WorldWideScience

Sample records for outdoor air experimental

  1. Healthy Air Outdoors

    Science.gov (United States)

    ... a few sources. Even natural sources such as fires and dust contribute to air pollution. Learn more ... Walks Cycling Events Donate a Car Memorial & Honor Gifts Planned Giving Christmas Seals ABOUT THE LUNG ASSOCIATION ...

  2. Outdoor air Pollution

    CSIR Research Space (South Africa)

    Forbes, PBC

    2016-07-01

    Full Text Available This chapter focuses on the air pollutants which are generally found in the troposphere and does not provide detail on specific areas where atmospheric pollutants and atmospheric chemistry may differ from that generally found, such as in the arctic...

  3. Radon parameters in outdoor air

    International Nuclear Information System (INIS)

    Porstendoerfer, J.; Zock, Ch.; Wendt, J.; Reineking, A.

    2002-01-01

    For dose estimation by inhalation of the short lived radon progeny in outdoor air, the equilibrium factor (F), the unattached fraction (f p ), and the activity size distribution of the radon progeny were measured. Besides the radon parameter the meteorological parameter like temperature, wind speed, and rainfall intensity were registered. The measurements were carried out continuously for several weeks to find out the variation with time (day/night) and for different weather conditions. The radon gas, the unattached and aerosol-attached radon progenies were measured with an monitor developed for continuous measurements in outdoor air with low activity concentrations. For the determination of the activity size distribution a low pressure online alpha cascade impactor was used. The measured values of the equilibrium factor varied between 0.5-0.8 depending on weather conditions and time of the day. For high pressure weather conditions a diurnal variation of the F-factor was obtained. A lower average value (F=0.25) was registered during rainy days. The obtained f p -values varied between 0.04 and 0.12. They were higher than expected. The measured activity size distribution of the radon progeny averaged over a measurement period of three weeks can be approximated by a sum of three log-normal distributions. The greatest activity fraction is adsorbed on aerosol particles in the accumulation size range (100-1000 nm) with activity median diameters and geometric standard deviation values between 250-450 nm and 1.5-3.0, respectively. The activity median diameter of this accumulation mode in outdoor air was significantly greater than in indoor air (150-250 nm). An influence of the weather conditions on the activity of the accumulation particles was not significant. In contrast to the results of measurements in houses a small but significant fraction of the radon progeny (average value: 2%) is attached on coarse particles (>1000 nm). This fraction varied between 0-10%. 20

  4. Relationships in indoor/outdoor air pollution

    International Nuclear Information System (INIS)

    Roed, J.

    1985-01-01

    Beryllium-7 and sulphurhexaflourid has been used as tracers in measurements designed to enable an estimate of the ratio of the outdoor to indoor time-integrated concentration for aerosols and non-reactive gasses of outdoor origin with a special reference to the reduction in inhalation dose that can be achieved by staying indoors during a pollution episode, especially a reactor accident. The effect of operating a vacuum cleaner during the pollution episode and airing shortly after is also investigated. Earlier relevant literature is reviewed and shows goos agreement with the results in this study. Protection factor from 1-12 has been found. (author)

  5. Outdoor air pollution and sperm quality.

    Science.gov (United States)

    Lafuente, Rafael; García-Blàquez, Núria; Jacquemin, Bénédicte; Checa, Miguel Angel

    2016-09-15

    Exposure to air pollution has been clearly associated with a range of adverse health effects, including reproductive toxicity, but its effects on male semen quality are still unclear. We performed a systematic review (up to June 2016) to assess the impact of air pollutants on sperm quality. We included 17 semi-ecological, panel, and cohort studies, assessing outdoor air pollutants, such as PM2.5, PM10, NOx, SO2, and O3, and their effects on DNA fragmentation, sperm count, sperm motility, and sperm morphology. Thirteen studies assessed air pollution exposure measured environmentally, and six used biomarkers of air pollution exposure (two did both). We rated the studies using the Newcastle-Ottawa Scale and assessed with the exposure method. Taking into account these factors and the number of studies finding significant results (positive or negative), the evidence supporting an effect of air pollution on DNA fragmentation is weak but suggestive, on sperm motility is limited and probably inexistent, on lower sperm count is inconclusive, and on sperm morphology is very suggestive. Because of the diversity of air pollutants and sperm parameters, and the studies' designs, we were unable to perform a meta-analysis. In summary, most studies concluded that outdoor air pollution affects at least one of the four semen quality parameters included in the review. However, results lack consistency, and furthermore, studies were not comparable. Studies using standardized air pollution and semen measures are required to obtain more reliable conclusions. CRD42015007175. Copyright © 2016 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

  6. Outdoor air dominates burden of disease from indoor exposures

    DEFF Research Database (Denmark)

    Hänninen, O.; Asikainen, A.; Carrer, P.

    2014-01-01

    Both indoor and outdoor sources of air pollution have significant public health impacts in Europe. Based on quantitative modelling of the burden of disease the outdoor sources dominate the impacts by a clear margin.......Both indoor and outdoor sources of air pollution have significant public health impacts in Europe. Based on quantitative modelling of the burden of disease the outdoor sources dominate the impacts by a clear margin....

  7. An experimental study on the negative effects of downwards flow of the melted frost over a multi-circuit outdoor coil in an air source heat pump during reverse cycle defrosting

    International Nuclear Information System (INIS)

    Song, Mengjie; Pan, Dongmei; Li, Ning; Deng, Shiming

    2015-01-01

    Highlights: • A special experimental rig was built and its details are reported. • The negative effects of downwards flowing of the melted frost were shown. • Defrosting duration was shortened after installing water collecting trays. • Temperature of melted frost decreased after installing trays. - Abstract: When the surface temperature of the outdoor coil in an air source heat pump (ASHP) unit is lower than both freezing point of water and the air dew point, frost can be formed and accumulated over outdoor coil surface. Frosting affects the energy efficiency, and periodic defrosting therefore is necessary. Reverse cycle defrosting is currently the most widely used defrosting method. A previous related study has indicated that during reverse cycle defrosting, downwards flow of the melted frost over a multi-circuit outdoor coil could affect the defrosting performance, without however giving detailed quantitative analysis of the effects. Therefore an experimental study on the effects has been carried out and a quantitative analysis conducted using the experimental data. In this paper, the detailed description of an experimental ASHP unit which was specifically built up is firstly reported. This is followed by presenting experimental results. Result analysis and conclusions are finally given

  8. Polluted air--outdoors and indoors.

    Science.gov (United States)

    Myers, I; Maynard, R L

    2005-09-01

    Many air pollutants which are considered important in ambient (outdoor) air are also found, sometimes at higher levels, in indoor air. With demanding standards having been set for many of these pollutants, both in the workplace and ambient air, consideration of the problems posed by indoor pollution is gaining pace. Studies on exposure to pollutants found in the indoor domestic environment are increasing and are contributing to an already significant compilation of datasets. Improvement in monitoring techniques has helped this process. Documented reports of fatalities from carbon monoxide poisonings are still worrying. However, studies on health effects of non-fatal, long term, low dose, indoor exposure to carbon monoxide and other pollutants, are still inconclusive and too infrequently documented. Of particular concern are the levels of air pollutants found in the domestic indoor environment in developing countries, despite simple interventions such as vented stoves having shown their value. Exposure to biomass smoke is still a level that would be considered unacceptable on health grounds in developed countries. As in the occupational environment, steps need to be taken to control the risks from exposure to the harmful constituents of indoor air in the home. However, the difficulty regarding regulation of the domestic indoor environment is its inherent privacy. Monitoring levels of pollutants in the home and ensuring regulations are adhered to, would likely prove difficult, especially when individual behaviour patterns and activities have the greatest influence on pollutant levels in indoor air. To this end, the Department of Health is developing guidance on indoor air pollution to encourage the reduction of pollutant levels in indoor domestic air. The importance of the effects of domestic indoor air on health and its contribution to the health of the worker are increasingly appreciated. Occupational physicians, by training and interest, are well placed to extend

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

    Science.gov (United States)

    The genotoxicity of ambient outdoor air, a review: Salmonella mutagenicityAbstractMutagens in urban air pollution come from anthropogenic sources (especially combustion sources) and are products of airborne chemical reactions. Bacterial mutation tests have been used ...

  10. Associations of outdoor air pollution with hemorrhagic stroke mortality.

    Science.gov (United States)

    Yorifuji, Takashi; Kawachi, Ichiro; Sakamoto, Tetsuro; Doi, Hiroyuki

    2011-02-01

    Evidence linking short-term exposure to outdoor air pollution with hemorrhagic stroke is inconsistent. We evaluated the associations between outdoor air pollution and specific types of stroke in Tokyo, Japan, from April 2003 to December 2008. We obtained daily counts of stroke mortality (n = 41,440) and concentrations of nitrogen dioxide as well as particles less than 2.5 μm in diameter. Time-series analysis was employed. Although same-day air pollutants were positively associated with ischemic stroke and intracerebral hemorrhage mortality, both air pollutants were more strongly associated with subarachnoid hemorrhage mortality: rate ratio was 1.041 (95% confidence interval: 1.011-1.072) for each 10 μg/m3 increase in the previous-day particles less than 2.5 μm. This study suggests that short-term exposure to outdoor air pollution increases the risks of hemorrhagic stroke mortality as well as ischemic stroke mortality.

  11. Chemical Characterization of the Indoor Air Quality of a University Hospital: Penetration of Outdoor Air Pollutants

    NARCIS (Netherlands)

    Scheepers, P.T.J.; Wel, L. van; Beckmann, G.; Anzion, R.B.M.

    2017-01-01

    For healthcare centers, local outdoor sources of air pollution represent a potential threat to indoor air quality (IAQ). The aim of this study was to study the impact of local outdoor sources of air pollution on the IAQ of a university hospital. IAQ was characterized at thirteen indoor and two

  12. Chemical Characterization of the Indoor Air Quality of a University Hospital : Penetration of Outdoor Air Pollutants

    NARCIS (Netherlands)

    Scheepers, Paul T J; Van Wel, Luuk; Beckmann, Gwendolyn; Anzion, Rob B M

    2017-01-01

    For healthcare centers, local outdoor sources of air pollution represent a potential threat to indoor air quality (IAQ). The aim of this study was to study the impact of local outdoor sources of air pollution on the IAQ of a university hospital. IAQ was characterized at thirteen indoor and two

  13. Microbiological Indoor and Outdoor Air Quality of Two Major ...

    African Journals Online (AJOL)

    Both indoor and outdoor air samples were assessed monthly for the three (3) months in the wet season (June – August, 2010) and dry season (November 2010 - January 2011) using the settled plate methods. The study sites were divided into nine (9) units which include accident and emergency ward, laboratory, male ward ...

  14. Estimating the burden of disease attributable to urban outdoor air ...

    African Journals Online (AJOL)

    Outdoor air pollution in urban areas in South Africa was estimated to cause 3.7% of the national mortality from cardiopulmonary disease and 5.1 % of mortality attributable to cancers of the trachea, bronchus and lung in adults aged 30 years and older, and 1.1 % of mortality from ARis in children under 5 years of age.

  15. Outdoor air pollution and lung cancer: what now?

    Directory of Open Access Journals (Sweden)

    Enrico Pira

    2013-12-01

    Full Text Available In the last decade a substantial number of epidemiological studies suggested that outdoor air pollution and in particular respirable particulate matter (PM10 and fine particulate matter (PM2.5 are associated with an increased risk of lung cancer.The most recent is a multicentre European study...

  16. Study on heat collector of the solar system utilizing outdoor air. Experimental results in cases of cold and warm regions; Gaiki donyushiki solar system no shunetsubu ni kansuru kenkyu. Kanreichi to ondanchi ni okeru shunetsu jikken to kosatsu

    Energy Technology Data Exchange (ETDEWEB)

    Komano, S; Ebara, Y [OM Solar Association, Shizuoka (Japan); Wada, H [Wada Building Constructors Co. Ltd., Hokkaido (Japan)

    1996-10-27

    An experiment on heat collection was made in the heat collector of a solar system utilizing outdoor air in cold and warm regions. In this system, outdoor air is heated by the air circulation layer on the roof exposed to solar radiation. The heated air is supplied to the object space for heating and ventilation. In the experiment in a cold region, the heat collection characteristics can be adjusted by putting a baffle plate in the air duct according to the experiment of a glass heat collector. The heat collecting air layer on only the iron roof may leak or freeze in the region subject to coldness or heavy snowfall. Therefore, preheat forms the space of a garret, and the preheat temperature comparatively becomes low. The data in which the heat collection characteristics can be adjusted using only a glass heat collector is required corresponding to the regional situation. In the experiment in a warm region, an experiment was made inclusive of the preheat for which outdoor air is absorbed at the eaves. As a result, the heat collection characteristics of preheat were improved. Moreover, a heat collection temperature of about 60{degree}C was obtained on the heat collection surface including the preheat. 1 ref., 12 figs., 3 tabs.

  17. Adverse respiratory effects of outdoor air pollution in the elderly.

    Science.gov (United States)

    Bentayeb, M; Simoni, M; Baiz, N; Norback, D; Baldacci, S; Maio, S; Viegi, G; Annesi-Maesano, I

    2012-09-01

    Compared to the rest of the population, the elderly are potentially highly susceptible to the effects of outdoor air pollution due to normal and pathological ageing. The purpose of the present review was to gather data on the effects on respiratory health of outdoor air pollution in the elderly, on whom data are scarce. These show statistically significant short-term and chronic adverse effects of various outdoor air pollutants on cardiopulmonary morbidity and mortality in the elderly. When exposed to air pollution, the elderly experience more hospital admissions for asthma and chronic obstructive pulmonary disease (COPD) and higher COPD mortality than others. Previous studies also indicate that research on the health effects of air pollution in the elderly has been affected by methodological problems in terms of exposure and health effect assessments. Few pollutants have been considered, and exposure assessment has been based mostly on background air pollution and more rarely on objective measurements and modelling. Significant progress needs to be made through the development of 'hybrid' models utilising the strengths of information on exposure in various environments to several air pollutants, coupled with daily activity exposure patterns. Investigations of chronic effects of air pollution and of multi-pollutant mixtures are needed to better understand the role of air pollution in the elderly. Lastly, smoking, occupation, comorbidities, treatment and the neighbourhood context should be considered as confounders or modifiers of such a role. In this context, the underlying biological, physiological and toxicological mechanisms need to be explored to better understand the phenomenon through a multidisciplinary approach.

  18. Outdoor Air Quality Level Inference via Surveillance Cameras

    Directory of Open Access Journals (Sweden)

    Zheng Zhang

    2016-01-01

    Full Text Available Air pollution is a universal problem confronted by many developing countries. Because there are very few air quality monitoring stations in cities, it is difficult for people to know the exact air quality level anytime and anywhere. Fortunately, large amount of surveillance cameras have been deployed in the cities and can capture image densely and conveniently in the cities. In this case, this provides the possibility to utilize surveillance cameras as sensors to obtain data and predict the air quality level. To this end, we present a novel air quality level inference approach based on outdoor images. Firstly, we explore several features extracted from images as the robust representation for air quality prediction. Then, to effectively fuse these heterogeneous and complementary features, we adopt multikernel learning to learn an adaptive classifier for air quality level inference. In addition, to facilitate the research, we construct an Outdoor Air Quality Image Set (OAQIS dataset, which contains high quality registered and calibrated images with rich labels, that is, concentration of particles mass (PM, weather, temperature, humidity, and wind. Extensive experiments on the OAQIS dataset demonstrate the effectiveness of the proposed approach.

  19. The Outdoor Air Pollution and Brain Health Workshop

    Science.gov (United States)

    Block, Michelle L.; Elder, Alison; Auten, Rick L.; Bilbo, Staci D.; Chen, Honglei; Chen, Jiu-Chiuan; Cory-Slechta, Deborah A.; Costa, Daniel; Diaz-Sanchez, David; Dorman, David C.; Gold, Diane; Gray, Kimberly; Jeng, Hueiwang Anna; Kaufman, Joel D.; Kleinman, Michael T.; Kirshner, Annette; Lawler, Cindy; Miller, David S.; Nadadur, Sri; Ritz, Beate; Semmens, Erin O.; Tonelli, Leonardo H.; Veronesi, Bellina; Wright, Robert O.; Wright, Rosalind

    2013-01-01

    Accumulating evidence suggests that outdoor air pollution may have a significant impact on central nervous system (CNS) health and disease. To address this issue, the National Institute of Environmental Health Sciences/National Institute of Health convened a panel of research scientists that was assigned the task of identifying research gaps and priority goals essential for advancing this growing field and addressing an emerging human health concern. Here, we review recent findings that have established the effects of inhaled air pollutants in the brain, explore the potential mechanisms driving these phenomena, and discuss the recommended research priorities/approaches that were identified by the panel. PMID:22981845

  20. Outdoor air pollution and respiratory health in Asia.

    Science.gov (United States)

    Chung, Kian Fan; Zhang, Junfeng; Zhong, Nanshan

    2011-10-01

    With the rapid economic development occurring in the last decade in many countries of Asia, the level of air pollution has increased from both industrial and motor vehicle emissions. Compared with Europe and North America, the potential health effects of this increasing air pollution in Asia remain largely unmeasured. Recent data published by the Health Effects Institute from some major cities in India and China reveal that a 10 µg/m(3) increase in PM(10) was associated with an increase in mortality of 0.6% in daily all-natural cause mortality, with higher risks being found at extremes of high temperatures and in the lowest economically advantaged population. Other Asian studies have confirmed the link between hospital admissions for the worsening of COPD and the increase in asthma prevalence to levels of outdoor air pollutants. Although potential health effects appear to be similar to already-published Western data, it is important that further studies be carried out in Asia that will inform the public and the authorities of the necessity to curb levels of outdoor air pollutants to acceptable levels. © 2011 The Authors. Respirology © 2011 Asian Pacific Society of Respirology.

  1. Endocrine disrupting chemicals in indoor and outdoor air

    Science.gov (United States)

    Rudel, Ruthann A.; Perovich, Laura J.

    The past 50 years have seen rapid development of new building materials, furnishings, and consumer products and a corresponding explosion in new chemicals in the built environment. While exposure levels are largely undocumented, they are likely to have increased as a wider variety of chemicals came into use, people began spending more time indoors, and air exchange rates decreased to improve energy efficiency. As a result of weak regulatory requirements for chemical safety testing, only limited toxicity data are available for these chemicals. Over the past 15 years, some chemical classes commonly used in building materials, furnishings, and consumer products have been shown to be endocrine disrupting chemicals - that is they interfere with the action of endogenous hormones. These include PCBs, used in electrical equipment, caulking, paints and surface coatings; chlorinated and brominated flame retardants, used in electronics, furniture, and textiles; pesticides, used to control insects, weeds, and other pests in agriculture, lawn maintenance, and the built environment; phthalates, used in vinyl, plastics, fragrances, and other products; alkylphenols, used in detergents, pesticide formulations, and polystyrene plastics; and parabens, used to preserve products like lotions and sunscreens. This paper summarizes reported indoor and outdoor air concentrations, chemical use and sources, and toxicity data for each of these chemical classes. While industrial and transportation-related pollutants have been shown to migrate indoors from outdoor sources, it is expected that indoor sources predominate for these consumer product chemicals; and some studies have identified indoor sources as the predominant factor influencing outdoor ambient air concentrations in densely populated areas. Mechanisms of action, adverse effects, and dose-response relationships for many of these chemicals are poorly understood and no systematic screening of common chemicals for endocrine disrupting

  2. Vehicle emissions and effects on air quality: indoors and outdoors

    International Nuclear Information System (INIS)

    Perry, R.; Gee, I.L.

    1994-01-01

    Vehicle emissions of non-regulated volatile organic compounds (VOCs), such as benzene, can form a major contribution to pollution of the indoor as well as the outdoor environment. Several of these compounds are considered to be a health risk and are important factors in the production of photochemical smog. The introduction of unleaded and particularly 'super unleaded' fuels has significantly increased levels of aromatic compounds in petrol world-wide and has led to changes in fuel composition with respect to olefins and the use of oxygenates. Increased aromatics, olefins and other compounds in fuels used in vehicles not fitted with catalytic converters have shown to increase emissions of benzene, 1,4-budatiene and other VOCs as well as contributing to increases in photochemical smog precursors. Increases in VOC levels in ambient air clearly produce increased indoor air pollution, particularly in naturally ventilated buildings. (author) 6 figs., 5 tabs., 30 refs

  3. Programming of respiratory health in childhood: influence of outdoor air pollution.

    Science.gov (United States)

    Wright, Rosalind J; Brunst, Kelly J

    2013-04-01

    This overview highlights recent experimental and epidemiological evidence for the programming effects of outdoor air pollution exposures during early development on lung function and chronic respiratory disorders, such as asthma and related allergic disorders. Air pollutants may impact anatomy and/or physiological functioning of the lung and interrelated systems. Programming effects may result from pollutant-induced shifts in a number of molecular, cellular, and physiological states and their interacting systems. Specific key regulatory systems susceptible to programming may influence lung development and vulnerability to respiratory diseases, including both central and peripheral components of neuroendocrine pathways and autonomic nervous system (ANS) functioning which, in turn, influence the immune system. Starting in utero, environmental factors, including air pollutants, may permanently organize these systems toward trajectories of enhanced pediatric (e.g., asthma, allergy) as well as adult disease risk (e.g., chronic obstructive pulmonary disease). Evidence supports a central role of oxidative stress in the toxic effects of air pollution. Additional research suggests xenobiotic metabolism and subcellular components, such as mitochondria are targets of ambient air pollution and play a role in asthma and allergy programming. Mechanisms operating at the level of the placenta are being elucidated. Epigenetic mechanisms may be at the roots of adaptive developmental programming. Optimal coordinated functioning of many complex processes and their networks of interaction are necessary for normal lung development and the maintenance of respiratory health. Outdoor air pollution may play an important role in early programming of respiratory health and is potentially amenable to intervention.

  4. Development of a versatile experimental setup for the evaluation of the photocatalytic properties of construction materials under realistic outdoor conditions.

    Science.gov (United States)

    Suárez, S; Portela, R; Hernández-Alonso, M D; Sánchez, B

    2014-10-01

    The interest on outdoor photocatalytic materials is growing in the last years. Nevertheless, most of the experimental devices designed for the assessment of their performance operate at controlled laboratory conditions, i.e., pollutant concentration, temperature, UV irradiation, and water vapor contents, far from those of real outdoor environments. The aim of the present study was the design and development of an experimental device for the continuous test of photocatalytic outdoor materials under sun irradiation using real outdoor air as feed, with the concomitant fluctuation of pollutant concentration, temperature, and water vapor content. A three-port measurement system based on two UV-transparent chambers was designed and built. A test chamber contained the photoactive element and a reference chamber to place the substrate without the photoactive element were employed. The third sampling point, placed outdoors, allowed the characterization of the surrounding air, which feeds the test chambers. Temperature, relative humidity (RH), and UV-A irradiance were monitored at each sampling point with specific sensors. NO x concentration was measured by a chemiluminescence NO x analyzer. Three automatic valves allowed the consecutive analysis of the concentration at the three points at fixed time intervals. The reliability of the analytical system was demonstrated by comparing the NO x concentration data with those obtained at the nearest weather station to the experimental device location. The use of a chamber-based reaction system leads to an attenuation of NO x and atmospheric parameter profiles, but maintaining the general trends. The air characterization results showed the wide operating window under which the photoactive materials should work outdoors, depending on the traffic intensity and the season, which are reproduced inside the test chambers. The designed system allows the measurement of the photoactivity of outdoor materials or the comparison of several

  5. Measuring Outdoor Air Intake Rates into Existing Building

    Energy Technology Data Exchange (ETDEWEB)

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

    2009-04-16

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

  6. Air ion concentrations in various urban outdoor environments

    Science.gov (United States)

    Ling, Xuan; Jayaratne, Rohan; Morawska, Lidia

    2010-06-01

    Atmospheric ions are produced by many natural and anthropogenic sources and their concentrations vary widely between different environments. There is very little information on their concentrations in different types of urban environments, how they compare across these environments and their dominant sources. In this study, we measured airborne concentrations of small ions, particles and net particle charge at 32 different outdoor sites in and around a major city in Australia and identified the main ion sources. Sites were classified into seven groups as follows: park, woodland, city centre, residential, freeway, power lines and power substation. Generally, parks were situated away from ion sources and represented the urban background value of about 270 ions cm -3. Median concentrations at all other groups were significantly higher than in the parks. We show that motor vehicles and power transmission systems are two major ion sources in urban areas. Power lines and substations constituted strong unipolar sources, while motor vehicle exhaust constituted strong bipolar sources. The small ion concentration in urban residential areas was about 960 cm -3. At sites where ion sources were co-located with particle sources, ion concentrations were inhibited due to the ion-particle attachment process. These results improved our understanding on air ion distribution and its interaction with particles in the urban outdoor environment.

  7. Chemical Characterization of the Indoor Air Quality of a University Hospital: Penetration of Outdoor Air Pollutants.

    Science.gov (United States)

    Scheepers, Paul T J; Van Wel, Luuk; Beckmann, Gwendolyn; Anzion, Rob B M

    2017-05-08

    For healthcare centers, local outdoor sources of air pollution represent a potential threat to indoor air quality (IAQ). The aim of this study was to study the impact of local outdoor sources of air pollution on the IAQ of a university hospital. IAQ was characterized at thirteen indoor and two outdoor locations and source samples were collected from a helicopter and an emergency power supply. Volatile organic compounds (VOC), acrolein, formaldehyde, nitrogen dioxide (NO₂), respirable particulate matter (PM-4.0 and PM-2.5) and their respective benz(a)pyrene contents were determined over a period of two weeks. Time-weighted average concentrations of NO₂ (4.9-17.4 μg/m³) and formaldehyde (2.5-6.4 μg/m³) were similar on all indoor and outdoor locations. The median concentration VOC in indoor air was 119 μg/m³ (range: 33.1-2450 μg/m³) and was fivefold higher in laboratories (316 μg/m³) compared to offices (57.0 μg/m³). PM-4.0 and benzo(a)pyrene concentration were lower in buildings serviced by a >99.95% efficiency particle filter, compared to buildings using a standard 80-90% efficiency filter ( p engines to any of the IAQ parameters measured in this study. Chemical IAQ was primarily driven by known indoor sources and activities.

  8. Residential outdoor air pollution and allergen sensitization in schoolchildren in Oslo, Norway

    NARCIS (Netherlands)

    Oftedal, B.; Brunekreef, B.; Nystad, W.; Nafstad, P.

    2007-01-01

    Background Epidemiological studies that have investigated the association between air pollution and atopy have found inconsistent results. Furthermore, often exposure to outdoor air pollution has had limited quality, and more individual exposure is needed. Objective To investigate the relations

  9. Outdoor air pollution and risk for kidney parenchyma cancer in 14 European cohorts

    NARCIS (Netherlands)

    Raaschou-Nielsen, Ole; Pedersen, Marie; Stafoggia, Massimo; Weinmayr, Gudrun; Andersen, Zorana J; Galassi, Claudia; Sommar, Johan; Forsberg, Bertil; Olsson, David; Oftedal, Bente; Krog, Norun H; Aasvang, Gunn Marit; Pyko, Andrei; Pershagen, Göran; Korek, Michal; De Faire, Ulf; Pedersen, Nancy L; Östenson, Claes-Göran; Fratiglioni, Laura; Sørensen, Mette; Eriksen, Kirsten T; Tjønneland, Anne; Peeters, Petra H; Bueno-de-Mesquita, Bas; Plusquin, Michelle; Key, Timothy J; Jaensch, Andrea; Nagel, Gabriele; Föger, Bernhard; Wang, Meng; Tsai, Ming-Yi; Grioni, Sara; Marcon, Alessandro; Krogh, Vittorio; Ricceri, Fulvio; Sacerdote, Carlotta; Migliore, Enrica; Tamayo, Ibon; Amiano, Pilar; Dorronsoro, Miren; Sokhi, Ranjeet; Kooter, Ingeborg; de Hoogh, Kees; Beelen, Rob|info:eu-repo/dai/nl/30483100X; Eeftens, Marloes|info:eu-repo/dai/nl/315028300; Vermeulen, Roel|info:eu-repo/dai/nl/216532620; Vineis, Paolo; Brunekreef, Bert|info:eu-repo/dai/nl/067548180; Hoek, Gerard|info:eu-repo/dai/nl/069553475

    2017-01-01

    Several studies have indicated weakly increased risk for kidney cancer among occupational groups exposed to gasoline vapors, engine exhaust, polycyclic aromatic hydrocarbons and other air pollutants, although not consistently. It was the aim to investigate possible associations between outdoor air

  10. Indoor-Outdoor Air Leakage of Apartments and Commercial Buildings

    Energy Technology Data Exchange (ETDEWEB)

    Price, P.N.; Shehabi, A.; Chan, R.W.; Gadgil, A.J.

    2006-06-01

    We compiled and analyzed available data concerning indoor-outdoor air leakage rates and building leakiness parameters for commercial buildings and apartments. We analyzed the data, and reviewed the related literature, to determine the current state of knowledge of the statistical distribution of air exchange rates and related parameters for California buildings, and to identify significant gaps in the current knowledge and data. Very few data were found from California buildings, so we compiled data from other states and some other countries. Even when data from other developed countries were included, data were sparse and few conclusive statements were possible. Little systematic variation in building leakage with construction type, building activity type, height, size, or location within the u.s. was observed. Commercial buildings and apartments seem to be about twice as leaky as single-family houses, per unit of building envelope area. Although further work collecting and analyzing leakage data might be useful, we suggest that a more important issue may be the transport of pollutants between units in apartments and mixed-use buildings, an under-studied phenomenon that may expose occupants to high levels of pollutants such as tobacco smoke or dry cleaning fumes.

  11. Chemical Characterization of the Indoor Air Quality of a University Hospital: Penetration of Outdoor Air Pollutants

    Directory of Open Access Journals (Sweden)

    Paul T. J. Scheepers

    2017-05-01

    Full Text Available For healthcare centers, local outdoor sources of air pollution represent a potential threat to indoor air quality (IAQ. The aim of this study was to study the impact of local outdoor sources of air pollution on the IAQ of a university hospital. IAQ was characterized at thirteen indoor and two outdoor locations and source samples were collected from a helicopter and an emergency power supply. Volatile organic compounds (VOC, acrolein, formaldehyde, nitrogen dioxide (NO2, respirable particulate matter (PM-4.0 and PM-2.5 and their respective benz(apyrene contents were determined over a period of two weeks. Time-weighted average concentrations of NO2 (4.9–17.4 μg/m3 and formaldehyde (2.5–6.4 μg/m3 were similar on all indoor and outdoor locations. The median concentration VOC in indoor air was 119 μg/m3 (range: 33.1–2450 μg/m3 and was fivefold higher in laboratories (316 μg/m3 compared to offices (57.0 μg/m3. PM-4.0 and benzo(apyrene concentration were lower in buildings serviced by a >99.95% efficiency particle filter, compared to buildings using a standard 80–90% efficiency filter (p < 0.01. No indications were found that support a significant contribution of known local sources such as fuels or combustion engines to any of the IAQ parameters measured in this study. Chemical IAQ was primarily driven by known indoor sources and activities.

  12. An experimental evaluation on air purification performance of Clean-Air Heat Pump (CAHP) air cleaner

    DEFF Research Database (Denmark)

    Sheng, Ying; Fang, Lei; Sun, Yuexia

    2018-01-01

    was 96.8%, which indicated that the most of gaseous pollutants were not accumulated in the CAHP. The regeneration temperature for the wheel could affect the air purification performance of CAHP. At 70 °C of regeneration temperature, the air-cleaning efficiency reached 96.7%. Up to 70% of the outdoor air......The escalation of energy consumption in buildings and heightened concerns about acceptable indoor air quality stimulate interest in the usage of air cleaner as an adjunct for indoor environmental conditioning. A regenerative desiccant wheel integrated into a ventilation system termed Clean-Air Heat...... Pump (CAHP) can improve the air quality during the process of dehumidification without using additional energy. An experimental study in a field lab was performed to investigate the air cleaning performance of CAHP. Photoacoustic gas analyzer-INNOVA was used to characterize chemical removal of indoor...

  13. Modeling indoor air pollution of outdoor origin in homes of SAPALDIA subjects in Switzerland.

    Science.gov (United States)

    Meier, Reto; Schindler, Christian; Eeftens, Marloes; Aguilera, Inmaculada; Ducret-Stich, Regina E; Ineichen, Alex; Davey, Mark; Phuleria, Harish C; Probst-Hensch, Nicole; Tsai, Ming-Yi; Künzli, Nino

    2015-09-01

    Given the shrinking spatial contrasts in outdoor air pollution in Switzerland and the trends toward tightly insulated buildings, the Swiss Cohort Study on Air Pollution and Lung and Heart Diseases in Adults (SAPALDIA) needs to understand to what extent outdoor air pollution remains a determinant for residential indoor exposure. The objectives of this paper are to identify determining factors for indoor air pollution concentrations of particulate matter (PM), ultrafine particles in the size range from 15 to 300nm, black smoke measured as light absorbance of PM (PMabsorbance) and nitrogen dioxide (NO2) and to develop predictive indoor models for SAPALDIA. Multivariable regression models were developed based on indoor and outdoor measurements among homes of selected SAPALDIA participants in three urban (Basel, Geneva, Lugano) and one rural region (Wald ZH) in Switzerland, various home characteristics and reported indoor sources such as cooking. Outdoor levels of air pollutants were important predictors for indoor air pollutants, except for the coarse particle fraction. The fractions of outdoor concentrations infiltrating indoors were between 30% and 66%, the highest one was observed for PMabsorbance. A modifying effect of open windows was found for NO2 and the ultrafine particle number concentration. Cooking was associated with increased particle and NO2 levels. This study shows that outdoor air pollution remains an important determinant of residential indoor air pollution in Switzerland. Copyright © 2015 Elsevier Ltd. All rights reserved.

  14. A survey of perfluoroalkyl sulfonamides in indoor and outdoor air using passive air samplers

    Energy Technology Data Exchange (ETDEWEB)

    Shoeib, M.; Harner, T. [Meteorological Service of Canada, Environment Canada (Canada); Wilford, B.; Jones, K. [Lancaster Univ. (United Kingdom). Environmental Science; Zhu, J. [Chemistry Research Division, Health Canada, Tunney' s Pasture, Ottawa (Canada)

    2004-09-15

    Perfluorooctane sulfonate (PFOS) has recently emerged as a priority environmental pollutant due to its widespread detection in biological samples from remote regions including the Arctic and the Mid-North Pacific Ocean. Because PFOS is fairly involatile, it is hypothesized that its occurrence in remote regions is the result of atmospheric transport of more volatile precursor compounds such as the perfluoroalkyl sulfonamides (PFASs). PFASs are used in variety of consumer products for water and oil resistance including surface treatments for fabric, upholstery, carpet, paper and leather. In a recent pilot study employing high volume air samples, indoor air concentrations of PFASs were approximately 100 times greater than outdoor levels. This is of significance because people typically spend about 90% of their time indoors 5 and this exposure may serve as an important uptake pathway. Indoor air also serves as a source of PFASs to the outside where PFASs are ultimately transported and distributed throughout the environment. The current study is intended to be a more comprehensive survey of indoor and outdoor air allowing more confident conclusions to be made. Passive air samplers comprised of polyurethane foam (PUF) disks were used. These are quiet, non-intrusive samplers that operate without the aid of a pump or electricity. Air movement delivers chemical to the sampler which has a high retention capacity for persistent organic pollutants (POPs). PUF disks samplers have been previously used successfully to monitor different classes of hydrophobic persistent organic pollutants POPs.

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

    International Nuclear Information System (INIS)

    Li, Shanshan; Williams, Gail; Guo, Yuming

    2016-01-01

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

  16. Outdoor-indoor air pollution in urban environment: Challenges and opportunity

    Directory of Open Access Journals (Sweden)

    Dennis Y.C. eLeung

    2015-01-01

    Full Text Available With the continual improvement in our quality of life, indoor air quality has become an important area of concern in the 21st century. Indoor air quality is affected by many factors including the type and running conditions of indoor pollution sources, ventilation conditions, as well as indoor activities. Studies revealed that the outdoor environment is also an important factor that cannot be neglected for indoor air quality studies. In this review, the indoor and outdoor air pollution relationships obtained from different studies are discussed in order to identify the key factors affecting the indoor air quality. As climate change is recognized as imposing impacts on the environment, how it affects the indoor air quality and the health impacts to the occupants will be evaluated in this paper. The major challenges and opportunities in indoor/outdoor air pollution studies will be highlighted.

  17. Outdoor air pollution and risk for kidney parenchyma cancer in 14 European cohorts

    DEFF Research Database (Denmark)

    Raaschou-Nielsen, Ole; Pedersen, Marie; Stafoggia, Massimo

    2017-01-01

    Several studies have indicated weakly increased risk for kidney cancer among occupational groups exposed to gasoline vapors, engine exhaust, polycyclic aromatic hydrocarbons and other air pollutants, although not consistently. It was the aim to investigate possible associations between outdoor ai...

  18. PubMed search filters for the study of putative outdoor air pollution determinants of disease

    OpenAIRE

    Curti, Stefania; Gori, Davide; Di Gregori, Valentina; Farioli, Andrea; Baldasseroni, Alberto; Fantini, Maria Pia; Christiani, David C; Violante, Francesco S; Mattioli, Stefano

    2016-01-01

    Objectives: Several PubMed search filters have been developed in contexts other than environmental. We aimed at identifying efficient PubMed search filters for the study of environmental determinants of diseases related to outdoor air pollution. Methods: We compiled a list of Medical Subject Headings (MeSH) and non-MeSH terms seeming pertinent to outdoor air pollutants exposure as determinants of diseases in the general population. We estimated proportions of potentially pertinent articles to...

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

    Science.gov (United States)

    Li, Shanshan; Williams, Gail; Guo, Yuming

    2016-07-01

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

  20. Prediction of Indoor Air Exposure from Outdoor Air Quality Using an Artificial Neural Network Model for Inner City Commercial Buildings

    Directory of Open Access Journals (Sweden)

    Avril Challoner

    2015-12-01

    Full Text Available NO2 and particulate matter are the air pollutants of most concern in Ireland, with possible links to the higher respiratory and cardiovascular mortality and morbidity rates found in the country compared to the rest of Europe. Currently, air quality limits in Europe only cover outdoor environments yet the quality of indoor air is an essential determinant of a person’s well-being, especially since the average person spends more than 90% of their time indoors. The modelling conducted in this research aims to provide a framework for epidemiological studies by the use of publically available data from fixed outdoor monitoring stations to predict indoor air quality more accurately. Predictions are made using two modelling techniques, the Personal-exposure Activity Location Model (PALM, to predict outdoor air quality at a particular building, and Artificial Neural Networks, to model the indoor/outdoor relationship of the building. This joint approach has been used to predict indoor air concentrations for three inner city commercial buildings in Dublin, where parallel indoor and outdoor diurnal monitoring had been carried out on site. This modelling methodology has been shown to provide reasonable predictions of average NO2 indoor air quality compared to the monitored data, but did not perform well in the prediction of indoor PM2.5 concentrations. Hence, this approach could be used to determine NO2 exposures more rigorously of those who work and/or live in the city centre, which can then be linked to potential health impacts.

  1. Prediction of Indoor Air Exposure from Outdoor Air Quality Using an Artificial Neural Network Model for Inner City Commercial Buildings.

    Science.gov (United States)

    Challoner, Avril; Pilla, Francesco; Gill, Laurence

    2015-12-01

    NO₂ and particulate matter are the air pollutants of most concern in Ireland, with possible links to the higher respiratory and cardiovascular mortality and morbidity rates found in the country compared to the rest of Europe. Currently, air quality limits in Europe only cover outdoor environments yet the quality of indoor air is an essential determinant of a person's well-being, especially since the average person spends more than 90% of their time indoors. The modelling conducted in this research aims to provide a framework for epidemiological studies by the use of publically available data from fixed outdoor monitoring stations to predict indoor air quality more accurately. Predictions are made using two modelling techniques, the Personal-exposure Activity Location Model (PALM), to predict outdoor air quality at a particular building, and Artificial Neural Networks, to model the indoor/outdoor relationship of the building. This joint approach has been used to predict indoor air concentrations for three inner city commercial buildings in Dublin, where parallel indoor and outdoor diurnal monitoring had been carried out on site. This modelling methodology has been shown to provide reasonable predictions of average NO₂ indoor air quality compared to the monitored data, but did not perform well in the prediction of indoor PM2.5 concentrations. Hence, this approach could be used to determine NO₂ exposures more rigorously of those who work and/or live in the city centre, which can then be linked to potential health impacts.

  2. Indoor and outdoor poly- and perfluoroalkyl substances (PFASs) in Korea determined by passive air sampler

    International Nuclear Information System (INIS)

    Kim, Seung-Kyu; Shoeib, Mahiba; Kim, Kyeong-Soo; Park, Jong-Eun

    2012-01-01

    Despite concerns to their increasing contribution to ecological and human exposure, the atmospheric levels of poly- and perfluoroalkyl substances (PFASs) have been determined mainly in Europe and North America. This study presents the indoor and outdoor air concentrations of volatile PFASs [fluorotelomer alcohols (FTOHs), and perfluoroalkyl sulfonamides/sulfonamidoethanols/sulfonamide ethyl acetate (FOSAs/FOSEs/FOSEA)] for the first time in Korean cities. In contrast to the good agreement observed for indoor FTOHs levels in Korea and Europea/North America, FOSAs/FOSEs levels were 10–100-fold lower in Korean indoor air, representing a cultural difference of indoor source. Korean outdoor air contained higher PFAS levels than indoor air, and additionally showed different PFAS composition profile from indoor air. Thus, indoor air would not likely be a main contributor to atmospheric PFAS contamination in Korea, in contrast to western countries. Inhalation exposure of volatile PFASs was estimated to be a minor contributor to PFOA and PFOS exposure in Korea. - Highlights: ► Volatile PFASs were measured in indoor and outdoor airs of Korea, for the first time. ► Cultural difference in indoor source was observed for Korea v.s. western countries. ► Furthermore, PFASs concentrations were higher in indoor air than outdoor air. ► Indoor air was not a major contributor to atmospheric PFASs contamination in Korea. ► Release from industrial activities was considered a possible source. - Korean outdoor air showed not only different PFAS composition profile but higher PFAS levels than indoor airs, indicating indoor air would not be a main source to Korean atmospheric PFASs.

  3. Relationship Between Air Quality and Outdoor Exercise Behavior in China: a Novel Mobile-Based Study.

    Science.gov (United States)

    Hu, Liang; Zhu, Li; Xu, Yaping; Lyu, Jiaying; Imm, Kellie; Yang, Lin

    2017-08-01

    Based on data collected from an exercise app, the study aims to provide empirical evidence on the relationship between air quality and patterns of outdoor exercise in China. Objective outdoor exercise data spanning 160 days were collected from 153 users of an exercise app, Tulipsport in China. Each exercise mode (running, biking, and walking, respectively) was organized into five air quality categories based on Air Quality Index (AQI): excellent, good, mild pollution, moderate pollution, and serious pollution. Key parameters of each app user were calculated and analyzed: the total number of exercise bouts, the average duration, and the average distance of each exercise mode in each air quality category. Multivariate analyses of variance indicate that the users were less likely to participate in outdoor running, biking, and walking (F = 24.16, p air pollution increased. However, there is no difference in terms of average distance and duration of exercise across different air pollution categories. People's participation in outdoor exercise is impeded by air pollution severity, but they stick to their exercise routines once exercise is initiated. Although people should protect themselves from health damages caused by exercising under pollution, the decreases in physical activity associated with air pollution may also pose an indirect risk to public health. The interactive relationship between air quality, exercise, and health warrants more empirical and interdisciplinary explorations.

  4. Lung functions at school age and chronic exposure to outdoor and indoor air pollution

    Energy Technology Data Exchange (ETDEWEB)

    Neuberger, M; Kundi, M; Wiesenberger, W [Vienna Univ. (Austria). Dept. of Preventive Medicine

    1996-12-31

    Early signs of lung function impairment have been found correlated with annual concentrations of outdoor air pollutants and with passive smoking. To investigate the combined effects of both indicators of chronic exposure to air pollution pulmonary functions in all elementary and high school children of an Austrian town was examined for 5 years. (author)

  5. Lung functions at school age and chronic exposure to outdoor and indoor air pollution

    Energy Technology Data Exchange (ETDEWEB)

    Neuberger, M.; Kundi, M.; Wiesenberger, W. [Vienna Univ. (Austria). Dept. of Preventive Medicine

    1995-12-31

    Early signs of lung function impairment have been found correlated with annual concentrations of outdoor air pollutants and with passive smoking. To investigate the combined effects of both indicators of chronic exposure to air pollution pulmonary functions in all elementary and high school children of an Austrian town was examined for 5 years. (author)

  6. Prototype Systems for Measuring Outdoor Air Intake Rates in Rooftop Air Handlers

    Energy Technology Data Exchange (ETDEWEB)

    Fisk, William J. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Chan, Wanyu R. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Hotchi, Toshifumi [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2015-01-01

    The widespread absence of systems for real-time measurement and feedback control, of minimum outdoor air intake rates in HVAC systems contributes to the poor control of ventilation rates in commercial buildings. Ventilation rates affect building energy consumption and influence occupant health. The project designed fabricated and tested four prototypes of systems for measuring rates of outdoor air intake into roof top air handlers. All prototypes met the ±20% accuracy target at low wind speeds, with all prototypes accurate within approximately ±10% after application of calibration equations. One prototype met the accuracy target without a calibration. With two of four prototype measurement systems, there was no evidence that wind speed or direction affected accuracy; however, winds speeds were generally below usually 3.5 m s-1 (12.6 km h-1) and further testing is desirable. The airflow resistance of the prototypes was generally less than 35 Pa at maximum RTU air flow rates. A pressure drop of this magnitude will increase fan energy consumption by approximately 4%. The project did not have resources necessary to estimate costs of mass produced systems. The retail cost of components and materials used to construct prototypes ranged from approximately $1,200 to $1,700. The test data indicate that the basic designs developed in this project, particularly the designs of two of the prototypes, have considerable merit. Further design refinement, testing, and cost analysis would be necessary to fully assess commercial potential. The designs and test results will be communicated to the HVAC manufacturing community.

  7. Observations on persistent organic pollutants in indoor and outdoor air using passive polyurethane foam samplers

    Science.gov (United States)

    Bohlin, Pernilla; Jones, Kevin C.; Tovalin, Horacio; Strandberg, Bo

    Air quality data of persistent organic pollutants (POPs) indoors and outdoors are sparse or lacking in several parts of the world, often hampered by the cost and inconvenience of active sampling techniques. Cheap and easy passive air sampling techniques are therefore helpful for reconnaissance surveys. As a part of the Megacity Initiative: Local and Global Research Observations (MILAGRO) project in Mexico City Metropolitan Area in 2006, a range of POPs (polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), organochlorine pesticides (OCPs), and polybrominated diphenyl ethers (PBDEs)) were analyzed in polyurethane foam (PUF) disks used as passive samplers in indoor and outdoor air. Results were compared to those from samplers deployed simultaneously in Gothenburg (Sweden) and Lancaster (United Kingdom). Using sampling rates suggested in the literature, the sums of 13 PAHs in the different sites were estimated to be 6.1-180 ng m -3, with phenanthrene as the predominant compound. Indoor PAH levels tended to be higher in Gothenburg and outdoor levels higher in Mexico City. The sum of PCBs ranged 59-2100 ng m -3, and seemed to be highest indoors in Gothenburg and Lancaster. PBDE levels (sum of seven) ranged 0.68-620 ng m -3, with the highest levels found in some indoor locations. OCPs (i.e. DDTs, HCHs, and chlordanes) were widely dispersed both outdoors and indoors at all three studied areas. In Gothenburg all POPs tended to be higher indoors than outdoors, while indoor and outdoor levels in Mexico City were similar. This could be due to the influence of indoor and outdoor sources, air exchange rates, and lifestyle factors. The study demonstrates how passive samplers can provide quick and cheap reconnaissance data simultaneously at many locations which can shed light on sources and other factors influencing POP levels in air, especially for the gaseous fractions.

  8. Experimental and numerical investigation on thermal management of an outdoor battery cabinet

    International Nuclear Information System (INIS)

    Meng, X.Z.; Lu, Z.; Jin, L.W.; Zhang, L.Y.; Hu, W.Y.; Wei, L.C.; Chai, J.C.

    2015-01-01

    Many forms of electronic equipment such as battery packs and telecom equipment must be stored in harsh outdoor environment. It is essential that these facilities be protected from a wide range of ambient temperatures and solar radiation. Temperature extremes greatly reduce lead-acid based battery performance and shorten battery life. Therefore, it is important to maintain the cabinet temperature within the optimal values between 20 °C and 30 °C to ensure battery stability and to extend battery lifespan. To this end, cabinet enclosures with proper thermal management have been developed to house such electronic equipment in a highly weather tight manner, especially for battery cabinet. In this paper, the flow field and temperature distribution inside an outdoor cabinet are studied experimentally and numerically. The battery cabinets house 24 batteries in two configurations namely, two-layer configuration and six-layer configuration respectively. The cabinet walls are maintained at a constant temperature by a refrigeration system. The cabinet's ability to protect the batteries from an ambient temperature as high as 50 °C is studied. An experimental facility is developed to measure the battery surface temperatures and to validate the numerical simulations. The differences between the experimental and computational fluid dynamic (CFD) results are within 5%. - Highlights: • Battery placement has significant effect on temperature field in battery cabinet. • The six-layer configuration achieves better temperature uniformity. • Internal air circulation depends on battery configuration. • Natural convection could be an effective solution satisfying safety concerns.

  9. Influence of different outdoor design conditions on design cooling load and design capacities of air conditioning equipments

    International Nuclear Information System (INIS)

    Aktacir, Mehmet Azmi; Bueyuekalaca, Orhan; Bulut, Huesamettin; Yilmaz, Tuncay

    2008-01-01

    Outdoor design conditions are important parameters for energy efficiency of buildings. The result of incorrect selection of outdoor design conditions can be dramatic in view of comfort and energy consumption. In this study, the influence of different outdoor design conditions on air conditioning systems is investigated. For this purpose, cooling loads and capacities of air conditioning equipments for a sample building located in Adana, Turkey are calculated using different outdoor design conditions recommended by ASHRAE, the current design data used in Turkey and the daily maximum dry and wet bulb temperatures of July 21st, which is generally accepted as the design day. The cooling coil capacities obtained from the different outdoor design conditions considered in this study are compared with each other. The cost analysis of air conditioning systems is also performed. It is seen that the selection of outdoor design conditions is a very critical step in calculation of the building cooling loads and design capacities of air conditioning equipments

  10. Analysis of Direct Outdoor Air Cooling Efficency for Combined Variable Air Volume Air-conditioning System in Stores in Cold Climates of China

    OpenAIRE

    Luo, Zhiwen

    2006-01-01

    Direct outdoor air cooling contributes a lot not only to the improvement of the indoor air quality but also to the energy saving. Its full use will reduce the water chiller’s running time especially in some stores where cooling load keeps much higher and longer than that in other buildings. A novel air-conditioning system named Combined Variable Air Volume system (CVAV), combining a normal AHU with a separate outdoor air supply system, was proposed firstly by the authors. The most attractive ...

  11. Meteorological factors influencing on the radon concentrations in indoor and outdoor airs

    International Nuclear Information System (INIS)

    Kojima, Hiroshi

    1989-01-01

    Factors influencing radon concentrations in indoor and outdoor airs are discussed. A balance between source and loss is required in determining the radon concentration. Source refers to as the outdoor and indoor exhalation rate from the ground and the building materials. Loss is caused by turbulent diffusion outdoors and ventilation indoors. A significant factor influencing the exhalation rate of indoor and outdoor radon may be the change in atmospheric pressure. A drop of pressure feeds the high concentration air under the ground or building materials into the open air, and contributes to the increased exhalation rate. The exhalation rate of radon closely depends on the moisture content of the ground or building materials. Up to a certain level of moisture, the radon exhalation increases with increasing moisture content because the emanation power increases by a recoil effect of a fluid present in the internal pores of the materials. Beyond a certain level of moisture, the exhalation decreases rapidly because the pores are filled with water. Radon exhalated from the ground is spread out by turbulent diffusion. The turbulent diffusion may be related to wind velocity and the lapse rate of temperature. There is a remakable difference between indoor and outdoor radon concentrations. The ventilation rate of the house exerted a great effect upon the indoor radon concentration. The ventilation rate is influenced by meteorological factors together with human activities. Of such factors, wind velocity and temperature gradient between indoor and outdoor airs may be the most significant. The correlation coefficients between RaA or radon and some meteorological factors were calculated on the data from the long term measurements on radon and its decay products in and out of a house under normal living conditions. The changes in atmospheric pressure and wind velocity are found to be a significant factor in the variation of concentration of these nuclides. (N.K.)

  12. Experimental evaluation of air distribution in mechanically ventilated residential rooms

    DEFF Research Database (Denmark)

    Tomasi, R.; Krajčík, M.; Simone, A.

    2013-01-01

    The effect of low ventilation rates (1 or 0.5 air change per hour) on thermal comfort and ventilation effectiveness was experimentally studied in a simulated residential room equipped with radiant floor heating/cooling and mixing ventilation systems. The tests were performed for various positions...... of supply and extract air terminals and different winter and summer boundary conditions. Vertical air temperature, operative temperature and air velocity profiles were measured in different positions in the room, and equivalent temperatures were derived, in order to characterize thermal comfort. Contaminant...... with unconditioned outdoor air supply, i.e. at the supply air temperatures higher than the room air temperature. Moreover, low floor temperatures were needed to maintain the desired reference temperature in the stratified thermal environment. Mainly in cooling conditions the ventilation effectiveness depended...

  13. Occupant Time Period of Thermal Adaption to Change of Outdoor Air Temperature in Naturally Ventilated Buildings

    DEFF Research Database (Denmark)

    liu, weiwei; Wargocki, Pawel; Xiong, Jing

    2014-01-01

    The present work proposed a method to determine time period of thermal adaption of occupants in naturally ventilated building, based on the relationship between their neutral temperatures and running mean outdoor air temperature. Based on the data of the field investigation, the subjects’ time...

  14. Outdoor air temperature and mortality in The Netherlands: a time-series analysis

    NARCIS (Netherlands)

    Kunst, A. E.; Looman, C. W.; Mackenbach, J. P.

    1993-01-01

    Death rates become progressively higher when outdoor air temperature rises above or falls below 20-25 degrees C. This study addresses the question of whether this relation is largely attributable to the direct effects of exposure to heat and cold on the human body in general, and on the circulatory

  15. The adverse pathophysiological effects of outdoor air pollution on the body tissues

    Directory of Open Access Journals (Sweden)

    Simona Perčič

    2018-04-01

    Full Text Available Long-term exposure to outdoor air pollution is a serious and common public health concern associated with growing morbidity and mortality worldwide. There are many published studies about the pathophysiological mechanisms involved in response of the body tissues to outdoor air pollution exposure. The aim of our review was to investigate the problem of outdoor air pollution and health effects of pathological mechanisms, with specific goal to point out public health intervention strategies based upon a clearer understanding of pathophysiological mechanisms of outdoor air pollution. A systematic literature review was carried out in two bibliographic databases, Science Direct and PubMed, in the period from January 1995 to December 2015. We conducted a systematic analysis of 95 studies, 43 of them being review studies and 52 original studies. The systematic analysis was done in three steps, for each body tissue separately (respiratory diseases, cardiovascular diseases, neurologic diseases and diabetes mellitus. This insight into literature review may help foster more effective preventive measures at the public health level as well as potential intervention strategies based upon a clearer understanding of the involved pathways.

  16. A comprehensive air quality investigation at an aquatic centre: Indoor/outdoor comparisons.

    Science.gov (United States)

    Tolis, Evangelos I; Panaras, Giorgos; Bartzis, John G

    2018-06-01

    Air quality and comfort parameters in a naturally ventilated aquatic centre were studied in relation to the outdoor pollution levels. Simultaneous measurements of PM 2.5, as well as of volatile organic compounds, were carried out for the indoor and outdoor environment of the aquatic centre. The chemical analysis of ionic species and trace elements associated with particulate matter was also performed. In addition, automated analyzer for NO 2 and O 3 was used in order to record the indoor and outdoor levels of these pollutants. Analysis of diurnal variation of the pollutants' concentration was applied to the collected data, allowing the identification of potential variation on the sources affecting the indoor air quality. PM 2.5 concentration was almost two times higher indoors than outdoors with average values of 13.96 and 6.78 μg/m 3 , respectively. Concerning the ion fraction of PM 2.5, SO 4 2- and Ca 2+ were the ions with higher concentration indoors with values of 1.06 and 0.93 μg/m 3 , respectively, while the percentage of Cl - to the PM 2.5 fraction of the indoor atmosphere (9%) was too high than outdoor ones (1%). These results showed that indoor air of swimming pool concerning PM 2.5 and ionic species is mainly affected by the chlorination process along with the comfort conditions (high relative humidity) created during the operation of the facility. The common volatile organic compound concentrations at indoor air are generally in higher levels, compared to the outdoor air with p,m-xylene and toluene to be the substances with the higher concentration for indoor and outdoor area, respectively (7.80 and 1.57 μg/m 3 ); nevertheless, values were rather low compared with the findings of other studies. Also, they clearly demonstrate a diurnal variation as a result of poor ventilation during night. As it was expected, chloroform showed the highest concentration compared to the other volatile organic compounds with values ranging from 3.35 to 135.89 μg/m 3

  17. Indoor and Outdoor Air Pollution- related Health Problem in Ethiopia ...

    African Journals Online (AJOL)

    Background: The health effects of air pollution are generally global problems, but they have, since recently become issues of particular concern for developing countries. This review assessed the situation of air pollution and related health effects in the context of Ethiopia. Methods: The materials reviewed in this publication ...

  18. PubMed search filters for the study of putative outdoor air pollution determinants of disease

    Science.gov (United States)

    Curti, Stefania; Gori, Davide; Di Gregori, Valentina; Farioli, Andrea; Baldasseroni, Alberto; Fantini, Maria Pia; Christiani, David C; Violante, Francesco S; Mattioli, Stefano

    2016-01-01

    Objectives Several PubMed search filters have been developed in contexts other than environmental. We aimed at identifying efficient PubMed search filters for the study of environmental determinants of diseases related to outdoor air pollution. Methods We compiled a list of Medical Subject Headings (MeSH) and non-MeSH terms seeming pertinent to outdoor air pollutants exposure as determinants of diseases in the general population. We estimated proportions of potentially pertinent articles to formulate two filters (one ‘more specific’, one ‘more sensitive’). Their overall performance was evaluated as compared with our gold standard derived from systematic reviews on diseases potentially related to outdoor air pollution. We tested these filters in the study of three diseases potentially associated with outdoor air pollution and calculated the number of needed to read (NNR) abstracts to identify one potentially pertinent article in the context of these diseases. Last searches were run in January 2016. Results The ‘more specific’ filter was based on the combination of terms that yielded a threshold of potentially pertinent articles ≥40%. The ‘more sensitive’ filter was based on the combination of all search terms under study. When compared with the gold standard, the ‘more specific’ filter reported the highest specificity (67.4%; with a sensitivity of 82.5%), while the ‘more sensitive’ one reported the highest sensitivity (98.5%; with a specificity of 47.9%). The NNR to find one potentially pertinent article was 1.9 for the ‘more specific’ filter and 3.3 for the ‘more sensitive’ one. Conclusions The proposed search filters could help healthcare professionals investigate environmental determinants of medical conditions that could be potentially related to outdoor air pollution. PMID:28003291

  19. PubMed search filters for the study of putative outdoor air pollution determinants of disease.

    Science.gov (United States)

    Curti, Stefania; Gori, Davide; Di Gregori, Valentina; Farioli, Andrea; Baldasseroni, Alberto; Fantini, Maria Pia; Christiani, David C; Violante, Francesco S; Mattioli, Stefano

    2016-12-21

    Several PubMed search filters have been developed in contexts other than environmental. We aimed at identifying efficient PubMed search filters for the study of environmental determinants of diseases related to outdoor air pollution. We compiled a list of Medical Subject Headings (MeSH) and non-MeSH terms seeming pertinent to outdoor air pollutants exposure as determinants of diseases in the general population. We estimated proportions of potentially pertinent articles to formulate two filters (one 'more specific', one 'more sensitive'). Their overall performance was evaluated as compared with our gold standard derived from systematic reviews on diseases potentially related to outdoor air pollution. We tested these filters in the study of three diseases potentially associated with outdoor air pollution and calculated the number of needed to read (NNR) abstracts to identify one potentially pertinent article in the context of these diseases. Last searches were run in January 2016. The 'more specific' filter was based on the combination of terms that yielded a threshold of potentially pertinent articles ≥40%. The 'more sensitive' filter was based on the combination of all search terms under study. When compared with the gold standard, the 'more specific' filter reported the highest specificity (67.4%; with a sensitivity of 82.5%), while the 'more sensitive' one reported the highest sensitivity (98.5%; with a specificity of 47.9%). The NNR to find one potentially pertinent article was 1.9 for the 'more specific' filter and 3.3 for the 'more sensitive' one. The proposed search filters could help healthcare professionals investigate environmental determinants of medical conditions that could be potentially related to outdoor air pollution. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

  20. Desiccant wheels for air humidification: An experimental and numerical analysis

    International Nuclear Information System (INIS)

    De Antonellis, Stefano; Intini, Manuel; Joppolo, Cesare Maria; Molinaroli, Luca; Romano, Francesco

    2015-01-01

    Highlights: • The use of desiccant wheel to humidify an air stream is investigated. • Air humidification is obtained by extracting water vapour from outdoor air. • Experimental tests in winter humidification conditions are performed. • The design of the proposed humidification system is numerically analyzed. • Effects of boundary conditions on humidification capacity are investigated. - Abstract: In this work the use of a desiccant wheel for air humidification is investigated through a numerical and experimental approach. In the proposed humidification system, water vapour is adsorbed from outdoor environment and it is released directly to the air stream supplied to the building. Such a system can be an interesting alternative to steam humidifiers in hospitals or, more generally, in applications where air contamination is a critical issue and therefore adiabatic humidifiers are not allowed. Performance of the proposed system is deeply investigated and optimal values of desiccant wheel configuration parameters are discussed. It is shown that in the investigated conditions, which are representative of Southern Europe winter climate, the system can properly match the latent load of the building. Finally, power consumption referred to the primary source of the proposed humidification system is compared to the one of steam humidifiers. The present analysis is carried out through experimental tests of a desiccant wheel in winter humidification conditions and through a phenomenological model of the device, based on heat and mass transfer equations.

  1. The global burden of disease due to outdoor air pollution.

    Science.gov (United States)

    Cohen, Aaron J; Ross Anderson, H; Ostro, Bart; Pandey, Kiran Dev; Krzyzanowski, Michal; Künzli, Nino; Gutschmidt, Kersten; Pope, Arden; Romieu, Isabelle; Samet, Jonathan M; Smith, Kirk

    As part of the World Health Organization (WHO) Global Burden of Disease Comparative Risk Assessment, the burden of disease attributable to urban ambient air pollution was estimated in terms of deaths and disability-adjusted life years (DALYs). Air pollution is associated with a broad spectrum of acute and chronic health effects, the nature of which may vary with the pollutant constituents. Particulate air pollution is consistently and independently related to the most serious effects, including lung cancer and other cardiopulmonary mortality. The analyses on which this report is based estimate that ambient air pollution, in terms of fine particulate air pollution (PM(2.5)), causes about 3% of mortality from cardiopulmonary disease, about 5% of mortality from cancer of the trachea, bronchus, and lung, and about 1% of mortality from acute respiratory infections in children under 5 yr, worldwide. This amounts to about 0.8 million (1.2%) premature deaths and 6.4 million (0.5%) years of life lost (YLL). This burden occurs predominantly in developing countries; 65% in Asia alone. These estimates consider only the impact of air pollution on mortality (i.e., years of life lost) and not morbidity (i.e., years lived with disability), due to limitations in the epidemiologic database. If air pollution multiplies both incidence and mortality to the same extent (i.e., the same relative risk), then the DALYs for cardiopulmonary disease increase by 20% worldwide.

  2. Concentration levels of radon in air, indoors and outdoors in houses of Mexico City

    International Nuclear Information System (INIS)

    Pena Garcia, P.

    1992-01-01

    Concentration levels of radon in air, indoors and outdoors have been obtained in houses from Mexico City, with the purpose of relating them with the local environment. Measurements were performed both outdoors and indoors in 60 unifamiliar houses. Track detectors, LR-115, Type II, were used in several detection arrangements during four recording periods with times of exposure of three months each, with the purpose of analyzing the fluctuations due to seasonal changes. Data were obtained about the construction materials were the detection systems were located in order to establish a correlation of radon levels with the climatic parameters and the construction materials. The results of radon concentrations both indoors or outdoors were lower than the international recommendations (148 Bq/m 3 ) (Author)

  3. A study of the reverse cycle defrosting performance on a multi-circuit outdoor coil unit in an air source heat pump – Part I: Experiments

    International Nuclear Information System (INIS)

    Qu, Minglu; Xia, Liang; Deng, Shiming; Jiang, Yiqiang

    2012-01-01

    Highlights: ► We experimental study the defrosting performance on a multi-circuit outdoor coil unit in an ASHP unit. ► We find that defrosting is quicker on the airside of upper circuits than that on the lower circuits. ► We discuss the effects of downwards flowing of the melted frost along the outdoor coil surface on defrosting performance. -- Abstract: When an air source heat pump (ASHP) unit operates in heating mode, frost can be accumulated on the surface of its finned outdoor coil which normally has multiple parallel circuits on its refrigerant side for minimized refrigerant pressure loss and enhanced heat transfer efficiency. On its airside, however, there is usually no segmentation corresponding to the number of refrigerant circuit. Frosting deteriorates the operation and energy efficiency of the ASHP unit and periodic defrosting becomes necessary. Currently the most widely used standard defrosting method for ASHPs is reverse cycle defrost. This paper, the first part of a two-part series, reports on the experimental part of a study of the reverse cycle defrosting performance on a multi-circuit outdoor coil unit in an experimental 6.5 kW heating capacity residential ASHP unit. Firstly the experimental ASHP unit is described and experimental procedures detailed. Secondly, the experimental results are reported. This is followed by the discussion on the effects of downwards flowing of the melted frost along a multi-circuit outdoor coil surface on defrosting performance. Finally, the evaluation of the defrosting efficiency for the experimental ASHP unit is provided. In the second part of the series, a modeling analysis on the effects of downwards flowing of the melted frost along the multi-circuit outdoor coil surface on defrosting performance of the experimental ASHP unit will be presented.

  4. Can we establish relationship between outdoor air ventilation and health based on the published epidemiological data?

    DEFF Research Database (Denmark)

    Carrer, Paolo; Wargocki, Pawel; Fanetti, Annaclara

    2015-01-01

    Appropriate exposure control is prerogative for reducing the burden of disease (BOD) due to inadequate air quality indoors (IAQ). Ventilation with outdoor air is one of the available exposure control methods and is widespread. It is often assumed that this method will bring tangible effects...... exposures at various levels of ventilation were no characterized. It was observed that available data have many limitations, such as insufficient statistical power, incomplete data on the strength of pollution sources, diversity and variability of ventilation rates, at which effects have been seen...... exposures affecting health. It is concluded, that currently available epidemiological data do not provide sound basis for outdoor air ventilation requirements that can be universally applicable in different public and residential buildings to protect against health risks. They show minimum rates at which...

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

    Science.gov (United States)

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

    2015-01-01

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

  6. Relationships of Indoor, Outdoor, and Personal Air (RIOPA). Part I. Collection methods and descriptive analyses.

    Science.gov (United States)

    Weisel, Clifford P; Zhang, Junfeng; Turpin, Barbara J; Morandi, Maria T; Colome, Steven; Stock, Thomas H; Spektor, Dalia M; Korn, Leo; Winer, Arthur M; Kwon, Jaymin; Meng, Qing Yu; Zhang, Lin; Harrington, Robert; Liu, Weili; Reff, Adam; Lee, Jong Hoon; Alimokhtari, Shahnaz; Mohan, Kishan; Shendell, Derek; Jones, Jennifer; Farrar, L; Maberti, Slivia; Fan, Tina

    2005-11-01

    This study on the relationships of indoor, outdoor, and personal air (RIOPA) was undertaken to collect data for use in evaluating the contribution of outdoor sources of air toxics and particulate matter (PM) to personal exposure. The study was not designed to obtain a population-based sample, but rather to provide matched indoor, outdoor, and personal concentrations in homes that varied in their proximity to outdoor pollution sources and had a wide range of air exchange rates (AERs). This design allowed examination of relations among indoor, outdoor, and personal concentrations of air toxics and PM across a wide range of environmental conditions; the resulting data set obtained for a wide range of environmental pollutants and AERs can be used to evaluate exposure models. Approximately 100 households with residents who do not smoke participated in each of three cities in distinct locations expected to have different climates and housing characteristics: Elizabeth, New Jersey; Houston, Texas; and Los Angeles County, California. Questionnaires were administered to characterize homes, neighborhoods, and personal activities that might affect exposures. The concentrations of a suite of volatile organic compounds (VOCs) and carbonyl compounds, as well as the fraction of airborne particulate matter with a mass median aerodynamic diameter personal air samples were collected simultaneously. During the same 48-hour period, the AER (exchanges/hr; x hr(-1)) was determined in each home, and carbonyl compounds were measured inside vehicle cabins driven by a subset of the participants. In most of the homes, measurements were made twice, during two different seasons, to obtain a wide distribution of AERs. This report presents in detail the data collection methods, quality control measures, and initial analyses of data distributions and relations among indoor, outdoor, and personal concentrations. The results show that indoor sources dominated personal and indoor air concentrations

  7. Estimating the burden of disease attributable to urban outdoor air ...

    African Journals Online (AJOL)

    PM10 and PM2.5 data from air-quality assessment studies in areas not covered by the network were also included. Population-attributable fractions calculated using risk coefficients presented in the WHO study were weighted by the proportion of the total population (33%) in urban environments, and applied to revised ...

  8. Indoor/Outdoor Air Quality Assessment at School near the Steel Plant in Taranto (Italy

    Directory of Open Access Journals (Sweden)

    A. Di Gilio

    2017-01-01

    Full Text Available This study aims to investigate the air quality in primary school placed in district of Taranto (south of Italy, an area of high environmental risk because of closeness between large industrial complex and urban settlement. The chemical characterization of PM2.5 was performed to identify origin of pollutants detected inside school and the comparison between indoor and outdoor levels of PAHs and metals allowed evaluating intrusion of outdoor pollutants or the existence of specific indoor sources. The results showed that the indoor and outdoor levels of PM2.5, BaP, Cd, Ni, As, and Pb never exceeded the target values issued by World Health Organization (WHO. Nevertheless, high metals and PAHs concentrations were detected especially when school were downwind to the steel plant. The I/O ratio showed the impact of outdoor pollutants, especially of industrial markers as Fe, Mn, Zn, and Pb, on indoor air quality. This result was confirmed by values of diagnostic ratio as B(aP/B(gP, IP/(IP + BgP, BaP/Chry, and BaP/(BaP + Chry, which showed range characteristics of coke and coal combustion. However, Ni and As showed I/O ratio of 2.5 and 1.4, respectively, suggesting the presence of indoor sources.

  9. Call-centre occupant response to new and used filters at two outdoor air supply rates

    DEFF Research Database (Denmark)

    Wargocki, Pawel; Wyon, David; Nielsen, J.

    2002-01-01

    A 2x2 replicaterd field intervention experiment was conducted in a call-centre providing a public telephone directory service: outdoor air supply rate was 8% or 80% of the total airflow of 430 L/s providing 3.5 h-1; and the supply air filters were either new or used (i.e. used in place for 6 mont......). Each of these 4 conditions was maintained for a full working week at a time. Room temperature and humidity averaged 24 deg.C and 27% RH. The 26 operators were blind to conditions and assessed perceived air quality (PAQ), the intensity of Sick Building Syndrome (SBS) symnptoms and self...

  10. Relation between 222Rn concentration in outdoor air and lower atmosphere

    International Nuclear Information System (INIS)

    Kataoka, Toshio; Mori, Tadashige; Yunoki, Eiji; Michihiro, Kenshuh; Sugiyama, Hirokazu; Shimizu, Mitsuo; Tsukamoto, Osamu; Sahashi, Ken.

    1991-01-01

    Using the height of the surface-based inversion layer obtained by the acoustic sounder returns and the variation of the 222 Rn concentration in the outdoor air during the presence of the surface-based inversion layer, the exhalation rate of 222 Rn is estimated to be 0.020 Bq·m -2 ·s -1 , which is observed elsewhere on land. Furthermore, the exposure rate at 1 m above the air-ground interface due to the short-lived 222 Rn daughters in the outdoor air during the presence of the surface-based inversion layer can be estimated using the height of the surface-based inversion layer and the 222 Rn concentrations in the outdoor air at the ground level before and after the onset of the surface-based inversion layer. From these treatment, it is clearly demonstrated that the monostatic acoustic sounder is useful as a supplementary method for a weather survey which forms a part of monitoring around the nuclear facilities. (author)

  11. Efficacy of an outdoor air pollution education program in a community at risk for asthma morbidity.

    Science.gov (United States)

    Dorevitch, Samuel; Karandikar, Abhijay; Washington, Gregory F; Walton, Geraldine Penny; Anderson, Renate; Nickels, Leslie

    2008-11-01

    Asthma management guidelines recommend avoiding exposure to indoor and outdoor air pollutants. A limitation of such recommendations is that they do not provide information about how the public should obtain and act on air quality information. Although the Air Quality Index (AQI) provides simplified outdoor air quality forecasts, communities with high rates of asthma morbidity tend to have low rates of internet access due to factors such as low socioeconomic status. Assessments of knowledge about air quality among low-income minority communities are lacking, as are community-based programs to educate the public about using the AQI. An air quality education program and system for disseminating air quality information were developed to promote pollutant avoidance during the reconstruction of a major highway in a low-income minority community on Chicago's South Side. The program, which centered on workshops run by community asthma educators, was evaluated using a pre-test, post-test, and 1-year follow-up questionnaire. A total of 120 community workshop participants completed at least a portion of the evaluation process. At baseline, knowledge about air quality was limited. Following the workshops, substantial increases were noted in rates of correct answers to questions about health effects of air pollution, the availability of air quality information, and the color code for an AQI category. Approximately 1 year after the workshops were held, few participants could recall elements of the training. Few participants have internet access, and alternative means of distributing air quality information were suggested by study participants. Baseline knowledge of air quality information was limited in the community studied. Air quality education workshops conducted by community educators can increase knowledge about outdoor air quality and its impact on health over the short term. Refresher workshops or other efforts to sustain the knowledge increase may be useful. Given the

  12. Performance of introducing outdoor cold air for cooling a plant production system with artificial light

    Directory of Open Access Journals (Sweden)

    Jun eWang

    2016-03-01

    Full Text Available The commercial use of a plant production system with artificial light (PPAL is limited by its high initial construction and operation costs. The electric-energy consumed by heat pumps, applied mainly for cooling, accounts for 15-35% of the total electric-energy used in a PPAL. To reduce the electric-energy consumption, an air exchanger with low capacity (180 W was used for cooling by introducing outdoor cold air. In this experiment, the indoor air temperature in two PPALs (floor area: 6.2 m2 each was maintained at 25ºC and 20ºC during light and dark periods, respectively, for lettuce production. In one PPAL (PPALe, an air exchanger (air flow rate: 250 m3 h-1 was used along with a heat pump (cooling capacity: 3.2 kW to maintain the indoor air temperature at the set-point. The other PPAL (PPALc with only a heat pump (cooling capacity: 3.2 kW was used for reference. Effects of introducing outdoor cold air on energy use efficiency, coefficient of performance (COP, electric-energy consumption for cooling and growth of lettuce were investigated. The results show that: when the air temperature difference between indoor and outdoor ranged from 20.2°C to 30.0°C: 1 the average energy use efficiency of the air exchanger was 2.8 and 3.4 times greater than the COP of the heat pumps in the PPALe and PPALc, respectively; 2 hourly electric-energy consumption in the PPALe reduced by 15.8-73.7% compared with that in the PPALc; 3 daily supply of CO2 in the PPALe reduced from 0.15 kg to 0.04 kg compared with that in the PPALc; 4 no significant difference in lettuce growth was observed in both PPALs. The results indicate that using air exchanger to introduce outdoor cold air should be considered as an effective way to reduce electric-energy consumption for cooling with little effects on plant growth in a PPAL.

  13. Microbial Air Contamination in Indoor and Outdoor Environment of Pig Farms

    Directory of Open Access Journals (Sweden)

    Silvana Popescu

    2014-05-01

    Full Text Available Ensuring a good air quality in pig farms is important for the health of animals and human workers. The aim of this study was the assessment of the microbiological quality of the air inside the pig houses and outside of these. The study was accomplished in two pig-fattening farms in Cluj County. The microbiological air quality was assessed in the cold and warm season, by determination of the total counts of mesophilic bacteria, staphylococci, streptococci, gram-negative bacteria and fungi. The bacterial and fungal counts varied in the air of the investigated farms. In relation to the season the mean counts of bacteria and fungi were significantly higher (P 0.05 were found between the values of the parameters determined from the indoor air and those obtained outside, from a distance of 5 m from the pig houses. The numbers of the bacteria and fungi in the outdoor air lowered as the distance from the farms increased, the differences being significant at 25 and 50 m (P < 0.05. The results of the study show a high bacterial contamination of the indoor and outdoor air of the pig farms.

  14. Toxicity and elemental composition of particulate matter from outdoor and indoor air of elementary schools in Munich, Germany.

    Science.gov (United States)

    Oeder, S; Dietrich, S; Weichenmeier, I; Schober, W; Pusch, G; Jörres, R A; Schierl, R; Nowak, D; Fromme, H; Behrendt, H; Buters, J T M

    2012-04-01

    Outdoor particulate matter (PM(10)) is associated with detrimental health effects. However, individual PM(10) exposure occurs mostly indoors. We therefore compared the toxic effects of classroom, outdoor, and residential PM(10). Indoor and outdoor PM(10) was collected from six schools in Munich during teaching hours and in six homes. Particles were analyzed by scanning electron microscopy and X-ray spectroscopy (EDX). Toxicity was evaluated in human primary keratinocytes, lung epithelial cells and after metabolic activation by several human cytochromes P450. We found that PM(10) concentrations during teaching hours were 5.6-times higher than outdoors (117 ± 48 μg/m(3) vs. 21 ± 15 μg/m(3), P particle number), organic (29%, probably originating from human skin), and Ca-carbonate particles (12%, probably originating from paper). Outdoor PM contained more Ca-sulfate particles (38%). Indoor PM at 6 μg/cm(2) (10 μg/ml) caused toxicity in keratinocytes and in cells expressing CYP2B6 and CYP3A4. Toxicity by CYP2B6 was abolished with the reactive oxygen species scavenger N-acetylcysteine. We concluded that outdoor PM(10) and indoor PM(10) from homes were devoid of toxicity. Indoor PM(10) was elevated, chemically different and toxicologically more active than outdoor PM(10). Whether the effects translate into a significant health risk needs to be determined. Until then, we suggest better ventilation as a sensible option. Indoor air PM(10) on an equal weight base is toxicologically more active than outdoor PM(10). In addition, indoor PM(10) concentrations are about six times higher than outdoor air. Thus, ventilation of classrooms with outdoor air will improve air quality and is likely to provide a health benefit. It is also easier than cleaning PM(10) from indoor air, which has proven to be tedious. © 2011 John Wiley & Sons A/S.

  15. Association between indoor and outdoor air pollution and adolescent asthma from 1995 to 1996 in Taiwan

    Energy Technology Data Exchange (ETDEWEB)

    Wang, T.N.; Ko, Y.C.; Chao, Y.Y.; Huang, C.C.; Lin, R.S.

    1999-10-01

    The study aim was to estimate the contribution of indoor and outdoor air pollution to the 1-year prevalence of adolescent asthma after personal susceptibility and other potential risk factors were taken into account. A large-scaled cross-sectional study was conducted among 165,173 high school students aged 11 to 16 years in the different communities of Kaohsiung and Pintong in Taiwan, from October 1995 to June 1996. Each student and his/her parents participating in the study completed a video and a written International Study of Asthma and Allergies in Childhood questionnaire about symptoms of wheezing and allergies, passive smoking, and demographic variables. After adjustment for potential confounders, adolescents exposed to cigarette smoking and environmental tobacco smoke were found to suffer from asthma at an increased frequency. The authors observed a statistically significant association between outdoor air pollution and asthma, after controlling for potential confound variables. Total suspended particulate, nitrogen dioxide, carbon monoxide, ozone, and airborne dust particles all displayed an independent association with asthma, respectively. There were no selection biases in this community-based study, which provides evidence that passive smoking and long-term, high average outdoor air pollution are independent risk factors of asthma.

  16. Experimental research on air propellers

    Science.gov (United States)

    Durand, William F

    1918-01-01

    The purposes of the experimental investigation on the performance of air propellers described in this report are as follows: (1) the development of a series of design factors and coefficients drawn from model forms distributed with some regularity over the field of air-propeller design and intended to furnish a basis of check with similar work done in other aerodynamic laboratories, and as a point of departure for the further study of special or individual types and forms; (2) the establishment of a series of experimental values derived from models and intended for later use as a basis for comparison with similar results drawn from certain selected full-sized forms and tested in free flight.

  17. National patterns in environmental injustice and inequality: outdoor NO2 air pollution in the United States.

    Science.gov (United States)

    Clark, Lara P; Millet, Dylan B; Marshall, Julian D

    2014-01-01

    We describe spatial patterns in environmental injustice and inequality for residential outdoor nitrogen dioxide (NO2) concentrations in the contiguous United States. Our approach employs Census demographic data and a recently published high-resolution dataset of outdoor NO2 concentrations. Nationally, population-weighted mean NO2 concentrations are 4.6 ppb (38%, p2.5 hours/week of physical activity). Inequality for NO2 concentration is greater than inequality for income (Atkinson Index: 0.11 versus 0.08). Low-income nonwhite young children and elderly people are disproportionately exposed to residential outdoor NO2. Our findings establish a national context for previous work that has documented air pollution environmental injustice and inequality within individual US metropolitan areas and regions. Results given here can aid policy-makers in identifying locations with high environmental injustice and inequality. For example, states with both high injustice and high inequality (top quintile) for outdoor residential NO2 include New York, Michigan, and Wisconsin.

  18. National patterns in environmental injustice and inequality: outdoor NO2 air pollution in the United States.

    Directory of Open Access Journals (Sweden)

    Lara P Clark

    Full Text Available We describe spatial patterns in environmental injustice and inequality for residential outdoor nitrogen dioxide (NO2 concentrations in the contiguous United States. Our approach employs Census demographic data and a recently published high-resolution dataset of outdoor NO2 concentrations. Nationally, population-weighted mean NO2 concentrations are 4.6 ppb (38%, p2.5 hours/week of physical activity. Inequality for NO2 concentration is greater than inequality for income (Atkinson Index: 0.11 versus 0.08. Low-income nonwhite young children and elderly people are disproportionately exposed to residential outdoor NO2. Our findings establish a national context for previous work that has documented air pollution environmental injustice and inequality within individual US metropolitan areas and regions. Results given here can aid policy-makers in identifying locations with high environmental injustice and inequality. For example, states with both high injustice and high inequality (top quintile for outdoor residential NO2 include New York, Michigan, and Wisconsin.

  19. Stroke and Long-Term Exposure to Outdoor Air Pollution From Nitrogen Dioxide A Cohort Study

    DEFF Research Database (Denmark)

    Andersen, Zorana Jovanovic; Kristiansen, Luise Cederkvist; Andersen, Klaus K.

    2012-01-01

    Background and Purpose-Years of exposure to tobacco smoke substantially increase the risk for stroke. Whether long-term exposure to outdoor air pollution can lead to stroke is not yet established. We examined the association between long-term exposure to traffic-related air pollution and incident...... and fatal stroke in a prospective cohort study.Methods-We followed 57 053 participants of the Danish Diet, Cancer and Health cohort in the Hospital Discharge Register for the first-ever hospital admission for stroke (incident stroke) between baseline (1993-1997) and 2006 and defined fatal strokes as death...

  20. Outdoor air pollution, family and neighborhood environment, and asthma in LA FANS children.

    Science.gov (United States)

    Wilhelm, Michelle; Qian, Lei; Ritz, Beate

    2009-03-01

    We examined associations between outdoor air pollution and childhood asthma, using measures of SES, neighborhood quality, and social support from the Los Angeles Family and Neighborhood Survey (LA FANS). We linked residential census tracts for 3114 children to government air monitoring stations and estimated average pollutant concentrations for the year before interview. CO and NO(2) levels increased and O(3) levels decreased as neighborhood quality decreased, yet correlations were low. Pollutant levels were not correlated with neighborhood support. Even after adjustment for social environment characteristics, LA FANS children living in high O(3), PM(10), and CO areas appeared to have worse asthma morbidity.

  1. The importance of determining the air exchange rate in flats and buildings for calculations of the averted indoor inhalation doses arising from contaminated outdoor air

    International Nuclear Information System (INIS)

    Jilek, Karel; Thomas, J.; Bulanek, B.; Lenk, J.; Marikova, S.

    2015-01-01

    The indoor-outdoor air exchange rate is an important parameter when refining estimates of the averted inhaled doses to population in houses and buildings after an emergency event resulting in contamination of outdoor air with a radioactive material. The air exchange rates measured in 70 occupied houses and in 20 unoccupied houses using N 2 O as the tracer gas are presented, and the results of modelling the averted doses in the residential buildings for both gaseous and aerosol outdoor contaminants are demonstrated. (orig.)

  2. A study protocol to evaluate the relationship between outdoor air pollution and pregnancy outcomes

    Directory of Open Access Journals (Sweden)

    Selemane Ismael

    2010-10-01

    Full Text Available Abstract Background The present study protocol is designed to assess the relationship between outdoor air pollution and low birth weight and preterm births outcomes performing a semi-ecological analysis. Semi-ecological design studies are widely used to assess effects of air pollution in humans. In this type of analysis, health outcomes and covariates are measured in individuals and exposure assignments are usually based on air quality monitor stations. Therefore, estimating individual exposures are one of the major challenges when investigating these relationships with a semi-ecologic design. Methods/Design Semi-ecologic study consisting of a retrospective cohort study with ecologic assignment of exposure is applied. Health outcomes and covariates are collected at Primary Health Care Center. Data from pregnant registry, clinical record and specific questionnaire administered orally to the mothers of children born in period 2007-2010 in Portuguese Alentejo Litoral region, are collected by the research team. Outdoor air pollution data are collected with a lichen diversity biomonitoring program, and individual pregnancy exposures are assessed with spatial geostatistical simulation, which provides the basis for uncertainty analysis of individual exposures. Awareness of outdoor air pollution uncertainty will improve validity of individual exposures assignments for further statistical analysis with multivariate regression models. Discussion Exposure misclassification is an issue of concern in semi-ecological design. In this study, personal exposures are assigned to each pregnant using geocoded addresses data. A stochastic simulation method is applied to lichen diversity values index measured at biomonitoring survey locations, in order to assess spatial uncertainty of lichen diversity value index at each geocoded address. These methods assume a model for spatial autocorrelation of exposure and provide a distribution of exposures in each study location

  3. A study protocol to evaluate the relationship between outdoor air pollution and pregnancy outcomes.

    Science.gov (United States)

    Ribeiro, Manuel C; Pereira, Maria J; Soares, Amílcar; Branquinho, Cristina; Augusto, Sofia; Llop, Esteve; Fonseca, Susana; Nave, Joaquim G; Tavares, António B; Dias, Carlos M; Silva, Ana; Selemane, Ismael; de Toro, Joaquin; Santos, Mário J; Santos, Fernanda

    2010-10-15

    The present study protocol is designed to assess the relationship between outdoor air pollution and low birth weight and preterm births outcomes performing a semi-ecological analysis. Semi-ecological design studies are widely used to assess effects of air pollution in humans. In this type of analysis, health outcomes and covariates are measured in individuals and exposure assignments are usually based on air quality monitor stations. Therefore, estimating individual exposures are one of the major challenges when investigating these relationships with a semi-ecologic design. Semi-ecologic study consisting of a retrospective cohort study with ecologic assignment of exposure is applied. Health outcomes and covariates are collected at Primary Health Care Center. Data from pregnant registry, clinical record and specific questionnaire administered orally to the mothers of children born in period 2007-2010 in Portuguese Alentejo Litoral region, are collected by the research team. Outdoor air pollution data are collected with a lichen diversity biomonitoring program, and individual pregnancy exposures are assessed with spatial geostatistical simulation, which provides the basis for uncertainty analysis of individual exposures. Awareness of outdoor air pollution uncertainty will improve validity of individual exposures assignments for further statistical analysis with multivariate regression models. Exposure misclassification is an issue of concern in semi-ecological design. In this study, personal exposures are assigned to each pregnant using geocoded addresses data. A stochastic simulation method is applied to lichen diversity values index measured at biomonitoring survey locations, in order to assess spatial uncertainty of lichen diversity value index at each geocoded address. These methods assume a model for spatial autocorrelation of exposure and provide a distribution of exposures in each study location. We believe that variability of simulated exposure values at

  4. A note on the relationship between outdoor and indoor exposure integrals for air pollution of outdoor origin

    International Nuclear Information System (INIS)

    Gjoerup, H.L.; Roed, J.

    1980-05-01

    Beryllium-7 created by cosmic radiation has been used as a tracer in preliminary measurements designed to enable an estimation of the ratio between outdoor and indoor exposure integrals for aerosols of outdoor origin, with special reference to the reduction in inhalation dose that can be achieved by staying indoors during reactor accidents. Earlier investigations relevant to this problem are reviewed. It is concluded that the reduction is inhalation dose offered by an average Danish house is roughly one order of magnitude. (author)

  5. The effect of future outdoor air pollution on human health and the contribution of climate change

    Science.gov (United States)

    Silva, R.; West, J. J.; Lamarque, J.; Shindell, D.; Collins, W.; Dalsoren, S. B.; Faluvegi, G. S.; Folberth, G.; Horowitz, L. W.; Nagashima, T.; Naik, V.; Rumbold, S.; Skeie, R.; Sudo, K.; Takemura, T.; Bergmann, D. J.; Cameron-Smith, P. J.; Cionni, I.; Doherty, R. M.; Eyring, V.; Josse, B.; MacKenzie, I. A.; Plummer, D.; Righi, M.; Stevenson, D. S.; Strode, S. A.; Szopa, S.; Zeng, G.

    2013-12-01

    At present, exposure to outdoor air pollution from ozone and fine particulate matter (PM2.5) causes over 2 million deaths per year, due to respiratory and cardiovascular diseases and lung cancer. Future ambient concentrations of ozone and PM2.5 will be affected by both air pollutant emissions and climate change. Here we estimate the potential impact of future outdoor air pollution on premature human mortality, and isolate the contribution of future climate change due to its effect on air quality. We use modeled present-day (2000) and future global ozone and PM2.5 concentrations from simulations with an ensemble of chemistry-climate models from the Atmospheric Chemistry and Climate Model Intercomparison Project (ACCMIP). Future air pollution was modeled for global greenhouse gas and air pollutant emissions in the four IPCC AR5 Representative Concentration Pathway (RCP) scenarios, for 2030, 2050 and 2100. All model outputs are regridded to a common 0.5°x0.5° horizontal resolution. Future premature mortality is estimated for each RCP scenario and year based on changes in concentrations of ozone and PM2.5 relative to 2000. Using a health impact function, changes in concentrations for each RCP scenario are combined with future population and cause-specific baseline mortality rates as projected by a single independent scenario in which the global incidence of cardiopulmonary diseases is expected to increase. The effect of climate change is isolated by considering the difference between air pollutant concentrations from simulations with 2000 emissions and a future year climate and simulations with 2000 emissions and climate. Uncertainties in the results reflect the uncertainty in the concentration-response function and that associated with variability among models. Few previous studies have quantified the effects of future climate change on global human health via changes in air quality, and this is the first such study to use an ensemble of global models.

  6. Assessment of polycyclic aromatic hydrocarbons in indoor and outdoor air of preschool environments (3–5 years old children)

    International Nuclear Information System (INIS)

    Oliveira, Marta; Slezakova, Klara; Delerue-Matos, Cristina; Pereira, Maria do Carmo; Morais, Simone

    2016-01-01

    This work characterizes levels of polycyclic aromatic hydrocarbons (PAHs) in indoor and outdoor air of preschool environments, and assesses the respective risks for 3–5-years old children. Eighteen gaseous and particulate (PM_1 and PM_2_._5) PAHs were collected indoors and outdoors during 63 days at preschools in Portugal. Gaseous PAHs accounted for 94–98% of total concentration (Σ_P_A_H_s). PAHs with 5–6 rings were predominantly found in PM_1 (54–74% particulate Σ_P_A_H_s). Lighter PAHs originated mainly from indoor sources whereas congeners with 4–6 rings resulted mostly from outdoor emissions penetration (motor vehicle, fuel burning). Total cancer risks of children were negligible according to USEPA, but exceeded (8–13 times) WHO health-based guideline. Carcinogenic risks due to indoor exposure were higher than for outdoors (4–18 times). - Highlights: • Lighter PAHs originate from indoor sources, 4–6 rings PAHs result from outdoors. • Gaseous PAHs account for the majority of PAH content in indoor air of preschools. • Lifetime lung cancer risk values exceed WHO health-based guideline level of 10"−"5. • Carcinogenic risks due to preschool indoor exposure are higher than for outdoors. - This work fills gap providing information on levels, phase distribution (gas, PM_1, PM_2_._5) and risks of polycyclic aromatic hydrocarbons in indoor and outdoor air of preschool settings.

  7. Air quality perception of pedestrians in an urban outdoor Mediterranean environment: A field survey approach.

    Science.gov (United States)

    Pantavou, Katerina; Lykoudis, Spyridon; Psiloglou, Basil

    2017-01-01

    Perception plays a significant role on people's response to preventive measures. In the view of public awareness, the aim of this study was to explore factors that affect air quality perception and to reveal its potential patterns. Air quality perception of individuals, in terms of dust and overall air quality, was examined in relation to air pollutants concentrations, meteorological variables, personal characteristics as well as their thermal sensation and health condition. The data used were obtained from environmental measurements, in situ and from stations, and questionnaire surveys conducted in an outdoor urban Mediterranean area, Athens, Greece. The participants were asked to report their air quality perception and thermal sensation based on predefined scales. A thermal index, Physiological Equivalent Temperature (PET), was estimated to obtain an objective measure of thermal sensation. Particulate matter (PM 10 ) and nitrogen oxide (NO) were associated with dust perception. Nitrogen oxides (NO x ) and carbon monoxide (CO) were associated to air quality perception. Age, area of residence, health symptoms and thermal sensation also affected the perception of air quality. Dusty or poor air quality conditions were more likely to be reported when pollutants' concentrations were increased. Younger people, participants residing in the city center, experiencing health symptoms or warm thermal sensation showed a trend towards reporting more unfavorable air quality conditions. Copyright © 2016 Elsevier B.V. All rights reserved.

  8. Exposure to Outdoor Air Pollution and Chronic Bronchitis in Adults: A Case-Control Study

    Directory of Open Access Journals (Sweden)

    P Salameh

    2012-08-01

    Full Text Available Background: Although Lebanon is a highly polluted country, so far no study has specifically been designed to assess the association between outdoor air pollution and chronic bronchitis in this country. Objective: To assess the association between exposure to outdoor air pollution and chronic bronchitis in Lebanon. Methods: A pilot case-control study was conducted in two tertiary care hospitals. Cases consisted of patients diagnosed with chronic bronchitis by a pulmonologist and those epidemiologically confirmed. Controls included individuals free of any respiratory signs or symptoms. After obtaining informed consent, a standardized questionnaire was administered. Results: Bivariate, stratified (over smoking status and gender and multivariate analyses revealed that passive smoking at home (ORa: 2.56, 95% CI: 1.73–3.80 and at work (ORa: 1.89, 95% CI: 1.13–3.17; older age (ORa: 1.75, 95% CI: 1.55–2.39; lower education (ORa: 1.44, 95% CI: 1.21–1.72; living close to a busy road (ORa: 1.95, 95% CI: 1.31– 2.89 and to a local power plant (ORa: 1.62, 95% CI: 1.07–2.45; and heating home by hot air conditioning (ORa: 1.85, 95% CI: 1.00–3.43 were moderately associated with chronic bronchitis; an inverse association was found with heating home electrically (ORa: 0.58, 95% CI: 0.39–0.85. A positive dose-effect relationship was observed in those living close to a busy road and to a local diesel exhaust source. Conclusion: Chronic bronchitis is associated with outdoor air pollution.

  9. Implications of chiral signatures of PCBs in soil, outdoor, and indoor air in the West Midlands conurbation, UK

    Energy Technology Data Exchange (ETDEWEB)

    Jamshidi, A.; Hazrati, S.; Harrad, S. [Birmigham Univ., Birmingham (United Kingdom)

    2005-07-01

    This paper provided additional data related to a study conducted to determine chiral signatures of polychlorinated biphenyl (PCBs) in outdoor air and topsoil from urban, rural and semi-urban locations in the United Kingdom's West Midlands conurbation. The study hypothesized that the ventilation of PCB-contaminated indoor air was a principal source of the racemic PCBs observed in outdoor air. Measurements of chiral signatures of PCBs in indoor air were measured. Chiral signatures of PCB 136 and 149 were expressed in terms of enantiomeric excess. Outdoor air and soil samples were collected from 10 sites located on a southwest to northeast transect of the conurbation at intervals of between 3 and 17 km. Topsoil and air samples were collected on a monthly basis to examine seasonal variability. Passive air samplers were used to provide a time-integrated atmospheric signal over each sampling period. Twenty indoor air samples were collected using PUF disk samplers. All samples were then extracted, purified, and subjected to enantioselective gas chromatography and mass spectrometry (GC-MS) analysis. Results suggested that chiral signatures in outdoor air for all target PCBs were racemic at all locations, and confirmed earlier hypotheses that the ventilation of PCB-contaminated indoor air is the principal source of PCB contamination in the urban atmosphere. It was concluded that actions to reduce PCB stocks remaining in use in indoor environments will result in a significant reduction in atmospheric concentrations. 7 refs., 2 tabs., 1 fig.

  10. Outdoor air pollution, exhaled 8-isoprostane and current asthma in adults: the EGEA study.

    Science.gov (United States)

    Havet, Anaïs; Zerimech, Farid; Sanchez, Margaux; Siroux, Valérie; Le Moual, Nicole; Brunekreef, Bert; Stempfelet, Morgane; Künzli, Nino; Jacquemin, Bénédicte; Matran, Régis; Nadif, Rachel

    2018-04-01

    Associations between outdoor air pollution and asthma in adults are still scarce, and the underlying biological mechanisms are poorly understood. Our aim was to study the associations between 1) long-term exposure to outdoor air pollution and current asthma, 2) exhaled 8-isoprostane (8-iso; a biomarker related to oxidative stress) and current asthma, and 3) outdoor air pollution and exhaled 8-iso.Cross-sectional analyses were conducted in 608 adults (39% with current asthma) from the first follow-up of the French case-control and family study on asthma (EGEA; the Epidemiological study of the Genetic and Environmental factors of Asthma). Data on nitrogen dioxide, nitrogen oxides, particulate matter with a diameter ≤10 and ≤2.5 µm (PM 10 and PM 2.5 ), road traffic, and ozone (O 3 ) were from ESCAPE (European Study of Cohorts for Air Pollution Effects) and IFEN (French Institute for the Environment) assessments. Models took account of city and familial dependence.The risk of current asthma increased with traffic intensity (adjusted (a)OR 1.09 (95% CI 1.00-1.18) per 5000 vehicles per day), with O 3 exposure (aOR 2.04 (95% CI 1.27-3.29) per 10 µg·m -3 ) and with exhaled 8-iso concentration (aOR 1.50 (95% CI 1.06-2.12) per 1 pg·mL -1 ). Among participants without asthma, exhaled 8-iso concentration increased with PM 2.5 exposure (adjusted (a)β 0.23 (95% CI 0.005-0.46) per 5 µg·m -3 ), and decreased with O 3 and O 3-summer exposures (aβ -0.20 (95% CI -0.39- -0.01) and aβ -0.52 (95% CI -0.77- -0.26) per 10 µg·m -3 , respectively).Our results add new insights into a potential role of oxidative stress in the associations between outdoor air pollution and asthma in adults. Copyright ©ERS 2018.

  11. Experimental analysis of an air-to-air heat recovery unit for balanced ventilation systems in residential buildings

    International Nuclear Information System (INIS)

    Fernandez-Seara, Jose; Diz, Ruben; Uhia, Francisco J.; Dopazo, Alberto; Ferro, Jose M.

    2011-01-01

    This paper deals with the experimental analysis of an air-to-air heat recovery unit equipped with a sensible polymer plate heat exchanger (PHE) for balanced ventilation systems in residential buildings. The PHE is arranged in parallel triangular ducts. An experimental facility was designed to reproduce the typical outdoor and exhaust air conditions with regard to temperature and humidity. The unit was tested under balanced operation conditions, as commonly used in practice. A set of tests was conducted under the reference operating conditions to evaluate the PHE performance. Afterwards, an experimental parametric analysis was conducted to investigate the influence of changing the operating conditions on the PHE performance. Experiments were carried out varying the inlet fresh air temperature, the exhaust air relative humidity and the air flow rate. The experimental results are shown and discussed in this paper.

  12. Outdoor and indoor air quality and cognitive ability in young children.

    Science.gov (United States)

    Midouhas, Emily; Kokosi, Theodora; Flouri, Eirini

    2018-02-01

    This study examined outdoor and indoor air quality at ages 9 months and 3 years and their association with cognitive ability at age 3 in England and Wales. Data from 8198 Millennium Cohort Study children were analysed using multilevel regression. Outdoor air quality was assessed with mean annual estimates of nitrogen dioxide (NO 2 ) levels within a standard small area (ward). Indoor air quality was measured with parent-reports of damp or condensation in the home and exposure to secondhand smoke in the home. Cognitive ability was assessed with the British Ability Scales Naming Vocabulary subscale and the Bracken School Readiness Assessment. In adjusted models, consistent exposure to high levels of NO 2 at age 9 months and age 3 years was associated with lower verbal ability at age 3 years. Damp/condensation and secondhand smoke in the home at either age or at both ages were correlated with lower school readiness at age 3 years. Exposures to damp/condensation at age 3 years or at both ages and secondhand smoke at either age or at both ages were associated with lower verbal ability at age 3 years. Young children's exposures to indoor damp or condensation and secondhand smoke are likely to be detrimental for their cognitive outcomes. However, there do not appear to be any short-term effects of NO 2 . Copyright © 2017 Elsevier Inc. All rights reserved.

  13. Continual monitoring of radon decay products concentration in indoor and outdoor air

    International Nuclear Information System (INIS)

    Petruf, P.; Holy, K.; Stanys, T.

    1998-01-01

    The goal of this work was the development of the method and construction and testing of measurement device for continual monitoring of radon daughters concentrations in the indoor and outdoor environment with regard to make possible to determine very low activities in the outdoor air (below % Bq/m 3 ). In this method air sample is drawn through the appropriate filter material. Radon and thoron daughters both attached and unattached on aerosols particles are collected on the filter surface and then the filter activity is counted. The silicon surface barrier detector with the active area of 200 mm 2 in monitor was used. The Millipore AW19-type filter was chosen and sampling rate of 30 l/min for collecting of the air samples. The determination of the individual activity concentrations in three-count method is based on the solution of the simultaneous equations describing the number of atoms of measured nuclides on the filter during and after sampling. The monitor was tested in three different environments (the average values of the activity concentrations of radon and its decay products in Bq/m 3 are given): in the basement of the building: 61.4 ± 5.0 of 222 Rn, 29.5 ± 2.8 of 218 Po, 14.1 ± 1.8 of 214 Pb and 12.1 ± 1.6 of 214 Bi; in the room on the second floor of the same building:22.2 ± 7.9 of 222 Rn, 7.3 ± 2.8 of 218 Po, 4.6 ± 1.9 of 214 Pb and 2.6 ± 1.2 of 214 Bi ; in the outdoor air in front of the building: 4.1 ± 2.7 of 222 Rn, 2.3 ± 0.9 of 218 Po, 1.5 ± 0.8 of 214 Pb and 1.4 ± 0.6 of 214 Bi. The results show a good agreement with expectations of the activity concentrations in three different environments. The monitor enables to determine low activity concentrations in the outdoor with an acceptable precision during one hour counting. The monitor can be used for the research of the correlation between the atmospheric stability and activity concentrations of radon decay products

  14. Adverse effect of outdoor air pollution on cardiorespiratory fitness in Chinese children

    Science.gov (United States)

    Gao, Yang; Chan, Emily Y. Y.; Zhu, Yingjia; Wong, Tze Wai

    2013-01-01

    Little is known about the health impact of air pollution on children's cardiovascular health. A cross-sectional study was conducted and data was analysed in 2048 Chinese schoolchildren (aged 8-10 years) in three districts of Hong Kong to examine the association between exposure to outdoor air pollution and cardiorespiratory fitness. Annual means of ambient PM10, SO2, NO2 and O3 from 1996 to 2003 were used to estimate individual exposure of the subjects. Cardiorespiratory fitness was measured for maximal oxygen uptake (VO2max), predicted by the multistage fitness test (MFT). Height and weight were measured and other potential confounders were collected with questionnaires. Analysis of covariance was performed to estimate the impact of air pollution on complete speed in the MFT and predicted VO2max. The results showed that children in high-pollution district had significantly lower complete speed and predicted VO2max compared to those in low- and moderate-pollution districts. Complete speed and predicted VO2max was estimated to reduce 0.327 km h-1 and 1.53 ml kg-1 min-1 per 10 μg m-3 increase in PM10 annual mean respectively, with those in girls being greater than in boys. Being physically active could not significantly result in improved cardiorespiratory fitness in polluted districts. The adverse effect seems to be independent of short-term exposure to air pollution. We concluded that long-term exposure to higher outdoor air pollution levels was negatively associated with cardiorespiratory fitness in Chinese schoolchildren, especially for girls. PM10 is the most relevant pollutant of the adverse effect. Elevated cardiorespiratory fitness observed in physically activate children could be negated by increased amount of inhaled pollutants during exercise.

  15. Prenatal exposure to outdoor air pollution and child behavioral problems at school age in Japan.

    Science.gov (United States)

    Yorifuji, Takashi; Kashima, Saori; Diez, Midory Higa; Kado, Yoko; Sanada, Satoshi; Doi, Hiroyuki

    2017-02-01

    Recent studies suggest positive associations between prenatal exposure to ambient air pollution and neurodevelopment of children, but evidence on the adverse effects of exposure to air pollution on child neurobehavioral development remains limited. We thus examined associations between prenatal exposure to outdoor air pollution and child behavioral problems at school age, using data from a nationwide population-based longitudinal survey in Japan, where participants were recruited in 2001 and are continuously followed. Suspended particulate matter (SPM), nitrogen dioxide, and sulfur dioxide concentrations during the 9months before birth were obtained at municipality level and assigned to those participants born in the corresponding municipality. We analyzed data from singleton births with linked pollution data available (e.g., n=33,911 for SPM). We used responses to survey questions about behavioral problems at age 8years. We conducted multilevel logistic regression analysis, adjusting for individual and municipality-level variables. Air pollution exposure during gestation was positively associated with risk for behavioral problems related to attention and delinquent or aggressive behavior. In the fully adjusted models, odds ratios following a one-interquartile-range increase in SPM were 1.06 (95% confidence interval: 1.01, 1.11) for interrupting others, 1.09 (1.03, 1.15) for failure to pay attention when crossing a street, 1.06 (1.01, 1.11) for lying, and 1.07 (1.02, 1.13) for causing public disturbance. Prenatal exposure to outdoor air pollution was associated with behavioral problems related to attention and delinquent or aggressive behavior at age 8years in a nationally representative sample in Japan. Copyright © 2016 Elsevier Ltd. All rights reserved.

  16. Home outdoor models for traffic-related air pollutants do not represent personal exposure measurements in Southern California

    International Nuclear Information System (INIS)

    Ducret-Stich, R; Gemperli, A; Ineichen, A; Phuleria, H C; Delfino, R J; Tjoa, T; Wu, J; Liu, L-J S

    2009-01-01

    Recent studies have used measurements or estimates of traffic-related air pollutants at home or school locations to link associations between exposure and health. However, little is known about the validity of these outdoor concentrations as an estimate for personal exposure to traffic. This paper compares modelled outdoor concentrations at home with personal exposure to traffic air pollution of 63 children in two areas in Los Angeles in 2003/2004. Exposure monitoring consisted of sixteen 10-day monitoring runs, with each run monitoring 4 subjects concurrently with the active personal DataRAM for particulate matter 25 ), elemental carbon (EC) and organic carbon (OC). One child per run had concurrent indoor/outdoor home monitoring. Measurements at central sites (24-hr PM 25 , EC, OC) were taken daily and concentrations of PM 25 , EC, and OC from traffic sources were calculated using the CALINE4 model for individual residences. We modelled outdoor concentrations of PM 2 5 , EC and OC with multilinear regression including GIS and meteorological parameters and adjusted for auto-correlation between repeated measurements. The model fit (R 2 ) for home outdoor estimates was 0.94, 0.74 and 0.80 for PM 25 , EC and OC, respectively. Comparisons between these outdoor estimates and the personal measurements showed a good agreement for PM 25 (R 2 =0.65-0.70) with a mean bias of -0.7±11.8|ag for the smog receptor area, and 18.9±16.2|ag for the traffic impacted area. However the outdoor estimates were not related to personal exposure for EC (R 2 =0.01-0.29) and OC (R 2 =0.03- 0.14). Conclusions: Predictions of outdoor concentrations can be used as approximations of personal exposure to PM 25 . However, they are not appropriate for estimating personal exposure to traffic-related air pollutants including EC and OC in studies of acute exposure-response relationships.

  17. Indoor and Outdoor Air Pollution- related Health Problem in Ethiopia: Review of Related Literature.

    Science.gov (United States)

    Tefera, Worku; Asfaw, Araya; Gilliland, Frank; Worku, Alemayehu; Wondimagegn, Mehari; Kumie, Abera; Samet, Jonathan; Berhane, Kiros

    2016-01-01

    worsening outdoor air pollution. This tentative conclusion carries with it the urgent need for more evidence-based research and capacity building in the areas of indoor and outdoor air pollution.

  18. [Measurement of Chemical Compounds in Indoor and Outdoor Air in Chiba City Using Diffusive Sampling Devices].

    Science.gov (United States)

    Sakamoto, Hironari; Uchiyama, Shigehisa; Kihara, Akiko; Tsutake, Toyoshige; Bekki, Kanae; Inaba, Yohei; Nakagome, Hideki; Kunugita, Naoki

    2015-01-01

    Indoor air quality (IAQ) is a major concern, because people on average spend the vast majority of their time indoors and they are repeatedly exposed to indoor air pollutants. In this study, to assess indoor air quality in Chiba City, gaseous chemical compounds were surveyed using four types of diffusive sampler. Gaseous chemical compounds such as carbonyls, volatile organic compounds (VOC), acid gases, basic gases, and ozone were measured in indoor and outdoor air of 50 houses throughout Chiba City in winter and summer. Four types of diffusive sampler were used in this study: DSD-BPE/DNPH packed with 2,4-dinitrophenyl hydrazine and trans-1,2-bis(2-pyridyl)ethylene-coated silica for ozone and carbonyls; VOC-SD packed with Carboxen 564 particles for volatile organic compounds; DSD-TEA packed with triethanolamine-impregnated silica for acid gases; and DSD-NH3 packed with phosphoric acid-impregnated silica for basic gases. Almost all compounds in indoor air were detected at higher concentrations in summer than in winter. However, the nitrogen dioxide concentration in indoor air particularly increased only in winter, which well correlated with the formic acid concentration (correlation coefficient=0.974). The compound with the highest concentrations in indoor air was p-dichlorobenzene, with recorded levels of 13,000 μg m(-3) in summer and 1,100 μg m(-3) in winter in indoor air. p-Dichlorobenzene in summer and nitrogen dioxide in winter are detected at markedly high concentrations. Pollution control and continuous monitoring of IAQ are indispensable for human health.

  19. The Los Angeles TEAM Study: personal exposures, indoor-outdoor air concentrations, and breath concentrations of 25 volatile organic compounds.

    Science.gov (United States)

    Wallace, L; Nelson, W; Ziegenfus, R; Pellizzari, E; Michael, L; Whitmore, R; Zelon, H; Hartwell, T; Perritt, R; Westerdahl, D

    1991-04-01

    The U.S. Environmental Protection Agency and the California Air Resources Board studied the exposures of 51 residents of Los Angeles, California, to 25 volatile organic chemicals (VOCs) in air and drinking water in 1987. A major goal of the study was to measure personal, indoor, and outdoor air concentrations, and breath concentrations of VOCs in persons living in households that had previously been measured in 1984. Other goals were to confirm the marked day-night and seasonal differences observed in 1984; to determine room-to-room variability within homes; to determine source emission rates by measuring air exchange rates in each home; and to extend the coverage of chemicals by employing additional sampling and analysis methods. A total of 51 homes were visited in February of 1987, and 43 of these were revisited in July of 1987. The results confirmed previous TEAM Study findings of higher personal and indoor air concentrations than outdoor concentrations of all prevalent chemicals (except carbon tetrachloride); higher personal, indoor, and outdoor air concentrations in winter than in summer; and (in winter only) higher outdoor concentrations at night than in the daytime. New findings included the following: (1) room-to-room variability of 12-hour average concentrations was very small, indicating that a single monitor may be adequate for estimating indoor concentrations over this time span; (2) "whole-house" source emission rates were relatively constant during both seasons, with higher rates for odorous chemicals such as p-dichlorobenzene and limonene (often used in room air fresheners) than for other classes of chemicals; (3) breath concentrations measured during morning and evening were similar for most participants, suggesting the suitability of breath measurements for estimating exposure in the home; (4) limited data obtained on two additional chemicals-toluene and methylene chloride-indicated that both were prevalent at fairly high concentrations and that

  20. A Critical Review of Naphthalene Sources and Exposures Relevant to Indoor and Outdoor Air

    Directory of Open Access Journals (Sweden)

    Chunrong Jia

    2010-07-01

    Full Text Available Both the recent classification of naphthalene as a possible human carcinogen and its ubiquitous presence motivate this critical review of naphthalene’s sources and exposures. We evaluate the environmental literature on naphthalene published since 1990, drawing on nearly 150 studies that report emissions and concentrations in indoor, outdoor and personal air. While naphthalene is both a volatile organic compound and a polycyclic aromatic hydrocarbon, concentrations and exposures are poorly characterized relative to many other pollutants. Most airborne emissions result from combustion, and key sources include industry, open burning, tailpipe emissions, and cigarettes. The second largest source is off-gassing, specifically from naphthalene’s use as a deodorizer, repellent and fumigant. In the U.S., naphthalene’s use as a moth repellant has been reduced in favor of para-dichlorobenzene, but extensive use continues in mothballs, which appears responsible for some of the highest indoor exposures, along with off-label uses. Among the studies judged to be representative, average concentrations ranged from 0.18 to 1.7 μg m-3 in non-smoker’s homes, and from 0.02 to 0.31 μg m-3 outdoors in urban areas. Personal exposures have been reported in only three European studies. Indoor sources are the major contributor to (non-occupational exposure. While its central tendencies fall well below guideline levels relevant to acute health impacts, several studies have reported maximum concentrations exceeding 100 μg m-3, far above guideline levels. Using current but draft estimates of cancer risks, naphthalene is a major environmental risk driver, with typical individual risk levels in the 10-4 range, which is high and notable given that millions of individuals are exposed. Several factors influence indoor and outdoor concentrations, but the literature is inconsistent on their effects. Further investigation is needed to better characterize naphthalene

  1. Respiratory disease in relation to outdoor air pollution in Kanpur, India.

    Science.gov (United States)

    Liu, Hai-Ying; Bartonova, Alena; Schindler, Martin; Sharma, Mukesh; Behera, Sailesh N; Katiyar, Kamlesh; Dikshit, Onkar

    2013-01-01

    This paper examines the effect of outdoor air pollution on respiratory disease in Kanpur, India, based on data from 2006. Exposure to air pollution is represented by annual emissions of sulfur dioxide (SO(2)), particulate matter (PM), and nitrogen oxides (NO(x)) from 11 source categories, established as a geographic information system (GIS)-based emission inventory in 2 km × 2 km grid. Respiratory disease is represented by number of patients who visited specialist pulmonary hospital with symptoms of respiratory disease. The results showed that (1) the main sources of air pollution are industries, domestic fuel burning, and vehicles; (2) the emissions of PM per grid are strongly correlated to the emissions of SO(2) and NO(x); and (3) there is a strong correlation between visits to a hospital due to respiratory disease and emission strength in the area of residence. These results clearly indicate that appropriate health and environmental monitoring, actions to reduce emissions to air, and further studies that would allow assessing the development in health status are necessary.

  2. Applying a novel extra-low temperature dedicated outdoor air system in office buildings for energy efficiency and thermal comfort

    International Nuclear Information System (INIS)

    Li, Han; Lee, W.L.; Jia, Jie

    2016-01-01

    Highlights: • A novel dedicated outdoor air system was proposed and investigated. • The proposed system adopts extra-low temperature outdoor air for space cooling. • The extra-low temperature air was generated by a multi-stage direct expansion coil. • Heat pipe was added to the proposed system to recover the waste cooling energy. • Energy and exergy analysis as well as thermal comfort analysis were conducted. - Abstract: A novel dedicated outdoor air system consisting of a multi-stage direct expansion coil and a zero-energy heat pipe to generate extra-low temperature outdoor air to avoid moisture-related problems was proposed in this study. The proposed system’s performance in achieving the desirable air conditions and better energy efficiency objectives is compared with a conventional direct expansion system for air-conditioning of a typical office building in Hong Kong based on simulation investigations. The simulations were carried out using equipment performance data of a pilot study, and realistic building and system characteristics. It was found that the proposed system, as compared to the conventional system, could reduce the annual indoor discomfort hours by 69.4%. An energy and exergy analysis was also conducted. It was revealed that the proposed system could reduce the annual air-conditioning energy use by 15.6% and the system exergy loss rate by 13.6%. The associated overall exergy efficiency was also found 18.6% higher. The findings of this study confirm that the proposed system is better than the conventional system in terms of both energy and exergy efficiency and the desirable air conditions.

  3. Comparison of background levels of culturable fungal spore concentrations in indoor and outdoor air in southeastern Austria

    Science.gov (United States)

    Haas, D.; Habib, J.; Luxner, J.; Galler, H.; Zarfel, G.; Schlacher, R.; Friedl, H.; Reinthaler, F. F.

    2014-12-01

    Background concentrations of airborne fungi are indispensable criteria for an assessment of fungal concentrations indoors and in the ambient air. The goal of this study was to define the natural background values of culturable fungal spore concentrations as reference values for the assessment of moldy buildings. The concentrations of culturable fungi were determined outdoors as well as indoors in 185 dwellings without visible mold, obvious moisture problems or musty odor. Samples were collected using the MAS-100® microbiological air sampler. The study shows a characteristic seasonal influence on the background levels of Cladosporium, Penicillium and Aspergillus. Cladosporium sp. had a strong outdoor presence, whereas Aspergillus sp. and Penicillium sp. were typical indoor fungi. For the region of Styria, the median outdoor concentrations are between 100 and 940 cfu/m³ for culturable xerophilic fungi in the course of the year. Indoors, median background levels are between 180 and 420 cfu/m³ for xerophilic fungi. The I/O ratios of the airborne fungal spore concentrations were between 0.2 and 2.0. For the assessment of indoor and outdoor air samples the dominant genera Cladosporium, Penicillium and Aspergillus should receive special consideration.

  4. Wireless Information-Theoretic Security in an Outdoor Topology with Obstacles: Theoretical Analysis and Experimental Measurements

    Directory of Open Access Journals (Sweden)

    Dagiuklas Tasos

    2011-01-01

    Full Text Available This paper presents a Wireless Information-Theoretic Security (WITS scheme, which has been recently introduced as a robust physical layer-based security solution, especially for infrastructureless networks. An autonomic network of moving users was implemented via 802.11n nodes of an ad hoc network for an outdoor topology with obstacles. Obstructed-Line-of-Sight (OLOS and Non-Line-of-Sight (NLOS propagation scenarios were examined. Low-speed user movement was considered, so that Doppler spread could be discarded. A transmitter and a legitimate receiver exchanged information in the presence of a moving eavesdropper. Average Signal-to-Noise Ratio (SNR values were acquired for both the main and the wiretap channel, and the Probability of Nonzero Secrecy Capacity was calculated based on theoretical formula. Experimental results validate theoretical findings stressing the importance of user location and mobility schemes on the robustness of Wireless Information-Theoretic Security and call for further theoretical analysis.

  5. Global premature mortality due to anthropogenic outdoor air pollution and the contribution of past climate change

    International Nuclear Information System (INIS)

    Silva, Raquel A; West, J Jason; Zhang Yuqiang; Anenberg, Susan C; Lamarque, Jean-François; Shindell, Drew T; Faluvegi, Greg; Collins, William J; Dalsoren, Stig; Skeie, Ragnhild; Folberth, Gerd; Rumbold, Steven; Horowitz, Larry W; Nagashima, Tatsuya; Naik, Vaishali; Sudo, Kengo; Takemura, Toshihiko; Bergmann, Daniel; Cameron-Smith, Philip; Cionni, Irene

    2013-01-01

    Increased concentrations of ozone and fine particulate matter (PM 2.5 ) since preindustrial times reflect increased emissions, but also contributions of past climate change. Here we use modeled concentrations from an ensemble of chemistry–climate models to estimate the global burden of anthropogenic outdoor air pollution on present-day premature human mortality, and the component of that burden attributable to past climate change. Using simulated concentrations for 2000 and 1850 and concentration–response functions (CRFs), we estimate that, at present, 470 000 (95% confidence interval, 140 000 to 900 000) premature respiratory deaths are associated globally and annually with anthropogenic ozone, and 2.1 (1.3 to 3.0) million deaths with anthropogenic PM 2.5 -related cardiopulmonary diseases (93%) and lung cancer (7%). These estimates are smaller than ones from previous studies because we use modeled 1850 air pollution rather than a counterfactual low concentration, and because of different emissions. Uncertainty in CRFs contributes more to overall uncertainty than the spread of model results. Mortality attributed to the effects of past climate change on air quality is considerably smaller than the global burden: 1500 (−20 000 to 27 000) deaths yr −1 due to ozone and 2200 (−350 000 to 140 000) due to PM 2.5 . The small multi-model means are coincidental, as there are larger ranges of results for individual models, reflected in the large uncertainties, with some models suggesting that past climate change has reduced air pollution mortality. (letter)

  6. Outdoor air pollution and respiratory health: a bibliometric analysis of publications in peer-reviewed journals (1900 - 2017).

    Science.gov (United States)

    Sweileh, Waleed M; Al-Jabi, Samah W; Zyoud, Sa'ed H; Sawalha, Ansam F

    2018-01-01

    Outdoor air pollution is a major threat to global public health that needs responsible participation of researchers at all levels. Assessing research output is an important step in highlighting national and international contribution and collaboration in a certain field. Therefore, the aim of this study was to analyze globally-published literature in outdoor air pollution - related respiratory health. Outdoor air pollution documents related to respiratory health were retrieved from Scopus database. The study period was up to 2017. Mapping of author keywords was carried out using VOSviewer 1.6.6. Search query yielded 3635 documents with an h -index of 137. There was a dramatic increase in the number of publications in the last decade of the study period. The most frequently encountered author keywords were: air pollution (835 occurrences), asthma (502 occurrences), particulate matter (198 occurrences), and children (203 occurrences). The United States of America ranked first (1082; 29.8%) followed by the United Kingdom (279; 7.7%) and Italy (198; 5.4%). Annual research productivity stratified by income and population size indicated that China ranked first (22.2) followed by the USA (18.8). Analysis of regional distribution of publications indicated that the Mediterranean, African, and South-East Asia regions had the least contribution. Harvard University (92; 2.5%) was the most active institution/organization followed the US Environmental Protection Agency (89; 2.4%). International collaboration was restricted to three regions: Northern America, Europe, and Asia. The top ten preferred journals were in the field of environmental health and respiratory health. Environmental Health Perspective was the most preferred journal for publishing documents in outdoor pollution in relation to respiratory health. Research on the impact of outdoor air pollution on respiratory health had accelerated lately and is receiving a lot of interest. Global research networks that include

  7. The performance and subjective responses of call-center operators with new and used supply air filters at two outdoor air supply rates

    DEFF Research Database (Denmark)

    Wargocki, Pawel; Wyon, David; Fanger, Povl Ole

    2004-01-01

    A 2X2 replicated field intervention experiment was conducted in a call-center providing a telephone directory service: outdoor air supply rate was adjusted to be 8% of the total airflow of 430 l/s (3.5/h)and the supply air filters were either new or had been in place for 6 months. One of these in......A 2X2 replicated field intervention experiment was conducted in a call-center providing a telephone directory service: outdoor air supply rate was adjusted to be 8% of the total airflow of 430 l/s (3.5/h)and the supply air filters were either new or had been in place for 6 months. One...

  8. Primary energy savings in desiccant and evaporative cooling-assisted 100% outdoor air system combined with a fuel cell

    International Nuclear Information System (INIS)

    Kim, Min-Hwi; Dong, Hae-Won; Park, Joon-Young; Jeong, Jae-Weon

    2016-01-01

    Highlights: • A LD-IDECOAS integrated with a PEMFC was proposed. • A pilot system was installed and tested during cooling operation. • The proposed system powered by the PEMFC saved 21% of the primary energy consumption during cooling. - Abstract: The main purpose of this study involved investigating the primary energy saving potential of a liquid desiccant and evaporative cooling-assisted 100% outdoor air system (LD-IDECOAS) integrated with a proton exchange membrane fuel cell (PEMFC). During the cooling season, the heat produced by the PEMFC was used to regenerate a weak desiccant solution, and the electricity generated was used to operate the LD-IDECOAS. A pilot LD-IDECOAS powered by a PEMFC was installed and operated in an office space to experimentally verify the annual operating energy savings of the proposed system. The findings indicated that the heat reclaimed from the PEMFC saved 42% of the desiccant solution regenerating energy when compared to that in the case of a conventional gas-fired water heater. The results also suggested that the LD-IDECOAS combined with a PEMFC consumed 21% less primary energy when compared with that of a system powered by grid electricity and a conventional gas-fired water heater.

  9. Analytical method for the evaluation of the outdoor air contamination by emerging pollutants using tree leaves as bioindicators.

    Science.gov (United States)

    Barroso, Pedro José; Martín, Julia; Santos, Juan Luis; Aparicio, Irene; Alonso, Esteban

    2018-01-01

    In this work, an analytical method, based on sonication-assisted extraction, clean-up by dispersive solid-phase extraction and determination by liquid chromatography-tandem mass spectrometry, has been developed and validated for the simultaneous determination of 15 emerging pollutants in leaves from four ornamental tree species. Target compounds include perfluorinated organic compounds, plasticizers, surfactants, brominated flame retardant, and preservatives. The method was optimized using Box-Behnken statistical experimental design with response surface methodology and validated in terms of recovery, accuracy, precision, and method detection and quantification limits. Quantification of target compounds was carried out using matrix-matched calibration curves. The highest recoveries were achieved for the perfluorinated organic compounds (mean values up to 87%) and preservatives (up to 88%). The lowest recoveries were achieved for plasticizers (51%) and brominated flame retardant (63%). Method detection and quantification limits were in the ranges 0.01-0.09 ng/g dry matter (dm) and 0.02-0.30 ng/g dm, respectively, for most of the target compounds. The method was successfully applied to the determination of the target compounds on leaves from four tree species used as urban ornamental trees (Citrus aurantium, Celtis australis, Platanus hispanica, and Jacaranda mimosifolia). Graphical abstract Analytical method for the biomonitorization of emerging pollutants in outdoor air.

  10. Relationship of Indoor, Outdoor and Personal Air (RIOPA) study: study design, methods and quality assurance/control results.

    Science.gov (United States)

    Weisel, Clifford P; Zhang, Junfeng; Turpin, Barbara J; Morandi, Maria T; Colome, Steven; Stock, Thomas H; Spektor, Dalia M; Korn, Leo; Winer, Arthur; Alimokhtari, Shahnaz; Kwon, Jaymin; Mohan, Krishnan; Harrington, Robert; Giovanetti, Robert; Cui, William; Afshar, Masoud; Maberti, Silvia; Shendell, Derek

    2005-03-01

    The Relationship of Indoor, Outdoor and Personal Air (RIOPA) Study was undertaken to evaluate the contribution of outdoor sources of air toxics, as defined in the 1990 Clean Air Act Amendments, to indoor concentrations and personal exposures. The concentrations of 18 volatile organic compounds (VOCs), 17 carbonyl compounds, and fine particulate matter mass (PM(2.5)) were measured using 48-h outdoor, indoor and personal air samples collected simultaneously. PM2.5 mass, as well as several component species (elemental carbon, organic carbon, polyaromatic hydrocarbons and elemental analysis) were also measured; only PM(2.5) mass is reported here. Questionnaires were administered to characterize homes, neighborhoods and personal activities that might affect exposures. The air exchange rate was also measured in each home. Homes in close proximity (<0.5 km) to sources of air toxics were preferentially (2:1) selected for sampling. Approximately 100 non-smoking households in each of Elizabeth, NJ, Houston, TX, and Los Angeles, CA were sampled (100, 105, and 105 respectively) with second visits performed at 84, 93, and 81 homes in each city, respectively. VOC samples were collected at all homes, carbonyls at 90% and PM(2.5) at 60% of the homes. Personal samples were collected from nonsmoking adults and a portion of children living in the target homes. This manuscript provides the RIOPA study design and quality control and assurance data. The results from the RIOPA study can potentially provide information on the influence of ambient sources on indoor air concentrations and exposure for many air toxics and will furnish an opportunity to evaluate exposure models for these compounds.

  11. Estimating cancer risk from outdoor concentrations of hazardous air pollutants in 1990

    Energy Technology Data Exchange (ETDEWEB)

    Woodruff, T.J.; Caldwell, J.; Cogliano, V.J.; Axelrad, D.A.

    2000-03-01

    A public health concern regarding hazardous air pollutants (HAPs) is their potential to cause cancer. It has been difficult to assess potential cancer risks from HAPs, due primarily to lack of ambient concentration data for the general population. The Environmental Protection Agency's Cumulative Exposure Project modeled 1990 outdoor concentrations of HAPs across the United States, which were combined with inhalation unit risk estimates to estimate the potential increase in excess cancer risk for individual carcinogenic HAPs. These were summed3d to provide an estimate of cancer risk from multiple HAPs. The analysis estimates a median excess cancer risk of 18 lifetime cancer cases per 100,000 people for all HAP concentrations. About 75% of estimated cancer risk was attributable to exposure to polycyclic organic matter, 1,3-butadiene, formaldehyde, benzene, and chromium. Consideration of some specific uncertainties, including underestimation of ambient concentrations, combining upper 95% confidence bound potency estimates, and changes to potency estimates, found that cancer risk may be underestimated by 15% or overestimated by 40--50%. Other unanalyzed uncertainties could make these under- or overestimates larger. This analysis used 1990 estimates of concentrations and can be used to track progress toward reducing cancer risk to the general population.

  12. Out-of-hospital cardiac arrests and outdoor air pollution exposure in Copenhagen, Denmark.

    Directory of Open Access Journals (Sweden)

    Janine Wichmann

    Full Text Available Cardiovascular disease is the number one cause of death globally and air pollution can be a contributing cause. Acute myocardial infarction and cardiac arrest are frequent manifestations of coronary heart disease. The objectives of the study were to investigate the association between 4 657 out-of-hospital cardiac arrests (OHCA and hourly and daily outdoor levels of PM(10, PM(2.5, coarse fraction of PM (PM(10-2.5, ultrafine particle proxies, NO(x, NO(2, O(3 and CO in Copenhagen, Denmark, for the period 2000-2010. Susceptible groups by age and sex was also investigated. A case-crossover design was applied. None of the hourly lags of any of the pollutants were significantly associated with OHCA events. The strongest association with OHCA events was observed for the daily lag4 of PM(2.5, lag3 of PM(10, lag3 of PM(10-2.5, lag3 of NO(x and lag4 of CO. An IQR increase of PM(2.5 and PM(10 was associated with a significant increase of 4% (95% CI: 0%; 9% and 5% (95% CI: 1%; 9% in OHCA events with 3 days lag, respectively. None of the other daily lags or other pollutants was significantly associated with OHCA events. Adjustment for O(3 slightly increased the association between OHCA and PM(2.5 and PM(10. No susceptible groups were identified.

  13. Outdoor air pollution, genetic susceptibility, and asthma management: opportunities for intervention to reduce the burden of asthma.

    Science.gov (United States)

    Gilliland, Frank D

    2009-03-01

    Outdoor air pollution at levels occurring in many urban areas around the world has substantial adverse effects on health. Children in general, and children with asthma in particular, are sensitive to the adverse effects of outdoor air pollutants, including ozone, nitrogen oxides, and respirable particulate matter. A growing number of studies also show that children living in environments near traffic have increased risks of new-onset asthma, asthma symptoms, exacerbations, school absences, and asthma-related hospitalizations. The large population of children exposed to high levels of outdoor air pollutants and the substantial risks for adverse health effects present unexploited opportunities to reduce the burden of asthma. Because the evidence indicates significant adverse effects of air pollution at current levels, there is clearly a need to reduce levels of regulated pollutants such as ozone, as well as unregulated pollutants in tailpipe emissions from motor vehicles. Achieving this long-term goal requires the active involvement of physicians and medical providers to ensure that the health of children is at the top of the list of competing priorities for regulatory policy decision-making. Clinical approaches include treatment to control asthma and patient education to reduce adverse effects of the disease. Reduction in exposures also can be approached at a policy level through changes in schools and school bus operations. Beyond clinical and public health approaches to reduce exposure, another strategy to be used before clean air goals are met is to decrease the susceptibility of children to air pollution. Emerging research indicates that dietary supplementation for individuals with low antioxidant levels is one promising approach to reducing susceptibility to air pollution. A second approach involves induction of enzymatic antioxidant defenses, especially for individuals with at-risk genetic variants of key antioxidant enzymes.

  14. Currently Commercially Available Chemical Sensors Employed for Detection of Volatile Organic Compounds in Outdoor and Indoor Air

    OpenAIRE

    Bartosz Szulczyński; Jacek Gębicki

    2017-01-01

    The paper presents principle of operation and design of the most popular chemical sensors for measurement of volatile organic compounds (VOCs) in outdoor and indoor air. It describes the sensors for evaluation of explosion risk including pellistors and IR-absorption sensors as well as the sensors for detection of toxic compounds such as electrochemical (amperometric), photoionization and semiconductor with solid electrolyte ones. Commercially available sensors for detection of VOCs and their ...

  15. Effectiveness of using pure copper and silver coupon corrosivity monitoring (CCM) metal strips to measure the severity levels of air pollutants in indoor and outdoor atmospheres

    CSIR Research Space (South Africa)

    Foax, LJ

    2008-10-01

    Full Text Available Severity levels of air pollutants rich in oxides, chlorides and sulphides were successfully measured in indoor and outdoor atmospheres using pure copper and silver coupon corrosivity monitoring (CCM) metal strips when the maximum exposure periods...

  16. Radiological characterisation and radon equilibrium factor in the outdoor air of a post-industrial urban area

    International Nuclear Information System (INIS)

    Rozas, S.; Idoeta, R.; Alegría, N.; Herranz, M.

    2016-01-01

    The radiological characterisation of outdoor air is always a complicated task due to the several radioactive emissions coming from the different radionuclides and also because of the very short half-lives of radionuclides in the natural radioactive series. In some places, this characterisation could result in unusual values because the natural presence of radionuclides with terrestrial origin can be modified by manmade activities. Nonetheless, this characterisation is useful not only for air quality control purposes but also because radon and its progeny in the outdoor air are the main contributors to human exposure from natural sources. In this study, we have carried out air particle sampling, followed by gamma-ray spectrometry, alpha spectrometry and beta counting determinations for this purpose. Subsequently, the outdoor air has been radiologically characterised through the obtained data and using a pre-existing analytical method to take into account the radioactive decays of short half-life radionuclides during sampling, sample preparation and measuring times. Bilbao was chosen to carry out this work. It is a medium-sized town located in northern Spain, close to the Atlantic Ocean and at sea level. This city has a recent industrial past as there were numerous steel mills and other heavy industries, including some quarries, and some open pit mines close to it, which concluded in a remediation program. So, it is a place where the air is potentially modified by manmade activities. The obtained results show that activity concentration values for long-lived radionuclides that precede radon and thoron are in the order of 10 −6  Bq m −3 and long-lived ones after radon are around 10 −4  Bq m −3 . Thoron progeny are around 2 × 10 −2  Bq m −3 and radon progeny are around 1.8 Bq m −3 . The mean radon equilibrium factor was 0.18. All of these values are close to the minimum UNSCEAR values, but show some variability, which highlights the importance

  17. Experimental apparatus to test air trap valves

    Science.gov (United States)

    Lemos De Lucca, Y. de F.; de Aquino, G. A.; Filho, J. G. D.

    2010-08-01

    It is known that the presence of trapped air within water distribution pipes can lead to irregular operation or even damage to the distribution systems and their components. The presence of trapped air may occur while the pipes are being filled with water, or while the pumping systems are in operation. The formation of large air pockets can produce the water hammer phenomenon, the instability and the loss of pressure in the water distribution networks. As a result, it can overload the pumps, increase the consumption of electricity, and damage the pumping system. In order to avoid its formation, all of the trapped air should be removed through "air trap valves". In Brazil, manufacturers frequently have unreliable sizing charts, which cause malfunctioning of the "air trap valves". The result of these malfunctions causes accidents of substantial damage. The construction of a test facility will provide a foundation of technical information that will be used to help make decisions when designing a system of pipelines where "air trap valves" are used. To achieve this, all of the valve characteristics (geometric, mechanic, hydraulic and dynamic) should be determined. This paper aims to describe and analyze the experimental apparatus and test procedure to be used to test "air trap valves". The experimental apparatus and test facility will be located at the University of Campinas, Brazil at the College of Civil Engineering, Architecture, and Urbanism in the Hydraulics and Fluid Mechanics laboratory. The experimental apparatus will be comprised of various components (pumps, steel pipes, butterfly valves to control the discharge, flow meter and reservoirs) and instrumentation (pressure transducers, anemometer and proximity sensor). It should be emphasized that all theoretical and experimental procedures should be defined while taking into consideration flow parameters and fluid properties that influence the tests.

  18. Experimental apparatus to test air trap valves

    Energy Technology Data Exchange (ETDEWEB)

    Lemos De Lucca, Y de F [CTH-DAEE-USP/FAAP/UNICAMP (Brazil); Aquino, G A de [SABESP/UNICAMP (Brazil); Filho, J G D, E-mail: yvone.lucca@gmail.co [Water Resources Department, University of Campinas-UNICAMP, Av. Albert Einstein, 951, Cidade Universitaria-Barao Geraldo-Campinas, S.P., 13083-852 (Brazil)

    2010-08-15

    It is known that the presence of trapped air within water distribution pipes can lead to irregular operation or even damage to the distribution systems and their components. The presence of trapped air may occur while the pipes are being filled with water, or while the pumping systems are in operation. The formation of large air pockets can produce the water hammer phenomenon, the instability and the loss of pressure in the water distribution networks. As a result, it can overload the pumps, increase the consumption of electricity, and damage the pumping system. In order to avoid its formation, all of the trapped air should be removed through 'air trap valves'. In Brazil, manufacturers frequently have unreliable sizing charts, which cause malfunctioning of the 'air trap valves'. The result of these malfunctions causes accidents of substantial damage. The construction of a test facility will provide a foundation of technical information that will be used to help make decisions when designing a system of pipelines where 'air trap valves' are used. To achieve this, all of the valve characteristics (geometric, mechanic, hydraulic and dynamic) should be determined. This paper aims to describe and analyze the experimental apparatus and test procedure to be used to test 'air trap valves'. The experimental apparatus and test facility will be located at the University of Campinas, Brazil at the College of Civil Engineering, Architecture, and Urbanism in the Hydraulics and Fluid Mechanics laboratory. The experimental apparatus will be comprised of various components (pumps, steel pipes, butterfly valves to control the discharge, flow meter and reservoirs) and instrumentation (pressure transducers, anemometer and proximity sensor). It should be emphasized that all theoretical and experimental procedures should be defined while taking into consideration flow parameters and fluid properties that influence the tests.

  19. Experimental demonstration of outdoor 2.2 Tbps super-channel FSO transmission system

    KAUST Repository

    Esmail, Maged Abdullah; Ragheb, Amr; Fathallah, Habib; Alouini, Mohamed-Slim

    2016-01-01

    Free space optic (FSO) is a wireless technology that promises high speed data rate with low deployment cost. Next generation wireless networks require more bandwidth which is not supported by todays wireless techniques. FSO can be a potential candidate for last mile bottle neck in wireless network and for many other applications. In this paper, we experimentally demonstrate a high speed FSO system using super-channel source and multi-format transmitter. The FSO system was installed outdoor on the building roof over 11.5 m distance and built using off-the-shelf components. We designed a comb source capable of generating multi-subcarriers with flexible spacing. Also we designed a multi-format transmitter capable of generating different complex modulation schemes. For single carrier transmission, we were able to transmit a 23 Gbaud 16-QAM signal over FSO link, achieving 320 Gbps with 6 b/s/Hz spectral efficiency. Then using our super-channel system, 12 equal gain subcarriers are generated and modulated by a DP-16QAM signal with different symbol rates. We achieved maximum symbol rate of 23 Gbaud (i.e. 2.2 Tbps) and spectral efficiency of 7.2 b/s/Hz. © 2016 IEEE.

  20. Experimental demonstration of outdoor 2.2 Tbps super-channel FSO transmission system

    KAUST Repository

    Esmail, Maged Abdullah

    2016-07-26

    Free space optic (FSO) is a wireless technology that promises high speed data rate with low deployment cost. Next generation wireless networks require more bandwidth which is not supported by todays wireless techniques. FSO can be a potential candidate for last mile bottle neck in wireless network and for many other applications. In this paper, we experimentally demonstrate a high speed FSO system using super-channel source and multi-format transmitter. The FSO system was installed outdoor on the building roof over 11.5 m distance and built using off-the-shelf components. We designed a comb source capable of generating multi-subcarriers with flexible spacing. Also we designed a multi-format transmitter capable of generating different complex modulation schemes. For single carrier transmission, we were able to transmit a 23 Gbaud 16-QAM signal over FSO link, achieving 320 Gbps with 6 b/s/Hz spectral efficiency. Then using our super-channel system, 12 equal gain subcarriers are generated and modulated by a DP-16QAM signal with different symbol rates. We achieved maximum symbol rate of 23 Gbaud (i.e. 2.2 Tbps) and spectral efficiency of 7.2 b/s/Hz. © 2016 IEEE.

  1. Seasonal impact of regional outdoor biomass burning on air pollution in three Indian cities: Delhi, Bengaluru, and Pune

    Science.gov (United States)

    Liu, Tianjia; Marlier, Miriam E.; DeFries, Ruth S.; Westervelt, Daniel M.; Xia, Karen R.; Fiore, Arlene M.; Mickley, Loretta J.; Cusworth, Daniel H.; Milly, George

    2018-01-01

    Air pollution in many of India's cities exceeds national and international standards, and effective pollution control strategies require knowledge of the sources that contribute to air pollution and their spatiotemporal variability. In this study, we examine the influence of a single pollution source, outdoor biomass burning, on particulate matter (PM) concentrations, surface visibility, and aerosol optical depth (AOD) from 2007 to 2013 in three of the most populous Indian cities. We define the upwind regions, or ;airsheds,; for the cities by using atmospheric back trajectories from the HYSPLIT model. Using satellite fire radiative power (FRP) observations as a measure of fire activity, we target pre-monsoon and post-monsoon fires upwind of the Delhi National Capital Region and pre-monsoon fires surrounding Bengaluru and Pune. We find varying contributions of outdoor fires to different air quality metrics. For the post-monsoon burning season, we find that a subset of local meteorological variables (air temperature, humidity, sea level pressure, wind speed and direction) and FRP as the only pollution source explained 39% of variance in Delhi station PM10 anomalies, 77% in visibility, and 30% in satellite AOD; additionally, per unit increase in FRP within the daily airshed (1000 MW), PM10 increases by 16.34 μg m-3, visibility decreases by 0.155 km, and satellite AOD increases by 0.07. In contrast, for the pre-monsoon burning season, we find less significant contributions from FRP to air quality in all three cities. Further, we attribute 99% of FRP from post-monsoon outdoor fires within Delhi's average airshed to agricultural burning. Our work suggests that although outdoor fires are not the dominant air pollution source in India throughout the year, post-monsoon fires contribute substantially to regional air pollution and high levels of population exposure around Delhi. During 3-day blocks of extreme PM2.5 in the 2013 post-monsoon burning season, which coincided

  2. First characterization of the endocrine-disrupting potential of indoor gaseous and particulate contamination: comparison with urban outdoor air (France).

    Science.gov (United States)

    Oziol, Lucie; Alliot, Fabrice; Botton, Jérémie; Bimbot, Maya; Huteau, Viviane; Levi, Yves; Chevreuil, Marc

    2017-01-01

    The composition of endocrine-disrupting compounds (EDCs) in the ambient air of indoor environments has already been described, but little is known about the inherent endocrine-disrupting potential of indoor air contamination. We therefore aimed to study the distribution of bioactive EDCs in the gaseous and particulate phases of indoor air using a cellular bioassay approach that integrates the interaction effects between chemicals. Organic air extracts, both gaseous and particulate, were taken from three indoor locations (office, apartment, and children's day care) in France and sampled in two different seasons in order to study their interference with the signaling of estrogen, androgen, and thyroid receptors. The experiments were also conducted on aerial extracts from an outdoor site (urban center). We found that gaseous and/or particulate extracts from all locations displayed estrogenicity, anti-androgenicity, and thyroidicity. Overall, indoor air extracts had a higher endocrine-disrupting potential compared to outdoor ones, especially during winter and in the day care. The biological activities were predominant for the gaseous extracts and tended to increase for the particulate extracts in cool conditions. In conclusion, our data confirmed the presence of bioactive EDCs in a gaseous state and highlighted their indoor origin and concentration, especially in the cold season.

  3. Monitoring of heavy metal concentrations in home outdoor air using moss bags

    Energy Technology Data Exchange (ETDEWEB)

    Rivera, Marcela, E-mail: arivera@creal.ca [Centre for Research in Environmental Epidemiology CREAL, Barcelona (Spain); Municipal Institute of Medical Research (IMIM-Hospital del Mar), Barcelona (Spain); Universitat Pompeu Fabra, Barcelona (Spain); CIBER Epidemiologia y Salud Publica (CIBERESP) (Spain); Zechmeister, Harald [University of Vienna, Faculty of Life Sciences, Vienna (Austria); Medina-Ramon, Mercedes; Basagana, Xavier [Centre for Research in Environmental Epidemiology CREAL, Barcelona (Spain); Municipal Institute of Medical Research (IMIM-Hospital del Mar), Barcelona (Spain); CIBER Epidemiologia y Salud Publica (CIBERESP) (Spain); Foraster, Maria [Centre for Research in Environmental Epidemiology CREAL, Barcelona (Spain); Municipal Institute of Medical Research (IMIM-Hospital del Mar), Barcelona (Spain); Universitat Pompeu Fabra, Barcelona (Spain); CIBER Epidemiologia y Salud Publica (CIBERESP) (Spain); Bouso, Laura [Centre for Research in Environmental Epidemiology CREAL, Barcelona (Spain); Municipal Institute of Medical Research (IMIM-Hospital del Mar), Barcelona (Spain); CIBER Epidemiologia y Salud Publica (CIBERESP) (Spain); Moreno, Teresa [Institute of Environmental Assessment and Water Research (IDAEA-CSIC), Barcelona (Spain); Solanas, Pascual; Ramos, Rafael [Research Unit, Family Medicine, Girona, Jordi Gol Institute for Primary Care Research (IDIAP Jordi Gol), Catalan Institute of Health, Catalunya (Spain); Department of Medical Sciences, School of Medicine, University of Girona (Spain); Koellensperger, Gunda [University of Natural Resources and Applied Life Sciences, Vienna (Austria); Deltell, Alexandre [Polytechnic School, GREFEMA, University of Girona (Spain); Vizcaya, David [Centre for Research in Environmental Epidemiology CREAL, Barcelona (Spain); Municipal Institute of Medical Research (IMIM-Hospital del Mar), Barcelona (Spain); Universitat Pompeu Fabra, Barcelona (Spain); CIBER Epidemiologia y Salud Publica (CIBERESP) (Spain)

    2011-04-15

    One monitoring station is insufficient to characterize the high spatial variation of traffic-related heavy metals within cities. We tested moss bags (Hylocomium splendens), deployed in a dense network, for the monitoring of metals in outdoor air and characterized metals' long-term spatial distribution and its determinants in Girona, Spain. Mosses were exposed outside 23 homes for two months; NO{sub 2} was monitored for comparison. Metals were not highly correlated with NO{sub 2} and showed higher spatial variation than NO{sub 2}. Regression models explained 61-85% of Cu, Cr, Mo, Pb, Sb, Sn, and Zn and 72% of NO{sub 2} variability. Metals were strongly associated with the number of bus lines in the nearest street. Heavy metals are an alternative traffic-marker to NO{sub 2} given their toxicological relevance, stronger association with local traffic and higher spatial variability. Monitoring heavy metals with mosses is appealing, particularly for long-term exposure assessment, as mosses can remain on site many months without maintenance. - Research highlights: > Moss bags can be used to measure the metal's long-term spatial distribution within cities. > Heavy metals in mosses are not highly correlated with ambient NO{sub 2} concentrations. > Heavy metals show higher spatial variation and association with traffic than NO{sub 2}. > Bus lines in the nearest street explain 75-85% of Mo, Cr, Sb, Sn and Cu variability. > Moss bags are useful for long-term at home exposure assessment in epidemiological studies. - The long-term spatial distribution of heavy metals, measured with moss bags, is mainly determined by proximity to bus lines.

  4. Monitoring of heavy metal concentrations in home outdoor air using moss bags

    International Nuclear Information System (INIS)

    Rivera, Marcela; Zechmeister, Harald; Medina-Ramon, Mercedes; Basagana, Xavier; Foraster, Maria; Bouso, Laura; Moreno, Teresa; Solanas, Pascual; Ramos, Rafael; Koellensperger, Gunda; Deltell, Alexandre; Vizcaya, David

    2011-01-01

    One monitoring station is insufficient to characterize the high spatial variation of traffic-related heavy metals within cities. We tested moss bags (Hylocomium splendens), deployed in a dense network, for the monitoring of metals in outdoor air and characterized metals' long-term spatial distribution and its determinants in Girona, Spain. Mosses were exposed outside 23 homes for two months; NO 2 was monitored for comparison. Metals were not highly correlated with NO 2 and showed higher spatial variation than NO 2 . Regression models explained 61-85% of Cu, Cr, Mo, Pb, Sb, Sn, and Zn and 72% of NO 2 variability. Metals were strongly associated with the number of bus lines in the nearest street. Heavy metals are an alternative traffic-marker to NO 2 given their toxicological relevance, stronger association with local traffic and higher spatial variability. Monitoring heavy metals with mosses is appealing, particularly for long-term exposure assessment, as mosses can remain on site many months without maintenance. - Research highlights: → Moss bags can be used to measure the metal's long-term spatial distribution within cities. → Heavy metals in mosses are not highly correlated with ambient NO 2 concentrations. → Heavy metals show higher spatial variation and association with traffic than NO 2 . → Bus lines in the nearest street explain 75-85% of Mo, Cr, Sb, Sn and Cu variability. → Moss bags are useful for long-term at home exposure assessment in epidemiological studies. - The long-term spatial distribution of heavy metals, measured with moss bags, is mainly determined by proximity to bus lines.

  5. Experimental study on air cleaning effect of clean air heat pump and its impact on ventilation requirement

    DEFF Research Database (Denmark)

    Fang, Lei; Sheng, Ying; Nie, Jinzhe

    2017-01-01

    This study investigated air purification effect of a Clean-Air Heat Pump (CAHP) which combined a desiccant wheel with a heat pump for both air cleaning and HVAC of buildings. The experiment was conducted in a field lab at four different outdoor air supply rates with and without air cleaning by CAHP....... Both sensory assessments of perceived air quality and chemical measurements of TVOC concentrations were conducted for evaluating the air cleaning performance of the CAHP. The results of experiment showed that running the CAHP improved significantly perceived air quality. At 2 L/s per person of outdoor...... air supply rate with operating the CAHP, the air quality was equivalent to the value at the higher outdoor air supply rate of 10 L/s per person without running CAHP. The TVOC measurements observed over 92% of efficiency on removal of indoor air VOCs and no VOCs accumulation on the desiccant wheel...

  6. Localized real-time information on outdoor air quality at kindergartens in Oslo, Norway using low-cost sensor nodes.

    Science.gov (United States)

    Castell, Nuria; Schneider, Philipp; Grossberndt, Sonja; Fredriksen, Mirjam F; Sousa-Santos, Gabriela; Vogt, Mathias; Bartonova, Alena

    2018-08-01

    In Norway, children in kindergartens spend significant time outdoors under all weather conditions, and there is thus a natural concern about the quality of outdoor air. It is well known that air pollution is associated with a wide variety of adverse health impacts for children, with greater impact on children with asthma. Especially during winter and spring, kindergartens in Oslo that are situated close to streets with busy traffic, or in areas where wood burning is used for house heating, can experience many days with bad air quality. During these periods, updated information on air quality levels can help the kindergarten teachers to plan appropriate outdoor activities and thus protect children's health. We have installed 17 low-cost air quality nodes in kindergartens in Oslo. These nodes are smaller, cheaper and less complex to use than traditional equipment. Performance evaluation shows that while they are less accurate and suffer from higher uncertainty than reference equipment, they still can provide reliable coarse information about local pollution. The main challenge when using this technology is that calibration parameters might change with time depending on the atmospheric conditions. Thus, even if the sensors are calibrated a priori, once deployed, and especially if they are deployed for a long time, it is not possible to determine if a node is over- or under-estimating the concentration levels. To enhance the data from the sensors, we employed a data fusion technique that allows generating a detailed air quality map merging the data from the sensors and the data from an urban model, thus being able to offer air quality information to any location within Oslo. We arranged a focus group with the participation of local administration, kindergarten staff and parents to understand their opinion and needs related to the air quality information that was provided to the participant kindergartens. They expressed concern about the data quality but agree that

  7. Polycyclic aromatic hydrocarbons and their derivatives in indoor and outdoor air in an eight-home study

    Science.gov (United States)

    Chuang, Jane C.; Mack, Gregory A.; Kuhlman, Michael R.; Wilson, Nancy K.

    A pilot field study was performed in Columbus, OH, during the winter of 1986/1987. The objectives were to determine the feasibility of the use of a newly developed quiet sampler in indoor air sampling for particles and semivolatile organic compounds (SVOC) and to measure the concentrations of polycyclic aromatic hydrocarbons (PAH), PAH derivatives, and nicotine in air in selected residences. Eight homes were chosen for sampling on the basis of these characteristics: electric/gas heating system, electric/gas cooking appliances, and the absence/presence of environmental tobacco smoke (ETS). The indoor sampler was equipped with a quartz-fiber filter to collect particles followed by XAD-4 resin to trap SVOC. A PS-1 sampler with a similar sampling module was used outdoors. The indoor air was sampled in the kitchen and living room areas over two consecutive 8-h periods. The outdoor air was sampled concurrently with the indoor samples over a 16-h period. Fifteen PAH, five nitro-PAH, five oxygenated PAH, and three nitrogen heterocyclic compounds were determined in these samples. The most abundant PAH found indoors was naphthalene. The indoor concentrations of PAH derivatives were lower than those of their parent compounds. Average concentrations of all but three target compounds (naphthalene dicarboxylic acid anhydride, pyrene dicarboxylic acid anhydride, and 2-nitrofluoranthene) were higher indoors than outdoors. Environmental tobacco smoke was the most significant influence on indoor pollutant levels. Homes with gas heating systems had higher indoor pollutant levels than homes with electric heating systems. However, the true effects of heating and cooking systems were not characterized as accurately as the effects of ETS because of the small sample sizes and the lack of statistical significance for most pollutant differences in the absence of ETS. The concentrations of PAH marker compounds (phenanthrene, fluoranthene, and pyrene) correlated well with the concentrations

  8. Experimental Air-Tightness Analysis in Mediterranean Buildings after Windows Retrofit

    Directory of Open Access Journals (Sweden)

    Francesca Romana d’Ambrosio Alfano

    2016-09-01

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

  9. Experimental analysis of indoor air quality improvement achieved by using a Clean-Air Heat Pump (CAHP) air-cleaner in a ventilation system

    DEFF Research Database (Denmark)

    Sheng, Ying; Fang, Lei; Nie, Jinzhe

    2017-01-01

    This study investigated the air purification effect of a Clean-Air Heat Pump (CAHP) air-cleaner which combined a silica gel rotor with a heat pump to achieve air cleaning, heating and ventilation in buildings. The experiments were conducted in a field laboratory and compared a low outdoor air...... supply rate with CAHP air purification of recirculated air with three different outdoor air supply rates without recirculation or air cleaning. Sensory assessments of perceived air quality and chemical measurements of TVOC concentration were used to evaluate the air-cleaning performance of the CAHP....... The results of the experiment showed that the operation of the CAHP significantly improved the perceived air quality in a room polluted by both human bio-effluents and building materials. At the outdoor airflow rate of 2 L/s per person, the indoor air quality with CAHP was equivalent to what was achieved...

  10. Characterization of particle number concentrations and PM2.5 in a school: influence of outdoor air pollution on indoor air.

    Science.gov (United States)

    Guo, Hai; Morawska, Lidia; He, Congrong; Zhang, Yanli L; Ayoko, Godwin; Cao, Min

    2010-07-01

    The impact of air pollution on school children's health is currently one of the key foci of international and national agencies. Of particular concern are ultrafine particles which are emitted in large quantities, contain large concentrations of toxins and are deposited deeply in the respiratory tract. In this study, an intensive sampling campaign of indoor and outdoor airborne particulate matter was carried out in a primary school in February 2006 to investigate indoor and outdoor particle number (PN) and mass concentrations (PM(2.5)), and particle size distribution, and to evaluate the influence of outdoor air pollution on the indoor air. For outdoor PN and PM(2.5), early morning and late afternoon peaks were observed on weekdays, which are consistent with traffic rush hours, indicating the predominant effect of vehicular emissions. However, the temporal variations of outdoor PM(2.5) and PN concentrations occasionally showed extremely high peaks, mainly due to human activities such as cigarette smoking and the operation of mower near the sampling site. The indoor PM(2.5) level was mainly affected by the outdoor PM(2.5) (r = 0.68, p changes to the modal structure of particle number and size distribution, even though the I/O ratio was different for different size classes. The I/O curves had a maximum value for particles with diameters of 100-400 nm under both occupied and unoccupied scenarios, whereas no significant difference in I/O ratio for PM(2.5) was observed between occupied and unoccupied conditions. Inspection of the size-resolved I/O ratios in the preschool centre and the classroom suggested that the I/O ratio in the preschool centre was the highest for accumulation mode particles at 600 nm after school hours, whereas the average I/O ratios of both nucleation mode and accumulation mode particles in the classroom were much lower than those of Aitken mode particles. The findings obtained in this study are useful for epidemiological studies to estimate the

  11. Volatile methyl siloxanes (VMS) concentrations in outdoor air of several Catalan urban areas

    Science.gov (United States)

    Gallego, E.; Perales, J. F.; Roca, F. J.; Guardino, X.; Gadea, E.

    2017-04-01

    Volatile methyl siloxanes (VMS) were evaluated in ten Catalan urban areas with different industrial impacts, such as petrochemical industry, electrical and mechanical equipment, metallurgical and chemical industries, municipal solid waste treatment plant and cement and food industries, during 2013-2015. 24 h samples were taken with LCMA-UPC pump samplers specially designed in our laboratory, with a flow range of 70 ml min-1. A sorbent-based sampling method, successfully developed to collect a wide-range of VOC, was used. The analysis was performed by automatic thermal desorption coupled with capillary gas chromatography/mass spectrometry detector. The presented methodology allows the evaluation of VMS together with a wide range of other VOC, increasing the number of compounds that can be determined in outdoor air quality assessment of urban areas. This aspect is especially relevant as a restriction of several VMS (D4 and D5) in consumer products has been made by the European Chemicals Agency and US EPA is evaluating to include D4 in the Toxic Substances Control Act, regarding the concern of the possible effects of these compounds in human health and the environment. ΣVMS concentrations (L2-L5, D3-D6 and trimethylsilanol) varied between 0.3 ± 0.2 μg m-3 and 18 ± 12 μg m-3, determined in a hotspot area. Observed VMS concentrations were generally of the same order of magnitude than the previously determined in Barcelona, Chicago and Zurich urban areas, but higher than the published from suburban sites and Arctic locations. Cyclic siloxanes concentrations were up to two-three orders of magnitude higher than those of linear siloxanes, accounting for average contributions to the total concentrations of 97 ± 6% for all samples except for the hotspot area, where cyclic VMS accounted for 99.9 ± 0.1%. D5 was the most abundant siloxane in 5 sampling points; however, differing from the generally observed in previous studies, D3 was the most abundant compound in the

  12. THE INDOOR-OUTDOOR AIR-POLLUTION CONTINUUM AND THE BURDEN OF CARDIOVASCULAR DISEASE: AN OPPORTUNITY FOR IMPROVING GLOBAL HEALTH.

    Science.gov (United States)

    Rajagopalan, Sanjay; Brook, Robert D

    2012-09-01

    Current understanding of the association between household air-pollution (HAP) and cardiovascular disease is primarily derived from outdoor air-pollution studies. The lack of accurate information on the contribution of HAP to cardiovascular events has prevented inclusion of such data in global burden of disease estimates with consequences in terms of health care allocation and national/international priorities. Understanding the health risks, exposure characterization, epidemiology and economics of the association between HAP and cardiovascular disease represents a pivotal unmet public health need. Interventions to reduce exposure to air-pollution in general, and HAP in particular are likely to yield large benefits and may represent a cost-effective and economically sustainable solution for many parts of the world. A multi-disciplinary effort that provides economically feasible technologic solutions in conjunction with experts that can assess the health, economic impact and sustainability are urgently required to tackle this problem.

  13. Currently Commercially Available Chemical Sensors Employed for Detection of Volatile Organic Compounds in Outdoor and Indoor Air

    Directory of Open Access Journals (Sweden)

    Bartosz Szulczyński

    2017-03-01

    Full Text Available The paper presents principle of operation and design of the most popular chemical sensors for measurement of volatile organic compounds (VOCs in outdoor and indoor air. It describes the sensors for evaluation of explosion risk including pellistors and IR-absorption sensors as well as the sensors for detection of toxic compounds such as electrochemical (amperometric, photoionization and semiconductor with solid electrolyte ones. Commercially available sensors for detection of VOCs and their metrological parameters—measurement range, limit of detection, measurement resolution, sensitivity and response time—were presented. Moreover, development trends and prospects of improvement of the metrological parameters of these sensors were highlighted.

  14. Relationship of Indoor and Outdoor Air Pollutants in a Naturally Ventilated Historical Building Envelope

    Czech Academy of Sciences Publication Activity Database

    López-Aparicio, S.; Smolík, Jiří; Mašková, Ludmila; Součková, M.; Grøntoft, T.; Ondráčková, Lucie; Stankiewicz, J.

    2011-01-01

    Roč. 46, č. 7 (2011), s. 1460-1468 ISSN 0360-1323 Grant - others:MF NF(CZ) A/CZ0046/2/0001 Institutional research plan: CEZ:AV0Z40720504 Keywords : indoor/outdoor ration * natural ventilation * ammonia Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 2.400, year: 2011

  15. Experimental evaluation on energy performance of innovative clean air heat pump for indoor environment control in summer and winter seasons

    DEFF Research Database (Denmark)

    Nie, Jinzhe; Fang, Lei; Olesen, Bjarne W.

    2014-01-01

    Based on the air purification capacity of regenerative silica gel rotor, an innovative clean air heat pump (CAHP) was designed, developed and investigated through experimental studies. The CAHP integrated air purification, dehumidification and heating/cooling in one unit. A prototype of the CAHP...... was developed. Laboratory experimental studies were conducted to investigate its energy performance under different outdoor climates including cold, mild-cold, mild-hot and extremely hot and humid climates. The energy performance of the CAHP was then evaluated by comparing with a conventional air source heat...... pump. The results showed that to keep same indoor air quality, the CAHP could save substantial amount of energy. For example, compared to the conventional air source heat pump, the CAHP could save up to 59%, 40%, 30% of electricity for ventilation and air conditioning in a test room in summer...

  16. Severe Urban Outdoor Air Pollution and Children's Structural and Functional Brain Development, From Evidence to Precautionary Strategic Action.

    Science.gov (United States)

    D'Angiulli, Amedeo

    2018-01-01

    According to the latest estimates, about 2 billion children around the world are exposed to severe urban outdoor air pollution. Transdisciplinary, multi-method findings from epidemiology, developmental neuroscience, psychology, and pediatrics, show detrimental outcomes associated with pre- and postnatal exposure are found at all ages. Affected brain-related functions include perceptual and sensory information processing, intellectual and cognitive development, memory and executive functions, emotion and self-regulation, and academic achievement. Correspondingly, with the breakdown of natural barriers against entry and translocation of toxic particles in the brain, the most common structural changes are responses promoting neuroinflammation and indicating early neurodegenerative processes. In spite of the gaps in current scientific knowledge and the challenges posed by non-scientific issues that influence policy, the evidence invites the conclusion that urban outdoor air pollution is a serious threat to healthy brain development which may set the conditions for neurodegenerative diseases. Such evidence supports the perspective that urgent strategic precautionary actions, minimizing exposure and attenuating its effects, are needed to protect children and their brain development.

  17. Severe Urban Outdoor Air Pollution and Children’s Structural and Functional Brain Development, From Evidence to Precautionary Strategic Action

    Directory of Open Access Journals (Sweden)

    Amedeo D’Angiulli

    2018-04-01

    Full Text Available According to the latest estimates, about 2 billion children around the world are exposed to severe urban outdoor air pollution. Transdisciplinary, multi-method findings from epidemiology, developmental neuroscience, psychology, and pediatrics, show detrimental outcomes associated with pre- and postnatal exposure are found at all ages. Affected brain-related functions include perceptual and sensory information processing, intellectual and cognitive development, memory and executive functions, emotion and self-regulation, and academic achievement. Correspondingly, with the breakdown of natural barriers against entry and translocation of toxic particles in the brain, the most common structural changes are responses promoting neuroinflammation and indicating early neurodegenerative processes. In spite of the gaps in current scientific knowledge and the challenges posed by non-scientific issues that influence policy, the evidence invites the conclusion that urban outdoor air pollution is a serious threat to healthy brain development which may set the conditions for neurodegenerative diseases. Such evidence supports the perspective that urgent strategic precautionary actions, minimizing exposure and attenuating its effects, are needed to protect children and their brain development.

  18. Seasonal fate and gas/particle partitioning of semi-volatile organic compounds in indoor and outdoor air

    Science.gov (United States)

    Moreau-Guigon, Elodie; Alliot, Fabrice; Gaspéri, Johnny; Blanchard, Martine; Teil, Marie-Jeanne; Mandin, Corinne; Chevreuil, Marc

    2016-12-01

    Fifty-eight semi-volatile organic compounds (SVOCs) were investigated simultaneously in three indoor (apartment, nursery and office building) and one outdoor environment in the centre of Paris (France). All of these compounds except tetrabromobisphenol A were quantified in the gaseous and particulate phases in all three environments, and at a frequency of 100% for the predominant compounds of each SVOC class. Phthalic acid esters (PAEs) were the most abundant group (di-iso-butyl phthalate: 29-661 ng m-3, diethyl phthalate: 15-542 ng m-3), followed by 4-nonylphenol (1.4-81 ng m-3), parabens (methylparaben: 0.03-2.5 ng m-3), hexachlorobenzene (HCB) (0.002-0.26 ng m-3) and pentachlorobenzene (PeCB) (0.001-0.23 ng m-3). Polycyclic aromatic hydrocarbons (as ∑8PAHs) ranged from 0.17 to 5.40 ng m-3, polychlorinated biphenyls (as ∑7PCBi) from 0.06 to 4.70 ng.m3 and polybromodiphenyl ethers (as ∑8PBDEs) from 0.002 to 0.40 ng m-3. For most pollutants, significantly higher concentrations were observed in the nursery compared to the apartment and office. Overall, the indoor air concentrations were up to ten times higher than outdoor air concentrations. Seasonal variations were observed for PAEs, PCBs and PAHs. SVOCs were predominantly identified in the gaseous phase (>90%), except for some high-molecular-weight PAEs, PAHs and PCBs.

  19. Report by the Commission of environment accounting and economy - Health and outdoor air quality

    International Nuclear Information System (INIS)

    Depoorter, Stephanie; Niklaus, Doris; Rafenberg, Christophe; Dron, Dominique

    2012-07-01

    After an overview of the issue of air pollution (definition, pollutant emission, population exposure, main air pollutants and emission sources, assessment of air quality in France), this report discusses the various impacts of air pollution on health and their related costs: pathologies associated with a bad air quality, categories which are more exposed than others, assessment of health impacts of air pollution, health costs. The next part describes the current policies aimed at improving air quality: European and international commitments, national policy, public policy tools, impacts of policies of struggle against air pollution by some pollutants, current researches and knowledge to be improved

  20. Annoyance Caused by Noise and Air Pollution during Pregnancy: Associated Factors and Correlation with Outdoor NO2 and Benzene Estimations.

    Science.gov (United States)

    Fernández-Somoano, Ana; Llop, Sabrina; Aguilera, Inmaculada; Tamayo-Uria, Ibon; Martínez, María Dolores; Foraster, Maria; Ballester, Ferran; Tardón, Adonina

    2015-06-18

    This study aimed to describe the degree of annoyance among pregnant women in a Spanish cohort and to examine associations with proximity to traffic, NO2 and benzene exposure. We included 2457 participants from the Spanish Childhood and Environment study. Individual exposures to outdoor NO2 and benzene were estimated, temporally adjusted for pregnancy. Interviews about sociodemographic variables, noise and air pollution were carried out. Levels of annoyance were assessed using a scale from 0 (none) to 10 (strong and unbearable); a level of 8 to 10 was considered high. The reported prevalence of high annoyance levels from air pollution was 11.2% and 15.0% from noise; the two variables were moderately correlated (0.606). Significant correlations between NO2 and annoyance from air pollution (0.154) and that from noise (0.181) were observed. Annoyance owing to noise and air pollution had a low prevalence in our Spanish population compared with other European populations. Both factors were associated with proximity to traffic. In multivariate models, annoyance from air pollution was related to NO2, building age, and country of birth; annoyance from noise was only related to the first two. The health burden of these exposures can be increased by stress caused by the perception of pollution sources.

  1. Cardiopulmonary benefits of reducing indoor particles of outdoor origin: a randomized, double-blind crossover trial of air purifiers.

    Science.gov (United States)

    Chen, Renjie; Zhao, Ang; Chen, Honglei; Zhao, Zhuohui; Cai, Jing; Wang, Cuicui; Yang, Changyuan; Li, Huichu; Xu, Xiaohui; Ha, Sandie; Li, Tiantian; Kan, Haidong

    2015-06-02

    Indoor exposure to fine particulate matter (PM2.5) from outdoor sources is a major health concern, especially in highly polluted developing countries such as China. Few studies have evaluated the effectiveness of indoor air purification on the improvement of cardiopulmonary health in these areas. This study sought to evaluate whether a short-term indoor air purifier intervention improves cardiopulmonary health. We conducted a randomized, double-blind crossover trial among 35 healthy college students in Shanghai, China, in 2014. These students lived in dormitories that were randomized into 2 groups and alternated the use of true or sham air purifiers for 48 h with a 2-week washout interval. We measured 14 circulating biomarkers of inflammation, coagulation, and vasoconstriction; lung function; blood pressure (BP); and fractional exhaled nitric. We applied linear mixed-effect models to evaluate the effect of the intervention on health outcome variables. On average, air purification resulted in a 57% reduction in PM2.5 concentration, from 96.2 to 41.3 μg/m3, within hours of operation. Air purification was significantly associated with decreases in geometric means of several circulating inflammatory and thrombogenic biomarkers, including 17.5% in monocyte chemoattractant protein-1, 68.1% in interleukin-1β, 32.8% in myeloperoxidase, and 64.9% in soluble CD40 ligand. Furthermore, systolic BP, diastolic BP, and fractional exhaled nitrous oxide were significantly decreased by 2.7%, 4.8%, and 17.0% in geometric mean, respectively. The impacts on lung function and vasoconstriction biomarkers were beneficial but not statistically significant. This intervention study demonstrated clear cardiopulmonary benefits of indoor air purification among young, healthy adults in a Chinese city with severe ambient particulate air pollution. (Intervention Study on the Health Impact of Air Filters in Chinese Adults; NCT02239744). Copyright © 2015 American College of Cardiology Foundation

  2. Using Social Media to Detect Outdoor Air Pollution and Monitor Air Quality Index (AQI): A Geo-Targeted Spatiotemporal Analysis Framework with Sina Weibo (Chinese Twitter).

    Science.gov (United States)

    Jiang, Wei; Wang, Yandong; Tsou, Ming-Hsiang; Fu, Xiaokang

    2015-01-01

    Outdoor air pollution is a serious problem in many developing countries today. This study focuses on monitoring the dynamic changes of air quality effectively in large cities by analyzing the spatiotemporal trends in geo-targeted social media messages with comprehensive big data filtering procedures. We introduce a new social media analytic framework to (1) investigate the relationship between air pollution topics posted in Sina Weibo (Chinese Twitter) and the daily Air Quality Index (AQI) published by China's Ministry of Environmental Protection; and (2) monitor the dynamics of air quality index by using social media messages. Correlation analysis was used to compare the connections between discussion trends in social media messages and the temporal changes in the AQI during 2012. We categorized relevant messages into three types, retweets, mobile app messages, and original individual messages finding that original individual messages had the highest correlation to the Air Quality Index. Based on this correlation analysis, individual messages were used to monitor the AQI in 2013. Our study indicates that the filtered social media messages are strongly correlated to the AQI and can be used to monitor the air quality dynamics to some extent.

  3. Using Social Media to Detect Outdoor Air Pollution and Monitor Air Quality Index (AQI: A Geo-Targeted Spatiotemporal Analysis Framework with Sina Weibo (Chinese Twitter.

    Directory of Open Access Journals (Sweden)

    Wei Jiang

    Full Text Available Outdoor air pollution is a serious problem in many developing countries today. This study focuses on monitoring the dynamic changes of air quality effectively in large cities by analyzing the spatiotemporal trends in geo-targeted social media messages with comprehensive big data filtering procedures. We introduce a new social media analytic framework to (1 investigate the relationship between air pollution topics posted in Sina Weibo (Chinese Twitter and the daily Air Quality Index (AQI published by China's Ministry of Environmental Protection; and (2 monitor the dynamics of air quality index by using social media messages. Correlation analysis was used to compare the connections between discussion trends in social media messages and the temporal changes in the AQI during 2012. We categorized relevant messages into three types, retweets, mobile app messages, and original individual messages finding that original individual messages had the highest correlation to the Air Quality Index. Based on this correlation analysis, individual messages were used to monitor the AQI in 2013. Our study indicates that the filtered social media messages are strongly correlated to the AQI and can be used to monitor the air quality dynamics to some extent.

  4. Experimental investigation of cavitation induced air release

    Directory of Open Access Journals (Sweden)

    Kowalski Karoline

    2017-01-01

    Full Text Available Variations in cross-sectional areas may lead to pressure drops below a critical value, such that cavitation and air release are provoked in hydraulic systems. Due to a relatively slow dissolution of gas bubbles, the performance of hydraulic systems will be affected on long time scales by the gas phase. Therefore predictions of air production rates are desirable to describe the system characteristics. Existing investigations on generic geometries such as micro-orifice flows show an outgassing process due to hydrodynamic cavitation which takes place on time scales far shorter than diffusion processes. The aim of the present investigation is to find a correlation between global, hydrodynamic flow characteristics and cavitation induced undissolved gas fractions generated behind generic flow constrictions such as an orifice or venturi tube. Experimental investigations are realised in a cavitation channel that enables an independent adjustment of the pressure level upstream and downstream of the orifice. Released air fractions are determined by means of shadowgraphy imaging. First results indicate that an increased cavitation activity leads to a rapid increase in undissolved gas volume only in the choking regime. The frequency distribution of generated gas bubble size seems to depend only indirectly on the cavitation intensity driven by an increase of downstream coalescence events due to a more densely populated bubbly flow.

  5. Experimental investigation of cavitation induced air release

    Science.gov (United States)

    Kowalski, Karoline; Pollak, Stefan; Hussong, Jeanette

    Variations in cross-sectional areas may lead to pressure drops below a critical value, such that cavitation and air release are provoked in hydraulic systems. Due to a relatively slow dissolution of gas bubbles, the performance of hydraulic systems will be affected on long time scales by the gas phase. Therefore predictions of air production rates are desirable to describe the system characteristics. Existing investigations on generic geometries such as micro-orifice flows show an outgassing process due to hydrodynamic cavitation which takes place on time scales far shorter than diffusion processes. The aim of the present investigation is to find a correlation between global, hydrodynamic flow characteristics and cavitation induced undissolved gas fractions generated behind generic flow constrictions such as an orifice or venturi tube. Experimental investigations are realised in a cavitation channel that enables an independent adjustment of the pressure level upstream and downstream of the orifice. Released air fractions are determined by means of shadowgraphy imaging. First results indicate that an increased cavitation activity leads to a rapid increase in undissolved gas volume only in the choking regime. The frequency distribution of generated gas bubble size seems to depend only indirectly on the cavitation intensity driven by an increase of downstream coalescence events due to a more densely populated bubbly flow.

  6. Measuring OutdoorAir Intake Rates Using Electronic Velocity Sensors at Louvers and Downstream of Airflow Straighteners

    Energy Technology Data Exchange (ETDEWEB)

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

    2008-10-01

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

  7. Experimental investigations of active air bearings

    DEFF Research Database (Denmark)

    Santos, Ilmar; Morosi, Stefano

    2012-01-01

    Along with traditional oil lubrication, increasing demand for high-speed applications has renewed attention to gas bearings technology. Traditional aerostatic and aerodynamic gas lubrication has been widely used in a variety of applications, ranging from high-speed spindles to micro and meso......-scale turbomachinery. The present paper deals with experimental rotordynamic testing of a flexible rotor supported by hybrid aerostaticaerodynamic gas journal bearing equipped with an electronic radial air injection system. From a rotordynamic point of view there are two phenomena that limit the widespread...... of traditional gas lubrication: 1) Low damping makes operation across critical speed dangerous, as even low level of unbalance can generate large vibration responses. This is especially problematic for gas bearing applications, which often operate in the supercritical region. Moreover, 2) An upper bound...

  8. Experimental research on air propellers V

    Science.gov (United States)

    Durand, W F; Lesley, E P

    1923-01-01

    In previous reports on experimental research on air propellers, by W. F. Durand and E. P. Lesley, as contained in the National Advisory Committee for Aeronautics reports nos. 14, 30, and 64, the investigations were made progressively and each without reference to results given in preceding reports and covering only information relating to forms perhaps adjacent in geometrical form and proportion. This report is a review of the entire series of results of the preceding reports with a view of examining through graphical and other appropriate means the nature of the history of the characteristics of operation as related to the systematic variations in characteristics of forms, etc., through the series of such characteristics.

  9. Distribution of Gas Phase Polycyclic Aromatic Hydrocarbons (PAHs in Selected Indoor and Outdoor Air Samples of Malaysia: a Case Study in Serdang, Selangor and Bachang, Malacca

    Directory of Open Access Journals (Sweden)

    Haris Hafizal Abd Hamid

    2017-07-01

    Full Text Available Distribution of 10 polycyclic aromatic hydrocarbons (PAHs in the gas phase of air from selected indoor and outdoor areas of Selangor and Malacca, Malaysia has been investigated. A locally designed Semi Permeable Membrane Device (SPMD was applied for passive air sampling for 37 days at selected locations. Cleanup was carried out with Gas Purge - Micro Syringe Extraction (GP-MSE and the final analysis was using Gas Chromatography-Mass Spectrometry (GC-MS. In this study, 6 indoor and 12 outdoor locations were selected for air sampling. A total of 10 compounds of PAHs (Ʃ10PAHs were determined in the range of 0.218 ng/m3 - 1.692 ng/m3 and 0.378 ng/m3 - 1.492 ng/m3 in outdoor and indoor samples respectively. In the outdoor samples, locations such as near a petrol station and heavy traffic showed the maximum levels of Ʃ10PAHs, while rooftop samples showed the lowest Ʃ10PAHs. The distribution of gas phase Ʃ10PAHs was influenced by vehicular emission. Low molecular weight (LMW compounds (2-3 rings were dominant in all samples (>70% indicating that SPMD has successfully sampled the gas phase of the air.

  10. Experimental Analysis on Solar Desiccant Air Conditioner

    OpenAIRE

    Dr. U. V. Kongre, C. M. Singh, A. B. Biswas

    2014-01-01

    The experiment investigated and evaluated the feasibility of an solar desiccant air conditioner. Its effectiveness as a possible air conditioner option used in household air conditioner or as an energy efficient and environmentally friendly alternative to conventional air conditioning units used in houses are evaluated. A solar water heater was used as heat gain. The model utilizes the technology of solar air conditioner system. The purpose in the long term wou...

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

    International Nuclear Information System (INIS)

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

    2009-01-01

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

  12. End-user perspective of low-cost sensors for outdoor air pollution monitoring

    OpenAIRE

    Rai, Aakash C.; Kumar, Prashant; Pilla, Francesco; Skouloudis, Andreas N.; Di Sabatino, Silvana; Ratti, Carlo; Yasar, Ansar; Rickerby, David

    2017-01-01

    Low-cost sensor technology can potentially revolutionise the area of air pollution monitoring by providing high-density spatiotemporal pollution data. Such data can be utilised for supplementing traditional pollution monitoring, improving exposure estimates, and raising community awareness about air pollution. However, data quality remains a major concern that hinders the widespread adoption of low-cost sensor technology. Unreliable data may mislead unsuspecting users and potentially lead to ...

  13. Out-of-Hospital Cardiac Arrests and Outdoor Air Pollution Exposure in Copenhagen, Denmark

    DEFF Research Database (Denmark)

    Wichmann, Janine; Folke, Fredrik; Torp-Pedersen, Christian

    2013-01-01

    -of-hospital cardiac arrests (OHCA) and hourly and daily outdoor levels of PM(10), PM(2.5), coarse fraction of PM (PM(10-2.5)), ultrafine particle proxies, NO(x), NO(2), O(3) and CO in Copenhagen, Denmark, for the period 2000-2010. Susceptible groups by age and sex was also investigated. A case-crossover design...... was applied. None of the hourly lags of any of the pollutants were significantly associated with OHCA events. The strongest association with OHCA events was observed for the daily lag4 of PM(2.5), lag3 of PM(10), lag3 of PM(10-2.5), lag3 of NO(x) and lag4 of CO. An IQR increase of PM(2.5) and PM(10......) was associated with a significant increase of 4% (95% CI: 0%; 9%) and 5% (95% CI: 1%; 9%) in OHCA events with 3 days lag, respectively. None of the other daily lags or other pollutants was significantly associated with OHCA events. Adjustment for O(3) slightly increased the association between OHCA and PM(2...

  14. Season, sex, age, and education as modifiers of the effects of outdoor air pollution on daily mortality in Shanghai, China: The Public Health and Air Pollution in Asia (PAPA) Study.

    Science.gov (United States)

    Kan, Haidong; London, Stephanie J; Chen, Guohai; Zhang, Yunhui; Song, Guixiang; Zhao, Naiqing; Jiang, Lili; Chen, Bingheng

    2008-09-01

    Various factors can modify the health effects of outdoor air pollution. Prior findings about modifiers are inconsistent, and most of these studies were conducted in developed countries. We conducted a time-series analysis to examine the modifying effect of season, sex, age, and education on the association between outdoor air pollutants [particulate matter air pollution for the warm season (April-September) and cool season (October-March) separately. For total mortality, we examined the association stratified by sex and age. Stratified analysis by educational attainment was conducted for total, cardiovascular, and respiratory mortality. Outdoor air pollution was associated with mortality from all causes and from cardiorespiratory diseases in Shanghai. An increase of 10 mug/m(3) in a 2-day average concentration of PM(10), SO(2), NO(2), and O(3) corresponds to increases in all-cause mortality of 0.25% [95% confidence interval (CI), 0.14-0.37), 0.95% (95% CI, 0.62-1.28), 0.97% (95% CI, 0.66-1.27), and 0.31% (95% CI, 0.04-0.58), respectively. The effects of air pollutants were more evident in the cool season than in the warm season, and females and the elderly were more vulnerable to outdoor air pollution. Effects of air pollution were generally greater in residents with low educational attainment (illiterate or primary school) compared with those with high educational attainment (middle school or above). Season, sex, age, and education may modify the health effects of outdoor air pollution in Shanghai. These findings provide new information about the effects of modifiers on the relationship between daily mortality and air pollution in developing countries and may have implications for local environmental and social policies.

  15. Association between Traffic Air Pollution and Reduced Forced Vital Capacity: A Study Using Personal Monitors for Outdoor Workers.

    Directory of Open Access Journals (Sweden)

    Ubiratan Paula Santos

    Full Text Available The effects of outdoor air pollution on lung function in adults are still controversial.Evaluate the effects of exposure to different levels of traffic-generated PM2.5 on workers' lung functions in São Paulo, Brazil.To cover a wide range of exposures, 101 non-smoking workers from three occupations (taxi drivers, traffic controllers, and forest rangers were selected for the study. After clinical evaluation, the participants were scheduled to attend four consecutive weekly visits in which they received a 24-hour personal PM2.5 sampler and had lung function tests measured on the following day. The association between the spirometric variables and the averaged PM2.5 levels was assessed using robust regression models adjusted for age, waist circumference, time at the job, daily work hours, diabetes or hypertension and former smoking habits.Relative to workers in the lowest exposed group (all measures 39.6 μg/m3 showed a reduction of predicted FVC (-12.2%; CI 95%: [-20.0% to -4.4%], a marginal reduction of predicted FEV1 (-9.1%; CI 95%: [-19.1% to 0.9%] and an increase of predicted FEF25-75%/FVC (14.9%; CI 95%: [2.9% to 26.8%] without changes of FEV1/FVC.Exposure to vehicular traffic air pollution is associated with a small but significant reduction of FVC without a reduction of FEV1/FVC.

  16. Air quality at outdoor community events: findings from fine particulate (PM2.5) sampling at festivals in Edmonton, Alberta.

    Science.gov (United States)

    Collins, Damian; Parsons, Marc; Zinyemba, Chaka

    2014-01-01

    Exposure to fine particulate matter (PM2.5) is associated with a broad range of health risks. This study assessed the impacts of cooking smoke and environmental tobacco smoke on air quality at outdoor community events in Edmonton, Alberta (Canada). Data were collected at three festivals in July-August 2011 using a portable real-time airborne particle monitor. The pooled mean PM2.5 level was 12.41 μg/m(3). Peak readings varied from 52 to 1877 μg/m(3). Mean PM2.5 near food stalls was 35.42 μg/m(3), which exceeds the WHO limit for 24 h exposure. Mean PM2.5 levels with smokers present were 16.39 μg/m(3) (all points) and 9.64 μg/m(3) (excluding points near food stalls). Although some smokers withdrew from common spaces, on average 20 smokers/hour were observed within 3 m. Extending smoking bans would improve air quality and address related concerns. However, food preparation is a more pressing area for policy action to reduce PM2.5 exposure at these community events.

  17. Outdoor air pollution as a possible modifiable risk factor to reduce mortality in post-stroke population

    Directory of Open Access Journals (Sweden)

    Anita Desikan

    2017-01-01

    Full Text Available Outdoor air pollution is a known risk factor for mortality and morbidity. The type of air pollutant most reliably associated with disease is particulate matter (PM, especially finer particulate matter that can reach deeper into the lungs like PM2.5 (particulate matter diameter < 2.5 μm. Some subpopulations may be particularly vulnerable to PM pollution. This review focuses on one subgroup, long-term stroke survivors, and the emerging evidence suggesting that survivors of a stroke may be at a higher risk from the deleterious effects of PM pollution. While the mechanisms for mortality are still under debate, long-term stroke survivors may be vulnerable to similar mechanisms that underlie the well-established association between PM pollution and cardiovascular disease. The fact that long-term stroke survivors of ischemic, but not hemorrhagic, strokes appear to be more vulnerable to the risk of death from higher PM pollution may also bolster the connection to ischemic heart disease. Survivors of an ischemic stroke may be more vulnerable to dying from higher concentrations of PM pollution than the general population. The clinical implications of this association suggest that reduced exposure to PM pollution may result in fewer deaths amongst stroke survivors.

  18. Preliminary evaluation, using passive tubes, of carbon monoxide concentrations in outdoor and indoor air at street level shops in Genoa (Italy)

    Science.gov (United States)

    Valerio, Federico; Pala, Mauro; Lazzarotto, Anna; Balducci, Daniele

    Preliminary information on carbon monoxide (CO) concentrations (exposure time: 8 h) both inside and outside 38 randomly selected shops situated on four heavy traffic streets of Genoa was obtained using passive diffusion tubes. Reproducibility and accuracy of this analytical method were tested in real outdoor urban conditions and found within 25%; the detection limit was 1 mgm -3 of CO. The highest mean CO concentrations (15.8 ± 2.2 mgm -3) were found inside shops on Balbi street, a narrow "canyon street". Only in two small shops and two bars (both with many smokers) and in a delicatessen, were indoor CO concentrations significantly higher than outdoor values. The mean outdoor CO concentrations (mgm -3) along the four streets considered (XX Settembre, Balbi, Rolando, Fillak) were 7.4 ± 2.2; 14.5 ± 8.7; 5.8 ± 0.4; 10.5 ± 3.7, respectively. No statistical difference was found, comparing the mean indoor CO concentration with the mean CO outdoor value, measured simultaneously along the sidewalks of each street. CO concentrations in 10 shops without smokers and the nearest outdoor measurements were linearly correlated ( r = 0.99; p statistically significant difference was found comparing indoor CO pollution in shops with smokers (CO: 8.0 ± 5.4) to those without smokers (CO: 7.1 ± 4.6). Forced ventilation, with air intake far from traffic, proved effective in some specific situations in reducing indoor CO concentrations.

  19. New insight into the distribution pattern, levels, and risk diagnosis of FRs in indoor and outdoor air at low- and high-altitude zones of Pakistan: Implications for sources and exposure.

    Science.gov (United States)

    Khan, Muhammad Usman; Besis, Athanasios; Li, Jun; Zhang, Gan; Malik, Riffat Naseem

    2017-10-01

    Data regarding flame retardants (FRs) in indoor and outdoor air and their exposure to population are scarce and especially unknown in the case of Pakistan. The current study was designed to probe FR concentrations and distribution pattern in indoor and outdoor air at different altitudinal zones (DAZs) of Pakistan with special emphasis on their risk to the exposed population. In this study, passive air samplers for the purpose of FR deposition were deployed in indoor and outdoor air at the industrial, rural, and background/colder zones/sites. All the indoor and outdoor air samples collected from DAZs were analyzed for the target FRs (9.30-472.30 pg/m 3 ), showing a decreasing trend as follows: ∑NBFRs > ∑PBDEs > ∑DP. However, significant correlations among FRs in the indoor and outdoor air at DAZs signified a similar source of FR origin that is used in different consumer goods. Furthermore, air mass trajectories revealed that movement of air over industrial area sources influenced concentrations of FRs at rural sites. The FR concentrations, estimated daily intake (EDI) and the hazard quotient (HQ), were recorded to be higher in toddlers than those in adults. In addition, indoor air samples showed higher FR levels, EDI and HQ, than outdoor air samples. An elevated FR concentrations and their prevalent exposure risks were recorded in the industrial zones followed by rural and background zones. The HQ for BDE-47 and BDE-99 in the indoor and outdoor air samples at different industrial and rural sites were recorded to be >1 in toddlers and adults, this further warrants a health risk in the population. However, FR investigation in indoor and outdoor air samples will provide a baseline data in Pakistan to take further steps by the government and agencies for its implementations. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. Cardiovascular effects of the combined exposure to noise and outdoor air pollution: A review

    NARCIS (Netherlands)

    Lekaviciute, J.; Kluizenaar, Y. de; Laszlo, H.E.; Hansell, A.; Floud, S.; Lercher, P.; Babisch, W.; Kephalopoulos, S.

    2012-01-01

    The combination of noise with other environmental stressors, particularly traffic-related air pollution, has been of growing interest in recent years. Cardiovascular effects are among the most evidence-based physical health outcomes. Moreover, the European Network on Noise and Health (ENNAH), which

  1. End-user perspective of low-cost sensors for outdoor air pollution monitoring.

    Science.gov (United States)

    Rai, Aakash C; Kumar, Prashant; Pilla, Francesco; Skouloudis, Andreas N; Di Sabatino, Silvana; Ratti, Carlo; Yasar, Ansar; Rickerby, David

    2017-12-31

    Low-cost sensor technology can potentially revolutionise the area of air pollution monitoring by providing high-density spatiotemporal pollution data. Such data can be utilised for supplementing traditional pollution monitoring, improving exposure estimates, and raising community awareness about air pollution. However, data quality remains a major concern that hinders the widespread adoption of low-cost sensor technology. Unreliable data may mislead unsuspecting users and potentially lead to alarming consequences such as reporting acceptable air pollutant levels when they are above the limits deemed safe for human health. This article provides scientific guidance to the end-users for effectively deploying low-cost sensors for monitoring air pollution and people's exposure, while ensuring reasonable data quality. We review the performance characteristics of several low-cost particle and gas monitoring sensors and provide recommendations to end-users for making proper sensor selection by summarizing the capabilities and limitations of such sensors. The challenges, best practices, and future outlook for effectively deploying low-cost sensors, and maintaining data quality are also discussed. For data quality assurance, a two-stage sensor calibration process is recommended, which includes laboratory calibration under controlled conditions by the manufacturer supplemented with routine calibration checks performed by the end-user under final deployment conditions. For large sensor networks where routine calibration checks are impractical, statistical techniques for data quality assurance should be utilised. Further advancements and adoption of sophisticated mathematical and statistical techniques for sensor calibration, fault detection, and data quality assurance can indeed help to realise the promised benefits of a low-cost air pollution sensor network. Copyright © 2017 Elsevier B.V. All rights reserved.

  2. The Global Contribution of Outdoor Air Pollution to the Incidence, Prevalence, Mortality and Hospital Admission for Chronic Obstructive Pulmonary Disease: A Systematic Review and Meta-Analysis

    Science.gov (United States)

    Song, Qingkun; Christiani, David C.; Wang, Xiaorong; Ren, Jun

    2014-01-01

    Objective: This study aimed to investigate the quantitative effects of outdoor air pollution, represented by 10 µg/m3 increment of PM10, on chronic obstructive pulmonary disease in China, United States and European Union through systematic review and meta-analysis. Methods: Publications in English and Chinese from PubMed and EMBASE were selected. The Cochrane Review Handbook of Generic Inverse Variance was used to synthesize the pooled effects on incidence, prevalence, mortality and hospital admission. Results: Outdoor air pollution contributed to higher incidence and prevalence of COPD. Short-term exposure was associated with COPD mortality increased by 6%, 1% and 1% in the European Union, the United States and China, respectively (p < 0.05). Chronic PM exposure produced a 10% increase in mortality. In a short-term exposure to 10 µg/m3 PM10 increment COPD mortality was elevated by 1% in China (p < 0.05) and hospital admission enrollment was increased by 1% in China, 2% in United States and 1% in European Union (p < 0.05). Conclusions: Outdoor air pollution contributes to the increasing burdens of COPD.10 µg/m3 increase of PM10 produced significant condition of COPD death and exacerbation in China, United States and European Union. Controlling air pollution will have substantial benefit to COPD morbidity and mortality. PMID:25405599

  3. Asthma in the vicinity of power stations: II. Outdoor air quality and symptoms

    International Nuclear Information System (INIS)

    Henry, R.L.; Bridgman, H.A.; Wlodarczyk, J.; Abramson, R.; Adler, J.A.; Hensley, M.J.

    1991-01-01

    To assess longitudinally the effect of living in the vicinity of coal-fired power stations on children with asthma, 99 schoolchildren with a history of wheezing in the previous 12 months were studied for 1 year, using daily diaries and measurements of air quality. The children had been identified in a cross-sectional survey of two coastal areas: Lake Munmorah (LM), within 5 km of two power stations, and Nelson Bay (NB), free from major industry. Daily air quality [sulphur dioxide (SO2) and nitrogen oxides (NOx)], respiratory symptoms, and treatment for asthma were recorded throughout the year. Measurements of SO2 and NOx at LM were well within recommended guidelines although they were several times higher than at NB: maximum daily levels in SO2 (micrograms/m3) were 26 at LM, 11 at NB (standard, 365); yearly average SO2 was 2 at LM, 0.3 at NB (standard, 60); yearly average NOx (micrograms/m3) was 2 at LM, 0.4 at NB (standard, 94). Marked weekly fluctuations occurred in the prevalence of cough, wheezing, and breathlessness, without any substantial differences between LM and NB. Overall, the prevalence of symptoms was low (10% for wheezing, 20% for any symptom). Whether the daily SO2 and NOx levels affected the occurrence of respiratory symptoms was investigated in children at LM using a logistic regression (Korn and Whittemore technique). For these children as a group, air quality measurements were not associated with the occurrence of symptoms

  4. Mortality and morbidity due to exposure to outdoor air pollution in Mashhad metropolis, Iran. The AirQ model approach.

    Science.gov (United States)

    Miri, Mohammad; Derakhshan, Zahra; Allahabadi, Ahmad; Ahmadi, Ehsan; Oliveri Conti, Gea; Ferrante, Margherita; Aval, Hamideh Ebrahimi

    2016-11-01

    In the past two decades, epidemiological studies have shown that air pollution is one of the causes of morbidity and mortality. In this study the effect of PM10, PM2.5, NO2, SO2 and O3 pollutants on human health among the inhabitants of Mashhad has been evaluated. To evaluate the health effects due to air pollution, the AirQ model software 3.3.2, developed by WHO European Centre for Environment and Health, was used. The daily data related to the pollutants listed above has been used for the short term health effects (total mortality, cardiovascular and respiratory mortality, hospitalization due to cardiovascular and respiratory diseases, chronic obstructive pulmonary disease and acute myocardial infarction). PM2.5 had the most health effects on Mashhad inhabitants. With increasing in each 10μg/m3, relative risk rate of pollutant concentration for total mortality due to PM10, PM2.5, SO 2 , NO 2 and O 3 was increased of 0.6%, 1.5%, 0.4%, 0.3% and 0.46% respectively and, the attributable proportion of total mortality attributed to these pollutants was respectively equal to 4.24%, 4.57%, 0.99%, 2.21%, 2.08%, and 1.61% (CI 95%) of the total mortality (correct for the non-accident) occurred in the year of study. The results of this study have a good compatibly with other studies conducted on the effects of air pollution on humans. The AirQ software model can be used in decision-makings as a useful and easy tool. Copyright © 2016 Elsevier Inc. All rights reserved.

  5. Acute effects of outdoor air pollution on emergency department visits due to five clinical subtypes of coronary heart diseases in shanghai, china.

    Science.gov (United States)

    Xie, Juan; He, Mingzhen; Zhu, Weiying

    2014-01-01

    Air pollution can be a contributing cause to the development and exacerbation of coronary heart disease (CHD), but there is little knowledge about the acute effects of air pollution on different clinical subtypes of CHD. We conducted a time-series study to investigate the association of air pollution (particulate matter with an aerodynamic diameter effects on sudden cardiac death, moderate effects on acute myocardial infarction and angina, weak effects on ischemic cardiomyopathy, and no effect on occult CHD. The associations were stronger among people aged 65 years or more than in younger individuals and in the cool season versus the warm one. Outdoor air pollution may have different effects of air pollution on 5 subtypes of CHD. Our results might be useful for the primary prevention of various subtypes of CHD exacerbated by air pollution.

  6. Experimental study of a combined system of solar Kang and solar air collector

    International Nuclear Information System (INIS)

    Wei, Wei; Ji, Jie; Chow, Tin-Tai; He, Wei; Chen, Haifei; Guo, Chao; Yu, Hancheng

    2015-01-01

    Highlights: • A combined system of solar Kang and solar air collector is proposed. • An experimental study on the combined system is made. • The mean air temperature reaches 18.5 °C and maintains above 18 °C for 13 h. • The corresponding mean indoor air temperature of the reference room is 8.9 °C. • The Kang surface temperature reaches 27 °C and maintains above 18 °C for 23 h. - Abstract: Chinese Kang is widely used as heated bed and for heat recovery of cooking stove in Northern China. However there are main drawbacks of indoor and outdoor air pollutant generation and heavy demands on solid fuel handling. A novel combined Kang system, which integrates solar Kang and solar air collector, is here proposed. Experiments were conducted to examine the alternative operating modes: (i) only solar air collector in service, (ii) only solar Kang in service, and (iii) both solar Kang and solar air collector in service. The results show that these three modes behave differently and have distinct effects on room thermal environment in winter. When this pollution-free system operates under the third combined mode, the room temperature increases significantly and the vertical temperature gradient reduces. The Kang surface temperature increases and its uniformity is improved. It is also found that the room air temperature is closely related to the Kang surface temperature. Furthermore, most of the time the thermal environment meets the occupant need. This paper reports the experimental work and investigates into the effects on indoor thermal environment as in rural residences in Northern China

  7. Intrauterine and early postnatal exposure to outdoor air pollution and lung function at preschool age.

    Science.gov (United States)

    Morales, Eva; Garcia-Esteban, Raquel; de la Cruz, Oscar Asensio; Basterrechea, Mikel; Lertxundi, Aitana; de Dicastillo, Maria D Martinez López; Zabaleta, Carlos; Sunyer, Jordi

    2015-01-01

    Effects of prenatal and postnatal exposure to air pollution on lung function at preschool age remain unexplored. We examined the association of exposure to air pollution during specific trimesters of pregnancy and postnatal life with lung function in preschoolers. Lung function was assessed with spirometry in preschoolers aged 4.5 years (n=620) participating in the INfancia y Medio Ambiente (INMA) cohort. Temporally adjusted land use regression (LUR) models were applied to estimate individual residential exposures to benzene and nitrogen dioxide (NO₂) during specific trimesters of pregnancy and early postnatal life (the first year of life). Recent and current (1 year and 1 week before lung function testing, respectively) exposures to NO₂ and nitrogen oxides (NOx) were also assessed. Exposure to higher levels of benzene and NO₂ during pregnancy was associated with reduced lung function. FEV1 estimates for an IQR increase in exposures during the second trimester of pregnancy were -18.4 mL, 95% CI -34.8 to -2.1 for benzene and -28.0 mL, 95% CI -52.9 to -3.2 for NO₂. Relative risk (RR) of low lung function (<80% of predicted FEV1) for an IQR increase in benzene and NO₂ during the second trimester of pregnancy were 1.22, 95% CI 1.02 to 1.46 and 1.30, 95% CI 0.97 to 1.76, respectively. Associations for early postnatal, recent and current exposures were not statistically significant. Stronger associations appeared among allergic children and those of lower social class. Prenatal exposure to residential traffic-related air pollution may result in long-term lung function deficits at preschool age. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  8. Field Demonstration of Active Desiccant-Based Outdoor Air Preconditioning Systems, Final Report: Phase 3; FINAL

    International Nuclear Information System (INIS)

    Fischer, J.

    2001-01-01

    This report summarizes an investigation of the performance of two active desiccant cooling systems that were installed as pilot systems in two locations-a college dormitory and a research laboratory-during the fall of 1999. The laboratory system was assembled in the field from commercially available Trane air-handling modules combined with a standard total energy recovery module and a customized active desiccant wheel, both produced by SEMCO. The dormitory system was a factory-built, integrated system produced by SEMCO that included both active desiccant and sensible-only recovery wheels, a direct-fired gas regeneration section, and a pre-piped Trane heat pump condensing section. Both systems were equipped with direct digital control systems, complete with full instrumentation and remote monitoring capabilities. This report includes detailed descriptions of these two systems, installation details, samples of actual performance, and estimations of the energy savings realized. These pi lot sites represent a continuation of previous active desiccant product development research (Fischer, Hallstrom, and Sand 2000; Fischer 2000). Both systems performed as anticipated, were reliable, and required minimal maintenance. The dehumidification/total-energy-recovery hybrid approach was particularly effective in all respects. System performance showed remarkable improvement in latent load handling capability and operating efficiency compared with the original conventional cooling system and with the conventional system that remained in another, identical wing of the facility. The dehumidification capacity of the pilot systems was very high, the cost of operation was very low, and the system was cost-effective, offering a simple payback for these retrofit installations of approximately 5 to 6 years. Most important, the dormitory system resolved numerous indoor air quality problems in the dormitory by providing effective humidity control and increased, continuous ventilation air

  9. Experimental testing of the thermal performance of finned air coolers

    International Nuclear Information System (INIS)

    Imhof, A.; Keller, J.; Koelliker, A.

    1988-05-01

    Finned heat exchangers are often used as regenerators in heat recovery systems or as a heat source for heat pump installations. These exchangers are usually operating as air coolers. Heat is extracted from the air flowing through the heat exchanger. If the fin temperature lies below the dew point at the air inlet, water vapour may be condensed, increasing the thermal performance of the cooler. If the air/water heat exchanger is installed outdoors, the blower is usually mounted directly at the exchaner's case. In general this leads to non-ideal air flow conditions. For the sizing of such components the manufacturers dispose of design rules which are based either on theoretical models or on experiments using a uniform air stream. These rules which are mostly internal codes of the individual companies presumably do not take into account some non-ideal conditions such as an inhomogeneous air flow, a poorly sized blower or an increased pressure drop between the fins due to condensed water vapour. Moreover, these codes are possibly not sophisticated enough to enable a correct sizing of the products for any given condition of operation, especially in heat pumps operating under condensation conditions. Therfore, the Swiss Federal Institute for Reactor Research (EIR) carried out a research program dealing with the thermal performance of commercially available finned air coolers. The results give a strong evidence that the sizing of finned air coolers involving a phase change in one of the heat transfer fluids is not yet a procedure belonging to the common knowledge of most of the manufacturers. Moreover, the correct sizing of the blower is at least as important as the sizing of the finned exchanger itself. However, it is evident that there are companies on the Swiss market which use already reliable design tools. 25 refs., 81 figs., 12 tabs

  10. Occurrence of benzothiazole, benzotriazole and benzenesulfonamide derivates in outdoor air particulate matter samples and human exposure assessment.

    Science.gov (United States)

    Maceira, Alba; Marcé, Rosa Maria; Borrull, Francesc

    2018-02-01

    Benzothiazole (BTHs), benzotriazole (BTRs) and benzenesulfonamide (BSAs) derivates are high production volume chemicals and they are used in several industrial and household applications, therefore it is expected their occurrence in various environments, especially water and air. In this study we developed a method based on gas chromatography-mass spectrometry (GC-MS) combined with pressurised liquid extraction (PLE) to simultaneously determine four BTR, five BTH and six BSA derivates in the particulate matter (PM 10 ) of outdoor air samples collected in quartz fibre filters (QFFs). To the best of our knowledge, this is the first time these compounds have been determined in open ambient environments. Under optimised conditions, method recoveries at the lower and upper concentration levels (0.8 and 4.2 ng m -3 ) ranged from 70 to 120%, except for 1-H-benzothiazole and 2-chlorobenzothiazole, which were about 50%. The repeatability of the method was usually below 20% (n = 3, %RSD) for both concentration levels. This method enables the contaminants to be detected at pg m -3 concentration levels. Several samples from two different sites influenced by local industries showed that BTRs, followed by BTHs, were the most detected compounds, whereas BSAs were hardly found. The most frequently determined compounds were 1-H-benzothiazole, 2-chlorobenzothiazole, 1-H-benzotriazole, 2-hydroxibenzothiazole, 5,6-dimethyl-1-H-benzotriazole and the isomers 4- and 5-methyl-1-H-benzotriazole. With the concentrations found, the human exposure assessment and health risk characterization via ambient inhalation were also evaluated taking into account different subpopulation groups classified by age for the two sampling points. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. Reducing indoor residential exposures to outdoor pollutants

    Energy Technology Data Exchange (ETDEWEB)

    Sherman, Max H.; Matson, Nance E.

    2003-07-01

    The basic strategy for providing indoor air quality in residences is to dilute indoor sources with outdoor air. This strategy assumes that the outdoor air does not have pollutants at harmful levels or that the outdoor air is, at least, less polluted than the indoor air. When this is not the case, different strategies need to be employed to ensure adequate air quality in the indoor environment. These strategies include ventilation systems, filtration and other measures. These strategies can be used for several types of outdoor pollution, including smog, particulates and toxic air pollutants. This report reviews the impacts that typical outdoor air pollutants can have on the indoor environment and provides design and operational guidance for mitigating them. Poor quality air cannot be used for diluting indoor contaminants, but more generally it can become an indoor contaminant itself. This paper discusses strategies that use the building as protection against potentially hazardous outdoor pollutants, including widespread pollutants, accidental events, and potential attacks.

  12. Experimental Setup For Study of Drop Deformation In Air Flow

    Directory of Open Access Journals (Sweden)

    Basalaev Sergey

    2017-01-01

    Full Text Available Experimental study for study of deformation of drops in air flow is considered. Experimental setup includes a module for obtaining the drops, an air flow system and measuring system. Module for formation of drops is in the form of vertically arranged dropper with capillary with the possibility of formation of fixed drops. Air flow supply system comprises an air pump coupled conduit through a regulating valve with a cylindrical pipe, installed coaxially with dropper. The measuring system includes the video camera located with possibility of visualization of drop and the Pitot gage for measurement of flow rate of air located in the output section of branch pipe. This experimental setup allows to provide reliable and informative results of the investigation of deformation of drops in the air flow.

  13. Experimental study on energy performance of clean air heat pump

    DEFF Research Database (Denmark)

    Fang, Lei; Nie, Jinzhe; Olesen, Bjarne W.

    2014-01-01

    An innovative clean air heat pump (CAHP) was designed and developed based on the air purification capacity of regenerative silica gel rotor. The clean air heat pump integrated air purification, dehumidification and cooling in one unit. A prototype of the clean air heat pump was developed...... to investigate its energy performance. Energy consumption of the prototype of CAHP was measured in laboratory at different climate conditions including mild-cold, mildhot and extremely hot and humid climates. The energy saving potential of the clean air heat pump compared to a conventional ventilation and air......-conditioning system was calculated. The experimental results showed that the clean air heat pump saved substantial amount of energy compared to the conventional system. For example, the CAHP can save up to 59% of electricity in Copenhagen, up to 40% of electricity in Milan and up to 30% of electricity in Colombo...

  14. Model calibration of a variable refrigerant flow system with a dedicated outdoor air system: A case study

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Dongsu [Mississippi State Univ., Starkville, MS (United States); Cox, Sam J. [Mississippi State Univ., Starkville, MS (United States); Cho, Heejin [Mississippi State Univ., Starkville, MS (United States); Im, Piljae [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2017-10-16

    With increased use of variable refrigerant flow (VRF) systems in the U.S. building sector, interests in capability and rationality of various building energy modeling tools to simulate VRF systems are rising. This paper presents the detailed procedures for model calibration of a VRF system with a dedicated outdoor air system (DOAS) by comparing to detailed measured data from an occupancy emulated small office building. The building energy model is first developed based on as-built drawings, and building and system characteristics available. The whole building energy modeling tool used for the study is U.S. DOE’s EnergyPlus version 8.1. The initial model is, then, calibrated with the hourly measured data from the target building and VRF-DOAS system. In a detailed calibration procedures of the VRF-DOAS, the original EnergyPlus source code is modified to enable the modeling of the specific VRF-DOAS installed in the building. After a proper calibration during cooling and heating seasons, the VRF-DOAS model can reasonably predict the performance of the actual VRF-DOAS system based on the criteria from ASHRAE Guideline 14-2014. The calibration results show that hourly CV-RMSE and NMBE would be 15.7% and 3.8%, respectively, which is deemed to be calibrated. As a result, the whole-building energy usage after calibration of the VRF-DOAS model is 1.9% (78.8 kWh) lower than that of the measurements during comparison period.

  15. Impact of Oxidant Gases on the Relationship between Outdoor Fine Particulate Air Pollution and Nonaccidental, Cardiovascular, and Respiratory Mortality.

    Science.gov (United States)

    Weichenthal, Scott; Pinault, Lauren L; Burnett, Richard T

    2017-11-27

    Outdoor fine particulate air pollution (PM 2.5 ) is known to increase mortality risk and is recognized as an important contributor to global disease burden. However, less is known about how oxidant gases may modify the chronic health effects of PM 2.5 . In this study, we examined how the oxidant capacity of O 3 and NO 2 (using a redox-weighted average, O x ) may modify the relationship between PM 2.5 and mortality in the 2001 Canadian Census Health and Environment Cohort. In total, 2,448,500 people were followed over a 10.6-year period. Each 3.86 µg/m 3 increase in PM 2.5 was associated with nonaccidental (Hazard Ratio (HR) = 1.095, 95% CI: 1.077, 1.112), cardiovascular (HR = 1.088, 95% CI: 1.059, 1.118), and respiratory mortality (HR = 1.110, 95% CI: 1.051, 1.171) in the highest tertile of O x whereas weaker/null associations were observed in the middle and lower tertiles. Analysis of joint non-linear concentration-response relationships for PM 2.5 and O x suggested threshold concentrations between approximately 23 and 25 ppb with O x concentrations above these values strengthening PM 2.5 -mortality associations. Overall, our findings suggest that oxidant gases enhance the chronic health risks of PM 2.5 . In some areas, reductions in O x concentrations may have the added benefit of reducing the public health impacts of PM 2.5 even if mass concentrations remain unchanged.

  16. An experimental study on defrosting heat supplies and energy consumptions during a reverse cycle defrost operation for an air source heat pump

    International Nuclear Information System (INIS)

    Dong Jiankai; Deng Shiming; Jiang Yiqiang; Xia Liang; Yao Yang

    2012-01-01

    For a space heating air source heat pump (ASHP) unit, when its outdoor coil surface temperature is below both the air dew point temperature and the freezing point of water, frost will form on its outdoor coil surface. Frosting affects its operational performance and energy efficiency. Therefore, periodic defrosting is necessary. Currently, the most widely used standard defrosting method for ASHP units is reverse cycle defrost. The energy that should have been used for space heating is used to melt frost, vaporize the melted frost off outdoor coil surface and heat ambient air during defrosting. It is therefore necessary to study the sources of heat supplies and the end-uses of the heat supplied during a reverse cycle defrost operation. In this paper, firstly, an experimental setup is described and experimental procedures are detailed. This is followed by reporting the experimental results and the evaluation of defrosting efficiency for the experimental ASHP unit. Finally, an evaluation of defrosting heat supplies and energy consumptions during a revere cycle defrost operation for the experimental ASHP unit is presented. The experimental and evaluation results indicated that the heat supply from indoor air contributed to 71.8% of the total heat supplied for defrosting and 59.4% of the supplied energy was used for melting frost. The maximum defrosting efficiency could be up to 60.1%. - Highlights: ► Heat supply and consumption during reverse cycle defrost was experimentally studied. ► Indoor air contributed to >70% of total heat supply when indoor fan was turned on. ► ∼60% of the supplied energy was used for melting frost. ► Alternate heat supply other than indoor air should be explored.

  17. Experimental study of CO/sub 2/-laser-induced air breakdown over long distances

    Energy Technology Data Exchange (ETDEWEB)

    Caressa, J.; Autric, M.; Dufresne, D.; Bournot, P.

    1979-11-01

    Results of an experimental study on air breakdown produced by radiation from a high-power CO/sub 2/ laser are presented. From these measurements, the breakdown threshold over a flux range (1.5 x 10/sup 8/ outdoors under typical atmosphere conditions. The temporal evolution of the energy transmitted through the breakdown region for different laser parameters (5

  18. Experimental analysis of humidification process by air passing through seawater

    International Nuclear Information System (INIS)

    El-Agouz, S.A.; Abugderah, M.

    2008-01-01

    An experimental investigation of humidification process by air passing through seawater is presented. The main objective of this work was to determine the humid air behaviour through single-stage of heating-humidifying processes. This experimental work studied the influence of the operating conditions such as the water temperature, the headwater difference, the air velocity and the inlet air temperature to evaporator chamber on the vapour content difference and humidification efficiency. Two cases of different inlet conditions of ambient and heated air cases are studied. The experimental results show that, the vapour content difference and the humidification efficiency of the system is strongly affected by the saline water temperature in the evaporator chamber, headwater difference and the air velocity. The inlet air temperature to evaporator chamber variation was found to have a small affect on the vapour content difference. The obtained maximum vapour content difference of the air was about 222 gr w /kg a at 75 deg. C for water and air. The obtained vapour content is high compared to that obtained in literature for single-stage and very similar for multi-stage

  19. Exhaled carbon monoxide: a non-invasive biomarker of short-term exposure to outdoor air pollution

    Directory of Open Access Journals (Sweden)

    Herve Lawin

    2017-04-01

    Full Text Available Abstract Background In urban settings of Africa with rapidly increasing population, traffic-related air pollution is a major contributor to outdoor air pollution (OAP. Although OAP has been identified as a leading cause of global morbidity and mortality, there is however, lack of a simple biomarker to assess levels of exposure to OAP in resource-poor settings. This study evaluated the role of exhaled carbon monoxide (exhCO as a potential biomarker of exposure to ambient carbon monoxide (ambCO from OAP. Methods This was a descriptive study conducted among male commercial motorcycle riders in Cotonou – the economic capital of Benin. The participants’ AmbCO was measured using a portable carbon monoxide (CO data logger for 8 h during the period of their shift. ExhCO was measured just before and immediately after their shift (8-h Participants were asked not to cook or to smoke during the day of the measurements. Linear regression analysis was used to assess the association between ambCO and exhCO for the last 2, 4 and 6 h of their shift. Results Of 170 participants who completed the study, their mean ± SD age was 42.2 ± 8.4 years, and their mean ± SD daily income was 7.3 ± 2.7$. Also, 95% of the participants’ used solid fuels for cooking and only 2% had ever smoked. Average exhCO increased by 5.1 ppm at the end of the shift (p = 0.004. Post-shift exhCO was significantly associated to ambCO, this association was strongest for the last 2 h of OAP exposure before exhCO measurement (β = 0.34, p < 0.001. Conclusion ExhCO level was associated with recent exposure to ambCO from OAP with measurable increase after 8 h of exposure. These findings suggest that ExhCO may be a potential biomarker of short-term exposure to OAP.

  20. Development and characterization of silica and titania based nano structured materials for the removal of indoor and outdoor air pollutants

    Science.gov (United States)

    Peiris, Thelge Manindu Nirasha

    photocatalytic activity. In contrast, our xerogel system shows comparatively high visible light photocatalytic activity for the titania based system, showing the importance of non-localized nature of photocatalysis. The Cobalt doped silica system shows interesting dark catalytic activity towards acetaldehyde and several other pollutants. Thus, in summary, based on the different activities we observed during our studies these materials could be successfully used to improve the quality of both indoor and outdoor air.

  1. Indoor air purification using heterogeneous photocatalytic oxidation. Part I: Experimental study

    NARCIS (Netherlands)

    Yu, Q.; Brouwers, H.J.H.

    2009-01-01

    Heterogeneous photocatalytic oxidation (PCO) has shown to be a promising air purifying technology in outdoor conditions using TiO2 as photocatalyst activated with UV light. Also to indoor air quality more and more attention is paid because of the very important role it plays on human health, and it

  2. Outdoor air pollution and emergency department visits for asthma among children and adults: A case-crossover study in northern Alberta, Canada

    Directory of Open Access Journals (Sweden)

    Rowe Brian H

    2007-12-01

    Full Text Available Abstract Background Recent studies have observed positive associations between outdoor air pollution and emergency department (ED visits for asthma. However, few have examined the possible confounding influence of aeroallergens, or reported findings among very young children. Methods A time stratified case-crossover design was used to examine 57,912 ED asthma visits among individuals two years of age and older in the census metropolitan area of Edmonton, Canada between April 1, 1992 and March 31, 2002. Daily air pollution levels for the entire region were estimated from three fixed-site monitoring stations. Similarly, daily levels of aeroallergens were estimated using rotational impaction sampling methods for the period between 1996 and 2002. Odds ratios and their corresponding 95% confidence intervals were estimated using conditional logistic regression with adjustment for temperature, relative humidity and seasonal epidemics of viral related respiratory disease. Results Positive associations for asthma visits with outdoor air pollution levels were observed between April and September, but were absent during the remainder of the year. Effects were strongest among young children. Namely, an increase in the interquartile range of the 5-day average for NO2 and CO levels between April and September was associated with a 50% and 48% increase, respectively, in the number of ED visits among children 2 – 4 years of age (p Conclusion Our findings, taken together, suggest that exposure to ambient levels of air pollution is an important determinant of ED visits for asthma, particularly among young children and the elderly.

  3. Experimental analysis and regression prediction of desiccant wheel behavior in high temperature heat pump and desiccant wheel air-conditioning system

    DEFF Research Database (Denmark)

    Sheng, Ying; Zhang, Yufeng; Sun, Yuexia

    2014-01-01

    The objectives of this study are to evaluate the performance of desiccant wheel (DW) in the running system and obtain the useful data for practical application. The combined influences of multiple variables on the performance of desiccant wheel are investigated based on evaluating the indexes...... of moisture removal capacity, dehumidification effectiveness, dehumidification coefficient of performance and sensible energy ratio. The results show that higher effect on the dehumidification is due to the regeneration temperature and outdoor air humidity ratio rather than the outdoor air temperature...... and the ratio between regeneration and process air flow rates. A simple method based on multiple linear regression theory for predicting the performance of the wheel has been proposed. The predicted values and the experimental data are compared and good agreements are obtained. Regression models are established...

  4. Outdoor Classrooms

    Science.gov (United States)

    Mayes, Valynda

    2010-01-01

    An outdoor classroom is the ideal vehicle for community involvement: Parents, native plant societies, 4-H, garden clubs, and master naturalists are all resources waiting to be tapped, as are local businesses offering support. If you enlist your community in the development and maintenance of your outdoor classroom, the entire community will…

  5. Measurement and health risk assessment of PM2.5, flame retardants, carbonyls and black carbon in indoor and outdoor air in kindergartens in Hong Kong.

    Science.gov (United States)

    Deng, Wen-Jing; Zheng, Hai-Long; Tsui, Anita K Y; Chen, Xun-Wen

    2016-11-01

    Indoor air pollution is closely related to children's health. Polybrominated diphenyl ethers (PBDEs) and dechlorane plus (DP) transmitted through indoor PM 2.5 and dust, along with carbonyl compounds and black carbon (BC) aerosol were analysed in five Hong Kong kindergartens. The results showed that 60% of the median PM 2.5 levels (1.3×10 1 to 2.9×10 1 μg/m 3 for indoor; 9.5 to 8.8×10 1 μg/m 3 for outdoor) in the five kindergartens were higher than the guidelines set by the World Health Organization (2.5×10 1 μg/m 3 ). Indoor PM 2.5 mass concentrations were correlated with outdoor PM 2.5 in four of the kindergartens. The PBDEs (0.10-0.64ng/m 3 in PM 2.5 ; 0.30-2.0×10 2 ng/g in dust) and DP (0.05-0.10ng/m 3 in PM 2.5 ; 1.3-8.7ng/g in dust) were detected in 100% of the PM 2.5 and dust samples. Fire retardant levels in the air were not correlated with the levels of dust in this study. The median BC concentrations varied by >7-fold from 8.8×10 2 ng/m -3 to 6.7×10 3 ng/m -3 and cooking events might have caused BC concentrations to rise both indoors and outdoors. The total concentrations of 16 carbonyls ranged from 4.7×10 1 μg/m 3 to 9.3×10 1 μg/m 3 indoors and from 1.9×10 1 μg/m 3 to 4.3×10 1 μg/m 3 outdoors, whilst formaldehyde was the most abundant air carbonyl. Indoor carbonyl concentrations were correlated with outdoor carbonyls in three kindergartens. The health risk assessment showed that hazard indexes (HIs) HIs of non-cancer risks from PBDEs and DPs were all lower than 0.08, whilst non-cancer HIs of carbonyl compounds ranged from 0.77 to 1.85 indoors and from 0.50 to 0.97 outdoors. The human intake of PBDEs and DP through inhalation of PM 2.5 accounted for 78% to 92% of the total intake. The cancer hazard quotients (HQs) of formaldehyde ranged from 4.5E-05 to 2.1E-04 indoors and from 1.9E-05 to 6.2E-05 outdoors. In general, the indoor air pollution in the five Hong Kong kindergartens might present adverse effects to children, although different

  6. Experimental evaluation of a direct air-cooled lithium bromide-water absorption prototype for solar air conditioning

    International Nuclear Information System (INIS)

    Gonzalez-Gil, A.; Izquierdo, M.; Marcos, J.D.; Palacios, E.

    2011-01-01

    A new direct air-cooled single-effect LiBr-H 2 O absorption prototype is described and proposed for use in solar cooling. As distinguishing aspects, it presents: an adiabatic absorber using flat-fan sheets; an air-cooling system that directly refrigerates both the condenser and the absorber and; the possibility of being operated also as a double-effect unit. A solar facility comprising a 48 m 2 field of flat-plate collectors was used to test the single-effect operation mode of the prototype. Results from an experimental campaign carried out in Madrid during summer 2010 are shown and operation parameters corresponding to two typical summer days are detailed. The prototype worked efficiently, with COP values around 0.6. Cooling power varied from 2 kW to 3.8 kW, which represented about 85% of the prototype's nominal capacity. Chilled water temperatures mostly ranged between 14 o C and 16 o C, although the lowest measured value was of 12.8 o C. Condensation and absorption temperatures were under 50 o C and 46 o C, respectively, even with outdoor temperatures of 40 o C. Driving water temperature ranged between 85 o C and 110 o C. As a mean, the system was able to meet 65% of the cooling demand corresponding to a room of 40 m 2 . No signs of crystallization were observed during about a hundred hours of operation. - Highlights: → A novel direct air-cooled single-effect absorption prototype is described. → Feasibility of air-cooled technology for LiBr-H 2 O absorption cooling is proved. → An adiabatic absorber using flat-fan sheets avoids crystallization of the solution. → A field of flat-plate collectors powers the chiller at temperatures from 85 to 110 o C. → The prototype works with thermal COP about 0.6.

  7. Indoor Air Pollution (Environmental Health Student Portal)

    Science.gov (United States)

    ... Students to Environmental Health Information Menu Home Air Pollution Air Pollution Home Indoor Air Pollution Outdoor Air Pollution ... Pollution Indoor Air Pollution Print this Page Air Pollution Air Pollution Home Indoor Air Pollution Outdoor Air Pollution ...

  8. Theoretical modelling and experimental study of air thermal conditioning process of a heat pump assisted solid desiccant cooling system

    DEFF Research Database (Denmark)

    Nie, Jinzhe; Li, Zan; Hu, Wenju

    2017-01-01

    purification aimed at improving indoor air quality and reducing building energy consumption. The heat and moisture transfer in adsorption desiccant rotor was theoretical modelled with one-dimensional partial differential equations. The theoretical model was validated with experimental measurements...... system, the energy performance of HP-SDC was more efficient mainly due to high efficient air purification capacity, reduction of cooling load and raised evaporation temperature. The energy performance of HP-SDC was sensitive to outdoor humidity ratio. Further improvements of HP-SDC energy efficiency......Taking the integrated gaseous contaminants and moisture adsorption potential of desiccant material, a new heat pump assisted solid desiccant cooling system (HP-SDC) was proposed based on the combination of desiccant rotor with heat pump. The HP-SDC was designed for dehumidification, cooling and air...

  9. Investigation the effect of outdoor air infiltration on the heat-shielding characteristics the outer walls of high-rise buildings

    Science.gov (United States)

    Vytchikov, Yu. S.; Kostuganov, A. B.; Saparev, M. E.; Belyakov, I. G.

    2018-03-01

    The presented article considers the influence of infiltrated outdoor air on the heat-shielding characteristics of the exterior walls of modern residential and public buildings. A review of the sources devoted to this problem confirmed its relevance at the present time, especially for high-rise buildings. The authors of the article analyzed the effect of longitudinal and transverse air infiltration on the heat-shielding characteristics of the outer wall of a 25-story building that was built in Samara. The results showed a significant reduction of the reduced resistance to the heat transfer of the outer wall when air is infiltrated through it. There are the results of full-scale examination of external walls to confirm the calculated data. Based on the results of the study carried out by the authors of the article, general recommendations on the internal finishing of the outer walls of high-rise buildings are given.

  10. Humidification tower for humid air gas turbine cycles: Experimental analysis

    International Nuclear Information System (INIS)

    Traverso, A.

    2010-01-01

    In the HAT (humid air turbine) cycle, the humidification of compressed air can be provided by a pressurised saturator (i.e. humidification tower or saturation tower), this solution being known to offer several attractive features. This work is focused on an experimental study of a pressurised humidification tower, with structured packing. After a description of the test rig employed to carry out the measuring campaign, the results relating to the thermodynamic process are presented and discussed. The experimental campaign was carried out over 162 working points, covering a relatively wide range of possible operating conditions. It is shown that the saturator behaviour, in terms of air outlet humidity and temperature, is primarily driven by, in decreasing order of relevance, the inlet water temperature, the inlet water over inlet dry air mass flow ratio and the inlet air temperature. The exit relative humidity is consistently over 100%, which may be explained partially by measurement accuracy and droplet entrainment, and partially by the non-ideal behaviour of air-steam mixtures close to saturation. Experimental results have been successfully correlated using a set of new non-dimensional groups: such a correlation is able to capture the air outlet temperature with a standard deviation σ = 2.8 K.

  11. Experimental evaluation of sodium to air heat exchanger performance

    International Nuclear Information System (INIS)

    Vinod, V.; Pathak, S.P.; Paunikar, V.D.; Suresh Kumar, V.A.; Noushad, I.B.; Rajan, K.K.

    2013-01-01

    Highlights: ► Sodium to air heat exchangers are used to remove the decay heat produced in fast breeder reactor after shutdown. ► Finned tube sodium to air heat exchanger with sodium on tube side was tested for its heat transfer performance. ► A one dimensional computer code was validated by the experimental data obtained. ► Non uniform sodium and air flow distribution was present in the heat exchanger. - Abstract: Sodium to air heat exchangers (AHXs) is used in Prototype Fast Breeder Reactor (PFBR) circuits to reject the decay heat produced by the radioactive decay of the fission products after reactor shutdown, to the atmospheric air. The heat removal through sodium to air heat exchanger maintains the temperature of reactor components in the pool within safe limits in case of non availability of normal heat transport path. The performance of sodium to air heat exchanger is very critical to ensure high reliability of the decay heat removal systems in sodium cooled fast breeder reactors. Hence experimental evaluation of the adequacy of the heat transfer capability gives confidence to the designers. A finned tube cross flow sodium to air heat exchanger of 2 MW heat transfer capacity with sodium on tube side and air on shell side was tested in the Steam Generator Test Facility at Indira Gandhi Center for Atomic Research, India. Heat transfer experiments were carried out with forced circulation of sodium and air, which confirmed the adequacy of heat removal capacity of the heat exchanger. The testing showed that 2.34 MW of heat power is transferred from sodium to air at nominal flow and temperature conditions. A one dimensional computer code developed for design and analysis of the sodium to air heat exchanger was validated by the experimental data obtained. An equivalent Nusselt number, Nu eq is derived by approximating that the resistance of heat transfer from sodium to air is contributed only by the film resistance of air. The variation of Nu eq with respect

  12. [Experimental study on spectra of compressed air microwave plasma].

    Science.gov (United States)

    Liu, Yong-Xi; Zhang, Gui-Xin; Wang, Qiang; Hou, Ling-Yun

    2013-03-01

    Using a microwave plasma generator, compressed air microwave plasma was excited under 1 - 5 atm pressures. Under different pressures and different incident microwave power, the emission spectra of compressed air microwave plasma were studied with a spectra measuring system. The results show that continuum is significant at atmospheric pressure and the characteristic will be weakened as the pressure increases. The band spectra intensity will be reduced with the falling of the incident microwave power and the band spectra were still significant. The experimental results are valuable to studying the characteristics of compressed air microwave plasma and the generating conditions of NO active groups.

  13. EXPERIMENTAL INVESTIGATION OF AN AIR CHARGED LOW POWERED STIRLING ENGINE

    Directory of Open Access Journals (Sweden)

    Can ÇINAR

    2004-01-01

    Full Text Available In this study, an air charged, low powered manufactured ? type Stirling engine was investigated experimentally. Tests were conducted at 800, 900 and 1000 °C hot source temperatures, 1, 1.5, 2, 2.5, 3, 3.5 bars air charge pressure. The variation of engine power depending on the charge pressure and hot source temperature for two different heat transfer area was investigated experimentally. Maximum output power was obtained at 1000 °C and 3 bars charge pressure as 58 W at 441 rpm. Engine speed was reached at 846 rpm without load.

  14. Fungal spore concentrations in indoor and outdoor air in university libraries, and their variations in response to changes in meteorological variables.

    Science.gov (United States)

    Flores, María Elena Báez; Medina, Pável Gaxiola; Camacho, Sylvia Páz Díaz; de Jesús Uribe Beltrán, Magdalena; De la Cruz Otero, María del Carmen; Ramírez, Ignacio Osuna; Hernández, Martín Ernesto Tiznado

    2014-08-01

    The fungal spore concentration (FSC) in the air poses a risk for human health. This work studied the FSC in university libraries and how it is affected by environmental factors. A total of 347 samples were obtained using a Microbio MB2(®) Aerosol Sampler. The wind speed (WS), cross wind (CW), temperature (T), relative humidity (HR), barometric pressure (BP) and dew point (DP) were recorded using a Kestrel(®) 4500 weather station. The median indoor/outdoor FSC was 360/1230 CFU m(-3). FSC correlated inversely with BP, HR and DP; and positively with WS and CW; whereas T showed negative or positive correlation with FSC, depending on the region or sampling time. Eleven fungal genera were found and the dominant isolates were identified as Aspergillus niger, Aspergillus tamarii and Aspergillus oryzae. All fungi identified are known to be allergenic. It was concluded that environmental variables can influence the air FSC in different ways.

  15. Microenvironmental air and soil monitoring of contaminants: An evaluation of indoor and outdoor levels in Chihuahua City

    Science.gov (United States)

    Delgado-Rios, Marcos

    Like most of the cities around the world Chihuahua City suffers atmospheric and soil pollution. This is a problem that requires immediate attention from both public authorities and the scientific community. Although it is known that high levels of heavy metals are present in the airborne particulate matter, soil and dust in many urban regions, the information about personal exposure to these pollutants in Chihuahua City is nonexistent. This study focuses on the analysis and characterization of lead and arsenic in the airborne and soil particulate matter present in the interiors of households and their surrounding outdoor environments in the southern part of Chihuahua City. The sampling area chosen for this study was located in the southern part of Chihuahua City. An atmospheric sampling point selected by the Centro de Investigacion en Materiales Avanzados (CIMAV) was selected as a geographical center, with a 2 km radius forming the sampling area. The households selected for analyses were located on Lombardo Toledano Street, a high-traffic street. The main objectives of this study were to establish the maximum exposure level in outdoor and indoor environments for particulate matter less than 10 mum (PM 10), Pb, and As, to determine the background level of Chihuahua City for these same elements, to determine the isotopic ratios of Pb206 and Pb207 in the indoor and outdoor atmospheric samples, and to verify if the source of the pollution is from anthropogenic and/or natural sources. Additionally, a comparison of the analytical data from X-ray fluorescence (XRF) versus the analytical data from inductively coupled plasma with optical emission spectroscopy (ICP-OES) was conducted. The comparison of these techniques was based on sample preparation, speed of analysis, and accuracy of results. In the case of sample preparation, two extraction techniques were performed for a comparison of the extraction/leaching of Pb and As from the samples. These microwave

  16. Indoor, outdoor, and personal exposure monitoring of particulate air pollution: the Baltimore elderly epidemiology-exposure pilot study

    Science.gov (United States)

    Williams, Ron; Creason, John; Zweidinger, Roy; Watts, Randall; Sheldon, Linda; Shy, Carl

    A 17-day pilot study investigating potential PM exposures of an elderly population was conducted near Baltimore, Maryland. Collection of residential indoor, residential outdoor, and ambient monitoring data associated with the subjects living at a common retirement facility was integrated with results from a paired epidemiological pilot study. This integration was used to investigate the potential pathophysiological health effects resulting from daily changes in estimated PM exposures with results reported elsewhere. Objectives of the exposure study were to determine the feasibility of performing PM exposure assessment upon an elderly population and establishing relationships between the various exposure measures including personal monitoring. PM 2.5 was determined to be the dominant outdoor size fraction (0.83 PM 2.5/PM 10 mass ratio by dichot monitoring). Individual 24-h PM 1.5 personal exposures ranged from 12 to 58 μg m -3. Comparison of data from matched sampling dates resulted in mean daily PM 1.5 personal, PM 2.5 outdoor, and PM 1.5 indoor concentrations of 34, 17, and 17 μg m -3, respectively. Activity patterns of the study population indicated a generally sedentary population spending a mean of 96% of each day indoors. Future studies would benefit from the use of a consistent sampling methodology across a larger number of PM measurement sites relevant to the elderly subjects, as well as a larger personal PM exposure study population to more successfully collect data needed in matched epidemiological-exposure studies.

  17. Dermal uptake of nicotine from air and clothing: Experimental verification

    DEFF Research Database (Denmark)

    Bekö, Gabriel; Morrison, Glenn; Weschler, Charles J.

    2017-01-01

    Studies suggest that dermal uptake of certain semivolatile organic compounds (SVOC) directly from air can be a significant exposure pathway. This has been experimentally confirmed for two phthalates (Weschler et al., 2015). Morrison et al. (2016) showed that clean clothing can impede, while cloth...

  18. Outdoor air pollution, preterm birth, and low birth weight: analysis of the world health organization global survey on maternal and perinatal health.

    Science.gov (United States)

    Fleischer, Nancy L; Merialdi, Mario; van Donkelaar, Aaron; Vadillo-Ortega, Felipe; Martin, Randall V; Betran, Ana Pilar; Souza, João Paulo

    2014-04-01

    Inhaling fine particles (particulate matter with diameter ≤ 2.5 μm; PM2.5) can induce oxidative stress and inflammation, and may contribute to onset of preterm labor and other adverse perinatal outcomes. We examined whether outdoor PM2.5 was associated with adverse birth outcomes among 22 countries in the World Health Organization Global Survey on Maternal and Perinatal Health from 2004 through 2008. Long-term average (2001-2006) estimates of outdoor PM2.5 were assigned to 50-km-radius circular buffers around each health clinic where births occurred. We used generalized estimating equations to determine associations between clinic-level PM2.5 levels and preterm birth and low birth weight at the individual level, adjusting for seasonality and potential confounders at individual, clinic, and country levels. Country-specific associations were also investigated. Across all countries, adjusting for seasonality, PM2.5 was not associated with preterm birth, but was associated with low birth weight [odds ratio (OR) = 1.22; 95% CI: 1.07, 1.39 for fourth quartile of PM2.5 (> 20.2 μg/m3) compared with the first quartile (levels of air pollution may be of concern for both outcomes.

  19. Outdoor recreation

    Science.gov (United States)

    J. M. Bowker; Ashley Askew; H. Ken Cordell; John C. Bergstrom

    2013-01-01

    Key FindingsBy 2060, the number of southern adults participating in each of 10 different popular outdoor recreation activities is projected to increase. Depending on future demographic, economic, land use, and population changes, the activity demonstrating the least growth in participants is hunting (8–25 percent). The activity projected to...

  20. Experimental and Numerical Investigation of Effect of Air Stability on Exhaled Air Dispersion

    DEFF Research Database (Denmark)

    Xu, Chunwen; Gong, Guangcai; Nielsen, Peter Vilhelm

    2014-01-01

    studies. As the thermal stratification under displacement ventilation blocks the vertical movement of exhaled air, the exhaled contaminant may be trapped between temperature stratifications. As the dispersion of contaminant is closely related to the health of human indoors, the temperature structure...... was used for experimental study, and a numerical person was built to simulate the manikin. The velocity, temperature and concentration of tracer gas in exhaled air are affected by air stability to different degrees. The similarity of this effect among these parameters can also be observed through numerical...

  1. Air Research

    Science.gov (United States)

    EPA's air research provides the critical science to develop and implement outdoor air regulations under the Clean Air Act and puts new tools and information in the hands of air quality managers and regulators to protect the air we breathe.

  2. Experimental investigation of a super performance dew point air cooler

    International Nuclear Information System (INIS)

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

    2017-01-01

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

  3. Experimental and calculated calibration of ionization chambers with air circulation

    CERN Document Server

    Peetermans, A

    1972-01-01

    The reports describes the method followed in order to calibrate the different ionization chambers with air circulation, used by the 'Health Physics Group'. The calculations agree more precisely with isotopes cited previously (/sup 11/C, /sup 13/N, /sup 15/O, /sup 41 /Ar, /sup 14/O, /sup 38/Cl) as well as for /sup 85/Kr, /sup 133/Xe, /sup 14/C and tritium which are used for the experimental standardisation of different chambers.

  4. Study on the Development of an Optimal Heat Supply Control Algorithm for Group Energy Apartment Buildings According to the Variation of Outdoor Air Temperature

    Directory of Open Access Journals (Sweden)

    Dong-Kurl Kwak

    2012-05-01

    Full Text Available In the present study, we have developed an optimal heat supply algorithm which minimizes the heat loss through the distribution pipe line in a group energy apartment. Heating load variation of a group energy apartment building according to the outdoor air temperature was predicted by a correlation obtained from calorimetry measurements of all households in the apartment building. Supply water temperature and mass flow rate were simultaneously controlled to minimize the heat loss rate through the distribution pipe line. A group heating apartment building located in Hwaseong city, Korea, which has 1473 households, was selected as the object building to test the present heat supply algorithm. Compared to the original heat supply system, the present system adopting the proposed control algorithm reduced the heat loss rate by 10.4%.

  5. An experimental investigation on reverse-cycle defrosting performance for an air source heat pump using an electronic expansion valve

    International Nuclear Information System (INIS)

    Qu, Minglu; Xia, Liang; Deng, Shiming; Jiang, Yiqiang

    2012-01-01

    Highlights: ► We experimentally studied the defrost performance under two EEV control strategies. ► The two EEV control strategies were fully open and controlled by a DS controller. ► When the EEV was under the DS controller, higher defrosting efficiency was obtained. -- Abstract: When an air source heat pump (ASHP) operates in heating mode, frost can be accumulated on the surface of its finned outdoor coil. Frosting deteriorates the operation and energy efficiency of the ASHP and periodic defrosting becomes necessary. Currently the most widely used standard defrosting method for ASHPs is reverse cycle defrost. On the other hand, electronic expansion valves (EEVs) are commonly used in heat pump/refrigeration systems, including ASHP units, as throttle regulators of refrigerant flow. This paper reports on an experimental investigation of the performance of a reverse cycle defrost operation for a 6.5 kW experimental heating capacity residential ASHP whose outdoor coil had four-parallel refrigerant circuits, and with an EEV as the refrigerant flow throttle regulator. The detailed descriptions of the experimental ASHP unit and the experimental procedures of ASHP are firstly presented. This is followed by reporting the comparative experiments of two control strategies for the EEV to investigate their effects on defrosting performance: the EEV being fully open and the EEV being regulated by a degree of refrigerant superheat (DS) controller. Experimental results revealed that when the EEV was regulated by the DS controller during defrosting, a higher defrosting efficiency and less heat wastage would be resulted in.

  6. Indoor and Outdoor Allergies.

    Science.gov (United States)

    Singh, Madhavi; Hays, Amy

    2016-09-01

    In last 30 to 40 years there has been a significant increase in the incidence of allergy. This increase cannot be explained by genetic factors alone. Increasing air pollution and its interaction with biological allergens along with changing lifestyles are contributing factors. Dust mites, molds, and animal allergens contribute to most of the sensitization in the indoor setting. Tree and grass pollens are the leading allergens in the outdoor setting. Worsening air pollution and increasing particulate matter worsen allergy symptoms and associated morbidity. Cross-sensitization of allergens is common. Treatment involves avoidance of allergens, modifying lifestyle, medical treatment, and immunotherapy. Copyright © 2016 Elsevier Inc. All rights reserved.

  7. Association of outdoor air pollution with the prevalence of asthma in children of Latin America and the Caribbean: A systematic review and meta-analysis.

    Science.gov (United States)

    Orellano, Pablo; Quaranta, Nancy; Reynoso, Julieta; Balbi, Brenda; Vasquez, Julia

    2017-12-06

    This study aimed to evaluate the association between asthma prevalence and outdoor air pollution in children in Latin America and the Caribbean. We searched studies in global and regional databases: PubMed, Scopus, LILACS and SciELO. Articles following a cross-sectional design, studying children from 0 to 18 years old, and comparing the prevalence of asthma in two or more areas of LAC countries with different air pollution levels were included. The exclusion criteria comprised air pollution not related to human activities. Database searches retrieved 384 records, while 20 studies were retained for qualitative and 16 for quantitative analysis, representing 48 442 children. We found a positive association, i.e. a higher prevalence of asthma in children living in a polluted environment, with pooled odds ratio (OR) of 1.34 (95% CI: 1.17-1.54). Heterogeneity between studies was moderate (I 2 : 68.39%), while the risk of bias was intermediate or high in 14 studies. In all the subgroup and sensitivity analyses, the pooled ORs were significant and higher than those found in the general analysis Conclusions: Our results showed that living in a polluted environment is significantly associated with children having asthma in LAC. Limitations of this study include the low number of studies performed in LAC countries, differences in methodologies and the risk of bias in individual studies.

  8. Outdoor Air Pollution and COPD-Related Emergency Department Visits, Hospital Admissions, and Mortality: A Meta-Analysis.

    Science.gov (United States)

    DeVries, Rebecca; Kriebel, David; Sama, Susan

    2017-02-01

    A systematic literature review was performed to identify all peer-reviewed literature quantifying the association between short-term exposures of particulate matter <2.5 microns (PM 2.5 ), nitrogen dioxide (NO 2 ), and sulfur dioxide (SO 2 ) and COPD-related emergency department (ED) visits, hospital admissions (HA), and mortality. These results were then pooled for each pollutant through meta-analyses with a random effects model. Subgroup meta-analyses were explored to study the effects of selected lag/averaging times and health outcomes. A total of 37 studies satisfied our inclusion criteria, contributing to a total of approximately 1,115,000 COPD-related acute events (950,000 HAs, 80,000 EDs, and 130,000 deaths) to our meta-estimates. An increase in PM 2.5 of 10 ug/m 3 was associated with a 2.5% (95% CI: 1.6-3.4%) increased risk of COPD-related ED and HA, an increase of 10 ug/m 3 in NO 2 was associated with a 4.2% (2.5-6.0%) increase, and an increase of 10 ug/m 3 in SO 2 was associated with a 2.1% (0.7-3.5%) increase. The strength of these pooled effect estimates, however, varied depending on the selected lag/averaging time between exposure and outcome. Similar pooled effects were estimated for each pollutant and COPD-related mortality. These results suggest an ongoing threat to the health of COPD patients from both outdoor particulates and gaseous pollutants. Ambient outdoor concentrations of PM 2.5 , NO 2 , and SO 2 were significantly and positively associated with both COPD-related morbidity and mortality.

  9. Experimental analysis of pressurised humidification tower for humid air gas turbine cycles. Part A: Experimental campaign

    International Nuclear Information System (INIS)

    Pedemonte, A.A.; Traverso, A.; Massardo, A.F.

    2008-01-01

    One of the most interesting methods of water introduction in a gas turbine circuit is represented by the humid air turbine cycle (HAT). In the HAT cycle, the humidification can be provided by a pressurised saturator (i.e. humidification tower or saturation tower), this solution being known to offer several attractive features. This part A is focused on an experimental study of a pressurised humidification tower, with structured packing inside. After a description of the test rig employed to carry out the measuring campaign, the results relating to the thermodynamic process are presented and discussed. The experimental campaign was carried out over 162 working points, covering a relatively wide range of possible operating conditions. Details about measured data are provided in the appendix. It is shown that the saturator's behaviour, in terms of air outlet humidity and temperature, is primarily driven by, in decreasing order of relevance, the inlet water temperature, the inlet water over inlet dry air mass flow ratio and the inlet air temperature. Finally, the exit relative humidity is shown to be consistently over 100%, which may be explained partially by measurement accuracy and droplet entrainment, and partially by the non-ideal behaviour of air-steam mixtures close to saturation

  10. Quantifying the co-impacts of energy sector decarbonisation on outdoor air pollution in the United Kingdom

    International Nuclear Information System (INIS)

    Lott, Melissa C.; Pye, Steve; Dodds, Paul E.

    2017-01-01

    The energy sector is a major contributor to greenhouse gas (GHG) emissions and other types of air pollution that negatively impact human health and the environment. Policy targets to achieve decarbonisation goals for national energy systems will therefore impact levels of air pollution. Advantages can be gained from considering these co-impacts when analysing technology transition scenarios in order to avoid tension between climate change and air quality policies. We incorporated non-GHG air pollution into a bottom-up, technoeconomic energy systems model that is at the core of UK decarbonisation policy development. We then used this model to assess the co-impacts of decarbonisation on other types of air pollution and evaluated the extent to which transition pathways would be altered if these other pollutants were considered. In a scenario where the UK meets its existing decarbonisation targets to 2050, including the costs of non-GHG air pollution led to a 40% and 45% decrease in PM_1_0 and PM_2_._5 pollution (respectively) between 2010 and 2050 due to changes in technology choice in residential heating. Conversely, limited change in the pollution profile for transportation were observed, suggesting that other policy strategies will be necessary to reduce pollution from transport. - Highlights: • Strategies to decarbonise energy systems should consider other air pollutants. • Energy systems models can show decarbonisation pathway co-impacts on PM, NO_x and SO_x. • Considering non-GHG pollution eliminates carbon & air quality policy tensions. • Transport particulate pollution challenges will only be addressed by modal shifting.

  11. Effect of long-term outdoor air pollution and noise on cognitive and psychological functions in adults.

    Science.gov (United States)

    Tzivian, Lilian; Winkler, Angela; Dlugaj, Martha; Schikowski, Tamara; Vossoughi, Mohammad; Fuks, Kateryna; Weinmayr, Gudrun; Hoffmann, Barbara

    2015-01-01

    It has been hypothesized that air pollution and ambient noise might impact neurocognitive function. Early studies mostly investigated the associations of air pollution and ambient noise exposure with cognitive development in children. More recently, several studies investigating associations with neurocognitive function, mood disorders, and neurodegenerative disease in adult populations were published, yielding inconsistent results. The purpose of this review is to summarize the current evidence on air pollution and noise effects on mental health in adults. We included studies in adult populations (≥18 years old) published in English language in peer-reviewed journals. Fifteen articles related to long-term effects of air pollution and eight articles on long-term effects of ambient noise were extracted. Both exposures were separately shown to be associated with one or several measures of global cognitive function, verbal and nonverbal learning and memory, activities of daily living, depressive symptoms, elevated anxiety, and nuisance. No study considered both exposures simultaneously and few studies investigated progression of neurocognitive decline or psychological factors. The existing evidence generally supports associations of environmental factors with mental health, but does not suffice for an overall conclusion about the independent effect of air pollution and noise. There is a need for studies investigating simultaneously air pollution and noise exposures in association mental health, for longitudinal studies to corroborate findings from cross-sectional analyses, and for parallel toxicological and epidemiological studies to elucidate mechanisms and pathways of action. Copyright © 2014 Elsevier GmbH. All rights reserved.

  12. Seasonal variation in outdoor, indoor, and personal air pollution exposures of women using wood stoves in the Tibetan Plateau: Baseline assessment for an energy intervention study.

    Science.gov (United States)

    Ni, Kun; Carter, Ellison; Schauer, James J; Ezzati, Majid; Zhang, Yuanxun; Niu, Hongjiang; Lai, Alexandra M; Shan, Ming; Wang, Yuqin; Yang, Xudong; Baumgartner, Jill

    2016-09-01

    Cooking and heating with coal and biomass is the main source of household air pollution in China and a leading contributor to disease burden. As part of a baseline assessment for a household energy intervention program, we enrolled 205 adult women cooking with biomass fuels in Sichuan, China and measured their 48-h personal exposure to fine particulate matter (PM2.5) and carbon monoxide (CO) in winter and summer. We also measured the indoor 48-h PM2.5 concentrations in their homes and conducted outdoor PM2.5 measurements during 101 (74) days in summer (winter). Indoor concentrations of CO and nitrogen oxides (NO, NO2) were measured over 48-h in a subset of ~80 homes. Women's geometric mean 48-h exposure to PM2.5 was 80μg/m(3) (95% CI: 74, 87) in summer and twice as high in winter (169μg/m(3) (95% CI: 150, 190), with similar seasonal trends for indoor PM2.5 concentrations (winter: 252μg/m(3); 95% CI: 215, 295; summer: 101μg/m(3); 95% CI: 91, 112). We found a moderately strong relationship between indoor PM2.5 and CO (r=0.60, 95% CI: 0.46, 0.72), and a weak correlation between personal PM2.5 and CO (r=0.41, 95% CI: -0.02, 0.71). NO2/NO ratios were higher in summer (range: 0.01 to 0.68) than in winter (range: 0 to 0.11), suggesting outdoor formation of NO2 via reaction of NO with ozone is a more important source of NO2 than biomass combustion indoors. The predictors of women's personal exposure to PM2.5 differed by season. In winter, our results show that primary heating with a low-polluting fuel (i.e., electric stove or wood-charcoal) and more frequent kitchen ventilation could reduce personal PM2.5 exposures. In summer, primary use of a gaseous fuel or electricity for cooking and reducing exposure to outdoor PM2.5 would likely have the greatest impacts on personal PM2.5 exposure. Copyright © 2016 Elsevier Ltd. All rights reserved.

  13. Changes in Transportation-Related Air Pollution Exposures by Race-Ethnicity and Socioeconomic Status: Outdoor Nitrogen Dioxide in the United States in 2000 and 2010.

    Science.gov (United States)

    Clark, Lara P; Millet, Dylan B; Marshall, Julian D

    2017-09-14

    Disparities in exposure to air pollution by race-ethnicity and by socioeconomic status have been documented in the United States, but the impacts of declining transportation-related air pollutant emissions on disparities in exposure have not been studied in detail. This study was designed to estimate changes over time (2000 to 2010) in disparities in exposure to outdoor concentrations of a transportation-related air pollutant, nitrogen dioxide (NO2), in the United States. We combined annual average NO2 concentration estimates from a temporal land use regression model with Census demographic data to estimate outdoor exposures by race-ethnicity, socioeconomic characteristics (income, age, education), and by location (region, state, county, urban area) for the contiguous United States in 2000 and 2010. Estimated annual average NO2 concentrations decreased from 2000 to 2010 for all of the race-ethnicity and socioeconomic status groups, including a decrease from 17.6 ppb to 10.7 ppb (-6.9 ppb) in nonwhite [non-(white alone, non-Hispanic)] populations, and 12.6 ppb to 7.8 ppb (-4.7 ppb) in white (white alone, non-Hispanic) populations. In 2000 and 2010, disparities in NO2 concentrations were larger by race-ethnicity than by income. Although the national nonwhite-white mean NO2 concentration disparity decreased from a difference of 5.0 ppb in 2000 to 2.9 ppb in 2010, estimated mean NO2 concentrations remained 37% higher for nonwhites than whites in 2010 (40% higher in 2000), and nonwhites were 2.5 times more likely than whites to live in a block group with an average NO2 concentration above the WHO annual guideline in 2010 (3.0 times more likely in 2000). Findings suggest that absolute NO2 exposure disparities by race-ethnicity decreased from 2000 to 2010, but relative NO2 exposure disparities persisted, with higher NO2 concentrations for nonwhites than whites in 2010. https://doi.org/10.1289/EHP959.

  14. Experimental investigation of a novel configuration of desiccant based evaporative air conditioning system

    International Nuclear Information System (INIS)

    Uçkan, İrfan; Yılmaz, Tuncay; Hürdoğan, Ertaç; Büyükalaca, Orhan

    2013-01-01

    Highlights: ► A novel desiccant based evaporative cooling system is developed and tested. ► Cooling capacity, COP and energy consumption of the system are evaluated. ► Indoor air conditions are in the range of thermal comfort zone and expanded comfort zone. ► Designing of the system have considerable effect on the energy consumption. - Abstract: A novel configuration of desiccant based evaporative cooling system for air conditioning application is developed and tested. At the beginning of the design stage of the system, an analysis is carried out in order to maximize the performance of the system. It is found based on configuration that outdoor air must be used for regeneration to increase performance of the system and so three air channels are used. Experiments are carried out to investigate the total performance of the system and performance of the components used during summer season in a hot and humid climate. Effectiveness values for both heat exchangers and evaporative coolers are calculated through this work. In addition to the cooling capacity, coefficient of performance (COP) and energy consumption of the system are also evaluated. Results show that the effectiveness for the heat exchangers and evaporative coolers are very high under different outdoor conditions. It is also shown from the results that indoor air conditions are in the range of thermal comfort zone defined by ASHRAE and expanded comfort zone for evaporative air conditioning applications.

  15. Parametric simulation and experimental analysis of earth air heat exchanger with solar air heating duct

    Directory of Open Access Journals (Sweden)

    Sanjeev Jakhar

    2016-06-01

    Full Text Available Earth air heat exchanger (EAHE systems are insufficient to meet the thermal comfort requirements in winter conditions. The low heating potential of such systems can be improved by integrating the system with solar air heating duct (SAHD. The aim of this paper is to present a model to estimate the heating potential for EAHE system with and without SAHD. The model is generated using TRNSYS 17 simulation tool and validated against experimental investigation on an experimental set-up in Ajmer, India. The experiment was done during the winter season, where the system was evaluated for different inlet flow velocities, length and depth of buried pipe. From the experimentation, it was observed that the depth of 3.7 m is sufficient for pipe burial and the 34 m length of pipe is sufficient to get optimum EAHE outlet temperature. It is also observed that increase in flow velocity results in drop in EAHE outlet temperature, while room temperature is found to increase for higher velocities (5 m/s. The COP of the system also increased up to 6.304 when assisted with solar air heating duct. The results obtained from the experiment data are in good agreement with simulated results within the variation of up to 7.9%.

  16. Filtered air plastic chamber as an experimental facility to prove visible damage of crops due to air pollution

    Energy Technology Data Exchange (ETDEWEB)

    Matsuoka, Y; Yoda, H; Omichi, S; Shiratori, K

    1975-01-01

    An experimental filtered air chamber was constructed to prove the visible damage of crops due to air pollution. The chamber was provided with another room into which non-filtered ambient air was introduced. The purified air was prepared by filtering ambient air with activated carbon. The average content of air pollutants in the purified air chamber was less than 10 to 20% of the ozone and 20% of the sulfur oxides in the ambient air. However, cultivated vegetables such as tobacco and spinach, which are susceptible to oxidant, showed no visible damage in the filtered air chamber, and showed the same damage in the nonfiltered air chamber as was seen in fields at the same time.

  17. Some Outdoor Educators' Experiences of Outdoor Education

    Science.gov (United States)

    Gunn, Terry

    2006-01-01

    The phenomenological study presented in this paper attempts to determine, from outdoor educators, what it meant for them to be teaching outdoor education in Victorian secondary schools during 2004. In 1999, Lugg and Martin surveyed Victorian secondary schools to determine the types of outdoor education programs being run, the objectives of those…

  18. Experimental technique of calibration of symmetrical air pollution ...

    Indian Academy of Sciences (India)

    Based on the inherent property of symmetry of air pollution models, a Symmetrical Air Pollution. Model ... process is in compliance with air pollution regula- ..... Ground simulation is achieved through MATLAB package which is based on least-.

  19. Experimental study of photocatalytic concrete products for air purification

    Energy Technology Data Exchange (ETDEWEB)

    Huesken, G.; Hunger, M.; Brouwers, H.J.H. [Department of Civil Engineering, Faculty of Engineering Technology, University of Twente, P.O. Box 217, 7500 AE Enschede (Netherlands)

    2009-12-15

    Air quality in inner-city areas is a topic which receives much attention nowadays but in the coming years, the overall interest on this topic will become even bigger. One major concern is caused by the reduction of the limiting values given by the European Council Directive 1999/30/EC [Relating to limit values for sulphur dioxide, nitrogen dioxide and oxides of nitrogen, particulate matter and lead in ambient air. Official Journal of the European Communities 1999, L 163/41-60] and increasing traffic rates especially for diesel powered passenger cars and freight vehicles. A promising approach for solving the problem of nitrogen oxides (NO{sub x}) is the photochemical conversion of nitrogen oxides to low concentrated nitrates due to heterogeneous photocatalytic oxidation (PCO) using titanium dioxide (TiO{sub 2}) as photocatalyst. A variety of products containing TiO{sub 2} are already available on the European market and their working mechanism under laboratory conditions is proven. However, there is still a lack of transforming the experimental results obtained under laboratory conditions to practical applications considering real world conditions. This paper presents the research conducted on photocatalytic concrete products with respect to the evaluation of air-purifying properties. The degradation process of nitric oxide (NO) under laboratory conditions is studied using a test setup for measuring the performance of photocatalytic active concrete products. The test setup uses the UV-A induced degradation of NO and is oriented on the ISO standard ISO 22197-1:2007. Besides the introduction of the test setup, a uniform measuring procedure is presented to the reader which allows for an evaluation and direct comparison of the performance of photocatalytic active concrete products. This kind of direct comparison was not possible so far. Furthermore, the results of a comparative study on varying photocatalytic concrete products of the European market will be discussed

  20. Distribution and congener profiles of short-chain chlorinated paraffins in indoor/outdoor glass window surface films and their film-air partitioning in Beijing, China.

    Science.gov (United States)

    Gao, Wei; Wu, Jing; Wang, Yawei; Jiang, Guibin

    2016-02-01

    Short-chain chlorinated paraffins (SCCPs) are a group of n-alkanes with carbon chain length of 10-13. In this work, paired indoor/outdoor samples of organic films on window glass surfaces from urban buildings in Beijing, China, were collected to measure the concentrations and congener distributions of SCCPs. The total SCCP levels ranged from 337 ng/m(2) to 114 μg/m(2), with total organic carbon (TOC) normalized concentrations of 365 μg/m(2)-365 mg/m(2). Overall, the concentrations of SCCPs on the interior films were higher than the concentrations on the exterior films, suggesting an important indoor environmental exposure of SCCPs to the general public. A significant linear relationship was found between the SCCP concentrations and TOC, with a correlation coefficient of R = 0.34 (p film-air partitioning model suggests that the indoor gas-phase SCCPs are related to their corresponding window film levels. Copyright © 2015 Elsevier Ltd. All rights reserved.

  1. Dynamic modeling of temperature change in outdoor operated tubular photobioreactors.

    Science.gov (United States)

    Androga, Dominic Deo; Uyar, Basar; Koku, Harun; Eroglu, Inci

    2017-07-01

    In this study, a one-dimensional transient model was developed to analyze the temperature variation of tubular photobioreactors operated outdoors and the validity of the model was tested by comparing the predictions of the model with the experimental data. The model included the effects of convection and radiative heat exchange on the reactor temperature throughout the day. The temperatures in the reactors increased with increasing solar radiation and air temperatures, and the predicted reactor temperatures corresponded well to the measured experimental values. The heat transferred to the reactor was mainly through radiation: the radiative heat absorbed by the reactor medium, ground radiation, air radiation, and solar (direct and diffuse) radiation, while heat loss was mainly through the heat transfer to the cooling water and forced convection. The amount of heat transferred by reflected radiation and metabolic activities of the bacteria and pump work was negligible. Counter-current cooling was more effective in controlling reactor temperature than co-current cooling. The model developed identifies major heat transfer mechanisms in outdoor operated tubular photobioreactors, and accurately predicts temperature changes in these systems. This is useful in determining cooling duty under transient conditions and scaling up photobioreactors. The photobioreactor design and the thermal modeling were carried out and experimental results obtained for the case study of photofermentative hydrogen production by Rhodobacter capsulatus, but the approach is applicable to photobiological systems that are to be operated under outdoor conditions with significant cooling demands.

  2. Health effects of outdoor air pollution. Committee of the Environmental and Occupational Health Assembly of the American Thoracic Society.

    Science.gov (United States)

    1996-01-01

    Particles, SOx, and acid aerosols are a complex group of distinct pollutants that have common sources and usually covary in concentration. During the past two decades, the chemical characteristics and the geographic distribution of sulfur oxide and particulate pollution have been altered by control strategies, specifically taller stacks for power plants, put in place in response to air pollution regulations adopted in the early 1970s. While the increasing stack heights have lowered local ambient levels, the residence time of SOx and particles in the air have been increased, thereby promoting transformation to various particulate sulfate compounds, including acidic sulfates. These sulfate particles constitute a large fraction of the total mass of smaller particles (kindergarten absences, to decrements in peak flow rates in normal children, and to increased medication use in children and adults with asthma. Although some epidemiologic studies suggest that acid aerosols are an important toxic component of PM10, other studies do not support this hypothesis. Dockery and Pope (408) recently reviewed the epidemiologic literature for adverse effects, assuming that reported associations can be attributed to acute particle mass exposures. Combined effects were estimated as percent increase in comparable measures of mortality and morbidity, associated with each 10 micrograms/m3 increase in daily mean PM10 exposure (Table 7). While total mortality increased by 1% for each 10 micrograms/m3 increase in PM10, respiratory mortality increased by 3.4% and cardiovascular mortality increased by 1.4%. Hospital admissions and emergency department visits increased approximately 1% for all respiratory complaints, and 2% to 3% for asthma. Exacerbation of asthma increased by about 3%, as did lower respiratory symptoms. Small decreases in lung function, approximately 0.1%, have also been observed. This review suggests that the epidemiologic studies of adverse morbidity measures are coherent

  3. Numerical modelling of negative discharges in air with experimental validation

    International Nuclear Information System (INIS)

    Tran, T N; Golosnoy, I O; Lewin, P L; Georghiou, G E

    2011-01-01

    Axisymmetric finite element models have been developed for the simulation of negative discharges in air without and with the presence of dielectrics. The models are based on the hydrodynamic drift-diffusion approximation. A set of continuity equations accounting for the movement, generation and loss of charge carriers (electrons, positive and negative ions) is coupled with Poisson's equation to take into account the effect of space and surface charges on the electric field. The model of a negative corona discharge (without dielectric barriers) in a needle-plane geometry is analysed first. The results obtained show good agreement with experimental observations for various Trichel pulse characteristics. With dielectric barriers introduced into the discharge system, the surface discharge exhibits some similarities and differences to the corona case. The model studies the dynamics of volume charge generation, electric field variations and charge accumulation over the dielectric surface. The predicted surface charge density is consistent with experimental results obtained from the Pockels experiment in terms of distribution form and magnitude.

  4. Our Breaths We Take: Outdoor Air Quality, Health, and Climate Change Consequences of Household Heating and Cooking with Solid Fuels

    Science.gov (United States)

    Chafe, Zoe Anna

    Worldwide, nearly 3 billion people--40% of the global population--burn wood, coal, and other solid fuels every day to cook their food; this number is even larger when including those who heat their homes with solid fuels as well. Exposure to pollution from heating and cooking fires causes about 3 million deaths each year, making it one of the biggest environmental health problems the world faces. The harm from this smoke is not restricted to those who breathe it, however: it contains gases and particles that contribute to global climate change as well. Chapter 2 shows that household cooking with solid fuels caused an estimated 12% of population-weighted ambient PM2.5 worldwide in 2010. Exposure to this air pollution caused the loss of 370,000 lives and 9.9 million disability-adjusted life years (DALYs) globally in the same year. In Chapter 3 I demonstrate that household heating with solid fuels caused an estimated 21% of population-weighted ambient PM2.5 in 2010 in Central Europe, 13% in Eastern Europe, 12% in Western Europe, and 8% in North America. Exposure to this air pollution results caused approximately 60,000 premature deaths in Europe, and nearly 10,000 deaths in North America, as well as an estimated 1.0 million disability-adjusted life years (DALYs) in Europe and 160,000 DALYs in North America. Chapter 4 addresses drivers of household wood combustion pollution in the San Francisco Bay Area, where the sector is the largest source of PM 2.5 and regulators recently introduced amendments to wood burning rules for the airshed. Fireplaces are the source of the vast majority (84%) of PM 2.5 from residential wood combustion in the San Francisco Bay Area, despite their use primarily as an aesthetic or recreational combustion activity. By evaluating hypothetical fuel and combustion device changeouts, I find that replacing fireplaces with gas would yield significant health and economic benefits. Specifically, retrofitting frequently used fireplaces (300,000 units

  5. Experimental analysis of fuzzy controlled energy efficient demand controlled ventilation economizer cycle variable air volume air conditioning system

    Directory of Open Access Journals (Sweden)

    Rajagopalan Parameshwaran

    2008-01-01

    Full Text Available In the quest for energy conservative building design, there is now a great opportunity for a flexible and sophisticated air conditioning system capable of addressing better thermal comfort, indoor air quality, and energy efficiency, that are strongly desired. The variable refrigerant volume air conditioning system provides considerable energy savings, cost effectiveness and reduced space requirements. Applications of intelligent control like fuzzy logic controller, especially adapted to variable air volume air conditioning systems, have drawn more interest in recent years than classical control systems. An experimental analysis was performed to investigate the inherent operational characteristics of the combined variable refrigerant volume and variable air volume air conditioning systems under fixed ventilation, demand controlled ventilation, and combined demand controlled ventilation and economizer cycle techniques for two seasonal conditions. The test results of the variable refrigerant volume and variable air volume air conditioning system for each techniques are presented. The test results infer that the system controlled by fuzzy logic methodology and operated under the CO2 based mechanical ventilation scheme, effectively yields 37% and 56% per day of average energy-saving in summer and winter conditions, respectively. Based on the experimental results, the fuzzy based combined system can be considered to be an alternative energy efficient air conditioning scheme, having significant energy-saving potential compared to the conventional constant air volume air conditioning system.

  6. Experimental studies of the air hybrid engine charging operation

    OpenAIRE

    Zhao, H; Ma, T; Lee, CY

    2014-01-01

    Over the last few years, theoretical and modelling studies have been carried out on the feasibility and potential of novel mild air hybrid engine concepts based on production components. These mild air hybrid concepts are able to convert vehicle brake energy into pneumatic energy in the form of compressed air stored in the air tank. The compressed air can then be used to crank-start the engine by either injecting and expanding in the cylinder or driving a production air starter. Thus, the reg...

  7. Theoretical and Experimental Evaluation of the Temperature Distribution in a Dry Type Air Core Smoothing Reactor of HVDC Station

    Directory of Open Access Journals (Sweden)

    Yu Wang

    2017-05-01

    Full Text Available The outdoor ultra-high voltage (UHV dry-type air-core smoothing reactors (DASR of High Voltage Direct Current systems are equipped with a rain cover and an acoustic enclosure. To study the convective heat transfer between the DASR and the surrounding air, this paper presents a coupled model of the temperature and fluid field based on the structural features and cooling manner. The resistive losses of encapsulations calculated by finite element method (FEM were used as heat sources in the thermal analysis. The steady fluid and thermal field of the 3-D reactor model were solved by the finite volume method (FVM, and the temperature distribution characteristics of the reactor were obtained. Subsequently, the axial and radial temperature distributions of encapsulation were investigated separately. Finally, an optical fiber temperature measurement scheme was used for an UHV DASR under natural convection conditions. Comparative analysis showed that the simulation results are in good agreement with the experimental data, which verifies the rationality and accuracy of the numerical calculation. These results can serve as a reference for the optimal design and maintenance of UHV DASRs.

  8. Analysis of an open-air swimming pool solar heating system by using an experimentally validated TRNSYS model

    Energy Technology Data Exchange (ETDEWEB)

    Ruiz, Elisa; Martinez, Pedro J. [Universidad Miguel Hernandez - Edificio Torreblanca, Avda. de la Universidad s/n, 03202 Elche (Spain)

    2010-01-15

    In the case of private outdoor swimming pools, seldom larger than 100 m{sup 2}, conventional auxiliary heating systems are being installed less and less. Solar heating is an option to extend the swimming season. The temperature evolution of an open-air swimming pool highly depends on the wind speed directly on the water surface, which at the same time is influenced by the surroundings of the pool. In this paper, the TRNSYS model of a private open-air pool with a 50-m{sup 2} surface was validated by registering the water temperature evolution and the meteorological data at the pool site. Evaporation is the main component of energy loss in swimming pools. Six different sets of constants found in literature were considered to evaluate the evaporative heat transfer coefficient with the purpose of finding the most suitable one for the TRNSYS pool model. In order to do that, the evolution of the pool water temperature predicted by the TRNSYS pool model was compared with the experimentally registered one. The simulation with TRNSYS of the total system, including the swimming pool and the absorber circuit integrated into the existing filter circuit, provided information regarding the increase of the pool temperature for different collector areas during the swimming season. This knowledge, together with the economic costs, support the decision about the absorber field size. (author)

  9. Outdoors classes

    Science.gov (United States)

    Szymanska-Markowska, Barbara

    2016-04-01

    Why should students be trapped within the four walls of the classroom when there are a lot of ideas to have lessons led in the different way? I am not a fan of having lessons at school. For many students it is also boring to stay only at school, too. So I decided to organize workshops and trips to Universities or outdoors. I created KMO ( Discoverer's Club for Teenagers) at my school where students gave me some ideas and we started to make them real. I teach at school where students don't like science. I try hard to change their point of view about it. That's why I started to take parts in different competitions with my students. Last year we measured noise everywhere by the use of applications on a tablet to convince them that noise is very harmful for our body and us. We examined that the most harmful noises were at school's breaks, near the motorways and in the households. We also proved that acoustic screens, which were near the motorways, didn't protect us from noise. We measured that 30 meters from the screens the noise is the same as the motorway. We won the main prize for these measurements. We also got awards for calculating the costs of a car supplied by powered by a solar panel. We measured everything by computer. This year we decided to write an essay about trees and weather. We went to the forest and found the cut trees because we wanted to read the age of tree from the stump. I hadn't known earlier that we could read the weather from the tree's grain. We examined a lot of trees and we can tell that trees are good carriers of information about weather and natural disasters. I started studies safety education and I have a lot of ideas how to get my students interested in this subject that is similar to P.E., physics and chemistry, too. I hope that I will use my abilities from European Space Education Resource Office and GIFT workshop. I plan to use satellite and space to teach my students how they can check information about terrorism, floods or other

  10. Asbestos fibres in indoor and outdoor air and the epidemiology of asbestos-related diseases in Quebec : summary and recommendation of the reports

    Energy Technology Data Exchange (ETDEWEB)

    DeGuire, L.; Lajoie, P.; Lemieux, C.; Poulin, M.

    2004-07-01

    An asbestos advisory committee was created in 1997 by Quebec's Ministry of Health to address concerns regarding exposure to asbestos fibres. Two sub-committees were subsequently formed. One sub-committee evaluated the pertinence and feasibility of assessing exposure in the general population, particularly in public buildings such as schools, while the other reviewed epidemiological studies in Quebec on mesothelioma, pulmonary cancers and asbestosis. Each sub-committee produced a report. This document summarizes the two reports and outlines the current scientific knowledge on the effects of asbestos on human health. The preventive programs and subsequent evaluations undertaken in Quebec with respect to sprayed asbestos in schools was described along with studies of asbestos exposure among workers in the mining sector. A study was also conducted within the asbestos processing industry to identify how many workers exceeded standard exposure limits. The standard time-weighted average exposure value currently in force in Quebec is 1 fibre per ml for chrysotile and 0.2 fibres per ml for amosite and crocidolite. A recommendation was made to revise this standard. In terms of outdoor air, the concentrations measured in recent years in mining towns have been generally very low. Along with asbestos-asphalt, asbestos waste taken to landfill sites may represent a significant source of exposure. A screening for asbestosis in the building and public works sector has shown that 1,500 workers (insulators, plumber-pipe fitters, elevator mechanics, fire protection mechanics and boiler-makers) experienced significant exposure to high concentrations of asbestos fibres in the ambient air. The 3 main health effects of asbestos exposure include mesothelioma of the pleura and peritoneum, pulmonary cancer and asbestosis. Each of these diseases appears after a latency period of 20 to 40 years, depending on the pathology. Epidemiological studies show a statistically significant increase

  11. Tackling the mortality from long-term exposure to outdoor air pollution in megacities: Lessons from the Greater Cairo case study.

    Science.gov (United States)

    Wheida, Ali; Nasser, Amira; El Nazer, Mostafa; Borbon, Agnes; Abo El Ata, Gehad A; Abdel Wahab, Magdy; Alfaro, Stephane C

    2018-01-01

    The poor outdoor air quality in megacities of the developing world and its impact on health is a matter of concern for both the local populations and the decision-makers. The objective of this work is to quantify the mortality attributable to long-term exposure to PM2.5, NO 2 , and O 3 in Greater Cairo (Egypt). We analyze the temporal and spatial variability of the three pollutants concentrations measured at 18 stations of the area. Then, we apply the method recommended by the WHO to estimate the excess mortality. In this assessment, three different shapes (log-linear, linear, and log-log) of the concentration-response functions (CRF) are used. With PM2.5 concentrations varying from 50 to more than 100µg/m 3 in the different sectors of the megacity, the spatial variability of this pollutant is found to be one important cause of uncertainty on the excess mortality associated with it. Also important is the choice of the CRF. With the average (75µg/m 3 ) PM2.5 concentration and the most favorable log-log shape of the CRF, 11% (CI, 9-14%) of the non-accidental mortality in the population older than 30 years can still be attributed to PM2.5, which corresponds to 12520 (CI, 10240-15930) yearly premature deaths. Should the Egyptian legal 70µg/m 3 PM10 limit (corresponding to approximately 37.5µg/m 3 for PM2.5) be met, this number would be reduced to 7970, meaning that 4550 premature deaths could be avoided each year. Except around some industrial or traffic hot spots, NO 2 concentration is found to be below the 40µg/m 3 air quality guideline of the WHO. However, the average concentration (34µg/m 3 ) of this gas exceeds the stricter 10µg/m 3 recommendation of the HRAPIE project and it is thus estimated that from 7850 to 10470 yearly deaths can be attributed to NO 2 . Finally, with the ozone concentration measured at one station only, it is found that, depending on the choice of the CRF, between 2.4% and 8.8% of the mortality due to respiratory diseases can be

  12. OUTDOOR EDUCATION AND GEOGRAPHICAL EDUCATION

    Directory of Open Access Journals (Sweden)

    ANDREA GUARAN

    2016-01-01

    Full Text Available This paper focuses on the reflection on the relationship between values and methodological principles of Outdoor Education and spatial and geographical education perspectives, especially in pre-school and primary school, which relates to the age between 3 and 10 years. Outdoor Education is an educational practice that is already rooted in the philosophical thought of the 16th and the 17th centuries, from John Locke to Jean-Jacques Rousseau, and in the pedagogical thought, in particular Friedrich Fröbel, and it has now a quite stable tradition in Northern Europe countries. In Italy, however, there are still few experiences and they usually do not have a systematic and structural modality, but rather a temporarily and experimentally outdoor organization. In the first part, this paper focuses on the reasons that justify a particular attention to educational paths that favour outdoors activities, providing also a definition of outdoor education and highlighting its values. It is also essential to understand that educational programs in open spaces, such as a forest or simply the schoolyard, surely offers the possibility to learn geographical situations. Therefore, the question that arises is how to finalize the best stimulus that the spatial location guarantees for the acquisition of knowledge, skills and abilities about space and geography.

  13. Experimental study of air evaporative cooling process using microporous membranes

    Directory of Open Access Journals (Sweden)

    Englart Sebastian

    2017-01-01

    Full Text Available This article describes the potential use of microporous membranes in evaporative cooling applications for air conditioning. The structure of membrane contractor and the measuring device are described. On the basis of the results of the measurements air cooling effectiveness coefficient has been determined.

  14. An experimental investigation of natural circulated air flow in the passive containment cooling system

    International Nuclear Information System (INIS)

    Ryu, S.H.; Oh, S.M.; Park, G.C.

    2004-01-01

    The objective of this study is to investigate the effects of air inlet position and external conditions on the natural circulated air flow rate in a passive containment cooling system of the advanced passive reactor. Experiments have been performed with 1/36 scaled segment type passive containment test facility. The air velocities and temperatures are measured through the air flow path. Also, the experimental results are compared with numerical calculations and show good agreement. (author)

  15. Air and the origin of the experimental plant physiology.

    Science.gov (United States)

    Pennazio, Sergio

    2005-01-01

    It is well known that oxygen and carbon dioxide are two chemicals which enter the plant metabolism as nutrients. The bases of this nowadays obvious statement were placed in the 18th century by means of the works of ingenious naturalists such as Robert Boyle, Stephen Hales, Joseph Priestley, Jam Ingenhousz, Lazzaro Spallanzani and Theodore De Saussure. Till the end of the 17th century, the atmospheric air was considered as an ineffable spirit, the function of which was of physical nature. Boyle was the first naturalist to admit the possibility that respiration were an exchange of vapours occurring in the blood. Stephen Hales realised that air could be fixed by plants under the influence of solar light. Priestley showed that plants could regenerate the bad air making it breathable. Ingenhousz demonstrated that the green parts of plants performed the complete purification of air only under the influence of the light. Spallanzani discovered that plants respire and guessed that the good air (oxygen) originated from the fixed air (carbon dioxide). Finally, Theodore De Saussure showed that plants were able to adsorb carbon dioxide and to release oxygen in a proportional air. All these discoveries benefited of the results coming from investigations of scholars of the so-called "pneumatic chemistry" (Boyle himself, George Ernst Stahl, Joseph Black, Priestley himself, and many more others. But among all the eminent scientists above mentioned stands out the genius of Antoine Laurent Lavoisier, who revolutionised the chemistry of the 18th century ferrying it towards the modern chemistry.

  16. NOAA NOS SOS, EXPERIMENTAL, 1853-present, Air Temperature

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The NOAA NOS SOS server is part of the IOOS DIF SOS Project. The stations in this dataset have air temperature data. *These services are for testing and evaluation...

  17. The Mica Creek Experimental Watershed: An Outdoor Laboratory for the Investigation of Hydrologic Processes in a Continental/Maritime Mountainous Environment

    Science.gov (United States)

    Link, T. E.; Gravelle, J.; Hubbart, J.; Warnsing, A.; Du, E.; Boll, J.; Brooks, E.; Cundy, T.

    2004-12-01

    Experimental catchments have proven to be extremely useful for investigations focused on fundamental hydrologic processes and on the impacts of land cover change on hydrologic regimes and water quality. Recent studies have illustrated how watershed responses to experimental treatments vary greatly between watersheds with differing physical, ecological and hydroclimatic characteristics. Meteorological and hydrological data within catchments are needed to help identify how hydrologic mechanisms may be altered by land cover alterations, and to both constrain and develop spatially-distributed physically based models. Existing instrumentation at the Mica Creek Experimental Watershed (MCEW) in northern Idaho is a fourth-order catchment that is undergoing expansion to produce a comprehensive dataset for model development and testing. The experimental catchments encompass a 28 km2 area spanning elevations from 975 to 1725 m msl. Snow processes dominate the hydrology of the catchment and climate conditions in the winter alternate between cold, dry continental and warm, moist maritime weather systems. Landcover is dominated by 80 year old second growth conifer forests, with partially cut (thinned) and clear-cut sub-catchments. Climate and precipitation data are collected at a SNOTEL site, three primary, and seven supplemental meteorological stations stratified by elevation and canopy cover. Manual snow depth measurements are recorded every 1-2 weeks during snowmelt, stratified by aspect, elevation and canopy cover. An air temperature transect spans three second-order sub-catchments to track air temperature lapse rate dynamics. Precipitation gauge arrays are installed within thinned and closed-canopy stands to track throughfall and interception loss. Nine paired and nested sub-catchments are monitored for flow, temperature, sediment, and nutrients. Hydroclimatic data are augmented by LiDAR and hyperspectral imagery for determination of canopy and topographic structure

  18. Experimental analysis of the thermal entrainment factor of air curtains in vertical open display cabinets for different ambient air conditions

    International Nuclear Information System (INIS)

    Gaspar, Pedro Dinis; Carrilho Goncalves, L.C.; Pitarma, R.A.

    2011-01-01

    The vertical open refrigerated display cabinets suffer alterations of their thermal performance and energy efficiency due to variations of ambient air conditions. The air curtain provides an aerothermodynamics insulation effect that can be evaluated by the thermal entrainment factor calculation as an engineering approximation or by the calculus of all sensible and latent thermal loads. This study presents the variation of heat transfer rate and thermal entrainment factor obtained through experimental tests carried out for different ambient air conditions, varying air temperature, relative humidity, velocity and its direction relatively to the display cabinet frontal opening. The thermal entrainment factor are analysed and compared with the total sensible and latent heats results for the experimental tests. From an engineering point of view, it is concluded that thermal entrainment factor cannot be used indiscriminately, although its use is suitable to design better cabinet under the same climate class condition.

  19. An experimental investigation on air-side performances of finned tube heat exchangers for indirect air-cooling tower

    Directory of Open Access Journals (Sweden)

    Du Xueping

    2014-01-01

    Full Text Available A tremendous quantity of water can be saved if the air cooling system is used, comparing with the ordinary water-cooling technology. In this study, two kinds of finned tube heat exchangers in an indirect air-cooling tower are experimentally studied, which are a plain finned oval-tube heat exchanger and a wavy-finned flat-tube heat exchanger in a cross flow of air. Four different air inlet angles (90°, 60 °, 45°, and 30° are tested separately to obtain the heat transfer and resistance performance. Then the air-side experimental correlations of the Nusselt number and friction factor are acquired. The comprehensive heat transfer performances for two finned tube heat exchangers under four air inlet angles are compared. For the plain finned oval-tube heat exchanger, the vertical angle (90° has the worst performance while 45° and 30° has the best performance at small ReDc and at large ReDc, respectively. For the wavy-finned flat-tube heat exchanger, the worst performance occurred at 60°, while the best performance occurred at 45° and 90° at small ReDc and at large ReDc, respectively. From the comparative results, it can be found that the air inlet angle has completely different effects on the comprehensive heat transfer performance for the heat exchangers with different structures.

  20. Experimental investigation of frictional resistance reduction with air layer on the hull bottom of a ship

    Directory of Open Access Journals (Sweden)

    Jang Jinho

    2014-06-01

    Full Text Available In an effort to cope with recent high oil price and global warming, developments of air lubricated ships have been pursued to reduce greenhouse gas emissions and to save fuel costs by reducing the frictional resistance. In this study, reduction in the frictional resistance by air lubrication with air layers generated on the lower surface of a flat plate was investigated experimentally in the large water tunnel of SSMB. The generated air layers were observed, and changes in the local frictional drag were measured at various flow rates of injected air. The results indicated that air lubrication with air layers might be useful in reducing the frictional resistance at specific conditions of air injection. Accordingly, resistance and self-propulsion tests for a 66K DWT bulk carrier were carried out in the towing tank of SSMB to estimate the expected net power savings.

  1. Experimental Study of Air Vessel Behavior for Energy Storage or System Protection in Water Hammer Events

    Directory of Open Access Journals (Sweden)

    Mohsen Besharat

    2017-01-01

    Full Text Available An experimental assessment of an air pocket (AP, confined in a compressed air vessel (CAV, has been investigated under several different water hammer (WH events to better define the use of protection devices or compressed air energy storage (CAES systems. This research focuses on the size of an AP within an air vessel and tries to describe how it affects important parameters of the system, i.e., the pressure in the pipe, stored pressure, flow velocity, displaced volume of water and water level in the CAV. Results present a specific range of air pockets based on a dimensionless parameter extractable for other real systems.

  2. An experimental evaluation of multi-pass solar air heaters

    Energy Technology Data Exchange (ETDEWEB)

    Satcunanathan, S.; Persad, P.

    1980-12-01

    Three collectors of identical dimensions but operating in the single-pass, two-pass and three-pass modes were tested simultaneously under ambient conditions. It was found that the two-pass air heater was consistently better than the single-pass air heater over the day for the range of mass flow rates considered. It was also found that at a mass flow rate of 0.0095 kg s/sup -1/ m/sup -2/, the thermal performances of the two-pass and three-pass collectors were identical, but at higher flow rates the two-pass collector was superior to the three-pass collector, the superiority decreasing with increasing mass flow rate.

  3. An experimental study of thermal comfort at different combinations of air and mean radiant temperature

    DEFF Research Database (Denmark)

    Simone, Angela; Olesen, Bjarne W.

    2009-01-01

    It is often discussed if a person prefers a low air temperature (ta) and a high mean radiant temperature (tr), vice-versa or it does not matter as long as the operative temperature is acceptable. One of the hypotheses is that it does not matter for thermal comfort but for perceived air quality......, a lower air temperature is preferred. This paper presents an experimental study with 30 human subjects exposed to three different combinations of air- and mean radiant temperature with an operative temperature around 23 °C. The subjects gave subjective evaluations of thermal comfort and perceived air...... quality during the experiments. The PMV-index gave a good estimation of thermal sensation vote (TSV) when the air and mean radiant temperature were the same. In the environment with different air- and mean radiant temperatures, a thermal comfort evaluation shows an error up to 1 scale unit on the 7-point...

  4. An experimental chamber simulating the equilibrium between radon and its daughters in mine air

    International Nuclear Information System (INIS)

    Domanski, T.; Chruscielewski, W.; Orzechowski, W.

    1981-01-01

    An experimental chamber simulating the equilibrium between radon and its daughters in uranium mine air is described. The apparatus is useful for testing track detectors, air samplers, masks and filters and for determining occupational exposures. Increasing the humidity of the chamber air and increasing the amounts of aerosol injected both increase the values of the equilibrium factor, F. The equilibrium in the chamber air decreases after the aerosol injection but by using controlled pulse injections it was shown that the stability of F could be maintained inside the chamber for 4 hours. Results are also given for the structure of the equilibrium between radon and its daughters Qsub(i)/Q 0 in the chamber air as a function of the chamber air factor F and also for the potential α-energy of unattached products in relation to the total α-potential energy of radon daughter products in the chamber air as a function of factor F. (U.K.)

  5. Leviathan and the air-pump Hobbes, Boyle, and the experimental life

    CERN Document Server

    Shapin, Steven

    2011-01-01

    Leviathan and the Air-Pump examines the conflicts over the value and propriety of experimental methods between two major seventeenth-century thinkers: Thomas Hobbes, author of the political treatise Leviathan and vehement critic of systematic experimentation in natural philosophy, and Robert Boyle, mechanical philosopher and owner of the newly invented air-pump. The issues at stake in their disputes ranged from the physical integrity of the air-pump to the intellectual integrity of the knowledge it might yield. Both Boyle and Hobbes were looking for ways of establishing knowledge tha

  6. Physiological responses to acute experimental hypoxia in the air ...

    Indian Academy of Sciences (India)

    When C. batrachus was exposed for different periods at experimental hypoxia level (0.98±0.1 mg/L, DO), hemoglobin and hematocrit concentrations were increased, along with decrease in mean cellular hemoglobin concentration, which reflected a physiological adaptation to enhance oxygen transport capacity. Significant ...

  7. Physiological responses to acute experimental hypoxia in the air ...

    Indian Academy of Sciences (India)

    2013-03-05

    Mar 5, 2013 ... for different periods at experimental hypoxia level (0.98±0.1 mg/L, DO), hemoglobin and hematocrit .... 2.1 Fish maintenance and acclimatization to normoxic .... method that uses glucose oxidase and peroxidase reaction to.

  8. Experimental study on fundamental phenomena in HTGR small break air-ingress accident

    International Nuclear Information System (INIS)

    Kim, Jae Soon; Hwang, Jin-Seok; Kim, Eung Soo; Kim, Byung Jun; Oh, Chang Ho

    2016-01-01

    Highlights: • Air-ingress phenomena on the small break in a HTGR are experimentally investigated. • Experiment is investigated for various break sizes, angles, and density ratios. • Maximum air-ingress rate is observed at 120° in break angle. • This study reveals that air-ingress in the small break is governed by; buoyancy and flow inertia. • A non-dimensional parameter is newly proposed to determine the air-ingress flow regimes. • Newly proposed parameter is based on buoyancy versus inertia force. - Abstract: This study experimentally investigates fundamental phenomena in the HTGR small break air-ingress accident. Several important parameters including density ratio, break angle, break size, and main flow velocity are considered in the measurement and the analysis. The test-section is made of a circular pipe with small holes drilled around the surface and it is installed in the helium/air flow circulation loop. Oxygen concentrations and flow rates are recorded during the tests with fixed break angles, break sizes, and flow velocities for measurement of the air-ingress rates. According to the experimental results, the higher density difference leads to the higher rates of air-ingress with large sensitivity of the break angles. It is also found that the break angle significantly affects the air-ingress rates, which is gradually increased from 0° to 120° and suddenly decreased to 180°. The minimum air ingress rate is found at 0° and the maximum, at 110°. The air-ingress rate increases with the break size due to the increased flow-exchange area. However, it is not directly proportional to the break area due to the complexity of the phenomena. The increased flow velocity in the channel inside enhances the air-ingress process. However, among all the parameters, the main flow velocity exhibits the lowest effect on this process. In this study, the Froude Number relevant to the small break air-ingress conditions are newly defined considering both heavy

  9. Experimental evaluation of enthalpy efficiency and gas-phase contaminant transfer in an enthalpy recovery unit with polymer membrane foils

    DEFF Research Database (Denmark)

    Nie, Jinzhe; Yang, Jianrong; Fang, Lei

    2015-01-01

    Experimental studies were conducted in a laboratory setting to investigate the enthalpy efficiency and gas-phase contaminant transfer in a polymer membrane enthalpy recovery unit. One commercially available polymer membrane enthalpy recovery unit was used as a reference unit. Simulated indoor air...... and outdoor air by twin chambers was connected to the unit. Three chemical gases were dosed to the indoor exhaust air to mimic indoor air contaminants. Based on the measurements of temperature, humidity ratio, and contaminant concentrations of the indoor exhaust air and outdoor air supply upstream...

  10. Experimental verification of air flow rate measurement for representative isokinetic air sampling in ventilation stacks

    International Nuclear Information System (INIS)

    Okruhlica, P.; Mrtvy, M.; Kopecky, Z.

    2009-01-01

    Nuclear facilities are obliged to monitor their discharge's influence on environment. Main monitored factions in NPP's ventilation stacks are usually noble gasses, particulates and iodine. These factions are monitored in air sampled from ventilation stack by means of sampling rosette and bypass followed with on-line measuring monitors and balance sampling devices with laboratory evaluations. Correct air flow rate measurement and representative iso-kinetic air sampling system is essential for physical correct and metrological accurate evaluation of discharge influence on environment. Pairs of measuring sensors (Anemometer, pressure gauge, thermometer and humidity meter) are symmetrically placed in horizontal projection of stack on positions based on measured air flow velocity distribution characteristic, Analogically diameter of sampling rosette nozzles and their placement in the middle of 6 - 7 annuluses are calculated for assurance of representative iso-kinetic sampling. (authors)

  11. Experimental verification of air flow rate measurement for representative isokinetic air sampling in ventilation stacks

    International Nuclear Information System (INIS)

    Okruhlica, P.; Mrtvy, M.; Kopecky, Z.

    2008-01-01

    Nuclear facilities are obliged to monitor their discharge's influence on environment. Main monitored factions in NPP's ventilation stacks are usually noble gasses, particulates and iodine. These factions are monitored in air sampled from ventilation stack by means of sampling rosette and bypass followed with on-line measuring monitors and balance sampling devices with laboratory evaluations. Correct air flow rate measurement and representative iso-kinetic air sampling system is essential for physical correct and metrological accurate evaluation of discharge influence on environment. Pairs of measuring sensors (Anemometer, pressure gauge, thermometer and humidity meter) are symmetrically placed in horizontal projection of stack on positions based on measured air flow velocity distribution characteristic, Analogically diameter of sampling rosette nozzles and their placement in the middle of 6- 7 annuluses are calculated for assurance of representative iso-kinetic sampling. (authors)

  12. Outdoorsman: Outdoor Cooking.

    Science.gov (United States)

    Alberta Dept. of Agriculture, Edmonton.

    This Outdoor Cookery manual provides information and instruction on the basic outdoor skills of building suitable cooking fires, handling fires safely, and storing food. The necessity of having the right kind of fire is stressed (high flames for boiling, low for stewing, and coals for frying and broiling). Tips on gauging temperature, what types…

  13. Outdoor radon variation in Romania

    International Nuclear Information System (INIS)

    Simion, Elena; Simion, Florin

    2008-01-01

    Full text: The results of a long-term survey (1992 - 2006) of the variations of outdoor radon concentrations in semi-natural location from Romania are reported in the present paper. Measurements, covering between two and four sessions of the day (morning, afternoon, evening and night), were performed on a daily bases by 37 Environmental Radioactivity Monitoring Stations from National Environmental Radioactivity Survey Network. The method used was based on indirect determination of outdoor radon from aerosol samples collected on glass micro-fibre filters by drawing the air through the filters. The sampling was performed in a fixed place at a height of 2 m above the ground surface. Total beta counting of aerosol samples collected was performed immediately and after 20 hours. Values recorded during the years of continuous measurement indicated the presence of several patterns in the long-term variation of outdoor radon concentration: diurnal, seasonal and annual variation. For diurnal variation, outdoor radon concentration shows a maximum values in the night (early hours) and minimum values by day (in the afternoon). On average, this maximum is a factor of 2 higher than the minimum. Late autumn - beginning of winter maximum and an early spring minimum are characteristic for seasonal patterns. In the long term a seasonal pattern was observed for diurnal variation, with an average diurnal maximum to minimum ratio of 1.33 in winter compared with 3.0 in the summer months. The variations of outdoor radon levels showed little correlation with the uranium concentration of the ground and were attributed to changes in soil moisture content. In dry seasons, because of the low precipitation, the soil was drying out in the summer allowing fractures to develop and radon to migrate easily through the ground. Depending on micro-climatic and geological conditions, outdoor radon average concentrations in different regions of Romania are from 1200 mBq/mc to 13065 mBq/mc. The smallest

  14. An experimental study of the air-side particulate fouling in finned-tube heat exchangers of air conditioners through accelerated tests

    International Nuclear Information System (INIS)

    Ahn, Young Chull; Cho, Jae Min; Lee, Jae Keun; Lee, Hyun Uk; Ahn, Seung Phyo; Youn, Deok Hyun; Kang, Tae Wook; Ock, Ju Jo

    2003-01-01

    The air-side particulate fouling in the heat exchangers of HVAC applications degrades the performance of cooling capacity, pressure drop across a heat exchanger, and indoor air quality. Indoor and outdoor air contaminants foul heat exchangers. The purpose of this study is to investigate the fouling characteristics trough accelerated tests. The fouling characteristics are analyzed as functions of a dust concentration (1.28 and 3.84 g/m 3 ), a face velocity (0.5, 1.0, and 1.5 m/s), and a surface condition. The cooling capacity in the slitted finned-tube heat exchangers at the face velocity of 1 m/s decreases about 2% and the pressure drop increases up to 57%. The rate of build-up of fouling is observed to be 3 times slower for this three-fold reduction of dust concentration whilst still approaching the same asymptotic level

  15. Experimental verification of a condenser with liquid–vapor separation in an air conditioning system

    International Nuclear Information System (INIS)

    Chen, Xueqing; Chen, Ying; Deng, Lisheng; Mo, Songping; Zhang, Haiyan

    2013-01-01

    Three liquid–vapor separation condensers (LSC) were tested to evaluate their ability to automatically separate the liquid and vapor during condensation. Each was used in a split-type air conditioner to investigate the performance. The performance of the LSC system having the greatest cooling capacity and energy efficiency ratio (EER) was then compared with that of the system having a baseline fin-and-tube condenser for various ambient temperatures from 29 °C to 43 °C. The results showed that both the cooling capacity and EER of the two systems were almost the same at the three standard conditions in the Chinese standard GB/T 7725-2004, with the LSC having just 67% of the heat transfer area of the baseline condenser. In addition, the LSC system was charged with only 80% of the refrigerant in the baseline system. -- Highlights: ► We tested three liquid–vapor separation condensers in an air conditioning system. ► The best system had the most uniform wall temperature and the smallest pressure drop. ► The LSC system performance with only 67% condenser area was as good as the baseline system. ► LSC system operations are compared for various outdoor temperatures

  16. Analytical and Experimental Study of Recycling Baffled Double-Pass Solar Air Heaters with Attached Fins

    Directory of Open Access Journals (Sweden)

    Chun Sheng Lin

    2013-03-01

    Full Text Available The study of the heat transfer of solar air heaters with a new design using an absorbing plate with fins and baffles, which facilitate the recycling of flowing air, is reported. The mathematical formulation and analytical analysis for such a recyclic baffled double-pass solar air heater were developed theoretically. The performance of the device was studied experimentally as well. The theoretical predicted and experimental results were compared with another design, i.e., a downward-type single-pass solar air heater without recycle and double-pass operations reported in our previous work. Significant improvement in heat-transfer efficiency is achieved with the baffle and fin design due to the recycling heating and the extended heat transfer area. The effects of mass flow rate and recycle ratio on the heat-transfer efficiency enhancement as well as on the power consumption increment are also discussed.

  17. Experimental study of air delivery into water-conveyance system of the radial-axial turbine

    Science.gov (United States)

    Maslennikova, Alexandra; Platonov, Dmitry; Minakov, Andrey; Dekterev, Dmitry

    2017-10-01

    The paper presents an experimental study of oscillatory response in the Francis turbine of hydraulic unit. The experiment was performed on large-scale hydrodynamic test-bench with impeller diameter of 0.3 m. The effect of air injection on the intensity of pressure pulsations was studied at the maximum pressure pulsations in the hydraulic unit. It was revealed that air delivery into the water-conveyance system of the turbine results in almost two-fold reduction of pressure pulsations.

  18. Experimental and simulation studies on a single pass, double duct solar air heater

    Energy Technology Data Exchange (ETDEWEB)

    Forson, F.K. [Kwame Nkrumah Univ. of Science and Technology, Dept. of Mechanical Engineering, Kumasi (Ghana); Rajakaruna, H. [De Montfort Univ., School of Engineering and Technology, Leicester (United Kingdom)

    2003-05-01

    A mathematical model of a single pass, double duct solar air heater (SPDDSAH) is described. The model provides a design tool capable of predicting: incident solar radiation, heat transfer coefficients, mean air flow rates, mean air temperature and relative humidity at the exit. Results from the simulation are presented and compared with experimental ones obtained on a full scale air heater and a small scale laboratory one. Reasonable agreement between the predicted and measured values is demonstrated. Predicted results from a parametric study are also presented. It is shown that significant improvement in the SPDDSAH performance can be obtained with an appropriate choice of the collector parameters and the top to bottom channel depth ratio of the two ducts. The air mass flow rate is shown to be the dominant factor in determining the overall efficiency of the heater. (Author)

  19. An experimental setup for the study of the steady air flow in a diesel engine chamber

    Directory of Open Access Journals (Sweden)

    Montanero José María

    2012-04-01

    Full Text Available We present an experimental setup for studying the steady air flow in a diesel engine chamber. An engine block containing the inlet manifold was placed on a test bench. A steady air stream crossed the inlet manifold and entered a glass chamber driven by a fan. A PIV system was set up around the bench to measure the in-chamber flow. An air spray gun was used as seed generator to producing sub-millimeter droplets, easily dragged by the air stream. Images of the in-flow chamber were acquired in the course of the experiments, and processed to measure the velocity field. The pressure drop driven the air current and the mass flow rate were also measured.

  20. Experimental and Numerical Analysis of a Water Emptying Pipeline Using Different Air Valves

    Directory of Open Access Journals (Sweden)

    Oscar E. Coronado-Hernández

    2017-02-01

    Full Text Available The emptying procedure is a common operation that engineers have to face in pipelines. This generates subatmospheric pressure caused by the expansion of air pockets, which can produce the collapse of the system depending on the conditions of the installation. To avoid this problem, engineers have to install air valves in pipelines. However, if air valves are not adequately designed, then the risk in pipelines continues. In this research, a mathematical model is developed to simulate an emptying process in pipelines that can be used for planning this type of operation. The one-dimensional proposed model analyzes the water phase propagation by a new rigid model and the air pockets effect using thermodynamic formulations. The proposed model is validated through measurements of the air pocket absolute pressure, the water velocity and the length of the emptying columns in an experimental facility. Results show that the proposed model can accurately predict the hydraulic characteristic variables.

  1. An experimental study of the air humidification process using a membrane contactor

    Directory of Open Access Journals (Sweden)

    Englart Sebastian

    2017-01-01

    Full Text Available The article presents the results of the experimental examination of the effectiveness of air humidification using a membrane module. The construction of the membrane module and the measuring stand is also discussed. In order to assess the effectiveness of air humidification using the membrane module, the measurements of temperature and humidity at the membrane module’s inlet and outlet, air flow rate, water flow rate and water temperature were taken. Based on the measurements, the effectiveness coefficients, E, have been determined. The power demand for the solution under study has also been discussed.

  2. Experimental study of the overpressures generated by the detonation of spherical air-hydrocarbon gaseous mixtures

    International Nuclear Information System (INIS)

    Brossard, J.

    1978-01-01

    The characteristics of the pressure waves transmitted by detonation of gaseous mixtures to the surrounding air were measured by tests made near the ground level in 1 to 54 m 3 spherical balloons containing air-acetylene or air-ethylene mixtures. As concerns the peak overpressure Δp, a theoretical dimensional analysis in accordance with the experimental results shows that Δp can be expressed as a function of two independent variables, which are the radial distance R and the volume V of the balloon . A semi-empirical formula, including ground effects, is proposed and its present validity range is given. (author)

  3. Experimental research on in-tube condensation in the presence of air

    International Nuclear Information System (INIS)

    Tanrikut, A.; Yesin, O.

    2000-01-01

    In this research work, in-tube condensation in the presence of air is investigated experimentally for different operating conditions, and inhibiting effect of air is analyzed by comparing the experimental data of air/steam mixture with the data of corresponding pure steam cases, with respect to temperature, heat flux, and heat transfer coefficient. The test matrix covers the range of; P=2-6 bar, Re v =45000-94000, and X i =0%-52%. The inhibiting effect of air manifests itself as a remarkable decrease in centerline temperature (10 deg. C - 50 deg. C), depending on inlet air mass fraction. However, the measured centerline temperature is suppressed compared to the predicted one, from the Gibbs-Dalton Law, which indicates that the centerline temperature measurements are highly affected by inner wall thermal conditions, possibly due to narrow channel and high vapor Reynolds number. Even at the lowest air quality (10%) the reduction of the heat flux is 20% while it reaches up to 50% for the quality of 40%. Maximum percent decrease of the heat transfer coefficient was observed in runs with the system pressure of 2 bar; 45% and 65%, for the air mass fraction of 10% and 28%, respectively. (author)

  4. Experimental test of a novel multi-surface trough solar concentrator for air heating

    International Nuclear Information System (INIS)

    Zheng Hongfei; Tao Tao; Ma Ming; Kang Huifang; Su Yuehong

    2012-01-01

    Highlights: ► We made a prototype novel multi-surface trough solar concentrator for air heating. ► Circular and rectangular types of receiver were chosen for air heating in the test. ► The changes of instantaneous system efficiency with different air flow were obtained. ► The system has the advantage of high collection temperature, which can be over 140 °C. ► The average efficiency can exceed 45% at the outlet temperature of above 60 °C. - Abstract: This study presents the experimental test of a novel multi-surface trough solar concentrator for air heating. Three receivers of different air flow channels are individually combined with the solar concentrator. The air outlet temperature and solar irradiance were recorded for different air flow rates under the real weather condition and used to determine the collection efficiency and time constant of the air heater system. The characteristics of the solar air heater with different airflow channels are compared, and the variation of the daily efficiency with the normalized temperature change is also presented. The testing results indicates that the highest temperature of the air heater with a circular glass receiver can be over 140 °C. When the collection temperature is around 60 °C, the collection efficiency can be over 45%. For the rectangular receivers, the system also has a considerable daily efficiency at a larger air flow rate. The air heater based on the novel trough solar concentrator would be suitable for space heating and drying applications.

  5. Winter Weather: Outdoor Safety

    Science.gov (United States)

    ... Extreme Heat Older Adults (Aged 65+) Infants and Children Chronic Medical Conditions Low Income Athletes Outdoor Workers Pets Hot Weather Tips Warning Signs and Symptoms FAQs Social Media How to Stay Cool Missouri Cooling Centers Extreme ...

  6. Experimental Characterization of Wings for a Hawkmoth-Sized Micro Air Vehicle

    Science.gov (United States)

    2014-03-27

    butterfly where the modeshapes were found to be identical with the Hawkmoth, lending more credence to the assertion that the wing modal ratios...EXPERIMENTAL CHARACTERIZATION OF WINGS FOR A HAWKMOTH-SIZED MICRO AIR VEHICLE THESIS Zachary R. Brown, Lieutenant Commander, USN AFIT-ENY-14-M-10...of the U.S. Government and is not subject to copyright protection in the United States. AFIT-ENY-14-M-10 EXPERIMENTAL CHARACTERIZATION OF WINGS FOR A

  7. Socioeconomic position and outdoor nitrogen dioxide (NO2) exposure in Western Europe : A multi-city analysis

    NARCIS (Netherlands)

    Temam, Sofia; Burte, Emilie; Adam, Martin; Antó, Josep M; Basagaña, Xavier; Bousquet, Jean; Carsin, Anne-Elie; Galobardes, Bruna; Keidel, Dirk; Künzli, Nino; Le Moual, Nicole; Sanchez, Margaux; Sunyer, Jordi; Bono, Roberto; Brunekreef, Bert; Heinrich, Joachim; de Hoogh, Kees; Jarvis, Debbie; Marcon, Alessandro; Modig, Lars; Nadif, Rachel; Nieuwenhuijsen, Mark; Pin, Isabelle; Siroux, Valérie; Stempfelet, Morgane; Tsai, Ming-Yi; Probst-Hensch, Nicole; Jacquemin, Bénédicte

    BACKGROUND: Inconsistent associations between socioeconomic position (SEP) and outdoor air pollution have been reported in Europe, but methodological differences prevent any direct between-study comparison. OBJECTIVES: Assess and compare the association between SEP and outdoor nitrogen dioxide (NO2)

  8. Outdoor thermal comfort.

    Science.gov (United States)

    Nikolopoulou, Marialena

    2011-06-01

    A review of the various approaches in understanding outdoor thermal comfort is presented. The emphasis on field surveys from around the world, particularly across Europe, enables us to understand thermal perception and evaluate outdoor thermal comfort conditions. The consistent low correlations between objective microclimatic variables, subjective thermal sensation and comfort outdoors, internationally, suggest that thermophysiology alone does not adequate describe these relationships. Focusing on the concept of adaptation, it tries to explain how this influences outdoor comfort, enabling us to inhabit and get satisfaction from outdoor spaces throughout the year. Beyond acclimatization and behavioral adaptation, through adjustments in clothing and changes to the metabolic heat, psychological adaptation plays a critical role to ensure thermal comfort and satisfaction with the outdoor environment. Such parameters include recent experiences and expectations; personal choice and perceived control, more important than whether that control is actually exercised; and the need for positive environmental stimulation suggesting that thermal neutrality is not a pre-requisite for thermal comfort. Ultimately, enhancing environmental diversity can influence thermal perception and experience of open spaces.

  9. Experimental and Numerical Analysis of Air Flow, Heat Transfer and Thermal Comfort in Buildings with Different Heating Systems

    Directory of Open Access Journals (Sweden)

    Sabanskis A.

    2016-04-01

    Full Text Available Monitoring of temperature, humidity and air flow velocity is performed in 5 experimental buildings with the inner size of 3×3×3 m3 located in Riga, Latvia. The buildings are equipped with different heating systems, such as an air-air heat pump, air-water heat pump, capillary heating mat on the ceiling and electric heater. Numerical simulation of air flow and heat transfer by convection, conduction and radiation is carried out using OpenFOAM software and compared with experimental data. Results are analysed regarding the temperature and air flow distribution as well as thermal comfort.

  10. Indoor radon concentration and outdoor/indoor pressure difference correlation

    International Nuclear Information System (INIS)

    Cechak, T.; Fronka, A.; Moucka, L.

    2004-01-01

    In the current approach to the radon issue, the radon risk for people living in a building is estimated based on the average indoor radon concentration. Short-term measurements as usually applied fail to reflect the wide range of radon variations arising from ventilation, radon supply and, in particular, human activities in the building. For this reason, efforts are made to find a new approach to the assessment of the quality of a building as a radon barrier, independent of the weather conditions and residential habits. A simple model of radon volume activity entering the building at a constant rate and simultaneously ventilated at a constant rate is applicable to this task. The rate of radon ingress can be regarded as a parameter making it possible to quantify the leakage of structures provided the barrier against the radon in a soil gas. The ventilation rate, on the other hand, characterizes the leakage of the whole building envelope at a given outdoor/indoor pressure difference. A unique measuring technique called the blower door exists whereby a defined pressure difference between the indoor and outdoor atmosphere can be established. Under such conditions both the ventilation rate and the rate of radon ingress can be measured and expressed as a function of the pressure difference. An analysis of the model of a room with a constant ventilation and constant radon supply is presented and the relationship between radon supply and ventilation rate can be assumed. Some experimental results show how the model can be utilized. The real indoor-outdoor air pressure differences, the indoor-soil air pressure differences, and some effects of different ventilation regimes are given. Other experiments, which have been done by using the blower door method, illustrate the possible effects and some restrictions for a routine application are discussed

  11. Experimental results of a direct air-cooled ammonia–lithium nitrate absorption refrigeration system

    International Nuclear Information System (INIS)

    Llamas-Guillén, S.U.; Cuevas, R.; Best, R.; Gómez, V.H.

    2014-01-01

    Absorption thermal cooling systems driven by renewable energy are a viable option in order to reduce fossil fuel consumption and the associated emissions. This work shows the results of an air cooled absorption cooling prototype working with an ammonia–lithium nitrate mixture at high ambient temperatures. An absorption refrigeration system was designed and built. The prototype is a one stage ammonia–lithium nitrate air cooled chiller. The experimental system was instrumented to evaluate each component. This paper shows the operation conditions in the experimental unit as well as some of the heat loads encountered at different operating conditions. The system was operated successfully at ambient temperatures in the range of 25–35 °C. A series of test showed that even at ambient temperatures it can be operated at evaporator temperatures below 10 °C producing chilled water for air conditioning applications such as radiative cooling panels. The system proved to stabilize very quickly and no risk of crystallization was encountered so the first results are promising in order to continue with the development of a more advanced prototype. - Highlights: •Experimental results of a direct air-cooled ammonia–lithium nitrate system. •The prototype is a one stage ammonia–lithium nitrate air cooled chiller. •The absorption system was operated successfully at ambient temperatures. •Cooling loads of 4.5 kW were reached in the chilled water side

  12. Experimental calibration of the mathematical model of Air Torque Position dampers with non-cascading blades

    Directory of Open Access Journals (Sweden)

    Bikić Siniša M.

    2016-01-01

    Full Text Available This paper is focused on the mathematical model of the Air Torque Position dampers. The mathematical model establishes a link between the velocity of air in front of the damper, position of the damper blade and the moment acting on the blade caused by the air flow. This research aims to experimentally verify the mathematical model for the damper type with non-cascading blades. Four different types of dampers with non-cascading blades were considered: single blade dampers, dampers with two cross-blades, dampers with two parallel blades and dampers with two blades of which one is a fixed blade in the horizontal position. The case of a damper with a straight pipeline positioned in front of and behind the damper was taken in consideration. Calibration and verification of the mathematical model was conducted experimentally. The experiment was conducted on the laboratory facility for testing dampers used for regulation of the air flow rate in heating, ventilation and air conditioning systems. The design and setup of the laboratory facility, as well as construction, adjustment and calibration of the laboratory damper are presented in this paper. The mathematical model was calibrated by using one set of data, while the verification of the mathematical model was conducted by using the second set of data. The mathematical model was successfully validated and it can be used for accurate measurement of the air velocity on dampers with non-cascading blades under different operating conditions. [Projekat Ministarstva nauke Republike Srbije, br. TR31058

  13. Perspectives of Elementary School Teachers on Outdoor Education

    Science.gov (United States)

    Palavan, Ozcan; Cicek, Volkan; Atabay, Merve

    2016-01-01

    Outdoor education stands out as one of the methods to deliver the desired educational outcomes taking the needs of the students, teachers and the curricular objectives into consideration. Outdoor education focuses on experimental, hands-on learning in real-life environments through senses, e.g., through visual, auditory, and tactile means,…

  14. Experimental measurement of fluid force coefficients for helical tube arrays in air cross flow

    International Nuclear Information System (INIS)

    Shen Shifang; Liu Reilan

    1993-01-01

    A helical coil steam generator is extensively used in the High Temperature Gas Cooled Reactor (HTGCR) and Sodium Cooled Reactor (SCR) nuclear power stations because of its compact structure, good heat-exchange, and small volume. The experimental model is established by the structure parameter of 200MW HTGCR. The fluid elastic instability of helical tube arrays in air cross flow is studied in this experiment, and the fluid force coefficients of helical tube arrays having the same notational direction of two adjacent layers in air cross flow are obtained. As compared to the fluid force coefficients of cylinder tube arrays, the fluid force coefficients of helical tube arrays are smaller in the low velocity area, and greater in the high velocity area. The experimental results help the study of the dynamic characteristics of helical tube arrays in air cross flow

  15. Experimental determination of the average energy necessary for the production of an ion pair in air

    International Nuclear Information System (INIS)

    Guiho, J.P.; Simoen, J.P.

    1975-01-01

    The determination of the average energy Wbarsub(a) necessary to form an ion pair in air in a 60 Co beam (which is one of the French primary references in dosimetry) is obtained from measurements of the exposure and absorbed doses from the beam in the center of a graphite disc. The differential flux density of the beam having been measured the experimental value of Wbarsub(a) is obtained for a mean real photon energy. The so determined value of Wbarsub(a) in dry air is: Wbarsub(a) = 33,96 +-0.34 JC -1 for Ebar = 1150 keV. This result is then compared to different published values. From this comparison the importance of different correcting terms such as the air humidity correction and the carbon/air stopping power ratio, which constitutes the main source of uncertainty, are considered. (author)

  16. Experimental investigations on performance of liquid desiccant-vapor compression hybrid air conditioner

    International Nuclear Information System (INIS)

    Mohan, B. Shaji; Tiwari, Shaligram; Maiya, M.P.

    2015-01-01

    A coupled desiccant column is integrated with a conventional room air conditioner (AC) to enhance dehumidification of the room air. One desiccant column (absorber) is placed after the evaporator the other (regenerator) after the condenser of the AC unit. Such a novel liquid desiccant vapour compression hybrid air conditioning system has been fabricated and tested in a balanced ambient room type calorimeter for very low flow rates of liquid desiccant (lithium bromide solution). The moisture from the cold supply air is transferred to the hot condenser air by the desiccant flowing in the loop, thereby complimenting the dehumidification of the room air at the evaporator. The supply air is also sensibly heated during the dehumidification process by liquid desiccant in the absorber, which together enables the hybrid system to maintain low humidity in the room. Whereas the liquid desiccant is regenerated by the condenser waste heat, the entire cooling is derived only by the AC unit. The experimental results show that an increase of room temperature reduces both dehumidification of process air and regeneration of liquid desiccant, whereas an increase of room specific humidity enhances both these for the flow rate of the liquid desiccant in the range of 0.2–1.6% of the air flow rate through the absorber. - Highlights: • A liquid desiccant vapor compression hybrid system is fabricated and tested. • The liquid desiccant reduces latent load but equally increases sensible load. • Hybrid system performance is studied for varying room temperature and humidity. • Higher room temperature lowers air dehumidification and desiccant regeneration. • Increase of room specific humidity enhances dehumidification and also regeneration

  17. An experimental study of the exergetic performance of an underground air tunnel system for greenhouse cooling

    International Nuclear Information System (INIS)

    Ozgener, Leyla; Ozgener, Onder

    2010-01-01

    The present study highlights the exergetic performance characteristics of an underground air tunnel for greenhouse cooling with a 47 m horizontal, 56 cm nominal diameter U-bend buried galvanized ground heat exchanger. This system was designed and installed in the Solar Energy Institute, Ege University, Izmir, Turkey. Underground air tunnel systems, also known as earth-to-air heat exchangers, are recognized to be outstanding heating, cooling and air heating systems. On the other hand, they have not been used yet in the Turkish market. Greenhouses also have important economical potential in Turkey's agricultural sector. Greenhouses should be cooled during the summer or hot days. In order to establish optimum growth conditions in greenhouses, renewable energy sources should be utilized as much as possible. It is expected that effective use of underground air tunnels with a suitable technology in the modern greenhouses will play a leading role in Turkey in the foreseeable future. The exergy transports between the components and the destructions in each of the components of the system are determined for the average measured parameters obtained from the experimental results. Exergetic efficiencies of the system components are determined in an attempt to assess their individual performances and the potential for improvements is also presented. The daily maximum cooling coefficient of performances (COP) values for the system are also obtained to be 15.8. The total average COP in the experimental period is found to be 10.09. The system COP was calculated based on the amount of cooling produced by the air tunnel and the amount of power required to move the air through the tunnel, while the exergetic efficiency of the air tunnel is found to be in a range among 57.8-63.2%. The overall exergy efficiency value for the system on a product/fuel basis is found to be 60.7%. (author)

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

    Directory of Open Access Journals (Sweden)

    Peter Wallner

    2015-11-01

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

  19. Experimental and Numerical Investigation of Flow Properties of Supersonic Helium-Air Jets

    Science.gov (United States)

    Miller, Steven A. E.; Veltin, Jeremy

    2010-01-01

    Heated high speed subsonic and supersonic jets operating on- or off-design are a source of noise that is not yet fully understood. Helium-air mixtures can be used in the correct ratio to simulate the total temperature ratio of heated air jets and hence have the potential to provide inexpensive and reliable flow and acoustic measurements. This study presents a combination of flow measurements of helium-air high speed jets and numerical simulations of similar helium-air mixture and heated air jets. Jets issuing from axisymmetric convergent and convergent-divergent nozzles are investigated, and the results show very strong similarity with heated air jet measurements found in the literature. This demonstrates the validity of simulating heated high speed jets with helium-air in the laboratory, together with the excellent agreement obtained in the presented data between the numerical predictions and the experiments. The very close match between the numerical and experimental data also validates the frozen chemistry model used in the numerical simulation.

  20. Experimental study of a novel capacity control algorithm for a multi-evaporator air conditioning system

    International Nuclear Information System (INIS)

    Xu Xiangguo; Pan Yan; Deng Shiming; Xia Liang; Chan Mingyin

    2013-01-01

    The use of a multi-evaporator air conditioning (MEAC) system is advantageous in terms of installation convenience, high design flexibility, being easy to maintain and commission, better indoor thermal comfort control and higher energy efficiency. While MEAC units worth billions of dollars are sold worldwide, the detailed accounts on compressor capacity control and refrigeration flow distribution amongst evaporators remain unavailable in public domain, mainly due to commercial confidentiality. Limited control algorithms for MEAC systems have been developed based on system simulation, and no experimental-based capacity controller developments and their controllability tests may be identified in open literature. In the study reported in this paper, a novel capacity control algorithm, which imitated On–Off control of a single evaporator air conditioning (A/C) system in each indoor unit of a MEAC system by using variable speed compressor and electronic expansion valves (EEVs), was developed. Controllability tests under various settings for experimentally validating the novel capacity control algorithm were carried out and the control algorithm was further improved based on the experimental results. - Highlights: ► A capacity control algorithm for a multi-evaporator air conditioning system was developed. ► Experimental controllability tests under various settings were carried out. ► The control algorithm was further improved based on the experimental results.

  1. Effects of mobile phone distraction on pedestrians' crossing behavior and visual attention allocation at a signalized intersection: An outdoor experimental study.

    Science.gov (United States)

    Jiang, Kang; Ling, Feiyang; Feng, Zhongxiang; Ma, Changxi; Kumfer, Wesley; Shao, Chen; Wang, Kun

    2018-06-01

    With the rapid growth in mobile phone use worldwide, traffic safety experts have begun to consider the impact of mobile phone distractions on pedestrian crossing safety. This study sought to investigate how mobile phone distractions (music distraction, phone conversation distraction and text distraction) affect the behavior of pedestrians while they are crossing the street. An outdoor-environment experiment was conducted among 28 college student pedestrians. Two HD videos and an eye tracker were employed to record and analyze crossing behavior and visual attention allocation. The results of the research showed that the three mobile phone distractions cause different levels of impairment to pedestrians' crossing performance, with the greatest effect from text distraction, followed by phone conversation distraction and music distraction. Pedestrians distracted by music initiate crossing later, have increased pupil diameter, and reduce their scanning frequency, fixation points and fixation times toward traffic signal area priorities. In addition to the above effects, pedestrians distracted by phone conversation cross the street more slowly, direct fewer fixation points to the right traffic area, and spend less fixation time and lower average fixation duration on the left traffic area. Moreover, pedestrians distracted by texting look left and right less often and switch, distribute and maintain less visual attention on the traffic environment. These findings may inform researchers, policy makers, and pedestrians. Copyright © 2018 Elsevier Ltd. All rights reserved.

  2. Coping with Indoor Air Pollution

    Science.gov (United States)

    ... Pollution > Coping with Indoor Air Pollution Font: Outdoor Pollution Indoor Air Pollution Asthma Triggers For Kids and Teachers Coping with Indoor Air Pollution Indoor air pollution is irritating to everyone: But people who ...

  3. Experimental Validation of Stratified Flow Phenomena, Graphite Oxidation, and Mitigation Strategies of Air Ingress Accidents

    Energy Technology Data Exchange (ETDEWEB)

    Chang Ho Oh; Eung Soo Kim; Hee Cheon No; Nam Zin Cho

    2008-12-01

    The US Department of Energy is performing research and development (R&D) that focuses on key phenomena that are important during challenging scenarios that may occur in the Next Generation Nuclear Plant (NGNP) Program / GEN-IV Very High Temperature Reactor (VHTR). Phenomena identification and ranking studies (PIRT) to date have identified the air ingress event, following on the heels of a VHTR depressurization, as very important (Schultz et al., 2006). Consequently, the development of advanced air ingress-related models and verification and validation (V&V) are very high priority for the NGNP program. Following a loss of coolant and system depressurization, air will enter the core through the break. Air ingress leads to oxidation of the in-core graphite structure and fuel. The oxidation will accelerate heat-up of the bottom reflector and the reactor core and will cause the release of fission products eventually. The potential collapse of the bottom reflector because of burn-off and the release of CO lead to serious safety problems. For estimation of the proper safety margin we need experimental data and tools, including accurate multi-dimensional thermal-hydraulic and reactor physics models, a burn-off model, and a fracture model. We also need to develop effective strategies to mitigate the effects of oxidation. The results from this research will provide crucial inputs to the INL NGNP/VHTR Methods R&D project. This project is focused on (a) analytical and experimental study of air ingress caused by density-driven, stratified, countercurrent flow, (b) advanced graphite oxidation experiments, (c) experimental study of burn-off in the bottom reflector, (d) structural tests of the burnt-off bottom reflector, (e) implementation of advanced models developed during the previous tasks into the GAMMA code, (f) full air ingress and oxidation mitigation analyses, (g) development of core neutronic models, (h) coupling of the core neutronic and thermal hydraulic models, and (i

  4. Experimental and numerical study of an evaporatively-cooled condenser of air-conditioning systems

    International Nuclear Information System (INIS)

    Islam, M.R.; Jahangeer, K.A.; Chua, K.J.

    2015-01-01

    The performance of an air-conditioning unit with evaporately-cooled condenser coil is studied experimentally and numerically. An experimental setup is fabricated by retrofitting a commercially available air-conditioning unit and installing comprehensive measuring sensors and controllers. Experimental result shows that the COP (Coefficient of Performance) of the evaporately-cooled air-conditioning unit increases by about 28% compared to the conventional air cooled air-conditioning unit. To analyze the heat and mass transfer processes involved in the evaporately-cooled condenser, a detailed theoretical model has been developed based on the fluid flow characteristics of the falling film and the thermodynamic aspect of the evaporation process. Simulated results agree well with experimental data. The numerical model provides new insights into the intrinsic links between operating variables and heat transfer characteristics of water film in evaluating the performance of evaporatively-cooled condenser system. Two heat transfer coefficients, namely, wall to bulk and bulk to interface are introduced and computed from the simulation results under different operating conditions. Finally, the overall heat transfer coefficient for the water film is computed and presented as a function of dimensionless variables which can conveniently be employed by engineers to design and analyze high performance evaporatively-cooled heat exchangers. - Highlights: • Performance of evaporatively-cooled condenser is investigated. • Local convective heat transfer coefficients of water film are determined. • Thermal resistance of water film is negligible. • Heat transfer with evaporated vapor plays significant role on performance. • Better condenser performance translates to an improvement in COP

  5. Early-life exposure to outdoor air pollution and respiratory health, ear infections, and eczema in infants from the INMA study

    DEFF Research Database (Denmark)

    Aguilera, Inmaculada; Pedersen, Marie; Garcia-Esteban, Raquel

    2013-01-01

    the first 12-18 months of age in a Spanish birth cohort of 2,199 infants. METHODS: We obtained parentally reported information on doctor-diagnosed lower respiratory tract infections (LRTI) and parental reports of wheezing, eczema, and ear infections. We estimated individual exposures to nitrogen dioxide (NO...... and lower respiratory tract infections in infants.......BACKGROUND: Prenatal and early-life periods may be critical windows for harmful effects of air pollution on infant health. OBJECTIVES: We studied the association of air pollution exposure during pregnancy and the first year of life with respiratory illnesses, ear infections, and eczema during...

  6. Experimental study of perforated suspended ceilings as diffuse ventilation air inlets

    DEFF Research Database (Denmark)

    Hviid, Christian Anker; Svendsen, Svend

    2013-01-01

    An experimental study is reported in this paper for a diffuse ceiling ventilation concept. The analyses were carried out with two different porous surfaces mounted in a suspended ceiling: perforated tiles of aluminium and of gypsum. Ventilation air was supplied above the suspended ceiling effecti...... surface which increases the potential and applicability of the concept. Risk of thermal discomfort was not disclosed but the study did show evidence of large fluctuating air movements which could stem from transient behaviour creating sensations of draught to the occupants....

  7. Experimental Study on Indoor Air Cleaning Technique of Nano-Titania Catalysis Under Plasma Discharge

    International Nuclear Information System (INIS)

    Gao Deli; Yang Xuechang; Zhou Fei; Wu Yuhuang

    2008-01-01

    In this study, a new technique of air cleaning by plasma combined with catalyst was proposed, which consisted of electrostatic precipitation, volatile organic compounds (VOCs) decomposition and sterilization. A novel indoor air purifier based on this technique was adopted. The experimental results showed that formaldehyde decomposition by the plasma-catalyst hybrid system was more efficient than that by plasma only. Positive discharge was better than negative discharge in formaldehyde removal. Meanwhile, the outlet concentration of ozone byproduct was effectively reduced by the nano-titania catalyst.

  8. Learning Arithmetic Outdoors in Junior High School--Influence on Performance and Self-Regulating Skills

    Science.gov (United States)

    Fägerstam, Emilia; Samuelsson, Joakim

    2014-01-01

    This study aims to explore the influence of outdoor teaching among students, aged 13, on arithmetic performance and self-regulation skills as previous research concerning outdoor mathematics learning is limited. This study had a quasi-experimental design. An outdoor and a traditional group answered a test and a self-regulation skills questionnaire…

  9. Predicting outdoor sound

    CERN Document Server

    Attenborough, Keith; Horoshenkov, Kirill

    2014-01-01

    1. Introduction  2. The Propagation of Sound Near Ground Surfaces in a Homogeneous Medium  3. Predicting the Acoustical Properties of Outdoor Ground Surfaces  4. Measurements of the Acoustical Properties of Ground Surfaces and Comparisons with Models  5. Predicting Effects of Source Characteristics on Outdoor Sound  6. Predictions, Approximations and Empirical Results for Ground Effect Excluding Meteorological Effects  7. Influence of Source Motion on Ground Effect and Diffraction  8. Predicting Effects of Mixed Impedance Ground  9. Predicting the Performance of Outdoor Noise Barriers  10. Predicting Effects of Vegetation, Trees and Turbulence  11. Analytical Approximations including Ground Effect, Refraction and Turbulence  12. Prediction Schemes  13. Predicting Sound in an Urban Environment.

  10. Quantifying air pollution attenuation within urban parks: An experimental approach in Shanghai, China

    International Nuclear Information System (INIS)

    Yin Shan; Shen Zhemin; Zhou Pisheng; Zou Xiaodong; Che Shengquan; Wang Wenhua

    2011-01-01

    Parks with various types of vegetations played an important role in ameliorating air quality in urban areas. However, the attenuation effect of urban vegetation on levels of air pollution was rarely been experimentally estimated. This study, using seasonal monitoring data of total suspended particles (TSP), sulfur dioxide (SO 2 ) and nitrogen dioxide (NO 2 ) from six parks in Pudong District, Shanghai, China, demonstrated vegetations in parks can remove large amount of airborne pollutants. In addition, crown volume coverage (CVC) was introduced to characterize vegetation conditions in parks and a mixed-effects model indicated that CVC and the pollution diffusion distance were key predictors influencing pollutants removal rate. Therefore, it could be estimated by regression analysis that in summer, urban vegetations in Pudong District could contribute to 9.1% of TSP removal, 5.3% of SO 2 and 2.6% of NO 2 . The results could be considered for a better park planning and improving air quality. - Highlights: → We examined markedly air pollution decline in urban vegetation patches by field experiments. → Crown volume coverage (CVC) served to characterize vegetation condition among different species. → CVC and pollutants diffusion distance were key predictors affecting air pollution attenuation within parks. - Crown volume coverage (CVC) and pollutants diffusion distance had been proved as key predictors influencing attenuation effect on levels of air pollutants in urban parks.

  11. Experimental investigation of thermal comfort and air quality in an automobile cabin during the cooling period

    Energy Technology Data Exchange (ETDEWEB)

    Kilic, M.; Akyol, S.M. [Uludag University, Department of Mechanical Engineering, Faculty of Engineering and Architecture, Bursa (Turkey)

    2012-08-15

    The air quality and thermal comfort strongly influenced by the heat and mass transfer take place together in an automobile cabin. In this study, it is aimed to investigate and assess the effects of air intake settings (recirculation and fresh air) on the thermal comfort, air quality satisfaction and energy usage during the cooling period of an automobile cabin. For this purpose, measurements (temperature, air velocity, CO{sub 2}) were performed at various locations inside the cabin. Furthermore, whole body and local responses of the human subjects were noted while skin temperatures were measured. A mathematical model was arranged in order to estimate CO{sub 2} concentration and energy usage inside the vehicle cabin and verified with experimental data. It is shown that CO{sub 2} level inside of the cabin can be greater than the threshold value recommended for the driving safety if two and more occupants exist in the car. It is also shown that an advanced climate control system may satisfy the requirements for the air quality and thermal comfort as well as to reduce the energy usage for the cooling of a vehicle cabin. (orig.)

  12. Quantifying air pollution attenuation within urban parks: An experimental approach in Shanghai, China

    Energy Technology Data Exchange (ETDEWEB)

    Yin Shan [School of Environmental Science and Engineering, Shanghai Jiao Tong University, 800 Dongchuan Rd, Shanghai 200240 (China); Institute of Urban and Regional Development, University of California, 316 Wurster Hall, Berkeley, CA 94720 (United States); Shen Zhemin [School of Environmental Science and Engineering, Shanghai Jiao Tong University, 800 Dongchuan Rd, Shanghai 200240 (China); Zhou Pisheng [School of Agriculture and Biology, Shanghai Jiao Tong University, 800 Dongchuan Rd, Shanghai 200240 (China); Zou Xiaodong [School of Environmental Science and Engineering, Shanghai Jiao Tong University, 800 Dongchuan Rd, Shanghai 200240 (China); Che Shengquan [School of Agriculture and Biology, Shanghai Jiao Tong University, 800 Dongchuan Rd, Shanghai 200240 (China); Wang Wenhua, E-mail: whwang@sjtu.edu.cn [School of Environmental Science and Engineering, Shanghai Jiao Tong University, 800 Dongchuan Rd, Shanghai 200240 (China)

    2011-08-15

    Parks with various types of vegetations played an important role in ameliorating air quality in urban areas. However, the attenuation effect of urban vegetation on levels of air pollution was rarely been experimentally estimated. This study, using seasonal monitoring data of total suspended particles (TSP), sulfur dioxide (SO{sub 2}) and nitrogen dioxide (NO{sub 2}) from six parks in Pudong District, Shanghai, China, demonstrated vegetations in parks can remove large amount of airborne pollutants. In addition, crown volume coverage (CVC) was introduced to characterize vegetation conditions in parks and a mixed-effects model indicated that CVC and the pollution diffusion distance were key predictors influencing pollutants removal rate. Therefore, it could be estimated by regression analysis that in summer, urban vegetations in Pudong District could contribute to 9.1% of TSP removal, 5.3% of SO{sub 2} and 2.6% of NO{sub 2}. The results could be considered for a better park planning and improving air quality. - Highlights: > We examined markedly air pollution decline in urban vegetation patches by field experiments. > Crown volume coverage (CVC) served to characterize vegetation condition among different species. > CVC and pollutants diffusion distance were key predictors affecting air pollution attenuation within parks. - Crown volume coverage (CVC) and pollutants diffusion distance had been proved as key predictors influencing attenuation effect on levels of air pollutants in urban parks.

  13. Experimental investigation of thermal comfort and air quality in an automobile cabin during the cooling period

    Science.gov (United States)

    Kilic, M.; Akyol, S. M.

    2012-08-01

    The air quality and thermal comfort strongly influenced by the heat and mass transfer take place together in an automobile cabin. In this study, it is aimed to investigate and assess the effects of air intake settings (recirculation and fresh air) on the thermal comfort, air quality satisfaction and energy usage during the cooling period of an automobile cabin. For this purpose, measurements (temperature, air velocity, CO2) were performed at various locations inside the cabin. Furthermore, whole body and local responses of the human subjects were noted while skin temperatures were measured. A mathematical model was arranged in order to estimate CO2 concentration and energy usage inside the vehicle cabin and verified with experimental data. It is shown that CO2 level inside of the cabin can be greater than the threshold value recommended for the driving safety if two and more occupants exist in the car. It is also shown that an advanced climate control system may satisfy the requirements for the air quality and thermal comfort as well as to reduce the energy usage for the cooling of a vehicle cabin.

  14. Experimental and Numerical Investigations of Air Cooling for a Large-Scale Motor

    Directory of Open Access Journals (Sweden)

    Chih-Chung Chang

    2009-01-01

    Full Text Available This article experimentally and numerically investigates the thermal performance of a 2350-kW completely enclosed motor, which is cooled through an air-to-air heat exchanger. The air in the heat exchanger includes external and internal flow paths. The external air driven by the rotation of the centrifugal fan goes through the heat exchanger mounted on the top of the frame. The internal air absorbs heat released from the stator and the rotor and then transfers the heat to the heat exchanger through the motion of two axial fans and the rotor. Several test rigs have been set up to measure the performance of the fan and the motor. The Fluent software package is adopted to analyze the complicated thermal-fluid interactions among the centrifugal fan, two axial fans, heat exchanger, stator, and rotor. The measured data, including the fan performance curves and the temperature profiles of the heat exchanger and the stator, show good agreement with the simulated results. The numerical calculations also show that the nonuniform external flow distribution through the heat exchanger and the air leakage between the axial fan and the rotor reduces the cooling ability of the motor. A detailed discussion is also included to improve the motor cooling performance.

  15. Outdoor recreation and ethnicity

    DEFF Research Database (Denmark)

    Gentin, Sandra

    recreation, activities, and preferred outdoor recreation areas) between the minority and majority populations and related these differences to the ethnic minorities’ cultural background. The second paper presents the empirical work of this thesis, which is based on a survey of adolescents’ outdoor recreation....... In the UK the focus on underrepresented groups seems closely related to the focus on equality for access, while specific focus on access for ethnic minorities is not addressed in the forest and nature legislation and the national forest programs in Denmark, Germany and the Netherlands. Paper 4 proposes...

  16. Experimental and numerical study of flow deflection effects on electronic air-cooling

    International Nuclear Information System (INIS)

    Arfaoui, Ahlem; Ben Maad, Rejeb; Hammami, Mahmoud; Rebay, Mourad; Padet, Jacques

    2009-01-01

    This work present a numerical and experimental investigation of the influence of transversal flow deflector on the cooling of a heated block mounted on a flat plate. The deflector is inclined and therefore it guides the air flow to the upper surface of the block. This situation is simulating the air-cooling of a rectangular integrated circuit or a current converter mounted on an electronic board. The electronic component are assumed dissipating a low or medium heat flux (with a density lower than 5000 W/m 2 ), as such the forced convection air cooling without fan or heat sink is still sufficient. The study details the effects of the angle of deflector on the temperature and the heat transfer coefficient along the surface of the block and around it. The results of the numerical simulations and the InfraRed camera measurements show that the deviation caused by deflector may significantly enhance the heat transfer on the top face of block

  17. Experimental characterization of mass, work and heat flows in an air cooled, single cylinder engine

    International Nuclear Information System (INIS)

    Perez-Blanco, H.

    2004-01-01

    Small air cooled engines, although large in numbers, receive scant attention in the literature. Experimental data for a four stroke, air cooled, single cylinder engine are presented in this report. Air to fuel ratios, indicated and output power, exhaust composition and heat loss are determined to result in suitable thermal and mechanical efficiencies. The data obtained are discussed with the perspective obtained from other literature references. Exhaust composition figures appear reasonable, but the measurement of the transient exhaust flows is still a concern. Based on the measurements, a graph illustrating the different energy transformations in the engine is produced. Undergraduate students in the curriculum routinely use the engine and the present work allows one to conclude that the measurement approach produces reasonable results. These results could be used by engine modelers and others interested in this wide field of technology

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

    Directory of Open Access Journals (Sweden)

    Foued Chabane

    2014-03-01

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

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

    Science.gov (United States)

    Chabane, Foued; Moummi, Noureddine; Benramache, Said

    2014-03-01

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

  20. An experimental study of solar desalination using free jets and an auxiliary hot air stream

    Science.gov (United States)

    Eid, Eldesouki I.; Khalaf-Allah, Reda A.; Dahab, Mohamed A.

    2018-04-01

    An experimental study for a solar desalination system based on jet-humidification with an auxiliary perpendicular hot air stream was carried out at Suez city, Egypt 29.9668°N, 32.5498°E. The tests were done from May to October 2016. The effects of nozzles situations and nozzle diameter with and without hot air stream on fresh water productivity were monitored. The results show that; the lateral and downward jets from narrow nozzles have more productivities than other situations. The hot air stream has to be adapted at a certain flow rate to get high values of productivity. The system productivity is (5.6 L/m 2 ), the estimated cost is (0.030063 / L) and the efficiency is 32.8%.

  1. Quasi-Experimental Approaches to Evaluating the Impact of Air Pollution on Children’s Health

    Science.gov (United States)

    Heep, Samantha; Neidell, Matthew

    2016-01-01

    Many studies have shown a correlation between air pollution and poor children’s health. This paper focuses on recent studies that employ quasi-experimental designs in an effort to minimize the effect of confounding factors. These studies are complementary to studies using other designs and confirm that reducing air pollution reduces infant mortality, low birth weight, prematurity, congenital anomalies, asthma hospitalizations, and school absences. These results suggest that lowering the thresholds for acceptable air pollution levels may be prudent, as research has consistently found that some pollutants have negative impacts even at levels below current regulatory thresholds. Policy makers should also consider providing more information to pregnant women and families about when and where the risk of pollution exposure is highest so that they can employ avoidance behavior. PMID:22147868

  2. Epidemiological and experimental studies of the influence of air pollution on development of the fetus

    Energy Technology Data Exchange (ETDEWEB)

    Kominami, Y; Nakamura, R; Maeda, Y; Nakakugi, K; Yamagiwa, H; Takemura, T; Koorida, Y; Kawai, K

    1973-12-01

    Medical examinations, miscarriages, and stillbirth statistics are given for Yokkaichi, Sakai, and Kitakyushu. The influence of air pollution on the fetus and placenta is investigated histologically. The experimental results of exposure of pregnant mice to sulfur dioxide are given. The extended residence of pregnant women in an air polluted region correlated with a trend towards hypertension, increased severity of edema, and positivity of proteinurea. The percentage of stillbirths was higher in the districts where a higher level of sulfur oxide existed. Morbidity of birth defects was higher in the polluted part of Sakai. The weight of placenta was higher due to the increase of moisture content, edema, fibrosis, and atrophy. No disturbances occurred in the acutely exposed rodent placenta which correlated with human data. Pregnant women in air polluted areas suffered from chronic disturbances in the vascular and renal systems which result in an increased percentage of stillbirth and placental edema which can cause birth defects.

  3. Absorber and regenerator models for liquid desiccant air conditioning systems. Validation and comparison using experimental data

    Energy Technology Data Exchange (ETDEWEB)

    Krause, M.; Heinzen, R.; Jordan, U.; Vajen, K. [Kassel Univ., Inst. of Thermal Engineering, Kassel (Germany); Saman, W.; Halawa, E. [Sustainable Energy Centre, Univ. of South Australia, Mawson Lakes, Adelaide (Australia)

    2008-07-01

    Solar assisted air conditioning systems using liquid desiccants represent a promising option to decrease high summer energy demand caused by electrically driven vapor compression machines. The main components of liquid desiccant systems are absorbers for dehumidifying and cooling of supply air and regenerators for concentrating the desiccant. However, high efficient and validated reliable components are required and the design and operation have to be adjusted to each respective building design, location, and user demand. Simulation tools can help to optimize component and system design. The present paper presents new developed numerical models for absorbers and regenerators, as well as experimental data of a regenerator prototype. The models have been compared with a finite-difference method model as well as experimental data. The data are gained from the regenerator prototype presented and an absorber presented in the literature. (orig.)

  4. Experimental Investigation of Flow Resistance in a Coal Mine Ventilation Air Methane Preheated Catalytic Oxidation Reactor

    OpenAIRE

    Zheng, Bin; Liu, Yongqi; Liu, Ruixiang; Meng, Jian; Mao, Mingming

    2015-01-01

    This paper reports the results of experimental investigation of flow resistance in a coal mine ventilation air methane preheated catalytic oxidation reactor. The experimental system was installed at the Energy Research Institute of Shandong University of Technology. The system has been used to investigate the effects of flow rate (200 Nm3/h to 1000 Nm3/h) and catalytic oxidation bed average temperature (20°C to 560°C) within the preheated catalytic oxidation reactor. The pressure drop and res...

  5. The Dirt on Outdoor Classrooms.

    Science.gov (United States)

    Rich, Steve

    2000-01-01

    Explains the planning procedure for outdoor classrooms and introduces an integrated unit on monarch butterflies called the Monarch Watch program. Makes recommendations to solve financial problems of outdoor classrooms. (YDS)

  6. Mapping of Outdoor Classrooms.

    Science.gov (United States)

    Horvath, Victor G.

    Mapping symbols adopted by the Michigan Department of Natural Resources are presented with their explanations. In an effort to provide standardization and familiarity teachers and other school people involved in an outdoor education program are encouraged to utilize the same symbols in constructing maps. (DK)

  7. Innovation and Outdoor Education

    Science.gov (United States)

    Beames, Simon

    2017-01-01

    Within our fast-paced, fluid society, it is arguable that outdoor education needs to be innovative to play a useful role in young people's overall educational enterprise. A critical view, however, would suggest that we must beware of accepting technological innovation for its own sake. Innovations (or improvements) in education can take the form…

  8. Experimental assessment of air permeability in a concrete shear wall subjected to simulated seismic loading

    International Nuclear Information System (INIS)

    Girrens, S.P.; Farrar, C.R.

    1991-07-01

    A safety concern for the proposed Special Nuclear Materials Laboratory (SNML) facility at the Los Alamos National Laboratory was air leakage from the facility if it were to experience a design basis earthquake event. To address this concern, a study was initiated to estimate air leakage, driven by wind-generated pressure gradients, from a seismically damaged concrete structure. This report describes a prototype experiment developed and performed to measure the air permeability in a reinforced concrete shear wall, both before and after simulated seismic loading. A shear wall test structure was fabricated with standard 4000-psi concrete mix. Static load-cycle testing was used to simulate earthquake loading. Permeability measurements were made by pressurizing one side of the shear wall above atmospheric conditions and recording the transient pressure decay. As long as the structure exhibited linear load displacement response, no variation in the air permeability was detected. However, experimental results indicate that the air permeability in the shear wall increased by a factor of 40 after the wall had been damaged (cracked). 17 figs., 8 tabs

  9. Outdoor Education and Science Achievement

    Science.gov (United States)

    Rios, José M.; Brewer, Jessica

    2014-01-01

    Elementary students have limited opportunities to learn science in an outdoor setting at school. Some suggest this is partially due to a lack of teacher efficacy teaching in an outdoor setting. Yet the research literature indicates that outdoor learning experiences develop positive environmental attitudes and can positively affect science…

  10. Sterilization efficacy of ultraviolet irradiation on microbial aerosols under dynamic airflow by experimental air conditioning systems

    International Nuclear Information System (INIS)

    Nakamura, Hiroshi

    1987-01-01

    In order to know the sterilization efficacy of ultraviolet irradiation on microbial aerosols, the size and the weight of the aerosol particles were evaluated, and these were irradiated under dynamic air flow created by an experimental air conditioning system. The experimental apparatus consisted of a high efficiency particulate air (HEPA) filter, an aerosol generator, spiral UV lamps placed around a quart glass tube, an Andersen air sampler and a vacuum pump. They were connected serially by stainless steel ducts (85 mm in diameter, 8 m in length). Six types of microbial aerosols generated from an ultrasonic nebulizer were irradiated by UV rays (wavelength 254 nm, mean density 9400 μW/cm 2 ). Their irradiation time ranged from 1.0 to 0.0625 seconds. The microbial aerosols were collected onto the trypticase soy agar (TSA) medium in the Andersen air sampler. After incubation, the number of colony forming units (CFU) were counted, and converted to particle counts. The diameter of microbial aerosol particles calculated by their log normal distribution were found to match the diameter of a single bacteria cell measured by a microscope. The sterilization efficacy of UV in standard airflow conditions (0.5 sec. irradiation) were found to be over 99.5 % in Staphylococcus aureus, Staphylococcus epidermidis, Serratia marcescens, Bacillus subtilis (vegetative cell) and Bacillus subtilis (spore) and 67 % in Aspergillus niger (conidium). In A. niger, which was the most resistant microbe to UV irradiation, the efficacy rose up to 79 % when irradiated for 1.0 sec., and it was observed that the growth speed of the colonies was slower than that of the controls. It was thought that UV rays caused some damage to the proliferation of A. niger cells. (author)

  11. Experimental study of film media used for evaporative pre-cooling of air

    International Nuclear Information System (INIS)

    He, Suoying; Guan, Zhiqiang; Gurgenci, Hal; Hooman, Kamel; Lu, Yuanshen; Alkhedhair, Abdullah M.

    2014-01-01

    Highlights: • Two film media were experimentally studied in a low-speed wind tunnel. • Correlations for heat transfer coefficient and pressure drop were developed. • Cellulose media provide higher cooling efficiency and pressure drop than PVC media. • Water entrainment of PVC media happens even at relatively low air velocities. - Abstract: An open-circuit low-speed wind tunnel was used to study the performance of evaporative cooling with cellulose and Polyvinyl Chloride (PVC) corrugated media. These two film media were selected as part of a broader investigation on pre-cooling the entering air of natural draft dry cooling towers. The heat and mass transfer and pressure drop across the two media with three thicknesses (i.e., 100, 200 and 300 mm) were experimentally studied in the wind tunnel. The test data were non-dimensionalized and curve fitted to yield a set of correlations. It was found that the pressure drop range of the cellulose media is 1.5–101.7 Pa while the pressure drops of the PVC media are much lower with the range of 0.9–49.2 Pa, depending on the medium thickness, air velocity and water flow rate. The cooling efficiencies of the cellulose media vary from 43% to 90% while the cooling efficiencies of the PVC media are 8% to 65%, depending on the medium thickness and air velocity. The water entrainment off the media was detected by water sensitive papers, and found that the cellulose media have negligible water entrainment under the studied conditions while care must be taken in the use of PVC media as water entrainment happens even at relatively low air velocities

  12. Experimental study of cooling BIPV modules by forced convection in the air channel

    International Nuclear Information System (INIS)

    Kaiser, A.S.; Zamora, B.; Mazón, R.; García, J.R.; Vera, F.

    2014-01-01

    Highlights: • An experimental setup for studying the effects of forced convection on cell temperature. • The induced velocity within the forced convection channel significantly affects the PV cooling. • Correlations for the Ross coefficient, module temperature, efficiency, and power output. • Prediction of the thermal behavior of the PV module in BIPV configurations. - Abstract: The efficiency of photovoltaic systems depends mainly on the cell temperature. Frequently, the PV collectors are installed on the top of the building. One cost effective method to regulate the temperature of rooftop integrated photovoltaic panels is to provide an open air channel beneath the panel. The cell temperature of these PV modules is very much influenced by the capability of ventilating this channel. The ventilation may be modified by different factors such as the wind velocity, the air gap size, and the forced convection induced by a fan or by a conventional air conditioning system. This paper describes an experimental setup to study the influence of the air gap size and the forced ventilation on the cell temperature (and consequently on the electrical efficiency of the PV module) of a BIPV configuration, for different values of the incident solar radiation, ambient temperatures, and aspect ratios, as well as for several forced ventilation conditions. Semi empirical correlations for the Ross coefficient, module temperature, electrical efficiency, and power output are proposed, showing a good agreement with respect to experimental measurements. A critical channel aspect ratio close to 0.11 can be considered to minimize overheating of PV devices. For a duct velocity V v = 6 m/s, a power output increase of 19% is observed over the natural ventilation case (V v = 0.5 m/s)

  13. Numerical calibration and experimental validation of a PCM-Air heat exchanger model

    International Nuclear Information System (INIS)

    Stathopoulos, N.; El Mankibi, M.; Santamouris, Mattheos

    2017-01-01

    Highlights: • Development of a PCM-Air heat exchanger experimental unit and its numerical model. • Differential Scanning Calorimetry for PCM properties. • Ineptitude of DSC obtained heat capacity curves. • Creation of adequate heat capacity curves depending on heat transfer rates. • Confrontation of numerical and experimental results and validation of the model. - Abstract: Ambitious goals have been set at international, European and French level for energy consumption and greenhouse gas emissions decrease of the building sector. Achieving them requires renewable energy integration, a technology that presents however an important drawback: intermittent energy production. In response, thermal energy storage (TES) technology applications have been developed in order to correlate energy production and consumption of the building. Phase Change Materials (PCMs) have been widely used in TES applications as they offer a high storage density and adequate phase change temperature range. It is important to accurately know the thermophysical properties of the PCM, both for experimental (system design) and numerical (correct prediction) purposes. In this paper, the fabrication of a PCM – Air experimental prototype is presented at first, along with the development of a numerical model simulating the downstream temperature evolution of the heat exchanger. Particular focus is given to the calibration method and the validation of the model using experimental characterization results. Differential scanning calorimetry (DSC) is used to define the thermal properties of the PCM. Initial numerical results are underestimated compared to experimental ones. Various factors were investigated, pointing to the ineptitude of the heat capacity parameter, as DSC results depend on heating/cooling rates. Adequate heat capacity curves were empirically determined, depending on heat transfer rates and based on DSC results and experimental observations. The results of the proposed model

  14. Numerical and experimental study on laminar round free jet of Ar discharging into stagnant air

    International Nuclear Information System (INIS)

    Fumizawa, Motoo; Hishida, Makoto; Kunugi, Tomoaki

    1990-01-01

    The objective of the present study is to investigate numerically and experimentally the behavior of the fluid flow and the mass transfer of argon gas (Ar) laminar round jet discharging into stagnant air along the gravity force. The SIMPLE method and two differential numerical schemes of PLDS and QUICK are used in the TEAM code modified by adding the binary diffusion equation. The solution domain is comprised of 80X40 grids of uniform size. As the result, the following were obtained: The half radius of Ar mass fraction obtained by QUICK was in good agreement with experimental result. The half radii of axial velocity and Ar mass fraction obtained by PLDS were larger than those by QUICK due to numerical viscosity. Numerical analyses by PLDS and QUICK schemes agreed well with experimental results on centerline Ar mass fraction. Computational times of PLDS and QUICK are about 40 min. and 120 min. respectively by FACOM VP100 computer in JAERI. (author)

  15. Experimental Investigation of Flow Resistance in a Coal Mine Ventilation Air Methane Preheated Catalytic Oxidation Reactor

    Directory of Open Access Journals (Sweden)

    Bin Zheng

    2015-01-01

    Full Text Available This paper reports the results of experimental investigation of flow resistance in a coal mine ventilation air methane preheated catalytic oxidation reactor. The experimental system was installed at the Energy Research Institute of Shandong University of Technology. The system has been used to investigate the effects of flow rate (200 Nm3/h to 1000 Nm3/h and catalytic oxidation bed average temperature (20°C to 560°C within the preheated catalytic oxidation reactor. The pressure drop and resistance proportion of catalytic oxidation bed, the heat exchanger preheating section, and the heat exchanger flue gas section were measured. In addition, based on a large number of experimental data, the empirical equations of flow resistance are obtained by the least square method. It can also be used in deriving much needed data for preheated catalytic oxidation designs when employed in industry.

  16. Effect of outdoor and indoor air pollution on lung function, bronchial hyperresponsiveness and risk of pulmonary disease of adults; Langzeitevaluation von Umwelteinfluessen auf Lungenfunktion, bronchiale Hyperreagibilitaet und Krankheitsrisiko von Erwachsenen

    Energy Technology Data Exchange (ETDEWEB)

    Eltschka, R [Freiburg Univ. (Germany). Zentrum Innere Medizin

    1992-10-01

    The effect of outdoor exposure to SO{sub 2}, NO{sub 2}, particulate pollutants, ozone and pollen on pulmonary function and respiratory discomfort was studied over a period of 1 1/2 yr in 133 no smoking adults at the city of Freiburg. Concentration of indoor and outdoor pollutants were measured. Between January and December 1989 we found in comparison with other large towns low levels of SO{sub 2}, NO{sub 2} and particulate combustion products. The evaluation of individual exposure to air pollutants with lung function measurements shows that participants with essential hyperreactivity demonstrate a significant decrease of the FEV1/IVC - ratio with a threshold value of about 30 {mu}g/m{sup 3} NO{sub 2}. The analyses of the longitudinal study shows a significant correlation between daily peakflow measurements and ozone levels in patients with symptomatic asthma bronchiale and chronic obstructive pulmonary disease. For pollen, SO{sub 2}, NO{sub 2} and anorganic particulate pollutants we did not find any significant effects on peak expiratory flow measurements. (orig./MG) [Deutsch] Der Einfluss von Aussenluftschadstoffen (SO{sub 2}, NO{sub 2}, Staub und Ozon) auf die Lunge wurde in Freiburg in Form einer 1 1/2-jaehrigen Longitudinalstudie bei 133 nicht rauchenden Erwachsenen untersucht. Waehrend des Beobachtungszeitraumes 10/88 - 4/90 erfolgte die Messung der Aussen- und Innenluftschadstoffe. Die Messungen des DW und der LFU zeigen fuer den Zeitraum Januar-Dezember 1989 im Vergleich zu anderen Grossstaedten niedrige Schwefeldioxid-, Stickoxid- und Staubkonzentrationen. Die Querschnittsuntersuchung mit Anamnesefragebogen, Bodyplethysmographie und inhalativem Provokationstest zeigt bei Teilnehmern mit essentieller Hyperreagibilitaet eine signifikante Abnahme des gemessenen und adjustierten Tiffeneau-Index durch NO{sub 2} mit einem Schwellenwert bei 30 {mu}g/m{sup 3}. Die multivariate Analyse der Longitudinalstudie zeigt bei Patienten mit symptomatischem Asthma und

  17. Experimental Investigation of Air Conditioner using the Desiccant Cooling System in Equatorial Climates

    Directory of Open Access Journals (Sweden)

    Abdullah Kamaruddin

    2018-01-01

    Full Text Available Indonesia lies in the tropical climate which requires air conditioning to increase working productivity of the people. Up to now people are still using the compressive cooling system which uses Freon as the refrigerant, which have been known to have a negative environmental impact. Therefore, new cooling system which is environmentally friendly is now needed. Desiccant cooling system manipulates the humidity condition of outside air in such a way so that the final temperature should become at 25 °C and RH of 65 %. Since it does not require refrigerant, a desiccant cooling has the potential to be developed in a tropical country like Indonesia. In this study an experimental desiccant cooling system has been designed and constructed and tested under laboratory condition. Experimental results have shown that the resulting air temperature was 26.1 °C with RH of 55.6 %, and average cooling capacity was 0.425 kW. The COP was found to be 0.44.

  18. Experimental study on frosting control of mobile air conditioning system with microchannel evaporator

    International Nuclear Information System (INIS)

    Qu Xiaohua; Shi Junye; Qi Zhaogang; Chen Jiangping

    2011-01-01

    In this paper, a newly developed frost control system is proposed. System bench tests and vehicle test in wind tunnel have been carried out to explore the anti-frosting performance of automotive air conditioning system with microchannel evaporator. The experimental results are compared with the baseline conventional laminated evaporator system. The test results show that the installation position of temperature sensor can dramatically affect the anti-frosting performance. The clutch switching on/off temperature range of the microchannel evaporator is also experimentally studied. The test results show that, with a proper installation position and on/off temperature range, the system COP can be improved, and meanwhile the panel vents' air off temperature can be reduced, and temperature swing can be reduced. - Highlights: → The frost control systems were tested with microchannel and laminated evaporators separately. → The installation position of temperature sensor affects the anti-frosting performance. → Temperature control range affects the anti-frosting performance. → The panel vents' air off temperature and swing can be reduced by proper control parameters. → The system COP can be improved by proper control parameters.

  19. Experimental investigation of thermal performance of a double-flow solar air heater having aluminium cans

    Energy Technology Data Exchange (ETDEWEB)

    Ozgen, Filiz; Esen, Mehmet; Esen, Hikmet [Department of Mechanical Education, Faculty of Technical Education, Firat University, 23119 Elazig (Turkey)

    2009-11-15

    This study experimentally investigates a device for inserting an absorbing plate made of aluminium cans into the double-pass channel in a flat-plate solar air heater (SAH). This method substantially improves the collector efficiency by increasing the fluid velocity and enhancing the heat-transfer coefficient between the absorber plate and air. These types of collectors had been designed as a proposal to use aluminium materials to build absorber plates of SAHs at a suitable cost. The collector had been covered with a 4-mm single glass plate, in order to reduce convective loses to the atmosphere. Three different absorber plates had been designed and tested for experimental study. In the first type (Type I), cans had been staggered as zigzag on absorber plate, while in Type II they were arranged in order. Type III is a flat plate (without cans). Experiments had been performed for air mass flow rates of 0.03 kg/s and 0.05 kg/s. The highest efficiency had been obtained for Type I at 0.05 kg/s. Also, comparison between the thermal efficiency of the SAH tested in this study with the ones reported in the literature had been presented, and a good agreement had been found. (author)

  20. Experimental research on the flow field uniformity in the filter house of a nuclear air cleaning system

    International Nuclear Information System (INIS)

    Jiang Feng; Yang Jun; Ye Suisheng

    2000-01-01

    The filter house structure is designed using similarity laws showing that the filter house structure causes a non-uniform flow field. The flow field is also measured experimentally. The air flow field is analyzed for different conditions. The results show that: (1) The HEPA filters affect the dispersion of the air flow; (2) The appropriate angle for air input to the rectifier satisfies the requirements for uniform air flow for the test conditions; (3) The rectifier has little influence on the air flow for operating conditions

  1. Experimental evidence of the thermal effect of lubricating oil sprayed in sliding-vane air compressors

    Directory of Open Access Journals (Sweden)

    Gianluca Valenti

    2014-11-01

    Full Text Available A way to increase the efficiency of positive-displacement air compressor is spraying the lube oil to exploit it not only as lubricating and sealing agent but also as thermal ballast. This work seeks the experimental evidence in sliding-vane compressors by measuring the air standard volume flow rate and the electrical power input of three diverse configurations. The first configuration, taken as the reference, employs a conventional injection system comprising calibrated straight orifices. The other two, referred to as advanced, adopt smaller orifices and pressure-swirl full-cone nozzles designed for the purpose; the third configuration utilizes a pump to boost the oil pressure. The laser imagining technique shows that the nozzles generate sprays that break-up within a short distance into spherical droplets, ligaments, ramifications and undefined structures. Tests on the packaged compressors reveal that the advanced configurations provide almost the same air flow rate while utilizing half of the oil because the sprays generate a good sealing. Moreover, the sprayed oil is acting as a thermal ballast because the electrical input is reduced by 3.5% and 3.0%, respectively, if the pump is present or not , while the specific energy requirement, accounting for the slightly reduced air flow, by 2.4% and 2.9%, respectively.

  2. Experimental investigation of hydrocarbon mixtures to replace HFC-134a in an automotive air conditioning system

    International Nuclear Information System (INIS)

    Wongwises, Somchai; Kamboon, Amnouy; Orachon, Banchob

    2006-01-01

    This paper presents an experimental study on the application of hydrocarbon mixtures to replace HFC-134a in automotive air conditioners. The hydrocarbons investigated are propane (R290), butane (R600) and isobutane (R600a). The measured data are obtained from an automotive air conditioning test facility utilizing HFC-134a as the refrigerant. The air conditioner, with a capacity of 3.5 kW driven by a Diesel engine, is charged and tested with four different ratios of hydrocarbon mixtures. The experiments are conducted at the same surrounding conditions. The temperature and pressure of the refrigerant at every major position in the refrigerant loop, the temperature, flow rate and humidity of air, torque and engine speed are recorded and analyzed. The parameters investigated are the refrigeration capacity, the compressor power and the coefficient of performance (COP). The results show that propane/butane/isobutane: 50%/40%/10% is the most appropriate alternative refrigerant to replace HFC-134a, having the best performance of all the hydrocarbon mixtures investigated

  3. Experimental Study on Intelligent Control Scheme for Fan Coil Air-Conditioning System

    Directory of Open Access Journals (Sweden)

    Yanfeng Li

    2013-01-01

    Full Text Available An intelligent control scheme for fan coil air-conditioning systems has been put forward in order to overcome the shortcomings of the traditional proportion-integral-derivative (PID control scheme. These shortcomings include the inability of anti-interference and large inertia. An intelligent control test rig of fan coil air-conditioning system has been built, and MATLAB/Simulink dynamics simulation software has been adopted to implement the intelligent control scheme. A software for data exchange has been developed to combine the intelligence control system and the building automation (BA system. Experimental tests have been conducted to investigate the effectiveness of different control schemes including the traditional PID control, fuzzy control, and fuzzy-PID control for fan coil air-conditioning system. The effects of control schemes have been compared and analyzed in robustness, static and dynamic character, and economy. The results have shown that the developed data exchange interface software can induce the intelligent control scheme of the BA system more effectively. Among the proposed control strategies, fuzzy-PID control scheme which has the advantages of both traditional PID and fuzzy schemes is the optimal control scheme for the fan coil air-conditioning system.

  4. Indoor Air Pollution

    Science.gov (United States)

    We usually think of air pollution as being outdoors, but the air in your house or office could also be polluted. Sources of indoor pollution include Mold and pollen Tobacco smoke Household products ...

  5. Outdoor recreation and ethnicity

    DEFF Research Database (Denmark)

    Gentin, Sandra

    recreation, activities, and preferred outdoor recreation areas) between the minority and majority populations and related these differences to the ethnic minorities’ cultural background. The second paper presents the empirical work of this thesis, which is based on a survey of adolescents’ outdoor recreation...... often reported using green areas to “drink beer with friends” and “do sunbathing”. The third paper reflects on the different national approaches towards ethnic minorities’ access to natural areas, in four example-countries Germany, Denmark, United Kingdom, and the Netherlands. This was done through....... In the UK the focus on underrepresented groups seems closely related to the focus on equality for access, while specific focus on access for ethnic minorities is not addressed in the forest and nature legislation and the national forest programs in Denmark, Germany and the Netherlands. Paper 4 proposes...

  6. Experimental verification of the air kerma to absorbed dose conversion factor Cw,u.

    Science.gov (United States)

    Mijnheer, B J; Wittkämper, F W; Aalbers, A H; van Dijk, E

    1987-01-01

    In a recently published code of practice for the dosimetry of high-energy photon beams, the absorbed dose to water is determined using an ionization chamber having an air kerma calibration factor and applying the air kerma to absorbed dose conversion factor Cw,u. The consistency of these Cw,u values has been determined for four commonly employed types of ionization chambers in photon beams with quality varying between 60Co gamma-rays and 25 MV X-rays. Using a graphite calorimeter, Cw,u has been determined for a graphite-walled ionization chamber (NE 2561) for the same qualities. The values of Cw,u determined with the calorimeter are within the experimental uncertainty equal to Cw,u values determined according to any of the recent dosimetry protocols.

  7. Modeling of air-gap membrane distillation process: A theoretical and experimental study

    KAUST Repository

    Alsaadi, Ahmad Salem

    2013-06-03

    A one dimensional (1-D) air gap membrane distillation (AGMD) model for flat sheet type modules has been developed. This model is based on mathematical equations that describe the heat and mass transfer mechanisms of a single-stage AGMD process. It can simulate AGMD modules in both co-current and counter-current flow regimes. The theoretical model was validated using AGMD experimental data obtained under different operating conditions and parameters. The predicted water vapor flux was compared to the flux measured at five different feed water temperatures, two different feed water salinities, three different air gap widths and two MD membranes with different average pore sizes. This comparison showed that the model flux predictions are strongly correlated with the experimental data, with model predictions being within +10% of the experimentally determined values. The model was then used to study and analyze the parameters that have significant effect on scaling-up the AGMD process such as the effect of increasing the membrane length, and feed and coolant flow rates. The model was also used to analyze the maximum thermal efficiency of the AGMD process by tracing changes in water production rate and the heat input to the process along the membrane length. This was used to understand the gain in both process production and thermal efficiency for different membrane surface areas and the resultant increases in process capital and water unit cost. © 2013 Elsevier B.V.

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

    Science.gov (United States)

    Shrestha, Suman K.

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

  9. Experimental investigation of wood combustion in a fixed bed with hot air

    Energy Technology Data Exchange (ETDEWEB)

    Markovic, Miladin, E-mail: m.markovic@utwente.nl; Bramer, Eddy A.; Brem, Gerrit

    2014-01-15

    Highlights: • Upward combustion is a new combustion concept with ignition by hot primary air. • Upward combustion has three stages: short drying, rapid devolatilization and char combustion. • Variation of fuel moisture and inert content have little influence on the combustion. • Experimental comparison between conventional and upward combustion is presented. - Abstract: Waste combustion on a grate with energy recovery is an important pillar of municipal solid waste (MSW) management in the Netherlands. In MSW incinerators fresh waste stacked on a grate enters the combustion chamber, heats up by radiation from the flame above the layer and ignition occurs. Typically, the reaction zone starts at the top of the waste layer and propagates downwards, producing heat for drying and devolatilization of the fresh waste below it until the ignition front reaches the grate. The control of this process is mainly based on empiricism. MSW is a highly inhomogeneous fuel with continuous fluctuating moisture content, heating value and chemical composition. The resulting process fluctuations may cause process control difficulties, fouling and corrosion issues, extra maintenance, and unplanned stops. In the new concept the fuel layer is ignited by means of preheated air (T > 220 °C) from below without any external ignition source. As a result a combustion front will be formed close to the grate and will propagate upwards. That is why this approach is denoted by upward combustion. Experimental research has been carried out in a batch reactor with height of 4.55 m, an inner diameter of 200 mm and a fuel layer height up to 1 m. Due to a high quality two-layer insulation adiabatic conditions can be assumed. The primary air can be preheated up to 350 °C, and the secondary air is distributed via nozzles above the waste layer. During the experiments, temperatures along the height of the reactor, gas composition and total weight decrease are continuously monitored. The influence of

  10. Experimental study on the influence of oxygen content in the combustion air on the combustion characteristics

    International Nuclear Information System (INIS)

    Bělohradský, Petr; Skryja, Pavel; Hudák, Igor

    2014-01-01

    This study was focused on the experimental investigation of the very promising combustion technology called as the oxygen-enhanced combustion (OEC), which uses the oxidant containing higher proportion of oxygen than in the atmospheric air, i.e. more than 21%. The work investigated and compared the characteristics of two OEC methods, namely the premix enrichment and air-oxy/fuel combustion, when the overall oxygen concentration was varied from 21% to 46%. The combustion tests were performed with the experimental two-gas-staged burner of low-NO x type at the burner thermal input of 750 kW for two combustion regimes – one-staged and two-staged combustion. The oxygen concentration in the flue gas was maintained in the neighborhood of 3% vol. (on dry basis). The aim of tests was to assess the impact of the oxidant composition, type of OEC method and fuel-staging on the characteristic combustion parameters in detail. The investigated parameters included the concentration of nitrogen oxides (NO x ) in the flue gas, flue gas temperature, heat flux to the combustion chamber wall, and lastly the stability, shape and dimensions of flame. It was observed that NO x emission is significantly lower when the air-oxy/fuel method is used compared to the premix enrichment method. Moreover, when the fuel was staged, NO x emission was below 120 mg/Nm 3 at all investigated oxygen flow rates. Increasing oxygen concentration resulted in higher heating intensity due to higher concentrations of CO 2 and H 2 O. The available heat at 46% O 2 was higher by 20% compared with that at 21% O 2 . - Highlights: • Premix-enrichment and air-oxy/fuel combustion methods were experimentally studied. • NO x increased sharply as oxygen concentration increased during PE tests. • NO x was below 120 mg/Nm 3 for all investigated oxygen flow rates in AO tests. • Radiative heat transfer was enhanced ca. 20% as O 2 concentration was increased. • OEC flames were observed stable, more luminous and

  11. Computational and experimental optimization of the exhaust air energy recovery wind turbine generator

    International Nuclear Information System (INIS)

    Tabatabaeikia, Seyedsaeed; Ghazali, Nik Nazri Bin Nik; Chong, Wen Tong; Shahizare, Behzad; Izadyar, Nima; Esmaeilzadeh, Alireza; Fazlizan, Ahmad

    2016-01-01

    Highlights: • Studying the viability of harvesting wasted energy by exhaust air recovery generator. • Optimizing the design using response surface methodology. • Validation of optimization and computation result by performing experimental tests. • Investigation of flow behaviour using computational fluid dynamic simulations. • Performing the technical and economic study of the exhaust air recovery generator. - Abstract: This paper studies the optimization of an innovative exhaust air recovery wind turbine generator through computational fluid dynamic (CFD) simulations. The optimization strategy aims to optimize the overall system energy generation and simultaneously guarantee that it does not violate the cooling tower performance in terms of decreasing airflow intake and increasing fan motor power consumption. The wind turbine rotor position, modifying diffuser plates, and introducing separator plates to the design are considered as the variable factors for the optimization. The generated power coefficient is selected as optimization objective. Unlike most of previous optimizations in field of wind turbines, in this study, response surface methodology (RSM) as a method of analytical procedures optimization has been utilised by using multivariate statistic techniques. A comprehensive study on CFD parameters including the mesh resolution, the turbulence model and transient time step values is presented. The system is simulated using SST K-ω turbulence model and then both computational and optimization results are validated by experimental data obtained in laboratory. Results show that the optimization strategy can improve the wind turbine generated power by 48.6% compared to baseline design. Meanwhile, it is able to enhance the fan intake airflow rate and decrease fan motor power consumption. The obtained optimization equations are also validated by both CFD and experimental results and a negligible deviation in range of 6–8.5% is observed.

  12. Set-up and calibration of an outdoor nozzle-type rainfall simulator for soil erosion studies at the Masse experimental station (central Italy)

    Science.gov (United States)

    Vergni, Lorenzo; Todisco, Francesca

    2016-04-01

    This contribution describes the technical characteristics and the preliminary calibration of a rainfall simulator recently installed by the Department of Agricultural, Food and Environmental Sciences (Perugia University) at the Masse experimental station located 20 km south of Perugia, in the region of Umbria (central Italy). The site includes some USLE plots of different length λ = 11 and 22 m and width w = 2, 4 and 8 m, oriented parallel to a 16 % slope and kept free of vegetation by frequent ploughing. Since 2008, the station enabled to collect data from more than 80 erosive events, that were mainly used to investigate the relationship between rainfall characteristics and soil loss. The relevant soil loss variability that characterizes erosive storm events with similar overall characteristics (duration and/or depth) can be explained by the different rainfall profile of erosive storms and by the different antecedent soil aggregate stability. To analyse in more detail these aspects, recently, the Masse experimental station has been equipped with a semi-portable rainfall simulator placed over two micro-plots of 1x1 m each, having the same topographic and pedologic conditions of the adjacent USLE plots. The rainfall simulator consists of four full-cone spray nozzles for each micro-plot, placed at the angles of a 0.18-m square, centred over the plot at a height of 2.7 m above the ground. The operating pressure is regulated by pressure regulating valves and checked by pressure gauges mounted in correspondence of each nozzle. An electronic control unit regulates the start and stop of the inlet solenoid valves. A range of rainfall intensities can be achieved, by activating different combinations of nozzles (15 different intensities) also during the same simulation trial. The particular design of the plots allows to collect separately the runoff volume deriving from the plots and the water volume fallen outside of the plot. In this way it is possible to derive, by

  13. Theoretical and experimental investigation of the destruction of graphites in a flow of dissociated air

    Science.gov (United States)

    Bovina, T. A.; Zviagin, Y. V.; Markelov, N. V.; Chudetskiy, Y. V.

    1986-01-01

    A method is presented for calculating the heating and erosion of blunt bodies made of graphite in a high-enthalpy flow of dissociated air, assuming chemical equilibrium on the surface and taking account of the thermal effects of combustion and sublimation of graphite. The analysis involves the use of a finite difference scheme to solve an equation of unsteady heat conduction. Attention is given to the equilibrium vaporization of C, C2 and C3 molecules. The calculations agree well with experimental data for a wide range of temperatures and stagnation pressures.

  14. Experimental and Theoretical Investigation of Impinging Jet Ventilation at Different Cross Sectional Area of Supply Air Duct

    Directory of Open Access Journals (Sweden)

    Ala'a Abbas Mahdi

    2018-03-01

    Full Text Available  An experimental and computational analysis of temperature and velocity distribution in an office room have been studied. Office room of dimensions (3m x 1.75m x 3m with two cross sectional types of supply air duct in the experimental part and three different cross sectional types of supply air duct in the theoretical part is usual as a tested model. The RNG k-  turbulence model was employed to solve the governing equations numerically and validated by comparing the numerical results with experimental data. The impinging jet concept has been proposed as a new ventilation strategy for use in office and industrial buildings. The present work focuses on evaluating the performance of a new impinging jet ventilation. In a theoretical study three types of supply air duct are adopted which are square supply air duct (Type-I, semi-elliptic supply air duct (Type-II and rectangle supply air duct (Type-III for two cases of air outlet terminal height from room foot level, 0.14h (case-I & 0.1h (case-II. The third type (rectangle duct gives lowest effective and discomfort conditions when compared with the other two types. This study investigated a number of factors influencing draught discomfort and temperature stratification in an office environment equipped with impinging jet ventilation IJV. The factors considered to be: shape of the air supply device, supply airflow rate and supply air temperature. Acceptable Air Distribution Performance Index (ADPI, effective temperature, and ventilation efficiency obtained that the square cross sectional area of supply air duct at 0.1h (case-II height from foot level gives more acceptable indoor air quality and human thermal comfort when compared with the other types. Also, this type gives good air distribution system not only promotes a comfortable and healthy environment for occupants, but also contributes to energy conservation.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2009-03-15

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

  16. Experimental vibration study of in-air and fluid coupled co-axial cylinders

    International Nuclear Information System (INIS)

    Chu, M.; Brown, S.; Lestingi, J.

    1979-01-01

    It was the objective of this study to develop and carry out an experimental program which would provide additional insight into the mechanics of fluid--solid interaction with respect to the response of a set of coaxial cylinders with water in the annulus. Such configurations are found in nuclear reactors in the vessel wall-thermal liner. The effects of cylinder thickness and the fluid filled annulus gap size on the resonant frequencies and mode shapes of the cylinders (either singly or coupled in air and a water environment) are presented in this paper; also included is an evaluation of damping for selected gaps and cylinder thicknesses. Details of the experimental setup and procedures are also outlined

  17. Experimental temperature analysis of simple & hybrid earth air tunnel heat exchanger in series connection at Bikaner Rajasthan India

    Science.gov (United States)

    Jakhar, O. P.; Sharma, Chandra Shekhar; Kukana, Rajendra

    2018-05-01

    The Earth Air Tunnel Heat Exchanger System is a passive air-conditioning system which has no side effect on earth climate and produces better cooling effect and heating effect comfortable to human body. It produces heating effect in winter and cooling effect in summer with the minimum power consumption of energy as compare to other air-conditioning devices. In this research paper Temperature Analysis was done on the two systems of Earth Air Tunnel Heat Exchanger experimentally for summer cooling purpose. Both the system was installed at Mechanical Engineering Department Government Engineering College Bikaner Rajasthan India. Experimental results concludes that the Average Air Temperature Difference was found as 11.00° C and 16.27° C for the Simple and Hybrid Earth Air Tunnel Heat Exchanger in Series Connection System respectively. The Maximum Air Temperature Difference was found as 18.10° C and 23.70° C for the Simple and Hybrid Earth Air Tunnel Heat Exchanger in Series Connection System respectively. The Minimum Air Temperature Difference was found as 5.20° C and 11.70° C for the Simple and Hybrid Earth Air Tunnel Heat Exchanger in Series Connection System respectively.

  18. Experimental study on two-stage air supply downdraft gasifier and dual fuel engine system

    Energy Technology Data Exchange (ETDEWEB)

    Nhuchhen, Daya Ram; Salam, P.A. [Asian Institute of Technology, Energy Field of Study, School of Environment Resource and Development, P. O. Box 4, Klong Luang, Pathumthani (Thailand)

    2012-06-15

    Biomass is a widely used renewable energy resource with net balanced carbon dioxide absorptions and emissions. An inefficient use of solid biomass in combustion process emits more gaseous pollutants, increasing the pollution level. Biomass gasification is one of the techniques to support efficient use of biomass. Multistage gasification is a method of gasification to improve quality of the producer gas in which two separate reactors are designed for separating gasification reactions. This study presents experimental results of gasification using Eucalyptus wood in a single long cylindrical reactor with two air supply ports, i.e., primary and secondary. The effect of different air supply rates on the heating values of the producer gas was studied. Optimum primary and secondary air supply rate of 100 and 80 l/min at equivalence ratio of 0.38 was observed with producer gas lower heating value of 4.72 MJ Nm{sup -3}. The performance of a diesel engine in the dual fuel mode was also evaluated. The overall gasifier engine system efficiency was 13.86 % at an electrical load of 10.54 kW{sub e} with specific energy consumption of 16.22 MJ kWh{sup -1}. The heat recovery system was designed and tested to recover heat from producer gas in the form of hot water. (orig.)

  19. Experimental performance study of a proposed desiccant based air conditioning system.

    Science.gov (United States)

    Bassuoni, M M

    2014-01-01

    An experimental investigation on the performance of a proposed hybrid desiccant based air conditioning system referred as HDBAC is introduced in this paper. HDBAC is mainly consisted of a liquid desiccant dehumidification unit integrated with a vapor compression system (VCS). The VCS unit has a cooling capacity of 5.27 kW and uses 134a as refrigerant. Calcium chloride (CaCl2) solution is used as the working desiccant material. HDBAC system is used to serve low sensible heat factor applications. The effect of different parameters such as, process air flow rate, desiccant solution flow rate, evaporator box and condenser box solution temperatures, strong solution concentration and regeneration temperature on the performance of the system is studied. The performance of the system is evaluated using some parameters such as: the coefficient of performance (COPa), specific moisture removal and energy saving percentage. A remarkable increase of about 54% in the coefficient of performance of the proposed system over VCS with reheat is achieved. A maximum overall energy saving of about 46% is observed which emphasizes the use of the proposed system as an energy efficient air conditioning system.

  20. Use of air monitoring and experimental aerosol data for intake assessment for Mayak plutonium workers

    International Nuclear Information System (INIS)

    Zaytseva, Yekaterina V.; Tretyakov, Fyodor D.; Romanov, Sergey A.; Miller, Guthrie; Bertelli, Luiz; Guilmette, Raymond A.

    2007-01-01

    One of the major uncertainties in reconstructing doses to Mayak Plutonium (Pu) workers is the unknown exposure patterns experienced by individuals. These uncertainties include the amounts of Pu inhaled, the temporal exposure pattern of Pu air concentration, the particle-size distribution and solubility of the inhaled aerosols. To date, little individual and workplace-specific information has been used to assess these parameters for the Mayak workforce. However, extensive workplace-specific alpha activity air monitoring data set has been collated, which, if coupled with individual occupational histories, can potentially provide customized intake scenarios for individual Mayak workers. The most available Pu air concentration data are annual averages, which exist for over 100 defined work stations at radiochemical and chemical-metallurgical manufacturing facilities and basically for the whole period of Mayak production operations. Much sparser but more accurate data on Pu concentrations in workers' breathing zone are available for some major workplaces and occupations. The latter demonstrate that within a working shift, Pu concentrations varied over a range of several orders of magnitude depending on the nature of the operations performed. An approach to use the collated data set for individual intake reconstruction is formulated and its practical application is demonstrated. Initial results of ongoing experimental study on historic particle size at Mayak PA and their implications for intake estimation are presented. (authors)

  1. Instability of automotive air conditioning system with a variable displacement compressor. Part 1. Experimental investigation

    Energy Technology Data Exchange (ETDEWEB)

    Tian, Changqing; Dou, Chunpeng; Yang, Xinjiang; Li, Xianting [Department of Building Science, School of Architecture, Tsinghua University, Beijing 100084 (People' s Republic of China)

    2005-11-01

    A test system is built first in order to investigate the instability of the automotive air conditioning (AAC) system with a variable displacement compressor (VDC), and hunting phenomena caused by the large external disturbance in the AAC system with a VDC and a thermal expansion valve, and in the AAC system with a VDC and a fixed-area throttling device are investigated experimentally in part 1 of this paper. The experimental results indicate that there also exist the hunting phenomena in the AAC system with a fixed-area throttling device. The system stability is found to be dependent on the direction of the external disturbance, and the system is apt to cause hunting when the condensing pressure decreases excessively since it may cause two-phase state at the throttling device inlet and make a large disturbance to the system. The piston stroke length will oscillate only when the oscillation amplitudes of forces acting on the wobble plate are great enough, otherwise the piston stroke length will be kept invariable, and then the system instability rule is also suitable for the AAC system with a fixed displacement compressor. From the experimental results, it is concluded that the two-phase flow at the throttling device inlet or at the evaporator outlet is the necessary condition but not sufficient condition for system hunting. Finally, a new concept, conservative stable region, is proposed based on the experimental results and theoretical analysis. (author)

  2. Environmental epidemiology applied to urban atmospheric pollution: a contribution from the Experimental Air Pollution Laboratory (LPAE

    Directory of Open Access Journals (Sweden)

    André Paulo Afonso de

    2000-01-01

    Full Text Available Systematic investigation on the effects of human exposure to environmental pollution using scientific methodology only began in the 20th century as a consequence of several environmental accidents followed by an unexpected mortality increase above expected mortality and as a result of observational epidemiological and toxicological studies conducted on animals in developed countries. This article reports the experience of the Experimental Air Pollution Laboratory at the School of Medicine, University of São Paulo, concerning the respiratory system and pathophysiological mechanisms involved in responses to exposure to pollution using toxicological and experimental procedures, complemented by observational epidemiological studies conducted in the city of São Paulo. It also describes these epidemiological studies, pointing out that air pollution is harmful to public health, not only among susceptible groups but also in the general population, even when the concentration of pollutants is below the limits set by environmental legislation. The study provides valuable information to support the political and economic decision-making processes aimed at preserving the environment and enhancing quality of life.

  3. Tilted wheel satellite attitude control with air-bearing table experimental results

    Science.gov (United States)

    Inumoh, Lawrence O.; Forshaw, Jason L.; Horri, Nadjim M.

    2015-12-01

    Gyroscopic actuators for satellite control have attracted significant research interest over the years, but their viability for the control of small satellites has only recently started to become clear. Research on variable speed gyroscopic actuators has long been focused on single gimbal actuators; double gimbal actuators typically operate at constant wheel spin rate and allow tilt angle ranges far larger than the ranges needed to operate most satellite missions. This research examines a tilted wheel, a newly proposed type of inertial actuator that can generate torques in all three principal axes of a rigid satellite using a spinning wheel and a double tilt mechanism. The tilt mechanism tilts the angular momentum vector about two axes providing two degree of freedom control, while variation of the wheel speed provides the third. The equations of motion of the system lead to a singularity-free system during nominal operation avoiding the need for complex steering logic. This paper describes the hardware design of the tilted wheel and the experimental setup behind both standalone and spherical air-bearing tables used to test it. Experimental results from the air bearing table are provided with the results depicting the high performance capabilities of the proposed actuator in torque generation.

  4. Experimental Investigation Evaporation of Liquid Mixture Droplets during Depressurization into Air Stream

    Science.gov (United States)

    Liu, L.; Bi, Q. C.; Terekhov, Victor I.; Shishkin, Nikolay E.

    2010-03-01

    The objective of this study is to develop experimental method to study the evaporation process of liquid mixture droplets during depressurization and into air stream. During the experiment, a droplet was suspended on a thermocouple; an infrared thermal imager was used to measure the droplet surface temperature transition. Saltwater droplets were used to investigate the evaporation process during depressurization, and volatile liquid mixtures of ethanol, methanol and acetone in water were applied to experimentally research the evaporation into air stream. According to the results, the composition and concentration has a complex influence on the evaporation rate and the temperature transition. With an increase in the share of more volatile component, the evaporation rate increases. While, a higher salt concentration in water results in a lower evaporation rate. The shape variation of saltwater droplet also depends on the mass concentration in solution, whether it is higher or lower than the eutectic point (22.4%). The results provide important insight into the complex heat and mass transfer of liquid mixture during evaporation.

  5. Terrain Mapping and Classification in Outdoor Environments Using Neural Networks

    OpenAIRE

    Alberto Yukinobu Hata; Denis Fernando Wolf; Gustavo Pessin; Fernando Osório

    2009-01-01

    This paper describes a three-dimensional terrain mapping and classification technique to allow the operation of mobile robots in outdoor environments using laser range finders. We propose the use of a multi-layer perceptron neural network to classify the terrain into navigable, partially navigable, and non-navigable. The maps generated by our approach can be used for path planning, navigation, and local obstacle avoidance. Experimental tests using an outdoor robot and a laser sensor demonstra...

  6. Experimental investigation on influence of porous material properties on drying process by a hot air jet

    International Nuclear Information System (INIS)

    Di Marco, P; Filippeschi, S

    2012-01-01

    The drying process of porous media is a subject of scientific interest, and different mathematical approaches can be found in the literature. A previous paper by the same authors showed that the celebrated Martin correlation for hot air jet heat and mass transfer yields different degrees of accuracy (from 15% to 65%, increasing at high values of input power) if tested on different fabrics, the remaining conditions being the same. In this paper the fabric drying has been experimentally investigated more in depth. A dedicated experimental apparatus for hot jet drying was assembled and operated, in which a hot jet impinges perpendicularly onto a wet fabric. A calibrated orifice was adopted to measure the jet flow rate, with an accuracy better than 3%. The drying power was determined by continuously weighing with a precision scale a moistened patch exposed to the drying jet. The effect of the time of the exposure and the initial amount of water has been evaluated for each sample. During the hot jet exposure, the temperature distribution over the wet patch has been observed by an infrared thermo-camera. A mathematical model of water transport inside and outside the fabric was developed, in order to evidence the governing transport resistances. The theoretical predictions have been compared with the experimental results, and showed the necessity to modify correlations and models accounting for fabric properties.

  7. Experimental and computational analysis of steam condensation in the presence of air and helium

    International Nuclear Information System (INIS)

    Bucci, M.

    2010-01-01

    Among the different phenomena expected to occur within nuclear reactor containments during a postulated loss of coolant accident, condensation on containment walls plays a major role, since it represents an important heat sink for evacuating the energy released by the discharge of the primary water. Nevertheless, condensation strongly affects other relevant phenomena, like containment atmosphere mixing, that influences the distribution of non-condensable gases hypothetically delivered in severe accident conditions. In this scenario, the role of condensation is not obvious, since it can locally aid the hydrogen produced by the oxidation of the core claddings to concentrate and reach flammability limits, providing a dangerous effect instead of a positive one. The understanding of condensation in the presence of air and hydrogen is therefore a fundamental task for the safety analyses of reactor containments. This research has been carried out with the aim to contribute to the understanding of these phenomena. A double strategy has been adopted, including complementary experimental and computational activities. Novel data have been made available by the CONAN facility, investigating the effects induced by light non-condensable gases in experimental configurations that were scarcely investigated in past studies. Computational fluid dynamics (CFD) condensation models have been developed and validated. The suitability of helium as a substitute for hydrogen in experimental activities has been investigated by theoretical and computational analyses allowing to establish simple criteria for the scaling of condensation tests in the presence of a light non-condensable gas. (authors)

  8. Experimental evaluation of automotive air-conditioning using HFC-134a and HC-134a

    Science.gov (United States)

    Nasution, Henry; Zainudin, Muhammad Amir; Aziz, Azhar Abdul; Latiff, Zulkarnain Abdul; Perang, Mohd Rozi Mohd; Rahman, Abd Halim Abdul

    2012-06-01

    An experimental study to evaluate the energy consumption of an automotive air conditioning is presented. In this study, these refrigerants will be tested using the experimental rig which simulated the actual cars as a cabin complete with a cooling system component of the actual car that is as the blower, evaporator, condenser, radiators, electric motor, which acts as a vehicle engine, and then the electric motor will operate the compressor using a belt and pulley system, as well as to the alternator will recharge the battery. The compressor working with the fluids HFC-134a and HC-134a and has been tested varying the speed in the range 1000, 1500, 2000 and 2500 rpm. The measurements taken during the one hour experimental periods at 2-minutes interval times for temperature setpoint of 20°C with internal heat loads 0, 500, 700 and 1000 W. The final results of this study show an overall better energy consumption of the HFC-134a compared with the HC-134a.

  9. Group Cooperation in Outdoor Education

    Science.gov (United States)

    Matthews, Bruce E.

    1978-01-01

    Utilizing the Beatles' Yellow Submarine fantasy (e.g., the Blue Meanies), this outdoor education program is designed for sixth graders and special education students. Activities developed at the Cortland Resident Outdoor Education Camp include a series of group stress/challenge activities to be accomplished by everyone in the group, as a group.…

  10. Outdoor Education: Definition and Philosophy.

    Science.gov (United States)

    Ford, Phyllis

    Because outdoor education programs occur in every geographic location, are sponsored by all levels of educational institutions, state and local government agencies, and private entrepreneurs, and have no nationally standardized curriculum or measures of competency or knowledge, outdoor education may best be defines as "education in, about, and for…

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

    DEFF Research Database (Denmark)

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

    2010-01-01

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

  12. Metrology for fire experiments in outdoor conditions

    CERN Document Server

    Silvani, Xavier

    2013-01-01

    Natural fires can be considered as scale-dependant, non-linear processes of mass, momentum and heat transport, resulting from a turbulent reactive and radiative fluid medium flowing over a complex medium, the vegetal fuel. In natural outdoor conditions, the experimental study of natural fires at real scale needs the development of an original metrology, one able to capture the large range of time and length scales involved in its dynamic nature and also able to resist the thermal, mechanical and chemical aggression of flames on devices. Robust, accurate and poorly intrusive tools must be carefully set-up and used for gaining very fluctuating data over long periods. These signals also need the development of original post-processing tools that take into account the non-steady nature of their stochastic components. Metrology for Fire Experiments in Outdoor Conditions closely analyzes these features, and also describes measurements techniques, the thermal insulation of fragile electronic systems, data acquisitio...

  13. Experimental Study Abour How the Thermal Plume Affects the Air Quality a Person Breathes

    DEFF Research Database (Denmark)

    Olmedo, Inés; Nielsen, Peter V.; Ruiz de Adana, Manuel

    2011-01-01

    of this research is to increase the knowledge of how the thermal plume generated by a person affects the PME and therefore the concentration of contaminants in the inhalation area. An experimental study in a displacement ventilation room was carried out. Experiments were developed in a full scale test chamber 4.......10 m (length), 3.2 m (width), 2.7 m (height). The incoming air is distributed through a wall-mounted displacement diffuser. A breathing thermal manikin exhaling through the mouth and inhaling through the nose was used. A tracer gas, N2O, was used to simulate the gaseous substances, which might...... be considered as biological contaminants, exhaled by the manikin. The manikin was operated in three different heat fluxes with a value of: 0W, 94 W and 120 W. During the experiments six concentration probes were situated in the room. Three concentration tubes were fixed on the surface of the manikin at three...

  14. Experimental study of hybrid interface cooling system using air ventilation and nanofluid

    Science.gov (United States)

    Rani, M. F. H.; Razlan, Z. M.; Bakar, S. A.; Desa, H.; Wan, W. K.; Ibrahim, I.; Kamarrudin, N. S.; Bin-Abdun, Nazih A.

    2017-09-01

    The hybrid interface cooling system needs to be established to chill the battery compartment of electric car and maintained its ambient temperature inside the compartment between 25°C to 35°C. The air cooling experiment has been conducted to verify the cooling capacity, compressor displacement volume, dehumidifying value and mass flow rate of refrigerant (R-410A). At the same time, liquid cooling system is analysed theoretically by comparing the performance of two types of nanofluid, i.e., CuO + Water and Al2O3 + Water, based on the heat load generated inside the compartment. In order for the result obtained to be valid and reliable, several assumptions are considered during the experimental and theoretical analysis. Results show that the efficiency of the hybrid interface cooling system is improved as compared to the individual cooling system.

  15. Structural Response of Submerged Air-Backed Plates by Experimental and Numerical Analyses

    Directory of Open Access Journals (Sweden)

    Lloyd Hammond

    2000-01-01

    Full Text Available This paper presents the results of a series of small-scale underwater shock experiments that measured the structural responses of submerged, fully clamped, air-backed, steel plates to a range of high explosive charge sizes. The experimental results were subsequently used to validate a series of simulations using the coupled LS-DYNA/USA finite element/boundary element codes. The modelling exercise was complicated by a significant amount of local cavitation occurring in the fluid adjacent to the plate and difficulties in modelling the boundary conditions of the test plates. The finite element model results satisfactorily predicted the displacement-time history of the plate over a range of shock loadings although a less satisfactory correlation was achieved for the peak velocities. It is expected that the predictive capability of the finite element model will be significantly improved once hydrostatic initialisation can be fully utilised with the LS-DYNA/USA software.

  16. Experimental Results Obtained with Air Liquide Cold Compression System CERN LHC and SNS Projects

    CERN Document Server

    Delcayre, F; Hamber, F; Hilbert, B; Monneret, E; Toia, J L

    2006-01-01

    Large scale collider facilities will make intensive use of superconducting magnets, operating below 2.0 K. This dictates high‐capacity refrigeration systems operating below 2.0 K. These systems, making use of cryogenic centrifugal compressors in a series arrangement with room temperature screw compressors will be coupled to a refrigerator, providing a certain power at 4.5 K. A first Air Liquide Cold Compression System (CCS) unit was built and delivered to CERN in 2001. Installed at the beginning of 2002, it was commissioned and tested successfully during year 2002. A series of four sets of identical CCS were then tested in 2004. Another set of four cryogenic centrifugal compressors (CCC) has been delivered to Thomas Jefferson National Accelerator Facility (JLAB) for the Spallation Neutron Source (SNS) in 2002. These compressors were tested and commissioned from December 2004 to July 2005. The experimental results obtained with these systems will be presented and discussed: the characteristics of the CCC wil...

  17. Experimental investigation of backreflection at air-core photonic bandgap fiber terminations

    Science.gov (United States)

    Xu, Xiaobin; Yan, Ming; Wu, Chunxiao; Song, Ningfang; Zhang, Chunxi

    2017-07-01

    Backreflection from the termination of air-core photonic bandgap fibers (PBFs) is experimentally investigated based on a range-extended Mach-Zehnder and Michelson hybrid (M2) interferometer. For primary waves generated by the fundamental modes, the reflectivity is about -90 dB; for secondary waves caused by other modes, the reflectivity is less than -80 dB when compared to the intensity of the primary wave and -20 to -50 dB when compared to their own incident intensity. To suppress the reflection, 3-centimeter PBF at the end is filled with alcohol through the capillary effect, and this proposed method is shown to be much more convenient and effective than the conventional angle cleaving method.

  18. An experimental investigation of performance of a double pass solar air heater with thermal storage medium

    Directory of Open Access Journals (Sweden)

    Ali Hafiz Muhammad

    2015-01-01

    Full Text Available The performance of a double pass solar air heater was experimentally investigated using four different configurations. First configuration contained only absorber plate whereas copper tubes filled with thermal storage medium (paraffin wax were added on the absorber plate in the second configuration. Aluminum and steel rods as thermal enhancer were inserted in the middle of paraffin wax of each tube for configurations three and four respectively. Second configuration provided useful heat for about 1.5 hours after the sunset compared to first configuration. Configurations three and four provided useful heat for about 2 hours after the sunset. The maximum efficiency of about 96% was achieved using configuration three (i.e. using Aluminum rods in the middle of copper tubes filled with paraffin wax.

  19. Outdoor schools: Limits and dilemmas

    Directory of Open Access Journals (Sweden)

    Irena Smetáčková

    2011-12-01

    Full Text Available Outdoor school is a stable element of Czech educational system. However,many changes have occurred during the last twenty years in the purposes of outdoorschools and in their organization. The article presents various school statistics andresults of research which included questionnaire survey in elementary schools in Pragueand a case study of two classes. The study found that the outdoor school programmesare getting shorter, budgets for outdoor schools are reduced, and prices of outdoorschool programmes for parents are increasing. Because of high prices, almost 20 % ofpupils cannot attend outdoor schools. Nevertheless, according to teachers, pupils andparents, the main purpose of outdoor school programmes is to create a better socialclimate in peer groups. Because of high rates of absence, this goal is partly invalid.Another purpose should be that teachers and children get to know each other better.This goal is invalid as well because many schools hire commercial agencies which limitsthe time that pupils and teachers spend together.

  20. Experimental investigation on natural circulation and air-injection enhanced circulation in a simple loop

    International Nuclear Information System (INIS)

    Walter Ambrosini; Nicola Forgione; Francesco Oriolo; Filippo Pellacani; Mariano Tarantino; Claudio Struckmann

    2005-01-01

    Full text of publication follows: Natural circulation represents an interesting phenomenon because of both the complex aspects characterising it and for the widespread application in industry. On the other hand, injection of a gas into a rising branch of a loop represents a means to establish or to enhance a circulation flow, as it occurs in the so-called 'air-lift' loops. Both natural circulation and gas-injection enhanced circulation are presently considered for cooling Accelerator Driven System (ADS) reactors. These are subcritical reactors in which the fission reaction chain is maintained by the injection of neutrons obtained by spallation reactions in a target through a high energy proton beam generated in an external accelerator. The capability of such reactors to be used as incinerators of long lived fission products makes them particularly interesting in the light of the closure of the nuclear fuel cycle. Some of the fluids proposed as coolants for these reactors are liquid metals, with main interest for lead and lead-bismuth eutectic (LBE). Experimental activities are being performed in support to the design of the reactor prototype by different organisations. The university of Pisa, in addition to provide cooperation in these large scale activities performed with LBE has set up a specific experimental program aimed at studying the fundamental mechanisms involved in natural circulation and gas-injection enhanced circulation. The adopted experimental facility consists in a simple loop, having a rectangular lay-out (roughly, 4 m tall and 1 m wide), equipped with a 5 kW, 1 m tall heater, a 2 m long pipe-in-pipe heat exchanger, an air injection device and a separator. The fluid adopted in the tests performed up to now is water, though studies for evaluating the feasibility of the adoption of different fluids have been undertaken. Experimental data reported in previous publications concerning this research were related to a relatively high range of gas

  1. Computational and experimental analysis of supersonic air ejector: Turbulence modeling and assessment of 3D effects

    International Nuclear Information System (INIS)

    Mazzelli, Federico; Little, Adrienne B.; Garimella, Srinivas; Bartosiewicz, Yann

    2015-01-01

    Highlights: • Computational and experimental assessment of computational techniques for ejector flows. • Comparisons to 2D/3D (k–ε, k–ε realizable, k–ω SST, and stress–ω RSM) turbulence models. • k–ω SST model performs best while ε-based models more accurate at low motive pressures. • Good on-design agreement across 2D and 3D models; off-design needs 3D simulations. - Abstract: Numerical and experimental analyses are performed on a supersonic air ejector to evaluate the effectiveness of commonly-used computational techniques when predicting ejector flow characteristics. Three series of experimental curves at different operating conditions are compared with 2D and 3D simulations using RANS, steady, wall-resolved models. Four different turbulence models are tested: k–ε, k–ε realizable, k–ω SST, and the stress–ω Reynolds Stress Model. An extensive analysis is performed to interpret the differences between numerical and experimental results. The results show that while differences between turbulence models are typically small with respect to the prediction of global parameters such as ejector inlet mass flow rates and Mass Entrainment Ratio (MER), the k–ω SST model generally performs best whereas ε-based models are more accurate at low motive pressures. Good agreement is found across all 2D and 3D models at on-design conditions. However, prediction at off-design conditions is only acceptable with 3D models, making 3D simulations mandatory to correctly predict the critical pressure and achieve reasonable results at off-design conditions. This may partly depend on the specific geometry under consideration, which in the present study has a rectangular cross section with low aspect ratio.

  2. Experimental study of the behavior of two laser produced plasmas in air

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Zefeng; Wei, Wenfu; Han, Jiaxun; Wu, Jian, E-mail: jxjawj@gmail.com; Li, Xingwen; Jia, Shenli [State Key Laboratory of Electrical Insulation and Power Equipment, Xi' an Jiaotong University, Shaanxi 710049 (China)

    2015-07-15

    The interactions among two laser ablated Al plasmas and their shock wave fronts (SWFs) induced by double laser pulses in air were studied experimentally. The evolution processes, including the expansion and interaction of the two plasmas and their shocks, were investigated by laser shadowgraphs, schlieren images, and interferograms. Remarkably, the distribution of the compressed air and the laser plasmas during the colliding process was clearly obtained using the Mach-Zehnder interferometer. From the refractive index profiles, typical plasmas density and gas density behind the shock front were estimated as ∼5.2 × 10{sup 18 }cm{sup −3} and ∼2.4 × 10{sup 20 }cm{sup −3}. A stagnation layer formed by the collision of gas behind the shock front is observed. The SWFs propagated, collided, and reflected with a higher velocity than plasmas. The results indicated that the slower plasma collided at middle, leading to the formation of the soft stagnation.

  3. Experimental investigation of a quad-rotor biplane micro air vehicle

    Science.gov (United States)

    Bogdanowicz, Christopher Michael

    Micro air vehicles are expected to perform demanding missions requiring efficient operation in both hover and forward flight. This thesis discusses the development of a hybrid air vehicle which seamlessly combines both flight capabilities: hover and high-speed forward flight. It is the quad-rotor biplane, which weighs 240 grams and consists of four propellers with wings arranged in a biplane configuration. The performance of the vehicle system was investigated in conditions representative of flight through a series of wind tunnel experiments. These studies provided an understanding of propeller-wing interaction effects and system trim analysis. This showed that the maximum speed of 11 m/s and a cruise speed of 4 m/s were achievable and that the cruise power is approximately one-third of the hover power. Free flight testing of the vehicle successfully highlighted its ability to achieve equilibrium transition flight. Key design parameters were experimentally investigated to understand their effect on overall performance. It was found that a trade-off between efficiency and compactness affects the final choice of the design. Design improvements have allowed for decreases in vehicle weight and ground footprint, while increasing structural soundness. Numerous vehicle designs, models, and flight tests have proven system scalability as well as versatility, including an upscaled model to be utilized in an extensive commercial package delivery system. Overall, the quad-rotor biplane is proven to be an efficient and effective multi-role vehicle.

  4. Experimental investigation of ultraviolet laser induced plasma density and temperature evolution in air

    International Nuclear Information System (INIS)

    Thiyagarajan, Magesh; Scharer, John

    2008-01-01

    We present measurements and analysis of laser induced plasma neutral densities and temperatures in dry air by focusing 200 mJ, 10 MW high power, 193 nm ultraviolet ArF (argon fluoride) laser radiation to a 30 μm radius spot size. We examine these properties that result from multiphoton and collisional cascade processes for pressures ranging from 40 Torr to 5 atm. A laser shadowgraphy diagnostic technique is used to obtain the plasma electron temperature just after the shock front and this is compared with optical emission spectroscopic measurements of nitrogen rotational and vibrational temperatures. Two-color laser interferometry is employed to measure time resolved spatial electron and neutral density decay in initial local thermodynamic equilibrium (LTE) and non-LTE conditions. The radiating species and thermodynamic characteristics of the plasma are analyzed by means of optical emission spectroscopy (OES) supported by SPECAIR, a special OES program for air constituent plasmas. Core plasma rotational and vibrational temperatures are obtained from the emission spectra from the N 2 C-B(2+) transitions by matching the experimental spectrum results with the SPECAIR simulation results and the results are compared with the electron temperature just behind the shock wave. The plasma density decay measurements are compared with a simplified electron density decay model that illustrates the dominant three-and two-body recombination terms with good correlation

  5. Spectral changes in conifers subjected to air pollution and water stress: Experimental studies

    Science.gov (United States)

    Westman, Walter E.; Price, Curtis V.

    1988-01-01

    The roles of leaf anatomy, moisture and pigment content, and number of leaf layers on spectral reflectance in healthy, pollution-stressed, and water-stressed conifer needles were examined experimentally. Jeffrey pine (Pinus jeffreyi) and giant sequoia (Sequoiadendron gigantea) were exposed to ozone and acid mist treatments in fumigation chambers; red pine (Pinus resinosa) needles were artificially dried. Infrared reflectance from stacked needles rose with free water loss. In an air-drying experiment, cell volume reductions induced by loss of turgor caused near-infrared reflectance (TM band 4) to drop after most free water was lost. Under acid mist fumigation, stunting of tissue development similarly reduced band 4 reflectance. Both artificial drying and pollutant fumigation caused a blue shift of the red edge of spectral reflectance curves in conifers, attributable to chlorophyll denaturation. Thematic mapper band ratio 4/3 fell and 5/4 rose with increasing pollution stress on artificial drying. Loss of water by air-drying, freeze-drying, or oven-drying enhanced spectral features, due in part to greater scattering and reduced water absorption. Grinding of the leaf tissue further enhanced the spectral features by increasing reflecting surfaces and path length. In a leaf-stacking experiment, an asymptote in visible and infrared reflectance was reached at 7-8 needle layers of red pine.

  6. An experimental study of the 14C transfer from air to rice plant by photosynthesis

    International Nuclear Information System (INIS)

    Jun, In; Kang, Heeseok; Keum, Dongkweon; Choi, Yongho; Lee, Hansoo; Lee, Changwoo

    2007-01-01

    Experimental studies were performed under controlled environmental conditions to observe the deposition and subsequent allocation of 14 C following a short-term fumigation of a major Korean crop with 14 CO 2 . The fumigation of the rice plants was performed at five different times during their growth in a transparent box and the fumigation time was 40 minutes. The 14 C in the fumigation box was collected into collection vials every 5 minutes using an air sampler. A duplicate plant sampling was made immediately after the end of fumigation and another is going to be made at the normal harvest time. After the 2nd and 3rd fumigation experiments, plant sampling was made 3 times more till harvest. The samples will be ground into powder after removing the moisture completely and the trapped 14 C in the carbosorb vials by sample oxidizer will be analyzed by Liquid Scintillation Counter. This paper only shows the analysis results of air samples because no plant sample was analyzed yet. (author)

  7. Simulation, experimental validation and kinematic optimization of a Stirling engine using air and helium

    International Nuclear Information System (INIS)

    Bert, Juliette; Chrenko, Daniela; Sophy, Tonino; Le Moyne, Luis; Sirot, Frédéric

    2014-01-01

    A Stirling engine with nominal output power of 1 kW is tested using air and helium as working gases. The influence of working pressure, engine speed and temperature of the hot source is studied, analyzing instantaneous gas pressure as well as instantaneous and stationary temperature at different positions to derive the effective power. A zero dimensional finite-time thermodynamic, three zones model of a generic Stirling engine is developed and successfully validated against experimental gas temperature and pressure in each zone, providing the effective power. This validation underlines the interest of different working gases as well as different geometric configurations for different applications. Furthermore, the validated model allows parametric studies of the engine, with regard to geometry, working gas and engine kinematics. It is used in order to optimize the kinematic of a Stirling engine for different working points and gases. - Highlights: • A Stirling engine of 1 kW is tested using air and helium as working gas. • Effects of working pressure, speed and temperature on power are studied. • A zero dimensional finite-time thermodynamic, three zones model of it is validated. • The validated model is used for parametric studies and optimization of the engine

  8. The laboratory environmental algae pond simulator (LEAPS) photobioreactor: Validation using outdoor pond cultures of Chlorella sorokiniana and Nannochloropsis salina

    Energy Technology Data Exchange (ETDEWEB)

    Huesemann, M.; Williams, P.; Edmundson, S.; Chen, P.; Kruk, R.; Cullinan, V.; Crowe, B.; Lundquist, T.

    2017-09-01

    A bench-scale photobioreactor system, termed Laboratory Environmental Algae Pond Simulator (LEAPS), was designed and constructed to simulate outdoor pond cultivation for a wide range of geographical locations and seasons. The LEAPS consists of six well-mixed glass column photobioreactors sparged with CO2-enriched air to maintain a set-point pH, illuminated from above by a programmable multicolor LED lighting (0 to 2,500 µmol/m2-sec), and submerged in a temperature controlled water-bath (-2 °C to >60 °C). Measured incident light intensities and water temperatures deviated from the respective light and temperature set-points on average only 2.3% and 0.9%, demonstrating accurate simulation of light and temperature conditions measured in outdoor ponds. In order to determine whether microalgae strains cultured in the LEAPS exhibit the same linear phase biomass productivity as in outdoor ponds, Chlorella sorokiniana and Nannochloropsis salina were cultured in the LEAPS bioreactors using light and temperature scripts measured previously in the respective outdoor pond studies. For Chlorella sorokiniana, the summer season biomass productivity in the LEAPS was 6.6% and 11.3% lower than in the respective outdoor ponds in Rimrock, Arizona, and Delhi, California; however, these differences were not statistically significant. For Nannochloropsis salina, the winter season biomass productivity in the LEAPS was statistically significantly higher (15.2%) during the 27 day experimental period than in the respective outdoor ponds in Tucson, Arizona. However, when considering only the first 14 days, the LEAPS biomass productivity was only 9.2% higher than in the outdoor ponds, a difference shown to be not statistically significant. Potential reasons for the positive or negative divergence in LEAPS performance, relative to outdoor ponds, are discussed. To demonstrate the utility of the LEAPS in predicting productivity, two other strains – Scenedesmus obliquus and Stichococcus minor

  9. Optimum selection of solar collectors for a solar-driven ejector air conditioning system by experimental and simulation study

    International Nuclear Information System (INIS)

    Zhang Wei; Ma Xiaoli; Omer, S.A.; Riffat, S.B.

    2012-01-01

    Highlights: ► Three solar collectors have been compared to drive ejector air conditioning system. ► A simulation program was constructed to study the effect parameters. ► The outdoor test were conducted to validate the solar collector modeling. ► Simulation program was found to predict solar collector performance accurately. ► The optimal design of solar collector system was carried out. - Abstract: In this paper, three different solar collectors are selected to drive the solar ejector air conditioning system for Mediterranean climate. The performance of the three selected solar collector are evaluated by computer simulation and lab test. Computer model is incorporated with a set of heat balance equations being able to analyze heat transfer process occurring in separate regions of the collector. It is found simulation and test has a good agreement. By the analysis of the computer simulation and test result, the solar ejector cooling system using the evacuated tube collector with selective surface and high performance heat pipe can be most economical when operated at the optimum generating temperature of the ejector cooling machine.

  10. Development of a three-dimensional PIV measurement technique for the experimental study of air bubble collapse phenomena

    International Nuclear Information System (INIS)

    Yang, Y.H.; Hassan, Y.A.; Schmidl, W.D.

    1995-01-01

    Particle image velocimetry (PIV) is a quantitative flow measurement technique. The objective of this study is to develop a new three-dimensional PIV technique for the experimental study of air bubble collapse phenomena. A three-dimensional measurement technique is necessary since bubble collapse is a three-dimensional phenomenon. The investigation of the velocity flow field around a collapsing air bubble can provide detailed three-dimensional quantitative information to help improve the understanding of the related heat transfer processes

  11. Experimental data and boundary conditions for a Double-Skin Facade building in external air curtain mode

    DEFF Research Database (Denmark)

    Larsen, Olena Kalyanova; Heiselberg, Per; Jensen, Rasmus Lund

    Frequent discussions of double skin façade energy performance have started a dialogue about the methods, models and tools for simulation of double façade systems and reliability of their results. Their reliability will increase with empirical validation of the software. Detailed experimental work...... was carried out in a full scale test facility ‘The Cube’, in order to compile three sets of high quality experimental data for validation purposes. The data sets are available for preheating mode, external air curtain mode and transparent insulation mode. The objective of this article is to provide the reader......’. This covers such problem areas as measurements of naturally induced air flow, measurements of air temperature under direct solar radiation exposure, etc. Finally, in order to create a solid foundation for software validation, the uncertainty and limitations in the experimental results are discussed. In part...

  12. Multiphysics modelling and experimental validation of an air-coupled array of PMUTs with residual stresses

    Science.gov (United States)

    Massimino, G.; Colombo, A.; D'Alessandro, L.; Procopio, F.; Ardito, R.; Ferrera, M.; Corigliano, A.

    2018-05-01

    In this paper a complete multiphysics modelling via the finite element method (FEM) of an air-coupled array of piezoelectric micromachined ultrasonic transducers (PMUT) and its experimental validation are presented. Two numerical models are described for the single transducer, axisymmetric and 3D, with the following features: the presence of fabrication induced residual stresses, which determine a non-linear initial deformed configuration of the diaphragm and a substantial fundamental mode frequency shift; the multiple coupling between different physics, namely electro-mechanical coupling for the piezo-electric model, thermo-acoustic-structural interaction and thermo-acoustic-pressure interaction for the waves propagation in the surrounding fluid. The model for the single transducer is enhanced considering the full set of PMUTs belonging to the silicon dye in a 4 × 4 array configuration. The results of the numerical multiphysics models are compared with experimental ones in terms of the initial static pre-deflection, of the diaphragm central point spectrum and of the sound intensity at 3.5 cm on the vertical direction along the axis of the diaphragm.

  13. CFD Code Validation against Stratified Air-Water Flow Experimental Data

    Directory of Open Access Journals (Sweden)

    F. Terzuoli

    2008-01-01

    Full Text Available Pressurized thermal shock (PTS modelling has been identified as one of the most important industrial needs related to nuclear reactor safety. A severe PTS scenario limiting the reactor pressure vessel (RPV lifetime is the cold water emergency core cooling (ECC injection into the cold leg during a loss of coolant accident (LOCA. Since it represents a big challenge for numerical simulations, this scenario was selected within the European Platform for Nuclear Reactor Simulations (NURESIM Integrated Project as a reference two-phase problem for computational fluid dynamics (CFDs code validation. This paper presents a CFD analysis of a stratified air-water flow experimental investigation performed at the Institut de Mécanique des Fluides de Toulouse in 1985, which shares some common physical features with the ECC injection in PWR cold leg. Numerical simulations have been carried out with two commercial codes (Fluent and Ansys CFX, and a research code (NEPTUNE CFD. The aim of this work, carried out at the University of Pisa within the NURESIM IP, is to validate the free surface flow model implemented in the codes against experimental data, and to perform code-to-code benchmarking. Obtained results suggest the relevance of three-dimensional effects and stress the importance of a suitable interface drag modelling.

  14. CFD Code Validation against Stratified Air-Water Flow Experimental Data

    International Nuclear Information System (INIS)

    Terzuoli, F.; Galassi, M.C.; Mazzini, D.; D'Auria, F.

    2008-01-01

    Pressurized thermal shock (PTS) modelling has been identified as one of the most important industrial needs related to nuclear reactor safety. A severe PTS scenario limiting the reactor pressure vessel (RPV) lifetime is the cold water emergency core cooling (ECC) injection into the cold leg during a loss of coolant accident (LOCA). Since it represents a big challenge for numerical simulations, this scenario was selected within the European Platform for Nuclear Reactor Simulations (NURESIM) Integrated Project as a reference two-phase problem for computational fluid dynamics (CFDs) code validation. This paper presents a CFD analysis of a stratified air-water flow experimental investigation performed at the Institut de Mecanique des Fluides de Toulouse in 1985, which shares some common physical features with the ECC injection in PWR cold leg. Numerical simulations have been carried out with two commercial codes (Fluent and Ansys CFX), and a research code (NEPTUNE CFD). The aim of this work, carried out at the University of Pisa within the NURESIM IP, is to validate the free surface flow model implemented in the codes against experimental data, and to perform code-to-code benchmarking. Obtained results suggest the relevance of three-dimensional effects and stress the importance of a suitable interface drag modelling

  15. Outdoor recreation-related outdoor education: scope of the research (1995-2010) 2

    OpenAIRE

    Lynch, Philippa

    2012-01-01

    Article made available with the permission of the New Zealand Journal of Outdoor Education. This is part two of an article on the scope of the New Zealand outdoor recreation-related outdoor education research published from January 1995 to June 2010. It draws on the literature covered the 2010 Sport and Recreation New Zealand-funded Outdoor Recreation Research Stocktake, which included outdoor education material. This part covers resources for outdoor recreation-related outdoor education, ...

  16. Performance of ultraviolet photocatalytic oxidation for indoor air applications: Systematic experimental evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Zhong, Lexuan [Department of Building, Civil and Environmental Engineering, Concordia University, Montreal, Quebec H3G 1M8 (Canada); Haghighat, Fariborz, E-mail: fariborz.haghighat@concordia.ca [Department of Building, Civil and Environmental Engineering, Concordia University, Montreal, Quebec H3G 1M8 (Canada); Lee, Chang-Seo [Department of Building, Civil and Environmental Engineering, Concordia University, Montreal, Quebec H3G 1M8 (Canada); Lakdawala, Ness [DECTRON International Inc., Montreal, Quebec (Canada)

    2013-10-15

    Highlights: • An innovative experimental set-up was designed and constructed for testing UV-PCO. • Test methodologies were developed to examine UV-PCO air cleaners for VOCs removal. • VOCs type, inlet concentration, flow rate, irradiance, and RH have influence on PCO. • Gas-phase ozonation with a variety of compounds was examined in a duct system. • Formation of by-products generated from incomplete conversion was investigated. -- Abstract: Photocatalytic oxidation (PCO) is a promising technology that has potential to be applied in mechanically ventilated buildings to improve indoor air quality (IAQ). However, the major research studies were done in bench-top scale reactors under ideal reaction conditions. In addition, no study has been carried out on the investigation of the ozonation and photolysis effect using a pilot duct system. The objective of this study is the development of methodologies to evaluate the performance of PCO systems. A systematic parametric evaluation of the effects of various kinetic parameters, such as compound's type, inlet concentration, airflow rate, light intensity, and relative humidity, was conducted, and new interpretations were provided from a fundamental analysis. In addition, the photolysis effect under vacuum ultraviolet (VUV) irradiation for a variety of volatile organic compounds (VOCs) was examined for the first time in a pilot duct system. The performance comparison of ultraviolet C (UVC)-PCO and VUV-PCO was also discussed due to the presence of ozone. Moreover, the formation of by-products generated with or without ozone generation was fully compared to evaluate the PCO technology.

  17. Performance of ultraviolet photocatalytic oxidation for indoor air applications: Systematic experimental evaluation

    International Nuclear Information System (INIS)

    Zhong, Lexuan; Haghighat, Fariborz; Lee, Chang-Seo; Lakdawala, Ness

    2013-01-01

    Highlights: • An innovative experimental set-up was designed and constructed for testing UV-PCO. • Test methodologies were developed to examine UV-PCO air cleaners for VOCs removal. • VOCs type, inlet concentration, flow rate, irradiance, and RH have influence on PCO. • Gas-phase ozonation with a variety of compounds was examined in a duct system. • Formation of by-products generated from incomplete conversion was investigated. -- Abstract: Photocatalytic oxidation (PCO) is a promising technology that has potential to be applied in mechanically ventilated buildings to improve indoor air quality (IAQ). However, the major research studies were done in bench-top scale reactors under ideal reaction conditions. In addition, no study has been carried out on the investigation of the ozonation and photolysis effect using a pilot duct system. The objective of this study is the development of methodologies to evaluate the performance of PCO systems. A systematic parametric evaluation of the effects of various kinetic parameters, such as compound's type, inlet concentration, airflow rate, light intensity, and relative humidity, was conducted, and new interpretations were provided from a fundamental analysis. In addition, the photolysis effect under vacuum ultraviolet (VUV) irradiation for a variety of volatile organic compounds (VOCs) was examined for the first time in a pilot duct system. The performance comparison of ultraviolet C (UVC)-PCO and VUV-PCO was also discussed due to the presence of ozone. Moreover, the formation of by-products generated with or without ozone generation was fully compared to evaluate the PCO technology

  18. Realistic Real-Time Outdoor Rendering in Augmented Reality

    Science.gov (United States)

    Kolivand, Hoshang; Sunar, Mohd Shahrizal

    2014-01-01

    Realistic rendering techniques of outdoor Augmented Reality (AR) has been an attractive topic since the last two decades considering the sizeable amount of publications in computer graphics. Realistic virtual objects in outdoor rendering AR systems require sophisticated effects such as: shadows, daylight and interactions between sky colours and virtual as well as real objects. A few realistic rendering techniques have been designed to overcome this obstacle, most of which are related to non real-time rendering. However, the problem still remains, especially in outdoor rendering. This paper proposed a much newer, unique technique to achieve realistic real-time outdoor rendering, while taking into account the interaction between sky colours and objects in AR systems with respect to shadows in any specific location, date and time. This approach involves three main phases, which cover different outdoor AR rendering requirements. Firstly, sky colour was generated with respect to the position of the sun. Second step involves the shadow generation algorithm, Z-Partitioning: Gaussian and Fog Shadow Maps (Z-GaF Shadow Maps). Lastly, a technique to integrate sky colours and shadows through its effects on virtual objects in the AR system, is introduced. The experimental results reveal that the proposed technique has significantly improved the realism of real-time outdoor AR rendering, thus solving the problem of realistic AR systems. PMID:25268480

  19. Realistic real-time outdoor rendering in augmented reality.

    Directory of Open Access Journals (Sweden)

    Hoshang Kolivand

    Full Text Available Realistic rendering techniques of outdoor Augmented Reality (AR has been an attractive topic since the last two decades considering the sizeable amount of publications in computer graphics. Realistic virtual objects in outdoor rendering AR systems require sophisticated effects such as: shadows, daylight and interactions between sky colours and virtual as well as real objects. A few realistic rendering techniques have been designed to overcome this obstacle, most of which are related to non real-time rendering. However, the problem still remains, especially in outdoor rendering. This paper proposed a much newer, unique technique to achieve realistic real-time outdoor rendering, while taking into account the interaction between sky colours and objects in AR systems with respect to shadows in any specific location, date and time. This approach involves three main phases, which cover different outdoor AR rendering requirements. Firstly, sky colour was generated with respect to the position of the sun. Second step involves the shadow generation algorithm, Z-Partitioning: Gaussian and Fog Shadow Maps (Z-GaF Shadow Maps. Lastly, a technique to integrate sky colours and shadows through its effects on virtual objects in the AR system, is introduced. The experimental results reveal that the proposed technique has significantly improved the realism of real-time outdoor AR rendering, thus solving the problem of realistic AR systems.

  20. Experimental investigation on the droplet entrainment from interfacial waves in air-water horizontal stratified flow

    International Nuclear Information System (INIS)

    Bae, Byeong Geon; Yun, Byong Jo; Kim, Kyoung Du

    2014-01-01

    It was mainly due to the fact that droplet entrainment affects the Peak Cladding Temperature (PCT) of the nuclear fuel rod in the Postulated accident conditions of NPP. Recently, droplet entrainment in the horizontally arranged primary piping system for the NPP is of interest because it affects directly the steam binding phenomena in the steam generators. Pan and Hanratty correlation is the only applicable one for the droplet entrainment rate model for horizontal flow. Moreover, there are no efforts for the model development on the basis of the droplet entrainment principal and physics phenomena. More recently, Korea Atomic Energy Research Institute (KAERI) proposed a new mechanistic droplet generation model applicable in the horizontal pipe for the SPACE code. However, constitutive relations in this new model require three model coefficients which have not yet been decided. The purpose of present work is determining three model coefficients by visualization experiment. For these model coefficients, the major physical parameters regarding the interfacial disturbance wave should be measured in this experiments. There are the wave slope, liquid fraction, wave hypotenuse length, wave velocity, wave frequency, and wavelength in the major physical parameters. The experiment was conducted at an air water horizontal rectangular channel with the PIV system. In this study, the experimental conditions were stratified-way flow during the droplet generation. Three coefficients were determined based on several data related to the interfacial wave. Additionally, we manufactured the parallel wire conductance probe to measure the fluctuating water level over time, and compared the wave height measured by the parallel wire conductance probe and image processing from images taken by high speed camera. Experimental investigation was performed for droplet entrainment from phase interface wave in an air-water stratified flow. In the experiments, we measured major physical parameters

  1. Study of Quilted Fabrics Used in Outdoor Clothing

    Directory of Open Access Journals (Sweden)

    Malgorzata Matusiak

    2017-12-01

    Full Text Available Quilted fabrics are more and more frequently used in outdoor clothing, especially jackets. They are usually composed of two or three layers connected together by sewing or thermal quilting. They are characterised by different properties, depending on the structure of the quilted fabrics. In the presented work, five variants of quilted fabrics were studied in terms of of their comfort-related properties, such as thermal resistance, thermal conductivity, thermal absorptivity, water-vapour resistance and air permeability. On the basis of the results, it was possible to assess the quilted fabrics from the point of view of their usability for outdoor clothing.

  2. Dose rate modelled for the outdoors of a gamma irradiation

    International Nuclear Information System (INIS)

    Mangussi, J

    2012-01-01

    A model for the absorbed dose rate calculation on the surroundings of a gamma irradiation plant is developed. In such plants, a part of the radiation emitted upwards reach's the outdoors. The Compton scatterings on the wall of the exhausting pipes through de plant roof and on the outdoors air are modelled. The absorbed dose rate generated by the scattered radiation as far as 200 m is calculated. The results of the models, to be used for the irradiation plant design and for the environmental studies, are showed on graphics (author)

  3. Definition: Conservation Education, Environmental Education, Outdoor Education.

    Science.gov (United States)

    1970

    Conservation education, outdoor education, and environmental education all have as a common goal the understanding and appreciation of the natural world. Outdoor education is a method of teaching wherein established disciplines, topics, and concepts which can best be taught outdoors are taught outdoors. Conservation education is the study of man's…

  4. The Cost of Becoming an Outdoor Instructor.

    Science.gov (United States)

    Cashel, Chris

    This article describes instructor criteria in three outdoor organizations: Outward Bound (OB), the National Outdoor Leadership School (NOLS), and the Wilderness Education Association (WEA). Common requirements for outdoor leadership programs are outdoor experience and skills, advanced first aid, CPR, and a minimum age requirement. Traditionally…

  5. 9 CFR 3.27 - Facilities, outdoor.

    Science.gov (United States)

    2010-01-01

    ... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Facilities, outdoor. 3.27 Section 3.27... Pigs and Hamsters Facilities and Operating Standards § 3.27 Facilities, outdoor. (a) Hamsters shall not be housed in outdoor facilities. (b) Guinea pigs shall not be housed in outdoor facilities unless...

  6. Experimental Determination of Demand Response Control Models and Cost of Control for Ensembles of Window-Mount Air Conditioners

    Energy Technology Data Exchange (ETDEWEB)

    Geller, Drew Adam [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Backhaus, Scott N. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-09-29

    Control of consumer electrical devices for providing electrical grid services is expanding in both the scope and the diversity of loads that are engaged in control, but there are few experimentally-based models of these devices suitable for control designs and for assessing the cost of control. A laboratory-scale test system is developed to experimentally evaluate the use of a simple window-mount air conditioner for electrical grid regulation services. The experimental test bed is a single, isolated air conditioner embedded in a test system that both emulates the thermodynamics of an air conditioned room and also isolates the air conditioner from the real-world external environmental and human variables that perturb the careful measurements required to capture a model that fully characterizes both the control response functions and the cost of control. The control response functions and cost of control are measured using harmonic perturbation of the temperature set point and a test protocol that further isolates the air conditioner from low frequency environmental variability.

  7. CFC Outdoor Tournament 2011

    CERN Multimedia

    2011-01-01

    Regardless of whether you’re a fan of the "beautiful game", you’ve probably heard that the CFC Outdoor Tournament 2011 is the sporting event of the year for the CERN Football Club. This unmissable social, cultural and sporting event will be a chance for CERNois to mingle with external visitors. In the 2011 edition of this legendary tournament, which is over 45 years old, the principle of “fair play” is once again on display. Ten teams – 8 from CERN – are competing for the CFC title. The tournament concludes with a final on 7 July final. Along with a thrilling match, there will also be a host of festivities for the final, including an exhibition game, the final awards ceremony, surprise gifts, a barbeque, musical performances, and more! Make sure to highlight 7 July (after 18.00) on your agenda, and take advantage of what will surely be an unforgettable day! The final tournament matches have been in progress since April and are ...

  8. Experimental validation of a local dehumidification system based on cold water droplets and air-to-air heat exchanger

    NARCIS (Netherlands)

    Janssen, E.G.O.N.; Hammink, H.A.J.; Hendriksen, L.J.A.M.

    2015-01-01

    Excessive humidity is a problem in Dutch growing circumstances. A traditional solution is heating and natural ventilation. To save energy a number of energy efficient dehumidification methods are developed, like mechanical ventilation with dry outside air or a curtain of cold water droplets. In this

  9. Experimental Study of Hydrogen Addition Effects on a Swirl-Stabilized Methane-Air Flame

    Directory of Open Access Journals (Sweden)

    Mao Li

    2017-11-01

    Full Text Available The effects of H2 addition on a premixed methane-air flame was studied experimentally with a swirl-stabilized gas turbine model combustor. Experiments with 0%, 25%, and 50% H2 molar fraction in the fuel mixture were conducted under atmospheric pressure. The primary objectives are to study the impacts of H2 addition on flame lean blowout (LBO limits, flame shapes and anchored locations, flow field characteristics, precessing vortex core (PVC instability, as well as the CO emission performance. The flame LBO limits were identified by gradually reducing the equivalence ratio until the condition where the flame physically disappeared. The time-averaged CH chemiluminescence was used to reveal the characteristics of flame stabilization, e.g., flame structure and stabilized locations. In addition, the inverse Abel transform was applied to the time-averaged CH results so that the distribution of CH signal on the symmetric plane of the flame was obtained. The particle image velocimetry (PIV was used to detect the characteristics of the flow field with a frequency of 2 kHz. The snapshot method of POD (proper orthogonal decomposition and fast Fourier transform (FFT were adopted to capture the most prominent coherent structures in the turbulent flow field. CO emission was monitored with an exhaust probe that was installed close to the combustor exit. The experimental results indicated that the H2 addition extended the flame LBO limits and the operation range of low CO emission. The influence of H2 addition on the flame shape, location, and flow field was observed. With the assistance of POD and FFT, the combustion suppression impacts on PVC was found.

  10. Experimental and numerical study of premixed hydrogen/air flame propagating in a combustion chamber.

    Science.gov (United States)

    Xiao, Huahua; Sun, Jinhua; Chen, Peng

    2014-03-15

    An experimental and numerical study of dynamics of premixed hydrogen/air flame in a closed explosion vessel is described. High-speed shlieren cinematography and pressure recording are used to elucidate the dynamics of the combustion process in the experiment. A dynamically thickened flame model associated with a detailed reaction mechanism is employed in the numerical simulation to examine the flame-flow interaction and effect of wall friction on the flame dynamics. The shlieren photographs show that the flame develops into a distorted tulip shape after a well-pronounced classical tulip front has been formed. The experimental results reveal that the distorted tulip flame disappears with the primary tulip cusp and the distortions merging into each other, and then a classical tulip is repeated. The combustion dynamics is reasonably reproduced in the numerical simulations, including the variations in flame shape and position, pressure build-up and periodically oscillating behavior. It is found that both the tulip and distorted tulip flames can be created in the simulation with free-slip boundary condition at the walls of the vessel and behave in a manner quite close to that in the experiments. This means that the wall friction could be unimportant for the tulip and distorted tulip formation although the boundary layer formed along the sidewalls has an influence to a certain extent on the flame behavior near the sidewalls. The distorted tulip flame is also observed to be produced in the absence of vortex flow in the numerical simulations. The TF model with a detailed chemical scheme is reliable for investigating the dynamics of distorted tulip flame propagation and its underlying mechanism. Copyright © 2014 Elsevier B.V. All rights reserved.

  11. Experimental research on photocatalytic oxidation air purification technology applied to aircraft cabins

    DEFF Research Database (Denmark)

    Sun, Yuexia; Fang, Lei; Wyon, David Peter

    2008-01-01

    The experiment presented in this report was performed in a simulated aircraft cabin to evaluate the air cleaning effects of two air purification devices that used photocatalytic oxidation (PCO) technology. Objective physical, chemical and physiological measurements and subjective human assessment...

  12. Theoretical and Experimental Investigations of Highly Uprated Diesel Engine with Temperature Regulator of Supercharging Air

    Directory of Open Access Journals (Sweden)

    G. A. Vershina

    2005-01-01

    Full Text Available Mathematical model of a highly uprated diesel engine with turbo-supercharging and intercooler of supercharging air is given in die paper. Theoretical study based on the model has made it possible to design and test an intercooler with a temperature regulator of supercharging air. Test results prove efficiency of temperature regulation of supercharging air in operation of an engine at low loads with excess air factor more than 3.2.

  13. Microfabricated Air-Microfluidic Sensor for Personal Monitoring of Airborne Particulate Matter: Design, Fabrication, and Experimental Results

    Science.gov (United States)

    We present the design and fabrication of a micro electro mechanical systems (MEMS) air-microfluidic particulate matter (PM) sensor, and show experimental results obtained from exposing the sensor to concentrations of tobacco smoke and diesel exhaust, two commonly occurring P...

  14. Experimental study of defoaming by air-borne power ultrasonic technology

    Science.gov (United States)

    Rodríguez, Germán; Riera, Enrique; Gallego-Juárez, Juan A.; Acosta, Víctor M.; Pinto, Alberto; Martínez, Ignacio; Blanco, Alfonso

    2010-01-01

    Foam is a dispersion of gas in a liquid in which the distances between the gas bubbles are very small. Foams are frequently generated in the manufacture of many products as result from the aeration and agitation of liquids, from the vaporization of the liquid and also from biological or chemical reactions. Foams are generally an unwanted product in industrial processes because they cause difficulties in process control and in equipment operation. The most efficient conventional method for defoaming is the use of chemical agents but they contaminate the product. High-intensity ultrasonic waves offer a clean procedure to break foam bubbles. The potential use of ultrasound for foam breaking that was known since many years has been recently reinforced by the application of a new type of ultrasonic defoamer based on the stepped-plate high-power transducers to generate air-borne ultrasound. This defoamer has been successfully applied in several industrial problems such as the control of excess foam produced during the filling operation of bottles and cans on high-speed canning lines and in fermenting vessels and other reactors of great dimensions. The treatment of such industrial problems requires the proper characterization and quantification of the main parameters involved in the mechanisms of the defoaming effect. This paper deals with an experimental study about the separate influence of such parameters with the aim of improving the application of the stepped-plate power ultrasonic generators for the production of the defoaming action on industrial processes

  15. Experimental Results Obtained with Air Liquide Cold Compression System: CERN LHC and SNS Projects

    Science.gov (United States)

    Delcayre, F.; Courty, J.-C.; Hamber, F.; Hilbert, B.; Monneret, E.; Toia, J.-L.

    2006-04-01

    Large scale collider facilities will make intensive use of superconducting magnets, operating below 2.0 K. This dictates high-capacity refrigeration systems operating below 2.0 K. These systems, making use of cryogenic centrifugal compressors in a series arrangement with room temperature screw compressors will be coupled to a refrigerator, providing a certain power at 4.5 K. A first Air Liquide Cold Compression System (CCS) unit was built and delivered to CERN in 2001. Installed at the beginning of 2002, it was commissioned and tested successfully during year 2002. A series of four sets of identical CCS were then tested in 2004. Another set of four cryogenic centrifugal compressors (CCC) has been delivered to Thomas Jefferson National Accelerator Facility (JLAB) for the Spallation Neutron Source (SNS) in 2002. These compressors were tested and commissioned from December 2004 to July 2005. The experimental results obtained with these systems will be presented and discussed: the characteristics of the CCC will be detailed. The principles of control for the CCC in series will be detailed.

  16. Experimental study of gas engine driven air to water heat pump in cooling mode

    International Nuclear Information System (INIS)

    Elgendy, E.; Schmidt, J.

    2010-01-01

    Nowadays a sustainable development for more efficient use of energy and protection of the environment is of increasing importance. Gas engine heat pumps represent one of the most practicable solutions which offer high energy efficiency and environmentally friendly for heating and cooling applications. In this paper, the performance characteristics of gas engine driven heat pump used in water cooling were investigated experimentally without engine heat recovery. The effects of several important factors (evaporator water inlet temperature, evaporator water volume flow rate, ambient air temperature, and engine speed) on the performance of gas engine driven heat pump were studied in a wide range of operating conditions. The results showed that primary energy ratio of the system increased by 22.5% as evaporator water inlet temperature increased from 13 o C to 24 o C. On the other hand, varying of engine speed from 1300 rpm to 1750 rpm led to decrease in system primary energy ratio by 13%. Maximum primary energy ratio has been estimated with a value of two over a wide range of operating conditions.

  17. Control strategy and experimental study on a novel defrosting method for air-source heat pump

    International Nuclear Information System (INIS)

    Liang Caihua; Zhang Xiaosong; Li Xiuwei; Chen Zhenqian

    2010-01-01

    A new defrosting method - the sensible heat defrosting method, aiming at shelving the various disadvantages of the conventional reverse cycle defrosting was proposed in this paper. The mechanism and process of this method was analysed. To guarantee the reliability, the self-organizing control algorithm with self-learning function was introduced based on the cardinal fuzzy control algorithm. Moreover, the control strategy was enacted; the corresponding self-organizing fuzzy control system was developed; the Micro Controller Unit (MCU) based control unit was accomplished; and the experimental study was conducted to investigate the sample machine of air-source heat pump system. The results of the experiments showed that the self-organizing control algorithm has good control characteristic and effect. On one hand, the adverse shock from the conventional reverse cycle defrosting to the refrigeration system could be avoided through this proposed method; on the other hand, the 'oil rush' could also be eliminated. Besides, the thermal comfort could be greatly improved since the temperature fluctuation range of the supplied water is narrowed by applying this new method in practice.

  18. Experimental and modeling study on effects of N2 and CO2 on ignition characteristics of methane/air mixture

    Directory of Open Access Journals (Sweden)

    Wen Zeng

    2015-03-01

    Full Text Available The ignition delay times of methane/air mixture diluted by N2 and CO2 were experimentally measured in a chemical shock tube. The experiments were performed over the temperature range of 1300–2100 K, pressure range of 0.1–1.0 MPa, equivalence ratio range of 0.5–2.0 and for the dilution coefficients of 0%, 20% and 50%. The results suggest that a linear relationship exists between the reciprocal of temperature and the logarithm of the ignition delay times. Meanwhile, with ignition temperature and pressure increasing, the measured ignition delay times of methane/air mixture are decreasing. Furthermore, an increase in the dilution coefficient of N2 or CO2 results in increasing ignition delays and the inhibition effect of CO2 on methane/air mixture ignition is stronger than that of N2. Simulated ignition delays of methane/air mixture using three kinetic models were compared to the experimental data. Results show that GRI_3.0 mechanism gives the best prediction on ignition delays of methane/air mixture and it was selected to identify the effects of N2 and CO2 on ignition delays and the key elementary reactions in the ignition chemistry of methane/air mixture. Comparisons of the calculated ignition delays with the experimental data of methane/air mixture diluted by N2 and CO2 show excellent agreement, and sensitivity coefficients of chain branching reactions which promote mixture ignition decrease with increasing dilution coefficient of N2 or CO2.

  19. FINAL REPORT on Experimental Validation of Stratified Flow Phenomena, Graphite Oxidation, and Mitigation Strategies of Air Ingress Accidents

    Energy Technology Data Exchange (ETDEWEB)

    Chang H. Oh; Eung S. Kim; Hee C. NO; Nam Z. Cho

    2011-01-01

    The U.S. Department of Energy is performing research and development that focuses on key phenomena that are important during challenging scenarios that may occur in the Next Generation Nuclear Plant (NGNP)/Generation IV very high temperature reactor (VHTR). Phenomena Identification and Ranking studies to date have identified the air ingress event, following on the heels of a VHTR depressurization, as very important. Consequently, the development of advanced air ingress-related models and verification & validation are of very high priority for the NGNP Project. Following a loss of coolant and system depressurization incident, air ingress will occur through the break, leading to oxidation of the in-core graphite structure and fuel. This study indicates that depending on the location and the size of the pipe break, the air ingress phenomena are different. In an effort to estimate the proper safety margin, experimental data and tools, including accurate multidimensional thermal-hydraulic and reactor physics models, a burn-off model, and a fracture model are required. It will also require effective strategies to mitigate the effects of oxidation, eventually. This 3-year project (FY 2008–FY 2010) is focused on various issues related to the VHTR air-ingress accident, including (a) analytical and experimental study of air ingress caused by density-driven, stratified, countercurrent flow, (b) advanced graphite oxidation experiments, (c) experimental study of burn-off in the core bottom structures, (d) structural tests of the oxidized core bottom structures, (e) implementation of advanced models developed during the previous tasks into the GAMMA code, (f) full air ingress and oxidation mitigation analyses, (g) development of core neutronic models, (h) coupling of the core neutronic and thermal hydraulic models, and (i) verification and validation of the coupled models.

  20. Analysis of the experimental data of air pollution using atmospheric dispersion modeling and rough set

    International Nuclear Information System (INIS)

    Halfa, I.K.I

    2008-01-01

    This thesis contains four chapters and list of references:In chapter 1, we introduce a brief survey about the atmospheric concepts and the topological methods for data analysis.In section 1.1, we give introduce a general introduction. We recall some of atmospheric fundamentals in Section 1.2. Section 1.3, shows the concepts of modern topological methods for data analysis.In chapter 2, we have studied the properties of atmosphere and focus on concept of Rough set and its properties. This concepts of rough set has been applied to analyze the atmospheric data.In section 2.1, we introduce a general introduction about concept of rough set and properties of atmosphere. Section 2.2 focuses on the concept of rough set and its properties and generalization of approximation of rough set theory by using topological space. In section 2.3 we have studied the stabilities of atmosphere for Inshas location for all seasons using different schemes and compared these schemes using statistical and rough set methods. In section 2.4, we introduce mixing height of plume for all seasons. Section 2.5 introduced seasonal surface layer turbulence processes for Inshas location. Section 2.6 gives a comparison between the seasonal surface layer turbulence processes for Inshas location and for different locations using rough set theory.In chapter 3 we focus on the concept of variable precision rough set (VPRS) and its properties and using it to compare, between the estimated and observed data of the concentration of air pollution for Inshas location. In Section 3.1 we introduce a general introduction about VPRS and air pollution. In Section 3.2 we have focused on the concept and properties of VPRS. In Section 3.3 we have introduced a method to estimate the concentration of air pollution for Inshas location using Gaussian plume model. Section 3.4 has showed the experimental data. The estimated data have been compared with the observed data using statistical methods in Section 3.5. In Section 3

  1. Research on Integration of Indoor and Outdoor Positioning in Professional Athletic Training

    Directory of Open Access Journals (Sweden)

    Yongqing Liu

    2018-02-01

    Full Text Available GNSS is widely used in professional athletic training as an outdoor location based services, and the indoor positioning technology has gradually flourished in the gymnasium. To keep up with the demand for athletic training in indoor and outdoor environment, integration of indoor and outdoor positioning technology can achieve a seamless indoor/outdoor position solution. The proposed method uses GPS/BEIDOU with IMU-MEMS technology for outdoor positioning and UWB with IMU-MEMS technology for indoor positioning to provide high precision positioning services. The experimental results show that the proposed method can achieve meter level position accuracy in outdoor environment and centimeter level position accuracy in indoor environment, it can provide precise and real-time positioning service for effective athletic training aid.

  2. Modeling emission rates and exposures from outdoor cooking

    Science.gov (United States)

    Edwards, Rufus; Princevac, Marko; Weltman, Robert; Ghasemian, Masoud; Arora, Narendra K.; Bond, Tami

    2017-09-01

    Approximately 3 billion individuals rely on solid fuels for cooking globally. For a large portion of these - an estimated 533 million - cooking is outdoors, where emissions from cookstoves pose a health risk to both cooks and other household and village members. Models that estimate emissions rates from stoves in indoor environments that would meet WHO air quality guidelines (AQG), explicitly don't account for outdoor cooking. The objectives of this paper are to link health based exposure guidelines with emissions from outdoor cookstoves, using a Monte Carlo simulation of cooking times from Haryana India coupled with inverse Gaussian dispersion models. Mean emission rates for outdoor cooking that would result in incremental increases in personal exposure equivalent to the WHO AQG during a 24-h period were 126 ± 13 mg/min for cooking while squatting and 99 ± 10 mg/min while standing. Emission rates modeled for outdoor cooking are substantially higher than emission rates for indoor cooking to meet AQG, because the models estimate impact of emissions on personal exposure concentrations rather than microenvironment concentrations, and because the smoke disperses more readily outdoors compared to indoor environments. As a result, many more stoves including the best performing solid-fuel biomass stoves would meet AQG when cooking outdoors, but may also result in substantial localized neighborhood pollution depending on housing density. Inclusion of the neighborhood impact of pollution should be addressed more formally both in guidelines on emissions rates from stoves that would be protective of health, and also in wider health impact evaluation efforts and burden of disease estimates. Emissions guidelines should better represent the different contexts in which stoves are being used, especially because in these contexts the best performing solid fuel stoves have the potential to provide significant benefits.

  3. ‘Getting Children Outdoors again’ - Outdoor Play for children in a rural North West of Ireland setting: A civic engagement Project

    OpenAIRE

    McGonagle, Michelle

    2017-01-01

    Children’s’ Outdoor play nowadays is the preferred approach to playing indoors which has become a constant focus of influences and powers of technology. Children spend hours on social media sites, isolated playing video games and lost in technologically powered screens (Larson et al, 2011). As a results of this disengagement with outdoors activities, children fall victims to many problems including obesity, social exclusion, and in some cases behavioural issues Fresh air and exercise are prob...

  4. Experimental study on the performance of a multi-functional domestic air conditioner with integrated water heater

    International Nuclear Information System (INIS)

    Dong, Jiankai; Li, Hui; Yao, Yang; Jiang, Yiqiang; Zhang, Xinran

    2017-01-01

    Highlights: • A novel MDACWH was presented and experimentally studied. • MDACWH has high performance on making domestic hot water and air conditioning. • The time for heating water reduced to 22.0 min after modification. • Average COP reached 4.32, which was 1.58 times higher than the unmodified unit. - Abstract: The recovery of condenser heat is concerned one of the most effective methods to curb energy consumption in residential dwellings. Aiming at recovering the condenser heat of domestic air conditioner, this paper experimentally studied a multi-functional domestic air conditioner with integrated water heater (MDACWH) which can effectively provide space – cooling and domestic hot water simultaneously. The dynamic operation characteristics, such as hot water supply and energy efficiency were tested to verify the availability of the MDACWH. The results showed that the MDACWH can effectively heat the domestic hot water without losing its cooling capacity. It was also found that with the use of MDACWH, the coefficient of comprehensive energy performance of the MDACWH was about 1.58 times higher than that of the unmodified experimental unit. Furthermore, the water-heating time was shorten remarkably from 128.5 min to 22.0 min. The novel domestic air conditioner, compared with the unmodified initial prototype, can be more practical and provide significant energy savings in space-cooling and hot water supply.

  5. Experimental Evaluation of a Total Heat Recovery Unit with Polymer Membrane Foils

    DEFF Research Database (Denmark)

    Fang, Lei; Yuan, Shu; Nie, Jinzhe

    2014-01-01

    A laboratory experimental study was conducted to investigate the energy performance of a total heat recovery unit using a polymer membranes heat exchanger. The study was conducted in twin climate chambers. One of the chambers simulated outdoor climate conditions and the other simulated the climate...... condition indoors. The airflows taken from the two chambers were connected into the total heat recovery unit and exchange heat in a polymer membrane foil heat exchanger installed inside the unit. The temperature and humidity of the air upstream and downstream of the heat exchanger were measured. Based...... on the measured temperature and humidity values, the temperature, humidity, and enthalpy efficiencies of the total heat recovery unit were calculated. The experiment was conducted in different combinations of outdoor climate conditions simulating warm and humid outdoor climates and air-conditioned indoor climate...

  6. Real scale experimental study for performance evaluation of unidirectional air diffuser perforated panels

    Science.gov (United States)

    Tăcutu, Laurenţiu; Nastase, Ilinca; Iordache, Vlad; Catalina, Tiberiu; Croitoru, Cristiana Verona

    2018-02-01

    Nowadays, there is an increasing emphasis on indoor air quality due to technological evolution and the fact that people spend most of the time in enclosed spaces. Also, energy efficiency is another related factor that gains more and more attention. Improving air distribution in an enclosure can lead to achieve these goals. This improvement can be done by adjustingthe air terminals position, theredimensions or the air diffuser perforations. The paper presents the study of 8 types of panels with different perforations shapes. The systems were characterized by flow, pressure loss and noise. Usualand special geometries were chosen, all having the same flowsurface. The perforated panels were mounted in a unidirectional air flow (UAF)diffuser, also called a laminar air flow (LAF)diffuser, that is placed in a real scale operating room (OR) in our laboratory.The purpose of this study is to determine whether changing the shape in the perforated panels can improve the technical parameters of the diffuser.

  7. Cough and environmental air pollution in China.

    Science.gov (United States)

    Zhang, Qingling; Qiu, Minzhi; Lai, Kefang; Zhong, Nanshan

    2015-12-01

    With fast-paced urbanization and increased energy consumption in rapidly industrialized modern China, the level of outdoor and indoor air pollution resulting from industrial and motor vehicle emissions has been increasing at an accelerated rate. Thus, there is a significant increase in the prevalence of respiratory symptoms such as coughing, wheezing, and decreased pulmonary function. Experimental exposure research and epidemiological studies have indicated that exposure to particulate matter, ozone, nitrogen dioxide, and environmental tobacco smoke have a harmful influence on development of respiratory diseases and are significantly associated with cough and wheeze. This review mainly discusses the effect of air pollutants on respiratory health, particularly with respect to cough, the links between air pollutants and microorganisms, and air pollutant sources. Particular attention is paid to studies in urban areas of China where the levels of ambient and indoor air pollution are significantly higher than World Health Organization recommendations. Copyright © 2015 Elsevier Ltd. All rights reserved.

  8. Experimental investigation of a two-inlet air-based building integrated photovoltaic/thermal (BIPV/T) system

    International Nuclear Information System (INIS)

    Yang, Tingting; Athienitis, Andreas K.

    2015-01-01

    Highlights: • BIPV/T system thermal efficiency is 5% higher using two inlets compared to one. • BIPV/T thermal efficiency is 7.6% higher using semi-transparent than opaque PV. • Detailed air temperature profile in BIPV/T channel is obtained. • Nusselt number correlations are developed. - Abstract: An experimental study of thermal characteristics of a novel two-inlet air-based open-loop building integrated photovoltaic/thermal (BIPV/T) system using a full-scale solar simulator is presented. Experimental prototypes of one-inlet and two-inlet BIPV/T systems were constructed for conducting comparative experiments. Variations of BIPV/T systems are also investigated including systems employing opaque mono-crystalline silicon photovoltaic (PV) panels and systems employing semi-transparent mono-crystalline PV panels. Experimental results demonstrate that an equivalent two-inlet system with frameless PV panels can increase the thermal efficiency by 5% compared to a conventional one-inlet system, and that the BIPV/T system with semi-transparent PV panels achieves 7.6% higher thermal efficiency due to the absorption of some solar radiation at the bottom surface in the BIPV/T system cavity. Also, the two-inlet BIPV/T design is easily implemented and does not add significant cost. Detailed air temperature measurements reveal that the mixing of the warm outlet air from the first section and the cool ambient air drawn in from the second inlet contributes to the improved performance of the two-inlet system. Based on a thermal network model of the BIPV/T system and experimental data, correlations are developed for the convective heat transfer coefficients in the two sections. These are necessary for further analysis and development of BIPV/T system with multiple inlets.

  9. Thermal Perception in the Mediterranean Area: Comparing the Mediterranean Outdoor Comfort Index (MOCI to Other Outdoor Thermal Comfort Indices

    Directory of Open Access Journals (Sweden)

    Iacopo Golasi

    2016-07-01

    Full Text Available Outdoor thermal comfort is an essential factor of people’s everyday life and deeply affects the habitability of outdoor spaces. However the indices used for its evaluation were usually developed for indoor environments assuming still air conditions and absence of solar radiation and were only later adapted to outdoor spaces. For this reason, in a previous study the Mediterranean Outdoor Comfort Index (MOCI was developed, which is an empirical index able to estimate the thermal perception of people living in the Mediterranean area. In this study it was compared numerically (by using the data obtained through a field survey with other selected thermal indices. This comparison, performed in terms of Spearman’s rho correlation coefficient, association Gamma, percentage of correct predictions and cross-tabulation analysis, led to identify the MOCI as the most suitable index to examine outdoor thermal comfort in the interested area. As a matter of fact it showed a total percentage of correct predictions of 35.5%. Good performances were reported even in thermophysiological indices as the Physiological Equivalent Temperature (PET and Predicted Mean Vote (PMV. Moreover it was revealed that adaptation and acclimatization phenomena tend to have a certain influence as well.

  10. Experimental study of condensate subcooling with the use of a model of an air-cooled condenser

    Science.gov (United States)

    Sukhanov, V. A.; Bezukhov, A. P.; Bogov, I. A.; Dontsov, N. Y.; Volkovitsky, I. D.; Tolmachev, V. V.

    2016-01-01

    Water-supply deficit is now felt in many regions of the world. This hampers the construction of new steam-turbine and combined steam-and-gas thermal power plants. The use of dry cooling systems and, specifically, steam-turbine air-cooled condensers (ACCs) expands the choice of sites for the construction of such power plants. The significance of condensate subcooling Δ t as a parameter that negatively affects the engineering and economic performance of steam-turbine plants is thereby increased. The operation and design factors that influence the condensate subcooling in ACCs are revealed, and the research objective is, thus, formulated properly. The indicated research was conducted through physical modeling with the use of the Steam-Turbine Air-Cooled Condenser Unit specialized, multipurpose, laboratory bench. The design and the combined schematic and measurement diagram of this test bench are discussed. The experimental results are presented in the form of graphic dependences of the condensate subcooling value on cooling ratio m and relative weight content ɛ' of air in steam at the ACC inlet at different temperatures of cooling air t ca ' . The typical ranges of condensate subcooling variation (4 ≤ Δ t ≤ 6°C, 2 ≤ Δ t ≤ 4°C, and 0 ≤ Δ t ≤ 2°C) are identified based on the results of analysis of the attained Δ t levels in the ACC and numerous Δ t reduction estimates. The corresponding ranges of cooling ratio variation at different temperatures of cooling air at the ACC inlet are specified. The guidelines for choosing the adjusted ranges of cooling ratio variation with account of the results of experimental studies of the dependences of the absolute pressure of the steam-air mixture in the top header of the ACC and the heat flux density on the cooling ratio at different temperatures of cooling air at the ACC inlet are given.

  11. Experimental study on split air conditioner with new hybrid equipment of energy storage and water heater all year round

    International Nuclear Information System (INIS)

    Wang Shaowei; Liu Zhenyan; Li Yuan; Zhao Keke; Wang Zhigang

    2005-01-01

    This paper presents a split air conditioner with a new hybrid equipment of energy storage and water heater all year round (ACWES). The authors made a special design on the storage tank to adjust the refrigerant capacity in the storage coils under different functions, instead of adding an accumulator to the system. An ACWES prototype, rebuilt from an original split air conditioner, has been finished, and experimental study of the operation processes of the prototype was done from which some important conclusions and suggestions have been made, which were helpful in the primary design and improvement of an ACWES system for potential users

  12. Experimental study of air-cooled water condensation in slightly inclined circular tube using infrared temperature measurement technique

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hyungdae [Nuclear Engineering Department, Kyung Hee University, Yongin (Korea, Republic of); Kwon, Tae-Soon [Korea Atomic Energy Research Institute, Daedeok-daero 989-111, Yuseong-gu, Daejeon 305-353 (Korea, Republic of); Kim, Dong Eok, E-mail: dekim@knu.ac.kr [Department of Precision Mechanical Engineering, Kyungpook National University, Sangju (Korea, Republic of)

    2016-11-15

    Highlights: • Air-cooled condensation experiments in an inclined Pyrex glass tube were performed. • High-resolution wall temperature data and flow regime formations could be obtained. • The local heat flux was strongly dependent on the air-side heat transfer. • A CFD analysis was conducted for calculating the local heat flux distribution. - Abstract: This study presents the results of an investigation of the air-cooled water condensation heat transfer characteristics inside a slightly inclined circular tube made of transparent Pyrex glass. The high-resolution wall temperature data and stratified film formations could be obtained with the assistance of an infrared (IR) thermometry technique and side-view visualization using a CCD camera. In all experimental cases, the condensation flow patterns were in the fully-stratified flow region. In addition, the experimentally measured void fraction corresponded well with the logarithmic mean void fraction model. The local temperature differences in the cooling air flow across the condenser tube and high-resolution temperature profiles on the tube’s outer wall were obtained in the experimental measurements. Under the experimental conditions of this study, the local heat flux distributions in the longitudinal direction of the test tube were strongly dependent on the cooling air velocity. And, with the help of IR thermometry, the tube outer wall temperature data at 45 local points could be measured. From the data, the asymmetry distribution of the local wall temperatures and the accurate location of the transition from two-phase mixture to single phase liquid inside the tube could be obtained. Also, the analysis of the thermal resistances by condensation, wall conduction and air convection showed that the air convective heat transfer behavior can play a dominant role to the local heat transfer characteristics. Finally, in order to obtain the local heat flux distribution along the tube’s outer wall, a two

  13. Experimental investigations of an air curtain device subjected to external perturbations

    International Nuclear Information System (INIS)

    Havet, M.; Rouaud, O.; Solliec, C.

    2003-01-01

    Although plane air jets are often used as dynamic barriers to separate two environments, only a few works have explored their sensitivity to perturbations. We investigated the influence of sharp changes of pressure on the flow field of a device designed to avoid air-borne contamination. Laser tomography and tracer gas experiments clearly indicate that the air curtain is strongly sensitive to perturbations such as draughts. The results highlight that the control of air curtains used in open protection devices should be further investigated

  14. Estimation of indoor and outdoor ratios of selected volatile organic compounds in Canada

    Science.gov (United States)

    Xu, Jing; Szyszkowicz, Mieczyslaw; Jovic, Branka; Cakmak, Sabit; Austin, Claire C.; Zhu, Jiping

    2016-09-01

    Indoor air and outdoor air concentration (I/O) ratio can be used to identify the origins of volatile organic compounds (VOCs). I/O ratios of 25 VOCs in Canada were estimated based on the data collected in various areas in Canada between September 2009 and December 2011. The indoor VOC data were extracted from the Canadian Health Measures Survey (CHMS). Outdoor VOC data were obtained from Canada's National Air Pollution Surveillance (NAPS) Network. The sampling locations covered nine areas in six provinces in Canada. Indoor air concentrations were found higher than outdoor air for all studied VOCs, except for carbon tetrachloride. Two different approaches were employed to estimate the I/O ratios; both approaches produced similar I/O values. The I/O ratios obtained from this study were similar to two other Canadian studies where indoor air and outdoor air of individual dwellings were measured. However, the I/O ratios found in Canada were higher than those in European cities and in two large USA cities, possibly due to the fact that the outdoor air concentrations recorded in the Canadian studies were lower. Possible source origins identified for the studied VOCs based on their I/O ratios were similar to those reported by others. In general, chlorinated hydrocarbons, short-chain (C5, C6) n-alkanes and benzene had significant outdoor sources, while long-chain (C10sbnd C12) n-alkanes, terpenes, naphthalene and styrene had significant indoor sources. The remaining VOCs had mixed indoor and outdoor sources.

  15. Experimental study on axisymmetric air intake for the supersonic transport; choonsokukiyo jikutaishogata air intake no jikken kenkyu

    Energy Technology Data Exchange (ETDEWEB)

    Sato, T. [Institute of the Space and Astronautical Science,Tokyo (Japan); Takagi, I. [Kawasaki Heavy Industries, Ltd., Kobe (Japan); Kojima, T.; Kobayashi, H. [The University of Tokyo, Tokyo (Japan)

    1998-12-05

    Mixed-compression type axisymmetric air intakes for ATREX engine have been tested in the supersonic wind tunnel from Mach 0.5 to 4 since 1993. The throat area of the intake can be variable with a translating center spike to accomplish starting and off-design operation since the ATREX intake must work well over the wide flight Mach number up to 6. Here are presented effects of the intake design Mach number, the air bleed from a center spike and/or a cowl around the throat, an angle of attack and blunt nose of the spike on the intake performance characteristics, that is total pressure recovery and mass capture ratio. It is found that bleeding from the center spike and the cowl influences mainly on total pressure recovery and mass capture ratio respectively. The advantage of rounding properly off the spike nose is confirmed. Small center spike cone angle and/or blunt nose is sensitive to the angle of attack. (author)

  16. Experimental study of the effects of swirl and air dilution on biogas non-premixed flame stability

    Directory of Open Access Journals (Sweden)

    Rowhani Amir

    2015-01-01

    Full Text Available An experimental investigation of the stability limits of biogas in a swirling non-premixed burner has been carried out. A mixture of 60% methane (CH4 and 40% carbon dioxide (CO2 was used to reach the typical biogas composition. Vane swirlers with 30º, 45º and 60º angles were used to make the swirling air. The biogas stability limits and flame behavior under swirling conditions were tested. Besides, effects of air dilution with nitrogen (N2 and CO2 on biogas stability limits were investigated. The results show that using swirl can enhance the flame stability limits approximately four or five times comparing to non-swirling air stream. Adding N2/CO2 to the air had negative effects on the flame stability but no changes were observed in the flame structure. The maximum air dilution was also obtained when 27% and 15% N2 was added to the swirling air under strong and weak swirl, respectively.

  17. Transdermal uptake of diethyl phthalate and di(n-butyl) phthalate directly from air: Experimental verification

    DEFF Research Database (Denmark)

    Weschler, Charles J.; Bekö, Gabriel; Koch, Holger M.

    2015-01-01

    of phthalate esters. Objectives: This study investigated transdermal uptake, directly from air, of diethyl phthalate (DEP) and di(n-butyl) phthalate (DnBP) in humans. Methods: In a series of experiments, six human participants were exposed for 6 hr in a chamber containing deliberately elevated air...

  18. Experimental research on photocatalytic oxidation air purification technology applied to aircraft cabins

    DEFF Research Database (Denmark)

    Sun, Yuexia; Fang, Lei; Wyon, David P.

    2005-01-01

    The experiment presented in this report was performed in a simulated aircraft cabin to evalu-ate the air cleaning effects of two air purification devices using Photocatalytic Oxidation (PCO) technology. Objective physical, chemical and physiological measurements and subjec-tive human assessments ...

  19. Experimental and numerical analysis of air and radiant cooling systems in offices

    DEFF Research Database (Denmark)

    Corgnati, S. P.; Perino, M.; Fracastoro, G. V.

    2009-01-01

    This paper analyses office cooling systems based on all air mixing ventilation systems alone or coupled with radiant ceiling panels. This last solution may be effectively applied to retrofit all air systems that are no longer able to maintain a suitable thermal comfort in the indoor environment, ...

  20. Psychological mechanisms in outdoor place and weather assessment: towards a conceptual model

    Science.gov (United States)

    Knez, Igor; Thorsson, Sofia; Eliasson, Ingegärd; Lindberg, Fredrik

    2009-01-01

    The general aim has been to illuminate the psychological mechanisms involved in outdoor place and weather assessment. This reasoning was conceptualized in a model, tentatively proposing direct and indirect links of influence in an outdoor place-human relationship. The model was subsequently tested by an empirical study, performed in a Nordic city, on the impact of weather and personal factors on participants’ perceptual and emotional estimations of outdoor urban places. In line with our predictions, we report significant influences of weather parameters (air temperature, wind, and cloudlessness) and personal factors (environmental attitude and age) on participants’ perceptual and emotional estimations of outdoor urban places. All this is a modest, yet significant, step towards an understanding of the psychology of outdoor place and weather assessment.

  1. PCM-air heat exchangers for free-cooling applications in buildings: Experimental results of two real-scale prototypes

    International Nuclear Information System (INIS)

    Lazaro, Ana; Dolado, Pablo; Marin, Jose M.; Zalba, Belen

    2009-01-01

    Latent heat storage using phase change materials (PCM) can be used for free-cooling. In this application low air temperature is used to solidify the PCM during the night and then during the next day, the inside air of a building can be cooled down by exchanging heat with PCM. Short times for charging and discharging the PCM are required. PCM have in general low thermal conductivity, therefore the heat exchanger design is very important to fulfil free-cooling requirements. This paper presents an experimental setup for testing PCM-air real-scale heat exchangers and the results for two real-scale prototypes. Results show that a heat exchanger using a PCM with lower thermal conductivity and lower total stored energy, but adequately designed, has higher cooling power and can be applied for free-cooling

  2. Experimental and computational study and development of the bituminous coal entrained-flow air-blown gasifier for IGCC

    International Nuclear Information System (INIS)

    Abaimov, N A; Osipov, P V; Ryzhkov, A F

    2016-01-01

    In the paper the development of the advanced bituminous coal entrained-flow air- blown gasifier for the high power integrated gasification combined cycle is considered. The computational fluid dynamics technique is used as the basic development tool. The experiment on the pressurized entrained-flow gasifier was performed by “NPO CKTI” JSC for the thermochemical processes submodel verification. The kinetic constants for Kuznetsk bituminous coal (flame coal), obtained by thermal gravimetric analysis method, are used in the model. The calculation results obtained by the CFD model are in satisfactory agreements with experimental data. On the basis of the verified model the advanced gasifier structure was suggested which permits to increase the hydrogen content in the synthesis gas and consequently to improve the gas turbine efficiency. In order to meet the specified requirements vapor is added on the second stage of MHI type gasifier and heat necessary for air gasification is compensated by supplemental heating of the blasting air. (paper)

  3. Experimental study on 800 nm femtosecond laser ablation of fused silica in air and vacuum

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Shi-zhen, E-mail: xusz@uestc.edu.cn [School of Physical Electronics, University of Electronic Science and Technology of China, Chengdu 610054 (China); Research Center of Laser Fusion, China Academy of Engineering Physics, Mianyang 621900 (China); Yao, Cai-zhen; Liao, Wei [Research Center of Laser Fusion, China Academy of Engineering Physics, Mianyang 621900 (China); Yuan, Xiao-dong, E-mail: yxd66my@163.com [Research Center of Laser Fusion, China Academy of Engineering Physics, Mianyang 621900 (China); Wang, Tao [School of Physical Electronics, University of Electronic Science and Technology of China, Chengdu 610054 (China); Research Center of Laser Fusion, China Academy of Engineering Physics, Mianyang 621900 (China); Zu, Xiao-tao [School of Physical Electronics, University of Electronic Science and Technology of China, Chengdu 610054 (China)

    2016-10-15

    Ablation rates of fused silica were studied as a function of femtosecond laser pulse fluences (0.7–41 J/cm{sup 2}) in air and vacuum. The experiment was conducted by using a Ti:sapphire laser that emits radiation at 800 nm with a pulse width of 35 fs and a repetition rate of 10 Hz. The morphology and ablation depth of laser-induced damage crater were evaluated by using optical microscopy and scanning electron microscopy (SEM). Ablation rates were calculated from the depth of craters induced by multiple laser pulses. Results showed that two ablation regimes, i.e. non-thermal and thermal ablation co-existed in air and vacuum at low and moderate fluences. A drop of ablation rate was observed at high fluence (higher than 9.5 J/cm{sup 2}) in air. While in vacuum, the ablation rate increased continuously with the increasing of laser fluence and much higher than that in air. The drop of ablation rate observed at high fluence in air was due to the strong defocusing effects associated with the non-equilibrium ionization of air. Furthermore, the laser-induced damage threshold (LIDT), which was determined from the relationship between crater area and the logarithm of laser energy, was found to depend on the number of incident pulses on the same spot, and similar phenomenon was observed in air and vacuum.

  4. Experimental investigation on the performance of an impinging jet solar air heater

    Directory of Open Access Journals (Sweden)

    T. Rajaseenivasan

    2017-03-01

    Full Text Available Investigation on an impinging jet solar air heater is performed and reported in this work. The air is supplied through an impinging jet pipe which contains the nozzles to distribute the air in the solar air heater. The air is released from the jet strikes the absorber plate which increases the heat transfer rate by creating turbulent flow in the collector. This study is focused on the parameters that affect the heat transfer characteristics and compared with conventional solar air heater. The system is examined by varying the angle of attack (0°, 10°, 20°, 30°, 60° and 90° and the nozzle diameter (3 mm, 5 mm and 7 mm in the air mass flow rate range of 0.012–0.016 kg/s. The study revealed that the highest performance is achieved with the 30° angle of attack, and the lowest performance is recorded with the 0°. The reduction in jet diameter increases the pressure loss in the collector. The better system performance is observed with the 5 mm diameter hole. The maximum thermal enhancement factor of 2.19 and efficiency of 55.8% are reached with the flow rate of 0.016 kg/s.

  5. Experimental Investigation of an Automobile Air-Conditioning System using Integrated Brushless Direct Current Motor Rotary Compressor

    Directory of Open Access Journals (Sweden)

    Sukri M.F.

    2016-01-01

    Full Text Available The present study presents an experimental investigation on the effect of condenser air inlet temperature and dimensionless parameter of X on the performance of automobile air-conditioning (AAC system using integrated brushless direct current motor-rotary compressor and electronic expansion valve. The other components of AAC system are from original component of AAC system used for medium size passenger car. The experimental results showed that the increment of the condenser air inlet temperature and X caused an increase in condensing temperature, cooling capacity and compressor work, while decreasing the coefficient of performance (COP. Meanwhile, the evaporating temperature increase with the increment of condenser air inlet temperature, but decrease with decrement of X. In general, AAC system have to work at higher value of X in order to produce more cooling capacity, thereby increment in compressor work also occurs due to energy balance. However, at higher value of X, the COP of the system dropped due to dominant increase in compressor power, as opposed to a rise in cooling capacity. Due to this reason, the best operation of this compressor occurs at X = 4.96 for constant T5 (35ºC, or at T5 = 30ºC for constant X (4.96.

  6. Experimental studies of applicability of the wet air oxidation for purification liquid radioactive waste

    International Nuclear Information System (INIS)

    Sergienko, V. I.; Dobrzansky, V. G.

    2005-01-01

    The scheme of handling with liquid radioactive waste (LRW) accepted to exploitation at atomic electric station (AWS) is often connected with evaporating technologies. In this case vat residues of evaporating systems with activity 10 5 -10 6 Bq/1 and containing to 200-300 g/1 of salts are delivered up to LRW storages for lasting keeping. This schema does not correlate to the modern safety standards of handling with LRW, therefore at present numerous works are being carried on including those using technology of accumulated vat residues processing. Some successful experiments on sorption purification of high-salt LRW from cesium radionuclides giving the principal contribution into the total activity of a certain LRW are known. Unfortunately, attempts of sorption purification of the vat residues from other long-lived radionuclides (mainly from 60 Co-radionuclide) were unsuccessful up to the present time. It is found with the fact that the vat residues contain a considerable amount of complexing agent producing stable complexes with transition metal radionuclides including those of 60 Co. Extreme oxidation of the vat residues for decomposition of radioactive organic complexes is one of the solutions of this problem. The works related to oxidation of LRW including the AES vat residues with ozone, hydrogen peroxide as well as photo catalytic and electrochemical oxidation are known, however, possibilities of wet air oxidation (WAO) for LRW processing are not studied till the present time. Condition for decomposition of cobalt complex compounds and necessary excess of oxidizing agent may be easily attained with WAO usage. The necessary experiments were carried out at the experimental plant with the great interface surface (oxygen-solutions) equal to 400m -1 and 3 mm probe bed thickness. The heating time of the reactor to the working temperature 250 .deg. C did not exceed 50 seconds. 20... 50-fold oxidizer excess was achieved by the initial oxygen pressure into the reactor

  7. Experimental Evaluation of Discharge Characteristics in Inhomogeneous Fields under Air Flow

    DEFF Research Database (Denmark)

    Vogel, Stephan; Holbøll, Joachim

    2018-01-01

    voltages and a laminar air flow up to 22 m/s. In the first setup, the gap was exposed to a variable DC potential of up to 100 kV in order to create space charges in the vicinity of the electrode. The impact of the air flow on partial discharges and the dynamic behavior of the space charges is evaluated...... by means of partial discharge measurement and ultraviolet photography. The results show that the air flow increases the frequency of partial discharges in the gap due to an increased rate of space charge removal in the high field area around the tip of the electrode. The partial discharge behavior shows...... higher dependency on air flow at positive tip polarity as compared to the negative polarity. In the second setup, the standard impulse voltage created by a multistage impulse voltage generator was superimposed to a DC voltage, which continuously created corona and space charges around the tip...

  8. Experimental Assessment of residential split type air-conditioning systems using alternative refrigerants to R-22 at high ambient temperatures

    International Nuclear Information System (INIS)

    Joudi, Khalid A.; Al-Amir, Qusay R.

    2014-01-01

    Highlights: • R290, R407C and R410A in residential split A/C units at high ambient. • 1 and 2 TR residential air conditioners with R22 alternatives at high ambient. • Residential split unit performance at ambients up to 55 °C with R22 alternatives. - Abstract: Steady state performance of residential air conditioning systems using R22 and alternatives R290, R407C, R410A, at high ambient temperatures, have been investigated experimentally. System performance parameters such as optimum refrigerant charge, coefficient of performance, cooling capacity, power consumption, pressure ratio, power per ton of refrigeration and TEWI environmental factor have been determined. All refrigerants were tested in the cooling mode operation under high ambient air temperatures, up to 55 °C, to determine their suitability. Two split type air conditioner of 1 and 2 TR capacities were used. A psychrometric test facility was constructed consisting of a conditioned cool compartment and an environmental duct serving the condenser. Air inside the conditioned compartment was maintained at 25 °C dry bulb and 19 °C wet bulb for all tests. In the environmental duct, the ambient air temperature was varied from 35 °C to 55 °C in 5 °C increments. The study showed that R290 is the better candidate to replace R22 under high ambient air temperatures. It has lower TEWI values and a better coefficient of performance than the other refrigerants tested. It is suitable as a drop-in refrigerant. R407C has the closest performance to R22, followed by R410A

  9. Experimental study on air ingress during a primary pipe rupture accident with a graphite reactor core simulator

    International Nuclear Information System (INIS)

    Takeda, Tetsuaki; Hishida, Makoto; Baba, Shinichi

    1991-11-01

    When a primary coolant pipe of a High Temperature Gas Cooled Reactor (HTGR) ruptures, helium gas in the reactor core blows out into the container, and the primary cooling system reduces the pressure. After the pressures are balanced between the reactor and the container, air is expected to enter into the reactor core from the breach. It seems to be probable that the graphite structures is oxidized by air. Hence, it is necessary to investigate the air ingress process and the behavior of the generating gases by the oxidation reactions. The previous experimental study is performed on the molecular diffusion and natural convection of the two component gas mixtures using a test model simulating simply the reactor. Objective of the study was to investigate the air ingress process during the early stage of the primary pipe rupture accident. However, since the model did not have any kind of graphite components, the reaction between graphite and oxygen was not simulated. The present model includes the reactor core and the high temperature plenum simulators made of graphite. The major results obtained in the present study are summarized in the followings: (1) The air ingress process with graphite oxidation reaction is similar to that without the reaction qualitatively. (2) When the reactor core simulator is maintained at low temperatures (lower than 450degC), the initiation time of the natural circulation of air is almost equal to that of the natural circulation of nitrogen. On the other hand, when the temperature of the reactor core simulator is high (more than 500degC), the initiation time of the natural circulation of air is earlier than that of nitrogen. (3) When the temperature of the reactor core simulator is higher than 600degC, oxygen is almost dissipated by the graphite structures. When the temperature of the reactor core simulator is below 700degC, carbon dioxide mainly is generated by the oxidation reactions. (author)

  10. Design considerations and experimental observations for the TAMU air-cooled reactor cavity cooling system for the VHTR

    Energy Technology Data Exchange (ETDEWEB)

    Sulaiman, S. A., E-mail: shamsulamri@tamu.edu; Dominguez-Ontiveros, E. E., E-mail: elvisdom@tamu.edu; Alhashimi, T., E-mail: jbudd123@tamu.edu; Budd, J. L., E-mail: dubaiboy@tamu.edu; Matos, M. D., E-mail: mailgoeshere@gmail.com; Hassan, Y. A., E-mail: yhasssan@tamu.edu [Department of Nuclear Engineering, Texas A and M University, College Station, TX, 77843-3133 (United States)

    2015-04-29

    The Reactor Cavity Cooling System (RCCS) is a promising passive decay heat removal system for the Very High Temperature Reactor (VHTR) to ensure reliability of the transfer of the core residual and decay heat to the environment under all off-normal circumstances. A small scale experimental test facility was constructed at Texas A and M University (TAMU) to study pertinent multifaceted thermal hydraulic phenomena in the air-cooled reactor cavity cooling system (RCCS) design based on the General Atomics (GA) concept for the Modular High Temperature Gas-Cooled Reactor (MHTGR). The TAMU Air-Cooled Experimental Test Facility is ⅛ scale from the proposed GA-MHTGR design. Groundwork for experimental investigations focusing into the complex turbulence mixing flow behavior inside the upper plenum is currently underway. The following paper illustrates some of the chief design considerations used in construction of the experimental test facility, complete with an outline of the planned instrumentation and data acquisition methods. Computational Fluid Dynamics (CFD) simulations were carried out to furnish some insights on the overall behavior of the air flow in the system. CFD simulations assisted the placement of the flow measurement sensors location. Preliminary experimental observations of experiments at 120oC inlet temperature suggested the presence of flow reversal for cases involving single active riser at both 5 m/s and 2.25 m/s, respectively and four active risers at 2.25 m/s. Flow reversal may lead to thermal stratification inside the upper plenum by means of steady state temperature measurements. A Particle Image Velocimetry (PIV) experiment was carried out to furnish some insight on flow patterns and directions.

  11. FY-09 Report: Experimental Validation of Stratified Flow Phenomena, Graphite Oxidation, and Mitigation Strategies of Air Ingress Accidents

    Energy Technology Data Exchange (ETDEWEB)

    Chang H. Oh; Eung S. Kim

    2009-12-01

    The Idaho National Laboratory (INL), under the auspices of the U.S. Department of Energy, is performing research and development that focuses on key phenomena important during potential scenarios that may occur in the Next Generation Nuclear Plant (NGNP)/Gen-IV very high temperature reactor (VHTR). Phenomena Identification and Ranking Studies to date have identified that an air ingress event following on the heels of a VHTR depressurization is a very important incident. Consequently, the development of advanced air ingress-related models and verification and validation data are a very high priority for the NGNP Project. Following a loss of coolant and system depressurization incident, air will enter the core through the break, leading to oxidation of the in-core graphite structure and fuel. If this accident occurs, the oxidation will accelerate heat-up of the bottom reflector and the reactor core and will eventually cause the release of fission products. The potential collapse of the core bottom structures causing the release of CO and fission products is one of the concerns. Therefore, experimental validation with the analytical model and computational fluid dynamic (CFD) model developed in this study is very important. Estimating the proper safety margin will require experimental data and tools, including accurate multidimensional thermal-hydraulic and reactor physics models, a burn-off model, and a fracture model. It will also require effective strategies to mitigate the effects of oxidation. The results from this research will provide crucial inputs to the INL NGNP/VHTR Methods Research and Development project. The second year of this three-year project (FY-08 to FY-10) was focused on (a) the analytical, CFD, and experimental study of air ingress caused by density-driven, stratified, countercurrent flow; (b) advanced graphite oxidation experiments and modeling; (c) experimental study of burn-off in the core bottom structures, (d) implementation of advanced

  12. Effect of the environmental stimuli upon the human body in winter outdoor thermal environment

    DEFF Research Database (Denmark)

    Sakoi, Tomonori; Kondo, Emi; Ishii, Jin

    2013-01-01

    the psychological thermal responses of the human body and winter outdoor thermal environment variables. Subjective experiments were conducted in the winter outdoor environment. Environmental factors and human psychological responses were measured. The relationship between the psychological thermal responses...... of the human body and the outdoor thermal environment index ETFe (enhanced conduction-corrected modified effective temperature) in winter was shown. The variables which influence the thermal sensation vote of the human body are air temperature, long-wave thermal radiation and short-wave solar radiation....... The variables that influence the thermal comfort vote of the human body are air temperature, humidity, short-wave solar radiation, long-wave thermal radiation, and heat conduction. Short-wave solar radiation, and heat conduction are among the winter outdoor thermal environment variables that affect...

  13. Formal education in outdoor studies: introduction

    OpenAIRE

    Prince, Heather

    2015-01-01

    Regional cultural perspectives involve outdoor studies in different ways in formal curricula. This section focuses on Western Europe, particularly the UK and Scandinavia, although also has a more international reach in Backman’s consideration of the training of teachers and in place-responsive teaching as described by Mannion and Lynch. ‘Outdoor studies’ is not seen in curricula per se but under various more specialised aspects such as outdoor play, outdoor learning, environmental education, ...

  14. Experimental study on mass transfer of contaminants through an enthalpy recovery unit with polymer membrane foils

    DEFF Research Database (Denmark)

    Nie, Jinzhe; Fang, Lei

    2014-01-01

    Laboratory experimental studies were conducted to investigate the mass transfer of contaminants through a total heat recovery unit with polymer membranes foils. The studies were conducted in twin climate chambers which simulated outdoor and indoor thermal climates. One manufacturd total heat...... chemical gases were used to simulate air contaminants. The concentrations of dosed contaminants in the supply and exhaust air upstream and downstream of the total heat recovery unit were measured with Multi-Gas Monitor Innova 1316 in real time. Experiment results showed that 5% to 9% of dosed contaminants...... could transfer from exhaust air to supply air through the enthalpy recovery unit. The mass transfer efficiency of contaminants was independent of the hygro-thermal differences between indoor and outdoor climate conditions. The mass transfer ratio of the chemical contaminants in the total heat recovery...

  15. Fear of moving outdoors and development of outdoor walking difficulty in older people

    DEFF Research Database (Denmark)

    Rantakokko, Merja; Mänty, Minna; Iwarsson, Susanne

    2009-01-01

    To study which individual characteristics and environmental factors correlate with fear of moving outdoors and whether fear of moving outdoors predicts development of mobility limitation.......To study which individual characteristics and environmental factors correlate with fear of moving outdoors and whether fear of moving outdoors predicts development of mobility limitation....

  16. Outdoor Education for Bereaved Children?

    Science.gov (United States)

    Renner, Hans-Georg

    2011-01-01

    For many outdoor education providers, bereaved children and young people at first appear to be a new target audience. A new target audience naturally raises questions of programme planning and can give the provider a pressurised need to succeed: "Do I as the organiser have to develop a whole new programme?", "May I be required to provide some form…

  17. Taking the New Curriculum Outdoors

    Science.gov (United States)

    Forsey, Katherine

    2014-01-01

    A review of research on outdoor learning by Rickinson "et al." (2004) highlights the demonstrable educational benefits and provides a source of support, justification and an evidence base for educators looking to undertake more learning outside the classroom. Bird (2004) also reviewed the widely reported health benefits of outdoor…

  18. Signature Pedagogies in Outdoor Education

    Science.gov (United States)

    Thomas, Glyn

    2015-01-01

    The new National health and physical education curriculum in Australia includes outdoor education activities as a viable way to achieve intended learning outcomes. However, most health and physical education teacher education courses do not provide a strong focus on the theories, skills and pedagogies that are unique to the effective use of…

  19. Multilayer Controller for Outdoor Vehicle

    DEFF Research Database (Denmark)

    Reske-Nielsen, Anders; Mejnertsen, Asbjørn; Andersen, Nils Axel

    2006-01-01

    A full software and hardware solution has been designed, implemented and tested for control of a small agricultural automatic tractor. The objective was to realise a user-friendly, multi-layer controller architecture for an outdoor platform. The collaborative research work was done as a part of a...

  20. Expanding & strengthening outdoor recreation research

    Science.gov (United States)

    Walter S. Hopkins

    1971-01-01

    Though the Forest Service has pioneered in outdoor recreation research, the funding for recreation research has been inadequate. Specific needs for research are outlined. There is a need to define recreation and recreation research in terms that busy legislators can understand.

  1. Should people be physically active outdoors on smog alert days?

    Science.gov (United States)

    Campbell, Monica E; Li, Qian; Gingrich, Sarah E; Macfarlane, Ronald G; Cheng, Shouquan

    2005-01-01

    Given the importance of physical activity to well-being, there is a need to encourage people to be physically active year-round. At the same time, many people are vulnerable to adverse health effects from air pollution, especially on smog alert days. This study was undertaken to determine when air pollution levels tend to be lowest so that the public can modify strenuous outdoor activity accordingly. Existing hourly air pollution data for Toronto were analyzed to determine how pollutant levels varied from hour to hour throughout each 24-hour day, to identify the times when pollution levels are at their lowest on average. Pollutant levels vary throughout the day, with concentrations of some pollutants (such as ozone, particles and sulphur dioxide) being highest during mid-day, and others (such as carbon monoxide and nitrogen dioxide) being highest with morning rush hour. Overall, pollutant concentrations tend to be lowest before seven a.m. and after eight p.m. The public should be encouraged to maintain regular physical activity outdoors while monitoring any air pollution-related symptoms. The intensity of outdoor activity should be reduced, or activities replaced with indoor exercise, at those Air Quality Index (AQI) levels that trigger individual symptoms and when AQI values exceed 50. Where possible, strenuous activity should be taken when and where air pollution levels tend to be lowest, namely early in the morning and in low-traffic areas. More research is required to guide development of health protective advice on exercising when air quality is poor.

  2. A Phenomenology of Outdoor Education Leader Experiences

    Science.gov (United States)

    Field, Stephanie C.; Lauzon, Lara L.; Meldrum, John T.

    2016-01-01

    Limited qualitative research exists on the experiences of outdoor education leaders. The purpose of this phenomenological study was to explore the job-related experiences of outdoor education leaders within and outside the workplace. Five participants who had experience as outdoor education leaders completed in-depth, one-on-one interviews about…

  3. Benchmarking Outdoor Expeditionary Program Risk Management Strategies

    Science.gov (United States)

    Meerts-Brandsma, Lisa; Furman, Nate; Sibthorp, Jim

    2017-01-01

    In 2003, the University of Utah and the National Outdoor Leadership School (NOLS) completed a study that developed a risk management taxonomy in the outdoor adventure industry and assessed how different outdoor expeditionary programs (OEPs) managed risk (Szolosi, Sibthorp, Paisley, & Gookin, 2003). By unifying the language around risk, the…

  4. Hinterbrand Lodge Outdoor Education Center. Program Information.

    Science.gov (United States)

    Dependents Schools (DOD), Washington, DC. European Area.

    Describing Department of Defense Dependents Schools Europe (DODDSEUR) use of Hinterbrand Lodge Outdoor Education Center, this document is directed to sponsors wishing to take groups to Hinterbrand for one or more of the five program options (outdoor education week, teacher weekend, school-designed outdoor education program, administrative faculty…

  5. Outdoor Leadership Skills: A Program Perspective

    Science.gov (United States)

    Shooter, Wynn; Sibthorp, Jim; Paisley, Karen

    2009-01-01

    Successful hiring, training, and pairing or grouping of staff requires administrators to consider the relationship between their programs' goals and the specific outdoor leadership skills of individual leaders. Authors have divided outdoor leadership skills into a three-category structure, and models of outdoor leadership have focused on skills…

  6. 9 CFR 3.52 - Facilities, outdoor.

    Science.gov (United States)

    2010-01-01

    ... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Facilities, outdoor. 3.52 Section 3.52 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE ANIMAL... outdoors when the atmospheric temperature falls below 40 °F. (d) Protection from predators. Outdoor housing...

  7. Objective Method for Selecting Outdoor Reporting Conditions for Photovoltaic Performance

    International Nuclear Information System (INIS)

    Maish, A.

    1999-01-01

    Outdoor performance of photovoltaic modules and systems depends on prevailing conditions at the time of measurement. Outdoor test conditions must be relevant to device performance and readily attainable. Flat-plate, nonconcentrator PV device performance is reported with respect to fixed conditions referred to as Standard Reporting Conditions (SRC) of 1 kW/m plane of array total irradiance, 25 C device temperature, and a reference spectral distribution at air mass 1.5 under certain atmospheric conditions. We report a method of analyzing historical meteorological and irradiance data to determine the range of outdoor environmental parameters and solar irradiance components that affect solar collector performance when the SRC 1 kW/m total irradiance value occurs outdoors. We used data from the 30 year U.S. National Solar Radiation Data Base (NSRDB) , restricting irradiance conditions to within +/- 25 W/m of 1 kW/m on a solar tracking flat-plate collector. The distributions of environmental parameter values under these conditions are non-Gaussian and site dependent. Therefore the median, as opposed to the mean, of the observed distributions is chosen to represent appropriate outdoor reporting conditions. We found the average medians for the direct beam component (834 W/m), ambient temperature (24.4 C), total column water vapor (1.4 cm), and air mass (1.43) are near commonly used SRC values. Average median wind speed (4.4 m/s) and broadband aerosol optical depth (0.08) were significantly different from commonly used values

  8. Experimental study of an air conditioning system to control a greenhouse microclimate

    International Nuclear Information System (INIS)

    Attar, I.; Naili, N.; Khalifa, N.; Hazami, M.; Lazaar, M.; Farhat, A.

    2014-01-01

    Highlights: • Contribution in the control of the greenhouse microclimate for pepper cultivation. • The energy storing in the ground and in the water ensure the greenhouse heating. • The circulation of the cold water in the exchangers ensures the greenhouse cooling. • The system makes the greenhouse appropriate for the pepper cultivation whole year. - Abstract: In this papper, a thermal model is developed to investigate the possibility to use the ground thermal energy for the greenhouse heating or cooling. A control system of the ground heat storing is integrated in a chapel greenhouse located in the premises of the Technology and Research Energy Center, Tunis, Tunisia. Polypropylene capillary heat exchangers, suspended in the air and buried into the ground of the greenhouse, are used to store or destore solar energy excess. During the day, the air-suspended exchangers recuperate the solar energy in excess. This recuperated energy is then stored into the ground through the buried exchangers. At night the stored thermal energy is brought back by the suspended exchangers to heat the greenhouse air. The purpose of this study is to contribute in the greenhouse microclimate control. In order to maintain the greenhouse air temperature at 20 °C, suitable for a defined agriculture, the solar energy and the cold water are respectively used for heating and cooling the greenhouse inside air. The design and construction of a chapel greenhouse equipped with the control system is carried out. The studied system is used, at the same time for; heating, cooling the greenhouse air and storing the solar energy in excess. Experiments were conducted during the years 2012–2013, to evaluate the effectiveness of the control system achieved. The measured values of the greenhouse air temperatures with and without the control system are discussed

  9. Air

    International Nuclear Information System (INIS)

    Gugele, B.; Scheider, J.; Spangl, W.

    2001-01-01

    In recent years several regulations and standards for air quality and limits for air pollution were issued or are in preparation by the European Union, which have severe influence on the environmental monitoring and legislation in Austria. This chapter of the environmental control report of Austria gives an overview about the legal situation of air pollution control in the European Union and in specific the legal situation in Austria. It gives a comprehensive inventory of air pollution measurements for the whole area of Austria of total suspended particulates, ozone, volatile organic compounds, nitrogen oxides, sulfur dioxide, carbon monoxide, heavy metals, benzene, dioxin, polycyclic aromatic hydrocarbons and eutrophication. For each of these pollutants the measured emission values throughout Austria are given in tables and geographical charts, the environmental impact is discussed, statistical data and time series of the emission sources are given and legal regulations and measures for an effective environmental pollution control are discussed. In particular the impact of fossil-fuel power plants on the air pollution is analyzed. (a.n.)

  10. Relationship between indoor and outdoor carbonaceous particulates in roadside households

    Energy Technology Data Exchange (ETDEWEB)

    Funasaka, K.; Miyazaki, T.; Tsuruho, K. [Osaka City Institute of Public Health and Environmental Sciences (Japan); Tamura, K. [The National Institute for Minamata Disease, Kumamoto (Japan); Mizuno, T. [Mie University (Japan). Dept. of Chemistry for Materials; Kuroda, K. [Osaka City University Medical School (Japan). Dept. of Preventive Medicine and Environmental Health

    2000-07-01

    Concentrations of particulate matter (PM) and carbonaceous particulates in indoor and outdoor air at roadside private households were measured in Osaka, Japan. The particulate samples were collected on filters using a portable AND sampler capable of separating particles into three different size ranges: over 10 {mu}m, 2-10 {mu}m (coarse) and below 2 {mu}m (fine) in aerodynamic diameter. The filters were weighed and then analyzed for elemental carbon (EC) and organic carbon (OC) by thermal oxidation using a CHN CORDER. The results showed that indoor fine PM concentration is considerably affected by fine EC and the fine EC in indoor air is significantly correlated to that in outdoor air, r = 0.86 (n = 30, p < 0.001). A simple estimation from EC content ratio in diesel exhaust particles indicated that about 30% of indoor particulates of less than 10 {mu}m (PM10) were contributed from diesel exhaust. Additionally, the size characteristics of outdoor PM at roadside and background sites were examined using Andersen Cascade Impactors. (author)

  11. Experimental study on airflow fluctuation characteristic of an underfloor air supply terminal unit

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Jinping [School of Electric Power, South China University of Technology, Guangzhou 510640 (China); State Key Laboratory of Subtropical Building Science, South China University of Technology, Guangzhou 510640 (China); Wu, Yanfang [Design Institute of Guangzhou Metro Corporation, Guangzhou 510010 (China)

    2010-11-15

    In order to investigate dynamic characteristic of underfloor air supply terminal unit, an IFV900A hot-wire anemometer was used to measure the corresponding velocity field. Turbulence intensity and power spectrum density exponent of air velocity signal were analyzed. The result showed that the outlet velocity distribution of underfloor air supply terminal unit was uniform. With increment of height, the velocity distribution trends to be uniform. Two velocity attenuation regions appear during airflow development. Turbulence intensity changes obviously with height. It is lower than that of mechanical wind. Turbulence intensity goes up with the increment of jetting distance. Power spectrum density exponent trends to the value of natural wind with increase of jetting distance and decrease of wind velocity. The exponent value approaches to the value of typical natural wind for the air velocity is 0.5 m/s under high supply air rate. With airflow diffusion, the fluctuation characteristic of airflow varies obviously with the jetting direction. The fluctuation characteristic of airflow changes to that of natural wind with the increase of height which can improve comfort of indoor environment. (author)

  12. Respiratory alterations due to urban air pollution: An experimental study in rats

    International Nuclear Information System (INIS)

    Saldiva, P.H.N.; King, M.; Delmonte, V.L.C.; Macchione, M.; Parada, M.A.C.; Daliberto, M.L.; Sakae, R.S.; Criado, P.M.P.; Silveira, P.L.P.; Zin, W.A.; Boehm, G.M.

    1992-01-01

    In order to assess the adverse effects of urban levels of air pollution, rats were used as biological indicators in a chronic exposure experiment. Animals were housed for 6 months in the center of Sao Paulo and were compared to controls kept for the same period in a clean area. Pollution levels were obtained from a State air pollution monitoring station, 200 m distant from the exposure place, which provided the levels of CO, SO 2 , particulates, and ozone. The animals were submitted to several tests focusing on the respiratory system, comprising pulmonary function tests, studies on mucociliary clearance and mucus rheology, histochemical evaluation of airways, bronchoalveolar lavage, and ultrastructural studies of the epithelium of the airways. Rats exposed to air pollution developed secretory cell hyperplasia in the airways, ultrastructural ciliary alterations, and a more rigid mucus, changes that caused mucociliary clearance impairment. In addition, nasal resistance and the number of inflammatory cells recovered by bronchoalveolar lavage were increased in air pollution exposed animals. The results obtained in the present investigation suggest that chronic exposure to urban levels of air pollution may cause respiratory lesions in rats

  13. Outdoor recreation-related outdoor education: scope of the research (1995-2010) I

    OpenAIRE

    Lynch, Philippa

    2012-01-01

    Article made available with the permission of the New Zealand Journal of Outdoor Education. This article reports on the scope of the New Zealand outdoor recreationrelated outdoor education research literature published from January 1995 to June 2010. It draws on the literature covered by the 2010 Sport and Recreation New Zealand-funded Outdoor Recreation Research Stocktake, which included outdoor education material. This article is divided into two parts, both published in this issue of th...

  14. Experimental study on occurrence-time ratio measurements of air entrainment in a suction sump

    International Nuclear Information System (INIS)

    Inagaki, K; Funaki, J; Hirata, K

    2009-01-01

    In order to get accurate measurements of air entrainment in a suction sump, we design some new simple bubble sensors, which can detect the existence of air bubbles inside a suction pipe with no disturbances by the sensors and with a fine spatial resolution. We force on an intermittency factor γ, that is, an occurrence-time ratio of the air entrainment, and compare the result by the present sensor with those by conventional two methods; namely, visual and auditory ones. As a result, we show the criteria which specify lower-accuracy conditions in the conventional methods. By the visual method, the accuracy of the γ becomes low, when γ is less than 0.05. By the auditory method, the accuracy of γ becomes low, when the submergence depth S of the suction pipe is close to the critical one S c .

  15. Experimental study of combustion characteristics of isolated pockets of hydrogen-air mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Manoubi, M.; LaFleche, M. [Univ. of Ottawa, Dept. of Mechanical Engineering, Ottawa, Ontario (Canada); Liang, Z., E-mail: zhe.liang@cnl.ca [Canadian Nuclear Laboratories, Chalk River, Ontario (Canada); Radulescu, M. [Univ. of Ottawa, Dept. of Mechanical Engineering, Ottawa, Ontario (Canada)

    2016-06-15

    This paper examines the dynamics of unconfined hydrogen-air flames and the criterion for flame propagation between neighbouring pockets of reactive gas separated by air using the soap bubble technique. The combustion events were visualized using high-speed schlieren or large-scale shadowgraph systems. It was revealed that for sufficiently lean hydrogen-air mixtures characterized by low flame speeds, buoyancy effects become important at small scales. The critical radius of hemispherical flame that will rise due to buoyancy is highly sensitive to the hydrogen concentration. The test results demonstrate that for transition of a flame between neighbouring pockets, the separation distance between the bubbles is mainly determined by the expansion ratio for near stoichiometric mixture, but it becomes much smaller for leaner mixtures because the flame kernel rises due to buoyant effects before the flame can reach the second bubble, thus the separation distance is no longer governed by the expansion ratio. (author)

  16. An experimental and numerical study of nitrogen oxide formation mechanisms in ammonia-hydrogen-air flames

    Science.gov (United States)

    Kumar, Praveen

    The demand for sustainable alternative fuels is ever-increasing in the power generation, transportation, and energy sectors due to the inherent non-sustainable characteristics and political constraints of current energy resources. A number of alternative fuels derived from cellulosic biomass, algae, or waste are being considered, along with the conversion of electricity to non-carbon fuels such as hydrogen or ammonia (NH3). The latter is receiving attention recently because it is a non-carbon fuel that is readily produced in large quantities, stored and transported with current infrastructure, and is often a byproduct of biomass or waste conversion processes. However, pure or anhydrous ammonia combustion is severely challenging due to its high auto-ignition temperature (650 °C), low reactivity, and tendency to promote NOx formation. As such, the present study focuses on two major aspects of the ammonia combustion. The first is an applied investigation of the potential to achieve pure NH3 combustion with low levels of emissions in flames of practical interest. In this study, a swirl-stabilized flame typically used in fuel-oil home-heating systems is optimized for NH3 combustion, and measurements of NO and NH3 are collected for a wide range of operating conditions. The second major focus of this work is on fundamental investigation of NO x formation mechanisms in flames with high levels of NH3 in H2. For laminar premixed and diffusion jet flames, experimental measurements of flame speeds, exhaust-gas sampling, and in-situ NO measurements (NO PLIF) are compared with numerically predicted flames using complex chemical kinetics within CHEMKIN and reacting CFD codes i.e., UNICORN. From the preliminary testing of the NOx formation mechanisms, (1) Tian (2) Konnov and (3) GRI-Mech3.0 in laminar premixed H2/NH 3 flames, the Tian and Konnov mechanisms are found to capture the reduction in measured flame speeds with increasing NH3 in the fuel mixture, both qualitatively and

  17. Experimental investigation of the formaldehyde removal mechanisms in a dynamic botanical filtration system for indoor air purification.

    Science.gov (United States)

    Wang, Zhiqiang; Pei, Jingjing; Zhang, Jensen S

    2014-09-15

    Botanical filtration has been proved to be effective for indoor gas pollutant removal. To understand the roles of different transport, storage and removal mechanism by a dynamic botanical air filter, a series of experimental investigations were designed and conducted in this paper. Golden Pothos (Epipremnum aureum) plants was selected for test, and its original soil or activated/pebbles root bed was used in different test cases. It was found that flowing air through the root bed with microbes dynamically was essential to obtain meaningful formaldehyde removal efficiency. For static potted plant as normally place in rooms, the clean air delivery rate (CADR), which is often used to quantify the air cleaning ability of portable air cleaners, was only ∼ 5.1m(3)/h per m(2) bed, while when dynamically with air flow through the bed, the CADR increased to ∼ 233 m(3)/h per m(2) bed. The calculated CADR due to microbial activity is ∼ 108 m(3)/h per m(2) bed. Moisture in the root bed also played an important role, both for maintaining a favorable living condition for microbes and for absorbing water-soluble compounds such as formaldehyde. The role of the plant was to introduce and maintain a favorable microbe community which effectively degraded the volatile organic compounds adsorbed or absorbed by the root bed. The presence of the plant increased the removal efficiency by a factor of two based on the results from the bench-scale root bed experiments. Copyright © 2014 Elsevier B.V. All rights reserved.

  18. A dynamic model and an experimental study for the internal air and soil temperatures in an innovative greenhouse

    International Nuclear Information System (INIS)

    Joudi, Khalid A.; Farhan, Ammar A.

    2015-01-01

    Highlights: • Simulation model for internal Greenhouse temperature including soil reflectance. • Greenhouse soil heat exchange affects internal temperature by approximately 12%. • Solar air heaters as greenhouse roof maintain better internal temperature year round. - Abstract: An innovative greenhouse which integrates a conventional greenhouse with roof mounted solar air heaters is used in this investigation. This design reduces the solar radiation incoming to the greenhouse in summer which reduced the load and cost of greenhouse cooling and provides a means of solar heating. Experimental measurements of the internal air and internal soil sub-layer temperatures in the greenhouse, without crops, were performed in Baghdad University, Baghdad, Iraq (33.3 °N, 44.4 °E). Measurements were recorded for clear and partly cloudy winter days. A dynamic model was developed to predict the all internal temperatures of the greenhouse. This model includes soil surface heat exchange with the greenhouse air which was found to give a more accurate prediction of the internal temperatures. Soil surface heat exchange has a positive contribution to the internal environment. The input parameters of the model were the measured meteorological conditions and the thermo-physical properties of the greenhouse components which include the cover, inside air, and soil. Comparisons between the predicted and measured results show good agreement. Also, results show that soil sub-layers inside the greenhouse at 50 cm depth are the best place for heat storage elements. The integrated system rendered maximum differences between ambient and internal air temperatures of 16 °C in February and 10 °C in June without operating any heating or cooling system

  19. The value of radiochromic film dosimetry around air cavities: experimental results and Monte Carlo simulations

    International Nuclear Information System (INIS)

    Paelinck, L; Reynaert, N; Thierens, H; Wagter, C de; Neve, W de

    2003-01-01

    In this study we investigate radiochromic film dosimetry around air cavities with particular focus on the perturbation of the dose distribution by the film when the film is parallel to the beam axis. We considered a layered polystyrene phantom containing an air cavity as a model for the air-soft tissue geometry that may occur after surgical resection of a paranasal sinus tumour. A radiochromic film type MD-55 was positioned within the phantom so that it intersected the cavity. Two phantom set-ups were examined. In the first case, the air cavity is at the centre of the phantom, thus the film is lying along the central beam axis. In the second case, the cavity and film are located 2 cm offset from the phantom centre and the central beam axis. In order to examine the influence of the film on the dose distribution and to interpret the film-measured results, Monte Carlo simulations were performed. The film was modelled rigorously to incorporate the composition and structure of the film. Two field configurations, a 1 x 10 cm 2 field and a 10 x 10 cm 2 field, were examined. The dose behind the air cavity is reduced by 6 to 7% for both field configurations when a film that intersects the cavity contains the central beam axis. This is due to the attenuation exerted by the film when photons cross the cavity. Offsetting the beam to the cavity and the film by 2 cm removes the dose reduction behind the air cavity completely. Another result was that the rebuild-up behind the cavity for the 10 x 10 cm 2 field, albeit less significant than for the 1 x 10 cm 2 field, could only be measured by the film that was placed offset with respect to the central beam axis. Although radiochromic film is approximately soft-tissue equivalent and energy independent as compared to radiographic films, care should be taken in the case of inhomogeneous phantoms when the film intersects air cavities and contains the beam central axis. Errors in dose measurement can be expected distal to the air cavity

  20. The nexus between energy systems and public health: an investigation into the co-impacts of energy sector technology transitions on outdoor air pollution and public health in The United Kingdom and Greater London

    OpenAIRE

    Lott, Melissa Christenberry

    2017-01-01

    There is significant value to be gained from insights on the trade-offs and synergies between proposed air quality and climate interventions. But, the models used in support of decarbonisation and air quality policies have not holistically considered these co-impacts. This thesis documents the use of an energy systems model to quantify the co-impacts of decarbonisation pathways on air pollution and vice versa in the United Kingdom. This manuscript further documents the soft-linking of this mo...

  1. Outdoor fungi and child asthma health service attendances.

    Science.gov (United States)

    Tham, Rachel; Dharmage, Shyamali C; Taylor, Philip E; Katelaris, Constance H; Vicendese, Don; Abramson, Michael J; Erbas, Bircan

    2014-08-01

    Asthma is a significant global public health issue. Severe asthma exacerbations can be triggered by environmental factors and require medical care from health services. Although it is known that fungal exposure may lead to allergic sensitization, little is understood about its impact on asthma exacerbations. This review aims to examine whether outdoor fungi play a significant role in child asthma exacerbations. Systematic search of seven electronic databases and hand searching for peer-reviewed studies published in English, up to 31 August 2013. Inclusion criteria were study population aged asthma, attended a health service; outdoor fungi exposure was reported. Quality and risk of bias assessments were conducted. Due to significant heterogeneity, meta-analysis was not conducted. Of the 1896 articles found, 15 were eligible. Findings were not consistent, possibly due to methodological variations in exposure classifications, statistical methods and inclusion of confounders. Cross-sectional studies found no or weak associations. All but one time series studies indicated an association that varied between fungal species. Increasing evidence indicates that asthmatic children are susceptible to asthma exacerbations when exposed to outdoor fungal spores. There is limited understanding of the contributions of different fungal species. Research is needed to investigate interactions of outdoor fungi with pollen, air pollutants and respiratory viruses. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  2. Experimental studies on removal of airborne haloanisoles by non-thermal plasma air purifiers

    DEFF Research Database (Denmark)

    Fang, Lei; Hallam, David; Bermúdez, Raúl

    2016-01-01

    A laboratory study was conducted to test the performance of non-thermal plasma air purifiers on its removal effectiveness of two haloanisoles – 2,4,6-trichloroanisole (TCA) and 2,4,6-Tribromoanisole (TBA). TCA and TBA are the two major compounds found in wine cellars that can contaminate wine to ...

  3. Experimental determination of the energy efficiency of an air-cooled chiller under part load conditions

    International Nuclear Information System (INIS)

    Yu, F.W.; Chan, K.T.

    2005-01-01

    In cities located in a subtropical climate, air-cooled chillers are commonly used to provide cooling to the indoor environment. This accounts for the increasing electricity demand of buildings over the decades. This paper investigates how the condensing temperature serves to accurately determine the energy efficiency, or coefficient of performance (COP), of air-cooled chillers under part load conditions. An experiment on an air-cooled reciprocating chiller showed that for any given operating condition, the COP of the chiller varies, depending on how the condensing temperature is controlled. A sensitivity analysis is implemented to investigate to what extent COP is responding to changes in operating variables and confirms that the condensing temperature is an adequate variable to gauge COP under various operating conditions. The specifications of the upper limit for the condensing temperature in order to improve the energy efficiency of air-cooled chillers are discussed. The results of this work will give designers and researchers a good idea about how to model chiller energy performance curves in the thermal and energy computation exercises

  4. Experimental Demonstration on Air Cavity Mode of Violin Using Holed Sheets of Paper

    Science.gov (United States)

    Matsutani, Akihiro

    2018-01-01

    The fundamental air cavity mode (A0) of a violin was investigated from the viewpoint of its dependence on the opening area and shape by using holed sheets of paper. The dependences of the frequency response of the A0 cavity mode on the shape, opening area, and orientation of the openings were observed. It was also demonstrated that the change of…

  5. Aerodynamics of flapping-wing Micro-Air-Vehicle : An integrated experimental and numerical study

    NARCIS (Netherlands)

    Deng, S.

    2016-01-01

    The interest in Micro Air Vehicles (MAVs) has stimulated continuous research activities, in view of their potential in civilian and military applications. An autonomous MAV with dedicated onboard sensors would be capable of executing mission in closed environments, such as surveillance, in door

  6. Experimental studies on improvement of coefficient of performance of window air conditioning unit

    Directory of Open Access Journals (Sweden)

    Tharves Mohideen Sheik Ismail

    2017-01-01

    Full Text Available This paper presents the performance analysis of a window air conditioner unit incorporated with wick less loop heat pipes (WLHP. The WLHP are located on the evaporator side of the air conditioning unit. The working medium for the WLHP is R134a refrigerant gas, an alternate refrigerant. The supply and return humidity of room air, the heat removal rat, and the coefficient of performance of the unit are analyzed for various ambient and room temperatures before and after incorporation of WLHP. The performance curves are drawn by comparing the power consumption and humidity collection rates for various room and ambient temperatures. The results show that coefficient of performance of the unit is improved by 18% to 20% after incorporation of WLHP due to pre-cooling of return air by WLHP, which reduces the thermal load on compressor. Similarly, the energy consumption is reduced by 20% to 25% due to higher thermostat setting and the humidity collection is improved by 35% due to pre-cooling effect of WLHP. The results are tabulated and conclusion drawn is presented based on the performance.

  7. Experimental study of hard X-rays emitted from meter-scale positive discharges in air

    NARCIS (Netherlands)

    P.O. Kochkin (Pavlo); C.V. Nguyen; A. van Deursen (Arie); U. M. Ebert (Ute)

    2012-01-01

    textabstractWe investigate structure and evolution of long positive spark breakdown; and we study at which stage pulses of hard x-rays are emitted. Positive high-voltage pulses of standardized lightning impulse wave form of about 1 MV were applied to about 1 m of ambient air. The discharge evolution

  8. Effects of experimental warming of air, soil and permafrost on carbon balance in Alaskan tundra

    Science.gov (United States)

    S.M. Natali; E.A.G. Schuur; C. Trucco; C.E. Hicks Pries; K.G. Crummer; A.F. Baron Lopez

    2011-01-01

    The carbon (C) storage capacity of northern latitude ecosystems may diminish as warming air temperatures increase permafrost thaw and stimulate decomposition of previously frozen soil organic C. However, warming may also enhance plant growth so that photosynthetic carbon dioxide (C02) uptake may, in part, offset respiratory losses. To determine...

  9. Full Scale Experimental Study on the Air Insulation of 765kV Transmission Lines

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jong Boo; Shin, Jeong Woon; Cho, Sung Bae; Chang, Sung Chil; Kwak, Joo Shik [Korea Electric Power Research Institute, Taejon (Korea, Republic of); Kim, Ik Soo; Lee, Heyoung Ho; Kang, Young Sik; Lee, Hong Sik; Choi, Beyoung Joo; Kim, Young Bae [Korea Electrotechnology Research Institute, Changwon (Korea, Republic of)

    1997-12-31

    Design and construction of testing yard. Technical specification of impulse voltage generator which was installed in testing yard. Corrosion and statistical analysis of test data. Test object setup and test results of flashover characteristic in various paths. Recommended optimum air clearance of 765kV transmission lines. (author). 163 refs., figs.

  10. Modeling of air-gap membrane distillation process: A theoretical and experimental study

    KAUST Repository

    Alsaadi, Ahmad Salem; Ghaffour, NorEddine; Li, Junde; Gray, Stephen R.; Francis, Lijo; Maab, Husnul; Amy, Gary L.

    2013-01-01

    A one dimensional (1-D) air gap membrane distillation (AGMD) model for flat sheet type modules has been developed. This model is based on mathematical equations that describe the heat and mass transfer mechanisms of a single-stage AGMD process

  11. Active vibration control of a cylindrical structure using flexible piezoactuators: experimental work in air and water environments

    International Nuclear Information System (INIS)

    Sohn, Jung Woo; Choi, Seung-Bok

    2014-01-01

    In the present work, the modal characteristics and vibration control performance of a cylindrical structure in air and water are experimentally investigated, and the results are presented in time and frequency domains. In order to achieve this goal, an end-capped cylindrical shell structure is considered as a host structure, and MFC (macro fiber composite) actuators, which are flexible, are bonded on the surface of the structure. After manufacturing a cylindrical shell structure with aluminum, a modal test is carried out, and the natural frequencies of the proposed structure are obtained and analyzed. To verify the modal test results, a finite element analysis is also performed, and the results are compared with the modal test results. By using the experimentally obtained modal characteristics, a state space control model is established. An optimal controller is then designed in order to control the unwanted vibration and is experimentally realized. It has been shown that the structural vibration can be effectively decreased with the optimal control methodology in both air and water environmental conditions. (technical note)

  12. Large eddy simulation and experimental study on vented gasoline-air mixture explosions in a semi-confined obstructed pipe.

    Science.gov (United States)

    Li, Guoqing; Du, Yang; Wang, Shimao; Qi, Sheng; Zhang, Peili; Chen, Wenzhuo

    2017-10-05

    In this work, LES simulation coupled with a TFC sub-grid combustion model has been performed in a semi-confined pipe (L/D=10, V=10L) in the presence of four hollow-square obstacles (BR=49.8%) with circular hollow cross-section, in order to study the premixed gasoline-air mixture explosions. The comparisons between simulated results and experimental results have been conducted. It was found that the simulated results were in good agreement with experimental data in terms of flame structures, flame locations and overpressure time histories. Moreover, the interaction between flame propagation process and obstacles, overpressure dynamics were analyzed. In addition, the effects of initial gasoline vapor concentration (lean (ϕ=1.3%), stoichiometric (ϕ=1.7%) and rich (ϕ=2.1%)), and the number of obstacles (from 1 to 4) were also investigated by experiments. Some of the experimental results have been compared with the literature data. It is found that the explosion parameters of gasoline-air mixtures (e.g. the maximum overpressure peaks, average overpressure growth rates, etc.) are different from some other fuels such as hydrogen, methane and LPG, etc. Copyright © 2017. Published by Elsevier B.V.

  13. Model validation using CFD-grade experimental database for NGNP Reactor Cavity Cooling Systems with water and air

    Energy Technology Data Exchange (ETDEWEB)

    Manera, Annalisa [Univ. of Michigan, Ann Arbor, MI (United States); Corradini, Michael [Univ. of Wisconsin, Madison, WI (United States); Petrov, Victor [Univ. of Michigan, Ann Arbor, MI (United States); Anderson, Mark [Univ. of Wisconsin, Madison, WI (United States); Tompkins, Casey [Univ. of Wisconsin, Madison, WI (United States); Nunez, Daniel [Univ. of Michigan, Ann Arbor, MI (United States)

    2018-02-13

    This project has been focused on the experimental and numerical investigations of the water-cooled and air-cooled Reactor Cavity Cooling System (RCCS) designs. At this aim, we have leveraged an existing experimental facility at the University of Wisconsin-Madison (UW), and we have designed and built a separate effect test facility at the University of Michigan. The experimental facility at UW has underwent several upgrades, including the installation of advanced instrumentation (i.e. wire-mesh sensors) built at the University of Michigan. These provides highresolution time-resolved measurements of the void-fraction distribution in the risers of the water-cooled RCCS facility. A phenomenological model has been developed to assess the water cooled RCCS system stability and determine the root cause behind the oscillatory behavior that occurs under normal two-phase operation. Testing under various perturbations to the water-cooled RCCS facility have resulted in changes in the stability of the integral system. In particular, the effects on stability of inlet orifices, water tank volume have and system pressure been investigated. MELCOR was used as a predictive tool when performing inlet orificing tests and was able to capture the Density Wave Oscillations (DWOs) that occurred upon reaching saturation in the risers. The experimental and numerical results have then been used to provide RCCS design recommendations. The experimental facility built at the University of Michigan was aimed at the investigation of mixing in the upper plenum of the air-cooled RCCS design. The facility has been equipped with state-of-theart high-resolution instrumentation to achieve so-called CFD grade experiments, that can be used for the validation of Computational Fluid Dynanmics (CFD) models, both RANS (Reynold-Averaged) and LES (Large Eddy Simulations). The effect of risers penetration in the upper plenum has been investigated as well.

  14. PARENTS ATTITUDE ABOUT OUTDOOR ACTIVITIES

    Directory of Open Access Journals (Sweden)

    Dragan Martinović

    2013-07-01

    Full Text Available A questionnaire-based survey was conducted on a sample of 238 parents whose children attend the third and fourth grades in two Belgrade elementary schools: “Oslobodioci Beograda” and “Borislav Pekic”. The aim of this study was to deter¬mi¬ne the incidence of outdoor activities and the attitude of the third and fourth graders’ parents towards it. Statistical data processing was based on the use of the –R, and every question represented a random variable. The analysis of the collected data has proved the presence of outdoor activities among these pupils and their positive attitude towards camping out, as well as a positive attitude of their parents.

  15. Experimental testing of a small sorption air cooler using composite material made from natural siliceous shale and chloride

    International Nuclear Information System (INIS)

    Liu, Hongzhi; Nagano, Katsunori; Morita, Atsushi; Togawa, Junya; Nakamura, Makoto

    2015-01-01

    A sorption air cooler experimental setup including a reactor and fin tube condenser/evaporator was built. The reactor was developed with inner copper fins and dual layers of curing copper meshes. Composite material made by impregnating LiCl into the mesopores of Wakkanai Siliceous Shale (WSS) micropowders was packed between the intervals of two fins. Heat transfer was enhanced by the attached fins, and the dual layers of curing meshes installed between each interval of two fins were designed to improve the sorbate mass transfer. On the other hand, the fin-tube evaporator/condenser with fins outside is valuable for improving the convective heat transfer between the functional water inside the evaporator/condenser and the flowing outside heat transfer medium, air. The sorption capacity of the composite material increased dramatically after being impregnated with LiCl. Among the four tested samples, WSS + 40 wt% LiCl exhibits the best performance. A regeneration temperature of 80 °C appears to be optimal for obtaining both a high COP and high specific cooling power. A lower condensation temperature can increase the cooling power. The sorption and desorption times of 60 min yield a reasonable compromise between cooling COP and mass specific cooling powers. The developed sorption air cooler system using WSS + 40 wt% LiCl can store heat at temperatures below 100 °C and produce cooling energy with a cooling coefficient of performance (COP) of approximately 0.3. - Highlights: • Mesoporous composite material was developed using natural siliceous shale and LiCl. • Properties of the developed material were measured. • A sorption air cooler experimental setup including an inner-fin reactor and a fin tube condenser/evaporator was built. • The performance of the composite material in the sorption air cooler was examined. • The sorption air cooler system can produce cooling energy with a cooling COP around 0.3

  16. Experimental Study of the Slit Spacing and Bed Height on the Thermal Performance of Slit-Glazed Solar Air Heater

    Directory of Open Access Journals (Sweden)

    Seyyed Mahdi Taheri Mousavi

    2017-01-01

    Full Text Available The thermal performances of three slit-glazed solar air heaters (SGSAHs were investigated experimentally. Three SGSAHs with different bed heights (7 cm, 5 cm, and 3 cm were fabricated with multiple glass panes used for glazing. The length, width, and thickness of each pane were 154 cm, 6 cm, and 0.4 cm, respectively. Ambient air was continuously withdrawn through the gaps between the glass panes by fans. The experiments were conducted for four different gap distances between the glass panes (0.5 mm, 1 mm, 2 mm, and 3 mm and the air mass flow rate was varied between 0.014 kg/s and 0.057 kg/s. The effects of air mass flux on the outlet temperature and thermal efficiency were studied. For the SGSAH with bed height of 7 cm and glass pane gap distance of 0.5 mm, the highest efficiency was obtained as 82% at a mass flow rate of 0.057 kg/s and the air temperature difference between the inlet and the outlet (∆T was maximum (27°C when the mass flow rate was least. The results demonstrate that for lower mass flow rates and larger gaps, the performance of SGSAH with a bed height of 3 cm was better compared to that of others. However, for higher mass flow rates, the SGSAH with 7 cm bed height performed better.

  17. Experimental investigation on large-area dielectric barrier discharge in atmospheric nitrogen and air assisted by the ultraviolet lamp.

    Science.gov (United States)

    Zhang, Yan; Gu, Biao; Wang, Wenchun; Wang, Dezhen; Peng, Xuwen

    2009-04-01

    In this paper, ultraviolet radiation produced by the ultraviolet lamp is employed to supply pre-ionization for the dielectric barrier discharge in N(2) or air at atmospheric pressure. The effect of the ultraviolet pre-ionization on improving the uniformity of the dielectric barrier discharge is investigated experimentally. The atmospheric pressure glow discharge of the large area (270 mm x 120 mm) is obtained successfully via the ultraviolet pre-ionization in atmospheric DBD in N(2) when the gas gap decrease to 3mm. Based on the emission spectra, the mechanism which ultraviolet pre-ionization improves the uniformity of the dielectric barrier discharge is discussed.

  18. Dynamic simulation of the air-cooled decay heat removal system of the German KNK-II experimental breeder reactor

    International Nuclear Information System (INIS)

    Schubert, B.K.

    1984-07-01

    A Dump Heat Exchanger and associated feedback control system models for decay heat removal in the German KNK-II experimental fast breeder reactor are presented. The purpose of the controller is to minimize temperature variations in the circuits and, hence, to prevent thermal shocks in the structures. The basic models for the DHX include the sodium-air thermodynamics and hydraulics, as well as a control system. Valve control models for the primary and intermediate sodium flow regulation during post shutdown conditions are also presented. These models have been interfaced with the SSC-L code. Typical results of sample transients are discussed

  19. Experimental investigation on a turbine compressor for air supply system of a fuel cell

    Energy Technology Data Exchange (ETDEWEB)

    Matsuda, Masayasu [Sumitomo Heavy Industries, Ltd., Yokosuka (Japan); Tsuchiyama, Syozo [Shipbuilding Research Association, Minato-ku, Tokyo (Japan)

    1996-12-31

    This report covers part of a joint study on a PEFC propulsion system for surface ships, summarized in a presentation to this Seminar, entitled {open_quotes}Study on a Polymer Electrolyte Fuel Cell (PEFC) Propulsion System for Surface Ships{close_quotes}, and which envisages application to a 1,500 DWT cargo vessel. The aspect treated here concerns a study on the air supply system for the PEFC, with particular reference to system components.

  20. Modelling and experimentation on air hybrid engine concepts for automotive applications

    OpenAIRE

    Psanis, Christodoulos

    2007-01-01

    This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University. Hybrid powertrains that use compressed air to help power a vehicle could dramatically improve the fuel economy, particularly in cities and urban areas where the traffic conditions involve a lot of starts and stops. In such conditions, a large amount of fuel is needed to accelerate the vehicle, and much of this is converted to heat in brake friction during decelerations. Capturing, storing and...

  1. An experimental investigation of a novel design air humidifier using direct solar thermal heating

    International Nuclear Information System (INIS)

    Abd-ur-Rehman, Hafiz M.; Al-Sulaiman, Fahad A.

    2016-01-01

    Highlights: • A novel solar driven multi-stage bubble column humidifier is developed and tested. • Single stage, two stage, and three stage configuration were tested. • Average day round absolute humidity is increased by 9% for 2 stage configuration. • Average day round absolute humidity is increased by 23% for 3 stage configuration. • Air absolute humidity increases up to 26% with the integration of Fresnel lens. - Abstract: In this study, a novel solar heated multi-stage bubble column humidifier is designed and tested. The overall objective of this work is to investigate the main operating parameters of the new humidifier. The study addresses the significance of the perforated plate geometric features, optimum balance of air superficial velocity and water column height, and the influence of inlet water temperature and inlet air relative humidity on the performance of the humidifier. The day round performance of the humidifier is investigated in single stage, two stage, and three stage configuration, in which each configuration was tested with and without the integration of the Fresnel lens. Findings show that the average day round absolute humidity, without Fresnel lens, increased up to 9% for the two stage configuration and 23% for the three stage configuration as compared to the single stage configuration of the humidifier. The integration of the Fresnel lens further increased the absolute humidity up to 25% as compared to the results obtained without the integration of the Fresnel lens under the same prevailing conditions, which is significant. Moreover, the current humidifier shows a higher humidification efficiency in the climatic conditions that have a lower inlet air relative humidity. Furthermore, the finding demonstrates that the newly developed multi-stage bubble column humidifier has better performance as compared to the conventional single stage bubble column humidifier. The findings from this study are of pivotal importance to understand

  2. Indoor air pollution

    International Nuclear Information System (INIS)

    Spengler, J.D.

    1985-01-01

    Although official efforts to control air pollution have traditionally focused on outdoor air, it is now apparent that elevated contaminant concentrations are common inside some private and public buildings. Concerns about potential public health problems due to indoor air pollution are based on evidence that urban residents typically spend more than 90 percent of their time indoors, concentrations of some contaminants are higher indoors than outdoors, and for some pollutants personal exposures are not characterized adequately by outdoor measurements. Among the more important indoor contaminants associated with health or irritation effects are passive tobacco smoke, radon decay products, carbon monoxide, nitrogen dioxide, formaldehyde, asbestos fibers, microorganisms and aeroallergens. Efforts to assess health risks associated with indoor air pollution are limited by insufficient information about the number of people exposed, the pattern and severity of exposures, and the health consequences of exposures. An overall strategy should be developed to investigate indoor exposures, health effects, control options, and public policy alternatives

  3. Evaluación de la calidad del aire interior y exterior en un jardín de niños de la Ciudad de México Evaluation of indoor and outdoor air quality of a nursery school in Mexico City

    Directory of Open Access Journals (Sweden)

    Marlene Cortez-Lugo

    1998-09-01

    Full Text Available Objetivo. Evaluar las diferencias en los niveles de ozono (O3 y bióxido de nitrógeno (NO2 en el interior y el exterior de una escuela en el suroeste de la Ciudad de México. Material y métodos. Se midieron diariamente estos contaminantes dentro y fuera del salón, de enero a abril de 1990, mediante monitoreo manual. Resultados. El NO2 adentro y afuera no sobrepasó la norma mexicana (0.21 ppm. El coeficiente de correlación entre las concentraciones máximas de NO2 de la estación de monitoreo local de la ciudad y el exterior del salón fue de 0.82 (pObjective. To evaluate the differences between indoor and outdoor ozone (O3 and nitrogen dioxide (NO2 levels at a school located in southwest Mexico City. Material and methods. Indoor and outdoor O3 and NO2 levels were measured daily between January and April 1990 by manual monitoring. Results. Indoor and outdoor concentrations of nitrogen dioxide did not surpass the Mexican standard (0.21 ppm. The correlation coefficient between maximum NO2 concentrations measured by the city’s local monitoring station and those measured outside the classroom was 0.82 (p< 0.001. Regarding ozone, its maximum outdoor concentration was 0.29 ppm and indoor concentrations were on average below 0.06 ppm (maximum = 0.17 ppm. The indoor/outdoor correlation coefficient was 0.72, and for every 1.7 ppm outside, there was 1.0 ppm inside (p< 0.05 Conclusions. Since the highest outdoors O3 concentrations were observed between 11:00 and 14:00 hrs, it is recommendable to have recess before this time.

  4. Numerical analysis and experimental validation of heat transfer characteristic for flat-plate solar air collector

    International Nuclear Information System (INIS)

    Hung, Tzu-Chen; Huang, Tsung-Jie; Lee, Duen-Sheng; Lin, Chih-Hung; Pei, Bau-Shei; Li, Zeng-Yao

    2017-01-01

    Highlights: • Various types of solar air collectors are discussed. • CFD has been used to validate the characteristics of heat transfer. • Solar Ray Tracing has been successfully used for thermal radiation flux. - Abstract: This study combines both concepts of solar ventilation technology and solar air collector. This is a quite innovative and potential facility to effectively use thermal energy and reduce the accumulation of heat in the indoor space simultaneously. The purpose of this study is to create a prototype and implement the experiments. Computational fluid dynamics (CFD) approach is employed to validate the characteristics of the flow and heat transfer. For the accuracy of numerical predictions, the method of Solar Ray Tracing was used for thermal radiation flux as boundary condition on the wall. The local heat transfer correlation was investigated to predict surrounding wind speed upon device cover. Three sorts of glasses and several aspect ratios of flow channels have been compared to conclude the optimal configuration. In addition, four important factors, such as the stagnant layer thickness, emissivity on the illustrated surface, mass flow rate and the height of the device, are also considered and discussed in detail. The result showed that the optimal design is dominated by the combination of an aspect ratio of 50 mm:10 mm, and appropriate mass flow rate to the height of the device. The present work on thermal energy collection can assist us in designing a powerful solar air collector in some potential applications.

  5. EXPERIMENTAL STUDY ON DOUBLE PASS SOLAR AIR HEATER WITH MESH LAYERS AS ABSORBER PLATE

    Directory of Open Access Journals (Sweden)

    Raheleh Nowzaria

    2014-01-01

    Full Text Available The double pass solar air heater is constructed and tested for thermal efficiency at a geographic location of Cyprus in the city of Famagusta. The absorber plate was replaced by fourteen steel wire mesh layers, 0.2 × 0.2 cm in cross section opening, and they were fixed in the duct parallel to the glazing. The distance between each set of wire mesh layers is 0.5cm to reduce the pressure drop. The wire mesh layers were painted with black before installing them into the collector. The obtained results show that as the mass flow rate increases, the efficiency of the system also increases. The temperature difference (ΔT between the inlet and outlet air through the system increases as the mass flow rate decreases. The maximum ΔT (53°C is achieved at the flow rate of 0.011 kg/s. The range of the mass flow rate used in this work is between 0.011 and 0.037 kg/s. It is also found that the average efficiency obtained for the double pass air collector is 53.7% for the mass flow rate of 0.037 kg/s.

  6. Determination of the Clean Air Delivery Rate (CADR of Photocatalytic Oxidation (PCO Purifiers for Indoor Air Pollutants Using a Closed-Loop Reactor. Part II: Experimental Results

    Directory of Open Access Journals (Sweden)

    Valérie Héquet

    2017-03-01

    Full Text Available The performances of a laboratory PhotoCatalytic Oxidation (PCO device were determined using a recirculation closed-loop pilot reactor. The closed-loop system was modeled by associating equations related to two ideal reactors: a perfectly mixed reservoir with a volume of VR = 0.42 m3 and a plug flow system corresponding to the PCO device with a volume of VP = 5.6 × 10−3 m3. The PCO device was composed of a pleated photocatalytic filter (1100 cm2 and two 18-W UVA fluorescent tubes. The Clean Air Delivery Rate (CADR of the apparatus was measured under different operating conditions. The influence of three operating parameters was investigated: (i light irradiance I from 0.10 to 2.0 mW·cm−2; (ii air velocity v from 0.2 to 1.9 m·s−1; and (iii initial toluene concentration C0 (200, 600, 1000 and 4700 ppbv. The results showed that the conditions needed to apply a first-order decay model to the experimental data (described in Part I were fulfilled. The CADR values, ranging from 0.35 to 3.95 m3·h−1, were mainly dependent on the light irradiance intensity. A square root influence of the light irradiance was observed. Although the CADR of the PCO device inserted in the closed-loop reactor did not theoretically depend on the flow rate (see Part I, the experimental results did not enable the confirmation of this prediction. The initial concentration was also a parameter influencing the CADR, as well as the toluene degradation rate. The maximum degradation rate rmax ranged from 342 to 4894 ppbv/h. Finally, this study evidenced that a recirculation closed-loop pilot could be used to develop a reliable standard test method to assess the effectiveness of PCO devices.

  7. Cardiovascular effects of air pollution.

    Science.gov (United States)

    Bourdrel, Thomas; Bind, Marie-Abèle; Béjot, Yannick; Morel, Olivier; Argacha, Jean-François

    2017-11-01

    Air pollution is composed of particulate matter (PM) and gaseous pollutants, such as nitrogen dioxide and ozone. PM is classified according to size into coarse particles (PM 10 ), fine particles (PM 2.5 ) and ultrafine particles. We aim to provide an original review of the scientific evidence from epidemiological and experimental studies examining the cardiovascular effects of outdoor air pollution. Pooled epidemiological studies reported that a 10μg/m 3 increase in long-term exposure to PM 2.5 was associated with an 11% increase in cardiovascular mortality. Increased cardiovascular mortality was also related to long-term and short-term exposure to nitrogen dioxide. Exposure to air pollution and road traffic was associated with an increased risk of arteriosclerosis, as shown by premature aortic and coronary calcification. Short-term increases in air pollution were associated with an increased risk of myocardial infarction, stroke and acute heart failure. The risk was increased even when pollutant concentrations were below European standards. Reinforcing the evidence from epidemiological studies, numerous experimental studies demonstrated that air pollution promotes a systemic vascular oxidative stress reaction. Radical oxygen species induce endothelial dysfunction, monocyte activation and some proatherogenic changes in lipoproteins, which initiate plaque formation. Furthermore, air pollution favours thrombus formation, because of an increase in coagulation factors and platelet activation. Experimental studies also indicate that some pollutants have more harmful cardiovascular effects, such as combustion-derived PM 2.5 and ultrafine particles. Air pollution is a major contributor to cardiovascular diseases. Promotion of safer air quality appears to be a new challenge in cardiovascular disease prevention. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  8. Experimental investigation of flooding in air-water counter-current flow with a vertical adiabatic multi-rod bundle

    International Nuclear Information System (INIS)

    Chung, Bub Dong; Kim, Hho Jung; Cha, Jong Hee; Cho, Sung Jae; Chun, Moon Hyun

    1991-01-01

    The process of flooding phenomenon in a vertical adiabatic 3 x 3 tube bundle flow channel has been studied experimentally. A series of tests was performed, using three types of tube bundle differing only in the number of spacer grids attached, to investigate the effects of spacer grids and multi-flow channel interactions on the air-water counter-current flow limitations. Experimentally determined flooding points at various water film Reynolds numbers for three different test sections are presented in graphical form and compared with entrainment criterion for co-current flow and instability criteria. In addition, empirical flooding correlations of the Kutateladze type are obtained for each type of test section using liquid penetration data

  9. Experimental investigations regarding the use of sand as an inhibitor of air convection in deep seismic boreholes

    Science.gov (United States)

    Holcomb, L. Gary; Sandoval, Leo; Hutt, Bob

    1998-01-01

    in long period data. However, low levels of tilt noise persisted even at great depth; this noise was caused by air convection in the vault in which the sensors were installed. Over the years, methods were developed to control the air motion with mechanical barriers (boxes) around the sensors and by stratifying (creating a situation in which the air temperature increases with height) the air in the vault near the seismometer. These methods decreased tilt noise in deep mines to very low levels. However, deep mines, that are economically and environmentally suitable and accessible to seismology, are not plentiful and are not evenly distributed over the earth's surface. Therefore, the borehole deployable Teledyne Geotech KS-36000 and later the KS-54000 sensor systems were developed to fulfill the need for instruments that could be installed at depth wherever high quality long period data was desired. Early in the development program, it became evident to the Teledyne Geotech personnel that air convection within the borehole was going to be a significant problem in KS deployments. Experimental and theoretical investigations conducted by Teledyne Geotech (see Douze and Sherwin, 1975, and Sherwin and Cook, 1976) produced a list of recommended installation procedures for reducing the effects of air convection. These procedures consisted of wrapping the sensor in a relatively thin layer of foam insulation, filling the free space volume in the vicinity of the centralizer-bail assembly with foam insulation, and the installation of styrofoam hole plugs immediately above the cable strain relief assembly at the top of the sensor package and at the top of the borehole. This technology has performed quite satisfactorily for over 20 years but evidence of tilt noise in the system output has persisted throughout the KS deployment program (the evidence was that the horizontal components were usually noisier than the vertical components) even in deep boreholes. Some deep borehole sites

  10. High-rise Buildings versus Outdoor Thermal Environment in Chongqing

    Directory of Open Access Journals (Sweden)

    Jin-sha Wang

    2007-10-01

    Full Text Available This paper gives a brief description of the over quick urbanization sinceChongqing, one of the biggest cities in China, has been a municipality directly under theCentral Government in 1997, excessive development and exceeding increase of high-risebuildings because of its special geographical position which finally leads to the worseningof the urban outdoor thermal environment. Then, this paper makes a bright balance to thefield measurement and simulated results of the wind speed field, temperature field of onemultifunctional high-rise building in Chongqing university located in the city center, andthe contrasted results validate the correctness of CFD in the outdoor thermal environmentalsimulation, expose the disadvantages of high-rise buildings on the aspects of blocking thewind field, decreasing wind speed which results in accumulation of the air-conditioningheat revolving around and periscian region where sunshine can not rip into. Finally, inorder to improve the urban outdoor thermal environment near the high-rise buildingsespecially for the angle of natural ventilation, this paper simulates the wind environment indifferent architectural compositions and architectural layouts by CFD, and the simulatedresults show that freestyle and tower buildings which can guarantee the wind speed andtake the air-conditioning heat away are much suitable and reasonable for the specialChongqing geography. These conclusions can also be used as a reference in othermountain cities, especially for the one with a great number of populations.

  11. Daily indoor-to-outdoor temperature and humidity relationships: a sample across seasons and diverse climatic regions.

    Science.gov (United States)

    Nguyen, Jennifer L; Dockery, Douglas W

    2016-02-01

    The health consequences of heat and cold are usually evaluated based on associations with outdoor measurements collected at a nearby weather reporting station. However, people in the developed world spend little time outdoors, especially during extreme temperature events. We examined the association between indoor and outdoor temperature and humidity in a range of climates. We measured indoor temperature, apparent temperature, relative humidity, dew point, and specific humidity (a measure of moisture content in air) for one calendar year (2012) in a convenience sample of eight diverse locations ranging from the equatorial region (10 °N) to the Arctic (64 °N). We then compared the indoor conditions to outdoor values recorded at the nearest airport weather station. We found that the shape of the indoor-to-outdoor temperature and humidity relationships varied across seasons and locations. Indoor temperatures showed little variation across season and location. There was large variation in indoor relative humidity between seasons and between locations which was independent of outdoor airport measurements. On the other hand, indoor specific humidity, and to a lesser extent dew point, tracked with outdoor, airport measurements both seasonally and between climates, across a wide range of outdoor temperatures. These results suggest that, in general, outdoor measures of actual moisture content in air better capture indoor conditions than outdoor temperature and relative humidity. Therefore, in studies where water vapor is among the parameters of interest for examining weather-related health effects, outdoor measurements of actual moisture content can be more reliably used as a proxy for indoor exposure than the more commonly examined variables of temperature and relative humidity.

  12. Experimental study of flow monitoring instruments in air-water, two-phase downflow

    International Nuclear Information System (INIS)

    Sheppard, J.D.; Hayes, P.H.; Wynn, M.C.

    1976-01-01

    The performance of a turbine meter, target flow meter (drag disk), and a gamma densitometer was studied in air-water, two-phase vertical downflow. Air and water were metered into an 0.0889-m-ID (3.5-in.) piping system; air flows ranged from 0.007 to 0.3 m 3 /sec (16 to 500 scfm) and water flows ranged from 0.0006 to 0.03 m 3 /sec (10 to 500 gpm). The study included effects of flow rate, quality, flow regime, and flow dispersion on the mean and fluctuating components of the instrument signals. Wire screen flow dispersers located at the inlet to the test section had a significant effect on the readings of the drag disk and gamma densitometer, but had little effect on the turbine. Further, when flow dispersers were used, mass flow rates determined from the three instrument readings and a two-velocity, slip flow model showed good agreement with actual mass flow rate over a three-fold range in quality; mass flows determined with the drag disk and densitometer readings assuming homogeneous flow were nearly as accurate. However, when mass flows were calculated using the turbine and densitometer or turbine and drag disk readings assuming homogeneous flow, results were scattered and relatively inaccurate compared to the actual mass flows. Turbine meter data were used with a two-velocity turbine model and continuity relationships for each phase to determine the void fraction and mean phase velocities in the test section. The void fraction was compared with single beam gamma densitometer results and fluid momentum calculated from a two-velocity model was compared with drag disk readings

  13. Swimming pools as heat sinks for air conditioners: Model design and experimental validation for natural thermal behavior of the pool

    Energy Technology Data Exchange (ETDEWEB)

    Woolley, Jonathan; Harrington, Curtis; Modera, Mark [University of California Davis, Western Cooling Efficiency Center, 1450 Drew Avenue, Suite 100, Davis, CA 95618 (United States)

    2011-01-15

    Swimming pools as thermal sinks for air conditioners could save approximately 40% on peak cooling power and 30% of overall cooling energy, compared to standard residential air conditioning. Heat dissipation from pools in semi-arid climates with large diurnal temperature shifts is such that pool heating and space cooling may occur concurrently; in which case heat rejected from cooling equipment could directly displace pool heating energy, while also improving space cooling efficiency. The performance of such a system relies on the natural temperature regulation of swimming pools governed by evaporative and convective heat exchange with the air, radiative heat exchange with the sky, and conductive heat exchange with the ground. This paper describes and validates a model that uses meteorological data to accurately predict the hourly temperature of a swimming pool to within 1.1 C maximum error over the period of observation. A thorough review of literature guided our choice of the most appropriate set of equations to describe the natural mass and energy exchange between a swimming pool and the environment. Monitoring of a pool in Davis, CA, was used to confirm the resulting simulations. Comparison of predicted and observed pool temperature for all hours over a 56 day experimental period shows an R-squared relatedness of 0.967. (author)

  14. Experimental Study of a Novel Direct-Expansion Variable Frequency Finned Solar/Air-Assisted Heat Pump Water Heater

    Directory of Open Access Journals (Sweden)

    Jing Qin

    2018-01-01

    Full Text Available A novel direct expansion variable frequency finned solar/air-assisted heat pump water heater was fabricated and tested in the enthalpy difference lab with a solar simulator. A solar/air source evaporator-collector with an automatic lifting glass cover plate was installed on the system. The system could be operated in three modes, namely, air, solar, and dual modes. The effects of the ambient temperature, solar irradiation, compressor frequency, and operating mode on the performance of this system were s