. Environ Health Perspect 123:1053–1058; http://dx.doi.org/10.1289/ehp.1308075 PMID:25850104

  7. UAS Air Traffic Controller Acceptability Study-2: Effects of Communications Delays and Winds in Simulation

    NASA Technical Reports Server (NTRS)

    Comstock, James R., Jr.; Ghatas, Rania W.; Consiglio, Maria C.; Chamberlain, James P.; Hoffler, Keith D.

    2016-01-01

    This study evaluated the effects of Communications Delays and Winds on Air Traffic Controller ratings of acceptability of horizontal miss distances (HMDs) for encounters between UAS and manned aircraft in a simulation of the Dallas-Ft. Worth East-side airspace. Fourteen encounters per hour were staged in the presence of moderate background traffic. Seven recently retired controllers with experience at DFW served as subjects. Guidance provided to the UAS pilots for maintaining a given HMD was provided by information from self-separation algorithms displayed on the Multi-Aircraft Simulation System. Winds tested did not affect the acceptability ratings. Communications delays tested included 0, 400, 1200, and 1800 msec. For longer communications delays, there were changes in strategy and communications flow that were observed and reported by the controllers. The aim of this work is to provide useful information for guiding future rules and regulations applicable to flying UAS in the NAS.

  8. Degradation Through Erosion: Mechanistic Studies on IN-718 Superalloy Under Hot Air Jet Conditions

    NASA Astrophysics Data System (ADS)

    Thirugnanasambantham, K. G.; Natarajan, S.

    2015-07-01

    IN718 is a Nickel-based superalloy, widely used in high-temperature applications such as aircraft, and land-based and marine turbines. This technical paper deals with high-temperature erosion behavior and its mechanism of IN718. The erosion mechanism of the IN718 was studied using hot air jet erosion experiments at 800 °C with varying parameters such as angle of impingement and erodent velocity. Characterization of the eroded samples was done using SEM micrographs and high-resolution universal tribometer to determine the erosion mechanisms. SEM micrographs of eroded samples reveal that lip formation, cutting, and ploughing are the dominant erosion mechanisms for IN718 at 45° angle of impingement, while at 90°, it is lip extrusion followed by flattening of lip and detachment of platelet. These mechanisms eventually retard the particle impact velocity, thus enhancing erosion resistance.

  9. Experimental study on the flame behaviors of premixed methane/air mixture in horizontal rectangular ducts

    NASA Astrophysics Data System (ADS)

    Chen, Dongliang; Sun, Jinhua; Chen, Sining; Liu, Yi; Chu, Guanquan

    2007-01-01

    In order to explore the flame propagation characteristics and tulip flame formation mechanism of premixed methane/air mixture in horizontal rectangular ducts, the techniques of Schlieren and high-speed video camera are used to study the flame behaviors of the premixed gases in a closed duct and opened one respectively, and the propagation characteristics in both cases and the formation mechanism of the tulip flame are analyzed. The results show that, the propagation flame in a closed duct is prior to form a tulip flame structure than that in an opened duct, and the tulip flame structure formation in a closed duct is related to the flame propagation velocity decrease. The sharp decrease of the flame propagation velocity is one of the reasons to the tulip flame formation, and the decrease of the flame propagation velocity is due to the decrease of the burned product flow velocity mainly.

  10. Fort Hall air emissions study, Fort Hall Indian Reservation, Fort Hall, Idaho

    SciTech Connect

    Metcalf, S.W.; Sonnenfeld, N.L.; Rolka, D.L.; Kaye, W.E.

    1995-11-01

    The Agency for Toxic Substances and Disease Registry (ATSDR) conducted a cross-sectional health study at the Fort Hall Indian Reservation in Idaho to investigate concerns about the health effects on reservation residents that might be attributed to two phosphate-processing plants located near the reservation`s southern border. In addition to increased particulates, air emissions from these plants included phosphorus pentoxide, cadmium, chromium, fluoride, uranium, and its daughter radionuclides. A total of 515 participants -- 229 from Fort Hall and 286 from a comparison group at the Duck Valley Indian Reservation -- were interviewed in person by trained American Indian interviewers. Approximately 100 residents of each reservation performed pulmonary function tests and provided urine specimens that were analyzed for cadmium, chromium, fluoride, and several renal biomarkers.

  11. Some air electricity phenomena caused by waterfalls: Correlative study of the spectra

    NASA Astrophysics Data System (ADS)

    Luts, Aare; Parts, Tiia-Ene; Laakso, Lauri; Hirsikko, Anne; Grönholm, Tiia; Kulmala, Markku

    2009-02-01

    According to our previous measurements, waterfalls permanently modify air ion spectra. In this paper we performed a correlative study of these results and proposed some pathways which can produce the observed waterfall ions. The small ion composition near waterfalls should be different from that further away due to gaseous OH - core (water shell) clusters. We assumed that the combination of factors (autoionization, fluctuating charge rearrangement, surface protrusions, collisions, Coulomb explosion) serves as the main source of observed intermediate ions, and an extra source for large ions. Evaporation of droplets produces nearly equal numbers of positive and negative intermediate and large ions. Waterfall-produced intermediate ions can attach to the waterfall-produced larger particles, which creates an additional link between the waterfall intermediate and large ions.

  12. Particulate and gaseous organic receptor modeling for the southern California Air Quality Study. Final report

    SciTech Connect

    Watson, J.G.; Chow, J.G.; Lu, Z.; Gertler, A.W.

    1993-11-01

    The Chemical Mass Balance (CMB) receptor model was applied to the chemically-speciated diurnal particulate matter samples and volatile organic compound (VOC) acquired during the summer and fall campaigns of the Southern California Air Quality Study (SCAQS). Source profiles applicable to the Los Angeles area were used to apportion PM[sub (2.5)] and PM[sub (10)] to primary paved road dust, primary construction dust, primary motor vehicle exhaust, primary marine aerosol, secondary ammonium nitrate, and secondary ammonium sulfate. Nonmethane hydrocarbon was apportioned to motor vehicle exhaust, liquid fuel, gasoline vapor, gas leaks, architectural and industrial coatings, and biogenic emissions. Suspended dust was the major contributor to PM(10) during the summer, while secondary ammonium nitrate and primary motor vehicle exhaust contributions were high in the fall. Motor vehicle exhaust was the major contributor to nonmethane hydrocarbons, ranging from 30% to 70% of the total.

  13. Experimental Study on Efficiency Improvement of R410A Scroll Compressor for Air Conditioner

    NASA Astrophysics Data System (ADS)

    Sawai, Kiyoshi; Sakuda, Atsushi; Iida, Noboru; Hiwata, Akira; Morimoto, Takashi; Ishii, Noriaki

    In scroll compressors, an increase in oil flow rate into thecompression chamber improves sealing effectsand decreases refrigerant leakage. On the other hand, as the oil supplies the heat energy, the suction refrigerantis heated and the volumetric efficiency degreases. In the present study, we made an apparatus which suppliesthe oil into the compression chamber while measuring the mass flow rate, thus investigating the relationshipbetween the oil flow rate and the compressor performance. Experimental results indicated that the presentR410A scroll compressor provided higher performance as the oil flow rate decreased under the rated conditionof the air-conditioner. In addition, based on the experimental results, we discussed that the oil flow in thecapillary installed in the orbiting scroll was considered to be a laminar flow, and the volumetric efficiencywould degrease by the effect of a quarter of the oil heat energy.

  14. Air Pollutant Mapping with a Mobile Laboratory During the BEE-TEX Field Study

    PubMed Central

    Yacovitch, Tara I.; Herndon, Scott C.; Roscioli, Joseph R.; Floerchinger, Cody; Knighton, W. Berk; Kolb, Charles E.

    2015-01-01

    The Aerodyne Mobile Laboratory was deployed to the Houston Ship Channel and surrounding areas during the Benzene and Other Toxics Exposure field study in February 2015. We evaluated atmospheric concentrations of volatile organic hydrocarbons and other hazardous air pollutants of importance to human health, including benzene, 1,3-butadiene, toluene, xylenes, ethylbenzenes, styrene, and NO2. Ambient concentration measurements were focused on the neighborhoods of Manchester, Harrisburg, and Galena Park. The most likely measured concentration of 1,3-butadiene in the Manchester neighborhood (0.17 ppb) exceeds the Environmental Protection Agency’s E-5 lifetime cancer risk level of 0.14 ppb. In all the three neighborhoods, the measured benzene concentration falls below or within the E-5 lifetime cancer risk levels of 0.4–1.4 ppb for benzene. Pollution maps as a function of wind direction show the impact of nearby sources. PMID:26819556

  15. Air Pollutant Mapping with a Mobile Laboratory During the BEE-TEX Field Study.

    PubMed

    Yacovitch, Tara I; Herndon, Scott C; Roscioli, Joseph R; Floerchinger, Cody; Knighton, W Berk; Kolb, Charles E

    2015-01-01

    The Aerodyne Mobile Laboratory was deployed to the Houston Ship Channel and surrounding areas during the Benzene and Other Toxics Exposure field study in February 2015. We evaluated atmospheric concentrations of volatile organic hydrocarbons and other hazardous air pollutants of importance to human health, including benzene, 1,3-butadiene, toluene, xylenes, ethylbenzenes, styrene, and NO2. Ambient concentration measurements were focused on the neighborhoods of Manchester, Harrisburg, and Galena Park. The most likely measured concentration of 1,3-butadiene in the Manchester neighborhood (0.17 ppb) exceeds the Environmental Protection Agency's E-5 lifetime cancer risk level of 0.14 ppb. In all the three neighborhoods, the measured benzene concentration falls below or within the E-5 lifetime cancer risk levels of 0.4-1.4 ppb for benzene. Pollution maps as a function of wind direction show the impact of nearby sources. PMID:26819556

  16. Surface-catalyzed air oxidation reactions of hydrazines: Tubular reactor studies

    NASA Technical Reports Server (NTRS)

    Kilduff, Jan E.; Davis, Dennis D.; Koontz, Steven L.

    1988-01-01

    The surface-catalyzed air oxidation reactions of hydrazine, monomethylhydrazine, unsymmetrical dimethylhydrazine, symmetrical dimethylhydrazine, trimethylhydrazine and tetramethylhydrazine were investigated in a metal-powder packed turbular flow reactor at 55 plus or minus 3 C. Hydrazine was completely reacted on all surfaces studied. The major products of monomethylhydrazine (MMH) oxidation were methanol, methane and methyldiazene. The di-, tri- and tetra-methyl hydrazines were essentially unreactive under these conditions. The relative catalytic reactivities toward MMH are: Fe greater than Al2O3 greater than Ti greater than Zn greater than 316 SS greater than Cr greater than Ni greater than Al greater than 304L SS. A kinetic scheme and mechanism involving adsorption, oxidative dehydrogenation and reductive elimination reactions on a metal oxide surface are proposed.

  17. Study and Development of an Air Conditioning System Operating on a Magnetic Heat Pump Cycle

    NASA Technical Reports Server (NTRS)

    Wang, Pao-Lien

    1991-01-01

    This report describes the design of a laboratory scale demonstration prototype of an air conditioning system operating on a magnetic heat pump cycle. Design parameters were selected through studies performed by a Kennedy Space Center (KSC) System Simulation Computer Model. The heat pump consists of a rotor turning through four magnetic fields that are created by permanent magnets. Gadolinium was selected as the working material for this demonstration prototype. The rotor was designed to be constructed of flat parallel disks of gadolinium with very little space in between. The rotor rotates in an aluminum housing. The laboratory scale demonstration prototype is designed to provide a theoretical Carnot Cycle efficiency of 62 percent and a Coefficient of Performance of 16.55.

  18. Air Pollution Studies in Tver Region of Russia using Moss-Biomonitoring with Nuclear Analytical Methods

    SciTech Connect

    Vergel, K. N.; Frontasyeva, M. V.; Pavlov, S. S.; Povtoreyko, E. A.

    2007-11-26

    Results of the trace element atmospheric deposition in the Tver region based on moss analysis are presented. Moss samples were collected in the summer of 1999 and 2004 from 174 sites evenly distributed over the region. As bioaccumulators, two common mosses were used: Pleurozium schreberi ({approx}80%) and Hylocomium splendens ({approx}20%). The moss samples were subject to neutron activation analysis at the IBR-2 reactor JINR Dubna. The purpose of this study was to determine deposition patterns of potent sources of air pollution such as the largest Russian thermal power plant nearby the town of Konakovo and to reveal previously unknown pollution sources located in towns and settlements within the sampled territory. Multivariate statistical analysis was applied to determine possible pollution sources over the examined territory. Comparison of the results obtained with those from other surveys in Russia and Europe shows that Tver region could be considered as a background territory for the Russian Federation.

  19. Air Pollution Studies in Tver Region of Russia using Moss-Biomonitoring with Nuclear Analytical Methods

    NASA Astrophysics Data System (ADS)

    Vergel, K. N.; Frontasyeva, M. V.; Pavlov, S. S.; Povtoreyko, E. A.

    2007-11-01

    Results of the trace element atmospheric deposition in the Tver region based on moss analysis are presented. Moss samples were collected in the summer of 1999 and 2004 from 174 sites evenly distributed over the region. As bioaccumulators, two common mosses were used: Pleurozium schreberi (˜80%) and Hylocomium splendens (˜20%). The moss samples were subject to neutron activation analysis at the IBR-2 reactor JINR Dubna. The purpose of this study was to determine deposition patterns of potent sources of air pollution such as the largest Russian thermal power plant nearby the town of Konakovo and to reveal previously unknown pollution sources located in towns and settlements within the sampled territory. Multivariate statistical analysis was applied to determine possible pollution sources over the examined territory. Comparison of the results obtained with those from other surveys in Russia and Europe shows that Tver region could be considered as a background territory for the Russian Federation.

  20. Enhanced Component Performance Study: Air-Operated Valves 1998–2013

    SciTech Connect

    Schroeder, John Alton

    2014-10-01

    This report presents a performance evaluation of air-operated valves (AOVs) at U.S. commercial nuclear power plants. The data used in this study are based on the operating experience failure reports from fiscal year 1998 through 2013 for the component reliability as reported in the Institute of Nuclear Power Operations (INPO) Consolidated Events Database (ICES). The AOV failure modes considered are failure-to-open/close, failure to operate or control, and spurious operation. The component reliability estimates and the reliability data are trended for the most recent 10-year period, while yearly estimates for reliability are provided for the entire active period. No statistically significant increasing or decreasing trends were identified in the AOV failure data.