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Sample records for air temperature ambient

  1. Passive radiative cooling below ambient air temperature under direct sunlight.

    PubMed

    Raman, Aaswath P; Anoma, Marc Abou; Zhu, Linxiao; Rephaeli, Eden; Fan, Shanhui

    2014-11-27

    Cooling is a significant end-use of energy globally and a major driver of peak electricity demand. Air conditioning, for example, accounts for nearly fifteen per cent of the primary energy used by buildings in the United States. A passive cooling strategy that cools without any electricity input could therefore have a significant impact on global energy consumption. To achieve cooling one needs to be able to reach and maintain a temperature below that of the ambient air. At night, passive cooling below ambient air temperature has been demonstrated using a technique known as radiative cooling, in which a device exposed to the sky is used to radiate heat to outer space through a transparency window in the atmosphere between 8 and 13 micrometres. Peak cooling demand, however, occurs during the daytime. Daytime radiative cooling to a temperature below ambient of a surface under direct sunlight has not been achieved because sky access during the day results in heating of the radiative cooler by the Sun. Here, we experimentally demonstrate radiative cooling to nearly 5 degrees Celsius below the ambient air temperature under direct sunlight. Using a thermal photonic approach, we introduce an integrated photonic solar reflector and thermal emitter consisting of seven layers of HfO2 and SiO2 that reflects 97 per cent of incident sunlight while emitting strongly and selectively in the atmospheric transparency window. When exposed to direct sunlight exceeding 850 watts per square metre on a rooftop, the photonic radiative cooler cools to 4.9 degrees Celsius below ambient air temperature, and has a cooling power of 40.1 watts per square metre at ambient air temperature. These results demonstrate that a tailored, photonic approach can fundamentally enable new technological possibilities for energy efficiency. Further, the cold darkness of the Universe can be used as a renewable thermodynamic resource, even during the hottest hours of the day. PMID:25428501

  2. 14 CFR 25.1527 - Ambient air temperature and operating altitude.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Ambient air temperature and operating... Information Operating Limitations § 25.1527 Ambient air temperature and operating altitude. The extremes of the ambient air temperature and operating altitude for which operation is allowed, as limited...

  3. 14 CFR 25.1527 - Ambient air temperature and operating altitude.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Ambient air temperature and operating... Information Operating Limitations § 25.1527 Ambient air temperature and operating altitude. The extremes of the ambient air temperature and operating altitude for which operation is allowed, as limited...

  4. 14 CFR 25.1527 - Ambient air temperature and operating altitude.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Ambient air temperature and operating... Information Operating Limitations § 25.1527 Ambient air temperature and operating altitude. The extremes of the ambient air temperature and operating altitude for which operation is allowed, as limited...

  5. 14 CFR 25.1527 - Ambient air temperature and operating altitude.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Ambient air temperature and operating... Information Operating Limitations § 25.1527 Ambient air temperature and operating altitude. The extremes of the ambient air temperature and operating altitude for which operation is allowed, as limited...

  6. 14 CFR 25.1527 - Ambient air temperature and operating altitude.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Ambient air temperature and operating... Information Operating Limitations § 25.1527 Ambient air temperature and operating altitude. The extremes of the ambient air temperature and operating altitude for which operation is allowed, as limited...

  7. Effect of Ambient Design Temperature on Air-Cooled Binary Plant Output

    SciTech Connect

    Dan Wendt; Greg Mines

    2011-10-01

    Air-cooled binary plants are designed to provide a specified level of power production at a particular air temperature. Nominally this air temperature is the annual mean or average air temperature for the plant location. This study investigates the effect that changing the design air temperature has on power generation for an air-cooled binary plant producing power from a resource with a declining production fluid temperature and fluctuating ambient temperatures. This analysis was performed for plants operating both with and without a geothermal fluid outlet temperature limit. Aspen Plus process simulation software was used to develop optimal air-cooled binary plant designs for specific ambient temperatures as well as to rate the performance of the plant designs at off-design operating conditions. Results include calculation of annual and plant lifetime power generation as well as evaluation of plant operating characteristics, such as improved power generation capabilities during summer months when electric power prices are at peak levels.

  8. Ambient temperature, air pollution, and heart rate variability in an aging population.

    PubMed

    Ren, Cizao; O'Neill, Marie S; Park, Sung Kyun; Sparrow, David; Vokonas, Pantel; Schwartz, Joel

    2011-05-01

    Studies show that ambient temperature and air pollution are associated with cardiovascular disease and that they may interact to affect cardiovascular events. However, few epidemiologic studies have examined mechanisms through which ambient temperature may influence cardiovascular function. The authors examined whether temperature was associated with heart rate variability (HRV) in a Boston, Massachusetts, study population and whether such associations were modified by ambient air pollution concentrations. The population was a cohort of 694 older men examined between 2000 and 2008. The authors fitted a mixed model to examine associations between temperature and air pollution and their interactions with repeated HRV measurements, adjusting for covariates selected a priori on the basis of their previous studies. Results showed that higher ambient temperature was associated with decreases in HRV measures (standard deviation of normal-to-normal intervals, low-frequency power, and high-frequency power) during the warm season but not during the cold season. These warm-season associations were significantly greater when ambient ozone levels were higher (>22.3 ppb) but did not differ according to levels of ambient fine (≤2.5 μm) particulate matter. The authors conclude that temperature and ozone, exposures to both of which are expected to increase with climate change, might act together to worsen cardiovascular health and/or precipitate cardiovascular events via autonomic nervous system dysfunction. PMID:21385834

  9. AMBIENT AIR MONITORING STRATEGY

    EPA Science Inventory

    The Clean Air Act requires EPA to establish national ambient air quality standards and to regulate as necessary, hazardous air pollutants. EPA uses ambient air monitoring to determine current air quality conditions, and to assess progress toward meeting these standards and relat...

  10. Ambient air pollution, temperature and out-of-hospital coronary deaths in Shanghai, China.

    PubMed

    Dai, Jinping; Chen, Renjie; Meng, Xia; Yang, Changyuan; Zhao, Zhuohui; Kan, Haidong

    2015-08-01

    Few studies have evaluated the effects of ambient air pollution and temperature in triggering out-of-hospital coronary deaths (OHCDs) in China. We evaluated the associations of air pollution and temperature with daily OHCDs in Shanghai, China from 2006 to 2011. We applied an over-dispersed generalized additive model and a distributed lag nonlinear model to analyze the effects of air pollution and temperature, respectively. A 10 μg/m(3) increase in the present-day PM10, PM2.5, SO2, NO2 and CO were associated with increases in OHCD mortality of 0.49%, 0.68%, 0.88%, 1.60% and 0.08%, respectively. A 1 °C decrease below the minimum-mortality temperature corresponded to a 3.81% increase in OHCD mortality on lags days 0-21, and a 1 °C increase above minimum-mortality temperature corresponded to a 4.61% increase over lag days 0-3. No effects were found for in-hospital coronary deaths. This analysis suggests that air pollution, low temperature and high temperature may increase the risk of OHCDs. PMID:25875162

  11. Synthesis of ammonia directly from air and water at ambient temperature and pressure

    PubMed Central

    Lan, Rong; Irvine, John T. S.; Tao, Shanwen

    2013-01-01

    The N≡N bond (225 kcal mol−1) in dinitrogen is one of the strongest bonds in chemistry therefore artificial synthesis of ammonia under mild conditions is a significant challenge. Based on current knowledge, only bacteria and some plants can synthesise ammonia from air and water at ambient temperature and pressure. Here, for the first time, we report artificial ammonia synthesis bypassing N2 separation and H2 production stages. A maximum ammonia production rate of 1.14 × 10−5 mol m−2 s−1 has been achieved when a voltage of 1.6 V was applied. Potentially this can provide an alternative route for the mass production of the basic chemical ammonia under mild conditions. Considering climate change and the depletion of fossil fuels used for synthesis of ammonia by conventional methods, this is a renewable and sustainable chemical synthesis process for future. PMID:23362454

  12. An artificial neural network approach for the forecast of ambient air temperature

    NASA Astrophysics Data System (ADS)

    Philippopoulos, Kostas; Deligiorgi, Despina; Kouroupetroglou, Georgios

    2014-05-01

    Ambient air temperature forecasting is one of the most significant aspects of environmental and climate research. Accurate temperature forecasts are important in the energy and tourism industry, in agriculture for estimating potential hazards, and within an urban context, in studies for assessing the risk of adverse health effects in the general population. The scope of this study is to propose an Artificial Neural Network (ANN) approach for the one-day ahead maximum (Tmax) and minimum (Tmin) air temperature forecasting. The ANNs are signal processing systems consisted by an assembly of simple interconnected processing elements (neurons) and in geosciences are mainly used in pattern recognition problems. In this study the feed-forward ANN models are selected, which are theoretically capable of estimating a measurable input-output function to any desired degree of accuracy. The method is implemented at a single site (Souda Airport) located at the island of Crete in southeastern Mediterranean and employs the hourly, Tmax and Tmin temperature observations over a ten-yearly period (January 2000 to December 2009). Separate ANN models are trained and tested for the forecast of Tmax and Tmin, which are based on the 24 previous day's hourly temperature records. The first six years are used for training the ANNs, the subsequent two for validating the models and the last two (January 2008 to December 2009) for testing the ANN's overall predicting accuracy. The model architecture consists of a single hidden layer and multiple experiments with varying number of neurons are performed (from 1 to 80 neurons with hyperbolic tangent sigmoid transfer functions). The selection of the optimum number of neurons in the hidden layer is based on a trial and error procedure and the performance is measured using the mean absolute error (MAE) on the validation set. A comprehensive set of model output statistics is used for examining the ability of the models to estimate both Tmax and Tmin

  13. Snow removal and ambient air temperature effects on forest soil temperatures in northern Vermont

    NASA Astrophysics Data System (ADS)

    Wang, D.; Decker, K. L.; Waite, C.; Scherbatskoy, T.

    2003-12-01

    We measured deciduous forest soil temperatures under control (unmanipulated) and snow-free (where snow is manually removed) conditions for four winters (at three soil depths) to determine effects of a snow cover reduction such as may occur as a result of climate change on Vermont forest soils. The four winters we studied were characterized as:`cold and snowy', `warm with low snow', `cold with low snow', and `cool with low snow'. Snow-free soils were colder than controls at 5 and 15 cm depth for all years, and at all depths in the two cold winters. Soil thermal variability generally decreased with both increased snow cover and soil depth. The effect of snow cover on soil freeze-thaw events was highly dependent on both the depth of snow and the soil temperature. Snow kept the soil warm and reduced soil temperature variability, but often this caused soil to remain near 0 deg C, resulting in more freeze-thaw events under snow at one or more soil depths. During the `cold snowy' winter, soils under snow had daily averages consistently >0 deg C, whereas snow-free soil temperatures commonly dropped below -3 deg C. During the `warm' year, temperatures of soil under snow were often lower than those of snow-free soils. The warmer winter resulted in less snow cover to insulate soil from freezing in the biologically active top 30 cm. The possible consequences of increased soil freezing include more root mortality and nutrient loss which would potentially alter ecosystem dynamics, decrease productivity of some tree species, and increase sugar maple mortality in northern hardwood forests.

  14. Ambient Temperature and Obesity

    PubMed Central

    Moellering, Douglas R.; Smith, Daniel L.

    2014-01-01

    Homeotherms maintain an optimal body temperature that is most often above their environment or ambient temperature. As ambient temperature decreases, energy expenditure (and energy intake) must increase to maintain thermal homeostasis. With the wide spread adoption of climate control, humans in modern society are buffered from temperature extremes and spend an increasing amount of time in a thermally comfortable state where energetic demands are minimized. This is hypothesized to contribute to the contemporary increase in obesity rates. Studies reporting exposures of animals and humans to different ambient temperatures are discussed. Additional consideration is given to the potentially altered metabolic and physiologic responses in obese versus lean subjects at a given temperature. The data suggest that ambient temperature is a significant contributor to both energy intake and energy expenditure, and that this variable should be more thoroughly explored in future studies as a potential contributor to obesity susceptibility. PMID:24707450

  15. Depicting the Dependency of Isoprene in Ambient Air and from Plants on Temperature and Solar Radiation by Using Regression Analysis

    NASA Astrophysics Data System (ADS)

    Saxena, Pallavi; Ghosh, Chirashree

    2016-07-01

    Among all sources of volatile organic compounds, isoprene emission from plants is an important part of the atmospheric hydrocarbon budget. In the present study, isoprene emission capacity at the bottom of the canopies of plant species viz. Dalbergia sissoo and Nerium oleander and in ambient air at different sites selected on the basis of land use pattern viz. near to traffic intersection with dense vegetation, away from traffic intersection with dense vegetation under floodplain area (Site I) and away from traffic intersection with dense vegetation under hilly ridge area (Site II) during three different seasons (monsoon, winter and summer) in Delhi were measured. In order to find out the dependence of isoprene emission rate on temperature and solar radiation, regression analysis has been performed. In case of dependency of isoprene in ambient air on temperature and solar radiation in selected seasons it has been found that high isoprene was found during summer season as compared to winter and monsoon seasons. Thus, positive linear relationship gives the best fit between temperature, solar rdaiation and isoprene during summer season as compared to winter and monsoon season. On the other hand, in case of isoprene emission from selected plant species, it has been found that high temperature and solar radiation promotes high isoprene emission rates during summer season as compared to winter and monsoon seasons in D. sissoo. Thus, positive linear relationship gives the best fit between temperature, solar radiation and isoprene emission rate during summer season as compared to winter and monsoon season. In contrast, in case of Nerium oleander, no such appropriate relationship was obtained. The study concludes that in ambient air, isoprene concentration was found to be high during summer season as compared to other seasons and gives best fit between temperature, solar radiation and isoprene. In case of plants, Dalbergia sissoo comes under high isoprene emission category

  16. 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

  17. Research Update: Direct conversion of amorphous carbon into diamond at ambient pressures and temperatures in air

    SciTech Connect

    Narayan, Jagdish Bhaumik, Anagh

    2015-10-01

    We report on fundamental discovery of conversion of amorphous carbon into diamond by irradiating amorphous carbon films with nanosecond lasers at room-temperature in air at atmospheric pressure. We can create diamond in the form of nanodiamond (size range <100 nm) and microdiamond (>100 nm). Nanosecond laser pulses are used to melt amorphous diamondlike carbon and create a highly undercooled state, from which various forms of diamond can be formed upon cooling. The quenching from the super undercooled state results in nucleation of nanodiamond. It is found that microdiamonds grow out of highly undercooled state of carbon, with nanodiamond acting as seed crystals.

  18. Evaluating different machine learning approaches for the interpolation of ambient air temperature at Mt. Kilimajaro, Tanzania

    NASA Astrophysics Data System (ADS)

    Appelhans, Tim; Mwangomo, Ephraim; Hardy, Douglas; Hemp, Andreas; Nauss, Thomas

    2015-04-01

    Spatially high resolution climate information is required for a variety of applications in but not limited to functional biodiversity research. In order to scale the generally plot-based research findings to a landscape level, spatial interpolation methods of meteorological variables are required. Based on a network of 60 observation plots across the southern slopes of Mt. Kilimanjaro, the skill of 14 machine learning algorithms in predicting spatial temperature patterns is tested and evaluated against the heavily utilized kriging approach. Based on a leave-many-out testing design, regression trees generally perform better than linear and non-linear regression models. The best individual performance has been observed by the Cubist model followed by stochastic gradient boosting, random forest and model averaged neural networks which except for the latter are all regression tree-based algorithms. While these machine learning algorithms perform better than kriging in this quantitative evaluation, the overall visual interpretation of the resulting air temperature maps is ambiguous. Here, a combined Cubist and residual kriging approach might be the best solution.

  19. Association between Daily Hospital Outpatient Visits for Accidents and Daily Ambient Air Temperatures in an Industrial City.

    PubMed

    Chau, Tang-Tat; Wang, Kuo-Ying

    2016-01-01

    An accident is an unwanted hazard to a person. However, accidents occur. In this work, we search for correlations between daily accident rates and environmental factors. To study daily hospital outpatients who were admitted for accidents during a 5-year period, 2007-2011, we analyzed data regarding 168,366 outpatients using univariate regression models; we also used multivariable regression models to account for confounding factors. Our analysis indicates that the number of male outpatients admitted for accidents was approximately 1.31 to 1.47 times the number of female outpatients (P < 0.0001). Of the 12 parameters (regarding air pollution and meteorology) considered, only daily temperature exhibited consistent and significant correlations with the daily number of hospital outpatient visits for accidents throughout the 5-year analysis period. The univariate regression models indicate that older people (greater than 66 years old) had the fewest accidents per 1-degree increase in temperature, followed by young people (0-15 years old). Middle-aged people (16-65 years old) were the group of outpatients that were more prone to accidents, with an increase in accident rates of 0.8-1.2 accidents per degree increase in temperature. The multivariable regression models also reveal that the temperature variation was the dominant factor in determining the daily number of outpatient visits for accidents. Our further multivariable model analysis of temperature with respect to air pollution variables show that, through the increases in emissions and concentrations of CO, photochemical O3 production and NO2 loss in the ambient air, increases in vehicular emissions are associated with increases in temperatures. As such, increases in hospital visits for accidents are related to vehicular emissions and usage. This finding is consistent with clinical experience which shows about 60% to 80% of accidents are related to traffic, followed by accidents occurred in work place. PMID:26815039

  20. Association between Daily Hospital Outpatient Visits for Accidents and Daily Ambient Air Temperatures in an Industrial City

    PubMed Central

    Chau, Tang-Tat; Wang, Kuo-Ying

    2016-01-01

    An accident is an unwanted hazard to a person. However, accidents occur. In this work, we search for correlations between daily accident rates and environmental factors. To study daily hospital outpatients who were admitted for accidents during a 5-year period, 2007–2011, we analyzed data regarding 168,366 outpatients using univariate regression models; we also used multivariable regression models to account for confounding factors. Our analysis indicates that the number of male outpatients admitted for accidents was approximately 1.31 to 1.47 times the number of female outpatients (P < 0.0001). Of the 12 parameters (regarding air pollution and meteorology) considered, only daily temperature exhibited consistent and significant correlations with the daily number of hospital outpatient visits for accidents throughout the 5-year analysis period. The univariate regression models indicate that older people (greater than 66 years old) had the fewest accidents per 1-degree increase in temperature, followed by young people (0–15 years old). Middle-aged people (16–65 years old) were the group of outpatients that were more prone to accidents, with an increase in accident rates of 0.8–1.2 accidents per degree increase in temperature. The multivariable regression models also reveal that the temperature variation was the dominant factor in determining the daily number of outpatient visits for accidents. Our further multivariable model analysis of temperature with respect to air pollution variables show that, through the increases in emissions and concentrations of CO, photochemical O3 production and NO2 loss in the ambient air, increases in vehicular emissions are associated with increases in temperatures. As such, increases in hospital visits for accidents are related to vehicular emissions and usage. This finding is consistent with clinical experience which shows about 60% to 80% of accidents are related to traffic, followed by accidents occurred in work place. PMID

  1. Alternative Refrigerant Evaluation for High-Ambient Temperature Environments: R-22 and R-410A Alternatives for Mini-Split Air Conditioners

    SciTech Connect

    Abdelaziz, Omar; Munk, Jeffrey D.; Shrestha, Som S.; Linkous, Randall Lee; Goetzler, William; Guernsey, Matt; Kassuga, Theo

    2015-08-01

    The Oak Ridge National Laboratory (ORNL) High-Ambient Temperature Testing Program for Low-GWP Refrigerants aims to develop an understanding of the performance of low-Global Warming Potential (low-GWP) alternatives to Hydrochlorofluorocarbon (HCFC) and Hydrofluorocarbon (HFC) refrigerants in mini-split air conditioners under high ambient temperature conditions. This interim working paper describes the parties involved, the alternative refrigerants selection process, the test procedures, and the preliminary results.

  2. Alternative Refrigerant Evaluation for High-Ambient-Temperature Environments: R-22 and R-410A Alternatives for Mini-Split Air Conditioners

    SciTech Connect

    Abdelaziz, Omar; Shrestha, Som S.; Munk, Jeffrey D.; Linkous, Randall Lee; Goetzler, William; Guernsey, Matt; Kassuga, Theo

    2015-10-01

    The Oak Ridge National Laboratory (ORNL) High-Ambient-Temperature Evaluation Program for low– global warming potential (Low-GWP) Refrigerants aims to develop an understanding of the performance of low-GWP alternative refrigerants to hydrochlorofluorocarbon (HCFC) and hydrofluorocarbon (HFC) refrigerants in mini-split air conditioners under high-ambient-temperature conditions. This final report describes the parties involved, the alternative refrigerant selection process, the test procedures, and the final results.

  3. Modeling the uptake of neutral organic chemicals on XAD passive air samplers under variable temperatures, external wind speeds and ambient air concentrations (PAS-SIM).

    PubMed

    Armitage, James M; Hayward, Stephen J; Wania, Frank

    2013-01-01

    The main objective of this study was to evaluate the performance and demonstrate the utility of a fugacity-based model of XAD passive air samplers (XAD-PAS) designed to simulate the uptake of neutral organic chemicals under variable temperatures, external wind speeds and ambient air concentrations. The model (PAS-SIM) simulates the transport of the chemical across the air-side boundary layer and within the sampler medium, which is segmented into a user-defined number of thin layers. Model performance was evaluated using data for polychlorinated biphenyls (PCBs) and polycyclic aromatic hydrocarbons (PAHs) from a field calibration study (i.e., active and XAD-PAS data) conducted in Egbert, Ontario, Canada. With some exceptions, modeled PAS uptake curves are in good agreement with the empirical PAS data. The results are highly encouraging, given the uncertainty in the active air sampler data used as input and other uncertainties related to model parametrization (e.g., sampler-air partition coefficients, the influence of wind speed on sampling rates). The study supports the further development and evaluation of the PAS-SIM model as a diagnostic (e.g., to aid interpretation of calibration studies and monitoring data) and prognostic (e.g., to inform design of future passive air sampling campaigns) tool. PMID:24175752

  4. Effects of ambient air temperature, humidity and rainfall on annual survival of adult little penguins Eudyptula minor in southeastern Australia.

    PubMed

    Ganendran, L B; Sidhu, L A; Catchpole, E A; Chambers, L E; Dann, P

    2016-08-01

    Seabirds are subject to the influences of local climate variables during periods of land-based activities such as breeding and, for some species, moult; particularly if they undergo a catastrophic moult (complete simultaneous moult) as do penguins. We investigated potential relationships between adult penguin survival and land-based climate variables (ambient air temperature, humidity and rainfall) using 46 years of mark-recapture data of little penguins Eudyptula minor gathered at a breeding colony on Phillip Island in southeastern Australia. Our results showed that adult penguin survival had a stronger association with land-based climate variables during the moult period, when birds were unable to go to sea for up to 3 weeks, than during the breeding period, when birds could sacrifice breeding success in favour of survival. Annual adult survival probability was positively associated with humidity during moult and negatively associated with rainfall during moult. Prolonged heat during breeding and moult had a negative association with annual adult survival. Local climate projections suggest increasing days of high temperatures, fewer days of rainfall which will result in more droughts (and by implication, lower humidity) and more extreme rainfall events. All of these predicted climate changes are expected to have a negative impact on adult penguin survival. PMID:26698160

  5. Effects of ambient air temperature, humidity and rainfall on annual survival of adult little penguins Eudyptula minor in southeastern Australia

    NASA Astrophysics Data System (ADS)

    Ganendran, L. B.; Sidhu, L. A.; Catchpole, E. A.; Chambers, L. E.; Dann, P.

    2015-12-01

    Seabirds are subject to the influences of local climate variables during periods of land-based activities such as breeding and, for some species, moult; particularly if they undergo a catastrophic moult (complete simultaneous moult) as do penguins. We investigated potential relationships between adult penguin survival and land-based climate variables (ambient air temperature, humidity and rainfall) using 46 years of mark-recapture data of little penguins Eudyptula minor gathered at a breeding colony on Phillip Island in southeastern Australia. Our results showed that adult penguin survival had a stronger association with land-based climate variables during the moult period, when birds were unable to go to sea for up to 3 weeks, than during the breeding period, when birds could sacrifice breeding success in favour of survival. Annual adult survival probability was positively associated with humidity during moult and negatively associated with rainfall during moult. Prolonged heat during breeding and moult had a negative association with annual adult survival. Local climate projections suggest increasing days of high temperatures, fewer days of rainfall which will result in more droughts (and by implication, lower humidity) and more extreme rainfall events. All of these predicted climate changes are expected to have a negative impact on adult penguin survival.

  6. Effects of ambient air temperature, humidity and rainfall on annual survival of adult little penguins Eudyptula minor in southeastern Australia

    NASA Astrophysics Data System (ADS)

    Ganendran, L. B.; Sidhu, L. A.; Catchpole, E. A.; Chambers, L. E.; Dann, P.

    2016-08-01

    Seabirds are subject to the influences of local climate variables during periods of land-based activities such as breeding and, for some species, moult; particularly if they undergo a catastrophic moult (complete simultaneous moult) as do penguins. We investigated potential relationships between adult penguin survival and land-based climate variables (ambient air temperature, humidity and rainfall) using 46 years of mark-recapture data of little penguins Eudyptula minor gathered at a breeding colony on Phillip Island in southeastern Australia. Our results showed that adult penguin survival had a stronger association with land-based climate variables during the moult period, when birds were unable to go to sea for up to 3 weeks, than during the breeding period, when birds could sacrifice breeding success in favour of survival. Annual adult survival probability was positively associated with humidity during moult and negatively associated with rainfall during moult. Prolonged heat during breeding and moult had a negative association with annual adult survival. Local climate projections suggest increasing days of high temperatures, fewer days of rainfall which will result in more droughts (and by implication, lower humidity) and more extreme rainfall events. All of these predicted climate changes are expected to have a negative impact on adult penguin survival.

  7. Part 2. Association of daily mortality with ambient air pollution, and effect modification by extremely high temperature in Wuhan, China.

    PubMed

    Qian, Zhengmin; He, Qingci; Lin, Hung-Mo; Kong, Lingli; Zhou, Dunjin; Liang, Shengwen; Zhu, Zhichao; Liao, Duanping; Liu, Wenshan; Bentley, Christy M; Dan, Jijun; Wang, Beiwei; Yang, Niannian; Xu, Shuangqing; Gong, Jie; Wei, Hongming; Sun, Huilin; Qin, Zudian

    2010-11-01

    Fewer studies have been published on the association between daily mortality and ambient air pollution in Asia than in the United States and Europe. This study was undertaken in Wuhan, China, to investigate the acute effects of air pollution on mortality with an emphasis on particulate matter (PM*). There were three primary aims: (1) to examine the associations of daily mortality due to all natural causes and daily cause-specific mortality (cardiovascular [CVD], stroke, cardiac [CARD], respiratory [RD], cardiopulmonary [CP], and non-cardiopulmonary [non-CP] causes) with daily mean concentrations (microg/m3) of PM with an aerodynamic diameter--10 pm (PM10), sulfur dioxide (SO2), nitrogen dioxide (NO2), or ozone (O3); (2) to investigate the effect modification of extremely high temperature on the association between air pollution and daily mortality due to all natural causes and daily cause-specific mortality; and (3) to assess the uncertainty of effect estimates caused by the change in International Classification of Disease (ICD) coding of mortality data from Revision 9 (ICD-9) to Revision 10 (ICD-10) code. Wuhan is called an "oven city" in China because of its extremely hot summers (the average daily temperature in July is 37.2 degrees C and maximum daily temperature often exceeds 40 degrees C). Approximately 4.5 million residents live in the core city area of 201 km2, where air pollution levels are higher and ranges are wider than the levels in most cities studied in the published literature. We obtained daily mean levels of PM10, SO2, and NO2 concentrations from five fixed-site air monitoring stations operated by the Wuhan Environmental Monitoring Center (WEMC). O3 data were obtained from two stations, and 8-hour averages, from 10:00 to 18:00, were used. Daily mortality data were obtained from the Wuhan Centres for Disease Prevention and Control (WCDC) during the study period of July 1, 2000, to June 30, 2004. To achieve the first aim, we used a regression of

  8. Ambient Air Temperature Does Not Predict whether Small or Large Workers Forage in Bumble Bees (Bombus impatiens)

    PubMed Central

    Couvillon, Margaret J.; Fitzpatrick, Ginny; Dornhaus, Anna

    2015-01-01

    Bumble bees are important pollinators of crops and other plants. However, many aspects of their basic biology remain relatively unexplored. For example, one important and unusual natural history feature in bumble bees is the massive size variation seen between workers of the same nest. This size polymorphism may be an adaptation for division of labor, colony economics, or be nonadaptive. It was also suggested that perhaps this variation allows for niche specialization in workers foraging at different temperatures: larger bees might be better suited to forage at cooler temperatures and smaller bees might be better suited to forage at warmer temperatures. This we tested here using a large, enclosed growth chamber, where we were able to regulate the ambient temperature. We found no significant effect of ambient or nest temperature on the average size of bees flying to and foraging from a suspended feeder. Instead, bees of all sizes successfully flew and foraged between 16°C and 36°C. Thus, large bees foraged even at very hot temperatures, which we thought might cause overheating. Size variation therefore could not be explained in terms of niche specialization for foragers at different temperatures. PMID:26005222

  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. Antimicrobial Applications of Ambient--Air Plasmas

    NASA Astrophysics Data System (ADS)

    Pavlovich, Matthew John

    The emerging field of plasma biotechology studies the applications of the plasma phase of matter to biological systems. "Ambient-condition" plasmas created at or near room temperature and atmospheric pressure are especially promising for biomedical applications because of their convenience, safety to patients, and compatibility with existing medical technology. Plasmas can be created from many different gases; plasma made from air contains a number of reactive oxygen and nitrogen species, or RONS, involved in various biological processes, including immune activity, signaling, and gene expression. Therefore, ambient-condition air plasma is of particular interest for biological applications. To understand and predict the effects of treating biological systems with ambient-air plasma, it is necessary to characterize and measure the chemical species that these plasmas produce. Understanding both gaseous chemistry and the chemistry in plasma-treated aqueous solution is important because many biological systems exist in aqueous media. Existing literature about ambient-air plasma hypothesizes the critical role of reactive oxygen and nitrogen species; a major aim of this dissertation is to better quantify RONS by produced ambient-air plasma and understand how RONS chemistry changes in response to different plasma processing conditions. Measurements imply that both gaseous and aqueous chemistry are highly sensitive to operating conditions. In particular, chemical species in air treated by plasma exist in either a low-power ozone-dominated mode or a high-power nitrogen oxide-dominated mode, with an unstable transition region at intermediate discharge power and treatment time. Ozone (O3) and nitrogen oxides (NO and NO2, or NOx) are mutually exclusive in this system and that the transition region corresponds to the transition from ozone- to nitrogen oxides-mode. Aqueous chemistry agrees well with to air plasma chemistry, and a similar transition in liquid-phase composition

  11. Short term association between ambient air pollution and mortality and modification by temperature in five Indian cities

    NASA Astrophysics Data System (ADS)

    Dholakia, Hem H.; Bhadra, Dhiman; Garg, Amit

    2014-12-01

    Indian cities are among the most polluted areas globally, yet assessments of short term mortality impacts due to pollution have been limited. Furthermore, studies examining temperature - pollution interactions on mortality are largely absent. Addressing this gap remains important in providing research evidence to better link health outcomes and air quality standards for India. Daily all-cause mortality, temperature, humidity and particulate matter less than 10 microns (PM10) data were collected for five cities - Ahmedabad, Bangalore, Hyderabad, Mumbai and Shimla spanning 2005-2012. Poisson regression models were developed to study short term impacts of PM10 as well as temperature - pollution interactions on daily all-cause mortality. We find that excess risk of mortality associated with a 10 μg/m3 PM10 increase is highest for Shimla (1.36%, 95% CI = -0.38%-3.1%) and the least for Ahmedabad (0.16%, 95% CI = -0.31%-0.62%). The corresponding values for Bangalore, Hyderabad and Mumbai are 0.22% (-0.04%-0.49%), 0.85% (0.06%-1.63%) and 0.2% (0.1%-0.3%) respectively. The relative health benefits of reducing pollution are higher for cleaner cities (Shimla) as opposed to dirtier cities (Mumbai). Overall we find that temperature and pollution interactions do not significantly impact mortality for the cities studied. This is one of the first multi-city studies that assess heterogeneity of air pollution impacts and possible modification due to temperature in Indian cities that are spread across climatic regions and topographies. Our findings highlight the need for pursuing stringent pollution control policies in Indian cities to minimize health impacts.

  12. Ambient air contamination: Characterization and detection techniques

    NASA Technical Reports Server (NTRS)

    Nulton, C. P.; Silvus, H. S.

    1985-01-01

    Techniques to characterize and detect sources of ambient air contamination are described. Chemical techniques to identify indoor contaminants are outlined, they include gas chromatography, or colorimetric detection. Organics generated from indoor materials at ambient conditions and upon combustion are characterized. Piezoelectric quartz crystals are used as precision frequency determining elements in electronic oscillators.

  13. Ambient-temperature co-oxidation catalysts

    NASA Technical Reports Server (NTRS)

    Upchurch, Billy T.; Schryer, David R.; Brown, Kenneth G.; Kielin, Erik J.

    1991-01-01

    Oxidation catalysts which operate at ambient temperature were developed for the recombination of carbon monoxide (CO) and oxygen (O2) dissociation products which are formed during carbon dioxide (CO2) laser operation. Recombination of these products to regenerate CO2 allows continuous operation of CO2 lasers in a closed cycle mode. Development of these catalyst materials provides enabling technology for the operation of such lasers from space platforms or in ground based facilities without constant gas consumption required for continuous open cycle operation. Such catalysts also have other applications in various areas outside the laser community for removal of CO from other closed environments such as indoor air and as an ambient temperature catalytic converter for control of auto emissions.

  14. Neutral gas temperature maps of the pin-to-plate argon micro discharge into the ambient air

    SciTech Connect

    Xu, S. F.; Zhong, X. X.; Majeed, Asif

    2015-03-15

    This study is designed to explore the two dimensional temperature maps of the atmospheric argon discharge consisting of pin-to-plane electrodes supplied by a high voltage DC source. After checking the stability of the micro discharge, the two dimensional image plane focused by a quartz lens was scanned by the fiber probe driven by a 3D Mobile Platform. The rotational and vibrational temperatures are calculated using nitrogen emissions collected by the high resolution spectrometer and high sensitive intensified charge coupled device. The rotational temperature varies from 1558.15 K to 2621.14 K and vibrational temperature varies from 3010.38 K to 3774.69 K, indicating a great temperature gradient due to small discharge size. The temperature maps show a lateral expansion and a sharp truncation in the radial direction. A double layers discharge is identified, where an arc discharge coats the glow discharge.

  15. Mechanical performance of reactive-air-brazed (RAB) ceramic/metal joints for solid oxide fuel cells at ambient temperature

    NASA Astrophysics Data System (ADS)

    Kuhn, B.; Wetzel, F. J.; Malzbender, J.; Steinbrech, R. W.; Singheiser, L.

    Mechanical integrity of the sealants in planar SOFC stacks is a key prerequisite for reliable operation. In this respect joining with metals rather than brittle glass-ceramics is considered to have advantages. Hence, as one of the joining solutions for SOFCs of planar design, reactive air brazing of ceramic cells into metallic frames gains increasing interest. Fracture experiments are carried out to characterize fracture energy and failure mechanisms of silver-based reactive-air-brazes, used for joining the zirconia electrolytes of anode supported planar cells with metallic Crofer22APU frames. The specimens are mechanically tested in notched beam bending geometry. In-situ observation in optical and SEM resolution reveals specific failure mechanisms. The influence of braze formulation and associated interfacial reactions on the crack path location is addressed. Discussion of the results focuses in particular on the role of oxide scale formation.

  16. 40 CFR 86.161-00 - Air conditioning environmental test facility ambient requirements.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... to simulate the impact of an ambient heat load on the power requirements of the vehicle's air... elements that are discussed are ambient air temperature and humidity, minimum test cell size, solar heating... be shown that all of the ambient test condition performance requirements are satisfied. (d)...

  17. 40 CFR 86.161-00 - Air conditioning environmental test facility ambient requirements.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... to simulate the impact of an ambient heat load on the power requirements of the vehicle's air... elements that are discussed are ambient air temperature and humidity, minimum test cell size, solar heating... be shown that all of the ambient test condition performance requirements are satisfied. (d)...

  18. 40 CFR 51.190 - Ambient air quality monitoring requirements.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 2 2010-07-01 2010-07-01 false Ambient air quality monitoring... PROGRAMS REQUIREMENTS FOR PREPARATION, ADOPTION, AND SUBMITTAL OF IMPLEMENTATION PLANS Ambient Air Quality Surveillance § 51.190 Ambient air quality monitoring requirements. The requirements for monitoring ambient...

  19. 40 CFR 51.190 - Ambient air quality monitoring requirements.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 2 2011-07-01 2011-07-01 false Ambient air quality monitoring... PROGRAMS REQUIREMENTS FOR PREPARATION, ADOPTION, AND SUBMITTAL OF IMPLEMENTATION PLANS Ambient Air Quality Surveillance § 51.190 Ambient air quality monitoring requirements. The requirements for monitoring ambient...

  20. 40 CFR 51.190 - Ambient air quality monitoring requirements.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 2 2014-07-01 2014-07-01 false Ambient air quality monitoring... PROGRAMS REQUIREMENTS FOR PREPARATION, ADOPTION, AND SUBMITTAL OF IMPLEMENTATION PLANS Ambient Air Quality Surveillance § 51.190 Ambient air quality monitoring requirements. The requirements for monitoring ambient...

  1. 40 CFR 51.190 - Ambient air quality monitoring requirements.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 2 2013-07-01 2013-07-01 false Ambient air quality monitoring... PROGRAMS REQUIREMENTS FOR PREPARATION, ADOPTION, AND SUBMITTAL OF IMPLEMENTATION PLANS Ambient Air Quality Surveillance § 51.190 Ambient air quality monitoring requirements. The requirements for monitoring ambient...

  2. 40 CFR 51.190 - Ambient air quality monitoring requirements.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 2 2012-07-01 2012-07-01 false Ambient air quality monitoring... PROGRAMS REQUIREMENTS FOR PREPARATION, ADOPTION, AND SUBMITTAL OF IMPLEMENTATION PLANS Ambient Air Quality Surveillance § 51.190 Ambient air quality monitoring requirements. The requirements for monitoring ambient...

  3. AMBIENT AIR NON-METHANE HYDROCARBON MONITOR

    EPA Science Inventory

    A monitor has been developed with adequate sensitivity and accuracy to measure continuously the concentration of non-methane hydrocarbons (NMHC) in ambient air. The monitor consists of pump and manifold system along with two basic instruments, a methane monitor and a flame-ioniza...

  4. Ambient Temperature and Morbidity: A Review of Epidemiological Evidence

    PubMed Central

    Ye, Xiaofang; Wolff, Rodney; Yu, Weiwei; Vaneckova, Pavla; Pan, Xiaochuan

    2011-01-01

    Objective: In this paper, we review the epidemiological evidence on the relationship between ambient temperature and morbidity. We assessed the methodological issues in previous studies and proposed future research directions. Data sources and data extraction: We searched the PubMed database for epidemiological studies on ambient temperature and morbidity of noncommunicable diseases published in refereed English journals before 30 June 2010. Forty relevant studies were identified. Of these, 24 examined the relationship between ambient temperature and morbidity, 15 investigated the short-term effects of heat wave on morbidity, and 1 assessed both temperature and heat wave effects. Data synthesis: Descriptive and time-series studies were the two main research designs used to investigate the temperature–morbidity relationship. Measurements of temperature exposure and health outcomes used in these studies differed widely. The majority of studies reported a significant relationship between ambient temperature and total or cause-specific morbidities. However, there were some inconsistencies in the direction and magnitude of nonlinear lag effects. The lag effect of hot temperature on morbidity was shorter (several days) compared with that of cold temperature (up to a few weeks). The temperature–morbidity relationship may be confounded or modified by sociodemographic factors and air pollution. Conclusions: There is a significant short-term effect of ambient temperature on total and cause-specific morbidities. However, further research is needed to determine an appropriate temperature measure, consider a diverse range of morbidities, and to use consistent methodology to make different studies more comparable. PMID:21824855

  5. Detection of hydrazines in ambient air

    SciTech Connect

    Not Available

    1986-12-01

    Hydrazine and monomethylhydrazine, two toxic components of rocket fuel, can pose a health hazard to people involved in various rocket-related activities, including space shuttle and missile site operations. An effective method for their detection at trace levels is thus essential to personnel safety, and researchers at the Naval Research Laboratory (NRL) are working to develop new methods for determination of both hydrazine and monomethylhdydrazine in ambient air. The project, sponsored by the National Aeronautics and Space Administration (NASA), involves the use of pattern recognition techniques to detect hydrazine vapors using microsensors, development of passive dosimeters, and evaluation of several new technologies for low-level hydrazine detection.

  6. 40 CFR 52.14 - State ambient air quality standards.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 3 2011-07-01 2011-07-01 false State ambient air quality standards. 52.14 Section 52.14 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS... quality standards. Any ambient air quality standard submitted with a plan which is less stringent than...

  7. 40 CFR 52.14 - State ambient air quality standards.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 3 2014-07-01 2014-07-01 false State ambient air quality standards. 52.14 Section 52.14 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS... quality standards. Any ambient air quality standard submitted with a plan which is less stringent than...

  8. 40 CFR 52.14 - State ambient air quality standards.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 3 2013-07-01 2013-07-01 false State ambient air quality standards. 52.14 Section 52.14 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS... quality standards. Any ambient air quality standard submitted with a plan which is less stringent than...

  9. 40 CFR 52.14 - State ambient air quality standards.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 3 2012-07-01 2012-07-01 false State ambient air quality standards. 52.14 Section 52.14 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS... quality standards. Any ambient air quality standard submitted with a plan which is less stringent than...

  10. Ambient air quality monitoring plan, Cumberland Steam Plant

    SciTech Connect

    Owen, A.E. Jr.; Carter, R.V.

    1981-09-01

    The Tennessee Valley Authority (TVA) has conducted ambient air quality monitoring at Cumberland Steam Plant since 1971. The monitoring network was operated to collect background air quality information prior to plant startup (1972) and to document ambient air quality after the plant reached full operating levels in 1973. This monitoring plan presents a new network design for Cumberland Steam Plant.

  11. Particulate Matter Levels in Ambient Air Adjacent to Industrial Area

    NASA Astrophysics Data System (ADS)

    Mohamed, R. M. S. R.; Nizam, N. M. S.; Al-Gheethi, A. A.; Lajis, A.; Kassim, A. H. M.

    2016-07-01

    Air quality in the residential areas adjacent to the industrial regions is of great concern due to the association with human health risks. In this work, the concentrations of particulate matter (PM10) in the ambient air of UTHM campus was investigated tostudy the air qualityand their compliance to the Malaysian Ambient Air Quality Guidelines (AAQG). The PM10 samples were taken over 24 hours from the most significant area at UTHM including Stadium, KolejKediamanTunDr. Ismail (KKTDI) and MakmalBahan. The meteorological parameters; temperature, relative humidity, wind speed and wind direction as well as particulate matterwere estimated by using E-Sampler Particulate Matter (PM10) Collector. The highest concentrations of PM10 (55.56 µg/m3) was recorded at MakmalBahan during the working and weekend days. However, these concentrations are less than 150 pg/m3. It can be concluded that although UTHM is surrounded by the industrial area, the air quality in the campus still within the standards limits.

  12. THE GENOTOXICITY OF AMBIENT OUTDOOR AIR, A REVIEW: SALMONELLA MUTAGENICITY

    EPA Science Inventory

    The genotoxicity of ambient outdoor air, a review: Salmonella mutagenicity

    Abstract
    Mutagens in urban air pollution come from anthropogenic sources (especially combustion sources) and are products of airborne chemical reactions. Bacterial mutation tests have been used ...

  13. Anode for rechargeable ambient temperature lithium cells

    NASA Technical Reports Server (NTRS)

    Huang, Chen-Kuo (Inventor); Surampudi, Subbarao (Inventor); Attia, Alan I. (Inventor); Halpert, Gerald (Inventor)

    1994-01-01

    An ambient room temperature, high density, rechargeable lithium battery includes a Li(x)Mg2Si negative anode which intercalates lithium to form a single crystalline phase when x is up to 1.0 and an amorphous phase when x is from 1 to 2.0. The electrode has good reversibility and mechanical strength after cycling.

  14. TRIETHYLTIN: AMBIENT TEMPERATURE ALTERS VISUAL SYSTEM TOXICITY

    EPA Science Inventory

    Previous studies have indicated that acute exposure to triethyltin (TET) increases latencies of the flash evoked response (VER) recorded from the rat cortex. TET also produces hypothermia, which may be modified by altering environmental (ambient) temperature. In this study, the r...

  15. 40 CFR 52.14 - State ambient air quality standards.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... quality standards. Any ambient air quality standard submitted with a plan which is less stringent than a national standard is not considered part of the plan. ... 40 Protection of Environment 3 2010-07-01 2010-07-01 false State ambient air quality standards....

  16. WORKSHOP ON SOURCE EMISSION AND AMBIENT AIR MONITORING OF MERCURY

    EPA Science Inventory

    AN EPA/ORD Workshop on Source Emission and Ambient Air Monitoring of Mercury was held on 9/13-14/99, Bloomington, Minnesota. The purpose of the workshop was to discuss the state-of-the-science in source and ambient air mercury monitoring as well as mercury monitoring research and...

  17. Immune defence under extreme ambient temperature

    PubMed Central

    Seppälä, Otto; Jokela, Jukka

    2011-01-01

    Owing to global climate change, the extreme weather conditions are predicted to become more frequent, which is suggested to have an even greater impact on ecological interactions than the gradual increase in average temperatures. Here, we examined whether exposure to high ambient temperature affects immune function of the great pond snail (Lymnaea stagnalis). We quantified the levels of several immune traits from snails maintained in a non-stressful temperature (15°C) and in an extreme temperature (30°C) that occurs in small ponds during hot summers. We found that snails exposed to high temperature had weaker immune defence, which potentially predisposes them to infections. However, while phenoloxidase and antibacterial activity of snail haemolymph were reduced at high temperature, haemocyte concentration was not affected. This suggests that the effect of high temperature on snail susceptibility to infections may vary across different pathogens because different components of invertebrate immune defence have different roles in resistance. PMID:20610417

  18. Ambient temperature modelling with soft computing techniques

    SciTech Connect

    Bertini, Ilaria; Ceravolo, Francesco; Citterio, Marco; Di Pietra, Biagio; Margiotta, Francesca; Pizzuti, Stefano; Puglisi, Giovanni; De Felice, Matteo

    2010-07-15

    This paper proposes a hybrid approach based on soft computing techniques in order to estimate monthly and daily ambient temperature. Indeed, we combine the back-propagation (BP) algorithm and the simple Genetic Algorithm (GA) in order to effectively train artificial neural networks (ANN) in such a way that the BP algorithm initialises a few individuals of the GA's population. Experiments concerned monthly temperature estimation of unknown places and daily temperature estimation for thermal load computation. Results have shown remarkable improvements in accuracy compared to traditional methods. (author)

  19. Ambient temperature sodium-sulfur batteries.

    PubMed

    Manthiram, Arumugam; Yu, Xingwen

    2015-05-13

    Ambient- or room-temperature sodium-sulfur batteries (RT Na-S) are gaining much attention as a low-cost option for large-scale electrical energy storage applications. However, their adoption is hampered by severe challenges. This concept paper summarizes first the operating principles, history, recent progress, and challenges of RT Na-S battery technology, and then suggests future directions towards enhancing performance in order for it to be a viable technology. PMID:25565554

  20. Particulate composition characteristics under different ambient air quality conditions.

    PubMed

    Tsai, Jiun-Horng; Chang, Lisa Tzu-Chi; Huang, Yao-Sheng; Chiang, Hung-Lung

    2011-07-01

    Particulate compositions including elemental carbon (EC), organic carbon (OC), water-soluble ionic species, and elemental compositions were investigated during the period from 2004 to 2006 in southern Taiwan. The correlation between the pollutant standard index (PSI) of ambient air quality and the various particle compositions was also addressed in this study. PSI revealed a correlation with fine (r = 0.74) and coarse (r = 0.80) particulate matter (PM). PSI manifested a significant correlation with the amount of analyzed ionic species (r approximately 0.80) in coarse and fine particles and a moderate correlation with carbon content (r = 0.63) in fine particles; however, it showed no correlation with elemental content. Although the ambient air quality ranged from good to moderate, the ionic species including chloride (Cl-), nitrate (NO3-), sulfate (SO4(2-)), sodium (Na+), ammonium (NH4+), magnesium (Mg2+), and calcium (Ca2+) increased significantly (1.5-3.7 times for Daliao and 1.8-6.9 times for Tzouying) in coarse PM. For fine particles, NO3-, SO4(2-), NH4+, and potassium (K+) also increased significantly (1.3-2.4 times for Daliao and 2.8-9.6 times for Tzouying) when the air quality went from good to moderate. For meteorological parameters, temperature evidenced a slightly negative correlation with PM concentration and PSI value, which implied a high PM concentration in the low-temperature condition. This reflects the high frequency of PM episodes in winter and spring in southern Taiwan. In addition, the mixing height increase from 980 to 1450 m corresponds to the air quality condition changing from unhealthy to good. PMID:21850835

  1. 76 FR 14812 - Additional Air Quality Designations for the 2006 24-Hour Fine Particle National Ambient Air...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-03-18

    ... Particle National Ambient Air Quality Standards, 110(k)(6) Correction and Technical Correction Related to... the Annual Fine Particles National Ambient Air Quality Standards Correction In rule document...

  2. Recognizing the impact of ambient air pollution on skin health.

    PubMed

    Mancebo, S E; Wang, S Q

    2015-12-01

    Ambient air pollution is a known public health hazard that negatively impacts non-cutaneous organs; however, our knowledge regarding the effects on skin remains limited. Current scientific evidence suggests there are four mechanisms by which ambient air pollutants cause adverse effects on skin health: (i) generation of free radicals, (ii) induction of inflammatory cascade and subsequent impairment of skin barrier, (iii) activation of the aryl hydrocarbon receptor (AhR) and (iv) alterations to skin microflora. In this review, we provide a comprehensive overview on ambient air pollutants and their relevant sources, and highlight current evidence of the effects on skin. PMID:26289769

  3. Effects of ambient air temperature, humidity, and wind speed on seminal traits in Braford and Nellore bulls at the Brazilian Pantanal

    NASA Astrophysics Data System (ADS)

    Menegassi, Silvio Renato Oliveira; Pereira, Gabriel Ribas; Bremm, Carolina; Koetz, Celso; Lopes, Flávio Guiselli; Fiorentini, Eduardo Custódio; McManus, Concepta; Dias, Eduardo Antunes; da Rocha, Marcela Kuczynski; Lopes, Rubia Branco; Barcellos, Júlio Otávio Jardim

    2016-04-01

    The aim of this study was to evaluate the bioclimatic thermal stress assessed by Equivalent Temperature Index (ETI) and Temperature Humidity Index (THI) on Braford and Nellore bulls sperm quality during the reproductive seasons at the tropical region in the Brazilian Pantanal. We used 20 bulls aged approximately 24 months at the beginning of the study. Five ejaculates per animal were collected using an electroejaculator. Temperature, air humidity, and wind speed data were collected every hour from the automatic weather station at the National Institute of Meteorology. Infrared thermography images data were collected to assess the testicular temperature gradient in each animal. Data were analyzed with ANOVA using MIXED procedure of SAS and means were compared using Tukey's HSD test. The THI and ETI at 12 days (epididymal transit) were higher in January (89.7 and 28.5, respectively) and February (90.0 and 29.0, respectively) compared to other months (P < 0.01). Total seminal defects differ only in Bradford bulls between the months of November and February. Nellore bulls had lower major defects (MaD) and total defects (TD) compared to Braford. Nellore bulls showed correlation between minor defects (MiD) and THI for 30 days (0.90) and 18 days (0.88; P < 0.05). Braford bulls showed correlation for MaD (0.89) in ETI for 12 days (P < 0.05). Infrared thermography showed no difference between animals. Reproductive response to environmental changes is a consequence of Nellore and Braford adaptation to climate stress conditions. Both THI and ETI environmental indexes can be used to evaluate the morphological changes in the seminal parameters in Nellore or Braford bulls; however, more experiments should be performed focusing on larger sample numbers and also in reproductive assessment during the consecutive years to assess fertility potential.

  4. 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...

  5. 78 FR 63933 - Approval and Promulgation of Air Quality Implementation Plans; Virginia; Revised Ambient Air...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-10-25

    ... AGENCY 40 CFR Part 52 Approval and Promulgation of Air Quality Implementation Plans; Virginia; Revised Ambient Air Quality Standards for Fine Particulate Matter AGENCY: Environmental Protection Agency (EPA... submitted by the Commonwealth of Virginia adding ambient air quality standards and associated...

  6. 75 FR 65594 - Approval and Promulgation of Air Quality Implementation Plans; Ohio; Ohio Ambient Air Quality...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-10-26

    ... AGENCY 40 CFR Part 52 Approval and Promulgation of Air Quality Implementation Plans; Ohio; Ohio Ambient Air Quality Standards AGENCY: Environmental Protection Agency (EPA). ACTION: Proposed rule. SUMMARY... consolidation of Ohio's Ambient Air Quality Standards (AAQS) into Ohio's State Implementation Plan (SIP)...

  7. 40 CFR 50.8 - National primary ambient air quality standards for carbon monoxide.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 2 2010-07-01 2010-07-01 false National primary ambient air quality... (CONTINUED) AIR PROGRAMS NATIONAL PRIMARY AND SECONDARY AMBIENT AIR QUALITY STANDARDS § 50.8 National primary ambient air quality standards for carbon monoxide. (a) The national primary ambient air quality...

  8. Sampling of nitrates in ambient air

    NASA Astrophysics Data System (ADS)

    Appel, B. R.; Tokiwa, Y.; Haik, M.

    Methods for the measurement of nitric acid, particulate nitrate and total inorganic nitrate (i.e. HNO 3 plus particulate nitrate) are compared using atmospheric samples from the Los Angeles Basin. Nitric acid was measured by (1) the nitrate collected on nylon or NaCl-impregnated cellulose filters after removal of particulate matter with Teflon prefilters, (2) long-path Fourier transform infrared spectroscopy (FTIR) performed by a collaborating investigator, and (3) the difference between total inorganic nitrate (TIN) and particulate nitrate (PN). TIN was measured by the sum of the nitrate collected with a Teflon prefilter and nylon or NaCl-impregnated after-filter. PN was measured by the nitrate able to penetrate a diffusion dénuder coated to remove acidic gases (e.g. HNO 3). Losses of nitrate from Teflon prefilters were determined by comparing the nitrate retained by these filters to the nitrate penetrating the acid gas denuder. TIN and the nitrate collected with glass fiber filters were compared to assess the origin of the artifact particulate nitrate on the latter. Nitric acid measurements using nylon or NaCl-impregnated after-filters were substantially higher than those by the difference technique. This correlated with losses of nitrate from the Teflon prefilters, which exceeded 50 % at high ambient temperature and low relative humidity. Nitric acid by the difference method exceeded that by FTIR by, on average, 20 %. Thus errors inferred in HNO 3 measurements by comparison to the difference measurements are considered minimum values. The high values for HNO 3 by the difference method are consistent with the partial loss of PN in the acid gas denuder. However, no loss of 0.1 μm to 3 μm diameter NH 4NO 3 particles was observed. Thus, if significant, such loss is restricted to coarse particulate nitrate. Heating the filter samplers was shown to increase sampling errors. Nitrate results obtained in short-term, low volume sampling with Gelman A glass fiber

  9. Artifact peroxides produced during cryogenic sampling of ambient air

    NASA Astrophysics Data System (ADS)

    Staffelbach, Thomas; Neftel, Albrecht; Dasgupta, Purnendu K.

    Peroxides were found to be produced as artifacts during cryogenic sampling with Horibe traps. Cryogenic trap sampling was compared to collection with a wet effluent diffusion denuder and a Nafion membrane diffusion denuder. Hydrogen peroxide and hydroxymethyl hydroperoxide measured in the cryogenic trap samples were significantly higher. In comparison, no evidence of artifact methyl hydroperoxide production was found. The amount of artifact H2O2 and HMHP produced increased with decreasing trap temperature. Spiking ambient air with ethene or isoprene showed that these hydrocarbons, in the presence of ozone, can be responsible for the artifact production of peroxides. Our results clearly suggest that the peroxide data obtained by cryogenic sampling and reported in the literature should be interpreted with caution.

  10. THE ENVIRONMENTAL PROTECTION AGENCY FOUR CORNERS AMBIENT AIR MONITORING NETWORK

    EPA Science Inventory

    This ambient air monitoring program was initiated with the overall objective of establishing an air quality base line for the Four Corners area of Arizona, Colorado, New Mexico, and Utah. The base line will be used in assessing the impact of the development of coal deposits and t...

  11. 40 CFR 52.995 - Enhanced ambient air quality monitoring.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 3 2014-07-01 2014-07-01 false Enhanced ambient air quality monitoring... air quality monitoring. (a) The Governor of the State of Louisiana submitted the photochemical... nonattainment area on September 10, 1993. This SIP submittal satisfies 40 CFR 58.20(f), which requires the...

  12. 40 CFR 52.995 - Enhanced ambient air quality monitoring.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 3 2012-07-01 2012-07-01 false Enhanced ambient air quality monitoring... air quality monitoring. (a) The Governor of the State of Louisiana submitted the photochemical... nonattainment area on September 10, 1993. This SIP submittal satisfies 40 CFR 58.20(f), which requires the...

  13. 40 CFR 52.995 - Enhanced ambient air quality monitoring.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 3 2013-07-01 2013-07-01 false Enhanced ambient air quality monitoring... air quality monitoring. (a) The Governor of the State of Louisiana submitted the photochemical... nonattainment area on September 10, 1993. This SIP submittal satisfies 40 CFR 58.20(f), which requires the...

  14. 40 CFR 52.995 - Enhanced ambient air quality monitoring.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 3 2011-07-01 2011-07-01 false Enhanced ambient air quality monitoring... air quality monitoring. (a) The Governor of the State of Louisiana submitted the photochemical... nonattainment area on September 10, 1993. This SIP submittal satisfies 40 CFR 58.20(f), which requires the...

  15. 40 CFR 52.995 - Enhanced ambient air quality monitoring.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 3 2010-07-01 2010-07-01 false Enhanced ambient air quality monitoring... air quality monitoring. (a) The Governor of the State of Louisiana submitted the photochemical... nonattainment area on September 10, 1993. This SIP submittal satisfies 40 CFR 58.20(f), which requires the...

  16. METHODOLOGY OF AMBIENT AIR MONITORING FOR POLYCYCLIC AROMATIC HYDROCARBONS

    EPA Science Inventory

    In the last decade, several studies of polycyclic aromatic hydrocarbons (PAH) in ambient air in the U.S. specifically investigated (1) the sampling efficiency of two sorbents for PAH in air: XAD-2 and polyurethane foam (PUP); (2) the storage stability of PAH on quartz fiber fil...

  17. Femtosecond laser ablation of polytetrafluoroethylene (Teflon) in ambient air

    NASA Astrophysics Data System (ADS)

    Wang, Z. B.; Hong, M. H.; Lu, Y. F.; Wu, D. J.; Lan, B.; Chong, T. C.

    2003-05-01

    Teflon, polytetrafluorethylene (PTFE), is an important material in bioscience and medical application due to its special characteristics (bio-compatible, nonflammable, antiadhesive, and heat resistant). The advantages of ultrashort laser processing of Teflon include a minimal thermal penetration region and low processing temperatures, precision removal of material, and good-quality feature definition. In this paper, laser processing of PTFE in ambient air by a Ti:sapphire femtosecond laser (780 nm, 110 fs) is investigated. It is found that the pulse number on each irradiated surface area must be large enough for a clear edge definition and the ablated depth increases with the pulse number. The air ionization effect at high laser fluences not only degrades the ablated structures quality but also reduces the ablation efficiency. High quality microstructures are demonstrated with controlling laser fluence below a critical fluence to exclude the air ionization effect. The ablated microstructures show strong adhesion property to liquids and clear edges that are suitable for bio-implantation applications. Theoretical calculation is used to analyze the evolution of the ablated width and depth at various laser fluences.

  18. a Study of Liquid - of Atomization Droplet Size Velocity and Temperature Distribution via Information Theory Spray Interaction with Ambient Air Motion.

    NASA Astrophysics Data System (ADS)

    Li, Xianguo

    Linear temporal instability analysis of a moving thin viscous liquid sheet of uniform thickness in an inviscid gas medium shows that surface tension always opposes, while surrounding gas and relative velocity between the sheet and gas favour the onset and development of instability. For gas Weber number smaller than the density ratio of gas to liquid, liquid viscosity enhances instability; If gas Weber number is slightly larger, aerodynamic and viscosity -induced instabilities interact with each other, displaying complicated effects of viscosity via Ohnesorge number; For much larger values of gas Weber numbers, aerodynamic instability dominates, liquid viscosity reduces disturbance growth rate and increases the dominant wavelength. Droplet probability distribution function (PDF) in sprays is formulated through information theory without resorting to the details of atomization processes. The derived analytical droplet size PDF is Nukiyama-Tanasawa type if conservation of mass is considered alone. If conservation of mass, momentum and energy is all taken into account, the joint droplet size and velocity PDF depends on Weber number, and compares favourably with measurements. Droplet velocity PDF is truncated Gaussian for any specific droplet size. Mean velocity approaches a constant value and velocity variance decreases as droplet size increases. Mean droplet diameters calculated agree well with observations. The computation indicates that atomization efficiency is very low, usually less than 1%. Droplet size, velocity and temperature PDF in sprays under combusting environment has also been derived. Effects of combustion on PDF occur mainly through the heat transferred into liquid sheet prior to its breakup. Experimental studies identify three modes of spray behaviours due to its interaction with various annular air flows, and show that bluff-body type of combustor has ability and easement to control aerodynamically spray angle, shape and droplet trajectories. It is

  19. Evaluating alternative refrigerants for high ambient temperature environments

    DOE PAGESBeta

    Abdelaziz, Omar; Shrestha, Som S.

    2016-01-01

    According to the Montreal Protocol, developing countries have started the phase out schedule of the ozone depleting substances, including HCFC refrigerants, in 2015 and expect them to reach 35% reduction in 2020. This commitment to the start the phase out of HCFC refrigerants, especially R-22, in developing countries is seen as an opportunity to introduce lower Global Warming Potential (GWP) refrigerants. Furthermore, this paper summarizes an investigation into the performance of lower GWP refrigerants in high ambient temperature environments, experienced in some of the developed countries, in mini-split air conditioning units.

  20. Evaluating Alternative Refrigerants for High Ambient Temperature Environments

    SciTech Connect

    Abdelaziz, Omar; Shrestha, Som S

    2016-01-01

    According to the Montreal Protocol, developing countries have started the phase out schedule of the ozone depleting substances, including HCFC refrigerants, in 2015 and expect them to reach 35% reduction in 2020. This commitment to the start the phase out of HCFC refrigerants, especially R-22, in developing countries is seen as an opportunity to introduce lower Global Warming Potential (GWP) refrigerants. This paper summarizes an investigation into the performance of lower GWP refrigerants in high ambient temperature environments, experienced in some of the developed countries, in mini-split air conditioning units.

  1. Control of flowering by ambient temperature.

    PubMed

    Capovilla, Giovanna; Schmid, Markus; Posé, David

    2015-01-01

    The timing of flowering is a crucial decision in the life cycle of plants since favourable conditions are needed to maximize reproductive success and, hence, the survival of the species. It is therefore not surprising that plants constantly monitor endogenous and environmental signals, such as day length (photoperiod) and temperature, to adjust the timing of the floral transition. Temperature in particular has been shown to have a tremendous effect on the timing of flowering: the effect of prolonged periods of cold, called the vernalization response, has been extensively studied and the underlying epigenetic mechanisms are reasonably well understood in Arabidopsis thaliana. In contrast, the effect of moderate changes in ambient growth temperature on the progression of flowering, the thermosensory pathway, is only starting to be understood on the molecular level. Several genes and molecular mechanisms underlying the thermosensory pathway have already been identified and characterized in detail. At a time when global temperature is rising due to climate change, this knowledge will be pivotal to ensure crop production in the future. PMID:25326628

  2. Effects of respirator ambient air cooling on thermophysiological responses and comfort sensations.

    PubMed

    Caretti, David M; Barker, Daniel J

    2014-01-01

    This investigation assessed the thermophysiological and subjective impacts of different respirator ambient air cooling options while wearing chemical and biological personal protective equipment in a warm environment (32.7 ± 0.4°C, 49.6 ± 6.5% RH). Ten volunteers participated in 90-min heat exposure trials with and without respirator (Control) wear and performed computer-generated tasks while seated. Ambient air cooling was provided to respirators modified to blow air to the forehead (FHC) or to the forehead and the breathing zone (BZC) of a full-facepiece air-purifying respirator using a low-flow (45 L·min(-1)) mini-blower. An unmodified respirator (APR) trial was also completed. The highest body temperatures (TTY) and least favorable comfort ratings were observed for the APR condition. With ambient cooling over the last 60 min of heat exposure, TTY averaged 37.4 ± 0.6°C for Control, 38.0 ± 0.4°C for APR, 37.8 ± 0.5°C for FHC, and 37.6 ± 0.7°C for BZC conditions independent of time. Both the FHC and BZC ambient air cooling conditions reduced facial skin temperatures, reduced the rise in body temperatures, and led to more favorable subjective comfort and thermal sensation ratings over time compared to the APR condition; however statistical differences among conditions were inconsistent. Independent of exposure time, average breathing apparatus comfort scores with BZC (7.2 ± 2.5) were significantly different from both Control (8.9 ± 1.4) and APR (6.5 ± 2.2) conditions when ambient cooling was activated. These findings suggest that low-flow ambient air cooling of the face under low work rate conditions and mild hyperthermia may be a practical method to minimize the thermophysiological strain and reduce perceived respirator discomfort. PMID:24730706

  3. Ambient air measurements of monoterpenes, oxygenated terpenes, and sesquiterpenes

    NASA Astrophysics Data System (ADS)

    Bouvier-Brown, N. C.; Goldstein, A. H.

    2007-12-01

    Chemical ozone loss within the forest canopy and the presence of biogenic VOC (BVOC) oxidation products in and above the canopy indirectly suggest the presence of very reactive BVOCs at Blodgett Forest. As a part of the 2007 BEARPEX campaign at this coniferous forest in the Sierra Nevada Mountains of California (1300 m elevation, 38.90° N, 120.63° W,), we quantified ambient concentrations of terpenes using a modified in-situ gas chromatograph with a mass spectrometer and a flame ionization detector (GC-MS-FID). The range of terpenes observed in ambient air matched enclosure based measurements of branch level emissions. To our knowledge, these observations represent the first quantification of the oxygenated monoterpene methyl chavicol and various sesquiterpenes in ambient air. Details of the instrument modifications, diurnal profiles of the terpenes, and comparison to branch level emissions will be presented.

  4. Water Power Calculator Temperature and Analog Input/Output Module Ambient Temperature Testing

    SciTech Connect

    Mark D. McKay

    2011-02-01

    Water Power Calculator Temperature and Analog input/output Module Ambient Temperature Testing A series of three ambient temperature tests were conducted for the Water Power Calculator development using the INL Calibration Laboratory’s Tenney Environmental Chamber. The ambient temperature test results demonstrate that the Moore Industries Temperature Input Modules, Analog Input Module and Analog Output Module, ambient temperature response meet or exceed the manufactures specifications

  5. Ambient air pollution and risk of ischemic stroke and TIA

    PubMed Central

    Lisabeth, LD; Escobar, JD; Dvonch, JT; Sanchez, BN; Majersik, JJ; Brown, DL; Smith, MA; Morgenstern, LB

    2009-01-01

    Background Data on the association between air pollution and cerebrovascular disease in the US are limited. The objective of this study was to investigate the association between short-term exposure to ambient air pollution and risk of ischemic cerebrovascular events in a US community. Methods Daily counts of ischemic strokes/TIAs (2001–2005) were obtained from the population-based Brain Attack Surveillance in Corpus Christi (BASIC) Project. Daily particulate matter <2.5μm in diameter (PM2.5), ozone (O3), and meteorological data were obtained from Texas Commission on Environmental Quality. To examine the association between PM2.5 and stroke/TIA risk, Poisson regression was used. Separate models included same day PM2.5, PM2.5 lagged 1–5 days, and an averaged lag effect. All models were adjusted for temperature, day of week and temporal trends in stroke/TIA. The effects of O3 were also investigated. Results Median PM2.5 was 7.0 μg/m3 (Inter Quartile Range (IQR): 4.8–10.0). There were borderline significant associations between same day (RR=1.03, 95% CI:0.99–1.07 for an IQR increase in PM2.5) and previous day (RR=1.03, 95% CI:1.00–1.07) PM2.5 and stroke/TIA risk. These associations were independent of O3, which demonstrated similar associations with stroke/TIA risk (same day RR=1.02, 95% CI: 0.97–1.08 and previous day RR=1.04, 95% CI: 0.99–1.09) in two pollutant models. Inference We observed associations between recent PM2.5 and O3 exposure and ischemic stroke/TIA risk even in this community with relatively low pollutant levels. This study provides data on environmental exposures and stroke risk in the US and suggests future research on ambient air pollution and stroke is warranted. PMID:18508356

  6. Effects of the ambient temperature on the airflow across a Caucasian nasal cavity.

    PubMed

    Burgos, M A; Sanmiguel-Rojas, E; Martín-Alcántara, A; Hidalgo-Martínez, M

    2014-03-01

    We analyse the effects of the air ambient temperature on the airflow across a Caucasian nasal cavity under different ambient temperatures using CFD simulations. A three-dimensional nasal model was constructed from high-resolution computed tomography images for a nasal cavity from a Caucasian male adult. An exhaustive parametric study was performed to analyse the laminar-compressible flow driven by two different pressure drops between the nostrils and the nasopharynx, which induced calm breathing flow rates ࣈ 5.7 L/min and ࣈ 11.3 L/min. The inlet air temperature covered the range - 10(o) C ⩽ To ⩽50(o) C. We observed that, keeping constant the wall temperature of the nasal cavity at 37(o) C, the ambient temperature affects mainly the airflow velocity into the valve region. Surprisingly, we found an excellent linear relationship between the ambient temperature and the air average temperature reached at different cross sections, independently of the pressure drop applied. Finally, we have also observed that the spatial evolution of the mean temperature data along the nasal cavity can be collapsed for all ambient temperatures analysed with the introduction of suitable dimensionless variables, and this evolution can be modelled with the help of hyperbolic functions, which are based on the heat exchanger theory. PMID:24574201

  7. Modulated corona nanosecond discharge in air under ambient pressure

    NASA Astrophysics Data System (ADS)

    Lepekhin, N. M.; Priseko, Yu. S.; Filippov, V. G.; Bulatov, M. U.; Sukharevskii, D. I.; Syssoev, V. S.

    2015-04-01

    A unique type of corona discharge-modulated corona nanosecond discharge-has been obtained, the parameters of which have been determined in a geometric system of electrodes with a sharply heterogeneous electric field in air under ambient pressure and natural humidity.

  8. ORGANOCHLORINE PESTICIDES IN THE AMBIENT AIR OF MEXICO

    EPA Science Inventory

    Recent and past use of organochlorine pesticides (OCPs) in Mexico has resulted in concentrations in ambient air that are 1-2 orders of magnitude above levels in the Great Lakes region. Atmospheric transport from Mexico and Central America may be contributing significant amounts ...

  9. COLLECTION, CHEMICAL FRACTIONATION, AND MUTAGENICITY BIOASSAY OF AMBIENT AIR PARTICULATE

    EPA Science Inventory

    The influence of industrialization and consequent increased concentration of urban particulate matter on the incidence of cancer has long been a concern. The first bioassays used to evaluate complex ambient air samples were whole-animal carcinogenesis bioassays. In these studies,...

  10. TECHNIQUE FOR MEASURING REDUCED FORMS OF SULFUR IN AMBIENT AIR

    EPA Science Inventory

    A new technique for measuring low concentrations of volatile sulfur compounds in ambient air is discussed. The technique consists of preconcentration of sulfur compounds by chemisorption on gold metal coated sand or gold foil surface followed by thermal desorption, separation, an...

  11. VOCS IN AMBIENT AIR NEAR WORLD TRADE CENTER SITE

    EPA Science Inventory

    Beginning on September 22, 2001 and continuing through February 2002, ambient air samples were collected at three sites within a block of ground zero and at a fourth site on the 16th floor of a building at 290 Broadway. Grab samples were collected in evacuated, electro-polished...

  12. Mound ambient air surveillance program: Description and path forward

    SciTech Connect

    Bauer, L R

    1992-08-01

    The ambient air monitoring program in place at Mound has undergone a number of changes since its installation. These changes have resulted from revisions to prevailing environmental regulations and guidance. Additional voluntary upgrades and modifications are planned. This report serves to update information on sampling station locations, equipment designs, operational criteria, and planned upgrades.

  13. METHODOLOGY FOR SITING AMBIENT AIR MONITORS AT THE NEIGHBORHOOD SCALE

    EPA Science Inventory

    In siting a monitor to measure compliance with U.S. National Ambient Air Quality Standards for particulate matter (PM), there is a need to characterize variations in PM concentration within a neighborhood-scale region in order to achieve monitor siting objectives.

    We p...

  14. Development of ambient temperature secondary lithium cells

    NASA Technical Reports Server (NTRS)

    Subbarao, S.; Shen, D. H.; Dawson, S.; Deligiannis, F.; Taraszkiewicz, J.; Halpert, Gerald

    1987-01-01

    JPL is developing ambient temperature secondary lithium cells for future spacecraft applications. Prior studies on experimental laboratory type Li-TiS2 cells yielded promising results in terms of cycle life and rate capability. To further assess the performance of this cell, 5 Ah engineering model cells were developed. Initially baseline cells were designed and fabricated. Each cell had 15 cathodes and 16 anodes and the ratio of anode to cathode capacity is 6:1. A solution of 1.5 molar LiAsF6 in 2Me-THF was used as the electrolyte. Cells were evaluated for their cycle life at C/1 and C/5 discharge rates and 100 percent depth of discharge. The cells were cycled between voltage limits 1.7 and 2.8 volts. The rate of charge in all cases is C/10. The results obtained indicate that cells can operate at C/10 to C/2 discharge rates and have an initial energy density of 70 Wh/kg. Cells delivered more than 100 cycles at C/2 discharge rate. The details of cell design, the test program, and the results obtained are described.

  15. Colorado Air Quality Control Regulations and Ambient Air Quality Standards.

    ERIC Educational Resources Information Center

    Colorado State Dept. of Health, Denver. Div. of Air Pollution Control.

    Regulations and standards relative to air quality control in Colorado are defined in this publication. Presented first are definitions of terms, a statement of intent, and general provisions applicable to all emission control regulations adopted by the Colorado Air Pollution Control Commission. Following this, three regulations are enumerated: (1)…

  16. Sampling frequency guidance for ambient air toxics monitoring.

    PubMed

    Bortnick, Steven M; Stetzer, Shannon L

    2002-07-01

    The U.S. Environmental Protection Agency (EPA) is in the process of designing a national network to monitor hazardous air pollutants (HAPs), also known as air toxics. The purposes of the expanded monitoring are to (1) characterize ambient concentrations in representative areas; (2) provide data to support and evaluate dispersion and receptor models; and (3) establish trends and evaluate the effectiveness of HAP emission reduction strategies. Existing air toxics data, in the form of an archive compiled by EPA's Office of Air Quality Planning and Standards (OAQPS), are used in this paper to examine the relationship between estimated annual average (AA) HAP concentrations and their associated variability. The goal is to assess the accuracy, or bias and precision, with which the AA can be estimated as a function of ambient concentration levels and sampling frequency. The results suggest that, for several air toxics, a sampling schedule of 1 in 3 days (1:3) or 1:6 days maybe appropriate for meeting some of the general objectives of the national network, with the more intense sampling rate being recommended for areas expected to exhibit relatively high ambient levels. PMID:12139351

  17. 40 CFR 50.4 - National primary ambient air quality standards for sulfur oxides (sulfur dioxide).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 2 2010-07-01 2010-07-01 false National primary ambient air quality... PROTECTION AGENCY (CONTINUED) AIR PROGRAMS NATIONAL PRIMARY AND SECONDARY AMBIENT AIR QUALITY STANDARDS § 50.4 National primary ambient air quality standards for sulfur oxides (sulfur dioxide). Link to...

  18. 40 CFR Appendix C to Part 58 - Ambient Air Quality Monitoring Methodology

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 6 2013-07-01 2013-07-01 false Ambient Air Quality Monitoring... PROGRAMS (CONTINUED) AMBIENT AIR QUALITY SURVEILLANCE Pt. 58, App. C Appendix C to Part 58—Ambient Air... temporary modification is approved, air quality data obtained with the method as temporarily modified...

  19. 40 CFR Appendix C to Part 58 - Ambient Air Quality Monitoring Methodology

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 6 2014-07-01 2014-07-01 false Ambient Air Quality Monitoring... PROGRAMS (CONTINUED) AMBIENT AIR QUALITY SURVEILLANCE Pt. 58, App. C Appendix C to Part 58—Ambient Air... temporary modification is approved, air quality data obtained with the method as temporarily modified...

  20. Undulator Hall Air Temperature Fault Scenarios

    SciTech Connect

    Sevilla, J.; Welch, J.; /SLAC

    2010-11-17

    Recent experience indicates that the LCLS undulator segments must not, at any time following tuning, be allowed to change temperature by more than about {+-}2.5 C or the magnetic center will irreversibly shift outside of acceptable tolerances. This vulnerability raises a concern that under fault conditions the ambient temperature in the Undulator Hall might go outside of the safe range and potentially could require removal and retuning of all the segments. In this note we estimate changes that can be expected in the Undulator Hall air temperature for three fault scenarios: (1) System-wide power failure; (2) Heating Ventilation and Air Conditioning (HVAC) system shutdown; and (3) HVAC system temperature regulation fault. We find that for either a system-wide power failure or an HVAC system shutdown (with the technical equipment left on), the short-term temperature changes of the air would be modest due to the ability of the walls and floor to act as a heat ballast. No action would be needed to protect the undulator system in the event of a system-wide power failure. Some action to adjust the heat balance, in the case of the HVAC power failure with the equipment left on, might be desirable but is not required. On the other hand, a temperature regulation failure of the HVAC system can quickly cause large excursions in air temperature and prompt action would be required to avoid damage to the undulator system.

  1. BIOLOGICAL EFFECTS OF OIL FLY ASH AND RELEVANCE TO AMBIENT AIR PARTICULATE MATTER

    EPA Science Inventory

    Epidemiologic studies have demonstrated increased human morbidity and mortality with elevations in the concentration of ambient air particulate matter (PM). Fugitive fly ash from the combustion of oil and residual fuel oil significantly contributes to the ambient air particle bur...

  2. Effect of ambient temperature on female endurance performance.

    PubMed

    Renberg, Julie; Sandsund, Mariann; Wiggen, Øystein Nordrum; Reinertsen, Randi Eidsmo

    2014-10-01

    Ambient temperature can affect physical performance, and an ambient temperature range of -4 °C to 11 °C is optimal for endurance performance in male athletes. The few similar studies of female athletes appear to have found differences in response to cold between the genders. This study investigated whether ambient temperature affects female endurance performance. Nine athletes performed six tests while running on a treadmill in a climatic chamber at different ambient temperatures: 20, 10, 1, -4, -9 and -14 °C and a wind speed of 5 m s(-1). The exercise protocol consisted of a 10-min warm-up, followed by four 5-min intervals at increasing intensities at 76%, 81%, 85%, and 89% of maximal oxygen consumption. This was followed by an incremental test to exhaustion. Although peak heart rate, body mass loss, and blood lactate concentration after the incremental test to exhaustion increased as the ambient temperature rose, no changes in time to exhaustion, running economy, running speed at lactate threshold or maximal oxygen consumption were found between the different ambient temperature conditions. Endurance performance during one hour of incremental exercise was not affected by ambient temperature in female endurance athletes. PMID:25436945

  3. 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.

  4. 40 CFR 50.16 - National primary and secondary ambient air quality standards for lead.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... secondary ambient air quality standards for lead (Pb) and its compounds are 0.15 micrograms per cubic meter, arithmetic mean concentration over a 3-month period, measured in the ambient air as Pb either by: (1) A... primary and secondary ambient air quality standards for Pb are met when the maximum arithmetic...

  5. 77 FR 38760 - National Ambient Air Quality Standards for Particulate Matter; Correction

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-29

    ... AGENCY 40 CFR Parts 50, 51, 52, 53, and 58 RIN 2060-AO47 National Ambient Air Quality Standards for... revise the national ambient air quality standards (NAAQS) for particulate matter (PM). This action...: Questions concerning the ``National Ambient Air Quality Standards for Particulate Matter'' proposed...

  6. 77 FR 30087 - Air Quality Designations for the 2008 Ozone National Ambient Air Quality Standards

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-05-21

    ...This rule establishes initial air quality designations for most areas in the United States, including areas of Indian country, for the 2008 primary and secondary national ambient air quality standards (NAAQS) for ozone. The designations for several counties in Illinois, Indiana, and Wisconsin that the EPA is considering for inclusion in the Chicago nonattainment area will be designated in a......

  7. 76 FR 76048 - Air Quality Designations for the 2008 Lead (Pb) National Ambient Air Quality Standards

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-12-06

    ... From the Federal Register Online via the Government Publishing Office ENVIRONMENTAL PROTECTION AGENCY 40 CFR Part 81 RIN 2060-AR17 Air Quality Designations for the 2008 Lead (Pb) National Ambient Air Quality Standards Correction In rule document 2011-29460 appearing on pages 72097-72120 in the issues...

  8. Ambient Air Sampling During Quantum-dot Spray Deposition

    SciTech Connect

    Jankovic, John Timothy; Hollenbeck, Scott M

    2010-01-01

    Ambient air sampling for nano-size particle emissions was performed during spot spray coating operations with a Sono-Tek Exactacoat Benchtop system (ECB). The ECB consisted of the application equipment contained within an exhaust enclosure. The enclosure contained numerous small access openings, including an exhaust hook-up. Door access comprised most of the width and height of the front. The door itself was of the swing-out type. Two types of nanomaterials, Cadmium selenide (Cd-Se) quantum-dots (QDs) and Gold (Au) QDs, nominally 3.3 and 5 nm in diameter respectively, were applied during the evaluation. Median spray drop size was in the 20 to 60 micrometer size range.1 Surface coating tests were of short duration, on the order of one-half second per spray and ten spray applications between door openings. The enclosure was ventilated by connection to a high efficiency particulate aerosol (HEPA) filtered house exhaust system. The exhaust rate was nominally 80 ft3 per minute producing about 5 air changes per minute. Real time air monitoring with a scanning mobility particle size analyzer (SMPS ) with a size detection limit of 7 nm indicated a significant increase in the ambient air concentration upon early door opening. A handheld condensation particle counter (CPC) with a lower size limit of 10 nm did not record changes in the ambient background. This increase in the ambient was not observed when door opening was delayed for 2 minutes (~10 air changes). The ventilated enclosure controlled emissions except for cases of rapid door opening before the overspray could be removed by the exhaust. A time delay sufficient to provide 10 enclosure air changes (a concentration reduction of more than 99.99 %) before door opening prevented the release of aerosol particles in any size.2 Scanning-transmission electron microscopy (STEM) and atomic force microscopy (AFM) demonstrated the presence of agglomerates in the surfaces of the spray applied deposition. A filtered air sample of

  9. Identification of ambient air sampling and analysis methods for the 189 Title III air toxics

    SciTech Connect

    Mukund, R.; Kelly, T.J.; Gordon, S.M.; Hays, M.J.

    1994-12-31

    The state of development of ambient air measurement methods for the 189 Hazardous Air Pollution (HAPs) in Title 3 of the Clean Air Act Amendments was surveyed. Measurement methods for the HAPs were identified by reviews of established methods, and by literature searches for pertinent research techniques. Methods were segregated by their degree of development into Applicable, Likely, and Potential methods. This survey identified a total of 183 methods, applicable at varying degrees to ambient air measurements of one or more HAPs. As a basis for classifying the HAPs and evaluating the applicability of measurement methods, a survey of a variety of chemical and physical properties of the HAPs was also conducted. The results of both the methods and properties surveys were tabulated for each of the 189 HAP. The current state of development of ambient measurement methods for the 189 HAPs was then assessed from the results of the survey, and recommendations for method development initiatives were developed.

  10. Ambient and Emission Trends of Toxic Air Contaminants in California.

    PubMed

    Propper, Ralph; Wong, Patrick; Bui, Son; Austin, Jeff; Vance, William; Alvarado, Álvaro; Croes, Bart; Luo, Dongmin

    2015-10-01

    After initiating a toxic air contaminant (TAC) identification and control program in 1984, the California Air Resources Board adopted regulations to reduce TAC emissions from cars, trucks, stationary sources, and consumer products. This study quantifies ambient concentration and emission trends for the period 1990-2012 for seven TACs that are responsible for most of the known cancer risk associated with airborne exposure in California. Of these seven, diesel particulate matter (DPM) is the most important; however DPM is not measured directly. Based on a novel surrogate method, DPM concentrations declined 68%, even though the state's population increased 31%, diesel vehicle-miles-traveled increased 81%, and the gross state product (GSP) increased 74%. Based on monitoring data, concentrations of benzene, 1,3-butadiene, perchloroethylene, and hexavalent chromium declined 88-94%. Also, the ambient and emissions trends for each of these four TACs were similar. Furthermore, these declines generally occurred earlier in California than elsewhere. However, formaldehyde and acetaldehyde, which are formed in the air photochemically from volatile organic compounds (VOCs), declined only 20-21%. The collective cancer risk from exposure to these seven reviewed TACs declined 76%. Significant reduction in cancer risk to California residents from implementation of air toxics controls (especially for DPM) is expected to continue. PMID:26340590

  11. Assessment of ambient air quality in the port of Naples.

    PubMed

    Prati, Maria Vittoria; Costagliola, Maria Antonietta; Quaranta, Franco; Murena, Fabio

    2015-08-01

    Two experimental monitoring campaigns were carried out in 2012 to investigate the air quality in the port of Naples, the most important in southern Italy for traffic of passengers and one of the most important for goods. Therefore, it represents an important air pollution source located close to the city of Naples. The concentrations of sulfur dioxide (SO₂), nitrogen dioxide (NO₂), and BTEX (benzene, toluene, ethylbenzene, and xylenes) in the air were measured at 15 points inside the Naples port area through the use of passive samplers. In addition, a mobile laboratory was positioned in a fixed point inside the port area to measure continuous concentration of pollutants together with particulate matter, ambient parameters, and wind direction and intensity. The pollution levels monitored were compared with those observed in the urban area of Naples and in other Mediterranean ports. Even though the observation time was limited, measured concentrations were also compared with limit values established by European legislation. All the measured pollutants were below the limits with the exception of nitrogen dioxide: its average concentration during the exposition time exceeded the yearly limit value. A spatial analysis of data, according to the measured wind direction and intensity, provided information about the effects that ship emissions have on ambient air quality in the port area. The main evidence indicates that ship emissions influence sulfur dioxide concentration more than any other pollutants analyzed. PMID:26029862

  12. Ambient air pollution and annoyance responses from pregnant women

    NASA Astrophysics Data System (ADS)

    Llop, Sabrina; Ballester, Ferran; Estarlich, Marisa; Esplugues, Ana; Fernández-Patier, Rosalia; Ramón, Rosa; Marco, Alfredo; Aguirre, Amelia; Sunyer, Jordi; Iñiguez, Carmen; INMA-Valencia cohort

    ObjectivesTo describe the degree of annoyance caused by air pollution and noise in pregnant women in a birth cohort; to determine the modifying factors and their relation with exposure to ambient nitrogen dioxide (NO 2). MethodsThe study population was 855 pregnant women in Valencia, Spain. Annoyance caused by air pollution and noise, and explanatory factors were obtained from 786 pregnant women through a questionnaire. NO 2 levels were determined combining measurements at 93 points within the area of study and using geostatistical techniques (kriging). ResultsIn all 7.9% of the women reported high annoyance caused by air pollution and 13.1% high annoyance caused by noise. There was a significant difference in the degree of annoyance due to both air pollution and noise depending on the area where the women lived and their working status. The degree of annoyance correlated better with measured NO 2 at the municipality level (air pollution: r=0.53; noise: r=0.44) than at the individual level (air pollution and noise: r=0.21). On multivariate analysis, being a housewife, higher NO 2 levels and high traffic density were associated with higher degrees of annoyance. ConclusionsThere was a high percentage of women who perceived medium-high annoyance due to noise and air pollution. Annoyance caused by environmental pollutants could lead to some psychological effects, which impair the quality of life, or even physiological ones, which affect prenatal development.

  13. Ambient-Temperature Sputtering Of Composite Oxide Films

    NASA Technical Reports Server (NTRS)

    Thakoor, Sarita

    1992-01-01

    Technique for deposition of homogeneous films of multicomponent oxides on substrates at ambient temperature based on sequential sputter deposition of individual metal components, as alternating ultra-thin layers, from multiple targets. Substrates rotated over sputtering targets of lead, zirconium, and titanium. Dc-magnetron sputtering of constituent metals in reactive ambient of argon and oxygen leads to formation of the respective metal oxides intermixed on extremely fine scale in desired composition. Compatible with low-temperature microelectronic processing.

  14. Ambient particulate matter air pollution and cardiopulmonary diseases.

    PubMed

    Thurston, George; Lippmann, Morton

    2015-06-01

    Population exposures to ambient outdoor particulate matter (PM) air pollution have been assessed to represent a major burden on global health. Ambient PM is a diverse class of air pollution, with characteristics and health implications that can vary depending on a host of factors, including a particle's original source of emission or formation. The penetration of inhaled particles into the thorax is dependent on their deposition in the upper respiratory tract during inspiration, which varies with particle size, flow rate and tidal volume, and in vivo airway dimensions. All of these factors can be quite variable from person to person, depending on age, transient illness, cigarette smoke and other short-term toxicant exposures that cause transient bronchoconstriction, and occupational history associated with loss of lung function or cumulative injury. The adverse effects of inhaled PM can result from both short-term (acute) and long-term (chronic) exposures to PM, and can range from relatively minor, such as increased symptoms, to very severe effects, including increased risk of premature mortality and decreased life expectancy from long-term exposure. Control of the most toxic PM components can therefore provide major health benefits, and can help guide the selection of the most human health optimal air quality control and climate change mitigation policy measures. As such, a continued improvement in our understanding of the nature and types of PM that are most dangerous to health, and the mechanism(s) of their respective health effects, is an important public health goal. PMID:26024349

  15. Competitive systems - Ambient temperature rechargeable batteries

    NASA Astrophysics Data System (ADS)

    dell, R. M.

    Recent in designs of aqueous electrolyte secondary batteries are presented. Operation principles, performance characteristics, and applications of various types of lead/acid batteries, alkaline electrolyte batteries, flow batteries, and battery/fuel cell hybrids (such as metal/air and hydrogen/metal oxide systems) are discussed. Consideration is given to the relative importance of such battery parameters as deep discharge capability, freedom from maintenance, shelf life, and cost, depending upon the specific application.

  16. Characterization of ambient air pollution for stochastic health models

    SciTech Connect

    Batterman, S.A.

    1981-08-01

    This research is an analysis of various measures of ambient air pollution useful in cross-sectional epidemiological investigations and rick assessments. The Chestnut Ridge area health effects investigation, which includes a cross-sectional study of respiratory symptoms in young children, is used as a case study. Four large coal-fired electric generating power plants are the dominant pollution sources in this area of western Pennsylvania. The air pollution data base includes four years of sulfur dioxide and five years of total suspended particulate concentrations at seventeen monitors. Some 70 different characterizations of pollution are constructed and tested. These include pollutant concentrations at various percentiles and averaging times, exceedence measures which show the amount of time a specified threshold concentration is exceeded, and several dosage measures which transform non-linear dose-response relationships onto pollutant concentrations.

  17. PREDICTING THE IMPACT OF TROPOSPHERIC OZONE ON ECOLOGICAL RESOURCES FOR SETTING NATIONAL AMBIENT AIR QUALITY STANDARDS

    EPA Science Inventory

    The Clean Air Act provides for establishing National Ambient Air Quality Standards (NAAQS) to protect public welfare (including crops, forests, ecosystems, and soils) from adverrse effects of air pollutants, including tropospheric ozone. The formulation of policies is science-bas...

  18. The State of Ambient Air Quality of Jeddah, Saudi Arabia

    NASA Astrophysics Data System (ADS)

    Hussain, M. M.; Aburizaiza, O. S.; Khwaja, H. A.; Siddique, A.; Nayebare, S. R.; Zeb, J.; Blake, D. R.

    2014-12-01

    Ambient air pollution in major cities of Saudi Arabia is a substantial environmental and health concern. A study was undertaken to assess the air quality of Jeddah, Saudi Arabia by the analysis of respirable particulate matter (PM2.5), black carbon (BC), trace metals (Na, Mg, Al, Si, S, Cl, K, Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, Br, Sr, Cd, Sb, and Pb), and water-soluble ions (F-, Cl-, NO3-, SO42-, C2O42-, and NH42+). Sulfur and BC mass concentration ranged 0.99 - 7.39 μg/m3 and 0.70 - 3.09 μg/m3, respectively, while the PM2.5 mass concentration ranged 23 - 186 μg/m3. Maximum BC contribution to PM2.5 was 5.6%. Atmospheric PM2.5 concentrations were well above the 24 h WHO guideline of 20 μg/m3. Air Quality Index (AQI) indicates that there were 8% days of moderate air quality, 28% days of unhealthy air quality for sensitive groups, 55% days of unhealthy air quality, and 9% days of very unhealthy air quality during the study period. Sulfate SO42- dominated the identifiable components. The major contributors to PM2.5 were soil and crustal material; vehicle emissions (black carbon factor); and fuel oil combustion in industries (sulfur factor), according to the Positive Matrix Factorization (PMF). This study highlights the importance of focusing control strategies not only on reducing PM concentration, but also on the reduction of toxic components of the PM, to most effectively protect human health and the environment.

  19. Monitoring ambient air for mutagenicity using the higher plant Tradescantia

    SciTech Connect

    Schairer, L A; Sautkulis, R C; Tempel, N R

    1981-01-01

    Final assessment of human health effects resulting from exposure to harmful environmental agents may rest with mammalian test system results. In vitro systems are short-term assays used most frequently for extrapolation to humans. However, no single assay system is adequate and the more expensive long-term tests must be augmented by multiple assays designed for redundancy or to fill gaps in present state of the art of environmental monitoring. The Tradescantia stamen hair test system is one such assay offering redundancy as well as filling the gap of monitoring ambient air for mutagenic agents. The flower color locus in heterozygous clones of Tradescantia mutates when exposed to such agents as fumigants, solvents, chemical additives or catalysts, and compounds requiring activation such as benzo (a) pyrene. The stamen hair system responds to low levels of airborne compounds. The Tradescantia stamen hair system was used as an in situ monitor for mutagens in ambient air in polluted industrial sites. Preliminary results from many sites showed a significant increase in mutation rate. The environment most consistently mutagenic was that downwind from petroleum refineries. No specific compounds or groups of compounds have as yet been correlated with the positive sites. (ERB)

  20. Sources of volatile organic compounds in Cairo's ambient air.

    PubMed

    Abu-Allaban, M; Lowenthal, D H; Gertler, A W; Labib, M

    2009-10-01

    The greater Cairo area suffers from extreme levels of gas and particulate phase air pollutants. In order to reduce the levels of ambient pollution, the USAID and the Egyptian Environmental Affairs Agency (EEAA) have supported the Cairo Air Improvement Project (CAIP). As part of this project, two intensive ambient monitoring studies were carried out during the period of February 22 to March 4 and October 27 to November 27, 1999. Volatile organic compounds (VOCs) were measured on a 24-h basis at six sampling stations during each of the intensive periods. During the February/March study, samples were collected daily, while in the October/November study samples were collected every other day. The six intensive measurement sites represented background levels, mobile source impacts, industrial impacts, and residential exposure. High levels of NMHC were observed at all locations. NMHC concentrations ranged from 365 ppb C at Helwan to 1,848 ppb C at El Qualaly during winter, 1999 and from 461 ppb C at Kaha to 2,037 ppb C at El Qualaly during fall, 1999. El Qualaly, the site chosen to represent mobile emissions, displayed the highest average NMHC concentrations of any site, by a factor of 2 or more. The highest mobile source contributions were estimated at this site. The major contributors to NMHC at all sites were mobile emissions, lead smelting, and compressed natural gas. PMID:18843549

  1. Warmer ambient temperatures depress liver function in a mammalian herbivore

    PubMed Central

    Kurnath, Patrice; Dearing, M. Denise

    2013-01-01

    Diet selection in mammalian herbivores is thought to be mainly influenced by intrinsic factors such as nutrients and plant secondary compounds, yet extrinsic factors like ambient temperature may also play a role. In particular, warmer ambient temperatures could enhance the toxicity of plant defence compounds through decreased liver metabolism of herbivores. Temperature-dependent toxicity has been documented in pharmacology and agriculture science but not in wild mammalian herbivores. Here, we investigated how ambient temperature affects liver metabolism in the desert woodrat, Neotoma lepida. Woodrats (n = 21) were acclimated for 30 days to two ambient temperatures (cool = 21°C, warm = 29°C). In a second experiment, the temperature exposure was reduced to 3.5 h. After temperature treatments, animals were given a hypnotic agent and clearance time of the agent was estimated from the duration of the hypnotic state. The average clearance time of the agent in the long acclimation experiment was 45% longer for animals acclimated to 29°C compared with 21°C. Similarly, after the short exposure experiment, woodrats at 29°C had clearance times 26% longer compared with 21°C. Our results are consistent with the hypothesis that liver function is reduced at warmer environmental temperatures and may provide a physiological mechanism through which climate change affects herbivorous mammals. PMID:24046878

  2. Low ambient temperature and neuroendocrine response to hypoglycemia in men.

    PubMed

    Jezová, D; Juránková, E; Kvetnanský, R; Kaciuba-Uscilko, H; Nazar, K; Vigas, M

    1995-12-01

    Nutritional factors, such as an excess or a deficiency of glucose, play an important role in neuroendocrine regulations. Hormonal and metabolic responses to hypoglycemia were examined in healthy non-obese volunteers under conditions of low ambient temperature. Hypoglycemia was induced by intravenous injection of insulin in two randomized trials performed at room temperature and at 4 degrees C. At room temperature, the typical neuroendocrine response to hypoglycemia was established. The increases of ACTH, beta-endorphin, growth hormone and cortisol in response to insulin hypoglycemia failed to be modified by low ambient temperature. Acute cold exposure significantly reduced epinephrine and totally inhibited prolactin response to insulin-induced hypoglycemia. In spite of significant changes in epinephrine response to hypoglycemia at low ambient temperature, no striking differences in plasma glucose levels compared to those measured at room temperature were observed. However, under conditions of low temperature the reestablishment of normoglycemia was delayed. No changes in free fatty acids were found under our experimental conditions. The presented data show that low ambient temperature exerts selective effects on some neuroendocrine and metabolic parameters. PMID:8653553

  3. 77 FR 12482 - Approval and Promulgation of Air Quality Implementation Plans; Indiana; Lead Ambient Air Quality...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-01

    ... November 12, 2008 (73 FR 66964) and codified at 40 CFR 50.16, ``National primary and secondary ambient air... the Federal Register (73 FR 66964) and codified at 40 CFR 50.16. The primary (health-based) Pb NAAQS... and Budget under Executive Order 12866 (58 FR 51735, October 4, 1993); Does not impose an...

  4. 77 FR 12524 - Approval and Promulgation of Air Quality Implementation Plans; Indiana; Lead Ambient Air Quality...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-01

    ... Ambient Air Quality Standards AGENCY: Environmental Protection Agency (EPA). ACTION: Proposed rule... Maintenance ] Section (AR-18J), U.S. Environmental Protection Agency, 77 West Jackson Boulevard, Chicago...-18J), U.S. Environmental Protection Agency, 77 West Jackson Boulevard, Chicago, Illinois 60604....

  5. Determination of methane in ambient air by multiplex gas chromatography

    NASA Technical Reports Server (NTRS)

    Valentin, J. R.; Carle, G. C.; Phillips, J. B.

    1985-01-01

    A multiplex gas chromatographic technique for the determination of methane in ambient air over extended periods is reported. A modest gas chromatograph which uses air as the carrier gas was modified by adding a silver oxide sample modulator for multiplex operation. The modulator selectively catalyzes the decomposition of methane in air. The resulting analytical system requires no consumables beyond power. A profile of the methane concentration in this laboratory was obtained for an 8-day period. During this period, methane concentration varied with an approximately daily period from a low of 1.53 + or - 0.60 ppm to a high of 4.63 + or - 0.59 ppm over the entire 8 days. Some of the measured concentrations are higher than those reported elsewhere indicating the presence of some local source or sources for methane. This work has demonstrated the utility of a relatively simple multiplex gas chromatograph for the analysis of environmental samples. The technique should be applicable to other trace components in air through use of other selective modulators.

  6. Dry deposition of polycyclic aromatic hydrocarbons in ambient air

    SciTech Connect

    Sheu, H.L.; Lee, W.J.; Su, C.C.; Chao, H.R.; Fan, Y.C.

    1996-12-01

    Dry deposition and air sampling were undertaken, simultaneously, in the ambient air of an urban site and a petrochemical-industry (PCI) plant by using several dry deposition plates and PS-1 samplers from January to May 1994 in southern Taiwan. The dry deposition plate with a smooth surface was always pointed into the wind. Twenty-one polycyclic aromatic hydrocarbons (PAHs) were analyzed by a gas chromatography/mass spectrometer (GC/MSD). The dry deposition flux of total-PAHs in urban and PCI sites averaged 166 and 211 {micro}g/m{sup 2}{center_dot}d, respectively. In general, the PAH dry deposition flux increased with increases in the PAH concentration in the ambient air. The PAH pattern of dry deposition flux in both urban and PCI sites were similar to the pattern measured by the filter of the PS-1 sampler and completely different from the PAH pattern in the gas phase. The higher molecular weight PAHs have higher dry deposition velocities. This is due to the fact that higher molecular weight PAHs primarily associated with the particle phase are deposited mostly by gravitational settling, while the gas phase PAHs were between 0.001 and 0.010 cm/s, only the lower molecular-weight PAHs--Nap and AcPy--had a significant fraction of dry deposition flux contributed by the gas phase. All the remaining higher molecular-weight PAHs had more than 94.5% of their dry deposition flux resulting from the particle phase. This is due to the fact that higher molecular weight PAHs have a greater fraction in the particle phase and the dry deposition velocities of particulates are much higher than those of the gas phase.

  7. 40 CFR 50.5 - National secondary ambient air quality standard for sulfur oxides (sulfur dioxide).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 2 2010-07-01 2010-07-01 false National secondary ambient air quality standard for sulfur oxides (sulfur dioxide). 50.5 Section 50.5 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS NATIONAL PRIMARY AND SECONDARY AMBIENT AIR QUALITY STANDARDS §...

  8. 40 CFR 50.15 - National primary and secondary ambient air quality standards for ozone.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... air quality standards for ozone. 50.15 Section 50.15 Protection of Environment ENVIRONMENTAL....15 National primary and secondary ambient air quality standards for ozone. (a) The level of the national 8-hour primary and secondary ambient air quality standards for ozone (O3) is 0.075 parts...

  9. 76 FR 60020 - Agency Information Collection Activities: Proposed Collection; Comment Request; Ambient Air...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-28

    ... institutions, industrial groups) use the ambient air quality data for many purposes. Some of the more prominent... FURTHER INFORMATION CONTACT: Laurie Trinca, Air Quality Assessment Division, Environmental Protection... pollution control agencies, and tribal entities which collect and report ambient air quality data for...

  10. 40 CFR Appendix C to Part 58 - Ambient Air Quality Monitoring Methodology

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Methodology C Appendix C to Part 58 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... Quality Monitoring Methodology 1.0 Purpose 2.0 SLAMS Ambient Air Monitoring Stations 3.0 NCore Ambient Air... appendix must be submitted to: Director, National Exposure Research Laboratory (MD-D205-03),...

  11. 40 CFR 50.16 - National primary and secondary ambient air quality standards for lead.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... air quality standards for lead. 50.16 Section 50.16 Protection of Environment ENVIRONMENTAL PROTECTION... National primary and secondary ambient air quality standards for lead. (a) The national primary and secondary ambient air quality standards for lead (Pb) and its compounds are 0.15 micrograms per cubic...

  12. 40 CFR 50.12 - National primary and secondary ambient air quality standards for lead.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... air quality standards for lead. 50.12 Section 50.12 Protection of Environment ENVIRONMENTAL PROTECTION... National primary and secondary ambient air quality standards for lead. (a) National primary and secondary ambient air quality standards for lead and its compounds, measured as elemental lead by a reference...

  13. 40 CFR 50.12 - National primary and secondary ambient air quality standards for lead.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... air quality standards for lead. 50.12 Section 50.12 Protection of Environment ENVIRONMENTAL PROTECTION... National primary and secondary ambient air quality standards for lead. (a) National primary and secondary ambient air quality standards for lead and its compounds, measured as elemental lead by a reference...

  14. 40 CFR 50.15 - National primary and secondary ambient air quality standards for ozone.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... air quality standards for ozone. 50.15 Section 50.15 Protection of Environment ENVIRONMENTAL....15 National primary and secondary ambient air quality standards for ozone. (a) The level of the national 8-hour primary and secondary ambient air quality standards for ozone (O3) is 0.075 parts...

  15. 40 CFR 50.15 - National primary and secondary ambient air quality standards for ozone.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... air quality standards for ozone. 50.15 Section 50.15 Protection of Environment ENVIRONMENTAL....15 National primary and secondary ambient air quality standards for ozone. (a) The level of the national 8-hour primary and secondary ambient air quality standards for ozone (O3) is 0.075 parts...

  16. 40 CFR 50.15 - National primary and secondary ambient air quality standards for ozone.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... air quality standards for ozone. 50.15 Section 50.15 Protection of Environment ENVIRONMENTAL....15 National primary and secondary ambient air quality standards for ozone. (a) The level of the national 8-hour primary and secondary ambient air quality standards for ozone (O3) is 0.075 parts...

  17. 40 CFR 50.15 - National primary and secondary ambient air quality standards for ozone.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... air quality standards for ozone. 50.15 Section 50.15 Protection of Environment ENVIRONMENTAL....15 National primary and secondary ambient air quality standards for ozone. (a) The level of the national 8-hour primary and secondary ambient air quality standards for ozone (O3) is 0.075 parts...

  18. 40 CFR 50.16 - National primary and secondary ambient air quality standards for lead.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... air quality standards for lead. 50.16 Section 50.16 Protection of Environment ENVIRONMENTAL PROTECTION... National primary and secondary ambient air quality standards for lead. (a) The national primary and secondary ambient air quality standards for lead (Pb) and its compounds are 0.15 micrograms per cubic...

  19. 40 CFR 50.12 - National primary and secondary ambient air quality standards for lead.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... air quality standards for lead. 50.12 Section 50.12 Protection of Environment ENVIRONMENTAL PROTECTION... National primary and secondary ambient air quality standards for lead. (a) National primary and secondary ambient air quality standards for lead and its compounds, measured as elemental lead by a reference...

  20. Methodology to apportion ambient air measurements to investigate potential effects on air quality near waste incinerators

    SciTech Connect

    Mukerjee, S.; Fox, D.L.; Stevens, R.K.; Shy, C.M.; Vescio, N.

    1993-01-01

    Ambient air samples at four sites located near two incinerators (a biomedical waste and a municipal incinerator) in the vicinity of Charlotte, North Carolina were acquired as part of a health effects study that is examining potential, short-term, lung dysfunctions associated with incinerator and other source emissions. Ambient monitoring was performed for one month intervals at a treatment and control community site for each of the two incinerator locations. Twelve-hour ambient samples were acquired by means of a Versatile Air Pollution Sampler (VAPS) which enabled sampling for fine (< 2.5 micrometers) and coarse (2.5 - 10 micrometers) particulate matter, acid-gases by diffusion sampling and fine carbon sampling on quartz filters. X-ray Fluorescence Spectroscopy (XRF) was used on the coarse and fine particulate filters to measure metals while Ion Chromatography (IC) analyzed acid gases. The Chemical Mass Balance Receptor Model (CMB) was then used on the average ambient data from each wind vector to apportion the contribution of ambient pollutants which were attributable to the sources of interest from a given wind direction.

  1. The TOMPs ambient air monitoring network - Continuous data on UK air quality for over 20 years.

    PubMed

    Graf, Carola; Katsoyiannis, Athanasios; Jones, Kevin C; Sweetman, Andrew J

    2016-10-01

    Long-term air monitoring datasets are needed for persistent organic pollutants (POPs) to assess the effectiveness of source abatement measures and the factors controlling ambient levels. The Toxic Organic Micro Pollutants (TOMPs) Network, which has operated since 1991, collects ambient air samples at six sites across England and Scotland, using high-volume active air samplers. The network provides long-term ambient air trend data for a range of POPs at both urban and rural locations. Data from the network provides the UK Government, regulators and researchers with valuable information on emission/source controls and on the effectiveness of international chemicals regulation such as the Stockholm Convention and UN/ECE Protocol on POPs. The target chemicals of TOMPs have been polychlorinated biphenyls (PCBs), polycyclic aromatic hydrocarbons (PAHs), polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), and, since 2010, polybrominated diphenyl ethers (PBDEs). The continuous monitoring of these compounds demonstrates the constant decline in UK air concentrations over the last two decades, with average clearance rates for PCDD/Fs in urban locations of 5.1 years and for PCBs across all sites 6.6 years. No significant declines in rural locations for PCDD/Fs have been observed. There is a strong observable link between the declining ambient air concentrations and the emission reductions estimated in the annually produced National Atmospheric Emission Inventory (NAEI) dataset. These findings clearly demonstrate the unique strengths of long-term consistent datasets for the evaluation of the success of chemical regulation and control. PMID:26843028

  2. The effect of ambient temperature on eigenfrequencies of a quasi-optical cylindrical dielectric resonator

    NASA Astrophysics Data System (ADS)

    Dormidontov, A. V.; Prokopenko, Yu. V.

    2013-04-01

    Effects of the temperature and refractive index of ambient air on the eigenfrequencies of a cylindrical dielectric resonator (CDR) featuring whispering-gallery modes have been studied. An attempt to separate the effects of two factors on the spectral and energy characteristics of a fluoroplastic CDR for a millimeter wavelength range has been made for the first time. It is established that the behavior of CDR eigenfrequencies and the stability of Q factors exhibit different characters when the temperature is varied from -60 to +60°C and the permittivity of air is changed from 1 to 1.0004. A CDR can be used as a sensor of ambient temperature accurate to within 10-4 K, provided that the resonance frequencies in the millimeter wavelength range are measured to within 1 kHz.

  3. Pollutant roses for daily averaged ambient air pollutant concentrations

    NASA Astrophysics Data System (ADS)

    Cosemans, Guido; Kretzschmar, Jan; Mensink, Clemens

    Pollutant roses are indispensable tools to identify unknown (fugitive) sources of heavy metals at industrial sites whose current impact exceeds the target values imposed for the year 2012 by the European Air Quality Daughter Directive 2004/207/EC. As most of the measured concentrations of heavy metals in ambient air are daily averaged values, a method to obtain high quality pollutant roses from such data is of practical interest for cost-effective air quality management. A computational scheme is presented to obtain, from daily averaged concentrations, 10° angular resolution pollutant roses, called PRP roses, that are in many aspects comparable to pollutant roses made with half-hourly concentrations. The computational scheme is a ridge regression, based on three building blocks: ordinary least squares regression; outlier handling by weighting based on expected values of the higher percentiles in a lognormal distribution; weighted averages whereby observed values, raised to a power m, and daily wind rose frequencies are used as weights. Distance measures are used to find the optimal value for m. The performance of the computational scheme is illustrated by comparing the pollutant roses, constructed with measured half-hourly SO 2 data for 10 monitoring sites in the Antwerp harbour, with the PRP roses made with the corresponding daily averaged SO 2 concentrations. A miniature dataset, made up of 7 daily concentrations and of half-hourly wind directions assigned to 4 wind sectors, is used to illustrate the formulas and their results.

  4. Volcanic gas emissions and their effect on ambient air character

    SciTech Connect

    Sutton, A.J.; Elias, T.

    1994-01-01

    This bibliography was assembled to service an agreement between Department of Energy and the USGS to provide a body of references and useful annotations for understanding background gas emissions from Kilauea volcano. The current East Rift Zone (ERZ) eruption of Kilauea releases as much as 500,000 metric tonnes of SO{sub 2} annually, along with lesser amounts of other chemically and radiatively active species including H{sub 2}S, HCl, and HF. Primary degassing locations on Kilauea are located in the summit caldera and along the middle ERZ. The effects of these emissions on ambient air character are a complex function of chemical reactivity, source geometry and effusivity, and local meteorology. Because of this complexity, we organized the bibliography into three main sections: (1) characterizing gases as they leave the edifice; (2) characterizing gases and chemical reaction products away from degassing sources; and (3) Hawaii Island meteorology.

  5. Incubation Temperature during Fetal Development Influences Morphophysiological Characteristics and Preferred Ambient Temperature of Chicken Hatchlings

    PubMed Central

    Morita, Viviane de Souza; de Almeida, Vitor Rosa; Matos, João Batista; Vicentini, Tamiris Iara; van den Brand, Henry; Boleli, Isabel Cristina

    2016-01-01

    Skin and feather characteristics, which play a critical role in body temperature maintenance, can be affected by incubation circumstances, such as incubation temperature. However, no study to date has assessed the influence of incubation temperature during the fetal stage on morphometric characteristics and vascular development of the skin, feather characteristics, and their relationship to hormone levels and preferred temperature in later life in chickens. Broiler breeder eggs were exposed to low (36°C), control (37.5°C), or high (39°C) temperatures (treatments LT, CK, and HT, respectively) from day 13 of incubation onward, because it is known that the endocrine axes are already established at this time. During this period, eggshell temperature of HT eggs (38.8±0.33°C) was higher than of LT (37.4±0.08°C) and CK eggs (37.8 ±0.15°C). The difference between eggshell and incubator air temperature diminished with the increasing incubation temperature, and was approximately zero for HT. HT hatchlings had higher surface temperature on the head, neck, and back, and thinner and more vascularized skin than did CK and LT hatchlings. No differences were found among treatments for body weight, total feather weight, number and length of barbs, barbule length, and plasma T4 concentration. LT hatchlings showed lower plasma T3 and GH, as well as lower T3/T4 ratio and decreased vascularity in the neck, back, and thigh skin compared to CK hatchlings. On the other hand, HT hatchlings had decreased skin thickness and increased vascularity, and preferred a higher ambient temperature compared to CK and HT hatchlings. In addition, for all treatments, surface temperature on the head was higher than of the other body regions. We conclude that changes in skin thickness and vascularity, as well as changes in thyroid and growth hormone levels, are the result of embryonic strategies to cope with higher or lower than normal incubation temperatures. Additionally exposure to increased

  6. Ambient temperature influences birds' decisions to eat toxic prey☆

    PubMed Central

    Chatelain, M.; Halpin, C.G.; Rowe, C.

    2013-01-01

    Aposematic prey warn predators of their toxicity using conspicuous signals. However, predators regularly include aposematic prey in their diets, particularly when they are in a poor energetic state and in need of nutrients. We investigated whether or not an environmental factor, ambient temperature, could change the energetic state of predators and lead to an increased intake of prey that they know to contain toxins. We found that European starlings, Sturnus vulgaris, increased their consumption of mealworm, Tenebrio molitor, prey containing quinine (a mild toxin) when the ambient temperature was reduced below their thermoneutral zone from 20 °C to 6 °C. The birds differed in their sensitivity to changes in ambient temperature, with heavier birds increasing the number of toxic prey they ate more rapidly with decreasing temperature compared to birds with lower body mass. This could have been the result of their requiring more nutrients at lower temperatures or being better able to detoxify quinine. Taken together, our results suggest that conspicuous coloration may be more costly at lower temperatures, and that aposematic prey may need to invest more in chemical defences as temperatures decline. Our study also provides novel insights into what factors affect birds' decisions to eat toxic prey, and demonstrates that selection pressures acting on prey defences can vary with changing temperature across days, seasons, climes, and potentially in response to climate change. PMID:24109148

  7. Ambient Air Pollution and Autism in Los Angeles County, California

    PubMed Central

    Becerra, Tracy Ann; Wilhelm, Michelle; Olsen, Jørn; Cockburn, Myles

    2012-01-01

    Background: The prevalence of autistic disorder (AD), a serious developmental condition, has risen dramatically over the past two decades, but high-quality population-based research addressing etiology is limited. Objectives: We studied the influence of exposures to traffic-related air pollution during pregnancy on the development of autism using data from air monitoring stations and a land use regression (LUR) model to estimate exposures. Methods: Children of mothers who gave birth in Los Angeles, California, who were diagnosed with a primary AD diagnosis at 3–5 years of age during 1998–2009 were identified through the California Department of Developmental Services and linked to 1995–2006 California birth certificates. For 7,603 children with autism and 10 controls per case matched by sex, birth year, and minimum gestational age, birth addresses were mapped and linked to the nearest air monitoring station and a LUR model. We used conditional logistic regression, adjusting for maternal and perinatal characteristics including indicators of SES. Results: Per interquartile range (IQR) increase, we estimated a 12–15% relative increase in odds of autism for ozone [odds ratio (OR) = 1.12, 95% CI: 1.06, 1.19; per 11.54-ppb increase] and particulate matter ≤ 2.5 µm (OR = 1.15; 95% CI: 1.06, 1.24; per 4.68-μg/m3 increase) when mutually adjusting for both pollutants. Furthermore, we estimated 3–9% relative increases in odds per IQR increase for LUR-based nitric oxide and nitrogen dioxide exposure estimates. LUR-based associations were strongest for children of mothers with less than a high school education. Conclusion: Measured and estimated exposures from ambient pollutant monitors and LUR model suggest associations between autism and prenatal air pollution exposure, mostly related to traffic sources. PMID:23249813

  8. Relationship between prostate-specific antigen levels and ambient temperature

    NASA Astrophysics Data System (ADS)

    Ohwaki, Kazuhiro; Endo, Fumiyasu; Hattori, Kazunori; Muraishi, Osamu

    2014-07-01

    We examined the association between prostate-specific antigen (PSA) and daily mean ambient temperature on the day of the test in healthy men who had three annual checkups. We investigated 9,694 men who visited a hospital for routine health checkups in 2007, 2008, and 2009. Although the means and medians of ambient temperature for the three years were similar, the mode in 2008 (15.8 °C) was very different from those in 2007 and 2009 (22.4 °C and 23.2 °C). After controlling for age, body mass index, and hematocrit, a multiple regression analysis revealed a U-shaped relationship between ambient temperature and PSA in 2007 and 2009 ( P < 0.001 and P = 0.004, respectively), but not in 2008 ( P = 0.779). In 2007, PSA was 13.5 % higher at 5 °C and 10.0 % higher at 30 °C than that at 18.4 °C (nadir). In 2009, PSA was 7.3 % higher at 5 °C and 6.8 % at 30 °C compared with the level at 17.7 °C (nadir). In logistic regression analysis, a U-shaped relationship was found for the prevalence of a higher PSA (> 2.5 ng/mL) by ambient temperature, with the lowest likelihood of having a high PSA at 17.8 °C in 2007 ( P = 0.038) and 15.5 °C in 2009 ( P = 0.033). When tested at 30 °C, there was a 57 % excess risk of having a high PSA in 2007 and a 61 % higher risk in 2009 compared with those at each nadir temperature. We found a U-shaped relationship between PSA and ambient temperature with the lowest level of PSA at 15-20 °C.

  9. Relationship between prostate-specific antigen levels and ambient temperature

    NASA Astrophysics Data System (ADS)

    Ohwaki, Kazuhiro; Endo, Fumiyasu; Hattori, Kazunori; Muraishi, Osamu

    2013-05-01

    We examined the association between prostate-specific antigen (PSA) and daily mean ambient temperature on the day of the test in healthy men who had three annual checkups. We investigated 9,694 men who visited a hospital for routine health checkups in 2007, 2008, and 2009. Although the means and medians of ambient temperature for the three years were similar, the mode in 2008 (15.8 °C) was very different from those in 2007 and 2009 (22.4 °C and 23.2 °C). After controlling for age, body mass index, and hematocrit, a multiple regression analysis revealed a U-shaped relationship between ambient temperature and PSA in 2007 and 2009 (P < 0.001 and P = 0.004, respectively), but not in 2008 (P = 0.779). In 2007, PSA was 13.5 % higher at 5 °C and 10.0 % higher at 30 °C than that at 18.4 °C (nadir). In 2009, PSA was 7.3 % higher at 5 °C and 6.8 % at 30 °C compared with the level at 17.7 °C (nadir). In logistic regression analysis, a U-shaped relationship was found for the prevalence of a higher PSA (> 2.5 ng/mL) by ambient temperature, with the lowest likelihood of having a high PSA at 17.8 °C in 2007 (P = 0.038) and 15.5 °C in 2009 (P = 0.033). When tested at 30 °C, there was a 57 % excess risk of having a high PSA in 2007 and a 61 % higher risk in 2009 compared with those at each nadir temperature. We found a U-shaped relationship between PSA and ambient temperature with the lowest level of PSA at 15-20 °C.

  10. Joint Effects of Ambient Air Pollutants on Pediatric AsthmaEmergency Department Visits in Atlanta, 1998–2004

    EPA Science Inventory

    Background: Because ambient air pollution exposure occurs in the form of mixtures, consideration of joint effects of multiple pollutants may advance our understanding of air pollution health effects. Methods: We assessed the joint effect of selected ambient air pollutant com...

  11. Joint Effects of Ambient Air Pollutants on Pediatric Asthma Emergency Department Visits in Atlanta, 1998–2004

    EPA Science Inventory

    Background: Because ambient air pollution exposure occurs in the form of mixtures, consideration of joint effects of multiple pollutants may advance our understanding of air pollution health effects. Methods: We assessed the joint effect of selected ambient air pollutant com...

  12. Ambient air pollution, weather changes, and outpatient visits for allergic conjunctivitis: A retrospective registry study

    PubMed Central

    Hong, Jiaxu; Zhong, Taoling; Li, Huili; Xu, Jianming; Ye, Xiaofang; Mu, Zhe; Lu, Yi; Mashaghi, Alireza; Zhou, Ying; Tan, Mengxi; Li, Qiyuan; Sun, Xinghuai; Liu, Zuguo; Xu, Jianjiang

    2016-01-01

    Allergic conjunctivitis is a common problem that significantly impairs patients’ quality of life. Whether air pollution serves as a risk factor for the development of allergic conjunctivitis remains elusive. In this paper, we assess the relationship between air pollutants and weather conditions with outpatient visits for allergic conjunctivitis. By using a time-series analysis based on the largest dataset ever assembled to date, we found that the number of outpatient visits for allergic conjunctivitis was significantly correlated with the levels of NO2, O3, and temperature, while its association with humidity was statistically marginal. No associations between PM10, PM2.5, SO2, or wind velocity and outpatient visits were seen. Subgroup analyses showed that sex seemed to modify the effects of humidity on outpatient visits for allergic conjunctivitis, but not for NO2, O3, or temperature. People younger than 40 were found to be susceptible to changes of all four parameters, while those older than 40 were only consistently affected by NO2 levels. Our findings revealed that higher levels of ambient NO2, O3, and temperature increase the chances of outpatient visits for allergic conjunctivitis. Ambient air pollution and weather changes may contribute to the worsening of allergic conjunctivitis. PMID:27033635

  13. Ambient air pollution, weather changes, and outpatient visits for allergic conjunctivitis: A retrospective registry study.

    PubMed

    Hong, Jiaxu; Zhong, Taoling; Li, Huili; Xu, Jianming; Ye, Xiaofang; Mu, Zhe; Lu, Yi; Mashaghi, Alireza; Zhou, Ying; Tan, Mengxi; Li, Qiyuan; Sun, Xinghuai; Liu, Zuguo; Xu, Jianjiang

    2016-01-01

    Allergic conjunctivitis is a common problem that significantly impairs patients' quality of life. Whether air pollution serves as a risk factor for the development of allergic conjunctivitis remains elusive. In this paper, we assess the relationship between air pollutants and weather conditions with outpatient visits for allergic conjunctivitis. By using a time-series analysis based on the largest dataset ever assembled to date, we found that the number of outpatient visits for allergic conjunctivitis was significantly correlated with the levels of NO2, O3, and temperature, while its association with humidity was statistically marginal. No associations between PM10, PM2.5, SO2, or wind velocity and outpatient visits were seen. Subgroup analyses showed that sex seemed to modify the effects of humidity on outpatient visits for allergic conjunctivitis, but not for NO2, O3, or temperature. People younger than 40 were found to be susceptible to changes of all four parameters, while those older than 40 were only consistently affected by NO2 levels. Our findings revealed that higher levels of ambient NO2, O3, and temperature increase the chances of outpatient visits for allergic conjunctivitis. Ambient air pollution and weather changes may contribute to the worsening of allergic conjunctivitis. PMID:27033635

  14. Ambient air pollution, weather changes, and outpatient visits for allergic conjunctivitis: A retrospective registry study

    NASA Astrophysics Data System (ADS)

    Hong, Jiaxu; Zhong, Taoling; Li, Huili; Xu, Jianming; Ye, Xiaofang; Mu, Zhe; Lu, Yi; Mashaghi, Alireza; Zhou, Ying; Tan, Mengxi; Li, Qiyuan; Sun, Xinghuai; Liu, Zuguo; Xu, Jianjiang

    2016-04-01

    Allergic conjunctivitis is a common problem that significantly impairs patients’ quality of life. Whether air pollution serves as a risk factor for the development of allergic conjunctivitis remains elusive. In this paper, we assess the relationship between air pollutants and weather conditions with outpatient visits for allergic conjunctivitis. By using a time-series analysis based on the largest dataset ever assembled to date, we found that the number of outpatient visits for allergic conjunctivitis was significantly correlated with the levels of NO2, O3, and temperature, while its association with humidity was statistically marginal. No associations between PM10, PM2.5, SO2, or wind velocity and outpatient visits were seen. Subgroup analyses showed that sex seemed to modify the effects of humidity on outpatient visits for allergic conjunctivitis, but not for NO2, O3, or temperature. People younger than 40 were found to be susceptible to changes of all four parameters, while those older than 40 were only consistently affected by NO2 levels. Our findings revealed that higher levels of ambient NO2, O3, and temperature increase the chances of outpatient visits for allergic conjunctivitis. Ambient air pollution and weather changes may contribute to the worsening of allergic conjunctivitis.

  15. A reversible long-life lithium-air battery in ambient air.

    PubMed

    Zhang, Tao; Zhou, Haoshen

    2013-01-01

    Electrolyte degradation, Li dendrite formation and parasitic reactions with H₂O and CO₂ are all directly correlated to reversibility and cycleability of Li-air batteries when operated in ambient air. Here we replace easily decomposable liquid electrolytes with a solid Li-ion conductor, which acts as both a catholyte and a Li protector. Meanwhile, the conventional solid air cathodes are replaced with a gel cathode, which contacts directly with the solid catholyte to form a closed and sustainable gel/solid interface. The proposed Li-air cell has sustained repeated cycling in ambient air for 100 cycles (~78 days), with discharge capacity of 2,000 mAh g(-1). The recharging is based largely on the reversible reactions of Li₂CO₃ product, originating from the initial discharge product of Li₂O₂ instead of electrolyte degradation. Our results demonstrate that a reversible long-life Li-air battery is attainable by coordinated approaches towards the focal issues of electrolytes and Li metal. PMID:23652005

  16. BOREAS TGB-7 Ambient Air Herbicide and Organochlorine Concentration Data

    NASA Technical Reports Server (NTRS)

    Waite, Don; Hall, Forrest G. (Editor); Conrad, Sara K. (Editor)

    2000-01-01

    The BOReal Ecosystem-Atmosphere Study Trace Gas Biogeochemistry (BOREAS TGB)-7 team measured the concentration and flux of several agricultural pesticides in air, rainwater, and dry deposition samples in order to determine the associated yearly deposition rates. This data set contains information on the ambient air concentration of seven herbicides [2,4- dichlorophenoxyacidic_acid (2,4-D), bromoxynil, dicamb, 2-methyl-4-chlorophenoxyacetic acid (MCPA), triallate, trifluralin, and diclop-methyl] known to appear in the atmosphere of the Canadian prairies. Also, the concentration of three herbicides (atrazine, alachlor, and metolachlor), two groups of insecticides (lindane and breakdown products and dichloro-diphenyl-trichloroethane (DDT) and breakdown products), and several polychlorinated biphenyls commonly used in the central United States was measured. All of these chemicals are reported, in the literature, to be transported in the atmosphere. Many have been reported to occur in boreal and arctic food chains. The sampling was carried out from 16-Jun to 13-Aug-1993 and 04-May to 20-Jul-1994 at the BOREAS site in the Prince Albert National Park (Waskesiu). The data are stored in tabular ASCII files. The data files are available on a CD-ROM (see document number 20010000884).

  17. Ambient air pollution by aromatic hydrocarbons in Algiers

    NASA Astrophysics Data System (ADS)

    Kerbachi, Rabah; Boughedaoui, Ménouèr; Bounoua, Lahouari; Keddam, Malika

    The analysis of the C 6-C 16 semi-volatile organic compounds reveals the presence of numerous aromatic hydrocarbons in the ambient air of Algiers. Three representative sites were chosen for sample collection at roadside, urban background and semi-rural areas. The following major monocyclic aromatic hydrocarbons were found: benzene, toluene, ethylbenzene, ( m, p)- and o-xylene, also referred to as BTEX. Near the road traffic, benzene and toluene mean concentrations were 27 and 39 μg m -3, respectively, with benzene concentration values higher than 40 μg m -3 often observed. At the urban site, the benzene concentration often exceeds the European regulatory limit of 10 μg m -3 while the compositional ratios of toluene to benzene and ( m- p) xylene to ethylbenzene are within the typical range of values observed in urban atmospheres worldwide. The seasonal variation indicates a decrease in concentration during summer of the reactive o-xylene compound. It is suggested that Algiers' source of high-level air pollution by aromatic hydrocarbons is related to car traffic emissions.

  18. 40 CFR 50.11 - National primary and secondary ambient air quality standards for oxides of nitrogen (with...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 2 2010-07-01 2010-07-01 false National primary and secondary ambient... PRIMARY AND SECONDARY AMBIENT AIR QUALITY STANDARDS § 50.11 National primary and secondary ambient air... national primary annual ambient air quality standard for oxides of nitrogen is 53 parts per billion...

  19. Ambient air pollution particles and the acute exacerbation of chronic obstructive pulmonary disease

    EPA Science Inventory

    Investigation has repeatedly demonstrated an association between exposure to ambient air pollution particles and numerous indices of human morbidity and mortality. Individuals with chronic obstructive pulmonary disease (COPD) are among those with an increased sensitivity to air p...

  20. HIGH VOLUME INJECTION FOR GCMS ANALYSIS OF PARTICULATE ORGANIC SPECIES IN AMBIENT AIR

    EPA Science Inventory

    Detection of organic species in ambient particulate matter typically requires large air sample volumes, frequently achieved by grouping samples into monthly composites. Decreasing the volume of air sample required would allow shorter collection times and more convenient sample c...

  1. 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...

  2. Low Ambient Temperature and Intracerebral Hemorrhage: The INTERACT2 Study

    PubMed Central

    Zheng, Danni; Arima, Hisatomi; Sato, Shoichiro; Gasparrini, Antonio; Heeley, Emma; Delcourt, Candice; Lo, Serigne; Huang, Yining; Wang, Jiguang; Stapf, Christian; Robinson, Thompson; Lavados, Pablo; Chalmers, John; Anderson, Craig S.

    2016-01-01

    Background Rates of acute intracerebral hemorrhage (ICH) increase in winter months but the magnitude of risk is unknown. We aimed to quantify the association of ambient temperature with the risk of ICH in the Intensive Blood Pressure Reduction in Acute Cerebral Haemorrhage Trial (INTERACT2) participants on an hourly timescale. Methods INTERACT2 was an international, open, blinded endpoint, randomized controlled trial of patients with spontaneous ICH (<6h of onset) and elevated systolic blood pressure (SBP, 150–220 mmHg) assigned to intensive (target SBP <140 mmHg) or guideline-recommended (SBP <180 mmHg) BP treatment. We linked individual level hourly temperature to baseline data of 1997 participants, and performed case-crossover analyses using a distributed lag non-linear model with 24h lag period to assess the association of ambient temperature and risk of ICH. Results were presented as overall cumulative odds ratios (ORs) and 95% CI. Results Low ambient temperature (≤10°C) was associated with increased risks of ICH: overall cumulative OR was 1.37 (0.99–1.91) for 10°C, 1.92 (1.31–2.81) for 0°C, 3.13 (1.89–5.19) for -10°C, and 5.76 (2.30–14.42) for -20°C, as compared with a reference temperature of 20°C.There was no clear relation of low temperature beyond three hours after exposure. Results were consistent in sensitivity analyses. Conclusions Exposure to low ambient temperature within several hours increases the risk of ICH. Trial Registration ClinicalTrials.gov NCT00716079 PMID:26859491

  3. Quantification Method for Electrolytic Sensors in Long-Term Monitoring of Ambient Air Quality.

    PubMed

    Masson, Nicholas; Piedrahita, Ricardo; Hannigan, Michael

    2015-01-01

    Traditional air quality monitoring relies on point measurements from a small number of high-end devices. The recent growth in low-cost air sensing technology stands to revolutionize the way in which air quality data are collected and utilized. While several technologies have emerged in the field of low-cost monitoring, all suffer from similar challenges in data quality. One technology that shows particular promise is that of electrolytic (also known as amperometric) sensors. These sensors produce an electric current in response to target pollutants. This work addresses the development of practical models for understanding and quantifying the signal response of electrolytic sensors. Such models compensate for confounding effects on the sensor response, such as ambient temperature and humidity, and address other issues that affect the usability of low-cost sensors, such as sensor drift and inter-sensor variability. PMID:26516860

  4. Quantification Method for Electrolytic Sensors in Long-Term Monitoring of Ambient Air Quality

    PubMed Central

    Masson, Nicholas; Piedrahita, Ricardo; Hannigan, Michael

    2015-01-01

    Traditional air quality monitoring relies on point measurements from a small number of high-end devices. The recent growth in low-cost air sensing technology stands to revolutionize the way in which air quality data are collected and utilized. While several technologies have emerged in the field of low-cost monitoring, all suffer from similar challenges in data quality. One technology that shows particular promise is that of electrolytic (also known as amperometric) sensors. These sensors produce an electric current in response to target pollutants. This work addresses the development of practical models for understanding and quantifying the signal response of electrolytic sensors. Such models compensate for confounding effects on the sensor response, such as ambient temperature and humidity, and address other issues that affect the usability of low-cost sensors, such as sensor drift and inter-sensor variability. PMID:26516860

  5. Growth of β-Ga2O3 single crystals using vertical Bridgman method in ambient air

    NASA Astrophysics Data System (ADS)

    Hoshikawa, K.; Ohba, E.; Kobayashi, T.; Yanagisawa, J.; Miyagawa, C.; Nakamura, Y.

    2016-08-01

    A new approach to β-Ga2O3 single crystal growth was studied, using the vertical Bridgman (VB) method in ambient air, while measuring the β-Ga2O3 melting temperature and investigating the effects of crucible composition and shape. β-Ga2O3 single crystals 25 mm in diameter were grown in platinum-rhodium alloy crucibles in ambient air, with no adhesion of the crystals to the crucible wall. Single crystal growth without a crystal seed was realized by (100) faceted growth with a growth direction perpendicular to the (100) faceted plane.

  6. Temperature Trapping: Energy-Free Maintenance of Constant Temperatures as Ambient Temperature Gradients Change.

    PubMed

    Shen, Xiangying; Li, Ying; Jiang, Chaoran; Huang, Jiping

    2016-07-29

    It is crucial to maintain constant temperatures in an energy-efficient way. Here we establish a temperature-trapping theory for asymmetric phase-transition materials with thermally responsive thermal conductivities. Then we theoretically introduce and experimentally demonstrate a concept of an energy-free thermostat within ambient temperature gradients. The thermostat is capable of self-maintaining a desired constant temperature without the need of consuming energy even though the environmental temperature gradient varies in a large range. As a model application of the concept, we design and show a different type of thermal cloak that has a constant temperature inside its central region in spite of the changing ambient temperature gradient, which is in sharp contrast to all the existing thermal cloaks. This work has relevance to energy-saving heat preservation, and it provides guidance both for manipulating heat flow without energy consumption and for designing new metamaterials with temperature-responsive or field-responsive parameters in many disciplines such as thermotics, optics, electromagnetics, acoustics, mechanics, electrics, and magnetism. PMID:27517778

  7. Temperature Trapping: Energy-Free Maintenance of Constant Temperatures as Ambient Temperature Gradients Change

    NASA Astrophysics Data System (ADS)

    Shen, Xiangying; Li, Ying; Jiang, Chaoran; Huang, Jiping

    2016-07-01

    It is crucial to maintain constant temperatures in an energy-efficient way. Here we establish a temperature-trapping theory for asymmetric phase-transition materials with thermally responsive thermal conductivities. Then we theoretically introduce and experimentally demonstrate a concept of an energy-free thermostat within ambient temperature gradients. The thermostat is capable of self-maintaining a desired constant temperature without the need of consuming energy even though the environmental temperature gradient varies in a large range. As a model application of the concept, we design and show a different type of thermal cloak that has a constant temperature inside its central region in spite of the changing ambient temperature gradient, which is in sharp contrast to all the existing thermal cloaks. This work has relevance to energy-saving heat preservation, and it provides guidance both for manipulating heat flow without energy consumption and for designing new metamaterials with temperature-responsive or field-responsive parameters in many disciplines such as thermotics, optics, electromagnetics, acoustics, mechanics, electrics, and magnetism.

  8. Ambient temperature and activation of implantable cardioverter defibrillators

    NASA Astrophysics Data System (ADS)

    McGuinn, L.; Hajat, S.; Wilkinson, P.; Armstrong, B.; Anderson, H. R.; Monk, V.; Harrison, R.

    2013-09-01

    The degree to which weather influences the occurrence of serious cardiac arrhythmias is not fully understood. To investigate, we studied the timing of activation of implanted cardiac defibrillators (ICDs) in relation to daily outdoor temperatures using a fixed stratum case-crossover approach. All patients attending ICD clinics in London between 1995 and 2003 were recruited onto the study. Temperature exposure for each ICD patient was determined by linking each patient's postcode of residence to their nearest temperature monitoring station in London and the South of England. There were 5,038 activations during the study period. Graphical inspection of ICD activation against temperature suggested increased risk at lower but not higher temperatures. For every 1 °C decrease in ambient temperature, risk of ventricular arrhythmias up to 7 days later increased by 1.2 % (95 % CI -0.6 %, 2.9 %). In threshold models, risk of ventricular arrhythmias increased by 11.2 % (0.5 %, 23.1 %) for every 1° decrease in temperature below 2 °C. Patients over the age of 65 exhibited the highest risk. This large study suggests an inverse relationship between ambient outdoor temperature and risk of ventricular arrhythmias. The highest risk was found for patients over the age of 65. This provides evidence about a mechanism for some cases of low-temperature cardiac death, and suggests a possible strategy for reducing risk among selected cardiac patients by encouraging behaviour modification to minimise cold exposure.

  9. 75 FR 2935 - Extension of Deadline for Promulgating Designations for the 2008 Ozone National Ambient Air...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-01-19

    ..., 2008, EPA promulgated revised 8-hour primary and secondary ozone NAAQS (73 FR 16436; March 27, 2008... promulgation of a new or revised national ambient air quality standard for any pollutant under section 109, the... a national ambient air quality standard, the Administrator shall promulgate the designations of...

  10. PROCEDURES FOR EVALUATING OPERATIONS OF AMBIENT AIR MONITORING NETWORKS - A MANUAL

    EPA Science Inventory

    This manual is designed to evaluate the efficiency of ambient air monitoring networks whose primary objective is to document compliance with or progress toward attaining ambient air quality standards. The manual provides methods to evaluate the efficiency of each of six operation...

  11. Test/QA Plan (TQAP) for Verification of Semi-Continuous Ambient Air Monitoring Systems

    EPA Science Inventory

    The purpose of the semi-continuous ambient air monitoring technology (or MARGA) test and quality assurance plan is to specify procedures for a verification test applicable to commercial semi-continuous ambient air monitoring technologies. The purpose of the verification test is ...

  12. 40 CFR Appendix C to Part 58 - Ambient Air Quality Monitoring Methodology

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Micropolitan Statistical Area site. If the candidate ARM for a network is already approved for purposes of this... Quality Monitoring Methodology 1.0 Purpose 2.0 SLAMS Ambient Air Monitoring Stations 3.0 NCore Ambient Air... ARM for purposes of section 2.1 of this appendix at a particular site or network of sites under...

  13. 40 CFR 50.17 - National primary ambient air quality standards for sulfur oxides (sulfur dioxide).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... standards for sulfur oxides (sulfur dioxide). 50.17 Section 50.17 Protection of Environment ENVIRONMENTAL....17 National primary ambient air quality standards for sulfur oxides (sulfur dioxide). (a) The level of the national primary 1-hour annual ambient air quality standard for oxides of sulfur is 75...

  14. 40 CFR 50.5 - National secondary ambient air quality standard for sulfur oxides (sulfur dioxide).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... standard for sulfur oxides (sulfur dioxide). 50.5 Section 50.5 Protection of Environment ENVIRONMENTAL....5 National secondary ambient air quality standard for sulfur oxides (sulfur dioxide). (a) The level... than 0.05 ppm shall be rounded up). (b) Sulfur oxides shall be measured in the ambient air as...

  15. 40 CFR 50.4 - National primary ambient air quality standards for sulfur oxides (sulfur dioxide).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... standards for sulfur oxides (sulfur dioxide). 50.4 Section 50.4 Protection of Environment ENVIRONMENTAL....4 National primary ambient air quality standards for sulfur oxides (sulfur dioxide). (a) The level...). (c) Sulfur oxides shall be measured in the ambient air as sulfur dioxide by the reference...

  16. 40 CFR 50.17 - National primary ambient air quality standards for sulfur oxides (sulfur dioxide).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... standards for sulfur oxides (sulfur dioxide). 50.17 Section 50.17 Protection of Environment ENVIRONMENTAL....17 National primary ambient air quality standards for sulfur oxides (sulfur dioxide). (a) The level of the national primary 1-hour annual ambient air quality standard for oxides of sulfur is 75...

  17. 40 CFR 50.17 - National primary ambient air quality standards for sulfur oxides (sulfur dioxide).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... standards for sulfur oxides (sulfur dioxide). 50.17 Section 50.17 Protection of Environment ENVIRONMENTAL....17 National primary ambient air quality standards for sulfur oxides (sulfur dioxide). (a) The level of the national primary 1-hour annual ambient air quality standard for oxides of sulfur is 75...

  18. 40 CFR 50.17 - National primary ambient air quality standards for sulfur oxides (sulfur dioxide).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... standards for sulfur oxides (sulfur dioxide). 50.17 Section 50.17 Protection of Environment ENVIRONMENTAL....17 National primary ambient air quality standards for sulfur oxides (sulfur dioxide). (a) The level of the national primary 1-hour annual ambient air quality standard for oxides of sulfur is 75...

  19. 40 CFR 50.4 - National primary ambient air quality standards for sulfur oxides (sulfur dioxide).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... standards for sulfur oxides (sulfur dioxide). 50.4 Section 50.4 Protection of Environment ENVIRONMENTAL....4 National primary ambient air quality standards for sulfur oxides (sulfur dioxide). (a) The level...). (c) Sulfur oxides shall be measured in the ambient air as sulfur dioxide by the reference...

  20. 40 CFR 50.5 - National secondary ambient air quality standard for sulfur oxides (sulfur dioxide).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... standard for sulfur oxides (sulfur dioxide). 50.5 Section 50.5 Protection of Environment ENVIRONMENTAL....5 National secondary ambient air quality standard for sulfur oxides (sulfur dioxide). (a) The level... than 0.05 ppm shall be rounded up). (b) Sulfur oxides shall be measured in the ambient air as...

  1. 40 CFR 50.5 - National secondary ambient air quality standard for sulfur oxides (sulfur dioxide).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... standard for sulfur oxides (sulfur dioxide). 50.5 Section 50.5 Protection of Environment ENVIRONMENTAL....5 National secondary ambient air quality standard for sulfur oxides (sulfur dioxide). (a) The level... than 0.05 ppm shall be rounded up). (b) Sulfur oxides shall be measured in the ambient air as...

  2. 40 CFR 50.4 - National primary ambient air quality standards for sulfur oxides (sulfur dioxide).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... standards for sulfur oxides (sulfur dioxide). 50.4 Section 50.4 Protection of Environment ENVIRONMENTAL....4 National primary ambient air quality standards for sulfur oxides (sulfur dioxide). (a) The level...). (c) Sulfur oxides shall be measured in the ambient air as sulfur dioxide by the reference...

  3. 40 CFR 50.17 - National primary ambient air quality standards for sulfur oxides (sulfur dioxide).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... standards for sulfur oxides (sulfur dioxide). 50.17 Section 50.17 Protection of Environment ENVIRONMENTAL....17 National primary ambient air quality standards for sulfur oxides (sulfur dioxide). (a) The level of the national primary 1-hour annual ambient air quality standard for oxides of sulfur is 75...

  4. 40 CFR 50.5 - National secondary ambient air quality standard for sulfur oxides (sulfur dioxide).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... standard for sulfur oxides (sulfur dioxide). 50.5 Section 50.5 Protection of Environment ENVIRONMENTAL....5 National secondary ambient air quality standard for sulfur oxides (sulfur dioxide). (a) The level... than 0.05 ppm shall be rounded up). (b) Sulfur oxides shall be measured in the ambient air as...

  5. 40 CFR 50.4 - National primary ambient air quality standards for sulfur oxides (sulfur dioxide).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... standards for sulfur oxides (sulfur dioxide). 50.4 Section 50.4 Protection of Environment ENVIRONMENTAL....4 National primary ambient air quality standards for sulfur oxides (sulfur dioxide). (a) The level...). (c) Sulfur oxides shall be measured in the ambient air as sulfur dioxide by the reference...

  6. 40 CFR 50.18 - National primary ambient air quality standards for PM2.5.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... standards for PM2.5. 50.18 Section 50.18 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... primary ambient air quality standards for PM2.5. (a) The national primary ambient air quality standards for PM2.5 are 12.0 micrograms per cubic meter (µg/m3) annual arithmetic mean concentration and 35...

  7. 40 CFR 50.18 - National primary ambient air quality standards for PM2.5.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... standards for PM2.5. 50.18 Section 50.18 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... primary ambient air quality standards for PM2.5. (a) The national primary ambient air quality standards for PM2.5 are 12.0 micrograms per cubic meter (µg/m3) annual arithmetic mean concentration and 35...

  8. Amine-Oxide Hybrid Materials for CO2 Capture from Ambient Air.

    PubMed

    Didas, Stephanie A; Choi, Sunho; Chaikittisilp, Watcharop; Jones, Christopher W

    2015-10-20

    Oxide supports functionalized with amine moieties have been used for decades as catalysts and chromatographic media. Owing to the recognized impact of atmospheric CO2 on global climate change, the study of the use of amine-oxide hybrid materials as CO2 sorbents has exploded in the past decade. While the majority of the work has concerned separation of CO2 from dilute mixtures such as flue gas from coal-fired power plants, it has been recognized by us and others that such supported amine materials are also perhaps uniquely suited to extract CO2 from ultradilute gas mixtures, such as ambient air. As unique, low temperature chemisorbents, they can operate under ambient conditions, spontaneously extracting CO2 from ambient air, while being regenerated under mild conditions using heat or the combination of heat and vacuum. This Account describes the evolution of our activities on the design of amine-functionalized silica materials for catalysis to the design, characterization, and utilization of these materials in CO2 separations. New materials developed in our laboratory, such as hyperbranched aminosilica materials, and previously known amine-oxide hybrid compositions, have been extensively studied for CO2 extraction from simulated ambient air (400 ppm of CO2). The role of amine type and structure (molecular, polymeric), support type and structure, the stability of the various compositions under simulated operating conditions, and the nature of the adsorbed CO2 have been investigated in detail. The requirements for an effective, practical air capture process have been outlined and the ability of amine-oxide hybrid materials to meet these needs has been discussed. Ultimately, the practicality of such a "direct air capture" process is predicated not only on the physicochemical properties of the sorbent, but also how the sorbent operates in a practical process that offers a scalable gas-solid contacting strategy. In this regard, the utility of low pressure drop monolith

  9. Surface Temperature variability from AIRS.

    NASA Astrophysics Data System (ADS)

    Ruzmaikin, A.; Dang, V. T.; Aumann, H. H.

    2015-12-01

    To address the existence and possible causes of the climate hiatus in the Earth's global temperature we investigate the trends and variability in the surface temperature using retrievals obtained from the measurements by the Atmospheric Infrared Sounder (AIRS) and its companion instrument, the Advanced Microwave Sounding Unit (AMSU), onboard of Aqua spacecraft in 2002-2014for the day and night conditions. The data used are L3 monthly means on a 1x1degree spatial grid. We separate the land and ocean temperatures, as well as temperatures in Artic, Antarctic and desert regions. We compare the satellite data with the new surface data produced by Karl et al. (2015) who denies the reality of the climate hiatus. The difference in the regional trends can help to explain why the global surface temperature remains almost unchanged but the frequency of occurrence of the extreme events increases under rising anthropogenic forcing. The day-night difference is an indicator of the anthropogenic trend. This work was supported by the Jet Propulsion Laboratory of the California Institute of Technology, under a contract with the National Aeronautics and Space Administration.

  10. Ambient air cooling arrangement having a pre-swirler for gas turbine engine blade cooling

    DOEpatents

    Lee, Ching-Pang; Tham, Kok-Mun; Schroeder, Eric; Meeroff, Jamie; Miller, Jr., Samuel R; Marra, John J

    2015-01-06

    A gas turbine engine including: an ambient-air cooling circuit (10) having a cooling channel (26) disposed in a turbine blade (22) and in fluid communication with a source (12) of ambient air: and an pre-swirler (18), the pre-swirler having: an inner shroud (38); an outer shroud (56); and a plurality of guide vanes (42), each spanning from the inner shroud to the outer shroud. Circumferentially adjacent guide vanes (46, 48) define respective nozzles (44) there between. Forces created by a rotation of the turbine blade motivate ambient air through the cooling circuit. The pre-swirler is configured to impart swirl to ambient air drawn through the nozzles and to direct the swirled ambient air toward a base of the turbine blade. The end walls (50, 54) of the pre-swirler may be contoured.

  11. Removal of polycyclic aromatic hydrocarbons (PAHs) from industrial sludges in the ambient air conditions: automotive industry.

    PubMed

    Karaca, Gizem; Tasdemir, Yucel

    2013-01-01

    Removal of polycyclic aromatic hydrocarbons (PAHs) existed in automotive industry treatment sludge was examined by considering the effects of temperature, UV, titanium dioxide (TiO2) and diethyl amine (DEA) in different dosages (i.e., 5% and 20%) in this study. Application of TiO2 and DEA to the sludge samples in ambient environment was studied. Ten PAH (Σ10 PAH) compounds were targeted and their average value in the sludge was found to be 4480 ± 1450 ng/g dry matter (DM). Total PAH content of the sludge was reduced by 25% in the ambient air environment. Meteorological conditions, atmospheric deposition, evaporation and sunlight irradiation played an effective role in the variations in PAH levels during the tests carried out in ambient air environment. Moreover, it was observed that when the ring numbers of PAHs increased, their removal rates also increased. Total PAH level did not change with the addition of 5% DEA and only 10% decreased with 5% TiO2 addition. PAH removal ratios were 8% and 32% when DEA (20%) and TiO2 (20%) were added, respectively. It was concluded that DEA was a weak photo-sensitizer yet TiO2 was effective only at 20% dosage. PMID:23485234

  12. MetNH3: Metrology for ammonia in ambient air

    NASA Astrophysics Data System (ADS)

    Braban, Christine; Twigg, Marsailidh; Tang, Sim; Leuenberger, Daiana; Ferracci, Valerio; Martin, Nick; Pascale, Celine; Hieta, Tuomas; Pogany, Andrea; Persijn, Stefan; van Wijk, Janneke; Gerwig, Holger; Wirtze, Klaus; Tiebe, Carlo; Balslev-Harder, David; Niederhausen, Bernhardt

    2015-04-01

    Measuring ammonia in ambient air is a sensitive and priority issue due to its harmful effects on human health and ecosystems. The European Directive 2001/81/EC on 'National Emission Ceilings for Certain Atmospheric Pollutants (NEC)' regulates ammonia emissions in the member states. However, there is a lack of regulation to ensure reliable ammonia measurements namely in applicable analytical technology, maximum allowed uncertainty, quality assurance and quality control (QC/QA) procedures as well as in the infrastructure to attain metrological traceability. Validated ammonia measurement data of high quality from air monitoring networks are vitally important for identifying changes due to implementations of environment policies, for understanding where the uncertainties in current emission inventories are derived from and for providing independent verification of atmospheric model predictions. The new EURAMET project MetNH3 aims to develop improved reference gas mixtures by static and dynamic gravimetric generation methods, develop and characterise laser based optical spectrometric standards and establish the transfer from high-accuracy standards to field applicable methods. MetNH3started in June 2014 and in this presentation the first results from the metrological characterisation of a commercially available cavity ring-down spectrometer (CRDS) will be discussed. Also first tests and results from a new design, Controlled Atmosphere Test Facility (CATFAC), which is to be characterised and used to validate the performance of diffusive samplers, denuders and on-line instruments, will be reported. CAFTEC can be used to control test parameters such as ammonia concentration, relative humidity and wind speed. Outline plans for international laboratory and field intercomparisons in 2016 will be presented.

  13. Cavity ring-down spectroscopy sensor development for high-time-resolution measurements of gaseous elemental mercury in ambient air

    NASA Astrophysics Data System (ADS)

    Pierce, A.; Obrist, D.; Moosmüller, H.; Faïn, X.; Moore, C.

    2013-06-01

    We describe further development of a previous laboratory prototype pulsed cavity ring-down spectroscopy (CRDS) sensor into a field-deployable system for high-time-resolution, continuous, and automated measurement of gaseous elemental mercury (GEM) concentrations in ambient air. We employed an external, isotopically enriched Hg cell for automated locking and stabilization of the laser wavelength on the GEM peak absorption during measurements. Further, we describe implementation of differential absorption measurements via a piezoelectric tuning element for pulse-by-pulse tuning of the laser wavelength onto and off of the GEM absorption line. This allowed us to continuously correct (at 25 Hz) for system baseline extinction losses unrelated to GEM absorption. Extensive measurement and calibration data obtained with the system were based on spike addition in both GEM-free air and ambient air. Challenges and interferences that occurred during measurements (particularly in ambient air) are discussed including temperature and ozone (O3) concentration fluctuations, and steps taken to reduce these. CRDS data were highly linear (r2 ≥ 0.98) with data from a commercial Tekran 2537 Hg analyzer across a wide range of GEM concentrations (0 to 127 ng m-3) in Hg-free and ambient air. Measurements during periods of stable background GEM concentrations provided a conservative instrument sensitivity estimate of 0.35 ng m-3 for the CRDS system when time averaged for 5 min. This sensitivity, along with concentration patterns observed in ambient air (with the CRDS system and verified with the Tekran analyzer), showed that the sensor was capable of characterizing GEM fluctuations in ambient air. The value of fast-response GEM measurements was shown by a series of GEM spike additions - highlighting that high-temporal-resolution measurement allowed for detailed characterization of fast concentration fluctuations not possible with traditional analyzers.

  14. Capture CO2 from Ambient Air Using Nanoconfined Ion Hydration.

    PubMed

    Shi, Xiaoyang; Xiao, Hang; Lackner, Klaus S; Chen, Xi

    2016-03-14

    Water confined in nanoscopic pores is essential in determining the energetics of many physical and chemical systems. Herein, we report a recently discovered unconventional, reversible chemical reaction driven by water quantities in nanopores. The reduction of the number of water molecules present in the pore space promotes the hydrolysis of CO3(2-) to HCO3(-) and OH(-). This phenomenon led to a nano-structured CO2 sorbent that binds CO2 spontaneously in ambient air when the surrounding is dry, while releasing it when exposed to moisture. The underlying mechanism is elucidated theoretically by computational modeling and verified by experiments. The free energy of CO3 (2-) hydrolysis in nanopores reduces with a decrease of water availability. This promotes the formation of OH(-), which has a high affinity to CO2 . The effect is not limited to carbonate/bicarbonate, but is extendable to a series of ions. Humidity-driven sorption opens a new approach to gas separation technology. PMID:26914978

  15. Measurement of total reduced sulfur compounds in ambient air

    SciTech Connect

    McQuaker, N.R.; Rajala, G.E.; Pengilly, D.

    1986-05-01

    Methods for the determination of total reduced sulfur (TRS) compounds in the ambient air based on coulometric detection (Philips Model PW 9700 analyzer) and thermal oxidation followed by detection using pulsed fluorescence (Teco Model 43 analyzer) have been evaluated. Analytical response factors, relative to H/sub 2/S, were determined for both the individual TRS compounds and compounds such as terpenes and carbonyl sulfide that may be a potential source of interference. The results for COS and terpenes indicate that in a typical monitoring situation normally encountered concentrations of these compounds are not expected to cause significant measurement bias. The results for the individual TRS compounds indicate that while variations in TRS composition are not a factor in assessing measurement bias for the thermal oxidation/pulsed fluorescence method, they are a factor for the Philips coulometric method; i.e., increasing positive measurement bias maybe introduced as the TRS composition shifts toward relatively less H/sub 2/S. Philips-Teco comparison data collected at a single site in the vicinity of three operating kraft pupil mills are compatible with these expectations. 8 references, 1 figure, 3 tables.

  16. ISS Ambient Air Quality: Updated Inventory of Known Aerosol Sources

    NASA Technical Reports Server (NTRS)

    Meyer, Marit

    2014-01-01

    Spacecraft cabin air quality is of fundamental importance to crew health, with concerns encompassing both gaseous contaminants and particulate matter. Little opportunity exists for direct measurement of aerosol concentrations on the International Space Station (ISS), however, an aerosol source model was developed for the purpose of filtration and ventilation systems design. This model has successfully been applied, however, since the initial effort, an increase in the number of crewmembers from 3 to 6 and new processes on board the ISS necessitate an updated aerosol inventory to accurately reflect the current ambient aerosol conditions. Results from recent analyses of dust samples from ISS, combined with a literature review provide new predicted aerosol emission rates in terms of size-segregated mass and number concentration. Some new aerosol sources have been considered and added to the existing array of materials. The goal of this work is to provide updated filtration model inputs which can verify that the current ISS filtration system is adequate and filter lifetime targets are met. This inventory of aerosol sources is applicable to other spacecraft, and becomes more important as NASA considers future long term exploration missions, which will preclude the opportunity for resupply of filtration products.

  17. The monitoring and fatigue behavior of CFCCs at ambient temperature and 1000{degrees}C

    SciTech Connect

    Miriyala, N.; Liaw, P.K.; McHargue, C.J.

    1997-04-01

    Metallographically polished flexure bars of Nicalon/SiC and Nicalon/alumina composites were subjected to monotonic and cycle-fatigue loadings, with loading either parallel or normal to the fabric plies. The fabric orientation did not significantly affect the mechanical behavior of the Nicalon/SiC composite at ambient temperature. However, the mechanical behavior of the Nicalon/alumina composite was significantly affected by the fabric orientation at ambient temperature in air and at 1000{degrees}C in argon atmosphere. In addition, there was a significant degradation in the fatigue performance of the alumina matrix composite at the elevated temperature, owing to creep in the material and degradation in the fiber strength.

  18. Traffic emission factors of ultrafine particles: effects from ambient air.

    PubMed

    Janhäll, Sara; Molnar, Peter; Hallquist, Mattias

    2012-09-01

    Ultrafine particles have a significant detrimental effect on both human health and climate. In order to abate this problem, it is necessary to identify the sources of ultrafine particles. A parameterisation method is presented for estimating the levels of traffic-emitted ultrafine particles in terms of variables describing the ambient conditions. The method is versatile and could easily be applied to similar datasets in other environments. The data used were collected during a four-week period in February 2005, in Gothenburg, as part of the Göte-2005 campaign. The specific variables tested were temperature (T), relative humidity (RH), carbon monoxide concentration (CO), and the concentration of particles up to 10 μm diameter (PM(10)); all indicators are of importance for aerosol processes such as coagulation and gas-particle partitioning. These variables were selected because of their direct effect on aerosol processes (T and RH) or as proxies for aerosol surface area (CO and PM(10)) and because of their availability in local monitoring programmes, increasing the usability of the parameterization. Emission factors are presented for 10-100 nm particles (ultrafine particles; EF(ufp)), for 10-40 nm particles (EF(10-40)), and for 40-100 nm particles (EF(40-100)). For EF(40-100) no effect of ambient conditions was found. The emission factor equations are calculated based on an emission factor for NO(x) of 1 g km(-1), thus the particle emission factors are easily expressed in units of particles per gram of NO(x) emitted. For 10-100 nm particles the emission factor is EF(ufp) = 1.8 × 10(15) × (1 - 0.095 × CO - 3.2 × 10(-3) × T) particles km(-1). Alternative equations for the EFs in terms of T and PM(10) concentration are also presented. PMID:22858604

  19. Stirling, near-ambient temperature refrigerators - Innovative compact designs

    NASA Astrophysics Data System (ADS)

    Walker, G.; Reader, G.; Fauvel, R.; Bingham, E. R.

    Opportunities for the development and application of 'near-ambient' temperature refrigerating systems in connection with public concern over the impact of Freon refrigerants on the earth's ozone layer are examined. Previous work is reviewed, and recent innovative concepts and designs for compact Stirling refrigerators that could be the basis for alternatives for Freon-free refrigeration are presented. The advantages offered by Stirling refrigerators are high thermodynamic performance, simplicity, compactness, low weight and low cost.

  20. Composition for producing polyurethane resin at ambient temperature

    SciTech Connect

    Kamatani, Y.; Nishino, K.; Tanaka, M.; Yamazaki, K.

    1984-06-26

    Disclosed is a composition for polyurethane resins which is ordinarily of two-package type and curable at ambient temperature and which comprises an isocyanate component having oxadiazinetrione ring as a curing agent and a polyol component, having in the molecule, at least one of a tertiary amino group, a quaternary ammonium group and a salt-formed carboxyl group as a main component. The composition has excellent curability and provides cured products excellent in adhesiveness and physical properties.

  1. Ambient temperature cadmium zinc telluride radiation detector and amplifier circuit

    DOEpatents

    McQuaid, James H.; Lavietes, Anthony D.

    1998-05-29

    A low noise, low power consumption, compact, ambient temperature signal amplifier for a Cadmium Zinc Telluride (CZT) radiation detector. The amplifier can be used within a larger system (e.g., including a multi-channel analyzer) to allow isotopic analysis of radionuclides in the field. In one embodiment, the circuit stages of the low power, low noise amplifier are constructed using integrated circuit (IC) amplifiers , rather than discrete components, and include a very low noise, high gain, high bandwidth dual part preamplification stage, an amplification stage, and an filter stage. The low noise, low power consumption, compact, ambient temperature amplifier enables the CZT detector to achieve both the efficiency required to determine the presence of radio nuclides and the resolution necessary to perform isotopic analysis to perform nuclear material identification. The present low noise, low power, compact, ambient temperature amplifier enables a CZT detector to achieve resolution of less than 3% full width at half maximum at 122 keV for a Cobalt-57 isotope source. By using IC circuits and using only a single 12 volt supply and ground, the novel amplifier provides significant power savings and is well suited for prolonged portable in-field use and does not require heavy, bulky power supply components.

  2. Ambient temperature cadmium zinc telluride radiation detector and amplifier circuit

    DOEpatents

    McQuaid, J.H.; Lavietes, A.D.

    1998-05-26

    A low noise, low power consumption, compact, ambient temperature signal amplifier for a Cadmium Zinc Telluride (CZT) radiation detector is disclosed. The amplifier can be used within a larger system (e.g., including a multi-channel analyzer) to allow isotopic analysis of radionuclides in the field. In one embodiment, the circuit stages of the low power, low noise amplifier are constructed using integrated circuit (IC) amplifiers , rather than discrete components, and include a very low noise, high gain, high bandwidth dual part preamplification stage, an amplification stage, and an filter stage. The low noise, low power consumption, compact, ambient temperature amplifier enables the CZT detector to achieve both the efficiency required to determine the presence of radionuclides and the resolution necessary to perform isotopic analysis to perform nuclear material identification. The present low noise, low power, compact, ambient temperature amplifier enables a CZT detector to achieve resolution of less than 3% full width at half maximum at 122 keV for a Cobalt-57 isotope source. By using IC circuits and using only a single 12 volt supply and ground, the novel amplifier provides significant power savings and is well suited for prolonged portable in-field use and does not require heavy, bulky power supply components. 9 figs.

  3. Laser plasma plume structure and dynamics in the ambient air: The early stage of expansion

    NASA Astrophysics Data System (ADS)

    Cirisan, M.; Jouvard, J. M.; Lavisse, L.; Hallo, L.; Oltra, R.

    2011-05-01

    Laser ablation plasma plume expanding into the ambient atmosphere may be an efficient way to produce nanoparticles. From that reason it would be interesting to study the properties of these laser induced plasmas formed under conditions that are known to be favorable for nanoparticles production. In general, plume behavior can be described as a two-stage process: a "violent" plume expansion due to the absorption of the laser beam energy (during the laser pulse) followed by a fast adiabatic expansion in the ambient gas (after the end of the laser pulse). Plasma plume may last a few microseconds and may have densities 10-6 times lower than the solid densities at temperatures close to the ambient temperature. Expansion of the plasma plume induced by the impact of a nanosecond laser beam (λ = 1064 nm) on the surface of metallic samples in the open air has been investigated by means of fast photography. Spatio-temporal evolution of the plume at the early stage of its expansion (first 330 ns) has been recorded. Structure and dynamics of the plasma plume have been investigated and compared to numerical simulations obtained with a hydro-code, as well as some scaling laws. In addition, measurements using different sample materials (Al, Fe, and Ti) have been performed in order to analyze the influence of target material on plume expansion.

  4. Promoted Metals Combustion at Ambient and Elevated Temperatures

    NASA Technical Reports Server (NTRS)

    Engel, Carl D.; Herald, Stephen D.; Davis, S. Eddie

    2005-01-01

    Promoted combustion testing of materials, Test 17 of NASA STD-6001, has been used to assess metal propensity to burn in oxygen rich environments. An igniter is used at the bottom end of a rod to promote ignition, and if combustion is sustained, the burning progresses from the bottom to the top of the rod. The physical mechanisms are very similar to the upward flammability test, Test 1 of NASA STD-6001. The differences are in the normal environmental range of pressures, oxygen content, and sample geometry. Upward flammability testing of organic materials can exhibit a significant transitional region between no burning to complete quasi-state burning. In this transitional region, the burn process exhibits a probabilistic nature. This transitional region has been identified for metals using the promoted combustion testing method at ambient initial temperatures. The work given here is focused on examining the transitional region and the quasi-steady burning region both at conventional ambient testing conditions and at elevated temperatures. A new heated promoted combustion facility and equipment at Marshall Space Flight Center have just been completed to provide the basic data regarding the metals operating temperature limits in contact with oxygen rich atmospheres at high pressures. Initial data have been obtained for Stainless Steel 304L, Stainless Steel 321, Haynes 214, and Inconel 718 at elevated temperatures in 100-percent oxygen atmospheres. These data along with an extended data set at ambient initial temperature test conditions are examined. The pressure boundaries of acceptable, non-burning usage is found to be lowered at elevated temperature.

  5. Measurements of ambient air lead concentrations in the city of Jeddah, Saudi Arabia

    SciTech Connect

    Abulfaraj, W.H.; Ahmed, M.; Mousli, K.M.; Erturk, F. )

    1990-01-01

    Lead concentrations were determined in six different locations in the Jeddah urban area by atomic absorption spectrometry. Correlations between the air-Pb data and traffic density were investigated. The lead concentration values obtained for the ambient air in Jeddah City ranged from 0.19 {mu}/m{sup 3} to 1.27 {mu}g/m{sup 3}. Comparison with ambient air quality standards from other countries indicates that certain areas in this city are approaching these guideline values.

  6. Recognizing the Challenges of Ambient Air Monitoring in the Persian Gulf

    NASA Astrophysics Data System (ADS)

    Meade, T. G.; Nicodemus, M. A.; Howard, J. M.

    2011-12-01

    In an effort to better estimate environmental exposure, the U.S. Army Public Health Command has been operating an ambient air monitoring station in Shuaiba Port, Kuwait since 2002. The focus has primarily been on monitoring criteria pollutants at a busy sea port where local industry (oil refineries, cement plant, petrochemical production, etc.) heavily impacts air quality. To compound the issues associated with day to day monitoring at a busy sea port, the region often experiences sand storms and temperatures up to 60°C. Average daily particulate matter concentrations at Shuaiba Port are an order of magnitude higher than similar industrial areas in the U.S. On days when sand storms occur ambient PM concentrations can be two or three orders higher than average daily U.S. concentrations. For example, 24-hour average PM10 concentrations from 2004-2010 for the month of June were 395 μg/m3. During sand storms, 24-hour average concentrations can reach as high as 4,000 μg/m3. This poster presents 2004-2010 particulate matter data collected at Shuaiba Port, Kuwait and outlines logistical and environmental challenges associated with air monitoring in the region.

  7. Panel discussion review: Session two - Interpretation of Observed Associations between Multiple Ambient Air Pollutants and Health Effects in Epidemiologic Analysis

    EPA Science Inventory

    Air pollution epidemiologic research has often utilized ambient air concentrations measured from centrally located monitors as a surrogate measure of exposure to these pollutants. Associations between these ambient concentrations and health outcomes such as lung function, hospita...

  8. 77 FR 39205 - Public Hearings for Proposed Rules-National Ambient Air Quality Standards for Particulate Matter

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-02

    ... Quality Standards for Particulate Matter AGENCY: Environmental Protection Agency (EPA). ACTION... titled, ``National Ambient Air Quality Standards for Particulate Matter,'' that is scheduled to be... and secondary national ambient air quality standards (NAAQS) for particulate matter (PM) to...

  9. FINE AMBIENT AIR PARTICULAR MATTER EXPOSURE INDUCES MOLECULAR ALTERATIONS INDICATIVE OF CARDIOVASCULAR DISEASE PROGRESSION IN ATHEROSCLEROTIC SUSCEPTIBLE MICE

    EPA Science Inventory

    Epidemiological, clinical, and toxicological studies have demonstrated that exposure to ambient air particulate matter (PM) can alter cardiovascular function and may influence cardiovascular disease (CVD). It has been shown that exposure to concentrated ambient air particles (CA...

  10. Measurement of volatile plant compounds in field ambient air by thermal desorption-gas chromatography-mass spectrometry.

    PubMed

    Cai, Xiao-Ming; Xu, Xiu-Xiu; Bian, Lei; Luo, Zong-Xiu; Chen, Zong-Mao

    2015-12-01

    Determination of volatile plant compounds in field ambient air is important to understand chemical communication between plants and insects and will aid the development of semiochemicals from plants for pest control. In this study, a thermal desorption-gas chromatography-mass spectrometry (TD-GC-MS) method was developed to measure ultra-trace levels of volatile plant compounds in field ambient air. The desorption parameters of TD, including sorbent tube material, tube desorption temperature, desorption time, and cold trap temperature, were selected and optimized. In GC-MS analysis, the selected ion monitoring mode was used for enhanced sensitivity and selectivity. This method was sufficiently sensitive to detect part-per-trillion levels of volatile plant compounds in field ambient air. Laboratory and field evaluation revealed that the method presented high precision and accuracy. Field studies indicated that the background odor of tea plantations contained some common volatile plant compounds, such as (Z)-3-hexenol, methyl salicylate, and (E)-ocimene, at concentrations ranging from 1 to 3400 ng m(-3). In addition, the background odor in summer was more abundant in quality and quantity than in autumn. Relative to previous methods, the TD-GC-MS method is more sensitive, permitting accurate qualitative and quantitative measurements of volatile plant compounds in field ambient air. PMID:26493981

  11. Valveless sampling of ambient air for analysis by capillary gas chromatography

    SciTech Connect

    Stephens, E.R. )

    1989-09-01

    A method for the high resolution, high sensitivity analysis of polluted air for individual organic compounds is described. Samples collected from 50 mL of ambient air at 87 K (liquid argon) are injected without use of a valve into a silica capillary column which is then temperature programmed from {minus}30{degree}C to 180{degree}C. Hydrocarbons (4 to 10 carbons) as well as carbonyl compounds, chlorinated compounds and terpenes can be identified and quantified. The detection limit, not strongly dependent on carbon number, is estimated to be 0.3 ppbc in a 50 mL sample. Use of small samples eliminates the need to remove water vapor, a procedure which might jeopardize sample integrity.

  12. Impact of a new gasoline benzene regulation on ambient air pollutants in Anchorage, Alaska

    NASA Astrophysics Data System (ADS)

    Yano, Yuriko; Morris, Stephen S.; Salerno, Christopher; Schlapia, Anne M.; Stichick, Mathew

    2016-05-01

    The purpose of this study was to quantify the impact of a new U.S. Environmental Protection Agency (EPA) standard that limits the amount of benzene allowed in gasoline on ambient benzene concentrations. This new standard, together with two companion regulations that limit cold-temperature automotive emissions and the permeability of portable fuel containers, was expected to lower the levels of ambient benzene and other volatile organic compounds (VOCs) nationwide. In this study the impact of the gasoline benzene standard was evaluated in Anchorage, Alaska in a two-phase ambient air monitoring study conducted before and after the new gasoline standard was implemented. Gasoline sold by Anchorage retailers was also evaluated in each phase to determine the content of benzene and other gasoline components. The average benzene content in Anchorage gasoline was reduced by 70%, from 5.05% (w/w) to 1.53% (w/w) following the implementation of the standard. The annual mean ambient benzene concentration fell by 51%, from 0.99 ppbv in Phase 1 to 0.49 ppbv in Phase 2. Analysis suggests the change in gasoline benzene content alone reduced benzene emissions by 46%. The changes in toluene, ethylbenzene, and xylene content in gasoline between Phase 1 and 2 were relatively small and the differences in the mean ambient concentrations of these compounds between phases were modest. Our results suggest that cold winter communities in high latitude and mountainous regions may benefit more from the gasoline benzene standard because of high benzene emissions resulting from vehicle cold start and a tendency to develop atmospheric stagnation conditions in the winter.

  13. Impact of a new gasoline benzene regulation on ambient air pollutants in Anchorage, Alaska

    NASA Astrophysics Data System (ADS)

    Yano, Yuriko; Morris, Stephen S.; Salerno, Christopher; Schlapia, Anne M.; Stichick, Mathew

    2016-05-01

    The purpose of this study was to quantify the impact of a new U.S. Environmental Protection Agency (EPA) standard that limits the amount of benzene allowed in gasoline on ambient benzene concentrations. This new standard, together with two companion regulations that limit cold-temperature automotive emissions and the permeability of portable fuel containers, was expected to lower the levels of ambient benzene and other volatile organic compounds (VOCs) nationwide. In this study the impact of the gasoline benzene standard was evaluated in Anchorage, Alaska in a two-phase ambient air monitoring study conducted before and after the new gasoline standard was implemented. Gasoline sold by Anchorage retailers was also evaluated in each phase to determine the content of benzene and other gasoline components. The average benzene content in Anchorage gasoline was reduced by 70%, from 5.05% (w/w) to 1.53% (w/w) following the implementation of the standard. The annual mean ambient benzene concentration fell by 51%, from 0.99 ppbv in Phase 1 to 0.49 ppbv in Phase 2. Analysis suggests the change in gasoline benzene content alone reduced benzene emissions by 46%. The changes in toluene, ethylbenzene, and xylene content in gasoline between Phase 1 and 2 were relatively small and the differences in the mean ambient concentrations of these compounds between phases were modest. Our results suggest that cold winter communities in high latitude and mountainous regions may benefit more from the gasoline benzene standard because of high benzene emissions resulting from vehicle cold start and a tendency to develop atmospheric stagnation conditions in the winter.

  14. Photoelectron Spectroscopy under Ambient Pressure and Temperature Conditions

    SciTech Connect

    Ogletree, D. Frank; Bluhm, Hendrik; Hebenstreit, Eleonore B.; Salmeron, Miquel

    2009-02-27

    We describe the development and applications of novel instrumentation for photoemission spectroscopy of solid or liquid surfaces in the presence of gases under ambient conditions or pressure and temperature. The new instrument overcomes the strong scattering of electrons in gases by the use of an aperture close to the surface followed by a differentially-pumped electrostatic lens system. In addition to the scattering problem, experiments in the presence of condensed water or other liquids require the development of special sample holders to provide localized cooling. We discuss the first two generations of Ambient Pressure PhotoEmission Spectroscopy (APPES) instruments developed at synchrotron light sources (ALS in Berkeley and BESSY in Berlin), with special focus on the Berkeley instruments. Applications to environmental science and catalytic chemical research are illustrated in two examples.

  15. Comparison of the genotoxic activities of extracts from ambient and forest fire polluted air. [Humans

    SciTech Connect

    Viau, C.J.; Lockard, J.M.; Enoch, H.G.; Sabharwal, P.S.

    1982-01-01

    The genotoxicity of airborne organic particles from forest fire smoke was compared to that from nonsmoky (ambient) urban air using the Salmonella reversion assay and the sister chromatid exchange (SCE) assay in cultured human lymphocytes. Salmonella strains TA98 and TA100 were used with and without the addition of Aroclor-induced rat liver homogenate (S9). Each sample induced dose-related increases in mutagenicity and SCE. However, on the basis of the volume of air sampled, the smoke-filled air induced 12 to 14 times more bacterial reversions in TA 100 and 16-38 times more reversion in TA98 than ambient air. Similarly, on a volume basis smoky air induced 43 times more SCE in human lymphocytes than did ambient air. The results indicate that the increased mutagenicity was due not only to the heavier particulate load of the air, but also to the increased specific mutagenicity of the particles.

  16. Effects of ambient oxidant air pollution in the San Joaquin Valley on Thompson seedless grapes

    SciTech Connect

    Brewer, R.F.; Ashcroft, R.

    1984-01-01

    Mature Thompson seedless grape vines were enclosed in specially constructed plastic covered chambers supplied with carbon filtered and non-filtered (ambient) air from time of bud break through leaf drop. Effects on vegetative growth and fruiting were determined for three seasons. No effects on fruit production were measured the first season after covering but vegetative growth increased 12% in chambers supplied with filtered air. By the third season fruit yields were 27.5% higher in the filtered as compared with ambient chambers. The only visible symptoms associated with exposure to the oxidants was accelerated senescence which appeared 3 weeks to 1 month earlier on vines receiving ambient or nonfiltered air.

  17. Physical factors in cataractogenesis: ambient ultraviolet radiation and temperature

    SciTech Connect

    Sliney, D.H.

    1986-05-01

    A number of environmental cofactors have been implicated in cataracto-genesis. Two have received the greatest attention: ultraviolet radiation (UVR) and ambient temperature. Unfortunately, both temperature and UVR levels vary similarly with geographical latitude. Careful attention to several more refined physical variables and the geometry of exposure may permit investigators to separate the contributory effects of these two physical agents. This paper briefly reviews the available data, estimates the variation of lenticular temperature with ambient temperature, and provides measurements of short-wavelength (UV-B) UVR exposure to the human eye with different meterological conditions. The study attempts to provide epidemiological investigators with more detailed information necessary to perform more accurate studies of cataract and other ocular pathologies that appear to be related to environmental factors. Ocular UV-B radiation exposure levels were measured at nine locations in the USA near 40 degrees latitude at elevations from sea level to 8000 ft. Terrain reflectance is shown to be much more important than terrain elevation; cloud cover and haze may actually increase ocular exposure; and the value of wearing brimmed hats and spectacles varies with the environment. Several avenues for future research are suggested.

  18. Use of a respirometer to measure oxidation rates of polymeric materials at ambient temperatures.

    SciTech Connect

    Assink, Roger Alan; Harris, Douglas Jeffrey; Celina, Mathias Christopher; Skutnik, Julie Michelle

    2005-06-01

    The use of a respirometer is introduced as a novel technique for measuring the oxidation rates of thermally degrading polymers. A dual channel respirometer with fuel cell detectors demonstrates sufficient sensitivity to measure the oxidation rates of low-density polymeric samples at ambient temperatures in a relatively short period of time. Samples of low-density polyurethane foam were aged for various lengths of time in sealed chambers at temperatures ranging from 23 to 110 C. The extent of oxygen depletion was measured by flushing the chamber with air and comparing the oxygen concentration in the chamber flow to that of a reference flow. Oxidation rates of the 0.1 g/cm{sup 3} polyurethane foam could be measured in less than 600 h of aging time at 23 C. This corresponds to approximately 2 ppm oxidation by weight. Oxidation rates of the foam were used to calculate acceleration factors over a wide temperature range, including ambient conditions. Acceleration factors for the compressive force of the polyurethane foam were determined at elevated temperatures. Assuming that the aging behavior of compressive force of the foam is correlated to its oxidation rate, it is possible to calculate acceleration factors for the compressive force and predict the performance of the foam at ambient temperatures.

  19. Influence of the Refractivity and Temperature of the Ambient Medium on the Eigenfrequencies of Quasioptical Cylindrical Dielectric Resonators

    NASA Astrophysics Data System (ADS)

    Dormidontov, A. V.; Prokopenko, Yu. V.

    2013-11-01

    We attempt for the first time to separate the influences of the temperature and refractivity of the ambient air space on the spectral and energy characteristics of cylindrical Teflon and leucosapphire resonators with the whispering gallery modes in the millimeter-wave range. It is found that under conditions of natural fluctuations of the above-mentioned factors of the studied ambient medium, the degree of temperature influence on the resonator eigenfrequencies is more significant. We demonstrate that quasioptical cylindrical dielectric resonators can be used as sensors of the temperature of the ambient air medium and ensure an accuracy of 10-4°C when their resonant frequencies are measured with an accuracy of 100 Hz. A method for determination of the air refractivity has been developed, which uses the considered resonator as a temperature sensor and a measuring cell of the microwave resonator refractometer. A refractometer sensor has been developed on the basis of two identical resonators with whispering gallery modes. The differential two-resonator refractometer compensates for the influence of changes in the temperature of the ambient medium on the measured difference of the eigenfrequencies of resonators with identical modes. It is found that the accuracy of determination of the air refractivity is ensured at a level of 10-2 if the frequency difference is measured with an accuracy of 10 Hz.

  20. Modeling, numerical simulation and experimental verification of the unsteady cooling of a solid body in quiescent ambient air

    NASA Astrophysics Data System (ADS)

    Campo, Antonio; Salazar, Abraham; Rebollo, Daniel

    The scope of the present article is two-fold. Firstly, to conduct an experiment to provide the temperature-time history of the cooling of a hot ball bearing in quiescent ambient air. Secondly, to predict the temporal variation of the bearing under the hypothesis of natural convection, radiation or natural convection coexists with radiation for a non-vanishing total hemispherical emissivity of the surface of the bearing. Numerical solutions of the three governing nonlinear lumped heat equations were carried out with a Runge-Kutta-Fehlberg (RKF45) algorithm accounting for automatic step size control. The experimental data was obtained with chrome steel ball bearings of diameter 0.953 cm (7/16 in) heated in an electric oven to a pre-set temperature. The heated bearing was exposed later to ambient air at atmospheric temperature and pressure.

  1. Moisture-swing sorption for carbon dioxide capture from ambient air: a thermodynamic analysis.

    PubMed

    Wang, Tao; Lackner, Klaus S; Wright, Allen B

    2013-01-14

    An ideal chemical sorbent for carbon dioxide capture from ambient air (air capture) must have a number of favourable properties, such as environmentally benign behaviour, a high affinity for CO(2) at very low concentration (400 ppm), and a low energy cost for regeneration. The last two properties seem contradictory, especially for sorbents employing thermal swing adsorption. On the other hand, thermodynamic analysis shows that the energy cost of an air capture device need only be slightly larger than that of a flue gas scrubber. The moisture swing separation process studied in this paper provides a novel approach to low cost CO(2) capture from air. The anionic exchange resin sorbent binds CO(2) when dry and releases it when wet. A thermodynamic model with coupled phase and chemical equilibria is developed to study the complex H(2)O-CO(2)-resin system. The moisture swing behaviour is compatible with hydration energies changing with the activity of water on the resin surfaces. This activity is in turn set by the humidity. The rearrangement of hydration water on the resin upon the sorption of a CO(2) molecule is predicted as a function of the humidity and temperature. Using water as fuel to drive the moisture swing enables an economical, large-scale implementation of air capture. By generating CO(2) with low partial pressures, the present technology has implications for in situ CO(2) utilizations which require low pressure CO(2) gas rather than liquid CO(2). PMID:23172123

  2. 40 CFR 50.10 - National 8-hour primary and secondary ambient air quality standards for ozone.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... ambient air quality standards for ozone. 50.10 Section 50.10 Protection of Environment ENVIRONMENTAL....10 National 8-hour primary and secondary ambient air quality standards for ozone. (a) The level of the national 8-hour primary and secondary ambient air quality standards for ozone, measured by...

  3. 40 CFR 50.10 - National 8-hour primary and secondary ambient air quality standards for ozone.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... ambient air quality standards for ozone. 50.10 Section 50.10 Protection of Environment ENVIRONMENTAL....10 National 8-hour primary and secondary ambient air quality standards for ozone. (a) The level of the national 8-hour primary and secondary ambient air quality standards for ozone, measured by...

  4. 40 CFR 50.9 - National 1-hour primary and secondary ambient air quality standards for ozone.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... ambient air quality standards for ozone. 50.9 Section 50.9 Protection of Environment ENVIRONMENTAL....9 National 1-hour primary and secondary ambient air quality standards for ozone. (a) The level of the national 1-hour primary and secondary ambient air quality standards for ozone measured by...

  5. 40 CFR 50.10 - National 8-hour primary and secondary ambient air quality standards for ozone.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... ambient air quality standards for ozone. 50.10 Section 50.10 Protection of Environment ENVIRONMENTAL....10 National 8-hour primary and secondary ambient air quality standards for ozone. (a) The level of the national 8-hour primary and secondary ambient air quality standards for ozone, measured by...

  6. 40 CFR 50.9 - National 1-hour primary and secondary ambient air quality standards for ozone.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... ambient air quality standards for ozone. 50.9 Section 50.9 Protection of Environment ENVIRONMENTAL....9 National 1-hour primary and secondary ambient air quality standards for ozone. (a) The level of the national 1-hour primary and secondary ambient air quality standards for ozone measured by...

  7. 40 CFR 50.9 - National 1-hour primary and secondary ambient air quality standards for ozone.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... ambient air quality standards for ozone. 50.9 Section 50.9 Protection of Environment ENVIRONMENTAL....9 National 1-hour primary and secondary ambient air quality standards for ozone. (a) The level of the national 1-hour primary and secondary ambient air quality standards for ozone measured by...

  8. 40 CFR 50.9 - National 1-hour primary and secondary ambient air quality standards for ozone.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... ambient air quality standards for ozone. 50.9 Section 50.9 Protection of Environment ENVIRONMENTAL....9 National 1-hour primary and secondary ambient air quality standards for ozone. (a) The level of the national 1-hour primary and secondary ambient air quality standards for ozone measured by...

  9. 77 FR 42495 - Release of Draft Documents Related to the Review of the National Ambient Air Quality Standards...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-19

    ... titled, Policy Assessment for the Review of the Ozone National Ambient Air Quality Standards: First... Review Plan for the Ozone National Ambient Air Quality Standards.\\1\\ A draft of the integrated review... Ambient Air Quality Standards: Scope and Methods Plan for Health Risk and Exposure Assessment and...

  10. 40 CFR 50.10 - National 8-hour primary and secondary ambient air quality standards for ozone.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... ambient air quality standards for ozone. 50.10 Section 50.10 Protection of Environment ENVIRONMENTAL....10 National 8-hour primary and secondary ambient air quality standards for ozone. (a) The level of the national 8-hour primary and secondary ambient air quality standards for ozone, measured by...

  11. 40 CFR 50.10 - National 8-hour primary and secondary ambient air quality standards for ozone.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... ambient air quality standards for ozone. 50.10 Section 50.10 Protection of Environment ENVIRONMENTAL....10 National 8-hour primary and secondary ambient air quality standards for ozone. (a) The level of the national 8-hour primary and secondary ambient air quality standards for ozone, measured by...

  12. 40 CFR Appendix S to Part 50 - Interpretation of the Primary National Ambient Air Quality Standards for Oxides of Nitrogen...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Ambient Air Quality Standards for Oxides of Nitrogen (Nitrogen Dioxide) S Appendix S to Part 50 Protection... National Ambient Air Quality Standards for Oxides of Nitrogen (Nitrogen Dioxide) 1. General (a) This... national ambient air quality standards for oxides of nitrogen as measured by nitrogen dioxide (“NO2...

  13. 40 CFR Appendix S to Part 50 - Interpretation of the Primary National Ambient Air Quality Standards for Oxides of Nitrogen...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Ambient Air Quality Standards for Oxides of Nitrogen (Nitrogen Dioxide) S Appendix S to Part 50 Protection... National Ambient Air Quality Standards for Oxides of Nitrogen (Nitrogen Dioxide) 1. General (a) This... national ambient air quality standards for oxides of nitrogen as measured by nitrogen dioxide (“NO2...

  14. 40 CFR Appendix S to Part 50 - Interpretation of the Primary National Ambient Air Quality Standards for Oxides of Nitrogen...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Ambient Air Quality Standards for Oxides of Nitrogen (Nitrogen Dioxide) S Appendix S to Part 50 Protection... National Ambient Air Quality Standards for Oxides of Nitrogen (Nitrogen Dioxide) 1. General (a) This... national ambient air quality standards for oxides of nitrogen as measured by nitrogen dioxide (“NO2...

  15. 40 CFR Appendix S to Part 50 - Interpretation of the Primary National Ambient Air Quality Standards for Oxides of Nitrogen...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Ambient Air Quality Standards for Oxides of Nitrogen (Nitrogen Dioxide) S Appendix S to Part 50 Protection... National Ambient Air Quality Standards for Oxides of Nitrogen (Nitrogen Dioxide) 1. General (a) This... national ambient air quality standards for oxides of nitrogen as measured by nitrogen dioxide (“NO2...

  16. 78 FR 34964 - Implementation of the 2008 National Ambient Air Quality Standards for Ozone: State Implementation...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-11

    ... Federal Register on June 6, 2013, (78 FR 34178) and is available at: http://www.epa.gov/air/ozonepollution... on June 6, 2013, (78 FR 34178) and is available at http://www.epa.gov/air/ozonepollution/actions.html... AGENCY 40 CFR Parts 50, 51, 70 and 71 Implementation of the 2008 National Ambient Air Quality...

  17. Ambient air-quality survey: Canadian Gypsum Company, Weston, Ontario: report

    SciTech Connect

    Chapman, R.

    1990-01-01

    A mobile air monitoring unit from the Air Resources Branch conducted an air quality survey in the vicinity of the Canadian Gypsum Company plant in northwest Toronto during the period July 24 to August 4, 1989. Survey objectives were to measure the ambient concentration of total reduced sulfur compounds (rotten egg odour) and various organic and chlorinated organic compounds.

  18. Ambient temperature normalization for infrared face recognition based on the second-order polynomial model

    NASA Astrophysics Data System (ADS)

    Wang, Zhengzi

    2015-08-01

    The influence of ambient temperature is a big challenge to robust infrared face recognition. This paper proposes a new ambient temperature normalization algorithm to improve the performance of infrared face recognition under variable ambient temperatures. Based on statistical regression theory, a second order polynomial model is learned to describe the ambient temperature's impact on infrared face image. Then, infrared image was normalized to reference ambient temperature by the second order polynomial model. Finally, this normalization method is applied to infrared face recognition to verify its efficiency. The experiments demonstrate that the proposed temperature normalization method is feasible and can significantly improve the robustness of infrared face recognition.

  19. Using a glass fiber separator in a single-chamber air-cathode microbial fuel cell shortens start-up time and improves anode performance at ambient and mesophilic temperatures.

    PubMed

    Zhang, Xiaoyuan; Liang, Peng; Shi, Juan; Wei, Jincheng; Huang, Xia

    2013-02-01

    A shorter start-up time and highly negative anode potentials are needed to improve single-chamber air-cathode microbial fuel cells (MFCs). Using a glass fiber separator reduced the start-up time from 10d to 8d at 20°C, and from 4d to 2d at 30°C, and enhanced coulombic efficiency (CE) from <60% to 89% (20°C) and 87% (30°C). Separators also reduced anode potentials by 20-190mV, charge transfer resistances by 76% (20°C) and 19% (30°C), and increased CV peak currents by 24% (20°C) and 8% (30°C) and the potential range for redox activity (-0.55 to 0.10mV vs. -0.49 to -0.24mV at 20°C). Using a glass fiber separator in an air-cathode MFC, combined with inoculation at a mesophilic temperature, are excellent strategies to shorten start-up time and to enhance anode performance and CE. PMID:23334007

  20. Comparison of exposure estimation methods for air pollutants: ambient monitoring data and regional air quality simulation.

    PubMed

    Bravo, Mercedes A; Fuentes, Montserrat; Zhang, Yang; Burr, Michael J; Bell, Michelle L

    2012-07-01

    Air quality modeling could potentially improve exposure estimates for use in epidemiological studies. We investigated this application of air quality modeling by estimating location-specific (point) and spatially-aggregated (county level) exposure concentrations of particulate matter with an aerodynamic diameter less than or equal to 2.5 μm (PM(2.5)) and ozone (O(3)) for the eastern U.S. in 2002 using the Community Multi-scale Air Quality (CMAQ) modeling system and a traditional approach using ambient monitors. The monitoring approach produced estimates for 370 and 454 counties for PM(2.5) and O(3), respectively. Modeled estimates included 1861 counties, covering 50% more population. The population uncovered by monitors differed from those near monitors (e.g., urbanicity, race, education, age, unemployment, income, modeled pollutant levels). CMAQ overestimated O(3) (annual normalized mean bias=4.30%), while modeled PM(2.5) had an annual normalized mean bias of -2.09%, although bias varied seasonally, from 32% in November to -27% in July. Epidemiology may benefit from air quality modeling, with improved spatial and temporal resolution and the ability to study populations far from monitors that may differ from those near monitors. However, model performance varied by measure of performance, season, and location. Thus, the appropriateness of using such modeled exposures in health studies depends on the pollutant and metric of concern, acceptable level of uncertainty, population of interest, study design, and other factors. PMID:22579357

  1. Comparison of exposure estimation methods for air pollutants: Ambient monitoring data and regional air quality simulation

    PubMed Central

    Bravo, Mercedes A.; Fuentes, Montserrat; Zhang, Yang; Burr, Michael J.; Bell, Michelle L.

    2012-01-01

    Air quality modeling could potentially improve exposure estimates for use in epidemiological studies. We investigated this application of air quality modeling by estimating location-specific (point) and spatially-aggregated (county level) exposure concentrations of particulate matter with an aerodynamic diameter less than or equal to 2.5 µm (PM2.5) and ozone (O3) for the eastern U.S. in 2002 using the Community Multi-scale Air Quality (CMAQ) modeling system and a traditional approach using ambient monitors. The monitoring approach produced estimates for 370 and 454 counties for PM2.5 and O3, respectively. Modeled estimates included 1861 counties, covering 50% more population. The population uncovered by monitors differed from those near monitors (e.g., urbanicity, race, education, age, unemployment, income, modeled pollutant levels). CMAQ overestimated O3 (annual normalized mean bias = 4.30%), while modeled PM2.5 had an annual normalized mean bias of −2.09%, although bias varied seasonally, from 32% in November to −27% in July. Epidemiology may benefit from air quality modeling, with improved spatial and temporal resolution and the ability to study populations far from monitors that may differ from those near monitors. However, model performance varied by measure of performance, season, and location. Thus, the appropriateness of using such modeled exposures in health studies depends on the pollutant and metric of concern, acceptable level of uncertainty, population of interest, study design, and other factors. PMID:22579357

  2. Capacity decline of ambient temperature secondary lithium battery

    NASA Technical Reports Server (NTRS)

    Shen, D. H.; Subbarao, S.; Nakamura, B. J.; Yen, S. P. S.; Bankston, C. P.

    1988-01-01

    The use of ambient temperature secondary lithium cells is limited primarily because of the poor cycle life performance. Much of the cell capacity is irreversibly lost upon cycling. Studies have been undertaken to understand the problem of capacity decline. Experimental Li-TiS2 cells were fabricated and tested for their cycle life performance. Cells were disassembled at different stages of cycle life, and cell active components were analyzed by various analytical techniques. The results of this study indicate that all the cell's active components/materials are undergoing degradation. Details of the experiments carried out and the results obtained are described.

  3. EVALUATION OF HIGH VOLUME PARTICLE SAMPLING AND SAMPLE HANDLING PROTOCOLS FOR AMBIENT URBAN AIR MUTAGENICITY DETERMINATIONS

    EPA Science Inventory

    An investigation of high volume particle sampling and sample handling procedures was undertaken to evaluate variations of protocols being used by the U.S Environmental Protection Agency. hese protocols are used in urban ambient air studies which collect ambient and source samples...

  4. 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...

  5. Ambient Air Mitigation Strategies for Reducing Exposures to Mobile Source PM2.5 Emissions

    EPA Science Inventory

    Presentation discussing ambient air mitigation strategies for near-road exposures. The presentation provides an overview of multiple methods, but focuses on the role roadside features (sound walls, vegetation) may play. This presentation summarizes preoviously published work by...

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

    EPA Science Inventory

    Background and Objectives: 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, population-based, case-c...

  7. METHODS FOR ESTIMATING ON-SITE AMBIENT AIR CONCENTRATIONS AT DISPOSAL SITES

    EPA Science Inventory

    Currently, Gaussian type dispersion modeling and point source approximation are combined to estimate the ambient air concentrations of pollutants dispersed downwind of an areawide emission source, using the approach of virtual point source approximation. The Gaussian dispersion m...

  8. Implications of Nitrogen-Climate Interactions for Ambient Air Pollution and Human Health

    NASA Astrophysics Data System (ADS)

    Haeuber, R.; Peel, J. L.; Garcia, V.; Neas, L.; Russell, A. G.

    2011-12-01

    Nitrogen oxides (NOX) are important components of ambient and indoor air pollution and are emitted from a range of combustion sources, including on-road mobile sources, electric power generators, and non-road mobile sources. While anthropogenic sources dominate, NOX is also formed by lightning and wildland fires and is emitted by soil. Reduced nitrogen (e.g., ammonia, NH3) is also emitted by various sources, including fertilizer application and animal waste decomposition. NOX, ozone and PM2.5 pollution related to atmospheric emissions of nitrogen and other pollutants can cause premature death and a variety of serious health effects. Climate change is expected to impact how nitrogen-related pollutants affect human health. For example, changes in temperature and precipitation patterns are projected to both lengthen the ozone season and intensify high ozone episodes in some areas. Other climate-related changes may increase the atmospheric release of nitrogen compounds through impacts on wildfire regimes, soil emissions, and biogenic emissions from terrestrial ecosystems. This session will examine the potential human health implications of climate change and nitrogen cycle interactions related to ambient air pollution.

  9. Inhalation intake of ambient air pollution in California's South Coast Air Basin

    NASA Astrophysics Data System (ADS)

    Marshall, Julian D.; Granvold, Patrick W.; Hoats, Abigail S.; McKone, Thomas E.; Deakin, Elizabeth; W Nazaroff, William

    Reliable estimates of inhalation intake of air pollution and its distribution among a specified population are important for environmental epidemiology, health risk assessment, urban planning, and environmental policy. We computed distributional characteristics of the inhalation intake of five pollutants for a group of ˜25,000 people (˜29,000 person-days) living in California's South Coast Air Basin. Our approach incorporates four main inputs: temporally resolved information about people's location (latitude and longitude), microenvironment, and activity level; temporally and spatially explicit model determinations of ambient concentrations; stochastically determined microenvironmental adjustment factors relating the exposure concentration to the ambient concentration; and, age-, gender-, and activity-specific breathing rates. Our study is restricted to pollutants of outdoor origin, i.e. it does not incorporate intake in a microenvironment from direct emissions into that microenvironment. Median estimated inhalation intake rates (μg d -1) are 53 for benzene, 5.1 for 1,3-butadiene, 8.7×10 -4 for hexavalent chromium in fine particulate matter (Cr-PM 2.5), 30 for diesel fine particulate matter (DPM 2.5), and 68 for ozone. For the four primary pollutants studied, estimated median intake rates are higher for non-whites and for individuals in low-income households than for the population as a whole. For ozone, a secondary pollutant, the reverse is true. Accounting for microenvironmental adjustment factors, population mobility and temporal correlations between pollutant concentrations and breathing rates affects the estimated inhalation intake by 40% on average. The approach presented here could be extended to quantify the impact on intakes and intake distributions of proposed changes in emissions, air quality, and urban infrastructure.

  10. The mass and speed dependence of meteor air plasma temperatures

    NASA Technical Reports Server (NTRS)

    Jenniskens, Peter; Laux, Christophe O.; Wilson, Michael A.; Schaller, Emily L.

    2004-01-01

    The speed and mass dependence of meteor air plasma temperatures is perhaps the most important data needed to understand how small meteoroids chemically change the ambient atmosphere in their path and enrich the ablated meteoric organic matter with oxygen. Such chemistry can play an important role in creating prebiotic compounds. The excitation conditions in various air plasma emissions were measured from high-resolution optical spectra of Leonid storm meteors during NASA's Leonid Multi-Instrument Aircraft Campaign. This was the first time a sufficient number and range of temperature measurements were obtained to search for meteoroid mass and speed dependencies. We found slight increases in temperature with decreasing altitude, but otherwise nearly constant values for meteoroids with speeds between 35 and 72 km/s and masses between 10(-5) g and 1 g. We conclude that faster and more massive meteoroids produce a larger emission volume, but not a higher air plasma temperature. We speculate that the meteoric plasma may be in multiphase equilibrium with the ambient atmosphere, which could mean lower plasma temperatures in a CO(2)-rich early Earth atmosphere.

  11. The association between ambient temperature and children's lung function in Baotou, China

    NASA Astrophysics Data System (ADS)

    Li, Shanshan; Guo, Yuming; Williams, Gail; Baker, Peter; Ye, Xiaofang; Madaniyazi, Lina; Kim, Dae-Seon; Pan, Xiaochuan

    2015-07-01

    The objective of this study is to examine the association between ambient temperature and children's lung function in Baotou, China. We recruited 315 children (8-12 years) from Baotou, China in the spring of 2004, 2005, and 2006. They performed three successive forced expiratory measurements three times daily (morning, noon, and evening) for about 5 weeks. The highest peak expiratory flow (PEF) was recorded for each session. Daily data on ambient temperature, relative humidity, and air pollution were monitored during the same period. Mixed models with a distributed lag structure were used to examine the effects of temperature on lung function while adjusting for individual characteristics and environmental factors. Low temperatures were significantly associated with decreases in PEF. The effects lasted for lag 0-2 days. For all participants, the cumulative effect estimates (lag 0-2 days) were -1.44 (-1.93, -0.94) L/min, -1.39 (-1.92, -0.86) L/min, -1.40 (-1.97, -0.82) L/min, and -1.28 (-1.69, -0.88) L/min for morning, noon, evening, and daily mean PEF, respectively, associated with 1 °C decrease in daily mean temperature. Generally, the effects of temperature were slightly stronger in boys than in girls for noon, evening, and daily mean PEF, while the effects were stronger in girls for morning PEF. PM2.5 had joint effects with temperature on children's PEF. Higher PM2.5 increased the impacts of low temperature. Low ambient temperatures are associated with lower lung function in children in Baotou, China. Preventive health policies will be required for protecting children from the cold weather.

  12. Crowdsourcing urban air temperatures from smartphone battery temperatures

    NASA Astrophysics Data System (ADS)

    Overeem, Aart; Robinson, James C. R.; Leijnse, Hidde; Steeneveld, Gert-Jan; Horn, Berthold K. P.; Uijlenhoet, Remko

    2014-05-01

    Accurate air temperature observations in urban areas are important for meteorology and energy demand planning. They are indispensable to study the urban heat island effect and the adverse effects of high temperatures on human health. However, the availability of temperature observations in cities is often limited. Here we show that relatively accurate air temperature information for the urban canopy layer can be obtained from an alternative, nowadays omnipresent source: smartphones. In this study, battery temperatures were collected by an Android application for smartphones. It has been shown that a straightforward heat transfer model can be employed to estimate daily mean air temperatures from smartphone battery temperatures for eight major cities around the world. The results demonstrate the enormous potential of this crowdsourcing application for real-time temperature monitoring in densely populated areas. Battery temperature data were collected by users of an Android application for cell phones (opensignal.com). The application automatically sends battery temperature data to a server for storage. In this study, battery temperatures are averaged in space and time to obtain daily averaged battery temperatures for each city separately. A regression model, which can be related to a physical model, is employed to retrieve daily air temperatures from battery temperatures. The model is calibrated with observed air temperatures from a meteorological station of an airport located in or near the city. Time series of air temperatures are obtained for each city for a period of several months, where 50% of the data is for independent verification. The methodology has been applied to Buenos Aires, London, Los Angeles, Paris, Mexico City, Moscow, Rome, and Sao Paulo. The evolution of the retrieved air temperatures often correspond well with the observed ones. The mean absolute error of daily air temperatures is less than 2 degrees Celsius, and the bias is within 1 degree

  13. Pulsed positive streamer discharges in air at high temperatures

    NASA Astrophysics Data System (ADS)

    Ono, Ryo; Kamakura, Taku

    2016-08-01

    Atmospheric-pressure air pulsed positive streamer discharges are generated in a 13 mm point-plane gap in the temperature range of 293 K–1136 K, and the effect of temperature on the streamer discharges is studied. When the temperature is increased, the product of applied voltage and temperature VT proportional to the reduced electric field can be used as a primary parameter that determines some discharge parameters regardless of temperature. For a given VT, the transferred charge per pulse, streamer diameter, product of discharge energy and temperature, and length of secondary streamer are almost constant regardless of T, whereas the streamer velocity decreases with increasing T and the decay rate of the discharge current is proportional to 1/T. The N2(C) emission intensity is approximately determined by the discharge energy independent of T. These results are useful to predict the streamer discharge and its reactive species production when the ambient temperature is increased.

  14. Effect of ambient temperature and relative humidity on interfacial temperature during early stages of drop evaporation

    NASA Astrophysics Data System (ADS)

    Fukatani, Yuki; Orejon, Daniel; Kita, Yutaku; Takata, Yasuyuki; Kim, Jungho; Sefiane, Khellil

    2016-04-01

    Understanding drop evaporation mechanisms is important for many industrial, biological, and other applications. Drops of organic solvents undergoing evaporation have been found to display distinct thermal patterns, which in turn depend on the physical properties of the liquid, the substrate, and ambient conditions. These patterns have been reported previously to be bulk patterns from the solid-liquid to the liquid-gas drop interface. In the present work the effect of ambient temperature and humidity during the first stage of evaporation, i.e., pinned contact line, is studied paying special attention to the thermal information retrieved at the liquid-gas interface through IR thermography. This is coupled with drop profile monitoring to experimentally investigate the effect of ambient temperature and relative humidity on the drop interfacial thermal patterns and the evaporation rate. Results indicate that self-generated thermal patterns are enhanced by an increase in ambient temperature and/or a decrease in humidity. The more active thermal patterns observed at high ambient temperatures are explained in light of a greater temperature difference generated between the apex and the edge of the drop due to greater evaporative cooling. On the other hand, the presence of water humidity in the atmosphere is found to decrease the temperature difference along the drop interface due to the heat of adsorption, absorption and/or that of condensation of water onto the ethanol drops. The control, i.e., enhancement or suppression, of these thermal patterns at the drop interface by means of ambient temperature and relative humidity is quantified and reported.

  15. Effect of ambient temperature and relative humidity on interfacial temperature during early stages of drop evaporation.

    PubMed

    Fukatani, Yuki; Orejon, Daniel; Kita, Yutaku; Takata, Yasuyuki; Kim, Jungho; Sefiane, Khellil

    2016-04-01

    Understanding drop evaporation mechanisms is important for many industrial, biological, and other applications. Drops of organic solvents undergoing evaporation have been found to display distinct thermal patterns, which in turn depend on the physical properties of the liquid, the substrate, and ambient conditions. These patterns have been reported previously to be bulk patterns from the solid-liquid to the liquid-gas drop interface. In the present work the effect of ambient temperature and humidity during the first stage of evaporation, i.e., pinned contact line, is studied paying special attention to the thermal information retrieved at the liquid-gas interface through IR thermography. This is coupled with drop profile monitoring to experimentally investigate the effect of ambient temperature and relative humidity on the drop interfacial thermal patterns and the evaporation rate. Results indicate that self-generated thermal patterns are enhanced by an increase in ambient temperature and/or a decrease in humidity. The more active thermal patterns observed at high ambient temperatures are explained in light of a greater temperature difference generated between the apex and the edge of the drop due to greater evaporative cooling. On the other hand, the presence of water humidity in the atmosphere is found to decrease the temperature difference along the drop interface due to the heat of adsorption, absorption and/or that of condensation of water onto the ethanol drops. The control, i.e., enhancement or suppression, of these thermal patterns at the drop interface by means of ambient temperature and relative humidity is quantified and reported. PMID:27176386

  16. Hydrogen confinement in carbon nanopores: extreme densification at ambient temperature.

    PubMed

    Gallego, Nidia C; He, Lilin; Saha, Dipendu; Contescu, Cristian I; Melnichenko, Yuri B

    2011-09-01

    In-situ small-angle neutron scattering studies of H(2) confined in small pores of polyfurfuryl alcohol-derived activated carbon at room temperature have provided for the first time its phase behavior in equilibrium with external H(2) at pressures up to 200 bar. The data were used to evaluate the density of the adsorbed fluid, which appears to be a function of both pore size and pressure and is comparable to the density of liquid H(2) in narrow nanopores at ∼200 bar. The surface-molecule interactions responsible for densification of H(2) within the pores create internal pressures that exceed the external gas pressure by a factor of up to ∼50, confirming the benefits of adsorptive storage over compressive storage. These results can be used to guide the development of new carbon adsorbents tailored for maximum H(2) storage capacities at near-ambient temperatures. PMID:21819066

  17. Hydrogen Confinement in Carbon Nanopores: Extreme Densification at Ambient Temperature

    SciTech Connect

    Gallego, Nidia C; He, Lilin; Saha, Dipendu; Contescu, Cristian I; Melnichenko, Yuri B

    2011-01-01

    In-situ small angle neutron scattering (SANS) studies of hydrogen confined in small pores of polyfurfuryl alcohol-derived activated carbon (PFAC) at room-temperature provided for the first time its phase behavior in equilibrium with external H2 at pressures up to 200 bar. The data was used to evaluate the density of the adsorbed fluid, which appears to be a function of both pore size and pressure, and approaches the liquid hydrogen density in narrow nanopores at 200 bar. The surface-molecule interactions responsible for densification of hydrogen within the pores create internal pressures which exceed by a factor of up to ~ 60 the external gas pressures, confirming the benefits of adsorptive over compressive storage. These results can be utilized to guide the development of new carbon adsorbents tailored for maximum hydrogen storage capacities at near ambient temperatures.

  18. Why is it so difficult to measure terpenes in ambient air?

    SciTech Connect

    Rasmussen, R.A.

    1994-12-31

    Biogenic compounds and in general terpenes make up a large fraction of the volatile organic compounds emitted into the ambient atmosphere. The measurement of terpenes is of importance in knowing the biogenic contribution to the atmospheric loading of organic compounds. The ambient concentrations of terpenes are usually low in the ambient atmosphere which may in itself result in difficulties in their analysis. The chemical and physical nature of the terpenes may also lead to difficulties in their analysis. Ambient air samples collected in SUMMA canisters under conditions in which terpenes should be present, and results of experiments with terpenes in SUMMA canisters will be discussed.

  19. Modelling of operation of a lithium-air battery with ambient air and oxygen-selective membrane

    NASA Astrophysics Data System (ADS)

    Sahapatsombut, Ukrit; Cheng, Hua; Scott, Keith

    2014-03-01

    A macro-homogeneous model has been developed to evaluate the impact of replacing pure oxygen with ambient air on the performance of a rechargeable non-aqueous Li-air battery. The model exhibits a significant reduction in discharge capacity, e.g. from 1240 to 226 mAh gcarbon-1 at 0.05 mA cm-2 when using ambient air rather than pure oxygen. The model correlates the relationship between the performance and electrolyte decomposition and formation of discharge products (such as Li2O2 and Li2CO3) under ambient air conditions. The model predicts a great benefit of using an oxygen-selective membrane on increasing capacity. The results indicate a good agreement between the experimental data and the model.

  20. Effect of pollutant-exposure ambient air in childhood and adulthood. Final report

    SciTech Connect

    Wegman, D.H.

    1987-06-16

    This study explored multivariate modeling to describe the relationship between respiratory health and ambient air pollution in three Los Angeles communities using data of respiratory symptoms and pulmonary function collected for the UCLA Population Studies of Chronic Obstructive Respiratory Disease. The modeling approach focused on adult non-commuting females whose ambient-air exposures were best represented by air-quality monitoring stations in the community of residence. Multivariate analysis did not provide a clear model that improved on earlier analyses based upon residence. Effects of birthplace or current abnormal respiratory health as indicators or potential susceptibility to air pollution were not identified. The results were judged indicative of limits in the data available for estimating ambient air exposures for individual study subjects.

  1. 40 CFR Appendix P to Part 50 - Interpretation of the Primary and Secondary National Ambient Air Quality Standards for Ozone

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Secondary National Ambient Air Quality Standards for Ozone P Appendix P to Part 50 Protection of Environment... Air Quality Standards for Ozone 1. General (a) This appendix explains the data handling conventions... air quality standards for ozone (O3) specified in § 50.15 are met at an ambient O3 air...

  2. 40 CFR Appendix P to Part 50 - Interpretation of the Primary and Secondary National Ambient Air Quality Standards for Ozone

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Secondary National Ambient Air Quality Standards for Ozone P Appendix P to Part 50 Protection of Environment... Air Quality Standards for Ozone 1. General (a) This appendix explains the data handling conventions... air quality standards for ozone (O3) specified in § 50.15 are met at an ambient O3 air...

  3. 40 CFR Appendix P to Part 50 - Interpretation of the Primary and Secondary National Ambient Air Quality Standards for Ozone

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Secondary National Ambient Air Quality Standards for Ozone P Appendix P to Part 50 Protection of Environment... Air Quality Standards for Ozone 1. General (a) This appendix explains the data handling conventions... air quality standards for ozone (O3) specified in § 50.15 are met at an ambient O3 air...

  4. 40 CFR Appendix P to Part 50 - Interpretation of the Primary and Secondary National Ambient Air Quality Standards for Ozone

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Secondary National Ambient Air Quality Standards for Ozone P Appendix P to Part 50 Protection of Environment... Air Quality Standards for Ozone 1. General (a) This appendix explains the data handling conventions... air quality standards for ozone (O3) specified in § 50.15 are met at an ambient O3 air...

  5. Comparison of stationary and personal air sampling with an air dispersion model for children's ambient exposure to manganese.

    PubMed

    Fulk, Florence; Haynes, Erin N; Hilbert, Timothy J; Brown, David; Petersen, Dan; Reponen, Tiina

    2016-09-01

    Manganese (Mn) is ubiquitous in the environment and essential for normal growth and development, yet excessive exposure can lead to impairments in neurological function. This study modeled ambient Mn concentrations as an alternative to stationary and personal air sampling to assess exposure for children enrolled in the Communities Actively Researching Exposure Study in Marietta, OH. Ambient air Mn concentration values were modeled using US Environmental Protection Agency's Air Dispersion Model AERMOD based on emissions from the ferromanganese refinery located in Marietta. Modeled Mn concentrations were compared with Mn concentrations from a nearby stationary air monitor. The Index of Agreement for modeled versus monitored data was 0.34 (48 h levels) and 0.79 (monthly levels). Fractional bias was 0.026 for 48 h levels and -0.019 for monthly levels. The ratio of modeled ambient air Mn to measured ambient air Mn at the annual time scale was 0.94. Modeled values were also time matched to personal air samples for 19 children. The modeled values explained a greater degree of variability in personal exposures compared with time-weighted distance from the emission source. Based on these results modeled Mn concentrations provided a suitable approach for assessing airborne Mn exposure in this cohort. PMID:27168393

  6. Ambient air pollution and congenital heart defects in Lanzhou, China

    NASA Astrophysics Data System (ADS)

    Jin, Lan; Qiu, Jie; Zhang, Yaqun; Qiu, Weitao; He, Xiaochun; Wang, Yixuan; Sun, Qingmei; Li, Min; Zhao, Nan; Cui, Hongmei; Liu, Sufen; Tang, Zhongfeng; Chen, Ya; Yue, Li; Da, Zhenqiang; Xu, Xiaoying; Huang, Huang; Liu, Qing; Bell, Michelle L.; Zhang, Yawei

    2015-07-01

    Congenital heart defects are the most prevalent type of birth defects. The association of air pollution with congenital heart defects is not well understood. We investigated a cohort of 8969 singleton live births in Lanzhou, China during 2010-2012. Using inverse distance weighting, maternal exposures to particulate matter with diameters ≤10 μm (PM10), nitrogen dioxide (NO2), and sulfur dioxide (SO2) were estimated as a combination of monitoring station levels for time spent at home and in a work location. We used logistic regression to estimate the associations, adjusting for maternal age, education, income, BMI, disease, folic acid intake and therapeutic drug use, and smoking; season of conception, fuel used for cooking and temperature. We found significant positive associations of Patent Ductus Arteriosus (PDA) with PM10 during the 1st trimester, 2nd trimester and the entire pregnancy (OR 1st trimester = 3.96, 95% confidence interval (CI): 1.36, 11.53; OR 2nd trimester = 3.59, 95% CI: 1.57, 8.22; OR entire pregnancy = 2.09, 95% CI: 1.21, 3.62, per interquartile range (IQR) increment for PM10 (IQR = 71.2, 61.6, and 27.4 μg m-3, respectively)), and associations with NO2 during 2nd trimester and the entire pregnancy (OR 2nd trimester = 1.92, 95% CI: 1.11, 3.34; OR entire pregnancy = 2.32, 95% Cl: 1.14, 4.71, per IQR increment for NO2 (IQR = 13.4 and 10.9 μg m-3, respectively)). The associations for congenital malformations of the great arteries and pooled cases showed consistent patterns. We also found positive associations for congenital malformations of cardiac septa with PM10 exposures in the 2nd trimester and the entire pregnancy, and SO2 exposures in the entire pregnancy. Results indicate a health burden from maternal exposures to air pollution, with increased risk of congenital heart defects.

  7. Ambient temperature-independent dual-band mid-infrared radiation thermometry.

    PubMed

    Lü, You; He, Xin; Wei, Zhong-Hui; Sun, Zhi-Yuan; Chang, Song-Tao

    2016-03-20

    For temperature measurements of targets at low temperatures, dual-band radiation thermometry using mid-infrared detectors has been investigated extensively. However, the accuracy is greatly affected by the reflected ambient radiation and stray radiation, which depend on the ambient temperature. To ensure measurement accuracy, an improved dual-band measurement model is established by considering the reflected ambient radiation and the stray radiation. The effect of ambient temperature fluctuation on temperature measurement is then further analyzed in detail. Experimental results of measuring a gray-body confirm that the proposed method yields high accuracy at varying ambient temperatures. This method provides a practical approach to remove the effect of ambient temperature fluctuations on temperature measurements. PMID:27140549

  8. Bonding of lithium niobate to silicon in ambient air using laser irradiation

    NASA Astrophysics Data System (ADS)

    Kawano, Hiroki; Takigawa, Ryo; Ikenoue, Hiroshi; Asano, Tanemasa

    2016-08-01

    In this paper, we introduce a bonding method in ambient air using laser irradiation to the face-to-face interface of dissimilar materials. This method is performed while keeping whole wafers of the materials at room temperature. We demonstrate the bonding of LiNbO3 to Si using pulsed nanosecond green laser irradiation. Laser use can minimize thermal stress owing to a large thermal expansion mismatch. The bonding characteristic obtained by an irradiation laser up to 2.5 J/cm2 in fluence is investigated. It is found that a LiNbO3 chip is strongly bonded to a Si chip by setting the laser fluence at the optimum range. A bond strength of over 2 MPa, which may be enough for the device applications, can be obtained.

  9. Hydrogen Storage at Ambient Temperature by the Spillover Mechanism

    SciTech Connect

    Yang , Ralph T.

    2011-02-04

    The goal of this project was to develop new nanostructured sorbent materials, using the hydrogen spillover mechanism that could meet the DOE 2010 system targets for on-board vehicle hydrogen storage. Hydrogen spillover may be broadly defined as the transport (i.e., via surface diffusion) of dissociated hydrogen adsorbed or formed on a first surface onto another surface. The first surface is typically a metal (that dissociates H2) and the second surface is typically the support on which the metal is doped. Hydrogen spillover is a well documented phenomenon in the catalysis literature, and has been known in the catalysis community for over four decades, although it is still not well understood.1, 2 Much evidence has been shown in the literature on its roles played in catalytic reactions. Very little has been studied on hydrogen storage by spillover at ambient temperature. However, it is also known to occur at such temperature, e.g., direct evidence has been shown for spillover on commercial fuel-cell, highly dispersed Pt/C, Ru/C and PtRu/C catalysts by inelastic neutron scattering.3 To exploit spillover for storage, among the key questions are whether spillover is reversible at ambient temperature and if the adsorption (refill) and desorption rates at ambient temperature are fast enough for automotive applications. In this project, we explored new sorbents by using a transition metal (e.g., Pt, Ru, Pd and Ni) as the H2 dissociation source and sorbents as the hydrogen receptor. The receptors included superactivated carbons (AX-21 and Maxsorb), metal organic frameworks (MOFs) and zeolites. Different metal doping methods have been used successfully to achieve high metal dispersion thereby allowing significant spillover enhancements, as well as a bridging technique used for bridging to MOFs. Among the metals tested, Pt is the hardest to achieve high metal dispersion (and consequently spillover) while Ru is the easiest to disperse. By properly dispersing Pt on

  10. 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

  11. Ambient air and its potential effects on conception in vitro.

    PubMed

    Cohen, J; Gilligan, A; Esposito, W; Schimmel, T; Dale, B

    1997-08-01

    Incidences of chemical air contamination (CAC) are common in assisted reproductive technology, but not reported in peer review format. Justified fear of car and industrial emissions clearly exists among reproductive specialists, but standards for air contents and gaseous emission limits have not been reported. Here, we describe air sampling methods and assay systems which can be applied to any laboratory or laboratory item. It was found that unfiltered outside air may be cleaner than high efficiency particulate air filtration (HEPA) filtered laboratory air or air obtained from incubators, due to accumulation of volatile organic compounds derived from adjacent spaces or specific laboratory products such as compressed CO2, sterile Petri dishes and other materials or devices known to release gaseous emissions. Specific groups of products such as anaesthetic gases, refrigerants, cleaning agents, hydrocarbons and aromatic compounds such as benzene and toluene are described. The latter were shown to accumulate specifically in incubators. Isopropyl alcohol was the most dominant product found, though it was not used by the laboratory staff. Concentrations of this agent were low in incubator air, indicating that it was probably absorbed by the water in the pan or by culture medium. Measures to counter CAC are proposed, including the use of activated carbon filters and oxidizing material placed in the central air handling systems, in separate free-standing units or even inside the incubators. PMID:9308805

  12. 40 CFR 50.6 - National primary and secondary ambient air quality standards for PM10.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... air quality standards for PM10. 50.6 Section 50.6 Protection of Environment ENVIRONMENTAL PROTECTION... National primary and secondary ambient air quality standards for PM10. (a) The level of the national... PM10 (particles with an aerodynamic diameter less than or equal to a nominal 10 micrometers) by: (1)...

  13. 40 CFR 50.6 - National primary and secondary ambient air quality standards for PM10.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... air quality standards for PM10. 50.6 Section 50.6 Protection of Environment ENVIRONMENTAL PROTECTION... National primary and secondary ambient air quality standards for PM10. (a) The level of the national... PM10 (particles with an aerodynamic diameter less than or equal to a nominal 10 micrometers) by: (1)...

  14. 76 FR 46083 - Secondary National Ambient Air Quality Standards for Oxides of Nitrogen and Sulfur

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-01

    ...This proposed rule is being issued as required by a consent decree governing the schedule for completion of this review of the air quality criteria and the secondary national ambient air quality standards (NAAQS) for oxides of nitrogen and oxides of sulfur. Based on its review, EPA proposes to retain the current nitrogen dioxide (NO2) and sulfur dioxide (SO2) secondary......

  15. SAMPLING AND ANALYSIS FOR POLYCHLORINATED DIBENZO-P-DIOXINS AND DIBENZOFURANS IN AMBIENT AIR

    EPA Science Inventory

    A short-term study for determination of polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) in ambient air in Green Bay, Wisconsin, has been completed. eneral Metals Works PS-1 air samplers equipped with particle filters and polyurethane foam (PUF)...

  16. 40 CFR 86.161-00 - Air conditioning environmental test facility ambient requirements.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 18 2011-07-01 2011-07-01 false Air conditioning environmental test facility ambient requirements. 86.161-00 Section 86.161-00 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CONTROL OF EMISSIONS FROM NEW AND IN-USE HIGHWAY VEHICLES AND ENGINES Emission Regulations...

  17. 40 CFR 86.161-00 - Air conditioning environmental test facility ambient requirements.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 19 2013-07-01 2013-07-01 false Air conditioning environmental test facility ambient requirements. 86.161-00 Section 86.161-00 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CONTROL OF EMISSIONS FROM NEW AND IN-USE HIGHWAY VEHICLES AND ENGINES Emission Regulations...

  18. 40 CFR 86.161-00 - Air conditioning environmental test facility ambient requirements.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 19 2014-07-01 2014-07-01 false Air conditioning environmental test facility ambient requirements. 86.161-00 Section 86.161-00 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CONTROL OF EMISSIONS FROM NEW AND IN-USE HIGHWAY VEHICLES AND ENGINES Emission Regulations...

  19. Environmental Technology Verification Report for Applikon MARGA Semi-Continuous Ambient Air Monitoring System

    EPA Science Inventory

    The verification test was conducted oer a period of 30 days (October 1 to October 31, 2008) and involved the continuous operation of duplicate semi-continuous monitoring technologies at the Burdens Creek Air Monitoring Site, an existing ambient-air monitoring station located near...

  20. Hydrogen cyanide in ambient air near a gold heap leach field: Measured vs. modeled concentrations

    NASA Astrophysics Data System (ADS)

    Orloff, Kenneth G.; Kaplan, Brian; Kowalski, Peter

    To extract gold from low-grade ores, a solution of sodium cyanide is trickled over pads of crushed ore. During this operation, small quantities of hydrogen cyanide gas may escape to the ambient air. To assess these emissions, we collected air samples at monitoring stations located on opposite sides of a gold heap leach field at distances ranging from 1100 to 1500 ft from the center of the field. Hydrogen cyanide was detected in 6 of 18 ambient air samples at concentrations ranging from 0.26 to 1.86 parts per billion (ppb). Ambient air samples collected at residential properties located within 2600 ft of the leach field did not contain detectable concentrations of cyanide (detection level of 0.2 ppb). We used site-specific data and two steady-state air dispersion models, ISCST3 and AERMOD, to predict ambient air concentrations of cyanide at the sampling points. The ISCST3 model over-predicted the measured 8-h concentrations of hydrogen cyanide by a factor of 2.4, on average, and the AERMOD model under-predicted the air concentrations of hydrogen cyanide by a factor of 0.76, on average. The major sources of uncertainty in the model predictions were the complex terrain of the area and the uncertainty in the emission rates of cyanide from the leach field. The measured and predicted concentrations of cyanide in the air samples were not at levels that would pose a human health hazard for acute or chronic exposures.

  1. 40 CFR 61.184 - Ambient air monitoring for inorganic arsenic.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... arsenic. 61.184 Section 61.184 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... for Inorganic Arsenic Emissions From Arsenic Trioxide and Metallic Arsenic Production Facilities § 61.184 Ambient air monitoring for inorganic arsenic. (a) The owner or operator of each source to...

  2. 40 CFR 61.184 - Ambient air monitoring for inorganic arsenic.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... arsenic. 61.184 Section 61.184 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... for Inorganic Arsenic Emissions From Arsenic Trioxide and Metallic Arsenic Production Facilities § 61.184 Ambient air monitoring for inorganic arsenic. (a) The owner or operator of each source to...

  3. 40 CFR 61.184 - Ambient air monitoring for inorganic arsenic.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... arsenic. 61.184 Section 61.184 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... for Inorganic Arsenic Emissions From Arsenic Trioxide and Metallic Arsenic Production Facilities § 61.184 Ambient air monitoring for inorganic arsenic. (a) The owner or operator of each source to...

  4. 40 CFR 61.184 - Ambient air monitoring for inorganic arsenic.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... arsenic. 61.184 Section 61.184 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... for Inorganic Arsenic Emissions From Arsenic Trioxide and Metallic Arsenic Production Facilities § 61.184 Ambient air monitoring for inorganic arsenic. (a) The owner or operator of each source to...

  5. 40 CFR 61.184 - Ambient air monitoring for inorganic arsenic.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... arsenic. 61.184 Section 61.184 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... for Inorganic Arsenic Emissions From Arsenic Trioxide and Metallic Arsenic Production Facilities § 61.184 Ambient air monitoring for inorganic arsenic. (a) The owner or operator of each source to...

  6. Waste combustion as a source of ambient air polybrominated diphenylesters (PBDEs)

    EPA Science Inventory

    The first comprehensive set of U.S. data on PBDE concentrations from waste combustion, with more than 40 BDE congeners reported, was compared to ambient air levels of bromodiphenylethers in the U.S. Concentrations of PBDEs were determined in the raw, pre-air pollution control sys...

  7. INDOOR/AMBIENT RESIDENTIAL AIR TOXICS RESULTS IN RURAL WESTERN MONTANA

    PubMed Central

    Ward, Tony J.; Underberg, Heidi; Jones, David; Hamilton, Raymond F.; Adams, Earle

    2009-01-01

    Indoor and ambient concentrations of 21 Volatile Organic Compounds (including 14 Hazardous Air Pollutants) were measured in the homes of nearly 80 western Montana (Missoula) high school students as part of the ‘Air Toxics Under the Big Sky’ program during the 2004/2005 and 2005/2006 school years. Target analytes were measured using low flow air sampling pumps and sorbent tubes, with analysis of the exposed samples by Thermal Desorption/Gas Chromatography/Mass Spectrometry (TD/GC/MS). The results reported here present the findings of the first indoor/ambient air toxics monitoring program conducted in a semi-rural valley location located in the Northern Rocky Mountain/western Montana region. Of all of the air toxics quantified in this study, toluene was found to be the most abundant compound in both the indoor and ambient environments during each of the two school years. Indoor log-transformed mean concentrations were found to be higher when compared with ambient log-transformed mean concentrations at P < 0.001 for the majority of the compounds, supporting the results of previous studies conducted in urban areas. For the air toxics consistently measured throughout this program, concentrations were approximately six times higher inside the student’s homes compared to those simultaneously measured directly outside their homes. For the majority of the compounds, there were no significant correlations between indoor and ambient concentrations. PMID:18548326

  8. Indoor/ambient residential air toxics results in rural western Montana.

    PubMed

    Ward, Tony J; Underberg, Heidi; Jones, David; Hamilton, Raymond F; Adams, Earle

    2009-06-01

    Indoor and ambient concentrations of 21 volatile organic compounds (including 14 hazardous air pollutants) were measured in the homes of nearly 80 western Montana (Missoula) high school students as part of the 'Air Toxics Under the Big Sky' program during the 2004/2005 and 2005/2006 school years. Target analytes were measured using low flow air sampling pumps and sorbent tubes, with analysis of the exposed samples by thermal desorption/gas chromatography/mass spectrometry (TD/GC/MS). The results reported here present the findings of the first indoor/ambient air toxics monitoring program conducted in a semi-rural valley location located in the Northern Rocky Mountain/Western Montana region. Of all of the air toxics quantified in this study, toluene was found to be the most abundant compound in both the indoor and ambient environments during each of the two school years. Indoor log-transformed mean concentrations were found to be higher when compared with ambient log-transformed mean concentrations at P < 0.001 for the majority of the compounds, supporting the results of previous studies conducted in urban areas. For the air toxics consistently measured throughout this program, concentrations were approximately six times higher inside the student's homes compared to those simultaneously measured directly outside their homes. For the majority of the compounds, there were no significant correlations between indoor and ambient concentrations. PMID:18548326

  9. Performance characteristics of ambient temperature secondary lithium cells

    NASA Technical Reports Server (NTRS)

    Deligiannis, F.; Shen, D.; Subbarao, S.; Whitcanack, L.; Halpert, G.

    1988-01-01

    State of art ambient temperature secondary lithium cells were evaluated to determine their performance capability and limitations and to assess the present status of the technology of these cells. Li-MoS2, Li-NbSe3 and Li-TiS2 cells were evaluated for their charge/discharge characteristics, rate capability, and cycle life performance. The cells evaluated have a cycle life of 100-250 cycles at moderate discharge rates (C/5). The specific energy of these cells is between 50 and 100 Wh/Kg, depending upon the system. This paper describes the details of the cell designs, the test procedures, and the results of the evaluation studies.

  10. HYDROCARBON AND CARBONYL OZONE PRECURSORS IN MEXICO CITY AMBIENT AIR

    EPA Science Inventory

    Urban air pollution is an environmental problem in many cities around the world that has serious immediate and long-term implications to the health of the population and to the physical environment. Mexico City, in particular, faces a severe air pollution problem. The city is...

  11. Ambient temperature: a factor affecting performance and physiological response of broiler chickens

    NASA Astrophysics Data System (ADS)

    Donkoh, A.

    1989-12-01

    An experiment was conducted to elucidate the influence of four constant ambient temperatures (20°, 25°, 30° and 35°C) on the performance and physiological reactions of male commercial broiler chicks from 3 to 7 weeks of age. A 12 h light-dark cycle was operated, while relative humidity and air circulation were not controlled. Exposure of broiler chickens to the 20°, 25°, 30° and 35°C treatments showed highly significant ( P<0.0001) depression in growth rate, food intake and efficiency of food utilization, and a significant increase in water consumption for the 30° and 35°C groups. Mortality was, however, not affected by the temperature treatments. Changes in physiological status, such as increased rectal temperatures, decreased concentration of red blood cells, haemoglobin, haematocrit, and total plasma protein were observed in birds housed in the higher temperature (30° and 35°C) environments. Moreover, in these broiler chickens, there was an increased blood glucose concentration and a decreased thyroid gland weight. These results indicate that continuous exposure of broiler chickens to high ambient temperatures markedly affects their performance and physiological response.

  12. Ambient and household air pollution: complex triggers of disease

    PubMed Central

    Farmer, Stephen A.; Nelin, Timothy D.; Falvo, Michael J.

    2014-01-01

    Concentrations of outdoor air pollution are on the rise, particularly due to rapid urbanization worldwide. Alternatively, poor ventilation, cigarette smoke, and other toxic chemicals contribute to rising concentrations of indoor air pollution. The World Health Organization recently reported that deaths attributable to indoor and outdoor air pollutant exposure are more than double what was originally documented. Epidemiological, clinical, and animal data have demonstrated a clear connection between rising concentrations of air pollution (both indoor and outdoor) and a host of adverse health effects. During the past five years, animal, clinical, and epidemiological studies have explored the adverse health effects associated with exposure to both indoor and outdoor air pollutants throughout the various stages of life. This review provides a summary of the detrimental effects of air pollution through examination of current animal, clinical, and epidemiological studies and exposure during three different periods: maternal (in utero), early life, and adulthood. Additionally, we recommend future lines of research while suggesting conceivable strategies to curb exposure to indoor and outdoor air pollutants. PMID:24929855

  13. Association between size-segregated particles in ambient air and acute respiratory inflammation.

    PubMed

    Han, Yiqun; Zhu, Tong; Guan, Tianjia; Zhu, Yi; Liu, Jun; Ji, Yunfang; Gao, Shuna; Wang, Fei; Lu, Huimin; Huang, Wei

    2016-09-15

    The health effects of particulate matter (PM) in ambient air are well documented. However, whether PM size plays a critical role in these effects is unclear in the population studies. This study investigated the association between the ambient concentrations of PM with varies sizes (5.6-560nm) and a biomarker of acute respiratory inflammation, the fraction of exhaled nitric oxide (FENO), in a panel of 55 elderly people in Shanghai, China. Linear mixed-effect model was fitted to estimate the association between FENO and moving average concentrations of PM, adjusting for temperature, relative humidity, day of the week, and age. Results showed that among the measured particles size range, Aitken-mode (20-100nm) particles had the strongest positive association with increased FENO when using moving average concentration of PM up to 24h prior to visits. The estimates were robust to the adjustment for gender, condition of chronic disease and use of medication, and to the sensitive analysis using different times of visits. The authors concluded that the association between acute respiratory inflammation and PM concentration of fine particulates depended on particle size, and suggested Aitken-mode particles may be the most responsible for this adverse health association. PMID:27179679

  14. DIAGNOSTIC EVALUATION OF AIR QUALITY MODELS USING ADVANCED METHODS WITH SPECIALIZED OBSERVATIONS OF SELECTED AMBIENT SPECIES -PART II

    EPA Science Inventory

    This is Part 2 of "Diagnostic Evaluation of Air Quality Models Using Advanced Methods with Specialized Observations of Selected Ambient Species". A limited field campaign to make specialized observations of selected ambient species using advanced and innovative instrumentation f...

  15. Ambient air pollution: an emerging risk factor for diabetes mellitus.

    PubMed

    Rao, Xiaoquan; Montresor-Lopez, Jessica; Puett, Robin; Rajagopalan, Sanjay; Brook, Robert D

    2015-06-01

    Growing evidence supports that air pollution has become an important risk factor for developing diabetes mellitus. Understanding the contributing effect of air pollution in population studies, elucidating the potential mechanisms involved, and identifying the most responsible pollutants are all required in order to promulgate successful changes in policy and to help formulate preventive measures in an effort to reduce the risk for diabetes. This review summarizes recent findings from epidemiologic studies and mechanistic insights that provide links between exposure to air pollution and a heightened risk for diabetes. PMID:25894943

  16. Electrical characteristics of multilayer MoS{sub 2} transistors at real operating temperatures with different ambient conditions

    SciTech Connect

    Kwon, Hyuk-Jun; Grigoropoulos, Costas P.; Jang, Jaewon Subramanian, Vivek; Kim, Sunkook

    2014-10-13

    Atomically thin, two-dimensional (2D) materials with bandgaps have attracted increasing research interest due to their promising electronic properties. Here, we investigate carrier transport and the impact of the operating ambient conditions on back-gated multilayer MoS{sub 2} field-effect transistors with a thickness of ∼50 nm at their realistic working temperatures and under different ambient conditions (in air and in a vacuum of ∼10{sup −5} Torr). Increases in temperature cause increases in I{sub min} (likely due to thermionic emission at defects), and result in decreased I{sub on} at high V{sub G} (likely due to increased phonon scattering). Thus, the I{sub on}/I{sub min} ratio decreases as the temperature increases. Moreover, the ambient effects with working temperatures on field effect mobilities were investigated. The adsorbed oxygen and water created more defect sites or impurities in the MoS{sub 2} channel, which can lead another scattering of the carriers. In air, the adsorbed molecules and phonon scattering caused a reduction of the field effect mobility, significantly. These channel mobility drop-off rates in air and in a vacuum reached 0.12 cm{sup 2}/V s K and 0.07 cm{sup 2}/V s K, respectively; the rate of degradation is steeper in air than in a vacuum due to enhanced phonon mode by the adsorbed oxygen and water molecules.

  17. A cavity ring-down spectroscopy sensor for measurements of gaseous elemental mercury - Part 1: Development for high time resolution measurements in ambient air

    NASA Astrophysics Data System (ADS)

    Pierce, A.; Obrist, D.; Moosmüller, H.; Faïn, X.; Moore, C.

    2012-12-01

    The ability to make high time resolution measurements of gaseous elemental mercury (GEM) concentrations in air is imperative for the understanding of mercury cycling. Here we describe further development and field implementation of a laboratory prototype pulsed cavity ring-down spectroscopy (CRDS) system for high time resolution, continuous and automated measurement of GEM concentrations in ambient air. In particular, we present use of an external, isotopically enriched Hg cell for automated wavelength locking and wavelength stabilization to maintain laser wavelength on the peak of GEM absorption line in ambient air. We further describe implementation of differential absorption measurements using a piezoelectric tuning element that allows for continuous accounting of system baseline extinction losses needed to calculate GEM absorption coefficients. Data acquisition systems and software programs were modified to acquire high-speed ring-down data at 50 Hz repetition rate as well as process and analyze data in real time. The system was installed in a mobile trailer, and inlet systems and temperature controls were designed to minimize effects of changes in ambient air temperature and ozone (O3) concentration. Data that identify technical challenges and interferences that occurred during measurements, including temperature fluctuations, interferences by ambient O3 and drifts in frequency conversion efficiencies are discussed. Successful development of a CRDS system capable of measuring ambient air GEM concentrations with high time resolution is based on minimizing these interferences.

  18. Benzene levels in ambient air and breath of smokers and nonsmokers in urban and pristine environments

    SciTech Connect

    Wester, R.C.; Maibach, H.I.; Gruenke, L.D.; Craig, J.C.

    1986-01-01

    Benzene levels in human breath and in ambient air were compared in the urban area of San Francisco (SF) and in a more remote coastal pristine setting of Stinson Beach, Calif. (SB). Benzene analysis was done by gas chromatography-mass spectroscopy (GC-MS). Ambient benzene levels were sevenfold higher in SF (2.6 +/- 1.3 ppb, n = 25) than SB (0.38 +/- 0.39 ppb, n = 21). In SF, benzene in smokers' breath (6.8 +/- 3.0 ppb) was greater than in nonsmokers' breath (2.5 +/- 0.8 ppb) and smokers' ambient air (3.3 +/- 0.8 ppb). In SB the same pattern was observed: benzene in smokers' breath was higher than in nonsmokers' breath and ambient air. Benzene in SF nonsmokers' breath was greater than in SB nonsmokers' breath. Marijuana-only smokers had benzene breath levels between those of smokers and nonsmokers. There was little correlation between benzene in breath and number of cigarettes smoked, or with other benzene exposures such as diet. Of special interest was the finding that benzene in breath of SF nonsmokers (2.5 +/- 0.8 ppb) was greater than that in nonsmokers ambient air (1.4 +/- 0.1 ppb). The same was true in SB, where benzene in nonsmokers breath was greater than ambient air (1.8 +/- 0.2 ppb versus 1.0 +/- 0.1 ppb on d 1 and 1.3 +/- 0.3 ppb versus 0.23 +/- 0.18 ppb on d 2). This suggests an additional source of benzene other than outdoor ambient air.

  19. Crowdsourcing urban air temperatures from smartphone battery temperatures

    NASA Astrophysics Data System (ADS)

    Overeem, A.; Robinson, J. C. R.; Leijnse, H.; Steeneveld, G. J.; Horn, B. K. P.; Uijlenhoet, R.

    2013-08-01

    Accurate air temperature observations in urban areas are important for meteorology and energy demand planning. They are indispensable to study the urban heat island effect and the adverse effects of high temperatures on human health. However, the availability of temperature observations in cities is often limited. Here we show that relatively accurate air temperature information for the urban canopy layer can be obtained from an alternative, nowadays omnipresent source: smartphones. In this study, battery temperatures were collected by an Android application for smartphones. A straightforward heat transfer model is employed to estimate daily mean air temperatures from smartphone battery temperatures for eight major cities around the world. The results demonstrate the enormous potential of this crowdsourcing application for real-time temperature monitoring in densely populated areas.

  20. Ambient air quality monitoring during the H1N1 influence period in Pune (India).

    PubMed

    Pathak, M; Deshpande, A; Mirashe, P K; Sorte, R B; Ojha, A

    2010-10-01

    Ambient air quality in an urban area is directly linked with activity level in the city including transport, business and industrial activities. Maharashtra Pollution Control Board (MPCB) has established an ambient air quality network in the city including state-of-the-art continuous air quality monitoring stations which indicate short duration air quality variations for criteria and non-criteria pollutants. The influence of H1N1 outbreak in Pune hitting its worst pandemic condition, led the civic authorities to implement stringent isolation measures including closure of schools, colleges, business malls, cinema halls, etc. Additionally, the fear of such a pandemic brought the city to a stand still. It was therefore necessary to assess the impacts of such activity level on ambient air quality in the city. It has been observed that such events have positive impacts on air quality of the city. There was a decrease in PM concentration almost to the tune of 30 to 40% if the impacts of precipitation, i.e. seasonal variations, are taken into account. Similarly, the non criteria pollutants too showed a marked but unusual decrease in their concentrations in this ever growing city. The influence of these in turn led to lowered concentrations of secondary pollutants, i.e. O3. Overall, the ambient air quality of Pune was found to be improved during the study period. PMID:22312797

  1. Controlled-Temperature Hot-Air Gun

    NASA Technical Reports Server (NTRS)

    Munoz, M. C.

    1986-01-01

    Materials that find applications in wind tunnels first tested in laboratory. Hot-Air Gun differs from commercial units in that flow rate and temperature monitored and controlled. With typical compressed-airsupply pressure of 25 to 38 psi (170 to 260 kPa), flow rate and maximum temperature are 34 stdft3/min (0.96 stdm3/min) and 1,090 degrees F (590 degrees C), respectively. Resembling elaborate but carefully regulated hot-air gun, setup used to apply blasts of air temperatures above 1,500 degrees F (815 degrees C) to test specimens.

  2. Contamination of Ambient Air with Acinetobacter baumannii on Consecutive Inpatient Days.

    PubMed

    Shimose, Luis A; Doi, Yohei; Bonomo, Robert A; De Pascale, Dennise; Viau, Roberto A; Cleary, Timothy; Namias, Nicholas; Kett, Daniel H; Munoz-Price, L Silvia

    2015-07-01

    Acinetobacter-positive patients had their ambient air tested for up to 10 consecutive days. The air was Acinetobacter positive for an average of 21% of the days; the rate of contamination was higher among patients colonized in the rectum than in the airways (relative risk [RR], 2.35; P = 0.006). Of the 6 air/clinical isolate pairs available, 4 pairs were closely related according to rep-PCR results. PMID:25926496

  3. Automatic electrochemical ambient air monitor for chloride and chlorine

    DOEpatents

    Mueller, Theodore R.

    1976-07-13

    An electrochemical monitoring system has been provided for determining chloride and chlorine in air at levels of from about 10-1000 parts per billion. The chloride is determined by oxidation to chlorine followed by reduction to chloride in a closed system. Chlorine is determined by direct reduction at a platinum electrode in 6 M H.sub.2 SO.sub.4 electrolyte. A fully automated system is utilized to (1) acquire and store a value corresponding to electrolyte-containing impurities, (2) subtract this value from that obtained in the presence of air, (3) generate coulometrically a standard sample of chlorine mixed with air sample, and determine it as chlorine and/or chloride, and (4) calculate, display, and store for permanent record the ratio of the signal obtained from the air sample and that obtained with the standard.

  4. Modeling of Magnetron Argon Plasma Issuing into Ambient Air

    NASA Astrophysics Data System (ADS)

    Li, Lin-Cun; Xia, Wei-Dong

    2008-01-01

    A mathematical model is presented to describe the heat transfer and fluid flow in a magnetron plasma torch, by means of a commercial computational fluid dynamics (CFD) code fluent. Specific calculations are presented for a gas-mixing system (i.e., an argon plasma discharging into an air environment), operating in a laminar mode. Numerical results show that an external axial magnetic field (AMF) may have a significant effect on the behavior of an arc plasma, i.e., the AMF will impel the plasma to retract axially and expand radially. In addition, the use of an AMF induces a strong air indraft at the torch spout, and the air mixing with the argon gas results in a marked increase in arc voltage. An increment in the amount of the oncoming argon gas restrains the quantity of the air indraft, and this should be responsible for a lower arc voltage in such an AMF torch when a larger gas inflow is used.

  5. 40 CFR Appendix K to Part 50 - Interpretation of the National Ambient Air Quality Standards for Particulate Matter

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 2 2012-07-01 2012-07-01 false Interpretation of the National Ambient Air Quality Standards for Particulate Matter K Appendix K to Part 50 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS NATIONAL PRIMARY AND SECONDARY AMBIENT AIR QUALITY STANDARDS Pt. 50, App. K Appendix K to Part...

  6. 40 CFR Appendix S to Part 50 - Interpretation of the Primary National Ambient Air Quality Standards for Oxides of Nitrogen...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Ambient Air Quality Standards for Oxides of Nitrogen (Nitrogen Dioxide) S Appendix S to Part 50 Protection... SECONDARY AMBIENT AIR QUALITY STANDARDS Pt. 50, App. S Appendix S to Part 50—Interpretation of the Primary... be submitted to EPA's Air Quality System (AQS), or otherwise available to EPA, meeting...

  7. 40 CFR Appendix N to Part 50 - Interpretation of the National Ambient Air Quality Standards for PM2.5

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... PROTECTION AGENCY (CONTINUED) AIR PROGRAMS NATIONAL PRIMARY AND SECONDARY AMBIENT AIR QUALITY STANDARDS Pt... determining when the annual and 24-hour primary and secondary national ambient air quality standards (NAAQS... appendix D of 40 CFR part 58, then 3 years of spatially averaged annual means will be averaged to...

  8. 40 CFR 50.13 - National primary and secondary ambient air quality standards for PM2.5.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... air quality standards for PM2.5. 50.13 Section 50.13 Protection of Environment ENVIRONMENTAL....13 National primary and secondary ambient air quality standards for PM2.5. (a) The national primary... the ambient air as PM2.5 (particles with an aerodynamic diameter less than or equal to a nominal...

  9. 40 CFR 50.13 - National primary and secondary ambient air quality standards for PM2.5.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... air quality standards for PM2.5. 50.13 Section 50.13 Protection of Environment ENVIRONMENTAL....13 National primary and secondary ambient air quality standards for PM2.5. (a) The national primary... the ambient air as PM2.5 (particles with an aerodynamic diameter less than or equal to a nominal...

  10. 40 CFR 50.13 - National primary and secondary ambient air quality standards for PM2.5.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... air quality standards for PM2.5. 50.13 Section 50.13 Protection of Environment ENVIRONMENTAL....13 National primary and secondary ambient air quality standards for PM2.5. (a) The national primary... the ambient air as PM2.5 (particles with an aerodynamic diameter less than or equal to a nominal...

  11. 40 CFR 50.13 - National primary and secondary ambient air quality standards for PM2.5.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... air quality standards for PM2.5. 50.13 Section 50.13 Protection of Environment ENVIRONMENTAL....13 National primary and secondary ambient air quality standards for PM2.5. (a) The national primary... the ambient air as PM2.5 (particles with an aerodynamic diameter less than or equal to a nominal...

  12. 40 CFR 50.13 - National primary and secondary ambient air quality standards for PM2.5.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... air quality standards for PM2.5. 50.13 Section 50.13 Protection of Environment ENVIRONMENTAL....13 National primary and secondary ambient air quality standards for PM2.5. (a) The national primary... the ambient air as PM2.5 (particles with an aerodynamic diameter less than or equal to a nominal...

  13. 46 CFR 153.370 - Minimum relief valve setting for ambient temperature cargo tanks.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Minimum relief valve setting for ambient temperature... temperature cargo tanks. The relief valve setting for a containment system that carries a cargo at ambient temperature must at least equal the cargo's vapor pressure at 46 °C (approx. 115 °F)....

  14. 46 CFR 153.370 - Minimum relief valve setting for ambient temperature cargo tanks.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 5 2012-10-01 2012-10-01 false Minimum relief valve setting for ambient temperature... temperature cargo tanks. The relief valve setting for a containment system that carries a cargo at ambient temperature must at least equal the cargo's vapor pressure at 46 °C (approx. 115 °F)....

  15. 46 CFR 153.370 - Minimum relief valve setting for ambient temperature cargo tanks.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 5 2013-10-01 2013-10-01 false Minimum relief valve setting for ambient temperature... temperature cargo tanks. The relief valve setting for a containment system that carries a cargo at ambient temperature must at least equal the cargo's vapor pressure at 46 °C (approx. 115 °F)....

  16. Air separation with temperature and pressure swing

    DOEpatents

    Cassano, Anthony A.

    1986-01-01

    A chemical absorbent air separation process is set forth which uses a temperature swing absorption-desorption cycle in combination with a pressure swing wherein the pressure is elevated in the desorption stage of the process.

  17. BRAIN TEMPERATURE MEASUREMENT IN RATS: A COMPARISON OF MICROWAVE AND AMBIENT TEMPERATURE EXPOSURES

    EPA Science Inventory

    The brain and core temperatures of rats and rat carcasses exposed to microwave radiation (2450 MHz) or elevated air temperatures were measured in two studies. In general, no substantial evidence for temperature differentials, or hot spots, in the brain of these animals was found....

  18. Biogenic hydrocarbon contribution to the ambient air of selected areas

    NASA Astrophysics Data System (ADS)

    Arnts, Robert R.; Meeks, Sarah A.

    In response to suggestions that biogenic emissions are responsible for high hydrocarbon concentrations described in several reports, a short-term sampling program was initiated in the reported areas to test this hypothesis. Limited numbers of whole-air samples were collected in Tedlar bags and analyzed by gas chromatography (GC) with flame ionization detection. Tulsa air was found to contain an average of 0.2% isoprene of the total nonmethane hydrocarbon (TNMHC) load. Rio Blanco County, Colorado, and Smoky Mountain air, respectively, averaged about 2 % and 4 % biogenic hydrocarbon of the total nonmethane hydrocarbon loads. Isoprene appears to be a dominant olefin in rural and remote areas. Although the tests were of short duration, results suggest monoterpenes and isoprene constitute only minor components in these areas relative to anthropogenic hydrocarbons.

  19. Evaluation of methodology for determination of polyhalogenated dibenzo-p-dioxins and dibenzofurans in ambient air

    SciTech Connect

    Harless, R.L.; Lewis, R.G.; McDaniel, D.D.; Gibson, J.F.; Dupuy, A.E.

    1991-01-01

    General Metals Works PS-1 PUF air samplers and an analytical method based on high resolution gas chromatography - high resolution mass spectrometry (HRGC-HRMS) were evaluated for determination of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDDs/PCDFs) and polybrominated dibenzo-p-dioxins and dibenzofurans (PBDDs/PBDFs) in ambient air. Dilute solutions of these compounds and 13C12-1234-TCDD were used to spike the filters of PS-1 air samplers which were then operated 24 hours to sample 350-400 cu m ambient air. After sampling, each quartz-fiber filter and polyurethane foam (PUF) were spiked with 13C12-labeled PCDD, PCDF, PBDD, and PBDF internal standards before separate Soxhlet extractions with benzene. The extracts were subjected to clean-up procedures using microcolumns of silica gel, alumina and carbon and then analyzed by HRGC-HRMS. Results derived from this study satisfied QA/QC requirements for analytical data and demonstrated that the methodology could accurately determine pg/cu m and sub-pg/cu m levels of these compounds in ambient air. Background levels detected in ambient air are also discussed.

  20. Optimization of non-aqueous electrolytes for Primary lithium/air batteries operated in Ambient Enviroment

    SciTech Connect

    Xu, Wu; Xiao, Jie; Zhang, Jian; Wang, Deyu; Zhang, Jiguang

    2009-07-07

    The selection and optimization of non-aqueous electrolytes for ambient operations of lithium/air batteries has been studied. Organic solvents with low volatility and low moisture absorption are necessary to minimize the change of electrolyte compositions and the reaction between lithium anode and water during discharge process. It is critical to make the electrolytes with high polarity so that it can reduce wetting and flooding of carbon based air electrode and lead to improved battery performance. For ambient operations, the viscosity, ionic conductivity, and oxygen solubility of the electrolyte are less important than the polarity of organic solvents once the electrolyte has reasonable viscosity, conductivity, and oxygen solubility. It has been found that PC/EC mixture is the best solvent system and LiTFSI is the most feasible salt for ambient operations of Li/air batteries. Battery performance is not very sensitive to PC/EC ratio or salt concentration.

  1. 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

  2. Comparison of Ambient Radon Concentrations in Air in the Northern Mojave Desert from Continuous and Integrating Instruments

    SciTech Connect

    David S. Shafer; David McGraw; Lynn H. Karr; Greg McCurdy; Tammy L. Kluesner; Karen J. Gray; Jeffrey Tappen

    2010-05-18

    As part of a program to characterize and baseline environmental parameters, ambient radon-222 (Rn) monitoring was conducted in the rural community of Amargosa Valley, NV, the closest community to Yucca Mountain. Passive integrating and continuous Rn monitoring instruments were deployed adjacent to the Community Environmental Monitoring Program (CEMP) station in Amargosa Valley. The CEMP station provided real-time ambient gamma exposure and meteorological data used to correct the integrated Rn measurements, verified the meteorological data collected by the continuous Rn monitoring instrument, and for provided instrumentation for evaluating the relationships between meteorological conditions and Rn concentrations. Hourly Rn concentrations in air measured by the continuous Rn monitoring instrument (AlphaGUARD®) were compared to the average hourly values for the integrating Rn measurements (E-PERM®) by dividing the total Rn measurements by the number of hours the instruments were deployed. The results of the comparison indicated that average hourly ambient Rn concentrations as measured by both methods ranged from 0.2 to 0.4 pico-curies per liter of air. Ambient Rn values for the AlphaGUARD exhibited diurnal variations. When Rn concentrations were compared with measurements of temperature (T), barometric pressure, and relative humidity, the correlation (inversely) was highest with T, albeit weakly.

  3. Simple and accurate quantification of BTEX in ambient air by SPME and GC-MS.

    PubMed

    Baimatova, Nassiba; Kenessov, Bulat; Koziel, Jacek A; Carlsen, Lars; Bektassov, Marat; Demyanenko, Olga P

    2016-07-01

    Benzene, toluene, ethylbenzene and xylenes (BTEX) comprise one of the most ubiquitous and hazardous groups of ambient air pollutants of concern. Application of standard analytical methods for quantification of BTEX is limited by the complexity of sampling and sample preparation equipment, and budget requirements. Methods based on SPME represent simpler alternative, but still require complex calibration procedures. The objective of this research was to develop a simpler, low-budget, and accurate method for quantification of BTEX in ambient air based on SPME and GC-MS. Standard 20-mL headspace vials were used for field air sampling and calibration. To avoid challenges with obtaining and working with 'zero' air, slope factors of external standard calibration were determined using standard addition and inherently polluted lab air. For polydimethylsiloxane (PDMS) fiber, differences between the slope factors of calibration plots obtained using lab and outdoor air were below 14%. PDMS fiber provided higher precision during calibration while the use of Carboxen/PDMS fiber resulted in lower detection limits for benzene and toluene. To provide sufficient accuracy, the use of 20mL vials requires triplicate sampling and analysis. The method was successfully applied for analysis of 108 ambient air samples from Almaty, Kazakhstan. Average concentrations of benzene, toluene, ethylbenzene and o-xylene were 53, 57, 11 and 14µgm(-3), respectively. The developed method can be modified for further quantification of a wider range of volatile organic compounds in air. In addition, the new method is amenable to automation. PMID:27154647

  4. Crowdsourcing urban air temperature measurements using smartphones

    NASA Astrophysics Data System (ADS)

    Balcerak, Ernie

    2013-10-01

    Crowdsourced data from cell phone battery temperature sensors could be used to contribute to improved real-time, high-resolution air temperature estimates in urban areas, a new study shows. Temperature observations in cities are in some cases currently limited to a few weather stations, but there are millions of smartphone users in many cities. The batteries in cell phones have temperature sensors to avoid damage to the phone.

  5. 75 FR 81126 - Revisions to Lead Ambient Air Monitoring Requirements

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-12-27

    ... of the State and local monitoring network. If after a review of the data from the monitoring study we... Worldwide Web through the Technology Transfer Network (TTN). Following the Administrator's signature, a copy... various areas of air pollution control. III. Background The EPA issued a final rule on November 12,...

  6. Economic Activity and Trends in Ambient Air Pollution

    PubMed Central

    Davis, Mary E.; Laden, Francine; Hart, Jaime E.; Garshick, Eric; Smith, Thomas J.

    2010-01-01

    Background One challenge in assessing the health effects of human exposure to air pollution in epidemiologic studies is the lack of widespread historical air pollutant monitoring data with which to characterize past exposure levels. Objectives Given the availability of long-term economic data, we relate economic activity levels to patterns in vehicle-related particulate matter (PM) over a 30-year period in New Jersey, USA, to provide insight into potential historical surrogate markers of air pollution. Methods We used statewide unemployment and county-level trucking industry characteristics to estimate historical coefficient of haze (COH), a marker of vehicle-related PM predominantly from diesel exhaust. A total of 5,920 observations were included across 25 different locations in New Jersey between 1971 and 2003. Results A mixed-modeling approach was employed to estimate the impact of economic indicators on measured COH. The model explained approximately 50% of the variability in COH as estimated by the overall R2 value. Peaks and lows in unemployment tracked negatively with similar extremes in COH, whereas employment in the trucking industry was positively associated with COH. Federal air quality regulations also played a large and significant role in reducing COH levels over the study period. Conclusions This new approach outlines an alternative method to reconstruct historical exposures that may greatly aid epidemiologic research on specific causes of health effects from urban air pollution. Economic activity data provide a potential surrogate marker of changes in exposure levels over time in the absence of direct monitoring data for chronic disease studies, but more research in this area is needed. PMID:20056563

  7. Ambient Temperature Influences Australian Native Stingless Bee (Trigona carbonaria) Preference for Warm Nectar

    PubMed Central

    Norgate, Melanie; Boyd-Gerny, Skye; Simonov, Vera; Rosa, Marcello G. P.; Heard, Tim A.; Dyer, Adrian G.

    2010-01-01

    The interaction between flowers and insect pollinators is an important aspect of the reproductive mechanisms of many plant species. Several laboratory and field studies indicate that raising flower temperature above ambient can be an advantage in attracting pollinators. Here we demonstrate that this preference for warmer flowers is, in fact, context-dependent. Using an Australian native bee as a model, we demonstrate for the first time a significant shift in behaviour when the ambient temperature reaches 34°C, at which point bees prefer ambient temperature nectar over warmer nectar. We then use thermal imaging techniques to show warmer nectar maintains the flight temperature of bees during the period of rest on flowers at lower ambient temperatures but the behavioural switch is associated with the body temperature rising above that maintained during flight. These findings suggest that flower-pollinator interactions are dependent upon ambient temperature and may therefore alter in different thermal environments. PMID:20711250

  8. 76 FR 6056 - Additional Air Quality Designations for the 2006 24-Hour Fine Particle National Ambient Air...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-02-03

    ... Protection Agency FR Federal Register NAAQS National Ambient Air Quality Standards NTTAA National Technology... (74 FR 58688), EPA deferred designations for three areas to evaluate further the reason for their high... November 13, 2009 notice (74 FR 58688), we also announced that our review of 2006-2008 monitoring data...

  9. 77 FR 65310 - Additional Air Quality Designations for the 2006 24-Hour Fine Particle National Ambient Air...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-26

    ... the 2006 24-hour Fine Particle (PM 2.5 ) National Ambient Air Quality Standards,'' 74 FR 58688... Federal Regulations DC District of Columbia EO Executive Order EPA Environmental Protection Agency FR... EPA finalized designations for the 2006 24-hour PM 2.5 NAAQS (74 FR 58688, November 13, 2009), the...

  10. Comparison of stationary and personal air sampling with an air dispersion model for children’s ambient exposure to manganese

    EPA Science Inventory

    Manganese (Mn) is ubiquitous in the environment and essential for normal growth and development, yet excessive exposure can lead to impairments in neurological function. This study modeled ambient Mn concentrations as an alternative to stationary and personal air sampling to asse...

  11. Raman Channel Temperature Measurement of SiC MESFET as a Function of Ambient Temperature and DC Power

    NASA Technical Reports Server (NTRS)

    Ponchak, George E.; Eldridge, Jeffrey J.; Krainsky, Isay L.

    2009-01-01

    Raman spectroscopy is used to measure the junction temperature of a Cree SiC MESFET as a function of the ambient temperature and DC power. The carrier temperature, which is approximately equal to the ambient temperature, is varied from 25 C to 450 C, and the transistor is biased with VDS=10V and IDS of 50 mA and 100 mA. It is shown that the junction temperature is approximately 52 and 100 C higher than the ambient temperature for the DC power of 500 and 1000 mW, respectively.

  12. Humidity-resistant ambient-temperature solid-electrolyte amperometric sensing apparatus

    DOEpatents

    Zaromb, S.

    1994-06-21

    Apparatus and methods for detecting selected chemical compounds in air or other gas streams at room or ambient temperature includes a liquid-free humidity-resistant amperometric sensor comprising a sensing electrode and a counter and reference electrode separated by a solid electrolyte. The sensing electrode preferably contains a noble metal, such as Pt black. The electrolyte is water-free, non-hygroscopic, and substantially water-insoluble, and has a room temperature ionic conductivity [>=]10[sup [minus]4] (ohm-cm)[sup [minus]1], and preferably [>=]0.01 (ohm-cm)[sup [minus]1]. The conductivity may be due predominantly to Ag[sup +] ions, as in Ag[sub 2]WO[sub 4], or to F[sup [minus

  13. Nowcasting daily minimum air and grass temperature

    NASA Astrophysics Data System (ADS)

    Savage, M. J.

    2016-02-01

    Site-specific and accurate prediction of daily minimum air and grass temperatures, made available online several hours before their occurrence, would be of significant benefit to several economic sectors and for planning human activities. Site-specific and reasonably accurate nowcasts of daily minimum temperature several hours before its occurrence, using measured sub-hourly temperatures hours earlier in the morning as model inputs, was investigated. Various temperature models were tested for their ability to accurately nowcast daily minimum temperatures 2 or 4 h before sunrise. Temperature datasets used for the model nowcasts included sub-hourly grass and grass-surface (infrared) temperatures from one location in South Africa and air temperature from four subtropical sites varying in altitude (USA and South Africa) and from one site in central sub-Saharan Africa. Nowcast models used employed either exponential or square root functions to describe the rate of nighttime temperature decrease but inverted so as to determine the minimum temperature. The models were also applied in near real-time using an open web-based system to display the nowcasts. Extrapolation algorithms for the site-specific nowcasts were also implemented in a datalogger in an innovative and mathematically consistent manner. Comparison of model 1 (exponential) nowcasts vs measured daily minima air temperatures yielded root mean square errors (RMSEs) <1 °C for the 2-h ahead nowcasts. Model 2 (also exponential), for which a constant model coefficient ( b = 2.2) was used, was usually slightly less accurate but still with RMSEs <1 °C. Use of model 3 (square root) yielded increased RMSEs for the 2-h ahead comparisons between nowcasted and measured daily minima air temperature, increasing to 1.4 °C for some sites. For all sites for all models, the comparisons for the 4-h ahead air temperature nowcasts generally yielded increased RMSEs, <2.1 °C. Comparisons for all model nowcasts of the daily grass

  14. Nowcasting daily minimum air and grass temperature.

    PubMed

    Savage, M J

    2016-02-01

    Site-specific and accurate prediction of daily minimum air and grass temperatures, made available online several hours before their occurrence, would be of significant benefit to several economic sectors and for planning human activities. Site-specific and reasonably accurate nowcasts of daily minimum temperature several hours before its occurrence, using measured sub-hourly temperatures hours earlier in the morning as model inputs, was investigated. Various temperature models were tested for their ability to accurately nowcast daily minimum temperatures 2 or 4 h before sunrise. Temperature datasets used for the model nowcasts included sub-hourly grass and grass-surface (infrared) temperatures from one location in South Africa and air temperature from four subtropical sites varying in altitude (USA and South Africa) and from one site in central sub-Saharan Africa. Nowcast models used employed either exponential or square root functions to describe the rate of nighttime temperature decrease but inverted so as to determine the minimum temperature. The models were also applied in near real-time using an open web-based system to display the nowcasts. Extrapolation algorithms for the site-specific nowcasts were also implemented in a datalogger in an innovative and mathematically consistent manner. Comparison of model 1 (exponential) nowcasts vs measured daily minima air temperatures yielded root mean square errors (RMSEs) <1 °C for the 2-h ahead nowcasts. Model 2 (also exponential), for which a constant model coefficient (b = 2.2) was used, was usually slightly less accurate but still with RMSEs <1 °C. Use of model 3 (square root) yielded increased RMSEs for the 2-h ahead comparisons between nowcasted and measured daily minima air temperature, increasing to 1.4 °C for some sites. For all sites for all models, the comparisons for the 4-h ahead air temperature nowcasts generally yielded increased RMSEs, <2.1 °C. Comparisons for all model nowcasts of the daily grass

  15. Ambient temperature effects on taste aversion conditioned by ethanol: contribution of ethanol-induced hypothermia.

    PubMed

    Cunningham, C L; Niehus, J S; Bachtold, J F

    1992-12-01

    Six experiments examined the effects of low (5-10 degrees C), normal (21 degrees C), or high (32 degrees) ambient temperature on conditioned taste aversion and body temperature changes produced by ethanol, lithium chloride, or morphine sulfate. Fluid-deprived rats received five to seven taste conditioning trials at 48-hr intervals. On each trial, access to saccharin at normal ambient temperature was followed by injection of drug or saline and placement for 6 hr into a temperature-controlled enclosure. Exposure to low ambient temperature facilitated, whereas exposure to high ambient temperature retarded acquisition of ethanol-induced conditioned taste aversion. The ability of an alteration in ambient temperature to influence conditioned taste aversion varied as a function of ethanol dose and was related to ambient temperature's effect on ethanol-induced hypothermia. More specifically, strength of conditioned taste aversion was negatively correlated with core body temperature after ethanol injection. Alterations in ambient temperature alone did not affect ingestion of a paired flavor solution in the absence of drug. Moreover, alterations in ambient temperature did not appear to influence conditioned taste aversion by changing ethanol pharmacokinetics. Finally, high and low ambient temperature did not affect development of taste aversion conditioned by lithium chloride or morphine sulfate. The overall pattern of data presented by these experiments supports the hypothesis that ambient-temperature influences strength of ethanol-induced conditioned taste aversion by altering the hypothermic response to ethanol. More generally, these data support the suggestion that body temperature change induced by ethanol is related to ethanol's aversive motivational effects and may be involved in modulating ethanol intake. PMID:1471766

  16. Nocturnal stomatal conductance and ambient air quality standards for ozone

    NASA Astrophysics Data System (ADS)

    Musselman, Robert C.; Minnick, Tamera J.

    Vegetation response to ozone depends on ozone conductance into leaves and the defensive action inside the leaf. Ozone parameters currently used for air quality standards do not incorporate conductance or defensive components. Nighttime flux has often been ignored in ozone metrics relating to plant response, since ozone concentration and conductance are considered to be minimal at night. However, ozone concentration can remain relatively high at night, particularly in mountainous areas. Although conductance is lower at night than during the day for most plants, nocturnal conductance can result in considerable ozone flux into plants. Further, plants can be more susceptible to ozone exposure at night than during the daytime, a result of lower plant defenses at night. Any ozone metric used to relate air quality to plant response should use a 24 h ozone exposure period to include the nighttime exposures. It should also incorporate plant defensive mechanisms or their surrogate.

  17. Energy requirements for CO2 capture from ambient air (DAC) competitive with capture from flue-gas (PCC)

    NASA Astrophysics Data System (ADS)

    Meinrenken, Christoph

    2015-03-01

    Capture of CO2, whether from a flue gas source (PCC) or from distributed sources via ambient air (DAC), is a key enabling technology to provide carbon for sustainable synthetic energy carriers such as solar fuels. Based on thermodynamic minimum considerations, DAC is often expected to require about 3 times more energy (per ton CO2 captured) than PCC because CO2 in ambient air is more dilute. Here, we calculate the energy required for a humidity swing-based DAC installation that uses an anionic exchange resin as sorbent. The calculation uses recently measured equilibrium CO2 loadings of the sorbent as function of partial CO2 pressure, temperature, and humidity. We calculate the installation's electricity consumption to be about 45 kJ per mole of pure CO2 at 1 bar (scenario-dependent). Furthermore, we estimate the amount of heat provided by ambient air and thus provide context of the overall energy and entropy balance and thermodynamic minimum views. The electricity consumption is competitive with typical parasitic loads of PCC-equipped coal-fired power plants (40-50 kJ per mole at same pressure) and significantly lower than predicted for other DAC installations such as Na(OH) sorbent-based systems. Our analyses elucidate why DAC is not always more energy-intensive that PCC, thus alleviating often cited concerns of significant cost impediments. Financial support by ABB for research presented herein is gratefully acknowledged.

  18. Exposure to Ambient Air Pollution and Premature Rupture of Membranes.

    PubMed

    Wallace, Maeve E; Grantz, Katherine L; Liu, Danping; Zhu, Yeyi; Kim, Sung Soo; Mendola, Pauline

    2016-06-15

    Premature rupture of membranes (PROM) is a major factor that predisposes women to preterm delivery. Results from previous studies have suggested that there are associations between exposure to air pollution and preterm birth, but evidence of a relationship with PROM is sparse. Modified Community Multiscale Air Quality models were used to estimate mean exposures to particulate matter less than 10 µm or less than 2.5 µm in aerodynamic diameter, nitrogen oxides, carbon monoxide, sulfur dioxide, and ozone among 223,375 singleton deliveries in the Air Quality and Reproductive Health Study (2002-2008). We used log-linear models with generalized estimating equations to estimate adjusted relative risks and 95% confidence intervals for PROM per each interquartile-range increase in pollutants across the whole pregnancy, on the day of delivery, and 5 hours before delivery. Whole-pregnancy exposures to carbon monoxide and sulfur dioxide were associated with an increased risk of PROM (for carbon monoxide, relative risk (RR) = 1.09, 95% confidence interval (CI): 1.04, 1.14; for sulfur dioxide, RR = 1.15, 95% CI: 1.06, 1.25) but not preterm PROM. Ozone exposure increased the risk of PROM on the day of delivery (RR = 1.06, 95% CI: 1.02, 1.09) and 1 day prior (RR = 1.04, 95% CI: 1.01, 1.07). In the 5 hours preceding delivery, there were 3%-7% increases in risk associated with exposure to ozone and particulate matter less than 2.5 µm in aerodynamic diameter and inverse associations with exposure to carbon monoxide and nitrogen oxides. Acute and long-term air pollutant exposures merit further study in relation to PROM. PMID:27188941

  19. Npvf: Hypothalamic Biomarker of Ambient Temperature Independent of Nutritional Status

    PubMed Central

    Jaroslawska, Julia; Chabowska-Kita, Agnieszka; Kaczmarek, Monika M.; Kozak, Leslie P.

    2015-01-01

    The mechanism by which mice, exposed to the cold, mobilize endogenous or exogenous fuel sources for heat production is unknown. To address this issue we carried out experiments using 3 models of obesity in mice: C57BL/6J+/+ (wild-type B6) mice with variable susceptibility to obesity in response to being fed a high-fat diet (HFD), B6. Ucp1-/- mice with variable diet-induced obesity (DIO) and a deficiency in brown fat thermogenesis and B6. Lep-/- with defects in thermogenesis, fat mobilization and hyperphagia. Mice were exposed to the cold and monitored for changes in food intake and body composition to determine their energy balance phenotype. Upon cold exposure wild-type B6 and Ucp1-/- mice with diet-induced obesity burned endogenous fat in direct proportion to their fat reserves and changes in food intake were inversely related to fat mass, whereas leptin-deficient and lean wild-type B6 mice fed a chow diet depended on increased food intake to fuel thermogenesis. Analysis of gene expression in the hypothalamus to uncover a central regulatory mechanism revealed suppression of the Npvf gene in a manner that depends on the reduced ambient temperature and degree of exposure to the cold, but not on adiposity, leptin levels, food intake or functional brown fat. PMID:26070086

  20. Ambient temperature and emergency room admissions for acute coronary syndrome in Taiwan

    NASA Astrophysics Data System (ADS)

    Liang, Wen-Miin; Liu, Wen-Pin; Chou, Sze-Yuan; Kuo, Hsien-Wen

    2008-01-01

    Acute coronary syndrome (ACS) is an important public health problem around the world. Since there is a considerable seasonal fluctuation in the incidence of ACS, climatic temperature may have an impact on the onset of this disease. The objective of this study was to assess the relationship between the average daily temperature, diurnal temperature range and emergency room (ER) admissions for ACS in an ER in Taichung City, Taiwan. A longitudinal study was conducted which assessed the correlation of the average daily temperature and the diurnal temperature range to ACS admissions to the ER of the city’s largest hospital. Daily ER admissions for ACS and ambient temperature were collected from 1 January 2000 to 31 March 2003. The Poisson regression model was used in the analysis after adjusting for the effects of holiday, season, and air pollutant concentrations. The results showed that there was a negative significant association between the average daily temperature and ER admissions for ACS. ACS admissions to the ER increased 30% to 70% when the average daily temperature was lower than 26.2°C. A positive association between the diurnal temperature range and ACS admissions was also noted. ACS admissions increased 15% when the diurnal temperature range was over 8.3°C. The data indicate that patients suffering from cardiovascular disease must be made aware of the increased risk posed by lower temperatures and larger changes in temperature. Hospitals and ERs should take into account the increased demand of specific facilities during colder weather and wider temperature variations.

  1. Temperature Tunable Air-Gap Etalon Filter

    NASA Technical Reports Server (NTRS)

    Krainak, Michael A.; Stephen, Mark A.; Lunt, David L.

    1998-01-01

    We report on experimental measurements of a temperature tuned air-gap etalon filter. The filter exhibits temperature dependent wavelength tuning of 54 pm/C. It has a nominal center wavelength of 532 nm. The etalon filter has a 27 pm optical bandpass and 600 pm free spectral range (finesse approximately 22). The experimental results are in close agreement with etalon theory.

  2. Physiological responses of Houbara bustards to high ambient temperatures.

    PubMed

    Tieleman, B Irene; Williams, Joseph B; LaCroix, Frédéric; Paillat, Patrick

    2002-02-01

    Desert birds often experience a scarcity of drinking water and food and must survive episodes of high ambient temperature (T(a)). The physiological mechanisms that promote survival during extended periods of high T(a) have received little attention. We investigated the physiological responses of wild-caught and captive-reared Houbara bustards, Chlamydotis macqueenii, to T(a) values ranging from below 0 degrees C to 55 degrees C, well above those in most previous studies of birds. Captive-reared Houbara bustards (mass 1245+/-242 g, N=7, mean +/- S.D.) in summer have a resting metabolic rate (RMR) of 261.4 kJ day(-1), 26 % below allometric predictions, and a total evaporative water loss (TEWL) at 25 degrees C of 25.8 g day(-1), 31 % below predictions. When T(a) exceeded body temperature (T(b)), the dry heat transfer coefficient decreased, a finding supporting the prediction that birds should minimize dry heat gain from the environment at high T(a) values. Houbara bustards withstand high T(a) values without becoming hyperthermic; at 45 degrees C, T(b) was on average 0.9 degrees C higher than at 25 degrees C. RMR and TEWL of captive-bred Houbara bustards were 23 % and 46 % higher in winter than in summer, respectively. Captive-reared Houbara bustards had a 17 % lower RMR and a 28 % lower TEWL than wild-born birds with similar genetic backgrounds. Differences in body composition between wild-caught and captive-reared birds were correlated with differences in physiological performance. PMID:11893764

  3. Ambient air cooling for concealed soft body armor in a hot environment.

    PubMed

    Ryan, Greg A; Bishop, Stacy H; Herron, Robert L; Katica, Charles P; Elbon, Bre'anna L; Bosak, Andrew M; Bishop, Phillip

    2014-01-01

    Concealed soft body armor inhibits convective and evaporative heat loss and increases heat storage, especially in hot environments. One option to potentially mitigate heat storage is to promote airflow under the soft body armor. The purpose of this study was to evaluate the effect of ambient air induction (∼100 liters per minute) on heat strain while wearing concealed soft body armor in a hot environment (wet bulb globe temperature = 30°C). A counter-balanced, repeated measures protocol was performed with nine healthy male volunteers. Participants were fitted with either a traditional or modified Level II concealed soft body armor. Participants performed cycles of 12 min of walking (1.25 liters per minute) and 3 min of arm curls (0.6 liters per minute) for a total of 60 min. Two-way repeated measures ANOVA was used to assess the mean differences in physiological measures (rectal temperature, heart rate, micro-environment [temperature and relative humidity]). Post hoc Bonferroni analysis and paired samples t-tests (alpha = 0.01) were conducted on omnibus significant findings. Perceptual measures (perceived exertion, thermal comfort) were analyzed using Wilcoxon Signed Ranks Tests. Modification led to an improvement in perceived exertion at 45 min (MOD: 10 ± 1; CON: 11 ± 2; p ≤ 0.001) and 60 min (MOD: 10 ± 2; CON: 12 ± 2; p ≤ 0.001) and a reduction in micro-environment temperature in MOD (1.0 ± 0.2°C, p = 0.03) compared to CON. Modification did not attenuate change in rectal temperature or heart rate (p < 0.01) during 60-min work bout. Change in rectal temperature approached significance between MOD and CON at the end of the work bout (MOD: 0.4 ± 0.2°C; CON: 0.7 ± 0.3°C; p = 0.048). The slope of rectal temperature was significantly greater (p = 0.04) under CON compared to MOD. These data suggest that air induction may provide small benefits while wearing concealed soft body armor, though improvements are needed to lessen physiological strain

  4. Effect of ambient air quality on throughfall acidity

    SciTech Connect

    Chen, C.W.; Clesceri, N.L.; Gherini, S.A.; Goldstein, R.A.

    1985-06-01

    Observations at Woods Lake-watershed in the Adirondacks (New York) indicate that precipitation is further acidified by passage through coniferous canopies; conversely, passage through deciduous canopies has a net alkalizing effect. Both effects are dependent upon the levels of air quality. If the aerosol concentrations were to decrease to 35% of the current levels, both types of canopy would have a net alkalizing effect on incident precipitation. If the aerosol concentrations doubled, both canopy types would be net acidifiers of throughfall. The experimental procedure of varying aerosol concentration in an enclosed chamber may provide a means for measuring foliar exudation.

  5. 40 CFR Appendix I to Part 50 - Interpretation of the 8-Hour Primary and Secondary National Ambient Air Quality Standards for Ozone

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... and Secondary National Ambient Air Quality Standards for Ozone I Appendix I to Part 50 Protection of... Secondary National Ambient Air Quality Standards for Ozone 1. General. This appendix explains the data... secondary ambient air quality standards for ozone specified in § 50.10 are met at an ambient ozone...

  6. 40 CFR Appendix I to Part 50 - Interpretation of the 8-Hour Primary and Secondary National Ambient Air Quality Standards for Ozone

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... and Secondary National Ambient Air Quality Standards for Ozone I Appendix I to Part 50 Protection of... Secondary National Ambient Air Quality Standards for Ozone 1. General. This appendix explains the data... secondary ambient air quality standards for ozone specified in § 50.10 are met at an ambient ozone...

  7. 40 CFR Appendix I to Part 50 - Interpretation of the 8-Hour Primary and Secondary National Ambient Air Quality Standards for Ozone

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... and Secondary National Ambient Air Quality Standards for Ozone I Appendix I to Part 50 Protection of... Secondary National Ambient Air Quality Standards for Ozone 1. General. This appendix explains the data... secondary ambient air quality standards for ozone specified in § 50.10 are met at an ambient ozone...

  8. 40 CFR Appendix I to Part 50 - Interpretation of the 8-Hour Primary and Secondary National Ambient Air Quality Standards for Ozone

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... and Secondary National Ambient Air Quality Standards for Ozone I Appendix I to Part 50 Protection of... Secondary National Ambient Air Quality Standards for Ozone 1. General. This appendix explains the data... secondary ambient air quality standards for ozone specified in § 50.10 are met at an ambient ozone...

  9. 40 CFR Appendix I to Part 50 - Interpretation of the 8-Hour Primary and Secondary National Ambient Air Quality Standards for Ozone

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... and Secondary National Ambient Air Quality Standards for Ozone I Appendix I to Part 50 Protection of... Secondary National Ambient Air Quality Standards for Ozone 1. General. This appendix explains the data... secondary ambient air quality standards for ozone specified in § 50.10 are met at an ambient ozone...

  10. Mutagenicity of ambient air pollutants collected near aluminum industries

    NASA Astrophysics Data System (ADS)

    Thrane, K. E.; Aune, T.; Søderlund, E.; Aune, K. Tveito; Hongslo, J.; Møller, M.

    Mutagenicity has been tested in air samples collected in the summer and in the winter near four Norwegian aluminum plants. The samples were separated into a particulate and a volatile fraction and tested for mutagenicity by a quantitative reversion assay which showed that the suspended particles were clearly mutagenic. The volatile part of the air pollutants were cytotoxic to the bacteria and showed only marginal mutagenicity. The particulate fractions were tested more extensively in the Ames Salmonella mutagenicity test, in two laboratories, using the strains TA 98 and TA 100 with and without enzymatic activation (S9). The mutagenicity was relatively high compared to particulate fractions from other areas with industry and dense traffic. The highest mutagenicity was found in TA 100 with enzymatic activation and the lowest in TA 100 without S9. The mutagenicity was influenced by wind speed and direction during sampling. The mutagenic activity was also determined in the nitroreductase deficient strains TA 98NR and TA 98/1.8DNP. A larger reduction in the activity was found compared to samples from other areas, thus indicating a difference in the sample composition.

  11. Tunable filter comparator for spectral calibration of near-ambient temperature blackbodies

    NASA Astrophysics Data System (ADS)

    Khromchenko, V. B.; Mekhontsev, S. N.; Hanssen, L. M.

    2007-09-01

    The calibration of infrared (IR) radiometers, thermal imagers and electro-optical systems relies on use of extended area blackbodies (BB) operating in the ambient environment. "Flat plate" designs, typically using a thermoelectric heat pump backed with an air- or liquid-cooled radiator, allow one to adequately meet the requirements of geometrical size and temperature span. The tradeoff comes in the form of limited temperature uniformity and lower emissivity that such an approach can provide given the limitations in achievable thermal conductivity of the plate and reflectance of the black paint, respectively. The availability of spectrally resolved radiance temperature data for infrared calibrators has become especially vital in the last few years with the widespread use of multi- and hyper-spectral electro-optical systems that enable better detection and identification of targets. In an effort to increase the measurement accuracy of IR spectral radiance of near-ambient BB calibrators, NIST has recently built a dedicated capability which is a part of its new AIRI (Advanced Infrared Radiometry and Imaging) facility. The Tunable Filter Comparator (TFC) is a key new element in this setup, allowing us to perform a precise comparison of the unit under test (UUT) with two reference blackbodies of known temperatures and emissivity. The report describes the major design features of the TFC comparator, the algorithm used for signal processing, and results of a performance evaluation of the TFC. The TFC development has enabled us to achieve BB radiance temperature comparisons with a standard deviation of 5 to 15 mK at temperatures of 15-150 C across the 3 to 5 µm and 8 to 12 µm atmospheric band ranges with a relative spectral resolution of 2 to 3%.

  12. Modeling monthly mean air temperature for Brazil

    NASA Astrophysics Data System (ADS)

    Alvares, Clayton Alcarde; Stape, José Luiz; Sentelhas, Paulo Cesar; de Moraes Gonçalves, José Leonardo

    2013-08-01

    Air temperature is one of the main weather variables influencing agriculture around the world. Its availability, however, is a concern, mainly in Brazil where the weather stations are more concentrated on the coastal regions of the country. Therefore, the present study had as an objective to develop models for estimating monthly and annual mean air temperature for the Brazilian territory using multiple regression and geographic information system techniques. Temperature data from 2,400 stations distributed across the Brazilian territory were used, 1,800 to develop the equations and 600 for validating them, as well as their geographical coordinates and altitude as independent variables for the models. A total of 39 models were developed, relating the dependent variables maximum, mean, and minimum air temperatures (monthly and annual) to the independent variables latitude, longitude, altitude, and their combinations. All regression models were statistically significant ( α ≤ 0.01). The monthly and annual temperature models presented determination coefficients between 0.54 and 0.96. We obtained an overall spatial correlation higher than 0.9 between the models proposed and the 16 major models already published for some Brazilian regions, considering a total of 3.67 × 108 pixels evaluated. Our national temperature models are recommended to predict air temperature in all Brazilian territories.

  13. INTERACTION OF AMBIENT TEMPERATURE AND MICROWAVE POWER DENSITY ON SCHEDULE-CONTROLLED BEHAVIOR IN THE RAT

    EPA Science Inventory

    Most guidelines of microwave exposure do not explicitly address effects of ambient temperature. The experiment revealed that ambient temperature potentiates the behavioral effects of intensity of irradiation. Sixty-four adult male Long-Evans rats were trained to insert their head...

  14. The influence of hypothalamic temperature and ambient temperature on thermoregulatory mechanisms in the pig

    PubMed Central

    Baldwin, B. A.; Ingram, D. L.

    1968-01-01

    1. Two types of temperature fluctuation have been recorded from the preoptic region of the conscious pig. One, which is associated with arousal or movement, and another, which is related to rhythms in respiration and blood pressure. 2. When the pigs were subjected to infra-red irradiation at various ambient temperatures it was found that there was no precise temperature of the preoptic region at which the respiratory frequency increased. 3. Local heating of the preoptic region was effective in increasing the respiratory frequency only when the ambient temperature was above 30° C. 4. Even when both the peripheral temperature and central temperatures were increased there was a delay of several minutes before the onset of panting. 5. Cooling the preoptic region of the hypothalamus prevented the onset of panting in a hot environment, and reduced respiratory frequency in an animal which was already panting. 6. Oxygen consumption was reduced in a cold environment when the preoptic region was warmed, and increased when it was cooled. No increase in oxygen consumption occurred when the hypothalamus was cooled in a hot environment. PMID:5685285

  15. Dependence of electric strength on the ambient temperature

    SciTech Connect

    Čaja, Alexander E-mail: patrik.nemec@fstroj.uniza.sk Nemec, Patrik E-mail: patrik.nemec@fstroj.uniza.sk Malcho, Milan E-mail: patrik.nemec@fstroj.uniza.sk

    2014-08-06

    At present, the volume concentration of electronic components in their miniaturization to different types of microchips and increasing their performance raises the problem of cooling such elements due to the increasing density of heat flow of heat loss. Compliance with safe operating temperature of active semiconductor element is very closely related to the reliability and durability not only components, but also the entire device. Often it is also necessary to electrically isolate the unit from the side of the cooler air. Cooling demand by natural convection is typical for applications with high operating reliability. To the reliability of the system for removing heat loss increased, it is necessary to minimize need to use the mechanically or electrically powered elements, such as circulation pumps or fans. Experience to date with applications of heat pipe in specific systems appears to be the most appropriate method of cooling.

  16. Open Air Silicon Deposition by Atmospheric Pressure Plasma under Local Ambient Gas Control

    NASA Astrophysics Data System (ADS)

    Naito, Teruki; Konno, Nobuaki; Yoshida, Yukihisa

    2015-09-01

    In this paper, we report open air silicon (Si) deposition by combining a silane free Si deposition technology and a newly developed local ambient gas control technology. Recently, material processing in open air has been investigated intensively. While a variety of materials have been deposited, there were only few reports on Si deposition due to the susceptibility to contamination and the hazardous nature of source materials. Since Si deposition is one of the most important processes in device fabrication, we have developed open air silicon deposition technologies in BEANS project. For a clean and safe process, a local ambient gas control head was designed. Process gas leakage was prevented by local evacuation, and air contamination was shut out by inert curtain gas. By numerical and experimental investigations, a safe and clean process condition with air contamination less than 10 ppm was achieved. Si film was deposited in open air by atmospheric pressure plasma enhanced chemical transport under the local ambient gas control. The film was microcrystalline Si with the crystallite size of 17 nm, and the Hall mobility was 2.3 cm2/V .s. These properties were comparable to those of Si films deposited in a vacuum chamber. This research has been conducted as one of the research items of New Energy and Industrial Technology Development Organization ``BEANS'' project.

  17. Application of amine-tethered solid sorbents for direct CO2 capture from the ambient air.

    PubMed

    Choi, Sunho; Drese, Jeffrey H; Eisenberger, Peter M; Jones, Christopher W

    2011-03-15

    While current carbon capture and sequestration (CCS) technologies for large point sources can help address the impact of CO(2) buildup on global climate change, these technologies can at best slow the rate of increase of the atmospheric CO(2) concentration. In contrast, the direct CO(2) capture from ambient air offers the potential to be a truly carbon negative technology. We propose here that amine-based solid adsorbents have significant promise as key components of a hypothetical air capture process. Specifically, the CO(2) capture characteristics of hyperbranched aminosilica (HAS) materials are evaluated here using CO(2) mixtures that simulate ambient atmospheric concentrations (400 ppm CO(2) = "air capture") as well as more traditional conditions simulating flue gas (10% CO(2)). The air capture experiments demonstrate that the adsorption capacity of HAS adsorbents are only marginally influenced even with a significant dilution of the CO(2) concentration by a factor of 250, while capturing CO(2) reversibly without significant degradation of performance in multicyclic operation. These results suggest that solid amine-based air capture processes have the potential to be an effective approach to extracting CO(2) from the ambient air. PMID:21323309

  18. Evaluation and Comparison of Chemiluminescence and UV Photometric Methods for Measuring Ozone Concentrations in Ambient Air

    EPA Science Inventory

    The current Federal Reference Method (FRM) for measuring concentrations of ozone in ambient air is based on the dry, gas-phase, chemiluminescence reaction between ethylene (C2H4) and any ozone (O3) that may be p...

  19. Chapter 7: Impact of Nitrogen and Climate Change Interactions on Ambient Air Pollution and Human Health

    EPA Science Inventory

    Nitrogen oxides (NOX) are important components of ambient and indoor air pollution and are emitted from a range of combustion sources, including on-road mobile sources, electric power generators, and non-road mobile sources. While anthropogenic sources dominate, NOX is also forme...

  20. NATIONAL PERFORMANCE AUDIT PROGRAM AMBIENT AIR AUDITS OF ANALYTICAL PROFEICIENCY--1988

    EPA Science Inventory

    This report presents the results of the U.S Environmental Protection Agencys 1988 National Ambient Air Performance Audit Program, Semiannual audits were conducted for lead, nitrate and sulfate on filter strips. ne audit was Conducted for high volume/PM10 size Selective inlet (ssi...

  1. Performance of the Proposed New Federal Reference Methods for Measuring Ozone Concentrations in Ambient Air

    EPA Science Inventory

    The current Federal Reference Method (FRM) for measuring concentrations of ozone in ambient air, described in EPA regulations at 40 CFR Part 50, Appendix D, is based on the dry, gas-phase, chemiluminescence reaction between ethylene (C2H4) and any ozone (O

  2. 78 FR 52893 - Implementation of the 2008 National Ambient Air Quality Standards for Ozone: State Implementation...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-27

    ... From the Federal Register Online via the Government Publishing Office ENVIRONMENTAL PROTECTION AGENCY 40 CFR Parts 50, 51, 70 and 71 RIN 2060-AR34 Implementation of the 2008 National Ambient Air Quality Standards for Ozone: State Implementation Plan Requirements Correction In proposed rule...

  3. Test/QA Plan for Verification of Semi-Continuous Ambient Air Monitoring Systems - Second Round

    EPA Science Inventory

    Test/QA Plan for Verification of Semi-Continuous Ambient Air Monitoring Systems - Second Round. Changes reflect performance of second round of testing at new location and with various changes to personnel. Additional changes reflect general improvements to the Version 1 test/QA...

  4. A STRINGENT COMPARISON OF SAMPLING AND ANALYSIS METHODS FOR VOCS IN AMBIENT AIR

    EPA Science Inventory

    A carefully designed study was conducted during the summer of 1998 to simultaneously collect samples of ambient air by canisters and compare the analysis results to direct sorbent preconcentration results taken at the time of sample collection. A total of 32 1-h sample sets we...

  5. NATIONAL PERFORMANCE AUDIT PROGRAM--AMBIENT AIR AUDITS OF ANALYTICAL PROFICIENCY--1987

    EPA Science Inventory

    This report presents the results of the U.S. Environmental Protection Agency's 1987 National Ambient Air Audit Program by pollutant and by analytical method. Semiannual audits were conducted for CO, Pb, NO3 and S04 (filter strips) and acid rain, and an annual audit was conducted ...

  6. OZONE AMBIENT AIR QUALITY STANDARD HAS BENEFICIAL EFFECT ON PONDEROSA PINE IN CALIFORNIA

    EPA Science Inventory

    Ambient air quality standards and control strategies are implemented to protect humans and vegetation from adverse effects. However, to date there has not been a simple and objective method to determine if the standards and resultant control strategies have reduced O3 impacts on ...

  7. COMPARISON OF FAST GC/TOFMS WITH METHOD TO-14 FOR ANALYSIS OF AMBIENT AIR SAMPLES

    EPA Science Inventory

    Field studies using portable gas chromatographs (PGC) to analyze volatile organic compounds in ambient air usually include, as reference standard method, the analysis of concurrent, collocated canister samples by EPA Method TO-14. Each laboratory analysis takes about an hour a...

  8. [Motor transport emission, ambient air quality, and the Moscow population's health].

    PubMed

    Ivanenko, A V; Volkova, I F; Kornienko, A P

    2007-01-01

    As of 2006, the city's motor transport fleet amounted to as many as 3 million units that annually consume about 5 million tons of petrol. The use rate of all kinds of vehicles has increased, resulting in the growth of the proportion of ambient air pollutants discharged by motor transport, which surpasses the increase of the absolute size of the fleet. The contribution of traveling sources to ambient air pollution is growing steadily and it has been recently about 90% (1 million tons). Implementation of measures and developed managerial decisions, and ecological programs, improvement of Moscow town-planning measures, and environment-improving measures against motor vehicles have contributed to a reduction in chemical and physical burdens on the population. The characteristics of the capital's ambient air pollution have been recently observed to become stable and improve. There is stabilization in morbidity due to respiratory diseases in all population groups. The prevalence of chronic respiratory diseases in children is on the decrease, the increase rate was 1.4% versus 33.5% in the preceding period. Assessment of carcinogenic risk showed that ambient air pollution and drinking water contamination had a negative impact on the Moscow population. PMID:18161184

  9. AEROSOL CHARACTERIZATION OF AMBIENT AIR NEAR A COMMERCIAL LURGI COAL GASIFICATION PLANT, KOSOVO REGION, YUGOSLAVIA

    EPA Science Inventory

    Ambient air samples were collected continuously from May 14-29, 1980 to determine if the emissions from a commercial Lurgi coal gasification plant could be identified downwind of the facility. Physical, inorganic, and organic analyses were carried out on the collected aerosol sam...

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

    EPA Science Inventory

    Background: A number of epidemiologic investigations have shown adverse effects of ambient air pollution on reproductive outcomes. A recent case-control study found associations between

    second gestational month carbon monoxide and ozone exposure and elevated risks of selec...

  11. USE OF BIOASSAY METHODS TO EVALUATE MUTAGENICITY OF AMBIENT AIR COLLECTED NEAR A MUNICIPAL WASTE COMBUSTOR

    EPA Science Inventory

    An ambient air sampling study was conducted around a municipal waste combustor with a primary goal being to develop procedures to evaluate the emissions of organic mutagens resulting from incomplete combustion of municipal waste. he products of incomplete combustion from incinera...

  12. Report on sampling and analysis of ambient air at the central waste complex

    SciTech Connect

    Stauffer, M., Fluor Daniel Hanford

    1997-02-13

    Over 160 ambient indoor air samples were collected from warehouses at the Central Waste Complex used for the storage of low- level radioactive and mixed wastes. These grab (SUMMA) samples were analyzed by gas chromatography-mass spectrometry using a modified EPA TO-14 procedure. The data from this survey suggest that several buildings had elevated concentrations of volatile organic compounds.

  13. 75 FR 9894 - Office of Research and Development; Ambient Air Monitoring Reference and Equivalent Methods...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-04

    .... This designation is made under the provisions of 40 CFR part 53, as amended on November 12, 2008 (73 FR... AGENCY Office of Research and Development; Ambient Air Monitoring Reference and Equivalent Methods: Designation of One New Equivalent Method AGENCY: Environmental Protection Agency. ACTION: Notice of...

  14. 75 FR 22126 - Office of Research and Development; Ambient Air Monitoring Reference and Equivalent Methods...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-04-27

    ... November 12, 2008 (73 FR 67057-67059). The new equivalent method for O 3 is an automated method that... AGENCY Office of Research and Development; Ambient Air Monitoring Reference and Equivalent Methods: Designation of One New Equivalent Method AGENCY: Environmental Protection Agency. ACTION: Notice of...

  15. 75 FR 45627 - Office of Research and Development; Ambient Air Monitoring Reference and Equivalent Methods...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-03

    ... of 40 CFR part 53, as amended on November 12, 2008 (73 FR 67057-67059). The new equivalent method for... AGENCY Office of Research and Development; Ambient Air Monitoring Reference and Equivalent Methods: Designation of One New Equivalent Method AGENCY: Environmental Protection Agency. ACTION: Notice of...

  16. 77 FR 55832 - Ambient Air Monitoring Reference and Equivalent Methods: Designation of a New Equivalent Method

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-09-11

    ... made under the provisions of 40 CFR part 53, as ] amended on August 31, 2011 (76 FR 54326-54341). The... AGENCY Ambient Air Monitoring Reference and Equivalent Methods: Designation of a New Equivalent Method AGENCY: Environmental Protection Agency. ACTION: Notice of the designation of a new equivalent method...

  17. 77 FR 60985 - Ambient Air Monitoring Reference and Equivalent Methods: Designation of Three New Equivalent Methods

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-05

    ... 53, as amended on August 31, 2011 (76 FR 54326-54341). The new equivalent methods are automated... AGENCY Ambient Air Monitoring Reference and Equivalent Methods: Designation of Three New Equivalent Methods AGENCY: Environmental Protection Agency. ACTION: Notice of the designation of three new...

  18. 75 FR 51039 - Office of Research and Development; Ambient Air Monitoring Reference and Equivalent Methods...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-18

    ... provisions of 40 CFR Part 53, as amended on November 12, 2008 (73 FR 67057-67059). The new PM 10 equivalent... AGENCY Office of Research and Development; Ambient Air Monitoring Reference and Equivalent Methods: Designation of Two New Equivalent Methods AGENCY: Environmental Protection Agency. ACTION: Notice of...

  19. 76 FR 62402 - Office of Research and Development; Ambient Air Monitoring Reference and Equivalent Methods...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-07

    ... provisions of 40 CFR part 53, as amended on June 22, 2010 (75 FR 35597). The new O 3 equivalent method is an... AGENCY Office of Research and Development; Ambient Air Monitoring Reference and Equivalent Methods; Designation of One New Equivalent Method AGENCY: Environmental Protection Agency. ACTION: Notice of...

  20. GC/MS ANALYSIS OF AMBIENT AIR AEROSOLS IN THE HOUSTON, TEXAS AREA

    EPA Science Inventory

    Ambient air aerosols and vapor samples were collected by Radian Corp., Austin, TX. in the Houston, Texas area using three different samplers. A High Volume sampler and dichotomous sampler were used for the collection of particulate matter; vapor-phase organic samples were collect...

  1. Case report: Atrial fibrillation following exposure to ambient air pollution particles

    EPA Science Inventory

    CONTEXT: Exposure to air pollution can result in the onset of atrial fibrillation. CASE PRESENTATION: We present a case of a 58 year old woman who volunteered to participate in a controlled exposure to concentrated ambient particles (CAPs). Twenty minutes into the exposure, there...

  2. CONCENTRATED AMBIENT AIR PARTICLES INDUCE PULMONARY INFLAMMATION IN HEALTHY HUMAN VOLUNTEERS

    EPA Science Inventory


    We tested the hypothesis that exposure of healthy volunteers to concentrated ambient particles (CAPS) is associated with an influx of inflammatory cells into the lower respiratory tract. Thirty-eight volunteers were exposed to either filtered air or particles concentrated fro...

  3. TUNGSTIC ACID TECHNIQUE FOR MONITORING NITRIC ACID AND AMMONIA IN AMBIENT AIR

    EPA Science Inventory

    A new measurement procedure has been applied in field studies for monitoring ambient concentrations of HNO3 and NH3. Preconcentration of these gases as well as separation from their particulate forms is achieved by pulling the sampled air through a diffusion tube coated with the ...

  4. Association between the ambient temperature and the occurrence of human Salmonella and Campylobacter infections.

    PubMed

    Yun, Josef; Greiner, Matthias; Höller, Christiane; Messelhäusser, Ute; Rampp, Albert; Klein, Günter

    2016-01-01

    Salmonella spp. and thermotolerant Campylobacter spp. are the most important causes of human bacterial diarrheal infections worldwide. These bacterial species are influenced by several factors like behaviour of the host, shedding, environment incl. directly or indirectly through ambient temperature, and the infections show seasonality. Therefore, the aim of our study was to investigate the association between the occurrence of human campylobacteriosis and salmonellosis and the ambient temperature. The number of campylobacteriosis and salmonellosis cases in two German metropolises, Munich and Berlin, and three rural regions was analysed with simultaneous consideration of the ambient temperature over a period of four years (2001 to 2004) using regression, time series, and cross-correlation analysis. The statistical analysis showed that an increase in the ambient temperature correlated positively with an increase in human Salmonella and Campylobacter cases. The correlation occurred with a delay of approximately five weeks. The seasonal rise in ambient temperature correlated with increased incidence of bacterial diarrheal infections. PMID:27324200

  5. Association between the ambient temperature and the occurrence of human Salmonella and Campylobacter infections

    PubMed Central

    Yun, Josef; Greiner, Matthias; Höller, Christiane; Messelhäusser, Ute; Rampp, Albert; Klein, Günter

    2016-01-01

    Salmonella spp. and thermotolerant Campylobacter spp. are the most important causes of human bacterial diarrheal infections worldwide. These bacterial species are influenced by several factors like behaviour of the host, shedding, environment incl. directly or indirectly through ambient temperature, and the infections show seasonality. Therefore, the aim of our study was to investigate the association between the occurrence of human campylobacteriosis and salmonellosis and the ambient temperature. The number of campylobacteriosis and salmonellosis cases in two German metropolises, Munich and Berlin, and three rural regions was analysed with simultaneous consideration of the ambient temperature over a period of four years (2001 to 2004) using regression, time series, and cross-correlation analysis. The statistical analysis showed that an increase in the ambient temperature correlated positively with an increase in human Salmonella and Campylobacter cases. The correlation occurred with a delay of approximately five weeks. The seasonal rise in ambient temperature correlated with increased incidence of bacterial diarrheal infections. PMID:27324200

  6. Effect of fireworks on ambient air quality in Malta

    NASA Astrophysics Data System (ADS)

    Camilleri, Renato; Vella, Alfred J.

    2010-11-01

    Religious festivals ( festas) in the densely populated Maltese archipelago (Central Mediterranean) are ubiquitous during summer when 86 of them are celebrated between June and October, each involving the burning of fireworks both in ground and aerial displays over a period of 3 days or longer per festival. We assessed the effect of fireworks on the air quality by comparing PM 10 and its content of Al, Ba, Cu, Sr and Sb which materials are used in pyrotechnic compositions. PM 10 was collected mainly from two sites, one in Malta (an urban background site) and the other in Gozo (a rural site) during July-August 2005 when 59 feasts were celebrated and September-October 2005 when only 11 feasts occurred. For both Malta and Gozo, PM 10 and metal concentration levels measured as weekly means were significantly higher during July-August compared to September-October and there exist strong correlations between PM 10 and total metal content. Additionally, for Malta dust, Al, Ba, Cu and Sr correlated strongly with each other and also with total concentration of all five metals. The same parameters measured in April 2006 in Malta were at levels similar to those found in the previous October. Ba and Sb in dust from the urban background site in Malta during July-August were at comparable or higher concentration than recently reported values in PM 10 from a heavily-trafficked London road and this suggests that these metals are locally not dominated by sources from roadside materials such as break liner wear but more likely by particulate waste from fireworks. Our findings point to the fact that festa firework displays contribute significantly and for a prolonged period every year to airborne dust in Malta where PM 10 is an intractable air quality concern. The presence in this dust of elevated levels of Ba and especially Sb, a possible carcinogen, is of concern to health.

  7. Determination of hexavalent chromium in ambient air: A story of method induced Cr(III) oxidation

    NASA Astrophysics Data System (ADS)

    Tirez, Kristof; Silversmit, Geert; Bleux, Nico; Adriaensens, Elke; Roekens, Edward; Servaes, Kelly; Vanhoof, Chris; Vincze, Laszlo; Berghmans, Patrick

    2011-09-01

    The accuracy of the determination of Cr(VI) in ambient particulate matter remains a challenge from the point of view of minimal Cr species interconversion. Knowledge of this method induced oxidation and reduction is particularly relevant for the determination of Cr(VI) in ambient particulate matter, as the level of observed Cr(III) oxidation (average of 1.7% in this study) can contribute significantly to the monitored range of measured Cr(VI) in PM 10. For Cr concentrations in PM 10 > 10 ng Cr m -3, this method induced oxidation could lead to false positive exceeding of an air quality guideline value of 0.2 ng Cr(VI) m -3 in PM 10. The median daily Cr(VI) concentration in PM 10 measured over a monitoring period of more than 2 months at two locations close to a stainless steel factory amounted to 0.9 ng Cr(VI) m -3 and 0.27 ng Cr(VI) m -3. Average daily Cr(VI)/Cr ratios in PM 10 of 3.5% and 2.6% were measured at these locations. The described monitoring for the determination of Cr(VI) in ambient air via alkaline impregnated filters is sensitive (method detection limit of 0.015 ng Cr(VI) m -3) and reproducible (precision of the method ˜25%). The average Cr(VI) recovery of 75% strongly indicates the effects of ambient sampling conditions and ambient particles on the Cr(VI) recoveries. The stability of the Cr(VI) and the Cr(III) spike on 0.12 M NaHCO 3 impregnated filters observed with XANES, indicates that the alkaline extraction of the filter in combination with the sampled air matrix is likely to induce the Cr conversions. The XANES spectra shows further that a Cr-spinel is the predominant component of Cr in ambient air PM 10 at the monitored locations.

  8. Detritiation of type 316 stainless steel by treatment with liquids at ambient temperature

    NASA Astrophysics Data System (ADS)

    Penzhorn, Ralf-Dieter; Torikai, Y.; Matsuyama, M.; Watanabe, K.

    2006-07-01

    The detritiation efficiency of type 316 stainless steel (SS316) using liquids reagents (distilled deionized water, concentrated aqueous ammonia or a diluted hydrochloric acid/nitric acid mixture) was investigated at ambient temperature by means of liquid scintillation counting (LSC) and β-ray-induced X-ray spectrometry (BIXS). After a fast initial removal of tritium trapped on the outermost surface of SS316 with a rate in the order water < ammonia < acid mixture a slow chronic liberation of tritium into all three liquids sets in. First results indicate that chronic release occurs with a rate of approx. 0.2% per day. The long-term release was found to be largely independent from the kind of liquid agent into which the metal is submerged and from the initial loading of the SS316 specimen. From a practical point of view, the release rate of tritium into liquids is too slow for conditioning applications. Complementary evidence for the occurrence of a chronic liberation of tritium from SS316 into air at ambient temperature was obtained from tritium depth profiling of aged specimens by acid etching.

  9. Do circadian genes and ambient temperature affect substrate-borne signalling during Drosophila courtship?

    PubMed Central

    Medina, Izarne; Casal, José; Fabre, Caroline C. G.

    2015-01-01

    ABSTRACT Courtship vibratory signals can be air-borne or substrate-borne. They convey distinct and species-specific information from one individual to its prospective partner. Here, we study the substrate-borne vibratory signals generated by the abdominal quivers of the Drosophila male during courtship; these vibrations travel through the ground towards courted females and coincide with female immobility. It is not known which physical parameters of the vibrations encode the information that is received by the females and induces them to pause. We examined the intervals between each vibratory pulse, a feature that was reported to carry information for animal communication. We were unable to find evidence of periodic variations in the lengths of these intervals, as has been reported for fly acoustical signals. Because it was suggested that the genes involved in the circadian clock may also regulate shorter rhythms, we search for effects of period on the interval lengths. Males that are mutant for the period gene produced vibrations with significantly altered interpulse intervals; also, treating wild type males with constant light results in similar alterations to the interpulse intervals. Our results suggest that both the clock and light/dark cycles have input into the interpulse intervals of these vibrations. We wondered if we could alter the interpulse intervals by other means, and found that ambient temperature also had a strong effect. However, behavioural analysis suggests that only extreme ambient temperatures can affect the strong correlation between female immobility and substrate-borne vibrations. PMID:26519517

  10. Do circadian genes and ambient temperature affect substrate-borne signalling during Drosophila courtship?

    PubMed

    Medina, Izarne; Casal, José; Fabre, Caroline C G

    2015-01-01

    Courtship vibratory signals can be air-borne or substrate-borne. They convey distinct and species-specific information from one individual to its prospective partner. Here, we study the substrate-borne vibratory signals generated by the abdominal quivers of the Drosophila male during courtship; these vibrations travel through the ground towards courted females and coincide with female immobility. It is not known which physical parameters of the vibrations encode the information that is received by the females and induces them to pause. We examined the intervals between each vibratory pulse, a feature that was reported to carry information for animal communication. We were unable to find evidence of periodic variations in the lengths of these intervals, as has been reported for fly acoustical signals. Because it was suggested that the genes involved in the circadian clock may also regulate shorter rhythms, we search for effects of period on the interval lengths. Males that are mutant for the period gene produced vibrations with significantly altered interpulse intervals; also, treating wild type males with constant light results in similar alterations to the interpulse intervals. Our results suggest that both the clock and light/dark cycles have input into the interpulse intervals of these vibrations. We wondered if we could alter the interpulse intervals by other means, and found that ambient temperature also had a strong effect. However, behavioural analysis suggests that only extreme ambient temperatures can affect the strong correlation between female immobility and substrate-borne vibrations. PMID:26519517

  11. Stability Issues in Ambient-Temperature Passive Magnetic Bearing Systems

    SciTech Connect

    Post, R.F.

    2000-02-17

    The ambient-temperature passive magnetic bearing system developed at the Lawrence Livermore National Laboratory achieves rotor-dynamic stability by employing special combinations of levitating and stabilizing elements. These elements, energized by permanent magnet material, create the magnetic and electrodynamic forces that are required for the stable levitation of rotating systems, such as energy-storage flywheels. Stability criteria, derived from theory, describe the bearing element parameters, i.e., stiffnesses and damping coefficients, that are required both to assure stable levitation (''Earnshaw-stability''), and stability against whirl-type rotor-dynamic instabilities. The work described in this report concerns experimental measurements and computer simulations that address some critical aspects of this overall stability problem. Experimentally, a test device was built to measure the damping coefficient of dampers that employ eddy currents induced in a metallic disc. Another test device was constructed for the purpose of measuring the displacement-dependent drag coefficient of annular permanent magnet bearing elements. In the theoretical developments a computer code was written for the purpose of simulating the rotor-dynamics of our passive bearing systems. This code is capable of investigating rotor-dynamic stability effects for both small-amplitude transient displacements (i.e., those within the linear regime), and for large-amplitude displacements, where non-linear effects can become dominant. Under the latter conditions a bearing system that is stable for small-amplitude displacements may undergo a rapidly growing rotor-dynamic instability once a critical displacement is exceeded. A new result of the study was to demonstrate that stiffness anisotropy of the bearing elements (which can be designed into our bearing system) is strongly stabilizing, not only in the linear regime, but also in the non-linear regime.

  12. PCDD/F emissions and distributions in Waelz plant and ambient air during different operating stages.

    PubMed

    Chi, Kai Hsien; Chang, Shu Hao; Chang, Moo Been

    2007-04-01

    Significant formation of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) has been observed in a typical Waelz process plant. In 2005, the Waelz plant investigated was equipped with a dust settling chamber (DSC), a venturi cooling tower, a cyclone (CY), and baghouse filter (BF). In early 2006 activated carbon injection (ACI) was adopted to reduce PCDD/F emissions from the plant investigated. Samplings of flue gases and ash were simultaneously conducted at different sampling points in the Waelz plantto evaluate removal efficiency and partitioning of PCDD/Fs between the gas phase and particulates. As the operating temperature of the dust settling chamber (DSC) is increased from 480 to 580 degrees C, the PCDD/F concentration measured at the DSC outlet decreases from 1220 to 394 ng-l-TEQ/Nm3. By applying ACI, the PCDD/F concentrations of stack gas decrease from 139-194 to 3.38 ng-l-TEQ/ Nm(3) (a reduction of 97.6-98.3%) while the PCDD/F concentration of reacted ash increases dramatically from 0.97 to 29.4 ng-l-TEQ/g, as the activated carbon injection rate is controlled at 40 kg/h. Additionally, ambient air PCDD/F concentrations were measured in the vicinity of this facility during different operating stages (shutdown, and operation with and without ACI). The ambient PCDD/F concentration measured downwind and 2.5 km from the Waelz plant decreases from 568 to 206 fg-I-TEQ/m(3) after ACI has been applied to collect the dioxins. Due to the high PCDD/F removal efficiency achieved with ACI + BF, about 24.3 and 3980 ng-l-TEQ/kg EAF-dust treated are discharged via stack gas and reacted ash, respectively, in this facility. PMID:17438809

  13. Generation of low-temperature air plasma for food processing

    NASA Astrophysics Data System (ADS)

    Stepanova, Olga; Demidova, Maria; Astafiev, Alexander; Pinchuk, Mikhail; Balkir, Pinar; Turantas, Fulya

    2015-11-01

    The project is aimed at developing a physical and technical foundation of generating plasma with low gas temperature at atmospheric pressure for food industry needs. As known, plasma has an antimicrobial effect on the numerous types of microorganisms, including those that cause food spoilage. In this work an original experimental setup has been developed for the treatment of different foods. It is based on initiating corona or dielectric-barrier discharge in a chamber filled with ambient air in combination with a certain helium admixture. The experimental setup provides various conditions of discharge generation (including discharge gap geometry, supply voltage, velocity of gas flow, content of helium admixture in air and working pressure) and allows for the measurement of the electrical discharge parameters. Some recommendations on choosing optimal conditions of discharge generation for experiments on plasma food processing are developed.

  14. 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.

  15. Application of a dry-gas meter for measuring air sample volumes in an ambient air monitoring network

    SciTech Connect

    Fritz, Brad G.

    2009-05-24

    Ambient air monitoring for non-research applications (e.g. compliance) occurs at locations throughout the world. Often, the air sampling systems employed for these purposes employee simple yet robust equipment capable of handling the rigors of demanding sampling schedules. At the Hanford Site (near Richland, Washington) concentrations of radionuclides in ambient air are monitored continuously at 44 locations. In 2004, mechanical dry-gas meters were incorporated into the Hanford Site ambient air sample collection system to allow the direct measurement of sample volumes. These meters replaced a portable airflow measurement system that required two manual flow measurements and a sample duration measurement to determine sample volume. A six-month evaluation of the dry-gas meters compared sample volumes calculated using the original flow rate method to the direct sample volume measurement (new method). The results of the evaluation indicate that use of the dry-gas meters result in accurate sample volume measurements and provide greater confidence in the measured sample volumes. In several years of in-network use, the meters have proven to be reliable and have resulted in an improved sampling system.

  16. 40 CFR 50.9 - National 1-hour primary and secondary ambient air quality standards for ozone.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...-hour standards are codified in 40 CFR part 81. (c) EPA's authority under paragraph (b) of this section... ambient air quality standards for ozone. 50.9 Section 50.9 Protection of Environment ENVIRONMENTAL....9 National 1-hour primary and secondary ambient air quality standards for ozone. (a) The level...

  17. A Direct sensitivity approach to predict hourly ozone resulting from compliance with the National Ambient Air Quality Standard

    EPA Science Inventory

    In setting primary ambient air quality standards, the EPA’s responsibility under the law is to establish standards that protect public health. As part of the current review of the ozone National Ambient Air Quality Standard (NAAQS), the US EPA evaluated the health exposure and ...

  18. 76 FR 20347 - Release of Draft Integrated Review Plan for the National Ambient Air Quality Standards for Lead

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-04-12

    ... (75 FR 8934). The draft IRP is being made available for consultation with CASAC and for public comment... AGENCY Release of Draft Integrated Review Plan for the National Ambient Air Quality Standards for Lead... National Ambient Air Quality Standards for Lead (draft IRP). This document contains the plans for...

  19. Monitoring of viable airborne SARS virus in ambient air

    NASA Astrophysics Data System (ADS)

    Agranovski, Igor E.; Safatov, Alexander S.; Pyankov, Oleg V.; Sergeev, Alexander N.; Agafonov, Alexander P.; Ignatiev, Georgy M.; Ryabchikova, Elena I.; Borodulin, Alexander I.; Sergeev, Artemii A.; Doerr, Hans W.; Rabenau, Holger F.; Agranovski, Victoria

    Due to recent SARS related issues (Science 300 (5624) 1394; Nature 423 (2003) 240; Science 300 (5627) 1966), the development of reliable airborne virus monitoring procedures has become galvanized by an exceptional sense of urgency and is presently in a high demand (In: Cox, C.S., Wathers, C.M. (Eds.), Bioaerosols Handbook, Lewis Publishers, Boca Raton, FL, 1995, pp. 247-267). Based on engineering control method (Aerosol Science and Technology 31 (1999) 249; 35 (2001) 852), which was previously applied to the removal of particles from gas carriers, a new personal bioaerosol sampler has been developed. Contaminated air is bubbled through porous medium submerged into liquid and subsequently split into multitude of very small bubbles. The particulates are scavenged by these bubbles, and, thus, effectively removed. The current study explores its feasibility for monitoring of viable airborne SARS virus. It was found that the natural decay of such virus in the collection fluid was around 0.75 and 1.76 lg during 2 and 4 h of continuous operation, respectively. Theoretical microbial recovery rates of higher than 55 and 19% were calculated for 1 and 2 h of operation, respectively. Thus, the new sampling method of direct non-violent collection of viable airborne SARS virus into the appropriate liquid environment was found suitable for monitoring of such stress sensitive virus.

  20. Experimental Study of the Momentum Coupling Coefficient with the Pulse Frequency and Ambient Pressure for Air-Breathing Laser Propulsion

    NASA Astrophysics Data System (ADS)

    Tang, Zhiping; Cai, Jian; Gong, Ping; Hu, Xiaojun; Tan, Rongqin; Zheng, Zhijun; Wu, Jin; Lu, Yan

    2006-05-01

    The air-breathing laser propulsion tests are conducted for parabolic models by using a high power TEA-CO2 pulsed laser. It is found the momentum coupling coefficient Cm varies with the pulse repeatable frequency and reaches the maximum near 50Hz. With a multi-use pendulum chamber, the change of Cm at different ambient pressure is measured. The experimental results show that the propulsion efficiency Cm does not decrease below the altitude of 10km, even increases a little bit. The calculated Cm fits the experimental result up to altitude 3km, then, they are separated. One possible reason is the temperature which is constant in the experiments.

  1. The dependence of surface temperature on IGBTs load and ambient temperature

    NASA Astrophysics Data System (ADS)

    Alexander, Čaja; Marek, Patsch

    2015-05-01

    Currently, older power electronics and electrotechnics are improvement and at the same time developing new and more efficient devices. These devices produce in their activities a significant part of the heat which, if not effectively drained, causing damage to these elements. In this case, it is important to develop new and more efficient cooling system. The most widespread of modern methods of cooling is the cooling by heat pipe. This contribution is aimed at cooling the insulated-gate bipolar transistor (IGBT) elements by loop heat pipe (LHP). IGBTs are very prone to damage due to high temperatures, and therefore is the important that the surface temperature was below 100°C. It was therefore created a model that examined what impact of surface temperature on the IGBT element and heat removal at different load and constant ambient temperature.

  2. Time and species dependent ambient air's effects on carbon clusters generated during femtosecond laser ablation of highly oriented pyrolytic graphite

    NASA Astrophysics Data System (ADS)

    Bao, Wenxia; Zhang, Nan; Feng, Peipei; Wu, Han; Zhu, Xiaonong

    2015-12-01

    Near infrared femtosecond laser is employed to ablate highly oriented pyrolytic graphite (HOPG) in ambient air and in vacuum respectively. The recorded transient emission spectra of the ablated plume with a time resolution of 2 ns indicate that the effects of air on the plume are dependent on both time and species. This finding provides important insights into the generation and decay mechanisms of different carbon radicals or clusters. At 1 or 2 ns after the laser pulse strikes the target, air weakens the Swan bands of C2 compared with the case in vacuum, an effect that may be caused by the quenching collisions between air molecules and C2 radicals. This result shows that C2 may be mainly generated by direct spallation from the target surface at the early stage of ablation. Emission spectra at large time delays present that the existence time of the Swan bands in air is longer than the lifetime of the upper electronic state of the Swan system, suggesting that the air-involved three-body recombination and collisional excitation that enhance the generation of emitting C2 overcome quenching collisions at large time delays. A spectral band at ~416 nm assigned to the transition from 1Σ u + to X 1Σ g + of C15 is more intense in air than in vacuum, indicating that C15 clusters are generated at least partially by the combination of smaller clusters in air. It is also found that air-assisted heat transfer makes the temperature of carbon clusters decrease more quickly in air than in vacuum, leading to a much shorter lifetime of the continuum in air.

  3. Association between exposure to ambient air pollution before conception date and likelihood of giving birth to girls in Guangzhou, China

    NASA Astrophysics Data System (ADS)

    Lin, Hualiang; Liang, Zhijiang; Liu, Tao; Di, Qian; Qian, Zhengmin; Zeng, Weilin; Xiao, Jianpeng; Li, Xing; Guo, Lingchuan; Ma, Wenjun; Zhao, Qingguo

    2015-12-01

    A few studies have linked ambient air pollution with sex ratio at birth. Most of these studies examined the long-term effects using spatial or temporal comparison approaches. This study aimed to investigate whether parental exposure to air pollution before conception date could affect the likelihood of the offspring being male or female. We used the information collected in a major maternal hospital in Guangzhou, China. The parental exposure to air pollution was assessed using the air pollution concentration before the conception date. Logistic regression models were used to assess the association between air pollution exposure and birth sex with adjustment for potential confounding factors, such as maternal age, parental education levels, long-term trend, season, and weather condition (mean temperature and relative humidity). The analysis revealed that higher air pollution was associated with higher probability of female newborns, with the effective exposure around one week prior to conception date. In the one-pollutant models, PM10, SO2 and NO2 had significant effects. For example, the excess risk was 0.61% (95% confidence interval (95% CI): 0.36%, 0.86%) for a 10 ug/m3 increase in lag 2 day's PM10, 0.42% (95% CI: 0.21%, 0.64%) for lag 3 day's SO2 and 0.97% (95% CI: 0.44%, 1.50%) for lag 3 day's NO2; and in two-pollutant models, PM10 remained statistically significant. These results suggest that parental exposure to ambient air pollution a few days prior to conception might be a contributing factor to higher probability of giving birth to female offspring in Guangzhou.

  4. Sub-to super-ambient temperature programmable microfabricated gas chromatography column

    DOEpatents

    Robinson, Alex L.; Anderson, Lawrence F.

    2004-03-16

    A sub- to super-ambient temperature programmable microfabricated gas chromatography column enables more efficient chemical separation of chemical analytes in a gas mixture by combining a thermoelectric cooler and temperature sensing on the microfabricated column. Sub-ambient temperature programming enables the efficient separation of volatile organic compounds and super-ambient temperature programming enables the elution of less volatile analytes within a reasonable time. The small heat capacity and thermal isolation of the microfabricated column improves the thermal time response and power consumption, both important factors for portable microanalytical systems.

  5. Optimized Arrangement of Constant Ambient Air Monitoring Stations in the Kanto Region of Japan

    PubMed Central

    Shirato, Shintaro; Iizuka, Atsushi; Mizukoshi, Atsushi; Noguchi, Miyuki; Yamasaki, Akihiro; Yanagisawa, Yukio

    2015-01-01

    Continuous ambient air monitoring systems have been introduced worldwide. However, such monitoring forces autonomous communities to bear a significant financial burden. Thus, it is important to identify pollutant-monitoring stations that are less efficient, while minimizing loss of data quality and mitigating effects on the determination of spatiotemporal trends of pollutants. This study describes a procedure for optimizing a constant ambient air monitoring system in the Kanto region of Japan. Constant ambient air monitoring stations in the area were topologically classified into four groups by cluster analysis and principle component analysis. Then, air pollution characteristics in each area were reviewed using concentration contour maps and average pollution concentrations. We then introduced three simple criteria to reduce the number of monitoring stations: (1) retain the monitoring station if there were similarities between its data and average data of the group to which it belongs; (2) retain the station if its data showed higher concentrations; and (3) retain the station if the monitored concentration levels had an increasing trend. With this procedure, the total number of air monitoring stations in suburban and urban areas was reduced by 36.5%. The introduction of three new types of monitoring stations is proposed, namely, mobile, for local non-methane hydrocarbon pollution, and Ox-prioritized. PMID:25764058

  6. FY 1994 ambient air monitoring report for McMurdo Station, Antarctica

    SciTech Connect

    Lugar, R.M.

    1994-12-01

    This report presents the results of ambient air monitoring performed during the 1994 fiscal year (FY 1994) in the vicinity of McMurdo Station, Antarctica. Routine monitoring was performed during the 1993-1994 austral summer at three locations for airborne particulate matter less than 10 micrometers (PM-10) and at two locations for carbon monoxide (CO), sulfur dioxide (SO{sub 2}), and nitrogen oxides (NO, NO{sub 2}, and NO{sub x}). Selected PM-10 filters were analyzed for arsenic, beryllium, cadmium, chromium, lead, mercury, and nickel. Additional air samples were collected at three McMurdo area locations and at Black Island for determination of the airborne concentration of polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs). Sampling site selection, sampling procedures, and quality assurance procedures used were consistent with US Environmental Protection Agency guidance for local ambient air quality networks.

  7. Adaptive Preheating Duration Control for Low-Power Ambient Air Quality Sensor Networks

    PubMed Central

    Baek, Yoonchul; Atiq, Mahin K.; Kim, Hyung Seok

    2014-01-01

    Ceramic gas sensors used for measuring ambient air quality have features suitable for practical applications such as healthcare and air quality management, but have a major drawback—large power consumption to preheat the sensor for accurate measurements. In this paper; the adaptive preheating duration control (APC) method is proposed to reduce the power consumption of ambient air quality sensor networks. APC reduces the duration of unnecessary preheating, thereby alleviating power consumption. Furthermore, the APC can allow systems to meet user requirements such as accuracy and periodicity factor when detecting the concentration of a target gas. A performance evaluation of the power consumption of gas sensors is conducted with various user requirements and factors that affect the preheating duration of the gas sensor. This shows that the power consumption of the APC is lower than that of continuous power supply methods and constant power supply/cutoff methods. PMID:24658619

  8. Crack growth in ASME SA-105 grade 2 steel in hydrogen at ambient temperature

    NASA Technical Reports Server (NTRS)

    Walter, R. J.

    1975-01-01

    Cyclic-load crack growth measurements were performed on ASME SA-105 Grade 2 steel specimens exposed to 10,000- and 15,000-psi hydrogen and to 5000-psi helium, all at ambient temperatures. The cyclic-load crack growth rate was found to be faster in high-pressure hydrogen than in helium. Cyclic-load crack growth rates in this steel were not reduced by preloading in air to a stress intensity of 1.5 times the cyclic K sub max in hydrogen. There are indications that holding under load in hydrogen, and loading and unloading in helium retards hydrogen-accelerated cyclic-load crack growth. Cyclic frequency and R (ratio of K sub min/k sub max) were important variables determining crack growth rate. The crack growth rate increased as a logarithm of the cycle duration and decreased with increasing R.

  9. AMBIENT TEMPERATURE AND DRIVING CYCLE EFFECTS FROM AN AUTOMOBILE POWERED BY LIQUIFIED PETROLEUM GAS

    EPA Science Inventory

    This paper describes an emissions study of a 1991 Chevrolet Lumina, powered by liquefied petroleum gas. he study was designed to obtain emissions information to predict how liquid petroleum gas usage impacts ambient air quality and air toxics concentrations. he study was also des...

  10. Applying policy and health effects of air pollution in South Korea: focus on ambient air quality standards

    PubMed Central

    Ha, Jongsik

    2014-01-01

    Objectives South Korea’s air quality standards are insufficient in terms of establishing a procedure for their management. The current system lacks a proper decision-making process and prior evidence is not considered. The purpose of this study is to propose a measure for establishing atmospheric environmental standards in South Korea that will take into consideration the health of its residents. Methods In this paper, the National Ambient Air Quality Standards (NAAQS) of the US was examined in order to suggest ways, which consider health effects, to establish air quality standards in South Korea. Up-to-date research on the health effects of air pollution was then reviewed, and tools were proposed to utilize the key results. This was done in an effort to ensure the reliability of the standards with regard to public health. Results This study showed that scientific research on the health effects of air pollution and the methodology used in the research have contributed significantly to establishing air quality standards. However, as the standards are legally binding, the procedure should take into account the effects on other sectors. Realistically speaking, it is impossible to establish standards that protect an entire population from air pollution. Instead, it is necessary to find a balance between what should be done and what can be done. Conclusions Therefore, establishing air quality standards should be done as part of an evidence-based policy that identifies the health effects of air pollution and takes into consideration political, economic, and social contexts. PMID:25300297

  11. Influence of breed, milk production, season, and ambient temperature on dairy cow reticulorumen temperature.

    PubMed

    Liang, D; Wood, C L; McQuerry, K J; Ray, D L; Clark, J D; Bewley, J M

    2013-08-01

    Automatic monitoring of core body temperature in dairy cattle could be useful for identification of illness, heat stress, general physiological stress, and estrus. The SmartBolus (TenXSys Inc., Eagle, ID) system used a reticulorumen bolus to automatically record and transmit dairy cow temperatures. The objective of this research was to characterize the influence of milk yield (MY), time of day, breed, ambient temperature (AT), and season on reticulorumen temperatures (RT) in lactating dairy cows. Continuous RT and AT were collected by SmartBolus transponders every 15 min (96 records per d) from 93 cows (65 Holstein, 18 crossbred, and 10 Jersey) for 615 d. Mean (±SD) daily RT, AT, and MY were 40.14±0.32°C, 12.20±10.61°C, and 33.85±8.67 kg, respectively. The maximum and minimum RT were recorded at 2330 and 1000 h, respectively. Ambient temperature increased RT. Summer RT was significantly greater than spring, fall, or winter RT. The effect of MY on RT varied by breed, season, and AT. Crossbred RT was significantly lower than Holstein RT after adjusting for MY. Crossbred RT responded less to increasing AT than did Holstein RT, potentially indicating improved heat tolerance among these crossbred dairy cows. Reticulorumen temperature increased more dramatically for cows with greater milk yield as AT increased, demonstrating that high-producing cows are more susceptible to heat stress than low-producing cows. These results could be useful in interpretation of automatic temperature system data, heat stress management, and genetic selection of heat-tolerant cows. PMID:23769360

  12. Characterization, identification of ambient air and road dust polycyclic aromatic hydrocarbons in central Taiwan, Taichung.

    PubMed

    Fang, Guor-Cheng; Chang, Cheng-Nan; Wu, Yuh-Shen; Fu, Peter Pi-Cheng; Yang, I-Lin; Chen, Ming-Hsiang

    2004-07-01

    The concentrations of ambient air polycyclic aromatic hydrocarbons (PAHs) were measured simultaneously in an industrial area (Taichung Industrial Park, TIP) and suburban area (Tunghai University, THU) in central Taiwan, Taichung. A total of samples were collected simultaneously at the two sites between August 2002 and March 2003. Particle-bound PAHs (p-PAHs) were collected on quartz filters and gas-phase PAHs (g-PAHs) on glass cartridges using polyurethane foam sampler, respectively. Both types of samples were extracted with dichloromethane/n-hexane mixture (50/50, v/v) for 24 h, then the extracts were subjected to gas chromatography/mass spectrometric analysis. Moreover, the roadside dust particle PAHs composition were also collected and analyzed at TIP, THU and traffic road sampling sites. The five main road lines in Taichung City were selected as traffic road sampling sites. Correlation studies between PAHs concentrations and meteorological parameters were revealed that temperature has greater effects (P>0.6) than other meteorological parameters such as wind speed, relative humidity and atmospheric pressure on g-PAHs and p-PAHs. PAHs sources were resolved by using principal component analysis and diagnostic ratios. The major sources of PAHs were combustion, traffic vehicle exhaust (diesel and gasoline engine), incinerator and industrial stationary sources at both sampling sites in central Taiwan. PMID:15172577

  13. 40 CFR 91.309 - Engine intake air temperature measurement.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Engine intake air temperature... Provisions § 91.309 Engine intake air temperature measurement. (a) Engine intake air temperature measurement... the supply system or in the air stream entering the engine. (b) The temperature measurements must...

  14. 40 CFR 91.309 - Engine intake air temperature measurement.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 20 2011-07-01 2011-07-01 false Engine intake air temperature... Provisions § 91.309 Engine intake air temperature measurement. (a) Engine intake air temperature measurement... the supply system or in the air stream entering the engine. (b) The temperature measurements must...

  15. 40 CFR 91.309 - Engine intake air temperature measurement.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 21 2012-07-01 2012-07-01 false Engine intake air temperature... Provisions § 91.309 Engine intake air temperature measurement. (a) Engine intake air temperature measurement... the supply system or in the air stream entering the engine. (b) The temperature measurements must...

  16. 40 CFR 91.309 - Engine intake air temperature measurement.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 21 2013-07-01 2013-07-01 false Engine intake air temperature... Provisions § 91.309 Engine intake air temperature measurement. (a) Engine intake air temperature measurement... the supply system or in the air stream entering the engine. (b) The temperature measurements must...

  17. 40 CFR 91.309 - Engine intake air temperature measurement.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 20 2014-07-01 2013-07-01 true Engine intake air temperature... Provisions § 91.309 Engine intake air temperature measurement. (a) Engine intake air temperature measurement... the supply system or in the air stream entering the engine. (b) The temperature measurements must...

  18. Acute effects of ozone on heart rate and body temperature in the unanesthetized, unrestrained rat maintained at different ambient temperatures

    SciTech Connect

    Watkinson, W.P.; Aileru, A.A.; Dowd, S.M.; Doerfler, D.L.; Tepper, J.S.

    1993-01-01

    The present studies were conducted to investigate the concentration-response characteristics of acute ozone (O3) exposure on the cardiovascular and thermoregulatory function of the unanesthetized, unrestrained rat, and to examine the modulating effects produced by changes in ambient temperature (T[sub a]) on the induced toxic response. For all studies, groups of male Fischer 344 rats (n=4-6/group) were implanted with radiotelemetry transmitters and allowed to recover overnight. The transmitters permitted continuous monitoring of electrocardiogram (ECG) and body core temperature (T[sub co]); heart rate (HR) was derived from the ECG signal. Frequency of breathing (f) was obtained in selected experiments by means of a Fenn box. All animals were monitored according to the following protocol: control (filtered air; 0.25 h); exposure (O3; 2 h); recovery (filtered air; 3-18 h). For the concentration-response experiments, O3 concentration was varied from 0.25-1.0 ppm and all exposures were conducted at an T[sub a] of 18-20 C. Significant decreases in HR and T[sub co] were demonstrated at O3 concentrations as low as 0.37 ppm.

  19. Ambient temperature liquefaction using liquid clathrates: Final technical report

    SciTech Connect

    Atwood, J.L.

    1988-06-22

    New air-stable liquid clathrates based on simple salts were used to effect liquefaction. The quantity of the liquefied products from the liquid clathrates based on (organic base/center dot/H)/sup + -/(Cl-H-Cl)/sup minus/ is among the highest yet observed. Indeed, liquid clathrates based on classic room temperature molten salts such as (pyridinium)(AlCl/sub 4/) have afforded yields of liquid material which may go as high as 70%. The work-up scheme for the (NBu/sub 4/)(Cl-H-Br) liquefaction products has afforded excellent mass balance. The first model hydrogenation runs in a liquid clathrate have been successfully carried out. In the liquid clathrate based on (NBu/sub 4/)(BF/sub 4/) and benzene, Wilkinson's catalyst has given almost complete conversion of cyclohexene to cyclohexane. Studies on the retention of cyclohexene and cyclohexane in the liquid clathrate phase are in progress. Initial indications are that cyclohexene is more compatible with the lower liquid layer than is cyclohexane.

  20. Advanced Catalysts for the Ambient Temperature Oxidation of Carbon Monoxide and Formaldehyde

    NASA Technical Reports Server (NTRS)

    Nalette, Tim; Eldridge, Christopher; Yu, Ping; Alpetkin, Gokhan; Graf, John

    2010-01-01

    The primary applications for ambient temperature carbon monoxide (CO) oxidation catalysts include emergency breathing masks and confined volume life support systems, such as those employed on the Shuttle. While Hopcalite is typically used in emergency breathing masks for terrestrial applications, in the 1970s, NASA selected a 2% platinum (Pt) on carbon for use on the Shuttle since it is more active and also more tolerant to water vapor. In the last 10-15 years there have been significant advances in ambient temperature CO oxidation catalysts. Langley Research Center developed a monolithic catalyst for ambient temperature CO oxidation operating under stoichiometric conditions for closed loop carbon dioxide (CO2) laser applications which is also advertised as having the potential to oxidize formaldehyde (HCHO) at ambient temperatures. In the last decade it has been discovered that appropriate sized nano-particles of gold are highly active for CO oxidation, even at sub-ambient temperatures, and as a result there has been a wealth of data reported in the literature relating to ambient/low temperature CO oxidation. In the shorter term missions where CO concentrations are typically controlled via ambient temperature oxidation catalysts, formaldehyde is also a contaminant of concern, and requires specially treated carbons such as Calgon Formasorb as untreated activated carbon has effectively no HCHO capacity. This paper examines the activity of some of the newer ambient temperature CO and formaldehyde (HCHO) oxidation catalysts, and measures the performance of the catalysts relative to the NASA baseline Ambient Temperature Catalytic Oxidizer (ATCO) catalyst at conditions of interest for closed loop trace contaminant control systems.

  1. Responses in rectal and skin temperatures to centrifugal forces in rats of different ambient temperatures

    NASA Astrophysics Data System (ADS)

    Ohara, K.; Sato, H.; Okuda, N.; Makino, Y.; Isobe, Y.

    1982-03-01

    Effects of centrifugation upon rectal (Tre) and tail skin temperatures (Ts) were studied in male Wistar rats at varying ambient temperature (Ta) using a centrifuge which was placed in a climatic chamber. Centrifugal forces of Gz of 3.0 were imposed on rats which were suspended at horizontal body position using a newly developed mesh suits holding method in the animal box placed on the rotating arm of the centrifuge. Headwards or tailwards forces were applied according to the experimental design. No significant difference of the responses was observed between the two force directions. Centrifugations imposed at different Ta of 15, 20, 25, 30 and 32.5‡C resulted in falls in Tre accompanied by rises in tail Ts at the cooler environments, while rises in Tre accompanied by falls in Ts in the warmer environments. The Ta at which the response pattern of Tre and Ts was reversed (critical ambient temperature) was 26.8±2.3 (mean and SE) and 27.9±2.8‡C, respectively. Tolerance to centrifugation was markedly increased in cooler environments than in wanner ones. It was suggested that the increased skin pressure due to centrifugation exerted some inhibitory effects upon central thermoregulatory ability.

  2. New screening approach for risk assessment of pesticides in ambient air

    NASA Astrophysics Data System (ADS)

    Yusà, Vicent; Coscollà, Clara; Millet, Maurice

    2014-10-01

    We present a novel screening approach for inhalation risk assessment of currently used pesticides (CUPs) in ambient air, based on the measurements of pesticide levels in the inhalable fraction of the particulate matter (PM10). Total concentrations in ambient air (gas + particle phases) were estimated using a theoretical model of distribution of semi-volatile organic compounds between the gas and the particulate phase based on the octanol-air partition (Koa) of each pesticide. The proposed approach was used in a pilot study conducted in a rural station in Valencia (Spain) from April through to October 2010. Twenty out of 82 analysed pesticides were detected in average concentrations ranging from 1.63 to 117.01 pg m-3. For adults, children and infants the estimated chronic inhalation risk, expressed as Hazard Quotient (HQ) was <1 for all pesticides. Likewise, the cumulative exposure for detected organophosphorus, pyrethroids and carbamates pesticides, was estimated using as metrics the Hazard Index (HI), which was less than 1 for the three families of pesticides assessed. The cancer risk estimated for the detected pesticides classified as Likely or Possible carcinogens was less than 1.15E-7 for infants. In our opinion, the screening approach proposed could be used in the monitoring and risk assessment of pesticides in ambient air.

  3. Assessment of ambient ozone air quality and evidence of transport effects in eastern Kern County, California

    SciTech Connect

    Beutelman, H.P.; Hallman, P.K.; Franz, J.A.

    1998-12-31

    Edwards AFB is located in the Mojave desert of southern California. The bulk of the base is located in the eastern part of Kern County, and is classified as serious non-attainment for ozone. However, geographically the eastern part of Kern County is separated form the western part of the county by some of the tallest mountains in the continental US. It has long been suspected, but not well quantified, that the air quality in eastern Kern County is impacted by transport of ozone from the San Joaquin area (as well as possible transport from the Los Angeles Basin area). Because of the significance of the ozone non-attainment designation with regards to the Department of Defense Base Realignment and Closure process, improved assessment of ambient ozone air quality and possible routes of transport in eastern Kern County was required. This was accomplished by; installing and operating an ambient air quality monitoring station at Edwards AFB; and comparing at least one year of data (ozone, NO{sub x} and meteorological) from the Edwards AFB station with similar data from the California Air Resources Board operated stations in the upwind locations (along possible transport routes) of Edison (western Kern County), Mojave (eastern Kern County) and Lancaster (northern Los Angeles County). Empirical analysis of this and other data indicate that; (1) compared to western Kern County, eastern Kern County is in a significantly different and isolated air basin; (2) the peak ambient ozone levels in eastern Kern County are substantially lower than in western Kern County; (3) peak ambient ozone levels in eastern Kern County occur late afternoon/early evening and are indicative of transport of ozone and (4) direct transport of ozone from the San Joaquin and/or South Coast area does occur (given proper conditions). This paper will address the elements of this study and its conclusions.

  4. Controls of air temperature variability over an Alpine Glacier

    NASA Astrophysics Data System (ADS)

    Shaw, Thomas; Brock, Ben; Ayala, Álvaro; Rutter, Nick

    2016-04-01

    Near surface air temperature (Ta) is one of the most important controls on energy exchange between a glacier surface and the overlying atmosphere. However, not enough detail is known about the controls on Ta across a glacier due to sparse data availability. Recent work has provided insights into variability of Ta along glacier centre-lines in different parts of the world, yet there is still a limited understanding of off-centreline variability in Ta and how best to estimate it from distant off-glacier locations. We present a new dataset of distributed 2m Ta records for the Tsanteleina Glacier in Northwest Italy from July-September, 2015. Data provide detailed information of lateral (across-glacier) and centre-line variations in Ta, with ~20,000 hourly observations from 17 locations. The suitability of different vertical temperature gradients (VTGs) in estimating air temperature is considered under a range of meteorological conditions and from different forcing locations. A key finding is that local VTGs account for a lot of Ta variability under a broad range of climatic conditions. However, across-glacier variability is found to be significant, particularly for high ambient temperatures and for localised topographic depressions. The relationship of spatial Ta patterns with regional-scale reanalysis data and alternative Ta estimation methodologies are also presented. This work improves the knowledge of local scale Ta variations and their importance to melt modelling.

  5. Ozone flux to vegetation and its relationship to plant response and ambient air quality standards

    NASA Astrophysics Data System (ADS)

    Musselman, Robert C.; Massman, William J.

    The National Ambient Air Quality Standard (NAAQS) for ozone is based on occurrences of the maximum 8 h average ambient ozone concentration. However, biologists have recommended a cumulative ozone exposure parameter to protect vegetation. In this paper we propose a third alternative which uses quantifiable flux-based numerical parameters as a replacement for cumulative ambient parameters. Herein we discuss the concept of ozone flux as it relates to plant response and the NAAQS, and document information needed before a flux-based ozone NAAQS for vegetation can be implemented. Additional research is needed in techniques for determining plant uptake and in the quantification of plant defensive mechanisms to ozone. Models which include feedback mechanisms should be developed to relate ozone flux, loading, and detoxification with photosynthesis and plant productivity.

  6. Response of sugarcane sucrose yields to carbon dioxide enrichment and elevated air temperature

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Four sugarcane cultivars (CP 72-2086, CP 73-1547, CP 88-1508, and CP 80-1827) were grown in elongated temperature-gradient greenhouses (TGG) at ambient or elevated carbon dioxide (CO2) of 360 or 720 µmol CO2 mol-1 air (ppm, mole fraction basis), respectively. Elevated CO2 was maintained by injection...

  7. The effects of electron thermal radiation on laser ablative shock waves from aluminum plasma into ambient air

    NASA Astrophysics Data System (ADS)

    Sai Shiva, S.; Leela, Ch.; Prem Kiran, P.; Sijoy, C. D.; Chaturvedi, S.

    2016-05-01

    The effect of electron thermal radiation on 7 ns laser ablative shock waves from aluminum (Al) plasma into an ambient atmospheric air has been numerically investigated using a one-dimensional, three-temperature (electron, ion, and radiation) radiation hydrodynamic code MULTI. The governing equations in Lagrangian form are solved using an implicit scheme for planar, cylindrical, and spherical geometries. The shockwave velocities (Vsw) obtained numerically are compared with our experimental values obtained over the intensity range of 2.0 × 1010 to 1.4 × 1011 W/cm2. It is observed that the numerically obtained Vsw is significantly influenced by the thermal radiation effects which are found to be dominant in the initial stage up to 2 μs depending on the input laser energy. Also, the results are found to be sensitive to the co-ordinate geometry used in the simulation (planar, cylindrical, and spherical). Moreover, it is revealed that shock wave undergoes geometrical transitions from planar to cylindrical nature and from cylindrical to spherical nature with time during its propagation into an ambient atmospheric air. It is also observed that the spatio-temporal evolution of plasma electron and ion parameters such as temperature, specific energy, pressure, electron number density, and mass density were found to be modified significantly due to the effects of electron thermal radiation.

  8. Technical specification for transferring ambient air monitoring data to the Oak Ridge Environmental Information System (OREIS)

    SciTech Connect

    1995-06-01

    In September 1994, a team was formed to develop, document, and implement technical specifications for transmitting ambient air environmental compliance and monitoring data to the Oak Ridge Environmental Information System (OREIS). The approach used to transmit this data is documented in the {open_quotes}Plan for Integrating Environmental Compliance and Monitoring Data into OREIS.{close_quotes} This plan addresses the consolidated data requirements defined by the Federal Facility Agreement (FFA) and the Tennessee Oversight Agreement (TOA) as they pertain to environmental compliance and monitoring data maintained by Energy Systems` Oak Ridge Environmental Management organizations. Ibis document describes. the requirements, responsibilities, criteria, and format for transmitting ambient air compliance and monitoring data to OREIS.

  9. Relationship between polynuclear aromatic hydrocarbons in ambient air and 1-hydroxypyrene in human urine

    SciTech Connect

    Zhao, Z.H.; Quan, W.Y.; Tian, D.H. )

    1992-10-01

    The relationship between urinary 1-hydroxypyrene and ambient polynuclear aromatic hydrocarbons (PAHs) was investigated with several groups of volunteers carrying personal air samplers. All the results demonstrate that there is a statistically significant correlation between 1-hydroxypyrene in human urine and pyrene and benzo(a)pyrene in ambient air. Smoking was found not to interfere this correlation when the smokers consume less than 20 cigarettes daily. Different sources of PAH pollution, such as certain industries and coal-burning, present their influence on 1-hydroxypyrene in their specific ways. It is suggested that 1-hydroxypyrene in human urine is an effective biological monitoring index for the assessment of human exposure to PAHs. 18 refs., 7 figs., 6 tabs.

  10. Measurement of gas-phase ionic mercury(II) species in ambient air

    SciTech Connect

    Stratton, W.J.; Lindberg, S.E.

    1995-12-31

    One of the important questions in the biogeochemical cycling of mercury is the speciation of mercury in the atmosphere. Although a large fraction of Hg in ambient air is Hg(O), a small fraction is believed to be gas-phase Hg(II). This fraction is highly water-soluble and thus is important to explaining the high concentration of Hg in precipitation. We have developed a novel technique for measuring gas-phase Hg(II), using a high-flow refluxing mist chamber to trap the water-soluble Hg(II) in an aerosol mist. Measured concentrations of gas-phase Hg(II) in ambient air are generally in the range 0.05-0.1 ng/m{sup 3}, or 2-4% of the total gaseous Hg. In this talk, representative data under different atmospheric and geographic conditions will be presented, along with a summary of some of the experimental difficulties and unanswered questions.

  11. 75 FR 71033 - Air Quality Designations for the 2008 Lead (Pb) National Ambient Air Quality Standards

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-11-22

    ... Agency FR Federal Register FRM Federal Reference Method IQ Intelligence Quotient NAAQS National Ambient..., known as the Tribal Authority Rule (TAR), on February 12, 1999. 63 FR 7254, codified at 40 CFR 49 (1999... a notice on July 8, 2010 (75 FR 39254) which invited the public to comment on EPA's...

  12. Ambient temperature enhanced acute cardiovascular-respiratory mortality effects of PM2.5 in Beijing, China

    NASA Astrophysics Data System (ADS)

    Li, Yi; Ma, Zhiqiang; Zheng, Canjun; Shang, Yu

    2015-12-01

    Studies have shown that temperature could modify the effect of ambient fine particles on mortality risk. In assessing air pollution effects, temperature is usually considered as a confounder. However, ambient temperature can alter people's physiological response to air pollution and might "modify" the impact of air pollution on health outcomes. This study investigated the interaction between daily PM2.5 and daily mean temperature in Beijing, China, using data for the period 2005-2009. Bivariate PM2.5-temperature response surfaces and temperature-stratified generalized additive model (GAM) were applied to study the effect of PM2.5 on cardiovascular, respiratory mortality, and total non-accidental mortality across different temperature levels. We found that low temperature could significantly enhance the effect of PM2.5 on cardiovascular mortality. For an increase of 10 μg/m3 in PM2.5 concentration in the lowest temperature range (-9.7˜2.6 °C), the relative risk (RR) of cardiovascular mortality increased 1.27 % (95 % CI 0.38˜2.17 %), which was higher than that of the whole temperature range (0.59 %, 95 % CI 0.22-1.16 %). The largest effect of PM2.5 on respiratory mortality appeared in the high temperature range. For an increase of 10 μg/m3 in PM2.5 concentration, RR of respiratory mortality increased 1.70 % (95 % CI 0.92˜3.33 %) in the highest level (23.50˜31.80 °C). For the total non-accidental mortality, significant associations appeared only in low temperature levels (-9.7˜2.6 °C): for an increase of 10 μg/m3 in current day PM2.5 concentration, RR increased 1.27 % (95 % CI 0.46˜2.00 %) in the lowest temperature level. No lag effect was observed. The results suggest that in air pollution mortality time series studies, the possibility of an interaction between air pollution and temperature should be considered.

  13. The effects of ambient temperature on cerebrovascular mortality: an epidemiologic study in four climatic zones in China

    PubMed Central

    2014-01-01

    Background Little evidence is available about the association between temperature and cerebrovascular mortality in China. This study aims to examine the effects of ambient temperature on cerebrovascular mortality in different climatic zones in China. Method We obtained daily data on weather conditions, air pollution and cerebrovascular deaths from five cities (Beijing, Tianjin, Shanghai, Wuhan, and Guangzhou) in China during 2004-2008. We examined city-specific associations between ambient temperature and the cerebrovascular mortality, while adjusting for season, long-term trends, day of the week, relative humidity and air pollution. We examined cold effects using a 1°C decrease in temperature below a city-specific threshold, and hot effects using a 1°C increase in temperature above a city-specific threshold. We used a meta-analysis to summarize the cold and hot effects across the five cities. Results Beijing and Tianjin (with low mean temperature) had lower thresholds than Shanghai, Wuhan and Guangzhou (with high mean temperature). In Beijing, Tianjin, Wuhan and Guangzhou cold effects were delayed, while in Shanghai there was no or short induction. Hot effects were acute in all five cities. The cold effects lasted longer than hot effects. The hot effects were followed by mortality displacement. The pooled relative risk associated with a 1°C decrease in temperature below thresholds (cold effect) was 1.037 (95% confidence interval (CI): 1.020, 1.053). The pooled relative risk associated with a 1°C increase in temperature above thresholds (hot effect) was 1.014 (95% CI: 0.979, 1.050). Conclusion Cold temperatures are significantly associated with cerebrovascular mortality in China, while hot effect is not significant. People in colder climate cities were sensitive to hot temperatures, while people in warmer climate cities were vulnerable to cold temperature. PMID:24690204

  14. INFLUENCE OF AMBIENT TEMPERATURE ON TAILPIPE EMISSIONS FROM LATE MODEL LIGHT-DUTY GASOLINE MOTOR VEHICLES

    EPA Science Inventory

    Motor vehicle emissions are sensitive to a number of variables including ambient temperature, driving schedule (speed vs time), and fuel composition. ydrocarbon, aldehyde, carbon monoxide, and oxides of nitrogen emissions were examined with nine recent technology 4-cylinder gasol...

  15. Improving ethanol production from alfalfa stems via ambient-temperature acid pretreatment and washing.

    PubMed

    Zhou, Shengfei; Weimer, Paul J; Hatfield, Ronald D; Runge, Troy M; Digman, Matthew

    2014-10-01

    The concept of co-production of liquid fuel (ethanol) along with animal feed on farm was proposed, and the strategy of using ambient-temperature acid pretreatment, ensiling and washing to improve ethanol production from alfalfa stems was investigated. Alfalfa stems were separated and pretreated with sulfuric acid at ambient-temperature after harvest, and following ensiling, after which the ensiled stems were subjected to simultaneous saccharification and fermentation (SSF) for ethanol production. Ethanol yield was improved by ambient-temperature sulfuric acid pretreatment before ensiling, and by washing before SSF. It was theorized that the acid pretreatment at ambient temperature partially degraded hemicellulose, and altered cell wall structure, resulted in improved cellulose accessibility, whereas washing removed soluble ash in substrates which could inhibit the SSF. The pH of stored alfalfa stems can be used to predict the ethanol yield, with a correlation coefficient of +0.83 for washed alfalfa stems. PMID:25151072

  16. Bonding of copper surface in ambient air using propylene carbonate as passivation layer

    NASA Astrophysics Data System (ADS)

    Zhu, Zhiyuan; Yu, Min; Phillips, Oluwadamilola; Liu, Lisha; Jin, Yufeng

    2015-07-01

    Bonding of a copper surface in a nonvacuum environment has been studied for the purpose of reducing manufacturing costs. Cu-Cu bonding in ambient air is demonstrated by using propylene carbonate (PPC) as a passivation layer. The decomposition of the PPC passivation layer during bonding would protect the copper surface from oxidation by providing a shielding gas atmosphere between the copper surface and the air. Further, the PPC passivation layer would also overcome the degradation of copper surface during storage in the atmosphere.

  17. Laser-induced fluorescence from N2(+) ions generated by a corona discharge in ambient air.

    PubMed

    Konthasinghe, Kumarasiri; Fitzmorris, Kristin; Peiris, Manoj; Hopkins, Adam J; Petrak, Benjamin; Killinger, Dennis K; Muller, Andreas

    2015-09-01

    In this work, we present the measurement of laser-induced fluorescence from N2(+) ions via the B(2)Σu(+)-X(2)Σg(+) band system in the near-ultraviolet. The ions were generated continuously by a plasma glow discharge in low pressure N2 and by a corona discharge in ambient air. The fluorescence decay time was found to rapidly decrease with increasing pressure leading to an extrapolated decay rate of ≍10(10) s(-1) at atmospheric pressure. In spite of this quenching, we were able to observe laser induced fluorescence in ambient air by means of a time-gated spectral measurement. In the process of comparing the emission signal with that of N2 spontaneous Raman scattering, ion concentrations in ambient air of order 10(8-)10(10) cm(-3) were determined. With moderate increases in laser power and collection efficiency, ion concentrations of less than 10(6) cm(-3) may be measurable, potentially enabling applications in atmospheric standoff detection of ionizing radiation from hazardous radioactive sources. PMID:26414524

  18. Ambient air monitoring plan for Ciudad Acuna and Piedra Negras, Coahuila, Mexico. Final report

    SciTech Connect

    Winberry, J.; Henning, L.; Crume, R.

    1998-01-01

    The Cities of Ciudad Acuna and Piedras Negras and the State of Coahuila in Mexico are interested in improving ambient air quality monitoring capabilities in the two cities through the establishment of a network of ambient air monitors. The purpose of the network is to characterize population exposure to potentially harmful air contaminants, possibly including sulfur dioxide (SO{sub 2}), nitrogen oxides (NO{sub x}), ozone (O{sub 3}), carbon monoxide (CO), total suspended particulate matter (TSP), particulate matter with aerodynamic diameter less than 100 micrometers PM-10, and lead. This report presents the results of an evaluation of existing air quality monitoring equipment and facilities in Ciudad Acuna and Piedras Negras. Additionally, the report presents recommendations for developing an air quality monitoring network for PM-10, SO{sub 2}, lead, and ozone in these cities, using a combination of both new and existing equipment. The human resources currently available and ultimately needed to operate and maintain the network are also discussed.

  19. 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

  20. Twenty years of measurement of polycyclic aromatic hydrocarbons (PAHs) in UK ambient air by nationwide air quality networks.

    PubMed

    Brown, Andrew S; Brown, Richard J C; Coleman, Peter J; Conolly, Christopher; Sweetman, Andrew J; Jones, Kevin C; Butterfield, David M; Sarantaridis, Dimitris; Donovan, Brian J; Roberts, Ian

    2013-06-01

    The impact of human activities on the health of the population and of the wider environment has prompted action to monitor the presence of toxic compounds in the atmosphere. Toxic organic micropollutants (TOMPs) are some of the most insidious and persistent of these pollutants. Since 1991 the United Kingdom has operated nationwide air quality networks to assess the presence of TOMPs, including polycyclic aromatic hydrocarbons (PAHs), in ambient air. The data produced in 2010 marked 20 years of nationwide PAH monitoring. This paper marks this milestone by providing a novel and critical review of the data produced since nationwide monitoring began up to the end of 2011 (the latest year for which published data is available), discussing how the networks performing this monitoring has evolved, and elucidating trends in the concentrations of the PAHs measured. The current challenges in the area and a forward look to the future of air quality monitoring for PAHs are also discussed briefly. PMID:23636622

  1. 40 CFR Appendix T to Part 50 - Interpretation of the Primary National Ambient Air Quality Standards for Oxides of Sulfur (Sulfur...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Ambient Air Quality Standards for Oxides of Sulfur (Sulfur Dioxide) T Appendix T to Part 50 Protection of... Ambient Air Quality Standards for Oxides of Sulfur (Sulfur Dioxide) 1. General (a) This appendix explains... ambient air quality standards for Oxides of Sulfur as measured by Sulfur Dioxide (“SO2 NAAQS”)...

  2. 40 CFR Appendix T to Part 50 - Interpretation of the Primary National Ambient Air Quality Standards for Oxides of Sulfur (Sulfur...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Ambient Air Quality Standards for Oxides of Sulfur (Sulfur Dioxide) T Appendix T to Part 50 Protection of... Ambient Air Quality Standards for Oxides of Sulfur (Sulfur Dioxide) 1. General (a) This appendix explains... ambient air quality standards for Oxides of Sulfur as measured by Sulfur Dioxide (“SO2 NAAQS”)...

  3. 40 CFR Appendix T to Part 50 - Interpretation of the Primary National Ambient Air Quality Standards for Oxides of Sulfur (Sulfur...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Ambient Air Quality Standards for Oxides of Sulfur (Sulfur Dioxide) T Appendix T to Part 50 Protection of... Ambient Air Quality Standards for Oxides of Sulfur (Sulfur Dioxide) 1. General (a) This appendix explains... ambient air quality standards for Oxides of Sulfur as measured by Sulfur Dioxide (“SO2 NAAQS”)...

  4. 40 CFR Appendix T to Part 50 - Interpretation of the Primary National Ambient Air Quality Standards for Oxides of Sulfur (Sulfur...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Ambient Air Quality Standards for Oxides of Sulfur (Sulfur Dioxide) T Appendix T to Part 50 Protection of... Ambient Air Quality Standards for Oxides of Sulfur (Sulfur Dioxide) 1. General (a) This appendix explains... ambient air quality standards for Oxides of Sulfur as measured by Sulfur Dioxide (“SO2 NAAQS”)...

  5. Coolant and ambient temperature control for chillerless liquid cooled data centers

    DOEpatents

    Chainer, Timothy J.; David, Milnes P.; Iyengar, Madhusudan K.; Parida, Pritish R.; Simons, Robert E.

    2016-02-02

    Cooling control methods include measuring a temperature of air provided to a plurality of nodes by an air-to-liquid heat exchanger, measuring a temperature of at least one component of the plurality of nodes and finding a maximum component temperature across all such nodes, comparing the maximum component temperature to a first and second component threshold and comparing the air temperature to a first and second air threshold, and controlling a proportion of coolant flow and a coolant flow rate to the air-to-liquid heat exchanger and the plurality of nodes based on the comparisons.

  6. Ambient air quality trends and driving factor analysis in Beijing, 1983-2007.

    PubMed

    Zhang, Ju; Ouyang, Zhiyun; Miao, Hong; Wang, Xiaoke

    2011-01-01

    The rapid development in Beijing, the capital of China, has resulted in serious air pollution problems. Meanwhile great efforts have been made to improve the air quality, especially since 1998. The variation in air quality under the interaction of pollution and control in this mega city has attracted much attention. We analyzed the changes in ambient air quality in Beijing since the 1980's using the Daniel trend test based on data from long-term monitoring stations. The results showed that different pollutants displayed three trends: a decreasing trend, an increasing trend and a flat trend. SO2, dustfall, B[a]P, NO2 and PM10 fit decreasing trend pattern, while NOx showed an increasing trend, and CO, ozone pollution, total suspended particulate (TSP), as well as Pb fit the flat trend. The cause of the general air pollution in Beijing has changed from being predominantly related to coal burning to mixed traffic exhaust and coal burning related pollution. Seasonally, the pollution level is typically higher during the heating season from November to the following March. The interaction between pollution sources change and implementation of air pollution control measures was the main driving factor that caused the variation in air quality. Changes of industrial structure and improved energy efficiency, the use of clean energy and preferred use of clean coal, reduction in pollution sources, and implementation of advanced environmental standards have all contributed to the reduction in air pollution, particularly since 1998. PMID:22432333

  7. A hybrid downscaling procedure for estimating the vertical distribution of ambient temperature in local scale

    NASA Astrophysics Data System (ADS)

    Yiannikopoulou, I.; Philippopoulos, K.; Deligiorgi, D.

    2012-04-01

    The vertical thermal structure of the atmosphere is defined by a combination of dynamic and radiation transfer processes and plays an important role in describing the meteorological conditions at local scales. The scope of this work is to develop and quantify the predictive ability of a hybrid dynamic-statistical downscaling procedure to estimate the vertical profile of ambient temperature at finer spatial scales. The study focuses on the warm period of the year (June - August) and the method is applied to an urban coastal site (Hellinikon), located in eastern Mediterranean. The two-step methodology initially involves the dynamic downscaling of coarse resolution climate data via the RegCM4.0 regional climate model and subsequently the statistical downscaling of the modeled outputs by developing and training site-specific artificial neural networks (ANN). The 2.5ox2.5o gridded NCEP-DOE Reanalysis 2 dataset is used as initial and boundary conditions for the dynamic downscaling element of the methodology, which enhances the regional representivity of the dataset to 20km and provides modeled fields in 18 vertical levels. The regional climate modeling results are compared versus the upper-air Hellinikon radiosonde observations and the mean absolute error (MAE) is calculated between the four grid point values nearest to the station and the ambient temperature at the standard and significant pressure levels. The statistical downscaling element of the methodology consists of an ensemble of ANN models, one for each pressure level, which are trained separately and employ the regional scale RegCM4.0 output. The ANN models are theoretically capable of estimating any measurable input-output function to any desired degree of accuracy. In this study they are used as non-linear function approximators for identifying the relationship between a number of predictor variables and the ambient temperature at the various vertical levels. An insight of the statistically derived input

  8. Intraurban Spatiotemporal Variability of Ambient Air Pollutants across Metropolitan St. Louis

    NASA Astrophysics Data System (ADS)

    Du, Li

    Ambient air monitoring networks have been established in the United States since the 1970s to comply with the Clean Air Act. The monitoring networks are primarily used to determine compliance but also provide substantive support to air quality management and air quality research including studies on health effects of air pollutants. The Roxana Air Quality Study (RAQS) was conducted at the fenceline of a petroleum refinery in Roxana, Illinois. In addition to providing insights into air pollutant impacts from the refinery, these measurements increased the St. Louis area monitoring network density for gaseous air toxics and fine particulate matter (PM2.5) speciation and thus provided an opportunity to examine intraurban spatiotemporal variability for these air quality parameters. This dissertation focused on exploring and assessing aspects of ambient air pollutant spatiotemporal variability in the St. Louis area from three progressively expanded spatial scales using a suite of methods and metrics. RAQS data were used to characterize air quality conditions in the immediate vicinity of the petroleum refinery. For example, PM2.5 lanthanoids were used to track impacts from refinery fluidized bed catalytic cracker emissions. RAQS air toxics data were interpreted by comparing to network data from the Blair Street station in the City of St. Louis which is a National Air Toxics Trends Station. Species were classified as being spatially homogeneous (similar between sites) or heterogeneous (different between sites) and in the latter case these differences were interpreted using surface winds data. For PM 2.5 species, there were five concurrently operating sites in the St. Louis area - including the site in Roxana - which are either formally part of the national Chemical Speciation Network (CSN) or rigorously follow the CSN sampling and analytical protocols. This unusually large number of speciation sites for a region the size of St. Louis motivated a detailed examination of

  9. An analysis of using semi-permeable membrane devices to assess persistent organic pollutants in ambient air of Alaska

    NASA Astrophysics Data System (ADS)

    Wu, Ted Hsin-Yeh

    A region of concern for persistent organic pollutants (POPS) contamination is the Arctic, because of POPs' ability to migrate long distances through the atmosphere toward cold regions, condense out of the atmosphere in those region, deposit in sensitive arctic ecosystems and bioaccumulate in Arctic species. Thus, monitoring of POP concentrations in the Arctic is necessary. However, traditional active air monitoring techniques for POPs may not be feasible in the Arctic, because of logistics and cost. While these issues may be overcome using passive air sampling devices, questions arise about the interpretation of the contaminant concentrations detected using the passive air samplers. In this dissertation semi-permeable membrane devices (SPMDs) containing triolein were characterized and evaluated for use in sampling the ambient air of Alaska for three classes of POPS (organochlorines [OCs], polychlorinated biphenyls [PCBs] and polyaromatic hydrocarbons [PAHs]). In addition, a SPMD-based sampling campaign for POPS was conducted simultaneously at five sites in Alaska during a one-year period. The POP concentrations obtained from the SPMDs were examined to determine the spatial and seasonal variability at the locations. POP concentrations detected in SPMDs were influenced by exposure to sunlight, concentrations of particulate-bound contaminants and changes in temperature. PAH concentrations in a SPMD mounted in a sunlight-blocking deployment unit were higher than in a SPMD exposed to sunlight (P = 0.007). PCB concentrations in SPMD exposed to filtered and non-filtered air were significantly different (P < 0.0001). Derived PAH air concentrations measured using SPMD were within a factor of approximately 7 of those obtained from an air sampler in Barrow, Alaska. The field study showed three distinct groups of samples. Barrow was separated from the sub-Arctic samples and a Homer sample (September-December) was distinct from the sub-Arctic samples. The separations suggest

  10. Using self-organizing maps to develop ambient air quality classifications: a time series example

    PubMed Central

    2014-01-01

    Background Development of exposure metrics that capture features of the multipollutant environment are needed to investigate health effects of pollutant mixtures. This is a complex problem that requires development of new methodologies. Objective Present a self-organizing map (SOM) framework for creating ambient air quality classifications that group days with similar multipollutant profiles. Methods Eight years of day-level data from Atlanta, GA, for ten ambient air pollutants collected at a central monitor location were classified using SOM into a set of day types based on their day-level multipollutant profiles. We present strategies for using SOM to develop a multipollutant metric of air quality and compare results with more traditional techniques. Results Our analysis found that 16 types of days reasonably describe the day-level multipollutant combinations that appear most frequently in our data. Multipollutant day types ranged from conditions when all pollutants measured low to days exhibiting relatively high concentrations for either primary or secondary pollutants or both. The temporal nature of class assignments indicated substantial heterogeneity in day type frequency distributions (~1%-14%), relatively short-term durations (<2 day persistence), and long-term and seasonal trends. Meteorological summaries revealed strong day type weather dependencies and pollutant concentration summaries provided interesting scenarios for further investigation. Comparison with traditional methods found SOM produced similar classifications with added insight regarding between-class relationships. Conclusion We find SOM to be an attractive framework for developing ambient air quality classification because the approach eases interpretation of results by allowing users to visualize classifications on an organized map. The presented approach provides an appealing tool for developing multipollutant metrics of air quality that can be used to support multipollutant health studies

  11. AMBIENT MEASUREMENT METHODS AND PROPERTIES OF THE 189 CLEAN AIR ACT HAZARDOUS AIR POLLUTANTS

    EPA Science Inventory

    Measurement methods for the 189 Hazardous Air Pollutants (HAPS) designated in Title III of the 1990 Clean Air Act Amendments are either identified or suggested for all but 10 of the compounds. n extensive list of chemical and physical properties are developed for all compounds. u...

  12. 40 CFR 50.7 - National primary and secondary ambient air quality standards for PM2.5.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... air quality standards for PM2.5. 50.7 Section 50.7 Protection of Environment ENVIRONMENTAL PROTECTION... National primary and secondary ambient air quality standards for PM2.5. (a) The national primary and... air as PM2.5 (particles with an aerodynamic diameter less than or equal to a nominal 2.5...

  13. 40 CFR 50.7 - National primary and secondary ambient air quality standards for PM2.5.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... air quality standards for PM2.5. 50.7 Section 50.7 Protection of Environment ENVIRONMENTAL PROTECTION... National primary and secondary ambient air quality standards for PM2.5. (a) The national primary and... air as PM2.5 (particles with an aerodynamic diameter less than or equal to a nominal 2.5...

  14. 40 CFR 50.7 - National primary and secondary ambient air quality standards for PM2.5.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... air quality standards for PM2.5. 50.7 Section 50.7 Protection of Environment ENVIRONMENTAL PROTECTION... National primary and secondary ambient air quality standards for PM2.5. (a) The national primary and... air as PM2.5 (particles with an aerodynamic diameter less than or equal to a nominal 2.5...

  15. 40 CFR 50.7 - National primary and secondary ambient air quality standards for PM2.5.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... air quality standards for PM2.5. 50.7 Section 50.7 Protection of Environment ENVIRONMENTAL PROTECTION... National primary and secondary ambient air quality standards for PM2.5. (a) The national primary and... air as PM2.5 (particles with an aerodynamic diameter less than or equal to a nominal 2.5...

  16. 40 CFR 50.7 - National primary and secondary ambient air quality standards for PM2.5.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... air quality standards for PM2.5. 50.7 Section 50.7 Protection of Environment ENVIRONMENTAL PROTECTION... National primary and secondary ambient air quality standards for PM2.5. (a) The national primary and... air as PM2.5 (particles with an aerodynamic diameter less than or equal to a nominal 2.5...

  17. The Association of Ambient Air Pollution and Physical Inactivity in the United States

    PubMed Central

    Roberts, Jennifer D.; Voss, Jameson D.; Knight, Brandon

    2014-01-01

    Background Physical inactivity, ambient air pollution and obesity are modifiable risk factors for non-communicable diseases, with the first accounting for 10% of premature deaths worldwide. Although community level interventions may target each simultaneously, research on the relationship between these risk factors is lacking. Objectives After comparing spatial interpolation methods to determine the best predictor for particulate matter (PM2.5; PM10) and ozone (O3) exposures throughout the U.S., we evaluated the cross-sectional association of ambient air pollution with leisure-time physical inactivity among adults. Methods In this cross-sectional study, we assessed leisure-time physical inactivity using individual self-reported survey data from the Centers for Disease Control and Prevention's 2011 Behavioral Risk Factor Surveillance System. These data were combined with county-level U.S. Environmental Protection Agency air pollution exposure estimates using two interpolation methods (Inverse Distance Weighting and Empirical Bayesian Kriging). Finally, we evaluated whether those exposed to higher levels of air pollution were less active by performing logistic regression, adjusting for demographic and behavioral risk factors, and after stratifying by body weight category. Results With Empirical Bayesian Kriging air pollution values, we estimated a statistically significant 16–35% relative increase in the odds of leisure-time physical inactivity per exposure class increase of PM2.5 in the fully adjusted model across the normal weight respondents (p-value<0.0001). Evidence suggested a relationship between the increasing dose of PM2.5 exposure and the increasing odds of physical inactivity. Conclusions In a nationally representative, cross-sectional sample, increased community level air pollution is associated with reduced leisure-time physical activity particularly among the normal weight. Although our design precludes a causal inference, these results provide

  18. Trends in Surface Temperature from AIRS.

    NASA Astrophysics Data System (ADS)

    Ruzmaikin, A.; Aumann, H. H.

    2014-12-01

    To address possible causes of the current hiatus in the Earth's global temperature we investigate the trends and variability in the surface temperature using retrievals obtained from the measurements by the Atmospheric Infrared Sounder (AIRS) and its companion instrument, the Advanced Microwave Sounding Unit (AMSU), onboard of Aqua spacecraft in 2002-2014. The data used are L3 monthly means on a 1x1degree spatial grid. We separate the land and ocean temperatures, as well as temperatures in Artic, Antarctic and desert regions. We find a monotonic positive trend for the land temperature but not for the ocean temperature. The difference in the regional trends can help to explain why the global surface temperature remains almost unchanged but the frequency of occurrence of the extreme events increases under rising anthropogenic forcing. The results are compared with the model studies. This work was supported by the Jet Propulsion Laboratory of the California Institute of Technology, under a contract with the National Aeronautics and Space Administration.

  19. Ambient Air Quality Assessment with Particular Reference to Particulates in Jharia Coalfield, Eastern India.

    PubMed

    Singh, Gurdeep; Roy, Debananda; Sinha, Sweta

    2014-01-01

    Jharia Coalfield is the critically polluted area with the intense mining and associated industrial activities. There has been widespread concern of particulate pollution with the alarming levels of Suspended Particulate Matter (SPM) and Respirable Particulate Matter (PM10 & PM2.5). Coke oven plants, coal washing, thermal power stations and associated activities coupled with the transportation activities, give rise to critical air pollution levels in the region. This study envisages the assessment of air pollution of the region with particular reference to SPM, PM10 and PM2.5. Eighteen monitoring stations were selected considering various sources of pollution such as mining, industrial, commercial and residential areas apart from siting criteria as per IS: 5182 Part XIV. Air quality monitoring was carried out following standard methodologies and protocols as per Central Pollution Control Board (CPCB)/ National Ambient Air Quality Standard (NAAQS) norms using Respirable Dust Samplers (RDS) and Fine Particulate Samplers (PM2.5 Samplers). This study reveals considerable load of particulates (SPM, PM10, PM 2.5) which exceed not only the NAAQS but also the coal mining areas standards of Jharia coalfield, thus falling under the category of critically polluted area. Air Quality Indexing has also been developed which provides a clear map of the deterioration of air quality and also presenting comparative ranking of all the monitoring locations with respect to air quality status in the study area. PMID:26445752

  20. Health effects of acute exposure to air polllution. Part II: Healthy subjects exposed to cencentrated ambient particles

    EPA Science Inventory

    The purpose of this study was to assess the impact of short-term exposure to concentrated ambient particles (CAPs*) on lung function and on inflammatory parameters in blood and airways of healthy human subjects. Particles were concentrated from the ambient air in Chapel Hill, Nor...

  1. 75 FR 10252 - Release of Draft Documents Related to the Review of the National Ambient Air Quality Standards...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-05

    ... Carbon Monoxide AGENCY: Environmental Protection Agency (EPA). ACTION: Availability of draft documents... Exposure Assessment to Support the Review of the Carbon Monoxide Primary National Ambient Air Quality... draft assessment document: Policy Assessment for the Review of the Carbon Monoxide National Ambient...

  2. Development of Quality Control Parameters and Electronic Data Recording for an Ambient Air Particle Inhalation Exposure System

    EPA Science Inventory

    Ambient air particle concentrating systems were installed by the US EPA in RTP, NC. These systems, designed by Harvard School of Public Health’s Department of Environmental Sciences and Engineering (Boston, MA), concentrated ambient fine and ultra-fine mode particulate matter (P...

  3. Polymer Electrolyte-Based Ambient Temperature Oxygen Microsensors for Environmental Monitoring

    NASA Technical Reports Server (NTRS)

    Hunter, Gary W.; Xu, Jennifer C.; Liu, Chung-Chiun

    2011-01-01

    An ambient temperature oxygen microsensor, based on a Nafion polymer electrolyte, has been developed and was microfabricated using thin-film technologies. A challenge in the operation of Nafion-based sensor systems is that the conductivity of Nafion film depends on the humidity in the film. Nafion film loses conductivity when the moisture content in the film is too low, which can affect sensor operation. The advancement here is the identification of a method to retain the operation of the Nafion films in lower humidity environments. Certain salts can hold water molecules in the Nafion film structure at room temperature. By mixing salts with the Nafion solution, water molecules can be homogeneously distributed in the Nafion film increasing the film s hydration to prevent Nafion film from being dried out in low-humidity environment. The presence of organics provides extra sites in the Nafion film to promote proton (H+) mobility and thus improving Nafion film conductivity and sensor performance. The fabrication of ambient temperature oxygen microsensors includes depositing basic electrodes using noble metals, and metal oxides layer on one of the electrode as a reference electrode. The use of noble metals for electrodes is due to their strong catalytic properties for oxygen reduction. A conducting polymer Nafion, doped with water-retaining components and extra sites facilitating proton movement, was used as the electrolyte material, making the design adequate for low humidity environment applications. The Nafion solution was coated on the electrodes and air-dried. The sensor operates at room temperature in potentiometric mode, which measures voltage differences between working and reference electrodes in different gases. Repeat able responses to 21-percent oxygen in nitrogen were achieved using nitrogen as a baseline gas. Detection of oxygen from 7 to 21 percent has also been demonstrated. The room-temperature oxygen micro sensor developed has extremely low power

  4. Assessing uncertain human exposure to ambient air pollution using environmental models in the Web

    NASA Astrophysics Data System (ADS)

    Gerharz, L. E.; Pebesma, E.; Denby, B.

    2012-04-01

    Ambient air quality can have significant impact on human health by causing respiratory and cardio-vascular diseases. Thereby, the pollutant concentration a person is exposed to can differ considerably between individuals depending on their daily routine and movement patterns. Using a straight forward approach this exposure can be estimated by integration of individual space-time paths and spatio-temporally resolved ambient air quality data. To allow a realistic exposure assessment, it is furthermore important to consider uncertainties due to input and model errors. In this work, we present a generic, web-based approach for estimating individual exposure by integration of uncertain position and air quality information implemented as a web service. Following the Model Web initiative envisioning an infrastructure for deploying, executing and chaining environmental models as services, existing models and data sources for e.g. air quality, can be used to assess exposure. Therefore, the service needs to deal with different formats, resolutions and uncertainty representations provided by model or data services. Potential mismatch can be accounted for by transformation of uncertainties and (dis-)aggregation of data under consideration of changes in the uncertainties using components developed in the UncertWeb project. In UncertWeb, the Model Web vision is extended to an Uncertainty-enabled Model Web, where services can process and communicate uncertainties in the data and models. The propagation of uncertainty to the exposure results is quantified using Monte Carlo simulation by combining different realisations of positions and ambient concentrations. Two case studies were used to evaluate the developed exposure assessment service. In a first study, GPS tracks with a positional uncertainty of a few meters, collected in the urban area of Münster, Germany were used to assess exposure to PM10 (particulate matter smaller 10 µm). Air quality data was provided by an

  5. Declining ambient air pollution and lung function improvement in Austrian children

    NASA Astrophysics Data System (ADS)

    Neuberger, Manfred; Moshammer, Hanns; Kundi, Michael

    Three thousand four hundred fifty-one Austrian elementary school children were examined (between 2 and 8 times) by spirometry by standardized methods, over a 5 yr period. The districts where they lived were grouped into those where NO 2 declined during this period (by at least 30 μg/m 3 measured as half year means) and those with less or no decline in ambient NO 2. In both groups of districts, SO 2 and TSP fell by similar amounts over this period. A continuous improvement of MEF25 (maximum exspiratory flow rate at 25% vital capacity) was found in districts with declining ambient NO 2. Populations did not differ in respect of anthropometric factors, passive smoking or socioeconomic status. A birth cohort from this study population which was followed up to age 18 confirmed the improved growth of MEF25 with decline in NO 2, while the improved growth of forced vital capacity was more related to decline in SO 2. This study provides the first evidence that improvements in the outdoor air quality during the 1980s are correlated with health benefits, and suggest that adverse effects on lung function related to ambient air pollution are reversible before adulthood. Improvement of small airway functions appeared to be more dependent on reductions of NO 2 than reduction in SO 2 and TSP.

  6. Ignition experiment of a fuel droplet in high-pressure high-temperature ambient

    SciTech Connect

    Nakanishi, Ryota; Kobayashi, Hideaki; Kato, Shinichiro; Niioka, Takashi

    1994-12-31

    In order to obtain the ignition behavior at supercritical pressures, ignition times of a single fuel droplet were measured in high-pressure high-temperature ambient. A suspended droplet of n-hexadecane or n-heptane with a diameter of 0.35--1.4 min was quickly immersed in an electric furnace with a temperature up to 950 K. Attachment of the droplet, movement of the furnace, and ignition measurement were carried out in an air vessel with pressures up to 3 MPa. At low pressures, ignition times of both fuels decreased with the initial droplet diameter and then increased. Therefore, the ignition time variation with the initial droplet diameter has a minimum. This phenomenon, however, disappeared at high pressures. Also, the ignitable limit of droplet diameter, below which the droplet vaporized completely before ignition, decreased as pressure increased. In the case of a droplet burning at high pressures, the preceding experiment showed that the burning rate constant increased and had a maximum around the critical pressure of fuel. This is significantly caused by variable properties around the critical point such as thermal conductivity and diffusion coefficient; and therefore, the present ignition time was expected to show similar characteristics due to the same reason. Ignition time, however, decreased monotonously with pressure, and even at supercritical pressures, the ignition time behavior did not change much. Being different from the case of combustion, it is suggested that drastic changes of properties did not take place in ignition processes.

  7. Humidity-resistant ambient-temperature solid-electrolyte amperometric sensing apparatus and methods

    DOEpatents

    Zaromb, Solomon

    2001-01-01

    Apparatus and methods for detecting selected chemical compounds in air or other gas streams at room or ambient temperature includes a liquid-free humidity-resistant amperometric sensor comprising a sensing electrode and a counter and reference electrode separated by a solid electrolyte. The sensing electrode preferably contains a noble metal, such as Pt black. The electrolyte is water-free, non-hygroscopic, and substantially water-insoluble, and has a room temperature ionic conductivity .gtoreq.10.sup.-4 (ohm-cm).sup.-1, and preferably .gtoreq.0.01 (ohm-cm).sup.-1. The conductivity may be due predominantly to Ag+ ions, as in Ag.sub.2 WO.sub.4.4AgI, or to F- ions, as in Ce.sub.0.95 Ca.sub.0.05 F.sub.2.95. Electrical contacts serve to connect the electrodes to potentiostating and detecting circuitry which controls the potential of the sensing electrode relative to the reference electrode, detects the signal generated by the sensor, and indicates the detected signal.

  8. Humidity-resistant ambient-temperature solid-electrolyte amperometric sensing apparatus

    DOEpatents

    Zaromb, Solomon

    1994-01-01

    Apparatus and methods for detecting selected chemical compounds in air or other gas streams at room or ambient temperature includes a liquid-free humidity-resistant amperometric sensor comprising a sensing electrode and a counter and reference electrode separated by a solid electrolyte. The sensing electrode preferably contains a noble metal, such as Pt black. The electrolyte is water-free, non-hygroscopic, and substantially water-insoluble, and has a room temperature ionic conductivity .gtoreq.10.sup.-4 (ohm-cm).sup.-1, and preferably .gtoreq.0.01 (ohm-cm).sup.-1. The conductivity may be due predominantly to Ag+ ions, as in Ag.sub.2 WO.sub.4.4AgI, or to F- ions, as in Ce.sub.0.95 Ca.sub.0.05 F.sub.2.95. Electrical contacts serve to connect the electrodes to potentiostating and detecting circuitry which controls the potential of the sensing electrode relative to the reference electrode, detects the signal generated by the sensor, and indicates the detected signal.

  9. A gravimetric approach to providing SI traceability for concentration measurement results of mercury vapor at ambient air levels

    NASA Astrophysics Data System (ADS)

    Ent, Hugo; van Andel, Inge; Heemskerk, Maurice; van Otterloo, Peter; Bavius, Wijnand; Baldan, Annarita; Horvat, Milena; Brown, Richard J. C.; Quétel, Christophe R.

    2014-11-01

    Current measurement and calibration capabilities for mercury vapor in air are maintained at levels of 0.2-40 μg Hg m-3. In this work, a mercury vapor generator has been developed to establish metrological traceability to the international system of units (SI) for mercury vapor measurement results ≤15 ng Hg m-3, i.e. closer to realistic ambient air concentrations (1-2 ng Hg m-3) [1]. Innovations developed included a modified type of diffusion cell, a new measurement method to weigh the loss in (mercury) mass of these diffusion cells during use (ca. 6-8 μg mass difference between successive weighings), and a new housing for the diffusion cells to maximize flow characteristics and to minimize temperature variations and adsorption effects. The newly developed mercury vapor generator system was tested by using diffusion cells generating 0.8 and 16 ng Hg min-1. The results also show that the filter system, to produce mercury free air, is working properly. Furthermore, and most importantly, the system is producing a flow with a stable mercury vapor content. Some additional improvements are still required to allow the developed mercury vapor generator to produce SI traceable mercury vapor concentrations, based upon gravimetry, at much lower concentration levels and reduced measurement uncertainties than have been achieved previously. The challenges to be met are especially related to developing more robust diffusion cells and better mass measurement conditions. The developed mercury vapor generator will contribute to more reliable measurement results of mercury vapor at ambient and background air levels, and also to better safety standards and cost reductions in industrial processes, such as the liquefied natural gas field, where aluminum main cryogenic heat exchangers are used which are particularly prone to corrosion caused by mercury.

  10. Assessment of heavy metal contents in the ambient air of the Coimbatore city, Tamilnadu, India.

    PubMed

    Vijayanand, C; Rajaguru, P; Kalaiselvi, K; Selvam, K Panneer; Palanivel, M

    2008-12-30

    Industrialization and urbanization are the two major causes of deteriorating air quality. To evaluate the ambient air quality of the Coimbatore city, suspended particulate matter (SPM) was collected at ten stations and analysed for the heavy metals content. The concentrations of seven heavy metals (Zn, Fe, Cu, Pb, Ni, Cr and Cd) were estimated. The level of SPM was found to be either at permissible or non-permissible limit depending upon the category of the sampling station. At majority of sampling stations, concentrations of Zn were found to be maximum than other heavy metals. The order of average concentrations of heavy metals in Coimbatore atmospheric air was Zn>Fe>Cu>Pb>Cr>Ni>Cd. The usage of Zn for protective coating on iron, steel etc. by the industries in Coimbatore city could be the major reason for the higher concentration of this heavy metal in this region. PMID:18471965

  11. Carcinogenicity of ambient air pollution: use of biomarkers, lessons learnt and future directions

    PubMed Central

    Vineis, Paolo

    2015-01-01

    The association between ambient air pollution (AAP) exposure and lung cancer risk has been investigated in prospective studies and the results are generally consistent, indicating that long-term exposure to air pollution can cause lung cancer. Biomarkers can enhance research on the health effects of air pollution by improving exposure assessment, increasing the understanding of mechanisms, and enabling the investigation of individual susceptibility. In this review, we assess DNA adducts as biomarkers of exposure to AAP and early biological effect, and DNA methylation as biomarker of early biological change and discuss critical issues arising from their incorporation in AAP health impact evaluations, such as confounding, individual susceptibilities, timing, intensity and duration of exposure, and investigated tissue. DNA adducts and DNA methylation are treated as paradigms. However, the lessons, learned from their use in the examination of AAP carcinogenicity, can be applied to investigations of other biomarkers involved in AAP carcinogenicity. PMID:25694819

  12. Continuous atomic spectrometric measurement of ambient levels of sulfur dioxide in air by mercury displacement detection

    SciTech Connect

    Marshall, G.; Midgley, D.

    1982-08-01

    The analytical atomic spectrometric technique of mercury displacement detection has been adapted so that sulfur dioxide can be determined at natural background levels in ambient air on a continuous basis with a 90% response time of 1-2 min. Sample air is drawn into the reaction vessel containing mercury (I) ion reagent and any sulfur dioxide present reacts to form elemental mercury which is measured, after being swept out of the solution by the same flow of sample air, by a mercury vapor detector. Reagent is continuously pumped through the analyzer and the instrument is calibrated with a permeation tube calibrator. The apparatus has a linear concentration range up to 100 ppB sulfur dioxide; this is much lower than can be obtained with existing commerical instruments. The apparatus is very precise and 6, 11, and 20 ppB sulfur dioxide can be measured with coefficients of variation of 1-2%.

  13. EFFECTS OF AMBIENT TEMPERATURE AND EXPOSURE TO 2450-MHZ MICROWAVE RADIATION ON EVAPORATIVE HEAT LOSS IN THE MOUSE

    EPA Science Inventory

    Whole-body evaporative heat loss was measured as whole-body evaporative water loss in mice during a 90 min exposure to 2450-MHz microwave radiation at an ambient temperature of 20 C and in non-exposed mice maintained at ambient temperature of 0, 25, 30, 33, and 35 C. The ambient-...

  14. An evaluation of ventilation system flow rates and levels of carbon dioxide, ambient temperature, and relative humidity in restaurants.

    PubMed

    Akbar-Khanzadeh, Farhang; Tan, Yin; Brown, Eric N; Akbar-Khanzadeh, Mahboubeh

    2002-09-01

    Studies of the indoor air quality of restaurants have rarely focused on ventilation system performance in relation to air pollutants and climatic factors. This study was conducted in eight restaurants to examine this issue by determining the ventilation flow rates and the levels of carbon dioxide (CO2), ambient temperature, and relative humidity during at least one complete shift of serving a meal. The mean values of number of dining patrons, ventilation flow rates, and the levels of CO2, ambient temperature, and relative humidity were not significantly different in the nonsmoking dining rooms and the smoking dining rooms. The mean ventilation flow rates in individual restaurants ranged from 42-113 cubic feet per minute per person (cfm/person), overall exceeding the recommended lower limit of 30 cfm/person. The mean levels of CO2 in two restaurants (646 and 819 ppm) were below, and in the other six restaurants (ranging 1,012-1,820 ppm) were above the recommended upper limit of 1000 ppm. The levels of CO2 in each restaurant significantly correlated with the number of dining patrons and in four restaurants accumulated gradually over time. In the nonsmoking dining rooms, the levels of CO2 increased significantly as the ventilation How rates decreased. The mean ambient temperature in restaurants (ranging from 22 degrees C - 24 degrees C) were within the recommended range of 20 degrees C - 26 degrees C. The mean relative humidity in six restaurants (ranging from 46%-59%) were within the recommended upper limit of 60 percent, and in two restaurants (62% and 71%) were slightly higher than this recommended limit. It was concluded that although the mean ventilation flow rates in all restaurants exceeded the recommended value, the design of the ventilation system or the distribution of air flow rate in some sections of restaurants were not appropriate to keep the levels of CO2 and relative humidity at some measurement locations below the recommended limits. PMID:12216594

  15. Does urban forestry have a quantitative effect on ambient air quality in an urban environment?

    NASA Astrophysics Data System (ADS)

    Irga, P. J.; Burchett, M. D.; Torpy, F. R.

    2015-11-01

    Increasing urban greenspace has been proposed as a means of reducing airborne pollutant concentrations; however limited studies provide experimental data, as opposed to model estimates, of its ability to do so. The current project examined whether higher concentrations of urban forestry might be associated with quantifiable effects on ambient air pollutant levels, whilst accounting for the predominant source of localized spatial variations in pollutant concentrations, namely vehicular traffic. Monthly air samples for one year were taken from eleven sites in central Sydney, Australia. The sample sites exhibited a range of different traffic density, population usage, and greenspace/urban forest density conditions. Carbon dioxide (CO2), carbon monoxide (CO), total volatile organic compounds (TVOCs), nitric oxide (NO), nitrogen dioxide (NO2), sulfur dioxide (SO2), total suspended particulate matter (TSP), suspended particles <10 μm in diameter (PM10) and particulate matter <2.5 μm (PM2.5), were recorded, using portable devices. It was found that air samples taken from sites with less greenspace frequently had high concentrations of all fractions of aerosolized particulates than other sites, whilst sites with high proximal greenspace had lower particulates, even when vehicular traffic was taken into account. No observable trends in concentrations of NO, TVOC and SO2 were observed, as recorded levels were generally very low across all sampled areas. The findings indicate, first, that within the urban areas of a city, localized differences in air pollutant loads occur. Secondly, we conclude that urban areas with proportionally higher concentrations of urban forestry may experience better air quality with regards to reduced ambient particulate matter; however conclusions about other air pollutants are yet to be elucidated.

  16. Effect of ambient air pollution on daily mortality rates in Guangzhou, China

    NASA Astrophysics Data System (ADS)

    Yu, Ignatius Tak Sun; Zhang, Yong hui; San Tam, Wilson Wai; Yan, Qing Hua; Xu, Yan jun; Xun, Xiao jun; Wu, Wei; Ma, Wen Jun; Tian, Lin Wei; Tse, Lap Ah; Lao, Xiang Qian

    2012-01-01

    We aimed to investigate the effects of ambient air pollutants on daily mortality in a relatively stable and homogeneous population in Guangzhou, China. Daily mortality, air pollution, and weather data between 2006 and 2009 were collected. The generalized additive model with poison regression was used to estimate the excessive risks (ERs) of air pollutants (PM 10, SO 2, and NO 2) on total, cardiovascular and respiratory mortality. The effects of lag0-1 were the greatest for total non-accidental and cardiovascular deaths. The increments of 10 μg m -3 in SO 2, NO 2, and PM 10 were associated with ERs of 1.54% (95%CI: 1.03-2.06%), 1.42% (95%CI: 1.06-1.78%), and 1.26% (95%CI: 0.86-1.66%) respectively for total non-accidental deaths, and 2.28% (95%CI: 1.40-3.16%), 1.81% (95%CI: 1.20-2.41%), and 1.79% (95%CI: 1.11-2.47%) respectively for cardiovascular deaths. For persons who died from respiratory disease, however, the maximum effects occurred at lag0. The ERs for SO 2, NO 2, and PM 10 were 1.36% (95%CI: 0.23-2.50%), 1.47% (95%CI: 0.66-2.29%) and 0.93% (95%CI: 0.03-1.83%), respectively. The effects of the three air pollutants on mortality were stronger in elderly and in women. The ERs in the present study were higher than those reported in Europe, the U.S., and most other Asian cities. Our findings show relatively higher ERs of daily mortality by ambient air pollutants in the center of Guangzhou, China, compared with estimates in other cities. Further studies with accurate exposure measurement among homogeneous population are needed to evaluate the precise magnitudes of the effects of the air pollutants.

  17. Is Air Temperature Enough to Predict Lake Surface Temperature?

    NASA Astrophysics Data System (ADS)

    Piccolroaz, S.; Toffolon, M.; Majone, B.

    2014-12-01

    Lake surface water (LST) is a key factor that controls most of the physical and ecological processes occurring in lakes. Reliable estimates are especially important in the light of recent studies, which revealed that inland water bodies are highly sensitive to climate, and are rapidly warming throughout the world. However, an accurate estimation of LST usually requires a significant amount of information that is not always available. In this work, we present an application of air2water, a lumped model that simulates LST as a function of air temperature only. In addition, air2water allows for a qualitative evaluation of the depth of the epilimnion during the annual stratification cycle. The model consists in a simplification of the complete heat budget of the well-mixed surface layer, and has a few parameters (from 4 to 8 depending on the version) that summarize the role of the different heat flux components. Model calibration requires only air and water temperature data, possibly covering sufficiently long historical periods in order to capture inter-annual variability and long-term trends. During the calibration procedure, the information included in input data is retrieved to directly inform model parameters, which can be used to classify the thermal behavior of the lake. In order to investigate how thermal dynamics are related to morphological features, the model has been applied to 14 temperate lakes characterized by different morphological and hydrological conditions, by different sources of temperature data (buoys, satellite), and by variable frequency of acquisition. A good agreement between observed and simulated LST has been achieved, with a RMSE in the order of 1°C, which is fully comparable to the performances of more complex process-based models. This application allowed for a deeper understanding of the thermal response of lakes as a function of their morphology, as well as for specific analyses as for example the investigation of the exceptional

  18. Ambient Temperature Changes and the Impact to Time Measurement Error

    NASA Astrophysics Data System (ADS)

    Ogrizovic, V.; Gucevic, J.; Delcev, S.

    2012-12-01

    Measurements in Geodetic Astronomy are mainly outdoors and performed during a night, when the temperature often decreases very quickly. The time-keeping during a measuring session is provided by collecting UTC time ticks from a GPS receiver and transferring them to a laptop computer. An interrupt handler routine processes received UTC impulses in real-time and calculates the clock parameters. The characteristics of the computer quartz clock are influenced by temperature changes of the environment. We exposed the laptop to different environmental temperature conditions, and calculate the clock parameters for each environmental model. The results show that the laptop used for time-keeping in outdoor measurements should be kept in a stable temperature environment, at temperatures near 20° C.

  19. Influence of chemical and physical forms of ambient air acids on airway doses

    SciTech Connect

    Larson, T.V.

    1989-02-01

    The effects of ambient relative humidity and particle size on acid deposition within the airways have been examined with a computer model. For H/sub 2/SO/sub 4/ particles initially at 90% relative humidity in ambient air that are inhaled via the nose or mouth, there is significant deposition of acid in the airways even in the presence of typical values of respiratory NH/sub 3/. When these same particles are found in a fog at 100.015% relative humidity, there is significant deposition of acid in the nasal region during nose breathing but insignificant deposition to the deep lung for either nose or mouth breathing. The factors governing the partitioning of labile acid gases in the gas and liquid phases prior to inhalation are also discussed.

  20. The contribution of nitro- and methylnitronaphthalenes to the vapor-phase mutagenicity of ambient air samples

    NASA Astrophysics Data System (ADS)

    Gupta, Pamela; Harger, William P.; Arey, Janet

    1- and 2-Nitronaphthalene (NN) and the 14 methylnitronaphthalene (MNN) isomers were identified and quantified in ambient vapor-phase samples collected in Redlands, CA during moderate photochemical air pollution. The mutagenic activities of NN and MNN standards were determined using a microsuspension-preincubation modification of the Ames Salmonella bacterial reversion assay in strain TA98 without microsomal activation. The calculated contributions of the NNs and MNNs to the total vapor-phase ambient mutagenic activity were ˜ 18 and ˜ 32% for daytime and nighttime composite samples, respectively. Enhanced mutagenic activity in the nighttime sample was attributed to NN and MNN formation from nighttime N03 radical-initiated reactions of naphthalene and the methylnaphthalenes.

  1. Responses in acral and non-acral skin vasomotion and temperature during lowering of ambient temperature.

    PubMed

    Elstad, Maja; Vanggaard, Leif; Lossius, Astrid H; Walløe, Lars; Bergersen, Tone Kristin

    2014-10-01

    Arteriovenous anastomoses (AVA) in acral skin (palms and soles) have a huge capacity to shunt blood directly from the arteries to the superficial venous plexus of the extremities. We hypothesized that acral skin, which supplies blood to the superficial venous plexus, has a stronger influence on blood flow adjustments during cooling in thermoneutral subjects than does non-acral skin. Thirteen healthy subjects were exposed to stepwise cooling from 32 °C to 25 °C and 17 °C in a climate chamber. Laser Doppler flux and skin temperature were measured simultaneously from the left and right third finger pulp and bilateral upper arm skin. Coherence and correlation analyses were performed of short-term fluctuations at each temperature interval. The flux from finger pulps showed the synchronous spontaneous fluctuations characteristic of skin areas containing AVAs. Fluctuation frequency, amplitude and synchronicity were all higher at 25 °C than at 32 °C and 17 °C (p<0.02). Bilateral flux from the upper arm skin showed an irregular, asynchronous vasomotor pattern with small amplitudes which were independent of ambient temperature. At 32 °C, ipsilateral median flux values from the right arm (95% confidence intervals) were 492 arbitrary units (au) (417, 537) in finger pulp and 43 au (35, 60) in upper arm skin. Flux values gradually decreased in finger pulp to 246 au (109, 363) at 25 °C, before an abrupt fall occurred at a median room temperature of 24 °C, resulting in a flux value of 79 au (31, 116) at 17 °C. In the upper arm skin a gradual fall throughout the cooling period to 21 au (13, 27) at 17 °C was observed. The fact that the response of blood flow to ambient cooling is stronger in acral skin than in non-acral skin suggests that AVAs have a greater capacity to adjust blood flow in thermoneutral zone than arterioles in non-acral skin. PMID:25436967

  2. Type 2 diabetes, but not obesity, prevalence is positively associated with ambient temperature

    PubMed Central

    Speakman, John R.; Heidari-Bakavoli, Sahar

    2016-01-01

    Cold exposure stimulates energy expenditure and glucose disposal. If these factors play a significant role in whole body energy balance, and glucose homeostasis, it is predicted that both obesity and type 2 diabetes prevalence would be lower where it is colder. Previous studies have noted connections between ambient temperature and obesity, but the direction of the effect is confused. No previous studies have explored the link of type 2 diabetes to ambient temperature. We used county level data for obesity and diabetes prevalence across the mainland USA and matched this to county level ambient temperature data. Average ambient temperature explained 5.7% of the spatial variation in obesity and 29.6% of the spatial variation in type 2 diabetes prevalence. Correcting the type 2 diabetes data for the effect of obesity reduced the explained variation to 26.8%. Even when correcting for obesity, poverty and race, ambient temperature explained 12.4% of the variation in the prevalence of type 2 diabetes, and this significant effect remained when latitude was entered into the model as a predictor. When obesity prevalence was corrected for poverty and race the significant effect of temperature disappeared. Enhancing energy expenditure by cold exposure will likely not impact obesity significantly, but may be useful to combat type 2 diabetes. PMID:27477955

  3. Type 2 diabetes, but not obesity, prevalence is positively associated with ambient temperature.

    PubMed

    Speakman, John R; Heidari-Bakavoli, Sahar

    2016-01-01

    Cold exposure stimulates energy expenditure and glucose disposal. If these factors play a significant role in whole body energy balance, and glucose homeostasis, it is predicted that both obesity and type 2 diabetes prevalence would be lower where it is colder. Previous studies have noted connections between ambient temperature and obesity, but the direction of the effect is confused. No previous studies have explored the link of type 2 diabetes to ambient temperature. We used county level data for obesity and diabetes prevalence across the mainland USA and matched this to county level ambient temperature data. Average ambient temperature explained 5.7% of the spatial variation in obesity and 29.6% of the spatial variation in type 2 diabetes prevalence. Correcting the type 2 diabetes data for the effect of obesity reduced the explained variation to 26.8%. Even when correcting for obesity, poverty and race, ambient temperature explained 12.4% of the variation in the prevalence of type 2 diabetes, and this significant effect remained when latitude was entered into the model as a predictor. When obesity prevalence was corrected for poverty and race the significant effect of temperature disappeared. Enhancing energy expenditure by cold exposure will likely not impact obesity significantly, but may be useful to combat type 2 diabetes. PMID:27477955

  4. Emissions and ambient air monitoring trends of lower olefins across Texas from 2002 to 2012.

    PubMed

    Myers, Jessica L; Phillips, Tracie; Grant, Roberta L

    2015-11-01

    Texas has the largest ambient air monitoring network in the country with approximately 83 monitoring sites that measure ambient air concentrations of volatile organic compounds (VOCs). The lower olefins, including 1,3-butadiene, ethylene, isoprene, and propylene, are a group of VOCs that can be measured in both 24h/every sixth-day canister samples and continuous 1-h Automated Gas Chromatography (AutoGC) samples. Based on 2012 Toxics Release Inventory data, the total reported industrial air emissions in Texas for these olefins, as compared to total national reported air emissions, were 79% for 1,3-butadiene, 62% for ethylene, 76% for isoprene, and 54% for propylene, illustrating that Texas industries are some of the major emitters for these olefins. The purpose of this study was to look at the patterns of annual average air monitoring data from 2002 to 2012 using Texas Commission on Environmental Quality (TCEQ) data for these four lower olefins. It should be emphasized that monitors may not be located close to or downwind of the highest emitters of these lower olefins. In addition, air monitors only provide a snapshot in time of air concentrations for their respective locations, and may not be able to discriminate emissions between specific sources. In 2012, the highest annual average air concentration for 1,3-butadiene was 1.28 ppb by volume (ppbv), which was measured at the Port Neches monitoring site in Region 10-Beaumont. For ethylene, the highest 2012 annual average air concentration was 5.77 ppbv, which was measured at the Dona Park monitoring site in TCEQ Region 14-Corpus Christi. Although reported industrial emissions of isoprene are predominantly from the Houston and Beaumont regions, trees are natural emitters of isoprene, and the highest ambient air concentrations tend to be from regions with large areas of coniferous and hardwood forests. This was observed with TCEQ Region 5-Tyler, which had the two highest isoprene annual average air concentrations for

  5. Ambient air pollution exposure and the incidence of related health effects among racial/ethnic minorities

    SciTech Connect

    Nieves, L.A.; Wernette, D.R.

    1997-02-01

    Differences among racial and ethnic groups in morbidity and mortality rates for diseases, including diseases with environmental causes, have been extensively documented. However, documenting the linkages between environmental contaminants, individual exposures, and disease incidence has been hindered by difficulties in measuring exposure for the population in general and for minority populations in particular. After briefly discussing research findings on associations of common air pollutants with disease incidence, the authors summarize recent studies of radial/ethnic subgroup differences in incidence of these diseases in the US. They then present evidence of both historic and current patterns of disproportionate minority group exposure to air pollution as measured by residence in areas where ambient air quality standards are violated. The current indications of disproportionate potential exposures of minority and low-income populations to air pollutants represent the continuation of a historical trend. The evidence of linkage between disproportionate exposure to air pollution of racial/ethnic minorities and low-income groups and their higher rates of some air pollution-related diseases is largely circumstantial. Differences in disease incidence and mortality rates among racial/ethnic groups are discussed for respiratory diseases, cancers, and lead poisoning. Pollutants of concern include CO, Pb, SO{sub 2}, O{sub 3}, and particulates.

  6. Effect of ambient temperature and humidity on emissions of an idling gas turbine

    NASA Technical Reports Server (NTRS)

    Kauffman, C. W.

    1977-01-01

    The effects of inlet pressure, temperature, and humidity on the oxides of nitrogen produced by an engine operating at takeoff power setting were investigated and numerous correction factors were formulated. The effect of ambient relative humidity on gas turbine idle emissions was ascertained. Experimentally, a nonvitiating combustor rig was employed to simulate changing combustor inlet conditions as generated by changing ambient conditions. Emissions measurements were made at the combustor exit. For carbon monoxide, a reaction kinetic scheme was applied within each zone of the combustor where initial species concentrations reflected not only local combustor characteristics but also changing ambient conditions.

  7. 40 CFR 1033.505 - Ambient conditions.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 1033.505 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR POLLUTION CONTROLS.... Correct NOX emissions as specified in 40 CFR 1065.670. Do not correct any other emissions for humidity... presumed that combustion air will be drawn from the ambient air. Thus, the ambient temperature limits...

  8. 40 CFR 1033.505 - Ambient conditions.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 1033.505 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR POLLUTION CONTROLS.... Correct NOX emissions as specified in 40 CFR 1065.670. Do not correct any other emissions for humidity... presumed that combustion air will be drawn from the ambient air. Thus, the ambient temperature limits...

  9. 40 CFR 1033.505 - Ambient conditions.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 1033.505 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR POLLUTION CONTROLS.... Correct NOX emissions as specified in 40 CFR 1065.670. Do not correct any other emissions for humidity... presumed that combustion air will be drawn from the ambient air. Thus, the ambient temperature limits...

  10. 40 CFR 1033.505 - Ambient conditions.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 1033.505 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR POLLUTION CONTROLS.... Correct NOX emissions as specified in 40 CFR 1065.670. Do not correct any other emissions for humidity... presumed that combustion air will be drawn from the ambient air. Thus, the ambient temperature limits...

  11. 40 CFR 1033.505 - Ambient conditions.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 1033.505 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR POLLUTION CONTROLS.... Correct NOX emissions as specified in 40 CFR 1065.670. Do not correct any other emissions for humidity... presumed that combustion air will be drawn from the ambient air. Thus, the ambient temperature limits...

  12. Industrial CO2 Removal: CO2 Capture from Ambient Air and Geological Sequestration

    SciTech Connect

    Dooley, James J.

    2011-06-08

    This abstract and its accompanying presentation will provide an overview of two distinct industrial processes for removing carbon dioxide (CO2) from the atmosphere as a means of addressing anthropogenic climate change. The first of these is carbon dioxide capture and storage (CCS) coupled with large scale biomass production (hereafter referred to as bioCCS). The second is CO2 capture from ambient air via industrial systems (hereafter referred to as direct air capture (DAC)). In both systems, the captured CO2 would be injected into deep geologic formations so as to isolate it from the atmosphere. The technical literature is clear that both of these technologies are technically feasible as of today (IPCC, 2005; Keith, 2009; Lackner, 2009; Luckow et al., 2010; Ranjan and Herzog, 2011). What is uncertain is the relative cost of these industrial ambient-air CO2 removal systems when compared to other emissions mitigation measures, the ultimate timing and scale of their deployment, and the resolution of potential site specific constraints that would impact their ultimate commercial deployment.

  13. Within-urban variability in ambient air pollution: Comparison of estimation methods

    NASA Astrophysics Data System (ADS)

    Marshall, Julian D.; Nethery, Elizabeth; Brauer, Michael

    An important component of air quality management and health risk assessment is improved understanding of spatial and temporal variability in pollutant concentrations. We compare, for Vancouver, Canada, three approaches for estimating within-urban spatiotemporal variability in ambient concentrations: spatial interpolation of monitoring data; an empirical/statistical model based on geographic analyses ("land-use regression"; LUR); and an Eulerian grid model (community multiscale air quality model, CMAQ). Four pollutants are considered—nitrogen oxide (NO), nitrogen dioxide (NO 2), carbon monoxide, and ozone—represent varying levels of spatiotemporal heterogeneity. Among the methods, differences in central tendencies (mean, median) and variability (standard deviation) are modest. LUR and CMAQ perform well in predicting concentrations at monitoring sites (average absolute bias: <50% for NO; <20% for NO 2). Monitors (LUR) offer the greatest (least) temporal resolution; LUR (monitors) offers the greatest (least) spatial resolution. Of note, the length scale of spatial variability is shorter for LUR (units: km; 0.3 for NO, 1 for NO 2) than for the other approaches (3-6 for NO, 4-6 for NO 2), indicating that the approaches offer different information about spatial attributes of air pollution. Results presented here suggest that for investigations incorporating spatiotemporal variability in ambient concentrations, the findings may depend on which estimation method is employed.

  14. Metallurgically lithiated SiOx anode with high capacity and ambient air compatibility.

    PubMed

    Zhao, Jie; Lee, Hyun-Wook; Sun, Jie; Yan, Kai; Liu, Yayuan; Liu, Wei; Lu, Zhenda; Lin, Dingchang; Zhou, Guangmin; Cui, Yi

    2016-07-01

    A common issue plaguing battery anodes is the large consumption of lithium in the initial cycle as a result of the formation of a solid electrolyte interphase followed by gradual loss in subsequent cycles. It presents a need for prelithiation to compensate for the loss. However, anode prelithiation faces the challenge of high chemical reactivity because of the low anode potential. Previous efforts have produced prelithiated Si nanoparticles with dry air stability, which cannot be stabilized under ambient air. Here, we developed a one-pot metallurgical process to synthesize LixSi/Li2O composites by using low-cost SiO or SiO2 as the starting material. The resulting composites consist of homogeneously dispersed LixSi nanodomains embedded in a highly crystalline Li2O matrix, providing the composite excellent stability even in ambient air with 40% relative humidity. The composites are readily mixed with various anode materials to achieve high first cycle Coulombic efficiency (CE) of >100% or serve as an excellent anode material by itself with stable cyclability and consistently high CEs (99.81% at the seventh cycle and ∼99.87% for subsequent cycles). Therefore, LixSi/Li2O composites achieved balanced reactivity and stability, promising a significant boost to lithium ion batteries. PMID:27313206

  15. In situ secondary organic aerosol formation from ambient pine forest air using an oxidation flow reactor

    NASA Astrophysics Data System (ADS)

    Palm, B. B.; Campuzano-Jost, P.; Ortega, A. M.; Day, D. A.; Kaser, L.; Jud, W.; Karl, T.; Hansel, A.; Hunter, J. F.; Cross, E. S.; Kroll, J. H.; Peng, Z.; Brune, W. H.; Jimenez, J. L.

    2015-11-01

    Ambient air was oxidized by OH radicals in an oxidation flow reactor (OFR) located in a montane pine forest during the BEACHON-RoMBAS campaign to study biogenic secondary organic aerosol (SOA) formation and aging. High OH concentrations and short residence times allowed for semi-continuous cycling through a large range of OH exposures ranging from hours to weeks of equivalent (eq.) atmospheric aging. A simple model is derived and used to account for the relative time scales of condensation of low volatility organic compounds (LVOCs) onto particles, condensational loss to the walls, and further reaction to produce volatile, non-condensing fragmentation products. More SOA production was observed in the OFR at nighttime (average 4 μg m-3 when LVOC fate corrected) compared to daytime (average 1 μg m-3 when LVOC fate corrected), with maximum formation observed at 0.4-1.5 eq. days of photochemical aging. SOA formation followed a similar diurnal pattern to monoterpenes, sesquiterpenes, and toluene + p-cymene concentrations, including a substantial increase just after sunrise at 07:00 LT. Higher photochemical aging (> 10 eq. days) led to a decrease in new SOA formation and a loss of preexisting OA due to heterogeneous oxidation followed by fragmentation and volatilization. When comparing two different commonly used methods of OH production in OFRs (OFR185 and OFR254), similar amounts of SOA formation were observed. We recommend the OFR185 mode for future forest studies. Concurrent gas-phase measurements of air after OH oxidation illustrate the decay of primary VOCs, production of small oxidized organic compounds, and net production at lower ages followed by net consumption of terpenoid oxidation products as photochemical age increased. New particle formation was observed in the reactor after oxidation, especially during times when precursor gas concentrations and SOA formation were largest. Approximately 6 times more SOA was formed in the reactor from OH oxidation than

  16. Stable oxygen isotope reconstruction of ambient temperature during the collapse of a cod (Gadus morhua) fishery.

    PubMed

    Jones, J Brin; Campana, Steven E

    2009-09-01

    Changing environmental conditions set against a backdrop of high exploitation can result in severe consequences for commercially harvested stocks. The collapse of the Eastern Scotian Shelf cod (Gadus morhua L.) off eastern Canada was primarily due to overexploitation but may have been exacerbated by a widespread temperature decline. Recent studies have called for accurate determination of ambient temperature (the actual temperature exposure history of the fish) before discarding environmental conditions as a factor in the collapse. We used the stable oxygen isotope composition of otoliths (delta18O(oto)) to reconstruct the ambient temperature history of Eastern Scotian Shelf cod from 1970 to 2000 in order to determine whether the stock experienced the temperature decline or shifted their distribution to avoid it. To correct delta18O(oto) for seawater isotope content (deltaO(w)), we generated a new meta-equation for the relationship between delta18O(w) (per mil) and salinity (S, in psu) on the Eastern Scotian Shelf: delta18O(w) = 0.539 x S - 18.790. The ambient temperature series revealed that the large-scale geographic distribution of mature cod remained constant through the cooling period, although their ambient temperature was cooler than expected in warmer periods and warmer than expected in cooler periods, indicating small-scale thermoregulatory movement. Although the mean hydrographic temperature was 4 degrees C, mature cod usually inhabited the coldest available waters (mean ambient temperature = 3 degrees C), while the juveniles usually inhabited warmer waters (mean ambient temperature = 5.5 degrees C). Length-at-age was significantly related to ambient temperature, especially in the early years of growth, and therefore declining ambient temperatures were at least partially responsible for declines in asymptotic length (up to age 8 yr). The most active thermoregulatory movement occurred during a moderate warming period; therefore extreme warming events (such

  17. AMBIENT AIR MEASUREMENTS OF HYDROGEN PEROXIDE IN THE CALIFORNIA SOUTH COAST AIR BASIN

    EPA Science Inventory

    Hydrogen peroxide (H2O2) concentrations have been measured at two locations (Claremont and Riverside) in the California South Coast Air Basin during the months of July and August 1977. Three different analytical methods were employed: a chemiluminescent method and two colorimetri...

  18. 78 FR 19990 - Approval and Promulgation of Air Quality Implementation Plans; Ohio; Ohio Ambient Air Quality...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-03

    ... the relocated air quality standard rules. This action was published at 75 FR 65572 as a direct final... previously approved, most notably including revisions that EPA had proposed to disapprove (see 70 FR 36901... Register on October 26, 2010 (75 FR 65572), on page 65574 in the second column, the paragraph numbered...

  19. 14 CFR 23.1157 - Carburetor air temperature controls.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Carburetor air temperature controls. 23... Powerplant Powerplant Controls and Accessories § 23.1157 Carburetor air temperature controls. There must be a separate carburetor air temperature control for each engine....

  20. 40 CFR 89.325 - Engine intake air temperature measurement.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Engine intake air temperature... Test Equipment Provisions § 89.325 Engine intake air temperature measurement. (a) Engine intake air temperature measurement must be made within 122 cm of the engine. The measurement location must be made...