WorldWideScience

Sample records for indoor particle sources

  1. Source specific risk assessment of indoor aerosol particles

    Energy Technology Data Exchange (ETDEWEB)

    Koivisto, A.J.

    2013-05-15

    In the urban environment, atmospheric aerosols consist mainly of pollutants from anthropogenic sources. The majority of these originate from traffic and other combustion processes. A fraction of these pollutants will penetrate indoors via ventilation. However, indoor air concentrations are usually predominated by indoor sources due to the small amount of dilution air. In modern societies, people spend most of their time indoors. Thus, their exposure is controlled mainly by indoor concentrations from indoor sources. During the last decades, engineering of nanosized structures has created a new field of material science. Some of these materials have been shown to be potentially toxic to human health. The greatest potential for exposure to engineered nanomaterials (ENMs) occurs in the workplace during production and handling of ENMs. In an exposure assessment, both gaseous and particulate matter pollutants need to be considered. The toxicities of the particles usually depend on the source and age. With time, particle morphology and composition changes due to their tendency to undergo coagulation, condensation and evaporation. The PM exposure risk is related to source specific emissions, and thus, in risk assessment one needs to define source specific exposures. This thesis describes methods for source specific risk assessment of airborne particulate matter. It consists of studies related to workers' ENM exposures during the synthesis of nanoparticles, packing of agglomerated TiO{sub 2} nanoparticles, and handling of nanodiamonds. Background particles were distinguished from the ENM concentrations by using different measurement techniques and indoor aerosol modelings. Risk characterization was performed by using a source specific exposure and calculated dose levels in units of particle number and mass. The exposure risk was estimated by using non-health based occupational exposure limits for ENMs. For the nanosized TiO{sub 2}, the risk was also assessed from dose

  2. Indoor emissions as a primary source of airborne allergenic fungal particles in classrooms.

    Science.gov (United States)

    Yamamoto, Naomichi; Hospodsky, Denina; Dannemiller, Karen C; Nazaroff, William W; Peccia, Jordan

    2015-04-21

    This study quantifies the influence of ventilation and indoor emissions on concentrations and particle sizes of airborne indoor allergenic fungal taxa and further examines geographical variability, each of which may affect personal exposures to allergenic fungi. Quantitative PCR and multiplexed DNA sequencing were employed to count and identify allergenic fungal aerosol particles indoors and outdoors in seven school classrooms in four different countries. Quantitative diversity analysis was combined with building characterization and mass balance modeling to apportion source contributions of indoor allergenic airborne fungal particles. Mass balance calculations indicate that 70% of indoor fungal aerosol particles and 80% of airborne allergenic fungal taxa were associated with indoor emissions; on average, 81% of allergenic fungi from indoor sources originated from occupant-generated emissions. Principal coordinate analysis revealed geographical variations in fungal communities among sites in China, Europe, and North America (p < 0.05, analysis of similarity), demonstrating that geography may also affect personal exposures to allergenic fungi. Indoor emissions including those released with occupancy contribute more substantially to allergenic fungal exposures in classrooms sampled than do outdoor contributions from ventilation. The results suggest that design and maintenance of buildings to control indoor emissions may enable reduced indoor inhalation exposures to fungal allergens.

  3. Size-Resolved Source Emission Rates of Indoor Ultrafine Particles Considering Coagulation.

    Science.gov (United States)

    Rim, Donghyun; Choi, Jung-Il; Wallace, Lance A

    2016-09-20

    Indoor ultrafine particles (UFP, log-normally distributed for three common indoor UFP sources: an electric stove, a natural gas burner, and a paraffin wax candle. Experimental investigations were performed in a full-scale test building. Size- and time-resolved concentrations of UFP ranging from 2 to 100 nm were monitored using a scanning mobility particle sizer (SMPS). Based on the temporal evolution of the particle size distribution during the source emission period, the size-dependent source emission rate was determined using a material-balance modeling approach. The results indicate that, for a given UFP source, the source strength varies with particle size and source type. The analytical model assuming a log-normally distributed source emission rate could predict the temporal evolution of the particle size distribution with reasonable accuracy for the gas stove and the candle. Including the effect of coagulation was found to increase the estimates of source strengths by up to a factor of 8. This result implies that previous studies on indoor UFP source strengths considering only deposition and ventilation might have largely underestimated the true values of UFP source strengths, especially for combustion due to the natural gas stove and the candle.

  4. Indoor airborne particle sources and outdoor haze days effect in urban office areas in Guangzhou.

    Science.gov (United States)

    Zhang, Manwen; Zhang, Sukun; Feng, Guixian; Su, Hui; Zhu, Fengzhi; Ren, Mingzhong; Cai, Zongwei

    2017-04-01

    To identify the sources of PM2.5 pollutants in work environments and determine whether the air quality inside an office was affected by a change in outdoor pollution status, concurrent indoor and outdoor measurements of PM2.5 were conducted at five different office spaces in the urban center of Guangzhou on low pollution days (non-episode days, NEDs), and high pollution days (haze episode days, EDs). Indoor-outdoor relationships between the PM2.5 mass and its chemical constituents, which included water-soluble ions, carbonaceous species, and metal elements, were investigated. A principle component analysis (PCA) was performed to further confirm the relationship between the indoor and outdoor PM2.5 pollution. The results reveal that (1) Printing and ETS (Environmental tobacco smoking) were found to be important office PM2.5 sources and associated with the enrichment of SO4(2-), OC, EC and some toxic metals indoors; (2) On EDs, serious outdoor pollution and higher air exchange rate greatly affected all studied office environments, masking the original differences of the indoor characteristics (3) Fresh air system could efficiently filter out most of the outside pollutants on both NEDs and EDs. Overall, the results of our study suggest that improper human behavior is associated with the day-to-day generation of indoor PM2.5 levels and sporadic outdoor pollution events can lead to poor indoor air quality in urban office environments. Moreover, fresh air system has been experimentally proved with data as an effective way to improve the air quality in office.

  5. Physical properties, chemical composition, sources, spatial distribution and sinks of indoor aerosol particles in a university lecture hall

    Science.gov (United States)

    Salma, I.; Dosztály, K.; Borsós, T.; Söveges, B.; Weidinger, T.; Kristóf, G.; Péter, N.; Kertész, Zs.

    2013-01-01

    PM10 mass, particle number (N) and CO2 concentrations, particle number size distributions and meteorological parameters were determined with high time resolution, and daily aerosol samples were collected in the PM10-2.0 and PM2.0 size fractions for chemical analysis in the middle of a university lecture hall for one week. Median concentrations for the PM10 mass and N of 15.3 μg m-3 and 3.7 × 103 cm-3, respectively were derived. The data are substantially smaller than the related outdoor levels or typical values for residences. There were considerable concentration differences for workdays, weekends and various lectures. Main sources of PM10 mass include the usage of chalk sticks for writing, wiping the blackboard, ordinary movements and actions of students and cleaning. High PM10 mass concentration levels up to 100 μg m-3 were realised for short time intervals after wiping the blackboard. The mass concentrations decreased rapidly after the emission source ceased to be active. Two classes of coarse particles were identified. General indoor dust particles exhibited a residence time of approximately 35 min, while the residence time for the chalk dust particles was approximately 20 min as lower estimates. Emission source rate for wiping the blackboard was estimated to be between 8 and 14 mg min-1. This represents a substantial emission rate but the source is active only up to 1 min. Suspension of the chalk (made mainly of gypsum) dust particles was confirmed by enrichment of Ca and S in the hall with respect to ambient urban aerosol. Contribution of ambient aerosol via the heating, ventilation and air conditioning (HVAC) facility was considerable for time intervals when the indoor sources of PM10 mass were not intensive. The HVAC facility introduces, however, the major amount of aerosol particles from the outdoors as far as their number concentration is regarded. Mean contribution of ultrafine particles to the total particle number was (69 ± 7)%, which is smaller

  6. Particles emitted from indoor combustion sources: size distribution measurement and chemical analysis.

    Science.gov (United States)

    Roy, A A; Baxla, S P; Gupta, Tarun; Bandyopadhyaya, R; Tripathi, S N

    2009-08-01

    This study is primarily focused toward measuring the particle size distribution and chemical analysis of particulate matter that originates from combustion sources typically found in Indian urban homes. Four such sources were selected: cigarette, incense stick, mosquito coil, and dhoop, the latter being actually a thick form of incense stick. Altogether, seven of the most popular brands available in the Indian market were tested. Particle size distribution in the smoke was measured using a scanning mobility particle sizer, using both long and nano forms of differential mobility analyzer (DMA), with readings averaged from four to six runs. The measurable particle size range of the nano DMA was 4.6 nm to 157.8 nm, whereas that of the long DMA was 15.7 nm to 637.8 nm. Therefore, readings obtained from the long and the nano DMA were compared for different brands as well as for different sources. An overlap was seen in the readings in the common range of measurement. The lowest value of peak concentration was seen for one brand of incense stick (0.9 x 10(6) cm(-3)), whereas the highest (7.1 x 10(6) cm(-3)) was seen for the dhoop. Generally, these sources showed a peak between 140 and 170 nm; however, 2 incense stick brands showed peaks at 79 nm and 89 nm. The dhoop showed results much different from the rest of the sources, with a mode at around 240 nm. Chemical analysis in terms of three heavy metals (cadmium, zinc, and lead) was performed using graphite tube atomizer and flame-atomic absorption spectrophotometer. Calculations were made to assess the expected cancer and noncancer risks, using published toxicity potentials for these three heavy metals. Our calculations revealed that all the sources showed lead concentrations much below the American Conference of Governmental Industrial Hygienists (ACGIH) threshold limit value (TLV) level. One of the two mosquito coil brands (M(2)) showed cadmium concentrations two times higher than the California Environmental

  7. The anthropogenic magnetic particles contain in indoor dust as markers of pollution emitted by different outside sources.

    Science.gov (United States)

    Szczepaniak, Iga; Górka-Kostrubiec, Beata

    2015-04-01

    The aim of the study was to explain the impact of magnetic particles originated from different external sources of pollution on the air quality inside apartments. We used the indoor dust as an indicator of air pollution inside apartments. For the study, a small town was chosen, in which dominated the local sources of pollution: (1) vehicle traffic (in the city center), (2) local heating plant, (3) individual households (in the suburbs) and (4) re-emission of soil particles from the contaminated post-industrial area. In each of four areas were selected several private apartments as a sampling points. Dust samples were collected by the owners of apartments from the floor surface using vacuum cleaners in the same time period (September 2014). The concentration-dependent magnetic parameters (magnetic susceptibility - and magnetization MS) were used to determine the level of the magnetic pollution of the indoor dust. The properties of magnetic particles (mineralogy, domain structure and grain size), and their chemical composition were used to describe and identify the source of air pollution inside the apartments. Generally, the results showed that in each of studied areas were observed flats with both: very high and low values of parameters depending on the concentration of magnetic particles. The biggest differences between the areas were visible in mineralogy of magnetic fraction of pollution. The research of apartments exposed to pollution generated by vehicle traffic (located in the city center) show a wide range of values χ (75-1021 -10-8 m3kg-1) and MS (35-656 -10-3 Am2kg-1). These differences were due to the high contribution of pure iron to magnetic fraction of pollution. Detailed analysis of the M (T) curves revealed two magnetic transitions: first at a temperature Tc = 585oC for magnetite and the second at Tc = 760oC for pure iron. For the dust samples from the city center the high values of χ and MS well correlated with high level of anthropogenic elements

  8. Arterial blood pressure responses to short-term exposure to fine and ultrafine particles from indoor sources - A randomized sham-controlled exposure study of healthy volunteers.

    Science.gov (United States)

    Soppa, Vanessa J; Schins, Roel P F; Hennig, Frauke; Nieuwenhuijsen, Mark J; Hellack, Bryan; Quass, Ulrich; Kaminski, Heinz; Sasse, Birgitta; Shinnawi, Samir; Kuhlbusch, Thomas A J; Hoffmann, Barbara

    2017-10-01

    Particulate air pollution is linked to adverse cardiovascular effects. The aim of the study was to investigate the effect of short-term exposure to indoor particles on blood pressure (BP). We analyzed the association of particle emissions from indoor sources (candle burning, toasting bread, frying sausages) with BP changes in 54 healthy volunteers in a randomized cross-over controlled exposure study. Particle mass concentration (PMC), size-specific particle number concentration (PNC) and lung-deposited particle surface area concentration (PSC) were measured during the 2h exposure. Systolic and diastolic blood pressure were measured before, during, directly, 2, 4 and 24h after exposure. We performed multiple mixed linear regression analyses of different particle metrics and BP. BP significantly increased with increasing PMC, PSC and PNC resulting from toasting bread. For example, an increase per 10µg/m(3) PM10 and PM2.5, systolic BP increased at all time points with largest changes 1h after exposure initiation of 1.5mmHg (95%-CI: 1.1; 1.9) and of 2.2mmHg (95%-CI: 1.3; 3.1), respectively. Our study suggests an association of short-term exposure to fine and ultrafine particles emitted from toasting bread with increases in BP. Particles emitted from frying sausages and candle burning did not consistently affect BP. Copyright © 2017. Published by Elsevier Inc.

  9. Source apportionment of indoor air pollution

    Science.gov (United States)

    Sexton, Ken; Hayward, Steven B.

    An understanding of the relative contributions from important pollutant sources to human exposures is necessary for the design and implementation of effective control strategies. In the past, societal efforts to control air pollution have focused almost exclusively on the outdoor (ambient) environment. As a result, substantial amounts of time and money have been spent to limit airborne discharges from mobile and stationary sources. Yet it is now recognized that exposures to elevated pollutant concentrations often occur as a result of indoor, rather than outdoor, emissions. While the major indoor sources have been identified, their relative impacts on indoor air quality have not been well defined. Application of existing source apportionment models to nonindustrial indoor environments is only just beginning. It is possible that these models might be used to distinguish between indoor and outdoor emissions, as well as to distinguish among indoor sources themselves. However, before the feasibility and suitability of source-apportionment methods for indoor applications can be assessed adequately, it is necessary to take account of model assumptions and associated data requirements. This paper examines the issue of indoor source apportionment and reviews the need for emission characterization studies to support such source-apportionment efforts.

  10. Temporal evolution of ultrafine particles and of alveolar deposited surface area from main indoor combustion and non-combustion sources in a model room.

    Science.gov (United States)

    Manigrasso, Maurizio; Vitali, Matteo; Protano, Carmela; Avino, Pasquale

    2017-11-15

    Aerosol number size distributions, PM mass concentrations, alveolar deposited surface areas (ADSAs) and VOC concentrations were measured in a model room when aerosol was emitted by sources frequently encountered in indoor environments. Both combustion and non-combustion sources were considered. The most intense aerosol emission occurred when combustion sources were active (as high as 4.1×10(7)particlescm(-3) for two meat grilling sessions; the first with exhaust ventilation, the second without). An intense spike generation of nucleation particles occurred when appliances equipped with brush electric motors were operating (as high as 10(6)particlescm(-3) on switching on an electric drill). Average UFP increments over the background value were highest for electric appliances (5-12%) and lowest for combustion sources (as low as -24% for tobacco cigarette smoke). In contrast, average increments in ADSA were highest for combustion sources (as high as 3.2×10(3)μm(2)cm(-3) for meat grilling without exhaust ventilation) and lowest for electric appliances (20-90μm(2)cm(-3)). The health relevance of such particles is associated to their ability to penetrate cellular structures and elicit inflammatory effects mediated through oxidative stress in a way dependent on their surface area. The highest VOC concentrations were measured (PID probe) for cigarette smoke (8ppm) and spray air freshener (10ppm). The highest PM mass concentration (PM1) was measured for citronella candle burning (as high as 7.6mgm(-3)). Copyright © 2017 Elsevier B.V. All rights reserved.

  11. Indoor Particle Contamination in Airlaid Papermaking Workshop

    Institute of Scientific and Technical Information of China (English)

    LIU Junjie; WANG Meng; PEI Jingjing

    2006-01-01

    An onsite testing based on eight-site air sampling was carried out in an airlaid papermaking workshop in Tianjin, China. By theoretical calculation, super absorbent polymer (SAP) size and its existent state in indoor static airflow were obtained. SAP content in the sampled air was test ed through chemical analysis method and found to be 3.0-7.2 times that of the human health limit in production areas. The concentrations of total suspending particles (TSP) and respirable particles were achieved by weighing. Particles of the most concern differ for varied function areas. Particles smaller than 10 μm are mostly produced in the main production process, and 73%-90% particles generated in packing areas are larger than 10 μm. SAP raw material particles can easily changed to suspending form by inevitable extrusion and frication. Correlation between respirable particles andTSP agrees well with that in atmospheric environment.

  12. Quantitative filter forensics for indoor particle sampling.

    Science.gov (United States)

    Haaland, D; Siegel, J A

    2017-03-01

    Filter forensics is a promising indoor air investigation technique involving the analysis of dust which has collected on filters in central forced-air heating, ventilation, and air conditioning (HVAC) or portable systems to determine the presence of indoor particle-bound contaminants. In this study, we summarize past filter forensics research to explore what it reveals about the sampling technique and the indoor environment. There are 60 investigations in the literature that have used this sampling technique for a variety of biotic and abiotic contaminants. Many studies identified differences between contaminant concentrations in different buildings using this technique. Based on this literature review, we identified a lack of quantification as a gap in the past literature. Accordingly, we propose an approach to quantitatively link contaminants extracted from HVAC filter dust to time-averaged integrated air concentrations. This quantitative filter forensics approach has great potential to measure indoor air concentrations of a wide variety of particle-bound contaminants. Future studies directly comparing quantitative filter forensics to alternative sampling techniques are required to fully assess this approach, but analysis of past research suggests the enormous possibility of this approach. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  13. Factors affecting the concentration of outdoor particles indoors (COPI): Identification of data needs and existing data

    Energy Technology Data Exchange (ETDEWEB)

    Thatcher, Tracy L.; McKone, Thomas E.; Fisk, William J.; Sohn, Michael D.; Delp, Woody W.; Riley, William J.; Sextro, Richard G.

    2001-12-01

    The process of characterizing human exposure to particulate matter requires information on both particle concentrations in microenvironments and the time-specific activity budgets of individuals among these microenvironments. Because the average amount of time spent indoors by individuals in the US is estimated to be greater than 75%, accurate characterization of particle concentrations indoors is critical to exposure assessments for the US population. In addition, it is estimated that indoor particle concentrations depend strongly on outdoor concentrations. The spatial and temporal variations of indoor particle concentrations as well as the factors that affect these variations are important to health scientists. For them, knowledge of the factors that control the relationship of indoor particle concentrations to outdoor levels is particularly important. In this report, we identify and evaluate sources of data for those factors that affect the transport to and concentration of outdoor particles in the indoor environment. Concentrations of particles indoors depend upon the fraction of outdoor particles that penetrate through the building shell or are transported via the air handling (HVAC) system, the generation of particles by indoor sources, and the loss mechanisms that occur indoors, such as deposition. To address these issues, we (i) identify and assemble relevant information including the behavior of particles during air leakage, HVAC operations, and particle filtration; (ii) review and evaluate the assembled information to distinguish data that are directly relevant to specific estimates of particle transport from those that are only indirectly useful and (iii) provide a synthesis of the currently available information on building air-leakage parameters and their effect on indoor particle matter concentrations.

  14. Using multiple continuous fine particle monitors to characterize tobacco, incense, candle, cooking, wood burning, and vehicular sources in indoor, outdoor, and in-transit settings

    Science.gov (United States)

    Ott, Wayne R.; Siegmann, Hans C.

    This study employed two continuous particle monitors operating on different measurement principles to measure concentrations simultaneously from common combustion sources in indoor, outdoor, and in-transit settings. The pair of instruments use (a) photo-charging (PC) operating on the principle ionization of fine particles that responds to surface particulate polycyclic aromatic hydrocarbons (PPAHs), and (b) diffusion charging (DC) calibrated to measure the active surface area of fine particles. The sources studied included: (1) secondhand smoke (cigarettes, cigars, and pipes), (2) incense (stick and cone), (3) candles used as food warmers, (4) cooking (toasting bread and frying meat), (5) fireplaces and ambient wood smoke, and (6) in-vehicle exposures traveling on California arterials and interstate highways. The ratio of the PC to the DC readings, or the PC/DC ratio, was found to be different for major categories of sources. Cooking, burning toast, and using a "canned heat" food warmer gave PC/DC ratios close to zero. Controlled experiments with 10 cigarettes averaged 0.15 ng mm -2 (ranging from 0.11 to 0.19 ng mm -2), which was similar to the PC/DC ratio for a cigar, although a pipe was slightly lower (0.09 ng mm -2). Large incense sticks had PC/DC ratios similar to those of cigarettes and cigars. The PC/DC ratios for ambient wood smoke averaged 0.29 ng mm -2 on 6 dates, or about twice those of cigarettes and cigars, reflecting a higher ratio of PAH to active surface area. The smoke from two artificial logs in a residential fireplace had a PC/DC ratio of 0.33-0.35 ng mm -2. The emissions from candles were found to vary, depending on how the candles were burned. If the candle flickered and generated soot, a higher PC/DC ratio resulted than if the candle burned uniformly in still air. Inserting piece of metal into the candle's flame caused high PPAH emissions with a record PC/DC reading of 1.8 ng mm -2. In-vehicle exposures measured on 43- and 50-min drives on a

  15. Ultrafine Particles in Residential Indoors and Doses Deposited in the Human Respiratory System

    Directory of Open Access Journals (Sweden)

    Maurizio Manigrasso

    2015-09-01

    Full Text Available Indoor aerosol sources may significantly contribute to the daily dose of particles deposited into the human respiratory system. Therefore, it is important to characterize the aerosols deriving from the operations currently performed in an indoor environment and also to estimate the relevant particle respiratory doses. For this aim, aerosols from indoor combustive and non-combustive sources were characterized in terms of aerosol size distributions, and the relevant deposition doses were estimated as a function of time, particle diameter and deposition site in the respiratory system. Ultrafine particles almost entirely made up the doses estimated. The maximum contribution was due to particles deposited in the alveolar region between the 18th and the 21st airway generation. When cooking operations were performed, respiratory doses per unit time were about ten-fold higher than the relevant indoor background dose. Such doses were even higher than those associated with outdoor traffic aerosol.

  16. Source apportionment of indoor PM10 in Elderly Care Centre.

    Science.gov (United States)

    Almeida-Silva, M; Faria, T; Saraga, D; Maggos, T; Wolterbeek, H T; Almeida, S M

    2016-04-01

    Source contribution to atmospheric particulate matter (PM) has been exhaustively modelled. However, people spend most of their time indoors where this approach is less explored. This evidence worsens considering elders living in Elderly Care Centres, since they are more susceptible. The present study aims to investigate the PM composition and sources influencing elderly exposure. Two 2-week sampling campaigns were conducted-one during early fall (warm phase) and another throughout the winter (cold phase). PM10 were collected with two TCR-Tecora(®) samplers that were located in an Elderly Care Centre living room and in the correspondent outdoor. Chemical analysis of the particles was performed by neutron activation analysis for element characterization, by ion chromatography for the determination of water soluble ions and by a thermal optical technique for the measurement of organic and elemental carbon. Statistical analysis showed that there were no statistical differences between seasons and environments. The sum of the indoor PM10 components measured in this work explained 57 and 53 % of the total PM10 mass measured by gravimetry in warm and cold campaigns, respectively. Outdoor PM10 concentrations were significantly higher during the day than night (p value < 0.05), as well as Ca(2+), Fe, Sb and Zn. The contribution of indoor and outdoor sources was assessed by principal component analysis and showed the importance of the highways and the airport located less than 500 m from the Elderly Care Centre for both indoor and outdoor air quality.

  17. Indoor-outdoor relationships of respirable sulfates and particles

    Science.gov (United States)

    Dockery, Douglas W.; Spengler, John D.

    Indoor and outdoor concentrations of respirable particulates and sulfates have been measured in 68 homes in six cities for at least 1 yr. A conservation of mass model was derived describing indoor concentrations in terms of outdoor concentrations, infiltration and indoor sources. The measured data were analysed to identify important building characteristics and to quantify their effect. The mean infiltration rate of outdoor fine particulates was found to be approximately 70%. Cigarette smoking was found to be the dominant indoor source of respirable particulates. Increased indoor concentrations of sulfates were found to be associated with smoking and also with gas stoves. The effect of full air conditioning of the building was to reduce infiltration of outdoor fine particulates by about one half, while preventing dilution and purging of internally generated pollutants. The model for indoor respirable particulate and sulfate levels was found to compare well with measurements.

  18. Deposition of fine and ultrafine particles on indoor surface materials

    DEFF Research Database (Denmark)

    Afshari, Alireza; Reinhold, Claus

    2008-01-01

    -scale test chamber. Experiments took place in a 32 m3 chamber with walls and ceiling made of glass. Prior to each experiment the chamber was flushed with outdoor air to reach an initial particle concentration typical of indoor air in buildings with natural ventilation. The decay of particle concentrations...... The aim of this study was the experimental determination of particle deposition for both different particle size fractions and different indoor surface materials. The selected surface materials were glass, gypsum board, carpet, and curtain. These materials were tested vertically in a full...... was monitored. Seven particle size fractions were studied. These comprised ultrafine and fine particles. Deposition was higher on carpet and curtain than on glass and gypsum board. Particles ranging from 0.3 to 0.5 µm had the lowest deposition. This fraction also has the highest penetration and its indoor...

  19. [Dust particles and metals in outdoor and indoor air of Upper Silesia].

    Science.gov (United States)

    Górny, R L; Jedrzejczak, A; Pastuszka, J S

    1995-01-01

    This work contains the results of the aerosol mass size distribution and preliminary studies on concentrations and size distribution of heavy metals (Pb, Zn, Cu, Mn, Fe and Cd) in indoor and outdoor environment in Upper Silesia (the highly industrialized region in the southern part of Poland). In studies, the measurements of aerosol concentration, mass size distribution, and evaluation of heavy metals concentration were made from December 1992 to April 1994 in some apartments in five towns in Upper Silesia and in one village in the Beskidy Mountains in both indoor and outdoor environments. The particles were fractionated in Andersen cascade impactor. The sampling time was 6-7 days and 4-5 days for indoor and outdoor respectively. Aerosol particulates were collected on A-type glass fiber collection substrate used later for determination of heavy concentrations by atomic absorption spectrophotometry (AAS 3, Carl Zeiss Jena). The dust was mineralized by the means of the mixture of hydrofluoric and nitric acids. The results of mass size distribution as well as the measurements of TSP for indoor and outdoor aerosol show that the main source of particulate matter indoors, in this region, are heavy polluted outdoor air and cigarette smoking. It can be said that, except homes in Knurów and Sosnowiec with hard smokers, the indoor levels of particulate pollution were significant lower than the outdoors levels. Whenever in the indoor environment appear additional source of particulate emission situation can changed. When we compare mass size distribution for outdoor aerosol and indoor aerosol contaminated by tobacco smoke, we can observed considerable increase of indoor aerosol level in the 0.33-0.54 microns size range. Besides, indoor aerosol status may be changed by coal stove emission (displacement of maximum peak to direction of coarse particles). The observed differences in concentration of particulate matter may also indicate the important differences in chemical and

  20. Removal of ultrafine particles from indoor environment

    DEFF Research Database (Denmark)

    Ardkapan, Siamak Rahimi

    technologies in order to improve indoor air quality. The objective of this study is to determine the effectiveness of portable air cleaners and to investigate the approaches of using these devices aiming at reducing the concentration of UFPs in the indoor environment. Experimental investigations...... and computational fluid dynamics (CFD) simulations were performed parallel in order to investigate the possibilities, limitations and possible applications to reach this aim. The Danish market was searched for portable air cleaners to be evaluated in the experiments. Five technologies were selected: Non Thermal...

  1. Residential indoor and outdoor coarse particles and associated endotoxin exposures

    Science.gov (United States)

    Wheeler, Amanda J.; Dobbin, Nina A.; Lyrette, Ninon; Wallace, Lance; Foto, Mark; Mallick, Ranjeeta; Kearney, Jill; Van Ryswyk, Keith; Gilbert, Nicolas L.; Harrison, Ian; Rispler, Kathleen; Héroux, Marie-Eve

    2011-12-01

    There is a growing body of evidence demonstrating that coarse particles (PM 10-2.5) have detrimental impacts upon health, especially for respiratory effects. There are limited data available for indoor residential exposures. Some data exist regarding the composition of this PM size fraction with emphasis on crustal elements and biological components. This study includes data from 146 homes sampled in Regina, Saskatchewan (SK) where 5-day integrated concurrent monitoring of indoor and outdoor coarse particles was conducted during the winter and summer of 2007. The coarse particle filters were subsequently analysed for endotoxin content to determine the contribution of this compound. Winter indoor geometric mean concentrations of coarse particles exceeded outdoor concentrations (3.73 μg m -3 vs 2.49 μg m -3; paired t-test p Endotoxin concentrations (EU μg -1) were lower indoors than outdoors in both seasons. Spatial variability of ambient coarse particles was assessed to determine the suitability of using a single monitoring station within a city to estimate exposure. The coefficients of variation between homes sampled simultaneously and the central monitoring station were calculated (median COV in summer = 15% and winter = 24%) and showed significant variability by week, especially during the summer months, suggesting a single site may be insufficient for characterizing exposure. Future studies should consider daily measurements per home to understand shorter term exposures and day to day variability of these pollutants.

  2. Indoor air quality environmental information handbook: Combustion sources

    Energy Technology Data Exchange (ETDEWEB)

    1990-06-01

    This environmental information handbook was prepared to assist both the non-technical reader (i.e., homeowner) and technical persons (such as researchers, policy analysts, and builders/designers) in understanding the current state of knowledge regarding combustion sources of indoor air pollution. Quantitative and descriptive data addressing the emissions, indoor concentrations, factors influencing indoor concentrations, and health effects of combustion-generated pollutants are provided. In addition, a review of the models, controls, and standards applicable to indoor air pollution from combustion sources is presented. The emphasis is on the residential environment. The data presented here have been compiled from government and privately-funded research results, conference proceedings, technical journals, and recent publications. It is intended to provide the technical reader with a comprehensive overview and reference source on the major indoor air quality aspects relating to indoor combustion activities, including tobacco smoking. In addition, techniques for determining potential concentrations of pollutants in residential settings are presented. This is an update of a 1985 study documenting the state of knowledge of combustion-generated pollutants in the indoor environment. 191 refs., 51 figs., 71 tabs.

  3. Groundwater treatment as a source of indoor radon.

    Science.gov (United States)

    Jantsikene, Alar; Kiisk, Madis; Suursoo, Siiri; Koch, Rein; Lumiste, Liie

    2014-11-01

    New Viimsi Parish water treatment plant (Northern Estonia) was investigated in order to determine whether the open filter columns serve as a source of (222)Rn generation in the treatment process and whether they influence indoor air (222)Rn activity concentrations. (222)Rn measurements of indoor (222)Rn were performed at different locations of the treatment plant; water samples from incoming raw water, from all the purification stages, consumers water and solid filter material from two filtration stages were analyzed.

  4. Effect of indoor-generated airborne particles on radon progeny dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Trassierra, C. Vargas [Department of Civil and Mechanical Engineering, University of Cassino and Southern Lazio, Cassino, FR (Italy); Stabile, L., E-mail: l.stabile@unicas.it [Department of Civil and Mechanical Engineering, University of Cassino and Southern Lazio, Cassino, FR (Italy); Cardellini, F.; Morawska, L. [National Institute of Ionizing Radiation Metrology (INMRI-ENEA), Rome (Italy); Buonanno, G. [Department of Civil and Mechanical Engineering, University of Cassino and Southern Lazio, Cassino, FR (Italy); International Laboratory for Air Quality and Health, Queensland University of Technology, Brisbane (Australia)

    2016-08-15

    Highlights: • Investigation of the interaction between particles and radon progeny dynamics. • Measurements of particles emitted by different indoor sources. • Tests performed in a controlled radon chamber. • Particle size strongly influences the radon progeny dynamics. • Particle surface area concentration is the key parameter of the radon-particle interaction. - Abstract: In order to investigate the interaction between radon progeny and particles, an experimental campaign was carried out in a radon chamber at the Italian National Institute of Ionizing Radiation Metrology, quantifying the amount of attached and unattached radon daughters present in air, as well as the equilibrium factor in the presence of particles generated through indoor sources. A fixed radon concentration was maintained, while particles were generated using incense sticks, mosquito coils and gas combustion. Aerosols were characterized in terms of particle concentrations and size distributions. Simultaneously, radon concentration and attached/unattached potential alpha energy concentration in the air were continuously monitored by two different devices, based on alpha spectroscopy techniques. The presence of particles was found to affect the attached fraction of radon decay products, in such a way that the particles acted as a sink for radionuclides. In terms of sources which emit large particles (e.g. incense, mosquito coils), which greatly increase particle surface area concentrations, the Equilibrium Factor was found to double with respect to the background level before particle generation sessions. On the contrary, the radon decay product dynamics were not influenced by gas combustion processes, mainly due to the small surface area of the particles emitted.

  5. Indoor source apportionment in urban communities near industrial sites

    Science.gov (United States)

    Tunno, Brett J.; Dalton, Rebecca; Cambal, Leah; Holguin, Fernando; Lioy, Paul; Clougherty, Jane E.

    2016-08-01

    Because fine particulate matter (PM2.5) differs in chemical composition, source apportionment is frequently used for identification of relative contributions of multiple sources to outdoor concentrations. Indoor air pollution and source apportionment is often overlooked, though people in northern climates may spend up to 90% of their time inside. We selected 21 homes for a 1-week indoor sampling session during summer (July to September 2011), repeated in winter (January to March 2012). Elemental analysis was performed using inductively-coupled plasma mass spectrometry (ICP-MS), and factor analysis was used to determine constituent grouping. Multivariate modeling was run on factor scores to corroborate interpretations of source factors based on a literature review. For each season, a 5-factor solution explained 86-88% of variability in constituent concentrations. Indoor sources (i.e. cooking, smoking) explained greater variability than did outdoor sources in these industrial communities. A smoking factor was identified in each season, predicted by number of cigarettes smoked. Cooking factors were also identified in each season, explained by frequency of stove cooking and stovetop frying. Significant contributions from outdoor sources including coal and motor vehicles were also identified. Higher coal and secondary-related elemental concentrations were detected during summer than winter. Our findings suggest that source contributions to indoor concentrations can be identified and should be examined in relation to health effects.

  6. Effect of source location on particle dispersion in displacement ventilation rooms

    Institute of Scientific and Technical Information of China (English)

    Ke Zhong; Yanming Kang; Youjun Wang

    2008-01-01

    A proposed computer model for predicting aerosol particle dispersion in indoor spaces was validated with experimental data found in the literature,and is then used to study the effect of the area and point source locations on particle dispersion in displacement ventilation (DV) rooms.The results show that aerosol source location has a strong impact on the spatial distribution and removal rate of indoor particles.Particle removal performance depends strongly on ventilation efficiency and particle deposition rate on indoor surfaces.Important consideration for both relative ventilation efficiency and deposition rate consists of the position of the aerosol source relative to the main airflow pattern and the occupied zone.

  7. Characterisation of particle emissions from the driving car fleet and the contribution to ambient and indoor particle concentrations

    Science.gov (United States)

    Palmgren, Finn; Wåhlin, Peter; Kildesø, Jan; Afshari, Alireza; Fogh, Christian L.

    The population is mainly exposed to high air pollution concentrations in the urban environment, where motor vehicle emissions constitute the main source of fine and ultrafine particles. These particles can penetrate deep into the respiratory system, and studies indicate that the smaller the particle, the larger the health impacts. The chemical composition, surface reactivity and physical properties are also important. However, the knowledge about chemical and physical properties of particles and the temporal and spatial variability of the smallest particles is still very limited. The present study summarises the first results of a larger project with the aims to improve the knowledge. The concentration and the emissions of ultrafine particles from petrol and diesel vehicles, respectively, have been quantified using Scanning Mobility Particle Sizer of ultrafine particles in the size range 6-700 nm and routine monitoring data from urban streets and urban background in Denmark. The quantification was carried out using receptor modelling. The number size distributions of petrol and diesel emissions showed a maximum at 20-30 nm and non-traffic at ≈100 nm. The contribution of ultrafine particles from diesel vehicles is dominating in streets. The same technique has been applied on PM 10, and ≈50% contribution from non-traffic. The technique has also been introduced in relation to elemental and organic carbon, and the first data showed strong correlation between traffic pollution and elemental carbon. The outdoor air quality has a significant effect on indoor pollution levels, and we spend most of the time indoors. Knowledge about the influence of ambient air pollution on the concentrations in the indoor environment is therefore crucial for assessment of human health effects of traffic pollution. The results of our studies will be included in air quality models for calculation of human exposure. Preliminary results from our first campaign showed, that the deposition

  8. A Particle Filter for Smartphone-Based Indoor Pedestrian Navigation

    Directory of Open Access Journals (Sweden)

    Andrea Masiero

    2014-11-01

    Full Text Available This paper considers the problem of indoor navigation by means of low-cost mobile devices. The required accuracy, the low reliability of low-cost sensor measurements and the typical unavailability of the GPS signal make indoor navigation a challenging problem. In this paper, a particle filtering approach is presented in order to obtain good navigation performance in an indoor environment: the proposed method is based on the integration of information provided by the inertial navigation system measurements, the radio signal strength of a standard wireless network and of the geometrical information of the building. In order to make the system as simple as possible from the user’s point of view, sensors are assumed to be uncalibrated at the beginning of the navigation, and an auto-calibration procedure of the magnetic sensor is performed to improve the system performance: the proposed calibration procedure is performed during regular user’s motion (no specific work is required. The navigation accuracy achievable with the proposed method and the results of the auto-calibration procedure are evaluated by means of a set of tests carried out in a university building.

  9. Transmitter antenna placement in indoor environments using particle swarm optimisation

    Science.gov (United States)

    Talepour, Zeinab; Tavakoli, Saeed; Ahmadi-Shokouh, Javad

    2013-07-01

    The aim of this article is to suitably locate the minimum number of transmitter antennas in a given indoor environment to achieve good propagation coverage. To calculate the electromagnetic field in various points of the environment, we develop a software engine, named ray-tracing engine (RTE), in Matlab. To achieve realistic calculations, all parameters of geometry and material of building are considered. Particle swarm optimisation is employed to determine good location of transmitters. Simulation results show that a full coverage is obtained through suitably locating three transmitters.

  10. Are Cockroaches an Important Source of Indoor Endotoxins?

    Science.gov (United States)

    Lai, Ka Man

    2017-01-18

    Endotoxins are common indoor biocontaminants. Their levels have been shown to link to many sources and factors. One of them is cockroach infestation but the role of cockroaches and contamination mechanisms are unclear. We hypothesized that not only is cockroach infestation a sign of poor hygiene, but it also contributes to indoor endotoxins via fecal contamination. In this study, different cockroach species were caught in homes. The endotoxin and allergen levels and their ratios in cockroach feces were determined. To estimate the amount of indoor endotoxins that originated from cockroaches, a new approach of using these new cockroach endotoxin and allergen ratios to compare with environmental data was employed. We found that Supella (S.) longipalpa, Periplaneta (P.) australasiae, and Blattella (B.) germanica were dominant in homes. On average, P. australasiae feces had a higher level but greater variation of endotoxins. B. germanica feces had the highest levels of allergens measured. Depending on environmental bacterial load and the type of cockroaches present, cockroach endotoxins in the environment may vary greatly. Cockroaches directly contribute to indoor endotoxins rather than just being a sign of poor hygiene. The type and extent of cockroach infestation should be taken into consideration when assessing and remediating indoor endotoxin contamination.

  11. Airborne particles in indoor environment of homes, schools, offices and aged care facilities: The main routes of exposure.

    Science.gov (United States)

    Morawska, L; Ayoko, G A; Bae, G N; Buonanno, G; Chao, C Y H; Clifford, S; Fu, S C; Hänninen, O; He, C; Isaxon, C; Mazaheri, M; Salthammer, T; Waring, M S; Wierzbicka, A

    2017-11-01

    It has been shown that the exposure to airborne particulate matter is one of the most significant environmental risks people face. Since indoor environment is where people spend the majority of time, in order to protect against this risk, the origin of the particles needs to be understood: do they come from indoor, outdoor sources or both? Further, this question needs to be answered separately for each of the PM mass/number size fractions, as they originate from different sources. Numerous studies have been conducted for specific indoor environments or under specific setting. Here our aim was to go beyond the specifics of individual studies, and to explore, based on pooled data from the literature, whether there are generalizable trends in routes of exposure at homes, schools and day cares, offices and aged care facilities. To do this, we quantified the overall 24h and occupancy weighted means of PM10, PM2.5 and PN - particle number concentration. Based on this, we developed a summary of the indoor versus outdoor origin of indoor particles and compared the means to the WHO guidelines (for PM10 and PM2.5) and to the typical levels reported for urban environments (PN). We showed that the main origins of particle metrics differ from one type of indoor environment to another. For homes, outdoor air is the main origin of PM10 and PM2.5 but PN originate from indoor sources; for schools and day cares, outdoor air is the source of PN while PM10 and PM2.5 have indoor sources; and for offices, outdoor air is the source of all three particle size fractions. While each individual building is different, leading to differences in exposure and ideally necessitating its own assessment (which is very rarely done), our findings point to the existence of generalizable trends for the main types of indoor environments where people spend time, and therefore to the type of prevention measures which need to be considered in general for these environments. Copyright © 2017 The Authors

  12. Distribution of polybrominated diphenyl ethers and dust particle size fractions adherent to skin in indoor dust, Pretoria, South Africa.

    Science.gov (United States)

    Kefeni, Kebede Keterew; Okonkwo, Jonathan O

    2014-03-01

    In order to determine human exposure to the indoor toxicant, selection of dust fraction and understanding dust particle size distribution in settled indoor dust are very important. This study examined the influence of dust particle size on the concentration of polybrominated diphenyl ethers (PBDEs) congeners, assessed the distribution of dust particle size and characterized the main indoor emission sources of PBDEs. Accordingly, the concentrations of PBDE congeners determined in different indoor dust fractions were found to be relatively higher in the order of dust particle size: 45-106 μm>(106-150 μm. The finding shows arbitrary selection of dust fractions for exposure determination may result in wrong conclusions. Statistically significant moderate correlation between the concentration of Σ9PBDEs and organic matter content calculated with respect to the total dust mass was also observed (r=0.55, p=0.001). On average, of total dust particle size <250 μm, 93.4 % (m/m%) of dust fractions was associated with less than 150 μm. Furthermore, of skin adherent dust fractions considered (<150 μm), 86 % (v/v%) is in the range of particle size 9.25-104.7 μm. Electronic materials treated with PBDEs were found the main emission sources of PBDE congeners in indoor environment. Based on concentrations of PBDEs determined and mass of indoor dust observed, 150 μm metallic sieve is adequate for human exposure risk assessment. However, research in this area is very limited and more research is required to generalize the fact.

  13. Indoor emission, dispersion and exposure of total particle-bound polycyclic aromatic hydrocarbons during cooking

    Science.gov (United States)

    Gao, Jun; Jian, Yating; Cao, Changsheng; Chen, Lei; Zhang, Xu

    2015-11-01

    Cooking processes highly contribute to indoor polycyclic aromatic hydrocarbon (PAH) pollution. High molecular weight and potentially carcinogenic PAHs are generally found attached to small particles, i.e., particulate phase PAHs (PPAHs). Due to the fact that indoor particle dynamics have been clear, describing the indoor dynamics of cooking-generated PPAHs within a specific time span is possible. This paper attempted to quantify the dynamic emission rate, simultaneous spatial dispersion and individual exposure of PPAHs using a cooking source. Experiments were conducted in a real-scale kitchen chamber to elucidate the time-resolved emission and effect of edible oil temperature and mass. Numerical simulations based on indoor particle dynamics were performed to obtain the spatial dispersion and individual inhalation intake of PPAHs under different emission and ventilation conditions. The present work examined the preheating cooking stage, at which edible oil is heated up to beyond its smoke point. The dynamic emission rate peak point occurred much earlier than the oil heating temperature. The total PPAH emission ranged from 2258 to 6578 ng upon heating 40-85 g of edible oil. The overall intake fraction by an individual within a period of 10 min, including 3 min for heating and 7 min for natural cooling, was generally ∼1/10,000. An important outcome of this work was that the overall intake fraction could be represented by multiplying the range hood escape efficiency by the inhalation-to-ventilation rate ratio, which would be no greater than the same ratio. The methodology and results of this work were extendible for the number-based assessment of PPAHs. This work is expected to help us understand the health risks due to inhalation exposure to cooking-generated PPAHs in the kitchen.

  14. Identification of tobacco smoke components in indoor breathable particles by SEM-EDS

    Science.gov (United States)

    Slezakova, K.; Pires, J. C. M.; Martins, F. G.; Pereira, M. C.; Alvim-Ferraz, M. C.

    2011-02-01

    Tobacco smoke is one of the greatest sources of indoor particles, which has been linked with serious health effects. Consequently, there has been a widespread interest in analysing tobacco related indoor particulate matter (PM). Nevertheless, the majority of performed studies focused on bulk chemical composition of tobacco related PM, but the knowledge of individual tobacco smoke particles is still limited. Therefore, more information on PM should be provided, namely concerning morphological and chemical characterisation of individual particles. Aiming to further understand the impact of tobacco smoke on human health, this work studied the influence of tobacco smoke on chemical and morphological characteristics of PM 10 and PM 2.5, collected at one site influenced by smoking and at one reference (non-smoking) site. Chemical and morphological characteristics of 4000 individual particles were determined by Scanning Electron Microscopy (SEM) combined with X-ray microanalysis (by Energy Dispersive Spectrometer - EDS). Cluster analysis (CA) was used to classify different particle groups that occurred in PM, aiming the identification of the respective emission sources. The results showed that tobacco smoke influenced the characteristics of both fine and coarse particles, this influence being stronger for fine fraction. The abundance of particles associated with tobacco smoke was 27% and 5% for PM 2.5 and PM 2.5-10, respectively; as expected, those particles were not identified in PM 2.5 and PM 2.5-10 of the reference (non-smoking) site. The results showed that at both sites PM was also influenced by outdoor sources. For PM 2.5-10, outdoor particles essentially originated from natural sources accounting for 35% and 15% at the smoking and reference sites, respectively. For PM 2.5, outdoor particles account for 38% and 29% at the smoking and reference sites, respectively; these particles showed considerable contribution (13% and 17%) from anthropogenic sources (mainly from

  15. Incense, sparklers and cigarettes are significant contributors to indoor benzene and particle levels

    Directory of Open Access Journals (Sweden)

    Werner Tirler

    2015-03-01

    Full Text Available Introduction. The increased use of incense, magic candles and other flameless products often produces indoor pollutants that may represent a health risk for humans. Today, in fact, incense and air fresheners are used inside homes as well as in public places including stores, shopping malls and places of worship. As a source of indoor contamination, the impact of smoke, incense and sparklers on human health cannot be ignored. Aim. In the present work, we report the results of an emission study regarding particles (PM10 and particle number concentration, PNC and benzene, produced by various incense sticks and sparklers. Results and discussion.The results obtained for benzene, PM10 and PNC, showed a strong negative influence on air quality when these products were used indoors. Various incense sticks gave completely different benzene results: from a small increase of the benzene concentration in the air, just slightly above the background levels of ambient air, to very high concentrations, of more than 200 µg/m³ of benzene in the test room after the incense sticks had been tested.

  16. Indoor aerosols

    DEFF Research Database (Denmark)

    Morawska, L.; Afshari, Alireza; N. Bae, G.

    2013-01-01

    Motivated by growing considerations of the scale, severity, and risks associated with human exposure to indoor particulate matter, this work reviewed existing literature to: (i) identify state-of-the-art experimental techniques used for personal exposure assessment; (ii) compare exposure levels...... reported for domestic/school settings in different countries (excluding exposure to environmental tobacco smoke and particulate matter from biomass cooking in developing countries); (iii) assess the contribution of outdoor background vs indoor sources to personal exposure; and (iv) examine scientific...... understanding of the risks posed by personal exposure to indoor aerosols. Limited studies assessing integrated daily residential exposure to just one particle size fraction, ultrafine particles, show that the contribution of indoor sources ranged from 19% to 76%. This indicates a strong dependence on resident...

  17. Particle Acceleration in Astrophysical Sources

    CERN Document Server

    Amato, Elena

    2015-01-01

    Astrophysical sources are extremely efficient accelerators. Some sources emit photons up to multi-TeV energies, a signature of the presence, within them, of particles with energies much higher than those achievable with the largest accelerators on Earth. Even more compelling evidence comes from the study of Cosmic Rays, charged relativistic particles that reach the Earth with incredibly high energies: at the highest energy end of their spectrum, these subatomic particles are carrying a macroscopic energy, up to a few Joules. Here I will address the best candidate sources and mechanisms as cosmic particle accelerators. I will mainly focus on Galactic sources such as Supernova Remnants and Pulsar Wind Nebulae, which being close and bright, are the best studied among astrophysical accelerators. These sources are held responsible for most of the energy that is put in relativistic particles in the Universe, but they are not thought to accelerate particles up to the highest individual energies, $\\approx 10^{20}$ eV...

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

    Science.gov (United States)

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

    2015-01-01

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

  19. Mass balance source apportionment modeling of indoor air pollution exposures during the Ethiopian coffee ceremony.

    Science.gov (United States)

    Keil, Chris; Coleman, Quincy; Brown, Alex; Kassa, Hailu

    2014-01-01

    Mass balance modeling was used to apportion previously measured carbon monoxide and respirable particle exposures of women preparing coffee during Ethiopian coffee ceremonies. The coffee ceremony generates smoke indoors from the use of charcoal and incense. This creates inhalation exposures, particularly for the women preparing the coffee. Understanding the health risks associated with this practice will be improved with knowledge of the relative contribution to combustion byproduct exposures from the different sources. Source fingerprints were developed in the laboratory for carbon monoxide and respirable particle emissions from charcoal and incense. A mass balance model determined that the majority of the carbon monoxide exposures were from charcoal use and that the respirable particle exposures were approximately half from incense and half from charcoal. Efforts to decrease health risks from these exposures must be directed by Ethiopian cultural stakeholders who understand the exposure conditions, the health risks, and the societal context.

  20. Exposure to ultrafine particles in relation to indoor events and dwelling characteristics

    DEFF Research Database (Denmark)

    Spilak, Michal; Frederiksen, Marie; Kolarik, Barbara

    2014-01-01

    Exposure to ultrafine particles (UFP) in homes is associated with health risks such as cardiovascular disease and/or respiratory problems. These risks are heightened by the long time that people spend indoors. Therefore reducing the particle concentration in homes leads to improved health among i....... Furthermore, the winter season was associated significantly with high UFP levels indoors. Results of our study also indicated that owning a pet, wood-type floors and floor levels close to the ground are associated with increased UFP levels....... occupants. The use of particle filtration units may be an effective way of reducing UFP indoors. The purpose of this study was to evaluate associations between UFP concentrations and dwelling characteristics, estimate UFP removal rates indoors and to assess the effectiveness of installed particle filtration...

  1. RELATIVE LEVELS OF INDOOR AND OUTDOOR PARTICLE NUMBER CONCENTRATIONS IN A RESIDENTIAL BUILDING IN XI'AN

    Institute of Scientific and Technical Information of China (English)

    Yanming Kang; Ke Zhong; Shun-Cheng Lee

    2006-01-01

    The time series of indoor and outdoor particle number concentrations in a naturally ventilated residential building in Xi'an were tested simultaneously for 7 days in summer. The relationships between indoor and outdoor concentrations were examined and discussed, and linear regression analysis was employed to correlate the indoor and outdoor concentrations. The diurnal cycles of indoor and outdoor particle concentrations of different particle size ranges all showed positive correlations between indoor and outdoor number concentrations. The I/O ratios of number concentrations varied with the increase of particle size in the range of 0.89 (±0.19) to 0.99 (±0.15).

  2. Small particles containing phthalic esters in the indoor environment - a pilot study

    DEFF Research Database (Denmark)

    Lundgren, B.; Bornehag, Carl-Gustaf; Cedhaim, L.

    2002-01-01

    Many chemicals in polymeric materials have low vapour pressure. Hypothetically such chemicals are emitted and may stay as particles or be adsorbed onto dust particles and become airborne. The aim of this pilot study has been to validate the methods for measuring phthalates on particles in indoor...

  3. Sources of Combustion Products: An Introduction to Indoor Air Quality

    Science.gov (United States)

    In addition to environmental tobacco smoke, other sources of combustion products are unvented kerosene and gas space heaters, woodstoves, fireplaces, and gas stoves. The major pollutants released are carbon monoxide, nitrogen dioxide, and particles.

  4. Chemical Source Localization using Mobile Robots in Indoor Arena

    Directory of Open Access Journals (Sweden)

    Yuli Zhang

    2013-07-01

    Full Text Available This paper presents a virtual-physics force based control strategy for swarm robotic chemical source localization. The control force includes: structure formation force, goal force, and obstacle avoidant force. For swarm formation, the robots maintain the regular polygon formation and a virtual robot is located at the center of the polygon. The motion of the virtual robot depends on the goal force which obtained from the sensor observations of the robots. Once the virtual robot moved to a new place, the robots would also move as a single body with the structure formation force and obstacle avoidant force. In this paper, we adopted chemotaxis as plume tracing algorithms. Simulation experiments in indoor arena without obstacle and with obstacles using different robot number are carried out respectively, and the results show that the proposed strategy can effectively navigate the mobile robotics swarms to the chemical source once selecting proper number of robots.  

  5. Indoor bioaerosol dynamics.

    Science.gov (United States)

    Nazaroff, William W

    2016-02-01

    Inhaling indoor air is the primary means by which humans are exposed to bioaerosols. Considering bacteria, fungi, and viruses, this study reviews the dynamic processes that govern indoor concentrations and fates of biological particulate material. Bioaerosol behavior is strongly coupled to particle size; this study emphasizes the range 0.1-10 μm in aerodynamic diameter. The principle of material balance allows concentrations to be determined from knowledge of important source and removal processes. Sources reviewed here include outdoor air introduced by air exchange plus indoor emission from occupants, occupant activities, and moldy materials. Important mechanisms that remove bioaerosols from indoor air include air exchange, deposition onto indoor surfaces, and active filtration. The review summarizes knowledge about size-dependent particle deposition in different regions of the respiratory tract, techniques for measuring indoor bioaerosols, and evidence for diseases caused by airborne exposure to bioaerosols. Future research challenges and opportunities are highlighted.

  6. Infant respiratory symptoms associated with indoor heating sources.

    Science.gov (United States)

    Triche, Elizabeth W; Belanger, Kathleen; Beckett, William; Bracken, Michael B; Holford, Theodore R; Gent, Janneane; Jankun, Thomas; McSharry, Jean-Ellen; Leaderer, Brian P

    2002-10-15

    This study examined the effects of indoor heating sources on infant respiratory symptoms during the heating season of the first year of life. Mothers delivering babies between 1993 and 1996 at 12 hospitals in Connecticut and Virginia were enrolled. Daily symptom and heating source use information about their infant was obtained every 2 weeks during the first year of life. Heating sources included fireplace, wood stove, kerosene heater, and gas space heater use. Four health outcomes were analyzed by reporting period: days of wheeze, episodes of wheeze, days of cough, and episodes of cough. A large percentage of infants had at least one episode of cough (88%) and wheeze (33%) during the heating season of the first year of life. Wood stove, fireplace, kerosene heater, and gas space heater use was intermittent across the study period. In adjusted Poisson regression models controlling for important confounders, gas space heater use was associated with episodes and days of wheeze. Wood stove use was associated with total days of cough, and kerosene heater use was associated with episodes of cough. Fireplace use was not associated with any of the respiratory symptoms. Use of some heating sources appears related to respiratory symptoms in infants.

  7. Indoor-outdoor particle effects on health in middle-aged and elderly

    DEFF Research Database (Denmark)

    Karottki, Dorina Gabriela; Bekö, Gabriel; Hemmingsen, Jette G.;

    2016-01-01

    support detrimental effect of UFP from traffic on vascular function. Indoor UFP and PM2.5 might contribute to cardiovascular risk through endothelial damage and vascular dysfunction, respectively, whereas indoor UFP dominated by candle burning appears to have adverse lung effects. The biomarkers provided......A series of 5 studies in a total of 300 middle-aged and elderly individuals have related exposure to indoor and outdoor ultrafine and fine particles for 5-48 h to effects on vascular and lung function with possible explanatory inflammation and oxidative stress biomarkers. The data consistently...

  8. Sources and dynamics of fluorescent particles in hospitals.

    Science.gov (United States)

    Pereira, M L; Knibbs, L D; He, C; Grzybowski, P; Johnson, G R; Huffman, J A; Bell, S C; Wainwright, C E; Matte, D L; Dominski, F H; Andrade, A; Morawska, L

    2017-09-01

    Fluorescent particles can be markers of bioaerosols and are therefore relevant to nosocomial infections. To date, little research has focused on fluorescent particles in occupied indoor environments, particularly hospitals. In this study, we aimed to determine the spatial and temporal variation of fluorescent particles in two large hospitals in Brisbane, Australia (one for adults and one for children). We used an Ultraviolet Aerodynamic Particle Sizer (UVAPS) to identify fluorescent particle sources, as well as their contribution to total particle concentrations. We found that the average concentrations of both fluorescent and non-fluorescent particles were higher in the adults' hospital (0.06×10(6) and 1.20×10(6)  particles/m(3) , respectively) than in the children's hospital (0.03×10(6) and 0.33×10(6)  particles/m(3) , respectively) (Pparticles was higher in the children's hospital. Based on the concentration results and using activity diaries, we were able to identify sources of particle production within the two hospitals. We demonstrated that particles can be easily generated by a variety of everyday activities, which are potential sources of exposure to pathogens. Future studies to further investigate their role in nosocomial infection are warranted. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  9. Indoor Particles Affect Vascular Function in the Aged

    DEFF Research Database (Denmark)

    Bräuner, Elvira Vaclavik; Forchhammer, Lykke; Møller, Peter

    2008-01-01

    -selectin, plasma amyloid A, C-reactive protein, fibrinogen, interleukin-6, tumor necrosis factor alpha, protein oxidation measured as 2-aminoadipic semialdehyde in plasma, urinary 8-iso-prostaglandin F2 and blood pressure. Indoor air filtration significantly improved microvascular function by 8.1% (95% confidence...

  10. Particle size distributions, PM2.5 concentrations and water- soluble inorganic ions in different public indoor environments: a case study in Jinan, China

    Institute of Scientific and Technical Information of China (English)

    Can DONG; Lingxiao YANG; Chao YAN; Qi YUAN; Yangchun YU; Wenxing WANG

    2013-01-01

    In this study, we collected particles with aerodynamic diameter≤2.5μm (PM2.5) from three different public indoor places (a supermarket, a commercial office, and a university dining hall) in Jinan, a medium-sized city located in northern China. Water- soluble inorganic ions of PM2.5 and particle size distributions were also measured. Both indoor and outdoor PM2.5 levels (102.3-143.8 μg·m- 3 and 160.2-301.3 μg·m-3, respectively) were substantially higher than the value recommended by the World Health Organization (25 I.μg·m-3), and outdoor sources were found to be the major contributors to indoor pollutants. Diurnal particle number size distributions were different, while the maximum volume concentrations all appeared to be approximately 300nm in the three indoor locations. Concentrations of indoor and outdoor PM2.5 were shown to exhibit the same variation trends for the supermarket and dining hall. For the office, PM2.5 concentrations during nighttime were observed to decrease sharply. Among others, SO42-, NH4+ and NO3- were found to be the dominant water-soluble ions of both indoor and outdoor particles. Concentrations of NO3- in the supermarket and office during the daytime were observed to decrease sharply, which might be attributed to the fact that the indoor temperature was much higher than the outdoor temperature. In addition, domestic activities such as cleaning, water usage, cooking, and smoking also played roles in degraded indoor air quality. However, the results obtained here might be negatively impacted by the small number of samples and short sampling durations.

  11. Reduction of indoor particles concentration using re-circulating filtration units in Danish dwellings

    DEFF Research Database (Denmark)

    Spilak, Michal; Frederiksen, Marie; Karottki, Gabriela D.;

    2012-01-01

    Exposure to particulate matter has been shown to be associated with an increased risk of cardiovascular and respiratory diseases. The indoor environment contributes significantly to the total exposure to air pollution because of the many hours spent here, quantity of sources and low ventilation....... This exposure can be reduced by using re-circulating filtration units, limiting the impact of outdoor pollution penetration, indoor emissions and decomposition of dust on heated surfaces. The objective of this study was to investigate whether reducing the indoor particulate concentration, by means of specially...

  12. Indoor heating sources and respiratory symptoms in nonsmoking women.

    Science.gov (United States)

    Triche, Elizabeth W; Belanger, Kathleen; Bracken, Michael B; Beckett, William S; Holford, Theodore R; Gent, Janneane F; McSharry, Jean-Ellen; Leaderer, Brian P

    2005-05-01

    Secondary heating appliances are important indoor sources of air pollution, including particulate matter, nitrogen dioxide (NO2), and sulfur dioxide (SO2). We hypothesized that the use of secondary heating sources increases respiratory symptoms in women living in nonsmoking households and specifically that concentrations of SO2 and NO2 emitted from heating sources are associated with respiratory symptoms. Mothers who delivered babies at 12 hospitals in Connecticut and Virginia (1993-1996) were enrolled. There were 888 women who contributed symptom and exposure information during the winter heating season (15 October to 15 April), for a total of 9783 reporting periods (median = 12 reporting periods per woman, interquartile range 11-12). Adjusted rate ratios (RRs) of effects of source use and measured concentrations on rate of days with symptoms were obtained using generalized estimating equations for a log-linear Poisson model, controlling age, education, race, history of allergies, number of children, dwelling type, and residence state. In adjusted models, each hour-per-day increase in kerosene heater use is associated with an increase in wheezing (RR = 1.06; 95% confidence interval (CI) = 1.01-1.11). Each hour of fireplace use is associated with increased cough (1.05; 1.01-1.09), sore throat (1.04; 1.00-1.08), and marginally with chest tightness (1.05; 0.99-1.12). Each 10 ppb increase in SO2 (a proxy for sulfate aerosol) is associated with increased wheezing (1.57; 1.10-2.26) and chest tightness (1.32; 1.01-1.71). Emissions from fireplaces, gas space heaters, and kerosene heaters may contribute to respiratory symptoms in a population of nonsmoking women.

  13. A Robust Indoor Autonomous Positioning System Using Particle Filter Based on ISM Band Wireless Communications

    Science.gov (United States)

    Ikeda, Takeshi; Kawamoto, Mitsuru; Sashima, Akio; Suzuki, Keiji; Kurumatani, Koichi

    In the field of the ubiquitous computing, positioning systems which can provide users' location information have paid attention as an important technical element which can be applied to various services, for example, indoor navigation services, evacuation services, market research services, guidance services, and so on. A lot of researchers have proposed various outdoor and indoor positioning systems. In this paper, we deal with indoor positioning systems. Many conventional indoor positioning systems use expensive infrastructures, because the propagated times of radio waves are used to measure users' positions with high accuracy. In this paper, we propose an indoor autonomous positioning system using radio signal strengths (RSSs) based on ISM band communications. In order to estimate users' positions, the proposed system utilizes a particle filter that is one of the Monte Carlo methods. Because the RSS information is used in the proposed system, the equipments configuring the system are not expensive compared with the conventional indoor positioning systems and it can be installed easily. Moreover, because the particle filter is used to estimate user's position, even if the RSS fluctuates due to, for example, multi-paths, the system can carry out position estimation robustly. We install the proposed system in one floor of a building and carry out some experiments in order to verify the validity of the proposed system. As a result, we confirmed that the average of the estimation errors of the proposed system was about 1.8 m, where the result is enough accuracy for achieving the services mentioned above.

  14. Radon in indoor concentrations and indoor concentrations of metal dust particles in museums and other public buildings.

    Science.gov (United States)

    Carneiro, G L; Braz, D; de Jesus, E F; Santos, S M; Cardoso, K; Hecht, A A; Dias da Cunha, Moore K

    2013-06-01

    The aim of this study was to evaluate the public and occupational exposure to radon and metal-bearing particles in museums and public buildings located in the city of Rio de Janeiro, Brazil. For this study, four buildings were selected: two historic buildings, which currently house an art gallery and an art museum; and two modern buildings, a chapel and a club. Integrated radon concentration measurements were performed using passive radon detectors with solid state nuclear track detector-type Lexan used as nuclear track detector. Air samplers with a cyclone were used to collect the airborne particle samples that were analyzed by the particle-induced X-ray emission technique. The average unattached-radon concentrations in indoor air in the buildings were above 40 Bq/m(3), with the exception of Building D as measured in 2009. The average radon concentrations in indoor air in the four buildings in 2009 were below the recommended reference level by World Health Organization (100 Bq/m(3)); however, in 2011, the average concentrations of radon in Buildings A and C were above this level, though lower than 300 Bq/m(3). The average concentrations of unattached radon were lower than 148 Bq/m(3) (4pCi/L), the USEPA level recommended to take action to reduce the concentrations of radon in indoor air. The unattached-radon average concentrations were also lower than the value recommended by the European Union for new houses. As the unattached-radon concentrations were below the international level recommended to take action to reduce the radon concentration in air, it was concluded that during the period of sampling, there was low risk to human health due to the inhalation of unattached radon in these four buildings.

  15. A novel particle filter approach for indoor positioning by fusing WiFi and inertial sensors

    Institute of Scientific and Technical Information of China (English)

    Zhu Nan; Zhao Hongbo; Feng Wenquan; Wang Zulin

    2015-01-01

    WiFi fingerprinting is the method of recording WiFi signal strength from access points (AP) along with the positions at which they were recorded, and later matching those to new mea-surements for indoor positioning. Inertial positioning utilizes the accelerometer and gyroscopes for pedestrian positioning. However, both methods have their limitations, such as the WiFi fluctuations and the accumulative error of inertial sensors. Usually, the filtering method is used for integrating the two approaches to achieve better location accuracy. In the real environments, especially in the indoor field, the APs could be sparse and short range. To overcome the limitations, a novel particle filter approach based on Rao Blackwellized particle filter (RBPF) is presented in this paper. The indoor environment is divided into several local maps, which are assumed to be independent of each other. The local areas are estimated by the local particle filter, whereas the global areas are com-bined by the global particle filter. The algorithm has been investigated by real field trials using a WiFi tablet on hand with an inertial sensor on foot. It could be concluded that the proposed method reduces the complexity of the positioning algorithm obviously, as well as offers a significant improvement in position accuracy compared to other conventional algorithms, allowing indoor positioning error below 1.2 m.

  16. A novel particle filter approach for indoor positioning by fusing WiFi and inertial sensors

    Directory of Open Access Journals (Sweden)

    Zhu Nan

    2015-12-01

    Full Text Available WiFi fingerprinting is the method of recording WiFi signal strength from access points (AP along with the positions at which they were recorded, and later matching those to new measurements for indoor positioning. Inertial positioning utilizes the accelerometer and gyroscopes for pedestrian positioning. However, both methods have their limitations, such as the WiFi fluctuations and the accumulative error of inertial sensors. Usually, the filtering method is used for integrating the two approaches to achieve better location accuracy. In the real environments, especially in the indoor field, the APs could be sparse and short range. To overcome the limitations, a novel particle filter approach based on Rao Blackwellized particle filter (RBPF is presented in this paper. The indoor environment is divided into several local maps, which are assumed to be independent of each other. The local areas are estimated by the local particle filter, whereas the global areas are combined by the global particle filter. The algorithm has been investigated by real field trials using a WiFi tablet on hand with an inertial sensor on foot. It could be concluded that the proposed method reduces the complexity of the positioning algorithm obviously, as well as offers a significant improvement in position accuracy compared to other conventional algorithms, allowing indoor positioning error below 1.2 m.

  17. Indoor aerosols

    DEFF Research Database (Denmark)

    Morawska, L.; Afshari, Alireza; N. Bae, G.;

    2013-01-01

    reported for domestic/school settings in different countries (excluding exposure to environmental tobacco smoke and particulate matter from biomass cooking in developing countries); (iii) assess the contribution of outdoor background vs indoor sources to personal exposure; and (iv) examine scientific......Motivated by growing considerations of the scale, severity, and risks associated with human exposure to indoor particulate matter, this work reviewed existing literature to: (i) identify state-of-the-art experimental techniques used for personal exposure assessment; (ii) compare exposure levels...... are likely to be a dominant environmental factor affecting human health. However, due to challenges associated with conducting epidemiological assessments, the role of indoor-generated particles has not been fully acknowledged, and improved exposure/risk assessment methods are still needed, together...

  18. Fine particles in homes of predominantly low-income families with children and smokers: Key physical and behavioral determinants to inform indoor-air-quality interventions

    Science.gov (United States)

    Bellettiere, John; Hughes, Suzanne C.; Nguyen, Benjamin; Berardi, Vincent; Liles, Sandy; Obayashi, Saori; Hofstetter, C. Richard; Blumberg, Elaine; Hovell, Melbourne F.

    2017-01-01

    Children are at risk for adverse health outcomes from occupant-controllable indoor airborne contaminants in their homes. Data are needed to design residential interventions for reducing low-income children's pollutant exposure. Using customized air quality monitors, we continuously measured fine particle counts (0.5 to 2.5 microns) over a week in living areas of predominantly low-income households in San Diego, California, with at least one child (under age 14) and at least one cigarette smoker. We performed retrospective interviews on home characteristics, and particle source and ventilation activities occurring during the week of monitoring. We explored the relationship between weekly mean particle counts and interview responses using graphical visualization and multivariable linear regression (base sample n = 262; complete cases n = 193). We found associations of higher weekly mean particle counts with reports of indoor smoking of cigarettes or marijuana, as well as with frying food, using candles or incense, and house cleaning. Lower particle levels were associated with larger homes. We did not observe an association between lower mean particle counts and reports of opening windows, using kitchen exhaust fans, or other ventilation activities. Our findings about sources of fine airborne particles and their mitigation can inform future studies that investigate more effective feedback on residential indoor-air-quality and better strategies for reducing occupant exposures. PMID:28545099

  19. Indoor and outdoor concentrations of fine particles, particle-bound PAHs and volatile organic compounds in Kaunas, Lithuania.

    Science.gov (United States)

    Kliucininkas, Linas; Martuzevicius, Dainius; Krugly, Edvinas; Prasauskas, Tadas; Kauneliene, Violeta; Molnar, Peter; Strandberg, Bo

    2011-01-01

    This complex study presents indoor and outdoor levels of air-borne fine particles, particle-bound PAHs and VOCs at two urban locations in the city of Kaunas, Lithuania, and considers possible sources of pollution. Two sampling campaigns were performed in January-February and March-April 2009. The mean outdoor PM(2.5) concentration at Location 1 in winter was 34.5 ± 15.2 µg m(-3) while in spring it was 24.7 ± 12.2 µg m(-3); at Location 2 the corresponding values were 36.7 ± 21.7 and 22.4 ± 19.4 µg m(-3), respectively. In general there was little difference between the PM concentrations at Locations 1 and 2. PM(2.5) concentrations were lower during the spring sampling campaign. These PM concentrations were similar to those in many other European cities; however, the levels of most PAHs analysed were notably higher. The mean sum PAH concentrations at Locations 1 and 2 in the winter campaign were 75.1 ± 32.7 and 32.7 ± 11.8 ng m(-3), respectively. These differences are greater than expected from the difference in traffic intensity at the two sites, suggesting that there is another significant source of PAH emissions at Location 1 in addition to the traffic. The low observed indoor/outdoor (I/O) ratios indicate that PAH emissions at the locations studied arise primarily from outdoor sources. The buildings at both locations have old windows with wooden frames that are fairly permissive in terms of air circulation. VOC concentrations were mostly low and comparable to those reported from Sweden. The mean outdoor concentrations of VOC's were: 0.7 ± 0.2, 3.0 ± 0.8, 0.5 ± 0.2, 3.5 ± 0.3, and 0.2 ± 0.1 µg m(-3), for benzene, toluene, ethylbenzene, sum of m-, p-, o-xylenes, and naphthalene, respectively. Higher concentrations of VOCs were observed during the winter campaign, possibly due to slower dispersion, slower chemical transformations and/or the lengthy "cold start" period required by vehicles in the wintertime. A trajectory analysis showed that air masses

  20. Removal of fine and ultrafine particles from indoor air environments by the unipolar ion emission

    Science.gov (United States)

    Uk Lee, Byung; Yermakov, Mikhail; Grinshpun, Sergey A.

    2004-09-01

    The continuous emission of unipolar ions was evaluated in order to determine its ability to remove fine and ultrafine particles from indoor air environments. The evolution of the indoor aerosol concentration and particle size distribution was measured in real time with the ELPI in a room-size (24.3 m3) test chamber where the ion emitter was operating. After the results were compared with the natural decay, the air cleaning factor was determined. The particle aerodynamic size range of ∼0.04-2 μm was targeted because it represents many bioaerosol agents that cause emerging diseases, as well as those that can be used for biological warfare or in the event of bioterrorism. The particle electric charge distribution (also measured in the test chamber with the ELPI) was rapidly affected by the ion emission. It was concluded that the corona discharge ion emitters (either positive or negative), which are capable of creating an ion density of 105-106 e± cm-3, can be efficient in controlling fine and ultrafine aerosol pollutants in indoor air environments, such as a typical office or residential room. At a high ion emission rate, the particle mobility becomes sufficient so that the particle migration results in their deposition on the walls and other indoor surfaces. Within the tested ranges of the particle size and ion density, the particles were charged primarily due to the diffusion charging mechanism. The particle removal efficiency was not significantly affected by the particle size, while it increased with increasing ion emission rate and the time of emission. The performance characteristics of three commercially available ionic air purifiers, which produce unipolar ions by corona discharge at relatively high emission rates, were evaluated. A 30-minute operation of the most powerful device among those tested resulted in the removal of about 97% of 0.1 μm particles and about 95% of 1 μm particles from the air in addition to the natural decay effect.

  1. Map-Based Indoor Pedestrian Navigation Using an Auxiliary Particle Filter

    Directory of Open Access Journals (Sweden)

    Chunyang Yu

    2017-07-01

    Full Text Available In this research, a non-infrastructure-based and low-cost indoor navigation method is proposed through the integration of smartphone built-in microelectromechanical systems (MEMS sensors and indoor map information using an auxiliary particle filter (APF. A cascade structure Kalman particle filter algorithm is designed to reduce the computational burden and improve the estimation speed of the APF by decreasing its update frequency and the number of particles used in this research. In the lower filter (Kalman filter, zero velocity update and non-holonomic constraints are used to correct the error of the inertial navigation-derived solutions. The innovation of the design lies in the combination of upper filter (particle filter map-matching and map-aiding methods to further constrain the navigation solutions. This proposed navigation method simplifies indoor positioning and makes it accessible to individual and group users, while guaranteeing the system’s accuracy. The availability and accuracy of the proposed algorithm are tested and validated through experiments in various practical scenarios.

  2. Indoor Particles Affect Vascular Function in the Aged

    DEFF Research Database (Denmark)

    Bräuner, Elvira Vaclavik; Forchhammer, Lykke; Møller, Peter

    2008-01-01

    endpoint and biomarkers of inflammation and oxidative stress as secondary endpoints in a healthy elderly population. Methods. Twenty-one non-smoking couples participated in a randomized, double-blind, cross-over study with two consecutive 48-h exposures to either particle filtered or non-filtered air (2533...

  3. LIMITATION OF POPULATION EXPOSURE INDOORS DUE TO NATURAL IRRADIATION SOURCES: IAEA NEW SAFETY STANDARDS PROJECT

    Directory of Open Access Journals (Sweden)

    I. P. Stamat

    2013-01-01

    Full Text Available An article contains the analysis of the main expected changes in the setting standards of population exposure from natural sources in connection with the publication of the new IAEA standard «Protection of the Public against Exposure Indoors due to Natural Sources of Radiation».

  4. Indoor-to-outdoor particle concentration ratio model for human exposure analysis

    Science.gov (United States)

    Lee, Jae Young; Ryu, Sung Hee; Lee, Gwangjae; Bae, Gwi-Nam

    2016-02-01

    This study presents an indoor-to-outdoor particle concentration ratio (IOR) model for improved estimates of indoor exposure levels. This model is useful in epidemiological studies with large population, because sampling indoor pollutants in all participants' house is often necessary but impractical. As a part of a study examining the association between air pollutants and atopic dermatitis in children, 16 parents agreed to measure the indoor and outdoor PM10 and PM2.5 concentrations at their homes for 48 h. Correlation analysis and multi-step multivariate linear regression analysis was performed to develop the IOR model. Temperature and floor level were found to be powerful predictors of the IOR. Despite the simplicity of the model, it demonstrated high accuracy in terms of the root mean square error (RMSE). Especially for long-term IOR estimations, the RMSE was as low as 0.064 and 0.063 for PM10 and PM2.5, respectively. When using a prediction model in an epidemiological study, understanding the consequence of the modeling error and justifying the use of the model is very important. In the last section, this paper discussed the impact of the modeling error and developed a novel methodology to justify the use of the model.

  5. Characterizing Aggregated Exposure to Primary Particulate Matter: Recommended Intake Fractions for Indoor and Outdoor Sources

    DEFF Research Database (Denmark)

    Fantke, Peter; Jolliet, Olivier; Apte, Joshua Schulz

    2017-01-01

    in Northern regions and Oceania and highest in Southeast Asia with population-weighted means across 3646 cities and 16 sub-continental regions of, respectively, 39 ppm (95% confidence interval: 4.3–160 ppm) and 2 ppm (95% confidence interval: 0.2–6.3 ppm). Intake fractions from residential and occupational...... indoor sources range from 470 ppm to 62,000 ppm, mainly as function of air exchange rate and occupancy. Indoor exposure typically contributes 80–90% to overall exposure from outdoor sources. Our framework facilitates improvements in air pollution reduction strategies and life cycle impact assessments....

  6. Analysis of feature selection with Probabilistic Neural Network (PNN) to classify sources influencing indoor air quality

    Science.gov (United States)

    Saad, S. M.; Shakaff, A. Y. M.; Saad, A. R. M.; Yusof, A. M.; Andrew, A. M.; Zakaria, A.; Adom, A. H.

    2017-03-01

    There are various sources influencing indoor air quality (IAQ) which could emit dangerous gases such as carbon monoxide (CO), carbon dioxide (CO2), ozone (O3) and particulate matter. These gases are usually safe for us to breathe in if they are emitted in safe quantity but if the amount of these gases exceeded the safe level, they might be hazardous to human being especially children and people with asthmatic problem. Therefore, a smart indoor air quality monitoring system (IAQMS) is needed that able to tell the occupants about which sources that trigger the indoor air pollution. In this project, an IAQMS that able to classify sources influencing IAQ has been developed. This IAQMS applies a classification method based on Probabilistic Neural Network (PNN). It is used to classify the sources of indoor air pollution based on five conditions: ambient air, human activity, presence of chemical products, presence of food and beverage, and presence of fragrance. In order to get good and best classification accuracy, an analysis of several feature selection based on data pre-processing method is done to discriminate among the sources. The output from each data pre-processing method has been used as the input for the neural network. The result shows that PNN analysis with the data pre-processing method give good classification accuracy of 99.89% and able to classify the sources influencing IAQ high classification rate.

  7. Gaussian mixture sigma-point particle filter for optical indoor navigation system

    Science.gov (United States)

    Zhang, Weizhi; Gu, Wenjun; Chen, Chunyi; Chowdhury, M. I. S.; Kavehrad, Mohsen

    2013-12-01

    With the fast growing and popularization of smart computing devices, there is a rise in demand for accurate and reliable indoor positioning. Recently, systems using visible light communications (VLC) technology have been considered as candidates for indoor positioning applications. A number of researchers have reported that VLC-based positioning systems could achieve position estimation accuracy in the order of centimeter. This paper proposes an Indoors navigation environment, based on visible light communications (VLC) technology. Light-emitting-diodes (LEDs), which are essentially semiconductor devices, can be easily modulated and used as transmitters within the proposed system. Positioning is realized by collecting received-signal-strength (RSS) information on the receiver side, following which least square estimation is performed to obtain the receiver position. To enable tracking of user's trajectory and reduce the effect of wild values in raw measurements, different filters are employed. In this paper, by computer simulations we have shown that Gaussian mixture Sigma-point particle filter (GM-SPPF) outperforms other filters such as basic Kalman filter and sequential importance-resampling particle filter (SIR-PF), at a reasonable computational cost.

  8. Sources for charged particles; Les sources de particules chargees

    Energy Technology Data Exchange (ETDEWEB)

    Arianer, J.

    1997-09-01

    This document is a basic course on charged particle sources for post-graduate students and thematic schools on large facilities and accelerator physics. A simple but precise description of the creation and the emission of charged particles is presented. This course relies on every year upgraded reference documents. Following relevant topics are considered: electronic emission processes, technological and practical considerations on electron guns, positron sources, production of neutral atoms, ionization, plasma and discharge, different types of positive and negative ion sources, polarized particle sources, materials for the construction of ion sources, low energy beam production and transport. (N.T.).

  9. In vitro exposure of human lung cells to emissions of several indoor air sources created in a climate chamber

    NARCIS (Netherlands)

    Bluyssen, P.M.; Alblas, M.J.; Tuinman, I.L.

    2013-01-01

    In the last decade, studies on indoor air pollution suggest a link between exposure to indoor particulate matter and compounds, in particular ultrafine particles and secondary organic aerosols, and several health effects. The mechanisms of how those complex mixtures relate to health effects are stil

  10. An indoor air aerosol model for outdoor contaminant transmission into occupied rooms

    Institute of Scientific and Technical Information of China (English)

    XIE Hui; ZHAO Shen; CAO Guo-qing

    2014-01-01

    The paper presents a simple model for outdoor air contaminant transmission into occupied rooms. In the model, several factors such as filtration, ventilation, deposition, re-emission, outdoor concentration and indoor sources are included. The model results show that the air exchange rate plays an important role in the transmission of outdoor contaminants into the indoor environment. The model shows that increasing the value of the filtration efficiency decreases the mass concentration of indoor particles. In addition, if outdoor aerosol particles have a periodic behaviour, indoor aerosol particles also behave periodically but smoother. Indoor sources are found to be able to increase indoor concentrations greatly and continuously.

  11. [Pollutions of indoor fine particles in four types of public places and the influencing factors].

    Science.gov (United States)

    Liu, Bo; Deng, Fu-rong; Guo, Xin-biao; Yang, Dong-mei; Teng, Xiu-quan; Zheng, Xu; Gao, Jing; Dong, Jing; Wu, Shao-wei

    2009-08-01

    To study the levels of pollutions caused by fine particulate matter (PM(2.5)) in the public places and investigate the possible influencing factors. A total of 20 public places in four types such as rest room in bath center, restaurant, karaoke bars and cyber cafe in Tongzhou district in Beijing were chosen in this study; indoor and outdoor PM(2.5) was monitored by TSI sidepak AM510. Data under varying conditions were collected and analyzed, such as doors or windows or mechanical ventilation devices being opened, rooms cramped with people and smoking. The average concentration of indoor PM(2.5) in 20 public places was (334.6 +/- 386.3) microg/m(3), ranging from 6 microg/m(3) to 1956 microg/m(3); while in bath center, restaurant, karaoke bars and cyber cafe were (116.9 +/- 100.1)microg/m(3), (317.9 +/- 235.3) microg/m(3), (750.6 +/- 521.6)microg/m(3) and (157.5 +/- 98.5) microg/m(3) respectively. The concentrations of PM(2.5) in restaurant (compared with bath center: Z = -10.785, P 1.5) points; r = 0.667, F = 14.442, P 1.556, t = 3.760, P = 0.007] when ventilation (score > 2) was relatively good. The number of smokers per cube meters (14.7 x 10(-3)) became the major influence factor when the ventilation score indoor PM(2.5) was attributed to smoking. This study indicated that smoking was the main source of indoor PM(2.5) in public places. Outdoor PM(2.5) should be correlated with indoor PM(2.5) concentration under drafty situation.

  12. Location identification for indoor instantaneous point contaminant source by probability-based inverse Computational Fluid Dynamics modeling.

    Science.gov (United States)

    Liu, X; Zhai, Z

    2008-02-01

    Indoor pollutions jeopardize human health and welfare and may even cause serious morbidity and mortality under extreme conditions. To effectively control and improve indoor environment quality requires immediate interpretation of pollutant sensor readings and accurate identification of indoor pollution history and source characteristics (e.g. source location and release time). This procedure is complicated by non-uniform and dynamic contaminant indoor dispersion behaviors as well as diverse sensor network distributions. This paper introduces a probability concept based inverse modeling method that is able to identify the source location for an instantaneous point source placed in an enclosed environment with known source release time. The study presents the mathematical models that address three different sensing scenarios: sensors without concentration readings, sensors with spatial concentration readings, and sensors with temporal concentration readings. The paper demonstrates the inverse modeling method and algorithm with two case studies: air pollution in an office space and in an aircraft cabin. The predictions were successfully verified against the forward simulation settings, indicating good capability of the method in finding indoor pollutant sources. The research lays a solid ground for further study of the method for more complicated indoor contamination problems. The method developed can help track indoor contaminant source location with limited sensor outputs. This will ensure an effective and prompt execution of building control strategies and thus achieve a healthy and safe indoor environment. The method can also assist the design of optimal sensor networks.

  13. Sources of variation for indoor nitrogen dioxide in rural residences of Ethiopia

    Directory of Open Access Journals (Sweden)

    Mekonen Eyassu

    2009-11-01

    Full Text Available Abstract Background Unprocessed biomass fuel is the primary source of indoor air pollution (IAP in developing countries. The use of biomass fuel has been linked with acute respiratory infections. This study assesses sources of variations associated with the level of indoor nitrogen dioxide (NO2. Materials and methods This study examines household factors affecting the level of indoor pollution by measuring NO2. Repeated measurements of NO2 were made using a passive diffusive sampler. A Saltzman colorimetric method using a spectrometer calibrated at 540 nm was employed to analyze the mass of NO2 on the collection filter that was then subjected to a mass transfer equation to calculate the level of NO2 for the 24 hours of sampling duration. Structured questionnaire was used to collect data on fuel use characteristics. Data entry and cleaning was done in EPI INFO version 6.04, while data was analyzed using SPSS version 15.0. Analysis of variance, multiple linear regression and linear mixed model were used to isolate determining factors contributing to the variation of NO2 concentration. Results A total of 17,215 air samples were fully analyzed during the study period. Wood and crop were principal source of household energy. Biomass fuel characteristics were strongly related to indoor NO2 concentration in one-way analysis of variance. There was variation in repeated measurements of indoor NO2 over time. In a linear mixed model regression analysis, highland setting, wet season, cooking, use of fire events at least twice a day, frequency of cooked food items, and interaction between ecology and season were predictors of indoor NO2 concentration. The volume of the housing unit and the presence of kitchen showed little relevance in the level of NO2 concentration. Conclusion Agro-ecology, season, purpose of fire events, frequency of fire activities, frequency of cooking and physical conditions of housing are predictors of NO2 concentration. Improved

  14. CANDLES AND INCENSE AS POTENTIAL SOURCES OF INDOOR AIR POLLUTION: MARKET ANALYSIS AND LITERATURE SEARCH

    Science.gov (United States)

    The report summarizes available information on candles and incense as potential sources of indoor air pollution. It covers market information and a review of the scientific literature. The market information collected focuses on production and sales data, typical uses in the U.S....

  15. European database on indoor air pollution sources in buildings: Current status of database structure and software

    NARCIS (Netherlands)

    Molina, J.L.; Clausen, G.H.; Saarela, K.; Plokker, W.; Bluyssen, P.M.; Bishop, W.; Oliveira Fernandes, E. de

    1996-01-01

    the European Joule II Project European Data Base for Indoor Air Pollution Sources in Buildings. The aim of the project is to produce a tool which would be used by designers to take into account the actual pollution of the air from the building elements and ventilation and air conditioning system com

  16. European database on indoor air pollution sources in buildings: Current status of database structure and software

    NARCIS (Netherlands)

    Molina, J.L.; Clausen, G.H.; Saarela, K.; Plokker, W.; Bluyssen, P.M.; Bishop, W.; Oliveira Fernandes, E. de

    1996-01-01

    the European Joule II Project European Data Base for Indoor Air Pollution Sources in Buildings. The aim of the project is to produce a tool which would be used by designers to take into account the actual pollution of the air from the building elements and ventilation and air conditioning system

  17. Accurate positioning of pedestrains in mixed indoor/outdoor settings : A particle filter approach to sensor and map fusion

    DEFF Research Database (Denmark)

    Toftkjær, Thomas

    the coverage of pedestrian positioning, for the professional person, such as rst responders, as well as for the ordinary citizen. Since GNSS alone cannot satisfy the availability and accuracy demands for all indoor settings, this thesis pursues a better understanding of the capabilities of GNSS indoors......, called particle lters, it is possible to use GPS measurements within ProPosition to improve pedestrian positioning accuracy by up to 2.5 meters, from 10 meters accuracy to 7.5 meters accuracy in investigated indoor environments. Secondly, this thesis furthermore proposes ProLoc, a particle lter framework...... and an extension to ProPosition, that advances the state-of-the-art in pedestrian positioning towards the pervasive research goals of full urban environment coverage, seamless indoor and outdoor positioning and the ability to run on ordinary user devices such as smartphones. Through ProLoc it is possible...

  18. 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

  19. Classifying Sources Influencing Indoor Air Quality (IAQ) Using Artificial Neural Network (ANN)

    OpenAIRE

    2015-01-01

    Monitoring indoor air quality (IAQ) is deemed important nowadays. A sophisticated IAQ monitoring system which could classify the source influencing the IAQ is definitely going to be very helpful to the users. Therefore, in this paper, an IAQ monitoring system has been proposed with a newly added feature which enables the system to identify the sources influencing the level of IAQ. In order to achieve this, the data collected has been trained with artificial neural network or ANN—a proven meth...

  20. Concentrations and Sources of Airborne Particles in a Neonatal Intensive Care Unit

    Science.gov (United States)

    Licina, Dusan; Bhangar, Seema; Brooks, Brandon; Baker, Robyn; Firek, Brian; Tang, Xiaochen; Morowitz, Michael J.; Banfield, Jillian F.; Nazaroff, William W.

    2016-01-01

    Premature infants in neonatal intensive care units (NICUs) have underdeveloped immune systems, making them susceptible to adverse health consequences from air pollutant exposure. Little is known about the sources of indoor airborne particles that contribute to the exposure of premature infants in the NICU environment. In this study, we monitored the spatial and temporal variations of airborne particulate matter concentrations along with other indoor environmental parameters and human occupancy. The experiments were conducted over one year in a private-style NICU. The NICU was served by a central heating, ventilation and air-conditioning (HVAC) system equipped with an economizer and a high-efficiency particle filtration system. The following parameters were measured continuously during weekdays with 1-min resolution: particles larger than 0.3 μm resolved into 6 size groups, CO2 level, dry-bulb temperature and relative humidity, and presence or absence of occupants. Altogether, over sixteen periods of a few weeks each, measurements were conducted in rooms occupied with premature infants. In parallel, a second monitoring station was operated in a nearby hallway or at the local nurses’ station. The monitoring data suggest a strong link between indoor particle concentrations and human occupancy. Detected particle peaks from occupancy were clearly discernible among larger particles and imperceptible for submicron (0.3–1 μm) particles. The mean indoor particle mass concentrations averaged across the size range 0.3–10 μm during occupied periods was 1.9 μg/m3, approximately 2.5 times the concentration during unoccupied periods (0.8 μg/m3). Contributions of within-room emissions to total PM10 mass in the baby rooms averaged 37–81%. Near-room indoor emissions and outdoor sources contributed 18–59% and 1–5%, respectively. Airborne particle levels in the size range 1–10 μm showed strong dependence on human activities, indicating the importance of indoor

  1. Concentrations and Sources of Airborne Particles in a Neonatal Intensive Care Unit.

    Directory of Open Access Journals (Sweden)

    Dusan Licina

    Full Text Available Premature infants in neonatal intensive care units (NICUs have underdeveloped immune systems, making them susceptible to adverse health consequences from air pollutant exposure. Little is known about the sources of indoor airborne particles that contribute to the exposure of premature infants in the NICU environment. In this study, we monitored the spatial and temporal variations of airborne particulate matter concentrations along with other indoor environmental parameters and human occupancy. The experiments were conducted over one year in a private-style NICU. The NICU was served by a central heating, ventilation and air-conditioning (HVAC system equipped with an economizer and a high-efficiency particle filtration system. The following parameters were measured continuously during weekdays with 1-min resolution: particles larger than 0.3 μm resolved into 6 size groups, CO2 level, dry-bulb temperature and relative humidity, and presence or absence of occupants. Altogether, over sixteen periods of a few weeks each, measurements were conducted in rooms occupied with premature infants. In parallel, a second monitoring station was operated in a nearby hallway or at the local nurses' station. The monitoring data suggest a strong link between indoor particle concentrations and human occupancy. Detected particle peaks from occupancy were clearly discernible among larger particles and imperceptible for submicron (0.3-1 μm particles. The mean indoor particle mass concentrations averaged across the size range 0.3-10 μm during occupied periods was 1.9 μg/m3, approximately 2.5 times the concentration during unoccupied periods (0.8 μg/m3. Contributions of within-room emissions to total PM10 mass in the baby rooms averaged 37-81%. Near-room indoor emissions and outdoor sources contributed 18-59% and 1-5%, respectively. Airborne particle levels in the size range 1-10 μm showed strong dependence on human activities, indicating the importance of indoor

  2. JV Task 86 - Identifying the Source of Benzene in Indoor Air Using Different Compound Classes from TO-15 Data

    Energy Technology Data Exchange (ETDEWEB)

    Steven B. Hawthorne

    2007-04-15

    Volatile organic compound (VOC) data that had already been collected using EPA method TO-15 at four different sites under regulatory scrutiny (a school, strip mall, apartment complex, and business/residential neighborhood) were evaluated to determine whether the source of indoor air benzene was outdoor air or vapor intrusion from contaminated soil. Both the use of tracer organics characteristic of different sources and principal component statistical analysis demonstrated that the source of indoor air at virtually all indoor sampling locations was a result of outdoor air, and not contaminated soil in and near the indoor air-sampling locations. These results show that proposed remediation activities to remove benzene-contaminated soil are highly unlikely to reduce indoor air benzene concentrations. A manuscript describing these results is presently being prepared for submission to a peer-reviewed journal.

  3. Sewer Gas: An Indoor Air Source of PCE to Consider During Vapor Intrusion Investigations.

    Science.gov (United States)

    Pennell, Kelly G; Scammell, Madeleine Kangsen; McClean, Michael D; Ames, Jennifer; Weldon, Brittany; Friguglietti, Leigh; Suuberg, Eric M; Shen, Rui; Indeglia, Paul A; Heiger-Bernays, Wendy J

    2013-01-01

    The United States Environmental Protection Agency (USEPA) is finalizing its vapor intrusion guidelines. One of the important issues related to vapor intrusion is background concentrations of volatile organic chemicals (VOCs) in indoor air, typically attributed to consumer products and building materials. Background concentrations can exist even in the absence of vapor intrusion and are an important consideration when conducting site assessments. In addition, the development of accurate conceptual models that depict pathways for vapor entry into buildings is important during vapor intrusion site assessments. Sewer gas, either as a contributor to background concentrations or as part of the site conceptual model, is not routinely evaluated during vapor intrusion site assessments. The research described herein identifies an instance where vapors emanating directly from a sanitary sewer pipe within a residence were determined to be a source of tetrachloroethylene (PCE) detected in indoor air. Concentrations of PCE in the bathroom range from 2.1 to 190 ug/m(3) and exceed typical indoor air concentrations by orders of magnitude resulting in human health risk classified as an "Imminent Hazard" condition. The results suggest that infiltration of sewer gas resulted in PCE concentrations in indoor air that were nearly two-orders of magnitude higher as compared to when infiltration of sewer gas was not known to be occurring. This previously understudied pathway whereby sewers serve as sources of PCE (and potentially other VOC) vapors is highlighted. Implications for vapor intrusion investigations are also discussed.

  4. Source Term Model for Fine Particle Resuspension from Indoor Surfaces

    Science.gov (United States)

    2008-02-01

    Material A (J) Reference steel-steel-vacuum 21.2×10-20 Soltani and Ahmadi (2004) glass-glass-dry air 8.5×10-20 Soltani and Ahmadi (2004) SiO2-SiO2...04-25, Engineer Research and Development Center, Construction Engineering Research Laboratory (ERDC-CERL), Champaign, IL. Soltani , M., and G

  5. Sources of Indoor Air Pollution and Respiratory Health in Preschool Children

    Directory of Open Access Journals (Sweden)

    Virginia Fuentes-Leonarte

    2009-01-01

    Full Text Available We carried out bibliographic searches in PubMed and Embase.com for the period from 1996 to 2008 with the aim of reviewing the scientific literature on the relationship between various sources of indoor air pollution and the respiratory health of children under the age of five. Those studies that included adjusted correlation measurements for the most important confounding variables and which had an adequate population size were considered to be more relevant. The results concerning the relationship between gas energy sources and children's respiratory health were heterogeneous. Indoor air pollution from biomass combustion in the poorest countries was found to be an important risk factor for lower respiratory tract infections. Solvents involved in redecorating, DYI work, painting, and so forth, were found to be related to an increased risk for general respiratory problems. The distribution of papers depending on the pollution source showed a clear relationship with life-style and the level of development.

  6. Assessment of exposure to indoor air contaminants from combustion sources: methodology and application.

    Science.gov (United States)

    Leaderer, B P; Zagraniski, R T; Berwick, M; Stolwijk, J A

    1986-08-01

    A methodology for assessing indoor air pollutant exposures is presented, with specific application to unvented combustion by-products. This paper describes the method as applied to a study of acute respiratory illness associated with the use of unvented kerosene space heaters in 333 residences in the New Haven, Connecticut, area from September 1982 to April 1983. The protocol serves as a prototype for a nested design of exposure assessment which could be applied to large-scale field studies of indoor air contaminant levels. Questionnaires, secondary records, and several methods of air monitoring offer a reliable method of estimating environmental exposures for assessing associations with health effects at a reasonable cost. Indoor to outdoor ratios of NO2 concentrations were found to be 0.58 +/- 0.31 for residences without known sources of NO2. Levels of NO2 were found to be comparable for homes with a kerosene heater only and those with a gas cooking stove only. Homes with a kerosene heater and a gas stove had average two-week NO2 levels approximately double those with only one source. Presence of tobacco smokers had a small but significant impact on indoor NO2 levels. Two-week average levels of indoor NO2 were found to be excellent predictors of total personal NO2 exposure for a small sample of adults. Residences with kerosene space heaters had SO2 levels corresponding to the number of hours of heater use and the sulfur content of the fuel. Formaldehyde levels were found to be low and not related to unvented combustion sources. NO2, SO2, and CO2 levels measured in some of the residences were found to exceed those levels specified in current national health standards.

  7. Particle beam generator using a radioactive source

    Energy Technology Data Exchange (ETDEWEB)

    Underwood, D.G.

    1991-12-31

    The apparatus of the present invention selects from particles emitted by a radioactive source those particles having momentum within a desired range and focuses the selected particles in a beam having at least one narrow cross-dimension, and at the same time attenuates potentially disruptive gamma rays and low energy particles. Two major components of the present invention are an achromatic bending and focusing system, which includes sector magnets and quadrupole, and a quadrupole doublet final focus system. Permanent magnets utilized in the apparatus are constructed of a ceramic (ferrite) material which is inexpensive and easily machined.

  8. Prediction of indoor concentration of 0.5-4 µm particles of outdoor origin in an uninhabited apartment

    DEFF Research Database (Denmark)

    Schneider, T.; Jensen, K.A.; Clausen, P.A.

    2004-01-01

    was estimated from concentration rebound measurements following HEPA filtering of the indoor air by fitting a simple deterministic model. The model included measured air exchange rates and published surface deposition loss rates. This model was then used to predict indoor particle concentration. The model...... apartments. The results suggest that factors such as particle chemical composition, within building transport patterns, and occupant behaviour in other apartments should be identified and quantified in future studies, and that these factors need to be included in predictive models. (C) 2004 Elsevier Ltd. All...

  9. Hollow latex particles functionalized with chitosan for the removal of formaldehyde from indoor air.

    Science.gov (United States)

    Nuasaen, Sukanya; Opaprakasit, Pakorn; Tangboriboonrat, Pramuan

    2014-01-30

    Chitosan and polyethyleneimine (PEI) functionalized hollow latex (HL) particles were conveniently fabricated by coating poly(methyl methacrylate-co-divinyl benzene-co-acrylic acid) (P(MMA/DVB/AA)) HL particles with 5 wt% chitosan or 14 wt% PEI. The materials were used as formaldehyde adsorbent, where their adsorbent activity was examined by Fourier Transform Infrared (FTIR) spectroscopy. The nucleophilic addition of amines to carbonyls generated a carbinolamine intermediate with a characteristic band at 1,020 cm(-1) and Schiff base product at 1650 cm(-1), whose intensity increased with prolonged formaldehyde exposure times. The major products observed in HL-chitosan were carbinolamine and Schiff base, whereas a small amount of Schiff base was obtained in HL-PEI particles, confirming a chemical bond formation without re-emission of formaldehyde. Compared to HL-PEI, HL-chitosan possesses higher formaldehyde adsorption efficiency. Besides providing opacity and whiteness, the multilayer HL-chitosan particles can effectively remove indoor air pollutants, i.e., formaldehyde gas, and, hence, would be useful in special coating applications.

  10. Use of On-Site GC/MS Analysis to Distinguish between Vapor Intrusion and Indoor Sources of VOC

    Science.gov (United States)

    2013-12-01

    ER-201119) Use of On-Site GC/MS Analysis to Distinguish between Vapor Intrusion and Indoor Sources of VOC December 2013 This document...SUBTITLE Use of On-Site GC/MS Analysis to Distinguish between Vapor Intrusion and Indoor Sources of VOC 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c...ANALYSIS TO EVALUATE VAPOR INTRUSION ........................ 21 6.3.1 Site-by-Site Analysis of Results: Building VI Classifications ................. 21

  11. Particle-Filter-Based WiFi-Aided Reduced Inertial Sensors Navigation System for Indoor and GPS-Denied Environments

    Directory of Open Access Journals (Sweden)

    M. M. Atia

    2012-01-01

    Full Text Available Indoor navigation is challenging due to unavailability of satellites-based signals indoors. Inertial Navigation Systems (INSs may be used as standalone navigation indoors. However, INS suffers from growing drifts without bounds due to error accumulation. On the other side, the IEEE 802.11 WLAN (WiFi is widely adopted which prompted many researchers to use it to provide positioning indoors using fingerprinting. However, due to WiFi signal noise and multipath errors indoors, WiFi positioning is scattered and noisy. To benefit from both WiFi and inertial systems, in this paper, two major techniques are applied. First, a low-cost Reduced Inertial Sensors System (RISS is integrated with WiFi to smooth the noisy scattered WiFi positioning and reduce RISS drifts. Second, a fast feature reduction technique is applied to fingerprinting to identify the WiFi access points with highest discrepancy power to be used for positioning. The RISS/WiFi system is implemented using a fast version of Mixture Particle Filter for state estimation as nonlinear non-Gaussian filtering algorithm. Real experiments showed that drifts of RISS are greatly reduced and the scattered noisy WiFi positioning is significantly smoothed. The proposed system provides smooth indoor positioning of 1 m accuracy 70% of the time outperforming each system individually.

  12. Laser ion source for particle accelerators

    CERN Document Server

    Sherwood, T R

    1995-01-01

    There is an interest in accelerating atomic nuclei to produce particle beams for medical therapy, atomic and nuclear physics, inertial confinement fusion and particle physics. Laser Ion Sources, in which ions are extracted from plasma created when a high power density laser beam pulse strikes a solid surface in a vacuum, are not in common use. However, some new developments in which heavy ions have been accelerated show that such sources have the potential to provide the beams required for high-energy accelerator systems.

  13. Characterization of decay and emission rates of ultrafine particles in indoor ice rink.

    Science.gov (United States)

    Kim, J; Lee, K

    2013-08-01

    The purposes of this study were to determine indoor ultrafine particle (UFP, diameter DiSCmini were 0.54 ± 0.21/h and 0.85 ± 0.34/h, respectively. The average decay rate of UFP surface area concentration was 0.33 ± 0.15/h. The average emission rates of UFP number concentrations measured by P-Trak and DiSCmini were 1.2 × 10(14) ± 6.5 × 10(13) particles/min and 3.3 × 10(14) ± 2.4 × 10(14) particles/min, respectively. The average emission rate of UFP surface area concentration was 3.1 × 10(11) ± 2.0 × 10(11) μm(2)/min. UFP emission rate was associated with resurfacer age. DiSCmini measured higher decay and emission rates than P-Trak due to their different measuring mechanisms and size ranges.

  14. A pilot investigation into associations between indoor airborne fungal and non-biological particle concentrations in residential houses in Brisbane, Australia.

    Science.gov (United States)

    Hargreaves, Megan; Parappukkaran, Sandhya; Morawska, Lidia; Hitchins, Jane; He, Congrong; Gilbert, Dale

    2003-08-01

    Indoor air contains a complex mixture of bioaerosols such as fungi, bacteria and allergens, as well as non-biological particles including products from various combustion processes. To date little work has been done to investigate the interactions and associations between particles of biological and non-biological origin, however, any occurring interactions could affect pollutant behaviour in the air and ultimately the effect they have on health. The aim of this work was to examine associations between the concentration levels of airborne particles and fungi measured in 14 residential suburban houses in Brisbane. The most frequently isolated fungal genus was Cladosporium, Curvularia, Alternaria, Fusarium and Penicillium. The average outdoor and indoor (living room) concentrations of fungal colony forming units were 1133+/-759 and 810+/-389, respectively. Average outdoor and indoor (normal ventilation) concentrations of submicrometre and supermicrometre particles were 23.8 x 10(3) and 21.7 x 10(3) (particles/cm(3)), 1.78 and 1.74 (particles/cm(3)), respectively. The study showed that no statistically significant associations between the fungal spore and submicrometre particle concentrations or PM(2.5) were present, while a weak but statistically significant relationship was found between fungal and supermicrometre particle concentrations (for the outdoors R(2)=0.4, P=0.03 and for a living room R(2)=0.3, P=0.04). A similarity in behaviour between the submicrometre particle and fungal spore concentrations was that the fungal spore concentrations were related directly to the distance from the source (a nearby park), in a very similar way in which the submicrometre particles originating from vehicle emissions from a road, were dependent on the distance to the road. In the immediate proximity to the park, fungal concentrations rose up to approximately 3100 CFU/m(3), whereas for houses more than 150 m away from the park the concentrations of fungi were below 1000 CFU/m(3

  15. Allergens, sources, particles, and molecules: Why do we make IgE responses?

    Science.gov (United States)

    Woodfolk, Judith A; Commins, Scott P; Schuyler, Alexander J; Erwin, Elizabeth A; Platts-Mills, Thomas A E

    2015-10-01

    Allergens are foreign proteins or glycoproteins that are the target of IgE antibody responses in humans. The relationship between subsequent exposure and the allergic symptoms is often or usually obvious; however, there is increasing evidence that in asthma, atopic dermatitis and some forms of food allergy the induction of symptoms is delayed or chronic. The primary exposure to inhaled allergens is to the particles, which are capable of carrying allergens in the air. Thus, the response reflects not only the properties of the proteins, but also the biological properties of the other constituents of the particle. This is best understood in relation to the mite fecal particles in which the contents include many different immunologically active substances. Allergic disease first became a major problem over 100 years ago, and for many years sensitization to pollens was the dominant form of these diseases. The rise in pediatric asthma correlates best with the move of children indoors, which started in 1960 and was primarily driven by indoor entertainment for children. While the causes of the increase are not simple they include both a major increase in sensitization to indoor allergens and the complex consequences of inactivity. Most recently, there has also been an increase in food allergy. Understanding this has required a reappraisal of the importance of the skin as a route for sensitization. Overall, understanding allergic diseases requires knowing about the sources, the particles and the routes of exposure as well as the properties of the individual allergens.

  16. Model-basedapproachtoaccountforthevariationofprimaryVOCemissions over time in the identification of indoor VOC sources

    DEFF Research Database (Denmark)

    Han, KwangHoon; Zhang, Jensen S.; Wargocki, Pawel

    2012-01-01

    identification method since materials age over time in real indoor environments. The method is based on the mixed air sample measurements containing pollutants from multiple aged materials and theemission signatures ofindividual new materials determined by PTR-MS. Three emission decay source models were employed......The study objectives were to improve the understanding ofthe long-term variationofVOCemission chromatograms of building materials and to develop a method toaccountfor this variation in the identification of individual sources ofVOCemissions. This is of importance forthe application ofthe source...... exhaust air was sampled by PTR-MS to construct a temporal profile ofemission signature unique to individual product type. The similar process was taken to measure mixture emissions from multiple materials, which is for applying and validating the developed method for source identification enhancement...

  17. Simultaneous indoor and outdoor on-line hourly monitoring of atmospheric volatile organic compounds in an urban building. The role of inside and outside sources.

    Science.gov (United States)

    de Blas, Maite; Navazo, Marino; Alonso, Lucio; Durana, Nieves; Gomez, Maria Carmen; Iza, Jon

    2012-06-01

    Indoor air quality (IAQ) has become a very important issue in recent years. As in developed countries people spend more than 90% of their time indoors, besides outdoor pollution assessment, the indoor one is also required. IAQ is not only affected by indoor sources linked to indoor activities, outdoor sources such as road or street traffic and industrial and commercial activities have their role too. Volatile organic compounds (VOCs) frequently show higher indoor mixing ratios with respect to the outdoor ones, and monitoring is required to report their indoor mixing ratios. Many studies have reported average indoor VOCs' mixing ratios in different environments, but their temporal variability has not been well documented. The main objective of this work was to simultaneously measure VOCs' indoor and outdoor mixing ratios with high time-resolution in order to assess the effect of sources inside and outside the building upon indoor mixing ratios of individual VOCs. Simultaneous hourly, continuous, and on-line measurements of C(2)-C(11) VOCs were performed inside and outside the School of Engineering of Bilbao (ETSI) building, located in the city center of Bilbao, an urban area in Northern Spain. The analysis of simultaneous data allowed the classification of VOCs based on their main sources. Some VOCs were mainly emitted by indoor sources (1-pentene, 2-methylpentane, n-hexane, methylcyclopentane, benzene, 1-heptene+2,2,4-trimethylbenzene, and tetrachloroethylene) or by outdoor sources (n-heptane, C(8) alkanes except trimethylpentanes and C(9) aromatics). Other VOCs, such as toluene, were emitted by both indoor and outdoor sources. The isoprene indoor pattern indicated that its main indoor source could be the air exhaled by people occupying the building. Some halocarbons, such as trichloroethylene, tetrachloroethylene, and carbon tetrachloride may be generated from the use inside the building of chlorine bleach containing products.

  18. Control of aerosol contaminants in indoor air: combining the particle concentration reduction with microbial inactivation.

    Science.gov (United States)

    Grinshpun, Sergey A; Adhikari, Atin; Honda, Takeshi; Kim, Ki Youn; Toivola, Mika; Rao, K S Ramchander; Reponen, Tiina

    2007-01-15

    An indoor air purification technique, which combines unipolar ion emission and photocatalytic oxidation (promoted by a specially designed RCI cell), was investigated in two test chambers, 2.75 m3 and 24.3 m3, using nonbiological and biological challenge aerosols. The reduction in particle concentration was measured size selectively in real-time, and the Air Cleaning Factor and the Clean Air Delivery Rate (CADR) were determined. While testing with virions and bacteria, bioaerosol samples were collected and analyzed, and the microorganism survival rate was determined as a function of exposure time. We observed that the aerosol concentration decreased approximately 10 to approximately 100 times more rapidly when the purifier operated as compared to the natural decay. The data suggest that the tested portable unit operating in approximately 25 m3 non-ventilated room is capable to provide CADR-values more than twice as great than the conventional closed-loop HVAC system with a rating 8 filter. The particle removal occurred due to unipolar ion emission, while the inactivation of viable airborne microorganisms was associated with photocatalytic oxidation. Approximately 90% of initially viable MS2 viruses were inactivated resulting from 10 to 60 min exposure to the photocatalytic oxidation. Approximately 75% of viable B. subtilis spores were inactivated in 10 min, and about 90% or greater after 30 min. The biological and chemical mechanisms that led to the inactivation of stress-resistant airborne viruses and bacterial spores were reviewed.

  19. The impact of mass transfer limitations on size distributions of particle associated SVOCs in outdoor and indoor environments

    DEFF Research Database (Denmark)

    Liu, Cong; Zhang, Yinping; Weschler, Charles J.

    2014-01-01

    ) previously proposed that the rate of mass transfer can impact polycyclic aromatic hydrocarbon (PAH) partitioning among different sized particles, especially for time scales relevant to urban aerosols. The present study quantitatively builds on this idea, presenting a model that incorporates dynamic SVOC....../particle interaction and applying this model to typical outdoor and indoor scenarios. The model indicates that the impact of mass transfer limitations on the size distribution of a particle-associated SVOC can be evaluated by the ratio of the time to achieve gas-particle equilibrium relative to the residence time...... of particles. The higher this ratio, the greater the influence of mass transfer limitations on the size distribution of particle-associated SVOCs. The influence of such constraints is largest on the fraction of particle-associated SVOCs in the coarse mode (>2μm). Predictions from the model have been found...

  20. Sources and transformations of atmospheric aerosol particles

    Science.gov (United States)

    Cross, Eben Spencer

    transported towards Europe. In this study, particles were highly processed prior to sampling, with residence times of a few days in the atmosphere. The MILAGRO campaign focused on the evolution of the Mexico City plume as it was transported north. During this study, regional and locally emitted particles were measured with residence times varying from minutes to days in the atmosphere. In both studies, the light scattering - AMS system provided detailed information about the density and composition of single particles, leading to important insights into how atmospheric processing transforms the particle properties. In Mexico City, the light scattering-AMS system was used for the first time as a true single particle mass spectrometer and revealed specific details about the atmospheric processing of primary particles from combustion sources. To quantify the radiative effects of the particles on climate, the processing and ultimate fate of primary emissions (often containing black carbon or soot) must be understood. To provide a solid basis for the interpretation of the data obtained during the field studies, experiments were conducted with a well characterized soot generation-sampling system developed by the Boston College research group. The laboratory soot source was combined with the light scattering - AMS system and a Cloud Condensation Nuclei Counter (CCNC) to measure the change in cloud-forming activity of soot particles as they are processed in the atmosphere. Because of the importance of black carbon in the atmosphere, several instruments have been developed to measure black carbon. In July of 2008, an intercomparison study of 18 instruments was conducted in the Boston College laboratory, with soot particles produced and processed to mimic a wide range of atmospherically-relevant conditions. Transformations in the physical, chemical, and optical properties of soot particles were monitored with the combined suite of aerosol instrumentation. Results from the

  1. The impact of mass transfer limitations on size distributions of particle associated SVOCs in outdoor and indoor environments

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Cong; Zhang, Yinping [Department of Building Science, Tsinghua University, Beijing (China); Weschler, Charles J., E-mail: weschlch@rwjms.rutgers.edu [Department of Building Science, Tsinghua University, Beijing (China); Environmental and Occupational Health Sciences Institute, Rutgers University, Piscataway, NJ (United States); International Center for Indoor Environment and Energy, Technical University of Denmark, Lyngby (Denmark)

    2014-11-01

    Semi-volatile organic compounds (SVOCs) partition between the gas phase and airborne particles. The size distribution of particle-associated SVOCs impacts their fate in outdoor and indoor environments, as well as human exposure to these compounds and subsequent health risks. Allen et al. (1996) previously proposed that the rate of mass transfer can impact polycyclic aromatic hydrocarbon (PAH) partitioning among different sized particles, especially for time scales relevant to urban aerosols. The present study quantitatively builds on this idea, presenting a model that incorporates dynamic SVOC/particle interaction and applying this model to typical outdoor and indoor scenarios. The model indicates that the impact of mass transfer limitations on the size distribution of a particle-associated SVOC can be evaluated by the ratio of the time to achieve gas–particle equilibrium relative to the residence time of particles. The higher this ratio, the greater the influence of mass transfer limitations on the size distribution of particle-associated SVOCs. The influence of such constraints is largest on the fraction of particle-associated SVOCs in the coarse mode (> 2 μm). Predictions from the model have been found to be in reasonable agreement with size distributions measured for PAHs at roadside and suburban locations in Japan. The model also quantitatively explains shifts in the size distributions of particle associated SVOCs compared to those for particle mass, and the manner in which these shifts vary with temperature and an SVOC's molecular weight. - Highlights: • Rate of mass transfer can impact SVOC partitioning among different sized particles. • Model was developed that incorporates dynamic SVOC/particle sorption. • Key parameters: mass-transfer coefficients, partition coefficient, residence time • Model explains observed SVOC size distribution shifts with temperature and MW. • Largest impact of mass transfer constraints: SVOC sorption to coarse

  2. Air filtration and indoor air quality

    DEFF Research Database (Denmark)

    Bekö, Gabriel

    2006-01-01

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

  3. Real-Time and Accurate Indoor Localization with Fusion Model of Wi-Fi Fingerprint and Motion Particle Filter

    Directory of Open Access Journals (Sweden)

    Xinlong Jiang

    2015-01-01

    Full Text Available As the development of Indoor Location Based Service (Indoor LBS, a timely localization and smooth tracking with high accuracy are desperately needed. Unfortunately, any single method cannot meet the requirement of both high accuracy and real-time ability at the same time. In this paper, we propose a fusion location framework with Particle Filter using Wi-Fi signals and motion sensors. In this framework, we use Extreme Learning Machine (ELM regression algorithm to predict position based on motion sensors and use Wi-Fi fingerprint location result to solve the error accumulation of motion sensors based location occasionally with Particle Filter. The experiments show that the trajectory is smoother as the real one than the traditional Wi-Fi fingerprint method.

  4. Indoor air pollution: Sources and control. (Latest citations from the NTIS bibliographic database). Published Search

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-02-01

    The bibliography contains citations concerning indoor air pollution in residential, commercial, industrial, and institutional buildings. Indoor air quality assessment, health hazard evaluation, and contaminant identification and measurement are discussed. Indoor air pollution control methods and equipment are evaluated. Air quality analyses of energy efficient buildings are presented. Indoor air pollution from radon and asbestos are discussed in other bibliographies. (Contains 50-250 citations and includes a subject term index and title list.) (Copyright NERAC, Inc. 1995)

  5. Indoor air pollution: Sources and control. (Latest citations from the NTIS bibliographic database). Published Search

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-12-01

    The bibliography contains citations concerning indoor air pollution in residential, commercial, industrial, and institutional buildings. Indoor air quality assessment, health hazard evaluation, and contaminant identification and measurement are discussed. Indoor air pollution control methods and equipment are evaluated. Air quality analyses of energy efficient buildings are presented. Indoor air pollution from radon and asbestos are discussed in other bibliographies.(Contains 50-250 citations and includes a subject term index and title list.) (Copyright NERAC, Inc. 1995)

  6. Chemical Characterization and Source Apportionment of Indoor and Outdoor Fine Particulate Matter (PM2.5) in Retirement Communities of the Los Angeles Basin

    Science.gov (United States)

    Hasheminassab, Sina; Daher, Nancy; Shafer, Martin M.; Schauer, James J.; Delfino, Ralph J.; Sioutas, Constantinos

    2014-01-01

    Concurrent indoor and outdoor measurements of fine particulate matter (PM2.5) were conducted at three retirement homes in the Los Angeles Basin during two separate phases (cold and warm) between 2005 and 2006. Indoor-to-outdoor relationships of PM2.5 chemical constituents were determined and sources of indoor and outdoor PM2.5 were evaluated using a molecular marker-based chemical mass balance (MM-CMB) model. Indoor levels of elemental carbon (EC) along with metals and trace elements were found to be significantly affected by outdoor sources. EC, in particular, displayed very high indoor-to-outdoor (I/O) mass ratios accompanied by strong I/O correlations, illustrating the significant impact of outdoor sources on indoor levels of EC. Similarly, indoor levels of polycyclic aromatic hydrocarbons (PAHs), hopanes, and steranes were strongly correlated with their outdoor components and displayed I/O ratios close to unity. On the other hand, concentrations of n-alkanes and organic acids inside the retirement communities were dominated by indoor sources (e.g. food cooking and consumer products), as indicated by their I/O ratios, which exceeded unity. Source apportionment results revealed that vehicular emissions were the major contributor to both indoor and outdoor PM2.5, accounting for 39 and 46% of total mass, respectively. Moreover, the contribution of vehicular sources to indoor levels was generally comparable to its corresponding outdoor estimate. Other water-insoluble organic matter (other WIOM), which accounts for emissions from uncharacterized primary biogenic sources, displayed a wider range of contributions, varying from 2 to 73% of PM2.5, across all sites and phases of the study. Lastly, higher indoor than outdoor contribution of other water-soluble organic matter (other WSOM) was evident at some of the sites, suggesting the production of secondary aerosols as well as direct emissions from primary sources (including cleaning or other consumer products) at the

  7. Dioxin-like PCB in indoor air contaminated with different sources

    Energy Technology Data Exchange (ETDEWEB)

    Heinzow, B.G.J.; Mohr, S.; Ostendorp, G. [Landesamt fuer Gesundheit und Arbeitssicherheit des Landes Schleswig-Holstein, Flintbek (Germany); Kerst, M.; Koerner, W. [Bayerisches Landesamt fuer Umweltschutz, Augsburg (Germany)

    2004-09-15

    Polychlorinated biphenyls (PCB) have been used in public building constructions for various purposes in the 1960s and 1970s, mainly as an additive to concrete, caulking, grout, paints, as a major constitutent of permanent elastic Thiokol rubber sealants and flame retardant coatings of acoustic ceiling tiles. Offgazing of semivolatile PCB from building materials can nowadays still result in considerable house-dust contamination and in indoor air concentrations exceeding 10,000 ng/m{sup 3}. In Germany, PCB levels in indoor air in non-occupational settings have been regulated with a tolerable total PCB concentration of 300 ng /m{sup 3} and an intervention level of 3000 ng/m{sup 3}. Lower re-entry criteria have been proposed by Michaud et al. Technical mixtures of PCB contain dioxin-like non- and mono-ortho substituted PCB congeners and are contaminated with trace amounts of polychlorinated dibenzodioxins (PCDD) and mainly dibenzofurans (PCDF), sharing overlapping toxic effects and physicochemical properties. We report here on levels of dioxinlike PCB measured in buildings with various PCB sources and correlations among PCDD/PCDF and dioxin-like PCB and di-ortho PCB.

  8. Measurement and apportionment of radon source terms for modeling indoor environments

    Energy Technology Data Exchange (ETDEWEB)

    Harley, N.H.

    1992-01-01

    During the present 2 1/2 year contract period, we have made significant Progress in modeling the source apportionment of indoor [sup 222]Rn and in [sup 222]Rn decay product dosimetry. Two additional areas were worked on which we believe are useful for the DOE Radon research Program. One involved an analysis of the research house data, grouping the hourly house [sup 222]Rn measurements into 2 day, 7 day and 90 day intervals to simulate the response of passive monitors. Another area requiring some attention resulted in a publication of 3 years of our indoor/outdoor measurements in a high-rise apartment. Little interest has been evinced in apartment measurements yet 20% of the US population lives in multiple-family dwellings, not in contact with the ground. These data together with a summary of all other published data on apartments showed that apartments have only about 50% greater [sup 222]Rn concentration than the measured outdoor [sup 222]Rn. Apartment dwellers generally represent a low risk group regarding [sup 222]Rn exposure. The following sections describe the main projects in some detail.

  9. Indoor air quality in energy-efficient dwellings: levels and sources of pollutants.

    Science.gov (United States)

    Derbez, Mickaël; Wyart, Guillaume; Le Ponner, Eline; Ramalho, Olivier; Ribéron, Jacques; Mandin, Corinne

    2017-09-28

    Worldwide, public policies are promoting energy-efficient buildings and accelerating the thermal renovation of existing buildings. The effects of these changes on the indoor air quality (IAQ) in these buildings remain insufficiently understood. In this context, a field study was conducted in 72 energy-efficient dwellings to describe the pollutants known to be associated with health concerns. Measured parameters included the concentrations of 19 volatile organic compounds and aldehydes, nitrogen dioxide, particulate matter (PM2.5 ), radon, temperature and relative humidity. The air stuffiness index and night-time air exchange rate were calculated from the monitored carbon dioxide (CO2 ) concentrations. Indoor and outdoor measurements were performed at each dwelling during one week in each of the two following seasons: heating and non-heating. Moreover, questionnaires were completed by the occupants to characterize the building, equipment, household and occupants' habits. Perspective on our results was provided by previous measurements made in low-energy European dwellings. Statistical comparisons with the French housing stock and a pilot study showed higher concentrations of terpenes, i.e., alpha-pinene and limonene, and hexaldehyde in our study than in previous studies. Alpha-pinene and hexaldehyde are emitted by wood or wood-based products used for the construction, insulation, decoration and furnishings of the dwellings, whereas limonene is more associated with discontinuous sources related to human activities. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  10. Dioxin-like PCB in indoor air contaminated with different sources

    Energy Technology Data Exchange (ETDEWEB)

    Heinzow, B.G.J.; Mohr, S.; Ostendorp, G. [Landesamt fuer Gesundheit und Arbeitssicherheit des Landes Schleswig-Holstein, Flintbek (Germany); Kerst, M.; Koerner, W. [Bayerisches Landesamt fuer Umweltschutz, Augsburg (Germany)

    2004-09-15

    Polychlorinated biphenyls (PCB) have been used in public building constructions for various purposes in the 1960s and 1970s, mainly as an additive to concrete, caulking, grout, paints, as a major constitutent of permanent elastic Thiokol rubber sealants and flame retardant coatings of acoustic ceiling tiles. Offgazing of semivolatile PCB from building materials can nowadays still result in considerable house-dust contamination and in indoor air concentrations exceeding 10,000 ng/m{sup 3}. In Germany, PCB levels in indoor air in non-occupational settings have been regulated with a tolerable total PCB concentration of 300 ng /m{sup 3} and an intervention level of 3000 ng/m{sup 3}. Lower re-entry criteria have been proposed by Michaud et al. Technical mixtures of PCB contain dioxin-like non- and mono-ortho substituted PCB congeners and are contaminated with trace amounts of polychlorinated dibenzodioxins (PCDD) and mainly dibenzofurans (PCDF), sharing overlapping toxic effects and physicochemical properties. We report here on levels of dioxinlike PCB measured in buildings with various PCB sources and correlations among PCDD/PCDF and dioxin-like PCB and di-ortho PCB.

  11. Source apportionment of indoor, outdoor and personal PM2.5 exposure of pregnant women in Barcelona, Spain

    Science.gov (United States)

    Minguillón, M. C.; Schembari, A.; Triguero-Mas, M.; de Nazelle, A.; Dadvand, P.; Figueras, F.; Salvado, J. A.; Grimalt, J. O.; Nieuwenhuijsen, M.; Querol, X.

    2012-11-01

    Exposure to air pollution has been shown to adversely affect foetal development in the case of pregnant women. The present study aims to investigate the PM composition and sources influencing personal exposure of pregnant women in Barcelona. To this end, indoor, outdoor and personal exposure measurements were carried out for a selection of 54 pregnant women between November 2008 and November 2009. PM2.5 samples were collected during two consecutive days and then analysed for black smoke (BS), major and trace elements, and polycyclic aromatic hydrocarbons (PAHs) concentrations. Personal information such as commuting patterns and cosmetics use was also collected. PM2.5 concentrations were higher for personal samples than for indoor and outdoor environments. Indoor, outdoor and personal BS and sulphate concentrations were strongly correlated, although some specific indoor and outdoor sulphate sources may exist. Average trace elements concentrations were similar indoor, outdoor and for personal exposure, but the correlations were moderate for most of them. Most of the PAHs concentrations showed strong correlations indoor-outdoor. A source apportionment analysis of the PM composition data by means of a Positive Matrix Factorization (PMF) resulted in the identification of six sources for the outdoor and indoor environments: secondary sulphate, fueloil + sea salt (characterized by V, Ni, Na and Mg), mineral, cigarette (characterized by K, Ce, Cd, benzo(k)fluoranthene and benzo(ghi)perylene), road traffic (characterized by BS and low weight PAHs), and industrial (characterized by Pb, Sn, Cu, Mn and Fe). For personal exposure two specific sources were found: cosmetics (characterized by abundance of Ca, Li, Ti and Sr and the absence of Al) and train/subway (characterized by Fe, Mn, Cu and Ba). The contribution of the sources varied widely among women, especially for cigarette (from zero to up to 4 μg m-3), train/subway (up to more than 6 μg m-3) and cosmetics (up to more

  12. Fine and Ultrafine Particles from Combustion Sources - Investigations with in-situ techniques

    Energy Technology Data Exchange (ETDEWEB)

    Pagels, Joakim

    2005-04-01

    Fine airborne particles are associated with adverse health effects in the human population. The aim of this research was to develop and evaluate methods for in-situ characterisation of fine and ultrafine particles and to determine their deposition in the human airways. The aim was also to increase knowledge about health and environmentally relevant properties of aerosols from biomass combustion and selected indoor sources. The methods include instrumental techniques such as Scanning Mobility Particle Sizer (SMPS), Electrical Low-Pressure Impactor (ELPI), Aerodynamic Particle Sizer (APS) and Tandem Differential Mobility Analysers (TDMA) based on volatility and hygroscopic growth. Filter samplers and impactors were used for collecting particles on substrates for subsequent chemical analysis. Emissions from local district heating plants (0.5-12 MW), based on moving grate combustion of woody fuels, were sampled with a dilution system and characterised. Particles from the indoor sources of cigarettes, incense and candles were examined in the laboratory by using an airtight 22 m{sup 3} stainless steel chamber. A set-up to determine respiratory deposition in humans was constructed. It was automatised and uses an electrical mobility spectrometer with an improved inversion algorithm to perform fast measurements of particles of different sizes in the inhaled and exhaled air. It was evaluated on human test-persons. The investigated biomass combustion sources emit high concentrations of fine and ultrafine particles. The chemical composition is dominated by KCl and K{sub 2}SO{sub 4}; Zn, Cd and Pb were also quantified. Elemental carbon was identified in particles larger than 150 nm during periods of incomplete combustion. The particle concentration depends on the fuel ash content and the combustion efficiency. The aerosol is essentially internally mixed with hygroscopic growth factors significantly higher than reported for diesel exhaust and environmental tobacco smoke. The

  13. Classifying Sources Influencing Indoor Air Quality (IAQ Using Artificial Neural Network (ANN

    Directory of Open Access Journals (Sweden)

    Shaharil Mad Saad

    2015-05-01

    Full Text Available Monitoring indoor air quality (IAQ is deemed important nowadays. A sophisticated IAQ monitoring system which could classify the source influencing the IAQ is definitely going to be very helpful to the users. Therefore, in this paper, an IAQ monitoring system has been proposed with a newly added feature which enables the system to identify the sources influencing the level of IAQ. In order to achieve this, the data collected has been trained with artificial neural network or ANN—a proven method for pattern recognition. Basically, the proposed system consists of sensor module cloud (SMC, base station and service-oriented client. The SMC contain collections of sensor modules that measure the air quality data and transmit the captured data to base station through wireless network. The IAQ monitoring system is also equipped with IAQ Index and thermal comfort index which could tell the users about the room’s conditions. The results showed that the system is able to measure the level of air quality and successfully classify the sources influencing IAQ in various environments like ambient air, chemical presence, fragrance presence, foods and beverages and human activity.

  14. Classifying Sources Influencing Indoor Air Quality (IAQ) Using Artificial Neural Network (ANN).

    Science.gov (United States)

    Saad, Shaharil Mad; Andrew, Allan Melvin; Shakaff, Ali Yeon Md; Saad, Abdul Rahman Mohd; Kamarudin, Azman Muhamad Yusof; Zakaria, Ammar

    2015-05-20

    Monitoring indoor air quality (IAQ) is deemed important nowadays. A sophisticated IAQ monitoring system which could classify the source influencing the IAQ is definitely going to be very helpful to the users. Therefore, in this paper, an IAQ monitoring system has been proposed with a newly added feature which enables the system to identify the sources influencing the level of IAQ. In order to achieve this, the data collected has been trained with artificial neural network or ANN--a proven method for pattern recognition. Basically, the proposed system consists of sensor module cloud (SMC), base station and service-oriented client. The SMC contain collections of sensor modules that measure the air quality data and transmit the captured data to base station through wireless network. The IAQ monitoring system is also equipped with IAQ Index and thermal comfort index which could tell the users about the room's conditions. The results showed that the system is able to measure the level of air quality and successfully classify the sources influencing IAQ in various environments like ambient air, chemical presence, fragrance presence, foods and beverages and human activity.

  15. Ultrafine particles from electric appliances and cooking pans: experiments suggesting desorption/nucleation of sorbed organics as the primary source.

    Science.gov (United States)

    Wallace, L A; Ott, W R; Weschler, C J

    2015-10-01

    Ultrafine particles are observed when metal surfaces, such as heating elements in electric appliances, or even empty cooking pans, are heated. The source of the particles has not been identified. We present evidence that particles >10 nm are not emitted directly from the heating elements or the metal surfaces. Using repeated heating of an electric burner, several types of cooking pans, and a steam iron, the increase in the number of particles (>10 nm) can be reduced to 0. After the devices are exposed to indoor air for several hours or days, subsequent heating results in renewed particle production, suggesting that organic matter has sorbed on their surfaces. Also, after a pan has been heated to the point that no increase in particles is observed, washing with detergent results in copious production of particles the next time the pan is heated. These observations suggest that detergent residue and organics sorbed from indoor air are the sources of the particles. We hypothesize that organic compounds are thermally desorbed from the hot surface as gaseous molecules; as they diffuse from the hot air near the pan into cooler air, selected compounds exceed their saturation concentration and nucleation occurs.

  16. Optimization of Indoor Thermal Comfort Parameters with the Adaptive Network-Based Fuzzy Inference System and Particle Swarm Optimization Algorithm

    Directory of Open Access Journals (Sweden)

    Jing Li

    2017-01-01

    Full Text Available The goal of this study is to improve thermal comfort and indoor air quality with the adaptive network-based fuzzy inference system (ANFIS model and improved particle swarm optimization (PSO algorithm. A method to optimize air conditioning parameters and installation distance is proposed. The methodology is demonstrated through a prototype case, which corresponds to a typical laboratory in colleges and universities. A laboratory model is established, and simulated flow field information is obtained with the CFD software. Subsequently, the ANFIS model is employed instead of the CFD model to predict indoor flow parameters, and the CFD database is utilized to train ANN input-output “metamodels” for the subsequent optimization. With the improved PSO algorithm and the stratified sequence method, the objective functions are optimized. The functions comprise PMV, PPD, and mean age of air. The optimal installation distance is determined with the hemisphere model. Results show that most of the staff obtain a satisfactory degree of thermal comfort and that the proposed method can significantly reduce the cost of building an experimental device. The proposed methodology can be used to determine appropriate air supply parameters and air conditioner installation position for a pleasant and healthy indoor environment.

  17. Conference particulate matter and indoor environment, I.N.E.R.I.S.; Particulate matter and indoor environment

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2005-07-01

    Comprehensive characterisation of indoor and outdoor air as well as pollution emission sources Integrated health and environmental risk assessment Scientific and technical basis for airborne pollution management and control Fine and coarse particles. The sources of indoor air pollution are originate separately, are transported separately, are removed from atmosphere by different mechanisms, have different optical properties, have different chemical properties, require different control techniques. for the health effects due to particles, they decrease the lung function, increase respiratory symptoms, increase chronic obstructive pulmonary diseases, increased cardiovascular disease, increased mortality. The different sources contributing to the highest concentrations are: concentrations: tobacco smoking, cooking, vacuuming, dusting and sweeping, heaters, stoves, fireplaces and some other non identified sources. In the future we want more focus on fine and ultra fine particles, investigate source apportionment of particles, better understanding and quantification of exposure, to implement guidelines for particle concentration in indoor air and find better cleaning technologies. (N.C.)

  18. Source identification, apportionment and toxicity of indoor and outdoor PM2.5 airborne particulates in a region characterised by wood burning.

    Science.gov (United States)

    Bravo-Linares, Claudio; Ovando-Fuentealba, Luis; Orellana-Donoso, Sandra; Gatica, Silvana; Klerman, Francisca; Mudge, Stephen M; Gallardo, Waldo; Pinaud, Jean Paul; Loyola-Sepulveda, Rodrigo

    2016-05-18

    The occurrence of airborne particulate matter has been flagged as "of concern" in several megacities, especially in Asia. Selected Chilean regions have similar problems as wood burning is the major source of heating in homes. This concern has led to mitigation measures restricting the burning of wood at periods when the particulate matter smaller than 2.5 μm (PM2.5) concentrations are predicted to be high. This work investigates the linkage between indoor and outdoor particle concentrations, determines their source through the polyaromatic hydrocarbon (PAH) signature and investigates the efficacy of the current management practice of burning restrictions. The PM2.5 fraction was collected at 12 different properties with coincident indoor and outdoor sampling using a low-volume active sampler for 24 hours. Indoor concentrations of PM2.5 ranged from 6 to 194 μg m(-3) with a mean of 72 μg m(-3) and corresponding outdoor concentrations ranged from 5 to 367 μg m(-3) with a mean of 85 μg m(-3) over the winter periods of 2014 and 2015; the Chilean national permitted maximum in outdoor air is 50 μg m(-3) in 24 hours. Higher concentrations were measured when the outdoor air temperature was lower. The PAHs were analysed on the PM2.5 fraction; the indoor concentrations ranged from 2 to 291 ng m(-3) with a mean of 51 ng m(-3) compared to an outdoor concentration between 3 and 365 ng m(-3) with a mean of 71 ng m(-3). Multivariate statistical analysis of the PAH profiles using principal components analysis (PCA) and polytopic vector analysis (PVA) identified wood burning, static and mobile diesel emissions and kerosene combustion as the major contributors to the particulate matter. When converted to toxicity equivalents (BaP-TEQ), the highest toxicity arising from PAHs in the indoor air was associated with a property that used a "leaky" combined wood stove and heater and also used a wood-fired brazier for local heating. In outdoor air, there was a relationship between the

  19. CATALOG OF MATERIALS AS POTENTIAL SOURCES OF INDOOR AIR EMISSIONS - VOLUME 1. INSULATION, WALLCOVERINGS, RESI- LIENT FLOOR COVERINGS, CARPET, ADHESIVES, SEALANTS AND CAULKS, AND PESTICIDES

    Science.gov (United States)

    The report discusses and presents data on constituents and emissions from products that have the potential to impact the indoor air environment. t is a tool to be used by researchers to help organize the study of materials as potential sources of indoor air emissions. ncluded are...

  20. Toxic effects of indoor and outdoor airborne particles relevant to carcinogenesis.

    NARCIS (Netherlands)

    Heussen, G.A.H.

    1993-01-01

    The mutagenicity of indoor and outdoor airborne particulate matter (APM) has been demonstrated by previous in vitro studies (Alink et al., 1983; Van Houdt et al., 1984, 1986, 1987). The aim of the present thesis was to contribute to a better understanding of the mode of action of AIM in the pathogen

  1. Indoor particles affect vascular function in the aged - An air filtration-based intervention study

    DEFF Research Database (Denmark)

    Brauner, E.V.; Forchhammer, L.; Moller, P.

    2008-01-01

    factors, P-selectin, plasma amyloid A, C-reactive protein, fibrinogen, IL-6, tumor necrosis factor-alpha, protein oxidation measured as 2-aminoadipic semialdehyde in plasma, urinary 8-iso-prostaglandin F-2 alpha, and blood pressure. Indoor air filtration significantly improved MVF by 8.1% (95% confidence...

  2. Toxic effects of indoor and outdoor airborne particles relevant to carcinogenesis

    NARCIS (Netherlands)

    Heussen, G.A.H.

    1993-01-01

    The mutagenicity of indoor and outdoor airborne particulate matter (APM) has been demonstrated by previous in vitro studies (Alink et al., 1983; Van Houdt et al., 1984, 1986, 1987). The aim of the present thesis was to contribute to a better understanding of the mode of action of AIM in the

  3. Performance of single mechanoluminescent particle as ubiquitous light source.

    Science.gov (United States)

    Terasaki, Nao; Xu, Chao-Nan

    2014-08-01

    In this study, we have investigated mechanoluminescent (ML) performance of single ML particle as ubiquitous light source. When using high-speed CCD camera with image intensifier and microscopic equipment, mechanoluminescence from single particle was observed. As to the quantitative ML evaluation of the single ML particle was carried out using photomultiplier, and successfully estimated the performance of the single ML particle as an intensity controllable light source in nW order.

  4. Sources and composition of urban aerosol particles

    Science.gov (United States)

    Vogt, M.; Johansson, C.; Mårtensson, M.; Struthers, H.; Ahlm, L.; Nilsson, D.

    2011-09-01

    From May 2008 to March 2009 aerosol emissions were measured using the eddy covariance method covering the size range 0.25 to 2.5 μm diameter (Dp) from a 105 m tower, in central Stockholm, Sweden. Supporting chemical aerosol data were collected at roof and street level. Results show that the inorganic fraction of sulfate, nitrate, ammonium and sea salt accounts for approximately 15% of the total aerosol mass traffic (as inferred from the ratio of the incremental concentrations of nitrogen oxides (NOx) and BC measured on a densely trafficked street) and the fluxes of non-volatile material at tower level are in close agreement, suggesting a traffic source of BC. We have estimated the emission factors (EFs) for non-volatile particles traffic activity data. Light (LDV) and heavy duty vehicle (HDV) EFs were estimated using multiple linear regression and reveal that for non-volatile particulate matter in the 0.25 to 0.6 μm Dp range, the EFHDV is approximately twice as high as the EFLDV, the difference not being statistically significant.

  5. Methods for forming particles from single source precursors

    Science.gov (United States)

    Fox, Robert V [Idaho Falls, ID; Rodriguez, Rene G [Pocatello, ID; Pak, Joshua [Pocatello, ID

    2011-08-23

    Single source precursors are subjected to carbon dioxide to form particles of material. The carbon dioxide may be in a supercritical state. Single source precursors also may be subjected to supercritical fluids other than supercritical carbon dioxide to form particles of material. The methods may be used to form nanoparticles. In some embodiments, the methods are used to form chalcopyrite materials. Devices such as, for example, semiconductor devices may be fabricated that include such particles. Methods of forming semiconductor devices include subjecting single source precursors to carbon dioxide to form particles of semiconductor material, and establishing electrical contact between the particles and an electrode.

  6. 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

    2017-01-01

    Background 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. Objectives To evaluate whether a short-term indoor air purifier intervention improves cardiopulmonary health. Methods 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 oxide (FeNO). We applied linear mixed-effect models to evaluate the effect of the intervention on health outcome variables. Results 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. Further, systolic BP, diastolic BP, and FeNO 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. Conclusion 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) PMID:26022815

  7. Contribution of incense burning to indoor PM10 and particle-bound polycyclic aromatic hydrocarbons under two ventilation conditions.

    Science.gov (United States)

    Lung, S-C C; Kao, M-C; Hu, S-C

    2003-06-01

    Burning incense to worship Gods and ancestors is a traditional practice prevalent in Asian societies. This work investigated indoor PM10 concentrations resulting from incense burning in household environments under two conditions: closed and ventilated. The exposure concentrations of particle-bound polycyclic aromatic hydrocarbons (PAHs) were estimated. The factors of potential exposure were also evaluated. Under both conditions, samples were taken at three locations: 0.3, 3.5 and 7 m away from the altar during three periods: incense burning, the first 3 h, and the 4-6 h after cessation of combustion. PAH concentrations of incense smoke were assessed in the laboratory. Personal environment monitors were used as sampling instruments. The results showed a significant contribution of incense burning to indoor PM10 and particulate PAH concentrations. PM10 concentrations near the altar during incense burning were 723 and 178 microg/m3, more than nine and 1.6 times background levels, under closed and ventilated conditions, respectively. Exposure concentrations of particle-bound PAHs were 0.088-0.45 microg/m3 during incense burning. On average, PM10 and associated PAH concentrations were about 371 and 0.23 microg/m3 lower, respectively, in ventilated environments compared with closed conditions. Concentrations were elevated for at least 6 h under closed conditions.

  8. Three dimensional indoor positioning based on visible light with Gaussian mixture sigma-point particle filter technique

    Science.gov (United States)

    Gu, Wenjun; Zhang, Weizhi; Wang, Jin; Amini Kashani, M. R.; Kavehrad, Mohsen

    2015-01-01

    Over the past decade, location based services (LBS) have found their wide applications in indoor environments, such as large shopping malls, hospitals, warehouses, airports, etc. Current technologies provide wide choices of available solutions, which include Radio-frequency identification (RFID), Ultra wideband (UWB), wireless local area network (WLAN) and Bluetooth. With the rapid development of light-emitting-diodes (LED) technology, visible light communications (VLC) also bring a practical approach to LBS. As visible light has a better immunity against multipath effect than radio waves, higher positioning accuracy is achieved. LEDs are utilized both for illumination and positioning purpose to realize relatively lower infrastructure cost. In this paper, an indoor positioning system using VLC is proposed, with LEDs as transmitters and photo diodes as receivers. The algorithm for estimation is based on received-signalstrength (RSS) information collected from photo diodes and trilateration technique. By appropriately making use of the characteristics of receiver movements and the property of trilateration, estimation on three-dimensional (3-D) coordinates is attained. Filtering technique is applied to enable tracking capability of the algorithm, and a higher accuracy is reached compare to raw estimates. Gaussian mixture Sigma-point particle filter (GM-SPPF) is proposed for this 3-D system, which introduces the notion of Gaussian Mixture Model (GMM). The number of particles in the filter is reduced by approximating the probability distribution with Gaussian components.

  9. On-site passive flux sampler measurement of emission rates of carbonyls and VOCs from multiple indoor sources

    Energy Technology Data Exchange (ETDEWEB)

    Shinohara, Naohide [Research Institute of Science for Safety and Sustainability (RISS), National Institute of Advanced Industrial Science and Technology (AIST), 16-1 Onogawa, Tsukuba City, Ibaraki 305-8569 (Japan); Kai, Yuya; Mizukoshi, Atsushi; Kumagai, Kazukiyo; Okuizumi, Yumiko; Jona, Miki; Yanagisawa, Yukio [Department of Environment Systems, Institute of Environmental Studies, Graduate School of Frontier Sciences, The University of Tokyo, 5-1-5 Kashiwa-no-ha, Kashiwa-shi, Chiba 277-8563 (Japan); Fujii, Minoru [Research Center for Material Cycles and Waste Management, National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba City, Ibaraki 305-8506 (Japan)

    2009-05-15

    In indoor environments with high levels of air pollution, it is desirable to remove major sources of emissions to improve air quality. In order to identify the emission sources that contribute most to the concentrations of indoor air pollutants, we used passive flux samplers (PFSs) to measure emission rates of carbonyl compounds and volatile organic compounds (VOCs) from many of the building materials and furnishings present in a room in a reinforced concrete building in Tokyo, Japan. The emission flux of formaldehyde from a desk was high (125 {mu}g/m{sup 2}/h), whereas fluxes from a door and flooring were low (21.5 and 16.5 {mu}g/m{sup 2}/h, respectively). The emission fluxes of toluene from the ceiling and the carpet were high (80.0 and 72.3 {mu}g/m{sup 2}/h, respectively), whereas that from the flooring was low (9.09 {mu}g/m{sup 2}/h). The indoor and outdoor concentrations of formaldehyde were 61.5 and 8.64 {mu}g/m{sup 3}, respectively, and those of toluene were 43.2 and 17.5 {mu}g/m{sup 3}, respectively. The air exchange rate of the room as measured by the perfluorocarbon tracer (PFT) method was 1.84/h. Taking into consideration the area of the emission sources, the carpet, ceiling, and walls were identified as the principal emission sources, contributing 24%, 20%, and 22% of the formaldehyde, respectively, and 22%, 27%, and 14% of the toluene, respectively, assuming that the emission rate from every major emission sources could be measured. In contrast, the door, the flooring, and the desk contributed little to the indoor levels of formaldehyde (1.0%, 0.54%, and 4.1%, respectively) and toluene (2.2%, 0.31%, and 0.85%, respectively). (author)

  10. INDOOR AIR QUALITY ANALYSIS

    OpenAIRE

    Wang, Xin

    2010-01-01

    With the development of modern architecture, one of the building's interior decoration, furnishings, appliances and equipment have become increasingly demanding, making construction of the indoor environment of increasing pollution, increasing pollution, indoor environmental pollution hazards to human is also a growing the greater. This thesis summarizes the major indoor air pollution sources and major pollutants. Indoor air pollutants are formaldehyde, radon, ammonia, total volatile org...

  11. Polycyclic aromatic hydrocarbons (PAHs) in indoor dusts of Guizhou, southwest of China: status, sources and potential human health risk.

    Science.gov (United States)

    Yang, Qin; Chen, Huaguo; Li, Baizhan

    2015-01-01

    Polycyclic aromatic hydrocarbons (PAHs) were analyzed for 136 indoor dust samples collected from Guizhou province, southwest of China. The ∑18PAHs concentrations ranged from 2.18 μg•g-1 to 14.20 μg•g-1 with the mean value of 6.78 μg•g-1. The highest Σ18PAHs concentration was found in dust samples from orefields, followed by city, town and village. Moreover, the mean concentration of Σ18PAHs in indoor dust was at least 10% higher than that of outdoors. The 4-6 rings PAHs, contributing more than 70% of ∑18PAHs, were the dominant species. PAHs ratios, principal component analysis with multiple linear regression (PCA-MLR) and hierarchical clustering analysis (HCA) were applied to evaluate the possible sources. Two major origins of PAHs in indoor dust were identified as vehicle emissions and coal combustion. The mean incremental lifetime cancer risk (ILCR) due to human exposure to indoor dust PAHs in city, town, village and orefield of Guizhou province, China was 6.14×10-6, 5.00×10-6, 3.08×10-6, 6.02×10-6 for children and 5.92×10-6, 4.83×10-6, 2.97×10-6, 5.81×10-6 for adults, respectively.

  12. Polycyclic aromatic hydrocarbons (PAHs in indoor dusts of Guizhou, southwest of China: status, sources and potential human health risk.

    Directory of Open Access Journals (Sweden)

    Qin Yang

    Full Text Available Polycyclic aromatic hydrocarbons (PAHs were analyzed for 136 indoor dust samples collected from Guizhou province, southwest of China. The ∑18PAHs concentrations ranged from 2.18 μg•g-1 to 14.20 μg•g-1 with the mean value of 6.78 μg•g-1. The highest Σ18PAHs concentration was found in dust samples from orefields, followed by city, town and village. Moreover, the mean concentration of Σ18PAHs in indoor dust was at least 10% higher than that of outdoors. The 4-6 rings PAHs, contributing more than 70% of ∑18PAHs, were the dominant species. PAHs ratios, principal component analysis with multiple linear regression (PCA-MLR and hierarchical clustering analysis (HCA were applied to evaluate the possible sources. Two major origins of PAHs in indoor dust were identified as vehicle emissions and coal combustion. The mean incremental lifetime cancer risk (ILCR due to human exposure to indoor dust PAHs in city, town, village and orefield of Guizhou province, China was 6.14×10-6, 5.00×10-6, 3.08×10-6, 6.02×10-6 for children and 5.92×10-6, 4.83×10-6, 2.97×10-6, 5.81×10-6 for adults, respectively.

  13. Particle-Filter-Based WiFi-Aided Reduced Inertial Sensors Navigation System for Indoor and GPS-Denied Environments

    OpenAIRE

    Atia, M. M.; M. J. Korenberg; A. Noureldin

    2012-01-01

    Indoor navigation is challenging due to unavailability of satellites-based signals indoors. Inertial Navigation Systems (INSs) may be used as standalone navigation indoors. However, INS suffers from growing drifts without bounds due to error accumulation. On the other side, the IEEE 802.11 WLAN (WiFi) is widely adopted which prompted many researchers to use it to provide positioning indoors using fingerprinting. However, due to WiFi signal noise and multipath errors indoors, WiFi positioning ...

  14. Particle-Filter-Based WiFi-Aided Reduced Inertial Sensors Navigation System for Indoor and GPS-Denied Environments

    OpenAIRE

    Atia, M. M.; Korenberg , M.J.; A. Noureldin

    2012-01-01

    Indoor navigation is challenging due to unavailability of satellites-based signals indoors. Inertial Navigation Systems (INSs) may be used as standalone navigation indoors. However, INS suffers from growing drifts without bounds due to error accumulation. On the other side, the IEEE 802.11 WLAN (WiFi) is widely adopted which prompted many researchers to use it to provide positioning indoors using fingerprinting. However, due to WiFi signal noise and multipath errors indoors, WiFi positioning ...

  15. Relative and contextual contribution of different sources to the composition and abundance of indoor air bacteria in residences

    OpenAIRE

    Miletto, Marzia; Steven E Lindow

    2015-01-01

    Background The study of the microbial communities in the built environment is of critical importance as humans spend the majority of their time indoors. While the microorganisms in living spaces, especially those in the air, can impact health and well-being, little is known of their identity and the processes that determine their assembly. We investigated the source-sink relationships of airborne bacteria in 29 homes in the San Francisco Bay Area. Samples taken in the sites expected to be sou...

  16. Estimating mortality derived from indoor exposure to particles of outdoor origin.

    Directory of Open Access Journals (Sweden)

    Wenjing Ji

    Full Text Available Following an extensive review of the literature, we further analyze the published data to examine the health effects of indoor exposure to particulate matter (PM of outdoor origin. We obtained data on all-cause, cardiovascular, and respiratory mortality per 10 μg/m3 increase in outdoor PM10 or PM2.5; the infiltration factors for buildings; and estimated time spent outdoors by individuals in the United States, Europe, China, and globally. These data were combined log-linear exposure-response model to estimate the all-cause, cardiovascular, and respiratory mortality of exposure to indoor PM pollution of outdoor origin. Indoor PM pollution of outdoor origin is a cause of considerable mortality, accounting for 81% to 89% of the total increase in mortality associated with exposure to outdoor PM pollution for the studied regions. The findings suggest that enhancing the capacity of buildings to protect occupants against exposure to outdoor PM pollution has significant potential to improve public health outcomes.

  17. Sources and composition of urban aerosol particles

    Directory of Open Access Journals (Sweden)

    M. Vogt

    2011-09-01

    Full Text Available From May 2008 to March 2009 aerosol emissions were measured using the eddy covariance method covering the size range 0.25 to 2.5 μm diameter (Dp from a 105 m tower, in central Stockholm, Sweden. Supporting chemical aerosol data were collected at roof and street level. Results show that the inorganic fraction of sulfate, nitrate, ammonium and sea salt accounts for approximately 15% of the total aerosol mass <1 μm Dp (PM1 with water soluble soil contributing 11% and water insoluble soil 47%. Carbonaceous compounds were at the most 27% of PM1 mass. It was found that heating the air from the tower to 200 °C resulted in the loss of approximately 60% of the aerosol volume at 0.25 μm Dp whereas only 40% of the aerosol volume was removed at 0.6 μm Dp. Further heating to 300 °C caused very little additional losses <0.6 μm Dp. The chemical analysis did not include carbonaceous compounds, but based on the difference between the total mass concentration and the sum of the analyzed non-carbonaceous materials, it can be assumed that the non-volatile particulate material (heated to 300 °C consists mainly of carbonaceous compounds, including elemental carbon. Furthermore, it was found that the non-volatile particle fraction <0.6 μm Dp correlated (r2 = 0.4 with the BC concentration at roof level in the city, supporting the assumption that the non-volatile material consists of carbonaceous compounds. The average diurnal cycles of the BC emissions from road traffic (as inferred from the ratio of the incremental concentrations of nitrogen oxides (NOx and BC measured on a densely trafficked street and the fluxes of non-volatile material at tower level are in close agreement, suggesting a traffic source of BC. We have estimated the emission factors (EFs for non

  18. Stacked dipole line source excitation of active nano-particles

    DEFF Research Database (Denmark)

    Arslanagic, Samel

    This work investigates electromagnetic properties of cylindrical active coated nano-particles excited by a stac- ked electric dipole line source. The nano-particles consist of a silica nano-core, layered by silver, gold, or copper nano-shell. Attention is devoted to the influence of the source...

  19. Chemical characterization and source apportionment of indoor and outdoor fine particulate matter (PM(2.5)) in retirement communities of the Los Angeles Basin.

    Science.gov (United States)

    Hasheminassab, Sina; Daher, Nancy; Shafer, Martin M; Schauer, James J; Delfino, Ralph J; Sioutas, Constantinos

    2014-08-15

    Concurrent indoor and outdoor measurements of fine particulate matter (PM2.5) were conducted at three retirement homes in the Los Angeles Basin during two separate phases (cold and warm) between 2005 and 2006. Indoor-to-outdoor relationships of PM2.5 chemical constituents were determined and sources of indoor and outdoor PM2.5 were evaluated using a molecular marker-based chemical mass balance (MM-CMB) model. Indoor levels of elemental carbon (EC) along with metals and trace elements were found to be significantly affected by outdoor sources. EC, in particular, displayed very high indoor-to-outdoor (I/O) mass ratios accompanied by strong I/O correlations, illustrating the significant impact of outdoor sources on indoor levels of EC. Similarly, indoor levels of polycyclic aromatic hydrocarbons (PAHs), hopanes, and steranes were strongly correlated with their outdoor components and displayed I/O ratios close to unity. On the other hand, concentrations of n-alkanes and organic acids inside the retirement communities were dominated by indoor sources (e.g. food cooking and consumer products), as indicated by their I/O ratios, which exceeded unity. Source apportionment results revealed that vehicular emissions were the major contributor to both indoor and outdoor PM2.5, accounting for 39 and 46% of total mass, respectively. Moreover, the contribution of vehicular sources to indoor levels was generally comparable to its corresponding outdoor estimate. Other water-insoluble organic matter (other WIOM), which accounts for emissions from uncharacterized primary biogenic sources, displayed a wider range of contributions, varying from 2 to 73% of PM2.5, across all sites and phases of the study. Lastly, higher indoor than outdoor contribution of other water-soluble organic matter (other WSOM) was evident at some of the sites, suggesting the production of secondary aerosols as well as direct emissions from primary sources (including cleaning or other consumer products) at the

  20. Indoor air quality and health

    Science.gov (United States)

    Jones, A. P.

    During the last two decades there has been increasing concern within the scientific community over the effects of indoor air quality on health. Changes in building design devised to improve energy efficiency have meant that modern homes and offices are frequently more airtight than older structures. Furthermore, advances in construction technology have caused a much greater use of synthetic building materials. Whilst these improvements have led to more comfortable buildings with lower running costs, they also provide indoor environments in which contaminants are readily produced and may build up to much higher concentrations than are found outside. This article reviews our current understanding of the relationship between indoor air pollution and health. Indoor pollutants can emanate from a range of sources. The health impacts from indoor exposure to combustion products from heating, cooking, and the smoking of tobacco are examined. Also discussed are the symptoms associated with pollutants emitted from building materials. Of particular importance might be substances known as volatile organic compounds (VOCs), which arise from sources including paints, varnishes, solvents, and preservatives. Furthermore, if the structure of a building begins to deteriorate, exposure to asbestos may be an important risk factor for the chronic respiratory disease mesothelioma. The health effects of inhaled biological particles can be significant, as a large variety of biological materials are present in indoor environments. Their role in inducing illness through immune mechanisms, infectious processes, and direct toxicity is considered. Outdoor sources can be the main contributors to indoor concentrations of some contaminants. Of particular significance is Radon, the radioactive gas that arises from outside, yet only presents a serious health risk when found inside buildings. Radon and its decay products are now recognised as important indoor pollutants, and their effects are

  1. Partitioning of phthalates among the gas phase, airborne particles and settled dust in indoor environments

    DEFF Research Database (Denmark)

    Weschler, Charles J.; Salthammer, Tunga; Fromme, Hermann

    2008-01-01

    . The particle concentration, C-particle, of a given phthalate was calculated from its total airborne concentration and the concentration of airborne particles (PM4). This required knowledge of the particle-gas partition coefficient, K., which was estimated from either the saturation vapor pressure (p......(s)) or the octanol/air partition coefficient (K-OA). For each phthalate in each apartment, the ratio of its particle concentration to its dust concentration (C-particle/C-Dust) was calculated, The median values of this ratio were within an order of magnitude of one another for five of the phthalate esters despite...

  2. A Crowd-Sourcing Indoor Localization Algorithm via Optical Camera on a Smartphone Assisted by Wi-Fi Fingerprint RSSI

    Directory of Open Access Journals (Sweden)

    Wei Chen

    2016-03-01

    Full Text Available Indoor positioning based on existing Wi-Fi fingerprints is becoming more and more common. Unfortunately, the Wi-Fi fingerprint is susceptible to multiple path interferences, signal attenuation, and environmental changes, which leads to low accuracy. Meanwhile, with the recent advances in charge-coupled device (CCD technologies and the processing speed of smartphones, indoor positioning using the optical camera on a smartphone has become an attractive research topic; however, the major challenge is its high computational complexity; as a result, real-time positioning cannot be achieved. In this paper we introduce a crowd-sourcing indoor localization algorithm via an optical camera and orientation sensor on a smartphone to address these issues. First, we use Wi-Fi fingerprint based on the K Weighted Nearest Neighbor (KWNN algorithm to make a coarse estimation. Second, we adopt a mean-weighted exponent algorithm to fuse optical image features and orientation sensor data as well as KWNN in the smartphone to refine the result. Furthermore, a crowd-sourcing approach is utilized to update and supplement the positioning database. We perform several experiments comparing our approach with other positioning algorithms on a common smartphone to evaluate the performance of the proposed sensor-calibrated algorithm, and the results demonstrate that the proposed algorithm could significantly improve accuracy, stability, and applicability of positioning.

  3. A Crowd-Sourcing Indoor Localization Algorithm via Optical Camera on a Smartphone Assisted by Wi-Fi Fingerprint RSSI.

    Science.gov (United States)

    Chen, Wei; Wang, Weiping; Li, Qun; Chang, Qiang; Hou, Hongtao

    2016-03-19

    Indoor positioning based on existing Wi-Fi fingerprints is becoming more and more common. Unfortunately, the Wi-Fi fingerprint is susceptible to multiple path interferences, signal attenuation, and environmental changes, which leads to low accuracy. Meanwhile, with the recent advances in charge-coupled device (CCD) technologies and the processing speed of smartphones, indoor positioning using the optical camera on a smartphone has become an attractive research topic; however, the major challenge is its high computational complexity; as a result, real-time positioning cannot be achieved. In this paper we introduce a crowd-sourcing indoor localization algorithm via an optical camera and orientation sensor on a smartphone to address these issues. First, we use Wi-Fi fingerprint based on the K Weighted Nearest Neighbor (KWNN) algorithm to make a coarse estimation. Second, we adopt a mean-weighted exponent algorithm to fuse optical image features and orientation sensor data as well as KWNN in the smartphone to refine the result. Furthermore, a crowd-sourcing approach is utilized to update and supplement the positioning database. We perform several experiments comparing our approach with other positioning algorithms on a common smartphone to evaluate the performance of the proposed sensor-calibrated algorithm, and the results demonstrate that the proposed algorithm could significantly improve accuracy, stability, and applicability of positioning.

  4. Investigation on particle matter concentration and bacterial bioaerosols in indoor air of prisons

    Directory of Open Access Journals (Sweden)

    Mohammad Sadegh Sekhavatjou

    2014-03-01

    Conclusion: Based on the results, the maximum contamination load and exceeded concentration was observed in public sections and bedchambers. This findings were attributed to the daily entry of new prisoners, high population density in prison, presence of ill prisoners, prisoners with hidden respiratory disease showing no symptoms yet, old building, climatic conditions of the region, low efficiency of ventilation systems, and influx of particulates. To filter and purify prison indoor air, it is crucial to take serious action plans such as reducing criminal population density, sanitary and engineering measures

  5. The indoor volatile organic compound (VOC) characteristics and source identification in a new university campus in Tianjin, China.

    Science.gov (United States)

    Kang, Jian; Liu, Junjie; Pei, Jingjing

    2017-06-01

    This study investigates the volatile organic compounds (VOCs) constituents and concentration levels on a new university campus, where all of the buildings including classrooms and student dormitories were newly built and decorated within 1 year. Investigated indoor environments include dormitories, classrooms, and the library. About 30 dormitory buildings with different furniture loading ratios were measured. The characteristics of the indoor VOCs species are analyzed and possible sources are identified. The VOCs were analyzed with gas chromatography-mass spectroscopy (GC-MS). It was found that the average total VOC (TVOC) concentration can reach 2.44 mg/m(3). Alkenes were the most abundant VOCs in dormitory rooms, contributing up to 86.5% of the total VOCs concentration. The concentration of α-pinene is the highest among the alkenes. Unlike the dormitory rooms, there is almost no room with TVOC concentration above 0.6 mg/m(3) in classroom and library buildings. Formaldehyde concentration in the dormitory rooms increased about 23.7% after the installation of furniture, and the highest level reached 0.068 mg/m(3). Ammonia released from the building antifreeze material results in an average indoor concentration of 0.28 mg/m(3), which is 100% over the threshold and should be seriously considered. Further experiments were conducted to analyze the source of the α-pinene and some alkanes in dormitory rooms. The results showed that the α-pinene mainly comes from the bed boards, while the wardrobes are the main sources of alkanes. The contribution of the pinewood bed boards to the α-pinene and TVOC concentration can reach up to above 90%. The same type rooms were sampled 1 year later and the decay rate of α-pinene is quite high, close to 100%, so that it almost cannot be detected in the sampled rooms. Analysis of indoor volatile organic compounds (VOCs) in newly built campus buildings in China identified the specific constituents of indoor VOCs contaminants exposed to

  6. Temperature dependence of the particle/gas partition coefficient: An application to predict indoor gas-phase concentrations of semi-volatile organic compounds.

    Science.gov (United States)

    Wei, Wenjuan; Mandin, Corinne; Blanchard, Olivier; Mercier, Fabien; Pelletier, Maud; Le Bot, Barbara; Glorennec, Philippe; Ramalho, Olivier

    2016-09-01

    The indoor gas-phase concentrations of semi-volatile organic compounds (SVOCs) can be predicted from their respective concentrations in airborne particles by applying the particle/gas partitioning equilibrium. The temperature used for partitioning is often set to 25°C. However, indoor temperatures frequently differ from this reference value. This assumption may result in errors in the predicted equilibrium gas-phase SVOC concentrations. To improve the prediction model, the temperature dependence of the particle/gas partition coefficient must be addressed. In this paper, a theoretical relationship between the particle/gas partition coefficient and temperature was developed based on the SVOC absorptive mechanism. The SVOC particle/gas partition coefficients predicted by employing the derived theoretical relationship agree well with the experimental data retrieved from the literature (R>0.93). The influence of temperature on the equilibrium gas-phase SVOC concentration was quantified by a dimensionless analysis of the derived relationship between the SVOC particle/gas partition coefficient and temperature. The predicted equilibrium gas-phase SVOC concentration decreased by between 31% and 53% when the temperature was lowered by 6°C, while it increased by up to 750% when the indoor temperature increased from 15°C to 30°C.

  7. Temperature dependence of the particle/gas partition coefficient: An application to predict indoor gas-phase concentrations of semi-volatile organic compounds

    Energy Technology Data Exchange (ETDEWEB)

    Wei, Wenjuan, E-mail: Wenjuan.Wei@cstb.fr [University of Paris-Est, Scientific and Technical Center for Building (CSTB), Health and Comfort Department, French Indoor Air Quality Observatory (OQAI), 84 Avenue Jean Jaurès, Champs sur Marne, 77447 Marne la Vallée Cedex 2 (France); Mandin, Corinne [University of Paris-Est, Scientific and Technical Center for Building (CSTB), Health and Comfort Department, French Indoor Air Quality Observatory (OQAI), 84 Avenue Jean Jaurès, Champs sur Marne, 77447 Marne la Vallée Cedex 2 (France); INSERM-U1085, Irset-Research Institute for Environmental and Occupational Health, Rennes (France); LERES-Environment and Health Research Laboratory (Irset and EHESP Technologic Platform), Rennes (France); Blanchard, Olivier [EHESP-School of Public Health, Sorbonne Paris Cité, Rennes (France); INSERM-U1085, Irset-Research Institute for Environmental and Occupational Health, Rennes (France); Mercier, Fabien [EHESP-School of Public Health, Sorbonne Paris Cité, Rennes (France); LERES-Environment and Health Research Laboratory (Irset and EHESP Technologic Platform), Rennes (France); INSERM-U1085, Irset-Research Institute for Environmental and Occupational Health, Rennes (France); Pelletier, Maud [EHESP-School of Public Health, Sorbonne Paris Cité, Rennes (France); INSERM-U1085, Irset-Research Institute for Environmental and Occupational Health, Rennes (France); Le Bot, Barbara [EHESP-School of Public Health, Sorbonne Paris Cité, Rennes (France); LERES-Environment and Health Research Laboratory (Irset and EHESP Technologic Platform), Rennes (France); INSERM-U1085, Irset-Research Institute for Environmental and Occupational Health, Rennes (France); and others

    2016-09-01

    The indoor gas-phase concentrations of semi-volatile organic compounds (SVOCs) can be predicted from their respective concentrations in airborne particles by applying the particle/gas partitioning equilibrium. The temperature used for partitioning is often set to 25 °C. However, indoor temperatures frequently differ from this reference value. This assumption may result in errors in the predicted equilibrium gas-phase SVOC concentrations. To improve the prediction model, the temperature dependence of the particle/gas partition coefficient must be addressed. In this paper, a theoretical relationship between the particle/gas partition coefficient and temperature was developed based on the SVOC absorptive mechanism. The SVOC particle/gas partition coefficients predicted by employing the derived theoretical relationship agree well with the experimental data retrieved from the literature (R > 0.93). The influence of temperature on the equilibrium gas-phase SVOC concentration was quantified by a dimensionless analysis of the derived relationship between the SVOC particle/gas partition coefficient and temperature. The predicted equilibrium gas-phase SVOC concentration decreased by between 31% and 53% when the temperature was lowered by 6 °C, while it increased by up to 750% when the indoor temperature increased from 15 °C to 30 °C. - Highlights: • A theoretical relationship between K{sub p} and temperature was developed. • The relationship was based on the SVOC absorptive mechanism. • The temperature impact was quantified by a dimensionless analysis.

  8. "EUROPART". Airborne particles in the indoor environment. A European interdisciplinary review of scientific evidence on associations between exposure to particles in buildings and health effects

    DEFF Research Database (Denmark)

    Schneider, T.; Sundell, Jan; Bischof, W.

    2003-01-01

    The relevance of particle mass, surface area or number concentration as risk indicators for health effects in non-industrial buildings has been assessed by a European interdisciplinary group of researchers (called EUROPART) by reviewing papers identified in Medline, Toxline, and OSH. Studies...... dealing with dermal effects or cancer or specifically addressing environmental tobacco smoke, house dust-mite, cockroach or animal allergens, microorganisms and pesticides were excluded. A total of 70 papers were reviewed, and eight were identified for the final review: Five experimental studies involving...... mainly healthy subjects, two cross-sectional office studies and one longitudinal study among elderly on cardiovascular effects. From most studies, no definite conclusions could be drawn. Overall, the group concluded that there is inadequate scientific evidence that airborne, indoor particulate mass...

  9. Europart - Airborne particles in the indoor environment. A European interdisciplinary review of scientific evidence on associations between exposure to particles in buildings and health effects

    DEFF Research Database (Denmark)

    Schneider, T.; Sundell, Jan; Bischof, W.

    2002-01-01

    The relevance of particle mass, surface area or number concentration as risk indicators for health effects in non-industrial buildings has been assessed by a European interdisciplinary group of researchers by reviewing papers identified in Medline, Toxline, and OSH. Studies dealing with dermal...... effects or cancer or specifically addressing environmental tobacco smoke, major allergens, and pesticides were excluded. Seventy-six papers were identified for evaluation and eight of these were judged to be conclusive and included in the final review: five experimental studies, two cross-sectional office...... studies, and a longitudinal study among elderly with cardiovascular conditions. Given the limited and inconclusive scientific evidence, the group concluded that indoor particulate mass or number concentrations cannot be used as generally applicable risk indicators of health effects in non...

  10. A study of characterize indoor particles in three non-smoking homes

    Science.gov (United States)

    Kamens, Richard; Lee, Chung-te; Wiener, Russell; Leith, David

    Aerosol concentrations and particle size distributions in three middle income homes were characterized over a three day period. Occupants of the homes were non-smokers. A single central sampling location between the kitchen and dining room areas was used in each of the homes. Thirty-seven and 47 mm prototype personal sampling inlets were collocated with two fixed PM 10 dichotomous ambient samplers to determine the average concentration of particulate mass during daytime and evening-early morning sampling periods. Particulate concentrations in the three homes ranged from 14 to 42 μg m -3. On average, 37% of the particle mass was collected in a fine (2.5 μm aerodynamic diameter or below) fraction, 26% was observed in a coarse fraction between 2.5 and 10 μm, and 37% was found in a fraction greater than 10 μm. Particle concentrations obtained with prototype personal samplers compared reasonably well to those obtained with 10 μm ambient air dichotomous samplers. Aerosol size information obtained from automated aerosol instruments suggests that the most significant event for generating small particles in all of the households was cooking. Household vacuum sweeping was the most significant large particle generating event. Electron photomicrographs indicated that particles below 1 μm dominate the particle size-number distribution. Biological and mineral based particles predominantly make up the 2.5-10 μm size range.

  11. Laser Plasma Particle Accelerators: Large Fields for Smaller Facility Sources

    Energy Technology Data Exchange (ETDEWEB)

    Geddes, Cameron G.R.; Cormier-Michel, Estelle; Esarey, Eric H.; Schroeder, Carl B.; Vay, Jean-Luc; Leemans, Wim P.; Bruhwiler, David L.; Cary, John R.; Cowan, Ben; Durant, Marc; Hamill, Paul; Messmer, Peter; Mullowney, Paul; Nieter, Chet; Paul, Kevin; Shasharina, Svetlana; Veitzer, Seth; Weber, Gunther; Rubel, Oliver; Ushizima, Daniela; Bethel, Wes; Wu, John

    2009-03-20

    Compared to conventional particle accelerators, plasmas can sustain accelerating fields that are thousands of times higher. To exploit this ability, massively parallel SciDAC particle simulations provide physical insight into the development of next-generation accelerators that use laser-driven plasma waves. These plasma-based accelerators offer a path to more compact, ultra-fast particle and radiation sources for probing the subatomic world, for studying new materials and new technologies, and for medical applications.

  12. Perfluoroalkyl contaminants in window film: indoor/outdoor, urban/rural, and winter/summer contamination and assessment of carpet as a possible source.

    Science.gov (United States)

    Gewurtz, Sarah B; Bhavsar, Satyendra P; Crozier, Patrick W; Diamond, Miriam L; Helm, Paul A; Marvin, Chris H; Reiner, Eric J

    2009-10-01

    Window film concentrations of ionic perfluoroalkyl contaminants (PFCs) were determined indoors and outdoors at urban, suburban, and rural sites in or near Toronto, Ontario, Canada, to identify locations of relatively elevated concentrations and the nature of potential sources. The role of carpet installation and floor wax application as possible sources was also evaluated by sampling indoor window films at five sites before and after new carpet installations, at one site before and after a floor wax application, and at two carpet stores. Low concentrations were found in all outdoor window films, with comparable relative proportions of individual PFCs among sites, suggesting similar sources to the outdoor environment and rapid air mixing. PFCs in indoor window film were up to 20-fold greater than outdoor, providing some evidence that a significant proportion of PFCs originate from the indoor environment, although precipitation wash-off of outdoor window film may be confounding these results. For both indoor and outdoor film, PFC concentrations generally changed between the summer and winter but the chemical profiles were similar between seasons. Concentrations of PFCs in window films increased one month post carpet installation at three of the five sites, suggesting that some of the carpets may have been a source to the indoor environment. Indoor window films from two carpet stores (sigmaPFC = 16 and 7 pg/cm2) contained higher concentrations than the other indoor locations (sigmaPFC = < MDL to 4.3 pg/cm2), which may reflect the carpets stored within these buildings. The use of window film allowed collection of a wide range of samples and the results can be used to focus the efforts of more traditional air sampling campaigns.

  13. 室内生物气溶胶颗粒行为特性研究%Study on Particles Behavioral of Indoor Bioaerosols

    Institute of Scientific and Technical Information of China (English)

    陈小明; 刘迎云; 刘泽华; 刘飞

    2011-01-01

    Bioaerosols, a membership of aerosol category, Its particle pollution characteristics on indoor air quality and human health effects are drawing more and more attention. This paper systematically reviews recent researches of domestic and overseas scholars on particles behavior of bioaerosols, and finally discusses the development direction of indoor bioaerosols particles behavior research.%生物气溶胶隶属气溶胶范畴,其颗粒污染特性对室内空气质量及人体健康的影响越来越受到人们的重视。本文较系统地综述了近年来国内外学者在生物气溶胶颗粒行为特性上的研究进展,并探讨了今后室内生物气溶胶颗粒行为研究的发展方向。

  14. The Two Sources of Solar Energetic Particles

    CERN Document Server

    Reames, Donald V

    2013-01-01

    Evidence for two different physical mechanisms for acceleration of solar energetic particles (SEPs) arose 50 years ago with radio observations of type III bursts, produced by outward streaming electrons, and type II bursts from coronal and interplanetary shock waves. Since that time we have found that the former are related to "impulsive" SEP events from impulsive flares or jets. Here, resonant stochastic acceleration, related to magnetic reconnection involving open field lines, produces not only electrons but 1000-fold enhancements of 3He/4He and of (Z>50)/O. Alternatively, in "gradual" SEP events, shock waves, driven out from the Sun by coronal mass ejections (CMEs), more democratically sample ion abundances that are even used to measure the coronal abundances of the elements. Sometimes residual impulsive suprathermal ions contribute to the seed population for shock acceleration, complicating the abundance picture, but this process has now been modeled theoretically. Initially, impulsive events define a poi...

  15. The health risks of incense use in the home: an underestimated source of indoor air pollution?

    Science.gov (United States)

    Roberts, Debbie; Pontin, David

    2016-03-01

    The health impact of indoor air pollution is a growing area of interest for public health professionals. People typically spend up to 90 per cent of their time indoors, particularly women, young children and elders. Although the adverse health effects of second-hand tobacco smoke are well recognised, the impact of burning incense in the home has received little attention in Western literature. Incense burning in the home is common in a number of cultures (particularly Asian, North African or Arabic). Many health visitors (HVs) work with communities who use incense regularly for religious/cultural reasons and it is a neglected area of study and research.The literature suggests that home incense use can have significant adverse health effects, particularly on cardiopulmonary morbidity and mortality. Further research is needed to identify which individuals are most susceptible, which types of incense are most harmful, and whether any actions can be taken to minimise exposure.

  16. Volatile organic compound conversion by ozone, hydroxyl radicals, and nitrate radicals in residential indoor air: Magnitudes and impacts of oxidant sources.

    Science.gov (United States)

    Waring, Michael S; Wells, J Raymond

    2015-04-01

    Indoor chemistry may be initiated by reactions of ozone (O3), the hydroxyl radical (OH), or the nitrate radical (NO3) with volatile organic compounds (VOC). The principal indoor source of O3 is air exchange, while OH and NO3 formation are considered as primarily from O3 reactions with alkenes and nitrogen dioxide (NO2), respectively. Herein, we used time-averaged models for residences to predict O3, OH, and NO3 concentrations and their impacts on conversion of typical residential VOC profiles, within a Monte Carlo framework that varied inputs probabilistically. We accounted for established oxidant sources, as well as explored the importance of two newly realized indoor sources: (i) the photolysis of nitrous acid (HONO) indoors to generate OH and (ii) the reaction of stabilized Criegee intermediates (SCI) with NO2 to generate NO3. We found total VOC conversion to be dominated by reactions both with O3, which almost solely reacted with d-limonene, and also with OH, which reacted with d-limonene, other terpenes, alcohols, aldehydes, and aromatics. VOC oxidation rates increased with air exchange, outdoor O3, NO2 and d-limonene sources, and indoor photolysis rates; and they decreased with O3 deposition and nitric oxide (NO) sources. Photolysis was a strong OH formation mechanism for high NO, NO2, and HONO settings, but SCI/NO2 reactions weakly generated NO3 except for only a few cases.

  17. Sources and perceptions of indoor and ambient air pollution in rural Alaska.

    Science.gov (United States)

    Ware, Desirae; Lewis, Johnnye; Hopkins, Scarlett; Boyer, Bert; Noonan, Curtis; Ward, Tony

    2013-08-01

    Even though Alaska is the largest state in the United States, much of the population resides in rural and underserved areas with documented disparities in respiratory health. This is especially true in the Yukon-Kuskokwim (southwest) and Ahtna (southcentral) Regions of Alaska. In working with community members, the goal of this study was to identify the air pollution issues (both indoors and outdoors) of concern within these two regions. Over a two-year period, 328 air quality surveys were disseminated within seven communities in rural Alaska. The surveys focused on understanding the demographics, home heating practices, indoor activities, community/outdoor activities, and air quality perceptions within each community. Results from these surveys showed that there is elevated potential for PM10/PM2.5 exposures in rural Alaska communities. Top indoor air quality concerns included mold, lack of ventilation or fresh air, and dust. Top outdoor air pollution concerns identified were open burning/smoke, road dust, and vehicle exhaust (e.g., snow machines, ATVs, etc.). These data can now be used to seek additional funding for interventions, implementing long-term, sustainable solutions to the identified problems. Further research is needed to assess exposures to PM10/PM2.5 and the associated impacts on respiratory health, particularly among susceptible populations such as young children.

  18. Characterizations, relationship, and potential sources of outdoor and indoor particulate matter bound polycyclic aromatic hydrocarbons (PAHs) in a community of Tianjin, Northern China.

    Science.gov (United States)

    Han, B; Bai, Z; Liu, Y; You, Y; Xu, J; Zhou, J; Zhang, J; Niu, C; Zhang, N; He, F; Ding, X

    2015-06-01

    Polycyclic aromatic hydrocarbons (PAHs) are among the most toxic air pollutants in China. However, because there are unsubstantial data on indoor and outdoor particulate PAHs, efforts in assessing inhalation exposure and cancer risk to PAHs are limited in China. This study measured 12 individual PAHs in indoor and outdoor environments at 36 homes during the non-heating period and heating period in 2009. Indoor PAH concentrations were comparable with outdoor environments in the non-heating period, but were lower in the heating period. The average indoor/outdoor ratios in both sampling periods were lower than 1, while the ratios in the non-heating period were higher than those in the heating period. Correlation analysis and coefficient of divergence also verified the difference between indoor and outdoor PAHs, which could be caused by high ventilation in the non-heating period. To support this conclusion, linear and robust regressions were used to estimate the infiltration factor to compare outdoor PAHs to indoor PAHs. The calculated infiltration factors obtained by the two models were similar in the non-heating period but varied greatly in the heating period, which may have been caused by the influence of ventilation. Potential sources were distinguished using a diagnostic ratio and a mixture of coal combustion and traffic emission, which are major sources of PAHs.

  19. Technical solutions for reducing indoor residential exposures to ultrafine particles from second-hand cigarette smoke infiltration

    DEFF Research Database (Denmark)

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

    2011-01-01

    was examined by investigating the removal of ultrafine particles from a lit cigarette in a laboratory environment. The results showed that in the case where the receiving flat was sealed, the concentration of particles in the receiving flat was non-correlated with (or independent of) the emission of particles...... in the source flat. The test of the air circulating ductwork showed that the removal efficiency ranged from approx. 30% to 60% after 10 minutes, i.e. when the cigarette had burned out....

  20. Indoor air particles and bioaerosols before and after renovation of moisture-damaged buildings: the effect on biological activity and microbial flora.

    Science.gov (United States)

    Huttunen, Kati; Rintala, Helena; Hirvonen, Maija-Riitta; Vepsäläinen, Asko; Hyvärinen, Anne; Meklin, Teija; Toivola, Mika; Nevalainen, Aino

    2008-07-01

    Many building-related health problems coincide with moisture damage and mold growth within a building. Their elimination is assumed to improve indoor air quality. The aim of this study was to follow the success of remediation in two individual buildings by analyzing the microbial flora and immunotoxicological activity of filter samples. We compare results from samples collected from indoor air in the moisture-damaged buildings before and after renovation and results from matched reference buildings and outdoor air. The microbial characteristics of the samples were studied by analyzing ergosterol content and determining the composition of fungal flora with quantitative polymerase chain reaction (QPCR). In addition, the concentrations of particles were monitored with optical particle counter (OPC). The immunotoxicological activity of collected particle samples was tested by exposing mouse macrophages (RAW264.7) for 24 h to particle suspension extracted from the filters, and measuring the viability of the exposed cells (MTT-test) and production of inflammatory mediators (nitric oxide, IL-6 and TNF*) in cell culture medium by enzyme-linked immunoassay (ELISA). The results show that for Location 1 the renovation decreased the immunotoxicological activity of the particles collected from damaged building, whereas no difference was detected in the corresponding samples collected from the reference building. Interestingly, only slight differences were seen in the concentration of fungi. In the Location 2, a decrease was seen in the concentration of fungi after the renovation, whereas no effect on the immunotoxicological responses was detected. In this case, the immunotoxicological responses to the indoor air samples were almost identical to those caused by the samples from outdoor air. This indicates that the effects of remediation on the indoor air quality may not necessarily be readily measurable either with microbial or toxicological parameters. This may be associated

  1. Coagulation in the presence of stochastic nano-particle sources

    Science.gov (United States)

    Vrtala, A.; Wagner, P. E.

    2000-08-01

    The behavior of atmospheric aerosols undergoing coagulation processes in the presence of aerosol particle sources with randomly distributed source strength is reported. Numerical calculations were performed for a set of different initial conditions and random source. It is shown that the interplay of aerosol formation and aging can lead to trimodal aerosols with modal radii corresponding to nucleation, the so called `Aitken' and accumulation mode.

  2. Indoor and outdoor airborne particles : an in vitro study on mutagenic potential and toxicological implications

    NARCIS (Netherlands)

    Houdt, van J.J.

    1988-01-01

    Introduction

    Air pollution components are present as gases and as particulate matter. As particle deposition takes place in various parts of the respiratory system particulate matter may have other toxicological implications than gaseous pollutants, which all may

  3. Indoor and outdoor airborne particles. An in vitro study on mutagenic potential and toxicological implications.

    NARCIS (Netherlands)

    Houdt, van J.J.

    1988-01-01

    IntroductionAir pollution components are present as gases and as particulate matter. As particle deposition takes place in various parts of the respiratory system particulate matter may have other toxicological implications than gaseous pollutants, which all may penetrate in the low

  4. Source identification of coarse particles in the Desert ...

    Science.gov (United States)

    The Desert Southwest Coarse Particulate Matter Study was undertaken to further our understanding of the spatial and temporal variability and sources of fine and coarse particulate matter (PM) in rural, arid, desert environments. Sampling was conducted between February 2009 and February 2010 in Pinal County, AZ near the town of Casa Grande where PM concentrations routinely exceed the U.S. National Ambient Air Quality Standards (NAAQS) for both PM10 and PM2.5. In this desert region, exceedances of the PM10 NAAQS are dominated by high coarse particle concentrations, a common occurrence in this region of the United States. This work expands on previously published measurements of PM mass and chemistry by examining the sources of fine and coarse particles and the relative contribution of each to ambient PM mass concentrations using the Positive Matrix Factorization receptor model (Clements et al., 2014). Highlights • Isolation of coarse particles from fine particle sources. • Unique chemical composition of coarse particles. • Role of primary biological particles on aerosol loadings.

  5. Impact of two-way air flow due to temperature difference on preventing the entry of outdoor particles using indoor positive pressure control method.

    Science.gov (United States)

    Chen, Chun; Zhao, Bin; Yang, Xudong

    2011-02-28

    Maintaining positive pressure indoors using mechanical ventilation system is a popular control method for preventing the entry of outdoor airborne particles. The idea is, as long as the supply air flow rate is larger than return air flow rate, the pressure inside the ventilated room should be positive since the superfluous air flow must exfiltrate from air leakages or other openings of the room to the outdoors. Based on experimental and theoretical analyses this paper aims to show the impact of two-way air flow due to indoor/outdoor temperature difference on preventing the entry of outdoor particles using positive pressure control method. The indoor positive pressure control method is effective only when the size of the opening area is restricted to a certain level, opening degree less than 30° in this study, due to the two-way air flow effect induced by differential temperature. The theoretical model was validated using the experimental data. The impacts of two-way air flow due to temperature difference and the supply air flow rate were also analyzed using the theoretical model as well as experimental data. For real houses, it seems that the idea about the positive pressure control method for preventing the entry of outdoor particles has a blind side.

  6. Measurement and apportionment of radon source terms for modeling indoor environments. Final progress report, March 1990--August 1992

    Energy Technology Data Exchange (ETDEWEB)

    Harley, N.H.

    1992-12-31

    During the present 2 1/2 year contract period, we have made significant Progress in modeling the source apportionment of indoor {sup 222}Rn and in {sup 222}Rn decay product dosimetry. Two additional areas were worked on which we believe are useful for the DOE Radon research Program. One involved an analysis of the research house data, grouping the hourly house {sup 222}Rn measurements into 2 day, 7 day and 90 day intervals to simulate the response of passive monitors. Another area requiring some attention resulted in a publication of 3 years of our indoor/outdoor measurements in a high-rise apartment. Little interest has been evinced in apartment measurements yet 20% of the US population lives in multiple-family dwellings, not in contact with the ground. These data together with a summary of all other published data on apartments showed that apartments have only about 50% greater {sup 222}Rn concentration than the measured outdoor {sup 222}Rn. Apartment dwellers generally represent a low risk group regarding {sup 222}Rn exposure. The following sections describe the main projects in some detail.

  7. Particle Concentrations Inside a Tavern Before and After Prohibition of Smoking: Evaluating the Performance of an Indoor Air Quality Model.

    Science.gov (United States)

    Ott, Wayne; Switzer, Paul; Robinson, John

    1996-12-01

    Measurements were made of respirable suspended particles (RSP) in a large sports tavern on 26 dates over approximately two years in which smoking was allowed, followed by measurements on 50 dates during the year after smoking was prohibited. The smoking prohibition occurred without warning when the city government passed a regulation restricting smoking in local restaurants and taverns. Two follow-up field surveys, consisting of 24 and 26 visits, respectively, were conducted to measure changes in RSP levels after smoking was prohibited. No decrease in tavern attendance was evident after smoking was prohibited. During the smoking period, the average RSP concentration was 56.8 |ig/m3 above the outdoor concentrations, but the average abruptly dropped to 5.9 ug/m3 above outdoor levels-a 90% decrease- on 24 visits in the first two months immediately after smoking was prohibited (first follow-up study). A second set of 26 follow-up visits (matched by time of day, day of the week, and season to the earlier smoking visits) yielded an average concentration of 12.9 jig/m3 above the outdoor levels, or an overall decrease in the average RSP concentration of 77% compared with the smoking period. During the smoking period, RSP concentrations more than 100 ug/m3 above outdoor levels occurred on 30.7% of the visits. During the 50 nonsmoking visits, 92% of the RSP concentrations were less than 20 u,g/m3 above outdoor levels, and no concentration exceeded 100 ug/m3 on any nonsmoking visit. The data show there was a striking decline in indoor RSP concentrations in the tavern after smoking was prohibited. The indoor concentration observed in the nonsmoking periods (9.1 u.g/m3 average for all nonsmoking visits) was attributed to cooking and resuspended dust. A mathematical model based on the mass balance equation was developed that included smoking, cooking, and resuspended dust. Using cigarette emission rates from the literature, the tavern volume of 521 m3, and the air exchange rate

  8. Source Apportionment of Fine Particles in Xinzhen, Beijing

    Institute of Scientific and Technical Information of China (English)

    JIN; Xiang-chun; ZHANG; Gui-ying; XIAO; Cai-jin; WANG; Ping-sheng; WANG; Xing-hua; HUA; Long; YAO; Yong-gang; YUAN; Guo-jun; NI; Bang-fa

    2013-01-01

    As the capital city of China,Beijing often suffers from hazy weather recently.In order to improve air quality,it is of great importance to perform source apportionment and source trajectory.A total of 140airborne particulate matter samples were collected at Xinzhen from May,2007 to July,2013 and their chemical compositions were analyzed by Particle Induced X-ray Emission(PIXE)and Energy Disperse-X

  9. Relationship between the Particulate Matter Concentrations in the Indoor and Ambient Air of the Tehran Children Hospital in 2007

    OpenAIRE

    Soheila Rezaei; Kazem Naddafi; Hossain Jabbari; Masoud Yonesian; Arsalan Jamshidi; Abdolmohamad Sadat; Alireza Raygan Shirazinejad

    2013-01-01

    Background and Objectives: In recent years exposure to fine airborne particles has been identified as an important factor affecting human health. Epidemiological studies have showed that the aerosol laden air can be an agent for microorganisms’ dispersion. Ignoring internal sources, ambient air quality significantly affects indoor air quality. Since people spend most of their times in the indoor spaces and little data are available on the general understanding of the indoor air quality, the...

  10. Recycling concrete: An undiscovered source of ultrafine particles

    Science.gov (United States)

    Kumar, Prashant; Morawska, Lidia

    2014-06-01

    While concrete recycling is practiced worldwide, there are many unanswered questions in relation to ultrafine particle (UFP; Dp recycling sites. In particular: (i) Does recycling produce UFPs and in what quantities? (ii) How do they disperse around the source? (iii) What impact does recycling have on ambient particle number concentrations (PNCs) and exposure? (iv) How effective are commonly used dust respirators to limit exposure? We measured size-resolved particles in the 5-560 nm range at five distances between 0.15 and 15.15 m that were generated by an experimentally simulated concrete recycling source and found that: (i) the size distributions were multimodal, with up to ˜93% of total PNC in the UFP size range; and (ii) dilution was a key particle transformation mechanism. UFPs showed a much slower decay rate, requiring ˜62% more distance to reach 10% of their initial concentration compared with their larger counterparts in the 100-560 nm size range. Compared with typical urban exposure during car journeys, exposure decay profiles showed up to ˜5 times higher respiratory deposition within 10 m of the source. Dust respirators were found to remove half of total PNC; however the removal factor for UFPs was only ˜57% of that observed in the 100-560 nm size range. These findings highlight a need for developing an understanding of the nature of the particles as well as for better control measures to limit UFP exposure.

  11. Reconstructing the Source in Heavy Ion Collisions from Particle Interferometry

    CERN Document Server

    Wiedemann, Urs Achim; Heinz, Ulrich W; Wiedemann, Urs Achim; Tomasik, Boris; Heinz, Ulrich

    1998-01-01

    The preliminary CERN SPS NA49 Pb+Pb 158 GeV/A negative one- and two-particle spectra at mid-rapidity are consistent with a source of temperature 130 MeV, lifetime 9 fm/c, transverse flow 0.35, and a transverse geometric size which is twice as large as the cold Pb nucleus.

  12. Finite Numbers of Sources, Particle Correlationsand the Color Glass Condensate

    CERN Document Server

    McLerran, Larry

    2015-01-01

    We show that for a finite number of emitting sources, the Color Glass Condensate produces substantial elliptic azimuthal anisotropy, characterized by $v_2$, for two and four particle correlations for momentum greater than or of the order the saturation momentum. The flow produced has the correct semi-quantitative features to describe flow seen in LHC experiments with p-Pb and pp collisions. This flow is induced by quantum mechanical interference between the waves of produced particles, and the flow itself is coupled to fluctuations in the positions of emitting sources. We shortly discuss generalizing these results to odd $v_n$, to correlations involving larger number of particles, and to transverse momentum scales $\\Lambda_{\\rm QCD} \\ll p_T \\ll Q_{\\rm sat}$.

  13. On source parameters from particle correlations and spectra

    CERN Document Server

    Ster, A; Lörstad, B

    1999-01-01

    Analytic and numeric approximations are studied in detail for a hydrodynamic parameterization of single-particle spectra and two-particle correlation functions in high energy hadron-proton and heavy ion reactions. Two very different sets of model parameters are shown to result in similarly shaped correlation functions and single particle spectra in a rather large region of the momentum space. However, the absolute normalization of the single-particle spectra is found to be highly sensitive to the choice of the model parameters. For data fitting the analytic formulas are re-phrased in terms of parameters of direct physical meaning, like mean transverse flow. The difference between the analytic and numeric approximations are determined as an analytic function of source parameters.

  14. Usefulness of Nonlinear Interpolation and Particle Filter in Zigbee Indoor Positioning

    Science.gov (United States)

    Zhang, Xiang; Wu, Helei; Uradziński, Marcin

    2014-12-01

    The key to fingerprint positioning algorithm is establishing effective fingerprint information database based on different reference nodes of received signal strength indicator (RSSI). Traditional method is to set the location area calibration multiple information sampling points, and collection of a large number sample data what is very time consuming. With Zigbee sensor networks as platform, considering the influence of positioning signal interference, we proposed an improved algorithm of getting virtual database based on polynomial interpolation, while the pre-estimated result was disposed by particle filter. Experimental result shows that this method can generate a quick, simple fine-grained localization information database, and improve the positioning accuracy at the same time. Kluczem do algorytmu pozycjonowania wykorzystującego metodę fi ngerprinting jest ustanowienie skutecznej bazy danych na podstawie informacji z radiowych nadajników referencyjnych przy wykorzystaniu wskaźnika mocy odbieranego sygnału (RSSI). Tradycyjna metoda oparta jest na przeprowadzeniu kalibracji obszaru lokalizacji na podstawie wielu punktów pomiarowych i otrzymaniu dużej liczby próbek, co jest bardzo czasochłonne.

  15. Receptor modeling application framework for particle source apportionment.

    Science.gov (United States)

    Watson, John G; Zhu, Tan; Chow, Judith C; Engelbrecht, Johann; Fujita, Eric M; Wilson, William E

    2002-12-01

    Receptor models infer contributions from particulate matter (PM) source types using multivariate measurements of particle chemical and physical properties. Receptor models complement source models that estimate concentrations from emissions inventories and transport meteorology. Enrichment factor, chemical mass balance, multiple linear regression, eigenvector. edge detection, neural network, aerosol evolution, and aerosol equilibrium models have all been used to solve particulate air quality problems, and more than 500 citations of their theory and application document these uses. While elements, ions, and carbons were often used to apportion TSP, PM10, and PM2.5 among many source types, many of these components have been reduced in source emissions such that more complex measurements of carbon fractions, specific organic compounds, single particle characteristics, and isotopic abundances now need to be measured in source and receptor samples. Compliance monitoring networks are not usually designed to obtain data for the observables, locations, and time periods that allow receptor models to be applied. Measurements from existing networks can be used to form conceptual models that allow the needed monitoring network to be optimized. The framework for using receptor models to solve air quality problems consists of: (1) formulating a conceptual model; (2) identifying potential sources; (3) characterizing source emissions; (4) obtaining and analyzing ambient PM samples for major components and source markers; (5) confirming source types with multivariate receptor models; (6) quantifying source contributions with the chemical mass balance; (7) estimating profile changes and the limiting precursor gases for secondary aerosols; and (8) reconciling receptor modeling results with source models, emissions inventories, and receptor data analyses.

  16. Outdoor and indoor sources of residential radiofrequency electromagnetic fields, personal cell phone and cordless phone use, and cognitive function in 5-6 years old children

    NARCIS (Netherlands)

    Guxens, Mònica; Vermeulen, Roel; van Eijsden, Manon; Beekhuizen, Johan; Vrijkotte, Tanja G M; van Strien, Rob T; Kromhout, Hans; Huss, Anke

    2016-01-01

    BACKGROUND: Little is known about the exposure of young children to radiofrequency electromagnetic fields (RF-EMF) and potentially associated health effects. We assessed the relationship between residential RF-EMF exposure from mobile phone base stations, residential presence of indoor sources, pers

  17. A comparison between tracer gas and aerosol particles distribution indoors: The impact of ventilation rate, interaction of airflows, and presence of objects

    DEFF Research Database (Denmark)

    Bivolarova, Mariya Petrova; Ondráček, Jakub; Melikov, Arsen Krikor

    2017-01-01

    room with mixing ventilation. Three layouts were arranged: an empty room, an office room with an occupant sitting in front of a table, and a single-bed hospital room. The room occupant was simulated by a thermal manikin. Monodisperse particles of three sizes (0.07, 0.7, and 3.5 μm) and nitrous oxide......The study investigated the separate and combined effects of ventilation rate, free convection flow produced by a thermal manikin, and the presence of objects on the distribution of tracer gas and particles in indoor air. The concentration of aerosol particles and tracer gas was measured in a test...... tracer gas were generated simultaneously at the same location in the room. The particles and gas concentrations were measured in the bulk room air, in the breathing zone of the manikin, and in the exhaust air. Within the breathing zone of the sitting occupant, the tracer gas emerged as reliable predictor...

  18. Spatial and temporal variability of incidental nanoparticles in indoor workplaces: impact on the characterization of point source exposures.

    Science.gov (United States)

    Niu, Jianjun; Rasmussen, Pat E; Magee, Robert; Nilsson, Gregory

    2015-01-01

    This study deployed a suite of direct-reading instruments in six locations inside one building to characterize variability of the background aerosol, including incidental nanoparticles (NP), over a six month period. The instrument suite consisted of a portable Condensation Particle Counter (CPC) and a Scanning Mobility Particle Sizer (SMPS) for assessing particle number concentrations and size distributions in the nano-scale range; an Aerodynamic Particle Sizer (APS) for assessing micron-scale particle number concentrations and size distributions; plus a desktop Aerosol Monitor (DustTrak DRX) and a Diffusion Charger (DC2000CE) for assessing total particle mass and surface area concentrations respectively. In terms of number concentration, NPs (source study using an older model laser printer as the emission source indicated that NPs emitted from the investigated printer were distinguishable from background. However, more recent low emitting printers are likely to be indistinguishable from background, and chemical characterization (e.g. VOCs, metals) would be required to help identify emission sources.

  19. 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 ...

  20. 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.

  1. Characterization and source profiling of volatile organic compounds in indoor air of private residences in Selangor State, Malaysia.

    Science.gov (United States)

    Sakai, Nobumitsu; Yamamoto, Shuta; Matsui, Yasuto; Khan, Md Firoz; Latif, Mohd Talib; Ali Mohd, Mustafa; Yoneda, Minoru

    2017-05-15

    Volatile Organic Compounds (VOCs) in indoor air were investigated at 39 private residences in Selangor State, Malaysia to characterize the indoor air quality and to identify pollution sources. Twenty-two VOCs including isomers (14 aldehydes, 5 aromatic hydrocarbons, acetone, trichloroethylene and tetrachloroethylene) were collected by 2 passive samplers for 24h and quantitated using high performance liquid chromatography and gas chromatography mass spectrometry. Source profiling based on benzene/toluene ratio as well as statistical analysis (cluster analysis, bivariate correlation analysis and principal component analysis) was performed to identify pollution sources of the detected VOCs. The VOCs concentrations were compared with regulatory limits of air quality guidelines in WHO/EU, the US, Canada and Japan to clarify the potential health risks to the residents. The 39 residences were classified into 2 groups and 2 ungrouped residences based on the dendrogram in the cluster analysis. Group 1 (n=30) had mainly toluene (6.87±2.19μg/m(3)), formaldehyde (16.0±10.1μg/m(3)), acetaldehyde (5.35±4.57μg/m(3)) and acetone (11.1±5.95μg/m(3)) at background levels. Group 2 (n=7) had significantly high values of formaldehyde (99.3±10.7μg/m(3)) and acetone (35.8±12.6μg/m(3)), and a tendency to have higher values of acetaldehyde (23.7±13.5μg/m(3)), butyraldehyde (3.35±0.41μg/m(3)) and isovaleraldehyde (2.30±0.39μg/m(3)). The 2 ungrouped residences showed particularly high concentrations of BTX (benzene, toluene and xylene: 235μg/m(3) in total) or acetone (133μg/m(3)). The geometric mean value of formaldehyde (19.2μg/m(3)) exceeded an 8-hour regulatory limit in Canada (9μg/m(3)), while those in other compounds did not exceed any regulatory limits, although a few residences exceeded at least one regulatory limit of benzene or acetaldehyde. Thus, the VOCs in the private residences were effectively characterized from the limited number of monitoring, and the

  2. Accurate positioning of pedestrains in mixed indoor/outdoor settings : A particle filter approach to sensor and map fusion

    DEFF Research Database (Denmark)

    Toftkjær, Thomas

    Pedestrian positioning with full coverage in urban environments is a long sought after research goal. This thesis proposes new techniques for handling the challenging task of truly pervasive pedestrian positioning. It shows that through sensor fusion one can both improve accuracy and extend...... the coverage of pedestrian positioning, for the professional person, such as rst responders, as well as for the ordinary citizen. Since GNSS alone cannot satisfy the availability and accuracy demands for all indoor settings, this thesis pursues a better understanding of the capabilities of GNSS indoors...... and an extension to ProPosition, that advances the state-of-the-art in pedestrian positioning towards the pervasive research goals of full urban environment coverage, seamless indoor and outdoor positioning and the ability to run on ordinary user devices such as smartphones. Through ProLoc it is possible...

  3. Report of the Snowmass T4 working group on particle sources: Positron sources, anti-proton sources and secondary beams

    Energy Technology Data Exchange (ETDEWEB)

    N. Mokhov et al.

    2002-12-05

    This report documents the activities of the Snowmass 2001 T4 Particle Sources Working Group. T4 was charged with examining the most challenging aspects of positron sources for linear colliders and antiproton sources for proton-antiproton colliders, and the secondary beams of interest to the physics community that will be available from the next generation of high-energy particle accelerators. The leading issues, limiting technologies, and most important R and D efforts of positron production, antiproton production, and secondary beams are discussed in this paper. A listing of T4 Presentations is included.

  4. Technical solutions for reducing indoor residential exposures to ultrafine particles from second-hand cigarette smoke infiltration

    DEFF Research Database (Denmark)

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

    2011-01-01

    An emerging public issue in Denmark is passive smoking in residential environments where non-smokers are exposed to harmful smoke from their neighbours. There are various ways that smoke infiltrates one flat from another. The air infiltration rate between two flats in a multi-storey building...... in which smoke infiltrates from one flat to another and also to examine technical solutions for preventing or reducing infiltration of ultrafine particles from the source flat to the receiving flat. One of the technical solutions examined was sealing of the floor in the receiving flat. The study...

  5. Sources of optically active aerosol particles over the Amazon forest

    Science.gov (United States)

    Guyon, Pascal; Graham, Bim; Roberts, Gregory C.; Mayol-Bracero, Olga L.; Maenhaut, Willy; Artaxo, Paulo; Andreae, Meinrat O.

    Size-fractionated ambient aerosol samples were collected at a pasture site and a primary rainforest site in the Brazilian Amazon Basin during two field campaigns (April-May and September-October 1999), as part of the European contribution to the Large-Scale Biosphere-Atmosphere Experiment in Amazonia (LBA-EUSTACH). The samples were analyzed for up to 19 trace elements by particle-induced X-ray emission analysis (PIXE), for equivalent black carbon (BC e) by a light reflectance technique and for mass concentration by gravimetric analysis. Additionally, we made continuous measurements of absorption and light scattering by aerosol particles. The vertical chemical composition gradients at the forest site have been discussed in a companion article (Journal of Geophysical Research-Atmospheres 108 (D18), 4591 (doi:4510.1029/2003JD003465)). In this article, we present the results of a source identification and quantitative apportionment study of the wet and dry season aerosols, including an apportionment of the measured scattering and absorption properties of the total aerosol in terms of the identified aerosol sources. Source apportionments (obtained from absolute principal component analysis) revealed that the wet and dry season aerosols contained the same three main components, but in different (absolute and relative) amounts: the wet season aerosol consisted mainly of a natural biogenic component, whereas pyrogenic aerosols dominated the dry season aerosol mass. The third component identified was soil dust, which was often internally mixed with the biomass-burning aerosol. All three components contributed significantly to light extinction during both seasons. At the pasture site, up to 47% of the light absorption was attributed to biogenic particles during the wet season, and up to 35% at the tower site during the wet-to-dry transition period. The results from the present study suggest that, in addition to pyrogenic particles, biogenic and soil dust aerosols must be

  6. Occurrence and source apportionment of halogenated flame retardants in the indoor air of Nepalese cities: Implication on human health

    Science.gov (United States)

    Yadav, Ishwar Chandra; Devi, Ningombam Linthoingmabi; Li, Jun; Zhang, Gan

    2017-07-01

    Elevated level of brominated- and chlorinated-flame retardants (FRs) have been accounted in ambient air across the globe. Despite what might be expected, restricted information is available on PBDEs and other halogenated FR contained indoor air in whole of Indian sub-continent especially in case of Nepal, sandwiched between two most populous countries i.e. India and China. It was conjectured that the level of halogenated flame retardant (HFRs) in Nepalese air would be high because they have not been liable to control in Nepal; and henceforth there is more plausibility of HFRs to be available in a diverse array of goods and consumer products. This study therefore aims to measure the occurrence, spatial distributions and sources of 15 brominated- and 2 chlorinated-FRs in indoor air from four major cities of Nepal. The overall concentrations of HFRs ranged from 16.1 to 6750 pg/m3 (median 334 pg/m3). The total concentrations of novel brominated fire retardants (NBFRs) were 20 and 100 times (13.2-6270 pg/m3) higher than PBDEs (2.2-353 pg/m3) and DPs (0.67-129 pg/m3), respectively indicating much higher usages of NBFRs in Nepal. The level of ∑PBDEs in air is identified with utilization of wide variety of consumers products and building materials containing FRs in Nepalese houses, while higher concentration of BDE-209 were subject to emission from materials containing deca-BDE formulation. Significantly higher concentrations of DBDPE than BDE-209 in air demonstrated a move to more prominent use of DBDPE as alternative to BDE-209. The lower fanti ratios suggests the DP level in this study was essentially affected by the long range atmospheric transport from remote DP source instead of commercial products. The exposure to BDE-47, -99, -153, -209 and HBB via inhalation was 3-4 orders of magnitude lower than corresponding RfD values, suggesting insignificant risk to Nepalese population. However, other modes of human exposure might still be significant in Nepal.

  7. A marine biogenic source of atmospheric ice-nucleating particles

    Energy Technology Data Exchange (ETDEWEB)

    Wilson, T. W.; Ladino, L. A.; Alpert, Peter A.; Breckels, M. N.; Brooks, I. M.; Browse, J.; Burrows, Susannah M.; Carslaw, K. S.; Huffman, J. A.; Judd, C.; Kilthau, W. P.; Mason, R. H.; McFiggans, Gordon; Miller, L. A.; Najera, J.; Polishchuk, E. A.; Rae, S.; Schiller, C. L.; Si, M.; Vergara Temprado, J.; Whale, Thomas; Wong, J P S; Wurl, O.; Yakobi-Hancock, J. D.; Abbatt, JPD; Aller, Josephine Y.; Bertram, Allan K.; Knopf, Daniel A.; Murray, Benjamin J.

    2015-09-09

    The formation of ice in clouds is facilitated by the presence of airborne ice nucleating particles1,2. Sea spray is one of the major global sources of atmospheric particles, but it is unclear to what extent these particles are capable of nucleating ice3–11. Here we show that material in the sea surface microlayer, which is enriched in surface active organic material representative of that found in sub-micron sea- spray aerosol12–21, nucleates ice under conditions that occur in mixed-phase clouds and high-altitude ice clouds. The ice active material is likely biogenic and is less than ~0.2 ?m in size. We also show that organic material (exudate) released by a common marine diatom nucleates ice when separated from cells and propose that organic material associated with phytoplankton cell exudates are a candidate for the observed ice nucleating ability of the microlayer samples. By combining our measurements with global model simulations of marine organic aerosol, we show that ice nucleating particles of marine origin are dominant in remote marine environments, such as the Southern Ocean, the North Pacific and the North Atlantic.

  8. Charged-particle beam diagnostics for the advanced photon source

    Science.gov (United States)

    Lumpkin, A. H.; Decker, G.; Kahana, E.; Patterson, D.; Sellyey, W.; Wang, X.; Chung, Y.

    1993-07-01

    Plans, prototypes, and initial test results for the charged-particle beam (e -, e +) diagnostic systems on the injector rings, their transport lines, and the storage ring for the Advanced Photon Source (APS) are presented. The APS will be a synchrotron radiation user facility with one of the world's brightest X-ray sources in the 10-keV regime. Its 200-MeV electron linac, 450-MeV positron linac, positron accumulator ring, 7-GeV injector synchrotron (IS), 7-GeV storage ring (SR), and undulator test lines will also demand the development and demonstration of key particle-beam characterization techniques over a wide range of parameter space. Some of these parameter values overlap or approach those projected for fourth generation light sources (linac-driven FELs and high brightness storage rings) as described at a recent workshop. Initial results from the diagnostics prototypes on the linac test stand operating at 45-MeV include current monitor data, beam loss monitor data, and video digitization using VME architecture.

  9. Chemical and morphological characteristics of indoor and outdoor particulate matter in an urban environment

    Science.gov (United States)

    Chithra, V. S.; Shiva Nagendra, S. M.

    2013-10-01

    Chemical characterization of suspended particulate matter (SPM) measured inside a naturally ventilated school building (indoor) and at an adjacent roadway (outdoor) in Chennai city was performed during monsoon, winter and summer seasons. The daily average indoor SPM concentrations in monsoon, winter and summer seasons were 158.18, 170.08 and 149.63 μg m-3, respectively. Indoor and outdoor samples were analyzed for 11 inorganic ions using ion chromatography and 28 elements by inductively coupled plasma optical emission spectrometry. Results indicated the dominance of SO (10.89 μg m-3) followed by NH (5.62 μg m-3), NO (5.35 μg m-3), Na+ (4.35 μg m-3) Ca2+ (4.08 μg m-3) and Cl- (3.47 μg m-3) ions in the indoor SPM. In the outdoor SPM, SO, NO and NH ions concentration were slightly higher while Ca2+, K+ and Mg2+ ions concentrations were higher in indoors. Among the elements, crustal element (Al, Fe, Ca, K, Mg and Na) concentrations were much higher (92.7% of the total elemental concentration) in indoor environment than those of toxic elements (Ba, Cr, Cu, Mn, Mo, Ni, Sr, Ti, V and Zn) emitted from vehicles. Analysis of elemental carbon (EC) and organic carbon (OC) components in indoor and outdoor PM indicated the predominance of OC. The indoor/outdoor (I/O) ratios for EC = 0.70 and OC = 0.82, indicating no significant indoor emission sources of OC and EC. To characterize the morphology, indoor and outdoor filters were examined by Scanning Electron Microscopy coupled with energy dispersive X-ray spectrometry. Soot and Al-Si rich particles were mostly found in indoor and outdoor SPM. The presence of toxic elements and soot particles in the indoor PM confirms the contributions of vehicular emissions from the adjacent motorway.

  10. Source apportionment of chloride ions in the indoor air in Tian Bay nuclear power plant%田湾核电站室内氯离子来源解析

    Institute of Scientific and Technical Information of China (English)

    陈发荣; 田黎; 郑立; 赵恒强; 何鹰; 郑晓玲; 王小如

    2014-01-01

    Concentration of chloride ions in the atmospheric absorbed solution (AAS) and total suspended particles (TSP) samples collected in Tian Bay nuclear power plant between 2005 and 2006 was determined by the way of ion chromatography. The distributions and variations of chloride ions in the indoor and outdoor air and the performance of air filter were also investigated. The results showed that the annual average concentrations of chloride ions were 28.12, 19.20, 4.22 and 0.11µg/m3in the outdoor AAS, indoor AAS, outdoor TSP and indoor TSP, respectively. The outdoor TSP could be effectively filtered by the existing air filter, but the filter efficiency of chloride ions in the outdoor air was only 32%. Besides, there was a significant positive correlation between the outdoor AAS and indoor AAS, and the correlation coefficien was 0.859. Therefore, it could be inferred that the chloride ions in the indoor air mainly came from outdoor sources.%根据2005~2006年江苏田湾核电站大气吸收液(AAS)和总悬浮颗粒物(TSP)中氯离子的一年数据,分析了室内外大气各种形态氯离子的分布特点及变化规律,并对过滤器性能进行了初步评价.结果表明:该站大气氯离子浓度大小依次为:室外吸收液>室内吸收液>室外TSP>室内TSP,年均值分别为28.12,19.20,4.22,0.11µg/m3.现有过滤器可以有效过滤室外总悬浮颗粒物,但对室外气体中氯离子的过滤效率仅为32%.相关性分析表明,室内外吸收液中氯离子浓度显著相关,相关性系数为0.859.因此,室内大气氯离子主要来源室外气态或微小气溶胶.

  11. New modes of particle accelerations techniques and sources. Formal report

    Energy Technology Data Exchange (ETDEWEB)

    Parsa, Z. [ed.

    1996-12-31

    This Report includes copies of transparencies and notes from the presentations made at the Symposium on New Modes of Particle Accelerations - Techniques and Sources, August 19-23, 1996 at the Institute for Theoretical Physics, University of California, Santa Barbara California, that was made available by the authors. Editing, reduction and changes to the authors contributions were made only to fulfill the printing and publication requirements. We would like to take this opportunity and thank the speakers for their informative presentations and for providing copies of their transparencies and notes for inclusion in this Report.

  12. Magnetic geometry and particle source drive of supersonic divertor regimes

    Science.gov (United States)

    Bufferand, H.; Ciraolo, G.; Dif-Pradalier, G.; Ghendrih, P.; Tamain, Ph; Marandet, Y.; Serre, E.

    2014-12-01

    We present a comprehensive picture of the mechanisms driving the transition from subsonic to supersonic flows in tokamak plasmas. We demonstrate that supersonic parallel flows into the divertor volume are ubiquitous at low density and governed by the divertor magnetic geometry. As the density is increased, subsonic divertor plasmas are recovered. On detachment, we show the change in particle source can also drive the transition to a supersonic regime. The comprehensive theoretical analysis is completed by simulations in ITER geometry. Such results are essential in assessing the divertor performance and when interpreting measurements and experimental evidence.

  13. An outbreak of swimming-pool related respiratory symptoms: An elusive source of trichloramine in a municipal indoor swimming pool.

    Science.gov (United States)

    Seys, Sven F; Feyen, Ludo; Keirsbilck, Stephan; Adams, Els; Dupont, Lieven J; Nemery, Benoit

    2015-06-01

    Several members of a swimming club complained of respiratory symptoms associated with attending a municipal indoor swimming pool. Trichloramine, a volatile chlorination by-product and a potent respiratory irritant, was the most probable culprit, but the exact cause for its presence in excessive concentrations remained elusive. Twenty-two competitive swimmers and six coaches were evaluated during the outbreak and nine swimmers and four coaches were re-evaluated one year later. Symptoms were recorded by non-standardized history taking; pulmonary function testing included spirometry, measurement of fraction of exhaled nitric oxide (FENO) and histamine provocation. Concentrations of trichloramine in air were measured repeatedly by the method of Héry. The most commonly reported symptoms consisted of cough (n=16), dyspnoea (n=13), tearing eyes (n=10) and blocked or runny nose (n=6). Mean FEV1% predicted was 109.1%. Mean FENO level was 19.7 ppb (higher than 25 ppb in 3 subjects). Airway hyperreactivity to histamine (PC20 ≤ 8 mg/ml) was detected in 22/26 subjects. Measured trichloramine concentrations in air exceeded the maximal concentration (WHO) of 0.5mg/m(3) four times between May and October 2011 and four times between January and March 2012. Polyamine compounds, present in glue used for repairing pipework, were identified as a probable external source of nitrogen resulting in increasing trichloramine concentrations. After the removal of the presumed cause of the excessive trichloramine concentrations, most subjects improved clinically, but several subjects remained symptomatic and had bronchial hyperreactivity. A high prevalence of airway hyperreactivity, accompanied by symptoms of upper and lower airways, was detected in swimmers who had been repeatedly exposed to high trichloramine concentrations. A glue containing polyamines, used to repair a pipework, was suspected to be the source of this excessive production of trichloramine. Copyright © 2015 Elsevier Gmb

  14. Dust exposure in indoor climbing halls.

    Science.gov (United States)

    Weinbruch, Stephan; Dirsch, Thomas; Ebert, Martin; Hofmann, Heiko; Kandler, Konrad

    2008-05-01

    The use of hydrated magnesium carbonate hydroxide (magnesia alba) for drying the hands is a strong source for particulate matter in indoor climbing halls. Particle mass concentrations (PM10, PM2.5 and PM1) were measured with an optical particle counter in 9 indoor climbing halls and in 5 sports halls. Mean values for PM10 in indoor climbing halls are generally on the order of 200-500 microg m(-3). For periods of high activity, which last for several hours, PM10 values between 1000 and 4000 microg m(-3) were observed. PM(2.5) is on the order of 30-100 microg m(-3) and reaches values up to 500 microg m(-3), if many users are present. In sports halls, the mass concentrations are usually much lower (PM10 sport in which magnesia alba is also used) similar dust concentrations as for indoor climbing were observed. The size distribution and the total particle number concentration (3.7 nm-10 microm electrical mobility diameter) were determined in one climbing hall by an electrical aerosol spectrometer. The highest number concentrations were between 8000 and 12 000 cm(-3), indicating that the use of magnesia alba is no strong source for ultrafine particles. Scanning electron microscopy and energy-dispersive X-ray microanalysis revealed that virtually all particles are hydrated magnesium carbonate hydroxide. In-situ experiments in an environmental scanning electron microscope showed that the particles do not dissolve at relative humidities up to 100%. Thus, it is concluded that solid particles of magnesia alba are airborne and have the potential to deposit in the human respiratory tract. The particle mass concentrations in indoor climbing halls are much higher than those reported for schools and reach, in many cases, levels which are observed for industrial occupations. The observed dust concentrations are below the current occupational exposure limits in Germany of 3 and 10 mg m(-3) for respirable and inhalable dust. However, the dust concentrations exceed the German guide

  15. Characterization of indoor aerosol temporal variations for the real-time management of indoor air quality

    Science.gov (United States)

    Ciuzas, Darius; Prasauskas, Tadas; Krugly, Edvinas; Sidaraviciute, Ruta; Jurelionis, Andrius; Seduikyte, Lina; Kauneliene, Violeta; Wierzbicka, Aneta; Martuzevicius, Dainius

    2015-10-01

    The study presents the characterization of dynamic patterns of indoor particulate matter (PM) during various pollution episodes for real-time IAQ management. The variation of PM concentrations was assessed for 20 indoor activities, including cooking related sources, other thermal sources, personal care and household products. The pollution episodes were modelled in full-scale test chamber representing a standard usual living room with the forced ventilation of 0.5 h-1. In most of the pollution episodes, the maximum concentration of particles in exhaust air was reached within a few minutes. The most rapid increase in particle concentration was during thermal source episodes such as candle, cigarette, incense stick burning and cooking related sources, while the slowest decay of concentrations was associated with sources, emitting ultrafine particle precursors, such as furniture polisher spraying, floor wet mopping with detergent etc. Placement of the particle sensors in the ventilation exhaust vs. in the centre of the ceiling yielded comparable results for both measured maximum concentrations and temporal variations, indicating that both locations were suitable for the placement of sensors for the management of IAQ. The obtained data provides information that may be utilized considering measurements of aerosol particles as indicators for the real-time management of IAQ.

  16. Single particle mass spectral signatures from vehicle exhaust particles and the source apportionment of on-line PM2.5 by single particle aerosol mass spectrometry.

    Science.gov (United States)

    Yang, Jian; Ma, Shexia; Gao, Bo; Li, Xiaoying; Zhang, Yanjun; Cai, Jing; Li, Mei; Yao, Ling'ai; Huang, Bo; Zheng, Mei

    2017-09-01

    In order to accurately apportion the many distinct types of individual particles observed, it is necessary to characterize fingerprints of individual particles emitted directly from known sources. In this study, single particle mass spectral signatures from vehicle exhaust particles in a tunnel were performed. These data were used to evaluate particle signatures in a real-world PM2.5 apportionment study. The dominant chemical type originating from average positive and negative mass spectra for vehicle exhaust particles are EC species. Four distinct particle types describe the majority of particles emitted by vehicle exhaust particles in this tunnel. Each particle class is labeled according to the most significant chemical features in both average positive and negative mass spectral signatures, including ECOC, NaK, Metal and PAHs species. A single particle aerosol mass spectrometry (SPAMS) was also employed during the winter of 2013 in Guangzhou to determine both the size and chemical composition of individual atmospheric particles, with vacuum aerodynamic diameter (dva) in the size range of 0.2-2μm. A total of 487,570 particles were chemically analyzed with positive and negative ion mass spectra and a large set of single particle mass spectra was collected and analyzed in order to identify the speciation. According to the typical tracer ions from different source types and classification by the ART-2a algorithm which uses source fingerprints for apportioning ambient particles, the major sources of single particles were simulated. Coal combustion, vehicle exhaust, and secondary ion were the most abundant particle sources, contributing 28.5%, 17.8%, and 18.2%, respectively. The fraction with vehicle exhaust species particles decreased slightly with particle size in the condensation mode particles. Copyright © 2017 Elsevier B.V. All rights reserved.

  17. Gamma Ray Burst as Sources of Exotic Particles

    CERN Document Server

    Morgan, Ian; De Pree, Erin; Tennyson, Kevin

    2015-01-01

    We consider the possible production of stable lightest first level KK particle (LKP) in baryonic gamma ray bursts (GRB) out flows. We numerically computed the energy-dependent cross-sections of Kaluza-Klein (KK) excitations for the Standard Model gauge bosons, photon and Z. Next, we determined the feasibility of producing these KK excitations in gamma-ray emitting regions of GRBs. We found that a GRB fireball that accelerates baryons to energies greater than 10^14 eV could produce KK excitations out to approximately 10^12 cm from the central engine, indicating that GRBs may be a significant source of the LKP. Finally, we explore the potential observational consequences of our results.

  18. Novel particle and radiation sources and advanced materials

    Science.gov (United States)

    Mako, Frederick

    2016-03-01

    The influence Norman Rostoker had on the lives of those who had the pleasure of knowing him is profound. The skills and knowledge I gained as a graduate student researching collective ion acceleration has fueled a career that has evolved from particle beam physics to include particle and radiation source development and advanced materials research, among many other exciting projects. The graduate research performed on collective ion acceleration was extended by others to form the backbone for laser driven plasma ion acceleration. Several years after graduate school I formed FM Technologies, Inc., (FMT), and later Electron Technologies, Inc. (ETI). Currently, as the founder and president of both FMT and ETI, the Rostoker influence can still be felt. One technology that we developed is a self-bunching RF fed electron gun, called the Micro-Pulse Gun (MPG). The MPG has important applications for RF accelerators and microwave tube technology, specifically clinically improved medical linacs and "green" klystrons. In addition to electron beam and RF source research, knowledge of materials and material interactions gained indirectly in graduate school has blossomed into breakthroughs in materials joining technologies. Most recently, silicon carbide joining technology has been developed that gives robust helium leak tight, high temperature and high strength joints between ceramic-to-ceramic and ceramic-to-metal. This joining technology has the potential to revolutionize the ethylene production, nuclear fuel and solar receiver industries by finally allowing for the practical use of silicon carbide as furnace coils, fuel rods and solar receptors, respectively, which are applications that have been needed for decades.

  19. Novel particle and radiation sources and advanced materials

    Energy Technology Data Exchange (ETDEWEB)

    Mako, Frederick [FM Technologies, Inc. and Electron Technologies, Inc. (United States)

    2016-03-25

    The influence Norman Rostoker had on the lives of those who had the pleasure of knowing him is profound. The skills and knowledge I gained as a graduate student researching collective ion acceleration has fueled a career that has evolved from particle beam physics to include particle and radiation source development and advanced materials research, among many other exciting projects. The graduate research performed on collective ion acceleration was extended by others to form the backbone for laser driven plasma ion acceleration. Several years after graduate school I formed FM Technologies, Inc., (FMT), and later Electron Technologies, Inc. (ETI). Currently, as the founder and president of both FMT and ETI, the Rostoker influence can still be felt. One technology that we developed is a self-bunching RF fed electron gun, called the Micro-Pulse Gun (MPG). The MPG has important applications for RF accelerators and microwave tube technology, specifically clinically improved medical linacs and “green” klystrons. In addition to electron beam and RF source research, knowledge of materials and material interactions gained indirectly in graduate school has blossomed into breakthroughs in materials joining technologies. Most recently, silicon carbide joining technology has been developed that gives robust helium leak tight, high temperature and high strength joints between ceramic-to-ceramic and ceramic-to-metal. This joining technology has the potential to revolutionize the ethylene production, nuclear fuel and solar receiver industries by finally allowing for the practical use of silicon carbide as furnace coils, fuel rods and solar receptors, respectively, which are applications that have been needed for decades.

  20. 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.

  1. Element Abundances and Source Plasma Temperatures of Solar Energetic Particles

    CERN Document Server

    Reames, Donald V

    2016-01-01

    Thirty years ago Breneman and Stone observed that the enhancement or suppression of element abundances in large solar energetic-particle (SEP) events varies as a power of the mass-to-charge ratio, A/Q, of the elements. Since Q during acceleration or transport may depend upon the source plasma temperature T, the pattern of element enhancements can provide a best-fit measure of T. The small SEP events we call 3He-rich or "impulsive" show average enhancements, relative to coronal abundances, rising as the 3.6 power of A/Q to a factor of ~1000 for (76<=Z<=82)/O and temperature in the range 2-4 MK. This acceleration is believed to occur in islands of magnetic reconnection on open field lines in solar flares and jets. It has been recently found that the large shock-accelerated "gradual" SEP events have a broad range of source plasma temperatures; 69% have coronal temperatures of T < 1.6 MK, while 24% have T ~ 3 MK, the latter suggesting a seed population containing residual impulsive suprathermal ions. Mos...

  2. Axion-Like particles from extragalactic High Energy sources

    Science.gov (United States)

    Conrad, J.; Meyer, M.; Montanino, D.

    2016-05-01

    Background radiation fields (such as Extragalactic Background Light, EBL, or Cosmic Microwave Background, CMB) pervade the Universe. Above a certain energy any gamma ray flux emitted by an extragalactic source should be attenuated by the process γ+ γ(bgk) → e + + e - pair production. We have considered a scenario in which the photons are partly converted into light Axion Like Particles (ALPs) in the local magnetic field of an (extragalactic) source. Then, while the unconverted fraction of photons undergo absorption, the ALP component travel to our galaxy where is converted back to photons by the galactic magnetic field resulting in a sort of cosmic light shining through wall effect. In particular, we have considered two scenarios: 1) conversion in the turbulent magnetic field inside a galaxy cluster; and 2) conversion of photons in the coherent magnetic field at parsec scales in a Blazar jet. Afterwards, we have also analyzed mock data coming from a hypothetical Imaging Air Cherenkov Telescopes (IACT) array with characteristics similar to the Cherenkov Telescope Array (CTA) and we have investigated the dependence of the sensitivity to detect a gamma ray excess on the magnetic field parameters.

  3. Element Abundances and Source Plasma Temperatures of Solar Energetic Particles

    Science.gov (United States)

    Reames, Donald V.

    2016-11-01

    Thirty years ago Breneman and Stone [1] observed that the enhancement or suppression of element abundances in large solar energetic-particle (SEP) events varies as a power of the mass-to-charge ratio, A/Q, of the elements. Since Q during acceleration or transport may depend upon the source plasma temperature T, the pattern of element enhancements can provide a best-fit measure of T. The small SEP events we call 3He-rich or “impulsive” show average enhancements, relative to coronal abundances, rising as the 3.6 power of A/Q to a factor of ∼1000 for (76magnetic reconnection on open field lines in solar flares and jets. It has been recently found that the large shock-accelerated “gradual” SEP events have a broad range of source plasma temperatures; 69% have coronal temperatures of T seed population containing residual impulsive suprathermal ions. Most of the large event-to-event abundance variations and their time variation are largely explained by variations in T magnified by A/Q-dependent fractionation during transport. However, the non-thermal variance of impulsive SEP events (∼30%) exceeds that of the ∼3 MK gradual events (∼10%) so that several small impulsive events must be averaged together with the ambient plasma to form the seed population for shock acceleration in these events.

  4. Neutral particle dynamics in a high-power RF source

    Energy Technology Data Exchange (ETDEWEB)

    Todorov, D., E-mail: dimitar-tdrv@phys.uni-sofia.bg; Paunska, Ts.; Shivarova, A. [Faculty of Physics, Sofia University, 5, J. Bourchier Blvd., Sofia BG-1164 (Bulgaria); Tarnev, Kh. [Department of Applied Physics, Technical University-Sofia, 8, Kl.Ohridski Blvd., Sofia BG-1000 (Bulgaria)

    2015-04-08

    Previous studies on the spatial discharge structure in the SPIDER source of negative hydrogen/deuterium ions carried out at low applied power are extended towards description of the discharge maintenance under the conditions of the actual rf power deposition of 100 kW planned for a single driver of the source. In addition to the expected higher electron density, the results show strong increase of the electron temperature and of the temperatures of the neutral species (hydrogen atoms and molecules). In the discussions, not only the spatial distribution of the plasma parameters but also that of the fluxes in the discharge (particle and energy fluxes) is involved. The obtained results come in confirmation of basic concepts for low-pressure discharge maintenance: (i) mutually related electron density and temperature as a display of the generalized Schottky condition, (ii) discharge behavior governed by the fluxes, i.e. strong nonlocality in the discharge, and (iii) a non-ambipolarity in the discharge regime, which originates from shifted maxima of the electron density and temperature and shows evidence in a vortex electron flux and in a dc current in a rf discharge, the latter resulting from a shift in the positions of the maxima of the electron density and plasma potential.

  5. Vascular and lung function related to ultrafine and fine particles exposure assessed by personal and indoor monitoring: a cross-sectional study

    DEFF Research Database (Denmark)

    Olsen, Yulia; Karottki, Dorina Gabriela; Jensen, Ditte Marie

    2014-01-01

    -related effects. Methods: Associations between vascular and lung function, inflammation markers and exposure in terms of particle number concentration (PNC; d = 10-300 nm) were studied in a cross-sectional design with personal and home indoor monitoring in the Western Copenhagen Area, Denmark. During 48-h, PNC...... and PM2.5 were monitored in living rooms of 60 homes with 81 non-smoking subjects (30-75 years old), 59 of whom carried personal monitors both when at home and away from home. We measured lung function in terms of the FEV1/FVC ratio, microvascular function (MVF) and pulse amplitude by digital artery...... tonometry, blood pressure and biomarkers of inflammation including C-reactive protein, and leukocyte counts with subdivision in neutrophils, eosinophils, monocytes, and lymphocytes in blood. Results: PNC from personal and stationary home monitoring showed weak correlation (r = 0.15, p = 0.24). Personal UFP...

  6. Outdoor infiltration and indoor contribution of UFP and BC, OC, secondary inorganic ions and metals in PM2.5 in schools

    Science.gov (United States)

    Rivas, I.; Viana, M.; Moreno, T.; Bouso, L.; Pandolfi, M.; Alvarez-Pedrerol, M.; Forns, J.; Alastuey, A.; Sunyer, J.; Querol, X.

    2015-04-01

    Infiltration of outdoor-sourced particles into indoor environments in 39 schools in Barcelona was assessed during school hours. Tracers of road traffic emissions (NO2, Equivalent Black Carbon (EBC), Ultrafine Particles (UFP), Sb), secondary inorganic aerosols (SO42-, NO3-, NH4+) and a number of PM2.5 trace elements showed median indoor/outdoor (I/O) ratios ≤ 1, indicating that outdoor sources importantly contributed to indoor concentrations. Conversely, OC and mineral components had I/O ratios>1. Different infiltration factors were found for traffic and secondary components (0.31-0.75 and 0.50-0.92, cold and warm season respectively), with maxima corresponding to EBC and Cd. Higher concentrations of indoor-generated particles were observed when closed windows hindered dispersion (cold season). Building age was not a major determinant of indoor levels. Neither were the window's material, except for NO2 (with an increase of 8 μg m-3 for wood framed windows) and the mineral components (also dependent on the presence of sand in a distance PVC framed windows than the wooden ones. Enlarged indoor concentrations of some trace elements suggest the presence of indoor sources that should be further investigated in order to achieve a healthier school indoor environment.

  7. Lead and cadmium in indoor air and the urban environment

    Energy Technology Data Exchange (ETDEWEB)

    Komarnicki, Guenter J.K. [Department of Ecotoxicology, Center of Public Health, Medical University of Vienna, Waehringer Str. 10, A-1090 Vienna (Austria)]. E-mail: guenter.komarnicki@meduniwien.ac.at

    2005-07-15

    The present study was conducted to find potential terrestrial biomonitors for heavy metals in indoor air in an urban environment. TSP, PM{sub 10}, and PM{sub 2.5} were collected in three retirement facilities in the urban area of Vienna. In addition, particulate matter and soil, vegetation, and isopods (Porcellio scaber L.) were collected in the adjacent garden areas. Aerosols were sampled with a low-volume air sampler. The sampled materials were wet ashed and total lead and cadmium contents were determined. Water-soluble heavy metal concentrations were measured in aqueous extracts from air exposed filters, soil, and vegetation. Lead and cadmium were analyzed by graphite furnace AAS. Lead contents in the vegetation were inferred from water-soluble lead in soils. Lead in isopods generally reflected the contents in vegetation. Cadmium in plants probably derived from soil solutions as well as from atmospheric input. Isopods reflected the total cadmium contents in soils. Particulate matter was dominated by PM{sub 2.5}, both with respect to mass concentrations and to heavy metal contents. The indoor aerosol was found to be influenced by human activity, indoor sources, and outdoor particles. Relationships between indoor airborne heavy metals and the contents in vegetation (lead and cadmium: positive) and isopods (lead: negative) were identified to have the potential for biomonitoring indoor air quality. - Urban vegetation and isopods are potential indicators for indoor aerial heavy metals.

  8. Nonlinear simulations of particle source effects on edge localized mode

    Energy Technology Data Exchange (ETDEWEB)

    Huang, J.; Tang, C. J. [College of Physical Science and Technology, Sichuan University, Chengdu 610065 (China); Key Laboratory of High Energy Density Physics and Technology of Ministry of Education, Sichuan University, Chengdu 610064 (China); Chen, S. Y., E-mail: sychen531@163.com [College of Physical Science and Technology, Sichuan University, Chengdu 610065 (China); Key Laboratory of High Energy Density Physics and Technology of Ministry of Education, Sichuan University, Chengdu 610064 (China); Southwestern Institute of Physics, Chengdu 610041 (China); Wang, Z. H. [Southwestern Institute of Physics, Chengdu 610041 (China)

    2015-12-15

    The effects of particle source (PS) with different intensities and located positions on Edge Localized Mode (ELM) are systematically studied with BOUT++ code. The results show the ELM size strongly decreases with increasing the PS intensity once the PS is located in the middle or bottom of the pedestal. The effects of PS on ELM depend on the located position of PS. When it is located at the top of the pedestal, peeling-ballooning (P-B) modes can extract more free energy from the pressure gradient and grow up to be a large filament at the initial crash phase and the broadening of mode spectrum can be suppressed by PS, which leads to more energy loss. When it is located in the middle or bottom of the pedestal, the extraction of free energy by P-B modes can be suppressed, and a small filament is generated. During the turbulence transport phase, the broader mode spectrum suppresses the turbulence transport when PS is located in the middle, while the zonal flow plays an important role in damping the turbulence transport when PS is located at the bottom.

  9. Discovery of a new extragalactic source population of energetic particles

    CERN Document Server

    Brown, A M; Graham, J; Lacroix, T; Chadwick, P M; Silk, J

    2016-01-01

    Radio galaxies are active galactic nuclei (AGN) containing supermassive black holes with mis-aligned relativistic jets. Centaurus A (Cen A) is the closest known gamma-ray emitting radio galaxy. Here, we report the discovery of a hardening in the Fermi-LAT gamma-ray spectrum of the core of Cen A above 2.4 GeV, at a significance of 5 sigma as well as evidence for variability below 2.4 GeV at 99%. These properties strongly support the hypothesis that the low energy component originates from leptons in the jet while the additional source of very high energy particles near the core of Cen A must originate from a different cosmic ray population. We show for the first time that the observed gamma-ray spectrum is compatible with either a very large localized enhancement (referred to as a spike) in the dark matter halo profile or a population of millisecond pulsars. A third explanation could be nevertheless the presence of a hadronic component injected by the jet. Our work constitutes the first robust indication of ne...

  10. What are the Sources of Solar Energetic Particles? Element Abundances and Source Plasma Temperatures

    CERN Document Server

    Reames, Donald V

    2015-01-01

    We have spent 50 years in heated discussion over which populations of solar energetic particles (SEPs) are accelerated at flares and which by shock waves driven out from the Sun by coronal mass ejections (CMEs). The association of the large "gradual" SEP events with shock acceleration is supported by the extensive spatial distribution of SEPs and by the delayed acceleration of the particles. The relative abundances of the elements in these gradual events are a measure of those in the ambient solar corona, differing from those in the photosphere by a widely-observed function of the first ionization potential (FIP) of the elements. SEP events we call "impulsive", the traditional "3He-rich" events with enhanced heavy-element abundances, are associated with type III radio bursts, flares, and narrow CMEs; they selectively populate flux tubes that thread a localized source, and they are fit to new particle-in-cell models of magnetic reconnection on open field lines as found in solar jets. These models help explain ...

  11. Submicron Particles during Macro- and Micro-Weldings Procedures in Industrial Indoor Environments and Health Implications for Welding Operators

    Directory of Open Access Journals (Sweden)

    Pasquale Avino

    2015-06-01

    Full Text Available One of the emerging risks in the engineering and electronic industries is the exposure of workers to ultrafine particles during (micro-welding operations, i.e., processes used for joining two metal parts heated locally, which constitute the base metal, with or without addition of another metal which is the filler metal, melted between the edges to be joined. The process is accompanied by formation of metallic fumes arising from the molten metal as well as by the emission of metal fumes of variable composition depending on the alloys welded and fused. The aim of this paper is to investigate the number, concentration and size distribution of submicron particles produced by (micro-welding processes. Particle number size distribution is continuously measured during (micro-welding operations by means of two instruments, i.e., Fast Mobility Particle Sizer and Nanoparticle Surface Area Monitor. The temporal variation of the particle number size distribution across the peaks evidences the strong and fast-evolving contribution of nucleation mode particles: peak values are maintained for less than 10 s. The implication of such contribution on human health is linked to the high deposition efficiency of submicronic particles in the alveolar interstitial region of the human respiratory system, where gas exchange occurs.

  12. Use of On-Site GC/MS Analysis to Distinguish Between Vapor Intrusion and Indoor Sources of VOCs

    Science.gov (United States)

    2013-11-01

    71DE Engineered Fluid Toluene Some paints and adhesives SprayPAK Enamel , Minwax Wood Finish Xylenes Adhesives , paints, gasoline Bonide Tree Sprays and...ay be less ef adhesives . H products con ion include ces of the e to its abil f indoor air h stakehold y interprete ncern, a fou samples ra rounds...Bonder, Radio Shack Anti Static Foaming Cleaner Chloroform Dry cleaned clothes, fire extinguishers, adhesive remover, chlorinated drinking water

  13. Particle Image Velocimetry Measurements of Turbulent Flow Within Outdoor and Indoor Urban Scale Models and Flushing Motions in Urban Canopy Layers

    Science.gov (United States)

    Takimoto, Hiroshi; Sato, Ayumu; Barlow, Janet F.; Moriwaki, Ryo; Inagaki, Atsushi; Onomura, Shiho; Kanda, Manabu

    2011-08-01

    We investigate the spatial characteristics of urban-like canopy flow by applying particle image velocimetry (PIV) to atmospheric turbulence. The study site was a Comprehensive Outdoor Scale MOdel (COSMO) experiment for urban climate in Japan. The PIV system captured the two-dimensional flow field within the canopy layer continuously for an hour with a sampling frequency of 30 Hz, thereby providing reliable outdoor turbulence statistics. PIV measurements in a wind-tunnel facility using similar roughness geometry, but with a lower sampling frequency of 4 Hz, were also done for comparison. The turbulent momentum flux from COSMO, and the wind tunnel showed similar values and distributions when scaled using friction velocity. Some different characteristics between outdoor and indoor flow fields were mainly caused by the larger fluctuations in wind direction for the atmospheric turbulence. The focus of the analysis is on a variety of instantaneous turbulent flow structures. One remarkable flow structure is termed `flushing', that is, a large-scale upward motion prevailing across the whole vertical cross-section of a building gap. This is observed intermittently, whereby tracer particles are flushed vertically out from the canopy layer. Flushing phenomena are also observed in the wind tunnel where there is neither thermal stratification nor outer-layer turbulence. It is suggested that flushing phenomena are correlated with the passing of large-scale low-momentum regions above the canopy.

  14. Distributions of the particle/gas and dust/gas partition coefficients for seventy-two semi-volatile organic compounds in indoor environment.

    Science.gov (United States)

    Wei, Wenjuan; Mandin, Corinne; Blanchard, Olivier; Mercier, Fabien; Pelletier, Maud; Le Bot, Barbara; Glorennec, Philippe; Ramalho, Olivier

    2016-06-01

    Particle/gas and dust/gas partition coefficients (Kp and Kd) are two key parameters that address the partitioning of semi-volatile organic compounds (SVOCs) between gas-phase, airborne particles, and settled dust in indoor environment. A number of empirical equations to calculate the values of Kp and Kd have been reported in the literature. Therefore, the difficulty lies in the selection of a specific empirical equation in a given situation. In this study, we retrieved from the literature 38 empirical equations for calculating Kp and Kd values from the SVOC saturation vapor pressure and octanol/air partition coefficient. These values were calculated for 72 SVOCs: 9 phthalates, 9 polybrominated diphenyl ethers (PBDEs), 11 polychlorinated biphenyls (PCBs), 22 biocides, 14 polycyclic aromatic hydrocarbons (PAHs), 3 alkylphenols, 2 synthetic musks, tributylphosphate, and bisphenol A. The mean and median values of log10Kp or log10Kd for most SVOCs were of the same order of magnitude. The distribution of log10Kp values was fitted to either a normal distribution (for 27 SVOCs) or a log-normal distribution (for 45 SVOCs). This work provides a reference distribution of the log10Kp for 72 SVOCs, and its use may reduce the bias associated with the selection of a specific value or equation.

  15. Indoor wayfinding and navigation

    CERN Document Server

    2015-01-01

    Due to the widespread use of navigation systems for wayfinding and navigation in the outdoors, researchers have devoted their efforts in recent years to designing navigation systems that can be used indoors. This book is a comprehensive guide to designing and building indoor wayfinding and navigation systems. It covers all types of feasible sensors (for example, Wi-Fi, A-GPS), discussing the level of accuracy, the types of map data needed, the data sources, and the techniques for providing routes and directions within structures.

  16. Indoor acoustic gain design

    Science.gov (United States)

    Concha-Abarca, Justo Andres

    2002-11-01

    The design of sound reinforcement systems includes many variables and usually some of these variables are discussed. There are criteria to optimize the performance of the sound reinforcement systems under indoor conditions. The equivalent acoustic distance, the necessary acoustic gain, and the potential acoustic gain are parameters which must be adjusted with respect to the loudspeaker array, electric power and directionality of loudspeakers, the room acoustics conditions, the distance and distribution of the audience, and the type of the original sources. The design and installation of front of the house and monitoring systems have individual criteria. This article is about this criteria and it proposes general considerations for the indoor acoustic gain design.

  17. Laser-accelerated proton beams as a new particle source

    Energy Technology Data Exchange (ETDEWEB)

    Nuernberg, Frank

    2010-11-15

    plasma physics group of the Technische Universitat Darmstadt initiated the development of a test stand to transport, focus and bunch rotate these beams by conventional ion optics and RF technology. The field strength of 7.5 T enabled collimation of protons with an energy of >10 MeV for the first time. In addition, the focusing capability of the solenoid provided a flux increase in the focal spot of about a factor of 174 at a distance of 40 cm from the source, compared to a beam without using the magnetic field. For a quantitative analysis of the experiment numerical simulations with the WarpRZ code were performed. The code, which was originally developed to study high current ion beams and aid in the pursuit of heavy-ion driven inertial confinement fusion, was modified to enable the use of laser-accelerated proton beams as particle source. The calculated energy-resolved beam parameters of RIS could be included, and the plasma simulation criteria were studied in detail. The geometrical boundaries of the experimental setup were used in the simulations. 2.99 x 10{sup 9} collimated protons in the energy range of 13.5{+-}1 MeV could be transported over a distance of 40 cm. In addition, 8.42 x 10{sup 9} protons in the energy range of 6.7{+-}0.2 MeV were focused into a spot of <2 mm in diameter. The transmission through the solenoid for both cases was about 18%. (orig.)

  18. Sources of organic ice nucleating particles in soils

    Science.gov (United States)

    Hill, Tom C. J.; DeMott, Paul J.; Tobo, Yutaka; Fröhlich-Nowoisky, Janine; Moffett, Bruce F.; Franc, Gary D.; Kreidenweis, Sonia M.

    2016-06-01

    Soil organic matter (SOM) may be a significant source of atmospheric ice nucleating particles (INPs), especially of those active > -15 °C. However, due to both a lack of investigations and the complexity of the SOM itself, the identities of these INPs remain unknown. To more comprehensively characterize organic INPs we tested locally representative soils in Wyoming and Colorado for total organic INPs, INPs in the heat-labile fraction, ice nucleating (IN) bacteria, IN fungi, IN fulvic and humic acids, IN plant tissue, and ice nucleation by monolayers of aliphatic alcohols. All soils contained ≈ 106 to ≈ 5 × 107 INPs g-1 dry soil active at -10 °C. Removal of SOM with H2O2 removed ≥ 99 % of INPs active > -18 °C (the limit of testing), while heating of soil suspensions to 105 °C showed that labile INPs increasingly predominated > -12 °C and comprised ≥ 90 % of INPs active > -9 °C. Papain protease, which inactivates IN proteins produced by the fungus Mortierella alpina, common in the region's soils, lowered INPs active at ≥ -11 °C by ≥ 75 % in two arable soils and in sagebrush shrubland soil. By contrast, lysozyme, which digests bacterial cell walls, only reduced INPs active at ≥ -7.5 or ≥ -6 °C, depending on the soil. The known IN bacteria were not detected in any soil, using PCR for the ina gene that codes for the active protein. We directly isolated and photographed two INPs from soil, using repeated cycles of freeze testing and subdivision of droplets of dilute soil suspensions; they were complex and apparently organic entities. Ice nucleation activity was not affected by digestion of Proteinase K-susceptible proteins or the removal of entities composed of fulvic and humic acids, sterols, or aliphatic alcohol monolayers. Organic INPs active colder than -10 to -12 °C were resistant to all investigations other than heat, oxidation with H2O2, and, for some, digestion with papain. They may originate from decomposing plant material, microbial

  19. Prochlorococcus as a Possible Source for Transparent Exopolymer Particles (TEP)

    KAUST Repository

    Agusti, Susana

    2017-04-26

    Transparent exopolymer particles (TEP), usually associated with phytoplankton blooms, promote the formation of marine aggregates. Their exportation to deep waters is considered a key component of the biological carbon pump. Here, we explored the role of solar radiation and picocyanobacteria in the formation of TEP in oligotrophic surface waters of the Atlantic and Pacific Oceans in ten on-deck incubation experiments during the Malaspina 2010 Expedition. TEP concentrations were low on the ocean’s surface although these concentrations were significantly higher on the surface of the Pacific (24.45 ± 2.3 μg XG Eq. L-1) than on the surface of the Atlantic Ocean (8.18 ± 4.56 μg XG Eq. L-1). Solar radiation induced a significant production of TEP in the on-deck experiments from the surface water of the Pacific Ocean, reaching values up to 187.3 μg XG Eq. L-1 compared with the low production observed in the dark controls. By contrast, TEP production in the Atlantic Ocean experiments was lower, and its formation was not related to the light treatments. Prochlorococcus sp. from the surface ocean was very sensitive to solar radiation and experienced a high cell decay in the Pacific Ocean experiments. TEP production in the on-deck incubation experiments was closely related to the observed cell decay rates of Prochlorococcus sp., suggesting that this picocyanobacteria genus is a potential source of TEP. The evidence to propose such potential role was derived experimentally, using natural communities including the presence of several species and a variety of processes. Laboratory experiments with cultures of a non-axenic strain of Prochlorococcus marinus were then used to test TEP production by this genus. TEP concentrations in the culture increased with increasing cell abundance during the exponential phase, reaching the highest TEP concentration at the beginning of the stationary phase. The average TEP concentration of 1474 ± 226 μg XG Eq. L-1 (mean ± SE) observed at

  20. Toward refined estimates of ambient PM2.5 exposure: Evaluation of a physical outdoor-to-indoor transport model.

    Science.gov (United States)

    Hodas, Natasha; Meng, Qingyu; Lunden, Melissa M; Turpin, Barbara J

    2014-02-01

    Because people spend the majority of their time indoors, the variable efficiency with which ambient PM2.5 penetrates and persists indoors is a source of error in epidemiologic studies that use PM2.5 concentrations measured at central-site monitors as surrogates for ambient PM2.5 exposure. To reduce this error, practical methods to model indoor concentrations of ambient PM2.5 are needed. Toward this goal, we evaluated and refined an outdoor-to-indoor transport model using measured indoor and outdoor PM2.5 species concentrations and air exchange rates from the Relationships of Indoor, Outdoor, and Personal Air Study. Herein, we present model evaluation results, discuss what data are most critical to prediction of residential exposures at the individual-subject and populations levels, and make recommendations for the application of the model in epidemiologic studies. This paper demonstrates that not accounting for certain human activities (air conditioning and heating use, opening windows) leads to bias in predicted residential PM2.5 exposures at the individual-subject level, but not the population level. The analyses presented also provide quantitative evidence that shifts in the gas-particle partitioning of ambient organics with outdoor-to-indoor transport contribute significantly to variability in indoor ambient organic carbon concentrations and suggest that methods to account for these shifts will further improve the accuracy of outdoor-to-indoor transport models.

  1. Particle-fluid interaction forces as the source of acceleration PDF invariance in particle size

    CERN Document Server

    Meller, Yosef

    2014-01-01

    The conditions allowing particle suspension in turbulent flow are of interest in many applications, but understanding them is complicated both by the nature of turbulence and by the interaction of flow with particles. Observations on small particles indicate an invariance of acceleration PDFs of small particles independent of size. We show to be true the postulated role of particle/fluid interaction forces in maintaining suspension. The 3D-PTV method, applied for two particle phases (tracers and inertial particles) simultaneously, was used to obtain velocity and acceleration data, and through the use of the particle's equation of motion the magnitude of forces representing either the flow or the particle interaction were derived and compared. The invariance of PDFs is shown to extend to the component forces, and lift forces are shown to be significant.

  2. Sources and characteristics of fine particles over the Yellow Sea and Bohai Sea using online single particle aerosol mass spectrometer.

    Science.gov (United States)

    Fu, Huaiyu; Zheng, Mei; Yan, Caiqing; Li, Xiaoying; Gao, Huiwang; Yao, Xiaohong; Guo, Zhigang; Zhang, Yuanhang

    2015-03-01

    Marine aerosols over the East China Seas are heavily polluted by continental sources. During the Chinese Comprehensive Ocean Experiment in November 2012, size and mass spectra of individual atmospheric particles in the size range from 0.2 to 2.0 μm were measured on board by a single particle aerosol mass spectrometer (SPAMS). The average hourly particle number (PN) was around 4560±3240 in the South Yellow Sea (SYS), 2900±3970 in the North Yellow Sea (NYS), and 1700±2220 in the Bohai Sea (BS). PN in NYS and BS varied greatly over 3 orders of magnitude, while that in SYS varied slightly. The size distributions were fitted with two log-normal modes. Accumulation mode dominated in NYS and BS, especially during episodic periods. Coarse mode particles played an important role in SYS. Particles were classified using an adaptive resonance theory based neural network algorithm (ART-2a). Six particle types were identified with secondary-containing, aged sea-salt, soot-like, biomass burning, fresh sea-salt, and lead-containing particles accounting for 32%, 21%, 18%, 16%, 4%, and 3% of total PN, respectively. Aerosols in BS were relatively enriched in particles from anthropogenic sources compared to SYS, probably due to emissions from more developed upwind regions and indicating stronger influence of continental outflow on marine environment. Variation of source types depended mainly on origins of transported air masses. This study examined rapid changes in PN, size distribution and source types of fine particles in marine atmospheres. It also demonstrated the effectiveness of high-time-resolution source apportionment by ART-2a.

  3. A Novel Source of Mesoscopic Particles for Laser Plasma Studies

    Science.gov (United States)

    2015-12-16

    05/2016 DISTRIBUTION A: Distribution approved for public release. AF Office Of Scientific Research (AFOSR)/ IOA Arlington, Virginia 22203 Air Force...particles is obtained (gas pulsing is essential to maintain the vacuum level). To visualise the particles, a shadowgraph based imag- ing set up was

  4. Linear Alkylbenzenesulfonates in indoor Floor Dust

    DEFF Research Database (Denmark)

    Wolkoff, Peder; Madsen, Jørgen Øgaard

    1999-01-01

    The amount of Linear Alkylbenzenesulfonates (LAS) in the particle fraction of floor dust sampled from 7 selected public buildings varied between 34 and 1500 microgram per gram dust, while the contents of the fibre fractions generally were higher with up to 3500 microgram LAS/g dust. The use...... of a cleaning agent with LAS resulted in an increase of the amount of LAS in the floor dust after floor wash relative to just before floor wash. However, the most important source of LAS in the indoor floor dust appears to be residues of detergent in clothing. Thus, a newly washed shirt contained 2960 microgram...

  5. Can Bohmian particle be a source of "continuous collapse" in GRW-type theories

    CERN Document Server

    Sverdlov, Roman

    2011-01-01

    The purpose of this paper is to unite Pilot Wave model with GRW ideas through a proposal that Bohmian particle serves as a source of continuous collapse. The continuous trajectory of a particle allows the particle-centered collapse mechanism to be continuous as well. This allows us to remove the "stochastic" element from typical GRW proposals.

  6. Test Method for High β Particle Emission Rate of 63Ni Source Plate

    Directory of Open Access Journals (Sweden)

    ZHANG Li-feng

    2015-01-01

    Full Text Available For the problem of measurement difficulties of β particle emission rate of Ni-63 source plate used for Ni-63 betavoltaic battery, a relative test method of scintillation current method was erected according to the measurement principle of scintillation detector.β particle emission rate of homemade Ni-63 source plate was tested by the method, and the test results were analysed and evaluated, it was initially thought that scintillation current method was a feasible way of testing β particle emission rate of Ni-63 source plate with high β particle emission rate.

  7. Relativistic Reconnection: an Efficient Source of Non-Thermal Particles

    CERN Document Server

    Sironi, Lorenzo

    2014-01-01

    In magnetized astrophysical outflows, the dissipation of field energy into particle energy via magnetic reconnection is often invoked to explain the observed non-thermal signatures. By means of two- and three-dimensional particle-in-cell simulations, we investigate anti-parallel reconnection in magnetically-dominated electron-positron plasmas. Our simulations extend to unprecedentedly long temporal and spatial scales, so we can capture the asymptotic state of the system beyond the initial transients, and without any artificial limitation by the boundary conditions. At late times, the reconnection layer is organized into a chain of large magnetic islands connected by thin X-lines. The plasmoid instability further fragments each X-line into a series of smaller islands, separated by X-points. At the X-points, the particles become unmagnetized and they get accelerated along the reconnection electric field. We provide definitive evidence that the late-time particle spectrum integrated over the whole reconnection r...

  8. EFFECTIVE SOURCE SIZES OF LOW RAPIDITY SOFT PARTICLE-EMISSION

    NARCIS (Netherlands)

    PEITZMANN, T; ALBRECHT, R; AWES, TC; BECKMANN, P; BERGER, F; BLOOMER, M; BLUME, C; BOCK, D; BOCK, R; CLAESSON, G; CLEWING, G; DRAGON, L; EKLUND, A; FERGUSON, RL; FRANZ, A; GARPMAN, S; GLASOW, R; GUSTAFSSON, HA; GUTBROD, HH; HOLKER, G; IDH, J; JACOBS, P; KAMPERT, KH; KOLB, BW; LOHNER, H; LUND, [No Value; OBENSHAIN, FE; OSKARSSON, A; OTTERLUND, [No Value; PLASIL, F; POSKANZER, AM; PURSCHKE, M; ROTERS, B; SAINI, S; SANTO, R; SCHMIDT, HR; SORENSEN, SP; STEFFENS, K; STEINHAEUSER, P; STENLUND, E; STUKEN, D; YOUNG, GR

    1994-01-01

    Correlations of positive pions and protons measured with the Plastic Ball detector in ultrarelativistic nucleus-nucleus collisions are studied. Source parameters are extracted for various projectile-target combinations. While the proton source can be explained by geometry, the pion source shows more

  9. Particle size distribution and air pollution patterns in three urban environments in Xi'an, China.

    Science.gov (United States)

    Niu, Xinyi; Guinot, Benjamin; Cao, Junji; Xu, Hongmei; Sun, Jian

    2015-10-01

    Three urban environments, office, apartment and restaurant, were selected to investigate the indoor and outdoor air quality as an inter-comparison in which CO2, particulate matter (PM) concentration and particle size ranging were concerned. In this investigation, CO2 level in the apartment (623 ppm) was the highest among the indoor environments and indoor levels were always higher than outdoor levels. The PM10 (333 µg/m(3)), PM2.5 (213 µg/m(3)), PM1 (148 µg/m(3)) concentrations in the office were 10-50% higher than in the restaurant and apartment, and the three indoor PM10 levels all exceeded the China standard of 150 µg/m(3). Particles ranging from 0.3 to 0.4 µm, 0.4 to 0.5 µm and 0.5 to 0.65 µm make largest contribution to particle mass in indoor air, and fine particles number concentrations were much higher than outdoor levels. Outdoor air pollution is mainly affected by heavy traffic, while indoor air pollution has various sources. Particularly, office environment was mainly affected by outdoor sources like soil dust and traffic emission; apartment particles were mainly caused by human activities; restaurant indoor air quality was affected by multiple sources among which cooking-generated fine particles and the human steam are main factors.

  10. Pilot Implementation of a Field Study Design to Evaluate the Impact of Source Control Measures on Indoor Air Quality in High Performance Homes

    Energy Technology Data Exchange (ETDEWEB)

    Widder, Sarah H.; Chamness, Michele A.; Petersen, Joseph M.; Singer, Brett C.; Maddalena, Randy L.; Destaillats, Hugo

    2014-10-20

    -emitting and “conventional” materials as installed in newly constructed residential homes using both (1) highly controlled, short-term active samples to precisely characterize the building-related chemical emissions and building contents and (2) a week-long passive sample designed to capture the impact of occupant behavior and related activities on measured IAQ contaminant levels indoors. The combination of detailed short-term measurements with the home under controlled/consistent conditions during pre- and post-occupancy and the week-long passive sampling data provide the opportunity to begin to separate the different emission sources and help isolate and quantify variability in the monitored homes. Between April and August 2014, the research team performed pre-occupancy and post-occupancy sampling in one conventional home and two homes built with low-emitting materials that were generally consistent with EPA’s Indoor airPLUS guidelines. However, for a number of reasons, the full experimental plan was not implemented. The project was intended to continue for up to three years to asses long-term changes in IAQ but the project was limited to one calendar year. As a result, several of the primary research questions related to seasonal impacts and the long-term trends in IAQ could not be addressed. In addition, there were several unexpected issues related to recruiting, availability of home types, and difficulty coordinating with builders/realtors/homeowners. Several field monitoring issues also came up that provide “lessons learned” that led to improvements to the original monitoring plan. The project produced a good experimental plan that is expected to be be useful for future efforts collecting data to support answering these same or similar research questions.

  11. Pilot Implementation of a Field Study Design to Evaluate the Impact of Source Control Measures on Indoor Air Quality in High Performance Homes

    Energy Technology Data Exchange (ETDEWEB)

    Widder, Sarah H. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Chamness, Michele A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Petersen, Joseph M. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Singer, Brett C. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Maddalena, Randy L. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Destaillats, Hugo [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Russell, M. L. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2014-10-01

    -emitting and “conventional” materials as installed in newly constructed residential homes using both (1) highly controlled, short-term active samples to precisely characterize the building-related chemical emissions and building contents and (2) a week-long passive sample designed to capture the impact of occupant behavior and related activities on measured IAQ contaminant levels indoors. The combination of detailed short-term measurements with the home under controlled/consistent conditions during pre- and post-occupancy and the week-long passive sampling data provide the opportunity to begin to separate the different emission sources and help isolate and quantify variability in the monitored homes. Between April and August 2014, the research team performed pre-occupancy and post-occupancy sampling in one conventional home and two homes built with low-emitting materials that were generally consistent with EPA’s Indoor airPLUS guidelines. However, for a number of reasons, the full experimental plan was not implemented. The project was intended to continue for up to three years to asses long-term changes in IAQ but the project was limited to one calendar year. As a result, several of the primary research questions related to seasonal impacts and the long-term trends in IAQ could not be addressed. In addition, there were several unexpected issues related to recruiting, availability of home types, and difficulty coordinating with builders/realtors/homeowners. Several field monitoring issues also came up that provide “lessons learned” that led to improvements to the original monitoring plan. The project produced a good experimental plan that is expected to be be useful for future efforts collecting data to support answering these same or similar research questions.

  12. Analysis of Multi-particle Production at RHIC by Two-source Statistical Model

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The data of multi-particle production in s1/2 =130 AGeV Au+Au collisions (RHIC) are analyzed by two-source statistical model which was successfully applied in analyzing the data of multi-particle production in 158 AGeV Pb+Pb collisions (SPS). It is found that sources in RHIC are different from that in SPS which has a small and hot inner source surrounded by a larger and cooler outer source. The two sources in RHIC are identical. They have the same temperature, volume, particle density and other thermodynamic quantities. Besides, the results of two-source model are identical with that of single-source model (the total volume of the two sources equals the volume of single source). The

  13. a Comparison of Simulated Annealing, Genetic Algorithm and Particle Swarm Optimization in Optimal First-Order Design of Indoor Tls Networks

    Science.gov (United States)

    Jia, F.; Lichti, D.

    2017-09-01

    The optimal network design problem has been well addressed in geodesy and photogrammetry but has not received the same attention for terrestrial laser scanner (TLS) networks. The goal of this research is to develop a complete design system that can automatically provide an optimal plan for high-accuracy, large-volume scanning networks. The aim in this paper is to use three heuristic optimization methods, simulated annealing (SA), genetic algorithm (GA) and particle swarm optimization (PSO), to solve the first-order design (FOD) problem for a small-volume indoor network and make a comparison of their performances. The room is simplified as discretized wall segments and possible viewpoints. Each possible viewpoint is evaluated with a score table representing the wall segments visible from each viewpoint based on scanning geometry constraints. The goal is to find a minimum number of viewpoints that can obtain complete coverage of all wall segments with a minimal sum of incidence angles. The different methods have been implemented and compared in terms of the quality of the solutions, runtime and repeatability. The experiment environment was simulated from a room located on University of Calgary campus where multiple scans are required due to occlusions from interior walls. The results obtained in this research show that PSO and GA provide similar solutions while SA doesn't guarantee an optimal solution within limited iterations. Overall, GA is considered as the best choice for this problem based on its capability of providing an optimal solution and fewer parameters to tune.

  14. Inorganic and carbonaceous components in indoor/outdoor particulate matter in two residential houses in Oslo, Norway.

    Science.gov (United States)

    Lazaridis, Mihalis; Aleksandropoulou, Victoria; Hanssen, Jan Erik; Dye, Christian; Eleftheriadis, Kostantinos; Katsivela, Eleftheria

    2008-03-01

    A detailed analysis of indoor/outdoor physicochemical aerosol properties has been performed. Aerosol measurements were taken at two dwellings, one in the city center and the other in the suburbs of the Oslo metropolitan area, during summer/fall and winter/spring periods of 2002-2003. In this paper, emphasis is placed on the chemical characteristics (water-soluble ions and carbonaceous components) of fine (PM2.5) and coarse (PM2.5-10) particles and their indoor/outdoor relationship. Results demonstrate that the carbonaceous species were dominant in all fractions of the PM10 particles (cut off size: 0.09-11.31 microm) during all measurement periods, except winter 2003, when increased concentrations of water-soluble inorganic ions were predominant because of sea salt transport. The concentration of organic carbon was higher in the fine and coarse PM10 fractions indoors, whereas elemental carbon was higher indoors only in the coarse fraction. In regards to the carbonaceous species, local traffic and secondary organic aerosol formation were, probably, the main sources outdoors, whereas indoors combustion activities such as preparation of food, burning of candles, and cigarette smoking were the main sources. In contrast, the concentrations of water-soluble inorganic ions were higher outdoors than indoors. The variability of water-soluble inorganic ion concentrations outdoors was related to changes in emissions from local anthropogenic sources, long-range transport of particles, sea salt emissions, and resuspension of roadside and soil dusts. In the indoor environment the infiltration of the outdoor air indoors was the major source of inorganic ions.

  15. Lead and cadmium in indoor air and the urban environment.

    Science.gov (United States)

    Komarnicki, Günter J K

    2005-07-01

    The present study was conducted to find potential terrestrial biomonitors for heavy metals in indoor air in an urban environment. TSP, PM(10), and PM(2.5) were collected in three retirement facilities in the urban area of Vienna. In addition, particulate matter and soil, vegetation, and isopods (Porcellio scaber L.) were collected in the adjacent garden areas. Aerosols were sampled with a low-volume air sampler. The sampled materials were wet ashed and total lead and cadmium contents were determined. Water-soluble heavy metal concentrations were measured in aqueous extracts from air exposed filters, soil, and vegetation. Lead and cadmium were analyzed by graphite furnace AAS. Lead contents in the vegetation were inferred from water-soluble lead in soils. Lead in isopods generally reflected the contents in vegetation. Cadmium in plants probably derived from soil solutions as well as from atmospheric input. Isopods reflected the total cadmium contents in soils. Particulate matter was dominated by PM(2.5), both with respect to mass concentrations and to heavy metal contents. The indoor aerosol was found to be influenced by human activity, indoor sources, and outdoor particles. Relationships between indoor airborne heavy metals and the contents in vegetation (lead and cadmium: positive) and isopods (lead: negative) were identified to have the potential for biomonitoring indoor air quality.

  16. Transport of Sputtered Particles in Capacitive Sputter Sources

    CERN Document Server

    Trieschmann, Jan

    2015-01-01

    The transport of sputtered aluminum inside a multi frequency capacitively coupled plasma chamber is simulated by means of a kinetic test multi-particle approach. A novel consistent set of scattering parameters obtained for a modified variable hard sphere collision model is presented for both argon and aluminum. An angular dependent Thompson energy distribution is fitted to results from Monte-Carlo simulations and used for the kinetic simulation of the transport of sputtered aluminum. For the proposed configuration the transport of sputtered particles is characterized under typical process conditions at a gas pressure of p = 0.5 Pa. It is found that - due to the peculiar geometric conditions - the transport can be understood in a one dimensional picture, governed by the interaction of the imposed and backscattered particle fluxes. It is shown that the precise geometric features play an important role only in proximity to the electrode edges, where the effect of backscattering from the outside chamber volume be...

  17. Indoor air quality and respiratory health effects in school children: The HITEA study

    NARCIS (Netherlands)

    Jacobs, J.H.

    2013-01-01

    A good air quality of the indoor environment is essential for human health; on average people spend more than 80% of their time indoors. The composition of indoor air is extremely complex and the quality can be influenced by several outdoor and indoor sources. In this thesis the effects of indoor ai

  18. Emissions and fate of brominated flame retardants in the indoor environment: A critical review of modelling approaches

    Energy Technology Data Exchange (ETDEWEB)

    Liagkouridis, Ioannis, E-mail: ioannis.liagkouridis@ivl.se [IVL Swedish Environmental Research Institute, P.O. Box 21060, SE 100 31 Stockholm (Sweden); ITM Department of Applied Environmental Science, Stockholm University, SE 106 91 Stockholm (Sweden); Cousins, Ian T. [ITM Department of Applied Environmental Science, Stockholm University, SE 106 91 Stockholm (Sweden); Cousins, Anna Palm [IVL Swedish Environmental Research Institute, P.O. Box 21060, SE 100 31 Stockholm (Sweden)

    2014-09-01

    This review explores the existing understanding and the available approaches to estimating the emissions and fate of semi-volatile organic compounds (SVOCs) and in particular focuses on the brominated flame retardants (BFRs). Volatilisation, an important emission mechanism for the more volatile compounds can be well described using current emission models. More research is needed, however, to better characterise alternative release mechanisms such as direct material–particle partitioning and material abrasion. These two particle-mediated emissions are likely to result in an increased chemical release from the source than can be accounted for by volatilisation, especially for low volatile compounds, and emission models need to be updated in order to account for these. Air–surface partitioning is an important fate process for SVOCs such as BFRs however it is still not well characterised indoors. In addition, the assumption of an instantaneous air–particle equilibrium adopted by current indoor fate models might not be valid for high-molecular weight, strongly sorbing compounds. A better description of indoor particle dynamics is required to assess the effect of particle-associated transport as this will control the fate of low volatile BFRs. We suggest further research steps that will improve modelling precision and increase our understanding of the factors that govern the indoor fate of a wide range of SVOCs. It is also considered that the appropriateness of the selected model for a given study relies on the individual characteristics of the study environment and scope of the study. - Highlights: • Current emission models likely underestimate the release of low volatile BFRs from products. • Material abrasion and direct material–dust partitioning are important, yet understudied emission mechanisms. • Indoor surfaces can be significant sinks, but the mechanism is poorly understood. • Indoor fate of low volatile BFRs is strongly associated with particle

  19. Evaluating heterogeneity in indoor and outdoor air pollution using land-use regression and constrained factor analysis.

    Science.gov (United States)

    Levy, Jonathan I; Clougherty, Jane E; Baxter, Lisa K; Houseman, E Andres; Paciorek, Christopher J

    2010-12-01

    Previous studies have identified associations between traffic exposures and a variety of adverse health effects, but many of these studies relied on proximity measures rather than measured or modeled concentrations of specific air pollutants, complicating interpretability of the findings. An increasing number of studies have used land-use regression (LUR) or other techniques to model small-scale variability in concentrations of specific air pollutants. However, these studies have generally considered a limited number of pollutants, focused on outdoor concentrations (or indoor concentrations of ambient origin) when indoor concentrations are better proxies for personal exposures, and have not taken full advantage of statistical methods for source apportionment that may have provided insight about the structure of the LUR models and the interpretability of model results. Given these issues, the primary objective of our study was to determine predictors of indoor and outdoor residential concentrations of multiple traffic-related air pollutants within an urban area, based on a combination of central site monitoring data; geographic information system (GIS) covariates reflecting traffic and other outdoor sources; questionnaire data reflecting indoor sources and activities that affect ventilation rates; and factor-analytic methods to better infer source contributions. As part of a prospective birth cohort study assessing asthma etiology in urban Boston, we collected indoor and/or outdoor 3-to-4 day samples of nitrogen dioxide (NO2) and fine particulate matter with an aerodynamic diameter or = 2.5 pm (PM2.5) at 44 residences during multiple seasons of the year from 2003 through 2005. We performed reflectance analysis, x-ray fluorescence spectroscopy (XRF), and high-resolution inductively coupled plasma-mass spectrometry (ICP-MS) on particle filters to estimate the concentrations of elemental carbon (EC), trace elements, and water-soluble metals, respectively. We derived

  20. Cross Infection in a Hospital Ward and Deposition of Particles Exhaled from a Source Manikin

    DEFF Research Database (Denmark)

    Nielsen, Peter V.; Li, Yuguo; Buus, Morten

    2009-01-01

    The cross infection in a hospital ward is studied. Deposition of particles exhaled from a source manikin is investigated in a full-scale hospital ward ventilated by downward directed ventilation. Deposition on vertical surfaces close to the source shows distribution of particles directed upwards...... in the room. Deposition at the four beds shows that particles smaller than 10 μm disperse evenly in the ward, indicating that particles smaller than this size are airborne. The influence of top and bottom extraction openings on dispersion of particles is investigated. Results show that vertical distribution...... in the room is not affected by the position of the return openings. Deposition of particles at the four beds gives some indication of a less wide spread of particles with the use of ceiling-mounted return openings, and thereby a better protection of patients compared with bottom return openings....

  1. EXACERBATION OF ATHEROSCLEROSIS FOLLOWING EXPOSURE TO VARIOUS COMBUSTION SOURCE PARTICLES

    Science.gov (United States)

    Exposure of ApoE knockout (ApoE-/-) mice to concentrated ambient particles (CAPs) has been shown to increase arterial plaque area and size. CAPs are a complex aerosol mixture consisting of wind-blown dust, emissions from the combustion of fossil fuels, and secondary tr...

  2. 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.

  3. Tracing the sources of particles in the East Rongbuk ice core from Mt. Qomolangma

    Institute of Scientific and Technical Information of China (English)

    XU JianZhong; HOU ShuGui; CHEN FuKun; REN JiaWen; QIN DaHe

    2009-01-01

    Sr-Nd-Pb isotopic tracer was applied, for the first time, to identifying the sources of the particles in the East Rongbuk ice core from Mt. Qomalangma (Everest). The results show that the particles in the dirty layers originate mainly from local sources, while the particles in the non-dirty layers are consistent with the features of dust from the arid regions in northwestern India. The HYSPLIT model shows that the air trajectory goes first through northwestern India before reaching the drilling site of ice core when dust storms occur in northwestern India, confirming northwestern India as a possible source of dust in the East Rongbuk ice core.

  4. Overview of sources of radioactive particles of Nordic relevance as well as a short description of available particle characterisation techniques

    Energy Technology Data Exchange (ETDEWEB)

    Lind, O.C.; Salbu, B. (Norwegian Univ. of Life Sciences (Norway)); Nygren, U.; Thaning, L.; Ramebaeck, H. (Swedish Defense Research Agency (FOI) (Sweden)); Sidhu, S. (Inst. for Energy Technology (Norway)); Roos, P. (Technical Univ. of Denmark. Risoe DTU, Roskilde (Denmark)); Poellaenen, R. (STUK (Finland)); Ranebo, Y.; Holm, E. (Univ. Lund (Sweden))

    2008-10-15

    The present overview report show that there are many existing and potential sources of radioactive particle contamination of relevance to the Nordic countries. Following their release, radioactive particles represent point sources of short- and long-term radioecological significance, and the failure to recognise their presence may lead to significant errors in the short- and long-term impact assessments related to radioactive contamination at a particular site. Thus, there is a need of knowledge with respect to the probability, quantity and expected impact of radioactive particle formation and release in case of specified potential nuclear events (e.g. reactor accident or nuclear terrorism). Furthermore, knowledge with respect to the particle characteristics influencing transport, ecosystem transfer and biological effects is important. In this respect, it should be noted that an IAEA coordinated research project was running from 2000-2006 (IAEA CRP, 2001) focussing on characterisation and environmental impact of radioactive particles, while a new IAEA CRP focussing on the biological effects of radioactive particles will be launched in 2008. (author)

  5. Position of the source of particles in solar electron events

    Science.gov (United States)

    Wang, Xue-yi; Huang, Yong-nian

    The ISEE-3 data for 51 solar electron events are analyzed and classified into Fe-rich and Fe-poor events. For Fe-rich events, the source is found to be in the high chromosphere; for the Fe-poor events, in the region between the chromosphere and corona. In both cases the source position differs from the position of the corresponding flare. A process of formation of these two types of events is proposed.

  6. Source apportionment of fine particles in Kuwait City.

    Science.gov (United States)

    Alolayan, Mohammad A; Brown, Kathleen W; Evans, John S; Bouhamra, Walid S; Koutrakis, Petros

    2013-03-15

    This study investigated major sources of PM2.5 in the atmosphere of Kuwait based on a sampling program conducted between February 2004 and October 2005. Three source identification techniques were used in this study: (1) a positive matrix factorization model; (2) backward trajectory profiles; and (3) concentration rose plots. Five major sources of PM2.5 were estimated. These were sand dust (sand storms), oil combustion (power plants), petrochemical industry (fertilizer, nylon or catalyst regeneration facilities), traffic (vehicle emissions and road dust) and transported emissions (emissions from outside Kuwait, such as those from automobiles, road dust or smelters). The estimated contributions to PM2.5 of these sources were: 54% from sand dust, 18% from oil combustion, 12% from petrochemical industry, 11% from traffic and 5% from anthropogenic sources transported from outside the country. Oil combustion, petrochemical industry and traffic were found to emanate from local sources, whereas sand dust and some emissions from traffic, and possibly smelters, appeared to originate from sources outside of Kuwait (transported). The PM2.5 levels in Kuwait during our previous sampling study averaged 53μg/m(3). More than half of the measured PM2.5 appears to have been due to crustal material, much originating outside of the country. However, the relatively high levels of PM2.5 contributed by anthropogenic local sources, such as oil combustion, petrochemical industry emissions, and traffic indicated that there may be great opportunities for Kuwait to improve public health. The application of cost-effective emission controls and development of forward looking environmental health policies have the potential to significantly reduce emissions, population exposures to PM2.5 and the burden of mortality and morbidity from air pollution.

  7. Laser-Accelerated Proton Beams as a New Particle Source

    OpenAIRE

    Nürnberg, Frank

    2010-01-01

    The framework of this thesis is the investigation of the generation of proton beams using high-intensity laser pulses. Today's high power, ultrashort pulse laser systems are capable of achieving laser intensities up to 10^21 W/cm^2. When focused onto thin foil targets, extremely high field gradients of the order of TV/m are produced on the rear side of the target resulting in the acceleration of protons to multi-MeV energies with an exponential spectrum including up to 10^13 particles. This a...

  8. Online laser desorption-multiphoton postionization mass spectrometry of individual aerosol particles: molecular source indicators for particles emitted from different traffic-related and wood combustion sources.

    Science.gov (United States)

    Bente, Matthias; Sklorz, Martin; Streibel, Thorsten; Zimmermann, Ralf

    2008-12-01

    Direct inlet aerosol mass spectrometry plays an increasingly important role in applied and fundamental aerosol and nanoparticle research. Laser desorption/ionization (LDI) based techniques for single particle time-of-flight mass spectrometry (LDI-SP-TOFMS) are a promising approach in the chemical analysis of single aerosol particles, especially for the detection of inorganic species and distinction of particle classes. However, until now the detection of molecular organic compounds on a single particle basis has been difficult due to the high laser power densities which are required for the LDI process as well as due to the inherent matrix effects associated with this ionization technique. By the application of a two-step approach, where an IR desorption laser pulse is applied to perform a gentle desorption of organic material from the single particle surface and a second UV-laser performs the soft ionization of the desorbed species, this drawback of laser based single particles mass spectrometry can be overcome. The postionization of the desorbed molecules has been accomplished in this work by resonance enhanced multiphoton ionization (REMPI) using a KrF excimer laser (248 nm). REMPI allows an almost fragmentation free trace analysis of polycyclic aromatic hydrocarbons (PAHs) and their derivatives from individual single particles (laser desorption-REMPI postionization-single particle-time-of-flight mass spectrometry or LD-REMPI-SP-TOFMS). Crucial system parameters of the home-built aerosol mass spectrometer such as the power densities and the relative timing of both lasers were optimized with respect to the detectability of particle source specific organic signatures using well characterized standard particles. In a second step, the LD-REMPI-SP-TOFMS system was applied to analyze different real world aerosols (spruce wood combustion, gasoline car exhaust, beech wood combustion, and diesel car exhaust). It was possible to distinguish the particles from different

  9. A location-based services system using indoor visible light sources%基于室内可见光照明的位置服务系统

    Institute of Scientific and Technical Information of China (English)

    娄鹏华; 张洪明; 郎凯; 姚敏玉; 徐正元

    2012-01-01

    This paper designs and realizes a location-based services system using indoor LED sources. This system applies LED identification (LED-ID) technology. The LED source transmits a unique ID code, which the receiver associates with geographic position to achieve its current location. The modulation and coding of the transmitter, as well as the demodulation and decoding of the receiver, are all realized by the single-chip processor which also provides UART interface to communicate with PC controller and mobile phone displayer. The PC controller sends location-based service messages to LED signal source,and then the source broadeasts its ID and the received message through space optical transmission. The mobile terminal installs an Android indoor positioning and navigation software which updates users' location and extra location service information in real time.%设计并实现了一种基于室内LED照明光源的位置服务系统。系统利用LED标签(LED—ID)技术,LED提供照明的同时广播自身的位置ID信息,移动终端将接收到的ID信息与位置关联,实现自身的被动定位。可见光通信的调制编码以及解调解码模块均采用单片机处理器(PC)实现,并提供UART接口分别与PC控制端和手机显示端进行通信。PC控制端向LED信号源发送位置服务信息,LED信号源通过空间光传输方式将自身位置ID和接收到的位置服务信息广播出去。手机使用终端加载有Android操作环境下的室内定位导航软件,可以实时更新位置和位置服务信息。

  10. The generation of diesel exhaust particle aerosols from a bulk source in an aerodynamic size range similar to atmospheric particles

    Directory of Open Access Journals (Sweden)

    Daniel J Cooney

    2008-08-01

    Full Text Available Daniel J Cooney1, Anthony J Hickey21Department of Biomedical Engineering; 2School of Pharmacy, University of North Carolina, Chapel Hill, NC, USAAbstract: The influence of diesel exhaust particles (DEP on the lungs and heart is currently a topic of great interest in inhalation toxicology. Epidemiological data and animal studies have implicated airborne particulate matter and DEP in increased morbidity and mortality due to a number of cardiopulmonary diseases including asthma, chronic obstructive pulmonary disorder, and lung cancer. The pathogeneses of these diseases are being studied using animal models and cell culture techniques. Real-time exposures to freshly combusted diesel fuel are complex and require significant infrastructure including engine operations, dilution air, and monitoring and control of gases. A method of generating DEP aerosols from a bulk source in an aerodynamic size range similar to atmospheric DEP would be a desirable and useful alternative. Metered dose inhaler technology was adopted to generate aerosols from suspensions of DEP in the propellant hydrofluoroalkane 134a. Inertial impaction data indicated that the particle size distributions of the generated aerosols were trimodal, with count median aerodynamic diameters less than 100 nm. Scanning electron microscopy of deposited particles showed tightly aggregated particles, as would be expected from an evaporative process. Chemical analysis indicated that there were no major changes in the mass proportion of 2 specific aromatic hydrocarbons (benzo[a]pyrene and benzo[k]fluoranthene in the particles resulting from the aerosolization process.Keywords: diesel exhaust particles, aerosol, inhalation toxicology

  11. Indoor airborne infection

    Energy Technology Data Exchange (ETDEWEB)

    Riley, R.L.

    1982-01-01

    Airborne infection from person to person is an indoor phenomenon. The infectious organisms are atomized by coughing, sneezing, singing, and even talking. The smallest droplets evaporate to droplet nuclei and disperse rapidly and randomly throughout the air of enclosed spaces. Droplet nuclei have negligible settling velocity and travel wherever the air goes. Outdoors, dilution is so rapid that the chance of inhaling an infectious droplet nucleus is minimal. Measles and other childhood contagions, the common respiratory virus infections, pulmonary tuberculosis, and Legionnaires' Disease are typically airborne indoors. In analyzing a measles outbreak, the probability that a susceptible person would breathe a randomly distributed quantum of airborne infection during one generation of an outbreak was expressed mathematically. Estimates of the rate of production of infectious droplet nuclei ranged between 93 and 8 per min, and the concentration in the air produced by the index case was about 1 quantum per 5 m/sup 3/ of air. Infectious aiborne particles are thus few and far between. Control of indoor airborne infection can be approached through immunization, therapeutic medication, and air disinfection with ultraviolet radiation.

  12. Magnetic pumping as a source of particle heating

    Science.gov (United States)

    Lichko, Emily; Egedal, Jan; Daughton, William; Kasper, Justin

    2016-10-01

    Magnetic pumping is a means of heating plasmas for both fusion and astrophysical applications. This study presents a generalized model, related to the compressional pumping model Fisk & Gloeckler applied to the solar wind (2006). Unlike previous models, this model includes diffusion of the anisotropic features which develop in velocity space, thereby allowing energy to be transferred to the particles directly from the turbulence. By using various orderings, the drift kinetic equation can be reduced to a more general form of Parker's equation with an anisotropic distribution function. Through expansions in both pitch angle and in space, it can be shown that this equation has power law solutions and results in an overall heating of the plasma. This form of heating is related to transit-time damping. Kinetic simulations were performed to test the theoretical model and explore regimes where spatial and velocity diffusion are of the same order of importance, regimes not easily available to analytical calculations. These simulations appear to confirm the pumping model in the appropriate limits.

  13. Outdoor-indoor air pollution in urban environment: challenges and opportunity

    OpenAIRE

    Dennis Y.C. eLeung

    2015-01-01

    With the continual improvement in our quality of life, indoor air quality has become an important area of concern in the twenty-first 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 pollutio...

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

    OpenAIRE

    Dennis Y.C. eLeung

    2015-01-01

    With the continual improvement in our quality of life, indoor air quality has become an important area of concern in the twenty-first 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 pollutio...

  15. Particle damage sources for fused silica optics and their mitigation on high energy laser systems.

    Science.gov (United States)

    Bude, J; Carr, C W; Miller, P E; Parham, T; Whitman, P; Monticelli, M; Raman, R; Cross, D; Welday, B; Ravizza, F; Suratwala, T; Davis, J; Fischer, M; Hawley, R; Lee, H; Matthews, M; Norton, M; Nostrand, M; VanBlarcom, D; Sommer, S

    2017-05-15

    High energy laser systems are ultimately limited by laser-induced damage to their critical components. This is especially true of damage to critical fused silica optics, which grows rapidly upon exposure to additional laser pulses. Much progress has been made in eliminating damage precursors in as-processed fused silica optics (the advanced mitigation process, AMP3), and very high damage resistance has been demonstrated in laboratory studies. However, the full potential of these improvements has not yet been realized in actual laser systems. In this work, we explore the importance of additional damage sources-in particular, particle contamination-for fused silica optics fielded in a high-performance laser environment, the National Ignition Facility (NIF) laser system. We demonstrate that the most dangerous sources of particle contamination in a system-level environment are laser-driven particle sources. In the specific case of the NIF laser, we have identified the two important particle sources which account for nearly all the damage observed on AMP3 optics during full laser operation and present mitigations for these particle sources. Finally, with the elimination of these laser-driven particle sources, we demonstrate essentially damage free operation of AMP3 fused silica for ten large optics (a total of 12,000 cm(2) of beam area) for shots from 8.6 J/cm(2) to 9.5 J/cm(2) of 351 nm light (3 ns Gaussian pulse shapes). Potentially many other pulsed high energy laser systems have similar particle sources, and given the insight provided by this study, their identification and elimination should be possible. The mitigations demonstrated here are currently being employed for all large UV silica optics on the National Ignition Facility.

  16. Indoor Environmental Quality Benefits of Apartment Energy Retrofits

    Energy Technology Data Exchange (ETDEWEB)

    Noris, Federico [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Adamkiewicz, Gary [Harvard School of Public Health, Boston MA (United States); Delp, William W. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Hotchi, Toshifumi [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Russell, Marion [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Singer, Brett C. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Spears, Michael [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Vermeer, Kimberly [Urban Habitate Initiatives Inc., Boston, MA (United States); Fisk, William J. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2013-06-01

    Sixteen apartments serving low-income populations in three buildings were retrofit with the goal of simultaneously reducing energy consumption and improving indoor environmental quality (IEQ). Retrofit measures varied among apartments and included, among others, envelope sealing, installation of continuous mechanical ventilation systems, upgrading bathroom fans and range hoods, attic insulation, replacement of heating and cooling systems, and adding wall-mounted particle air cleaners. IEQ parameters were measured, generally for two one-week periods before and after the retrofits. The measurements indicate an overall improvement in IEQ conditions after the retrofits. Comfort conditions, bathroom humidity, and concentrations of carbon dioxide, acetaldehyde, volatile organic compounds, and particles generally improved. Formaldehyde and nitrogen dioxide levels decreased in the building with the highest concentrations, were unchanged in a second building, and increased in a third building. IEQ parameters other than particles improved more in apartments with continuous mechanical ventilation systems installed. In general, but not consistently, larger percent increases in air exchange rates were associated with larger percent decreases in indoor levels of the pollutants that primarily come from indoor sources.

  17. A Hybrid 3D Indoor Space Model

    Science.gov (United States)

    Jamali, Ali; Rahman, Alias Abdul; Boguslawski, Pawel

    2016-10-01

    GIS integrates spatial information and spatial analysis. An important example of such integration is for emergency response which requires route planning inside and outside of a building. Route planning requires detailed information related to indoor and outdoor environment. Indoor navigation network models including Geometric Network Model (GNM), Navigable Space Model, sub-division model and regular-grid model lack indoor data sources and abstraction methods. In this paper, a hybrid indoor space model is proposed. In the proposed method, 3D modeling of indoor navigation network is based on surveying control points and it is less dependent on the 3D geometrical building model. This research proposes a method of indoor space modeling for the buildings which do not have proper 2D/3D geometrical models or they lack semantic or topological information. The proposed hybrid model consists of topological, geometrical and semantical space.

  18. A Hybrid 3D Indoor Space Model

    Directory of Open Access Journals (Sweden)

    A. Jamali

    2016-10-01

    Full Text Available GIS integrates spatial information and spatial analysis. An important example of such integration is for emergency response which requires route planning inside and outside of a building. Route planning requires detailed information related to indoor and outdoor environment. Indoor navigation network models including Geometric Network Model (GNM, Navigable Space Model, sub-division model and regular-grid model lack indoor data sources and abstraction methods. In this paper, a hybrid indoor space model is proposed. In the proposed method, 3D modeling of indoor navigation network is based on surveying control points and it is less dependent on the 3D geometrical building model. This research proposes a method of indoor space modeling for the buildings which do not have proper 2D/3D geometrical models or they lack semantic or topological information. The proposed hybrid model consists of topological, geometrical and semantical space.

  19. Efficient implementation of superquadric particles in Discrete Element Method within an open-source framework

    Science.gov (United States)

    Podlozhnyuk, Alexander; Pirker, Stefan; Kloss, Christoph

    2016-09-01

    Particle shape representation is a fundamental problem in the Discrete Element Method (DEM). Spherical particles with well known contact force models remain popular in DEM due to their relative simplicity in terms of ease of implementation and low computational cost. However, in real applications particles are mostly non-spherical, and more sophisticated particle shape models, like superquadric shape, must be introduced in DEM. The superquadric shape can be considered as an extension of spherical or ellipsoidal particles and can be used for modeling of spheres, ellipsoids, cylinder-like and box(dice)-like particles just varying five shape parameters. In this study we present an efficient C++ implementation of superquadric particles within the open-source and parallel DEM package LIGGGHTS. To reduce computational time several ideas are employed. In the particle-particle contact detection routine we use the minimum bounding spheres and the oriented bounding boxes to reduce the number of potential contact pairs. For the particle-wall contact an accurate analytical solution was found. We present all necessary mathematics for the contact detection and contact force calculation. The superquadric DEM code implementation was verified on test cases such as angle of repose and hopper/silo discharge. The simulation results are in good agreement with experimental data and are presented in this paper. We show adequacy of the superquadric shape model and robustness of the implemented superquadric DEM code.

  20. Efficient implementation of superquadric particles in Discrete Element Method within an open-source framework

    Science.gov (United States)

    Podlozhnyuk, Alexander; Pirker, Stefan; Kloss, Christoph

    2017-01-01

    Particle shape representation is a fundamental problem in the Discrete Element Method (DEM). Spherical particles with well known contact force models remain popular in DEM due to their relative simplicity in terms of ease of implementation and low computational cost. However, in real applications particles are mostly non-spherical, and more sophisticated particle shape models, like superquadric shape, must be introduced in DEM. The superquadric shape can be considered as an extension of spherical or ellipsoidal particles and can be used for modeling of spheres, ellipsoids, cylinder-like and box(dice)-like particles just varying five shape parameters. In this study we present an efficient C++ implementation of superquadric particles within the open-source and parallel DEM package LIGGGHTS. To reduce computational time several ideas are employed. In the particle-particle contact detection routine we use the minimum bounding spheres and the oriented bounding boxes to reduce the number of potential contact pairs. For the particle-wall contact an accurate analytical solution was found. We present all necessary mathematics for the contact detection and contact force calculation. The superquadric DEM code implementation was verified on test cases such as angle of repose and hopper/silo discharge. The simulation results are in good agreement with experimental data and are presented in this paper. We show adequacy of the superquadric shape model and robustness of the implemented superquadric DEM code.

  1. Co-formation of hydroperoxides and ultra-fine particles during the reactions of ozone with a complex VOC mixture under simulated indoor conditions

    DEFF Research Database (Denmark)

    Fan, Z.H.; Weschler, Charles J.; Han, IK

    2005-01-01

    in the O-3/23 VOCs system. The present study confirmed the findings of a previous study carried out in a real-world office and generated new findings regarding co-formation of UFP. Through a comparative analysis of H2O2* yields under different reaction conditions, this study demonstrates that VOCs co......) under simulated indoor conditions. The VOC mixture contained 23 compounds, including two terpenes (d-limonene and alpha-pinene), two unsaturated alkenes (1-decene and 1-octene), and 19 other saturated organic compounds. These compounds are commonly found in indoor air but their concentrations were...

  2. A Breath of Fresh Air: Addressing Indoor Air Quality

    Science.gov (United States)

    Palliser, Janna

    2011-01-01

    Indoor air pollution refers to "chemical, biological, and physical contamination of indoor air," which may result in adverse health effects (OECD 2003). The causes, sources, and types of indoor air pollutants will be addressed in this article, as well as health effects and how to reduce exposure. Learning more about potential pollutants in home…

  3. A Breath of Fresh Air: Addressing Indoor Air Quality

    Science.gov (United States)

    Palliser, Janna

    2011-01-01

    Indoor air pollution refers to "chemical, biological, and physical contamination of indoor air," which may result in adverse health effects (OECD 2003). The causes, sources, and types of indoor air pollutants will be addressed in this article, as well as health effects and how to reduce exposure. Learning more about potential pollutants in home…

  4. Source apportionment of single aerosol particles in the atmosphere of Shanghai city

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    A nuclear microprobe with high spatial resolution and high analyti cal sensitivity was applied to analyze atmospheric aerosol at five monitoring sites in Shanghai city. Meantime, a new pattern recognition technique, which used the micro PIXE spectrum of a single aerosol particle as its fingerprint, was developed to identify the origin of the particle. The results showed that the major contributors to the at mosphere pollution were soil dust (31.6%), building dust (30.8%), and the next were vehicle exhaust (13.7%), metallurgic industry excrements (5.6%), oil combustion (5%) and coal combustion (2.3%). Besides these, about 10% of the particles could not be identified. Based on the cluster analysis of these particles, they could be divided into eight groups. By inference, they might belong to some sub-pollution sources from soil dust, building dust and metallurgic industry excrements. Moreover, some new pollution sources from tyres and chemical plants were also revealed.

  5. Evaluation and guidelines for using polyurethane foam (PUF) passive air samplers in double-dome chambers to assess semi-volatile organic compounds (SVOCs) in non-industrial indoor environments.

    Science.gov (United States)

    Bohlin, Pernilla; Audy, Ondřej; Škrdlíková, Lenka; Kukučka, Petr; Vojta, Šimon; Přibylová, Petra; Prokeš, Roman; Čupr, Pavel; Klánová, Jana

    2014-11-01

    Indoor air pollution has been recognized as an important risk factor for human health, especially in areas where people tend to spend most of their time indoors. Many semi-volatile organic compounds (SVOCs) have primarily indoor sources and are present in orders of magnitude higher concentrations indoors than outdoors. Despite this, awareness of SVOCs in indoor air and assessment of the link between indoor concentrations and human health have lagged behind those of outdoor air. This is partially related to challenges associated with indoor sampling of SVOCs. Passive air samplers (PASs), which are widely accepted in established outdoor air monitoring networks, have been used to fill the knowledge gaps on indoor SVOCs distribution. However, their applicability for indoor environments and the assessment of human health risks lack sufficient experimental data. To address this issue, we performed an indoor calibration study of polyurethane foam (PUF) PAS deployed in a double-dome chamber, covering both legacy and new SVOC classes. PUF-PAS and a continuous low-volume active air sampler (AAS) were co-deployed for a calibration period of twelve weeks. Based on the results from this evaluation, PUF-PAS in a double-bowl chamber is recommended for indoor sampling and health risk assessment of gas phase SVOCs, including novel brominated flame retardants (nBFR) providing sufficient exposure time is applied. Data for particle associated SVOCs suffered from significant uncertainties caused by low level of detection and low precision in this study. A more open chamber design for indoor studies may allow for higher sampling rates (RS) and better performance for the particle associated SVOCs.

  6. Numerical Simulation and Experimental Research on Indoor Environment Separated with Down-Feed Air Curtain

    Institute of Scientific and Technical Information of China (English)

    GUO Chunmei; ZHANG Yufeng; CHANG Ru; WANG Xiaodong

    2009-01-01

    Indoor environment separated with down.feed air curtain was numerically simulated and experimentally researched.Indoor airflow and temperature fields separated with air curtain were numerically simulated.Resuits show that both polluted airflow and thermal air current can be separated with a down.feed air curtain to prevent contaminants from spreading in the room space.In a test chamber.the smoke of burning Tibetan incense served as the source of contaminants.and the probe test shows that 1.0 pm is the prevailing diameter of the smoke particles.During the release of the smoke.the particle concentration of the indoor air was tested with a laser particle counter at the points of three different heights from the floor when the air curtain was running or not.Experimental results show that the higher the test point is located,the lower the particle concentration is,implying that the separating or isolating eflfect decreases as the air velocity of the curtain reduces along with the height descends.According to both simulation and experimental results.down.feed air curtain can separate indoor environment effectively when the supply air velocity of air curtain is not less than 3 m/s.In order to strengthen separation effect,it is suggested that the supply air velocity be speeded up to 5 m/s.

  7. Distribution of legacy and emerging semivolatile organic compounds in five indoor matrices in a residential environment.

    Science.gov (United States)

    Melymuk, Lisa; Bohlin-Nizzetto, Pernilla; Vojta, Šimon; Krátká, Martina; Kukučka, Petr; Audy, Ondřej; Přibylová, Petra; Klánová, Jana

    2016-06-01

    Seven types of indoor samples, covering five indoor matrices, were collected in a residential room, and analyzed for five classes of semivolatile organic compounds (SVOCs). The goal was to improve the understanding of the relationship between indoor air, surface films and dust, based on differences in sources, physicochemical properties, and indoor environmental characteristics. Comparisons of the five matrices (gas- and particle-phase air, floor dust, surface dust/films and window films) demonstrated that within our test room a semi-quantitative measurement of the SVOC distributions and concentrations could be obtained by air, and composite dust or furniture surface wipes. Dust concentrations varied within the room, and spot samples were not necessarily representative of the average room conditions. Polyurethane foam passive air samplers (PUF-PAS) successfully quantified the total air concentrations of the studied SVOC compound groups, as indoor air concentrations were dominated by gas-phase compounds, however air concentrations of individual particle-bound compounds had higher uncertainty. Measured concentrations of dust/surfaces could be used to estimate air concentrations of legacy SVOCs, demonstrating equilibrium in the room. However, air concentrations of current-use compounds (flame retardants, polycyclic aromatic hydrocarbons (PAHs)) could not be estimated from dust/surface concentrations, demonstrating the influence of ongoing primary emissions and non-equilibrium status in the room.

  8. Studying passive ultrafine particle dispersion in a room with a heat source

    DEFF Research Database (Denmark)

    Ardkapan, Siamak Rahimi; Nielsen, Peter V.; Afshari, Alireza

    2014-01-01

    of passive particles in a room with displacement ventilation system. In addition, some experiments are performed to verify the accuracy of the simulation results. According to the comparison of the experiment and the simulations in front of supply opening, the k–ε model seems to give better results than...... the k–ω model. It is shown that, in order to have an accurate result, the simulation of radiation effect is essential. Furthermore, the results of particle simulations show that when the passive particle source is in the height of 1.5 m and the heater is at the height of 0.5 m, the average concentration...

  9. Application of CR-39 Microfilm for Rapid Discrimination Between Alpha-Particle Sources

    Directory of Open Access Journals (Sweden)

    Nidal Dwaikat

    2017-06-01

    Full Text Available This work presents a new technique for discriminating between alpha particles of different energy levels. In a first study, two groups of alpha particles emitted from radium-226 and americium-241 sources were successfully separated using a CR-39 microfilm of appropriate thickness. This thickness was adjusted by chemical etching before and after irradiation so that lower-energy particles were stopped within the detector, while higher-energy particles were revealed on the back side of the detector. The number of tracks on the front side of the microfilm represented all alpha particles incident on that side from the two sources. However, the number of tracks on the back side of the microfilm represented only the long-range alpha particles of higher energy that arrived at that side. Therefore, by subtracting the number of tracks on the back side from the number of tracks on the front side, one could easily determine the number of tracks for the short-range alpha particles of lower energy that remained embedded in the microfilm. Discrimination of the two energy levels is thus achieved in a simple, fast, and reliable process.

  10. Application of CR-39 microfilm for rapid discrimination between alpha-particle sources

    Energy Technology Data Exchange (ETDEWEB)

    Dwaikat, Nidal; Al-karmi, Anan M. [Dept. of Physics, King Fahd University of Petroleum and Minerals, Dhahran (Saudi Arabia)

    2017-06-15

    This work presents a new technique for discriminating between alpha particles of different energy levels. In a first study, two groups of alpha particles emitted from radium-226 and americium-241 sources were successfully separated using a CR-39 microfilm of appropriate thickness. This thickness was adjusted by chemical etching before and after irradiation so that lower-energy particles were stopped within the detector, while higher-energy particles were revealed on the back side of the detector. The number of tracks on the front side of the microfilm represented all alpha particles incident on that side from the two sources. However, the number of tracks on the back side of the microfilm represented only the long-range alpha particles of higher energy that arrived at that side. Therefore, by subtracting the number of tracks on the back side from the number of tracks on the front side, one could easily determine the number of tracks for the short-range alpha particles of lower energy that remained embedded in the microfilm. Discrimination of the two energy levels is thus achieved in a simple, fast, and reliable process.

  11. Use of Compound-Specific Stable Isotope Analysis to Distinguish between Vapor Intrusion and Indoor Sources of VOC

    Science.gov (United States)

    2013-12-01

    Program GC gas chromatography GSI GSI Environmental GW groundwater HC hydrocarbons IRMS isotope ratio mass spectrometer µg/L micrograms per...per thousand PHC petroleum hydrocarbons pp positive pressure ppbV parts per billion by volume QA quality assurance sq ft square feet TCE...environmental samples can be used to 1) distinguish between different sources of the contaminants, and 2) understand biodegradation and other

  12. The Mineralogy and Possible Sources of Spring Dust Particles over Beijing

    Institute of Scientific and Technical Information of China (English)

    SHAO Longyi; LI Weijun; XIAO Zhenghui; SUN Zhenquan

    2008-01-01

    A severe Asian Dust Storm (ADS) event occurred on 16-17 April 2006 in northern China. The mineral compositions of dust samples were analyzed using X-ray diffraction (XRD). The results indicated that dust particles of the "17 April 2006" dust storm were dominated by quartz (37.4%) and clay (32.9%), followed by plagioclase (13.7%), with small amounts of calcite, K-feldspar, dolomite, hornblende and gypsum (all less than 10%). The clay fractions with diameter less than 2 fim were separated from the dust storm particles by centrifuging and were further analyzed by XRD. The results revealed that the clay species were mainly illite/smectite mixed layers (I/S) (49%) and illite (34%), with small amount of kaolinite (8%) and chlorite (9%). In order to evaluate the feasibility of using the mineralogy to trace the sources of dust particles, the XRD results of the "17 April 2006" dustfall particles were compared with the dust particles over past years. The results confirmed that the finer dust particles represented by the ADS PMio displayed a smaller quartz/clay ratio than the dustfall particles. The dust storm particles, either from the ADS PMio or from the "17 April 2006" dustfall, showed a lower level of dolomite contents and lower dolomite/clay ratios compared with the non-dust storm dustfall particles. This implies that dolomite could be used to distinguish between the dust contributions from local and non-local sources. Similar trends were found for the gypsum and the gypsum/clay ratio. Moreover, the two dustfall samples had a lower level of illite/smectite mixed layers and a higher level of illite than airborne PMio, implying that the dustfall particles tend to be enriched with illite in its clay fraction.

  13. Dependence of {alpha}-particle backscattering on energy and source backing

    Energy Technology Data Exchange (ETDEWEB)

    Timon, A. Fernandez [ESCET, Universidad Rey Juan Carlos, C/ Tulipan s/n, 28933 Mostoles, Madrid (Spain)], E-mail: alfonso.fernandez@urjc.es; Vargas, M. Jurado [Departamento de Fisica, Universidad de Extremadura, Avda. Elvas s/n, 06071 Badajoz (Spain)

    2007-09-21

    Measurement of {alpha}-particle sources using 2{pi} counting detectors requires corrections for backscattering, and these depend on the material used as source backing and on the {alpha}-particle energy. This dependence has been analyzed theoretically by some authors, although assuming some simplifying approximations. In this work, we analyze the dependence of the backscattering coefficient B on energy and source backing, but by means of the Monte Carlo simulation code SRIM, thus avoiding the simplifying approximations assumed in the theoretical models. To study the dependence on the backing, we simulated {sup 210}Po point sources deposited on various backing materials with atomic numbers ranging from 4 to 79. The dependence on energy was studied by simulating {alpha}-particle point sources deposited on a platinum backing, with energies between 3 and 8 MeV. We found that the dependence of the backscattering coefficient B on {alpha}-particle energy and also on the mass number A of the backing approximately follows power function laws, in concordance with the theoretical models, although with exponents somewhat different from those established theoretically. In addition, although it was found that the scattering angle distribution is not Gaussian, our results confirm that there is a linear relationship between the backscattering coefficient B and the mean scattering angle {phi}, as suggested by the Crawford theory.

  14. Quantifying primary and secondary source contributions to ultrafine particles in the UK urban background

    Science.gov (United States)

    Hama, S. M. L.; Cordell, R. L.; Monks, P. S.

    2017-10-01

    Total particle number (TNC, ≥7 nm diameter), particulate matter (PM2.5), equivalent black carbon (eBC) and gaseous pollutants (NO, NO2, NOx, O3, CO) have been measured at an urban background site in Leicester over two years (2014 and 2015). A derived chemical climatology for the pollutants showed maximum concentrations for all pollutants during the cold period except O3 which peaked during spring. Quantification of primary and secondary sources of ultrafine particles (UFPs) was undertaken using eBC as a tracer for the primary particle number concentration in the Leicester urban area. At the urban background site, which is influenced by fresh vehicle exhaust emissions, TNC was segregated into two components, TNC = N1 + N2. The component N1 represents components directly emitted as particles and compounds which nucleate immediately after emission. The component N2 represents the particles formed during the dilution and cooling of vehicle exhaust emissions and by in situ new particle formation (NPF). The values of highest N1 (49%) were recorded during the morning rush hours (07:00-09:00 h), correlating with NOx, while the maximum contribution of N2 to TNC was found at midday (11:00-14:00 h), at around 62%, correlated with O3. Generally, the percentage of N2 (57%) was greater than the percentage of N1 (43%) for all days at the AURN site over the period of the study. For the first time the impact of wind speed and direction on N1 and N2 was explored. The overall data analysis shows that there are two major sources contributing to TNC in Leicester: primary sources (traffic emissions) and secondary sources, with the majority of particles being of secondary origin.

  15. Source attribution of insoluble light-absorbing particles in seasonal snow across northern China

    Directory of Open Access Journals (Sweden)

    R. Zhang

    2013-06-01

    Full Text Available Seasonal snow samples obtained at 46 sites in 6 provinces of China in January and February 2010 were analyzed for a suite of chemical species and these data are combined with previously determined concentrations of insoluble light-absorbing particles (ILAP, including all particles that absorb light in the 650–700 nm wavelength interval. The ILAP, together with 14 other analytes, are used as input to a positive matrix factorization (PMF receptor model to explore the sources of ILAP in the snow. The PMF analysis for ILAP sources is augmented with backward trajectory cluster analysis and the geographic locations of major source areas for the three source types. The two analyses are consistent and indicate that three factors/sources were responsible for the measured light absorption of snow: a soil dust source, an industrial pollution source, and a biomass and / or biofuel burning source. Soil dust was the main source of the ILAP, accounting for ~53% of ILAP on average.

  16. Preparation of modified waterworks sludge particles as adsorbent to enhance coagulation of slightly polluted source water.

    Science.gov (United States)

    Chen, Wei; Gao, Xiaohong; Xu, Hang; Wang, Kang; Chen, Taoyuan

    2017-07-04

    Without treatment, waterworks sludge is ineffective as an adsorbent. In this study, raw waterworks sludge was used as the raw material to prepare modified sludge particles through high-temperature calcination and alkali modification. The feasibility of using a combination of modified particles and polyaluminum chloride (PAC) as a coagulant for treatment of slightly polluted source water was also investigated. The composition, structure, and surface properties of the modified particles were characterized, and their capabilities for removing ammonia nitrogen and turbidity were determined. The results indicate that the optimal preparation conditions for the modified sludge particles were achieved by preparing the particles with a roasting temperature of 483.12 °C, a roasting time of 3.32 h, and a lye concentration of 3.75%. Furthermore, enhanced coagulation is strengthened with the addition of modified sludge particles, which is reflected by reduction of the required PAC dose and enhancement of the removal efficiency of ammonia nitrogen and turbidity by over 80 and 93%, respectively. Additional factors such as pH, temperature, dose, and dosing sequence were also evaluated. The optimum doses of modified particles and PAC were 40 and 15 mg/L, respectively, and adding modified particles at the same time as or prior to adding PAC improves removal efficiency.

  17. Source identification and health risk assessment of metals in indoor dust in the vicinity of phosphorus mining, Guizhou Province, China.

    Science.gov (United States)

    Yang, Qin; Chen, Huaguo; Li, Baizhan

    2015-01-01

    An investigation was performed to identify the sources of arsenic (As) and heavy metals in house dust and to assess the associated human health risks in the vicinity of phosphorus (P) mining in Guizhou, China. The concentrations and spatial distributions of mercury (Hg), As, cadmium (Cd), lead (Pb), iron (Fe), copper (Cu), manganese (Mn), and P in 23 house dust samples from the study area were determined. Greater concentrations of As and Pb were found compared with values in other investigations in various countries. Pollution sources were identified using multivariate statistical analysis. As, Pb, Mn, and Hg pollution was mainly attributed to mining activities, and Mn and Cd levels were largely associated with automobile emissions. The dominant wind direction and the distance of the residence from the mining region were found to play an important role in element distributions. A health risk assessment showed that As and Pb should be paid more attention, although the noncancer risks of the studied elements were within the safe range and the cancer risks of As and Cd are within the acceptable range under present conditions.

  18. Source, Transportation and Removal of Indoor Air Microbes: a Review of Recent Researches%室内空气微生物污染来源、传播和去除方法研究进展

    Institute of Scientific and Technical Information of China (English)

    李艳菊; 祁建城; 张宗兴; 侯丽丽

    2011-01-01

    室内微生物污染对人体健康、室内环境、公共卫生安全等方面产生巨大影响.该文介绍了室内空气微生物的种类、来源,分析了污染现状、微生物传播规律的实验和数值模拟研究的进展,阐述了通风过滤、化学熏蒸、光催化反应、臭氧、溶菌酶、紫外灯等控制微生物污染的方法.基于目前情况,今后需在微生物调查研究、抗菌技术、消毒评价、灭菌设备等方面开展更多研究.%The indoor air microbial pollution has huge impacts on human health,indoor environment and public hygiene safety. This paper presented the species and source of indoor microbes,analyzed the status of indoor microbial pollution and transportation research carried out by experimental and numerical simulation method,expatiated several removal methods on indoor microbes, such as air filtration, chemical fumigant, photocatalytie reaction, ozone,lysozyme, UV lights. In terms of presented condition,more studies,related with microbe investigated research,antibacterial techniques,disinfection evaluation and sterilization equipments, should be conducted on in the future.

  19. Urban background levels of particle number concentration and sources in Vilnius, Lithuania

    Science.gov (United States)

    Byčenkienė, Steigvilė; Plauškaitė, Kristina; Dudoitis, Vadimas; Ulevicius, Vidmantas

    2014-06-01

    This study presents results of research on urban aerosol particles with a focus on the aerosol particle number concentration (PNC) and the particle size distribution. The real time measurements of aerosol PNC (> 4.5 nm) and number size distributions (9-840 nm) were performed. The seasonal variations essentially comprised the minimum monthly mean in October 2010 (3400 ± 3000 cm- 3) and the maximum in April 2011 (19,000 ± 15,000 cm- 3). The mean annual PNC was 10,000 ± 8000 cm- 3 with an average mode size of 30-50 nm. The presence of strong diurnal patterns in aerosol PNC was evident as a direct effect of three sources of aerosol particles (nucleation, traffic, and residential heating). Hybrid receptor modeling potential source contribution function (PSCF) and concentration weighted trajectory (CWT) were used by incorporating 72-h backward trajectories and measurements of PNC in Vilnius. The results of trajectory clustering and the PSCF method demonstrated that possible additional source areas contributing to the elevated particle number concentration in Vilnius could be industrial areas in central Europe. Principal component analysis (PCA) revealed highest loadings for PNC, PM10, NOx, NO, NO2 and SO2 concentrations, indicating combustion processes occurring in vehicle engines and use of sulfur-containing fossil fuels for residential heating.

  20. Impact of the Excitation Source and Plasmonic Material on Cylindrical Active Coated Nano-Particles

    DEFF Research Database (Denmark)

    Arslanagic, Samel; Liu, Yan; Malureanu, Radu

    2011-01-01

    , as well as to their far-field radiation characteristics, in the presence of an electric or a magnetic line source. A constant frequency canonical gain model is used to account for the gain introduced in the dielectric part of the nano-particle, whereas three different plasmonic materials (silver, gold...

  1. Cylindrical active coated nano-particles excited by electric and magnetic line sources

    DEFF Research Database (Denmark)

    Arslanagic, Samel; Liu, Y.; Malureanu, Radu

    2011-01-01

    Cylindrical active coated nano-particles comprised of a silica nano-cylinder core covered with a plasmonic nano-shell are investigated with regard to their near- and far-field properties. The source of excitation is taken to be an electric or a magnetic line current, while three different plasmonic...

  2. Cylindrical active coated nano-particles excited by electric and magnetic line sources

    DEFF Research Database (Denmark)

    Arslanagic, Samel; Liu, Y.; Malureanu, Radu

    2011-01-01

    Cylindrical active coated nano-particles comprised of a silica nano-cylinder core covered with a plasmonic nano-shell are investigated with regard to their near- and far-field properties. The source of excitation is taken to be an electric or a magnetic line current, while three different plasmonic...

  3. Selection of particle characteristics to distinguish amongst potential sources of particulate matter in poultry and pigs.

    NARCIS (Netherlands)

    Cambra-Lopez, M.; Hermosilla, T.; Aarnink, A.J.A.; Ogink, N.

    2011-01-01

    The knowledge on the contribution of individual sources to particulate matter (PM) in different size fractions is essential to improve PM reduction from livestock houses. We investigated which input data (particle chemical, morphological or combined characteristics) were best to distinguish amongst

  4. Application of atomic and nuclear techniques to the study of inhomogeneities in electrodeposited {alpha}-particle sources

    Energy Technology Data Exchange (ETDEWEB)

    Martin Sanchez, A. E-mail: ams@unex.es; Nuevo, M.J.; Jurado Vargas, M.; Diaz Bejarano, J.; Silva, M.F. da; Roldan Garcia, C.; Paul, A.; Ferrero Calabuig, J.L.; Mendez Vilas, A.; Juanes Barber, D

    2002-05-01

    Three {alpha}-particle sources made by different methods of electrodeposition were analysed using {alpha}-particle spectrometry, Rutherford backscattering (RBS), and atomic force microscopy (AFM) on several surface zones. The thickness and homogeneity of these sources was studied using RBS, and the results were analysed jointly with those obtained with {alpha}-particle spectrometry and AFM techniques. The comparison of the electrodeposition methods showed that the most homogeneous electrodeposited zones corresponded to the source made with a stirring cathode.

  5. Characterization of Source Signatures of Fine Roadway Particles by Pyrolysis-GC-MS

    Science.gov (United States)

    van Bergen, S. K.; Holmén, B. A.

    2001-12-01

    Fine particulate matter, defined as particles with an aerodynamic diameter less than 2.5 μ m (PM2.5), is of growing concern due to its detrimental effects on human health and the environment. Roadway traffic generates a significant fraction of PM2.5 in urban areas. Since exposure to fine particles derived from mobile sources commonly occurs, understanding the physicochemical processes that contribute to the generation, transport and atmospheric reactivity of roadway PM is important. Factors that influence the properties of roadway PM include: the mass, number and size distribution of the particles as well as their chemical composition. These factors are partially determined by the sources of the roadway particles. The focus of this effort is to identify unique organic chemical profiles of known roadway sources of PM using a new rapid characterization technique. A pyrolysis GC-MS analytical method is being developed to uniquely characterize the sources of roadway PM2.5 such as brake dust, tire wear, and direct emissions from diesel and gasoline engines. The source profiles will be used in conjunction with measurements of the composition of ambient roadway PM to determine the importance of the various roadway sources. The advantages of this technique over conventional solvent extractions include: smaller (mg) sample mass requirements, short extraction times and minimal sample handing. Preliminary two-step pyrolysis results will be presented for PM samples from individual sources and an ambient roadway. Specific analytical issues that will be discussed include: modifications of commercial pyrolysis hardware to improve reproducibility; desorption versus pyrolysis; developing appropriate pyrolysis programs for heterogenous sample materials; and method detection limits.

  6. Sources and mixing state of size-resolved elemental carbon particles in a European megacity: Paris

    Directory of Open Access Journals (Sweden)

    R. M. Healy

    2012-02-01

    Full Text Available An Aerosol Time-Of-Flight Mass Spectrometer (ATOFMS was deployed to investigate the size-resolved chemical composition of single particles at an urban background site in Paris, France, as part of the MEGAPOLI winter campaign in January/February 2010. ATOFMS particle counts were scaled to match coincident Twin Differential Mobility Particle Sizer (TDMPS data in order to generate hourly size-resolved mass concentrations for the single particle classes observed. The total scaled ATOFMS particle mass concentration in the size range 150–1067 nm was found to agree very well with the sum of concurrent High-Resolution Time-of-Flight Aerosol Mass Spectrometer (HR-ToF-AMS and Multi-Angle Absorption Photometer (MAAP mass concentration measurements of organic carbon (OC, inorganic ions and black carbon (BC (R2 = 0.91. Clustering analysis of the ATOFMS single particle mass spectra allowed the separation of elemental carbon (EC particles into four classes: (i EC attributed to biomass burning (ECbiomass, (ii EC attributed to traffic (ECtraffic, (iii EC internally mixed with OC and ammonium sulfate (ECOCSOx, and (iv EC internally mixed with OC and ammonium nitrate (ECOCNOx. Average hourly mass concentrations for EC-containing particles detected by the ATOFMS were found to agree reasonably well with semi-continuous quantitative thermal/optical EC and optical BC measurements (r2 = 0.61 and 0.65–0.68 respectively, n = 552. The EC particle mass assigned to fossil fuel and biomass burning sources also agreed reasonably well with BC mass fractions assigned to the same sources using seven-wavelength aethalometer data (r2 = 0.60 and 0.48, respectively, n = 568. Agreement between the ATOFMS and other instrumentation improved noticeably when a period influenced by significantly aged, internally mixed EC particles was removed from the intercomparison. 88% and 12% of EC particle

  7. Sources and mixing state of size-resolved elemental carbon particles in a European megacity: Paris

    Science.gov (United States)

    Healy, R. M.; Sciare, J.; Poulain, L.; Kamili, K.; Merkel, M.; Müller, T.; Wiedensohler, A.; Eckhardt, S.; Stohl, A.; Sarda-Estève, R.; McGillicuddy, E.; O'Connor, I. P.; Sodeau, J. R.; Wenger, J. C.

    2012-02-01

    An Aerosol Time-Of-Flight Mass Spectrometer (ATOFMS) was deployed to investigate the size-resolved chemical composition of single particles at an urban background site in Paris, France, as part of the MEGAPOLI winter campaign in January/February 2010. ATOFMS particle counts were scaled to match coincident Twin Differential Mobility Particle Sizer (TDMPS) data in order to generate hourly size-resolved mass concentrations for the single particle classes observed. The total scaled ATOFMS particle mass concentration in the size range 150-1067 nm was found to agree very well with the sum of concurrent High-Resolution Time-of-Flight Aerosol Mass Spectrometer (HR-ToF-AMS) and Multi-Angle Absorption Photometer (MAAP) mass concentration measurements of organic carbon (OC), inorganic ions and black carbon (BC) (R2 = 0.91). Clustering analysis of the ATOFMS single particle mass spectra allowed the separation of elemental carbon (EC) particles into four classes: (i) EC attributed to biomass burning (ECbiomass), (ii) EC attributed to traffic (ECtraffic), (iii) EC internally mixed with OC and ammonium sulfate (ECOCSOx), and (iv) EC internally mixed with OC and ammonium nitrate (ECOCNOx). Average hourly mass concentrations for EC-containing particles detected by the ATOFMS were found to agree reasonably well with semi-continuous quantitative thermal/optical EC and optical BC measurements (r2 = 0.61 and 0.65-0.68 respectively, n = 552). The EC particle mass assigned to fossil fuel and biomass burning sources also agreed reasonably well with BC mass fractions assigned to the same sources using seven-wavelength aethalometer data (r2 = 0.60 and 0.48, respectively, n = 568). Agreement between the ATOFMS and other instrumentation improved noticeably when a period influenced by significantly aged, internally mixed EC particles was removed from the intercomparison. 88% and 12% of EC particle mass was apportioned to fossil fuel and biomass burning respectively using the ATOFMS data

  8. Sources and mixing state of size-resolved elemental carbon particles in a European megacity: Paris

    Directory of Open Access Journals (Sweden)

    R. M. Healy

    2011-11-01

    Full Text Available An Aerosol Time-Of-Flight Mass Spectrometer (ATOFMS was deployed to investigate the size-resolved chemical composition of single particles at an urban background site in Paris, France, as part of the MEGAPOLI winter campaign in January/February 2010. ATOFMS particle counts were scaled to match coincident Twin Differential Mobility Particle Sizer (TDMPS data in order to generate hourly size-resolved mass concentrations for the single particle classes observed. The total scaled ATOFMS particle mass concentration in the size range 150–1067 nm was found to agree very well with the sum of concurrent High-Resolution Time-of-Flight Aerosol Mass Spectrometer (HR-ToF-AMS and Multi-Angle Absorption Photometer (MAAP mass concentration measurements of organic carbon (OC, inorganic ions and black carbon (BC (R2 = 0.91. Clustering analysis of the ATOFMS single particle mass spectra allowed the separation of elemental carbon (EC particles into four classes: (i EC attributed to biomass burning (ECbiomass, (ii EC attributed to traffic (ECtraffic, (iii EC internally mixed with OC and ammonium sulfate (ECOCSOx, and (iv EC internally mixed with OC and ammonium nitrate (ECOCNOx. Average hourly mass concentrations for EC-containing particles detected by the ATOFMS were found to agree reasonably well with semi-continuous quantitative thermal/optical EC and optical BC measurements (r2 = 0.61 and 0.65–0.68, respectively, n = 552. The EC particle mass assigned to fossil fuel and biomass burning sources also agreed reasonably well with BC mass fractions assigned to the same sources using seven-wavelength aethalometer data (r2 = 0.60 and 0.48, respectively, n = 568. Agreement between the ATOFMS and other instrumentation improved noticeably when a period influenced by significantly aged, internally mixed EC particles was removed from the intercomparison. 88 % and 12 % of EC

  9. DualSPHysics: Open-source parallel CFD solver based on Smoothed Particle Hydrodynamics (SPH)

    Science.gov (United States)

    Crespo, A. J. C.; Domínguez, J. M.; Rogers, B. D.; Gómez-Gesteira, M.; Longshaw, S.; Canelas, R.; Vacondio, R.; Barreiro, A.; García-Feal, O.

    2015-02-01

    DualSPHysics is a hardware accelerated Smoothed Particle Hydrodynamics code developed to solve free-surface flow problems. DualSPHysics is an open-source code developed and released under the terms of GNU General Public License (GPLv3). Along with the source code, a complete documentation that makes easy the compilation and execution of the source files is also distributed. The code has been shown to be efficient and reliable. The parallel power computing of Graphics Computing Units (GPUs) is used to accelerate DualSPHysics by up to two orders of magnitude compared to the performance of the serial version.

  10. Magnetism of outdoor and indoor settled dust and its utilization as a tool for revealing the effect of elevated particulate air pollution on cardiovascular mortality

    Science.gov (United States)

    Jordanova, Diana; Jordanova, Neli; Lanos, Philippe; Petrov, Petar; Tsacheva, Tsenka

    2012-08-01

    Settled indoor and outdoor dusts in urban environment represent an important source of secondary pollution. Magnetic characteristics of the settled dust from six cities in Bulgaria are explored, allowing comparison on a national (country) scale. Monthly variations of the mass-specific magnetic susceptibilities (χindoor) and (χoutdoor) and calculated dust loading rates for a period of 17 months do not show seasonal variability, probably due to the dominant role of traffic-related emissions and soil-derived particles in the settled dust. The main magnetic mineral is magnetite, present as spherules and irregular particles of pseudo-single-domain grain sizes. Systematically lower remanence coercivities are obtained for outdoor dusts when compared with the corresponding indoor samples, implying that penetration of smaller particles of ambient origin indoors is the main source of the indoor dust. Mean yearly values of the ratio (χindoor/χoutdoor) for each city show statistically significant correlation with mortality due to cardiovascular diseases. This ratio reveals the source- and site-specific importance of the anthropogenically derived toxicogenic fraction. Heavy metal content of the settled dust is related to the contribution from several pollution sources (soil-derived, combustion and industrial), discriminated through analysis of principal components. SEM/EDX analyses reveal abundant presence of anthopogenic Fe-containing spherules, irregular particles and diesel exhaust conglomerates. High molecular weight polyaromatic hydrocarbons (PAH) dominate the total PAH content of the outdoor dust samples. The observed linear correlation between total PAH content, coercivity of remanence and the ratio Mrs/χ suggest either adsorption of PAHs on iron oxide particles and especially magnetite, or emission related increase in total PAH concentration along with a decrease of effective magnetic grain size of the accompanying magnetic fraction.

  11. Forces between a partially coherent fluctuating source and a magnetodielectric particle

    CERN Document Server

    Auñon, Juan Miguel

    2013-01-01

    We address the forces exerted by the electromagnetic ?eld emitted by a planar uctuating source on dielectric particles that have arose much interest because of their recently shown magnetodielectric behavior. In this context, we analyze as a particular case the modi?cation of the Casimir and Van der Waals forces. We study the e?ect of the source coherence length as well as the interplay between the force from the radiated ?eld and that from the electric and magnetic dipoles induced on the particle. This allows a control of these interactions as well as of the weight and interference e?ects between the ?elds from both kinds of induced dipoles, in particular when large changes in their di?erential scattering cross section occur due to Kerker minimum forward or zero backward conditions; thus opening new paths to nanoparticle ensembling and manipulation. The influence of surface waves of the source is also studied.

  12. Improvement Schemes for Indoor Mobile Location Estimation: A Survey

    Directory of Open Access Journals (Sweden)

    Jianga Shang

    2015-01-01

    Full Text Available Location estimation is significant in mobile and ubiquitous computing systems. The complexity and smaller scale of the indoor environment impose a great impact on location estimation. The key of location estimation lies in the representation and fusion of uncertain information from multiple sources. The improvement of location estimation is a complicated and comprehensive issue. A lot of research has been done to address this issue. However, existing research typically focuses on certain aspects of the problem and specific methods. This paper reviews mainstream schemes on improving indoor location estimation from multiple levels and perspectives by combining existing works and our own working experiences. Initially, we analyze the error sources of common indoor localization techniques and provide a multilayered conceptual framework of improvement schemes for location estimation. This is followed by a discussion of probabilistic methods for location estimation, including Bayes filters, Kalman filters, extended Kalman filters, sigma-point Kalman filters, particle filters, and hidden Markov models. Then, we investigate the hybrid localization methods, including multimodal fingerprinting, triangulation fusing multiple measurements, combination of wireless positioning with pedestrian dead reckoning (PDR, and cooperative localization. Next, we focus on the location determination approaches that fuse spatial contexts, namely, map matching, landmark fusion, and spatial model-aided methods. Finally, we present the directions for future research.

  13. Providing better indoor environmental quality brings economicbenefits

    Energy Technology Data Exchange (ETDEWEB)

    Fisk, William; Seppanen, Olli

    2007-06-01

    This paper summarizes the current scientific evidence that improved indoor environmental quality can improve work performance and health. The review indicates that work and school work performance is affected by indoor temperature and ventilation rate. Pollutant source removal can sometimes improve work performance. Based on formal statistical analyses of existing research results, quantitative relationships are provided for the linkages of work performance with indoor temperature and outdoor air ventilation rate. The review also indicates that improved health and related financial savings are obtainable from reduced indoor tobacco smoking, prevention and remediation of building dampness, and increased ventilation. Example cost-benefit analyses indicate that many measures to improve indoor temperature control and increase ventilation rates will be highly cost effective, with benefit-cost ratios as high as 80 and annual economic benefits as high as $700 per person.

  14. Variability of total exposure to PM{sub 2.5} related to indoor and outdoor pollution sources

    Energy Technology Data Exchange (ETDEWEB)

    Jedrychowski, Wieslaw A.; Pac, Agnieszka; Jacek, Ryszard; Sochacka-Tatara, Elzbieta [Chair of Epidemiology and Preventive Medicine, Medical College, Jagiellonian University, 7A, Kopernika St., 31-034 Krakow (Poland); Perera, Frederica P.; Whyatt, Robin M. [Columbia Center for Children' s Environmental Health, Mailman School of Public Health, Columbia University, New York (United States); Spengler, John D.; Dumyahn, Thomas S. [Harvard School of Public Health, Harvard University, Boston, MA (United States)

    2006-07-31

    The study is a part of an ongoing prospective cohort study on the relationship between the exposure to environmental factors during pregnancy and birth outcomes and health of newborns. We have measured personal PM{sub 2.5} level in the group of 407 non-smoking pregnant women during the 2nd trimester of pregnancy. On average, the participants from the city center were exposed to higher exposure than those from the outer city area (GM=42.0 {mu}g/m{sup 3}, 95% CI: 36.8-48.0 vs. 35.8 {mu}g/m{sup 3}, 95% CI: 33.5-38.2 {mu}g/m{sup 3}). More than 20% of study subjects were affected by high level of PM{sub 2.5} pollution (above 65 {mu}g/m{sup 3}). PM{sub 2.5} concentrations were higher during the heating season (GM=43.4 {mu}g/m{sup 3}, 95% CI: 40.1-46.9 {mu}g/m{sup 3}) compared to non-heating season (GM=29.8 {mu}g/m{sup 3}, 95% CI: 27.5-32.2 {mu}g/m{sup 3}). Out of all potential outdoor air pollution sources (high traffic density, bus depot, waste incinerator, industry etc.) considered in the bivariate analysis, only the proximity of industrial plant showed significant impact on the personal exposure (GM=54.3 {mu}g/m{sup 3}, 95% CI: 39.4-74.8 {mu}g/m{sup 3}) compared with corresponding figure for those who did not declare living near the industrial premises (GM=36.2 {mu}g/m{sup 3}, 95% CI: 34.1-38.4 {mu}g/m{sup 3}). The subjects declaring high exposure to ETS (>10 cigarettes daily) have shown very high level of personal exposure (GM=88.8 {mu}g/m{sup 3}, 95% CI: 73.9-106.7 {mu}g/m{sup 3}) compared with lower ETS exposure ({<=}10 cigarettes) (GM=46.3 {mu}g/m{sup 3}, 95% CI: 40.0-53.5 {mu}g/m{sup 3}) and no-ETS exposure group (GM=33.9 {mu}g/m{sup 3}, 95% CI: 31.8-36.1 {mu}g/m{sup 3}). The contribution of the background ambient PM{sub 10} level was very strong determinant of the total personal exposure to PM{sub 2.5} and it explained about 31% of variance between the subjects followed by environmental tobacco smoke (10%), home heating by coal/wood stoves (2%), other types of

  15. Constraining sources of ultrahigh energy cosmic rays and shear acceleration mechanism of particles in relativistic jets

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Ruoyu

    2015-06-10

    Ultrahigh energy cosmic rays are extreme energetic particles from outer space. They have aroused great interest among scientists for more than fifty years. However, due to the rarity of the events and complexity of the process of their propagation to Earth, they are still one of the biggest puzzles in modern high energy astrophysics. This dissertation is dedicated to study the origin of ultrahigh energy cosmic rays from various aspects. Firstly, we discuss a possible link between recently discovered sub-PeV/PeV neutrinos and ultrahigh energy cosmic rays. If these two kinds of particles share the same origin, the observation of neutrinos may provide additional and non-trivial constraints on the sources of ultrahigh energy cosmic rays. Secondly, we jointly employ the chemical composition measurement and the arrival directions of ultrahigh energy cosmic rays, and find a robust upper limit for distances of sources of ultrahigh energy cosmic rays above ∝55 EeV, as well as a lower limit for their metallicities. Finally, we study the shear acceleration mechanism in relativistic jets, which is a more efficient mechanism for the acceleration of higher energy particle. We compute the acceleration efficiency and the time-dependent particle energy spectrum, and explore the feature of synchrotron radiation of the accelerated particles. The possible realizations of this mechanism for acceleration of ultrahigh energy cosmic rays in different astrophysical environments is also discussed.

  16. Chemical characteristics and source of size-fractionated atmospheric particle in haze episode in Beijing

    Science.gov (United States)

    Tan, Jihua; Duan, Jingchun; Zhen, Naijia; He, Kebin; Hao, Jiming

    2016-01-01

    The abundance, behavior, and source of chemical species in size-fractionated atmospheric particle were studied with a 13-stage low pressure impactor (ELPI) during high polluted winter episode in Beijing. Thirty three elements (Al, Ca, Fe, K, Mg, Na, Si, Sc, Ti, V, Cr, Mn, Co, Ni, Cu, Zn, Ga, Ge, As, Se, Sr, Zr, Mo, Ag, Cd, In, Sn, Sb, Cs, Ba, Hg, Tl, and Pb) and eight water soluble ions (Cl-, NO3-, SO42 -, NH4+, Na+, K+, Ca2 +, and Mg2 +) were determined by ICP/MS and IC, respectively. The size distribution of TC (OC + EC) was reconstructed. Averagely, 51.5 ± 5.3% and 74.1 ± 3.7% of the total aerosol mass was distributed in the sub-micron (PM1) and fine particle (PM2.5), respectively. A significant shift to larger fractions during heavy pollution episode was observed for aerosol mass, NH4+, SO42 -, NO3-, K, Fe, Cu, Zn, Cd, and Pb. The mass size distributions of NH4+, SO42 -, NO3-, and K were dominated by accumulation mode. Size distributions of elements were classified into four main types: (I) elements were enriched within the accumulation mode (water soluble ions. Dust, vehicle, aged coal combustion, and sea salt were identified, and the size resolved source apportionments were discussed. Aged coal combustion was the important source of fine particles and dust contributed most to coarse particle.

  17. Chemical composition and sources of particle pollution in affluent and poor neighborhoods of Accra, Ghana

    Science.gov (United States)

    Zhou, Zheng; Dionisio, Kathie L.; Verissimo, Thiago G.; Kerr, Americo S.; Coull, Brent; Arku, Raphael E.; Koutrakis, Petros; Spengler, John D.; Hughes, Allison F.; Vallarino, Jose; Agyei-Mensah, Samuel; Ezzati, Majid

    2013-12-01

    The highest levels of air pollution in the world now occur in developing country cities, where air pollution sources differ from high-income countries. We analyzed particulate matter (PM) chemical composition and estimated the contributions of various sources to particle pollution in poor and affluent neighborhoods of Accra, Ghana. Elements from earth’s crust were most abundant during the seasonal Harmattan period between late December and late January when Saharan dust is carried to coastal West Africa. During Harmattan, crustal particles accounted for 55 μg m-3 (37%) of fine particle (PM2.5) mass and 128 μg m-3 (42%) of PM10 mass. Outside Harmattan, biomass combustion, which was associated with higher black carbon, potassium, and sulfur, accounted for between 10.6 and 21.3 μg m-3 of fine particle mass in different neighborhoods, with its contribution largest in the poorest neighborhood. Other sources were sea salt, vehicle emissions, tire and brake wear, road dust, and solid waste burning. Reducing air pollution in African cities requires policies related to energy, transportation and urban planning, and forestry and agriculture, with explicit attention to impacts of each strategy in poor communities. Such cross-sectoral integration requires emphasis on urban environment and urban poverty in the post-2015 Development Agenda.

  18. New scheme of the Discrete Sources Method for light scattering analysis of a particle breaking interface

    Science.gov (United States)

    Eremin, Yuri; Wriedt, Thomas

    2014-12-01

    The Discrete Sources Method (DSM) has been modified to analyze polarized light scattering by an axial symmetric penetrable nanoparticle partially embedded into a substrate. The new numerical scheme of the DSM enables to consider scattering from such substrate defects as flat particles, mounds, pits and voids. A detailed description of the numerical scheme is provided. The developed computer model has been employed to investigate scattering from a shallow particle and pit. Simulation results corresponding to the Differential Scattering Cross-Section and the integral response for P/S polarized light are presented.

  19. Lung Cancer in Chinese Women: Evidence for an Interaction between Tobacco Smoking and Exposure to Inhalants in the Indoor Environment

    OpenAIRE

    TANG, Li; Lim, Wei-Yen; Eng, Philip; Leong, Swan Swan; Lim, Tow Keang; Ng, Alan W. K.; Tee, Augustine; Seow, Adeline

    2010-01-01

    Background Epidemiologic data suggest that Chinese women have a high incidence of lung cancer in relation to their smoking prevalence. In addition to active tobacco smoke exposure, other sources of fumes and airborne particles in the indoor environment, such as cooking and burning of incense and mosquito coils, have been considered potential risk factors for lung cancer. Objectives We used a case–control study to explore effects of inhalants from combustion sources common in the domestic envi...

  20. Spatial variability of fine and coarse particle composition and sources in Cyprus

    Science.gov (United States)

    Achilleos, Souzana; Wolfson, Jack M.; Ferguson, Stephen T.; Kang, Choong-Min; Hadjimitsis, Diofantos G.; Hadjicharalambous, Marios; Achilleos, Constantia; Christodoulou, Andri; Nisanzti, Argyro; Papoutsa, Christiana; Themistocleous, Kyriacos; Athanasatos, Spyros; Perdikou, Skevi; Koutrakis, Petros

    2016-03-01

    Southern and Eastern European countries exceed WHO and EU air quality standards very often, and are influenced by both local and external sources from Europe, Asia and Africa. However, there are limited data on particle composition and source profiles. We collected PM2.5 and PM10 samples (particulate matter with aerodynamic diameter less than 2.5 and 10 μm, respectively) in four cities in Cyprus using Harvard Impactors. Measurements were conducted between January 2012 and January 2013. We analyzed these samples for mass concentration and chemical composition, and conducted a source apportionment analysis using Positive Matrix Factorization (PMF). All sites complied with PM2.5 and PM10 WHO daily standards for most of the days. As in other Eastern European countries, we found higher sulfate contribution and less organic carbon than in the Western and central Europe. For PM2.5, seven source types were identified including regional sulfur, traffic emissions, biomass, re-suspended soil, oil combustion, road dust, and sea salt. In all four sites, regional sulfur was the predominant source (> 30%). High inter-site correlations were observed for both PM2.5 component concentrations and source contributions, may be because a large fraction of PM2.5 is transported. Finally, for PM10 -2.5 (coarse particles with aerodynamic diameter between 2.5 and 10 μm) three sources were identified, which include road dust, soil, and sea salt. Significant inter-site correlations were also observed for coarse particles. All dust storm samples, except one, had PM levels below the daily standard. However, mineral dust, defined as the total mass of crustal metal oxides, increased up to ten times during the dust events.

  1. Effect of Calcium Sources and Particle Size on Performance and Eggshell Quality in Laying Hens

    Directory of Open Access Journals (Sweden)

    Arzu Erol Tunç

    2015-01-01

    Full Text Available An experiment was conducted to determine the effect of different combination calcium sources and particle size on performance and egg shell quality in layer hens. In the experiment, 198 brown laying hens at 44 week of age were randomly assigned into 11 treatments groups. The experimental diets consisted of different calcium sources (Fine limestone, large limestone, large oyster shell and large egg shell and their different combination. The experimental unit consisted of a groups of three hens, thus each treatment was replicated six times. Different calcium sources and particle size addition to the laying hens diet had no significantly effect on body weight gain, egg production, egg mass, feed intake, feed conversion ratio, egg specific gravity, egg shell weight, egg shell thickness and egg shell breaking strength but egg weight had significantly affected by the treatments. The significantly highest egg weight was found in laying hens fed with 50 % fine limestone and 50 % large limestone. Dietary different Ca sources had a significant effect on Ca, P and Mg as mineral contents of eggshell and tibia. In the present study, when dietary large calcium sources (limestone, oyster shell and egg shell had no effect on performance and eggshell quality parameters in laying hens. However, dietary containing at least 50 % large calcium sources had positive effect on mineral contents of tibia.

  2. Health benefits of particle filtration.

    Science.gov (United States)

    Fisk, W J

    2013-10-01

    The evidence of health benefits of particle filtration in homes and commercial buildings is reviewed. Prior reviews of papers published before 2000 are summarized. The results of 16 more recent intervention studies are compiled and analyzed. Also, reviewed are four studies that modeled health benefits of using filtration to reduce indoor exposures to particles from outdoors. Prior reviews generally concluded that particle filtration is, at best, a source of small improvements in allergy and asthma health effects; however, many early studies had weak designs. A majority of recent intervention studies employed strong designs and more of these studies report statistically significant improvements in health symptoms or objective health outcomes, particularly for subjects with allergies or asthma. The percentage improvement in health outcomes is typically modest, for example, 7% to 25%. Delivery of filtered air to the breathing zone of sleeping allergic or asthmatic persons may be more consistently effective in improving health than room air filtration. Notable are two studies that report statistically significant improvements, with filtration, in markers that predict future adverse coronary events. From modeling, the largest potential benefits of indoor particle filtration may be reductions in morbidity and mortality from reducing indoor exposures to particles from outdoor air.

  3. Health Benefits of Particle Filtration

    Energy Technology Data Exchange (ETDEWEB)

    Fisk, William J.

    2013-10-01

    The evidence of health benefits of particle filtration in homes and commercial buildings is reviewed. Prior reviews of papers published before 2000 are summarized. The results of 16 more recent intervention studies are compiled and analyzed. Also reviewed are four studies that modeled health benefits of using filtration to reduce indoor exposures to particles from outdoors. Prior reviews generally concluded that particle filtration is, at best, a source of small improvements in allergy and asthma health effects; however, many early studies had weak designs. A majority of recent intervention studies employed strong designs and more of these studies report statistically significant improvements in health symptoms or objective health outcomes, particularly for subjects with allergies or asthma. The percentage improvement in health outcomes is typically modest, e.g., 7percent to 25percent. Delivery of filtered air to the breathing zone of sleeping allergic or asthmatic persons may be more consistently effective in improving health than room air filtration. Notable are two studies that report statistically significant improvements, with filtration, in markers that predict future adverse coronary events. From modeling, the largest potential benefits of indoor particle filtration may be reductions in morbidity and mortality from reducing indoor exposures to particles from outdoor air.

  4. Health Benefits of Particle Filtration

    Energy Technology Data Exchange (ETDEWEB)

    Fisk, William J.

    2013-10-01

    The evidence of health benefits of particle filtration in homes and commercial buildings is reviewed. Prior reviews of papers published before 2000 are summarized. The results of 16 more recent intervention studies are compiled and analyzed. Also, reviewed are four studies that modeled health benefits of using filtration to reduce indoor exposures to particles from outdoors. Prior reviews generally concluded that particle filtration is, at best, a source of small improvements in allergy and asthma health effects; however, many early studies had weak designs. A majority of recent intervention studies employed strong designs and more of these studies report statistically significant improvements in health symptoms or objective health outcomes, particularly for subjects with allergies or asthma. The percent age improvement in health outcomes is typically modest, for example, 7percent to 25percent. Delivery of filtered air to the breathing zone of sleeping allergic or asthmatic persons may be more consistently effective in improving health than room air filtration. Notable are two studies that report statistically significant improvements, with filtration, in markers that predict future adverse coronary events. From modeling, the largest potential benefits of indoor particle filtration may be reductions in morbidity and mortality from reducing indoor exposures to particles from outdoor air.

  5. Electron beam ion sources for use in second generation synchrotrons for medical particle therapy

    Science.gov (United States)

    Zschornack, G.; Ritter, E.; Schmidt, M.; Schwan, A.

    2014-02-01

    Cyclotrons and first generation synchrotrons are the commonly applied accelerators in medical particle therapy nowadays. Next generation accelerators such as Rapid Cycling Medical Synchrotrons (RCMS), direct drive accelerators, or dielectric wall accelerators have the potential to improve the existing accelerator techniques in this field. Innovative accelerator concepts for medical particle therapy can benefit from ion sources which meet their special requirements. In the present paper we report on measurements with a superconducting Electron Beam Ion Source, the Dresden EBIS-SC, under the aspect of application in combination with RCMS as a well proven technology. The measurements indicate that this ion source can offer significant advantages for medical particle therapy. We show that a superconducting EBIS can deliver ion pulses of medically relevant ions such as protons, C4 + and C6 + ions with intensities and frequencies required for RCMS [S. Peggs and T. Satogata, "A survey of Hadron therapy accelerator technology," in Proceedings of PAC07, BNL-79826- 2008-CP, Albuquerque, New Mexico, USA, 2007; A. Garonna, U. Amaldi et al., "Cyclinac medical accelerators using pulsed C6 +/H+_2 ion sources," in Proceedings of EBIST 2010, Stockholm, Sweden, July 2010]. Ion extraction spectra as well as individual ion pulses have been measured. For example, we report on the generation of proton pulses with up to 3 × 109 protons per pulse and with frequencies of up to 1000 Hz at electron beam currents of 600 mA.

  6. The feasibility of [sup 225]Ac as a source of [alpha]-particles in radioimmunotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Geerlings, M.W.; Hout, R. van der (Akzo nv, Arnhem (Netherlands)); Kaspersen, F.M. (Organon International bv, Oss (Netherlands)); Apostolides, C. (Commission of the European Communities, Karlsruhe (Germany). European Inst. for Transuranium Elements)

    1993-02-01

    This paper proposes the utilization of [sup 225]Ac for the [alpha]-radioimmunotherapy of cancer. The isotope decays with a radioactive half-life of 10 days into a cascade of short-lived [alpha]-and [beta]-emitting isotopes. In addition, when indicated by the pharmacokinetic requirements of particular clinical applications, [sup 213]Bi, with a radioactive half-life of 47 min, can be chosen as an alternative source of [alpha]-particles in radioimmunotherapy. This isotope is the last [alpha] emitter in the [sup 225]Ac decay-cascade and can be extracted from a [sup 225]Ac source at the bedside of the patient. [sup 225]Ac can quasi ad infinitum be obtained from one of its precursors, [sup 229]Th, which can be made available by various means. The indications for the use of [alpha]-particles as an alternative to more traditional classes of radiation are derived from the particle-kinetic characteristics and the radioactive half-life of their source isotope, as well as from the properties of the target-selective carrier moiety for the source isotope. It may be expected that useful applications, complementary to and/or in conjunction with other means of therapy will be identified. (author).

  7. 吸入室内可吸入颗粒物净化器的研究进展%Research Progress of Indoor Inhalable Particle Purifiers

    Institute of Scientific and Technical Information of China (English)

    林灵杰; 金卫冕; 何佳琳; 胡炜

    2015-01-01

    阐述了可吸入颗粒物的基本特征、来源以及对人体的危害.介绍了过滤式、静电式和水介质式三类可吸入颗粒物净化技术的原理和特点 ,对比了三类净化技术的优缺点.对现有空气净化器进行了市场调查 ,分析了空气净化器的价格分布以及各品牌的市场定位.结合可吸入颗粒物的净化技术和当前空气净化器市场状况 ,总结了空气净化技术和空气净化器的发展趋势.%The article summarizes the characteristics ,sources and harmful effects on person of inhalable particles. Then ,the article introduces the theories and features of three purification technologies of inhalable particle ,including filtration technology ,electrostatic technology and aqueous medium technology.Through the comparison of the merit and demerit of the three purification technologies as well as the market research of the existing air purifiers , the article analyzes the price distribution of air purifier and the market orientations of different brands.Based on the current of purification technologies and air purifier's market , the article concludes the development tendency of purification technologies and air purifier.

  8. Indoor air quality

    DEFF Research Database (Denmark)

    Jensen, Trine Susanne; Recevska, Ieva

     The objective of the 35th specific agreement is to provide support to the EEA activities in Environment and Health (E&H) on the topic of indoor air quality. The specific objectives have been to provide an overview of indoor air related projects in EU and indoor air related policies as well...... as idenfiying "good practices" to reduce health impact of indoor air exposure and suggest areas for future improvements....

  9. Indoor air quality

    DEFF Research Database (Denmark)

    Jensen, Trine Susanne; Recevska, Ieva

     The objective of the 35th specific agreement is to provide support to the EEA activities in Environment and Health (E&H) on the topic of indoor air quality. The specific objectives have been to provide an overview of indoor air related projects in EU and indoor air related policies as well...... as idenfiying "good practices" to reduce health impact of indoor air exposure and suggest areas for future improvements....

  10. Development of the MICROMEGAS Detector for Measuring the Energy Spectrum of Alpha Particles by using a 241-Am Source

    CERN Document Server

    Kim, Do Yoon; Shin, Jae Won; Park, Tae-Sun; Hong, Seung-Woo; Andriamonje, Samuel; Kadi, Yacine; Tenreiro, Claudio

    2016-01-01

    We have developed MICROMEGAS (MICRO MEsh GASeous) detectors for detecting {\\alpha} particles emitted from an 241-Am standard source. The voltage applied to the ionization region of the detector is optimized for stable operation at room temperature and atmospheric pressure. The energy of {\\alpha} particles from the 241-Am source can be varied by changing the flight path of the {\\alpha} particle from the 241 Am source. The channel numbers of the experimentally-measured pulse peak positions for different energies of the {\\alpha} particles are associated with the energies deposited by the alpha particles in the ionization region of the detector as calculated by using GEANT4 simulations; thus, the energy calibration of the MICROMEGAS detector for {\\alpha} particles is done. For the energy calibration, the thickness of the ionization region is adjusted so that {\\alpha} particles may completely stop in the ionization region and their kinetic energies are fully deposited in the region. The efficiency of our MICROMEGA...

  11. Indoor multipath mitigation

    DEFF Research Database (Denmark)

    Dragünas, Kostas; Borre, Kai

    2010-01-01

    There are many applications that require continuous positioning in combined outdoor urban and indoor environments. GNSS has been used for a long time in outdoor environments, while indoor positioning is still a challenging task. One of the major degradations that GNSS receivers experience indoors...

  12. Mathematical models for predicting indoor air quality from smoking activity.

    Science.gov (United States)

    Ott, W R

    1999-05-01

    Much progress has been made over four decades in developing, testing, and evaluating the performance of mathematical models for predicting pollutant concentrations from smoking in indoor settings. Although largely overlooked by the regulatory community, these models provide regulators and risk assessors with practical tools for quantitatively estimating the exposure level that people receive indoors for a given level of smoking activity. This article reviews the development of the mass balance model and its application to predicting indoor pollutant concentrations from cigarette smoke and derives the time-averaged version of the model from the basic laws of conservation of mass. A simple table is provided of computed respirable particulate concentrations for any indoor location for which the active smoking count, volume, and concentration decay rate (deposition rate combined with air exchange rate) are known. Using the indoor ventilatory air exchange rate causes slightly higher indoor concentrations and therefore errs on the side of protecting health, since it excludes particle deposition effects, whereas using the observed particle decay rate gives a more accurate prediction of indoor concentrations. This table permits easy comparisons of indoor concentrations with air quality guidelines and indoor standards for different combinations of active smoking counts and air exchange rates. The published literature on mathematical models of environmental tobacco smoke also is reviewed and indicates that these models generally give good agreement between predicted concentrations and actual indoor measurements.

  13. Interference between source-free radiation and radiation from sources: Particle-like behavior for classical radiation

    Science.gov (United States)

    Boyer, Timothy H.

    2017-09-01

    A simple junior-level electrodynamics problem is used to illustrate the interference between a source-free standing plane wave and a wave generated by a pulse in a current sheet. Depending upon the relative phases between the standing wave and the current pulse and also upon the relative magnitudes, we can find quite different patterns of emitted energy and momentum. If the source gives a large radiation pulse so that the source-free plane wave can be neglected, then the radiation spreads out symmetrically on either side of the current sheet. However, if the radiation sheet gives a pulse with fields comparable to those of the standing wave, then we can find a single radiation pulse moving to the right while the current sheet recoils to the left or the situation with the directions reversed. The example is a crude illustration of particle-like behavior arising from conventional classical electromagnetic behavior in the presence of source-free radiation. The discussion makes contact with the ideas of photons in modern physics.

  14. Sources and transformations of particle-bound polycyclic aromatic hydrocarbons in Mexico City

    Directory of Open Access Journals (Sweden)

    L. C. Marr

    2006-01-01

    Full Text Available Understanding sources, concentrations, and transformations of polycyclic aromatic hydrocarbons (PAHs in the atmosphere is important because of their potent mutagenicity and carcinogenicity. The measurement of particle-bound PAHs by three different methods during the Mexico City Metropolitan Area field campaign in April 2003 presents a unique opportunity for characterization of these compounds and intercomparison of the methods. The three methods are (1 collection and analysis of bulk samples for time-integrated gas- and particle-phase speciation by gas chromatography/mass spectrometry; (2 aerosol photoionization for fast detection of PAHs on particles' surfaces; and (3 aerosol mass spectrometry for fast analysis of size and chemical composition. This research represents the first time aerosol mass spectrometry has been used to measure ambient PAH concentrations and the first time that fast, real-time methods have been used to quantify PAHs alongside traditional filter-based measurements in an extended field campaign. Speciated PAH measurements suggest that motor vehicles and garbage and wood burning are important sources in Mexico City. The diurnal concentration patterns captured by aerosol photoionization and aerosol mass spectrometry are generally consistent. Ambient concentrations of particle-phase PAHs typically peak at ~110 ng m-3 during the morning rush hour and rapidly decay due to changes in source activity patterns and dilution as the boundary layer rises, although surface-bound PAH concentrations decay faster. The more rapid decrease in surface versus bulk PAH concentrations during the late morning suggests that freshly emitted combustion-related particles are quickly coated by secondary aerosol material in Mexico City's atmosphere and may also be transformed by heterogeneous reactions.

  15. Particle swarm optimization and its application in MEG source localization using single time sliced data

    Science.gov (United States)

    Lin, Juan; Liu, Chenglian; Guo, Yongning

    2014-10-01

    The estimation of neural active sources from the magnetoencephalography (MEG) data is a very critical issue for both clinical neurology and brain functions research. A widely accepted source-modeling technique for MEG involves calculating a set of equivalent current dipoles (ECDs). Depth in the brain is one of difficulties in MEG source localization. Particle swarm optimization(PSO) is widely used to solve various optimization problems. In this paper we discuss its ability and robustness to find the global optimum in different depths of the brain when using single equivalent current dipole (sECD) model and single time sliced data. The results show that PSO is an effective global optimization to MEG source localization when given one dipole in different depths.

  16. Measurement of the Internal Magnetic Field of Plasmas using an Alpha Particle Source

    Energy Technology Data Exchange (ETDEWEB)

    S.J. Zweben; D.S. Darrow; P.W. Ross; J.L. Lowrance; G. Renda

    2004-05-13

    The internal magnetic fields of plasmas can be measured under certain conditions from the integrated v x B deflection of MeV alpha particles emitted by a small radioactive source. This alpha source and large-area alpha particle detector would be located inside the vacuum vessel but outside the plasma. Alphas with a typical energy of 5.5 MeV (241Am) can reach the center of almost all laboratory plasmas and magnetic fusion devices, so this method can potentially determine the q(r) profile of tokamaks or STs. Orbit calculations, background evaluations, and conceptual designs for such a vxB (or ''AVB'') detector are described.

  17. Personal exposure to ultrafine particles.

    Science.gov (United States)

    Wallace, Lance; Ott, Wayne

    2011-01-01

    Personal exposure to ultrafine particles (UFP) can occur while people are cooking, driving, smoking, operating small appliances such as hair dryers, or eating out in restaurants. These exposures can often be higher than outdoor concentrations. For 3 years, portable monitors were employed in homes, cars, and restaurants. More than 300 measurement periods in several homes were documented, along with 25 h of driving two cars, and 22 visits to restaurants. Cooking on gas or electric stoves and electric toaster ovens was a major source of UFP, with peak personal exposures often exceeding 100,000 particles/cm³ and estimated emission rates in the neighborhood of 10¹² particles/min. Other common sources of high UFP exposures were cigarettes, a vented gas clothes dryer, an air popcorn popper, candles, an electric mixer, a toaster, a hair dryer, a curling iron, and a steam iron. Relatively low indoor UFP emissions were noted for a fireplace, several space heaters, and a laser printer. Driving resulted in moderate exposures averaging about 30,000 particles/cm³ in each of two cars driven on 17 trips on major highways on the East and West Coasts. Most of the restaurants visited maintained consistently high levels of 50,000-200,000 particles/cm³ for the entire length of the meal. The indoor/outdoor ratios of size-resolved UFP were much lower than for PM₂.₅ or PM₁₀, suggesting that outdoor UFP have difficulty in penetrating a home. This in turn implies that outdoor concentrations of UFP have only a moderate effect on personal exposures if indoor sources are present. A time-weighted scenario suggests that for typical suburban nonsmoker lifestyles, indoor sources provide about 47% and outdoor sources about 36% of total daily UFP exposure and in-vehicle exposures add the remainder (17%). However, the effect of one smoker in the home results in an overwhelming increase in the importance of indoor sources (77% of the total).

  18. Application of particle swarm optimization blind source separation technology in fault diagnosis of gearbox

    Institute of Scientific and Technical Information of China (English)

    黄晋英; 潘宏侠; 毕世华; 杨喜旺

    2008-01-01

    Blind source separation (BBS) technology was applied to vibration signal processing of gearbox for separating different fault vibration sources and enhancing fault information. An improved BSS algorithm based on particle swarm optimization (PSO) was proposed. It can change the traditional fault-enhancing thought based on de-noising. And it can also solve the practical difficult problem of fault location and low fault diagnosis rate in early stage. It was applied to the vibration signal of gearbox under three working states. The result proves that the BSS greatly enhances fault information and supplies technological method for diagnosis of weak fault.

  19. The optical theorem for local source excitation of a particle near a plane interface

    Science.gov (United States)

    Eremin, Yuri; Wriedt, Thomas

    2015-11-01

    Based on classic Maxwell's theory and the Gauss Theorem we extended the Optical Theorem to the case of a penetrable particle excited by a local source deposited near a plane interface. We demonstrate that the derived Extinction Cross-Section involves the total point source radiating cross-section and some definite integrals responsible for the scattering by the interface. The derived extinction cross-section can be employed to estimate the quantum yield and the optical antenna efficiency without computation of the absorption cross-section.

  20. Aero particles characterization emitted by mobile sources;Caracterizacion de aeroparticulas emitidas por fuentes moviles

    Energy Technology Data Exchange (ETDEWEB)

    Rojas V, A.; Romero G, E. T.; Lopez G, H., E-mail: elizabeth.romero@inin.gob.m [ININ, Departamento de Quimica, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico)

    2009-07-01

    In our country, the mobile sources that conform most of the emissions at the atmosphere, are concentrated on the urban areas. For the present work, samples coming from the escapes of terrestrial transport were obtained, such as: passenger buses, load transport and particular vehicles of the Metropolitan area of the Toluca valley. The material was analyzed by means of scanning electron microscopy of low vacuum and X-ray diffraction. The objective was to characterize the emitted particles by mobile sources, morphological and chemically to know the structure, size and elements that compose them. (Author)

  1. Solar Sources of $^{3}$He-rich Solar Energetic Particle Events in Solar Cycle 24

    OpenAIRE

    Nitta, Nariaki V.; Mason, Glenn M.; Wang, Linghua; Cohen, Christina M. S.; Wiedenbeck, Mark E.

    2015-01-01

    Using high-cadence extreme-ultraviolet (EUV) images obtained by the Atmospheric Imaging Assembly (AIA) on board the Solar Dynamics Observatory, we investigate the solar sources of 26 $^{3}$He-rich solar energetic particle (SEP) events at $\\lesssim$1 MeV nucleon$^{-1}$ that were well-observed by the Advanced Composition Explorer during solar cycle 24. Identification of the solar sources is based on the association of $^{3}$He-rich events with type III radio bursts and electron events as observ...

  2. Kinetic modeling of particle dynamics in H{sup −} negative ion sources (invited)

    Energy Technology Data Exchange (ETDEWEB)

    Hatayama, A., E-mail: akh@ppl.appi.keio.ac.jp; Shibata, T.; Nishioka, S.; Ohta, M.; Yasumoto, M.; Nishida, K.; Yamamoto, T. [Faculty of Science and Technology, Keio University, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama, 223-8522 (Japan); Miyamoto, K. [Naruto University of Education, 748 Nakashima, Takashima, Naruto-cho, Naruto-shi, Tokushima 772-8502 (Japan); Fukano, A. [Monozukuri Department, Tokyo Metropolitan College of Industrial Technology, Shinagawa, Tokyo 140-0011 (Japan); Mizuno, T. [Department of Management Science, College of Engineering, Tamagawa University, Machida, Tokyo 194-8610 (Japan)

    2014-02-15

    Progress in the kinetic modeling of particle dynamics in H{sup −} negative ion source plasmas and their comparisons with experiments are reviewed, and discussed with some new results. Main focus is placed on the following two topics, which are important for the research and development of large negative ion sources and high power H{sup −} ion beams: (i) Effects of non-equilibrium features of EEDF (electron energy distribution function) on H{sup −} production, and (ii) extraction physics of H{sup −} ions and beam optics.

  3. Particle Swarm Optimization Recurrent Neural Network Based Z-source Inverter Fed Induction Motor Drive

    OpenAIRE

    R. Selva Santhose Kumar; S.M. Girirajkumar

    2014-01-01

    In this study, the proposal is made for Particle Swarm Optimization (PSO) Recurrent Neural Network (RNN) based Z-Source Inverter Fed Induction Motor Drive. The proposed method is used to enhance the performance of the induction motor while reducing the Total Harmonic Distortion (THD), eliminating the oscillation period of the stator current, torque and speed. Here, the PSO technique uses the induction motor speed and reference speed as the input parameters. From the input parameters, it optim...

  4. INDOOR AND OUTDOOR SOURCE CONTRIBUTIONS TO PERSONAL PM2.5 FOR A PANEL OF INDIVIDUALS WITH CARDIOVASCULAR DISEASE OR COPD LIVING IN BOSTON, MA

    Science.gov (United States)

    Repeated personal, home indoor, home outdoor, and ambient particulate and gaseous pollutant levels were characterized for individuals with cardiovascular disease or COPD and their partners living in the Boston area. Health status was determined by self-reported history of myoc...

  5. Metal-bearing fine particle sources in a coastal industrialized environment

    Science.gov (United States)

    Mbengue, Saliou; Alleman, Laurent Y.; Flament, Pascal

    2017-01-01

    Fine (primary or secondary submicron particles and mechanical procedures in open air, or local traffic, which lead to the emission of coarser particles (> 1 μm). The trace elements As, Cd, Ni, Pb, Sb, V and Zn, characteristics of the local industrial activities display 60% to 85% of their mass in the submicron and ultrafine fractions and appear highly enriched, by reference to the crustal source. High atmospheric pressure periods, corresponding to northeasterly winds, induce the highest contributions of metalworking emissions and the highest PM2.5 concentrations (32.5 ± 11.9 μg·m- 3). A Principal Component Analysis of the dataset produces 7 factors associated to metallurgy-, steelworks-, oil processing-, coal combustion-, neighboring traffic-, dust resuspension- and sea salt-sources, that explain the obtained concentrations. A Multiple Linear Regression Analysis confirms that Fe-Mn alloy refining, iron- and steel-making are the main sources (> 40%) controlling metal concentrations in PM2.5. Less predictably, resuspended dust and fresh/aged sea salts are also significant contributors (≈ 20%). Considering the related health hazards, authorities should pay more attention to the exposure of people living in this area and the possible impact of fine particles in terms of public health.

  6. Characteristics and sources of intermediate size particles in recovery boilers : final project report.

    Energy Technology Data Exchange (ETDEWEB)

    Baxter, Larry L. (Brigham Young University, Provo, UT); Shaddix, Christopher R.; Verrill, Christopher L. (Georgia Institute of Technology, Institute of Paper Science and Technology, Atlanta, GA); Wessel, Richard A. (Babcock & Wilcox Company, Barberton, OH)

    2005-02-01

    As part of the U.S. Department of Energy (DOE) Office of Industrial Technologies (OIT) Industries of the Future (IOF) Forest Products research program, a collaborative investigation was conducted on the sources, characteristics, and deposition of particles intermediate in size between submicron fume and carryover in recovery boilers. Laboratory experiments on suspended-drop combustion of black liquor and on black liquor char bed combustion demonstrated that both processes generate intermediate size particles (ISP), amounting to 0.5-2% of the black liquor dry solids mass (BLS). Measurements in two U.S. recovery boilers show variable loadings of ISP in the upper furnace, typically between 0.6-3 g/Nm{sup 3}, or 0.3-1.5% of BLS. The measurements show that the ISP mass size distribution increases with size from 5-100 {micro}m, implying that a substantial amount of ISP inertially deposits on steam tubes. ISP particles are depleted in potassium, chlorine, and sulfur relative to the fuel composition. Comprehensive boiler modeling demonstrates that ISP concentrations are substantially overpredicted when using a previously developed algorithm for ISP generation. Equilibrium calculations suggest that alkali carbonate decomposition occurs at intermediate heights in the furnace and may lead to partial destruction of ISP particles formed lower in the furnace. ISP deposition is predicted to occur in the superheater sections, at temperatures greater than 750 C, when the particles are at least partially molten.

  7. Particle backtracking improves breeding subpopulation discrimination and natal-source identification in mixed populations.

    Directory of Open Access Journals (Sweden)

    Michael E Fraker

    Full Text Available We provide a novel method to improve the use of natural tagging approaches for subpopulation discrimination and source-origin identification in aquatic and terrestrial animals with a passive dispersive phase. Our method integrates observed site-referenced biological information on individuals in mixed populations with a particle-tracking model to retrace likely dispersal histories prior to capture (i.e., particle backtracking. To illustrate and test our approach, we focus on western Lake Erie's yellow perch (Perca flavescens population during 2006-2007, using microsatellite DNA and otolith microchemistry from larvae and juveniles as natural tags. Particle backtracking showed that not all larvae collected near a presumed hatching location may have originated there, owing to passive drift during the larval stage that was influenced by strong river- and wind-driven water circulation. Re-assigning larvae to their most probable hatching site (based on probabilistic dispersal trajectories from the particle backtracking model improved the use of genetics and otolith microchemistry to discriminate among local breeding subpopulations. This enhancement, in turn, altered (and likely improved the estimated contributions of each breeding subpopulation to the mixed population of juvenile recruits. Our findings indicate that particle backtracking can complement existing tools used to identify the origin of individuals in mixed populations, especially in flow-dominated systems.

  8. Characteristics and sources of intermediate size particles in recovery boilers : final project report.

    Energy Technology Data Exchange (ETDEWEB)

    Baxter, Larry L. (Brigham Young University, Provo, UT); Shaddix, Christopher R.; Verrill, Christopher L. (Georgia Institute of Technology, Institute of Paper Science and Technology, Atlanta, GA); Wessel, Richard A. (Babcock & Wilcox Company, Barberton, OH)

    2005-02-01

    As part of the U.S. Department of Energy (DOE) Office of Industrial Technologies (OIT) Industries of the Future (IOF) Forest Products research program, a collaborative investigation was conducted on the sources, characteristics, and deposition of particles intermediate in size between submicron fume and carryover in recovery boilers. Laboratory experiments on suspended-drop combustion of black liquor and on black liquor char bed combustion demonstrated that both processes generate intermediate size particles (ISP), amounting to 0.5-2% of the black liquor dry solids mass (BLS). Measurements in two U.S. recovery boilers show variable loadings of ISP in the upper furnace, typically between 0.6-3 g/Nm{sup 3}, or 0.3-1.5% of BLS. The measurements show that the ISP mass size distribution increases with size from 5-100 {micro}m, implying that a substantial amount of ISP inertially deposits on steam tubes. ISP particles are depleted in potassium, chlorine, and sulfur relative to the fuel composition. Comprehensive boiler modeling demonstrates that ISP concentrations are substantially overpredicted when using a previously developed algorithm for ISP generation. Equilibrium calculations suggest that alkali carbonate decomposition occurs at intermediate heights in the furnace and may lead to partial destruction of ISP particles formed lower in the furnace. ISP deposition is predicted to occur in the superheater sections, at temperatures greater than 750 C, when the particles are at least partially molten.

  9. Particle Transport along Magnetic Null Lines as Sputter or Antihydrogen Source

    Science.gov (United States)

    Lane, R. A.; Ordonez, C. A.

    Particle transport along null magnetic lines is investigated using classical trajectory Monte Carlo simulations and described as a traveling wave and through diffusion equations. A magnetic null line is defined as a one-dimensional region where the magnetic field magnitude is zero. This region may take any shape in three-dimensional space. The field used in the simulations is generated by two infinite wires of negligible thickness carrying identical current and separated by a small distance. Thus, an infinite magnetic null line exists directly between the wires. The particle trajectories are simulated by solving the equations of motion for each simulated particle of a mono- energetic set. Each is considered individually, with all trajectories starting from the same position along the null line. Each trajectory is simulated until it reaches a specified distance from the initial point or a maximum time elapses. The simulation is repeated using a full set for multiple endpoints and maximum times for ten different amounts of current in the wires. Each current value is selected so that no particles can travel more than seven times the distance between the wires from the null line. The fraction of particles that reach the endpoint in a given time is calculated and used to describe particle transport parallel to the null line. The results are given in normalized, dimensionless units and their possible applications as an antihydrogen source and use in ultra-high purity sputter are discussed. The results are used to find the conditions necessary to obtain a steady and uniform particle flux suitable for ultra-high purity sputter, assuming that plasma is generated near the null line.

  10. Child exposure to indoor and outdoor air pollutants in schools in Barcelona, Spain.

    Science.gov (United States)

    Rivas, I; Viana, M; Moreno, T; Pandolfi, M; Amato, F; Reche, C; Bouso, L; Àlvarez-Pedrerol, M; Alastuey, A; Sunyer, J; Querol, X

    2014-08-01

    Proximity to road traffic involves higher health risks because of atmospheric pollutants. In addition to outdoor air, indoor air quality contributes to overall exposure. In the framework of the BREATHE study, indoor and outdoor air pollution was assessed in 39 schools in Barcelona. The study quantifies indoor and outdoor air quality during school hours of the BREATHE schools. High levels of fine particles (PM2.5), nitrogen dioxide (NO2), equivalent black carbon (EBC), ultrafine particle (UFP) number concentration and road traffic related trace metals were detected in school playgrounds and indoor environments. PM2.5 almost doubled (factor of 1.7) the usual urban background (UB) levels reported for Barcelona owing to high school-sourced PM2.5 contributions: [1] an indoor-generated source characterised mainly by organic carbon (OC) from organic textile fibres, cooking and other organic emissions, and by calcium and strontium (chalk dust) and; [2] mineral elements from sand-filled playgrounds, detected both indoors and outdoors. The levels of mineral elements are unusually high in PM2.5 because of the breakdown of mineral particles during playground activities. Moreover, anthropogenic PM components (such as OC and arsenic) are dry/wet deposited in this mineral matter. Therefore, PM2.5 cannot be considered a good tracer of traffic emissions in schools despite being influenced by them. On the other hand, outdoor NO2, EBC, UFP, and antimony appear to be good indicators of traffic emissions. The concentrations of NO2 are 1.2 times higher at schools than UB, suggesting the proximity of some schools to road traffic. Indoor levels of these traffic-sourced pollutants are very similar to those detected outdoors, indicating easy penetration of atmospheric pollutants. Spatial variation shows higher levels of EBC, NO2, UFP and, partially, PM2.5 in schools in the centre than in the outskirts of Barcelona, highlighting the influence of traffic emissions. Mean child exposure to

  11. SOLAR SOURCES OF {sup 3}He-RICH SOLAR ENERGETIC PARTICLE EVENTS IN SOLAR CYCLE 24

    Energy Technology Data Exchange (ETDEWEB)

    Nitta, Nariaki V. [Lockheed Martin Advanced Technology Center, Dept/A021S, B/252, 3251 Hanover Street, Palo Alto, CA 94304 (United States); Mason, Glenn M. [Applied Physics Laboratory, Johns Hopkins University, Laurel, MD 20723 (United States); Wang, Linghua [Institute of Space Physics and Applied Technology, Peking University, Beijing 100871 (China); Cohen, Christina M. S. [California Institute of Technology, Pasadena, CA 91125 (United States); Wiedenbeck, Mark E., E-mail: nitta@lmsal.com, E-mail: glenn.mason@jhuapl.edu, E-mail: wanglhwang@gmail.com, E-mail: cohen@srl.caltech.edu, E-mail: mark.e.wiedenbeck@jpl.nasa.gov [Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 (United States)

    2015-06-20

    Using high-cadence EUV images obtained by the Atmospheric Imaging Assembly (AIA) on board the Solar Dynamics Observatory, we investigate the solar sources of 26 {sup 3}He-rich solar energetic particle events at ≲1 MeV nucleon{sup −1} that were well-observed by the Advanced Composition Explorer during solar cycle 24. Identification of the solar sources is based on the association of {sup 3}He-rich events with type III radio bursts and electron events as observed by Wind. The source locations are further verified in EUV images from the Solar and Terrestrial Relations Observatory, which provides information on solar activities in the regions not visible from the Earth. Based on AIA observations, {sup 3}He-rich events are not only associated with coronal jets as emphasized in solar cycle 23 studies, but also with more spatially extended eruptions. The properties of the {sup 3}He-rich events do not appear to be strongly correlated with those of the source regions. As in the previous studies, the magnetic connection between the source region and the observer is not always reproduced adequately by the simple potential field source surface model combined with the Parker spiral. Instead, we find a broad longitudinal distribution of the source regions extending well beyond the west limb, with the longitude deviating significantly from that expected from the observed solar wind speed.

  12. Source apportionment of chlorinated polycyclic aromatic hydrocarbons associated with ambient particles in a Japanese megacity

    Science.gov (United States)

    Kamiya, Yuta; Iijima, Akihiro; Ikemori, Fumikazu; Okuda, Tomoaki; Ohura, Takeshi

    2016-12-01

    Chlorinated polycyclic aromatic hydrocarbons (ClPAHs) are novel species of environmental contaminants whose possible sources remain unclear. The occurrence of ClPAHs within total suspended particles (TSP) is compared with weekly air samples at two sites of differing characteristics (industrial and residential) in the megacity of Nagoya, Japan. Samples were collected over 12 months during 2011–2012. All 24 species of targeted ClPAHs were detected at both industrial and residential sites, where mean concentrations of total ClPAHs in TSP were 20.7 and 14.1 pg/m3, respectively. High concentrations at the industrial site were frequently observed during winter, suggesting potent seasonal ClPAH sources there. Positive matrix factorization modeling of particulate ClPAH source identification and apportioning were conducted for datasets including ClPAHs, PAHs, elements and ions, plus elemental carbons in TSP. Eight factors were identified as possible ClPAH sources, with estimates that the dominant one was a specific source of ClPAH emission (31%), followed by traffic (23%), photodegradable and semi-volatile species (18%), long-range transport (11%), and industry and oil combustion (10%). Source contributions of ClPAHs differed substantially from those of PAHs. This suggests specific and/or potent ClPAH sources in the local area, and that the production mechanisms between ClPAHs and PAHs are substantially different.

  13. Associations between personal, indoor, and residential outdoor pollutant concentrations: implications for exposure assessment to size-fractionated particulate matter.

    Science.gov (United States)

    Arhami, Mohammad; Polidori, Andrea; Delfino, Ralph J; Tjoa, Thomas; Sioutas, Constantinos

    2009-04-01

    The physical and chemical characteristics of indoor, outdoor, and personal quasi-ultrafine (matter (PM) levels, their particle components, and gaseous co-pollutants. Seasonal and spatial differences in the concentrations of all measured species were evaluated at all sites on the basis of P values for product terms. Outdoor quasi-ultrafine (UF) and, to a lesser extent, accumulation-mode particles were the two fractions that best correlated with outdoor concentrations of carbon monoxide (CO), nitrogen dioxide (NO2), nitrogen oxides (NOx; during both phases of the study), and ozone (O3; only during the warmer months). Outdoor and indoor concentrations of CO, NO2, and NOx were more positively correlated to personal quasi-UF particles than larger size fractions. Despite these findings, it seems unlikely that these gaseous co-pollutants could confound epidemiologic associations between quasi-UF particles and adverse health effects. Overall, measured gaseous co-pollutants were weak surrogates of personal exposure to accumulation-mode PM, at least for subjects with similar exposure profiles and living in similar urban locations. Indoor sources were not significant contributors to personal exposure of accumulation and quasi-UF PM, which is predominantly influenced by primary emitted pollutants of outdoor origin. Correlations between personal coarse-mode PM and both outdoor and indoor gaseous co-pollutant concentrations were weak at all sites and during all seasons.

  14. Emission factors and source apportionment for abrasion particles produced by road traffic

    Science.gov (United States)

    Bukowiecki, N.; Lienemann, P.; Figi, R.; Hill, M.; Richard, A.; Furger, M.; Rickers, K.; Cliff, S. S.; Baltensperger, U.; Gehrig, R.

    2009-04-01

    Particle emissions of road traffic are generally associated with fresh exhaust emissions only. However, recent studies identified a clear contribution of non-exhaust emissions to the PM10 load of the ambient air. These emissions consist of particles produced by abrasion from brakes, road wear, tire wear, as well as resuspension of deposited road dust. For many urban environments, quantitative information about the contributions of the individual abrasion processes is still scarce. For effective PM10 reduction scenarios it is of particular interest to know whether road wear, resuspension or fresh abrasion from vehicles is dominating the non-exhaust PM10 contribution. In Switzerland, the emissions of road traffic abrasion particles into the ambient air were characterized in the project APART (Abrasion Particles produced by Road Traffic). The project aimed at finding the contribution of the non-exhaust sources to total traffic-related PM10 and PM2.5 for different traffic conditions, by determining specific elemental fingerprint signatures for the various sources. This was achieved by hourly elemental mass concentration measurements in three size classes (2.5-10, 1-2.5 and 0.1-1 micrometers) with a rotating drum impactor (RDI) and subsequent synchrotron radiation X-ray fluorescence spectrometry (SR-XRF). The elemental fingerprint measurements were embedded into a large set of aerosol, gas phase, meteorological and traffic count measurements. To identify traffic related emissions, measurements were performed upwind and downwind of selected roads. For a better investigation of road wear, a road wear simulator was applied in additional experiments. This allows for the identification and quantification of the different source contributions by means of source-receptor modeling, and for the calculation of real-world emission factors for the individual abrasion sources. The preliminary analysis of hourly resolved trace element measurements in a street canyon in Zürich showed

  15. 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.

    2017-01-01

    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 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 < 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. PMID:28481324

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

    Science.gov (United States)

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

    2012-01-01

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

  17. Sources and transformations of particle-bound polycyclic aromatic hydrocarbons in Mexico City

    Directory of Open Access Journals (Sweden)

    L. C. Marr

    2005-12-01

    Full Text Available Understanding sources, concentrations, and transformation of polycyclic aromatic hydrocarbons (PAHs in the atmosphere is important because of their potent mutagenicity and carcinogenicity. The measurement of particle-bound PAHs by three different methods during the Mexico City Metropolitan Area field campaign in April 2003 presents a unique opportunity for characterization of these compounds and assessment of the methods. The three methods are (1 collection and analysis of bulk samples for time-integrated gas- and particle-phase speciation by gas chromatography/mass spectrometry; (2 aerosol photoionization for fast detection of PAHs on particles' surfaces; and (3 aerosol mass spectrometry for fast analysis of size and chemical composition. This research represents the first time aerosol mass spectrometry has been used to measure ambient PAH concentrations and the first time that fast, real-time methods have been used to quantify PAHs alongside traditional filter-based measurements in an extended field campaign. Speciated PAH measurements suggest that motor vehicles and garbage and wood burning are important sources in Mexico City. The diurnal concentration patterns captured by aerosol photoionization and aerosol mass spectrometry are generally consistent. Ambient concentrations typically peak at ~110 ng m−3 during the morning rush hour and rapidly decay due to changes in source activity patterns and dilution as the boundary layer rises, although surface-bound PAH concentrations decay faster. The more rapid decrease in surface versus bulk PAH concentrations during the late morning suggests that freshly emitted combustion-related particles are quickly coated by secondary aerosol material in Mexico City's atmosphere and may also be transformed by heterogeneous reactions.

  18. Air conditioning and source-specific particles as modifiers of the effect of PM(10) on hospital admissions for heart and lung disease.

    Science.gov (United States)

    Janssen, Nicole A H; Schwartz, Joel; Zanobetti, Antonella; Suh, Helen H

    2002-01-01

    Studies on acute effects of particulate matter (PM) air pollution show significant variability in exposure-effect relations among cities. Recent studies have shown an influence of ventilation on personal/indoor-outdoor relations and stronger associations of adverse effects with combustion-related particles. We evaluated whether differences in prevalence of air conditioning (AC) and/or the contribution of different sources to total PM(10) emissions could partly explain the observed variability in exposure-effect relations. We used regression coefficients of the relation between PM(10) and hospital admissions for chronic obstructive pulmonary disease (COPD), cardiovascular disease (CVD), and pneumonia from a recent study in 14 U.S. cities. We obtained data on the prevalence of AC from the 1993 American Housing Survey and data on PM(10) emissions by source category, vehicle miles traveled (VMT), and population density from the U.S. EPA. We analyzed data using meta-regression techniques. PM(10) regression coefficients for CVD and COPD decreased significantly with increasing percentage of homes with central AC when cities were stratified by whether their PM(10) concentrations peaked in winter or non-winter months. PM(10) coefficients for CVD increased significantly with increasing percentage of PM(10) emission from highway vehicles, highway diesels, oil combustion, metal processing, decreasing percentage of PM(10) emission from fugitive dust, and increasing population density and VMT/mile(2). In multivariate analysis, only percentage of PM(subscript)10(/subscript) from highway vehicles/diesels and oil combustion remained significant. For COPD and pneumonia, associations were less significant but the patterns of the associations were similar to that for CVD. The results suggest that air conditioning and proportion of especially traffic-related particles significantly modify the effect of PM(10) on hospital admissions, especially for CVD. PMID:11781164

  19. A Map/INS/Wi-Fi Integrated System for Indoor Location-Based Service Applications.

    Science.gov (United States)

    Yu, Chunyang; Lan, Haiyu; Gu, Fuqiang; Yu, Fei; El-Sheimy, Naser

    2017-06-02

    In this research, a new Map/INS/Wi-Fi integrated system for indoor location-based service (LBS) applications based on a cascaded Particle/Kalman filter framework structure is proposed. Two-dimension indoor map information, together with measurements from an inertial measurement unit (IMU) and Received Signal Strength Indicator (RSSI) value, are integrated for estimating positioning information. The main challenge of this research is how to make effective use of various measurements that complement each other in order to obtain an accurate, continuous, and low-cost position solution without increasing the computational burden of the system. Therefore, to eliminate the cumulative drift caused by low-cost IMU sensor errors, the ubiquitous Wi-Fi signal and non-holonomic constraints are rationally used to correct the IMU-derived navigation solution through the extended Kalman Filter (EKF). Moreover, the map-aiding method and map-matching method are innovatively combined to constrain the primary Wi-Fi/IMU-derived position through an Auxiliary Value Particle Filter (AVPF). Different sources of information are incorporated through a cascaded structure EKF/AVPF filter algorithm. Indoor tests show that the proposed method can effectively reduce the accumulation of positioning errors of a stand-alone Inertial Navigation System (INS), and provide a stable, continuous and reliable indoor location service.

  20. Fine-Tuning Two-Particle Interferometry Effects from Opacity and Temperature Gradients in the Source

    CERN Document Server

    Tomasik, Boris; Tomasik, Boris; Heinz, Ulrich

    1998-01-01

    A comprehensive model study of Bose-Einstein correlation radii in heavy ion collisions is presented. The starting point is a longitudinally and transversally expanding fireball, represented at freeze-out by an azimuthally symmetric emission function. The freeze-out temperature is allowed to feature transverse and temporal gradients. Their effects on the correlation radii are studied. In particular, we evaluate numerically their dependence on the transverse mass of the particle pairs and check a recent suggestion, based on analytical approximations, that for certain reasonable source parameters all three correlation radii satisfy simultaneously a 1/\\sqrt{M_\\perp} scaling. We also investigate quantitatively how the correlation radii are affected if the source becomes ``opaque''. We find a strong sensitivity to opaqueness for the temporal radius parameter R_0 in the YKP parametrization. A qualitative comparison with preliminary data from 158 A GeV/c Pb+Pb collisions at CERN indicates that the source is not opaqu...

  1. Sustainable indoor lighting

    CERN Document Server

    Mercatelli, Luca; Farini, Alessandro

    2015-01-01

    Encompassing a thorough survey of the lighting techniques applied to internal illumination characterized by high efficiency, optimized color and architectural integration, a consolidated summary of the latest scientific, technical and architectural research is presented in order to give the reader an overview of the different themes with their interactions and mutual effects.   This book describes light principles, methodologies and realisations for indoor illumination at low consumption. Power efficiency, color characteristics and architectural aspects are analyzed in terms of their  practical application, with the interactions between scientific, technological and architectural features considered in order to supply a complete overview, which can be read both at technical level and at user level. Introducing photometric and radiometric quantities and laws, the book first discusses tests and measurements assessing lighting and color characteristics before examining in detail artificial light sources with p...

  2. Lead sources and transfer in the coastal Mediterranean: evidence from stable lead isotopes in marine particles

    Science.gov (United States)

    Alleman, L. Y.; Hamelin, B.; Véron, A. J.; Miquel, J.-C.; Heussner, S.

    Time series of settling and suspended particles have been collected by sediment traps and in situ pumps respectively, under contrasted hydrographic conditions in the Gulf of Lions and the Ligurian Sea, northwestern Mediterranean. Lead concentrations measured in sediment trap samples vary from 41±7 ppm in the Ligurian Sea to 58±10 ppm in the Gulf of Lions. These concentrations, 2-10 times lower than those measured previously in the Gulf of Lions, reflect the reduction of lead fallout from gasoline during the last decade. While atmospheric lead still originates mainly from anthropogenic emissions (automotive and industrial exhausts), stable lead isotopes demonstrate that anthropogenic and lithogenic lead are in similar proportions in the marine particles from the northwestern Mediterranean. Sequential extraction analyses performed on trap samples suggest that the isotopic variations can be explained by a three-component mixing between anthropogenic, natural soluble, and natural refractory sources. In the suspended particulate matter from the Gulf of Lions, lead concentrations range from 0.2 to 30 ng/ l, with isotopic compositions comparable to those of the settling particles ( 206Pb/ 207Pb from 1.165 to 1.178). This indicates a common origin in these two types of particles, probably mainly controlled by the Rhône River discharge and by resuspension processes on the continental shelf. By contrast, lead concentrations are lower in the suspended matter samples from the Ligurian Sea (0.5 to 1.7 ng/ l). In this case, the isotopic signature (1.165±0.002) is in equilibrium with the dissolved fraction, as previously found in other oligotrophic sites in the open ocean, where the suspended particles are mainly of biological origin and lead essentially authigenic in these particles.

  3. Estimate of main local sources to ambient ultrafine particle number concentrations in an urban area

    Science.gov (United States)

    Rahman, Md Mahmudur; Mazaheri, Mandana; Clifford, Sam; Morawska, Lidia

    2017-09-01

    Quantifying and apportioning the contribution of a range of sources to ultrafine particles (UFPs, D statistical modelling and other exploratory tools. The Bayesian model was trained on the PNC data on days where NP formations were known to have not occurred, hourly traffic counts, solar radiation data, and smooth daily trend. The model was applied to apportion and quantify the contribution of NP formations and local traffic and non-traffic sources to UFPs. The data analysis incorporated long-term measured time-series of total PNC (D ≥ 6 nm), particle number size distributions (PSD, D = 8 to 400 nm), PM2.5, PM10, NOx, CO, meteorological parameters and traffic counts at a stationary monitoring site. The developed Bayesian model showed reliable predictive performances in quantifying the contribution of NP formation events to UFPs (up to 4 × 104 particles cm- 3), with a significant day to day variability. The model identified potential NP formation and no-formations days based on PNC data and quantified the sources contribution to UFPs. Exploratory statistical analyses show that total mean PNC during the middle of the day was up to 32% higher than during peak morning and evening traffic periods, which were associated with NP formation events. The majority of UFPs measured during the peak traffic and NP formation periods were between 30-100 nm and smaller than 30 nm, respectively. To date, this is the first application of Bayesian model to apportion different sources contribution to UFPs, and therefore the importance of this study is not only in its modelling outcomes but in demonstrating the applicability and advantages of this statistical approach to air pollution studies.

  4. Analysis of ultrasonically rotating droplet using moving particle semi-implicit and distributed point source methods

    Science.gov (United States)

    Wada, Yuji; Yuge, Kohei; Tanaka, Hiroki; Nakamura, Kentaro

    2016-07-01

    Numerical analysis of the rotation of an ultrasonically levitated droplet with a free surface boundary is discussed. The ultrasonically levitated droplet is often reported to rotate owing to the surface tangential component of acoustic radiation force. To observe the torque from an acoustic wave and clarify the mechanism underlying the phenomena, it is effective to take advantage of numerical simulation using the distributed point source method (DPSM) and moving particle semi-implicit (MPS) method, both of which do not require a calculation grid or mesh. In this paper, the numerical treatment of the viscoacoustic torque, which emerges from the viscous boundary layer and governs the acoustical droplet rotation, is discussed. The Reynolds stress traction force is calculated from the DPSM result using the idea of effective normal particle velocity through the boundary layer and input to the MPS surface particles. A droplet levitated in an acoustic chamber is simulated using the proposed calculation method. The droplet is vertically supported by a plane standing wave from an ultrasonic driver and subjected to a rotating sound field excited by two acoustic sources on the side wall with different phases. The rotation of the droplet is successfully reproduced numerically and its acceleration is discussed and compared with those in the literature.

  5. Indoor air quality – buildings design

    Directory of Open Access Journals (Sweden)

    Juhásová Šenitková Ingrid

    2017-01-01

    Full Text Available Growing attention is being paid to indoor air quality as one of the main health and well-being factors. The indoor research is concerned mostly to indoor air chemicals within indoor engineering related to building design. The providing good indoor air quality can be achieved effectively by avoiding or reducing indoor air pollution sources and by selecting low-polluting building materials, both being low-cost and energyefficient solutions. On the base of the last large experimental monitoring results, it was possible to know the level of selected indoor chemicals occurrence, rank them as well as to predict the tendencies of occurrence and establish the priorities for the future. There has been very limited attention to rigorous analysis of buildings actual environmental impacts to date. Healthy/green/sustainable building practices are typically applied in unsystematic and inconsistent ways often without resolution of inherent conflicts between and among such practices. Designers, products manufacturers, constructors, and owners declare their buildings and the applied technologies to be beneficial to the environment without validating those claims.

  6. Monte Carlo study of radial energy deposition from primary and secondary particles for narrow and large proton beamlet source models.

    Science.gov (United States)

    Peeler, Christopher R; Titt, Uwe

    2012-06-21

    In spot-scanning intensity-modulated proton therapy, numerous unmodulated proton beam spots are delivered over a target volume to produce a prescribed dose distribution. To accurately model field size-dependent output factors for beam spots, the energy deposition at positions radial to the central axis of the beam must be characterized. In this study, we determined the difference in the central axis dose for spot-scanned fields that results from secondary particle doses by investigating energy deposition radial to the proton beam central axis resulting from primary protons and secondary particles for mathematical point source and distributed source models. The largest difference in the central axis dose from secondary particles resulting from the use of a mathematical point source and a distributed source model was approximately 0.43%. Thus, we conclude that the central axis dose for a spot-scanned field is effectively independent of the source model used to calculate the secondary particle dose.

  7. Particle source and edge confinement study based on spectroscopic diagnosis in the LHD

    Science.gov (United States)

    Goto, M.; Sawada, K.; Oishi, T.; Morita, S.

    2016-08-01

    The particle source rate profile from edge to core region of the LHD (Large Helical Device) plasma is derived by a detailed analysis of the Balmer-α line of neutral hydrogen. The results are used for evaluating the particle confinement time for a plasma volume within a given magnetic flux surface, {τ\\text{p}}≤ft({{r}\\text{eff}}\\right) , where r eff is the averaged minor radius of the flux surface. Characteristics of the particle confinement are evaluated in terms of {τ\\text{p}}≤ft({{r}\\text{eff}}\\right) for different conditions of the plasma. A discharge with {{B}\\text{ax}}=0.41 T, where B ax is the magnetic field strength at the magnetic axis, gives {τ\\text{p}}≤ft({{r}\\text{eff}}\\right)∼ 0.01 s at the edge region, which is approximately one order of magnitude smaller than that of a discharge with {{B}\\text{ax}}=2.75 T, while the both discharges give similar {τ\\text{p}}≤ft({{r}\\text{eff}}\\right) in the core region. This result confirms that the high confinement performance in the strong magnetic field discharges can be ascribed, at least in part, to a high particle confinement characteristics in the plasma edge region.

  8. Solar source of energetic particles in interplanetary space during the 2006 December 13 event

    CERN Document Server

    Li, C; Vial, J -C; Owen, C J; Matthews, S A; Tang, Y H; Fang, C; Fazakerley, A N

    2013-01-01

    An X3.4 solar flare and a fast halo coronal mass ejection (CME) occurred on 2006 December 13, accompanied by a high flux of energetic particles recorded both in near-Earth space and at ground level. Our purpose is to provide evidence of flare acceleration in a major solar energetic particle (SEP) event. We first present observations from ACE/EPAM, GOES, and the Apatity neutron monitor. It is found that the initial particle release time coincides with the flare emission and that the spectrum becomes softer and the anisotropy becomes weaker during particle injection, indicating that the acceleration source changes from a confined coronal site to a widespread interplanetary CME-driven shock. We then describe a comprehensive study of the associated flare active region. By use of imaging data from HINODE/SOT and SOHO/MDI magnetogram, we infer the flare magnetic reconnection rate in the form of the magnetic flux change rate. This correlates in time with the microwave emission, indicating a physical link between the...

  9. Are Ventilation Filters Degrading Indoor Air Quality in California Classrooms?

    Energy Technology Data Exchange (ETDEWEB)

    Fisk, William J.; Destaillats, H.; Apte, M.G.; Destaillats,, Hugo; Fisk, Michael G. Apte and William J.

    2008-10-01

    Heating, ventilating, and cooling classrooms in California consume substantial electrical energy. Indoor air quality (IAQ) in classrooms affects studenthealth and performance. In addition to airborne pollutants that are emitted directly by indoor sources and those generated outdoors, secondary pollutants can be formed indoors by chemical reaction of ozone with other chemicals and materials. Filters are used in nearly all classroom heating, ventilation and air?conditioning (HVAC) systems to maintain energy-efficient HVAC performance and improve indoor air quality; however, recent evidence indicates that ozone reactions with filters may, in fact, be a source of secondary pollutants. This project quantitatively evaluated ozone deposition in HVAC filters and byproduct formation, and provided a preliminary assessment of the extent towhich filter systems are degrading indoor air quality. The preliminary information obtained will contribute to the design of subsequent research efforts and the identification of energy efficient solutions that improve indoor air quality in classrooms and the health and performance of students.

  10. Overview of charged-particle beam diagnostics for the advanced photon source (APS)

    Science.gov (United States)

    Lumpkin, A. H.; Decker, G.; Kahana, E.; Patterson, D.; Sellyey, W.; Votaw, A.; Wang, X.; Chung, Y.

    1992-07-01

    Plans, prototypes, and initial test results for the charged-particle beam (e-,e+) diagnostic systems on the injector rings, their transport lines, and the storage ring for the Advanced Photon Source (APS) are presented. The APS will be a synchrotron radiation user facility with one of the world's brightest x-ray sources in the 10-keV to 100-keV regime. Its 200-MeV electron linac, 450-MeV positron linac, positron accumulator ring, 7-GeV booster synchrotron, 7-GeV storage ring, and undulator test lines will also demand the development and demonstration of key particle-beam characterization techniques over a wide range of parameter space. Some of these parameter values overlap or approach those projected for fourth generation light sources (linac-driven FELs and high brightness storage rings) as described at a recent workshop. Initial results from the diagnostics prototypes on the linac test stand operating at 45-MeV include current monitor data, beam loss monitor data, and video digitization using VME architecture.

  11. Charged-particle beam diagnostics for the Advanced Photon Source (APS)

    Science.gov (United States)

    Lumpkin, A. H.; Decker, G.; Kahana, E.; Patterson, D.; Sellyey, W.; Wang, X.; Chung, Y.

    1992-08-01

    Plans, prototypes, and initial test results for the charged-particle beam (e-), e(+) diagnostic systems on the injector rings, their transport lines, and the storage ring for the Advanced Photon Source (APS) are presented. The APS will be a synchrotron radiation user facility with one of the world's brightest x-ray sources in the 10-keV to 100-keV regime. Its 200-MeV electron linac, 450-MeV positron linac, positron accumulator ring, 7-GeV booster synchrotron, 7-GeV storage ring, and undulator test lines will also demand the development and demonstration of key particle-beam characterization techniques over a wide range of parameter space. Some of these parameter values overlap or approach those projected for fourth generation light sources (linac-driven FELs and high brightness storage rings) as described at a recent workshop. Initial results from the diagnostics prototypes on the linac test stand operating at 45-MeV include current monitor data, beam loss monitor data, and video digitization using VME architecture.

  12. Ice Nucleating Particle Properties in the Saharan Air Layer Close to the Dust Source

    Science.gov (United States)

    Boose, Y.; Garcia, I. M.; Rodríguez, S.; Linke, C.; Schnaiter, M.; Nickovic, S.; Lohmann, U.; Kanji, Z. A.; Sierau, B.

    2015-12-01

    In August 2013 and 2014 measurements of ice nucleating particle (INP) concentrations, aerosol particle size distributions, chemistry and fluorescence were conducted at the Izaña Atmospheric Observatory located at 2373 m asl on Tenerife, west off the African shore. During summer, the observatory is frequently within the Saharan Air Layer and thus often exposed to dust. Absolute INP concentrations and activated fractions at T=-40 to -15°C and RHi=100-150 % were measured. In this study, we discuss the in-situ measured INP properties with respect to changes in the chemical composition, the biological content, the source regions as well as transport pathways and thus aging processes of the dust aerosol. For the first time, ice crystal residues were also analyzed with regard to biological content by means of their autofluorescence signal close to a major dust source region. Airborne dust samples were collected with a cyclone for additional offline analysis in the laboratory under similar conditions as in the field. Both, in-situ and offline dust samples were chemically characterized using single-particle mass spectrometry. The DREAM8 dust model extended with dust mineral fractions was run to simulate meteorological and dust aerosol conditions for ice nucleation. Results show that the background aerosol at Izaña was dominated by carbonaceous particles, which were hardly ice-active under the investigated conditions. When Saharan dust was present, INP concentrations increased by up to two orders of magnitude even at water subsaturated conditions at T≤-25°C. Differences in the ice-activated fraction were found between different dust periods which seem to be linked to variations in the aerosol chemical composition (dust mixed with changing fractions of sea salt and differences in the dust aerosol itself). Furthermore, two biomass burning events in 2014 were identified which led to very low INP concentrations under the investigated temperature and relative humidity

  13. Primary and secondary organic aerosol origin by combined gas-particle phase source apportionment

    Directory of Open Access Journals (Sweden)

    M. Crippa

    2013-08-01

    Full Text Available Secondary organic aerosol (SOA, a prominent fraction of particulate organic mass (OA, remains poorly constrained. Its formation involves several unknown precursors, formation and evolution pathways and multiple natural and anthropogenic sources. Here a combined gas-particle phase source apportionment is applied to wintertime and summertime data collected in the megacity of Paris in order to investigate SOA origin during both seasons. This was possible by combining the information provided by an aerosol mass spectrometer (AMS and a proton transfer reaction mass spectrometer (PTR-MS. A better constrained apportionment of primary OA (POA sources is also achieved using this methodology, making use of gas-phase tracers. These tracers made possible the discrimination between biogenic and continental/anthropogenic sources of SOA. We found that continental SOA was dominant during both seasons (24–50% of total OA, while contributions from photochemistry-driven SOA (9% of total OA and marine emissions (13% of total OA were also observed during summertime. A semi-volatile nighttime component was also identified (up to 18% of total OA during wintertime. This approach was successfully applied here and implemented in a new source apportionment toolkit.

  14. Controlling Indoor Air Pollution from Moxibustion

    Directory of Open Access Journals (Sweden)

    Chung-Yen Lu

    2016-06-01

    Full Text Available Indoor air quality (IAQ control of hospitals plays a critical role in protecting both hospital staffs and patients, particularly those who are highly susceptible to the adverse effects of indoor noxious hazards. However, moxibustion in outpatient departments (OPDs of traditional Chinese medicine (TCM may be a source of indoor air pollution in hospitals. Some studies have investigated indoor air pollution during moxibustion in Chinese medicine clinics (CMCs and moxibustion rooms, demonstrating elevated air pollutants that pose a threat to the health of medical staff and patients. Our study investigated the indoor air pollutants of indoor carbon dioxide (CO2, carbon monoxide (CO, formaldehyde (HCHO, total volatile organic compounds (TVOCs, airborne particulate matter with a diameter of ≤10 µm (PM10 and ≤2.5 µm (PM2.5 during moxibustion in an acupuncture and moxibustion room of the OPD in a hospital in Taipei. To evaluate the different control strategies for indoor air pollution from moxibution, a comparison of air pollutants during moxibution among the methods of using alternative old moxa wools, local exhaust ventilation and an air cleaner was conducted. In this study, burning alternative old moxa wools for moxibustion obviously reduced all gaseous pollutants except for aerosols comparing burning fresh moxa wools. Using local exhaust ventilation reduced most of the aerosols after burning moxa. We also found that using an air cleaner was inefficient for controlling indoor air pollutants, particularly gaseous pollutants. Therefore, combining replacing alternative old moxa wools and local exhaust ventilation could be a suitable design for controlling indoor air pollution during moxibustion therapy.

  15. Total volatile organic compounds (TVOC) in indoor air quality investigations

    DEFF Research Database (Denmark)

    Mølhave, L.; Clausen, Geo; Berglund, B.

    1997-01-01

    The amount of volatile organic compounds (VOCs) in indoor air, usually called TVOC (total volatile organic compounds), has been measured using different definitions and techniques which yield different results. This report recommends a definition of TVOC referring to a specified range of VOCs...... for characterizing indoor pollution and for improving source control as required from the points of view of health, comfort, energy efficiency and sustainability. (C) Indoor Air (1997)....

  16. Indoor environment program - 1995 annual report

    Energy Technology Data Exchange (ETDEWEB)

    Daisey, J.M.

    1996-06-01

    Buildings use approximately one-third of the energy consumed in the United States. The potential energy savings derived from reduced infiltration and ventilation in buildings are substantial, since energy use associated with conditioning and distributing ventilation air is about 5.5 EJ per year. However, since ventilation is the dominant mechanism for removing pollutants from indoor sources, reduction of ventilation can have adverse effects on indoor air quality, and on the health, comfort, and productivity of building occupants. The Indoor Environment Program in LBL`s Energy and Environment Division was established in 1977 to conduct integrated research on ventilation, indoor air quality, and energy use and efficiency in buildings for the purpose of reducing energy liabilities associated with airflows into, within, and out of buildings while maintaining or improving occupant health and comfort. The Program is part of LBL`s Center for Building Science. Research is conducted on building energy use and efficiency, ventilation and infiltration, and thermal distribution systems; on the nature, sources, transport, transformation, and deposition of indoor air pollutants; and on exposure and health risks associated with indoor air pollutants. Pollutants of particular interest include radon; volatile, semivolatile, and particulate organic compounds; and combustion emissions, including environmental tobacco smoke, CO, and NO{sub x}.

  17. Indoor environment program. 1994 annual report

    Energy Technology Data Exchange (ETDEWEB)

    Daisey, J.M.

    1995-04-01

    Buildings use approximately one-third of the energy consumed in the United States. The potential energy savings derived from reduced infiltration and ventilation in buildings are substantial, since energy use associated with conditioning and distributing ventilation air is about 5.5 EJ per year. However, since ventilation is the dominant mechanism for removing pollutants from indoor sources, reduction of ventilation can have adverse effects on indoor air quality, and on the health, comfort, and productivity of building occupants. The Indoor Environment Program in LBL`s Energy and Environment Division was established in 1977 to conduct integrated research on ventilation, indoor air quality, and energy use and efficiency in buildings for the purpose of reducing energy liabilities associated with airflows into, within, and out of buildings while maintaining or improving occupant health and comfort. The Program is part of LBL`s Center for Building Science. Research is conducted on building energy use and efficiency, ventilation and infiltration, and thermal distribution systems; on the nature, sources, transport, transformation, and deposition of indoor air pollutants; and on exposure and health risks associated with indoor air pollutants. Pollutants of particular interest include radon; volatile, semivolatile, and particulate organic compounds; and combustion emissions, including environmental tobacco smoke, CO, and NO{sub x}.

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

    National Research Council Canada - National Science Library

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

    2014-01-01

    The combination of magnetic and geochemical methods was used to determine the mineralogy, grain size and domain structure of magnetic particles in indoor dust collected in 195 sites in Warsaw, Poland...

  19. Indoor Climate Quality Assessment -

    DEFF Research Database (Denmark)

    Ansaldi, Roberta; Asadi, Ehsan; Costa, José Joaquim

    This Guidebook gives building professionals useful support in the practical measurements and monitoring of the indoor climate in buildings. It is evident that energy consumption in a building is directly influenced by required and maintained indoor comfort level. Wireless technologies for measure...... for measurement and monitoring have allowed a significantly increased number of possible applications, especially in existing buildings. The Guidebook illustrates several cases with the instrumentation of the monitoring and assessment of indoor climate....

  20. Temperature-dependent accumulation mode particle and cloud nuclei concentrations from biogenic sources during WACS 2010

    Directory of Open Access Journals (Sweden)

    L. Ahlm

    2012-10-01

    Full Text Available Submicron aerosol particles collected simultaneously at the mountain peak (2182 m a.s.l. and at a forested mid-mountain site (1300 m a.s.l. on Whistler Mountain, British Columbia, Canada, during June and July 2010 were analyzed by Fourier transform infrared (FTIR spectroscopy for quantification of organic functional groups. Positive matrix factorization (PMF was applied to the FTIR spectra. Three PMF factors associated with (1 combustion, (2 biogenics, and (3 vegetative detritus, were identified at both sites. The biogenic factor was correlated with both temperature and several volatile organic compounds (VOCs. The combustion factor dominated the submicron particle mass during the beginning of the campaign when the temperature was lower and advection was from the Vancouver area, but as the temperature started to rise in early July the biogenic factor came to dominate as a result of increased emissions of biogenic VOCs and thereby increased formation of secondary organic aerosol (SOA. On average, the biogenic factor represented 69% and 49% of the submicron organic particle mass at Whistler Peak and at the mid-mountain site, respectively. The lower fraction at the mid-mountain site was a result of more vegetative detritus there, and also higher influence from local combustion sources.

    The biogenic factor was strongly correlated (r ~ 0.9 to number concentration of particles with diameter (Dp> 100 nm, whereas the combustion factor was better correlated to number concentration of particles with Dp < 100 nm (r~ 0.4. The number concentration of cloud condensation nuclei (CCN was correlated (r ~ 0.7 to the biogenic factor for supersaturations (S of 0.2% or higher, which indicates that particle condensational growth from biogenic vapors was an important factor in controlling the CCN concentration for clouds where S≥0.2%. Both the number concentration of particles with

  1. Temperature-dependent accumulation mode particle and cloud nuclei concentrations from biogenic sources during WACS 2010

    Directory of Open Access Journals (Sweden)

    L. Ahlm

    2013-03-01

    Full Text Available Submicron aerosol particles collected simultaneously at the mountain peak (2182 m a.s.l. and at a forested mid-mountain site (1300 m a.s.l. on Whistler Mountain, British Columbia, Canada, during June and July 2010 were analyzed by Fourier transform infrared (FTIR spectroscopy for quantification of organic functional groups. Positive matrix factorization (PMF was applied to the FTIR spectra. Three PMF factors associated with (1 combustion, (2 biogenics, and (3 vegetative detritus were identified at both sites. The biogenic factor was correlated with both temperature and several volatile organic compounds (VOCs. The combustion factor dominated the submicron particle mass during the beginning of the campaign, when the temperature was lower and advection was from the Vancouver area, but as the temperature started to rise in early July, the biogenic factor came to dominate as a result of increased emissions of biogenic VOCs, and thereby increased formation of secondary organic aerosol (SOA. On average, the biogenic factor represented 69% and 49% of the submicron organic particle mass at Whistler Peak and at the mid-mountain site, respectively. The lower fraction at the mid-mountain site was a result of more vegetative detritus there, and also higher influence from local combustion sources. The biogenic factor was strongly correlated (r~0.9 to number concentration of particles with diameter (Dp> 100 nm, whereas the combustion factor was better correlated to number concentration of particles with Dpr~0.4. The number concentration of cloud condensation nuclei (CCN was correlated (r~0.7 to the biogenic factor for supersaturations (S of 0.2% or higher, which indicates that particle condensational growth from biogenic vapors was an important factor in controlling the CCN concentration for clouds where S≥0.2%. Both the number concentration of particles with Dp>100 nm and numbers of CCN for S≥0.2% were correlated to temperature. Considering the biogenic

  2. User Manual and Source Code for a LAMMPS Implementation of Constant Energy Dissipative Particle Dynamics (DPD-E)

    Science.gov (United States)

    2014-06-01

    User Manual and Source Code for a LAMMPS Implementation of Constant Energy Dissipative Particle Dynamics ( DPD -E) by James P. Larentzos...Energy Dissipative Particle Dynamics ( DPD -E) James P. Larentzos Engility Corporation John K. Brennan, Joshua D. Moore, and William D. Mattson...Constant Energy Dissipative Particle Dynamics ( DPD -E) 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) James P

  3. Summary report: Working group 5 on {open_quotes}Particle Beam Sources{close_quotes}

    Energy Technology Data Exchange (ETDEWEB)

    Serafini, L. [INFN-Milano and UCLA Dept. of Physics and Astronomy 405 Hilgard Ave., Los Angeles, California 90095-1547 (United States); Yeremian, A.D. [SLAC---Stanford, P.O. Box 4349, M/S 26, Stanford, California 94309 (United States)

    1997-03-01

    We report here on the activity carried in the working group on {open_quotes}Particle Beam Sources,{close_quotes} which was actually focused on electron beams and mostly covered the progress and future perspectives of laser driven RF photo-injectors. Recent experimental work on other types of electron sources were also presented: the pulsed power guns in our working group, while the plasma-based electron injectors in a joint session held with the working group on {open_quotes}Plasma-Based Accelerator Concepts.{close_quotes} Several beam dynamics issues of general interest in the field of high brightness beams production and manipulation have also been addressed by discussions and a number of communications in our working group. {copyright} {ital 1997 American Institute of Physics.}

  4. Single particle imaging with soft x-rays at the Linac Coherent Light Source

    Science.gov (United States)

    Martin, Andrew V.; Andreasson, Jakob; Aquila, Andrew; Bajt, Saša; Barends, Thomas R. M.; Barthelmess, Miriam; Barty, Anton; Benner, W. Henry; Bostedt, Christoph; Bozek, John D.; Bucksbaum, Phillip; Caleman, Carl; Coppola, Nicola; DePonte, Daniel P.; Ekeberg, Tomas; Epp, Sascha W.; Erk, Benjamin; Farquar, George R.; Fleckenstein, Holger; Foucar, Lutz; Frank, Matthias; Gumprecht, Lars; Hampton, Christina Y.; Hantke, Max; Hartmann, Andreas; Hartmann, Elisabeth; Hartmann, Robert; Hau-Riege, Stephan P.; Hauser, Günther; Holl, Peter; Hoemke, André; Jönsson, Olof; Kassemeyer, Stephan; Kimmel, Nils; Kiskinova, Maya; Krasniqi, Faton; Krzywinski, Jacek; Liang, Mengning; Loh, Ne-Te Duane; Lomb, Lukas; Maia, Filipe R. N. C.; Marchesini, Stefano; Messerschmidt, Marc; Nass, Karol; Odic, Duško; Pedersoli, Emanuele; Reich, Christian; Rolles, Daniel; Rudek, Benedikt; Rudenko, Artem; Schmidt, Carlo; Schultz, Joachim; Seibert, M. Marvin; Shoeman, Robert L.; Sierra, Raymond G.; Soltau, Heike; Starodub, Dmitri; Steinbrener, Jan; Stellato, Francesco; Strüder, Lothar; Svenda, Martin; Tobias, Herbert; Ullrich, Joachim; Weidenspointner, Georg; Westphal, Daniel; White, Thomas A.; Williams, Garth; Hajdu, Janos; Schlichting, Ilme; Bogan, Michael J.; Chapman, Henry N.

    2011-06-01

    Results of coherent diffractive imaging experiments performed with soft X-rays (1-2 keV) at the Linac Coherent Light Source are presented. Both organic and inorganic nano-sized objects were injected into the XFEL beam as an aerosol focused with an aerodynamic lens. The high intensity and femtosecond duration of X-ray pulses produced by the Linac Coherent Light Source allow structural information to be recorded by X-ray diffraction before the particle is destroyed. Images were formed by using iterative methods to phase single shot diffraction patterns. Strategies for improving the reconstruction methods have been developed. This technique opens up exciting opportunities for biological imaging, allowing structure determination without freezing, staining or crystallization.

  5. Indoor, outdoor, and regional summer and winter concentrations of PM10, PM2.5, SO4(2)-, H+, NH4+, NO3-, NH3, and nitrous acid in homes with and without kerosene space heaters.

    Science.gov (United States)

    Leaderer, B P; Naeher, L; Jankun, T; Balenger, K; Holford, T R; Toth, C; Sullivan, J; Wolfson, J M; Koutrakis, P

    1999-03-01

    Twenty-four-hour samples of PM10 (mass of particles with aerodynamic diameter heater. All homes sampled in the summer were located in southwest Virginia. All but 20 homes sampled in the winter were also located in southwest Virginia; the remainder of the homes were located in Connecticut. For homes without tobacco combustion, the regional air monitoring site (Vinton, VA) appeared to provide a reasonable estimate of concentrations of PM2.5 and SO42- during summer months outside and inside homes within the region, even when a substantial number of the homes used air conditioning. Average indoor/outdoor ratios for PM2.5 and SO42- during the summer period were 1.03 +/- 0.71 and 0.74 +/- 0.53, respectively. The indoor/outdoor mean ratio for sulfate suggests that on average approximately 75% of the fine aerosol indoors during the summer is associated with outdoor sources. Kerosene heater use during the winter months, in the absence of tobacco combustion, results in substantial increases in indoor concentrations of PM2.5, SO42-, and possibly H+, as compared to homes without kerosene heaters. During their use, we estimated that kerosene heaters added, on average, approximately 40 microg/m3 of PM2.5 and 15 microg/m3 of SO42- to background residential levels of 18 and 2 microg/m3, respectively. Results from using sulfuric acid-doped Teflon (E.I. Du Pont de Nemours & Co., Wilmington, DE) filters in homes with kerosene heaters suggest that acid particle concentrations may be substantially higher than those measured because of acid neutralization by ammonia. During the summer and winter periods indoor concentrations of ammonia are an order of magnitude higher indoors than outdoors and appear to result in lower indoor acid particle concentrations. Nitrous acid levels are higher indoors than outdoors during both winter and summer and are substantially higher in homes with unvented combustion sources.

  6. Indoor multipath mitigation

    DEFF Research Database (Denmark)

    Dragünas, Kostas

    2010-01-01

    There are many applications that require continuous positioning in combined outdoor urban and indoor environments. GNSS has been used for a long time in outdoor environments, while indoor positioning is still a challenging task. One of the major degradations that GNSS receivers experience indoors...... is the presence of multipath. The current paper analyzes several available multipath mitigation techniques which would be suitable for indoor applications. A few deconvolution based techniques such as the Projection Onto Convex Sets and the Deconvolution Approach are selected for closer investigation...

  7. Regional source identification using Lagrangian stochastic particle dispersion and HYSPLIT backward-trajectory models.

    Science.gov (United States)

    Koracin, Darko; Vellore, Ramesh; Lowenthal, Douglas H; Watson, John G; Koracin, Julide; McCord, Travis; DuBois, David W; Chen, L W Antony; Kumar, Naresh; Knipping, Eladio M; Wheeler, Neil J M; Craig, Kenneth; Reid, Stephen

    2011-06-01

    The main objective of this study was to investigate the capabilities of the receptor-oriented inverse mode Lagrangian Stochastic Particle Dispersion Model (LSPDM) with the 12-km resolution Mesoscale Model 5 (MM5) wind field input for the assessment of source identification from seven regions impacting two receptors located in the eastern United States. The LSPDM analysis was compared with a standard version of the Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) single-particle backward-trajectory analysis using inputs from MM5 and the Eta Data Assimilation System (EDAS) with horizontal grid resolutions of 12 and 80 km, respectively. The analysis included four 7-day summertime events in 2002; residence times in the modeling domain were computed from the inverse LSPDM runs and HYPSLIT-simulated backward trajectories started from receptor-source heights of 100, 500, 1000, 1500, and 3000 m. Statistics were derived using normalized values of LSPDM- and HYSPLIT-predicted residence times versus Community Multiscale Air Quality model-predicted sulfate concentrations used as baseline information. From 40 cases considered, the LSPDM identified first- and second-ranked emission region influences in 37 cases, whereas HYSPLIT-MM5 (HYSPLIT-EDAS) identified the sources in 21 (16) cases. The LSPDM produced a higher overall correlation coefficient (0.89) compared with HYSPLIT (0.55-0.62). The improvement of using the LSPDM is also seen in the overall normalized root mean square error values of 0.17 for LSPDM compared with 0.30-0.32 for HYSPLIT. The HYSPLIT backward trajectories generally tend to underestimate near-receptor sources because of a lack of stochastic dispersion of the backward trajectories and to overestimate distant sources because of a lack of treatment of dispersion. Additionally, the HYSPLIT backward trajectories showed a lack of consistency in the results obtained from different single vertical levels for starting the backward trajectories. To

  8. ELM simulation experiments on Pilot-PSI using simultaneous high flux plasma and transient heat/particle source

    NARCIS (Netherlands)

    De Temmerman, G.; Zielinski, J. J.; van Diepen, S.; Marot, L.; Price, M.

    2011-01-01

    A new experimental setup has been developed for edge localized mode (ELM) simulation experiments with relevant steady-state plasma conditions and transient heat/particle source. The setup is based on the Pilot-PSI linear plasma device and allows the superimposition of a transient heat/particle pulse

  9. IN VIVO EVIDENCE OF FREE RADICAL FORMATION IN THE RAT LUNG AFTER EXPOSURE TO AN EMISSION SOURCE AIR POLLUTION PARTICLE

    Science.gov (United States)

    Exposure to air pollution particles can be associated with increased human morbidity and mortality. The mechanism(s) of lung injury remains unknown. We tested the hypothesis that lung exposure to oil fly ash (an emission source air pollution particle) causes in vivo free radical ...

  10. Chemical characterization of atmospheric particles and source apportionment in the vicinity of a steelmaking industry

    Energy Technology Data Exchange (ETDEWEB)

    Almeida, S.M., E-mail: smarta@ctn.ist.utl.pt [Centro de Ciências e Tecnologias Nucleares, Instituto Superior Técnico, Universidade de Lisboa, Estrada Nacional 10, 139.7 km, 2695-066 Bobadela LRS (Portugal); Lage, J. [Centro de Ciências e Tecnologias Nucleares, Instituto Superior Técnico, Universidade de Lisboa, Estrada Nacional 10, 139.7 km, 2695-066 Bobadela LRS (Portugal); Fernández, B. [Global R& D, ArcelorMittal, Avilés (Spain); Garcia, S. [Instituto de Soldadura e Qualidade, Av. Prof. Dr. Cavaco Silva, 33, 2740-120 Porto Salvo (Portugal); Reis, M.A.; Chaves, P.C. [Centro de Ciências e Tecnologias Nucleares, Instituto Superior Técnico, Universidade de Lisboa, Estrada Nacional 10, 139.7 km, 2695-066 Bobadela LRS (Portugal)

    2015-07-15

    The objective of this work was to provide a chemical characterization of atmospheric particles collected in the vicinity of a steelmaking industry and to identify the sources that affect PM{sub 10} levels. A total of 94 PM samples were collected in two sampling campaigns that occurred in February and June/July of 2011. PM{sub 2.5} and PM{sub 2.5–10} were analyzed for a total of 22 elements by Instrumental Neutron Activation Analysis and Particle Induced X-ray Emission. The concentrations of water soluble ions in PM{sub 10} were measured by Ion Chromatography and Indophenol-Blue Spectrophotometry. Positive Matrix Factorization receptor model was used to identify sources of particulate matter and to determine their mass contribution to PM{sub 10}. Seven main groups of sources were identified: marine aerosol identified by Na and Cl (22%), steelmaking and sinter plant represented by As, Cr, Cu, Fe, Ni, Mn, Pb, Sb and Zn (11%), sinter plant stack identified by NH{sub 4}{sup +}, K and Pb (12%), an unidentified Br source (1.8%), secondary aerosol from coke making and blast furnace (19%), fugitive emissions from the handling of raw material, sinter plant and vehicles dust resuspension identified by Al, Ca, La, Si, Ti and V (14%) and sinter plant and blast furnace associated essentially with Fe and Mn (21%). - Highlights: • Emissions from steelworks are very complex. • The larger steelworks contribution to PM{sub 10} was from blast furnace and sinter plant. • Sinter plant stack emissions contributed for 12% of the PM{sub 10} mass. • Secondary aerosol from coke making and blast furnace contributed for 19% of the PM{sub 10}. • Fugitive dust emissions highly contribute to PM{sub 10} mass.

  11. 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....

  12. Impact of interannual variations in aerosol particle sources on orographic precipitation over California's Central Sierra Nevada

    Science.gov (United States)

    Creamean, J. M.; Ault, A. P.; White, A. B.; Neiman, P. J.; Ralph, F. M.; Minnis, P.; Prather, K. A.

    2015-01-01

    Aerosols that serve as cloud condensation nuclei (CCN) and ice nuclei (IN) have the potential to profoundly influence precipitation processes. Furthermore, changes in orographic precipitation have broad implications for reservoir storage and flood risks. As part of the CalWater field campaign (2009-2011), the variability and associated impacts of different aerosol sources on precipitation were investigated in the California Sierra Nevada using an aerosol time-of-flight mass spectrometer for precipitation chemistry, S-band profiling radar for precipitation classification, remote sensing measurements of cloud properties, and surface meteorological measurements. The composition of insoluble residues in precipitation samples collected at a surface site contained mostly local biomass burning and long-range transported dust and biological particles (2009), local sources of biomass burning and pollution (2010), and long-range transport from distant sources (2011). Although differences in the sources were observed from year-to-year, the most consistent source of dust and biological residues were associated with storms consisting of deep convective cloud systems with significant quantities of precipitation initiated in the ice phase. Further, biological residues were dominant (up to 40%) during storms with relatively warm cloud temperatures (up to -15 °C), supporting the important role bioparticles can play as ice nucleating particles. On the other hand, lower percentages of residues from local biomass burning and pollution were observed over the three winter seasons (on average 31 and 9%, respectively). When precipitation quantities were relatively low, these residues most likely served as CCN, forming smaller more numerous cloud droplets at the base of shallow cloud systems, and resulting in less efficient riming processes. The correlation between the source of aerosols within clouds and precipitation type and quantity will be further probed in models to understand the

  13. Source appointment of fine particle number and volume concentration during severe haze pollution in Beijing in January 2013.

    Science.gov (United States)

    Liu, Zirui; Wang, Yuesi; Hu, Bo; Ji, Dongsheng; Zhang, Junke; Wu, Fangkun; Wan, Xin; Wang, Yonghong

    2016-04-01

    Extreme haze episodes repeatedly shrouded Beijing during the winter of 2012-2013, causing major environmental and health problems. To better understand these extreme events, particle number size distribution (PNSD) and particle chemical composition (PCC) data collected in an intensive winter campaign in an urban site of Beijing were used to investigate the sources of ambient fine particles. Positive matrix factorization (PMF) analysis resolved a total of eight factors: two traffic factors, combustion factors, secondary aerosol, two accumulation mode aerosol factors, road dust, and long-range transported (LRT) dust. Traffic emissions (54%) and combustion aerosol (27%) were found to be the most important sources for particle number concentration, whereas combustion aerosol (33%) and accumulation mode aerosol (37%) dominated particle volume concentrations. Chemical compositions and sources of fine particles changed dynamically in the haze episodes. An enhanced role of secondary inorganic species was observed in the formation of haze pollution. Regional transport played an important role for high particles, contribution of which was on average up to 24-49% during the haze episodes. Secondary aerosols from urban background presented the largest contributions (45%) for the rapid increase of fine particles in the severest haze episode. In addition, the invasion of LRT dust aerosols further elevated the fine particles during the extreme haze episode. Our results showed a clear impact of regional transport on the local air pollution, suggesting the importance of regional-scale emission control measures in the local air quality management of Beijing.

  14. Single discharge of the matrix source of negative hydrogen ions: Influence of the neutral particle dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Paunska, Ts.; Todorov, D., E-mail: dimitar-tdrv@phys.uni-sofia.bg; Shivarova, A. [Faculty of Physics, Sofia University, BG-1164 Sofia (Bulgaria); Tarnev, Kh. [Department of Applied Physics, Technical University–Sofia, BG-1000 Sofia (Bulgaria)

    2015-04-08

    The study presents two-dimensional (2D) fluid-plasma-model description of a planar-coil inductively-driven discharge, considered as a single element of a matrix source of volume-produced negative hydrogen ions. Whereas the models developed up to now have been directed towards description of the charged particle behavior in the discharge, including that of the negative ions, this model stresses on the role of the neutral particle dynamics and of the surface processes in the formation of the discharge structure. The latter is discussed based on comparison of results obtained for discharges in a flowing gas and at a constant gas pressure as well as for different values of the coefficient of atom recombination on the walls. The conclusions are that the main plasma parameters – electron density and temperature and plasma potential – determining the gas discharge regime stay stable, regardless of changes in the redistribution of the densities of the neutral particles and of the positive ions. With regards to the volume production of the ions, which requires high density of (vibrationally excited) molecules, the impact on the degree of dissociation of the coefficient of atom recombination on the wall is discussed.

  15. INVESTIGATING PARTICLE ACCELERATION IN PROTOSTELLAR JETS: THE TRIPLE RADIO CONTINUUM SOURCE IN SERPENS

    Energy Technology Data Exchange (ETDEWEB)

    Rodríguez-Kamenetzky, Adriana; Valotto, Carlos [Instituto de Astronomía Teórica y Experimental, (IATE-UNC), X5000BGR Córdoba (Argentina); Carrasco-González, Carlos; Rodríguez, Luis F. [Instituto de Radioastronomía y Astrofísica (IRyA-UNAM), 58089 Morelia, México (Mexico); Araudo, Anabella [University of Oxford, Astrophysics, Keble Road, Oxford OX1 3RH (United Kingdom); Torrelles, José M. [Institut de Ciències de l’Espai (CSIC-IEEC) and Institut de Ciències del Cosmos (UB-IEEC), Martí i Franquès 1, E-08028 Barcelona (Spain); Anglada, Guillem [Instituto de Astrofísica de Andalucía, CSIC, Camino Bajo de Huétor 50, E-18008 Granada (Spain); Martí, Josep [Dept. de Física, EPS de Jaén, Universidad de Jaén, Campus Las Lagunillas s/n, A3-402, E-23071 Jaén (Spain)

    2016-02-10

    While most protostellar jets present free–free emission at radio wavelengths, synchrotron emission has also been proposed to be present in a handful of these objects. The presence of nonthermal emission has been inferred by negative spectral indices at centimeter wavelengths. In one case (the HH 80-81 jet arising from a massive protostar), its synchrotron nature was confirmed by the detection of linearly polarized radio emission. One of the main consequences of these results is that synchrotron emission implies the presence of relativistic particles among the nonrelativistic material of these jets. Therefore, an acceleration mechanism should be taking place. The most probable scenario is that particles are accelerated when the jets strongly impact against the dense envelope surrounding the protostar. Here we present an analysis of radio observations obtained with the Very Large Array of the triple radio source in the Serpens star-forming region. This object is known to be a radio jet arising from an intermediate-mass protostar. It is also one of the first protostellar jets where the presence of nonthermal emission was proposed. We analyze the dynamics of the jet and the nature of the emission and discuss these issues in the context of the physical parameters of the jet and the particle acceleration phenomenon.

  16. Concentrations of PM(2.5) mass and components in residential and non-residential indoor microenvironments: the Sources and Composition of Particulate Exposures study.

    Science.gov (United States)

    Brown, Kathleen W; Sarnat, Jeremy A; Koutrakis, Petros

    2012-01-01

    Although short in duration, air pollutant exposures occurring in non-residential microenvironments (MEs), including restaurants, vehicles and commercial locations, can represent a large fraction of total personal exposures. For the Sources and Composition of Particulate Exposures study, a novel compact sampling system was developed, facilitating simultaneous measurement of highly speciated PM(2.5) mass in a range of commercial and residential locations. This sampler also included 1-min measurements of PM(2.5) mass and ultrafine particle (UFP) counts. Sampling was conducted in a number of MEs (retail stores, restaurants and vehicles) throughout Atlanta. Chemically resolved particulate measurements in these locations are of interest for both exposure scientists and epidemiologists but have typically not been conducted because of logistical constraints associated with sampling these trace constituents. We present measurements from a non-random sample of locations that are limited in their generalizability but provide several promising hypothesis-generating results. PM(2.5) mass concentrations greater than 100  μg/m(3), and UFPs>10(5) particles /cm(3) were measured during several events in the restaurant and vehicle. Somewhat unexpectedly, the grocery store ME, along with the restaurant and vehicle, also had the highest levels of elemental carbon (EC), organic carbon (OC) and most elements. In-vehicle concentrations of soil-related elements (Al, Ca, Fe, K and Ti) and auto-related elements (EC, OC, Zn and Cu) were higher than those measured at a central ambient site. The lowest concentrations for most pollutants were found in the hospital and retail locations. It is questionable whether periodic, high PM concentrations in the grocery store and restaurant pose health risks for customers; however, individuals working in these locations may be exposed to levels of concern.

  17. Solar Sources of $^{3}$He-rich Solar Energetic Particle Events in Solar Cycle 24

    CERN Document Server

    Nitta, Nariaki V; Wang, Linghua; Cohen, Christina M S; Wiedenbeck, Mark E

    2015-01-01

    Using high-cadence extreme-ultraviolet (EUV) images obtained by the Atmospheric Imaging Assembly (AIA) on board the Solar Dynamics Observatory, we investigate the solar sources of 26 $^{3}$He-rich solar energetic particle (SEP) events at $\\lesssim$1 MeV nucleon$^{-1}$ that were well-observed by the Advanced Composition Explorer during solar cycle 24. Identification of the solar sources is based on the association of $^{3}$He-rich events with type III radio bursts and electron events as observed by Wind. The source locations are further verified in EUV images from the Solar and Terrestrial Relations Observatory, which provides information on solar activities in the regions not visible from the Earth. Based on AIA observations, $^{3}$He-rich events are not only associated with coronal jets as emphasized in solar cycle 23 studies, but also with more spatially extended eruptions. The properties of the $^{3}$He-rich events do not appear to be strongly correlated with those of the source regions. As in the previous...

  18. Indoor air quality at life and work environments in Rome, Italy.

    Science.gov (United States)

    Romagnoli, P; Balducci, C; Perilli, M; Vichi, F; Imperiali, A; Cecinato, A

    2016-02-01

    The air quality of three different microenvironments (school, dwelling, and coffee bar) located in the city of Rome, Italy, was assessed. Indoor and outdoor concentrations of polycyclic aromatic hydrocarbons (PAHs) associated with PM2.5 particles were determined during an intensive 3-week sampling campaign conducted in March 2013. In interiors, total particulate PAHs ranged from 1.53 to 4.96 ng/m(3) while outdoor air contained from 2.75 to 3.48 ng/m(3). In addition, gaseous toxicants, i.e., NO2, NOx , SO2, O3, and BTEX (benzene, toluene, ethyl-benzene, and xylene isomers), were determined both in internal and external air. To solve the origin of indoor and outdoor PAHs, several source apportionment methods were applied. Multivariate analysis revealed that emissions from motor vehicles, biomass burning for heating purposes, and soil resuspension were the major sources of PAHs in the city. No linear correlation was established between indoor and outdoor values for PM2.5 and BTEX; the respective indoor/outdoor concentration ratios exceed unity except for PM2.5 in the no smoking home and benzene in all school floors. This suggests that important internal sources such as tobacco smoking, cleaning products, and resuspension dust contributed to indoor pollution. Using the monitoring stations of ARPA Lazio regional network as reference, the percentage within PAH group of benzo[a]pyrene, which is the WHO marker for the carcinogenic risk estimates, was ca. 50% higher in all locations investigated.

  19. An assessment of indoor air quality in recent Mexican immigrant housing in Commerce City, Colorado

    Science.gov (United States)

    Miller, Shelly L.; Scaramella, Peter; Campe, Joseph; Goss, Cynthia W.; Diaz-Castillo, Sandra; Hendrikson, Ed; DiGuiseppi, Carolyn; Litt, Jill

    An indoor air quality assessment was conducted on 100 homes of recent Mexican immigrants in Commerce City, Colorado, an urban industrial community north of Denver. Head of households were administered a family health survey, filled out an activity diary, and participated in a home inspection. Carbon monoxide (CO) and carbon dioxide (CO 2) were measured for 24 h inside the main living area and outside of the homes. Harvard Impactors were used to collect 24-h samples of PM 2.5 at the same locations for gravimetric analysis. Dust samples were collected by vacuuming carpeting and flooring at four locations within the home and analyzed by ELISA for seven allergens. Mean indoor and outdoor PM 2.5 levels were 27.2 and 8.5 μg m -3, respectively. Indoor PM 2.5 and CO 2 were elevated in homes for which the number of hours with door/window open was zero compared to homes in which the number of hours was high (>15 h). Indoor PM 2.5 levels did not correlate with outdoor levels and tended to increase with number of inhabitants, and results indicate that the source of indoor particles were occupants and their activities, excluding smoking and cooking. Mean indoor CO 2 and CO levels were 1170 and 2.4 ppm, respectively. Carbon monoxide was higher than the 24-h National Ambient Air Quality Standard in 3 of the homes. The predominant allergens were cat ( Fel d 1) and mouse ( Mus m 1) allergens, found in 20 and 34 homes, respectively.

  20. Introduction to Indoor Air Quality

    Science.gov (United States)

    ... United States Environmental Protection Agency Search Search Indoor Air Quality (IAQ) Contact Us Share Introduction to Indoor Air Quality Health Effects Primary Causes Identifying Problems Improving IAQ ...

  1. Using Crowdsourced Geodata for Agent-Based Indoor Evacuation Simulations

    Directory of Open Access Journals (Sweden)

    Alexander Zipf

    2012-08-01

    Full Text Available Crowdsourced geodata has been proven to be a rich and major data source for environmental simulations and analysis, as well as the visualization of spatial phenomena. With the increasing size and complexity of public buildings, such as universities or hotels, there is also an increasing demand for information about indoor spaces. Trying to stimulate this growing demand, both researchers and Volunteered Geographic Information (VGI communities envision to extend established communities towards indoors. It has already been showcased that VGI from OpenStreetMap (OSM can be utilized for different applications in Spatial Data Infrastructures (SDIs as well as for simple shortest path computations inside buildings. The here presented research now tries to utilize crowdsourced indoor geodata for more complex indoor routing scenarios of multiple users. Essentially, it will be investigated if, and to what extent, the available data can be utilized for performing indoor evacuation simulations with the simulation framework MATSim. That is, this paper investigates the suitability of crowdsourced indoor information from OSM (IndoorOSM for evacuation simulations. Additionally, the applicability of MATSim for agent-based indoor evacuation simulations is conducted. The paper discusses the automatic generation simulation-related data, and provides experimental results for two different evacuation scenarios. Furthermore, limitations of the IndoorOSM data and the MATSim framework for indoor evacuation simulations are elaborated and discussed.

  2. 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.

  3. A sensor fusion method for Wi-Fi-based indoor positioning

    Directory of Open Access Journals (Sweden)

    Dongsoo Han

    2016-06-01

    Full Text Available This paper presents a sensor fusion method for a Wi-Fi-based indoor positioning system, named the KAist Indoor LOcating System (KAILOS, which was developed to realize a global indoor positioning system (GIPS that utilizes crowd-sourced fingerprints. KAILOS supports the deployment of indoor positioning systems in buildings by collecting indoor maps and fingerprint DBs of buildings for the GIPS. Thereby, KAILOS provides a method based on sensor fusion for volunteers to develop indoor positioning systems for their buildings. KAILOS has been made available online for public use. In addition, various location-based applications can also be developed using KAILOS.

  4. Impact of kerosene space heaters on indoor air quality.

    Science.gov (United States)

    Hanoune, B; Carteret, M

    2015-09-01

    In recent years, the use of kerosene space heaters as additional or principal heat source has been increasing, because these heaters allow a continuous control on the energy cost. These devices are unvented, and all combustion products are released into the room where the heaters are operated. The indoor air quality of seven private homes using wick-type or electronic injection-type kerosene space heaters was investigated. Concentrations of CO, CO2, NOx, formaldehyde and particulate matter (0.02-10 μm) were measured, using time-resolved instruments when available. All heaters tested are significant sources of submicron particles, NOx and CO2. The average NO2 and CO2 concentrations are determined by the duration of use of the kerosene heaters. These results stress the need to regulate the use of unvented combustion appliances to decrease the exposure of people to air contaminants. Copyright © 2014 Elsevier Ltd. All rights reserved.

  5. Your Indoor Spaces

    Science.gov (United States)

    Exchange: The Early Childhood Leaders' Magazine Since 1978, 2007

    2007-01-01

    In the July 24, 2007 edition of "ExchangeEveryday", readers were asked to submit great indoor space elements from their early childhood programs. Readers sent photographs and brief descriptions of creative elements of their indoor environments. A sampling of ideas are shown on this article.

  6. Distribution and possible sources of PBDEs in indoor dust in Guangzhou City%广州市室内尘土中多溴联苯醚的分布特点及来源

    Institute of Scientific and Technical Information of China (English)

    黄玉妹; 陈来国; 文丽君; 许振成; 彭晓春; 叶芝祥; 曾敏

    2009-01-01

    Dust samples were collected randomly from forty-six houses, twelve offices, seventeen outdoor sites, two televisions and two computers in Guangzhou City to determine the concentrations, distribution and possible sources of PBDEs in indoor dust. Concentration of Σ_(10)PBDEs (sum of BDE28,47, 66, 85, 99,100, 153,154, 183, and 209) varied from 564.3 to 9654ng/g (median 2686ng/g, mean 3407ng/g) for house dust, and from 1737 to 4408 ng/g (median: 3133ng/g; mean: 3179ng/g) for office dust. BDE209 was the dominant congener detected, with an average contribution of 97.4% and 99.0% to Σ_(10)PBDEs for house dust and office dust, respectively, whereas BDE47, 99 and 183 were the most abundant congeners of Σ_9PBDEs (BDE209 excluded). Σ_(10)PBDEs concentration in indoor dust was higher than that in the outdoor dust, indicating possible indoor emission sources for PBDEs indoors. The predominant commercial products source for PBDEs in indoor dust was Deca-BDE formulations, followed by Penta-BDE, and the contribution of Octa-BDE was minimal.%随机采集了广州市46个家庭和12个办公室内尘土样品,同时采集了17个室外尘上样品、2个电视机和2个电脑尘土样品并分析了室内尘土中多溴联苯醚(PBDEs)的含量,单体分布及来源.结果表明,家庭尘土中∑_(10)PBDEs(BDE28,47,66,85,99,100,153,154,183,209之和)的含量为564.3~9654ng/g,中值和均值分别为2686,3407ng/g;办公室尘土中∑_(10)PBDEs的含量为1737~4408ng/g,中值和均值分别为3133,3179ng/g.室内尘土中PBDEs的最主要单体为BDE209,分别占家庭尘土和办公室尘土∑_(10)PBDEs的97.4%和99.0%.BDE47、99和183在室内尘土中含量也较高.大多数室内尘土中∑_(10)PBDEs的含量高于室外,说明室内可能有重要的PBDEs释放源.室内尘土中PBDEs的主要工业品来源为十溴联苯醚,五溴联苯醚次之,八溴联苯醚较少.

  7. Isotopic composition for source identification of mercury in atmospheric fine particles

    Science.gov (United States)

    Huang, Qiang; Chen, Jiubin; Huang, Weilin; Fu, Pingqing; Guinot, Benjamin; Feng, Xinbin; Shang, Lihai; Wang, Zhuhong; Wang, Zhongwei; Yuan, Shengliu; Cai, Hongming; Wei, Lianfang; Yu, Ben

    2016-09-01

    The usefulness of mercury (Hg) isotopes for tracing the sources and pathways of Hg (and its vectors) in atmospheric fine particles (PM2.5) is uncertain. Here, we measured Hg isotopic compositions in 30 potential source materials and 23 PM2.5 samples collected in four seasons from the megacity Beijing (China) and combined the seasonal variation in both mass-dependent fractionation (represented by the ratio 202Hg / 198Hg, δ202Hg) and mass-independent fractionation of isotopes with odd and even mass numbers (represented by Δ199Hg and Δ200Hg, respectively) with geochemical parameters and meteorological data to identify the sources of PM2.5-Hg and possible atmospheric particulate Hg transformation. All PM2.5 samples were highly enriched in Hg and other heavy metals and displayed wide ranges of both δ202Hg (-2.18 to 0.51 ‰) and Δ199Hg (-0.53 to 0.57 ‰), as well as small positive Δ200Hg (0.02 to 0.17 ‰). The results indicated that the seasonal variation in Hg isotopic composition (and elemental concentrations) was likely derived from variable contributions from anthropogenic sources, with continuous input due to industrial activities (e.g., smelting, cement production and coal combustion) in all seasons, whereas coal combustion dominated in winter and biomass burning mainly found in autumn. The more positive Δ199Hg of PM2.5-Hg in spring and early summer was likely derived from long-range-transported Hg that had undergone extensive photochemical reduction. The study demonstrated that Hg isotopes may be potentially used for tracing the sources of particulate Hg and its vectors in the atmosphere.

  8. Study of the atmospheric chemistry of radon progeny in laboratory and real indoor atmospheres

    Energy Technology Data Exchange (ETDEWEB)

    Hopke, P.K.

    1992-07-01

    This report describes studies on the chemical and physical behavior of the [sup 218]Po atom immediately following its formation by the alpha decay of radon. Because small changes in size for activity in the sub-10 nm size range result in large changes in the delivered dose per unit exposure, this behavior must be understood if the exposure to radon progeny and its dose to the cells in the respiratory tract are to be fully assessed. The specific tasks of the controlled laboratory studies are to determine the formation rates of [center dot]OH radicals formed by the radiolysis of air following radon decay, to examine the formation of particles by the radiolytic oxidation of substances like SO[sub 2] ethylene, and H[sub 2]S to lower vapor pressure compounds and determine the role of gas phase additives such as H[sub 2]O and NH[sub 3] in determining the particle size, to measure the rate of ion-induced nucleation using a thermal diffusion cloud chamber, and to measure the neutralization rate of [sup 218]Po[sub x][sup +] in O[sub 2] at low radon concentrations. Tasks of the exposure studies in occupied indoor spaces are to initiate measurements of the activity size distributions in actual homes with occupants present so that the variability of the indoor activity size distributions can be assessed with respect to indoor aerosol sources and general lifestyle variations of the occupants, to initiate a prospective study of the utility of measurement of deposited [sup 210]Pb embedded in glass surfaces as a measure of the long-term, integrated exposure of the population to radon, and to develop the methodology to determine the hygroscopicity of the indoor aerosol so that the changes in deposition efficiency of the radioactive indoor aerosol with hygroscopic growth in the respiratory tract can be assessed.

  9. International standards for the indoor environment.

    Science.gov (United States)

    Olesen, B W

    2004-01-01

    On the international level, International Organization for Standardization (ISO), European Committee for Standardization (CEN) and American Society of Heating, Refrigerating and Air Conditioning Engineers (ASHRAE) are writing and reviewing standards relating to the indoor environment on a regular basis. This presentation will focus on the development of standards for the indoor thermal environment and indoor air quality (ventilation). In the future, recommendations for acceptable indoor environments will be specified as classes. This allows for national differences in the requirements as well as for designing buildings for different quality levels. Several of these standards have been developed mainly by experts from Europe, North America and Japan. Are there, however, special considerations relating to South-East Asia (lifestyle, outdoor climate, economy) that are not dealt with in these standards and that will require the revision of existing standards? Critical issues are: adaptation, the effect of increased air velocity, humidity, type of indoor pollutant sources, etc. This paper will present an overview of existing methods, and discuss areas where revision of present standards or the development of new standards, are needed. The international standards for the indoor environment provide the designer with criteria, which are internationally recognized, for the design of buildings and systems.

  10. Concentration levels and source apportionment of ultrafine particles in road microenvironments

    Science.gov (United States)

    Argyropoulos, G.; Samara, C.; Voutsa, D.; Kouras, A.; Manoli, E.; Voliotis, A.; Tsakis, A.; Chasapidis, L.; Konstandopoulos, A.; Eleftheriadis, K.

    2016-03-01

    A mobile laboratory unit (MOBILAB) with on-board instrumentation (Scanning Mobility Particle Sizer, SMPS; Ambient NOx analyzer) was used to measure size-resolved particle number concentrations (PNCs) of quasi-ultrafine particles (UFPs, 9-372 nm), along with NOx, in road microenvironments. On-road measurements were carried out in and around a large Greek urban agglomeration, the Thessaloniki Metropolitan Area (TMA). Two 2-week measurement campaigns were conducted during the warm period of 2011 and the cold period of 2012. During each sampling campaign, MOBILAB was driven through a 5-day inner-city route and a second 5-day external route covering in total a wide range of districts (urban, urban background, industrial and residential), and road types (major and minor urban roads, freeways, arterial and interurban roads). All routes were conducted during working days, in morning and in afternoon hours under real-world traffic conditions. Spatial classification of MOBILAB measurements involved the assignment of measurement points to location bins defined by the aspect ratio of adjacent urban street canyons (USCs). Source apportionment was further carried out, by applying Positive Matrix Factorization (PMF) to particle size distribution data. Apportioned PMF factors were interpreted, by employing a two-step methodology, which involved (a) statistical association of PMF factor contributions with 12 h air-mass back-trajectories ending at the TMA during MOBILAB measurements, and (b) Multiple Linear Regression (MLR) using PMF factor contributions as the dependent variables, while relative humidity, solar radiation flux, and vehicle speed were used as the independent variables. The applied data analysis showed that low-speed cruise and high-load engine operation modes are the two dominant sources of UFPs in most of the road microenvironments in the TMA, with significant contributions from background photochemical processes during the warm period, explaining the reversed

  11. Chemical characteristics and source apportionment of atmospheric particles during heating period in Harbin, China

    Institute of Scientific and Technical Information of China (English)

    Likun Huang; Guangzhi Wang

    2014-01-01

    Atmospheric particles (total suspended particles (TSPs); particulate matter (PM) with particle size below 10 μm,PM10; particulate matter with particle size below 2.5 μm,PM2.5)were collected and analyzed during heating and non-heating periods in Harbin.The sources of PM10 and PM2.5 were identified by the chemical mass balance (CMB) receptor model.Results indicated that PM2.5/TSP was the most prevalent and PM2.5 was the main component of PM10,while the presence of PM10-100 was relatively weak.SC42-and NO3-concentrations were more significant than other ions during the heating period.As compared with the non-heating period,Mn,Ni,Pb,S,Si,Ti,Zn,As,Ba,Cd,Cr,Fe and K were relatively higher during the heating period.In particular,Mn,Ni,S,Si,Ti,Zn and As in PM2.5 were obviously higher during the heating period.Organic carbon (OC) in the heating period was 2-5 times higher than in the non-heating period.Elemental carbon (EC) did not change much.OC/EC ratios were 8-11 during the heating period,which was much higher than in other Chinese cities (OC/EC:4-6).Results from the CMB indicated that 11 pollution sources were identified,of which traffic,coal combustion,secondary sulfate,secondary nitrate,and secondary organic carbon made the greatest contnbution.Before the heating period,dust and petrochemical industry made a larger contribution.In the heating period,coal combustion and secondary sulfate were higher.After the heating period,dust and petrochemical industry were highen Some hazardous components in PM2.5 were higher than in PM10,because PM2.5 has a higher ability to absorb toxic substances.Thus PM2.5 pollution is more significant regarding human health effects in the heating period.

  12. Indoor Climate Quality Assessment -

    DEFF Research Database (Denmark)

    Ansaldi, Roberta; Asadi, Ehsan; Costa, José Joaquim

    This Guidebook gives building professionals useful support in the practical measurements and monitoring of the indoor climate in buildings. It is evident that energy consumption in a building is directly influenced by required and maintained indoor comfort level. Wireless technologies for measure......This Guidebook gives building professionals useful support in the practical measurements and monitoring of the indoor climate in buildings. It is evident that energy consumption in a building is directly influenced by required and maintained indoor comfort level. Wireless technologies...... for measurement and monitoring have allowed a significantly increased number of possible applications, especially in existing buildings. The Guidebook illustrates several cases with the instrumentation of the monitoring and assessment of indoor climate....

  13. A high-order WENO-Z finite difference based particle-source-in-cell method for computation of particle-laden flows with shocks

    Science.gov (United States)

    Jacobs, Gustaaf B.; Don, Wai-Sun

    2009-03-01

    A high-order particle-source-in-cell (PSIC) algorithm is presented for the computation of the interaction between shocks, small scale structures, and liquid and/or solid particles in high-speed engineering applications. The improved high-order finite difference weighted essentially non-oscillatory (WENO-Z) method for solution of the hyperbolic conservation laws that govern the shocked carrier gas flow, lies at the heart of the algorithm. Finite sized particles are modeled as points and are traced in the Lagrangian frame. The physical coupling of particles in the Lagrangian frame and the gas in the Eulerian frame through momentum and energy exchange, is numerically treated through high-order interpolation and weighing. The centered high-order interpolation of the fluid properties to the particle location is shown to lead to numerical instability in shocked flow. An essentially non-oscillatory interpolation (ENO) scheme is devised for the coupling that improves stability. The ENO based algorithm is shown to be numerically stable and to accurately capture shocks, small flow features and particle dispersion. Both the carrier gas and the particles are updated in time without splitting with a third-order Runge-Kutta TVD method. One and two-dimensional computations of a shock moving into a particle cloud demonstrates the characteristics of the WENO-Z based PSIC method (PSIC/WENO-Z). The PSIC/WENO-Z computations are not only in excellent agreement with the numerical simulations with a third-order Rusanov based PSIC and physical experiments in [V. Boiko, V.P. Kiselev, S.P. Kiselev, A. Papyrin, S. Poplavsky, V. Fomin, Shock wave interaction with a cloud of particles, Shock Waves, 7 (1997) 275-285], but also show a significant improvement in the resolution of small scale structures. In two-dimensional simulations of the Mach 3 shock moving into forty thousand bronze particles arranged in the shape of a rectangle, the long time accuracy of the high-order method is demonstrated

  14. Particle Filter with Integrated Voice Activity Detection for Acoustic Source Tracking

    Directory of Open Access Journals (Sweden)

    Anders M. Johansson

    2007-01-01

    Full Text Available In noisy and reverberant environments, the problem of acoustic source localisation and tracking (ASLT using an array of microphones presents a number of challenging difficulties. One of the main issues when considering real-world situations involving human speakers is the temporally discontinuous nature of speech signals: the presence of silence gaps in the speech can easily misguide the tracking algorithm, even in practical environments with low to moderate noise and reverberation levels. A natural extension of currently available sound source tracking algorithms is the integration of a voice activity detection (VAD scheme. We describe a new ASLT algorithm based on a particle filtering (PF approach, where VAD measurements are fused within the statistical framework of the PF implementation. Tracking accuracy results for the proposed method is presented on the basis of synthetic audio samples generated with the image method, whereas performance results obtained with a real-time implementation of the algorithm, and using real audio data recorded in a reverberant room, are published elsewhere. Compared to a previously proposed PF algorithm, the experimental results demonstrate the improved robustness of the method described in this work when tracking sources emitting real-world speech signals, which typically involve significant silence gaps between utterances.

  15. Coated Particles Fuel Compact-General Purpose Heat Source for Advanced Radioisotope Power Systems

    Science.gov (United States)

    El-Genk, Mohamed S.; Tournier, Jean-Michel

    2003-01-01

    Coated Particles Fuel Compacts (CPFC) have recently been shown to offer performance advantage for use in Radioisotope Heater Units (RHUs) and design flexibility for integrating at high thermal efficiency with Stirling Engine converters, currently being considered for 100 We. Advanced Radioisotope Power Systems (ARPS). The particles in the compact consist of 238PuO2 fuel kernels with 5-μm thick PyC inner coating and a strong ZrC outer coating, whose thickness depends on the maximum fuel temperature during reentry, the fuel kernel diameter, and the fraction of helium gas released from the kernels and fully contained by the ZrC coating. In addition to containing the helium generated by radioactive decay of 238Pu for up to 10 years before launch and 10-15 years mission lifetime, the kernels are intentionally sized (>= 300 μm in diameter) to prevent any adverse radiological effects on reentry. This paper investigates the advantage of replacing the four iridium-clad 238PuO2 fuel pellets, the two floating graphite membranes, and the two graphite impact shells in current State-Of-The-Art (SOA) General Purpose Heat Source (GPHS) with CPFC. The total mass, thermal power, and specific power of the CPFC-GPHS are calculated as functions of the helium release fraction from the fuel kernels and maximum fuel temperature during reentry from 1500 K to 2400 K. For the same total mass and volume as SOA GPHS, the generated thermal power by single-size particles CPFC-GPHS is 260 W at Beginning-Of-Mission (BOM), versus 231 W for the GPHS. For an additional 10% increase in total mass, the CPFC-GPHS could generate 340 W BOM; 48% higher than SOA GPHS. The corresponding specific thermal power is 214 W/kg, versus 160 W/kg for SOA GPHS; a 34% increase. Therefore, for the same thermal power, the CPFC-GPHS is lighter than SOA GPHS, while it uses the same amount of 238PuO2 fuel and same aeroshell. For the same helium release fraction and fuel temperature, binary-size particles CPFC-GPHS could

  16. Chemical composition and sources of coastal marine aerosol particles during the 2008 VOCALS-REx campaign

    Directory of Open Access Journals (Sweden)

    Y.-N. Lee

    2013-10-01

    Full Text Available The chemical composition of aerosol particles (Dp ≤ 1.5 μm was measured over the southeast Pacific ocean during the VOCALS-REx experiment between 16~October and 15 November 2008 using the US DOE G-1 aircraft. The objective of these flights was to gain an understanding of the sources and evolution of these aerosols, and how they interacted with the marine stratus cloud layer that prevails in this region of the globe. Our measurements showed that the marine boundary layer (MBL aerosol mass was dominated by non-sea-salt SO42−, followed by Na+, Cl−, Org, NH4+, and NO3−, in decreasing order of importance; CH3SO3−1 (MSA, Ca2+, and K+ rarely exceeded their limits of detection of ~0.05 and ~0.15 μg m−3 for anions and cations, respectively. The aerosols were strongly acidic as the NH4+ to SO42− equivalence ratio was typically − deficits caused by both HNO3 and H2SO4, and were externally mixed with SO42− particles as the AMS detected no NO3− whilst uptake of HNO3 occurred only on SSA particles. The SSA loading as a function of wind speed agreed with that calculated from published relationships, and contributed only a small fraction of the total accumulation mode particle number. Vertical distribution of MBL SSA particles (Dp ≤ ~1.5 μm was uniform, suggesting a very limited dilution from entrainment of free tropospheric (FT air. It was inferred that because all of the aerosol species (except SSA exhibited a strong land-to-sea gradient, they were of continental origin. Comparison of relative changes in median values using LOWESS fits as proxies suggests that (1 an oceanic source of NH3 is present between 72° W and 76° W, and (2 additional organic aerosols from biomass burns or biogenic precursors were emitted from coastal regions south of 31° S, with possible cloud processing, and (3 FT contributions to MBL gas and aerosols were negligible. Positive Matrix Factorization analysis of organic aerosol mass spectra obtained with

  17. [Indoor environments, work and health].

    Science.gov (United States)

    Abbritti, G

    2004-01-01

    Nowadays, the activities of most of the working population are carried out in confined, non-industrial environments such as offices, hospitals, libraries, social and leisure centres and means of transport. Sub-optimal air quality in these confined spaces can lead to discomfort, ailments and even diseases. The impact and diffusion of these effects have led to the organisation and funding of large-scale epidemiological investigations in many countries and the nomination of working parties by governments, health agencies and international scientific societies. Over the past 20 years studies on indoor environments have identified sources of risk of various pollutants, established the levels of potentially dangerous concentrations and, for most of them, have provided effective measures. However, the effects of many biological agents and chemical mixtures still remain to be defined and effective guidelines are needed for high quality indoor air. Identifying and managing indoor risk factors presupposes a specific methodology: the specialist in occupational medicine can play a key role in risk assessment, in the early diagnosis of building-related illnesses and in the prevention of both short- and long-term effects.

  18. Characterization and Source Term Assessments of Radioactive Particles from Marshall Islands Using Non-Destructive Analytical Techniques

    Energy Technology Data Exchange (ETDEWEB)

    Jernstrom, J; Eriksson, M; Simon, R; Tamborini, G; Bildstein, O; Carlos-Marquez, R; Kehl, S R; Betti, M; Hamilton, T

    2005-06-11

    A considerable fraction of radioactivity entering the environment from different nuclear events is associated with particles. The impact of these events can only be fully assessed where there is some knowledge about the mobility of particle bound radionuclides entering the environment. The behavior of particulate radionuclides is dependent on several factors, including the physical, chemical and redox state of the environment, the characteristics of the particles (e.g., the chemical composition, crystallinity and particle size) and on the oxidative state of radionuclides contained in the particles. Six plutonium-containing particles stemming from Runit Island soil (Marshall Islands) were characterized using non-destructive analytical and microanalytical methods. By determining the activity of {sup 239,240}Pu and {sup 241}Am isotopes from their gamma peaks structural information related to Pu matrix was obtained, and the source term was revealed. Composition and elemental distribution in the particles were studied with synchrotron radiation based micro X-ray fluorescence (SR-{mu}-XRF) spectrometry. Scanning electron microscope equipped with energy dispersive X-ray detector (SEMEDX) and secondary ion mass spectrometer (SIMS) were used to examine particle surfaces. Based on the elemental composition the particles were divided into two groups; particles with plain Pu matrix, and particles where the plutonium is included in Si/O-rich matrix being more heterogeneously distributed. All of the particles were identified as fragments of initial weapons material. As containing plutonium with low {sup 240}Pu/{sup 239}Pu atomic ratio, {approx}2-6%, which corresponds to weapons grade plutonium, the source term was identified to be among the safety tests conducted in the history of Runit Island.

  19. Source identification of PM 2.5 particles measured in Gwangju, Korea

    Science.gov (United States)

    Lee, Hanlim; Park, Seung S.; Kim, Kyung W.; Kim, Young J.

    The UNMIX and Chemical Mass Balance (CMB) receptor models were used to investigate sources of PM 2.5 aerosols measured between March 2001 and February 2002 in Gwangju, Korea. Measurements of PM 2.5 particles were used for the analysis of carbonaceous species (organic (OC) and elemental carbon (EC)) using the thermal manganese dioxide oxidation (TMO) method, the investigation of seven ionic species using ion chromatography (IC), and the analysis of twenty-four metal species using Inductively Coupled Plasma (ICP)-Atomic Emission Spectrometry (AES)/ICP-Mass Spectrometry (MS). According to annual average PM 2.5 source apportionment results obtained from CMB calculations, diesel vehicle exhaust was the major contributor, accounting for 33.4% of the measured PM 2.5 mass (21.5 μg m - 3 ), followed by secondary sulfate (14.6%), meat cooking (11.7%), secondary organic carbon (8.9%), secondary nitrate (7.6%), urban dust (5.5%), Asian dust (4.4%), biomass burning (2.8%), sea salt (2.7%), residual oil combustion (2.6%), gasoline vehicle exhaust (1.9%), automobile lead (0.5%), and components of unknown sources (3.4%). Seven PM 2.5 sources including diesel vehicles (29.6%), secondary sulfate (17.4%), biomass burning (14.7%), secondary nitrate (12.6%), gasoline vehicles (12.4%), secondary organic carbon (5.8%) and Asian dust (1.9%) were identified from the UNMIX analysis. The annual average source apportionment results from the two models are compared and the reasons for differences are qualitatively discussed for better understanding of PM 2.5 sources. Additionally, the impact of air mass pathways on the PM 2.5 mass was evaluated using air mass trajectories calculated with the Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) backward trajectory model. Source contributions to PM 2.5 collected during the four air mass patterns and two event periods were calculated with the CMB model and analyzed. Results of source apportionment revealed that the contribution of

  20. Fine particle coal as a source of energy in small-user applications

    Energy Technology Data Exchange (ETDEWEB)

    Rajan, S.

    1990-11-01

    The use of fine particle micronized coal as a source of energy for home heating applications has been explored in previous years under this program in a 150,000 Btu/hr pulse combustor. Experimental studies have been conducted on the combustion characteristics of micronized coal and combustion efficiencies have been measured. Emission levels of NO{sub x} and SO{sub 2} have been measured. In this final year of the program, the combustion and emissions characteristics of micronized coal were further explored in terms of the influence of stoichiometric ratio and frequency effects. Also, a model has been proposed which has potential for incorporating the unsteady mixing occurring in pulse combustors. 31 refs., 21 figs., 3 tabs.

  1. The properties of low energy neutral particles in a neutral beam source: A molecular dynamics study

    Energy Technology Data Exchange (ETDEWEB)

    Park, Seung-hoon, E-mail: physh@kaist.ac.k [Department of Physics, Korea Advanced Institute of Science and Technology, Yuseong-gu, Daejeon, 305-701 (Korea, Republic of); Yoo, Suk Jae [National Fusion Research Institute, Daejeon 305-333 (Korea, Republic of); Chang, Choong-Seock [Department of Physics, Korea Advanced Institute of Science and Technology, Yuseong-gu, Daejeon, 305-701 (Korea, Republic of); Courant Institute of Mathematical Sciences, New York University, Mercer Street, New York, NY 10012 (United States)

    2010-09-01

    Application of a hyperthermal neutral beam source is one of the candidate methods of reducing plasma induced damage problems. The neutral beam is generated by vertical collisions between energetic ions and a reflector composed of metal. However, it is difficult to measure the neutral angle and energy distribution experimentally. We simulate the hyperthermal neutral beam (HNB) generation using a molecular dynamics algorithm. In order to obtain a low energy neutral beam, ions with various energies are vertically projected onto the reflector surface. A rough surface structure that has been experimentally measured is used for a realistic simulation. The energy distributions are obtained and the ratio of energy of reflected neutral particles agrees with experimental data.

  2. Coronal Sources of Impulsive Fe-Rich Solar Energetic Particle Events

    CERN Document Server

    Kahler, Stephen; Cliver, Edward

    2015-01-01

    We review recent work on 111 Fe-rich impulsive solar energetic ($\\sim$ 3 MeV/nuc) particle (SEP) events observed from 1994 to 2013. Strong elemental abundance enhancements scale with A/Q, the ion mass-to-charge ratio, as (A/Q)$^{\\alpha}$, where 2 $$ 10 MK. Only a small number of SEP events slightly outside this temperature range were found in an expanded search of impulsive Fe-rich events. Event characteristics are similar for events isolated in time and those occurring in clusters. The current challenge is to determine the solar sources of the Fe-rich events. Ambient coronal regions in the 2.5--3.2 MK range are broadly distributed both in and outside active regions. We explore the possibility of acceleration from thermal plasmas at reconnecting current sheets in the context of observed standard and blowout jets. Recent current sheet reconnection modelling provides a basis for the A/Q enhancements.

  3. Axion-Like Particle Imprint in Cosmological Very-High-Energy Sources

    Energy Technology Data Exchange (ETDEWEB)

    Dominguez, A.; /Seville U. /IAA, Granada /Madrid, Autonoma U.; Sanchez-Conde, M.A.; /IAC, La Laguna /IAC, La Laguna /KIPAC, Menlo Park /SLAC; Prada, F.; /IAA, Granada

    2012-06-13

    Discoveries of very high energy (VHE) photons from distant blazars suggest that, after correction by extragalactic background light (EBL) absorption, there is a flatness or even a turn-up in their spectra at the highest energies that cannot be easily explained by the standard framework. Here, it is shown that a possible solution to this problem is achieved by assuming the existence of axion-like particles (ALPs) with masses {approx} 1 neV. The ALP scenario is tested making use of observations of the highest redshift blazars known in the VHE energy regime, namely 3C 279, 3C 66A, PKS 1222+216 and PG 1553+113. In all cases, better fits to the observed spectra are found when including ALPs rather than considering EBL only. Interestingly, quite similar critical energies for photon/ALP conversions are also derived, independently of the source considered.

  4. SOLAR ENERGETIC PARTICLE EVENT ONSETS: FAR BACKSIDE SOLAR SOURCES AND THE EAST–WEST HEMISPHERIC ASYMMETRY

    Energy Technology Data Exchange (ETDEWEB)

    Kahler, S. W., E-mail: stephen.kahler@kirtland.af.mil [Air Force Research Laboratory, Space Vehicles Directorate, 3550 Aberdeen Avenue, Kirtland AFB, NM 87117 (United States)

    2016-03-10

    Prompt onsets and short rise times to peak intensities Ip have been noted in a few solar energetic (E > 10 MeV) particle (SEP) events from far behind (≥25°) the west limb. We discuss 15 archival and recent examples of these prompt events, giving their source longitudes, onset and rise times, and associated coronal mass ejection (CME) speeds. Their timescales and CME speeds are not exceptional in comparison with a larger set of SEP events from behind the west limb. A further statistical comparison of observed timescales of SEP events from behind the west limb with events similarly poorly magnetically connected to the eastern hemisphere (EH) shows the longer timescales of the latter group. We interpret this result in terms of a difference between SEP production at parallel shocks on the eastern flanks of western backside events and at perpendicular shocks on the western flanks of EH events.

  5. Hydrogen Ionic Plasma and Particle Dynamics in Negative Ion Source for NBI

    Science.gov (United States)

    Tsumori, Katsuyoshi

    2013-10-01

    Three negative-ion-based neutral beam injectors (NBIs) have been developed for plasma heating in the Large Helical Device. The NBIs achieve successfully the nominal injection power and beam energy, and understanding of the production and transport mechanisms of H- ion is required to obtain more stable high power beam. In the ion source development, we have found hydrogen ionic plasmas with extremely low electron density are produced in the beam extraction region. The plasma is measured with a combination of an electrostatic probe, millimeter-wave interferometer and cavity ring down (CRD). It has been observed for the first time that the charge neutrality of the ionic plasma is broken with H- extraction and electrons compensate the extracted H- charge. The influence of the extraction field widely affects to the ionic plasma in the extraction region. Two-dimensional particle-in-cell simulation (2D-PIC) has been applied to investigate the particle transport and reproduces the production of the ionic plasma and electron compensation due to H- extraction. In particle model, produced H- ions leave from the Cs covered PG surface in opposite direction to beam extraction. The direction can be changed with the electric field and collective effect due to the presence of plasma. A new technique using CCD camera with H α filter applied to measure the two-dimensional distribution of H- density. In the ionic plasma, H α light is emitted via electron-impact excitation and mutual neutralization processes with H- ion and proton. Comparing the results obtained with optical emission spectroscopy, electrostatic probe and CRD, it is shown the H α emission is dominated with the mutual neutralization. By subtracting the CCD images with and without beam extraction, it becomes clear that H- ions are extracted not directly from the PG surface but from the bulk of the ionic plasma. The result suggests the initial energy of H- ion is dumped rapidly in the ionic plasma.

  6. Modeling laser produced plasmas with smoothed particle hydrodynamics for next generation advanced light sources

    Science.gov (United States)

    Holladay, Robert; Griffith, Alec; Murillo, Michael S.

    2016-10-01

    A computational model has been developed to study the evolution of a plasma generated by next-generation advanced light sources such as SLAC's LCLS and LANL's proposed MaRIE. Smoothed Particle Hydrodynamics (SPH) is used to model the plasma evolution because of the ease with which it handles the open boundary conditions and large deformations associated with these experiments. Our work extends the basic SPH method by utilizing a two-fluid model of an electron-ion plasma that also incorporates time dependent ionization and recombination by allowing the SPH fluid particles to have an evolving mass based on the mean ionization state of the plasma. Additionally, inter-species heating, thermal conduction, and electric fields are also accounted for. The effects of various initial conditions and model parameters will be presented, with the goal of using this framework to develop a model that can be used in the design and interpretation of future experiments. This work was supported by the Los Alamos National Laboratory Computational Physics Workshop.

  7. Temperature of the Source Plasma in Gradual Solar Energetic Particle Events

    CERN Document Server

    Reames, Donald V

    2015-01-01

    Scattering, during interplanetary transport in large, "gradual" solar energetic-particle (SEP) events, can cause element abundance enhancements or suppressions that depend upon the mass-to-charge ratio A/Q of the ions as an increasing power law early in events and a decreasing power law of the residual ions later. Since the Q values for the ions depend upon the source plasma temperature T, best fits to the power-law dependence of enhancements vs. A/Q provide a fundamentally new method to determine the most probable value of T for these events. We find that fits to the times of increasing and decreasing powers give similar values of T, most commonly (69%) in the range of 0.8-1.6 MK, consistent with the acceleration of ambient coronal plasma by shock waves driven out from the Sun by coronal mass ejections (CMEs). However, 24% of the SEP events studied showed plasma of 2.5-3.2 MK, typical of that previously determined for the smaller impulsive SEP events; these particles may be reaccelerated preferentially by qu...

  8. Magnetospheric Eternally Collapsing Objects (MECOs): Likely New Class of Source of COsmic Particle Acceleration

    CERN Document Server

    Mitra, A

    2005-01-01

    It is known that spinning pulsars could be source of VHE-UHE cosmic particle acceleration. It is also conjectured that (fictitious) spinning Black Holes (BH) could be sites of cosmic particle acceleration. However, it has been shown by Mitra and Leiter and Robertson that General Relativity (GR) actually does not allow the existence or formation of finite mass BHs. It was predicted that the BH Candiadates (BHCs) have strong intrinsic magnetic fields (like pulsars) instead of Event Horizons. And this prediction has tentatively been verified in a series of papers by Robertson & Leiter. Thus all observed BH Candidates are actually not BHs, and, they are expected to be MECOs. Stellar mass MECOs are GR analogs of conventionally known isolated pulsars. While pulsars are/have (i) COLD, i.e., not supported by radiation pressure, MECOs are HOT, i.e., supported primarily by trapped radiation pressure, (ii) upper mass limit of 3-4 $M_solar$ MECOs, being HOT, have no Upper Mass Limit, (iii) surface gravitational red s...

  9. Preliminary study on preparation of BCNO phosphor particles using citric acid as carbon source

    Energy Technology Data Exchange (ETDEWEB)

    Nuryadin, Bebeh W.; Pratiwi, Tripuspita; Faryuni, Irfana D.; Iskandar, Ferry, E-mail: ferry@fi.itb.ac.id; Abdullah, Mikrajuddin; Khairurrijal [Department of Physics, Faculty of Mathematics and Natural Sciences, Institut Teknologi Bandung, Ganesha 10 Bandung, Indonesia 40132 (Indonesia); Ogi, Takashi; Okuyama, Kikuo [Department of Chemical Engineering, Graduate School of Engineering, Hiroshima University, 1-4-1 Kagamiyama, Higashi Hiroshima, Japan 739-8527 (Japan)

    2015-04-16

    A citric acid was used as a carbon source in the preparation of boron carbon oxy-nitride (BCNO) phosphor particles by a facile process. The preparation process was conducted at relatively low temperature 750 °C and at ambient pressure. The prepared BCNO phosphors showed a high photoluminescence (PL) performance at peak emission wavelength of 470 nm under excitation by a UV light 365 nm. The effects of carbon/boron and nitrogen/boron molar ratios on the PL properties were also investigated. The result showed that the emission spectra with a wavelength peak ranging from 444 nm to 496 nm can be obtained by varying carbon/boron ratios from 0.1 to 0.9. In addition, the observations showed that the BCNO phosphor material has two excitation peaks located at the 365 nm (UV) and 420 nm (blue). Based on these observations, we believe that the citric acid derived BCNO phosphor particles can be a promising inexpensive material for phosphor conversion-based white LED.

  10. Mercury isotopes of atmospheric particle bound mercury for source apportionment study in urban Kolkata, India

    Directory of Open Access Journals (Sweden)

    Reshmi Das

    2016-04-01

    Full Text Available Abstract The particle bound mercury (PBM in urban-industrial areas is mainly of anthropogenic origin, and is derived from two principal sources: Hg bound to particulate matter directly emitted by industries and power generation plants, and adsorption of gaseous elemental mercury (GEM and gaseous oxidized mercury (GOM on air particulates from gas or aqueous phases. Here, we measured the Hg isotope composition of PBM in PM10 samples collected from three locations, a traffic junction, a waste incineration site and an industrial site in Kolkata, the largest metropolis in Eastern India. Sampling was carried out in winter and monsoon seasons between 2013–2015. The objective was to understand whether the isotope composition of the PBM represents source composition. The PBM collected from the waste burning site showed little mass independent fractionation (MIF (Δ199Hg = +0.12 to -0.11‰, similar to the signature in liquid Hg and Hg ores around the world with no seasonal variations. Samples from the industrial site showed mostly negative MDF and MIF (δ202Hg = -1.34 to -3.48 ‰ and Δ199Hg = +0.01 to -0.31‰. The MDF is consistent with PBM generated by coal combustion however, the MIF is 0.15‰ more negative compared to the Hg isotope ratios in Indian coals. The traffic junction PBM is probably not produced in situ, but has travelled some distances from nearby industrial sources. The longer residence time of this PBM in the atmosphere has resulted in-aerosol aqueous photoreduction. Thus, the MIF displays a larger range (Δ199Hg = +0.33 to -0.30‰ compared to the signature from the other sites and with more positive values in the humid monsoon season. Different Hg isotopic signature of PBM in the three different sampling locations within the same city indicates that both source and post emission atmospheric transformations play important roles in determining isotopic signature of PBM.

  11. Source apportionment of PM2.5 chemically speciated mass and particle number concentrations in New York City

    Science.gov (United States)

    Masiol, M.; Hopke, P. K.; Felton, H. D.; Frank, B. P.; Rattigan, O. V.; Wurth, M. J.; LaDuke, G. H.

    2017-01-01

    The major sources of fine particulate matter (PM2.5) in New York City (NYC) were apportioned by applying positive matrix factorization (PMF) to two different sets of particle characteristics: mass concentrations using chemical speciation data and particle number concentrations (PNC) using number size distribution, continuously monitored gases, and PM2.5 data. Post-processing was applied to the PMF results to: (i) match with meteorological data, (ii) use wind data to detect the likely locations of the local sources, and (iii) use concentration weighted trajectory models to assess the strength of potential regional/transboundary sources. Nine sources of PM2.5 mass were apportioned and identified as: secondary ammonium sulfate, secondary ammonium nitrate, road traffic exhaust, crustal dust, fresh sea-salt, aged sea-salt, biomass burning, residual oil/domestic heating and zinc. The sources of PNC were investigated using hourly average number concentrations in six size bins, gaseous air pollutants, mass concentrations of PM2.5, particulate sulfate, OC, and EC. These data were divided into 3 periods indicative of different seasonal conditions. Five sources were resolved for each period: secondary particles, road traffic, NYC background pollution (traffic and oil heating largely in Manhattan), nucleation and O3-rich aerosol. Although traffic does not account for large amounts of PM2.5 mass, it was the main source of particles advected from heavily trafficked zones. The use of residual oil had limited impacts on PM2.5 mass but dominates PNC in cold periods.

  12. Indoor air quality in Latino homes in Boulder, Colorado

    Science.gov (United States)

    Escobedo, Luis E.; Champion, Wyatt M.; Li, Ning; Montoya, Lupita D.

    2014-08-01

    Indoor concentrations of airborne pollutants can be several times higher than those found outdoors, often due to poor ventilation, overcrowding, and the contribution of indoor sources within a home. Americans spend most of their time indoors where exposure to poor indoor air quality (IAQ) can result in diminished respiratory and cardiovascular health. This study measured the indoor air quality in 30 homes of a low-income Latino community in Boulder, Colorado during the summer of 2012. Participants were administered a survey, which included questions on their health conditions and indoor air pollution sources like cigarette smoke, heating fuel, and building materials. Twenty-four hour samples of fine particulate matter (PM2.5) from the indoor air were collected in each home; ambient PM2.5 samples were collected each day as well. Concurrent air samples were collected onto 47 mm Teflo and Tissuquartz filter at each location. Teflo filters were analyzed gravimetrically to measure PM2.5 and their extracts were used to determine levels of proteins and endotoxins in the fine fraction. The Tissuquartz filters were analyzed for elemental and organic carbon content (EC/OC). Results indicated that the indoor air contained higher concentrations of PM2.5 than the ambient air, and that the levels of OC were much higher than EC in both indoor and outdoor samples. This community showed no smoking in their homes and kept furry pets indoors at very low rates; therefore, cooking is likely the primary source of indoor PM. For responders with significant exposure to PM, it appeared to be primarily from occupational environments or childhood exposure abroad. Our findings indicate that for immigrant communities such as this, it is important to consider not only their housing conditions but also the relevant prior exposures when conducting health assessments.

  13. Space subdivision for indoor applications

    NARCIS (Netherlands)

    Zlatanova, S.; Liu, L.; Sithole, G.; Zhao, J.; Mortari, F.

    2014-01-01

    This report makes an overview of 2D, 2,5D and 3D approaches for indoor space subdivision for the purpose of indoor navigation. The report starts with a conceptual framework for indoor space utilisation. We introduce and elaborate on the concepts of indoor space (navigable and non-navigable), agent,

  14. Space subdivision for indoor applications

    NARCIS (Netherlands)

    Zlatanova, S.; Liu, L.; Sithole, G.; Zhao, J.; Mortari, F.

    2014-01-01

    This report makes an overview of 2D, 2,5D and 3D approaches for indoor space subdivision for the purpose of indoor navigation. The report starts with a conceptual framework for indoor space utilisation. We introduce and elaborate on the concepts of indoor space (navigable and non-navigable), agent,

  15. Source apportionment of single particles sampled at the industrially polluted town of Port Talbot, United Kingdom by ATOFMS

    Science.gov (United States)

    Taiwo, Adewale M.; Harrison, Roy M.; Beddows, David C. S.; Shi, Zongbo

    2014-11-01

    Single particle analysis of an industrially polluted atmosphere in Port Talbot, South Wales, United Kingdom was conducted using Aerosol-Time-of-Flight Mass Spectrometry (ATOFMS). During the four week sampling campaign, a total of 5,162,018 particles were sized in the size range 0.2-1.9 μm aerodynamic diameter. Of these, 580,798 were successfully ionized generating mass spectra. K-means clustering employed for analysing ATOFMS data utilized 96% of the hit particles to generate 20 clusters. Similar clusters were merged together and 17 clusters were generated from which 7 main particle groups were identified. The particle classes include: K-rich particles (K-CN, K-NO3, K-EC, K-Cl-PO3 and K-HSO4), aged sea salt (Na-NO3), silicate dust (Na-HSiO2), sulphate rich particles (K-HSO4), nitrate rich particles (AlO-NO3), Ca particles (Ca-NO3), carbon-rich particles (Mn-OC, Metallic-EC, EC, EC-NO3 and OC-EC), and aromatic hydrocarbon particles (Arom-CN, Fe-PAH-NO3 and PAH-CN). With the aid of wind sector plots, the K-Cl-PO3 and Na-HSiO2 particle clusters were related to the steelworks blast furnace/sinter plant while Ca-rich particles arose from blast furnace emissions. K-CN, K-EC, Na-HSiO2, K-HSO4, Mn-OC, Arom-CN, Fe-PAH-NO3, and PAH-CN particles were closely linked with emissions from the cokemaking and mills (hot and cold) steelworks sections. The source factors identified by the ATOFMS were compared with those derived from multivariate analysis using Multilinear Engine (ME-2) applied to filter samples analysed off-line. Both methods of source apportionment identified common source factors including those within the steelworks (blast furnace, sinter, cokemaking), as well as marine, traffic and secondary particles, but quantitative attribution of mass is very different.

  16. Seasonal variation, sources and gas/particle partitioning of polycyclic aromatic hydrocarbons in Guangzhou, China.

    Science.gov (United States)

    Yang, Yunyun; Guo, Pengran; Zhang, Qian; Li, Deliang; Zhao, Lan; Mu, Dehai

    2010-05-15

    Air samples were collected weekly at an urban site and a suburban site in Guangzhou City, China, from April 2005 to March 2006, to measure the concentrations of polycyclic aromatic hydrocarbons (PAHs) in the ambient air and study their seasonal variations, gas/particle partitioning, origins and sources. The concentrations of summation Sigma16-PAHs (particle+gas) were 129.9+/-73.1 ng m(-)(3) at the urban site and 120.4+/-48.5 ng m(-)(3) at the suburban site, respectively. It was found that there was no significant difference in PAH concentrations between the urban and suburban sites. Seasonal variations of PAH concentrations at the two sampling sites were similar, with higher levels in the winter that gradually decreased to the lowest levels in the summer. The average concentrations of summation Sigma16-PAHs in the winter samples were approximately three times higher than those of the summer samples because in the summer local emissions dominated, and in the winter the contribution from outside sources or transported PAHs is increased. The plot of logK(p) versus logP(L)(0) for the data sets of summer and winter season samples had significantly different slopes at both sampling sites. The slopes for the winter samples were steeper than those for the summer samples. It was also observed that gas/particle partitioning of PAHs showed different characteristics depending on air parcel trajectories. Steeper slopes were obtained for an air parcel that traveled across the continent to the sampling site from the northern or northeastern sector, whereas shallower slopes were obtained for air masses that traveled across the sea from the southern or eastern sector. Diagnostic ratio analytical results imply that the origins of PAHs were mainly from petroleum combustion and coal/biomass burning. The anthracene/phenanthrene and benzo[a]anthracene/chrysene ratios in the winter were significantly lower than those in the summer, which indicate that there might be long

  17. Indoor Environmental Control Practices and Asthma Management.

    Science.gov (United States)

    Matsui, Elizabeth C; Abramson, Stuart L; Sandel, Megan T

    2016-11-01

    Indoor environmental exposures, particularly allergens and pollutants, are major contributors to asthma morbidity in children; environmental control practices aimed at reducing these exposures are an integral component of asthma management. Some individually tailored environmental control practices that have been shown to reduce asthma symptoms and exacerbations are similar in efficacy and cost to controller medications. As a part of developing tailored strategies regarding environmental control measures, an environmental history can be obtained to evaluate the key indoor environmental exposures that are known to trigger asthma symptoms and exacerbations, including both indoor pollutants and allergens. An environmental history includes questions regarding the presence of pets or pests or evidence of pests in the home, as well as knowledge regarding whether the climatic characteristics in the community favor dust mites. In addition, the history focuses on sources of indoor air pollution, including the presence of smokers who live in the home or care for children and the use of gas stoves and appliances in the home. Serum allergen-specific immunoglobulin E antibody tests can be performed or the patient can be referred for allergy skin testing to identify indoor allergens that are most likely to be clinically relevant. Environmental control strategies are tailored to each potentially relevant indoor exposure and are based on knowledge of the sources and underlying characteristics of the exposure. Strategies include source removal, source control, and mitigation strategies, such as high-efficiency particulate air purifiers and allergen-proof mattress and pillow encasements, as well as education, which can be delivered by primary care pediatricians, allergists, pediatric pulmonologists, other health care workers, or community health workers trained in asthma environmental control and asthma education.

  18. Perpendicular Diffusion in the Transport of Solar Energetic Particles from Unconnected Sources: The Counter-streaming Particle Beams Revisited

    CERN Document Server

    He, H -Q

    2015-01-01

    In some solar energetic particle (SEP) events, a counter-streaming particle beam with a deep depression of flux near 90 degrees pitch angle during the beginning phase is observed. Two different interpretations exist in the community to explain this interesting phenomenon. One explanation invokes the hypothesis of an outer reflecting boundary or a magnetic mirror beyond the observer. The other one considers the effect of the perpendicular diffusion on the transport process of SEPs in the interplanetary space. In this work, we revisit the problem of the counter-streaming particle beams observed in SEP events and discuss the possible mechanisms responsible for the formation of this phenomenon. We clarify some results in previous works.

  19. Size distribution of chemical elements and their source apportionment in ambient coarse, fine, and ultrafine particles in Shanghai urban summer atmosphere.

    Science.gov (United States)

    Lü, Senlin; Zhang, Rui; Yao, Zhenkun; Yi, Fei; Ren, Jingjing; Wu, Minghong; Feng, Man; Wang, Qingyue

    2012-01-01

    Ambient coarse particles (diameter 1.8-10 microm), fine particles (diameter 0.1-1.8 microm), and ultrafine particles (diameter chemical elements was analyzed by means of an enrichment factor method. Our results showed that the average mass concentrations of coarse particles, fine particles and ultrafine particles in the summer air were 9.38 +/- 2.18, 8.82 +/- 3.52, and 2.02 +/- 0.41 microg/m3, respectively. The mass percentage of the fine particles accounted for 51.47% in the total mass of PM10, indicating that fine particles are the major component in the Shanghai ambient particles. SEM/EDX results showed that the coarse particles were dominated by minerals, fine particles by soot aggregates and fly ashes, and ultrafine particles by soot particles and unidentified particles. SRXRF results demonstrated that crustal elements were mainly distributed in the coarse particles, while heavy metals were in higher proportions in the fine particles. Source apportionment revealed that Si, K, Ca, Fe, Mn, Rb, and Sr were from crustal sources, and S, Cl, Cu, Zn, As, Se, Br, and Pb from anthropogenic sources. Levels of P, V, Cr, and Ni in particles might be contributed from multi-sources, and need further investigation.

  20. Particle Swarm Optimization Recurrent Neural Network Based Z-source Inverter Fed Induction Motor Drive

    Directory of Open Access Journals (Sweden)

    R. Selva Santhose Kumar

    2014-06-01

    Full Text Available In this study, the proposal is made for Particle Swarm Optimization (PSO Recurrent Neural Network (RNN based Z-Source Inverter Fed Induction Motor Drive. The proposed method is used to enhance the performance of the induction motor while reducing the Total Harmonic Distortion (THD, eliminating the oscillation period of the stator current, torque and speed. Here, the PSO technique uses the induction motor speed and reference speed as the input parameters. From the input parameters, it optimizes the gain of the PI controller and generates the reference quadrature axis current. By using the RNN, the reference three phase current for accurate control pulses of the voltage source inverter is predicted. The RNN is trained by the input motor actual quadrature axis current and the reference quadrature axis current with the corresponding target reference three phase current. The training process utilized the supervised learning process. Then the proposed technique is implemented in the MATLAB/SIMULINK platform and the effectiveness is analyzed by comparing with the other techniques such as PSO-Radial Biased Neural Network (RBNN and PSO-Artificial Neural Network (ANN. The comparison results demonstrate the superiority of the proposed approach and confirm its potential to solve the problem.

  1. Effect of gas and kerosene space heaters on indoor air quality: a study in homes of Santiago, Chile.

    Science.gov (United States)

    Ruiz, Pablo A; Toro, Claudia; Cáceres, Jorge; López, Gianni; Oyola, Pedro; Koutrakis, Petros

    2010-01-01

    The impact of outdoor and indoor pollution sources on indoor air quality in Santiago, Chile was investigated. Toward this end, 16 homes were sampled in four sessions. Each session included an outdoor site and four homes using different unvented space heaters (electric or central heating, compressed natural gas, liquefied petroleum gas, and kerosene). Average outdoor fine particulate matter (PM2.5) concentrations were very high (55.9 microg x m(-3)), and a large fraction of these particles penetrated indoors. PM2.5 and several PM2.5 components (including sulfate, elemental carbon, organic carbon, metals, and polycyclic aromatic hydrocarbons) were elevated in homes using kerosene heaters. Nitrogen dioxide (NO2) and ultrafine particles (UFPs) were higher in homes with combustion heaters as compared with those with electric heaters or central heating. A regression model was used to assess the effect of heater use on continuous indoor PM2.5 concentrations when windows were closed. The model found an impact only for kerosene heaters (45.8 microg m(-3)).

  2. Long-term aerosol measurements in Gran Canaria, Canary Islands: Particle concentration, sources and elemental composition

    Science.gov (United States)

    Gelado-Caballero, MaríA. D.; López-GarcíA, Patricia; Prieto, Sandra; Patey, Matthew D.; Collado, Cayetano; HéRnáNdez-Brito, José J.

    2012-02-01

    There are very few sets of long-term measurements of aerosol concentrations over the North Atlantic Ocean, yet such data is invaluable in quantifying atmospheric dust inputs to this ocean region. We present an 8-year record of total suspended particles (TSP) collected at three stations on Gran Canaria Island, Spain (Taliarte at sea level, Tafira 269 m above sea level (a.s.l.) and Pico de la Gorra 1930 m a.s.l.). Using wet and dry deposition measurements, the mean dust flux was calculated at 42.3 mg m-2 d-1. Air mass back trajectories (HYSPLIT, NOAA) suggested that the Sahara desert is the major source of African dust (dominant during 32-50% of days), while the Sahel desert was the major source only 2-10% of the time (maximum in summer). Elemental composition ratios of African samples indicate that, despite the homogeneity of the dust in collected samples, some signatures of the bedrocks can still be detected. Differences were found for the Sahel, Central Sahara and North of Sahara regions in Ti/Al, Mg/Al and Ca/Al ratios, respectively. Elements often associated with pollution (Pb, Cd, Ni, Zn) appeared to share a common origin, while Cu may have a predominantly local source, as suggested by a decrease in the enrichment factor (EF) of Cu during dust events. The inter-annual variability of dust concentrations is investigated in this work. During winter, African dust concentration measurements at the Pico de la Gorra station were found to correlate with the North Atlantic Oscillation (NAO) index.

  3. Traffic induced particle resuspension in Paris: Emission factors and source contributions

    Science.gov (United States)

    Amato, F.; Favez, O.; Pandolfi, M.; Alastuey, A.; Querol, X.; Moukhtar, S.; Bruge, B.; Verlhac, S.; Orza, J. A. G.; Bonnaire, N.; Le Priol, T.; Petit, J.-F.; Sciare, J.

    2016-03-01

    Gaining knowledge on the process of particle resuspension from urban paved roads is of particular importance considering the increasing relevance of this source in urban air quality management and the lack of basic information on emission factors and source contributions. In this study we performed extensive field measurements for the quantification of the emission factors from different types of road in the city of Paris, and investigated the causes of their variability and the contributions to the ambient air PM10 observed across one year at one traffic monitoring site in the ring road of Paris. Results show agreement between lower road dust loadings (RD10: 0.7-2.2 mg m-2) and emission factors (5.4-9.0 mg vehicle-1 km-1) at inner-roads of Paris, compared to the ring road (2.4 mg m-2 and 17 mg vehicle-1 km-1, respectively), where the two parameters are estimated independently. The higher values in the ring road were likely caused by the poor state of pavement and higher share of heavy duty vehicles. Road wear, brake wear and a carbonaceous source, were almost equally responsible for 96% of RD10. At the traffic monitoring site located at the ring road (220,000 vehicle/day), the contributions of road dust emissions were estimated by receptor modeling to be 13% of PM10 on an annual mean (6.3 μg m-3), while the sum of vehicle exhaust and wear accounted for 47% resulting in a total traffic contribution of 60% of PM10. Road salting resulted to be a minor contributor (1% of annual mean) also in winter time (2%).

  4. Towards Mobile Information Systems for Indoor Space

    Directory of Open Access Journals (Sweden)

    Xiaoxiang Zhang

    2016-01-01

    Full Text Available With the rapid development of Internet of things (IOT and indoor positioning technologies such as Wi-Fi and RFID, indoor mobile information systems have become a new research hotspot. Based on the unique features of indoor space and urgent needs on indoor mobile applications, in this paper we analyze some key issues in indoor mobile information systems, including positioning technologies in indoor environments, representation models for indoor spaces, query processing techniques for indoor moving objects, and index structures for indoor mobile applications. Then, we present an indoor mobile information management system named IndoorDB. Finally, we give some future research topics about indoor mobile information systems.

  5. Indoor environmental health

    CSIR Research Space (South Africa)

    Parsons, SA

    2010-04-01

    Full Text Available Indoor Environmental Health (IEH) is a comprehensive term that includes the effects of quantity of air, light and noise in a space and the physical, physiological and psychological aspects from colours, aesthetics, services, outdoor climate...

  6. Indoor climate seminar. Sisaeilmastoseminaari

    Energy Technology Data Exchange (ETDEWEB)

    Seppaenen, O. (ed.) (Helsinki Univ. of Technology, Otaniemi (Finland). Lab. of Heating, Ventilation and Air Conditioning)

    1990-01-01

    The national energy research programme LVIS-2000: Future Building Services is concerned with the control of energy use and indoor climate in buildings of the future. The projects were presented at a one day seminar arranged by the Laboratory of Heating and Ventilation of the Technical Research Centre in Finland which is coordinating the programme. The topics presented at the seminar were: The effect of indoor air on health in office buildings, The effect of air temperature on performance of office work, Emissions from building and interior materials, Experiences of odour panels in indoor climate research, Mould spores and bacteries in the indoor air of rural houses, Ventilation systems in future buildings, Demonstration project of ventilation systems in a block of flats.

  7. Indoor climate seminar; Sisaeilmastoseminaari

    Energy Technology Data Exchange (ETDEWEB)

    Seppaenen, O. [ed.] [Helsinki Univ. of Technology, Otaniemi (Finland). Lab. of Heating, Ventilation and Air Conditioning

    1990-12-31

    The national energy research programme LVIS-2000: Future Building Services is concerned with the control of energy use and indoor climate in buildings of the future. The projects were presented at a one day seminar arranged by the Laboratory of Heating and Ventilation of the Technical Research Centre in Finland which is coordinating the programme. The topics presented at the seminar were: The effect of indoor air on health in office buildings, The effect of air temperature on performance of office work, Emissions from building and interior materials, Experiences of odour panels in indoor climate research, Mould spores and bacteries in the indoor air of rural houses, Ventilation systems in future buildings, Demonstration project of ventilation systems in a block of flats.

  8. Indoor environmental health

    CSIR Research Space (South Africa)

    Parsons, S

    2010-01-01

    Full Text Available Indoor Environmental Health (IEH) is a comprehensive term that includes the effects of quantity of air, light and noise in a space and the physical, physiological and psychological aspects from colours, aesthetics, services, outdoor climate...

  9. Great Indoors Awards 2007

    Index Scriptorium Estoniae

    2007-01-01

    Hollandis Maastrichtis jagati 17. XI esimest korda rahvusvahelist auhinda The Great Indoors Award. Aasta sisekujundusfirmaks valiti Masamichi Katayama asutatud Wonderwall. Auhinna said veel Zaha Hadid, Heatherwick Studio, Ryui Nakamura Architects ja Item Idem

  10. Internal Combustion Engines as the Main Source of Ultrafine Particles in Residential Neighborhoods: Field Measurements in the Czech Republic

    Directory of Open Access Journals (Sweden)

    Jitka Stolcpartova

    2015-11-01

    Full Text Available Ultrafine particles (UFP, diameter < 100 nm exposure has already been associated with adverse effects on human health. Spatial distribution of UFP is non-uniform; they concentrate in the vicinity of the source, e.g. traffic, because of their short lifespan. This work investigates spatial distribution of UFP in three areas in the Czech Republic with different traffic load: High traffic (Prague neighborhood—Sporilov, commuter road vicinity (Libeznice, and a small city with only local traffic (Celakovice. Size-resolved measurements of particles in the 5–500 nm range were taken with a particle classifier mounted, along with batteries, GPS and other accessories, on a handcart and pushed around the areas, making one-minute or longer stops at places of interest. Concentrations along main roads were elevated in comparison with places farther from the road; this pattern was observed in all sites, while particle number distributions both close and away from main roads had similar patterns. The absence of larger particles, the relative absence of higher concentrations of particles away from the main roads, and similar number distributions suggest that high particle number concentrations cannot be readily attributed to sources other than internal combustion engines in vehicles and mobile machinery (i.e., mowers and construction machines.

  11. Morphology, composition, and mixing state of primary particles from combustion sources - crop residue, wood, and solid waste.

    Science.gov (United States)

    Liu, Lei; Kong, Shaofei; Zhang, Yinxiao; Wang, Yuanyuan; Xu, Liang; Yan, Qin; Lingaswamy, A P; Shi, Zongbo; Lv, Senlin; Niu, Hongya; Shao, Longyi; Hu, Min; Zhang, Daizhou; Chen, Jianmin; Zhang, Xiaoye; Li, Weijun

    2017-07-11

    Morphology, composition, and mixing state of individual particles emitted from crop residue, wood, and solid waste combustion in a residential stove were analyzed using transmission electron microscopy (TEM). Our study showed that particles from crop residue and apple wood combustion were mainly organic matter (OM) in smoldering phase, whereas soot-OM internally mixed with K in flaming phase. Wild grass combustion in flaming phase released some Cl-rich-OM/soot particles and cardboard combustion released OM and S-rich particles. Interestingly, particles from hardwood (pear wood and bamboo) and softwood (cypress and pine wood) combustion were mainly soot and OM in the flaming phase, respectively. The combustion of foam boxes, rubber tires, and plastic bottles/bags in the flaming phase released large amounts of soot internally mixed with a small amount of OM, whereas the combustion of printed circuit boards and copper-core cables emitted large amounts of OM with Br-rich inclusions. In addition, the printed circuit board combustion released toxic metals containing Pb, Zn, Sn, and Sb. The results are important to document properties of primary particles from combustion sources, which can be used to trace the sources of ambient particles and to know their potential impacts in human health and radiative forcing in the air.

  12. Distribution pattern of legacy and "novel" brominated flame retardants in different particle size fractions of indoor dust in Birmingham, United Kingdom.

    Science.gov (United States)

    Al-Omran, Layla Salih; Harrad, Stuart

    2016-08-01

    This study investigates the particle size distribution of eight polybrominated diphenyl ethers (PBDEs) and five "novel" brominated flame retardants (NBFRs) in settled house dust. Elevated surface dust (ESD) and floor dust (FD) were collected from 5 homes in Birmingham, UK, yielding a total of 10 samples. Each sample was fractionated into three different particle sizes: 125-250 μm (P1), 63-125 μm (P2) and 25-63 μm (P3). Non-fractionated bulk dust samples (BD) were also analysed. BDE-209 predominated, comprising an average 74.3%, 77.3%, 69.2%, and 62.7% ΣBFRs of BD, P1, P2 and P3 respectively. Σ5NBFRs contributed 24.2%, 21.5%, 29.0% and 35.3% ΣBFRs, while Σ7tri-hepta-BDEs represented 1.5%, 1.2%, 1.7%, and 2.0% ΣBFRs. BEH-TEBP was the predominant NBFR contributing 76.9%, 75.1%, 83.1%, and 83.9% ΣNBFRs in BD, P1, P2 and P3 respectively; followed by DBDPE which contributed 20.1%, 21.9%, 14.1% and 13.9% ΣNBFRs. EH-TBB, BTBPE and PBEB were the least abundant NBFRs. Concentrations of Σ7tri-hepta-BDEs and BEH-TEBP in P3 exceeded significantly (P surface area to volume ratio, rather than by variations in organic carbon content. Copyright © 2016. Published by Elsevier Ltd.

  13. Source apportionment of particles at Station Nord, North East Greenland during 2008–2010 using COPREM and PMF analysis

    DEFF Research Database (Denmark)

    Nguyen, Quynh; Skov, Henrik; Sørensen, Lise Lotte;

    2013-01-01

    , which were all influenced by metal industries. One anthropogenic source was dominated by Zn of which air mass back trajectories using the Hybrid Single Particle Lagrangian Integrated Trajectory (HYSPLIT) model suggested a Canadian Arctic origin, despite certain influences from Southern and Eastern......In order to develop strategies for controlling and reducing Arctic air pollution, there is a need to understand the basic mechanisms for determining the fate of air pollution in the Arctic. Sources of atmospheric particles at Station Nord (81° 36' N, 16° 40' W) in North East Greenland were...

  14. Image Based Indoor Navigation

    OpenAIRE

    Noreikis, Marius

    2014-01-01

    Over the last years researchers proposed numerous indoor localisation and navigation systems. However, solutions that use WiFi or Radio Frequency Identification require infrastructure to be deployed in the navigation area and infrastructureless techniques, e.g. the ones based on mobile cell ID or dead reckoning suffer from large accuracy errors. In this Thesis, we present a novel approach of infrastructure-less indoor navigation system based on computer vision Structure from Motion techniques...

  15. Impacts of natural emission sources on particle pollution levels in Europe

    Science.gov (United States)

    Liora, Natalia; Poupkou, Anastasia; Giannaros, Theodore M.; Kakosimos, Konstantinos E.; Stein, Olaf; Melas, Dimitrios

    2016-07-01

    The main objective of this work is the study of the impact of windblown dust, sea-salt aerosol and biogenic emissions on particle pollution levels in Europe. The Natural Emissions MOdel (NEMO) and the modelling system consisted of the Weather Research and Forecasting model (WRF) and the Comprehensive Air Quality model with extensions (CAMx) were applied in a 30 km horizontal resolution grid, which covered Europe and the adjacent areas for the year 2009. Air quality simulations were performed for different emission scenarios in order to study the contribution of each natural emission source individually and together to air quality levels in Europe. The simulations reveal that the exclusion of windblown dust emissions decreases the mean seasonal PM10 levels by more than 3.3 μg/m3 (∼20%) in the Eastern Mediterranean during winter while an impact of 3 μg/m3 was also found during summer. The results suggest that sea-salt aerosol has a significant effect on PM levels and composition. Eliminating sea-salt emissions reduces PM10 seasonal concentrations by around 10 μg/m3 in Mediterranean Sea during summer while a decrease of up to 6 μg/m3 is found in Atlantic Ocean during autumn. Sea-salt particles also interact with the anthropogenic component and therefore their absence in the atmosphere decreases significantly the nitrates in aerosols where shipping activities are present. The exclusion of biogenic emissions in the model runs leads to a significant reduction of secondary organic aerosols of more than 90% while an increase in PM2.5 levels in central Europe and Eastern Mediterranean is found due to their interaction with anthropogenic component.

  16. New particle formation events as a source for cloud condensation nuclei in an urban environment

    Science.gov (United States)

    Wonaschütz, Anna; Burkart, Julia; Wagner, Robert; Reischl, Georg; Steiner, Gerhard; Hitzenberger, Regina

    2014-05-01

    Nucleation and growth events have been observed in many remote, urban and rural environments. The new particles can contribute significantly to cloud condensation nuclei concentrations, after growing into the appropriate size range (Kerminen et al., 2012). Several studies have attempted to quantify this contribution (e.g. Asmi et al., 2011, Matsui et al., 2013), but only a limited number of them to date have used simultaneous measurements of CCN concentrations and particle size distributions for this purpose (e.g. Levin et al., 2012). In this study, a data set from an urban background station, consisting of 22 months of size distribution and 12 months of CCN concentration measurements (Burkart et al., 2011, Burkart et al., 2012) with 10 months of overlapping measurements is combined to explore the variability of CCN concentrations, their possible causes, and the contribution of nucleation and growth events to CCN concentrations. Consistent with observations in many other locations, nucleation and growth events occur on 30% of all days in spring and summer, on 11% of days in fall and on 4% of days in winter. This suggests a potentially large source of CCN from nucleation and growth events, particularly in the warm season. We acknowledge funding from FWF (Austrian Science Fund) P19515-N20 References: Asmi E., Kivekas, N., Kerminen, V. M., Komppula, M., Hyvarinen, A. P., Hatakka, J., Viisanen, Y., and Lihavainen, H.: Secondary new particle formation in Northern Finland Pallas site between the years 2000 and 2010, Atmos. Chem. Phys., 11, 12959-12972, doi: 10.5194/acp-11-12959-2011, 2011 Burkart J., Steiner, G., Reischl, G., and Hitzenberger, R.: Long-term study of cloud condensation nuclei (CCN) acticvation of the atmospheric aerosol in Vienna, Atmos. Environ., 45, 5751-5759, doi: 10.1016/j.atmosenv.2011.07.022, 2011. Burkart J., Hitzenberger, R., Reischl, G., Bauer, H., Leder, K., and Puxbaum, H.: Activation of "synthetic ambient" aerosols - relation to chemical

  17. The study of indoor air pollution by means of magnetometry

    Science.gov (United States)

    Jelenska, M.; Górka-Kostrubiec, B.; Król, E.

    2012-04-01

    various contribution of MD grains. XARM /SIRM indicates the dominant size of particles between 0.03 and 0.1 um. Concentration of 20 elements demonstrate linear correlation with X, ARM, SIRM and Ms values with the best correlation between concentration of heavy metals and Ms. As the results of the study several rules of spatial and seasonal distribution of pollution inside the city were established. The finest particles were found in dust from the highest floor and from the places lying the most away from the source of pollution. High contamination level is find not only for places exposed to heavy traffic but also in rural area with frequent use of coal for home heating.

  18. Effect of substrate particle size and additional nitrogen source on production of lignocellulolytic enzymes by Pleurotus ostreatus strains.

    Science.gov (United States)

    Membrillo, Isabel; Sánchez, Carmen; Meneses, Marcos; Favela, Ernesto; Loera, Octavio

    2008-11-01

    Two strains of Pleurotus ostreatus (IE-8 and CP-50) were grown on defined medium added with wheat straw extract (WSE). Mycelia from these cultures were used as an inoculum for solid fermentation using sugar cane bagasse (C:N=142). This substrate was used separately either as a mixture of heterogeneous particle sizes (average size 2.9 mm) or as batches with two different particle sizes (0.92 mm and 1.68 mm). Protein enrichment and production of lignocellulolytic enzymes on each particle size was compared. The effect of ammonium sulphate (AS) addition was also analyzed (modified C:N=20), this compound favored higher levels of protein content. Strain CP-50 showed the highest increase of protein content (48% on particle size of 1.68 mm) when compared to media with no additional N source. However, strain IE-8 produced the highest levels of all enzymes: xylanases (5.79 IU/g dry wt on heterogeneous particles) and cellulases (0.18 IU/g dry wt on smallest particles), both without the addition of AS. The highest laccase activity (0.040 IU/g dry wt) was obtained on particles of 1.68 mm in the presence of AS. Since effect of particle size and addition AS was different for each strain, these criteria should be considered for diverse biotechnological applications.

  19. 四种类型公共场所室内细颗粒物水平影响因素的研究%Pollutions of indoor fine particles in four types of public places and the Influencing factors

    Institute of Scientific and Technical Information of China (English)

    刘波; 邓芙蓉; 郭新彪; 杨冬梅; 滕秀全; 郑旭; 高静; 董静; 吴少伟

    2009-01-01

    235.3 )μg/ m3,(750.6±521.6)μg/m3 and(157.5±98.5)μg/m3 respectively. The concentrations of PM2.5 in restaurant (compared with bath center: Z= -10.785,P 2 ) was relatively good. The number of smokers per cube meters ( 14. 7 ×10-3) became the major influence factor when the ventilation soore≤2 (b=140.957, t= 3.108, P= 0.013) and 51.8% increases of indoor PM2.5was attributed to smoking. Conclusion This study indicated that smoking was the main source of indoor PM2.5 in public places. Outdoor PM2.5 should be correlated with indoor PM2.5 concentration under drafty situation.

  20. Combustion-generated indoor air pollution

    Energy Technology Data Exchange (ETDEWEB)

    Hollowell, C.D.; Budnitz, R.J.; Traynor, G.W.

    1976-12-01

    It is obvious from this study that elevated levels of gaseous air pollutants (CO, NO, NO/sub 2/, and SO/sub 2/) and particulate sulfur and nitrogen compounds are present in indoor environments with gas cooking and heating appliances. High levels of CO and NO/sub 2/ approach or exceed promulgated and proposed ambient air quality standards. Such findings certainly indicate a potential impact of combustion-generated indoor air pollution on human health; and if borne out by further work, they may ultimately have a large impact on the future design of epidemiological studies, on energy conservation strategies for buildings, and on the need for more stringent control of air pollution from indoor combustion sources.

  1. Impact of operating wood-burning stoves on indoor air quality

    DEFF Research Database (Denmark)

    Afshari, Alireza; Jensen, Ole Michael; Bergsøe, Niels Christian;

    2011-01-01

    A field study on the impact of operating and reloading wood-burning stoves on the indoor air quality was carried out during two consecutive winters. In contrast to the majority of recent studies, which focussed on the ambient air quality and the penetration of particles to the indoor air, this st......A field study on the impact of operating and reloading wood-burning stoves on the indoor air quality was carried out during two consecutive winters. In contrast to the majority of recent studies, which focussed on the ambient air quality and the penetration of particles to the indoor air...

  2. Particle loading rates for HVAC filters, heat exchangers, and ducts.

    Science.gov (United States)

    Waring, M S; Siegel, J A

    2008-06-01

    The rate at which airborne particulate matter deposits onto heating, ventilation, and air-conditioning (HVAC) components is important from both indoor air quality (IAQ) and energy perspectives. This modeling study predicts size-resolved particle mass loading rates for residential and commercial filters, heat exchangers (i.e. coils), and supply and return ducts. A parametric analysis evaluated the impact of different outdoor particle distributions, indoor emission sources, HVAC airflows, filtration efficiencies, coils, and duct system complexities. The median predicted residential and commercial loading rates were 2.97 and 130 g/m(2) month for the filter loading rates, 0.756 and 4.35 g/m(2) month for the coil loading rates, 0.0051 and 1.00 g/month for the supply duct loading rates, and 0.262 g/month for the commercial return duct loading rates. Loading rates are more dependent on outdoor particle distributions, indoor sources, HVAC operation strategy, and filtration than other considered parameters. The results presented herein, once validated, can be used to estimate filter changing and coil cleaning schedules, energy implications of filter and coil loading, and IAQ impacts associated with deposited particles. The results in this paper suggest important factors that lead to particle deposition on HVAC components in residential and commercial buildings. This knowledge informs the development and comparison of control strategies to limit particle deposition. The predicted mass loading rates allow for the assessment of pressure drop and indoor air quality consequences that result from particle mass loading onto HVAC system components.

  3. Particle model of full-size ITER-relevant negative ion source.

    Science.gov (United States)

    Taccogna, F; Minelli, P; Ippolito, N

    2016-02-01

    This work represents the first attempt to model the full-size ITER-relevant negative ion source including the expansion, extraction, and part of the acceleration regions keeping the mesh size fine enough to resolve every single aperture. The model consists of a 2.5D particle-in-cell Monte Carlo collision representation of the plane perpendicular to the filter field lines. Magnetic filter and electron deflection field have been included and a negative ion current density of j(H(-)) = 660 A/m(2) from the plasma grid (PG) is used as parameter for the neutral conversion. The driver is not yet included and a fixed ambipolar flux is emitted from the driver exit plane. Results show the strong asymmetry along the PG driven by the electron Hall (E × B and diamagnetic) drift perpendicular to the filter field. Such asymmetry creates an important dis-homogeneity in the electron current extracted from the different apertures. A steady state is not yet reached after 15 μs.

  4. Particle model of full-size ITER-relevant negative ion source

    Energy Technology Data Exchange (ETDEWEB)

    Taccogna, F., E-mail: francesco.taccogna@nanotec.cnr.it; Minelli, P. [CNR-Nanotec, Bari 70126 (Italy); INFN, Bari 70126 (Italy); Ippolito, N. [INFN, Bari 70126 (Italy)

    2016-02-15

    This work represents the first attempt to model the full-size ITER-relevant negative ion source including the expansion, extraction, and part of the acceleration regions keeping the mesh size fine enough to resolve every single aperture. The model consists of a 2.5D particle-in-cell Monte Carlo collision representation of the plane perpendicular to the filter field lines. Magnetic filter and electron deflection field have been included and a negative ion current density of j{sub H{sup −}} = 660 A/m{sup 2} from the plasma grid (PG) is used as parameter for the neutral conversion. The driver is not yet included and a fixed ambipolar flux is emitted from the driver exit plane. Results show the strong asymmetry along the PG driven by the electron Hall (E × B and diamagnetic) drift perpendicular to the filter field. Such asymmetry creates an important dis-homogeneity in the electron current extracted from the different apertures. A steady state is not yet reached after 15 μs.

  5. Solar energetic particles a modern primer on understanding sources, acceleration and propagation

    CERN Document Server

    Reames, Donald V

    2017-01-01

    This concise primer introduces the non-specialist reader to the physics of solar energetic particles (SEP) and systematically reviews the evidence for the two main mechanisms which lead to the so-called impulsive and gradual SEP events. More specifically, the timing of the onsets, the longitude distributions, the high-energy spectral shapes, the correlations with other solar phenomena (e.g. coronal mass ejections), as well as the all-important elemental and isotopic abundances of SEPs are investigated. Impulsive SEP events are related to magnetic reconnection in solar flares and jets. The concept of shock acceleration by scattering on self-amplified Alfvén waves is introduced, as is the evidence of reacceleration of impulsive-SEP material in the seed population accessed by the shocks in gradual events. The text then develops processes of transport of ions out to an observer. Finally, a new technique to determine the source plasma temperature in both impulsive and gradual events is demonstrated. Last but not ...

  6. Simulations of the L H transition dynamics with different heat and particle sources

    Institute of Scientific and Technical Information of China (English)

    李会东; 王占辉; Jan Weiland; 冯灏; 孙卫国

    2015-01-01

    It is crucial to increase the total stored energy by realizing the transition from a low confinement (L-mode) state to a high confinement (H-mode) state in magnetic confinement fusion. The L–H transition process is simulated by using the predictive transport code based on Weiland’s fl uid model. Based on the equilibrium parameters obtained from equilibrium fitting (EFIT) in the experiment, the electron density ne, electron temperature Te, ion temperatures Ti, ion poloidal Vp, and toroidal momenta Vt are simulated self-consistently. The L–H transition dynamic behaviors with the formation of the transport barriers of ion and electron temperatures, the electron density, and the ion toroidal momenta are analyzed. During the L–H transition, the strong poloidal fl ow shear in the edge transport barrier region is observed. The crashes of the electron and ion temperature pedestals are also observed during the L–H transition. The effects of the heating and particle sources on the L–H transition process are studied systematically, and the critical power threshold of the L–H transition is also found.

  7. Particle model of full-size ITER-relevant negative ion source

    Science.gov (United States)

    Taccogna, F.; Minelli, P.; Ippolito, N.

    2016-02-01

    This work represents the first attempt to model the full-size ITER-relevant negative ion source including the expansion, extraction, and part of the acceleration regions keeping the mesh size fine enough to resolve every single aperture. The model consists of a 2.5D particle-in-cell Monte Carlo collision representation of the plane perpendicular to the filter field lines. Magnetic filter and electron deflection field have been included and a negative ion current density of jH- = 660 A/m2 from the plasma grid (PG) is used as parameter for the neutral conversion. The driver is not yet included and a fixed ambipolar flux is emitted from the driver exit plane. Results show the strong asymmetry along the PG driven by the electron Hall (E × B and diamagnetic) drift perpendicular to the filter field. Such asymmetry creates an important dis-homogeneity in the electron current extracted from the different apertures. A steady state is not yet reached after 15 μs.

  8. Particle Acceleration Inside Thunderstorms and the Variation in Source Spectra of Terrestrial Gamma-ray Flashes

    Science.gov (United States)

    Cramer, Eric; Dwyer, Joseph R.; Briggs, Michael S.; Rassoul, Hamid K.

    2016-03-01

    One of the unresolved questions in the atmospheric sciences is the origin of Terrestrial Gamma-ray Flashes (TGFs). These flashes are short but intense gamma ray bursts emanating from Earth's atmosphere. This phenomenon has been observed by gamma ray detectors on orbiting satellites, e.g. NASA Fermi, intended to study astrophysical phenomena such as Gamma-ray Bursts. TGFs are thought to originate inside thunderstorms where electrons can be accelerated and emit radiation in the multi MeV range due to bremsstrahlung interactions with air molecules. These so called ``runaway electrons'' are seeded from cosmic ray air showers hitting the Earth's atmosphere from (extra) galactic sources. In this work, we present a Monte Carlo model that simulates particle physics inside a thunderstorm region. The subsequent transport of high energy gamma rays through the Earth's atmosphere and up to satellite orbit is also included. We show that by varying both the potential difference and the ambient electric field inside the thundercloud, different electron and photon energy distributions are produced. This effect may be detectable by orbiting spacecraft, and therefore serves as a method to remote sense the electric fields that exist inside thunderstorms.

  9. Effect of an electric field on superfluid helium scintillation produced by alpha-particle sources

    CERN Document Server

    Ito, T M; Ramsey, J; Karcz, M; Liu, C -Y; Long, J C; Reddy, T G; Seidel, G M

    2012-01-01

    We report a study of the intensity and time dependence of scintillation produced by weak alpha particle sources in superfluid helium in the presence of an electric field (0 - 45 kV/cm) in the temperature range of 0.2 K to 1.1 K at the saturated vapor pressure. Both the prompt and the delayed components of the scintillation exhibit a reduction in intensity with the application of an electric field. The reduction in the intensity of the prompt component is well approximated by a linear dependence on the electric field strength with a reduction of 15% at 45 kV/cm. When analyzed using the Kramers theory of columnar recombination, this electric field dependence leads to the conclusion that roughly 40% of the scintillation results from species formed from atoms originally promoted to excited states and 60% from excimers created by ionization and subsequent recombination with the charges initially having a cylindrical Gaussian distribution about the alpha track of 60 nm radius. The intensity of the delayed component...

  10. Effect of an electric field on superfluid helium scintillation produced by α-particle sources

    Science.gov (United States)

    Ito, T. M.; Clayton, S. M.; Ramsey, J.; Karcz, M.; Liu, C.-Y.; Long, J. C.; Reddy, T. G.; Seidel, G. M.

    2012-04-01

    We report a study of the intensity and time dependence of scintillation produced by weak α-particle sources in superfluid helium in the presence of an electric field (0-45 kV/cm) in the temperature range of 0.2 to 1.1 K at the saturated vapor pressure. Both the prompt and the delayed components of the scintillation exhibit a reduction in intensity with the application of an electric field. The reduction in the intensity of the prompt component is well approximated by a linear dependence on the electric field strength with a reduction of 15% at 45 kV/cm. When analyzed using the Kramers theory of columnar recombination, this electric field dependence leads to the conclusion that roughly 40% of the scintillation results from species formed from atoms originally promoted to excited states and 60% from excimers created by ionization and subsequent recombination with the charges initially having a cylindrical Gaussian distribution about the α track of 60 nm radius. The intensity of the delayed component of the scintillation has a stronger dependence on the electric field strength and on temperature. The implications of these data on the mechanisms affecting scintillation in liquid helium are discussed.

  11. Identifying indoor environmental patterns from bioaerosol material using HPLC.

    Science.gov (United States)

    Staton, Sarah J R; Castillo, Josemar A; Taylor, Thomas J; Herckes, Pierre; Hayes, Mark A

    2013-01-01

    A substantial portion of the atmospheric particle budget is of biological origin (human and animal dander, plant and insect debris, etc.). These bioaerosols can be considered information-rich packets of biochemical data specific to the organism of origin. In this study, bioaerosol samples from various indoor environments were analyzed to create identifiable patterns attributable to a source level of occupation. Air samples were collected from environments representative of human high-traffic- and low-traffic indoor spaces along with direct human skin sampling. In all settings, total suspended particulate matter was collected and the total aerosol protein concentration ranged from 0.03 to 1.2 μg/m(3). High performance liquid chromatography was chosen as a standard analysis technique for the examination of aqueous aerosol extracts to distinguish signatures of occupation compared to environmental background. The results of this study suggest that bioaerosol "fingerprinting" is possible with the two test environments being distinguishable at a 97% confidence interval.

  12. Indoor Air Quality and Ventilation in Residential Deep Energy Retrofits

    Energy Technology Data Exchange (ETDEWEB)

    Less, Brennan; Walker, Iain

    2014-06-01

    Because airtightening is a significant part of Deep Energy Retrofits (DERs), concerns about ventilation and Indoor Air Quality (IAQ) have emerged. To investigate this, ventilation and IAQ were assessed in 17 non-smoking California Deep Energy Retrofit homes. Inspections and surveys were used to assess household activities and ventilation systems. Pollutant sampling performed in 12 homes included six-day passive samples of nitrogen dioxide (NO2), formaldehyde and air exchange rate (AER); time-resolved data loggers were used to measure particle counts. Half of the homes provided continuous mechanical ventilation. Despite these homes being twice as airtight (3.0 and 7.6 ACH50, respectively), their median AER was indistinguishable from naturally vented homes (0.36 versus 0.37 hr--1). Numerous problems were found with ventilation systems; however, pollutant levels did not reach levels of concern in most homes. Ambient NO2 standards were exceeded in some gas cooking homes that used legacy ranges with standing pilots, and in Passive House-style homes without range hoods exhausted to outside. Cooking exhaust systems were installed and used inconsistently. The majority of homes reported using low-emitting materials, and formaldehyde levels were approximately half those in conventional new CA homes (19.7 versus 36 ?g/m3), with emissions rates nearly 40percent less (12.3 versus 20.6 ?g/m2/hr.). Presence of air filtration systems led to lower indoor particle number concentrations (PN>0.5: 8.80E+06 PN/m3 versus 2.99E+06; PN>2.5: 5.46E+0.5 PN/m3 versus 2.59E+05). The results indicate that DERs can provide adequate ventilation and IAQ, and that DERs should prioritize source control, particle filtration and well-designed local exhaust systems, while still providing adequate continuous ventilation.

  13. Bio-aerosols in indoor environment: composition, health effects and analysis.

    Science.gov (United States)

    Srikanth, Padma; Sudharsanam, Suchithra; Steinberg, Ralf

    2008-01-01

    Bio-aerosols are airborne particles that are living (bacteria, viruses and fungi) or originate from living organisms. Their presence in air is the result of dispersal from a site of colonization or growth. The health effects of bio-aerosols including infectious diseases, acute toxic effects, allergies and cancer coupled with the threat of bioterrorism and SARS have led to increased awareness on the importance of bio-aerosols. The evaluation of bio-aerosols includes use of variety of methods for sampling depending on the concentration of microorganisms expected. There have been problems in developing standard sampling methods, in proving a causal relationship and in establishing threshold limit values for exposures due to the complexity of composition of bio-aerosols, variations in human response to their exposure and difficulties in recovering microorganisms. Currently bio-aerosol monitoring in hospitals is carried out for epidemiological investigation of nosocomial infectious diseases, research into airborne microorganism spread and control, monitoring biohazardous procedures and use as a quality control measure. In India there is little awareness regarding the quality of indoor air, mould contamination in indoor environments, potential source for transmission of nosocomial infections in health care facilities. There is an urgent need to undertake study of indoor air, to generate baseline data and explore the link to nosocomial infections. This article is a review on composition, sources, modes of transmission, health effects and sampling methods used for evaluation of bio-aerosols, and also suggests control measures to reduce the loads of bio-aerosols.

  14. Standards for securing adequate indoor air quality across Europe

    DEFF Research Database (Denmark)

    Wargocki, Pawel; Carrer, P.; de Oliveira Fernandes, E.

    2013-01-01

    and is determined mainly considering the metabolic CO2 production. It is only applicable if all other pollutants meet WHO guidelines for ambient and indoor air quality. If they do not meet these guidelines after applying source control and when air used for ventilation is clean health-based ventilation rate should......Background: Inadequate IAQ causes a loss of 2 million healthy life years annually in the EU. Europeans spend typically over 85–90% of their time indoors and the main factors that affect negatively the characteristics of the air they breathe are outdoor air used to ventilate indoor spaces and indoor...... effects of IAQ into different components: exposures to indoor and outdoor air pollutants, association with different morbidities and the way ventilation based approaches could minimise their impact. Disability adjusted life years (DALYs), a common metric to allow comparability of impacts on various types...

  15. Indoor air quality in green-renovated vs. non-green low-income homes of children living in a temperate region of US (Ohio)

    Energy Technology Data Exchange (ETDEWEB)

    Coombs, Kanistha C. [University of Cincinnati, Department of Environmental Health, P.O. Box 670056, Cincinnati, OH (United States); Chew, Ginger L. [Centers for Disease Control and Prevention (CDC), National Center for Environmental Health, Air Pollution and Respiratory Health Branch, 4770 Buford Hwy., N.E., MS-F60, Atlanta, GA (United States); Schaffer, Christopher [University of Cincinnati, Department of Environmental Health, P.O. Box 670056, Cincinnati, OH (United States); Ryan, Patrick H. [University of Cincinnati, Department of Environmental Health, P.O. Box 670056, Cincinnati, OH (United States); Department of Pediatrics, Cincinnati Children' s Hospital Medical Center, 3333 Burnet Ave, Cincinnati, OH (United States); Brokamp, Cole; Grinshpun, Sergey A. [University of Cincinnati, Department of Environmental Health, P.O. Box 670056, Cincinnati, OH (United States); Adamkiewicz, Gary [Harvard University, T.H. Chan School of Public Health, Department of Environmental Health, 401 Park Drive, Boston, MA (United States); Chillrud, Steve [Columbia University, Lamont-Doherty Earth Observatory, Geochemistry Division, P.O. Box 8000, Palisades, New York (United States); Hedman, Curtis [University of Wisconsin-Madison, Wisconsin State Laboratory of Hygiene, 465 Henry Mall, Madison, WI (United States); Colton, Meryl [Harvard University, T.H. Chan School of Public Health, Department of Environmental Health, 401 Park Drive, Boston, MA (United States); Ross, Jamie [Columbia University, Lamont-Doherty Earth Observatory, Geochemistry Division, P.O. Box 8000, Palisades, New York (United States); Reponen, Tiina [University of Cincinnati, Department of Environmental Health, P.O. Box 670056, Cincinnati, OH (United States)

    2016-06-01

    Green eco-friendly housing includes approaches to reduce indoor air pollutant sources and to increase energy efficiency. Although sealing/tightening buildings can save energy and reduce the penetration of outdoor pollutants, an adverse outcome can be increased buildup of pollutants with indoor sources. The objective of this study was to determine the differences in the indoor air quality (IAQ) between green and non-green homes in low-income housing complexes. In one housing complex, apartments were renovated using green principles (n = 28). Home visits were conducted immediately after the renovation, and subsequently at 6 months and at 12 months following the renovation. Of these homes, eight homes had pre-renovation home visits; this allowed pre- and post-renovation comparisons within the same homes. Parallel visits were conducted in non-green (control) apartments (n = 14) in a nearby low-income housing complex. The IAQ assessments included PM{sub 2.5}, black carbon, ultrafine particles, sulfur, total volatile organic compounds (VOCs), formaldehyde, and air exchange rate. Data were analyzed using linear mixed-effects models. None of the indoor pollutant concentrations were significantly different between green and non-green homes. However, we found differences when comparing the concentrations before and after renovation. Measured immediately after renovation, indoor black carbon concentrations were significantly lower averaging 682 ng/m{sup 3} in post-renovation vs. 2364 ng/m{sup 3} in pre-renovation home visits (p = 0.01). In contrast, formaldehyde concentrations were significantly higher in post-renovated (0.03 ppm) than in pre-renovated homes (0.01 ppm) (p = 0.004). Questionnaire data showed that opening of windows occurred less frequently in homes immediately post-renovation compared to pre-renovation; this factor likely affected the levels of indoor black carbon (from outdoor sources) and formaldehyde (from indoor sources) more than the renovation status

  16. Dynamic behavior of semivolatile organic compounds in indoor air

    Energy Technology Data Exchange (ETDEWEB)

    Loy, Michael David Van [Univ. of California, Berkeley, CA (United States)

    1998-12-09

    Exposures to a wide range of air pollutants are often dominated by those occurring in buildings because of three factors: 1) most people spend a large fraction of their time indoors, 2) many pollutants have strong indoor sources, and 3) the dilution volume in buildings is generally several orders of magnitude smaller than that of an urban airshed. Semivolatile organic compounds (SVOCS) are emitted by numerous indoor sources, including tobacco combustion, cooking, carpets, paints, resins, and glues, so indoor gasphase concentrations of these compounds are likely to be elevated relative to ambient levels. The rates of uptake and release of reversibly sorbing SVOCS by indoor materials directly affect both peak concentrations and persistence of the pollutants indoors after source elimination. Thus, accurate predictions of SVOC dynamics in indoor air require an understanding of contaminant sorption on surface materials such as carpet and wallboard. The dynamic behaviors of gas-phase nicotine and phenanthrene were investigated in a 20 ms stainless steel chamber containing carpet and painted wallboard. Each compound was studied independently, first in the empty chamber, then with each sorbent individually, and finally with both sorbents in the chamber.

  17. Physical properties of the arctic summer aerosol particles in relation to sources at Ny-Alesund, Svalbard

    Indian Academy of Sciences (India)

    C G Deshpande; A K Kamra

    2014-02-01

    Measurements of the number concentration and size distribution of aerosol particles in the size range of 0.5–20 m diameter were made with an aerodynamic particle sizer at an Arctic site at Ny-Alesund, Svalbard in August–September 2007 during the International Polar Year 2007–2008. Data are analyzed to study the aerosol number concentration–wind speed relationships. The sea-salt particles of marine origin generated within the Arctic circle are identified as the main source of the Arctic summer aerosols. Total number concentration of aerosol particles increases with increase in wind speed, the increase being more when winds from open leads over the oceanic sector are reaching the station as compared to when winds from pack ice in other directions are reaching the station. The larger increase with winds from the oceanic sector is attributed to the enhanced bubble-breaking activity and increased entrainment of dimethyl sulphide particles at the sea surface. Although, the increase in total aerosol number concentration associated with the winds from the oceanic sector is spread over the whole range of particle sizes, the increase in coarse mode particles is more prominent than that in the accumulation mode particles. The age of airmass over pack ice is also an important factor to determine the aerosol concentration over the Arctic region. The process of rainout/washout of the aerosol particles due to drizzle/snowfall is an effective sink mechanism in the Arctic environment. The aerosol particle concentration starts decreasing within a few minutes from the start of these events but requires a few hours to restore to the normal background aerosol level after the end of event.

  18. Source apportionment of particles at Station Nord, North East Greenland during 2008–2010 using COPREM and PMF analysis

    DEFF Research Database (Denmark)

    Nguyen, Quynh; Skov, Henrik; Sørensen, Lise Lotte

    2013-01-01

    In order to develop strategies for controlling and reducing Arctic air pollution, there is a need to understand the basic mechanisms for determining the fate of air pollution in the Arctic. Sources of atmospheric particles at Station Nord (81° 36' N, 16° 40' W) in North East Greenland were......, which were all influenced by metal industries. One anthropogenic source was dominated by Zn of which air mass back trajectories using the Hybrid Single Particle Lagrangian Integrated Trajectory (HYSPLIT) model suggested a Canadian Arctic origin, despite certain influences from Southern and Eastern...... evaluated for a two-year period from March 2008 to February 2010. Source apportionment using Positive Matrix Factorization (PMF) and COnstrained Physical REceptor Model (COPREM) was based on measurements of black carbon, elements (Al, Si, S, K, Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, Ga, As, Se, Br, Rb, Sr, Zr...

  19. Arthroscopic surgical tools: A source of metal particles and possible joint damage

    Science.gov (United States)

    Pedowitz, Robert A.; Billi, Fabrizio; Kavanaugh, Aaron; Colbert, Andrew; Liu, Sen; Savoie, Felix H.; You, Zongbing

    2013-01-01

    Purpose Our goals were (1) to characterize metal micro-particles created by standard arthroscopic instruments, and (2) to examine the in-vitro cellular responses induced by those particles, including possible synergistic effects with local anesthetic. Methods We applied standard surgical tools to 16 foam bone blocks immersed in saline (plus 3 non-instrumented controls). Eight specimens had four minutes of exposure to a 4.0 mm full radius shaver rotating forward at 6,000 RPM. In the other blocks, four holes were created with a 3.0 mm drill via a sleeve. Particles were isolated onto silicon wafers by density gradient ultra-centrifugation, and SEM analyzed a minimum of 1000 particles per wafer. Metal particles were then isolated and purified. Aliquots of sterilized micro-particles were applied to cultured bovine chondrocytes (+/- local anesthetic) and to cultured human or bovine synoviocytes. Chondrocyte viability was assessed with live/dead cell assay by flow cytometry. Synoviocyte responses were assessed with qPCR. Results Stainless steel or aluminum particles were found in each sample (same composition as surgical instruments). Average particle size was 1 to 2 μm (range 50 nm to 20 μm). Chondrocyte exposure (1 hour) to metal debris induced a small but statistically significant increase in cell death, without any synergistic effect of local anesthetic. Proinflammatory chemokines were consistently upregulated in both human and bovine synoviocytes exposed to metallic micro-particles for 3, 24, and 48 hours. Conclusions The current study demonstrates that metallic microdebris is liberated by common arthroscopic instruments, at scales much smaller than previously recognized. These particles are bioactive as demonstrated by the in-vitro synoviocyte responses initiated by metallic micro-particles. Clinical Relevance Our findings suggest that metallic micro-particles could induce intra-articular damage via a synoviocyte-mediated cytokine response if their concentrations

  20. Very High Efficiency, Miniaturized, Long-Lived Alpha Particle Power Source Using Diamond Devices for Extreme Space Environments

    Science.gov (United States)

    Kolawa, Elizabeth A. (Inventor); Patel, Jagdishbhai U. (Inventor); Fleurial, Jean-Pierre (Inventor)

    2004-01-01

    A power source that converts a-particle energy into electricity by coulomb collision in doped diamond films is described. Alpha particle decay from curium-244 creates electron-hole pairs by free- ing electrons and holes inside the crystal lattice in N- and P-doped diamond films. Ohmic contacts provide electrical connection to an electronic device. Due to the built-in electric field at the rectifying junction across the hT- and P-doped diamond films, the free electrons are constrained to traveling in generally one direction. This one direction then supplies electrons in a manner similar to that of a battery. The radioactive curium layer may be disposed on diamond films for even distribution of a-particle radiation. The resulting power source may be mounted on a diamond substrate that serves to insulate structures below the diamond substrate from a-particle emission. Additional insulation or isolation may be provided in order to prevent damage from a-particle collision. N-doped silicon may be used instead of N-doped diamond.

  1. Analysis of particle production in ultrarelativistic heavy-ion collisions within a two-source statistical model

    CERN Document Server

    Zhong Dao Lu; Fuchs, C; Zabrodin, E E; 10.1103/PhysRevC.66.044905

    2002-01-01

    The experimental data on hadron yields and ratios in central lead- lead and gold-gold collisions at 158A GeV/c (SPS) and square root s =130A GeV (RHIC), respectively, are analyzed within a two-source statistical model of an ideal hadron gas. A comparison with the standard thermal model is given. The two sources, which can reach the chemical and thermal equilibrium separately and may have different temperatures, particle and strangeness densities, and other thermodynamic characteristics, represent the expanding system of colliding heavy ions, where the hot central fireball is embedded in a larger but cooler fireball. The volume of the central source increases with rising bombarding energy. Results of the two-source model fit to RHIC experimental data at midrapidity coincide with the results of the one-source thermal model fit, indicating the formation of an extended fireball, which is three times larger than the corresponding core at SPS. (49 refs).

  2. Analysis of particle production in ultra-relativistic heavy ion collisions within a two-source statistical model

    CERN Document Server

    Lu, Z D; Fuchs, C; Zabrodin, E E; Lu, Zhong-Dao; Faesler, Amand

    2002-01-01

    The experimental data on hadron yields and ratios in central lead-lead and gold-gold collisions at 158 AGeV/$c$ (SPS) and $\\sqrt{s} = 130$ AGeV (RHIC), respectively, are analysed within a two-source statistical model of an ideal hadron gas. A comparison with the standard thermal model is given. The two sources, which can reach the chemical and thermal equilibrium separately and may have different temperatures, particle and strangeness densities, and other thermodynamic characteristics, represent the expanding system of colliding heavy ions, where the hot central fireball is embedded in a larger but cooler fireball. The volume of the central source increases with rising bombarding energy. Results of the two-source model fit to RHIC experimental data at midrapidity coincide with the results of the one-source thermal model fit, indicating the formation of an extended fireball, which is three times larger than the corresponding core at SPS.

  3. Source apportionment of wide range particle size spectra and black carbon collected at the airport of Venice (Italy)

    Science.gov (United States)

    Masiol, Mauro; Vu, Tuan V.; Beddows, David C. S.; Harrison, Roy M.

    2016-08-01

    Atmospheric particles are of high concern due to their toxic properties and effects on climate, and large airports are known as significant sources of particles. This study investigates the contribution of the Airport of Venice (Italy) to black carbon (BC), total particle number concentrations (PNC) and particle number size distributions (PNSD) over a large range (14 nm-20 μm). Continuous measurements were conducted between April and June 2014 at a site located 110 m from the main taxiway and 300 m from the runway. Results revealed no significantly elevated levels of BC and PNC, but exhibited characteristic diurnal profiles. PNSD were then analysed using both k-means cluster analysis and positive matrix factorization. Five clusters were extracted and identified as midday nucleation events, road traffic, aircraft, airport and nighttime pollution. Six factors were apportioned and identified as probable sources according to the size profiles, directional association, diurnal variation, road and airport traffic volumes and their relationships to micrometeorology and common air pollutants. Photochemical nucleation accounted for ∼44% of total number, followed by road + shipping traffic (26%). Airport-related emissions accounted for ∼20% of total PNC and showed a main mode at 80 nm and a second mode beyond the lower limit of the SMPS (pollution and local resuspension. An analysis of BC levels over different wind sectors revealed no especially significant contributions from specific directions associated with the main local sources, but a potentially significant role of diurnal dynamics of the mixing layer on BC levels. The approaches adopted in this study have identified and apportioned the main sources of particles and BC at an international airport located in area affected by a complex emission scenario. The results may underpin measures for improving local and regional air quality, and health impact assessment studies.

  4. Sources of organic compounds in fine soil and sand particles during winter in the metropolitan area of Riyadh, Saudi Arabia.

    Science.gov (United States)

    Rushdi, Ahmed I; Al-Mutlaq, Khalid; Simoneit, Bernd R T

    2005-11-01

    Major advances have been made in molecular marker analysis to distinguish between natural and anthropogenic organic matter inputs to the atmosphere. Resuspension of soil and sand by wind is one of the major mechanisms that produces particle dusts in the atmosphere. Soil and sand samples from the Riyadh area were collected in winter 2002, sieved to remove coarse particles and extracted with a mixture of dichloromethane and methanol (3:1, v:v). The total extracts were analyzed by gas chromatography-mass spectrometry in order to characterize the contents and identify the potential sources of the organic components. The major organic compounds of these extracts were derived from natural biogenic and anthropogenic sources. Organic compounds from natural sources, mainly vegetation, were major in samples from outside the city of Riyadh and included n-alkanes, n-alkanoic acids, n- alkanols, methyl alkanoates, and sterols. Anthropogenic inputs were significant in the fine particles of soil and sand samples collected from populated areas of the city. They consisted mainly of n-alkanes, hopanes, UCM (from vehicular emissions), and plasticizers (from discarded plastics, e.g., shopping bags). Carbohydrates had high concentrations in all samples and indicate sources from decomposed cellulose fibers and/or the presence of viable microbiota such as bacteria and fungi.

  5. Indoor air and allergic diseases

    Energy Technology Data Exchange (ETDEWEB)

    Kunkel, G.; Rudolph, R.; Muckelmann, R.

    1982-01-01

    Allergies may be the source of a variety of clinical symptoms. With regard to indoor air, however, the subject will be limited to inhalative allergies. These are diseases which are caused and supported by allergens entering the human organism via the respiratory pathway. The fundamentals of the origin of inhalative allergies are briefly discussed as well as the antigen-antibody reaction and the differentiation between different allergic reactions (Types I and II). In addition, the importance of repetitive infections of the upper respiratory tract for the occurrence of allergies of the respiratory system is pointed out. The most common allergies develop at the mucosae of the nose (allergic rhinitis) and of the bronchiale (allergic asthma bronchiale). Their symptomatology is discussed. Out of the allergologically interesting components of indoor air the following are to be considered primarily: house dust, components of house dust (house dust mite, trogoderma angustum, tenebrio molitor), epithelia of animals, animal feeds, mildew and occupational substances. Unspecific irritants (chemico-physical irritations) which are not acting as allergens, have to be clearly separated from these most frequent allergens. As a possibility of treatment for the therapeutist and the patient, there is the allergen prophylaxis, i.e. an extensive sanitation of the patient's environment including elimination of the allergens and, in addition, an amelioration of the quality of the air with regard to unspecific irritants. To conclude, some socio-medical aspects of respiratory diseases are discussed.

  6. Spatial flow influence factor: A novel concept for indoor air pollutant control

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    This paper puts forward a novel concept, the spatial flow influence factor (SFIF), which provides a new insight into the airflow structure. This concept is very helpful in the control of indoor air pollutants since: (1) for a given indoor airflow and given sources of volatile organic compounds (VOCs), the optimal arrangement of the VOC sources can easily be obtained; (2) for given positions of VOC sources and occupied regions (or target regions), the optimal indoor airflow pattern or organization can be determined; (3) the SFIF for an indoor space can also be regarded as the indoor air safety index of that space. To illustrate this concept, we present several examples of applying a SFIF to indoor air VOC control.

  7. Analysis of charged particle emission sources and coalescence in E/A=61 (MeVAr)-Ar-36+Al-27, Sn-112 and Sn-124 collisions

    NARCIS (Netherlands)

    Avdeichikov, [No Value; Ghetti, R; Helgesson, J; Jakobsson, B; Golubev, P; Colonna, N; Wilschut, HW; Avdeitchikov, V.

    2004-01-01

    Single-particle kinetic energy spectra and two-particle small angle correlations of protons (p), deuterons (d) and tritons (t) have been measured simultaneously in 61 A MeV Ar-36 + Al-27, Sn-112 and Sn-124 collisions. Characteristics of the emission sources have been derived from a "source identific

  8. Study of the atmospheric chemistry of radon progeny in laboratory and real indoor atmospheres. Progress report, May 1, 1993--January 31, 1994

    Energy Technology Data Exchange (ETDEWEB)

    Hopke, P.K.

    1993-01-01

    Progress is reported on the chemical and physical behavior of the {sup 218}Po atom immediately following its formation by the alpha decay of radon. Two areas of radon progeny behavior are being pursued; laboratory studies under controlled conditions to better understand the fundamental physical and chemical processes that affect the progeny`s atmospheric behavior and studies in actual indoor environments to develop a better assessment of the exposure of the occupants of that space to the size and concentration of the indoor radioactive aerosol. The specific tasks addressed were to determine the formation rates of {center_dot}OH radicals formed by the radiolysis of air following radon decay, to examine the formation of particles by the radiolytic oxidation of substances like SO{sub 2}, ethylene, and H{sub 2}S to lower vapor pressure compounds and determine the role of gas phase additives such as H{sub 2}O and NH{sub 3} in determining the particle size, to measure the rate of ion-induced nucleation using a thermal diffusion cloud chamber, and to measure the neutralization rate of {sup 218}PoO{sub x}{sup +} in O{sub 2} at low radon concentrations. Initial measurements were conducted of the activity size distributions in actual homes with occupants present so that the variability of the indoor activity size distributions can be assessed with respect to indoor aerosol sources and general lifestyle variations of the occupants. A prospective study of the utility of measurement of deposited {sup 210}Pb embedded in glass surfaces as a measure of the long-term, integrated exposure of the population to radon are described. Methodology was developed to determine the hygroscopicity of the indoor aerosol so that the changes in deposition efficiency of the radioactive indoor aerosol with hygroscopic growth in the respiratory tract can be assessed.

  9. Indoor Air Quality

    DEFF Research Database (Denmark)

    Selman, Ayser Dawod; Heiselberg, Per

    Overall purpose of the research is to provide an overview of the relevance and importance of various defined Indoor Air Quality (IAQ) parameters in a European perspective. Based on the report it should be possible to prioritize which countries to target for further activities as well as it should...

  10. Indoor Tanning (For Teens)

    Science.gov (United States)

    ... Can Get Weight Loss Surgery? Choosing the Right Sport for You Shyness Indoor ... in the sun is bad for you — sun worshippers have prematurely aging skin, wrinkles, and maybe even skin cancer to look forward to. But what about tanning ...

  11. Indoor Air Quality

    DEFF Research Database (Denmark)

    Selman, Ayser Dawod; Heiselberg, Per

    Overall purpose of the research is to provide an overview of the relevance and importance of various defined Indoor Air Quality (IAQ) parameters in a European perspective. Based on the report it should be possible to prioritize which countries to target for further activities as well as it should...

  12. Modeling indoor air pollution

    National Research Council Canada - National Science Library

    Pepper, D. W; Carrington, David B

    2009-01-01

    ... and ventilation from the more popular textbooks and monographs. We wish to especially acknowledge Dr. Xiuling Wang, who diligently converted many of our old FORTRAN codes into MATLAB files, and also developed the COMSOL example files. Also we thank Ms. Kathryn Nelson who developed the website for the book and indoor air quality computer codes. We are grateful to ...

  13. Indoor Radon Measurement In The City Of Edirne, Turkey

    Science.gov (United States)

    Bozkurt, A.; Kam, E.

    2007-04-01

    This study assesses the indoor radon concentrations for the city of Edirne situated in the European part of Turkey (Eastern Thrace). A total of 88 CR-39 nuclear track detectors were kept in basements of the selected apartment buildings and houses for passively determining the indoor radon levels of the dwellings for a period of three months. The detectors were then collected and a chemical process of etching was applied to the films. At this stage, the tracks left by alpha particles on the films exposed to radon gas were visible and were counted with a microscope (500×magnification) to estimate the corresponding indoor radon concentrations. The average indoor radon concentration was found to be 49.2 Bq/m3 equivalent to an annual effective dose of 1.24 mSv. The measurement results obtained in this study show no significant departure from the other parts of the country.

  14. System and method for measuring particles in a sample stream of a flow cytometer using a low power laser source

    Energy Technology Data Exchange (ETDEWEB)

    Graves, Steven W; Habbersett, Robert C

    2013-10-22

    A system and method for analyzing a particle in a sample stream of a flow cytometer or the like. The system has a light source, such as a laser pointer module, for generating a low powered light beam and a fluidics apparatus which is configured to transport particles in the sample stream at substantially low velocity through the light beam for interrogation. Detectors, such as photomultiplier tubes, are configured to detect optical signals generated in response to the light beam impinging the particles. Signal conditioning circuitry is connected to each of the detectors to condition each detector output into electronic signals for processing and is designed to have a limited frequency response to filter high frequency noise from the detector output signals.

  15. System and method for measuring particles in a sample stream of a flow cytometer using low-power laser source

    Energy Technology Data Exchange (ETDEWEB)

    Graves, Steven W.; Habbersett, Robert C.

    2014-07-01

    A system and method for analyzing a particle in a sample stream of a flow cytometer or the like. The system has a light source, such as a laser pointer module, for generating a low powered light beam and a fluidics apparatus which is configured to transport particles in the sample stream at substantially low velocity through the light beam for interrogation. Detectors, such as photomultiplier tubes, are configured to detect optical signals generated in response to the light beam impinging the particles. Signal conditioning circuitry is connected to each of the detectors to condition each detector output into electronic signals for processing and is designed to have a limited frequency response to filter high frequency noise from the detector output signals.

  16. VERTIGO (VERtical Transport In the Global Ocean): A study of particle sources and flux attenuation in the North Pacific

    Science.gov (United States)

    Buesseler, K. O.; Trull, T. W.; Steinberg, D. K.; Silver, M. W.; Siegel, D. A.; Saitoh, S.-I.; Lamborg, C. H.; Lam, P. J.; Karl, D. M.; Jiao, N. Z.; Honda, M. C.; Elskens, M.; Dehairs, F.; Brown, S. L.; Boyd, P. W.; Bishop, J. K. B.; Bidigare, R. R.

    2008-07-01

    The VERtical Transport In the Global Ocean (VERTIGO) study examined particle sources and fluxes through the ocean's "twilight zone" (defined here as depths below the euphotic zone to 1000 m). Interdisciplinary process studies were conducted at contrasting sites off Hawaii (ALOHA) and in the NW Pacific (K2) during 3-week occupations in 2004 and 2005, respectively. We examine in this overview paper the contrasting physical, chemical and biological settings and how these conditions impact the source characteristics of the sinking material and the transport efficiency through the twilight zone. A major finding in VERTIGO is the considerably lower transfer efficiency ( Teff) of particulate organic carbon (POC), POC flux 500/150 m, at ALOHA (20%) vs. K2 (50%). This efficiency is higher in the diatom-dominated setting at K2 where silica-rich particles dominate the flux at the end of a diatom bloom, and where zooplankton and their pellets are larger. At K2, the drawdown of macronutrients is used to assess export and suggests that shallow remineralization above our 150-m trap is significant, especially for N relative to Si. We explore here also surface export ratios (POC flux/primary production) and possible reasons why this ratio is higher at K2, especially during the first trap deployment. When we compare the 500-m fluxes to deep moored traps, both sites lose about half of the sinking POC by >4000 m, but this comparison is limited in that fluxes at depth may have both a local and distant component. Certainly, the greatest difference in particle flux attenuation is in the mesopelagic, and we highlight other VERTIGO papers that provide a more detailed examination of the particle sources, flux and processes that attenuate the flux of sinking particles. Ultimately, we contend that at least three types of processes need to be considered: heterotrophic degradation of sinking particles, zooplankton migration and surface feeding, and lateral sources of suspended and sinking

  17. VERTIGO (VERtical Transport In the Global Ocean): A study of particle sources and flux attenuation in the North Pacific

    Energy Technology Data Exchange (ETDEWEB)

    Buesseler, K.O.; Trull, T.W.; Steinberg, D.K.; Silver, M.W.; Siegel, D.A.; Saitoh, S.-I.; Lamborg, C.H.; Lam, P.J.; Karl, D.M.; Jiao, N.Z.; Honda, M.C.; Elskens, M.; Dehairs, F.; Brown, S.L.; Boyd, P.W.; Bishop, J.K.B.; Bidigare, R.R.

    2008-06-10

    The VERtical Transport In the Global Ocean (VERTIGO) study examined particle sources and fluxes through the ocean's 'twilight zone' (defined here as depths below the euphotic zone to 1000 m). Interdisciplinary process studies were conducted at contrasting sites off Hawaii (ALOHA) and in the NW Pacific (K2) during 3 week occupations in 2004 and 2005, respectively. We examine in this overview paper the contrasting physical, chemical and biological settings and how these conditions impact the source characteristics of the sinking material and the transport efficiency through the twilight zone. A major finding in VERTIGO is the considerably lower transfer efficiency (T{sub eff}) of particulate organic carbon (POC), POC flux 500/150 m, at ALOHA (20%) vs. K2 (50%). This efficiency is higher in the diatom-dominated setting at K2 where silica-rich particles dominate the flux at the end of a diatom bloom, and where zooplankton and their pellets are larger. At K2, the drawdown of macronutrients is used to assess export and suggests that shallow remineralization above our 150 m trap is significant, especially for N relative to Si. We explore here also surface export ratios (POC flux/primary production) and possible reasons why this ratio is higher at