Chemical characteristics and source apportionment of fine particulate organic carbon in Hong Kong during high particulate matter episodes in winter 2003

Science.gov (United States)

Li, Yun-Chun; Yu, Jian Zhen; Ho, Steven Sai Hang; Schauer, James J.; Yuan, Zibing; Lau, Alexis K. H.; Louie, Peter K. K.

2013-02-01

PM2.5 samples were collected at six general stations and one roadside station in Hong Kong in two periods of high particulate matter (PM) in 2003 (27 October-4 November and 30 November-13 December). The highest PM2.5 reached 216 μg m- 3 during the first high PM period and 113 μg m- 3 during the second high PM period. Analysis of synoptic weather conditions identified individual sampling days under dominant influence of one of three types of air masses, that is, local, regional and long-range transported (LRT) air masses. Roadside samples were discussed separately due to heavy influences from vehicular emissions. This research examines source apportionment of fine organic carbon (OC) and contribution of secondary organic aerosol on high PM days under different synoptic conditions. Six primary OC (POC) sources (vehicle exhaust, biomass burning, cooking, cigarette smoke, vegetative detritus, and coal combustion) were identified on the basis of characteristic organic tracers. Individual POC source contributions were estimated using chemical mass balance model. In the roadside and the local samples, OC was dominated by the primary sources, accounting for more than 74% of OC. In the samples influenced by regional and LRT air masses, secondary OC (SOC), which was approximated to be the difference between the total measured OC and the apportioned POC, contributed more than 54% of fine OC. SOC was highly correlated with water-soluble organic carbon and sulfate, consistent with its secondary nature.

Radioactivity in fine papers

International Nuclear Information System (INIS)

Taylor, H.W.; Singh, B.

1993-01-01

The radioactivity of fine papers has been studied through γ-ray spectroscopy with an intrinsic Ge detector. Samples of paper from European and North American sources were found to contain very different amounts of 226 Ra and 232 Th. The processes which introduce radionuclides into paper are discussed. The radioactivity from fine papers makes only a small contribution to an individual's annual radiation dose; nevertheless it is easily detectable and perhaps, avoidable. (Author)

Origin of fine carbonaceous particulate matter in the Western Mediterranean Basin: fossil versus modern sources

Science.gov (United States)

Cruz Minguillón, María.; Perron, Nolwenn; Querol, Xavier; Szidat, Sönke; Fahrni, Simon; Wacker, Lukas; Reche, Cristina; Cusack, Michael; Baltensperger, Urs; Prévôt, André S. H.

2010-05-01

The present work was carried out in the frame of the international field campaign DAURE (Determination of the sources of atmospheric Aerosols in Urban and Rural Environments in the western Mediterranean). The objective of this campaign is to study the aerosol pollution episodes occurring at regional scale during winter and summer in the Western Mediterranean Basin. As part of this campaign, this work focuses on identifying the origin of fine carbonaceous aerosols. To this end, fine particulate matter (PM1) samples were collected during two different seasons (February-March and July 2009) at two sites: an urban site (Barcelona, NE Spain) and a rural European Supersite for Atmospheric Aerosol Research (Montseny, NE Spain). Subsequently, 14C analyses were carried out on these samples, both in the elemental carbon (EC) fraction and the organic carbon (OC) fraction, in order to distinguish between modern carbonaceous sources (biogenic emissions and biomass burning emissions) and fossil carbonaceous sources (mainly road traffic). Preliminary results from the winter period show that 40% of the OC at Barcelona has a fossil origin whereas at Montseny this percentage is 30%. These values can be considered as unexpected given the nature of the sites. Nevertheless, the absolute concentrations of fossil OC at Barcelona and Montseny differ by a factor of 2 (the first being higher), since the total OC at Montseny is lower than at Barcelona. Further evaluation of results and comparison with other measurements carried out during the campaign are required to better evaluate the origin of the fine carbonaceous matter in the Western Mediterranean Basin. Acknowledgements: Spanish Ministry of Education and Science, for a Postdoctoral Grant awarded to M.C. Minguillón in the frame of Programa Nacional de Movilidad de Recursos Humanos del Plan nacional de I-D+I 2008-2011. Spanish Ministry of Education and Science, for the Acción Complementaria DAURE CGL2007-30502-E/CLI.

Chemical composition of Martian fines

Science.gov (United States)

Clark, B. C.; Baird, A. K.; Weldon, R. J.; Tsusaki, D. M.; Schnabel, L.; Candelaria, M. P.

1982-01-01

Of the 21 samples acquired for the Viking X-ray fluorescence spectrometer, 17 were analyzed to high precision. Compared to typical terrestrial continental soils and lunar mare fines, the Martian fines are lower in Al, higher in Fe, and much higher in S and Cl concentrations. Protected fines at the two lander sites are almost indistinguishable, but concentration of the element S is somewhat higher at Utopia. Duricrust fragments, successfully acquired only at the Chryse site, invariably contained about 50% higher S than fines. No elements correlate positively with S, except Cl and possibly Mg. A sympathetic variation is found among the triad Si, Al, Ca; positive correlation occurs between Ti and Fe. Sample variabilities are as great within a few meters as between lander locations (4500 km apart), implying the existence of a universal Martian regolith component of constant average composition. The nature of the source materials for the regolith fines must be mafic to ultramafic.

Identification and characterization of fine and coarse particulate matter sources in a middle-European urban environment

International Nuclear Information System (INIS)

Kertesz, Zs.; Szoboszlai, Z.; Angyal, A.; Dobos, E.; Borbely-Kiss, I.

2010-01-01

In this work a source apportionment study is presented which aimed to characterize the PM 2.5 and PM 2.5-10 sources in the urban area of Debrecen, East-Hungary by using streaker samples, IBA methods and positive matrix factorization (PMF) analysis. Samples of fine (PM 2.5 ) and coarse (PM 2.5-10 ) urban particulate matter were collected with 2 h time resolution in the frame of five sampling campaigns during 2007-2009 in different seasons in the downtown of Debrecen. Elemental concentrations from Al to Pb of over 1000 samples were obtained by particle induced X-ray emission (PIXE); concentrations of black carbon (BC) were determined with a smoke stain reflectometer. On this data base source apportionment was carried out by using the PMF method. Seven factors were identified for both size fractions, including soil dust, traffic, secondary aerosol - sulphates, domestic heating, oil combustion, agriculture and an unknown factor enriched with chlorine. Seasonal and daily variation of the different factors was studied as well as their dependence on meteorological parameters. Besides determining the time patterns characteristic to the city, several emission episodes were identified including a Saharan dust intrusion on 21st-24th May, 2008.

Determination of cobalt in biological samples by line-source and high-resolution continuum source graphite furnace atomic absorption spectrometry using solid sampling or alkaline treatment

International Nuclear Information System (INIS)

Ribeiro, Anderson Schwingel; Vieira, Mariana Antunes; Furtado da Silva, Alessandra; Borges, Daniel L. Gallindo; Welz, Bernhard; Heitmann, Uwe; Curtius, Adilson Jose

2005-01-01

Two procedures for the determination of Co in biological samples by graphite furnace atomic absorption spectrometry (GF AAS) were compared: solid sampling (SS) and alkaline treatment with tetramethylammonium hydroxide (TMAH) using two different instruments for the investigation: a conventional line-source (LS) atomic absorption spectrometer and a prototype high-resolution continuum source atomic absorption spectrometer. For the direct introduction of the solid samples, certified reference materials (CRM) were ground to a particle size ≤50 μm. Alkaline treatment was carried out by placing about 250 mg of the sample in polypropylene flasks, adding 2 mL of 25% m/v tetramethylammonium hydroxide and de-ionized water. Due to its unique capacity of providing a 3-D spectral plot, a high-resolution continuum source (HR-CS) graphite furnace atomic absorption spectrometry was used as a tool to evaluate potential spectral interferences, including background absorption for both sample introduction procedures, revealing that a continuous background preceded the atomic signal for pyrolysis temperatures lower than 700 deg. C. Molecular absorption bands with pronounced rotational fine structure appeared for atomization temperatures >1800 deg. C probably as a consequence of the formation of PO. After optimization had been carried out using high resolution continuum source atomic absorption spectrometry, the optimized conditions were adopted also for line-source atomic absorption spectrometry. Six biological certified reference materials were analyzed, with calibration against aqueous standards, resulting in agreement with the certified values (according to the t-test for a 95% confidence level) and in detection limits as low as 5 ng g -1

Fine-grained suspended sediment source identification for the Kharaa River basin, northern Mongolia

Science.gov (United States)

Rode, Michael; Theuring, Philipp; Collins, Adrian L.

2015-04-01

Fine sediment inputs into river systems can be a major source of nutrients and heavy metals and have a strong impact on the water quality and ecosystem functions of rivers and lakes, including those in semiarid regions. However, little is known to date about the spatial distribution of sediment sources in most large scale river basins in Central Asia. Accordingly, a sediment source fingerprinting technique was used to assess the spatial sources of fine-grained (source discrimination with geochemical composite fingerprints based on a new Genetic Algorithm (GA)-driven Discriminant Function Analysis, the Kruskal-Wallis H-test and Principal Component Analysis. The composite fingerprints were subsequently used for numerical mass balance modelling with uncertainty analysis. The contributions of the individual sub-catchment spatial sediment sources varied from 6.4% (the headwater sub-catchment of Sugnugur Gol) to 36.2% (the Kharaa II sub-catchment in the middle reaches of the study basin) with the pattern generally showing higher contributions from the sub-catchments in the middle, rather than the upstream, portions of the study area. The importance of riverbank erosion was shown to increase from upstream to midstream tributaries. The source tracing procedure provides results in reasonable accordance with previous findings in the study region and demonstrates the general applicability and associated uncertainties of an approach for fine-grained sediment source investigation in large scale semi-arid catchments. The combined application of source fingerprinting and catchment modelling approaches can be used to assess whether tracing estimates are credible and in combination such approaches provide a basis for making sediment source apportionment more compelling to catchment stakeholders and managers.

Quantifying sources of fine sediment supplied to post-fire debris flows using fallout radionuclide tracers

Science.gov (United States)

Smith, Hugh; Sheridan, Gary; Nyman, Petter; Child, David; Lane, Patrick; Hotchkis, Michael

2013-04-01

The supply of fine sediment and ash has been identified as an important factor contributing to the initiation of runoff-generated debris flows after fire. However, despite the significance of fines for post-fire debris flow generation, no investigations have sought to quantify sources of this material in debris flow affected catchments. In this study, we employ fallout radionuclides (Cs-137, excess Pb-210 and Pu-239,240) as tracers to measure proportional contributions of fine sediment (bank sources to levee and terminal fan deposits formed by post-fire debris flows in two forest catchments in southeastern Australia. While Cs-137 and excess Pb-210 have been widely used in sediment tracing studies, application of Pu as a tracer represents a recent development and was limited to only one catchment. The estimated range in hillslope surface contributions of fine sediment to individual debris flow deposits in each catchment was 22-69% and 32-74%, respectively. No systematic change in the source contributions to debris flow deposits was observed with distance downstream from channel initiation points. Instead, spatial variability in source contributions was largely influenced by the pattern of debris flow surges forming the deposits. Linking the sediment tracing with interpretation of depositional evidence allowed reconstruction of temporal sequences in sediment source contributions to debris flow surges. Hillslope source inputs dominated most elevated channel deposits such as marginal levees that were formed under peak flow conditions. This indicated the importance of hillslope runoff and sediment supply for debris flow generation in both catchments. In contrast, material stored within channels that was deposited during subsequent surges was predominantly channel-derived. The results demonstrate that fallout radionuclide tracers may provide unique information on the changing source contributions of fine sediment during debris flow events.

Particle identification by means of fine sampling dE/dX measurements

Energy Technology Data Exchange (ETDEWEB)

Imanishi, A; Ishii, T; Ohshima, T; Okuno, H; Shiino, K [Tokyo Univ., Tanashi (Japan). Inst. for Nuclear Study; Naito, F [Tokyo Univ. of Agriculture and Technology, Koganei (Japan). Faculty of Technology; Matsuda, T [Osaka Univ., Toyonaka (Japan). Faculty of Engineering Science

1983-04-01

Identification of relativistic charged particles by means of fine sampling d E/d X measurements with a longitudinal drift chamber has been studied. Using a fast-sampling ADC (25 MHz), dE/dX was measured in a 1.4 mm gas thickness over an electron drift space of 51 mm. For the simulated 1 m long tracks of pions and electrons of 500 MeV/c, a particle separation of 10sigma - 12sigma has been obtained, where sigma is the r.m.s. resolution of the dE/dX measurement. This result with fine sampling is better by a factor of 1.7 compared to the dE/dX measurement, with 21 mm sampling thickness. Further improvement achievable by reducing the correlation between neighbouring samples and simplification of electronics by use of the delta-ray clipping method are also discussed.

Fine-Grained Energy Modeling for the Source Code of a Mobile Application

DEFF Research Database (Denmark)

Li, Xueliang; Gallagher, John Patrick

2016-01-01

The goal of an energy model for source code is to lay a foundation for the application of energy-aware programming techniques. State of the art solutions are based on source-line energy information. In this paper, we present an approach to constructing a fine-grained energy model which is able...

Organic composition and source apportionment of fine aerosol at Monterrey, Mexico, based on organic markers

Directory of Open Access Journals (Sweden)

Y. Mancilla

2016-01-01

Full Text Available Primary emissions from anthropogenic and biogenic sources as well as secondary formation are responsible for the pollution levels of ambient air in major urban areas. These sources release fine particles into the air that negatively impact human health and the environment. Organic molecular markers, which are compounds that are unique to specific PM2.5 sources, can be utilized to identify the major emission sources in urban areas. In this study, 43 representative PM2.5 samples, for both daytime and nighttime periods, were built from individual samples collected in an urban site of the Monterrey metropolitan area (MMA during the spring and fall of 2011 and 2012. The samples were analyzed for organic carbon, elemental carbon, and organic molecular markers. Several diagnostic tools were employed for the preliminary identification of emission sources. Organic compounds for eight compound classes were quantified. The n-alkanoic acids were the most abundant, followed by n-alkanes, wood smoke markers, and levoglucosan/alkenoic acids. Polycyclic aromatic hydrocarbons (PAHs and hopanes were less abundant. The carbon preference index (0.7–2.6 for n-alkanes indicates a major contribution of anthropogenic and mixed sources during the fall and the spring, respectively. Hopanes levels confirmed the contribution from gasoline and diesel engines. In addition, the contribution of gasoline and diesel vehicle exhaust was confirmed and identified by the PAH concentrations in PM2.5. Diagnostic ratios of PAHs showed emissions from burning coal, wood, biomass, and other fossil fuels. The total PAHs and elemental carbon were correlated (r2 =  0.39–0.70 across the monitoring periods, reinforcing that motor vehicles are the major contributors of PAHs. Cholesterol levels remained constant during the spring and fall, showing evidence of the contribution of meat-cooking operations, while the isolated concentrations of levoglucosan suggested occasional biomass

Characterization of polar organic compounds and source analysis of fine organic aerosols in Hong Kong

Science.gov (United States)

Li, Yunchun

Organic aerosols, as an important fraction of airborne particulate mass, significantly affect the environment, climate, and human health. Compared with inorganic species, characterization of individual organic compounds is much less complete and comprehensive because they number in thousands or more and are diverse in chemical structures. The source contributions of organic aerosols are far from being well understood because they can be emitted from a variety of sources as well as formed from photochemical reactions of numerous precursors. This thesis work aims to improve the characterization of polar organic compounds and source apportionment analysis of fine organic carbon (OC) in Hong Kong, which consists of two parts: (1) An improved analytical method to determine monocarboxylic acids, dicarboxylic acids, ketocarboxylic acids, and dicarbonyls collected on filter substrates has been established. These oxygenated compounds were determined as their butyl ester or butyl acetal derivatives using gas chromatography-mass spectrometry. The new method made improvements over the original Kawamura method by eliminating the water extraction and evaporation steps. Aerosol materials were directly mixed with the BF 3/BuOH derivatization agent and the extracting solvent hexane. This modification improves recoveries for both the more volatile and the less water-soluble compounds. This improved method was applied to study the abundances and sources of these oxygenated compounds in PM2.5 aerosol samples collected in Hong Kong under different synoptic conditions during 2003-2005. These compounds account for on average 5.2% of OC (range: 1.4%-13.6%) on a carbon basis. Oxalic acid was the most abundant species. Six C2 and C3 oxygenated compounds, namely oxalic, malonic, glyoxylic, pyruvic acids, glyoxal, and methylglyoxal, dominated this suite of oxygenated compounds. More efforts are therefore suggested to focus on these small compounds in understanding the role of oxygenated

Sources and geographical origins of fine aerosols in Paris (France)

International Nuclear Information System (INIS)

Bressi, M.; Nicolas, J.B.; Sciare, J.; Feron, A.; Nonnaire, N.; Petit, J.E.

2014-01-01

The present study aims at identifying and apportioning fine aerosols to their major sources in Paris (France) - the second most populated - larger urban zone - in Europe - and determining their geographical origins. It is based on the daily chemical composition of PM2.5 examined over 1 year at an urban background site of Paris (Bressi et al., 2013). Positive matrix factorization (EPA PMF3.0) was used to identify and apportion fine aerosols to their sources; bootstrapping was performed to determine the adequate number of PMF factors, and statistics (root mean square error, coefficient of determination, etc.) were examined to better model PM2.5 mass and chemical components. Potential source contribution function (PSCF) and conditional probability function (CPF) allowed the geographical origins of the sources to be assessed; special attention was paid to implement suitable weighting functions. Seven factors, namely ammonium sulfate (A.S.)-rich factor, ammonium nitrate (A.N.)-rich factor, heavy oil combustion, road traffic, biomass burning, marine aerosols and metal industry, were identified; a detailed discussion of their chemical characteristics is reported. They contribute 27, 24, 17, 14, 12, 6 and 1% of PM2.5 mass (14.7 μgm -3 ) respectively on the annual average; their seasonal variability is discussed. The A.S.- and A.N.-rich factors have undergone mid- or long-range transport from continental Europe; heavy oil combustion mainly stems from northern France and the English Channel, whereas road traffic and biomass burning are primarily locally emitted. Therefore, on average more than half of PM2.5 mass measured in the city of Paris is due to mid- or long-range transport of secondary aerosols stemming from continental Europe, whereas local sources only contribute a quarter of the annual averaged mass. These results imply that fine-aerosol abatement policies conducted at the local scale may not be sufficient to notably reduce PM2.5 levels at urban background sites

Association of fine particulate matter from different sources with daily mortality in six US cities

Energy Technology Data Exchange (ETDEWEB)

Laden, F.; Neas, L.M.; Dockery, D.W.; Schwartz, J. [Harvard University, Boston, MA (USA). School of Medicine, Brigham & Womens Hospital

2000-07-01

In this study, the authors use the elemental composition of size-fractionated particles to identify several distinct source-related fractions of fine particles and examined the association of these fractions with daily mortality in each of six US cities. Using specific rotation factor analysis for each city, a silicon factor classified as soil and crustal material, a lead factor classified as motor vehicle exhaust, a selenium factor representing coal combustion, and up to two additional factors were identified. Daily counts of deaths from National Center for Health Statistics records were extracted and city-specific associations of mortality with each source factor were estimated. Combined effect estimates were calculated as the inverse variance weighted mean of the city-specific estimates. Results indicated that combustion particles in the fine fraction from mobile and coal combustion sources, but not fine crustal particles, are associated with increased mortality.

Molecular marker analysis as a guide to the sources of fine organic aerosols

International Nuclear Information System (INIS)

Rogge, W.F.; Cass, G.R.; Hildemann, L.M.; Simoneit, B.R.T.

1992-07-01

The molecular composition of fine particulate (D p ≥ 2 μm) organic aerosol emissions from the most important sources in the Los Angeles area has been determined. Likewise, ambient concentration patterns for more than 80 single organic compounds have been measured at four urban sites (West Los Angeles, Downtown Los Angeles, Pasadena, and Rubidoux) and at one remote offshore site (San Nicolas Island). It has been found that cholesterol serves as a marker compound for emissions from charbroilers and other meat cooking operations. Vehicular exhaust being emitted from diesel and gasoline powered engines can be traced in the Los Angeles atmosphere using fossil petroleum marker compounds such as steranes and pentacyclic triterpanes (e.g., hopanes). Biogenic fine particle emission sources such as plant fragments abraded from leaf surfaces by wind and weather can be traced in the urban atmosphere. Using distinct and specific source organic tracers or assemblages of organic compounds characteristic for the sources considered it is possible to estimate the influence of different source types at any urban site where atmospheric data are available

Source apportionment of fine organic aerosol in Mexico City during the MILAGRO experiment 2006

Directory of Open Access Journals (Sweden)

E. A. Stone

2008-03-01

Full Text Available Organic carbon (OC comprises a large fraction of fine particulate matter (PM_2.5 in Mexico City. Daily and select 12-h PM_2.5 samples were collected in urban and peripheral sites in Mexico City from 17–30 March 2006. Samples were analyzed for OC and elemental carbon (EC using thermal-optical filter-based methods. Real-time water-soluble organic carbon (WSOC was collected at the peripheral site. Organic compounds, particularly molecular markers, were quantified by soxhlet extraction with methanol and dichloromethane, derivitization, and gas chromatography with mass spectrometric detection (GCMS. A chemical mass balance model (CMB based on molecular marker species was used to determine the relative contribution of major sources to ambient OC. Motor vehicles, including diesel and gasoline, consistently accounted for 49% of OC in the urban area and 32% on the periphery. The daily contribution of biomass burning to OC was highly variable, and ranged from 5–26% at the urban site and 7–39% at the peripheral site. The remaining OC unapportioned to primary sources showed a strong correlation with WSOC and was considered to be secondary in nature. Comparison of temporally resolved OC showed that contributions from primary aerosol sources during daylight hours were not significantly different from nighttime. This study provides quantitative understanding of the important sources of OC during the MILAGRO 2006 field campaign.

Source contributions of fine particulate matter during one winter haze episodes in Xi'an, China

Science.gov (United States)

Yang, X.; Wu, Q.

2017-12-01

Long-term exposure to high levels of fine particulate matter (PM2.5) is found to be associated with adverse effects on human health, ecological environment and climate change. Identification the major source regions of fine particulate matter are essential to proposing proper joint prevention and control strategies for heavy haze mitigation. In this work, the Comprehensive Air Quality Model with extensions (CAMx) together with the Particulate Source Apportionment Technology (PSAT) and the Weather Research and Forecast Model (WRF), have been applied to analyze the major source regions of PM2.5 in Xi'an during the heavy haze episodes in winter (29, December, 2016 - 5 January 2017), and the framework of the model system is shown in Fig. 1. Firstly, according to the model evaluation of the daily PM2.5 concentrations for the two months, the model has well performance, and the fraction of predictions within a factor of 2 of the observations (FAC2) is 84%, while the correlation coefficient (R) is 0.80 in Xi'an. By using the PSAT in CAMx model, a detailed source region contribution matrix is derived for all points within the Xi'an region and its six surrounding areas, and long-range regional transport. The results show that the local emission in Xi'an is the mainly sources at downtown area, which contributing 72.9% as shown in Fig.2, and the contribution rate of transportations between adjacent areas depends on wind direction. Meanwhile, three different suburban areas selected for detailed analysis in fine particles sources. Comparing to downtown area, the sources of suburban areas are more multiply, and the transportations make the contribution 40%-82%. In the suburban areas, regional inflows play an important role in the fine particles concentrations, indicating a strong need for regional joint emission control efforts. The results enhance the quantitative understanding of the PM2.5 source regions and provide a basis for policymaking to advance the control of pollution

Temporal variations of fine and coarse particulate matter sources in Jeddah, Saudi Arabia.

Science.gov (United States)

Lim, Chris C; Thurston, George D; Shamy, Magdy; Alghamdi, Mansour; Khoder, Mamdouh; Mohorjy, Abdullah M; Alkhalaf, Abdulrahman K; Brocato, Jason; Chen, Lung Chi; Costa, Max

2018-02-01

This study provides the first comprehensive analysis of the seasonal variations and weekday/weekend differences in fine (aerodynamic diameter Saudi Arabia. Air quality samples were collected over 1 yr, from June 2011 to May 2012 at a frequency of three times per week, and analyzed. The average mass concentrations of PM 2.5 (21.9 μg/m 3 ) and PM 10 (107.8 μg/m 3 ) during the sampling period exceeded the recommended annual average levels by the World Health Organization (WHO) for PM 2.5 (10 μg/m 3 ) and PM 10 (20 μg/m 3 ), respectively. Similar to other Middle Eastern locales, PM 2.5-10 is the prevailing mass component of atmospheric particulate matter at Jeddah, accounting for approximately 80% of the PM 10 mass. Considerations of enrichment factors, absolute principal component analysis (APCA), concentration roses, and backward trajectories identified the following source categories for both PM 2.5 and PM 2.5-10 : (1) soil/road dust, (2) incineration, and (3) traffic; and for PM 2.5 only, (4) residual oil burning. Soil/road dust accounted for a major portion of both the PM 2.5 (27%) and PM 2.5-10 (77%) mass, and the largest source contributor for PM 2.5 was from residual oil burning (63%). Temporal variations of PM 2.5-10 and PM 2.5 were observed, with the elevated concentration levels observed for mass during the spring (due to increased dust storm frequency) and on weekdays (due to increased traffic). The predominant role of windblown soil and road dust in both the PM 2.5 and PM 2.5-10 masses in this city may have implications regarding the toxicity of these particles versus those in the Western world where most PM health assessments have been made in the past. These results support the need for region-specific epidemiological investigations to be conducted and considered in future PM standard setting. Temporal variations of fine and coarse PM mass, elemental constituents, and sources were examined in Jeddah, Saudi Arabia, for the first time. The main source

Source identification of fine-grained suspended sediment in the Kharaa River basin, northern Mongolia

Energy Technology Data Exchange (ETDEWEB)

Theuring, Philipp [Department of Aquatic Ecosystem Analysis and Management — ASAM, Helmholtz Centre for Environmental Research — UFZ, Brückstrasse 3a, D-39114 Magdeburg (Germany); Collins, Adrian L. [Sustainable Soils and Grassland Systems Department, Rothamsted Research, North Wyke, Okehampton, Devon EX20 2SB (United Kingdom); Rode, Michael [Department of Aquatic Ecosystem Analysis and Management — ASAM, Helmholtz Centre for Environmental Research — UFZ, Brückstrasse 3a, D-39114 Magdeburg (Germany)

2015-09-01

Fine sediment inputs into river systems can be a major source of nutrients and heavy metals and have a strong impact on water quality and ecosystem functions of rivers and lakes, including those in semiarid regions. However, little is known to date about the spatial distribution of sediment sources in most large scale river basins in Central Asia. Accordingly, a sediment source fingerprinting technique was used to assess the spatial sources of fine-grained (< 10 μm) sediment in the 15 000 km{sup 2} Kharaa River basin in northern Mongolia. Variation in geochemical composition (e.g. in Ti, Sn, Mo, Mn, As, Sr, B, U, Ca and Sb) was used for sediment source discrimination with geochemical composite fingerprints based on Genetic Algorithm (GA)-driven Discriminant Function Analysis, the Kruskal–Wallis H-test and Principal Component Analysis. All composite fingerprints yielded a satisfactory GOF (> 0.97) and were subsequently used for numerical mass balance modelling with uncertainty analysis. The contributions of the individual sub-catchment spatial sediment sources varied from 6.4% (the headwater sub-catchment of Sugnugur Gol) to 36.2% (the Kharaa II sub-catchment in the middle reaches of the study basin), generally showing higher contributions from the sub-catchments in the middle, rather than the upstream, portions of the study area. The importance of river bank erosion is shown to increase from upstream to midstream tributaries. The source tracing procedure provides results in reasonable accordance with previous findings in the study region and demonstrates the applicability and associated uncertainties of the approach for fine-grained sediment source investigation in large scale semi-arid catchments. - Highlights: • Applied statistical approach for selecting composite fingerprints in Mongolia. • Geochemical fingerprinting for the definition of source areas in semiarid catchment. • Test of applicability of sediment sourcing in large scale semi-arid catchments

Characteristics of fine and coarse particles of natural and urban aerosols of Brazil

International Nuclear Information System (INIS)

Orsini, C.M.Q.; Tabacniks, M.H.; Artaxo Netto, P.E.; Andrade, M.F.; Kerr, A.

1986-02-01

Fine and coarse particles have been sampled from 1982 to 1985 in one natural forest seacoast site (Jureia) and five urban-industrial cities (Vitoria, Salvador, Porto Alegre, Sao Paulo, and Belo Horizonte). The time variations of concentrations in air and the relative elemental compositions of fine and coarse particle fractions, sampled by Nuclepore stacked filter units (SFU), have been determined gravimetrically and by PIXE analysis, respectively. Enrichment factors and correlation coefficients of the trace elements measured lead to unambiguous characterization of soil dust and sea salt, both major aerosol sources that emit coarse particles, and soil dust is also a significant source of fine particles. (Author) [pt

New methods and standards for fine dust

International Nuclear Information System (INIS)

Spielvogel, Juergen; Hartstock, Stefan; Grimm, Hans

2009-01-01

There seems to be common agreement that PM10 is a suboptimal quantity for the quantification of potential dangers from fine dust due to a number of reasons, notably because the chemical composition of the particles is not considered, because the size distribution is disregarded, and because of sampling artefacts. In a first step for improving the particle measurements, the European Community has published new directives for ambient air in June 2008 (EU 2008), which as a main part included new regulations for PM2.5 measurements, in addition to the further on valid regulations for PM10. The comparison of PM2.5 and PM10 may allow a source apportionment and a better assessment of the influence of fine dust on human health. The source apportionment may allow more effective fine dust reduction strategies.

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 Source apportionment of the 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.

The importance of source positions during radio fine structure observations

International Nuclear Information System (INIS)

Chernov, Guennadi P.; Yan Yi-Hua; Fu Qi-Jun

2014-01-01

The measurement of positions and sizes of radio sources in the observations of the fine structure of solar radio bursts is a determining factor for the selection of the radio emission mechanism. The identical parameters describing the radio sources for zebra structures (ZSs) and fiber bursts confirm there is a common mechanism for both structures. It is very important to measure the size of the source in the corona to determine if it is distributed along the height or if it is point-like. In both models of ZSs (the double plasma resonance (DPR) and the whistler model) the source must be distributed along the height, but by contrast to the stationary source in the DPR model, in the whistler model the source should be moving. Moreover, the direction of the space drift of the radio source must correlate with the frequency drift of stripes in the dynamic spectrum. Some models of ZSs require a local source, for example, the models based on the Bernstein modes, or on explosive instability. The selection of the radio emission mechanism for fast broadband pulsations with millisecond duration also depends on the parameters of their radio sources. (mini-volume: solar radiophysics — recent results on observations and theories)

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.

Source-specific fine particulate air pollution and systemic inflammation in ischaemic heart disease patients

Science.gov (United States)

Siponen, Taina; Yli-Tuomi, Tarja; Aurela, Minna; Dufva, Hilkka; Hillamo, Risto; Hirvonen, Maija-Riitta; Huttunen, Kati; Pekkanen, Juha; Pennanen, Arto; Salonen, Iiris; Tiittanen, Pekka; Salonen, Raimo O; Lanki, Timo

2015-01-01

Objective To compare short-term effects of fine particles (PM2.5; aerodynamic diameter <2.5 µm) from different sources on the blood levels of markers of systemic inflammation. Methods We followed a panel of 52 ischaemic heart disease patients from 15 November 2005 to 21 April 2006 with clinic visits in every second week in the city of Kotka, Finland, and determined nine inflammatory markers from blood samples. In addition, we monitored outdoor air pollution at a fixed site during the study period and conducted a source apportionment of PM2.5 using the Environmental Protection Agency's model EPA PMF 3.0. We then analysed associations between levels of source-specific PM2.5 and markers of systemic inflammation using linear mixed models. Results We identified five source categories: regional and long-range transport (LRT), traffic, biomass combustion, sea salt, and pulp industry. We found most evidence for the relation of air pollution and inflammation in LRT, traffic and biomass combustion; the most relevant inflammation markers were C-reactive protein, interleukin-12 and myeloperoxidase. Sea salt was not positively associated with any of the inflammatory markers. Conclusions Results suggest that PM2.5 from several sources, such as biomass combustion and traffic, are promoters of systemic inflammation, a risk factor for cardiovascular diseases. PMID:25479755

Luna 24 regolith breccias: A possible source of the fine size material of the Luna 24 regolith

Science.gov (United States)

Rode, O. D.; Lindstrom, M. M.

1994-01-01

The regolith breccias from the Luna 24 core were analyzed. The Luna 24 regolith is a mixture of fine and coarse grain materials. The comparable analysis of the grain size distributions, the modal and chemical compositions of the breccias, and the regolith from the same levels show that the friable slightly litificated breccia with a friable fine grain matrix may be a source of fine grain material of the Luna 24 present day regolith.

Pesticide residues in individual versus composite samples of apples after fine or coarse spray quality application

NARCIS (Netherlands)

Poulsen, M.; Wenneker, M.; Withagen, J.C.M.; Christensen, H.B.

2012-01-01

In this study, field trials on fine and coarse spray quality application of pesticides on apples were performed. The main objectives were to study the variation of pesticide residue levels in individual fruits versus composite samples, and the effect of standard fine spray quality application versus

Diagnostic Air Quality Model Evaluation of Source-Specific Primary and Secondary Fine Particulate Carbon

Science.gov (United States)

Ambient measurements of 78 source-specific tracers of primary and secondary carbonaceous fine particulate matter collected at four midwestern United States locations over a full year (March 2004–February 2005) provided an unprecedented opportunity to diagnostically evaluate...

Revisit to diffraction anomalous fine structure

International Nuclear Information System (INIS)

Kawaguchi, T.; Fukuda, K.; Tokuda, K.; Shimada, K.; Ichitsubo, T.; Oishi, M.; Mizuki, J.; Matsubara, E.

2014-01-01

The diffraction anomalous fine structure method has been revisited by applying this measurement technique to polycrystalline samples and using an analytical method with the logarithmic dispersion relation. The diffraction anomalous fine structure (DAFS) method that is a spectroscopic analysis combined with resonant X-ray diffraction enables the determination of the valence state and local structure of a selected element at a specific crystalline site and/or phase. This method has been improved by using a polycrystalline sample, channel-cut monochromator optics with an undulator synchrotron radiation source, an area detector and direct determination of resonant terms with a logarithmic dispersion relation. This study makes the DAFS method more convenient and saves a large amount of measurement time in comparison with the conventional DAFS method with a single crystal. The improved DAFS method has been applied to some model samples, Ni foil and Fe 3 O 4 powder, to demonstrate the validity of the measurement and the analysis of the present DAFS method

Investigating organic matter in Fanno Creek, Oregon, Part 2 of 3: sources, sinks, and transport of organic matter with fine sediment

Science.gov (United States)

Keith, Mackenzie K.; Sobieszczyk, Steven; Goldman, Jami H.; Rounds, Stewart A.

2014-01-01

Organic matter (OM) is abundant in Fanno Creek, Oregon, USA, and has been tied to a variety of water-quality concerns, including periods of low dissolved oxygen downstream in the Tualatin River, Oregon. The key sources of OM in Fanno Creek and other Tualatin River tributaries have not been fully identified, although isotopic analyses from previous studies indicated a predominantly terrestrial source. This study investigates the role of fine sediment erosion and deposition (mechanisms and spatial patterns) in relation to OM transport. Geomorphic mapping within the Fanno Creek floodplain shows that a large portion (approximately 70%) of the banks are eroding or subject to erosion, likely as a result of the imbalance caused by anthropogenic alteration. Field measurements of long- and short-term bank erosion average 4.2 cm/year and average measurements of deposition for the watershed are 4.8 cm/year. The balance between average annual erosion and deposition indicates an export of 3,250 metric tons (tonnes, t) of fine sediment to the Tualatin River—about twice the average annual export of 1,880 t of sediment at a location 2.4 km from the creek’s mouth calculated from suspended sediment load regressions from continuous turbidity data and suspended sediment samples. Carbon content from field samples of bank material, combined with fine sediment export rates, indicates that about 29–67 t of carbon, or about 49–116 t of OM, from bank sediment may be exported to the Tualatin River from Fanno Creek annually, an estimate that is a lower bound because it does not account for the mass wasting of organic-rich O and A soil horizons that enter the stream.

Sample-angle feedback for diffraction anomalous fine-structure spectroscopy

International Nuclear Information System (INIS)

Cross, J.O.; Elam, W.T.; Harris, V.G.; Kirkland, J.P.; Bouldin, C.E.; Sorensen, L.B.

1998-01-01

Diffraction anomalous fine-structure (DAFS) experiments measure Bragg peak intensities as continuous functions of photon energy near a core-level excitation. Measuring the integrated intensity at each energy makes the experiments prohibitively slow; however, in many cases DAFS can be collected quickly by measuring only the peak intensity at the center of the rocking curve. A piezoelectric-actuator-driven stage has been designed and tested as part of a sample-angle feedback circuit for locking onto the maximum of the rocking curve while the energy is scanned. Although software peak-tracking requires only a simple calculation of diffractometer angles, it is found that the additional hardware feedback dramatically improves the reproducibility of the data

Determining the sources of fine-grained sediment using the Sediment Source Assessment Tool (Sed_SAT)

Science.gov (United States)

Gorman Sanisaca, Lillian E.; Gellis, Allen C.; Lorenz, David L.

2017-07-27

A sound understanding of sources contributing to instream sediment flux in a watershed is important when developing total maximum daily load (TMDL) management strategies designed to reduce suspended sediment in streams. Sediment fingerprinting and sediment budget approaches are two techniques that, when used jointly, can qualify and quantify the major sources of sediment in a given watershed. The sediment fingerprinting approach uses trace element concentrations from samples in known potential source areas to determine a clear signature of each potential source. A mixing model is then used to determine the relative source contribution to the target suspended sediment samples.The computational steps required to apportion sediment for each target sample are quite involved and time intensive, a problem the Sediment Source Assessment Tool (Sed_SAT) addresses. Sed_SAT is a user-friendly statistical model that guides the user through the necessary steps in order to quantify the relative contributions of sediment sources in a given watershed. The model is written using the statistical software R (R Core Team, 2016b) and utilizes Microsoft Access® as a user interface but requires no prior knowledge of R or Microsoft Access® to successfully run the model successfully. Sed_SAT identifies outliers, corrects for differences in size and organic content in the source samples relative to the target samples, evaluates the conservative behavior of tracers used in fingerprinting by applying a “Bracket Test,” identifies tracers with the highest discriminatory power, and provides robust error analysis through a Monte Carlo simulation following the mixing model. Quantifying sediment source contributions using the sediment fingerprinting approach provides local, State, and Federal land management agencies with important information needed to implement effective strategies to reduce sediment. Sed_SAT is designed to assist these agencies in applying the sediment fingerprinting

Dual Source Time-of-flight Mass Spectrometer and Sample Handling System

Science.gov (United States)

Brinckerhoff, W.; Mahaffy, P.; Cornish, T.; Cheng, A.; Gorevan, S.; Niemann, H.; Harpold, D.; Rafeek, S.; Yucht, D.

We present details of an instrument under development for potential NASA missions to planets and small bodies. The instrument comprises a dual ionization source (laser and electron impact) time-of-flight mass spectrometer (TOF-MS) and a carousel sam- ple handling system for in situ analysis of solid materials acquired by, e.g., a coring drill. This DSTOF instrument could be deployed on a fixed lander or a rover, and has an open design that would accommodate measurements by additional instruments. The sample handling system (SHS) is based on a multi-well carousel, originally de- signed for Champollion/DS4. Solid samples, in the form of drill cores or as loose chips or fines, are inserted through an access port, sealed in vacuum, and transported around the carousel to a pyrolysis cell and/or directly to the TOF-MS inlet. Samples at the TOF-MS inlet are xy-addressable for laser or optical microprobe. Cups may be ejected from their holders for analyzing multiple samples or caching them for return. Samples are analyzed with laser desorption and evolved-gas/electron-impact sources. The dual ion source permits studies of elemental, isotopic, and molecular composition of unprepared samples with a single mass spectrometer. Pulsed laser desorption per- mits the measurement of abundance and isotope ratios of refractory elements, as well as the detection of high-mass organic molecules in solid samples. Evolved gas analysis permits similar measurements of the more volatile species in solids and aerosols. The TOF-MS is based on previous miniature prototypes at JHU/APL that feature high sensitivity and a wide mass range. The laser mode, in which the sample cup is directly below the TOF-MS inlet, permits both ablation and desorption measurements, to cover elemental and molecular species, respectively. In the evolved gas mode, sample cups are raised into a small pyrolysis cell and heated, producing a neutral gas that is elec- tron ionized and pulsed into the TOF-MS. (Any imaging

Composition and source apportionment of fine particulate matter during extended calm periods in the city of Rijeka, Croatia

Science.gov (United States)

Ivošević, T.; Orlić, I.; Bogdanović Radović, I.; Čargonja, M.; Stelcer, E.

2017-09-01

In the city of Rijeka, Croatia, an extended, two-year aerosol pollution monitoring campaign was recently completed. During that period, 345 samples of fine fraction of aerosols were collected on stretched Teflon filters. All samples were analyzed by Ion Beam Analysis techniques Proton Induced X-ray Emission and Proton Induced γ-Ray Emission and concentrations of 22 elements were determined. Concentrations of black carbon were determined by Laser Integrated Plate Method. For the Bay of Kvarner, where the city of Rijeka is located, long periods of calm weather are common. As a consequence, during these periods, air pollution is steadily increasing. To pin-point and characterize local, mostly anthropogenic, air pollution sources, only samples collected during the extended calm periods were used in this work. As a cut-off wind speed, speed of 1.5 m/s was used. In that way, out of all 345 samples, only 188 were selected. Those samples were statistically evaluated by means of positive matrix factorization. Results show that from all anthropogenic sources (vehicles, secondary sulphates, smoke, heavy oil combustion, road dust, industry Fe and port activities) only secondary sulphates and heavy oil combustion were significantly higher (40% and 50%, respectively) during calm periods. On the other hand, natural components of aerosol pollution such as soil and sea salts, (typically present in concentrations of 1.4% and 9%, respectively) are practically non-existent for calm weather conditions.

Assessment of Fine Aggregates from Different Sources in Ibadan and Environs for Concrete Production

Directory of Open Access Journals (Sweden)

W. O. Ajagbe

2018-03-01

Full Text Available Assessment of natural sand being used as fine aggregate for concrete production in Ibadan and its environs was carried out. Ten sources (F1 – F10 were selected for the study; four (F5, F6, F7, F8 were river sand sources while six (F1, F2, F3, F4, F9, F10 were burrow pit sand sources. Samples from each source were subjected to sieve analysis, atterberg limit, bulk density, specific gravity, water absorption, sand equivalent, clay lumps and friable particles, amount of materials passing 75μm and organic impurities adopting ASTM standard procedures. Results revealed that sand from river sources met all the criteria for concrete production stated in ASTM standard while sand from burrow pits deviated from limits of the standard in some respects. F10 had water absorption of 2.6% which exceeded maximum 2% specified, F9 was not free from clay lumps and friable particles with a significant value of 6% as against 3% maximum specification. F1, F2, F3, F4, F9 and F10 have more amounts of materials passing the 75μm sieve ranging from 10.8% for F9 to 20.1% for F10 than maximum of 5% in standard specification while F1, F9 and F10 showed an indication of having organic impurities. It is recommended that performance test be conducted on concrete made from burrow pits sand before use for concrete production. The knowledge of this study can be used as a prospecting tool for selecting suitable sand for the production of quality concrete.

HONO and Inorganic Fine Particle Composition in Typical Monsoon Region with Intensive Anthropogenic Emission: In-situ Observations and Source Identification.

Science.gov (United States)

Xie, Y.; Nie, W.; Ding, A.; Huang, X.

2015-12-01

Yangtze River Delta (YRD) is one of the most typical monsoon area with probably the most largest population intensity in the world. With sharply economic development and the large anthropogenic emissions, fine particle pollution have been one of the major air quality problem and may further have impact on the climate system. Though a lot of control policy (sulfur emission have been decreasing from 2007) have been conducted in the region, studies showed the sulfate in fine particles still take major fraction as the nitrate from nitrogen oxides increased significantly. In this study, the role of inorganic chemical compositions in fine particles was investigated with two years in-situ observation. Sulfate and Nitrate contribute to fine particle mass equally in general, but sulfate contributes more during summer and nitrate played more important role in winter. Using lagrangian dispersion backward modeling and source contribution clustering method, the impact of airmass coming from different source region (industrial, dust, biogenic emissions, etc) on fine particle inorganic compositions were discussed. Furthermore, we found two unique cases showing in-situ implications for sulfate formation by nitrogen dioxide oxidation mechanisms. It was showed that the mixing of anthropogenic pollutants with long-range transported mineral dust and biomass burning plume would enhance the sulfate formation by different chemistry mechanisms. This study focus on the complex aspects of fine particle formation in airmasses from different source regions: . It highlights the effect of NOx in enhancing the atmospheric oxidization capacity and indicates a potentially very important impact of increasing NOx on air pollution formation and regional climate change in East Asia.

Readout electronics for fine dE/dx sampling with a longitudinal drift chamber

International Nuclear Information System (INIS)

Imanishi, A.; Shiino, K.; Ishii, T.; Ohshima, T.; Okuno, H.

1982-04-01

A fast, low noise preamplifier, a signal shaping filter and a fast sampling ADC circuit have been developed for fine sampling dE/dx measurement with a longitudinal drift chamber. dE/dx has been sampled with a time interval of 40 ns which corresponds to a gas thickness of 1.4 mm in Ar(90%)/CH 4 (10%). Parameters of each circuit have been adjusted to match with this sampling interval. It is found that the signal tail cancellation is crucial to obtain better dE/dx resolution when the wider drift space is used, and this can be realized with a pole-zero shortening filter and a semi-Gaussian shaping integrator. (author)

Chemical characterisation of fine particles from biomass burning

Energy Technology Data Exchange (ETDEWEB)

Saarnio, K.

2013-10-15

Biomass burning has lately started to attract attention because there is a need to decrease the carbon dioxide (CO{sub 2}) emissions from the combustion of fossil fuels. Biomass is considered as CO{sub 2} neutral fuel. However, the burning of biomass is one of the major sources of fine particles both at the local and global scale. In addition to the use of biomass as a fuel for heat energy production, biomass burning emissions can be caused, e.g. by slash-and-burn agriculture and wild open-land fires. Indeed, the emissions from biomass burning are crucially important for the assessment of the potential impacts on global climate and local air quality and hence on human health. The chemical composition of fine particles has a notable influence on these impacts. The overall object of this thesis was to gain knowledge on the chemistry of fine particles that originate from biomass burning as well as on the contribution of biomass burning emissions to the ambient fine particle concentrations. For this purpose novel analytical methods were developed and tested in this thesis. Moreover, the thesis is based on ambient aerosol measurements that were carried out in six European countries at 12 measurement sites during 2002-2011. Additionally, wood combustion experiments were conducted in a laboratory. The measurements included a wide range of techniques: filter and impactor samplings, offline chemical analyses (chromatographic and mass spectrometric techniques, thermal-optical method), and online measurements of particles' physical properties and chemical composition (incl. particle number and mass concentrations and size distributions, concentrations of carbonaceous components, water-soluble ions, and tracer compounds). This thesis presents main results of different studies aimed towards chemical characterisation of fine particle emissions from biomass burning. It was found that wood combustion had a significant influence on atmospheric fine particle concentrations in

Quantitative analysis of fine needle aspiration biopsy samples

International Nuclear Information System (INIS)

Rajer, M.; Kmet, M.

2005-01-01

Background. The fine needle aspiration biopsy (FNAB) is one of the methods used in tumour evaluation. Since a certain number of tumour cells are needed for a complete diagnostic algorithm, we wanted to test how many cells remain in the needle and syringe after routine stains have been made and which factors influence this number. The remaining cells are used in ancillary diagnostic procedures. Materials and methods. One hundred fifty two FNAB samples of tumours of the breast, thyroid and lymph nodes were included in our study. We counted the cells which were left in the needle and the syringe after the standard smears had been made. Buerker-Tuerk's chamber was used for this purpose. Results. The number of cells depended on the organ from which the cells had been aspirated, on the type of tumour and, in the case of breast cancer, also on the level of experience of the FNAB performer. The percentage of samples with too few cells for all modern diagnostic methods (<5x105 ) is lowest in FNAB of lymph nodes (4.9%), followed by breast (16.7%) and thyroid (18%). Conclusions. We concluded that FNAB in the majority of cases grants a sufficient number of cells for the standard microscopic evaluation and also ancillary diagnostic procedures. (author)

Volatile, Isotope, and Organic Analysis of Martian Fines with the Mars Curiosity Rover

Science.gov (United States)

Leshin, L. A.; Mahaffy, P. R.; Webster, C. R.; Cabane, M.; Coll, P.; Conrad, P. G.; Archer, P. D.; Atreya, S. K.; Brunner, A. E.; Buch, A.; Eigenbrode, J. L.; Flesch, G. J.; Franz, H. B.; Freissinet, C.; Glavin, D. P.; McAdam, A. C.; Miller, K. E.; Ming, D. W.; Morris, R. V.; Navarro-González, R.; Niles, P. B.; Owen, T.; Pepin, R. O.; Squyres, S.; Steele, A.; Stern, J. C.; Summons, R. E.; Sumner, D. Y.; Sutter, B.; Szopa, C.; Teinturier, S.; Trainer, M. G.; Wray, J. J.; Grotzinger, J. P.; Kemppinen, Osku; Bridges, Nathan; Johnson, Jeffrey R.; Minitti, Michelle; Cremers, David; Bell, James F.; Edgar, Lauren; Farmer, Jack; Godber, Austin; Wadhwa, Meenakshi; Wellington, Danika; McEwan, Ian; Newman, Claire; Richardson, Mark; Charpentier, Antoine; Peret, Laurent; King, Penelope; Blank, Jennifer; Weigle, Gerald; Schmidt, Mariek; Li, Shuai; Milliken, Ralph; Robertson, Kevin; Sun, Vivian; Baker, Michael; Edwards, Christopher; Ehlmann, Bethany; Farley, Kenneth; Griffes, Jennifer; Miller, Hayden; Newcombe, Megan; Pilorget, Cedric; Rice, Melissa; Siebach, Kirsten; Stack, Katie; Stolper, Edward; Brunet, Claude; Hipkin, Victoria; Léveillé, Richard; Marchand, Geneviève; Sánchez, Pablo Sobrón; Favot, Laurent; Cody, George; Flückiger, Lorenzo; Lees, David; Nefian, Ara; Martin, Mildred; Gailhanou, Marc; Westall, Frances; Israël, Guy; Agard, Christophe; Baroukh, Julien; Donny, Christophe; Gaboriaud, Alain; Guillemot, Philippe; Lafaille, Vivian; Lorigny, Eric; Paillet, Alexis; Pérez, René; Saccoccio, Muriel; Yana, Charles; Armiens-Aparicio, Carlos; Rodríguez, Javier Caride; Blázquez, Isaías Carrasco; Gómez, Felipe Gómez; Gómez-Elvira, Javier; Hettrich, Sebastian; Malvitte, Alain Lepinette; Jiménez, Mercedes Marín; Martínez-Frías, Jesús; Martín-Soler, Javier; Martín-Torres, F. Javier; Jurado, Antonio Molina; Mora-Sotomayor, Luis; Caro, Guillermo Muñoz; López, Sara Navarro; Peinado-González, Verónica; Pla-García, Jorge; Manfredi, José Antonio Rodriguez; Romeral-Planelló, Julio José; Fuentes, Sara Alejandra Sans; Martinez, Eduardo Sebastian; Redondo, Josefina Torres; Urqui-O'Callaghan, Roser; Mier, María-Paz Zorzano; Chipera, Steve; Lacour, Jean-Luc; Mauchien, Patrick; Sirven, Jean-Baptiste; Manning, Heidi; Fairén, Alberto; Hayes, Alexander; Joseph, Jonathan; Sullivan, Robert; Thomas, Peter; Dupont, Audrey; Lundberg, Angela; Melikechi, Noureddine; Mezzacappa, Alissa; DeMarines, Julia; Grinspoon, David; Reitz, Günther; Prats, Benito; Atlaskin, Evgeny; Genzer, Maria; Harri, Ari-Matti; Haukka, Harri; Kahanpää, Henrik; Kauhanen, Janne; Kemppinen, Osku; Paton, Mark; Polkko, Jouni; Schmidt, Walter; Siili, Tero; Fabre, Cécile; Wilhelm, Mary Beth; Poitrasson, Franck; Patel, Kiran; Gorevan, Stephen; Indyk, Stephen; Paulsen, Gale; Gupta, Sanjeev; Bish, David; Schieber, Juergen; Gondet, Brigitte; Langevin, Yves; Geffroy, Claude; Baratoux, David; Berger, Gilles; Cros, Alain; d'Uston, Claude; Forni, Olivier; Gasnault, Olivier; Lasue, Jérémie; Lee, Qiu-Mei; Maurice, Sylvestre; Meslin, Pierre-Yves; Pallier, Etienne; Parot, Yann; Pinet, Patrick; Schröder, Susanne; Toplis, Mike; Lewin, Éric; Brunner, Will; Heydari, Ezat; Achilles, Cherie; Oehler, Dorothy; Coscia, David; Israël, Guy; Dromart, Gilles; Robert, François; Sautter, Violaine; Le Mouélic, Stéphane; Mangold, Nicolas; Nachon, Marion; Stalport, Fabien; François, Pascaline; Raulin, François; Cameron, James; Clegg, Sam; Cousin, Agnès; DeLapp, Dorothea; Dingler, Robert; Jackson, Ryan Steele; Johnstone, Stephen; Lanza, Nina; Little, Cynthia; Nelson, Tony; Wiens, Roger C.; Williams, Richard B.; Jones, Andrea; Kirkland, Laurel; Treiman, Allan; Baker, Burt; Cantor, Bruce; Caplinger, Michael; Davis, Scott; Duston, Brian; Edgett, Kenneth; Fay, Donald; Hardgrove, Craig; Harker, David; Herrera, Paul; Jensen, Elsa; Kennedy, Megan R.; Krezoski, Gillian; Krysak, Daniel; Lipkaman, Leslie; Malin, Michael; McCartney, Elaina; McNair, Sean; Nixon, Brian; Posiolova, Liliya; Ravine, Michael; Salamon, Andrew; Saper, Lee; Stoiber, Kevin; Supulver, Kimberley; Van Beek, Jason; Van Beek, Tessa; Zimdar, Robert; French, Katherine Louise; Iagnemma, Karl; Goesmann, Fred; Goetz, Walter; Hviid, Stubbe; Johnson, Micah; Lefavor, Matthew; Lyness, Eric; Breves, Elly; Dyar, M. Darby; Fassett, Caleb; Blake, David F.; Bristow, Thomas; DesMarais, David; Edwards, Laurence; Haberle, Robert; Hoehler, Tori; Hollingsworth, Jeff; Kahre, Melinda; Keely, Leslie; McKay, Christopher; Wilhelm, Mary Beth; Bleacher, Lora; Brinckerhoff, William; Choi, David; Dworkin, Jason P.; Floyd, Melissa; Garvin, James; Harpold, Daniel; Jones, Andrea; Martin, David K.; Pavlov, Alexander; Raaen, Eric; Smith, Michael D.; Tan, Florence; Meyer, Michael; Posner, Arik; Voytek, Mary; Anderson, Robert C.; Aubrey, Andrew; Beegle, Luther W.; Behar, Alberto; Blaney, Diana; Brinza, David; Calef, Fred; Christensen, Lance; Crisp, Joy A.; DeFlores, Lauren; Ehlmann, Bethany; Feldman, Jason; Feldman, Sabrina; Hurowitz, Joel; Jun, Insoo; Keymeulen, Didier; Maki, Justin; Mischna, Michael; Morookian, John Michael; Parker, Timothy; Pavri, Betina; Schoppers, Marcel; Sengstacken, Aaron; Simmonds, John J.; Spanovich, Nicole; Juarez, Manuel de la Torre; Vasavada, Ashwin R.; Yen, Albert; Cucinotta, Francis; Jones, John H.; Rampe, Elizabeth; Nolan, Thomas; Fisk, Martin; Radziemski, Leon; Barraclough, Bruce; Bender, Steve; Berman, Daniel; Dobrea, Eldar Noe; Tokar, Robert; Vaniman, David; Williams, Rebecca M. E.; Yingst, Aileen; Lewis, Kevin; Cleghorn, Timothy; Huntress, Wesley; Manhès, Gérard; Hudgins, Judy; Olson, Timothy; Stewart, Noel; Sarrazin, Philippe; Grant, John; Vicenzi, Edward; Wilson, Sharon A.; Bullock, Mark; Ehresmann, Bent; Hamilton, Victoria; Hassler, Donald; Peterson, Joseph; Rafkin, Scot; Zeitlin, Cary; Fedosov, Fedor; Golovin, Dmitry; Karpushkina, Natalya; Kozyrev, Alexander; Litvak, Maxim; Malakhov, Alexey; Mitrofanov, Igor; Mokrousov, Maxim; Nikiforov, Sergey; Prokhorov, Vasily; Sanin, Anton; Tretyakov, Vladislav; Varenikov, Alexey; Vostrukhin, Andrey; Kuzmin, Ruslan; Clark, Benton; Wolff, Michael; McLennan, Scott; Botta, Oliver; Drake, Darrell; Bean, Keri; Lemmon, Mark; Schwenzer, Susanne P.; Anderson, Ryan B.; Herkenhoff, Kenneth; Lee, Ella Mae; Sucharski, Robert; Hernández, Miguel Ángel de Pablo; Ávalos, Juan José Blanco; Ramos, Miguel; Kim, Myung-Hee; Malespin, Charles; Plante, Ianik; Muller, Jan-Peter; Ewing, Ryan; Boynton, William; Downs, Robert; Fitzgibbon, Mike; Harshman, Karl; Morrison, Shaunna; Dietrich, William; Kortmann, Onno; Palucis, Marisa; Williams, Amy; Lugmair, Günter; Wilson, Michael A.; Rubin, David; Jakosky, Bruce; Balic-Zunic, Tonci; Frydenvang, Jens; Jensen, Jaqueline Kløvgaard; Kinch, Kjartan; Koefoed, Asmus; Madsen, Morten Bo; Stipp, Susan Louise Svane; Boyd, Nick; Campbell, John L.; Gellert, Ralf; Perrett, Glynis; Pradler, Irina; VanBommel, Scott; Jacob, Samantha; Rowland, Scott; Atlaskin, Evgeny; Savijärvi, Hannu; Boehm, Eckart; Böttcher, Stephan; Burmeister, Sönke; Guo, Jingnan; Köhler, Jan; García, César Martín; Mueller-Mellin, Reinhold; Wimmer-Schweingruber, Robert; Bridges, John C.; McConnochie, Timothy; Benna, Mehdi; Bower, Hannah; Blau, Hannah; Boucher, Thomas; Carmosino, Marco; Elliott, Harvey; Halleaux, Douglas; Rennó, Nilton; Wong, Michael; Elliott, Beverley; Spray, John; Thompson, Lucy; Gordon, Suzanne; Newsom, Horton; Ollila, Ann; Williams, Joshua; Vasconcelos, Paulo; Bentz, Jennifer; Nealson, Kenneth; Popa, Radu; Kah, Linda C.; Moersch, Jeffrey; Tate, Christopher; Day, Mackenzie; Kocurek, Gary; Hallet, Bernard; Sletten, Ronald; Francis, Raymond; McCullough, Emily; Cloutis, Ed; ten Kate, Inge Loes; Kuzmin, Ruslan; Arvidson, Raymond; Fraeman, Abigail; Scholes, Daniel; Slavney, Susan; Stein, Thomas; Ward, Jennifer; Berger, Jeffrey; Moores, John E.

2013-09-01

Samples from the Rocknest aeolian deposit were heated to ~835°C under helium flow and evolved gases analyzed by Curiosity’s Sample Analysis at Mars instrument suite. H2O, SO2, CO2, and O2 were the major gases released. Water abundance (1.5 to 3 weight percent) and release temperature suggest that H2O is bound within an amorphous component of the sample. Decomposition of fine-grained Fe or Mg carbonate is the likely source of much of the evolved CO2. Evolved O2 is coincident with the release of Cl, suggesting that oxygen is produced from thermal decomposition of an oxychloride compound. Elevated δD values are consistent with recent atmospheric exchange. Carbon isotopes indicate multiple carbon sources in the fines. Several simple organic compounds were detected, but they are not definitively martian in origin.

Application of pulsed OSL to polymineral fine-grained samples

International Nuclear Information System (INIS)

Feathers, James K.; Casson, M. Aksel; Schmidt, Amanda Henck; Chithambo, Makaiko L.

2012-01-01

Pulsed OSL is applied to nine fine-grained sediment samples from Sichuan province, China, using stimulating pulses of 10 μs on and 240 μs off, with an infrared exposure prior to each OSL measurement. Comparison of fading rates between pulsed and non-pulsed signals, the latter also obtained with a preceding IR exposure, shows that fading is significant for mainly the non-pulsed signals. Presence of a pulsed IRSL and the magnitudes of b-value to correct for lower alpha efficiency suggest that pulsing does not fully remove a significant feldspar signal, only a fading component. Comparison with ages of quartz extracts shows that pulsed OSL ages are consistent, while CW-OSL ages are slightly older and CW-IRSL ages are much older. The older ages suggest a less well-bleached feldspar component.

INAA in combination with other analytical techniques in the study of urban aerosol sources

International Nuclear Information System (INIS)

Binh, N.T.; Truong, Y.; Ngo, N.T.; Sieu, L.N.; Hien, P.D.

2000-01-01

Concentrations of elements in fine and coarse PM10 samples collected in Ho Chi Minh City were determined by INAA for the purpose of characterising air pollution sources using multivariate receptor modeling techniques. Seven sources common to coarse and fine samples were identified. Resuspended soil dust is dominant in the coarse samples accounting for 41% of the particulate mass. In the fine samples, vehicle emissions and coal burning are most important accounting for about 20% each. Although a great number of elements were included in the input data for receptor modeling, the interpretation of emission sources was not always straightforward. Information on other source markers were needed. Therefore, a polarography method was used for quantifying lead, and recently, ion chromatography method became available for quantifying secondary sulphates, nitrates and other water soluble ions. (author)

Chemical mass balance source apportionment of fine and PM10 in the Desert Southwest, USA

Directory of Open Access Journals (Sweden)

Andrea L. Clements

2016-03-01

Full Text Available The Desert Southwest Coarse Particulate Matter Study was undertaken in Pinal County, Arizona, to better understand the origin and impact of sources of fine and coarse particulate matter (PM in rural, arid regions of the U.S. southwestern desert. The desert southwest experiences some of the highest PM10 mass concentrations in the country. To augment previously reported results, 6-week aggregated organic speciation data that included ambient concentrations of n-alkanes, polycyclic aromatic hydrocarbons, organic acids, and saccharides were used in chemical mass balance modeling (CMB. A set of re-suspended soil samples were analyzed for specific marker species to provide locally-appropriate source profiles for the CMB analysis. These profiles, as well as previously collected plant and fungal spore profiles from the region, were combined with published source profiles for other relevant sources and used in the CMB analysis. The six new region-specific source profiles included both organic and inorganic species for four crustal material sources, one plant detritus source, and one fungal spore source.Results indicate that up to half of the ambient PM2.5 was apportioned to motor vehicles with the highest regional contribution observed in the small urban center of Casa Grande. Daily levels of apportioned crustal material accounted for up to 50% of PM2.5 mass with the highest contributions observed at the sites closest to active agricultural areas. Apportioned secondary PM, biomass burning, and road dust typically contributed less than 35% as a group to the apportioned PM2.5 mass. Crustal material was the primary source apportioned to PM10 and accounted for between 50–90% of the apportioned mass. Of the other sources apportioned to PM10, motor vehicles and road dust were the largest contributors at the urban and one of the rural sites, whereas road dust and meat cooking operations were the largest contributors at the other rural site.

Chemical Composition and Emission Sources of the Fine Particulate Matters in a Southeast Asian Mega City (Dhaka, Bangladesh)

Science.gov (United States)

Salam, Abdus

2016-04-01

Air pollution has significant impact on human health, climate change, agriculture, visibility reduction, and also on the atmospheric chemistry. There are many studies already reported about the direct relation of the human mortality and morbidity with the increase of the atmospheric particulate matters. Especially, fine particulate matters can easily enter into the human respiratory system and causes many diseases. Particulate matters have the properties to absorb the solar radiation and impact on the climate. Dhaka, Bangladesh is a densely populated mega-city in the world. About 16 million inhabitants are living within an area of 360 square kilometers. Air quality situation has been degrading due to unplanned growth, increasing vehicles, severe traffic jams, brick kilns, industries, construction, and also transboundary air pollution. A rapidly growing number of vehicles has worsen the air quality in spite of major policy interventions, e.g., ban of two-stroke and three-wheeled vehicles, phase out of 20 years old vehicles, conversion to compressed natural gas (CNGs), etc. Introduction of CNGs to reduce air pollution was not the solution for fine particles at all, as evidence shows that CNGs and diesel engines are the major sources of fine particles. High concentration of the air pollutants in Dhaka city such as PM, carbonaceous species (black and organic carbon), CO, etc. has already been reported. PM2.5 mass, chemical composition (e.g., BC, OC, SO42-, NO3-, trace elements, etc.), aerosol Optical Depth (AOD) and emission sources of our recent measurements at the highly polluted south East Asian Mega city (Dhaka) Bangladesh will be presented in the conference. PM2.5 samples were collected on filters with Digital PM2.5 sampler (Switzerland) and Air photon, USA. BC was measured from filters (with thermal and optical method) and also real time with an Aethalometer AE42 (Magee Scitific., USA). Water soluble ions were determined from filters with ion chromatogram. AOD

Quantitative characterization of urban sources of organic aerosol by high-resolution gas chromatography

International Nuclear Information System (INIS)

Hildemann, L.M.; Mazurek, M.A.; Cass, G.R.; Simoneit, B.R.T.

1991-01-01

Fine aerosol emissions have been collected from a variety of urban combustion sources, including an industrial boiler, a fireplace, automobiles, diesel trucks, gas-fired home appliances, and meat cooking operations, by use of a dilution sampling system. Other sampling techniques have been utilized to collect fine aerosol samples of paved road dust, brake wear, tire wear, cigarette smoke, tar pot emissions, and vegetative detritus. The organic matter contained in each of these samples has been analyzed via high-resolution gas chromatography. By use of a simple computational approach, a quantitative, 50-parameter characterization of the elutable fine organic aerosol emitted from each source type has been determined. The organic mass distribution fingerprints obtained by this approach are shown to differ significantly from each other for most of the source types tested, using hierarchical cluster analysis

Using 239Pu as a tracer for fine sediment sources in the Daly River, Northern Australia

Directory of Open Access Journals (Sweden)

Lal R.

2015-01-01

Full Text Available The Daly River drains a large (52500 km2 and mainly undisturbed catchment in the Australian wet–dry tropics. Clearing and cropping since 2002 have raised concerns about possible increased sediment input into the river and motivated this study of its fine sediment sources. Using 239Pu as a tracer it is shown that the fine sediments originate mainly from erosion by gullying and channel change. Although the results also indicate that the surface soil contribution to the river channel sediments from sheet erosion has increased to 5-22% for the Daly River and 7-28% for the Douglas River (a tributary of the Daly River in 2009 vs. 3-6% for the Daly River and 4-9% for the Douglas River in 2005. This excess top soil likely originates from thecleared land adjacent to the Daly River since 2005. However, channel widening largely as a result of hydrologic change is still the dominant sediment source in this catchment.

Observations of fine particulate nitrated phenols in four sites in northern China: concentrations, source apportionment, and secondary formation

Science.gov (United States)

Wang, Liwei; Wang, Xinfeng; Gu, Rongrong; Wang, Hao; Yao, Lan; Wen, Liang; Zhu, Fanping; Wang, Weihao; Xue, Likun; Yang, Lingxiao; Lu, Keding; Chen, Jianmin; Wang, Tao; Zhang, Yuanghang; Wang, Wenxing

2018-03-01

Filter samples of fine particulate matters were collected at four sites in northern China (urban, rural, and mountain) in summer and winter, and the contents of nine nitrated phenols were quantified in the laboratory with the use of ultra-high-performance liquid chromatography coupled with mass spectrometry. During the sampling periods, the concentrations of particulate nitrated phenols exhibited distinct temporal and spatial variation. On average, the total concentration of particulate nitrated phenols in urban Jinan in the wintertime reached 48.4 ng m-3, and those in the summertime were 9.8, 5.7, 5.9, and 2.5 ng m-3 in urban Jinan, rural Yucheng and Wangdu, and Mt. Tai, respectively. The elevated concentrations of nitrated phenols in wintertime and in urban areas demonstrate the apparent influences of anthropogenic sources. The positive matrix factorization receptor model was then applied to determine the origins of particulate nitrated phenols in northern China. The five major source factors were traffic, coal combustion, biomass burning, secondary formation, and aged coal combustion plume. Among them, coal combustion played a vital role, especially at the urban site in the wintertime, with a contribution of around 55 %. In the summertime, the observed nitrated phenols were highly influenced by aged coal combustion plumes at all of the sampling sites. Meanwhile, in remote areas, contributions from secondary formation were significant. Further correlation analysis indicates that nitrosalicylic acids were produced mostly from secondary formation that was dominated by NO2 nitration.

Fine Particulate Pollution and Source Apportionment in the Urban Centers for Africa, Asia and Latin America

Science.gov (United States)

Guttikunda, S. K.; Johnson, T. M.; Procee, P.

2004-12-01

Fossil fuel combustion for domestic cooking and heating, power generation, industrial processes, and motor vehicles are the primary sources of air pollution in the developing country cities. Over the past twenty years, major advances have been made in understanding the social and economic consequences of air pollution. In both industrialized and developing countries, it has been shown that air pollution from energy combustion has detrimental impacts on human health and the environment. Lack of information on the sectoral contributions to air pollution - especially fine particulates, is one of the typical constraints for an effective integrated urban air quality management program. Without such information, it is difficult, if not impossible, for decision makers to provide policy advice and make informed investment decisions related to air quality improvements in developing countries. This also raises the need for low-cost ways of determining the principal sources of fine PM for a proper planning and decision making. The project objective is to develop and verify a methodology to assess and monitor the sources of PM, using a combination of ground-based monitoring and source apportionment techniques. This presentation will focus on four general tasks: (1) Review of the science and current activities in the combined use of monitoring data and modeling for better understanding of PM pollution. (2) Review of recent advances in atmospheric source apportionment techniques (e.g., principal component analysis, organic markers, source-receptor modeling techniques). (3) Develop a general methodology to use integrated top-down and bottom-up datasets. (4) Review of a series of current case studies from Africa, Asia and Latin America and the methodologies applied to assess the air pollution and its sources.

Apollo rocks, fines and soil cores

Science.gov (United States)

Allton, J.; Bevill, T.

Apollo rocks and soils not only established basic lunar properties and ground truth for global remote sensing, they also provided important lessons for planetary protection (Adv. Space Res ., 1998, v. 22, no. 3 pp. 373-382). The six Apollo missions returned 2196 samples weighing 381.7 kg, comprised of rocks, fines, soil cores and 2 gas samples. By examining which samples were allocated for scientific investigations, information was obtained on usefulness of sampling strategy, sampling devices and containers, sample types and diversity, and on size of sample needed by various disciplines. Diversity was increased by using rakes to gather small rocks on the Moon and by removing fragments >1 mm from soils by sieving in the laboratory. Breccias and soil cores are diverse internally. Per unit weight these samples were more often allocated for research. Apollo investigators became adept at wringing information from very small sample sizes. By pushing the analytical limits, the main concern was adequate size for representative sampling. Typical allocations for trace element analyses were 750 mg for rocks, 300 mg for fines and 70 mg for core subsamples. Age-dating and isotope systematics allocations were typically 1 g for rocks and fines, but only 10% of that amount for core depth subsamples. Historically, allocations for organics and microbiology were 4 g (10% for cores). Modern allocations for biomarker detection are 100mg. Other disciplines supported have been cosmogenic nuclides, rock and soil petrology, sedimentary volatiles, reflectance, magnetics, and biohazard studies . Highly applicable to future sample return missions was the Apollo experience with organic contamination, estimated to be from 1 to 5 ng/g sample for Apollo 11 (Simonheit &Flory, 1970; Apollo 11, 12 &13 Organic contamination Monitoring History, U.C. Berkeley; Burlingame et al., 1970, Apollo 11 LSC , pp. 1779-1792). Eleven sources of contaminants, of which 7 are applicable to robotic missions, were

Source Apportionment of Primary and Secondary Fine Particulate Matter in China

Science.gov (United States)

Hu, J.; Zhang, H.; Ying, Q.

2015-12-01

In the past few decades, China have been facing extreme particulate matter (PM) pollution problems due to the combination of fast increase of population, industrialization, urbanization and associated energy consumption and lagging of sufficient emission control measures. Studies have identified the major components of fine PM (PM2.5) in China include primary PM (which is directly emitted into the atmosphere), sulfate and nitrate (which are mainly secondary PM, i.e., formed from gaseous precursors), and organic aerosols (which can be primary or secondary). Contributions of different source sectors to the different PM components are substantially different; therefore source apportionment of these components can provide critical information needed for policy makers to design effective emission control strategies. In the current study, a source-oriented version of the Community Multiscale Air Quality (CMAQ) model that directly tracks the contributions from multiple emission sources to primary and secondary PM2.5 is developed, and then applied to determine the regional contributions of power, industry, transportation and residential sectors to primary PM, nitrate and sulfate concentrations in China. Four months in 2012-2013 are simulated to predict the seasonal variations of source contributions. Model predictions are evaluated with ambient measured concentrations. The source-oriented CMAQ model is capable of reproducing most of the available PM10 and PM2.5 mass, and PM2.5 EC, POC, nitrate and sulfate observations. Predicted source contributions for EC also generally agree with to the source contributions estimated by receptor models reported in previous studies. Model predictions suggest residential is a major contributor to primary PM (30-70%) in the spring and winter, and industrial contributes 40-60% of primary PM in the summer and fall; Transportation is an important source for EC (20-30%); Power sector is the dominating source of nitrate and sulfate in both

Water Soluble Organic Nitrogen (WSON) in Ambient Fine Particles Over a Megacity in South China: Spatiotemporal Variations and Source Apportionment

Science.gov (United States)

Yu, Xu; Yu, Qingqing; Zhu, Ming; Tang, Mingjin; Li, Sheng; Yang, Weiqiang; Zhang, Yanli; Deng, Wei; Li, Guanghui; Yu, Yuegang; Huang, Zhonghui; Song, Wei; Ding, Xiang; Hu, Qihou; Li, Jun; Bi, Xinhui; Wang, Xinming

2017-12-01

Organic nitrogen aerosols are complex mixtures and important compositions in ambient fine particulate matters (PM2.5), yet their sources and spatiotemporal patterns are not well understood particularly in regions influenced by intensive human activities. In this study, filter-based ambient PM2.5 samples at four stations (one urban, two rural, plus one urban roadside) and PM samples from combustion sources (vehicle exhaust, ship emission, and biomass burning) were collected in the coastal megacity Guangzhou, south China, for determining water soluble organic nitrogen (WSON) along with other organic and inorganic species. The annual average WSON concentrations, as well as the ratios of WSON to water soluble total nitrogen, were all significantly higher at rural sites than urban sites. Average WSON concentrations at the four sites during the wet season were quite near each other, ranging from 0.41 to 0.49 μg/m3; however, they became 2 times higher at the rural sites than at the urban sites during the dry season. Five major sources for WSON were identified through positive matrix factorization analysis. Vehicle emission (29.3%), biomass burning (22.8%), and secondary formation (20.2%) were three dominant sources of WSON at the urban station, while vehicle emission (45.4%) and dust (28.6%) were two dominant sources at the urban roadside station. At the two rural sites biomass burning (51.1% and 34.1%, respectively) and secondary formation (17.8% and 30.5%, respectively) were dominant sources of WSON. Ship emission contributed 8-12% of WSON at the four sites. Natural vegetation seemed to have very minor contribution to WSON.

Sources and oxidative potential of water-soluble humic-like substances (HULISWS) in fine particulate matter (PM2.5) in Beijing

Science.gov (United States)

Ma, Yiqiu; Cheng, Yubo; Qiu, Xinghua; Cao, Gang; Fang, Yanhua; Wang, Junxia; Zhu, Tong; Yu, Jianzhen; Hu, Di

2018-04-01

Water-soluble humic-like substances (HULISWS) are a major redox-active component of ambient fine particulate matter (PM2.5); however, information on their sources and associated redox activity is limited. In this study, HULISWS mass concentration, various HULISWS species, and dithiothreitol (DTT) activity of HULISWS were quantified in PM2.5 samples collected during a 1-year period in Beijing. Strong correlation was observed between HULISWS and DTT activity; both exhibited higher levels during the heating season than during the nonheating season. Positive matrix factorization analysis of both HULISWS and DTT activity was performed. Four combustion-related sources, namely coal combustion, biomass burning, waste incineration, and vehicle exhausts, and one secondary factor were resolved. In particular, waste incineration was identified as a source of HULISWS for the first time. Biomass burning and secondary aerosol formation were the major contributors ( > 59 %) to both HULISWS and associated DTT activity throughout the year. During the nonheating season, secondary aerosol formation was the most important source, whereas during the heating season, the predominant contributor was biomass burning. The four combustion-related sources accounted for > 70 % of HULISWS and DTT activity, implying that future reduction in PM2.5 emissions from combustion activities can substantially reduce the HULISWS burden and their potential health impact in Beijing.

Source apportionment of airborne particulate matter using organic compounds as tracers

Science.gov (United States)

Schauer, James J.; Rogge, Wolfgang F.; Hildemann, Lynn M.; Mazurek, Monica A.; Cass, Glen R.; Simoneit, Bernd R. T.

A chemical mass balance receptor model based on organic compounds has been developed that relates source contributions to airborne fine particle mass concentrations. Source contributions to the concentrations of specific organic compounds are revealed as well. The model is applied to four air quality monitoring sites in southern California using atmospheric organic compound concentration data and source test data collected specifically for the purpose of testing this model. The contributions of up to nine primary particle source types can be separately identified in ambient samples based on this method, and approximately 85% of the organic fine aerosol is assigned to primary sources on an annual average basis. The model provides information on source contributions to fine mass concentrations, fine organic aerosol concentrations and individual organic compound concentrations. The largest primary source contributors to fine particle mass concentrations in Los Angeles are found to include diesel engine exhaust, paved road dust, gasoline-powered vehicle exhaust, plus emissions from food cooking and wood smoke, with smaller contribution from tire dust, plant fragments, natural gas combustion aerosol, and cigarette smoke. Once these primary aerosol source contributions are added to the secondary sulfates, nitrates and organics present, virtually all of the annual average fine particle mass at Los Angeles area monitoring sites can be assigned to its source.

Source Apportionment of Suspended Sediment Sources using 137Cs and 210Pbxs

Science.gov (United States)

Lamba, J.; Karthikeyan, K.; Thompson, A.

2017-12-01

A study was conducted in the Pleasant Valley Watershed (50 km 2) in South Central Wisconsin to better understand sediment transport processes using sediment fingerprinting technique. Previous studies conducted in this watershed showed that resuspension of fine sediment deposited on the stream bed is an important source of suspended sediment. To better understand the role of fine sediment deposited on the stream bed, fallout radionuclides,137Cs and 210Pbxs were used to determine relative contribution to suspended sediment from in-stream (stream bank and stream bed) and upland sediment sources. Suspended sediment samples were collected during the crop growing season. Potential sources of suspended sediment considered in this study included cropland, pasture and in-stream (stream bed and stream bank). Suspended sediment sources were determined at a subwatershed level. Results of this study showed that in-stream sediment sources are important sources of suspended sediment. Future research should be conducted to better understand the role of legacy sediment in watershed-level sediment transport processes.

Observations of fine particulate nitrated phenols in four sites in northern China: concentrations, source apportionment, and secondary formation

Directory of Open Access Journals (Sweden)

L. Wang

2018-03-01

Full Text Available Filter samples of fine particulate matters were collected at four sites in northern China (urban, rural, and mountain in summer and winter, and the contents of nine nitrated phenols were quantified in the laboratory with the use of ultra-high-performance liquid chromatography coupled with mass spectrometry. During the sampling periods, the concentrations of particulate nitrated phenols exhibited distinct temporal and spatial variation. On average, the total concentration of particulate nitrated phenols in urban Jinan in the wintertime reached 48.4 ng m−3, and those in the summertime were 9.8, 5.7, 5.9, and 2.5 ng m−3 in urban Jinan, rural Yucheng and Wangdu, and Mt. Tai, respectively. The elevated concentrations of nitrated phenols in wintertime and in urban areas demonstrate the apparent influences of anthropogenic sources. The positive matrix factorization receptor model was then applied to determine the origins of particulate nitrated phenols in northern China. The five major source factors were traffic, coal combustion, biomass burning, secondary formation, and aged coal combustion plume. Among them, coal combustion played a vital role, especially at the urban site in the wintertime, with a contribution of around 55 %. In the summertime, the observed nitrated phenols were highly influenced by aged coal combustion plumes at all of the sampling sites. Meanwhile, in remote areas, contributions from secondary formation were significant. Further correlation analysis indicates that nitrosalicylic acids were produced mostly from secondary formation that was dominated by NO2 nitration.

The new Chalk River AMS ion source, sample changer and external sample magazine

International Nuclear Information System (INIS)

Koslowsky, V.T.; Bray, N.; Imahori, Y.; Andrews, H.R.; Davies, W.G.

1997-01-01

A new sample magazine, sample changer and ion source have been developed and are in routine use at Chalk River. The system features a readily accessible 40-sample magazine at ground potential that is external to the ion source and high-voltage cage. The samples are held in an inert atmosphere and can be individually examined or removed; they can be exchanged en masse as a complete magazine concurrent with an AMS measurement. On-line sample changing is done with a pneumatic rabbit transfer system employing two stages of differential pumping. At Chalk River this is routinely performed across a 200 kV potential. Sample positioning is precise, and hundreds of 36 Cl and 129 I samples have been measured over a period of several days without interruption or alteration of ion source operating conditions. (author)

Apportionment of the sources of high fine particulate matter concentration events in a developing aerotropolis in Taoyuan, Taiwan.

Science.gov (United States)

Chuang, Ming-Tung; Chen, Yu-Chieh; Lee, Chung-Te; Cheng, Chung-Hao; Tsai, Yu-Jen; Chang, Shih-Yu; Su, Zhen-Sen

2016-07-01

To investigate the characteristics and contributions of the sources of fine particulate matter with a size of up to 2.5 μm (PM2.5) during the period when pollution events could easily occur in Taoyuan aerotropolis, Taiwan, this study conducted sampling at three-day intervals from September 2014 to January 2015. Based on the mass concentration of PM2.5, the sampling days were classified into high PM2.5 concentration event days (PM2.5>35 μg m(-3)) and non-event days (PM2.5<35 μg m(-3)). In addition, the chemical species, including water-soluble inorganic ions, carbonaceous components, and metal elements, were analyzed. The sources of pollution and their contributions were estimated using the positive matrix factorization (PMF) model. Furthermore, the effect of the weather type on the measurement results was also explored based on wind field conditions. The mass fractions of Cl(-) and NO3(-) increased when a high PM2.5 concentration event occurred, and they were also higher under local emitted conditions than under long range transported conditions, indicating that secondary nitrate aerosols were the major increasing local species that caused high PM2.5 concentration events. Seven sources of pollution could be distinguished using the PMF model on the basis of the characteristics of the species. Industrial emissions, coal combustion/urban waste incineration, and local emissions from diesel/gasoline vehicles were the main sources that contributed to pollution on high PM2.5 concentration event days. In order to reduction of high PM2.5 concentration events, the control of diesel and gasoline vehicle emission is important and should be given priority. Copyright © 2016 Elsevier Ltd. All rights reserved.

Chemical composition and source apportionment of aerosol over the Klang valley

International Nuclear Information System (INIS)

Shamsiah Abdul Rahman; Mohd Suhaimi Hamzah; Abdul Khalik Wood; Nazaratul Ashifa Abdullah Salim; Mohd Suhaimi Elias; Eswiza Sanuri

2009-01-01

This paper reports the study of aerosol chemical composition of fine particles (PM 2.5) and possible sources of air pollution over the Klang Valley, Kuala Lumpur, based on the samples collected for a period of 6 years from July 2000 to Jun 2006. Samples collected were measured for mass, black carbon and elemental content of Na, Mg, Al, Si, P, S, Cl, K, Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, As, Br and Pb. The fine aerosol mass concentration ranged from 11 - 110 ?g/m3. Black carbon is the major component of the fine aerosol with the weight fraction of 20%, whilst S is the major elemental content with the weight fraction about 5% as relative to the fine particle mass. The factor analysis method, positive matrix factorization (PMF) was then used to confirm the possible sources. The result of PMF analysis produced five-factor sources that contribute to the fine particles in the Klang Valley area. The five factors represent sea spray, industry, motor vehicles, smoke and soil. Motor vehicle is the main source of particulates in the area, with an average contribution of 51% of the fine mass concentration, followed by industry, smoke, sea spray and soil, with average contribution of 28%, 14%, 3.6% and 2.1%, respectively. (Author)

Computing the Free Energy Barriers for Less by Sampling with a Coarse Reference Potential while Retaining Accuracy of the Target Fine Model.

Science.gov (United States)

Plotnikov, Nikolay V

2014-08-12

Proposed in this contribution is a protocol for calculating fine-physics (e.g., ab initio QM/MM) free-energy surfaces at a high level of accuracy locally (e.g., only at reactants and at the transition state for computing the activation barrier) from targeted fine-physics sampling and extensive exploratory coarse-physics sampling. The full free-energy surface is still computed but at a lower level of accuracy from coarse-physics sampling. The method is analytically derived in terms of the umbrella sampling and the free-energy perturbation methods which are combined with the thermodynamic cycle and the targeted sampling strategy of the paradynamics approach. The algorithm starts by computing low-accuracy fine-physics free-energy surfaces from the coarse-physics sampling in order to identify the reaction path and to select regions for targeted sampling. Thus, the algorithm does not rely on the coarse-physics minimum free-energy reaction path. Next, segments of high-accuracy free-energy surface are computed locally at selected regions from the targeted fine-physics sampling and are positioned relative to the coarse-physics free-energy shifts. The positioning is done by averaging the free-energy perturbations computed with multistep linear response approximation method. This method is analytically shown to provide results of the thermodynamic integration and the free-energy interpolation methods, while being extremely simple in implementation. Incorporating the metadynamics sampling to the algorithm is also briefly outlined. The application is demonstrated by calculating the B3LYP//6-31G*/MM free-energy barrier for an enzymatic reaction using a semiempirical PM6/MM reference potential. These modifications allow computing the activation free energies at a significantly reduced computational cost but at the same level of accuracy compared to computing full potential of mean force.

Source apportionment of fine particulate matter in China in 2013 using a source-oriented chemical transport model.

Science.gov (United States)

Shi, Zhihao; Li, Jingyi; Huang, Lin; Wang, Peng; Wu, Li; Ying, Qi; Zhang, Hongliang; Lu, Li; Liu, Xuejun; Liao, Hong; Hu, Jianlin

2017-12-01

China has been suffering high levels of fine particulate matter (PM 2.5 ). Designing effective PM 2.5 control strategies requires information about the contributions of different sources. In this study, a source-oriented Community Multiscale Air Quality (CMAQ) model was applied to quantitatively estimate the contributions of different source sectors to PM 2.5 in China. Emissions of primary PM 2.5 and gas pollutants of SO 2 , NO x , and NH 3 , which are precursors of particulate sulfate, nitrate, and ammonium (SNA, major PM 2.5 components in China), from eight source categories (power plants, residential sources, industries, transportation, open burning, sea salt, windblown dust and agriculture) were separately tracked to determine their contributions to PM 2.5 in 2013. Industrial sector is the largest source of SNA in Beijing, Xi'an and Chongqing, followed by agriculture and power plants. Residential emissions are also important sources of SNA, especially in winter when severe pollution events often occur. Nationally, the contributions of different source sectors to annual total PM 2.5 from high to low are industries, residential sources, agriculture, power plants, transportation, windblown dust, open burning and sea salt. Provincially, residential sources and industries are the major anthropogenic sources of primary PM 2.5 , while industries, agriculture, power plants and transportation are important for SNA in most provinces. For total PM 2.5 , residential and industrial emissions are the top two sources, with a combined contribution of 40-50% in most provinces. The contributions of power plants and agriculture to total PM 2.5 are about 10%, respectively. Secondary organic aerosol accounts for about 10% of annual PM 2.5 in most provinces, with higher contributions in southern provinces such as Yunnan (26%), Hainan (25%) and Taiwan (21%). Windblown dust is an important source in western provinces such as Xizang (55% of total PM 2.5 ), Qinghai (74%), Xinjiang (59

Sources and oxidative potential of water-soluble humic-like substances (HULISWS in fine particulate matter (PM2.5 in Beijing

Directory of Open Access Journals (Sweden)

Y. Ma

2018-04-01

Full Text Available Water-soluble humic-like substances (HULISWS are a major redox-active component of ambient fine particulate matter (PM2.5; however, information on their sources and associated redox activity is limited. In this study, HULISWS mass concentration, various HULISWS species, and dithiothreitol (DTT activity of HULISWS were quantified in PM2.5 samples collected during a 1-year period in Beijing. Strong correlation was observed between HULISWS and DTT activity; both exhibited higher levels during the heating season than during the nonheating season. Positive matrix factorization analysis of both HULISWS and DTT activity was performed. Four combustion-related sources, namely coal combustion, biomass burning, waste incineration, and vehicle exhausts, and one secondary factor were resolved. In particular, waste incineration was identified as a source of HULISWS for the first time. Biomass burning and secondary aerosol formation were the major contributors ( >  59 % to both HULISWS and associated DTT activity throughout the year. During the nonheating season, secondary aerosol formation was the most important source, whereas during the heating season, the predominant contributor was biomass burning. The four combustion-related sources accounted for  >  70 % of HULISWS and DTT activity, implying that future reduction in PM2.5 emissions from combustion activities can substantially reduce the HULISWS burden and their potential health impact in Beijing.

Dark energy with fine redshift sampling

Science.gov (United States)

Linder, Eric V.

2007-03-01

The cosmological constant and many other possible origins for acceleration of the cosmic expansion possess variations in the dark energy properties slow on the Hubble time scale. Given that models with more rapid variation, or even phase transitions, are possible though, we examine the fineness in redshift with which cosmological probes can realistically be employed, and what constraints this could impose on dark energy behavior. In particular, we discuss various aspects of baryon acoustic oscillations, and their use to measure the Hubble parameter H(z). We find that currently considered cosmological probes have an innate resolution no finer than Δz≈0.2 0.3.

Dark energy with fine redshift sampling

International Nuclear Information System (INIS)

Linder, Eric V.

2007-01-01

The cosmological constant and many other possible origins for acceleration of the cosmic expansion possess variations in the dark energy properties slow on the Hubble time scale. Given that models with more rapid variation, or even phase transitions, are possible though, we examine the fineness in redshift with which cosmological probes can realistically be employed, and what constraints this could impose on dark energy behavior. In particular, we discuss various aspects of baryon acoustic oscillations, and their use to measure the Hubble parameter H(z). We find that currently considered cosmological probes have an innate resolution no finer than Δz≅0.2-0.3

Non-destructive XRF analyses of fine-grained basalts from Eiao, Marquesas Islands

International Nuclear Information System (INIS)

Charleux, M.; McAlister, A.; Mills, P.R.; Lundblad, S.P.

2014-01-01

The Marquesan island of Eiao was an important source of fine-grained basalt in Central East Polynesia, with examples being identified in archaeological assemblages throughout the region. However, compared to many other large-scale Polynesian basalt sources, little has been published about the physical extent and geochemical variability of tool-quality basalt on Eiao; prior to our study, only a single site with evidence of stone extraction had been identified and geochemical information was limited to less than two dozen samples. In this paper we report geochemical data for 225 additional basalt specimens collected on Eiao. Our analyses were conducted non-destructively using three EDXRF instruments: one lab-based unit and two portable analysers. The majority of our sample, identified here as Group 1, possesses geochemical and physical characteristics similar to those reported in previous studies. Group 1 samples were collected from various locations on Eiao suggesting that, rather than being limited to a single quarry site, fine-grained basalt was extracted from multiple sources throughout the island. In addition, we identified a second group (Group 2), which possesses a distinct geochemistry, a coarser grain and often an unusual reddish colour. Evidence from Eiao indicates that Group 2 stone was regularly utilised and our analysis of an adze collected on Hiva Oa Island suggests that this material was distributed at least as far as the southern Marquesas. (author)

Comparison of fine particle measurements from a direct-reading instrument and a gravimetric sampling method.

Science.gov (United States)

Kim, Jee Young; Magari, Shannon R; Herrick, Robert F; Smith, Thomas J; Christiani, David C

2004-11-01

Particulate air pollution, specifically the fine particle fraction (PM2.5), has been associated with increased cardiopulmonary morbidity and mortality in general population studies. Occupational exposure to fine particulate matter can exceed ambient levels by a large factor. Due to increased interest in the health effects of particulate matter, many particle sampling methods have been developed In this study, two such measurement methods were used simultaneously and compared. PM2.5 was sampled using a filter-based gravimetric sampling method and a direct-reading instrument, the TSI Inc. model 8520 DUSTTRAK aerosol monitor. Both sampling methods were used to determine the PM2.5 exposure in a group of boilermakers exposed to welding fumes and residual fuel oil ash. The geometric mean PM2.5 concentration was 0.30 mg/m3 (GSD 3.25) and 0.31 mg/m3 (GSD 2.90)from the DUSTTRAK and gravimetric method, respectively. The Spearman rank correlation coefficient for the gravimetric and DUSTTRAK PM2.5 concentrations was 0.68. Linear regression models indicated that log, DUSTTRAK PM2.5 concentrations significantly predicted loge gravimetric PM2.5 concentrations (p gravimetric PM2.5 concentrations was found to be modified by surrogate measures for seasonal variation and type of aerosol. PM2.5 measurements from the DUSTTRAK are well correlated and highly predictive of measurements from the gravimetric sampling method for the aerosols in these work environments. However, results from this study suggest that aerosol particle characteristics may affect the relationship between the gravimetric and DUSTTRAK PM2.5 measurements. Recalibration of the DUSTTRAK for the specific aerosol, as recommended by the manufacturer, may be necessary to produce valid measures of airborne particulate matter.

Use of spatially distributed time-integrated sediment sampling networks and distributed fine sediment modelling to inform catchment management.

Science.gov (United States)

Perks, M T; Warburton, J; Bracken, L J; Reaney, S M; Emery, S B; Hirst, S

2017-11-01

Under the EU Water Framework Directive, suspended sediment is omitted from environmental quality standards and compliance targets. This omission is partly explained by difficulties in assessing the complex dose-response of ecological communities. But equally, it is hindered by a lack of spatially distributed estimates of suspended sediment variability across catchments. In this paper, we demonstrate the inability of traditional, discrete sampling campaigns for assessing exposure to fine sediment. Sampling frequencies based on Environmental Quality Standard protocols, whilst reflecting typical manual sampling constraints, are unable to determine the magnitude of sediment exposure with an acceptable level of precision. Deviations from actual concentrations range between -35 and +20% based on the interquartile range of simulations. As an alternative, we assess the value of low-cost, suspended sediment sampling networks for quantifying suspended sediment transfer (SST). In this study of the 362 km 2 upland Esk catchment we observe that spatial patterns of sediment flux are consistent over the two year monitoring period across a network of 17 monitoring sites. This enables the key contributing sub-catchments of Butter Beck (SST: 1141 t km 2 yr -1 ) and Glaisdale Beck (SST: 841 t km 2 yr -1 ) to be identified. The time-integrated samplers offer a feasible alternative to traditional infrequent and discrete sampling approaches for assessing spatio-temporal changes in contamination. In conjunction with a spatially distributed diffuse pollution model (SCIMAP), time-integrated sediment sampling is an effective means of identifying critical sediment source areas in the catchment, which can better inform sediment management strategies for pollution prevention and control. Copyright © 2017 Elsevier Ltd. All rights reserved.

Apportionment of the sources of high fine particulate matter concentration events in a developing aerotropolis in Taoyuan, Taiwan

International Nuclear Information System (INIS)

Chuang, Ming-Tung; Chen, Yu-Chieh; Lee, Chung-Te; Cheng, Chung-Hao; Tsai, Yu-Jen; Chang, Shih-Yu; Su, Zhen-Sen

2016-01-01

To investigate the characteristics and contributions of the sources of fine particulate matter with a size of up to 2.5 μm (PM 2.5 ) during the period when pollution events could easily occur in Taoyuan aerotropolis, Taiwan, this study conducted sampling at three-day intervals from September 2014 to January 2015. Based on the mass concentration of PM 2.5 , the sampling days were classified into high PM 2.5 concentration event days (PM 2.5 >35 μg m −3 ) and non-event days (PM 2.5 <35 μg m −3 ). In addition, the chemical species, including water-soluble inorganic ions, carbonaceous components, and metal elements, were analyzed. The sources of pollution and their contributions were estimated using the positive matrix factorization (PMF) model. Furthermore, the effect of the weather type on the measurement results was also explored based on wind field conditions. The mass fractions of Cl − and NO 3 − increased when a high PM 2.5 concentration event occurred, and they were also higher under local emitted conditions than under long range transported conditions, indicating that secondary nitrate aerosols were the major increasing local species that caused high PM 2.5 concentration events. Seven sources of pollution could be distinguished using the PMF model on the basis of the characteristics of the species. Industrial emissions, coal combustion/urban waste incineration, and local emissions from diesel/gasoline vehicles were the main sources that contributed to pollution on high PM 2.5 concentration event days. In order to reduction of high PM 2.5 concentration events, the control of diesel and gasoline vehicle emission is important and should be given priority. - Highlights: • The mass fractions of NH 4 + , K + , Cl − and NO 3 − increased during PM 2.5 event days. • Reduction of coal combustion/urban waste incineration emissions should be prioritized. • The control of vehicle emission is important in the locally emitted periods. • Secondary

SOURCE SAMPLING FINE PARTICULATE MATTER: A KRAFT PROCESS RECOVERY BOILER AT A PULP AND PAPER FACILITY, VOLUMES 1 AND 2

Science.gov (United States)

Fine particulate matter of aerodynamic diameter 2.5 m or less (PM-2.5) has been found harmful to human health, and a National Ambient Air Quality Standard for PM-2.5 was promulgated by the U.S. Environmental Protection Agency in July 1997. A national network of ambient monitorin...

Stratified source-sampling techniques for Monte Carlo eigenvalue analysis

International Nuclear Information System (INIS)

Mohamed, A.

1998-01-01

In 1995, at a conference on criticality safety, a special session was devoted to the Monte Carlo ''Eigenvalue of the World'' problem. Argonne presented a paper, at that session, in which the anomalies originally observed in that problem were reproduced in a much simplified model-problem configuration, and removed by a version of stratified source-sampling. In this paper, stratified source-sampling techniques are generalized and applied to three different Eigenvalue of the World configurations which take into account real-world statistical noise sources not included in the model problem, but which differ in the amount of neutronic coupling among the constituents of each configuration. It is concluded that, in Monte Carlo eigenvalue analysis of loosely-coupled arrays, the use of stratified source-sampling reduces the probability of encountering an anomalous result over that if conventional source-sampling methods are used. However, this gain in reliability is substantially less than that observed in the model-problem results

Sr-Nd-Hf Isotopic Analysis of <10 mg Dust Samples: Implications for Ice Core Dust Source Fingerprinting

DEFF Research Database (Denmark)

Ujvari, Gabor; Wegner, Wencke; Klötzli, Urs

2018-01-01

Combined Sr‐Nd‐Hf isotopic data of two reference materials (AGV‐1/BCR2) and 50, 10, and 5 mg aliquots of carbonate‐free fine grain (isotopic...... compositions (ICs) demonstrate that robust isotopic ratios can be obtained from 5 to 10 mg size rock samples using the ion exchange/mass spectrometry techniques applied. While 87Sr/86Sr ratios of dust aluminosilicate fractions are affected by even small changes in pretreatments, Nd isotopic ratios are found...... to be insensitive to acid leaching, grain‐size or weathering effects. However, the Nd isotopic tracer is sometimes inconclusive in dust source fingerprinting (BEI and NUS both close to ɛNd(0) –10). Hafnium isotopic values (

Evaluation of Rock Powdering Methods to Obtain Fine-grained Samples for CHEMIN, a Combined XRD/XRF Instrument

Science.gov (United States)

Chipera, S. J.; Vaniman, D. T.; Bish, D. L.; Sarrazin, P.; Feldman, S.; Blake, D. F.; Bearman, G.; Bar-Cohen, Y.

2004-01-01

A miniature XRD/XRF (X-ray diffraction / X-ray fluorescence) instrument, CHEMIN, is currently being developed for definitive mineralogic analysis of soils and rocks on Mars. One of the technical issues that must be addressed to enable remote XRD analysis is how best to obtain a representative sample powder for analysis. For powder XRD analyses, it is beneficial to have a fine-grained sample to reduce preferred orientation effects and to provide a statistically significant number of crystallites to the X-ray beam. Although a two-dimensional detector as used in the CHEMIN instrument will produce good results even with poorly prepared powder, the quality of the data will improve and the time required for data collection will be reduced if the sample is fine-grained and randomly oriented. A variety of methods have been proposed for XRD sample preparation. Chipera et al. presented grain size distributions and XRD results from powders generated with an Ultrasonic/Sonic Driller/Corer (USDC) currently being developed at JPL. The USDC was shown to be an effective instrument for sampling rock to produce powder suitable for XRD. In this paper, we compare powder prepared using the USDC with powder obtained with a miniaturized rock crusher developed at JPL and with powder obtained with a rotary tungsten carbide bit to powders obtained from a laboratory bench-scale Retsch mill (provides benchmark mineralogical data). These comparisons will allow assessment of the suitability of these methods for analysis by an XRD/XRF instrument such as CHEMIN.

Flow cytometric evaluation of peripheral blood and bone marrow and fine-needle aspirate samples from multiple sites in dogs with multicentric lymphoma.

Science.gov (United States)

Joetzke, Alexa E; Eberle, Nina; Nolte, Ingo; Mischke, Reinhard; Simon, Daniela

2012-06-01

To determine whether the extent of disease in dogs with lymphoma can be assessed via flow cytometry and to evaluate the suitability of fine-needle aspirates from the liver and spleen of dogs for flow cytometric examination. 44 dogs with multicentric B-cell (n = 35) or T-cell lymphoma (9) and 5 healthy control dogs. Procedures-Peripheral blood and bone marrow samples and fine-needle aspirates of lymph node, liver, and spleen were examined via flow cytometry. Logarithmically transformed T-cell-to-B-cell percentage ratio (log[T:B]) values were calculated. Thresholds defined by use of log(T:B) values of samples from control dogs were used to determine extranodal lymphoma involvement in lymphoma-affected dogs; results were compared with cytologic findings. 12 of 245 (5%) samples (9 liver, 1 spleen, and 2 bone marrow) had insufficient cellularity for flow cytometric evaluation. Mean log(T:B) values of samples from dogs with B-cell lymphoma were significantly lower than those of samples from the same site in dogs with T-cell lymphoma and in control dogs. In dogs with T-cell lymphoma, the log(T:B) of lymph node, bone marrow, and spleen samples was significantly higher than in control dogs. Of 165 samples assessed for extranodal lymphoma involvement, 116 (70%) tested positive via flow cytometric analysis; results agreed with cytologic findings in 133 of 161 (83%) samples evaluated via both methods. Results suggested that flow cytometry may aid in detection of extranodal lymphoma involvement in dogs, but further research is needed. Most fine-needle aspirates of liver and spleen were suitable for flow cytometric evaluation.

Effectiveness of stream-sediment sampling along the Rio Ojo Caliente, New Mexico

International Nuclear Information System (INIS)

Wenrich-Verbeek, K.J.

1977-01-01

During 1976 a detailed geochemical study was conducted of the water and stream sediments in the tributaries of the Rio Ojo Caliente above the USGS gaging station 4 km below La Madera to determine: (1) the source of the anomaly in the water and (2) why the stream sediment samples did not contain a corresponding anomaly. The low uranium content of the stream sediments from these high uranium waters can be explained by (1) the presence of a ground water source for the uranium and (2) insufficient time for the uranium in the water to be adsorbed onto the sediments. Although a stream sediment anomaly in the streams containing high uranium waters can not be established with a size fraction less than 150 μm, enough uranium has been adsorbed by the fine fraction that a small local anomaly can be outlined using only the fraction size less than 90 μm. Thus, because adsorption appears to be a major control on the uranium in the fine fraction and detrital minerals control the uranium in the coarse fraction, if it is assumed that buried deposits are of prime importance because most surface deposits have been recognized, then sampling should be restricted to the fine fraction (less than 90 μm). Nevertheless, in a case where ground water is the contributing source for uranium, as was shown above by the low anomalous uranium values, even in the fine fraction, stream sediment sampling alone is not an effective technique for detecting uranium anomalies. This emphasizes the necessity of water sampling in conjunction with stream-sediment sampling

[Pollution characteristics and source of the atmospheric fine particles and secondary inorganic compounds at Mount Dinghu in autumn season].

Science.gov (United States)

Liu, Zi-Rui; Wang, Yue-Si; Liu, Quan; Liu, Lu-Ning; Zhang, De-Qiang

2011-11-01

Real-time measurements of PM2.5, secondary inorganic compounds in PM2.5 (SO4(2-), NH4(+), and NO3(-)) and related gaseous pollutants were conducted at Mount Dinghu, a regional background station of the Pearl River Delta (PRD), in October and November 2008 by using a conventional R&P TEOM and a system of rapid collection of fine particles and ion chromatography (RCFP-IC). Sources and transportation of atmospheric particles during the experiment were discussed with principal component analysis and backward trajectories calculated using HYSPLIT model. The average daily mass concentrations of PM2.5 were 76.9 microg x m(-3) during sampling period, and average daily mass concentrations of SO4(2-), NH4(+), and NO3(-) were 20.0 microg x m(-3), 6.8 microg x m(-3) and 2.6 microg x m(-3), respectively. The sum of these three secondary inorganic compounds accounted for more than one third of the PM2.5 mass concentration, which had become the major source of atmospheric fine particles at Mount Dinghu. The diurnal variation of PM2.5, SO4(2-), and NH4(+) all showed a "bimodal" distribution with two peaks appeared at 10:00 am and at 16:00 pm, respectively, whereas NO3(-s) howed "single peak" distribution peaked at 10:00 am. The mass concentrations of SO4(2-) in PM2.5 had the similar diurnal variation with that of SO2, SO4(2-) in PM2.5 was mainly transformed from SO2, whereas NO3(-) showed difference diurnal variation with that of NO2, and the second conversion rate of NO2 was far lower than that of SO2. NH4(+) in PM2.5 existed mainly in the form of sulfate, nitrate and chloride. Both of principal component analysis and back trajectory analysis showed that the variations of PM2.5 and secondary inorganic compounds at Mount Dinghu were mainly affected by the long-range transport air mass passed over Guangzhou, Huizhou and other highly industrialized areas which carried air pollutants to the observation site, at the same time local sulfate originated from secondary formation also

Household Air Pollution: Sources and Exposure Levels to Fine Particulate Matter in Nairobi Slums

Directory of Open Access Journals (Sweden)

Kanyiva Muindi

2016-07-01

Full Text Available With 2.8 billion biomass users globally, household air pollution remains a public health threat in many low- and middle-income countries. However, little evidence on pollution levels and health effects exists in low-income settings, especially slums. This study assesses the levels and sources of household air pollution in the urban slums of Nairobi. This cross-sectional study was embedded in a prospective cohort of pregnant women living in two slum areas—Korogocho and Viwandani—in Nairobi. Data on fuel and stove types and ventilation use come from 1058 households, while air quality data based on the particulate matters (PM2.5 level were collected in a sub-sample of 72 households using the DustTrak™ II Model 8532 monitor. We measured PM2.5 levels mainly during daytime and using sources of indoor air pollutions. The majority of the households used kerosene (69.7% as a cooking fuel. In households where air quality was monitored, the mean PM2.5 levels were high and varied widely, especially during the evenings (124.6 µg/m3 SD: 372.7 in Korogocho and 82.2 µg/m3 SD: 249.9 in Viwandani, and in households using charcoal (126.5 µg/m3 SD: 434.7 in Korogocho and 75.7 µg/m3 SD: 323.0 in Viwandani. Overall, the mean PM2.5 levels measured within homes at both sites (Korogocho = 108.9 µg/m3 SD: 371.2; Viwandani = 59.3 µg/m3 SD: 234.1 were high. Residents of the two slums are exposed to high levels of PM2.5 in their homes. We recommend interventions, especially those focusing on clean cookstoves and lighting fuels to mitigate indoor levels of fine particles.

Portable ultrahigh-vacuum sample storage system for polarization-dependent total-reflection fluorescence x-ray absorption fine structure spectroscopy

Energy Technology Data Exchange (ETDEWEB)

Watanabe, Yoshihide, E-mail: e0827@mosk.tytlabs.co.jp; Nishimura, Yusaku F.; Suzuki, Ryo; Beniya, Atsushi; Isomura, Noritake [Toyota Central R& D Labs., Inc., Yokomichi 41-1, Nagakute, Aichi 480-1192 (Japan); Uehara, Hiromitsu; Asakura, Kiyotaka; Takakusagi, Satoru [Catalysis Research Center, Hokkaido University, Kita 21-10, Sapporo, Hokkaido 001-0021 (Japan); Nimura, Tomoyuki [AVC Co., Ltd., Inada 1450-6, Hitachinaka, Ibaraki 312-0061 (Japan)

2016-03-15

A portable ultrahigh-vacuum sample storage system was designed and built to investigate the detailed geometric structures of mass-selected metal clusters on oxide substrates by polarization-dependent total-reflection fluorescence x-ray absorption fine structure spectroscopy (PTRF-XAFS). This ultrahigh-vacuum (UHV) sample storage system provides the handover of samples between two different sample manipulating systems. The sample storage system is adaptable for public transportation, facilitating experiments using air-sensitive samples in synchrotron radiation or other quantum beam facilities. The samples were transferred by the developed portable UHV transfer system via a public transportation at a distance over 400 km. The performance of the transfer system was demonstrated by a successful PTRF-XAFS study of Pt{sub 4} clusters deposited on a TiO{sub 2}(110) surface.

Radionuclides deposition and fine sediment transport in a forested watershed, central Japan

Science.gov (United States)

Nam, S.; Gomi, T.; Kato, H.; Tesfaye, T.; Onda, Y.

2011-12-01

We investigated radionuclides deposition and fine sediment transport in a 13 ha headwater watershed, Tochigi prefecture, located in 98.94 km north of Tokyo. The study site was within Karasawa experimental forest, Tokyo University of Agriculture and Technology. We conducted fingerprinting approach, based on the activities of fallout radionuclides, including caesium-134 (Cs-134) caesium-137 (Cs-137) and excess lead-210 (Pb-210ex). For indentifying specific sources of fine sediment, we sampled tree, soil on forested floor, soil on logging road surface, stream bed and stream banks. We investigated the radionuclides (i.e., as Cs-134, Cs-137 and Pb-210ex) deposition on tree after accident of nuclear power plants on March 11, 2011. We sampled fruits, leaves, branches, stems, barks on Japanese cedar (Sugi) and Japanese cypress (Hinoki). To analyze the samples, gammaray spectrometry was performed at a laboratory at the University of Tsukuba (Tsukuba City, Japan) using n-type coaxial low-energy HPGe gamma detectors (EGC-200-R and EGC25-195-R of EURYSIS Co., Lingolsheim, France) coupled with a multichannel analyzer. We also collected soil samples under the forest canopy in various soil depths from 2, 5, 10, 20, 30 cm along transect of hillslopes. Samples at forest road were collected road segments crossing on the middle section of monitoring watersheds. Fine sediment transport in the streams were collected at the outlet of 13 ha watersheds using integrated suspended sediment samplers. This study indicates the some portion of radio nuclide potentially remained on the tree surface. Part of the deposited radionuclides attached to soil particles and transported to the streams. Most of the fine sediment can be transported on road surface and/or near stream side (riparian zones).

SOURCE SAMPLING FINE PARTICULATE MATTER: A KRAFT PROCESS HOGGED FUEL BOILER AT A PULP AND PAPER FACILITY, VOLUMES 1 AND 2

Science.gov (United States)

Fine particulate matter of aerodynamic diameter 2.5 m or less (PM-2.5) has been found harmful to human health, and a National Ambient Air Quality Standard for PM-2.5 was promulgated by the U.S. Environmental Protection Agency in July 1997. A national network of ambient monitorin...

Fine and coarse PM composition and sources in rural and urban sites in Switzerland: local or regional pollution?

Science.gov (United States)

Minguillón, M C; Querol, X; Baltensperger, U; Prévôt, A S H

2012-06-15

The chemical composition and sources of ambient particulate matter (PM) in Switzerland were studied. PM(1) and PM(10) samples were collected in winter and summer at an urban background site in Zurich and a rural background site in Payerne. Concentrations of major and trace elements, NO(3)(-), SO(4)(2-), NH(4)(+), organic and elemental carbon were determined. A subsequent Positive Matrix Factorization (PMF) analysis was performed. PM(10) and PM(1) concentrations varied similarly at both sites, with average PM(10) concentrations 24-25 μg/m(3) and 13-14 μg/m(3) in winter and summer, respectively, and average PM(1) concentrations 12-17 μg/m(3) and 6-7 μg/m(3). The influence of local sources was found to be higher in winter. PM was dominated by nitrate and organic matter in winter, and by mineral matter and organic matter in summer. Trace element concentrations related to road traffic (Zn, Cu, Sb, Sn) were higher at Zurich. Concentrations of Tl and Cs, attributed to the influence of a glass industry, were higher at Payerne. The elements mainly present in the coarse fraction were those related to mineral matter and brake and tyre abrasion (Cu, Mn, Ti, Sb, Sr, Bi, Li, La, Nd), and those in the fine fraction were related to high temperature anthropogenic processes (Pb, As, Cd, Tl, Cs). Common PM(1) and PM(1-10) sources identified by PMF were: ammonium nitrate, present in winter, negligible in summer; ammonium sulfate+K(biomass burning)+road traffic; and road traffic itself, related to exhaust emissions in PM(1) and to road dust resuspension in PM(1-10). Size-fraction specific sources were: a PM(1) glass industry source characterized by Cs, Tl, Rb, Li and Na, only present in Payerne; a PM(1) background source characterized by V, Ni, sulfate and Fe; two PM(1-10) mineral-related sources, with higher contribution in summer; a PM(1-10) salt source; and a PM(1-10) organic source, with higher contribution in summer, attributed to bioaerosols. Copyright © 2012 Elsevier B

Handbook on simultaneous x-ray and γ-ray ion beam methods for fine particle analysis

International Nuclear Information System (INIS)

Cohen, D.D.

2000-01-01

Sampling, measurement, characterisation and source appointment of fine atmospheric particles has become increasingly important in recent times. This is due in part to the realisation that the fine particle pollution caused by anthropogenic activities plays a key role in certain aspects of human health, pollution transport and global climate change. This publication discusses accelerator based ion beam analysis (IBA) methods of particle induced X-ray emission (PIXE) and particle induced γ-ray emission (PIGE) as applied to aerosol analysis. These techniques are sensitive, multielemental, mainly non-destructive, require no sample preparation, have short analysis times and can be used to analyse hundreds of filter samples a day in batch processing with minimum operator interaction. The aspects discussed in the publication include: the basics of the techniques; spectrum analysis; system calibration and blank subtraction; quantification; sensitivity; measurement errors

Pesticide residues in individual versus composite samples of apples after fine or coarse spray quality application

DEFF Research Database (Denmark)

Poulsen, Mette E.; Wenneker, Marcel; Withagen, Jacques

2012-01-01

. None of the results for the pesticides residues measured in individual apples exceeded the EU Maximum Residue Levels (MRLs). However, there was a large variation in the residues levels in the apples, with levels from 0.01 to 1.4 mg kg−1 for captan, the pesticide with the highest variation, and from 0.......01 to 0.2 mg kg−1 for pyraclostrobin, the pesticide with the lowest variation. Residues of fenoxycarb and indoxacarb were only found in a few apples, probably due to the early application time of these two compounds. The evaluation of the effect of spray quality did not show any major difference between......In this study, field trials on fine and coarse spray quality application of pesticides on apples were performed. The main objectives were to study the variation of pesticide residue levels in individual fruits versus composite samples, and the effect of standard fine spray quality application...

Assessment of Fine Aggregates from Different Sources in Ibadan ...

African Journals Online (AJOL)

OLUWASOGO

shown in Table 2 ranges from 14% to 17%, which confirmed that the fine grained ..... Management, 6 (1): 12 – 22. BSI (British Standard ... (5th ed.),. Pearson Education Limited, England. Obla, K. H. (2011). Variation in Concrete Performance.

Identification of sources of aerosol particles in three locations in eastern Botswana

Science.gov (United States)

Chimidza, S.; Moloi, K.

2000-07-01

Airborne particles have been collected using a dichotomous virtual impactor at three different locations in the eastern part of Botswana: Serowe, Selibe-Phikwe, and Francistown. The particles were separated into two fractions (fine and coarse). Sampling at the three locations was done consecutively during the months of July and August, which are usually dry and stable. The sampling time for each sample was 12 hours during the day. For elemental composition, energy-dispersive x-ray fluorescence technique was used. Correlations and principal component analysis with varimax rotation were used to identify major sources of aerosol particles. In all the three places, soil was found to be the main source of aerosol particles. A copper-nickel mine and smelter at Selibe-Phikwe was found to be not only a source of copper and nickel particles in Selibe-Phikwe but also a source of these particles in far places like Serowe. In Selibe-Phikwe and Francistown, car exhaust was found to be the major source of fine particles of lead and bromine.

Fine particulate matter in the indoor air of barbeque restaurants: Elemental compositions, sources and health risks

International Nuclear Information System (INIS)

Taner, Simge; Pekey, Beyhan; Pekey, Hakan

2013-01-01

Cooking is a significant source of indoor particulate matter that can cause adverse health effects. In this study, a 5-stage cascade impactor was used to collect particulate matter from 14 restaurants that cooked with charcoal in Kocaeli, the second largest city in Turkey. A total of 24 elements were quantified using ICP-MS. All of the element contents except for Mn were higher for fine particles (PM 2.5 ) than coarse particles (PM >2.5 ), and the major trace elements identified in the PM 2.5 included V, Se, Zn, Cr, As, Cu, Ni, and Pb. Principle component analysis (PCA) and enrichment factor (EF) calculations were used to determine the sources of PM 2.5 . Four factors that explained over 77% of the total variance were identified by the PCA. These factors included charcoal combustion, indoor activities, crustal components, and road dust. The Se, As, Cd, and V contents in the PM 2.5 were highly enriched (EF > 100). The health risks posed by the individual metals were calculated to assess the potential health risks associated with inhaling the fine particles released during charcoal cooking. The total hazard quotient (total HQ) for a PM 2.5 of 4.09 was four times greater than the acceptable limit (i.e., 1.0). In addition, the excess lifetime cancer risk (total ELCR) for PM 2.5 was 1.57 × 10 −4 , which is higher than the acceptable limit of 1.0 × 10 −6 . Among all of the carcinogenic elements present in the PM 2.5 , the cancer risks resulting from Cr(VI) and As exposure were the highest (i.e., 1.16 × 10 −4 and 3.89 × 10 −5 , respectively). Overall, these results indicate that the lifetime cancer risk associated with As and Cr(VI) exposure is significant at selected restaurants, which is of concern for restaurant workers. - Highlights: • Particulate emissions from charcoal combustion in the BBQ restaurants were studied. • Vanadium, Se, Zn, Cr and As were found as high concentrations in PM 2.5 . • Charcoal combustion and indoor activities were the

Fine particulate matter in the indoor air of barbeque restaurants: Elemental compositions, sources and health risks

Energy Technology Data Exchange (ETDEWEB)

Taner, Simge; Pekey, Beyhan, E-mail: bpekey@kocaeli.edu.tr; Pekey, Hakan

2013-06-01

Cooking is a significant source of indoor particulate matter that can cause adverse health effects. In this study, a 5-stage cascade impactor was used to collect particulate matter from 14 restaurants that cooked with charcoal in Kocaeli, the second largest city in Turkey. A total of 24 elements were quantified using ICP-MS. All of the element contents except for Mn were higher for fine particles (PM{sub 2.5}) than coarse particles (PM{sub >2.5}), and the major trace elements identified in the PM{sub 2.5} included V, Se, Zn, Cr, As, Cu, Ni, and Pb. Principle component analysis (PCA) and enrichment factor (EF) calculations were used to determine the sources of PM{sub 2.5}. Four factors that explained over 77% of the total variance were identified by the PCA. These factors included charcoal combustion, indoor activities, crustal components, and road dust. The Se, As, Cd, and V contents in the PM{sub 2.5} were highly enriched (EF > 100). The health risks posed by the individual metals were calculated to assess the potential health risks associated with inhaling the fine particles released during charcoal cooking. The total hazard quotient (total HQ) for a PM{sub 2.5} of 4.09 was four times greater than the acceptable limit (i.e., 1.0). In addition, the excess lifetime cancer risk (total ELCR) for PM{sub 2.5} was 1.57 × 10{sup −4}, which is higher than the acceptable limit of 1.0 × 10{sup −6}. Among all of the carcinogenic elements present in the PM{sub 2.5}, the cancer risks resulting from Cr(VI) and As exposure were the highest (i.e., 1.16 × 10{sup −4} and 3.89 × 10{sup −5}, respectively). Overall, these results indicate that the lifetime cancer risk associated with As and Cr(VI) exposure is significant at selected restaurants, which is of concern for restaurant workers. - Highlights: • Particulate emissions from charcoal combustion in the BBQ restaurants were studied. • Vanadium, Se, Zn, Cr and As were found as high concentrations in PM{sub 2.5}. �

A Multi-Sample Cs-Sputter Negative Ion Source

International Nuclear Information System (INIS)

Alton, G.D.; Ball, J.A.; Bao, Y.; Cui, B.; Reed, C.A.; Williams, C.

1998-01-01

A multi-sample Cs sputter negative-ion source, equipped with a conical-geometry, W-surface-ionizer has been designed and fabricated that permits sample changes without disruption of on-line accelerator operation. Sample changing is effected by actuating an electro-pneumatic control system located at ground potential that drives an air-motor-driven sample-indexing-system mounted at high voltage; this arrangement avoids complications associated with indexing mechanisms that rely on electronic power-supplies located at high potential. In-beam targets are identified by LED indicator lights derived from a fiber-optic, Gray-code target-position sensor. Aspects of the overall source design and details of the indexing mechanism along with operational parameters, ion optics. intensities, and typical emittances for a variety of negative-ion species will be presented in this report

A Multi-Sample Cs-Sputter Negative Ion Source

Energy Technology Data Exchange (ETDEWEB)

Alton, G.D.; Ball, J.A.; Bao, Y.; Cui, B.; Reed, C.A.; Williams, C.

1998-10-05

A multi-sample Cs sputter negative-ion source, equipped with a conical-geometry, W-surface-ionizer has been designed and fabricated that permits sample changes without disruption of on-line accelerator operation. Sample changing is effected by actuating an electro-pneumatic control system located at ground potential that drives an air-motor-driven sample-indexing-system mounted at high voltage; this arrangement avoids complications associated with indexing mechanisms that rely on electronic power-supplies located at high potential. In-beam targets are identified by LED indicator lights derived from a fiber-optic, Gray-code target-position sensor. Aspects of the overall source design and details of the indexing mechanism along with operational parameters, ion optics. intensities, and typical emittances for a variety of negative-ion species will be presented in this report.

Muted response of fine-grained sediment to a wildfire in British Columbia: the role of landscape disturbances and driving forces

Science.gov (United States)

Owens, P. N.; Giles, T. R.; Blake, W. H.; Petticrew, E. L.; Bol, R.

2012-04-01

In August 2003 a severe wildfire burnt the majority of Fishtrap Creek, a 170 km2 watershed near the city of Kamloops in central British Columbia. The objective of this study was to determine the influence of the wildfire on the amount and composition of fine sediment delivery and transport in the system and to see if the wildfire altered the main sources of sediment. In addition, the findings are compared with that of a nearby watershed, Jamieson Creek, with similar characteristics that was unburnt. In both watersheds, suspended sediment concentrations and fluxes were determined using ISCO automatic water samplers. Changes in sediment sources were determined by collecting bulk sediment and source material samples, and by analysing these samples for a range of properties, including environmental radionuclides and C and N isotopes. Results suggest that following the wildfire there was no major response in fine sediment delivery and transport in Fishtrap Creek, when compared to Jamieson Creek, although there were noticeable differences in the composition of the fine sediment transported and stored in the channel bed. This muted response may be due to the fairly low rainfall amounts in the period immediately following the wildfire. Environmental fallout radionuclides (caesium-137 and unsupported lead-210) showed that there was limited increase (bank) sources of sediment. Recent changes in sediment fluxes and sediment sources relate more to bank erosion processes, probably due to loss of root strength and cohesion. The results suggest that in some situations wildfire may not produce the dramatic increases in hillslope erosion and sediment transport often documented in other watersheds. In Fishtrap Creek, channel bank erosion appears to be important in supplying fine material to the channel and this suggests that attention should be directed at managing the riparian zone in watersheds affected by wildfires.

Sources and Chemical Composition of Atmospheric Fine Particles in Rabigh, Saudi Arabia

Science.gov (United States)

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

2014-12-01

Air pollution research in Saudi Arabia and the whole of Middle East is at its inception, making air pollution in the region a significant problem. This study presents the first detailed data on fine particulate matter (PM2.5) concentrations of Black Carbon (BC), ions, and trace metals at Rabigh, Saudi Arabia, and assesses their sources. Results showed several characteristic aspects of air pollution at Rabigh. Daily levels of PM2.5 and BC showed significant temporal variability ranging from 12.2 - 75.9 µg/m3 and 0.39 - 1.31 µg/m3, respectively. More than 90% of the time, the daily PM2.5 exceeded the 24 h WHO guideline of 20 µg/m3. Sulfate, NO3-, and NH4+ dominated the identifiable components. Trace metals with significantly higher concentrations included Si, S, Ca, Al, Fe, Na, Cl, Mg, K, and Ti, with average concentrations of 3.1, 2.2, 1.6, 1.2, 1.1, 0.7, 0.7, 0.5, 0.4 and 0.1 µg/m3, respectively. Based on the Air Quality Index (AQI), there were 44% days of moderate air quality, 33% days of unhealthy air quality for sensitive groups, and 23% days of unhealthy air quality throughout the study period. Two categories of aerosol trace metal sources were defined: anthropogenic (S, V, Cr, Ni, Cu, Zn, Br, Cd, Sb, and Pb) and naturally derived elements (Si, Al, and Fe). The extent of anthropogenic contribution was estimated by the degree of enrichment of these elements compared to the crustal composition. Soil resuspension and/or mobilization is an important source of "natural" elements, while "anthropogenic" elements originate primarily from fossil fuel combustion and industries. Ni and V correlated strongly pointing to combustion of heavy fuel oil as the likely source. A positive matrix factorization (PMF) was used to obtain information about possible sources. Our study highlights the need for stringent laws on PM2.5 emission control to protect human health and the environment.

Open source laboratory sample rotator mixer and shaker

Directory of Open Access Journals (Sweden)

Karankumar C. Dhankani

2017-04-01

Full Text Available An open-source 3-D printable laboratory sample rotator mixer is developed here in two variants that allow users to opt for the level of functionality, cost saving and associated complexity needed in their laboratories. First, a laboratory sample rotator is designed and demonstrated that can be used for tumbling as well as gentle mixing of samples in a variety of tube sizes by mixing them horizontally, vertically, or any position in between. Changing the mixing angle is fast and convenient and requires no tools. This device is battery powered and can be easily transported to operate in various locations in a lab including desktops, benches, clean hoods, chemical hoods, cold rooms, glove boxes, incubators or biological hoods. Second, an on-board Arduino-based microcontroller is incorporated that adds the functionality of a laboratory sample shaker. These devices can be customized both mechanically and functionally as the user can simply select the operation mode on the switch or alter the code to perform custom experiments. The open source laboratory sample rotator mixer can be built by non-specialists for under US$30 and adding shaking functionality can be done for under $20 more. Thus, these open source devices are technically superior to the proprietary commercial equipment available on the market while saving over 90% of the costs.

Levels, chemical composition and sources of fine aerosol particles (PM1) in an area of the Mediterranean basin

International Nuclear Information System (INIS)

Caggiano, Rosa; Macchiato, Maria; Trippetta, Serena

2010-01-01

Daily samples of fine aerosol particles (i.e., PM1, aerosol particles with an aerodynamic diameter less than 1.0 μm) were collected in Tito Scalo - Southern Italy - from April 2006 to March 2007. Measurements were performed by means of a low-volume gravimetric sampler, and each PM1 sample was analyzed by means of Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES) or Atomic Absorption Spectrometry (GFAAS and FAAS) techniques in order to determine its content in fourteen trace elements (Al, Ca, Cd, Cr, Cu, Fe, K, Mg, Mn, Na, Ni, Pb, Ti and Zn). During the period examined, PM1 daily concentrations ranged between 0.3 μg m -3 and 55 μg m -3 with a mean value of 8 μg m -3 , a standard deviation of 7 μg m -3 and a median value of 6 μg m -3 . As far as PM1 chemical composition is concerned, the mean values of the trace element concentrations decreased in the following order: Ca > Fe > Al > Na > K > Cr > Mg > Pb > Ni ∼ Ti ∼ Zn > Cd ∼ Cu > Mn. Principal Component Analysis (PCA) allowed the identification of three probable PM1 sources: industrial emissions, traffic and re-suspension of soil dust. Moreover, the results of a procedure applied to study the potential long-range transport contribution to PM1 chemical composition, showed that trace element concentrations do not seem to be affected by air mass origin and path. This was probably due to the strong impact of the local emission sources and the lack of the concentration measurements of some important elements and compounds that could better reveal the long-range transport influence on PM1 measurements at ground level.

Levels, chemical composition and sources of fine aerosol particles (PM1) in an area of the Mediterranean basin.

Science.gov (United States)

Caggiano, Rosa; Macchiato, Maria; Trippetta, Serena

2010-01-15

Daily samples of fine aerosol particles (i.e., PM1, aerosol particles with an aerodynamic diameter less than 1.0mum) were collected in Tito Scalo - Southern Italy - from April 2006 to March 2007. Measurements were performed by means of a low-volume gravimetric sampler, and each PM1 sample was analyzed by means of Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES) or Atomic Absorption Spectrometry (GFAAS and FAAS) techniques in order to determine its content in fourteen trace elements (Al, Ca, Cd, Cr, Cu, Fe, K, Mg, Mn, Na, Ni, Pb, Ti and Zn). During the period examined, PM1 daily concentrations ranged between 0.3microgm(-3) and 55microgm(-3) with a mean value of 8 microg m(-3), a standard deviation of 7microgm(-3) and a median value of 6microgm(-3). As far as PM1 chemical composition is concerned, the mean values of the trace element concentrations decreased in the following order: Ca>Fe>Al>Na>K>Cr>Mg>Pb>Ni approximately Ti approximately Zn>Cd approximately Cu>Mn. Principal Component Analysis (PCA) allowed the identification of three probable PM1 sources: industrial emissions, traffic and re-suspension of soil dust. Moreover, the results of a procedure applied to study the potential long-range transport contribution to PM1 chemical composition, showed that trace element concentrations do not seem to be affected by air mass origin and path. This was probably due to the strong impact of the local emission sources and the lack of the concentration measurements of some important elements and compounds that could better reveal the long-range transport influence on PM1 measurements at ground level. Copyright 2009 Elsevier B.V. All rights reserved.

Monte Carlo stratified source-sampling

International Nuclear Information System (INIS)

Blomquist, R.N.; Gelbard, E.M.

1997-01-01

In 1995, at a conference on criticality safety, a special session was devoted to the Monte Carlo open-quotes eigenvalue of the worldclose quotes problem. Argonne presented a paper, at that session, in which the anomalies originally observed in that problem were reproduced in a much simplified model-problem configuration, and removed by a version of stratified source-sampling. The original test-problem was treated by a special code designed specifically for that purpose. Recently ANL started work on a method for dealing with more realistic eigenvalue of the world configurations, and has been incorporating this method into VIM. The original method has been modified to take into account real-world statistical noise sources not included in the model problem. This paper constitutes a status report on work still in progress

Characterization and source apportionment of fine particulate sources at Rijeka, Croatia from 2013 to 2015

International Nuclear Information System (INIS)

Ivošević, Tatjana; Stelcer, Eduard; Orlić, Ivica; Bogdanović Radović, Iva; Cohen, David

2016-01-01

PM_2_._5 daily aerosol samples were collected in Rijeka, Croatia during period from 6th August 2013 to 29th January 2015. In total, 259 samples were collected on Teflon filters and analyzed by PIXE and PIGE techniques to give information on 21 elements from Na to Pb. Additionally, black carbon was determined with the Laser Integrated Plate Method. Results were statistically evaluated using Positive Matrix Factorization (PMF). Eight major pollution sources: auto, smoke, secondary sulfates, heavy oil combustion, sea spray, road dust, industry iron and soil dust were identified together with their relative contributions in total PM_2_._5 pollution.

[Sampling methods for PM2.5 from stationary sources: a review].

Science.gov (United States)

Jiang, Jing-Kun; Deng, Jian-Guo; Li, Zhen; Li, Xing-Hua; Duan, Lei; Hao, Ji-Ming

2014-05-01

The new China national ambient air quality standard has been published in 2012 and will be implemented in 2016. To meet the requirements in this new standard, monitoring and controlling PM2,,5 emission from stationary sources are very important. However, so far there is no national standard method on sampling PM2.5 from stationary sources. Different sampling methods for PM2.5 from stationary sources and relevant international standards were reviewed in this study. It includes the methods for PM2.5 sampling in flue gas and the methods for PM2.5 sampling after dilution. Both advantages and disadvantages of these sampling methods were discussed. For environmental management, the method for PM2.5 sampling in flue gas such as impactor and virtual impactor was suggested as a standard to determine filterable PM2.5. To evaluate environmental and health effects of PM2.5 from stationary sources, standard dilution method for sampling of total PM2.5 should be established.

Important sources and chemical species of ambient fine particles related to adverse health effects

Science.gov (United States)

Heo, J.

2017-12-01

Although many epidemiological studies have reported that exposure to ambient fine particulate matter (PM2.5) has been linked to increases in mortality and mobidity health outcomes, the key question of which chemical species and sources of PM2.5 are most harmful to public health remains unanswered in the air pollution research area. This study was designed to address the key question with evaluating the risks of exposure to chemical species and source-specific PM2.5 mass on morbidity. Hourly measurements of PM2.5 mass and its major chemical species, including organic carbon, elemental carbon, ions, and trace elements, were observed from January 1 to December 31, 2013 at four of the PM2.5 supersites in urban environments in Korea and the reuslts were used in a positive matrix factorization to estimate source contributions to PM2.5 mass. Nine sources, including secondary sulfate, secondary nitrate, mobile, biomass burning, roadway emission, industry, oil combustion, soil, and aged sea salt, were identified and secondary inorganic aerosol factors (i.e. secondary sulfalte, and secondary nitrate) were the dominant sources contributing to 40% of the total PM2.5 mass in the study region. In order to evaluate the risks of exposure to chemical species and sources of PM2.5 on morbidity, emergency room visits for cardivascular disease and respiratory disease were considered. Hourly health outcomes were compared with hourly measurments of the PM2.5 chemical species and sources using a poission generalized linear model incorporating natural splines, as well as time-stratified case-crossover design. The PM2.5 mass and speveral chemical components, such as organic carbon, elemetal carbon, zinc, and potassium, were strongly associated with morbidity. Source-apporitionmened PM2.5 mass derived from biomass burning, and mobile sources, was significantly associated with cardiovascular and respiratory diseases. The findings represent that local combustion may be particularly important

Cause-specific stillbirth and exposure to chemical constituents and sources of fine particulate matter.

Science.gov (United States)

Ebisu, Keita; Malig, Brian; Hasheminassab, Sina; Sioutas, Constantinos; Basu, Rupa

2018-01-01

The stillbirth rate in the United States is relatively high, but limited evidence is available linking stillbirth with fine particulate matter (PM 2.5 ), its chemical constituents and sources. In this study, we explored associations between cause-specific stillbirth and prenatal exposures to those pollutants with using live birth and stillbirth records from eight California locations during 2002-2009. ICD-10 codes were used to identify cause of stillbirth from stillbirth records. PM 2.5 total mass and chemical constituents were collected from ambient monitors and PM 2.5 sources were quantified using Positive Matrix Factorization. Conditional logistic regression was applied using a nested case-control study design (N = 32,262). We found that different causes of stillbirth were associated with different PM 2.5 sources and/or chemical constituents. For stillbirths due to fetal growth, the odds ratio (OR) per interquartile range increase in gestational age-adjusted exposure to PM 2.5 total mass was 1.23 (95% confidence interval (CI): 1.06, 1.44). Similar associations were found with resuspended soil (OR=1.25, 95% CI: 1.10, 1.42), and secondary ammonium sulfate (OR=1.45, 95% CI: 1.18, 1.78). No associations were found between any pollutants and stillbirths caused by maternal complications. This study highlighted the importance of investigating cause-specific stillbirth and the differential toxicity levels of specific PM 2.5 sources and chemical constituents. Copyright © 2017 Elsevier Inc. All rights reserved.

The Bologna complete sample of nearby radio sources. II. Phase referenced observations of faint nuclear sources

Science.gov (United States)

Liuzzo, E.; Giovannini, G.; Giroletti, M.; Taylor, G. B.

2009-10-01

Aims: To study statistical properties of different classes of sources, it is necessary to observe a sample that is free of selection effects. To do this, we initiated a project to observe a complete sample of radio galaxies selected from the B2 Catalogue of Radio Sources and the Third Cambridge Revised Catalogue (3CR), with no selection constraint on the nuclear properties. We named this sample “the Bologna Complete Sample” (BCS). Methods: We present new VLBI observations at 5 and 1.6 GHz for 33 sources drawn from a sample not biased toward orientation. By combining these data with those in the literature, information on the parsec-scale morphology is available for a total of 76 of 94 radio sources with a range in radio power and kiloparsec-scale morphologies. Results: The fraction of two-sided sources at milliarcsecond resolution is high (30%), compared to the fraction found in VLBI surveys selected at centimeter wavelengths, as expected from the predictions of unified models. The parsec-scale jets are generally found to be straight and to line up with the kiloparsec-scale jets. A few peculiar sources are discussed in detail. Tables 1-4 are only available in electronic form at http://www.aanda.org

Chemical characterization and sources of personal exposure to fine particulate matter in the general population of Guangzhou, China

Science.gov (United States)

Chen, Xiao-Cui; Jahn, Heiko J.; Engling, Guenter; Ward, Tony J.; Kraemer, Alexander; Ho, Kin-Fai; Hung-Lam Yim, Steve; Chan, Chuen-Yu

2017-04-01

Fine particulate matter pollution severely deteriorates the environmental conditions and negatively impacts human health in the Chinese megacity Guangzhou. Concurrent ambient and personal measurements of fine particulate matter (PM2.5) were conducted in Guangzhou, China. Personal-to-ambient (P-C) relationships of PM2.5 chemical components were determined and sources of personal PM2.5 exposure were evaluated using principal component analysis along with a mixed-effects model. Water-soluble inorganic ions (mainly secondary inorganic ions) and anhydrosugars exhibited median personal-to-ambient (P/C) ratios < 1 accompanied by strong P-C correlations, indicating that these constituents in personal PM2.5 were significantly affected by ambient sources. Conversely, elemental carbon (EC) and calcium (Ca2+) showed median P/C ratios greater than unity, which indicated that among subjects who spent a great amount of time indoors, aside from particles of ambient origin, individual's total exposure to PM2.5 includes contributions of non-ambient exposure while indoors and outdoors (e.g., local traffic, indoor sources, personal activities). SO42- displayed very low coefficient of divergence (COD) values coupled with strong P-C correlations, implying a uniform distribution of SO42- in the urban area of Guangzhou. EC, Ca2+, and levoglucosan were otherwise heterogeneously distributed across individuals in different districts. Regional air pollution (50.4 ± 0.9%), traffic-related particles (8.6 ± 0.7%), dust-related particles (5.8 ± 0.7%), and biomass burning emissions (2.0 ± 0.2%) were moderate to high positive sources of personal PM2.5 exposure in Guangzhou. The observed positive and significant contribution of Ca2+ to personal PM2.5 exposure, highlighting indoor sources and/or personal activities, were driving factors determining personal exposure to dust-related particles. Considerable discrepancies (COD values ranging from 0.42 to 0.50) were shown between ambient

Characterization and source apportionment of fine particulate sources at Rijeka, Croatia from 2013 to 2015

Energy Technology Data Exchange (ETDEWEB)

Ivošević, Tatjana, E-mail: tatjana.ivosevic14@gmail.com [Faculty of Engineering, University of Rijeka, Vukovarska 58, HR-51000 Rijeka (Croatia); Stelcer, Eduard [Australian Nuclear Science and Technology Organisation, Locked Bag 2001, Kirrawee DC, NSW 2232 (Australia); Orlić, Ivica [Department of Physics, University of Rijeka, Radmile Matejčić 2, HR-51000 Rijeka (Croatia); Bogdanović Radović, Iva [Laboratory for Ion Beam Interactions, Ruđer Bošković Institute, Bijenička 54, HR-10000 Zagreb (Croatia); Cohen, David [Australian Nuclear Science and Technology Organisation, Locked Bag 2001, Kirrawee DC, NSW 2232 (Australia)

2016-03-15

PM{sub 2.5} daily aerosol samples were collected in Rijeka, Croatia during period from 6th August 2013 to 29th January 2015. In total, 259 samples were collected on Teflon filters and analyzed by PIXE and PIGE techniques to give information on 21 elements from Na to Pb. Additionally, black carbon was determined with the Laser Integrated Plate Method. Results were statistically evaluated using Positive Matrix Factorization (PMF). Eight major pollution sources: auto, smoke, secondary sulfates, heavy oil combustion, sea spray, road dust, industry iron and soil dust were identified together with their relative contributions in total PM{sub 2.5} pollution.

Source identification and seasonal variation of polycyclic aromatic hydrocarbons associated with atmospheric fine and coarse particles in the Metropolitan Area of Porto Alegre, RS, Brazil

Science.gov (United States)

Teixeira, Elba Calesso; Agudelo-Castañeda, Dayana M.; Fachel, Jandyra Maria Guimarães; Leal, Karen Alam; Garcia, Karine de Oliveira; Wiegand, Flavio

2012-11-01

The purpose of the present study was to evaluate the polycyclic aromatic hydrocarbons (PAHs) in fine (PM2.5) and coarse particles (PM2.5-10) in an urban and industrial area in the Metropolitan Area of Porto Alegre (MAPA), Brazil. Sixteen U.S. Environmental Protection Agency (EPA) priority polycyclic aromatic hydrocarbons (PAHs) were measured. Filters containing ambient air particulate were extracted with dichloromethane using Soxhlet. Extracts were later analyzed, for determining PAH concentrations, using a gaseous chromatograph coupled with a mass spectrometer (GC-MS). The polycyclic aromatic hydrocarbons (PAHs) were more concentrated in PM2.5 with an average of 70% of total PAHs in the MAPA. The target PAH apportionment among the main emission sources was carried out by diagnostic PAH concentration ratios, and principal component analysis (PCA). PAHs with higher molecular weight showed higher percentages in the fine particles in the MAPA. Based on the diagnostic ratios and PCA analysis, it may be concluded that the major contribution of PAHs was from vehicular sources (diesel and gasoline), especially in the PM2.5 fraction, as well as coal and wood burning. The winter/summer ratio in the PM2.5 and PM2.5-10 fractions in the MAPA was 3.1 and 1.8, respectively, revealing the seasonal variation of PAHs in the two fractions. The estimated toxicity equivalent factor (TEF), used to assess the contribution of the carcinogenic potency, confirms a significant presence of the moderately active carcinogenic PAHs BaP and DahA in the samples collected in the MAPA.

How to Perform Precise Soil and Sediment Sampling? One solution: The Fine Increment Soil Collector (FISC)

Energy Technology Data Exchange (ETDEWEB)

Mabit, L.; Toloza, A. [Soil and Water Management and Crop Nutrition Laboratory, IAEA, Seibersdorf (Austria); Meusburger, K.; Alewell, C. [Environmental Geosciences, Department of Environmental Sciences, University of Basel, Basel (Switzerland); Iurian, A-R. [Babes-Bolyai University, Faculty of Environmental Science and Engineering, Cluj-Napoca (Romania); Owens, P. N. [Environmental Science Program and Quesnel River Research Centre, University of Northern British Columbia, Prince George, British Columbia (Canada)

2014-07-15

Soil and sediment related research for terrestrial agrienvironmental assessments requires accurate depth incremental sampling to perform detailed analysis of physical, geochemical and biological properties of soil and exposed sediment profiles. Existing equipment does not allow collecting soil/sediment increments at millimetre resolution. The Fine Increment Soil Collector (FISC), developed by the SWMCN Laboratory, allows much greater precision in incremental soil/sediment sampling. It facilitates the easy recovery of collected material by using a simple screw-thread extraction system (see Figure 1). The FISC has been designed specifically to enable standardized scientific investigation of shallow soil/sediment samples. In particular, applications have been developed in two IAEA Coordinated Research Projects (CRPs): CRP D1.20.11 on “Integrated Isotopic Approaches for an Area-wide Precision Conservation to Control the Impacts of Agricultural Practices on Land Degradation and Soil Erosion” and CRP D1.50.15 on “Response to Nuclear Emergencies Affecting Food and Agriculture.”.

How to Perform Precise Soil and Sediment Sampling? One solution: The Fine Increment Soil Collector (FISC)

International Nuclear Information System (INIS)

Mabit, L.; Toloza, A.; Meusburger, K.; Alewell, C.; Iurian, A-R.; Owens, P.N.

2014-01-01

Soil and sediment related research for terrestrial agrienvironmental assessments requires accurate depth incremental sampling to perform detailed analysis of physical, geochemical and biological properties of soil and exposed sediment profiles. Existing equipment does not allow collecting soil/sediment increments at millimetre resolution. The Fine Increment Soil Collector (FISC), developed by the SWMCN Laboratory, allows much greater precision in incremental soil/sediment sampling. It facilitates the easy recovery of collected material by using a simple screw-thread extraction system (see Figure 1). The FISC has been designed specifically to enable standardized scientific investigation of shallow soil/sediment samples. In particular, applications have been developed in two IAEA Coordinated Research Projects (CRPs): CRP D1.20.11 on “Integrated Isotopic Approaches for an Area-wide Precision Conservation to Control the Impacts of Agricultural Practices on Land Degradation and Soil Erosion” and CRP D1.50.15 on “Response to Nuclear Emergencies Affecting Food and Agriculture.”

New complete sample of identified radio sources. Part 2. Statistical study

International Nuclear Information System (INIS)

Soltan, A.

1978-01-01

Complete sample of radio sources with known redshifts selected in Paper I is studied. Source counts in the sample and the luminosity - volume test show that both quasars and galaxies are subject to the evolution. Luminosity functions for different ranges of redshifts are obtained. Due to many uncertainties only simplified models of the evolution are tested. Exponential decline of the liminosity with time of all the bright sources is in a good agreement both with the luminosity- volume test and N(S) realtion in the entire range of observed flux densities. It is shown that sources in the sample are randomly distributed in scales greater than about 17 Mpc. (author)

Mercury, trace elements and organic constituents in atmospheric fine particulate matter, Shenandoah National Park, Virginia, USA: A combined approach to sampling and analysis

Science.gov (United States)

Kolker, A.; Engle, M.A.; Orem, W.H.; Bunnell, J.E.; Lerch, H.E.; Krabbenhoft, D.P.; Olson, M.L.; McCord, J.D.

2008-01-01

Compliance with U.S. air quality regulatory standards for atmospheric fine particulate matter (PM2.5) is based on meeting average 24 hour (35 ?? m-3) and yearly (15 ??g m-3) mass-per-unit-volume limits, regardless of PM2.5 composition. Whereas this presents a workable regulatory framework, information on particle composition is needed to assess the fate and transport of PM2.5 and determine potential environmental/human health impacts. To address these important non-regulatory issues an integrated approach is generally used that includes (1) field sampling of atmospheric particulate matter on filter media, using a size-limiting cyclone, or with no particle-size limitation; and (2) chemical extraction of exposed filters and analysis of separate particulate-bound fractions for total mercury, trace elements and organic constituents, utilising different USGS laboratories optimised for quantitative analysis of these substances. This combination of sampling and analysis allowed for a more detailed interpretation of PM2.5 sources and potential effects, compared to measurements of PM2.5 abundance alone. Results obtained using this combined approach are presented for a 2006 air sampling campaign in Shenandoah National Park (Virginia, USA) to assess sources of atmospheric contaminants and their potential impact on air quality in the Park. PM2.5 was collected at two sampling sites (Big Meadows and Pinnacles) separated by 13.6 km. At both sites, element concentrations in PM2.5 were low, consistent with remote or rural locations. However, element/Zr crustal abundance enrichment factors greater than 10, indicating anthropogenic input, were found for Hg, Se, S, Sb, Cd, Pb, Mo, Zn and Cu, listed in decreasing order of enrichment. Principal component analysis showed that four element associations accounted for 84% of the PM 2.5 trace element variation; these associations are interpreted to represent: (1) crustal sources (Al, REE); (2) coal combustion (Se, Sb), (3) metal production

Evidence for the distortion product frequency place as a source of distribution product otoacoustic emission (DPOAE) fine structure in humans : I. Fine structure and higher-order DPOAE as a function of the frequency ratio f2/f1

NARCIS (Netherlands)

Mauermann, M; Uppenkamp, S; van Hengel, P.W.J.; Kollmeier, B

1999-01-01

Critical experiments were performed in order to validate the two-source hypothesis of distortion product otoacoustic emissions (DPOAE) generation. Measurements of the spectral fine structure of DPOAE in response to stimulation with two sinusoids have been:performed with normal-hearing subjects. The

Reference volumetric samples of gamma-spectroscopic sources

International Nuclear Information System (INIS)

Taskaev, E.; Taskaeva, M.; Grigorov, T.

1993-01-01

The purpose of this investigation is to determine the requirements for matrices of reference volumetric radiation sources necessary for detector calibration. The first stage of this determination consists in analysing some available organic and nonorganic materials. Different sorts of food, grass, plastics, minerals and building materials have been considered, taking into account the various procedures of their processing (grinding, screening, homogenizing) and their properties (hygroscopy, storage life, resistance to oxidation during gamma sterilization). The procedures of source processing, sample preparation, matrix irradiation and homogenization have been determined. A rotation homogenizing device has been elaborated enabling to homogenize the matrix activity irrespective of the vessel geometry. 33 standard volumetric radioactive sources have been prepared: 14 - on organic matrix and 19 - on nonorganic matrix. (author)

Local and regional sources of fine and coarse particulate matter based on traffic and background monitoring

Science.gov (United States)

Dimitriou, Konstantinos; Kassomenos, Pavlos

2014-05-01

The aim of this study was to identify local and exogenous sources affecting particulate matter (PM) levels in five major cities of Northern Europe namely: London, Paris, Hamburg, Copenhagen and Stockholm. Besides local emissions, PM profile at urban and suburban areas of the European Union (EU) is also influenced by regional PM sources due to atmospheric transport, thus geographical city distribution is of a great importance. At each city, PM10, PM2.5, NO2, SO2, CO and O3 air pollution data from two air pollution monitoring stations of the EU network were used. Different background characteristics of the selected two sampling sites at each city facilitated comparisons, providing a more exact analysis of PM sources. Four source apportionment methods: Pearson correlations among the levels of particulates and gaseous pollutants, characterisation of primal component analysis components, long-range transport analysis and extrapolation of PM size distribution ratios were applied. In general, fine (PM2.5) and coarse (PM10) particles were highly correlated, thus common sources are suggested. Combustion-originated gaseous pollutants (CO, NO2, SO2) were strongly associated to PM10 and PM2.5, primarily at areas severely affected by traffic. On the contrary, at background stations neighbouring important natural sources of particles or situated in suburban areas with rural background, natural emissions of aerosols were indicated. Series of daily PM2.5/PM10 ratios showed that minimum fraction values were detected during warm periods, due to higher volumes of airborne biogenic PM coarse, mainly at stations with important natural sources of particles in their vicinity. Hybrid single-particle Lagrangian integrated trajectory model was used, in order to extract 4-day backward air mass trajectories that arrived in the five cities which are under study during days with recorded PM10 exceedances. At all five cities, a significantly large fraction of those trajectories were classified

Development of a compact powdery sample negative ion source

Energy Technology Data Exchange (ETDEWEB)

Wada, Motoi [Doshisha Univ., Tanabe, Kyoto (Japan). Faculty of Engineering; Sasao, Mamiko; Kawano, Hiroyuki

1997-02-01

A gas-feed-free compact negative ion source can be realized by utilizing the process of electron stimulated desorption from powdery sample. A negative ion source of this type is designed to be attached to a standard 1.33 inch copper-gasket-flange. The ion source is operated stable with LiH powder for more than 10 hours with the mass-separated negative hydrogen ion current of 1 nA. The source causes minute gas emission, and particularly suitable for ion beam applications in which a good vacuum is required. The present status of the compact ion source development is briefly described. (author)

Characterization and indentification of air pollution sources in Metro Manila

International Nuclear Information System (INIS)

Santos, Flora L.; Pabroa, Preciosa Corazon B.; Racho, Joseph Michael D.; Morco, Ryan P.; Bautista VII, Angel T.; Bucal, Camille Grace D.

2010-01-01

Air particulates matter (PM 1 0 and PM 2 .5) is a mixture of different pollutant sources which can be of anthropogenic and/or natural origin. Identification and apportionment of pollutant sources is important to be able to have better understanding of prevailing conditions in the area and thus better air quality management can be applied. Results have shown that in all the sampling sites, a major fraction of pollutant sources come from vehicular or traffic-oriented sources, comprising more than 30% of PM 2 .5. Of particular great concern especially in the residents of the area are the high Pb levels in Valenzuela City. In 2005, the annual mean level of PM 1 0 Pb in Valenzuela was 0.267 μg/m 3 while the other PNRI sampling sites registered annual mean levels between 0033 to 0.085 μ/m 3 . The high Pb condition is reflected in the source apportionment studies with Pb sources showing up in both the coarse (PM 1 0-2.5) and the fine fractions (PM 2 .5). The CPF analysis plots of 2008 Pb levels in both the coarse and the fine fractions show patterns for probable sources in 2008. Further study of the location of battery recycling facilities and other possible sources of lead is needed to validate the results of the CPF determination. (author)

Mineralogical characterization of quarry fines from Tracuateua city, state of Para, Brazil

International Nuclear Information System (INIS)

Costa, J.H.B. da; Negrao, R.C.; Angelica, R.S.; Universidade Federal do Para

2011-01-01

The aim of this study was to characterize the mineralogy quarry fines samples for its reuse and thus contributing to mitigate the environmental impact caused by this waste. In order to achieve the results, samples were collected and prepared for assays and identification of the mineralogical phases present in the quarry fines from the samples. X-ray diffraction and optical microscopy techniques were used. The quarry of fines characterization was based on qualitatively identification the minerals present in the samples. It was detected the presence of quartz, muscovite and feldspar (albite and microclinite) by x-ray diffraction technique and microscopic and macroscopic observations. Moreover, the size distribution was determined, and the samples presented a medium to fine size (ranging from 9,5 mm to 0,075 mm) and the grains presented an irregular and angular shapes. (author)

Revealing transboundary and local air pollutant sources affecting Metro Manila through receptor modeling studies

International Nuclear Information System (INIS)

Pabroa, Preciosa Corazon B.; Bautista VII, Angel T.; Santos, Flora L.; Racho, Joseph Michael D.

2011-01-01

Ambient fine particulate matter (PM 2 .5) levels at the Metro Manila air sampling stations of the Philippine Nuclear Research Research Institute were found to be above the WHO guideline value of 10 μg m 3 indicating, in general, very poor air quality in the area. The elemental components of the fine particulate matter were obtained using the energy-dispersive x-ray fluorescence spectrometry. Positive matrix factorization, a receptor modelling tool, was used to identify and apportion air pollution sources. Location of probable transboundary air pollutants were evaluated using HYSPLIT (Hybrid Single Particle Lagrangian Integrated Trajectory Model) while location of probable local air pollutant sources were determined using the conditional probability function (CPF). Air pollutant sources can either be natural or anthropogenic. This study has shown natural air pollutant sources such as volcanic eruptions from Bulusan volcano in 2006 and from Anatahan volcano in 2005 to have impacted on the region. Fine soils was shown to have originated from China's Mu US Desert some time in 2004. Smoke in the fine fraction in 2006 show indications of coming from forest fires in Sumatra and Borneo. Fine particulate Pb in Valenzuela was shown to be coming from the surrounding area. Many more significant air pollution impacts can be evaluated with the identification of probable air pollutant sources with the use of elemental fingerprints and locating these sources with the use of HYSPLIT and CPF. (author)

A new sample of faint Gigahertz Peaked Spectrum radio sources

NARCIS (Netherlands)

Snellen, IAG; Schilizzi, RT; de Bruyn, AG; Miley, GK; Rengelink, RB; Rottgering, HJ

The Westerbork Northern Sky Survey (WENSS) has been used to select a sample of Gigahertz Peaked Spectrum (GPS) radio sources at flux densities one to two orders of magnitude lower than bright GPS sources investigated in earlier studies. Sources with inverted spectra at frequencies above 325 MHz have

Combining stable isotope and carbohydrate analyses in phloem sap and fine roots to study seasonal changes of source-sink relationships in a Mediterranean beech forest.

Science.gov (United States)

Scartazza, Andrea; Moscatello, Stefano; Matteucci, Giorgio; Battistelli, Alberto; Brugnoli, Enrico

2015-08-01

Carbon isotope composition (δ(13)C) and carbohydrate content of phloem sap and fine roots were measured in a Mediterranean beech (Fagus sylvatica L.) forest throughout the growing season to study seasonal changes of source-sink relationships. Seasonal variations of δ(13)C and content of phloem sap sugars, collected during the daylight period, reflected the changes in soil and plant water status. The correlation between δ(13)C and content of phloem sap sugars, collected from plants belonging to different social classes, was significantly positive only during the driest month of July. In this month, δ(13)C of phloem sap sugars was inversely related to the increment of trunk radial growth and positively related to δ(13)C of fine roots. We conclude that the relationship between δ(13)C and the amount of phloem sap sugars is affected by a combination of causes, such as sink strength, tree social class, changes in phloem anatomy and transport capacity, and phloem loading of sugars to restore sieve tube turgor following the reduced plant water potential under drought conditions. However, δ(13)C and sugar composition of fine roots suggested that phloem transport of leaf sucrose to this belowground component was not impaired by mild drought and that sucrose was in a large part allocated towards fine roots in July, depending on tree social class. Hence, fine roots could represent a functional carbon sink during the dry seasonal periods, when transport and use of assimilates in other sink tissues are reduced. These results indicate a strict link between above- and belowground processes and highlight a rapid response of this Mediterranean forest to changes in environmental drivers to regulate source-sink relationships and carbon sink capacity. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Sources of atmospheric aerosol from long-term measurements (5 years) of chemical composition in Athens, Greece.

Science.gov (United States)

Paraskevopoulou, D; Liakakou, E; Gerasopoulos, E; Mihalopoulos, N

2015-09-15

To identify the sources of aerosols in Greater Athens Area (GAA), a total of 1510 daily samples of fine (PM 2.5) and coarse (PM 10-2,5) aerosols were collected at a suburban site (Penteli), during a five year period (May 2008-April 2013) corresponding to the period before and during the financial crisis. In addition, aerosol sampling was also conducted in parallel at an urban site (Thissio), during specific, short-term campaigns during all seasons. In all these samples mass and chemical composition measurements were performed, the latest only at the fine fraction. Particulate organic matter (POM) and ionic masses (IM) are the main contributors of aerosol mass, equally contributing by accounting for about 24% of the fine aerosol mass. In the IM, nss-SO4(-2) is the prevailing specie followed by NO3(-) and NH4(+) and shows a decreasing trend during the 2008-2013 period similar to that observed for PM masses. The contribution of water in fine aerosol is equally significant (21 ± 2%), while during dust transport, the contribution of dust increases from 7 ± 2% to 31 ± 9%. Source apportionment (PCA and PMF) and mass closure exercises identified the presence of six sources of fine aerosols: secondary photochemistry, primary combustion, soil, biomass burning, sea salt and traffic. Finally, from winter 2012 to winter 2013 the contribution of POM to the urban aerosol mass is increased by almost 30%, reflecting the impact of wood combustion (dominant fuel for domestic heating) to air quality in Athens, which massively started in winter 2013. Copyright © 2015 Elsevier B.V. All rights reserved.

Relations between Playing Activities and Fine Motor Development

Science.gov (United States)

Suggate, Sebastian; Stoeger, Heidrun; Pufke, Eva

2017-01-01

Children's fine motor skills (FMS) are being increasingly recognized as an important aspect of preschool development; yet, we know very little about the experiences that foster their development. We utilized a parent-administered children's fine and gross motor activities questionnaire (MAQ) to investigate links with FMS. We recruited a sample of…

MID-INFRARED ATOMIC FINE-STRUCTURE EMISSION-LINE SPECTRA OF LUMINOUS INFRARED GALAXIES: SPITZER/IRS SPECTRA OF THE GOALS SAMPLE

Energy Technology Data Exchange (ETDEWEB)

Inami, H. [National Optical Astronomy Observatory, Tucson, AZ 85719 (United States); Armus, L.; Stierwalt, S.; Díaz-Santos, T.; Surace, J.; Howell, J.; Marshall, J. [Spitzer Science Center, California Institute of Technology, CA 91125 (United States); Charmandaris, V. [Department of Physics and Institute of Theoretical and Computational Physics, University of Crete, GR-71003 Heraklion (Greece); Groves, B. [Max Planck Institute for Astronomy, Königstuhl 17, D-69117 Heidelberg (Germany); Kewley, L. [Research School of Astronomy and Astrophysics, The Australian National University, Cotter Road, Weston Creek, ACT 2611 (Australia); Petric, A. [Department of Astronomy, California Institute of Technology, MS 320-47, Pasadena, CA 91125 (United States); Rich, J. [The Observatories, Carnegie Institute of Washington, 813 Santa Barbara Street, Pasadena, CA 91101 (United States); Haan, S. [CSIRO Astronomy and Space Science, Marsfield, NSW 2122 (Australia); Evans, A. S. [Department of Astronomy, University of Virginia, P.O. Box 400325, Charlottesville, VA 22904 (United States); Mazzarella, J.; Lord, S. [Infrared Processing and Analysis Center, MS 100-22, California Institute of Technology, Pasadena, CA 91125 (United States); Appleton, P. [NASA Herschel Science Center, 770 South Wilson Avenue, Pasadena, CA 91125 (United States); Spoon, H. [Astronomy Department, Cornell University, Ithaca, NY 14853 (United States); Frayer, D. [National Radio Astronomy Observatory, P.O. Box 2, Green Bank, WV 24944 (United States); Matsuhara, H., E-mail: inami@noao.edu [Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency (Japan); and others

2013-11-10

We present the data and our analysis of mid-infrared atomic fine-structure emission lines detected in Spitzer/Infrared Spectrograph high-resolution spectra of 202 local Luminous Infrared Galaxies (LIRGs) observed as part of the Great Observatories All-sky LIRG Survey (GOALS). We readily detect emission lines of [S IV], [Ne II], [Ne V], [Ne III], [S III]{sub 18.7{sub μm}}, [O IV], [Fe II], [S III]{sub 33.5{sub μm}}, and [Si II]. More than 75% of these galaxies are classified as starburst-dominated sources in the mid-infrared, based on the [Ne V]/[Ne II] line flux ratios and equivalent width of the 6.2 μm polycyclic aromatic hydrocarbon feature. We compare ratios of the emission-line fluxes to those predicted from stellar photo-ionization and shock-ionization models to constrain the physical and chemical properties of the gas in the starburst LIRG nuclei. Comparing the [S IV]/[Ne II] and [Ne III]/[Ne II] line ratios to the Starburst99-Mappings III models with an instantaneous burst history, the emission-line ratios suggest that the nuclear starbursts in our LIRGs have ages of 1-4.5 Myr, metallicities of 1-2 Z{sub ☉}, and ionization parameters of 2-8 × 10{sup 7} cm s{sup –1}. Based on the [S III]{sub 33.5{sub μm}}/[S III]{sub 18.7{sub μm}} ratios, the electron density in LIRG nuclei is typically one to a few hundred cm{sup –3}, with a median electron density of ∼300 cm{sup –3}, for those sources above the low density limit for these lines. We also find that strong shocks are likely present in 10 starburst-dominated sources of our sample. A significant fraction of the GOALS sources (80) have resolved neon emission-line profiles (FWHM ≥600 km s{sup –1}) and five show clear differences in the velocities of the [Ne III] or [Ne V] emission lines, relative to [Ne II], of more than 200 km s{sup –1}. Furthermore, six starburst and five active galactic nucleus dominated LIRGs show a clear trend of increasing line width with ionization potential

Computational workflow for the fine-grained analysis of metagenomic samples.

Science.gov (United States)

Pérez-Wohlfeil, Esteban; Arjona-Medina, Jose A; Torreno, Oscar; Ulzurrun, Eugenia; Trelles, Oswaldo

2016-10-25

The field of metagenomics, defined as the direct genetic analysis of uncultured samples of genomes contained within an environmental sample, is gaining increasing popularity. The aim of studies of metagenomics is to determine the species present in an environmental community and identify changes in the abundance of species under different conditions. Current metagenomic analysis software faces bottlenecks due to the high computational load required to analyze complex samples. A computational open-source workflow has been developed for the detailed analysis of metagenomes. This workflow provides new tools and datafile specifications that facilitate the identification of differences in abundance of reads assigned to taxa (mapping), enables the detection of reads of low-abundance bacteria (producing evidence of their presence), provides new concepts for filtering spurious matches, etc. Innovative visualization ideas for improved display of metagenomic diversity are also proposed to better understand how reads are mapped to taxa. Illustrative examples are provided based on the study of two collections of metagenomes from faecal microbial communities of adult female monozygotic and dizygotic twin pairs concordant for leanness or obesity and their mothers. The proposed workflow provides an open environment that offers the opportunity to perform the mapping process using different reference databases. Additionally, this workflow shows the specifications of the mapping process and datafile formats to facilitate the development of new plugins for further post-processing. This open and extensible platform has been designed with the aim of enabling in-depth analysis of metagenomic samples and better understanding of the underlying biological processes.

Computational workflow for the fine-grained analysis of metagenomic samples

Directory of Open Access Journals (Sweden)

Esteban Pérez-Wohlfeil

2016-10-01

Full Text Available Abstract Background The field of metagenomics, defined as the direct genetic analysis of uncultured samples of genomes contained within an environmental sample, is gaining increasing popularity. The aim of studies of metagenomics is to determine the species present in an environmental community and identify changes in the abundance of species under different conditions. Current metagenomic analysis software faces bottlenecks due to the high computational load required to analyze complex samples. Results A computational open-source workflow has been developed for the detailed analysis of metagenomes. This workflow provides new tools and datafile specifications that facilitate the identification of differences in abundance of reads assigned to taxa (mapping, enables the detection of reads of low-abundance bacteria (producing evidence of their presence, provides new concepts for filtering spurious matches, etc. Innovative visualization ideas for improved display of metagenomic diversity are also proposed to better understand how reads are mapped to taxa. Illustrative examples are provided based on the study of two collections of metagenomes from faecal microbial communities of adult female monozygotic and dizygotic twin pairs concordant for leanness or obesity and their mothers. Conclusions The proposed workflow provides an open environment that offers the opportunity to perform the mapping process using different reference databases. Additionally, this workflow shows the specifications of the mapping process and datafile formats to facilitate the development of new plugins for further post-processing. This open and extensible platform has been designed with the aim of enabling in-depth analysis of metagenomic samples and better understanding of the underlying biological processes.

Fine and coarse elemental components in the urban aerosol of Sao Paulo, Brazil

International Nuclear Information System (INIS)

Boueres, L.C.S.; Orsini, C.M.Q.

1981-01-01

Using cascade impactor sampling and PIXE analysis we have measured particle size distributions for approximately 15 elements in the Sao Paulo urban atmosphere. These elements, in our case, may be classified, according to their occurrence in fine or coarse aerosol log-normal modes, into three groups: (a) soil dust reference elements (coarse particle mode): Ti, Si and Ca; (b) anthropogenic fine particle mode: Zn, Br and Pb; and (c) mixed bimodal elements: S, K, V, Cr, Mn, Ni, Cu and Fe. All of the soil dust reference elements show consistently the log-normal parameters MMAD approx. 5.5 μm and sigmasub(g) approx. 3.2 (mass median aerodynamic diameter and geometric standard deviation, respectively). Enrichment factor calculations for Ti, Si, Ca and K in the coarse particle fraction (> 2 μmad), relative to Fe and the standard crustal aerosol values of Lawson and Winchester, show that Ti and Si are mainly soil derived while Ca and K may have significant industrial components in this particle fraction (i.e. coarse mode). The fine mode parameters for the other elements show variations with element suggesting different air pollution sources (such as motor vehicles, resuspended dust, refuse burning, industrial activities, etc.) and/or different chemical pathways, which presumably could be identifiable. For example, the modal parameters for group (b) are: Zn, MMAD = 0.9 μm, sigmasub(g) = 2.2; Br, MMAD = 0.5 μm, sigmasub(g) = 4.0; Pb, MMAD = 0.6 μm, sigmasub(g) = 3.0; thus suggesting a common source (automotive) for Br and Pb, unrelated to the source of Zn (possibly refuse burning). (orig.)

Characterization of traffic-related ambient fine particulate matter (PM2.5) in an Asian city: Environmental and health implications

Science.gov (United States)

Zhang, Zhi-Hui; Khlystov, Andrey; Norford, Leslie K.; Tan, Zhen-Kang; Balasubramanian, Rajasekhar

2017-07-01

Vehicular traffic emission is an important source of particulate pollution in most urban areas. The detailed chemical speciation of traffic-related PM2.5 (fine particles) is relatively sparse in the literature, especially in Asian cities. To fill this knowledge gap, we carried out an intensive field study in Singapore from November 2015 to February 2016. PM2.5 samples were collected concurrently at a typical roadside microenvironment and at an urban background site. A detailed chemical speciation of PM2.5 samples was conducted to gain insights into the emission characteristics of traffic-related fine aerosols. Analyses of diagnostic ratios and molecular markers of selected chemical species were explored for source attribution of different classes of chemical constituents in traffic-related PM2.5. The human health risk due to inhalation of the particulate-bound PAHs (polycyclic aromatic hydrocarbons) and toxic trace elements was estimated for both adults and children. The overall results of the study indicate that gasoline-powered vehicles make a higher contribution to traffic-related fine aerosol components such as organic carbon (OC), particle-bound PAHs and particulate ammonium than that of diesel-powered vehicles. However, both types of vehicles contribute to traffic-related EC emissions significantly. The combustion of petroleum fuels and lubricating oil make significant contributions to the emission of n-alkanes and hopanes into the urban atmosphere, respectively. The study further reveals that some toxic trace elements are emitted from non-exhaust sources and that aromatic acids represent an important component of secondary organic aerosols. The emission of toxic trace elements from non-exhaust sources is of particular concern as they could pose a higher carcinogenic risk to both adults and children than other chemical species.

Occurrence and sources of aliphatic hydrocarbons in surface soils from Riyadh city, Saudi Arabia

Directory of Open Access Journals (Sweden)

Ahmed I. Rushdi

2013-01-01

Full Text Available Soil particles contain a variety of anthropogenic and natural organic components derived from many sources such as industrial and traffic fossil fuel emissions and terrestrial biota. The organic contents of soil and sand from the Arabian region have not fully characterized. Thus, samples of fine soil particles (sieved to <125 μM were collected from the Riyadh area in November 2006 (late summer and February 2007 (late winter. The samples were extracted with a mixture of dichloromethane/hexane and analyzed by gas chromatography–mass spectroscopy (GCMS in order to characterize the chemical composition and sources of aliphatic hydrocarbons. The results showed that both anthropogenic and natural biogenic inputs were the major sources of the aliphatic hydrocarbons in these extracts. Vehicular emission products and discarded plastics were the major anthropogenic sources in the fine particles of the soils and ranged from 64% to 96% in November 2006 and from 70% to 92% in February 2007. Their tracers were n-alkanes, hopanes, sterane, plasticizers and UCM. Vegetation was also a major natural source of hydrocarbon compounds in samples ranging from ∼0% to18% in November 2006 and from 1% to 13% in February 2007 and included n-alkanes and triterpenoids.

MOTORIC STIMULATION RELATED TO FINE MOTORIC DEVELOPMENT ON CHILD

Directory of Open Access Journals (Sweden)

Mira Triharini

2017-07-01

Full Text Available Introduction: Motor developmental stimulation is an activity undertaken to stimulate the children basic skills and so they can grow and develop optimally. Children who obtain a direct stimulus will grow faster than who get less stimulus. Mother’s behavior of stimulation is very important for children, it is considering as the basic needs of children and it must be fulfilled. Providing good stimulation could optimize fine motor development in children. The purpose of this study was to analyze mother’s behavior about motor stimulation with fine motor development in toddler age 4-5 years old. Method: Design have been  used in this study was cross sectional. Population were mothers and their toddler in Group A of Dharma Wanita Persatuan Driyorejo Gresik Preschool. Sample were 51 respondents recruited by using purposive sampling technique according to inclusion and exclusion criteria. The independent variable was mother’s behavior about motor stimulation whereas dependent variable was fine motor development in toddler. The data were collected using questionnaire and conducting observation on fine motor development based on Denver Development Screening Test (DDST. Data then analyzed using Spearman Rho (r test to find relation between mother’s behaviors about stimulation motor on their toddler fine motor development. Result: Results  of this study showed that there were correlations between mother’s knowledge and fine motor development in toddler (p=0.000, between mother’s attitude and fine motor development in toddler (p=0.000, and between mother’s actions and fine motor development in toddler (p=0.000. Analysis: In sort study found that there were relation between fine motor development and mother’s behavior. Discussion: Therefore mother’s behavior needed to be improved. Further research about stimulation motor and fine motor development aspects in toddler is required.

Emissions and measure analysis of fine particles 2000-2020; Emissionen und Massnahmenanalyse Feinstaub 2000-2020

Energy Technology Data Exchange (ETDEWEB)

Joerss, Wolfram; Handke, Volker [Institut fuer Zukunftsstudien und Technologiebewertung gGmbH (IZT), Berlin (Germany)

2007-08-15

With this study, the Federal Environmental Agency's emission inventory on total suspended particles and the fine fractions PM{sub 1}0 and PM{sub 2}.5 was updated. On that basis, a reference scenario was developed for anthropogenic emissions of particulate matter up to the years 2010, 2015 and 2020. In addition, potential additional emission reduction measures were systematically collected and quantified. At the source groups which contribute most strongly to the emissions there are clear differences between the fine fractions and in the course of time. In particular, with the total fine the emission freight is very broadly distributed over many source groups. With PM{sub 2}.5, the emissions are more strongly concentrated on a limited number of source groups. The decrease of the emissions in the years between 2000 and 2020 in the reference scenario takes place in source groups with high portions of PM{sub 2}.5 of the emissions of total fine particles.

Emissions and measure analysis of fine particles 2000-2020; Emissionen und Massnahmenanalyse Feinstaub 2000-2020

Energy Technology Data Exchange (ETDEWEB)

Joerss, Wolfram; Handke, Volker [Institut fuer Zukunftsstudien und Technologiebewertung gGmbH (IZT), Berlin (Germany)

2007-08-15

With this study, the Federal Environmental Agency's emission inventory on total suspended particles and the fine fractions PM{sub 1}0 and PM{sub 2}.5 was updated. On that basis, a reference scenario was developed for anthropogenic emissions of particulate matter up to the years 2010, 2015 and 2020. In addition, potential additional emission reduction measures were systematically collected and quantified. At the source groups which contribute most strongly to the emissions there are clear differences between the fine fractions and in the course of time. In particular, with the total fine the emission freight is very broadly distributed over many source groups. With PM{sub 2}.5, the emissions are more strongly concentrated on a limited number of source groups. The decrease of the emissions in the years between 2000 and 2020 in the reference scenario takes place in source groups with high portions of PM{sub 2}.5 of the emissions of total fine particles.

Estimation of sediment sources using selected chemical tracers in the Perry lake basin, Kansas, USA

Science.gov (United States)

Juracek, K.E.; Ziegler, A.C.

2009-01-01

The ability to achieve meaningful decreases in sediment loads to reservoirs requires a determination of the relative importance of sediment sources within the contributing basins. In an investigation of sources of fine-grained sediment (clay and silt) within the Perry Lake Basin in northeast Kansas, representative samples of channel-bank sources, surface-soil sources (cropland and grassland), and reservoir bottom sediment were collected, chemically analyzed, and compared. The samples were sieved to isolate the TOC), and 137Cs were selected for use in the estimation of sediment sources. To further account for differences in particle-size composition between the sources and the reservoir bottom sediment, constituent ratio and clay-normalization techniques were used. Computed ratios included TOC to TN, TOC to TP, and TN to TP. Constituent concentrations (TN, TP, TOC) and activities (137Cs) were normalized by dividing by the percentage of clay. Thus, the sediment-source estimations involved the use of seven sediment-source indicators. Within the Perry Lake Basin, the consensus of the seven indicators was that both channel-bank and surface-soil sources were important in the Atchison County Lake and Banner Creek Reservoir subbasins, whereas channel-bank sources were dominant in the Mission Lake subbasin. On the sole basis of 137Cs activity, surface-soil sources contributed the most fine-grained sediment to Atchison County Lake, and channel-bank sources contributed the most fine-grained sediment to Banner Creek Reservoir and Mission Lake. Both the seven-indicator consensus and 137Cs indicated that channel-bank sources were dominant for Perry Lake and that channel-bank sources increased in importance with distance downstream in the basin. ?? 2009 International Research and Training Centre on Erosion and Sedimentation and the World Association for Sedimentation and Erosion Research.

Saccharide Composition in Fine and Coarse Particulate Matter and Soils in Central Arizona and Use of Saccharides as Molecular Markers for Source Apportionment

Science.gov (United States)

Jia, Y.; Clements, A.; Fraser, M.

2009-04-01

were analyzed in size segregated soil and ambient PM samples at Higley; intra- and inter- comparisons were made between the ambient PM and three types of soil dust samples (agricultural soil, native soil, road dust) based on the particle size (fine vs. coarse), seasonality, and relative composition of 12 saccharide compounds. Based on the ambient concentrations of major saccharides and a number of other specific compounds (including elemental and organic carbon, ions, metals, alkanes, organic acids, and polycyclic aromatic hydrocarbons) that are simultaneously resolved in Higley PM samples, a Positive Matrix Factorization (PMF) model was performed to determine the key contributors to PM10 and PM2.5 levels. Six distinct factors were isolated, with two factors dominated by the enrichment of saccharide compounds. There was not consistency between the source profiles of these two saccharide rich source factors with the saccharide composition of the local size-segregated soil samples, which implies that there may be other major sources contributing to ambient PM saccharides. One possible alternative is that PBAPs that are injected directly into the atmosphere instead of residing in the surface soil and being re-entrained through soil erosion or agricultural processing. To our knowledge, this study is the first of its kind to compare the saccharide composition between the fine and coarse fraction of different soils types in two seasons, and to relate the contribution from soil dust to ambient PM using saccharide species. REFERENCE [1] AirData: Access to Air Pollution data. [cited 2009 Jan 11, 2009]; Available from: http://www.epa.gov/air/data/index.html [2] Allergy and Asthma in the Southwestern United States. [cited 2009 Jan 11, 2009]; Available from: http://allergy.peds.arizona.edu/southwest/swpollen.html [3] Cox, C.S., Wathes, C.M., 1995. Bioaerosols Handbook, Lewis Publishers, NY [4] Simoneit, B.R.T., Elias, V.O., et al., 2004. "Sugars - Dominant water-soluble organic

High time-resolved elemental components in fine and coarse particles in the Pearl River Delta region of Southern China: Dynamic variations and effects of meteorology.

Science.gov (United States)

Zhou, Shengzhen; Davy, Perry K; Wang, Xuemei; Cohen, Jason Blake; Liang, Jiaquan; Huang, Minjuan; Fan, Qi; Chen, Weihua; Chang, Ming; Ancelet, Travis; Trompetter, William J

2016-12-01

Hourly-resolved PM 2.5 and PM 10-2.5 samples were collected in the industrial city Foshan in the Pearl River Delta region, China. The samples were subsequently analyzed for elemental components and black carbon (BC). A key purpose of the study was to understand the composition of particulate matter (PM) at high-time resolution in a polluted urban atmosphere to identify key components contributing to extreme PM concentration events and examine the diurnal chemical concentration patterns for air quality management purposes. It was found that BC and S concentrations dominated in the fine mode, while elements with mostly crustal and oceanic origins such as Si, Ca, Al and Cl were found in the coarse size fraction. Most of the elements showed strong diurnal variations. S did not show clear diurnal variations, suggesting regional rather than local origin. Based on empirical orthogonal functions (EOF) method, 3 forcing factors were identified contributing to the extreme events of PM 2.5 and selected elements, i.e., urban direct emissions, wet deposition and a combination of coarse mode sources. Conditional probability functions (CPF) were performed using wind profiles and elemental concentrations. The CPF results showed that BC and elemental Cl, K, Fe, Cu and Zn in the fine mode were mostly from the northwest, indicating that industrial emissions and combustion were the main sources. For elements in the coarse mode, Si, Al, K, Ca, Fe and Ti showed similar patterns, suggesting same sources such as local soil dust/construction activities. Coarse elemental Cl was mostly from the south and southeast, implying the influence of marine aerosol sources. For other trace elements, we found vanadium (V) in fine PM was mainly from the sources located to the southeast of the measuring site. Combined with CPF results of S and V in fine PM, we concluded shipping emissions were likely an important elemental emission source. Copyright © 2016. Published by Elsevier B.V.

Sample preparations for spark source mass spectrography

International Nuclear Information System (INIS)

Catlett, C.W.; Rollins, M.B.; Griffin, E.B.; Dorsey, J.G.

1977-10-01

Methods have been developed for the preparation of various materials for spark source mass spectrography. The essential features of these preparations (all which can provide adequate precision in a cost-effective manner) consist in obtaining spark-stable electrode sample pieces, a common matrix, a reduction of anomolous effects in the spark, the incorporation of a suitable internal standard for plate response normalization, and a reduction in time

Two-year study of atmospheric aerosols in Alta Floresta, Brazil: Multielemental composition and source apportionment

International Nuclear Information System (INIS)

Maenhaut, Willy; Fernandez-Jimenez, Maria-Teresa; Rajta, Istvan; Artaxo, Paulo

2002-01-01

Atmospheric aerosol samples were collected nearly continuously from August 1996 until September 1998 at Alta Floresta in a primary forest region of the Amazon basin, Brazil. The sampling device consisted of a stacked filter unit (SFU), which separates the aerosol into a coarse (2-10 μm equivalent aerodynamic diameter (EAD)) and a fine (<2 μm EAD) size fraction. The coarse and fine filters of all SFU samples (205 in total) were analysed for the particulate mass (PM), black carbon (BC), and up to 47 elements (from Na upward). The multielemental analyses were done by a combination of PIXE and instrumental neutron activation analysis. Absolute principal component analysis was used for source (source type) identification and apportionment. Five components were identified in the fine size fraction, i.e. mineral dust, a biomass burning (pyrogenic) component (with PM, BC, S, K, Zn, Br, Rb and I, having loadings in the range 0.7-0.9), a Na/Ca component, a biogenic component (with P), and an almost pure Pb component. On average 67% of the fine PM was attributed to the pyrogenic component, 14% to the mineral dust, 7% each to the biogenic and Na/Ca components, and 4% to the Pb component. The relative contribution from the pyrogenic aerosol varied substantially with season, however. It was generally between 60% and 100% during the dry season. During the wet season, on the other hand, it often became insignificant. During that season, most of the fine aerosol was attributed to the biogenic component

effect of fines content on the engineering properties of reconstituted

African Journals Online (AJOL)

2012-11-03

Nov 3, 2012 ... Reconstitution of the natural soil (0% fines content) yielded soil samples having fines content between ... action to different stabilizing agents are better under- .... tion cracking, whereas clay soils with too low plastic limit (PL) ...

Aerosol composition and source apportionment in Santiago de Chile

Science.gov (United States)

Artaxo, Paulo; Oyola, Pedro; Martinez, Roberto

1999-04-01

Santiago de Chile, São Paulo and Mexico City are Latin American urban areas that suffer from heavy air pollution. In order to study air pollution in Santiago area, an aerosol source apportionment study was designed to measure ambient aerosol composition and size distribution for two downtown sampling sites in Santiago. The aerosol monitoring stations were operated in Gotuzo and Las Condes during July and August 1996. The study employed stacked filter units (SFU) for aerosol sampling, collecting fine mode aerosol (dpsource apportionment was performed using Absolute Principal Factor Analysis (APFA). Very high aerosol concentrations were observed (up to 400 μg/m 3 PM 10). The main aerosol particle sources in Santiago are resuspended soil dust and traffic emissions. Coarse particles account for 63% of PM 10 aerosol in Gotuzo and 53% in Las Condes. A major part of this component is resuspended soil dust. In the fine fraction, resuspended soil dust accounts for 15% of fine mass, and the aerosols associated with transportation activities account for a high 64% of the fine particle mass. Sulfate particle is an important component of the aerosol in Santiago, mainly originating from gas-to-particle conversion from SO 2. In the Gotuzo site, sulfates are the highest aerosol component, accounting for 64.5% of fine mass. Direct traffic emissions are generally mixed with resuspended soil dust. It is difficult to separate the two components, because the soil dust in downtown Santiago is contaminated with Pb, Br, Cl, and other heavy metals that are also tracers for traffic emissions. Residual oil combustion is observed, with the presence of V, S and Ni. An aerosol components from industrial emissions is also present, with the presence of several heavy metals such as Zn, Cu and others. A factor with molybdenum, arsenic, copper and sulfur was observed frequently, and it results from emissions of copper smelters.

Investigation and Applications of In-Source Oxidation in Liquid Sampling-Atmospheric Pressure Afterglow Microplasma Ionization (LS-APAG) Source.

Science.gov (United States)

Xie, Xiaobo; Wang, Zhenpeng; Li, Yafeng; Zhan, Lingpeng; Nie, Zongxiu

2017-06-01

A liquid sampling-atmospheric pressure afterglow microplasma ionization (LS-APAG) source is presented for the first time, which is embedded with both electrospray ionization (ESI) and atmospheric pressure afterglow microplasma ionization (APAG) techniques. This ion source is capable of analyzing compounds with diverse molecule weights and polarities. An unseparated mixture sample was detected as a proof-of-concept, giving complementary information (both polarities and non-polarities) with the two ionization modes. It should also be noted that molecular mass can be quickly identified by ESI with clean and simple spectra, while the structure can be directly studied using APAG with in-source oxidation. The ionization/oxidation mechanism and applications of the LS-APAG source have been further explored in the analysis of nonpolar alkanes and unsaturated fatty acids/esters. A unique [M + O - 3H] + was observed in the case of individual alkanes (C 5 -C 19 ) and complex hydrocarbons mixture under optimized conditions. Moreover, branched alkanes generated significant in-source fragments, which could be further applied to the discrimination of isomeric alkanes. The technique also facilitates facile determination of double bond positions in unsaturated fatty acids/esters due to diagnostic fragments (the acid/ester-containing aldehyde and acid oxidation products) generated by on-line ozonolysis in APAG mode. Finally, some examples of in situ APAG analysis by gas sampling and surface sampling were given as well. Graphical Abstract ᅟ.

The effect of limited availability of N or water on C allocation to fine roots and annual fine root turnover in Alnus incana and Salix viminalis.

Science.gov (United States)

Rytter, Rose-Marie

2013-09-01

The effect of limited nitrogen (N) or water availability on fine root growth and turnover was examined in two deciduous species, Alnus incana L. and Salix viminalis L., grown under three different regimes: (i) supply of N and water in amounts which would not hamper growth, (ii) limited N supply and (iii) limited water supply. Plants were grown outdoors during three seasons in covered and buried lysimeters placed in a stand structure and filled with quartz sand. Computer-controlled irrigation and fertilization were supplied through drip tubes. Production and turnover of fine roots were estimated by combining minirhizotron observations and core sampling, or by sequential core sampling. Annual turnover rates of fine roots water availability. Fine root production (treatments in Salix; i.e., absolute length and biomass production increased in the order: water limited treatment effects were detected for fine roots 1-2 mm. Proportionally more C was allocated to fine roots (≤2 mm) in N or water-limited Salix; 2.7 and 2.3 times the allocation to fine roots in the unlimited regime, respectively. Estimated input to soil organic carbon increased by ca. 20% at N limitation in Salix. However, future studies on fine root decomposition under various environmental conditions are required. Fine root growth responses to N or water limitation were less pronounced in Alnus, thus indicating species differences caused by N-fixing capacity and slower initial growth in Alnus, or higher fine root plasticity in Salix. A similar seasonal growth pattern across species and treatments suggested the influence of outer stimuli, such as temperature and light.

Source apportionment of population representative samples of PM(2.5) in three European cities using structural equation modelling.

Science.gov (United States)

Ilacqua, Vito; Hänninen, Otto; Saarela, Kristina; Katsouyanni, Klea; Künzli, Nino; Jantunen, Matti

2007-10-01

Apportionment of urban particulate matter (PM) to sources is central for air quality management and efficient reduction of the substantial public health risks associated with fine particles (PM(2.5)). Traffic is an important source combustion particles, but also a significant source of resuspended particles that chemically resemble Earth's crust and that are not affected by development of cleaner motor technologies. A substantial fraction of urban ambient PM originates from long-range transport outside the immediate urban environment including secondary particles formed from gaseous emissions of mainly sulphur, nitrogen oxides and ammonia. Most source apportionment studies are based on small number of fixed monitoring sites and capture well population exposures to regional and long-range transported particles. However, concentrations from local sources are very unevenly distributed and the results from such studies are therefore poorly representative of the actual exposures. The current study uses PM(2.5) data observed at population based random sampled residential locations in Athens, Basle and Helsinki with 17 elemental constituents, selected VOCs (xylenes, trimethylbenzenes, nonane and benzene) and light absorbance (black smoke). The major sources identified across the three cities included crustal, salt, long-range transported inorganic and traffic sources. Traffic was associated separately with source categories with crustal (especially Athens and Helsinki) and long-range transported chemical composition (all cities). Remarkably high fractions of the variability of elemental (R(2)>0.6 except for Ca in Basle 0.38) and chemical concentrations (R(2)>0.5 except benzene in Basle 0.22 and nonane in Athens 0.39) are explained by the source factors of an SEM model. The RAINS model that is currently used as the main tool in developing European air quality management policies seems to capture the local urban fraction (the city delta term) quite well, but underestimates

Bulk - Samples gamma-rays activation analysis (PGNAA) with Isotopic Neutron Sources

International Nuclear Information System (INIS)

HASSAN, A.M.

2009-01-01

An overview is given on research towards the Prompt Gamma-ray Neutron Activation Analysis (PGNAA) of bulk-samples. Some aspects in bulk-sample PGNAA are discussed, where irradiation by isotopic neutron sources is used mostly for in-situ or on-line analysis. The research was carried out in a comparative and/or qualitative way or by using a prior knowledge about the sample material. Sometimes we need to use the assumption that the mass fractions of all determined elements add up to 1. The sensitivity curves are also used for some elements in such complex samples, just to estimate the exact percentage concentration values. The uses of 252 Cf, 241 Arn/Be and 239 Pu/Be isotopic neutron sources for elemental investigation of: hematite, ilmenite, coal, petroleum, edible oils, phosphates and pollutant lake water samples have been mentioned.

Organic Geochemistry and Rock-Eval Pyrolysis of Eocene fine Sediments, East Ketungau Basin, West Kalimantan

Directory of Open Access Journals (Sweden)

M.H. Hermiyanto Zajuli

2014-06-01

Full Text Available DOI: 10.17014/ijog.v6i2.119Indonesia contains many Paleogene and Neogene basins which some of them have been proven to be a very prolific producer of oil and gas. A study on the result of Rock-Eval pyrolysis and biomarker undertaken on the Eocene Mandai Group was able to assess hydrocarbon potential of the Paleogene fine sediments in the frontier basin, especially West Kalimantan area. East Ketungau Basin is located in the western Kalimantan, bounded with Melawi Basin by the Semitau High in the south and West Ketungau Basin in the west. The Mandai Group was deposited in the East Ketungau Basin during Eocene, consisting of sandstone and mudstone facies. Mudstone facies comprises shale, claystone, and coal. Seven samples of Eocene fine sediments collected from East Ketungau Basin were analyzed by Rock-Eval pyrolisis and three samples for biomarker to evaluate their hydrocarbon potential. The Rock-Eval pyrolisis result of Mandai Group shows that TOC value of this facies ranges from 0.34 % to 5.16 %, Potential Yield (PY between 0.06 and 4.78 mg HC/g rock, and Hydrogen Index (HI from 12 to 89. Based on that result, the fine sediments of Mandai Group are included into a gas prone source rock potential with poor to fair categories. Moreover Tmax values vary from 426o C to 451o C. The Eocene fine sediments of Mandai Group fall under kerogen type III. Based on Tmax and biomarker analyses, the maturity of the sediments is situated within immature to mature level. The fine sediments of Mandai Group were deposited in a terrestrial to marine environment under anoxic to sub-oxic condition.

Religious Burning as a Major Source of Atmospheric Fine Aerosols in Lhasa city in the Tibetan Plateau

Science.gov (United States)

Liu, S.; Cui, Y.; Zhixuan, B.; Bian, J.; McKeen, S. A.; Watts, L. A.; Ciciora, S. J.; Gao, R. S.

2017-12-01

Measurements of aerosols in the Tibetan Plateau are scant due to the high altitude and harsh climate. To bridge this gap, we carried out the first field measurements of aerosol size distributions in Lhasa, a major city in the Tibetan Plateau that has been experiencing fast urbanization and reduced air quality. Aerosol number size distribution was continuously measured using an optical particle size spectrometer near the center of Lhasa city during the Asian summer monsoon season in 2016. The mass concentration of fine particles was modulated by boundary layer dynamics, with an average of 11 µg m-3 and the high values exceeding 50 µg m-3 during religious holidays. Daytime high concentration coincided with the religious burning of biomass and incense in the temples during morning hours, which produced heavy smoke. Factor analysis revealed a factor that is likely induced by religious burning. The factor contributed 34% of the campaign-average fine particle mass and the contribution reached up to 80% during religious holidays. The mass size distribution of aerosols produced from religious burnings peaked at 500 nm, indicating that these particles could efficiently decrease visibility and promote health risk. Because of its significance, our results suggest that more attention should be paid to religious burning, a currently under-studied source, in the Tibetan Plateau and in other regions of the world where religious burnings are frequently practiced.

Relation between aerosol sources and meteorological parameters for inhalable atmospheric particles in Sao Paulo City, Brazil

Science.gov (United States)

Andrade, Fatima; Orsini, Celso; Maenhaut, Willy

Stacked filter units were used to collect atmospheric particles in separate coarse and fine fractions at the Sao Paulo University Campus during the winter of 1989. The samples were analysed by particle-induced X-ray emission (PIXE) and the data were subjected to an absolute principal component analysis (APCA). Five sources were identified for the fine particles: industrial emissions, which accounted for 13% of the fine mass; emissions from residual oil and diesel, explaining 41%; resuspended soil dust, with 28%; and emissions of Cu and of Mg, together with 18%. For the coarse particles, four sources were identified: soil dust, accounting for 59% of the coarse mass; industrial emissions, with 19%; oil burning, with 8%; and sea salt aerosol, with 14% of the coarse mass. A data set with various meteorological parameters was also subjected to APCA, and a correlation analysis was performed between the meteorological "absolute principal component scores" (APCS) and the APCS from the fine and coarse particle data sets. The soil dust sources for the fine and coarse aerosol were highly correlated with each other and were anticorrelated with the sea breeze component. The industrial components in the fine and coarse size fractions were also highly positively correlated. Furthermore, the industrial component was related with the northeasterly wind direction and, to a lesser extent, with the sea breeze component.

Dynamically Polarized Sample for Neutron Scattering At the Spallation Neutron Source

International Nuclear Information System (INIS)

Pierce, Josh; Zhao, J. K.; Crabb, Don

2009-01-01

The recently constructed Spallation Neutron Source at the Oak Ridge National Laboratory is quickly becoming the world's leader in neutron scattering sciences. In addition to the world's most intense pulsed neutron source, we are continuously constructing state of the art neutron scattering instruments as well as sample environments to address today and tomorrow's challenges in materials research. The Dynamically Polarized Sample project at the SNS is aimed at taking maximum advantage of polarized neutron scattering from polarized samples, especially biological samples that are abundant in hydrogen. Polarized neutron scattering will allow us drastically increase the signal to noise ratio in experiments such as neutron protein crystallography. The DPS project is near completion and all key components have been tested. Here we report the current status of the project.

Comparison of Fine Needle Aspiration and Fine Needle Nonaspiration Cytology of Thyroid Nodules: A Meta-Analysis

Directory of Open Access Journals (Sweden)

Hongming Song

2015-01-01

Full Text Available Background. Fine needle aspiration cytology (FNAC and fine needle nonaspiration cytology (FNNAC are useful cost-effective techniques for preoperatively assessing thyroid lesions. Both techniques have advantages and disadvantages, and there is controversy over which method is superior. This meta-analysis was performed to evaluate the differences between FNAC and FNNAC for diagnosis of thyroid nodules. Methods. Primary publications were independently collected by two reviewers from PubMed, Web of Science, Google Scholar, EBSCO, OALib, and the Cochrane Library databases. The following search terms were used: fine needle, aspiration, capillary, nonaspiration, sampling without aspiration, thyroid, and cytology. The last search was performed on February 1, 2015. Results. Sixteen studies comprising 1,842 patients and 2,221 samples were included in this study. No statistically significant difference was observed between FNAC and FNNAC groups with respect to diagnostically inadequate smears, diagnostically superior smears, diagnostic performance (accuracy, sensitivity, specificity, negative predictive value, and positive predictive value, area under the summary receiver operating characteristic curve, average score of each parameter (background blood or clot, amount of cellular material, degree of cellular degeneration, degree of cellular trauma, and retention of appropriate architecture, and total score of five parameters. Conclusion. FNAC and FNNAC are equally useful in assessing thyroid nodules.

Religious burning as a potential major source of atmospheric fine aerosols in summertime Lhasa on the Tibetan Plateau

Science.gov (United States)

Cui, Yu Yan; Liu, Shang; Bai, Zhixuan; Bian, Jianchun; Li, Dan; Fan, Kaiyu; McKeen, Stuart A.; Watts, Laurel A.; Ciciora, Steven J.; Gao, Ru-Shan

2018-05-01

We carried out field measurements of aerosols in Lhasa, a major city in the Tibetan Plateau that has been experiencing fast urbanization and industrialization. Aerosol number size distribution was continuously measured using an optical particle size spectrometer near the center of Lhasa city during the Asian summer monsoon season in 2016. The mass concentration of fine particles was modulated by boundary layer dynamics, with an average of 11 μg m-3 and the high values exceeding 50 μg m-3 during religious holidays. Daytime high concentration coincided with the religious burning of biomass and incense in the temples during morning hours, which produced heavy smoke. Factor analysis revealed a factor that likely represented religious burning. The factor contributed 34% of the campaign-average fine particle mass and the contribution reached up to 80% during religious holidays. The mass size distribution of aerosols produced from religious burnings peaked at ∼500 nm, indicating that these particles could efficiently decrease visibility and promote health risk. Because of its significance, our results suggest that further studies of religious burning, a currently under-studied source, are needed in the Tibetan Plateau and in other regions of the world where religious burnings are frequently practiced.

Levels and sources of particulate lead in air at Kwabenya, Accra, Ghana

International Nuclear Information System (INIS)

Ofosu, F.G.; Aboh, I.J.K.

2008-01-01

The Government of Ghana by Legislation Instrument L.I 1732 banned the production, importation, storage, sale and use of leaded gasoline in Ghana with effect from 1 st January 2004. The aim of this work is to find out the contribution of lead to the atmospheric aerosol two years after the coming into force of the ban. The sampling was done using a Gent sampler with stacked filter units and the aerosol collected size fractionated into PM 2.5 (fine) and PM 10-2.5 (Coarse). Energy dispersive x-ray fluorescence (EDXRF) analysis was used to identify and quantify lead (Pb) and other elements in both the coarse and fine fractions. The average concentration of Pb in the ambient air was 1.49 ngm -3 and 0.70 ngm -3 for the coarse and fine fractions respectively. The average total of both the coarse and fine fractions (which is PM 10 ) was 2.19 ngm -3 , which is well below the US EPA set standard of 1.5 μgm -3 . Source apportionment on the fine fraction using Principal Component Analysis (PCA) showed that mostly soil/dust and to a lesser extent combustion processes were the sources of the Pb. (au)

Analysis of inconsistent source sampling in monte carlo weight-window variance reduction methods

Directory of Open Access Journals (Sweden)

David P. Griesheimer

2017-09-01

Full Text Available The application of Monte Carlo (MC to large-scale fixed-source problems has recently become possible with new hybrid methods that automate generation of parameters for variance reduction techniques. Two common variance reduction techniques, weight windows and source biasing, have been automated and popularized by the consistent adjoint-driven importance sampling (CADIS method. This method uses the adjoint solution from an inexpensive deterministic calculation to define a consistent set of weight windows and source particles for a subsequent MC calculation. One of the motivations for source consistency is to avoid the splitting or rouletting of particles at birth, which requires computational resources. However, it is not always possible or desirable to implement such consistency, which results in inconsistent source biasing. This paper develops an original framework that mathematically expresses the coupling of the weight window and source biasing techniques, allowing the authors to explore the impact of inconsistent source sampling on the variance of MC results. A numerical experiment supports this new framework and suggests that certain classes of problems may be relatively insensitive to inconsistent source sampling schemes with moderate levels of splitting and rouletting.

Aerosol composition and source apportionment in Santiago de Chile

International Nuclear Information System (INIS)

Artaxo, Paulo; Oyola, Pedro; Martinez, Roberto

1999-01-01

Santiago de Chile, Sao Paulo and Mexico City are Latin American urban areas that suffer from heavy air pollution. In order to study air pollution in Santiago area, an aerosol source apportionment study was designed to measure ambient aerosol composition and size distribution for two downtown sampling sites in Santiago. The aerosol monitoring stations were operated in Gotuzo and Las Condes during July and August 1996. The study employed stacked filter units (SFU) for aerosol sampling, collecting fine mode aerosol (dp 10 mass of particles smaller than 10 μm) and black carbon concentration were also measured. Particle-Induced X-ray Emission (PIXE) was used to measure the concentration of 22 trace elements at levels below 0.5 ng m -3 . Quantitative aerosol source apportionment was performed using Absolute Principal Factor Analysis (APFA). Very high aerosol concentrations were observed (up to 400 μg/m 3 PM 10 ). The main aerosol particle sources in Santiago are resuspended soil dust and traffic emissions. Coarse particles account for 63% of PM 10 aerosol in Gotuzo and 53% in Las Condes. A major part of this component is resuspended soil dust. In the fine fraction, resuspended soil dust accounts for 15% of fine mass, and the aerosols associated with transportation activities account for a high 64% of the fine particle mass. Sulfate particle is an important component of the aerosol in Santiago, mainly originating from gas-to-particle conversion from SO 2 . In the Gotuzo site, sulfates are the highest aerosol component, accounting for 64.5% of fine mass. Direct traffic emissions are generally mixed with resuspended soil dust. It is difficult to separate the two components, because the soil dust in downtown Santiago is contaminated with Pb, Br, Cl, and other heavy metals that are also tracers for traffic emissions. Residual oil combustion is observed, with the presence of V, S and Ni. An aerosol components from industrial emissions is also present, with the presence of

Subsoil erosion dominates the supply of fine sediment to rivers draining into Princess Charlotte Bay, Australia.

Science.gov (United States)

Olley, Jon; Brooks, Andrew; Spencer, John; Pietsch, Timothy; Borombovits, Daniel

2013-10-01

The Laura-Normanby River (catchment area: 24,350 km(2)), which drains into Princess Charlotte Bay, has been identified in previous studies as the third largest contributor of sediment to the Great Barrier Reef World Heritage Area. These catchment scale modelling studies also identified surface soil erosion as supplying >80% of the sediment. Here we use activity concentrations of the fallout radionuclides (137)Cs and (210)Pbex to test the hypothesis that surface soil erosion dominates the supply of fine (river systems draining into Princess Charlotte Bay. Our results contradict these previous studies, and are consistent with channel and gully erosion being the dominant source of fine sediment in this catchment. The hypothesis that surface soil erosion dominates the supply of fine sediment to Princess Charlotte Bay is rejected. River sediment samples were collected using both time-integrated samplers and sediment drape deposits. We show that there is no detectable difference in (137)Cs and (210)Pbex activity concentrations between samples collected using these two methods. Two methods were also used to collect samples to characterise (137)Cs and (210)Pbex concentrations in sediment derived from surface soil erosion; sampling of surface-wash deposits and deployment of surface runoff traps that collected samples during rain events. While there was no difference in the (137)Cs activity concentrations for samples collected using these two methods, (210)Pbex activity concentrations were significantly higher in the samples collected using the runoff traps. The higher (210)Pbex concentrations are shown to be correlated with loss-on-ignition (r(2) = 0.79) and therefore are likely to be related to higher organic concentrations in the runoff trap samples. As a result of these differences we use a three end member mixing model (channel/gully, hillslope surface-wash and hillslope runoff traps) to determine the relative contribution from surface soil erosion. Probability

Permeability of Granite Including Macro-Fracture Naturally Filled with Fine-Grained Minerals

Science.gov (United States)

Nara, Yoshitaka; Kato, Masaji; Niri, Ryuhei; Kohno, Masanori; Sato, Toshinori; Fukuda, Daisuke; Sato, Tsutomu; Takahashi, Manabu

2018-03-01

Information on the permeability of rock is essential for various geoengineering projects, such as geological disposal of radioactive wastes, hydrocarbon extraction, and natural hazard risk mitigation. It is especially important to investigate how fractures and pores influence the physical and transport properties of rock. Infiltration of groundwater through the damage zone fills fractures in granite with fine-grained minerals. However, the permeability of rock possessing a fracture naturally filled with fine-grained mineral grains has yet to be investigated. In this study, the permeabilities of granite samples, including a macro-fracture filled with clay and a mineral vein, are investigated. The permeability of granite with a fine-grained mineral vein agrees well with that of the intact sample, whereas the permeability of granite possessing a macro-fracture filled with clay is lower than that of the macro-fractured sample. The decrease in the permeability is due to the filling of fine-grained minerals and clay in the macro-fracture. It is concluded that the permeability of granite increases due to the existence of the fractures, but decreases upon filling them with fine-grained minerals.

Estimation of sediment sources using selected chemical tracers in the Perry lake basin, Kansas, USA

Science.gov (United States)

Juracek, K.E.; Ziegler, A.C.

2009-01-01

The ability to achieve meaningful decreases in sediment loads to reservoirs requires a determination of the relative importance of sediment sources within the contributing basins. In an investigation of sources of fine-grained sediment (clay and silt) within the Perry Lake Basin in northeast Kansas, representative samples of channel-bank sources, surface-soil sources (cropland and grassland), and reservoir bottom sediment were collected, chemically analyzed, and compared. The samples were sieved to isolate the phosphorus), organic and total carbon, 25 trace elements, and the radionuclide cesium-137 (137Cs). On the basis of substantial and consistent compositional differences among the source types, total nitrogen (TN), total phosphorus (TP), total organic carbon (TOC), and 137Cs were selected for use in the estimation of sediment sources. To further account for differences in particle-size composition between the sources and the reservoir bottom sediment, constituent ratio and clay-normalization techniques were used. Computed ratios included TOC to TN, TOC to TP, and TN to TP. Constituent concentrations (TN, TP, TOC) and activities (137Cs) were normalized by dividing by the percentage of clay. Thus, the sediment-source estimations involved the use of seven sediment-source indicators. Within the Perry Lake Basin, the consensus of the seven indicators was that both channel-bank and surface-soil sources were important in the Atchison County Lake and Banner Creek Reservoir subbasins, whereas channel-bank sources were dominant in the Mission Lake subbasin. On the sole basis of 137Cs activity, surface-soil sources contributed the most fine-grained sediment to Atchison County Lake, and channel-bank sources contributed the most fine-grained sediment to Banner Creek Reservoir and Mission Lake. Both the seven-indicator consensus and 137Cs indicated that channel-bank sources were dominant for Perry Lake and that channel-bank sources increased in importance with distance

Currents trends in the application of IBA techniques to air pollution source fingerprinting and source apportionment

International Nuclear Information System (INIS)

Cohen, David; Stelcer, Ed.; Atanacio, Armand; Crawford, Jagoda

2013-01-01

Full text: IBA techniques have been used for many years to characterise fine particle air pollution. This is not new the techniques are well established. Typically 2-3 MeV protons are used to bombard thin filter papers and up to four simultaneous techniques like PIXE, PIGE, RBS and ERDA will be applied to obtain (μg/g) concentrations for elements from hydrogen to lead. Generally low volume samplers are used to sample between 20-30 m 3 of air over a 24 hour period, this together with IBA's sensitivity means that concentrations down to 1 ng/m 3 of air sampled can be readily achieved with only a few minutes of proton irradiation. With these short irradiation times and low sensitivities for a broad range of elements in the periodic table, large numbers of samples can be obtained and analysed very quickly and easily. At ANSTO we have used IBA methods to acquire a database of over 50,000 filters from 85 different sites through Australia and Asia, each filter has been analysed for more than 21 different chemical species. Large databases extending over many years means that modern statistical techniques like positive matrix factorisation (PMF) can be used to define well characterised source fingerprints and source contributions for a range of different fine particle air pollutants. In this paper we will discuss these PMF techniques and show how they identify both natural sources like sea spray and windblown soils as well as anthropogenic sources like automobiles, biomass burning, coal-fired power stations and industrial emissions. These data are particularly useful for Governments, EPA's and managers of pollution to better understanding pollution sources and their relative contributions and hence to better manage air pollution. Current trends are to take these IBA and PMF techniques a step further and to combine them with wind speed and back trajectory data to better pin point and identify emission sources. We show how this is now being applied on both a local

Currents trends in the application of IBA techniques to air pollution source fingerprinting and source apportionment

Energy Technology Data Exchange (ETDEWEB)

Cohen, David; Stelcer, Ed.; Atanacio, Armand; Crawford, Jagoda [Australian Nuclear Science and Technology Organisation, Kirrawee DC (Australia)

2013-07-01

Full text: IBA techniques have been used for many years to characterise fine particle air pollution. This is not new the techniques are well established. Typically 2-3 MeV protons are used to bombard thin filter papers and up to four simultaneous techniques like PIXE, PIGE, RBS and ERDA will be applied to obtain (μg/g) concentrations for elements from hydrogen to lead. Generally low volume samplers are used to sample between 20-30 m{sup 3} of air over a 24 hour period, this together with IBA's sensitivity means that concentrations down to 1 ng/m{sup 3} of air sampled can be readily achieved with only a few minutes of proton irradiation. With these short irradiation times and low sensitivities for a broad range of elements in the periodic table, large numbers of samples can be obtained and analysed very quickly and easily. At ANSTO we have used IBA methods to acquire a database of over 50,000 filters from 85 different sites through Australia and Asia, each filter has been analysed for more than 21 different chemical species. Large databases extending over many years means that modern statistical techniques like positive matrix factorisation (PMF) can be used to define well characterised source fingerprints and source contributions for a range of different fine particle air pollutants. In this paper we will discuss these PMF techniques and show how they identify both natural sources like sea spray and windblown soils as well as anthropogenic sources like automobiles, biomass burning, coal-fired power stations and industrial emissions. These data are particularly useful for Governments, EPA's and managers of pollution to better understanding pollution sources and their relative contributions and hence to better manage air pollution. Current trends are to take these IBA and PMF techniques a step further and to combine them with wind speed and back trajectory data to better pin point and identify emission sources. We show how this is now being applied on both

Fine particle magnetic mineralogy of archaeological ceramics

International Nuclear Information System (INIS)

Atkinson, D; King, J A

2005-01-01

This study investigated the magnetic mineralogy of a worldwide collection of archaeological pottery. The mineral types, the mass fractions and the domain states of the constituent magnetic fine particles were elucidated from a range of measurements including magnetic hysteresis behaviour, the acquisition of isothermal remanence, low field susceptibility and thermomagnetic curves. The magnetic mineralogy of most samples was dominated by magnetite. Titanomagnetites with limited titanium substitution and cation deficient magnetites (indicative of low temperature oxidation) were dominant in some samples. Haematite was detected in 53% of the samples, but seldom contributed much to the saturation magnetization. Magnetic particle sizes are skewed to smaller sizes, with sherds mostly having a large superparamagnetic or a stable single domain fraction. Low temperature susceptibility data suggest that 30% of samples had some multidomain component. The percentage by mass of magnetic material in the ancient pottery studied was less than 0.8% for all but one of the samples and the majority of samples contain less than 0.3% by weight of magnetic fine particles. The presence of low temperature oxidation in many samples and the occurrence of a multidomain component in a third of the collection suggest that ancient pottery may not always be suitable for determining the intensity of the ancient geomagnetic field

Fine particulates over South Asia: Review and meta-analysis of PM2.5 source apportionment through receptor model.

Science.gov (United States)

Singh, Nandita; Murari, Vishnu; Kumar, Manish; Barman, S C; Banerjee, Tirthankar

2017-04-01

Fine particulates (PM 2.5 ) constitute dominant proportion of airborne particulates and have been often associated with human health disorders, changes in regional climate, hydrological cycle and more recently to food security. Intrinsic properties of particulates are direct function of sources. This initiates the necessity of conducting a comprehensive review on PM 2.5 sources over South Asia which in turn may be valuable to develop strategies for emission control. Particulate source apportionment (SA) through receptor models is one of the existing tool to quantify contribution of particulate sources. Review of 51 SA studies were performed of which 48 (94%) were appeared within a span of 2007-2016. Almost half of SA studies (55%) were found concentrated over few typical urban stations (Delhi, Dhaka, Mumbai, Agra and Lahore). Due to lack of local particulate source profile and emission inventory, positive matrix factorization and principal component analysis (62% of studies) were the primary choices, followed by chemical mass balance (CMB, 18%). Metallic species were most regularly used as source tracers while use of organic molecular markers and gas-to-particle conversion were minimum. Among all the SA sites, vehicular emissions (mean ± sd: 37 ± 20%) emerged as most dominating PM 2.5 source followed by industrial emissions (23 ± 16%), secondary aerosols (22 ± 12%) and natural sources (20 ± 15%). Vehicular emissions (39 ± 24%) also identified as dominating source for highly polluted sites (PM 2.5 >100 μgm -3 , n = 15) while site specific influence of either or in combination of industrial, secondary aerosols and natural sources were recognized. Source specific trends were considerably varied in terms of region and seasonality. Both natural and industrial sources were most influential over Pakistan and Afghanistan while over Indo-Gangetic plain, vehicular, natural and industrial emissions appeared dominant. Influence of vehicular emission was

Use of sediment source fingerprinting to assess the role of subsurface erosion in the supply of fine sediment in a degraded catchment in the Eastern Cape, South Africa.

Science.gov (United States)

Manjoro, Munyaradzi; Rowntree, Kate; Kakembo, Vincent; Foster, Ian; Collins, Adrian L

2017-06-01

Sediment source fingerprinting has been successfully deployed to provide information on the surface and subsurface sources of sediment in many catchments around the world. However, there is still scope to re-examine some of the major assumptions of the technique with reference to the number of fingerprint properties used in the model, the number of model iterations and the potential uncertainties of using more than one sediment core collected from the same floodplain sink. We investigated the role of subsurface erosion in the supply of fine sediment to two sediment cores collected from a floodplain in a small degraded catchment in the Eastern Cape, South Africa. The results showed that increasing the number of individual fingerprint properties in the composite signature did not improve the model goodness-of-fit. This is still a much debated issue in sediment source fingerprinting. To test the goodness-of-fit further, the number of model repeat iterations was increased from 5000 to 30,000. However, this did not reduce uncertainty ranges in modelled source proportions nor improve the model goodness-of-fit. The estimated sediment source contributions were not consistent with the available published data on erosion processes in the study catchment. The temporal pattern of sediment source contributions predicted for the two sediment cores was very different despite the cores being collected in close proximity from the same floodplain. This highlights some of the potential limitations associated with using floodplain cores to reconstruct catchment erosion processes and associated sediment source contributions. For the source tracing approach in general, the findings here suggest the need for further investigations into uncertainties related to the number of fingerprint properties included in un-mixing models. The findings support the current widespread use of ≤5000 model repeat iterations for estimating the key sources of sediment samples. Copyright © 2016 Elsevier

Suspended sediments from upstream tributaries as the source of downstream river sites

Science.gov (United States)

Haddadchi, Arman; Olley, Jon

2014-05-01

Understanding the efficiency with which sediment eroded from different sources is transported to the catchment outlet is a key knowledge gap that is critical to our ability to accurately target and prioritise management actions to reduce sediment delivery. Sediment fingerprinting has proven to be an efficient approach to determine the sources of sediment. This study examines the suspended sediment sources from Emu Creek catchment, south eastern Queensland, Australia. In addition to collect suspended sediments from different sites of the streams after the confluence of tributaries and outlet of the catchment, time integrated suspended samples from upper tributaries were used as the source of sediment, instead of using hillslope and channel bank samples. Totally, 35 time-integrated samplers were used to compute the contribution of suspended sediments from different upstream waterways to the downstream sediment sites. Three size fractions of materials including fine sand (63-210 μm), silt (10-63 μm) and fine silt and clay (<10 μm) were used to find the effect of particle size on the contribution of upper sediments as the sources of sediment after river confluences. And then samples were analysed by ICP-MS and -OES to find 41 sediment fingerprints. According to the results of Student's T-distribution mixing model, small creeks in the middle and lower part of the catchment were major source in different size fractions, especially in silt (10-63 μm) samples. Gowrie Creek as covers southern-upstream part of the catchment was a major contributor at the outlet of the catchment in finest size fraction (<10 μm) Large differences between the contributions of suspended sediments from upper tributaries in different size fractions necessitate the selection of appropriate size fraction on sediment tracing in the catchment and also major effect of particle size on the movement and deposition of sediments.

LibCPIXE: A PIXE simulation open-source library for multilayered samples

International Nuclear Information System (INIS)

Pascual-Izarra, C.; Barradas, N.P.; Reis, M.A.

2006-01-01

Most particle induced X-ray emission (PIXE) data analysis codes are not focused on handling multilayered samples. We have developed an open-source library called 'LibCPIXE', for PIXE data analysis. It is written in standard C and implements functions for simulating X-ray yields of PIXE spectra taken from arbitrary samples, including multilayered targets. The library is designed to be fast, portable, modular and scalable, as well as to facilitate its incorporation into any existing program. In order to demonstrate the capabilities of the library, a program called CPIXE was developed and used to analyze various real samples involving both bulk and layered samples. Just as the library, the CPIXE source code is freely available under the General Public License. We demonstrate that it runs both under GNU/Linux systems as well as under MS Windows. There is in principle no limitation to port it to other platforms

Sources of variability in collection and preparation of paint and lead-coating samples.

Science.gov (United States)

Harper, S L; Gutknecht, W F

2001-06-01

Chronic exposure of children to lead (Pb) can result in permanent physiological impairment. Since surfaces coated with lead-containing paints and varnishes are potential sources of exposure, it is extremely important that reliable methods for sampling and analysis be available. The sources of variability in the collection and preparation of samples were investigated to improve the performance and comparability of methods and to ensure that data generated will be adequate for its intended use. Paint samples of varying sizes (areas and masses) were collected at different locations across a variety of surfaces including metal, plaster, concrete, and wood. A variety of grinding techniques were compared. Manual mortar and pestle grinding for at least 1.5 min and mechanized grinding techniques were found to generate similar homogenous particle size distributions required for aliquots as small as 0.10 g. When 342 samples were evaluated for sample weight loss during mortar and pestle grinding, 4% had 20% or greater loss with a high of 41%. Homogenization and sub-sampling steps were found to be the principal sources of variability related to the size of the sample collected. Analysis of samples from different locations on apparently identical surfaces were found to vary by more than a factor of two both in Pb concentration (mg cm-2 or %) and areal coating density (g cm-2). Analyses of substrates were performed to determine the Pb remaining after coating removal. Levels as high as 1% Pb were found in some substrate samples, corresponding to more than 35 mg cm-2 Pb. In conclusion, these sources of variability must be considered in development and/or application of any sampling and analysis methodologies.

An alternative subspace approach to EEG dipole source localization

Science.gov (United States)

Xu, Xiao-Liang; Xu, Bobby; He, Bin

2004-01-01

In the present study, we investigate a new approach to electroencephalography (EEG) three-dimensional (3D) dipole source localization by using a non-recursive subspace algorithm called FINES. In estimating source dipole locations, the present approach employs projections onto a subspace spanned by a small set of particular vectors (FINES vector set) in the estimated noise-only subspace instead of the entire estimated noise-only subspace in the case of classic MUSIC. The subspace spanned by this vector set is, in the sense of principal angle, closest to the subspace spanned by the array manifold associated with a particular brain region. By incorporating knowledge of the array manifold in identifying FINES vector sets in the estimated noise-only subspace for different brain regions, the present approach is able to estimate sources with enhanced accuracy and spatial resolution, thus enhancing the capability of resolving closely spaced sources and reducing estimation errors. The present computer simulations show, in EEG 3D dipole source localization, that compared to classic MUSIC, FINES has (1) better resolvability of two closely spaced dipolar sources and (2) better estimation accuracy of source locations. In comparison with RAP-MUSIC, FINES' performance is also better for the cases studied when the noise level is high and/or correlations among dipole sources exist.

An alternative subspace approach to EEG dipole source localization

International Nuclear Information System (INIS)

Xu Xiaoliang; Xu, Bobby; He Bin

2004-01-01

In the present study, we investigate a new approach to electroencephalography (EEG) three-dimensional (3D) dipole source localization by using a non-recursive subspace algorithm called FINES. In estimating source dipole locations, the present approach employs projections onto a subspace spanned by a small set of particular vectors (FINES vector set) in the estimated noise-only subspace instead of the entire estimated noise-only subspace in the case of classic MUSIC. The subspace spanned by this vector set is, in the sense of principal angle, closest to the subspace spanned by the array manifold associated with a particular brain region. By incorporating knowledge of the array manifold in identifying FINES vector sets in the estimated noise-only subspace for different brain regions, the present approach is able to estimate sources with enhanced accuracy and spatial resolution, thus enhancing the capability of resolving closely spaced sources and reducing estimation errors. The present computer simulations show, in EEG 3D dipole source localization, that compared to classic MUSIC, FINES has (1) better resolvability of two closely spaced dipolar sources and (2) better estimation accuracy of source locations. In comparison with RAP-MUSIC, FINES' performance is also better for the cases studied when the noise level is high and/or correlations among dipole sources exist

Characterization of urban aerosol sources in Debrecen, Hungary

International Nuclear Information System (INIS)

Kertesz, Zs.; Szoboszlai, T.; Angyal, A.; Dobos, E.; Borbely-Kiss, I.

2009-01-01

Complete text of publication follows. Aerosol pollution represents significant health hazard in urban environments. Despite the fact that Debrecen has not a much stressed environment the city is highly exposed to aerosol pollution. In order to evaluate the impact of aerosol particles on health, the knowledge of the particle size distribution, chemical composition, sources, and their change in time and space is needed. This work presents a source apportionment study of fine (particles with aerodynamic diameter less than 2.5 μm) and coarse (particles with aerodynamic diameter between 2.5 and 10 μm) particulate matter in Debrecen by following the evolution of the elemental components with hourly time resolution. The variation of the elemental concentrations, their periodicity, correlation with other elements and meteorological parameters were studied on samples collected in different seasons. Aerosol sources were determined using the positive matrix factorization (PMF) method. Aerosol samples were collected in the garden of the ATOMKI with a 2-stage sequential streaker sampler manufactured by PIXE International, which collected the fine and coarse fraction separately with few hours' time resolution. Between October 2007 and January 2009 five 10-days long sampling campaigns were carried out. The elemental composition was determined by Particle Induced X-ray emission (PIXE) for Z ≥ 13, and the elemental carbon (BC) content was estimated with a smoke stain reflectometer. Source apportionment was carried out with the PMF receptor model developed for aerosol source characterization, provided by US EPA. Mass of species apportioned to factor, percentage of species apportioned to factors and average factor contributions of the campaigns, of working days and weekends and within the days were calculated. The PMF analysis resulted seven factors in the fine and seven factors in the coarse mode. The main sources of atmospheric aerosol in the city of Debrecen were traffic

A systematic examination of a random sampling strategy for source apportionment calculations.

Science.gov (United States)

Andersson, August

2011-12-15

Estimating the relative contributions from multiple potential sources of a specific component in a mixed environmental matrix is a general challenge in diverse fields such as atmospheric, environmental and earth sciences. Perhaps the most common strategy for tackling such problems is by setting up a system of linear equations for the fractional influence of different sources. Even though an algebraic solution of this approach is possible for the common situation with N+1 sources and N source markers, such methodology introduces a bias, since it is implicitly assumed that the calculated fractions and the corresponding uncertainties are independent of the variability of the source distributions. Here, a random sampling (RS) strategy for accounting for such statistical bias is examined by investigating rationally designed synthetic data sets. This random sampling methodology is found to be robust and accurate with respect to reproducibility and predictability. This method is also compared to a numerical integration solution for a two-source situation where source variability also is included. A general observation from this examination is that the variability of the source profiles not only affects the calculated precision but also the mean/median source contributions. Copyright © 2011 Elsevier B.V. All rights reserved.

Tracing catchment fine sediment sources using the new SIFT (SedIment Fingerprinting Tool) open source software.

Science.gov (United States)

Pulley, S; Collins, A L

2018-09-01

The mitigation of diffuse sediment pollution requires reliable provenance information so that measures can be targeted. Sediment source fingerprinting represents one approach for supporting these needs, but recent methodological developments have resulted in an increasing complexity of data processing methods rendering the approach less accessible to non-specialists. A comprehensive new software programme (SIFT; SedIment Fingerprinting Tool) has therefore been developed which guides the user through critical data analysis decisions and automates all calculations. Multiple source group configurations and composite fingerprints are identified and tested using multiple methods of uncertainty analysis. This aims to explore the sediment provenance information provided by the tracers more comprehensively than a single model, and allows for model configurations with high uncertainties to be rejected. This paper provides an overview of its application to an agricultural catchment in the UK to determine if the approach used can provide a reduction in uncertainty and increase in precision. Five source group classifications were used; three formed using a k-means cluster analysis containing 2, 3 and 4 clusters, and two a-priori groups based upon catchment geology. Three different composite fingerprints were used for each classification and bi-plots, range tests, tracer variability ratios and virtual mixtures tested the reliability of each model configuration. Some model configurations performed poorly when apportioning the composition of virtual mixtures, and different model configurations could produce different sediment provenance results despite using composite fingerprints able to discriminate robustly between the source groups. Despite this uncertainty, dominant sediment sources were identified, and those in close proximity to each sediment sampling location were found to be of greatest importance. This new software, by integrating recent methodological developments in

Quantifying the sources of ozone, fine particulate matter, and regional haze in the Southeastern United States.

Science.gov (United States)

Odman, M Talat; Hu, Yongtao; Russell, Armistead G; Hanedar, Asude; Boylan, James W; Brewer, Patricia F

2009-07-01

A detailed sensitivity analysis was conducted to quantify the contributions of various emission sources to ozone (O3), fine particulate matter (PM2.5), and regional haze in the Southeastern United States. O3 and particulate matter (PM) levels were estimated using the Community Multiscale Air Quality (CMAQ) modeling system and light extinction values were calculated from modeled PM concentrations. First, the base case was established using the emission projections for the year 2009. Then, in each model run, SO2, primary carbon (PC), NH3, NO(x) or VOC emissions from a particular source category in a certain geographic area were reduced by 30% and the responses were determined by calculating the difference between the results of the reduced emission case and the base case. The sensitivity of summertime O3 to VOC emissions is small in the Southeast and ground-level NO(x) controls are generally more beneficial than elevated NO(x) controls (per unit mass of emissions reduced). SO2 emission reduction is the most beneficial control strategy in reducing summertime PM2.5 levels and improving visibility in the Southeast and electric generating utilities are the single largest source of SO2. Controlling PC emissions can be very effective locally, especially in winter. Reducing NH3 emissions is an effective strategy to reduce wintertime ammonium nitrate (NO3NH4) levels and improve visibility; NO(x) emissions reductions are not as effective. The results presented here will help the development of specific emission control strategies for future attainment of the National Ambient Air Quality Standards in the region.

A comparison of four gravimetric fine particle sampling methods.

Science.gov (United States)

Yanosky, J D; MacIntosh, D L

2001-06-01

A study was conducted to compare four gravimetric methods of measuring fine particle (PM2.5) concentrations in air: the BGI, Inc. PQ200 Federal Reference Method PM2.5 (FRM) sampler; the Harvard-Marple Impactor (HI); the BGI, Inc. GK2.05 KTL Respirable/Thoracic Cyclone (KTL); and the AirMetrics MiniVol (MiniVol). Pairs of FRM, HI, and KTL samplers and one MiniVol sampler were collocated and 24-hr integrated PM2.5 samples were collected on 21 days from January 6 through April 9, 2000. The mean and standard deviation of PM2.5 levels from the FRM samplers were 13.6 and 6.8 microg/m3, respectively. Significant systematic bias was found between mean concentrations from the FRM and the MiniVol (1.14 microg/m3, p = 0.0007), the HI and the MiniVol (0.85 microg/m3, p = 0.0048), and the KTL and the MiniVol (1.23 microg/m3, p = 0.0078) according to paired t test analyses. Linear regression on all pairwise combinations of the sampler types was used to evaluate measurements made by the samplers. None of the regression intercepts was significantly different from 0, and only two of the regression slopes were significantly different from 1, that for the FRM and the MiniVol [beta1 = 0.91, 95% CI (0.83-0.99)] and that for the KTL and the MiniVol [beta1 = 0.88, 95% CI (0.78-0.98)]. Regression R2 terms were 0.96 or greater between all pairs of samplers, and regression root mean square error terms (RMSE) were 1.65 microg/m3 or less. These results suggest that the MiniVol will underestimate measurements made by the FRM, the HI, and the KTL by an amount proportional to PM2.5 concentration. Nonetheless, these results indicate that all of the sampler types are comparable if approximately 10% variation on the mean levels and on individual measurement levels is considered acceptable and the actual concentration is within the range of this study (5-35 microg/m3).

Source identification and metallic profiles of size-segregated particulate matters at various sites in Delhi.

Science.gov (United States)

Hazarika, Naba; Jain, V K; Srivastava, Arun

2015-09-01

A study of elemental composition in the ambient air of Delhi was carried out in the monsoon, winter and summer seasons at four different sites from August 2012 to April 2013 in the size ranges 10 μm using "Dekati PM10" impactor. At each site, three samples were collected and were analyzed by energy-dispersive X-ray fluorescence (EDXRF). The presence of elements was found to be very common and highly concentrated in aerosol particles at all the sites, which are Na, Al, Si, K, Ca, Zn and Ba. Total suspended particulate matters (TSPMs) of fine particles were found high in comparison to coarse particles at all seasons. The TSPM of fine particles was found to be varied in the range from 303.6 to 416.2 μg/m(3). Similarly, the range of coarse TSPM was observed from 162.9 to 262.8 μg/m(3). Correlation matrices were observed between fine (size ranges 10 μm) size particles for all elements with seasons. Source apportionments of elements were carried out using MS Excel 2010 through XLSTAT software. The source apportionments between fine and coarse particles were carried out through factor analysis and dominated sources found to be crustal re-suspension and industrial activities.

Sources of carbonaceous aerosol in the Amazon basin

Directory of Open Access Journals (Sweden)

S. Gilardoni

2011-03-01

Full Text Available The quantification of sources of carbonaceous aerosol is important to understand their atmospheric concentrations and regulating processes and to study possible effects on climate and air quality, in addition to develop mitigation strategies.

In the framework of the European Integrated Project on Aerosol Cloud Climate Interactions (EUCAARI fine (D_p < 2.5 μm and coarse (2.5 μm < D_p <10 μm aerosol particles were sampled from February to June (wet season and from August to September (dry season 2008 in the central Amazon basin. The mass of fine particles averaged 2.4 μg m⁻³ during the wet season and 4.2 μg m⁻³ during the dry season. The average coarse aerosol mass concentration during wet and dry periods was 7.9 and 7.6 μg m⁻³, respectively. The overall chemical composition of fine and coarse mass did not show any seasonality with the largest fraction of fine and coarse aerosol mass explained by organic carbon (OC; the average OC to mass ratio was 0.4 and 0.6 in fine and coarse aerosol modes, respectively. The mass absorbing cross section of soot was determined by comparison of elemental carbon and light absorption coefficient measurements and it was equal to 4.7 m² g⁻¹ at 637 nm. Carbon aerosol sources were identified by Positive Matrix Factorization (PMF analysis of thermograms: 44% of fine total carbon mass was assigned to biomass burning, 43% to secondary organic aerosol (SOA, and 13% to volatile species that are difficult to apportion. In the coarse mode, primary biogenic aerosol particles (PBAP dominated the carbonaceous aerosol mass. The results confirmed the importance of PBAP in forested areas.

The source apportionment results were employed to evaluate the ability of global chemistry transport models to simulate carbonaceous aerosol sources in a regional tropical background site. The comparison showed an overestimation

Predictors of indoor fine particulate matter in infants' bedrooms in Denmark.

Science.gov (United States)

Raaschou-Nielsen, Ole; Sørensen, Mette; Hertel, Ole; Chawes, Bo L K; Vissing, Nadja; Bønnelykke, Klaus; Bisgaard, Hans

2011-01-01

Particulate matter (PM) in ambient air is responsible for adverse health effects in adults and children. Relatively little is known about the concentrations, sources and health effects of PM in indoor air. To identify sources of fine PM in infants' bedrooms. We conducted 1122 measurements of fine PM (PM(2.5) and black smoke) in the bedrooms of 389 infants and registered indoor activities and characteristics of the house. We used mixed models to identify and quantify associations between predictors and concentrations. The concentration of PM(2.5) was 2.8 times (95% confidence interval [CI], 1.4-5.5 times) higher in houses where people smoked; the concentration increased by 19% (95% CI, 15-23%) per doubling of the amount of tobacco smoked and decreased by 16% (95% CI, 9-27%) per 5-m increase in the distance between the smoking area and the infant's bedroom. Frying without a range hood was associated with a 32% (95% CI, 12-54%) higher PM(2.5) concentration per time per day, whereas frying with use of a range hood did not increase the concentration in the infant's bedroom. Use of a fireplace, stove, candles or vacuum-cleaner, interior rebuilding or renovation, local traffic, inner city residence and cold season increased the fine PM concentration. Open windows decreased the PM(2.5) concentration in homes with smokers but increased the concentration in non-smoking homes. We identified several sources of fine PM in infants' bedrooms. The concentrations can be reduced by use of a range hood for frying, by not using candles, a fireplace or a stove, by increasing the distance between the bedroom and the smoking area and by opening windows in houses of smokers. Smoking is a strong predictor of fine PM in infants' bedrooms and should be avoided. Copyright © 2010 Elsevier Inc. All rights reserved.

Two Model-Based Methods for Policy Analyses of Fine Particulate Matter Control in China: Source Apportionment and Source Sensitivity

Science.gov (United States)

Li, X.; Zhang, Y.; Zheng, B.; Zhang, Q.; He, K.

2013-12-01

Anthropogenic emissions have been controlled in recent years in China to mitigate fine particulate matter (PM2.5) pollution. Recent studies show that sulfate dioxide (SO2)-only control cannot reduce total PM2.5 levels efficiently. Other species such as nitrogen oxide, ammonia, black carbon, and organic carbon may be equally important during particular seasons. Furthermore, each species is emitted from several anthropogenic sectors (e.g., industry, power plant, transportation, residential and agriculture). On the other hand, contribution of one emission sector to PM2.5 represents contributions of all species in this sector. In this work, two model-based methods are used to identify the most influential emission sectors and areas to PM2.5. The first method is the source apportionment (SA) based on the Particulate Source Apportionment Technology (PSAT) available in the Comprehensive Air Quality Model with extensions (CAMx) driven by meteorological predictions of the Weather Research and Forecast (WRF) model. The second method is the source sensitivity (SS) based on an adjoint integration technique (AIT) available in the GEOS-Chem model. The SA method attributes simulated PM2.5 concentrations to each emission group, while the SS method calculates their sensitivity to each emission group, accounting for the non-linear relationship between PM2.5 and its precursors. Despite their differences, the complementary nature of the two methods enables a complete analysis of source-receptor relationships to support emission control policies. Our objectives are to quantify the contributions of each emission group/area to PM2.5 in the receptor areas and to intercompare results from the two methods to gain a comprehensive understanding of the role of emission sources in PM2.5 formation. The results will be compared in terms of the magnitudes and rankings of SS or SA of emitted species and emission groups/areas. GEOS-Chem with AIT is applied over East Asia at a horizontal grid

Winter fine particulate air quality in Cranbrook, British Columbia, 1973 to 1999

International Nuclear Information System (INIS)

McDonald, L.E.

2001-06-01

Fine particulate levels in Cranbrook, BC, are analyzed and reported based on monitoring records which began in 1973. Prior to 1988 the sampler collected all particle sizes, but was subsequently replaced with a selective size inlet to capture only PM 1 0 particles or smaller. A mathematical relationship was produced and used to convert historical total suspended particulates measurements to PM 1 0. It was determined that only monitoring records obtained during the winter months could be reliably converted in this fashion; however, that was not a problem since the winter months happen to correspond to the highest levels of fine particulates. Results of the analysis showed increased levels of PM 1 0 from the early 1970s to the early 1980s; during this time average and maximum annual PM 1 0 levels in Cranbrook were higher than those in Los Angeles in 1999. Winter PM 1 0 levels began to fall through the late 1980s and early 1990s. The lowest average and maximum (18 microgram/cubic metre and 47 microgram/cubic metre, respectively) was recorded in the winter of 1996/1997. Worst conditions were recorded in 1980/1981 when 15 of 21 samples exceeded the current provincial PM 1 0 air quality objective of 50 microgram/cubic metre. In the five winters between 1994/1995 and 1998/1999 only three of 109 samples exceeded the provincial objective. There appears to be no correlation between known changes in industrial and mobile sources of pollutants and historical patterns of fine particulate air pollution in Cranbrook, BC. Observation and experience over three decades suggest that the major source of PM 1 0 in Cranbrook was combustion of wood for home heating. The most probable major cause of the improvements in winter air quality was identified as the gradual conversion from wood to natural gas fired appliances through the 1980s and the 1990s. The 115 per cent increase in the cost of natural gas in the last two years unfortunately, will again make wood an attractive alternative

Interaction of fine sediment with alluvial streambeds

Science.gov (United States)

Jobson, Harvey E.; Carey, William P.

1989-01-01

More knowledge is needed about the physical processes that control the transport of fine sediment moving over an alluvial bed. The knowledge is needed to design rational sampling and monitoring programs that assess the transport and fate of toxic substances in surface waters because the toxics are often associated with silt- and clay-sized particles. This technical note reviews some of the past research in areas that may contribute to an increased understanding of the processes involved. An alluvial streambed can have a large capacity to store fine sediments that are extracted from the flow when instream concentrations are high and it can gradually release fine sediment to the flow when the instream concentrations are low. Several types of storage mechanisms are available depending on the relative size distribution of the suspended load and bed material, as well as the flow hydraulics. Alluvial flow tends to segregate the deposited material according to size and density. Some of the storage locations are temporary, but some can store the fine sediment for very long periods of time.

SOURCE SIGNATURES OF FINE PARTICULATE MATTER FROM PETROLEUM REFINING AND FUEL USE

Energy Technology Data Exchange (ETDEWEB)

Gerald P. Huffman; Frank E. Huggins; Naresh Shah; Artur Braun; Yuanzhi Chen; J. David Robertson; Joseph Kyger; Adel F. Sarofim; Ronald J. Pugmire; Henk L.C. Meuzelaar; JoAnn Lighty

2003-07-31

The molecular structure and microstructure of a suite of fine particulate matter (PM) samples produced by the combustion of residual fuel oil and diesel fuel were investigated by an array of analytical techniques. Some of the more important results are summarized below. Diesel PM (DPM): A small diesel engine test facility was used to generate a suite of diesel PM samples from different fuels under engine load and idle conditions. C XANES, {sup 13}C NMR, XRD, and TGA were in accord that the samples produced under engine load conditions contained more graphitic material than those produced under idle conditions, which contained a larger amount of unburned diesel fuel and lubricating oil. The difference was enhanced by the addition of 5% of oxygenated compounds to the reference fuel. Scanning transmission x-ray micro-spectroscopy (STXM) was able to distinguish particulate regions rich in C=C bonds from regions rich in C-H bonds with a resolution of {approx}50 nm. The former are representative of more graphitic regions and the latter of regions rich in unburned fuel and oil. The dominant microstructure observed by SEM and TEM consisted of complex chain-like structures of PM globules {approx}20-100 nm in mean diameter, with a high fractal dimension. High resolution TEM revealed that the graphitic part of the diesel soot consisted of onion-like structures made up of graphene layers. Typically 3-10 graphene layers make up the ''onion rings'', with the layer spacing decreasing as the number of layers increases. ROFA PM: Residual oil fly ash (ROFA) PM has been analyzed by a new approach that combines XAFS spectroscopy with selective leaching procedures. ROFA PM{sub 2.5} and PM{sub 2.5+} produced in combustion facilities at the U.S. EPA National Risk Management Research Laboratory (NRML) were analyzed by XAFS before and after leaching with water, acid (1N HCl), and pentane. Both water and acid leaching removed most of the metal sulfates, which were the

The application of IBA techniques to air pollution source fingerprinting and source apportionment

Energy Technology Data Exchange (ETDEWEB)

Cohen, D.D., E-mail: dcz@ansto.gov.au; Stelcer, E.; Atanacio, A.; Crawford, J.

2014-01-01

IBA techniques have been used to measure elemental concentrations of more than 20 different elements found in fine particle (PM2.5) air pollution. These data together with their errors and minimum detectable limits were used in Positive Matrix Factorisation (PMF) analyses to quantitatively determine source fingerprints and their contributions to the total measured fine mass. Wind speed and direction back trajectory data from the global HYSPLIT codes were then linked to these PMF fingerprints to quantitatively identify the location of the sources.

Relativistic rise measurements with very fine sampling intervals

International Nuclear Information System (INIS)

Ludlam, T.; Platner, E.D.; Polychronakos, V.A.; Lindenbaum, S.J.; Kramer, M.A.; Teramoto, Y.

1980-01-01

The motivation of this work was to determine whether the technique of charged particle identification via the relativistic rise in the ionization loss can be significantly improved by virtue of very small sampling intervals. A fast-sampling ADC and a longitudinal drift geometry were used to provide a large number of samples from a single drift chamber gap, achieving sampling intervals roughly 10 times smaller than any previous study. A single layer drift chamber was used, and tracks of 1 meter length were simulated by combining together samples from many identified particles in this detector. These data were used to study the resolving power for particle identification as a function of sample size, averaging technique, and the number of discrimination levels (ADC bits) used for pulse height measurements

Occurrence of organic pollutants in recovered soil fines from construction and demolition waste.

Science.gov (United States)

Jang, Y C; Townsend, T G

2001-01-01

The objective of this study was to characterize recovered soil fines from construction and demolition (C&D) waste recycling facilities for trace organic pollutants. Over a period of 18 months, five sampling trips were made to 14 C&D waste recycling facilities in Florida. Screened soil fines were collected from older stockpiles and newly generated piles at the sites. The samples were analyzed for the total concentration (mg/kg) of a series of volatile organic compound (VOCs) and semi-volatile organic compounds (semi-VOCs). The synthetic precipitation leaching procedure (SPLP) test was also performed to evaluate the leachability of the trace organic chemicals. During the total analysis only a few volatile organic compounds were commonly found in the samples (trichlorofluoromethane, toluene, 4-isopropyltoluene, trimethylbenzene, xylenes, and methylene chloride). A total of nine VOCs were detected in the leaching test. Toluene showed the highest leachability among the compounds (61.3-92.0%), while trichlorofluoromethane, the most commonly detected compound from both the total and leaching tests, resulted in the lowest leachability (1.4-39.9%). For the semi-VOC analysis, three base-neutral semi-VOC compounds (bis(2-ethylhexyl)phthalate, butyl benzyl phthalate, and di-n-butyl phthalate) and several PAHs (acenaphthene, pyrene, fluoranthene, and phenanthrene) were commonly detected in C&D fines samples. These compounds also leached during the SPLP leaching test (0.1-25%). No acid extractable compounds, pesticides, or PCBs were detected. The results of this study were further investigated to assess risk from land applied recovered soil fines by comparing total and leaching concentrations of recovered soil fines samples to risk-based standards. The results of this indicate that the organic chemicals in recovered soil fines from C&D debris recycling facilities were not of a major concern in terms of human risk and leaching risk to groundwater under reuse and contact scenarios.

Fine and coarse components in surface sediments from Bikini Lagoon

Energy Technology Data Exchange (ETDEWEB)

Noshkin, V. E., LLNL

1997-01-01

In 1979, 21 years after the moratorium on nuclear testing in the Marshall Islands, surface sediment samples (to depths of 2 and 4 cm) were collected from 87 locations in the lagoon of Bikini Atoll, one of the two sites in the Marshall Islands used by the United States to test nuclear devices from 1946 through 1958. The main purpose for the collections was to map the distribution of long-lived man-made radionuclides associated with the bottom material. In addition the samples were processed to estimate the fraction of fine and coarse components to show, by comparison, what modifications occurred in the composition since the sediments were first described in samples collected before testing in 1946. Nuclear testing produced more finely divided material that is now found in the surface sediment layer over large areas of the lagoon and especially in regions of the lagoon and reef adjacent to test sites. The 5 cratering events alone at Bikini Atoll redistributed sufficient material to account for the higher inventory of fine material found over the surface 4 cm of the sediment of the lagoon. Although the fraction of fine material in the bottom sediments was altered by the nuclear events, the combined processes of formation, transport and deposition were not sufficiently dynamic to greatly change the general geographical features of the major sedimentary components over most of the lagoon floor.

A primary assessment of a daybreak 2200 OSL reader using fine grain quartz and CaSO4:Tm TLD

International Nuclear Information System (INIS)

Zhang Keqi; Chen Jie; Lu Yanchou; Wang Changsheng; Yang Chuancheng

2007-01-01

Daybreak 2200 OSL readers are widely used for luminescence dating applications. As the sample irradiation and illumination may affect discs in adjacent positions, it is critical to confirm that these factors do not introduce significant systematic errors. Effects of cross-irradiation and cross-bleaching were examined and quantified using fine-grain quartz and highly sensitive CaSO 4 :Tm dosimeters, and the irradiation offset time was measured. The cross-bleaching effect on adjacent aliquots is non-linear with no more than 15% OSL signal reduction following 10ks illumination with the power of blue LED being at 95% maximum. But at positions other than the nearest neighboring sample, almost no effect of cross-bleaching was found. The cross-talk dose, even to the nearest samples, was about 0.02% of the applied dose, and it decreased with increasing distance from the source. Offset time of the built-in Beta source shutter is 0.22 s, which can be neglected in regular dating, and leak dose of the source can be ignored as well. Finally, measurement consistency at Position 0.5, 10, ..... and 55 of the sample tray is better than 3% in relative standard deviation. (authors)

Device for the analysis of fine dusts

International Nuclear Information System (INIS)

Riemer, F.; Tausch, W.; Torge, R.

1978-01-01

The invention deals with a device that brings graphite bulbs containing samples of fine dusts automatically to the spectrometer for analysis and transports them away afterwards, a great number of individual measurements thus being quickly performed. The device consists of magazines, means of transport for them etc., and, if necessary, also a furnace for thermal preparation of the samples. (RW) 891 RW/RW 892 MKO [de

318-MHz variability of complete samples of extragalactic radio sources. II

International Nuclear Information System (INIS)

Dennison, B.; Broderick, J.J.; Ledden, J.E.; O'Dell, S.L.; Condon, J.J.

1981-01-01

We report the remainder of two- and three-epoch 318-MHz observations of extragalactic sources in samples complete to 3 Jy at 1400 MHz and 1 Jy at 5000 MHz. From analysis of this low-frequency variability survey, we find that steep-spectrum (α> or =0.5) sources do not appear to vary, but about 40% of all flat-spectrum (α<0.5) sources exhibit low-frequency variability exceeding 8% over approx.5 yr. Among the flat-spectrum sources, those with inverted spectra show the largest fractional variations. We also find that the incidence of low-frequency variability is strongly correlated with the determination that a source is an optically violent variable. These statistical properties are consistent with models invoking relativistic beaming of radio and optical emission

Investigation of spectral interferences in the determination of lead in fertilizers and limestone samples using high-resolution continuum source graphite furnace atomic absorption spectrometry

Energy Technology Data Exchange (ETDEWEB)

Borges, Aline R. [Instituto de Química, Universidade Federal do Rio Grande do Sul, Av. Bento Gonçalves 9500, 91501-970 Porto Alegre, RS (Brazil); Instituto Nacional de Ciência e Tecnologia do CNPq — INCT de Energia e Ambiente, Universidade Federal da Bahia, Salvador, BA (Brazil); Becker, Emilene M.; François, Luciane L.; Jesus, Alexandre de [Instituto de Química, Universidade Federal do Rio Grande do Sul, Av. Bento Gonçalves 9500, 91501-970 Porto Alegre, RS (Brazil); Vale, Maria Goreti R. [Instituto de Química, Universidade Federal do Rio Grande do Sul, Av. Bento Gonçalves 9500, 91501-970 Porto Alegre, RS (Brazil); Instituto Nacional de Ciência e Tecnologia do CNPq — INCT de Energia e Ambiente, Universidade Federal da Bahia, Salvador, BA (Brazil); Welz, Bernhard [Instituto Nacional de Ciência e Tecnologia do CNPq — INCT de Energia e Ambiente, Universidade Federal da Bahia, Salvador, BA (Brazil); Departamento de Química, Universidade Federal de Santa Catarina, 88040-900 Florianópolis, SC (Brazil); Dessuy, Morgana B., E-mail: mbdessuy@ufrgs.br [Instituto de Química, Universidade Federal do Rio Grande do Sul, Av. Bento Gonçalves 9500, 91501-970 Porto Alegre, RS (Brazil); Andrade, Jailson B. de [Instituto Nacional de Ciência e Tecnologia do CNPq — INCT de Energia e Ambiente, Universidade Federal da Bahia, Salvador, BA (Brazil)

2014-11-01

In the present work, spectral interferences on the determination of lead in fertilizer and limestone samples were investigated using high-resolution continuum source graphite furnace atomic absorption spectrometry at the main analytical lines: 217.001 and 283.306 nm. For these investigations, samples were introduced into the furnace as slurry together with a mixture of Pd and Mg as chemical modifier. Spectral interferences were observed for some samples at both analytical lines. In order to verify whether a wet digestion procedure would avoid these interferences, a reference method for wet digestion of fertilizers was employed as an alternative sample preparation procedure. However, the same interferences were also observed in the digested samples. In order to identify and eliminate the fine-structured background using a least-squares background correction, reference spectra were generated using the combination of different species. The use of the latter technique allowed the elimination of spectral interferences for most of the investigated samples, making possible the determination of lead in fertilizer and limestone samples free of interferences. The best results were found using a reference spectrum of NH{sub 4}H{sub 2}PO{sub 4} at 217.001 nm, and a mixture of H{sub 2}SO{sub 4} + Ca and HNO{sub 3} + Ca at the 283.306 nm line. The accuracy of the method was evaluated using a certified reference material “Trace Elements in Multi-Nutrient Fertilizer”. Similar results were obtained using line source graphite furnace atomic absorption spectrometry with Zeeman-effect background correction, indicating that the latter technique was also capable to correct the spectral interferences, at least in part. - Highlights: • Spectral interferences on the determination of lead in fertilizers and limestone. • The analytical lines at 217.001 nm and 283.306 nm using HR-CS GF AAS. • Various combinations of compounds were used to create reference spectra. • LSBC

3D source localization of interictal spikes in epilepsy patients with MRI lesions

Science.gov (United States)

Ding, Lei; Worrell, Gregory A.; Lagerlund, Terrence D.; He, Bin

2006-08-01

The present study aims to accurately localize epileptogenic regions which are responsible for epileptic activities in epilepsy patients by means of a new subspace source localization approach, i.e. first principle vectors (FINE), using scalp EEG recordings. Computer simulations were first performed to assess source localization accuracy of FINE in the clinical electrode set-up. The source localization results from FINE were compared with the results from a classic subspace source localization approach, i.e. MUSIC, and their differences were tested statistically using the paired t-test. Other factors influencing the source localization accuracy were assessed statistically by ANOVA. The interictal epileptiform spike data from three adult epilepsy patients with medically intractable partial epilepsy and well-defined symptomatic MRI lesions were then studied using both FINE and MUSIC. The comparison between the electrical sources estimated by the subspace source localization approaches and MRI lesions was made through the coregistration between the EEG recordings and MRI scans. The accuracy of estimations made by FINE and MUSIC was also evaluated and compared by R2 statistic, which was used to indicate the goodness-of-fit of the estimated sources to the scalp EEG recordings. The three-concentric-spheres head volume conductor model was built for each patient with three spheres of different radii which takes the individual head size and skull thickness into consideration. The results from computer simulations indicate that the improvement of source spatial resolvability and localization accuracy of FINE as compared with MUSIC is significant when simulated sources are closely spaced, deep, or signal-to-noise ratio is low in a clinical electrode set-up. The interictal electrical generators estimated by FINE and MUSIC are in concordance with the patients' structural abnormality, i.e. MRI lesions, in all three patients. The higher R2 values achieved by FINE than MUSIC

3D source localization of interictal spikes in epilepsy patients with MRI lesions

International Nuclear Information System (INIS)

Ding Lei; Worrell, Gregory A; Lagerlund, Terrence D; He Bin

2006-01-01

The present study aims to accurately localize epileptogenic regions which are responsible for epileptic activities in epilepsy patients by means of a new subspace source localization approach, i.e. first principle vectors (FINE), using scalp EEG recordings. Computer simulations were first performed to assess source localization accuracy of FINE in the clinical electrode set-up. The source localization results from FINE were compared with the results from a classic subspace source localization approach, i.e. MUSIC, and their differences were tested statistically using the paired t-test. Other factors influencing the source localization accuracy were assessed statistically by ANOVA. The interictal epileptiform spike data from three adult epilepsy patients with medically intractable partial epilepsy and well-defined symptomatic MRI lesions were then studied using both FINE and MUSIC. The comparison between the electrical sources estimated by the subspace source localization approaches and MRI lesions was made through the coregistration between the EEG recordings and MRI scans. The accuracy of estimations made by FINE and MUSIC was also evaluated and compared by R 2 statistic, which was used to indicate the goodness-of-fit of the estimated sources to the scalp EEG recordings. The three-concentric-spheres head volume conductor model was built for each patient with three spheres of different radii which takes the individual head size and skull thickness into consideration. The results from computer simulations indicate that the improvement of source spatial resolvability and localization accuracy of FINE as compared with MUSIC is significant when simulated sources are closely spaced, deep, or signal-to-noise ratio is low in a clinical electrode set-up. The interictal electrical generators estimated by FINE and MUSIC are in concordance with the patients' structural abnormality, i.e. MRI lesions, in all three patients. The higher R 2 values achieved by FINE than MUSIC

Fine Motor Skills and Executive Function Both Contribute to Kindergarten Achievement

Science.gov (United States)

Cameron, Claire E.; Brock, Laura L.; Murrah, William M.; Bell, Lindsay H.; Worzalla, Samantha L.; Grissmer, David; Morrison, Frederick J.

2012-01-01

This study examined the contribution of executive function (EF) and multiple aspects of fine motor skills to achievement on 6 standardized assessments in a sample of middle-socioeconomic status kindergarteners. Three- and 4-year-olds' (n = 213) fine and gross motor skills were assessed in a home visit before kindergarten, EF was measured at fall…

Measuring the gypsum content of C&D debris fines.

Science.gov (United States)

Musson, Stephen E; Xu, Qiyong; Townsend, Timothy G

2008-11-01

Construction and demolition (C&D) debris recycling facilities often produce a screened material intended for use as alternative daily cover (ADC) at active landfills or for shaping and grading at closed landfills. This product contains soil and small pieces of wood, concrete, gypsum drywall, shingles and other components of C&D debris. Concerns have been raised over the contribution of gypsum drywall in C&D debris fines to odor problems at landfills where the product is used. To address such concerns, limitations may be placed on the percentage of gypsum (or sulfate) that can occur, and standardized testing procedures are required to permit valid compliance testing. A test procedure was developed for measuring the gypsum content in C&D debris fines. The concentration of sulfate leached in an aqueous solution was used to estimate the initial gypsum content of the sample. The impact of sample size and leaching time were evaluated. Precision and accuracy increased with increasing gypsum content. Results from replicate samples had an average relative standard deviation of 9%. The gypsum content of fines obtained from different facilities in the US varied widely from 1% to over 25%. These variations not only occurred between differing facilities, but within batches produced within a single facility.

Source apportionment and location by selective wind sampling and Positive Matrix Factorization.

Science.gov (United States)

Venturini, Elisa; Vassura, Ivano; Raffo, Simona; Ferroni, Laura; Bernardi, Elena; Passarini, Fabrizio

2014-10-01

In order to determine the pollution sources in a suburban area and identify the main direction of their origin, PM2.5 was collected with samplers coupled with a wind select sensor and then subjected to Positive Matrix Factorization (PMF) analysis. In each sample, soluble ions, organic carbon, elemental carbon, levoglucosan, metals, and Polycyclic Aromatic Hydrocarbons (PAHs) were determined. PMF results identified six main sources affecting the area: natural gas home appliances, motor vehicles, regional transport, biomass combustion, manufacturing activities, and secondary aerosol. The connection of factor temporal trends with other parameters (i.e., temperature, PM2.5 concentration, and photochemical processes) confirms factor attributions. PMF analysis indicated that the main source of PM2.5 in the area is secondary aerosol. This should be mainly due to regional contributions, owing to both the secondary nature of the source itself and the higher concentration registered in inland air masses. The motor vehicle emission source contribution is also important. This source likely has a prevalent local origin. The most toxic determined components, i.e., PAHs, Cd, Pb, and Ni, are mainly due to vehicular traffic. Even if this is not the main source in the study area, it is the one of greatest concern. The application of PMF analysis to PM2.5 collected with this new sampling technique made it possible to obtain more detailed results on the sources affecting the area compared to a classical PMF analysis.

A hazard to health? Fine particles arouse worldwide interest

Energy Technology Data Exchange (ETDEWEB)

Karas, J; Oesch, P

1998-07-01

The most recent studies show that particles contained in the air that we breathe may have harmful effects on the health of asthmatics, children and old people in particular. Particle material found in ambient air is formed by emissions resulting from traffic, industry and other use of fuels. Nature`s own sources also have a significant effect on particle concentrations. The mechanisms by which fine particles may produce negative health effects are so far unknown. At present it is therefore impossible to assess the effects of emissions of fine particles resulting, for instance, from the use of fossil fuels

A recommended procedure for establishing the source level relationships between heroin case samples of unknown origins

Directory of Open Access Journals (Sweden)

Kar-Weng Chan

2014-06-01

Full Text Available A recent concern of how to reliably establish the source level relationships of heroin case samples is addressed in this paper. Twenty-two trafficking heroin case samples of unknown origins seized from two major regions (Kuala Lumpur and Penang in Malaysia were studied. A procedure containing six major steps was followed to analyze and classify these samples. Subsequently, with the aid of statistical control samples, reliability of the clustering result was assessed. The final outcome reveals that the samples seized from the two regions in 2013 had highly likely originated from two different sources. Hence, the six-step procedure is sufficient for any chemist who attempts to assess the relative source level relationships of heroin samples.

Insights into metals in individual fine particles from municipal solid waste using synchrotron radiation-based micro-analytical techniques.

Science.gov (United States)

Zhu, Yumin; Zhang, Hua; Shao, Liming; He, Pinjing

2015-01-01

Excessive inter-contamination with heavy metals hampers the application of biological treatment products derived from mixed or mechanically-sorted municipal solid waste (MSW). In this study, we investigated fine particles of heavy metal content, using bulk detection techniques. A total of 17 individual fine particles were evaluated using synchrotron radiation-based micro-X-ray fluorescence and micro-X-ray diffraction. We also discussed the association, speciation and source apportionment of heavy metals. Metals were found to exist in a diffuse distribution with heterogeneous intensities and intense hot-spots of metals revealed the potential sources of fine particles from size-reduced waste fractions (such as scraps of organic wastes or ceramics) or from the importation of other particles. The diverse sources of heavy metal pollutants within the fine particles suggested that separate collection and treatment of the biodegradable waste fraction (such as food waste) is a preferable means of facilitating the beneficial utilization of the stabilized products. Copyright © 2014. Published by Elsevier B.V.

Source profiles of particulate matter emissions from a pilot-scale boiler burning North American coal blends.

Science.gov (United States)

Lee, S W

2001-11-01

Recent awareness of suspected adverse health effects from ambient particulate matter (PM) emission has prompted publication of new standards for fine PM with aerodynamic diameter less than 2.5 microm (PM2.5). However, scientific data on fine PM emissions from various point sources and their characteristics are very limited. Source apportionment methods are applied to identify contributions of individual regional sources to tropospheric particulate concentrations. The existing industrial database developed using traditional source measurement techniques provides total emission rates only, with no details on chemical nature or size characteristics of particulates. This database is inadequate, in current form, to address source-receptor relationships. A source dilution system was developed for sampling and characterization of total PM, PM2.5, and PM10 (i.e., PM with aerodynamic diameter less than 10 pm) from residual oil and coal combustion. This new system has automatic control capabilities for key parameters, such as relative humidity (RH), temperature, and sample dilution. During optimization of the prototype equipment, three North American coal blends were burned using a 0.7-megawatt thermal (MWt) pulverized coal-fired, pilot-scale boiler. Characteristic emission profiles, including PM2.5 and total PM soluble acids, and elemental and carbon concentrations for three coal blends are presented. Preliminary results indicate that volatile trace elements such as Pb, Zn, Ti, and Se are preferentially enriched in PM2.5. PM2.5 is also more concentrated in soluble sulfates relative to total PM. Coal fly ash collected at the outlet of the electrostatic precipitator (ESP) contains about 85-90% PM10 and 30-50% PM2.5. Particles contain the highest elemental concentrations of Si and Al while Ca, Fe, Na, Ba, and K also exist as major elements. Approximately 4-12% of the materials exists as soluble sulfates in fly ash generated by coal blends containing 0.2-0.8% sulfur by mass

Characterization and sources of air particulate matter at Kwabenya, near Accra, Ghana

International Nuclear Information System (INIS)

Aboh, I. J. K.

2009-01-01

Gravimetric, reflectometric and elemental analyses have been carried out on airborne particulate matter sampled in a semi-rural area of Kwabenya, near Accra-Ghana. The PM 10 aerosols were sampled using a Gent sampler, size segregating the aerosol into coarse (PM 10-2.5 ) and fine (PM 1.5 ) fractions. The data and derived information were generated from 216 days of sampling spanning a period of about 14 months, 28 th December 2005 to 12 th February 2007. The particulate matter (PM) at Kwabenya was dominated by the coarse particulates and showed low levels during the Rainy season and high levels during the Harmattan period. The levels measured during the 2006/07 Harmattan were very high. The mass concentration for the measuring period were in the following ranges; coarse (PM 10-2.5 ) fraction (0.16 - 1794.01 µg/m 3 ); PM 2.5 (fine) fraction (0.50 - 430.23 µg/m 3 ) and PM 10 (0.87 µg/m 3 to 2064.89 µg/m 3 ). Additional information about the ambient air was obtained through the subsequent determination of elemental concentration using energy dispersive x-ray fluorescence (EDXRF) analysis and black carbon (BC) concentration through the b lack smoke method . The elements identified and quantified with the Quantitative X-ray Analysis System (QXAS) package software were: AI, Si, S, CI, K, Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, Br, Rb, Sr and Pb in the coarse fraction. The following elements were identified and quantified in the fine fraction: AI, Si, S, K, Ca, Ti, Mn, Fe, Cu, Zn, Br, Rb, Sr and Pb. Validation of the quantitative methods with the standard reference filter SRM2783 gave very good agreement (within ± 15%) for most elements analysed except for Ni (±43%)which was very close to the detection limit. The elemental concentrations in the two fractions vary from season to season. Using simple correlation analysis some elements correlate, the elemental correlations also vary from season to season, for example during the Harmattan S, CI, V, Br and Sr correlated very

Fine motor skills in children with Down syndrome

Directory of Open Access Journals (Sweden)

Memišević Haris

2014-01-01

Full Text Available Fine motor skills are very important for children's overall functioning. Their development is necessary for many everyday activities such as dressing, feeding, holding objects, etc. Moreover, fine motor skills are also correlated to the children's academic success at school. Recent research suggests a close relationship between motor skills and intelligence. Given the relative paucity of literature on fine motor skills in different etiological groups of children with intellectual disability (ID, we examined these skills in children with Down syndrome. The sample for this study comprised 90 children with ID, aged 7-15, who were divided in three etiological groups: 1. Down syndrome, 2. Organic/other genetic cause of ID and 3. Unknown etiology of ID. Fine motor skills were assessed by the Purdue Pegboard Test. The results of this study indicate that children with Down syndrome did not differ statistically significantly from the other two etiological groups. On the other hand, children with unknown etiology of ID performed statistically better than children with organic/other genetic cause of ID. An additional goal was to examine fine motor skills in children with Down syndrome in relation to the child's sex. There were no statistically significant differences in fine motor skills between girls and boys with Down syndrome. It is important to provide children with Down syndrome, and all other children with ID, with early (rehabilitation programs for the improvement of their fine motor skills. Special educators and rehabilitators should play a crucial role in the assessment and in creating programs for the development of these skills.

Martian regolith geochemistry and sampling techniques

Science.gov (United States)

Clark, B. C.

Laboratory study of samples of the intermediate and fine-grained regolith, including duricrust peds, is a fundamental prerequisite for understanding the types of physical and chemical weathering processes on Mars. The extraordinary importance of such samples is their relevance to understanding past changes in climate, availability (and possible physical state) of water, eolian forces, the thermal and chemical influences of volcanic and impact processes, and the inventory and fates of Martian volatiles. Fortunately, this regolith material appears to be ubiquitous over the Martian surface, and should be available at many different landing sites. Viking data has been interpreted to indicate a smectite-rich regolith material, implying extensive weathering involving aqueous activity and geochemical alteration. An all-igneous source of the Martian fines has also been proposed. The X-ray fluorescence measurement data set can now be fully explained in terms of a simple two-component model. The first component is silicate, having strong geochemical similarities with Shergottites, but not other SNC meteorites. The second component is salt. Variations in these components could produce silicate and salt-rich beds, the latter being of high potential importance for microenvironments in which liquid water (brines) could exist. It therefore would be desirable to scan the surface of the regolith for such prospects.

Martian regolith geochemistry and sampling techniques

Science.gov (United States)

Clark, B. C.

1988-01-01

Laboratory study of samples of the intermediate and fine-grained regolith, including duricrust peds, is a fundamental prerequisite for understanding the types of physical and chemical weathering processes on Mars. The extraordinary importance of such samples is their relevance to understanding past changes in climate, availability (and possible physical state) of water, eolian forces, the thermal and chemical influences of volcanic and impact processes, and the inventory and fates of Martian volatiles. Fortunately, this regolith material appears to be ubiquitous over the Martian surface, and should be available at many different landing sites. Viking data has been interpreted to indicate a smectite-rich regolith material, implying extensive weathering involving aqueous activity and geochemical alteration. An all-igneous source of the Martian fines has also been proposed. The X-ray fluorescence measurement data set can now be fully explained in terms of a simple two-component model. The first component is silicate, having strong geochemical similarities with Shergottites, but not other SNC meteorites. The second component is salt. Variations in these components could produce silicate and salt-rich beds, the latter being of high potential importance for microenvironments in which liquid water (brines) could exist. It therefore would be desirable to scan the surface of the regolith for such prospects.

Hybrid subgroup decomposition method for solving fine-group eigenvalue transport problems

International Nuclear Information System (INIS)

Yasseri, Saam; Rahnema, Farzad

2014-01-01

Highlights: • An acceleration technique for solving fine-group eigenvalue transport problems. • Coarse-group quasi transport theory to solve coarse-group eigenvalue transport problems. • Consistent and inconsistent formulations for coarse-group quasi transport theory. • Computational efficiency amplified by a factor of 2 using hybrid SGD for 1D BWR problem. - Abstract: In this paper, a new hybrid method for solving fine-group eigenvalue transport problems is developed. This method extends the subgroup decomposition method to efficiently couple a new coarse-group quasi transport theory with a set of fixed-source transport decomposition sweeps to obtain the fine-group transport solution. The advantages of the quasi transport theory are its high accuracy, straight-forward implementation and numerical stability. The hybrid method is analyzed for a 1D benchmark problem characteristic of boiling water reactors (BWR). It is shown that the method reproduces the fine-group transport solution with high accuracy while increasing the computational efficiency up to 12 times compared to direct fine-group transport calculations

Krypton and xenon in lunar fines

Science.gov (United States)

Basford, J. R.; Dragon, J. C.; Pepin, R. O.; Coscio, M. R., Jr.; Murthy, V. R.

1973-01-01

Data from grain-size separates, stepwise-heated fractions, and bulk analyses of 20 samples of fines and breccias from five lunar sites are used to define three-isotope and ordinate intercept correlations in an attempt to resolve the lunar heavy rare gas system in a statistically valid approach. Tables of concentrations and isotope compositions are given.

Sahara Coal: the fine art of collecting fines for profit

Energy Technology Data Exchange (ETDEWEB)

Schreckengost, D.; Arnold, D.

1984-09-01

A considerable increase in the volume of fines in rom coal caused Sahara Coal in Illinois to redesign the fine coal system in their Harrisburg preparation plant. Details of the new design, and particularly the fine refuse system which dewaters and dries 28 mesh x O clean coal, are given. Results have exceeded expectations in reducing product losses, operating costs and slurry pond cleaning costs.

Fine-Scale Bacterial Beta Diversity within a Complex Ecosystem (Zodletone Spring, OK, USA): The Role of the Rare Biosphere

Science.gov (United States)

Youssef, Noha H.; Couger, M. B.; Elshahed, Mostafa S.

2010-01-01

Background The adaptation of pyrosequencing technologies for use in culture-independent diversity surveys allowed for deeper sampling of ecosystems of interest. One extremely well suited area of interest for pyrosequencing-based diversity surveys that has received surprisingly little attention so far, is examining fine scale (e.g. micrometer to millimeter) beta diversity in complex microbial ecosystems. Methodology/Principal Findings We examined the patterns of fine scale Beta diversity in four adjacent sediment samples (1mm apart) from the source of an anaerobic sulfide and sulfur rich spring (Zodletone spring) in southwestern Oklahoma, USA. Using pyrosequencing, a total of 292,130 16S rRNA gene sequences were obtained. The beta diversity patterns within the four datasets were examined using various qualitative and quantitative similarity indices. Low levels of Beta diversity (high similarity indices) were observed between the four samples at the phylum-level. However, at a putative species (OTU0.03) level, higher levels of beta diversity (lower similarity indices) were observed. Further examination of beta diversity patterns within dominant and rare members of the community indicated that at the putative species level, beta diversity is much higher within rare members of the community. Finally, sub-classification of rare members of Zodletone spring community based on patterns of novelty and uniqueness, and further examination of fine scale beta diversity of each of these subgroups indicated that members of the community that are unique, but non novel showed the highest beta diversity within these subgroups of the rare biosphere. Conclusions/Significance The results demonstrate the occurrence of high inter-sample diversity within seemingly identical samples from a complex habitat. We reason that such unexpected diversity should be taken into consideration when exploring gamma diversity of various ecosystems, as well as planning for sequencing-intensive metagenomic

Using temporal sampling to improve attribution of source populations for invasive species.

Directory of Open Access Journals (Sweden)

Sharyn J Goldstien

Full Text Available Numerous studies have applied genetic tools to the identification of source populations and transport pathways for invasive species. However, there are many gaps in the knowledge obtained from such studies because comprehensive and meaningful spatial sampling to meet these goals is difficult to achieve. Sampling populations as they arrive at the border should fill the gaps in source population identification, but such an advance has not yet been achieved with genetic data. Here we use previously acquired genetic data to assign new incursions as they invade populations within New Zealand ports and marinas. We also investigated allelelic frequency change in these recently established populations over a two-year period, and assessed the effect of temporal genetic sampling on our ability to assign new incursions to their population of source. We observed shifts in the allele frequencies among populations, as well as the complete loss of some alleles and the addition of alleles novel to New Zealand, within these recently established populations. There was no significant level of genetic differentiation observed in our samples between years, and the use of these temporal data did alter the assignment probability of new incursions. Our study further suggests that new incursions can add genetic variation to the population in a single introduction event as the founders themselves are often more genetically diverse than theory initially predicted.

Monitoring and Method development of Hg in Istanbul Airborne Particulates by Solid Sampling Continuum Source-High Resolution Electrothermal Atomic Absorption Spectromerty

Directory of Open Access Journals (Sweden)

Soydemir E.

2014-07-01

Full Text Available In this work, a method has been developed and monitoring for the determination of mercury in PM2.5 airborne particulates by solid sampling high-resolution continuum source electrothermal atomic absorption spectrometry. The PM2.5 airborne particulates were collected on quartz filters using high volume samplers (500 L/min in Istanbul (Turkey for 96 hours every month in one year. At first, experimental conditions as well as the validation tests were optimized using collected filter. For this purpose, the effects of atomization temperature, amount of sample intoduced in to the furnace, addition of acids and/or KMnO4 on the sample, covering of graphite tube and platform or using of Ag nanoparticulates, Au nanoparticulates, and Pd solutions on the accuracy and precision were investigated. After optimization of the experimental conditions, the mercury concentrations were determined in the collected filter. The filters with PM2.5 airborne particulates were dried, divided into small fine particles and then Hg concentrations were determined directly. In order to eliminate any error due to the sensitivity difference between aqueous standards and solid samples, the quantification was performed using solid calibrants. The limit of detection, based on three times the standard deviations for ten atomizations of an unused filter, was 30 ng/g. The Hg content was dependent on the sampling site, season etc, ranging from samples, addition of AuNPs, AgNPs and Pd solution for amalgamation effects on the recoveries were investigated. The results were compared using statistical tests.

Metre-wavelength fine structure in 30 extragalactic radio sources with sizes of a few arcsec

International Nuclear Information System (INIS)

Banhatti, D.G.; Ananthakrishnan, S.; Pramesh Rao, A.

1983-01-01

Interplanetary scintillation (IPS) observations at 327 MHz of an unbiased sample of 30 extragalactic radio sources having overall sizes between 1 and 4 arcsec, and flux densities greater than 1 Jy at 327 MHz are reported. From VLBI observations, these sources have been reported to contain compact components of sizes < approx.= to 0.02 arcsec contributing on an average about 25 per cent of the total emission at 5 HGz. The IPS observations show that about 45 per cent of the total emission at 327 MHz arises from structures of sizes between 0.05 and 0.5 arcsec (corresponding typically to 0.5 to 5 kpc). A comparison of the VLBI and IPS results indicates that the VLBI and IPS components probably refer to the same physical features in these sources. (author)

Fine particulate matter in the tropical environment: monsoonal effects, source apportionment, and health risk assessment

Science.gov (United States)

Khan, M. F.; Latif, M. T.; Saw, W. H.; Amil, N.; Nadzir, M. S. M.; Sahani, M.; Tahir, N. M.; Chung, J. X.

2016-01-01

The health implications of PM2.5 in the tropical region of Southeast Asia (SEA) are significant as PM2.5 can pose serious health concerns. PM2.5 concentration and sources here are strongly influenced by changes in the monsoon regime from the south-west quadrant to the north-east quadrant in the region. In this work, PM2.5 samples were collected at a semi-urban area using a high-volume air sampler at different seasons on 24 h basis. Analysis of trace elements and water-soluble ions was performed using inductively coupled plasma mass spectroscopy (ICP-MS) and ion chromatography (IC), respectively. Apportionment analysis of PM2.5 was carried out using the United States Environmental Protection Agency (US EPA) positive matrix factorization (PMF) 5.0 and a mass closure model. We quantitatively characterized the health risks posed to human populations through the inhalation of selected heavy metals in PM2.5. 48 % of the samples collected exceeded the World Health Organization (WHO) 24 h PM2.5 guideline but only 19 % of the samples exceeded 24 h US EPA National Ambient Air Quality Standard (NAAQS). The PM2.5 concentration was slightly higher during the north-east monsoon compared to south-west monsoon. The main trace metals identified were As, Pb, Cd, Ni, Mn, V, and Cr while the main ions were SO42-, NO3-, NH4+, and Na. The mass closure model identified four major sources of PM2.5 that account for 55 % of total mass balance. The four sources are mineral matter (MIN) (35 %), secondary inorganic aerosol (SIA) (11 %), sea salt (SS) (7 %), and trace elements (TE) (2 %). PMF 5.0 elucidated five potential sources: motor vehicle emissions coupled with biomass burning (31 %) were the most dominant, followed by marine/sulfate aerosol (20 %), coal burning (19 %), nitrate aerosol (17 %), and mineral/road dust (13 %). The hazard quotient (HQ) for four selected metals (Pb, As, Cd, and Ni) in PM2.5 mass was highest in PM2.5 mass from the coal burning source and least in PM2.5 mass

Interlaboratory comparison of three microbial source tracking quantitative polymerase chain reaction (qPCR) assays from fecal-source and environmental samples

Science.gov (United States)

Stelzer, Erin A.; Strickler, Kriston M.; Schill, William B.

2012-01-01

During summer and early fall 2010, 15 river samples and 6 fecal-source samples were collected in West Virginia. These samples were analyzed by three laboratories for three microbial source tracking (MST) markers: AllBac, a general fecal indicator; BacHum, a human-associated fecal indicator; and BoBac, a ruminant-associated fecal indicator. MST markers were analyzed by means of the quantitative polymerase chain reaction (qPCR) method. The aim was to assess interlaboratory precision when the three laboratories used the same MST marker and shared deoxyribonucleic acid (DNA) extracts of the samples, but different equipment, reagents, and analyst experience levels. The term assay refers to both the markers and the procedure differences listed above. Interlaboratory precision was best for all three MST assays when using the geometric mean absolute relative percent difference (ARPD) and Friedman's statistical test as a measure of interlaboratory precision. Adjustment factors (one for each MST assay) were calculated using results from fecal-source samples analyzed by all three laboratories and applied retrospectively to sample concentrations to account for differences in qPCR results among labs using different standards and procedures. Following the application of adjustment factors to qPCR results, ARPDs were lower; however, statistically significant differences between labs were still observed for the BacHum and BoBac assays. This was a small study and two of the MST assays had 52 percent of samples with concentrations at or below the limit of accurate quantification; hence, more testing could be done to determine if the adjustment factors would work better if the majority of sample concentrations were above the quantification limit.

Efficiency of Micro-fine Cement Grouting in Liquefiable Sand

International Nuclear Information System (INIS)

Mirjalili, Mojtaba; Mirdamadi, Alireza; Ahmadi, Alireza

2008-01-01

In the presence of strong ground motion, liquefaction hazards are likely to occur in saturated cohesion-less soils. The risk of liquefaction and subsequent deformation can be reduced by various ground improvement methods including the cement grouting technique. The grouting method was proposed for non-disruptive mitigation of liquefaction risk at developed sites susceptible to liquefaction. In this research, a large-scale experiment was developed for assessment of micro-fine cement grouting effect on strength behavior and liquefaction potential of loose sand. Loose sand samples treated with micro-fine grout in multidirectional experimental model, were tested under cyclic and monotonic triaxial loading to investigate the influence of micro-fine grout on the deformation properties and pore pressure response. The behavior of pure sand was compared with the behavior of sand grouted with a micro-fine cement grout. The test results were shown that cement grouting with low concentrations significantly decreased the liquefaction potential of loose sand and related ground deformation

Characterization and source estimation of size-segregated aerosols during 2008-2012 in an urban environment in Beijing

International Nuclear Information System (INIS)

Yu, Lingda; Wang, Guangfu; Zhang, Renjiang

2013-01-01

Full text: During 2008-2012, size-segregated aerosol samples were collected using an eight-stage cascade impactor at Beijing Normal University (BNU) Site, China. These samples were analyzed using particle induced X-ray emission (PIXE) analysis for concentrations of 21 elements consisting of Mg, AI, Si, P, S, CI, K, Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, As, Se, Br, Ba and Pb. The size-resolved data sets were then analyzed using the positive matrix factorization (PMF) technique in order to identify possible sources and estimate their contribution to particulate matter mass. Nine sources were resolved in eight size ranges (025 ∼ 16μm) and included secondary sulphur, motor vehicles, coal combustion; oil combustion, road dust, biomass burning, soil dust, diesel vehicles and metal processing. PMF analysis of size-resolved source contributions showed that natural sources represented by soil dust and road dust contributed about 57% to the predicted primary particulate matter (PM) mass in the coarse size range(>2μm). On the other hand, anthropogenic sources such as secondary sulphur, coal and oil combustion, biomass burning and motor vehicle contributed about 73% in the fine size range <2μm). The diesel vehicles and secondary sulphur source contributed the most in the ultra-fine size range (<0.25μm) and was responsible for about 52% of the primary PM mass. (author)

Characterization and source estimation of size-segregated aerosols during 2008-2012 in an urban environment in Beijing

Energy Technology Data Exchange (ETDEWEB)

Yu, Lingda [Key Laboratory of Beam Technology and Materiais Modification of Ministry of Education, College of Nuclear Science and Technology, Beijing Normal University, Beijing (China); Wang, Guangfu, E-mail: guangfuw@bnu.edu.cn [Beijing Radiation Center, Beijing (China); Zhang, Renjiang [Key Laboratory of Regional Climate-Environment Research for Temperate Eas tAsia (RCE-TEA), Institute of Atmospheric Physics, Chinese Academy of Science, Beijing (China)

2013-07-01

Full text: During 2008-2012, size-segregated aerosol samples were collected using an eight-stage cascade impactor at Beijing Normal University (BNU) Site, China. These samples were analyzed using particle induced X-ray emission (PIXE) analysis for concentrations of 21 elements consisting of Mg, AI, Si, P, S, CI, K, Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, As, Se, Br, Ba and Pb. The size-resolved data sets were then analyzed using the positive matrix factorization (PMF) technique in order to identify possible sources and estimate their contribution to particulate matter mass. Nine sources were resolved in eight size ranges (025 ∼ 16μm) and included secondary sulphur, motor vehicles, coal combustion; oil combustion, road dust, biomass burning, soil dust, diesel vehicles and metal processing. PMF analysis of size-resolved source contributions showed that natural sources represented by soil dust and road dust contributed about 57% to the predicted primary particulate matter (PM) mass in the coarse size range(>2μm). On the other hand, anthropogenic sources such as secondary sulphur, coal and oil combustion, biomass burning and motor vehicle contributed about 73% in the fine size range <2μm). The diesel vehicles and secondary sulphur source contributed the most in the ultra-fine size range (<0.25μm) and was responsible for about 52% of the primary PM mass. (author)

Characteristics, sources and evolution of fine aerosol (PM1) at urban, coastal and forest background sites in Lithuania

NARCIS (Netherlands)

Masalaite, A.; Holzinger, R.; Remeikis, V.; Roeckmann, Thomas; Dusek, U.

The chemical and isotopic composition of organic aerosol (OA) samples collected on PM1 filters was determined as a function of desorption temperature to investigate the main sources of organic carbon and the effects of photochemical processing on atmospheric aerosol. The filter samples were

Fine motor skills and executive function both contribute to kindergarten achievement

Science.gov (United States)

Cameron, Claire E.; Brock, Laura L.; Murrah, William M.; Bell, Lindsay H.; Worzalla, Samantha L.; Grissmer, David; Morrison, Frederick J.

2012-01-01

This study examined the contribution of executive function (EF) and multiple aspects of fine motor skills to achievement on six standardized assessments in a sample of middle-SES kindergarteners. 3- and 4-year-olds’ (N=213) fine and gross motor skills were assessed in a home visit before kindergarten; EF was measured at fall of kindergarten; and Woodcock-Johnson III (WJ III) Tests of Academic Achievement were administered at fall and spring. Correlations indicated that EF and fine motor skills appeared distinct. Further, controlling for background variables, higher levels of both EF and fine motor skills, specifically design copy, predicted higher achievement on multiple subtests at kindergarten entry, as well as improvement from fall to spring. Implications for research on school readiness are discussed. PMID:22537276

Facilitating Fine Grained Data Provenance using Temporal Data Model

NARCIS (Netherlands)

Huq, M.R.; Wombacher, Andreas; Apers, Peter M.G.

2010-01-01

E-science applications use fine grained data provenance to maintain the reproducibility of scientific results, i.e., for each processed data tuple, the source data used to process the tuple as well as the used approach is documented. Since most of the e-science applications perform on-line

Assessment of the effect of population and diary sampling methods on estimation of school-age children exposure to fine particles.

Science.gov (United States)

Che, W W; Frey, H Christopher; Lau, Alexis K H

2014-12-01

Population and diary sampling methods are employed in exposure models to sample simulated individuals and their daily activity on each simulation day. Different sampling methods may lead to variations in estimated human exposure. In this study, two population sampling methods (stratified-random and random-random) and three diary sampling methods (random resampling, diversity and autocorrelation, and Markov-chain cluster [MCC]) are evaluated. Their impacts on estimated children's exposure to ambient fine particulate matter (PM2.5 ) are quantified via case studies for children in Wake County, NC for July 2002. The estimated mean daily average exposure is 12.9 μg/m(3) for simulated children using the stratified population sampling method, and 12.2 μg/m(3) using the random sampling method. These minor differences are caused by the random sampling among ages within census tracts. Among the three diary sampling methods, there are differences in the estimated number of individuals with multiple days of exposures exceeding a benchmark of concern of 25 μg/m(3) due to differences in how multiday longitudinal diaries are estimated. The MCC method is relatively more conservative. In case studies evaluated here, the MCC method led to 10% higher estimation of the number of individuals with repeated exposures exceeding the benchmark. The comparisons help to identify and contrast the capabilities of each method and to offer insight regarding implications of method choice. Exposure simulation results are robust to the two population sampling methods evaluated, and are sensitive to the choice of method for simulating longitudinal diaries, particularly when analyzing results for specific microenvironments or for exposures exceeding a benchmark of concern. © 2014 Society for Risk Analysis.

Experiments with radioactive samples at the Advanced Photon Source

International Nuclear Information System (INIS)

Veluri, V. R.; Justus, A.; Glagola, B.; Rauchas, A.; Vacca, J.

2000-01-01

The Advanced Photon Source (APS) at Argonne National Laboratory is a national synchrotron-radiation light source research facility. The 7 GeV electron Storage Ring is currently delivering intense high brilliance x-ray beams to a total of 34 beamlines with over 120 experiment stations to members of the international scientific community to carry out forefront basic and applied research in several scientific disciplines. Researchers come to the APS either as members of Collaborative Access Teams (CATs) or as Independent Investigators (IIs). Collaborative Access Teams comprise large number of investigators from universities, industry, and research laboratories with common research objectives. These teams are responsible for the design, construction, finding, and operation of beamlines. They are the owners of their experimental enclosures (''hutches'') designed and built to meet their specific research needs. Fig. 1 gives a plan view of the location of the Collaborative Access Teams by Sector and Discipline. In the past two years, over 2000 individual experiments were conducted at the APS facility. Of these, about 60 experiments involved the use of radioactive samples, which is less than 3% of the total. However, there is an increase in demand for experiment stations to accommodate the use of radioactive samples in different physical forms embedded in various matrices with activity levels ranging from trace amounts of naturally occurring radionuclides to MBq (mCi) quantities including transuranics. This paper discusses in some detail the steps in the safety review process for experiments involving radioactive samples and how ALARA philosophy is invoked at each step and implemented

Mathematical modeling of atmospheric fine particle-associated primary organic compound concentrations

Science.gov (United States)

Rogge, Wolfgang F.; Hildemann, Lynn M.; Mazurek, Monica A.; Cass, Glen R.; Simoneit, Bernd R. T.

1996-08-01

An atmospheric transport model has been used to explore the relationship between source emissions and ambient air quality for individual particle phase organic compounds present in primary aerosol source emissions. An inventory of fine particulate organic compound emissions was assembled for the Los Angeles area in the year 1982. Sources characterized included noncatalyst- and catalyst-equipped autos, diesel trucks, paved road dust, tire wear, brake lining dust, meat cooking operations, industrial oil-fired boilers, roofing tar pots, natural gas combustion in residential homes, cigarette smoke, fireplaces burning oak and pine wood, and plant leaf abrasion products. These primary fine particle source emissions were supplied to a computer-based model that simulates atmospheric transport, dispersion, and dry deposition based on the time series of hourly wind observations and mixing depths. Monthly average fine particle organic compound concentrations that would prevail if the primary organic aerosol were transported without chemical reaction were computed for more than 100 organic compounds within an 80 km × 80 km modeling area centered over Los Angeles. The monthly average compound concentrations predicted by the transport model were compared to atmospheric measurements made at monitoring sites within the study area during 1982. The predicted seasonal variation and absolute values of the concentrations of the more stable compounds are found to be in reasonable agreement with the ambient observations. While model predictions for the higher molecular weight polycyclic aromatic hydrocarbons (PAH) are in agreement with ambient observations, lower molecular weight PAH show much higher predicted than measured atmospheric concentrations in the particle phase, indicating atmospheric decay by chemical reactions or evaporation from the particle phase. The atmospheric concentrations of dicarboxylic acids and aromatic polycarboxylic acids greatly exceed the contributions that

Temperature-dependent fine structure splitting in InGaN quantum dots

Science.gov (United States)

Wang, Tong; Puchtler, Tim J.; Zhu, Tongtong; Jarman, John C.; Kocher, Claudius C.; Oliver, Rachel A.; Taylor, Robert A.

2017-07-01

We report the experimental observation of temperature-dependent fine structure splitting in semiconductor quantum dots using a non-polar (11-20) a-plane InGaN system, up to the on-chip Peltier cooling threshold of 200 K. At 5 K, a statistical average splitting of 443 ± 132 μeV has been found based on 81 quantum dots. The degree of fine structure splitting stays relatively constant for temperatures less than 100 K and only increases above that temperature. At 200 K, we find that the fine structure splitting ranges between 2 and 12 meV, which is an order of magnitude higher than that at low temperatures. Our investigations also show that phonon interactions at high temperatures might have a correlation with the degree of exchange interactions. The large fine structure splitting at 200 K makes it easier to isolate the individual components of the polarized emission spectrally, increasing the effective degree of polarization for potential on-chip applications of polarized single-photon sources.

Tracing of aerosol sources in an urban environment using chemical, Sr isotope, and mineralogical characterization.

Science.gov (United States)

Duarte, Regina M B O; Matos, João T V; Paula, Andreia S; Lopes, Sónia P; Ribeiro, Sara; Santos, José Francisco; Patinha, Carla; da Silva, Eduardo Ferreira; Soares, Rosário; Duarte, Armando C

2017-04-01

In the framework of two national research projects (ORGANOSOL and CN-linkAIR), fine particulate matter (PM 2.5 ) was sampled for 17 months at an urban location in the Western European Coast. The PM 2.5 samples were analyzed for organic carbon (OC), water-soluble organic carbon (WSOC), elemental carbon (EC), major water-soluble inorganic ions, mineralogical, and for the first time in this region, strontium isotope ( 87 Sr/ 86 Sr) composition. Organic matter dominates the identifiable urban PM 2.5 mass, followed by secondary inorganic aerosols. The acquired data resulted also in a seasonal overview of the carbonaceous and inorganic aerosol composition, with an important contribution from primary biomass burning and secondary formation processes in colder and warmer periods, respectively. The fossil-related primary EC seems to be continually present throughout the sampling period. The 87 Sr/ 86 Sr ratios were measured on both the labile and residual PM 2.5 fractions as well as on the bulk PM 2.5 samples. Regardless of the air mass origin, the residual fractions are more radiogenic (representative of a natural crustal dust source) than the labile fractions, whose 87 Sr/ 86 Sr ratios are comparable to that of seawater. The 87 Sr/ 86 Sr ratios and the mineralogical composition data further suggest that sea salt and mineral dust are important primary natural sources of fine aerosols throughout the sampling period.

Insights into metals in individual fine particles from municipal solid waste using synchrotron radiation-based micro-analytical techniques

Institute of Scientific and Technical Information of China (English)

Yumin Zhu; Hua Zhang; Liming Shao; Pinjing He

2015-01-01

Excessive inter-contamination with heavy metals hampers the application of biological treatment products derived from mixed or mechanically-sorted municipal solid waste (MSW).In this study,we investigated fine particles of ＜2 mm,which are small fractions in MSW but constitute a significant component of the total heavy metal content,using bulk detection techniques.A total of 17 individual fine particles were evaluated using synchrotron radiation-based micro-X-ray fluorescence and micro-X-ray diffraction.We also discussed the association,speciation and source apportionment of heavy metals.Metals were found to exist in a diffuse distribution with heterogeneous intensities and intense hot-spots of ＜10 μm within the fine particles.Zn-Cu,Pb-Fe and Fe-Mn-Cr had significant correlations in terms of spatial distribution.The overlapped enrichment,spatial association,and the mineral phases of metals revealed the potential sources of fine particles from size-reduced waste fractions (such as scraps of organic wastes or ceramics) or from the importation of other particles.The diverse sources of heavy metal pollutants within the fine particles suggested that separate collection and treatment of the biodegradable waste fraction (such as food waste) is a preferable means of facilitating the beneficial utilization of the stabilized products.

Toddlers’ Fine Motor Milestone Achievement is Associated with Early Touchscreen Scrolling

Directory of Open Access Journals (Sweden)

Rachael Bedford

2016-08-01

Full Text Available Touchscreen technologies provide an intuitive and attractive source of sensory/cognitive stimulation for young children. Despite fears that usage may have a negative impact on toddlers’ cognitive development, empirical evidence is lacking. The current study presents results from the UK Toddler Attentional Behaviours and LEarning with Touchscreens (TABLET project, examining the association between toddlers’ touchscreen use and the attainment of developmental milestones. Data were gathered in an online survey of 715 parents of 6- to 36-month-olds to address two research questions: 1 How does touchscreen use change from 6 to 36 months? 2 In toddlers (19 to 36 months i.e., above the median age, n = 366, how does retrospectively reported age of first touchscreen usage relate to gross motor (i.e., walking, fine motor (i.e., stacking blocks and language (i.e., producing two-word utterances milestones? In our sample, the proportion of children using touchscreens, as well as the average daily usage time, increased with age (youngest quartile, 6-11 months: 51.22% users, 8.53 minutes per day; oldest quartile, 26-36 months: 92.05% users, average use of 43.95 minutes per day. In toddlers, aged 19-36 months, age of first touchscreen use was significantly associated with fine motor (stacking blocks, p = 0.03, after controlling for covariates age, sex, mother’s education (a proxy for SES as well as age of early fine motor milestone achievement (pincer grip. This effect was only present for active scrolling of the touchscreen p = 0.04, not for video watching. No significant relationships were found between touchscreen use and either gross motor or language milestones. Touchscreen use increases rapidly over the first three years of life. In the current study, we find no evidence to support a negative association between the age of first touchscreen usage and developmental milestones. Indeed, earlier touchscreen use, specifically scrolling of the screen, was

Exogenous sample contamination. Sources and interference.

Science.gov (United States)

Cornes, Michael P

2016-12-01

Clinical laboratory medicine is involved in the vast majority of patient care pathways. It has been estimated that pathology results inform 60-70% of critical patient care decisions. The primary goal of the laboratory is to produce precise and accurate results which reflect the true situation in vivo. It is not surprising that interference occurs in laboratory analysis given the complexity of some of the assays used to perform them. Interference is defined as "the effect of a substance upon any step in the determination of the concentration or catalytic activity of the metabolite". Exogenous interferences are defined as those that derive from outside of the body and are therefore not normally found in a specimen and can cause either a positive or negative bias in analytical results. Interferences in analysis can come from various sources and can be classified as endogenous or exogenous. Exogenous substances could be introduced at any point in the sample journey. The laboratory must take responsibility for the quality of results produced. It has a responsibility to have processes in place to identify and minimise the occurrence and effect contamination and interference. To do this well the laboratory needs to work with clinicians and manufacturers. Failure to identify an erroneous result could have an impact on patient care, patient safety and also on hospital budgets. However it is not always easy to recognise interferences. This review summarises the types and sources of exogenous interference and some steps to minimise the impact they have. Crown Copyright © 2016. Published by Elsevier Inc. All rights reserved.

Identification of metals into fine particles (PM2.5) during the dry cold season in the Toluca City

International Nuclear Information System (INIS)

Martinez P, A. A.; Aldape U, F.

2008-01-01

To know the elemental content of fine particles PM 2.5 that can affect people in the Toluca City, such as metals and another, it was made a campaign collection of fine particles during dry-cold ( November 2006-March 2007). The aerosol samples were collected on Teflon filters with an equipment BGI model PQ200 mark authorized by the Environment Protection Agency (EPA), every other day with a time resolution of 24 h. The determination of the elemental composition of the samples was performed by means of the technique Particle Induced X-Ray Emission (PIXE). The results of the analysis showed consistently 13 elements S, Cl, K, Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, as, throughout the collection period. We calculated the enrich factor that separates the elements of the natural component of the anthropogenic component. The correlation matrix shows the pairs of elements that are contained in the same air mass as Vanadium and Nickel. From the results it is concluded that the sources that gave rise to these particles are the burning of fossil fuels in motor vehicles, lubricants, additives and burning tires wear of automotive vehicles, besides the products used in agricultural activities. (Author)

Fine particulate matter in the tropical environment: monsoonal effects, source apportionment, and health risk assessment

Directory of Open Access Journals (Sweden)

M. F. Khan

2016-01-01

Full Text Available The health implications of PM2.5 in the tropical region of Southeast Asia (SEA are significant as PM2.5 can pose serious health concerns. PM2.5 concentration and sources here are strongly influenced by changes in the monsoon regime from the south-west quadrant to the north-east quadrant in the region. In this work, PM2.5 samples were collected at a semi-urban area using a high-volume air sampler at different seasons on 24 h basis. Analysis of trace elements and water-soluble ions was performed using inductively coupled plasma mass spectroscopy (ICP-MS and ion chromatography (IC, respectively. Apportionment analysis of PM2.5 was carried out using the United States Environmental Protection Agency (US EPA positive matrix factorization (PMF 5.0 and a mass closure model. We quantitatively characterized the health risks posed to human populations through the inhalation of selected heavy metals in PM2.5. 48 % of the samples collected exceeded the World Health Organization (WHO 24 h PM2.5 guideline but only 19 % of the samples exceeded 24 h US EPA National Ambient Air Quality Standard (NAAQS. The PM2.5 concentration was slightly higher during the north-east monsoon compared to south-west monsoon. The main trace metals identified were As, Pb, Cd, Ni, Mn, V, and Cr while the main ions were SO42−, NO3−, NH4+, and Na. The mass closure model identified four major sources of PM2.5 that account for 55 % of total mass balance. The four sources are mineral matter (MIN (35 %, secondary inorganic aerosol (SIA (11 %, sea salt (SS (7 %, and trace elements (TE (2 %. PMF 5.0 elucidated five potential sources: motor vehicle emissions coupled with biomass burning (31 % were the most dominant, followed by marine/sulfate aerosol (20 %, coal burning (19 %, nitrate aerosol (17 %, and mineral/road dust (13 %. The hazard quotient (HQ for four selected metals (Pb, As, Cd, and Ni in PM2.5 mass was highest in PM2.5 mass from the coal burning

Limited Effects of Variable-Retention Harvesting on Fungal Communities Decomposing Fine Roots in Coastal Temperate Rainforests.

Science.gov (United States)

Philpott, Timothy J; Barker, Jason S; Prescott, Cindy E; Grayston, Sue J

2018-02-01

Fine root litter is the principal source of carbon stored in forest soils and a dominant source of carbon for fungal decomposers. Differences in decomposer capacity between fungal species may be important determinants of fine-root decomposition rates. Variable-retention harvesting (VRH) provides refuge for ectomycorrhizal fungi, but its influence on fine-root decomposers is unknown, as are the effects of functional shifts in these fungal communities on carbon cycling. We compared fungal communities decomposing fine roots (in litter bags) under VRH, clear-cut, and uncut stands at two sites (6 and 13 years postharvest) and two decay stages (43 days and 1 year after burial) in Douglas fir forests in coastal British Columbia, Canada. Fungal species and guilds were identified from decomposed fine roots using high-throughput sequencing. Variable retention had short-term effects on β-diversity; harvest treatment modified the fungal community composition at the 6-year-postharvest site, but not at the 13-year-postharvest site. Ericoid and ectomycorrhizal guilds were not more abundant under VRH, but stand age significantly structured species composition. Guild composition varied by decay stage, with ruderal species later replaced by saprotrophs and ectomycorrhizae. Ectomycorrhizal abundance on decomposing fine roots may partially explain why fine roots typically decompose more slowly than surface litter. Our results indicate that stand age structures fine-root decomposers but that decay stage is more important in structuring the fungal community than shifts caused by harvesting. The rapid postharvest recovery of fungal communities decomposing fine roots suggests resiliency within this community, at least in these young regenerating stands in coastal British Columbia. IMPORTANCE Globally, fine roots are a dominant source of carbon in forest soils, yet the fungi that decompose this material and that drive the sequestration or respiration of this carbon remain largely

X-ray absorption fine structure spectroscopic determination of plutonium speciation at the Rocky Flats Environmental Technology Site

International Nuclear Information System (INIS)

Lezama-pacheco, Juan S.; Conradson, Steven D.; Clark, David L.

2008-01-01

X-ray Absorption Fine Structure spectroscopy was used to probe the speciation of the ppm level Pu in thirteen soil and concrete samples from the Rocky Flats Environmental Technology Site in support of the site remediation effort that has been successfully completed since these measurements. In addition to X-ray Absorption Near Edge Spectra, two of the samples yielded Extended X-ray Absorption Fine Structure spectra that could be analyzed by curve-fits. Most of these spectra exhibited features consistent with PU(IV), and more specificaJly, PuO 2+x -type speciation. Two were ambiguous, possibly indicating that Pu that was originally present in a different form was transforming into PuO 2+x , and one was interpreted as demonstrating the presence of an unusual Pu(VI) compound, consistent with its source being spills from a PUREX purification line onto a concrete floor and the resultant extreme conditions. These experimental results therefore validated models that predicted that insoluble PuO 2+x would be the most stable form of Pu in equilibrium with air and water even when the source terms were most likely Pu metal with organic compounds or a Pu fire. A corollary of these models' predictions and other in situ observations is therefore that the minimal transport of Pu that occurred on the site was via the resuspension and mobilization of colloidal particles. Under these conditions, the small amounts of diffusely distributed Pu that were left on the site after its remediation pose only a negligible hazard.

Characterization of Fine Particulate Matter in Sharjah, United Arab Emirates Using Complementary Experimental Techniques

Directory of Open Access Journals (Sweden)

Nasser M. Hamdan

2018-04-01

Full Text Available Airborne particulate matter (PM pollutants were sampled from an urban background site in Sharjah, United Arab Emirates. The fine fraction (PM2.5 (particulates with aerodynamic diameters of less than 2.5 μm was collected on 47-mm Teflon filters and analyzed using a combined set of non-destructive techniques in order to provide better understanding of the sources of pollutants and their interaction during transport in the atmosphere. These techniques included gravimetric analysis, equivalent black carbon (EBC, X-ray fluorescence, scanning electron microscopy, and X-ray diffraction. Generally, the PM2.5 concentrations are within the limits set by the World Health Organization (WHO and the United States (US Environmental Protection Agency. The EBC content is in the range of 10–12% of the total PM concentration (2–4 µg m−3, while S (as ammonium sulfate, Ca (as calcite, gypsum, and calcium carbonate, Si (as quartz, Fe, and Al were the major sources of PM pollution. EBC, ammonium sulfate, Zn, V, and Mn originate from anthropogenic sources such as fossil fuel burning, traffic, and industrial emissions. Natural elements such as Ca, Fe, Al, Si, and Ti are due to natural sources such as crustal materials (enhanced during dust episodes and sea salts. The average contribution of natural sources in the total PM2.5 mass concentration over the sampling period is about 40%, and the contribution of the secondary inorganic compounds is about 27% (mainly ammonium sulfate in our case. The remaining 22% is assumed to be secondary organic compounds.

Implications for new physics from fine-tuning arguments: II. Little Higgs models

International Nuclear Information System (INIS)

Casas, J.A.; Espinosa, J.R.; Hidalgo, I.

2005-01-01

We examine the fine-tuning associated to electroweak breaking in Little Higgs scenarios and find it to be always substantial and, generically, much higher than suggested by the rough estimates usually made. This is due to implicit tunings between parameters that can be overlooked at first glance but show up in a more systematic analysis. Focusing on four popular and representative Little Higgs scenarios, we find that the fine-tuning is essentially comparable to that of the Little Hierarchy problem of the Standard Model (which these scenarios attempt to solve) and higher than in supersymmetric models. This does not demonstrate that all Little Higgs models are fine-tuned, but stresses the need of a careful analysis of this issue in model-building before claiming that a particular model is not fine-tuned. In this respect we identify the main sources of potential fine-tuning that should be watched out for, in order to construct a successful Little Higgs model, which seems to be a non-trivial goal. (author)

Charge neutrality of fine particle (dusty) plasmas and fine particle cloud under gravity

Energy Technology Data Exchange (ETDEWEB)

Totsuji, Hiroo, E-mail: totsuji-09@t.okadai.jp

2017-03-11

The enhancement of the charge neutrality due to the existence of fine particles is shown to occur generally under microgravity and in one-dimensional structures under gravity. As an application of the latter, the size and position of fine particle clouds relative to surrounding plasmas are determined under gravity. - Highlights: • In fine particle (dusty) plasmas, the charge neutrality is much enhanced by the existence of fine particles. • The enhancement of charge neutrality generally occurs under microgravity and gravity. • Structure of fine particle clouds under gravity is determined by applying the enhanced charge neutrality.

Micro-mechanical investigation of the effect of fine content on mechanical behavior of gap graded granular materials using DEM

Directory of Open Access Journals (Sweden)

Taha Habib

2017-01-01

Full Text Available In this paper, we present a micro-mechanical study of the effect of fine content on the behavior of gap graded granular samples by using numerical simulations performed with the Discrete Element Method. Different samples with fine content varied from 0% to 30% are simulated. The role of fine content in reinforcing the granular skeleton and in supporting the external deviatoric stress is then brought into the light.

Field studies of hydrodynamic conditions and fine-sediment suspension in the Kapar coastal region, Malaysia

International Nuclear Information System (INIS)

Abdul Kadir Ishak

2006-01-01

Field studies to determine the hydrodynamics and fine-sediment transport were carried out at the Kapar coastal region, on the west coast of the Malaysian Peninsula. Several observation stations were established to measure near-bed tidal currents, suspended sediment concentration (SSC), water temperature, salinity and tidal elevation. It was found that resuspension (erosion) and deposition of fine sediment occurred during every tidal cycle, with greater transport occurred during the ebb than the flood. This become the major source of fine sediment that contribute to the siltation problem in this region. The high resuspension and entrainment of sediment into the flow column was due to a high near-bed current velocity which was at its peak at 1.3 m/s (during spring tides) and easily-eroded fine particles recently settled during previous tidal cycles. Significant erosion (and deposition) took place during the spring tides but little erosion was observed during the neap. The secondary source of fine sediment is from Sungai Kelang transported to the area by ebb currents in particular during spring tides. The measurement data also showed that the current flows around an industrial construction, the Kapar power station, had been modified and greatly reduced, which had resulted in a significant siltation problem in this region. This study contributes to a better understanding of the influence of hydrodynamics on the physical processes relating to the resuspension, transport and deposition of the fine-sediment in this region. (Author)

Get out of Fines Free: Recruiting Student Usability Testers via Fine Waivers

Science.gov (United States)

Hockenberry, Benjamin; Blackburn, Kourtney

2016-01-01

St. John Fisher College's Lavery Library's Access Services and Systems departments began a pilot project in which students with overdue fines tested usability of library Web sites in exchange for fine waivers. Circulation staff promoted the program and redeemed fine waiver vouchers at the Checkout Desk, while Systems staff administered testing and…

Fine-particle sodium tracer for long-range transport of the Kuwaiti oil-fire smoke

Energy Technology Data Exchange (ETDEWEB)

Lowenthal, D.H.; Borys, R.D.; Rogers, C.F.; Chow, J.C.; Stevens, R.K.

1993-04-23

Evidence for long-range transport of the Kuwaiti oil-fire smoke during the months following the Persian Gulf War has been more or less indirect. However, more-recent data on the aerosol chemistry of Kuwaiti oil-fire plumes provides a direct link between those fires and aerosols collected at the Mauna Loa Observatory (MLO) during the late spring and summer of 1991. By itself, temporal covariation of fine-particle concentrations of elemental carbon, sulfur, and the noncrustal V/Zn ratio in MLO aerosols suggested a link to large-scale oil-combustion sources, but not necessarily to Kuwait. However, high concentrations of fine-particle (0.1-1.0 microm diameter) NaCl were observed in the 'white' oil-fire plumes over Kuwait during the summer of 1991. In the absence of other demonstratable sources of fine-particle Na, these relationships provide a direct link between the Kuwaiti oil-fires and aerosol composition observed at MLO. (Copyright (c) 1993 American Geophysical Union.)

The fine art of ‘sourcery’

CERN Multimedia

2009-01-01

The commissioning of the new Linac4 source – first element of the new acceleration chain for the upgrade of the LHC (sLHC) – started at the beginning of July. After years of preparation but after only a few hours of fine-tuning of the numerous parameters involved, the source has delivered its first negative ions. The civil engineering work for the new Linac4 going on near Restaurant 2.While the LHC is preparing for restart, teams of experts involved in the sLHC project are also working on the new facilities that will allow the LHC to run at higher luminosity. The beginning of the new chain of accelerators is Linac4, whose excavation works started October last year. "The particle source that we are commissioning now will be installed at the beginning of the path", explains Maurizio Vretenar, Linac4 project leader. "It is a critical element of the chain as all protons that will circulate in the CERN accelerators will originate from it." The Linac 4 source is differ...

[Health evaluation of fine particulate matter in indoor air].

Science.gov (United States)

2008-11-01

When evaluating the health effects of indoor air fine particulate matter, the indoor dynamics as well as the physical, chemical and biological properties of fine particles have to be considered. The indoor air fraction PM2.5 largely stems from outdoor air. Accordingly, the German Working Group on Indoor Guideline Values of the Federal Environmental Agency and the States' Health Authorities also recommends WHO's (2006) 24-hour mean guideline value of 25 microg PM2,5 per cubic meter for indoor air evaluation. In contrast to PM2.5, coarse particles (PM10) in schools, kindergartens and dwellings show much higher indoor air concentrations. Additional sources indoors have to be assumed. Because of the different composition of indoor air compared to outdoor air and due to the lack of dose-response relationships of coarse particles in indoor air, the health effects of indoor air PM10 can not be evaluated yet. Sufficient and consistent ventilation is an indispensable basis to reduce PM concentrations in indoor spaces. Furthermore, known sources of PM indoors should be detected consequently and subsequently minimized.

Monte Carlo importance sampling for the MCNP trademark general source

International Nuclear Information System (INIS)

Lichtenstein, H.

1996-01-01

Research was performed to develop an importance sampling procedure for a radiation source. The procedure was developed for the MCNP radiation transport code, but the approach itself is general and can be adapted to other Monte Carlo codes. The procedure, as adapted to MCNP, relies entirely on existing MCNP capabilities. It has been tested for very complex descriptions of a general source, in the context of the design of spent-reactor-fuel storage casks. Dramatic improvements in calculation efficiency have been observed in some test cases. In addition, the procedure has been found to provide an acceleration to acceptable convergence, as well as the benefit of quickly identifying user specified variance-reduction in the transport that effects unstable convergence

Assessment of Population Exposure to Coarse and Fine Particulate Matter in the Urban Areas of Chennai, India

Directory of Open Access Journals (Sweden)

Ramachandran Prasannavenkatesh

2015-01-01

Full Text Available Research outcomes from the epidemiological studies have found that the course (PM10 and the fine particulate matter (PM2.5 are mainly responsible for various respiratory health effects for humans. The population-weighted exposure assessment is used as a vital decision-making tool to analyze the vulnerable areas where the population is exposed to critical concentrations of pollutants. Systemic sampling was carried out at strategic locations of Chennai to estimate the various concentration levels of particulate pollution during November 2013–January 2014. The concentration of the pollutants was classified based on the World Health Organization interim target (IT guidelines. Using geospatial information systems the pollution and the high-resolution population data were interpolated to study the extent of the pollutants at the urban scale. The results show that approximately 28% of the population resides in vulnerable locations where the coarse particulate matter exceeds the prescribed standards. Alarmingly, the results of the analysis of fine particulates show that about 94% of the inhabitants live in critical areas where the concentration of the fine particulates exceeds the IT guidelines. Results based on human exposure analysis show the vulnerability is more towards the zones which are surrounded by prominent sources of pollution.

Assessment of Population Exposure to Coarse and Fine Particulate Matter in the Urban Areas of Chennai, India.

Science.gov (United States)

Prasannavenkatesh, Ramachandran; Andimuthu, Ramachandran; Kandasamy, Palanivelu; Rajadurai, Geetha; Kumar, Divya Subash; Radhapriya, Parthasarathy; Ponnusamy, Malini

2015-01-01

Research outcomes from the epidemiological studies have found that the course (PM10) and the fine particulate matter (PM2.5) are mainly responsible for various respiratory health effects for humans. The population-weighted exposure assessment is used as a vital decision-making tool to analyze the vulnerable areas where the population is exposed to critical concentrations of pollutants. Systemic sampling was carried out at strategic locations of Chennai to estimate the various concentration levels of particulate pollution during November 2013-January 2014. The concentration of the pollutants was classified based on the World Health Organization interim target (IT) guidelines. Using geospatial information systems the pollution and the high-resolution population data were interpolated to study the extent of the pollutants at the urban scale. The results show that approximately 28% of the population resides in vulnerable locations where the coarse particulate matter exceeds the prescribed standards. Alarmingly, the results of the analysis of fine particulates show that about 94% of the inhabitants live in critical areas where the concentration of the fine particulates exceeds the IT guidelines. Results based on human exposure analysis show the vulnerability is more towards the zones which are surrounded by prominent sources of pollution.

Discharge modulates stream metabolism dependence on fine particulate organic carbon in a Mediterranean WWTP-influenced stream

Science.gov (United States)

Drummond, J. D.; Bernal, S.; Meredith, W.; Schumer, R.; Martí Roca, E.

2017-12-01

Waste water treatment plant (WWTP) effluents constitute point source inputs of fine sediment, nutrients, carbon, and microbes to stream ecosystems. A range of responses to these inputs may be observed in recipient streams, including increases in respiration rates, which augment CO2 emissions to the atmosphere. Yet, little is known about which fractions of organic carbon (OC) contribute the most to stream metabolism in WWTP-influenced streams. Fine particulate OC (POC) represents ca. 40% of the total mass of OC in river networks, and is generally more labile than dissolved OC. Therefore, POC inputs from WWTPs could contribute disproportionately to higher rates of heterotrophic metabolism by stream microbial communities. The aim of this study was to investigate the influence of POC inputs from a WWTP effluent on the metabolism of a Mediterranean stream over a wide range of hydrologic conditions. We hypothesized that POC inputs would have a positive effect on respiration rates, and that the response to POC availability would be larger during low flows when the dilution capacity of the recipient stream is negligible. We focused on the easily resuspended fine sediment near the sediment-water interface (top 3 cm), as this region is a known hot spot for biogeochemical processes. For one year, samples of resuspended sediment were collected bimonthly at 7 sites from 0 to 800 m downstream of the WWTP point source. We measured total POC, organic matter (OM) content (%), and the associated metabolic activity of the resuspended sediment using the resazurin-resorufin smart tracer system as a proxy for aerobic ecosystem respiration. Resuspended sediment showed no difference in total POC over the year, while the OM content increased with decreasing discharge. This result together with the decreasing trend of total POC observed downstream of the point source during autumn after a long dry period, suggests that the WWTP effluent was the main contributor to stream POC. Furthermore

A new approach to the combination of IBA techniques and wind back trajectory data to determine source contributions to long range transport of fine particle air pollution

Energy Technology Data Exchange (ETDEWEB)

Cohen, David D., E-mail: dcz@ansto.gov.au [Australian Nuclear Science and Technology Organisation, Locked Bag 2001, Kirrawee DC, NSW 2232 (Australia); Crawford, Jagoda; Stelcer, Eduard; Atanacio, Armand [Australian Nuclear Science and Technology Organisation, Locked Bag 2001, Kirrawee DC, NSW 2232 (Australia)

2012-02-15

A new approach to link HYSPLIT back trajectories to the source of fine particle pollution as characterised by standard IBA techniques is discussed. The example of the long range transport of desert dust from inland Australia across the eastern coast is used to show that over a 10-year period extreme soil events originated from major agricultural regions some 30% of the time and that dust from known deserts are not always the problem.

Advanced Fine Particulate Characterization Methods

Energy Technology Data Exchange (ETDEWEB)

Steven Benson; Lingbu Kong; Alexander Azenkeng; Jason Laumb; Robert Jensen; Edwin Olson; Jill MacKenzie; A.M. Rokanuzzaman

2007-01-31

The characterization and control of emissions from combustion sources are of significant importance in improving local and regional air quality. Such emissions include fine particulate matter, organic carbon compounds, and NO{sub x} and SO{sub 2} gases, along with mercury and other toxic metals. This project involved four activities including Further Development of Analytical Techniques for PM{sub 10} and PM{sub 2.5} Characterization and Source Apportionment and Management, Organic Carbonaceous Particulate and Metal Speciation for Source Apportionment Studies, Quantum Modeling, and High-Potassium Carbon Production with Biomass-Coal Blending. The key accomplishments included the development of improved automated methods to characterize the inorganic and organic components particulate matter. The methods involved the use of scanning electron microscopy and x-ray microanalysis for the inorganic fraction and a combination of extractive methods combined with near-edge x-ray absorption fine structure to characterize the organic fraction. These methods have direction application for source apportionment studies of PM because they provide detailed inorganic analysis along with total organic and elemental carbon (OC/EC) quantification. Quantum modeling using density functional theory (DFT) calculations was used to further elucidate a recently developed mechanistic model for mercury speciation in coal combustion systems and interactions on activated carbon. Reaction energies, enthalpies, free energies and binding energies of Hg species to the prototype molecules were derived from the data obtained in these calculations. Bimolecular rate constants for the various elementary steps in the mechanism have been estimated using the hard-sphere collision theory approximation, and the results seem to indicate that extremely fast kinetics could be involved in these surface reactions. Activated carbon was produced from a blend of lignite coal from the Center Mine in North Dakota and

Multiple-source tracking: Investigating sources of pathogens, nutrients, and sediment in the Upper Little River Basin, Kentucky, water years 2013–14

Science.gov (United States)

Crain, Angela S.; Cherry, Mac A.; Williamson, Tanja N.; Bunch, Aubrey R.

2017-09-20

, and manure and septic wastes. In the NFLR Basin, a positive linear relation was observed between nitrate concentrations and nitrogen isotope ratios (δ15NNO3) (R2=0.56; p-value fertilizer and soil-derived nitrate sources.A sediment-fingerprinting approach was used to quantify the relative contribution of four upland sources in the SFLR Basin (agricultural, pasture, riparian/forest, and streambank) to understand how land management affects suspended-sediment concentration. Carbon isotope ratios (δ13C), together with calcium and carbon concentrations, were the best indicators of sediment source; the uncertainty was less than 11 percent. Fine-sediment samples collected at the SFLR Basin outlet indicated streambanks as the largest source of the fine sediment to the stream followed by cropland and riparian/forest-source areas, respectively; pasture was a minor contributing source. Streambanks and cropland were essentially equal contributors of fine sediment at the NFLR Basin outlet.

Electrosmotic conductivity in fine grained soils; Permeabilita' elettroosmotica in terreni a grana fine

Energy Technology Data Exchange (ETDEWEB)

Fava, G.; Giaco' , A.; Pasqualini, E.; Sani, D. [Ancona Univ., Ancona (Italy). Dipt. di Scienze dei Materiali e della Terra

1999-10-01

In this work, aspects relating to the process of mass and energy flows in fine grained soil under an electrical field are considered. A suitable apparatus for the study of electrokinetic phenomena and the measure of electrosmotic conductivity coefficients is projected and constructed. The obtained results are reliable and in accord with the common literature data. The values of the electrosmotic conductivity obtained depend on the cation exchange capacity of utilised soils and on the effective porosity of investigated samples. [Italian] Nel presente lavoro sono presi in esame gli aspetti generali relativi ai processi che regolano i flussi di materia e di energia nei terreni a grana fine in presenza di un campo elettrico. Vengono presentati i risultati di una sperimentazione su di un dispositivo appositamente progettato e realizzato per la misura della permeabilita' elettroosmotica e lo studio del trasporto elettrocinetico. I dati ottenuti sono risultati ripetibili e confrontabili con valori di letteratura consolidati. E' stato riscontrato che i coefficienti di permeabilita' elettroosmotica dipendono dalla capacita' di scambio cationico del terreno selezionato e dalla porosita' efficace dei campioni.

Comparison of the physical and chemical characteristics of fine road dust at different urban sites.

Science.gov (United States)

Lee, Kwang Yul; Batmunkh, Tsatsral; Joo, Hung Soo; Park, Kihong

2018-04-18

The size distribution and chemical components of a fine fraction (road dust collected at urban sites in Korea (Gwangju) and Mongolia (Ulaanbaatar) where distinct urban characteristics exist were measured. A clear bimodal size distribution was observed for the resuspended fine road dust at the urban sites in Korea. The first mode peaked at 100-110 nm, and the second peak was observed at 435-570 nm. Ultrafine mode (~30 nm) was found for the fine road dust at the Mongolia site, which was significantly affected by residential coal/biomass burning. The contribution of the water-soluble ions to the fine road dust was higher at the sites in Mongolia (15.8-16.8%) than at those in Korea (1.2-4.8%). Sulfate and chloride were the most dominant ionic species for the fine road dust in Mongolia. As (arsenic) was also much higher for the Mongolian road dust than the others. The sulfate, chloride, and As mainly come from coal burning activity, suggesting that coal and biomass combustion in Mongolia during the heating season should affect the size and chemical components of the fine road dust. Cu (copper) and Zn (zinc), carbonaceous particles (organic carbon [OC] and elemental carbon [EC]) increased at sites in Korea, suggesting that the fine road dust at these sites was significantly affected by the high volume of traffic (engine emission and brake/tire wear). Our results suggest that chemical profiles for road dust specific to certain sites should be applied to more accurately apportion road dust source contributing to the ambient particulate matter. Size and chemical characteristics of fine road dust at sites having distinct urban characteristics were examined. Residential coal and biomass burning and traffic affected physiochemical properties of the fine road dust. Different road dust profiles at different sites should be needed to determine the ambient PM2.5 sources more accurately.

Anne Fine

Directory of Open Access Journals (Sweden)

Philip Gaydon

2015-04-01

Full Text Available An interview with Anne Fine with an introduction and aside on the role of children’s literature in our lives and development, and our adult perceptions of the suitability of childhood reading material. Since graduating from Warwick in 1968 with a BA in Politics and History, Anne Fine has written over fifty books for children and eight for adults, won the Carnegie Medal twice (for Goggle-Eyes in 1989 and Flour Babies in 1992, been a highly commended runner-up three times (for Bill’s New Frock in 1989, The Tulip Touch in 1996, and Up on Cloud Nine in 2002, been shortlisted for the Hans Christian Andersen Award (the highest recognition available to a writer or illustrator of children’s books, 1998, undertaken the positon of Children’s Laureate (2001-2003, and been awarded an OBE for her services to literature (2003. Warwick presented Fine with an Honorary Doctorate in 2005. Philip Gaydon’s interview with Anne Fine was recorded as part of the ‘Voices of the University’ oral history project, co-ordinated by Warwick’s Institute of Advanced Study.

Chemical characterization and sources of personal exposure to fine particulate matter (PM2.5) in the megacity of Guangzhou, China.

Science.gov (United States)

Chen, Xiao-Cui; Jahn, Heiko J; Engling, Guenter; Ward, Tony J; Kraemer, Alexander; Ho, Kin-Fai; Yim, S H L; Chan, Chuen-Yu

2017-12-01

Concurrent ambient and personal measurements of fine particulate matter (PM 2.5 ) were conducted in eight districts of Guangzhou during the winter of 2011. Personal-to-ambient (P-C) relationships of PM 2.5 chemical components were determined and sources of personal PM 2.5 exposures were evaluated using principal component analysis and a mixed-effects model. Water-soluble inorganic ions (e.g., SO 4 2- , NO 3 - , NH 4 + , C 2 O 4 2- ) and anhydrosugars (e.g., levoglucosan, mannosan) exhibited median personal-to-ambient (P/C) ratios personal PM 2.5 were significantly affected by ambient sources. Conversely, elemental carbon (EC) and calcium (Ca 2+ ) showed median P/C ratios greater than unity, illustrating significant impact of local traffic, indoor sources, and/or personal activities on individual's exposure. SO 4 2- displayed very low coefficient of divergence (COD) values coupled with strong P-C correlations, implying a uniform distribution of SO 4 2- in the urban area of Guangzhou. EC, Ca 2+ , and levoglucosan were otherwise heterogeneously distributed across individuals in different districts. Regional air pollution (50.4 ± 0.9%), traffic-related particles (8.6 ± 0.7%), dust-related particles (5.8 ± 0.7%), and biomass burning emissions (2.0 ± 0.2%) were moderate to high positive sources of personal PM 2.5 exposure in Guangzhou. The observed positive and significant contribution of Ca 2+ to personal PM 2.5 exposure, highlighting indoor sources and/or personal activities, were driving factors determining personal exposure to dust-related particles. Considerable discrepancies (COD values ranging from 0.42 to 0.50) were shown between ambient concentrations and personal exposures, indicating caution should be taken when using ambient concentrations as proxies for personal exposures in epidemiological studies. Copyright © 2017 Elsevier Ltd. All rights reserved.

Fibroadenoma: can fine needle aspiration biopsy avoid short term follow-up?

Science.gov (United States)

Leconte, I; Abraham, C; Galant, C; Sy, M; Berlière, M; Fellah, L

2012-10-01

To confirm whether fine needle aspiration biopsy (FNAB) can avoid close monitoring, a source of worry for women patients with a suspected fibroadenoma found by ultrasound, and requiring their compliance. Over 39months, 427 nodules with a diagnosis of fibroadenoma were sampled in 372 patients using ultrasound-guided FNAB. The sonographic appearance of all the nodules suggested BI-RADS category 3 fibroadenomas. The mean size of the fibroadenomas was 9mm. The mean duration of follow-up was 29.7months. Seven nodules had atypical cytology: a microbiopsy and/or excision found a simple fibroadenoma (n=3), mastitis (n=1), a fibroadenoma associated with a papilloma (n=1), fibrosis (n=1) and normal tissue (n=1). Seven other nodules were resected during treatment for synchronous cancer, and were diagnosed as fibroadenomas. Two hundred and seventy-six nodules were followed-up (121 patients were lost to follow-up [n=132]) and the appearance of 263 nodules (95.29%) was stable. Seven nodules, which had increased in size, underwent another FNAB or microbiopsy or surgery. Five nodules were not found again. The borders of one nodule showed modifications. The use of fine needle aspiration biopsy, interpreted by an experienced cytologist, means that short term follow-up of fibroadenomas can be avoided. Copyright © 2012 Éditions françaises de radiologie. Published by Elsevier Masson SAS. All rights reserved.

Use of FTA cards for the storage of breast carcinoma nucleic acid on fine-needle aspiration samples.

Science.gov (United States)

Peluso, Anna Lucia; Cascone, Anna Maria; Lucchese, Lucrezia; Cozzolino, Immacolata; Ieni, Antonio; Mignogna, Chiara; Pepe, Stefano; Zeppa, Pio

2015-10-01

The preservation and storage of nucleic acids is important for DNA molecular techniques. The material obtained by fine-needle aspiration (FNA) is often scanty and can not be wasted. FTA cards are filter papers that immobilize and stabilize nucleic acids and can be stored at room temperature. The current study evaluated whether nucleic acids of breast carcinoma cells, obtained by FNA in a clinical setting, may be collected, stored, and preserved on FTA cards. Thirty breast carcinoma, 5 non-Hodgkin lymphoma (NHL), and 5 benign reactive lymph node (RLN) cell samples obtained by FNA were stored at -80 °C and on FTA cards. DNA extraction and polymerase chain reaction were performed on cells at -80 °C and on 2 punched disks of FTA cards. Fifty nanograms of extracted DNA from both sample types were used to amplify the Janus Kinase 2 (JAK2) gene. The mean value of DNA extracted from breast carcinoma cells was 28.19 ng/µL for that stored at -80 °C and 3.28 ng/µL for that stored on FTA cards. Agarose gel analysis demonstrated expected bands of DNA in 29 cases (97%) with both methods. The mean value of DNA extracted from NHL and RLN samples was 37.54 ng/µL and 4.28 ng/µL, respectively, and agarose gel analysis demonstrated bands of high molecular weight DNA in both methods. Significant differences in DNA yield were found between storage at -80 °C and FTA cards (PFTA cards can be conveniently used for the storage of breast carcinoma cells obtained by FNA, thus providing a reliable alternative to traditional methods. © 2015 American Cancer Society.

Fine Needle Aspiration Cytology In Tumour Diagnosis | Obaseki ...

African Journals Online (AJOL)

Fine needle aspiration cytology (FNAC), a technique for obtaining cellular material for cytological examination and diagnosis using a 21- gauge or smaller needle, is performed using a 5, 10, or 20ml syringe either freehand or using special syringe holders. It allows a minimally invasive, rapid diagnosis of tissue samples but

Evaluation of Skin Surface as an Alternative Source of Reference DNA Samples: A Pilot Study.

Science.gov (United States)

Albujja, Mohammed H; Bin Dukhyil, Abdul Aziz; Chaudhary, Abdul Rauf; Kassab, Ahmed Ch; Refaat, Ahmed M; Babu, Saranya Ramesh; Okla, Mohammad K; Kumar, Sachil

2018-01-01

An acceptable area for collecting DNA reference sample is a part of the forensic DNA analysis development. The aim of this study was to evaluate skin surface cells (SSC) as an alternate source of reference DNA sample. From each volunteer (n = 10), six samples from skin surface areas (forearm and fingertips) and two traditional samples (blood and buccal cells) were collected. Genomic DNA was extracted and quantified then genotyped using standard techniques. The highest DNA concentration of SSC samples was collected using the tape/forearm method of collection (2.1 ng/μL). Cotton swabs moistened with ethanol yielded higher quantities of DNA than swabs moistened with salicylic acid, and it gave the highest percentage of full STR profiles (97%). This study supports the use of SSC as a noninvasive sampling technique and as a extremely useful source of DNA reference samples among certain cultures where the use of buccal swabs can be considered socially unacceptable. © 2017 American Academy of Forensic Sciences.

Source apportionment of fine particles and its chemical components over the Yangtze River Delta, China during a heavy haze pollution episode

Science.gov (United States)

Li, L.; An, J. Y.; Zhou, M.; Yan, R. S.; Huang, C.; Lu, Q.; Lin, L.; Wang, Y. J.; Tao, S. K.; Qiao, L. P.; Zhu, S. H.; Chen, C. H.

2015-12-01

contributors to organic carbon. Results show that the Yangtze River Delta region should focus on the joint pollution control of industrial processing, combustion emissions, mobile source emissions, and fugitive dust. Regional transport of air pollution among the cities are prominent, and the implementation of regional joint prevention and control of air pollution will help to alleviate fine particulate matter concentrations under heavy pollution case significantly.

Hydrological modelling of fine sediments in the Odzi River, Zimbabwe

African Journals Online (AJOL)

Hydrological modelling of fine sediments in the Odzi River, Zimbabwe. ... An analysis of the model structure and a comparison with the rating curve function ... model validation through split sample and proxy basin comparison was performed.

A Global Perspective of Fine Particulate Matter Pollution and Its Health Effects.

Science.gov (United States)

Mukherjee, Arideep; Agrawal, Madhoolika

Fine particulate matter (PM) in the ambient air is implicated in a variety of human health issues throughout the globe. Regulation of fine PM in the atmosphere requires information on the dimension of the problem with respect to variations in concentrations and sources. To understand the current status of fine particles in the atmosphere and their potential harmful health effects in different regions of the world this review article was prepared based on peer-reviewed scientific papers, scientific reports, and database from government organizations published after the year 2000 to evaluate the global scenario of the PM 2.5 (particles levels and exceedances of national and international standards were several times higher in Asian countries, while levels in Europe and USA were mostly well below the respective standards. Vehicular traffic has a significant influence on PM 2.5 levels in urban areas; followed by combustion activities (biomass, industrial, and waste burning) and road dust. In urban atmosphere, fine particles are mostly associated with different health effects with old aged people, pregnant women, and more so children being the most susceptible ones. Fine PM chemical constituents severely effect health due to their carcinogenic or mutagenic nature. Most of the research indicated an exceedance of fine PM level of the standards with a diverse array of health effects based on PM 2.5 chemical constituents. Emission reduction policies with epidemiological studies are needed to understand the benefits of sustainable control measures for fine PM mitigation.

Molecular testing guidelines for lung adenocarcinoma: Utility of cell blocks and concordance between fine-needle aspiration cytology and histology samples

Science.gov (United States)

Heymann, Jonas J.; Bulman, William A.; Maxfield, Roger A.; Powell, Charles A.; Halmos, Balazs; Sonett, Joshua; Beaubier, Nike T.; Crapanzano, John P.; Mansukhani, Mahesh M.; Saqi, Anjali

2014-01-01

Background: Lung cancer is a leading cause of mortality, and patients often present at a late stage. More recently, advances in screening, diagnosing, and treating lung cancer have been made. For instance, greater numbers of minimally invasive procedures are being performed, and identification of lung adenocarcinoma driver mutations has led to the implementation of targeted therapies. Advances in molecular techniques enable use of scant tissue, including cytology specimens. In addition, per recently published consensus guidelines, cytology-derived cell blocks (CBs) are preferred over direct smears. Yet, limited comparison of molecular testing of fine-needle aspiration (FNA) CBs and corresponding histology specimens has been performed. This study aimed to establish concordance of epidermal growth factor receptor (EGFR) and Kirsten rat sarcoma (KRAS) virus homolog testing between FNA CBs and histology samples from the same patients. Materials and Methods: Patients for whom molecular testing for EGFR or KRAS was performed on both FNA CBs and histology samples containing lung adenocarcinoma were identified retrospectively. Following microdissection, when necessary, concordance of EGFR and KRAS molecular testing results between FNA CBs and histology samples was evaluated. Results: EGFR and/or KRAS testing was performed on samples obtained from 26 patients. Concordant results were obtained for all EGFR (22/22) and KRAS (17/17) mutation analyses performed. Conclusions: Identification of mutations in lung adenocarcinomas affects clinical decision-making, and it is important that results from small samples be accurate. This study demonstrates that molecular testing on cytology CBs is as sensitive and specific as that on histology. PMID:24987443

Molecular testing guidelines for lung adenocarcinoma: Utility of cell blocks and concordance between fine-needle aspiration cytology and histology samples

Directory of Open Access Journals (Sweden)

Jonas J. Heymann

2014-01-01

Full Text Available Background: Lung cancer is a leading cause of mortality, and patients often present at a late stage. More recently, advances in screening, diagnosing, and treating lung cancer have been made. For instance, greater numbers of minimally invasive procedures are being performed, and identification of lung adenocarcinoma driver mutations has led to the implementation of targeted therapies. Advances in molecular techniques enable use of scant tissue, including cytology specimens. In addition, per recently published consensus guidelines, cytology-derived cell blocks (CBs are preferred over direct smears. Yet, limited comparison of molecular testing of fine-needle aspiration (FNA CBs and corresponding histology specimens has been performed. This study aimed to establish concordance of epidermal growth factor receptor (EGFR and Kirsten rat sarcoma (KRAS virus homolog testing between FNA CBs and histology samples from the same patients. Materials and Methods: Patients for whom molecular testing for EGFR or KRAS was performed on both FNA CBs and histology samples containing lung adenocarcinoma were identified retrospectively. Following microdissection, when necessary, concordance of EGFR and KRAS molecular testing results between FNA CBs and histology samples was evaluated. Results: EGFR and/or KRAS testing was performed on samples obtained from 26 patients. Concordant results were obtained for all EGFR (22/22 and KRAS (17/17 mutation analyses performed. Conclusions: Identification of mutations in lung adenocarcinomas affects clinical decision-making, and it is important that results from small samples be accurate. This study demonstrates that molecular testing on cytology CBs is as sensitive and specific as that on histology.

Downstream Fining of Polydispersed Gravity Currents Along a V-Shaped Valley.

Science.gov (United States)

Besson, C. K.; Meriaux, C. A. M. D.

2014-12-01

Turbidity currents belong to the class of currents transporting sediments, whose deposits exhibit downstream grain size fining. In this study, the objective was to better understand the relationship between downstream fining and grain sizes at the source. To this end, we performed four lock-exchange experiments of polydispersed and turbulent gravity currents flowing along a 5-m long V-shaped valley. The particle volumetric concentrations were typically 3%. The four currents were made of 1) Silicon Carbide (SiC), 2) Glass Beads (GBs), 3) a combined poorly sorted SiC/GBs, and 4) a moderately sorted combined SiC/GBs. We used the Morphologi G3 tool developed by Malvern Instruments Corporate (Malvern Instruments Ltd, UK) for the grain size analyses. We first established a criterion for identifying the appropriate number of grain size classes nbclassfor characterizing the grain size distributions. We considered the four statistical indicators that are the arithmetic mean size dmean, the standard deviation σd, the skewness Skd, and the kurtosis Kd, and show that the four indicators for the initial grain size distributions reach plateaux when nb_class≥ 20. Hence we chose nbclass=20 as being our appropriate bin width. These four indicators were then calculated for samples taken along the deposits to establish the grain size distributions along the deposits. The subsequent profiles of dmean, σd, Skd, and Kd with distance from the lock show highly variable behaviours between the different initial distributions. In particular, the distance over which the loss of the largest grains of the initial distribution occurs [dmean> dmean(initial)], can cover up to half the runout length. Curiously, the different rates of fining estimated from the curves (dmean/ dmean(initial)) as a function of downstream distance (x/x_runout) do not appear to be well correlated with the sedimentation velocities based on dmean(initial). This is currently being investigated.

Deposition velocities to Sorbus aria, Acer campestre, Populus deltoides x trichocarpa 'Beaupre', Pinus nigra and x Cupressocyparis leylandii for coarse, fine and ultra-fine particles in the urban environment

International Nuclear Information System (INIS)

Freer-Smith, P.H.; Beckett, K.P.; Taylor, Gail

2005-01-01

Trees are effective in the capture of particles from urban air to the extent that they can significantly improve urban air quality. As a result of their aerodynamic properties conifers, with their smaller leaves and more complex shoot structures, have been shown to capture larger amounts of particle matter than broadleaved trees. This study focuses on the effects of particle size on the deposition velocity of particles (Vg) to five urban tree species (coniferous and broadleaved) measured at two field sites, one urban and polluted and a second more rural. The larger uptake to conifers is confirmed, and for broadleaves and conifers Vg values are shown to be greater for ultra-fine particles (Dp<1.0 μm) than for fine and coarse particles. This is important since finer particles are more likely to be deposited deep in the alveoli of the human lung causing adverse health effects. The finer particle fraction is also shown to be transported further from the emission source; in this study a busy urban road. In further sets of data the aqueous soluble and insoluble fractions of the ultra-fines were separated, indicating that aqueous insoluble particles made up only a small proportion of the ultra-fines. Much of the ultra-fine fraction is present as aerosol. Chemical analysis of the aqueous soluble fractions of coarse, fine and ultra-fine particles showed the importance of nitrates, chloride and phosphates in all three size categories at the polluted and more rural location

Identifying the source of fluvial terrace deposits using XRF scanning and Canonical Discriminant Analysis: A case study of the Chihshang terraces, eastern Taiwan

Science.gov (United States)

Chang, Queenie; Lee, Jian-Cheng; Hunag, Jyh-Jaan; Wei, Kuo-Yen; Chen, Yue-Gau; Byrne, Timothy B.

2018-05-01

The source of fluvial deposits in terraces provides important information about the catchment fluvial processes and landform evolution. In this study, we propose a novel approach that combines high-resolution Itrax-XRF scanning and Canonical Discriminant Analysis (CDA) to identify the source of fine-grained fluvial terrace deposits. We apply this approach to a group of terraces that are located on the hanging wall of the Chihshang Fault in eastern Taiwan with two possible sources, the Coastal Range on the east and the Central Range on the west. Our results of standard samples from the two potential sources show distinct ranges of canonical variables, which provided a better separation ability than individual chemical elements. We then tested the possibility of using this approach by applying it to several samples with known sediment sources and obtain positive results. Applying this same approach to the fine-grained sediments in Chihshang terraces indicates that they are mostly composed of Coastal Range material but also contain some inputs from the Central Range. In two lowest terraces T1 and T2, the fine-grained deposits show significant Central Range component. For terrace T4, the results show less Central Range input and a trend of decreasing Central Range influences up section. The Coastal Range material becomes dominant in the two highest terraces T7 and T10. Sediments in terrace T5 appear to have been potentially altered by post-deposition chemical alteration processes and are not included in the analysis. Our results show that the change in source material in the terraces deposits was relatively gradual rather than the sharp changes suggested by the composition of the gravels and conglomerates. We suggest that this change in sources is related to the change in dominant fluvial processes that controlled by the tectonic activity.

JIGSAW PUZZLE IMPROVE FINE MOTOR ABILITIES OF UPPER EXTREMITIES IN POST-STROKE ISCHEMIC CLIENTS

Directory of Open Access Journals (Sweden)

Kusnanto Kusnanto

2017-06-01

Full Text Available Introduction: Ischemic stroke is a disease caused by focal cerebral ischemia, where is a decline in blood flow that needed for neuronal metabolism, leading to neurologic deficit include motor deficit such as fine motor skills impairment. Therapy of fine motor skills disorders is to improve motor function, prevent contractures and complications. These study aimed to identify the effect of playing Jigsaw Puzzle on muscle strength, extensive motion, and upper extremity fine motor skills in patients with ischemic stroke at Dr. Moewardi Hospital, Surakarta. Methods: Experimental Quasi pre-posttest one group control. The number of samples were 34 respondents selected using purposive sampling technique. The samples were divided into intervention and control groups. The intervention group was 17 respondents who were given standard treatment hospital and played Jigsaw Puzzle 2 times a day for six days. Control group is one respondent given by hospital standard therapy without given additional Jigsaw Puzzle game. Evaluation of these research is done on the first and seventh day for those groups. Result: The results showed that muscle strength, the range of joint motion and fine motor skills of upper extremities increased (p = 0.001 significantly after being given the Jigsaw Puzzle games. These means playing Jigsaw Puzzle increase muscle strength, the range of joint motion and upper extremity fine motor skill of ischemic stroke patients. Discussion and conclusion: Jigsaw puzzle game administration as additional rehabilitation therapy in upper extremity fine motor to minimize the occurrence of contractures and motor disorders in patients with ischemic stroke. Jigsaw puzzle game therapy capable of creating repetitive motion as a key of neurological rehabilitation in Ischemic Stroke. This study recommends using jigsaw puzzle game as one of intervention in the nursing care of Ischemic Stroke patients.

Soft sensor for real-time cement fineness estimation.

Science.gov (United States)

Stanišić, Darko; Jorgovanović, Nikola; Popov, Nikola; Čongradac, Velimir

2015-03-01

This paper describes the design and implementation of soft sensors to estimate cement fineness. Soft sensors are mathematical models that use available data to provide real-time information on process variables when the information, for whatever reason, is not available by direct measurement. In this application, soft sensors are used to provide information on process variable normally provided by off-line laboratory tests performed at large time intervals. Cement fineness is one of the crucial parameters that define the quality of produced cement. Providing real-time information on cement fineness using soft sensors can overcome limitations and problems that originate from a lack of information between two laboratory tests. The model inputs were selected from candidate process variables using an information theoretic approach. Models based on multi-layer perceptrons were developed, and their ability to estimate cement fineness of laboratory samples was analyzed. Models that had the best performance, and capacity to adopt changes in the cement grinding circuit were selected to implement soft sensors. Soft sensors were tested using data from a continuous cement production to demonstrate their use in real-time fineness estimation. Their performance was highly satisfactory, and the sensors proved to be capable of providing valuable information on cement grinding circuit performance. After successful off-line tests, soft sensors were implemented and installed in the control room of a cement factory. Results on the site confirm results obtained by tests conducted during soft sensor development. Copyright © 2014 ISA. Published by Elsevier Ltd. All rights reserved.

Predictors of indoor fine particulate matter in infants' bedrooms in Denmark

DEFF Research Database (Denmark)

Raaschou-Nielsen, Ole; Sørensen, Mette; Hertel, Ole

2011-01-01

conducted 1122 measurements of fine PM (PM2.5 and black smoke) in the bedrooms of 389 infants and registered indoor activities and characteristics of the house. We used mixed models to identify and quantify associations between predictors and concentrations. Results The concentration of PM2.5 was 2.8 times....... Frying without a range hood was associated with a 32% (95% CI, 12–54%) higher PM2.5 concentration per time per day, whereas frying with use of a range hood did not increase the concentration in the infant’s bedroom. Use of a fireplace, stove, candles or vacuum-cleaner, interior rebuilding or renovation......, local traffic, inner city residence and cold season increased the fine PM concentration. Open windows decreased the PM2.5 concentration in homes with smokers but increased the concentration in non-smoking homes. Conclusions We identified several sources of fine PM in infants’ bedrooms...

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

DEVELOPMENT OF FINE MOTOR COORDINATION AND VISUAL-MOTOR INTEGRATION IN PRESCHOOL CHILDREN

Directory of Open Access Journals (Sweden)

Haris MEMISEVIC

2013-03-01

Full Text Available Fine motor skills are prerequisite for many everyday activities and they are a good predictor of a child's later academic outcome. The goal of the present study was to assess the effects of age on the development of fine motor coordination and visual-motor integration in preschool children. The sample for this study consisted of 276 preschool children from Canton Sara­jevo, Bosnia and Herzegovina. We assessed children's motor skills with Beery Visual Motor Integration Test and Lafayette Pegboard Test. Data were analyzed with one-way ANOVA, followed by planned com­parisons between the age groups. We also performed a regression analysis to assess the influence of age and motor coordination on visual-motor integration. The results showed that age has a great effect on the development of fine motor skills. Furthermore, the results indicated that there are possible sensitive periods at preschool age in which the development of fine motor skills is accelerated. Early intervention specialists should make a thorough evaluations of fine motor skills in preschool children and make motor (rehabilitation programs for children at risk of fine motor delays.

Sources of variability in the determination by evaporation method of gross alpha activity in water samples

Energy Technology Data Exchange (ETDEWEB)

Baeza, A.; Corbacho, J.A. [LARUEX, Caceres (Spain). Environmental Radioactivity Lab.

2013-07-01

Determining the gross alpha activity concentration of water samples is one way to screen for waters whose radionuclide content is so high that its consumption could imply surpassing the Total Indicative Dose as defined in European Directive 98/83/EC. One of the most commonly used methods to prepare the sources to measure gross alpha activity in water samples is desiccation. Its main advantages are the simplicity of the procedure, the low cost of source preparation, and the possibility of simultaneously determining the gross beta activity. The preparation of the source, the construction of the calibration curves, and the measurement procedure itself involve, however, various factors that may introduce sufficient variability into the results to significantly affect the screening process. We here identify the main sources of this variability, and propose specific procedures to follow in the desiccation process that will reduce the uncertainties, and ensure that the result is indeed representative of the sum of the activities of the alpha emitters present in the sample. (orig.)

Alternative potassium source for the cultivation of ornamental sunflower

Directory of Open Access Journals (Sweden)

Sabrina Thereza dos Santos Torqueti

2016-06-01

Full Text Available ABSTRACT Brazil is dependent on importation of fertilizers, especially the potassics. Rocks and minerals that contain nutrients have a potential for use in agriculture as fertilizer, especially those of slow solubilization and that exhibit residual effect. In this context, the objective was to assess the feasibility of glauconite rock as potassium source for the cultivation of ornamental sunflower. The experiment was conducted under controlled conditions arranged in an entirely randomized design, in a 4x4 + 4 factorial scheme, with four replicates and one plant per plot. Four glauconite-based fertilizers were used as a potassium source: fine grained glauconite, fine grained organo-mineral glauconite, coarse grained glauconite and coarse grained organo-mineral glauconite, in four doses, as well as an additional treatment with four doses of KCl, the principal conventional source of the nutrient. The height of the flower stalks, the diameter of the stem and floral capitulum, the number of cultivation days and post-harvest durability were evaluated. The application of KCl yielded the production of flower stems with greater height and larger capitulum diameter in relation to the supply of glauconite. Among the glauconite based fertilizers, the fine grained organo-mineral product provided the best flower charateristics. The postharvest commercial durability of the flower stalks was higher in plants that received the glauconite and fine grained organo-mineral glauconite. The fine grained organo-mineral glauconite surpasses all other alternative sources of potassium in relation to the agronomic characteristics evaluated.

Radiological and microanalytical studies of fine Melnik wines

International Nuclear Information System (INIS)

Tonev, Dimiter; Geleva, Elena; Damianova, Anna; Grigorov, Todor; Goutev, Nikolai; Protohristov, Hristo; Stoyanov, Chavdar; Bashev, Vladimir; Popov, Evgeni; Tringovska, Ivanka; Kostova, Dimitrina

2016-01-01

Nuclear methods and chemical fingerprinting can help in the process of determination of the year of production (vintage) and the geographical provenance or designation of origin of high quality wines. For the first time we report results obtained for fine Bulgarian wines from Melnik region, as well as, vineyard soil, vine stems and grape leaves. The gamma-ray activity of the radioisotope 137 Cs has been measured also for the first time in wines from different vintages using low background, high resolution gamma-ray spectrometry. The specific concentrations of 16 elements have been measured in samples from soil, vine stems, grape leaves and fine wines from the type Shiroka Melnishka, which are grown in typical Melnik vineyard by means of Inductively Coupled Plasma-Optical Emission Spectrometry (ICP-OES). The obtained radiological and chemical correlations can be used as initial data base in order to determinate the wine vintage back to 1986 and, eventually, as tool to establish the designation of origin of the Melnik fine wine and the quality of the wine

Preparation of archaeological samples for its dating by thermoluminescence

International Nuclear Information System (INIS)

Mejia F, D.

2000-01-01

The present work shows the results of the preparation of archaeological samples for their dating by thermoluminescence (Tl) using the Fine grain technique established by Zimmerman but with the varying of such preparation was realized in normal daylight conditions, only the taking of the Tl readings were realized in dark room and red light. In the chapter 1 basic concepts are described about: matter constitution, radioactivity, units and radiation magnitudes, and thermoluminescence. In the chapter 2 some theoretical aspects on dating are showed. It is described how realizing the samples collection, the fine grain method, the determination of the accumulated dose through the years or paleodoses (P=Q+I) by mean of the increasing to obtain the dose equivalent dose (Q) and the signal regeneration method to obtain the correction factor by supra linearity (1), the determination of the annual dose rate to apply the age equation and the evaluation of the age uncertainty with the error limits. The development of experimental part with samples from the archaeological site named Edzna in Campeche, Mexico is described in the chapter 3. The results are presented in the chapter 4. It was obtained an age for the sample named CH7 it was obtained an age of 389 ± years. In conclusion the preparation of the archaeological samples for their dating by Tl in the conditions before mentioned is reliable, but they must be realized more studies with samples of well known age, preparing them in normal daylight conditions and simultaneously in dark room with red light. In order to observe how respond the minerals present in the sample at different dose rapidity, the same samples must be radiated with radiation sources with different dose rate. (Author)

Distribution of inert gases in fines from the Cayley-Descartes region

Science.gov (United States)

Walton, J. R.; Lakatos, S.; Heymann, D.

1973-01-01

The inert gases in 14 different fines and in one sample of 2 to 4 mm fines from Apollo 16 were measured by mass spectroscopy with respect to trapped solar wind gases, cosmogenic gases, and 'parentless' Ar-40. Such studies are helpful for the understanding of regolith evolution, of transport of regolith fines, and of the lunar atmosphere. The Apollo 16 soils are unique because they represent, after Luna 20, the second and much more extensive record from the lunar highlands. The landing site presents the problem of materials from the Cayley Formation vs those from the Descartes Formation. There are two large, relatively fresh craters in the area, North Ray and South Ray, whose ejecta patterns may be recognized in the inert-gas record.

Analyses of fine paste ceramics

International Nuclear Information System (INIS)

Sabloff, J.A.

1980-01-01

Four chapters are included: history of Brookhaven fine paste ceramics project, chemical and mathematical procedures employed in Mayan fine paste ceramics project, and compositional and archaeological perspectives on the Mayan fine paste ceramics

IBA and synchrotron methods for sub-micron fine particle characterisation

International Nuclear Information System (INIS)

Cohen, D.D.; Siegele, R. Stampfl. A.; Cai, Z.; Ilinski, P.; Rodrigues, W.; Legnini, D.G.; Yun, W.; Lai, B.

1999-01-01

Fine air-borne particles, whose average diameters are 2.5 μm and less (PM2.5), are known to play significant roles in a number of human and environmental issues. They may penetrate deep into the human lung system and are believed, due to their small size or due to toxins adsorbed onto their surfaces, to be responsible for up to 60,000 and 10,000 deaths in the U.S. and U.K. respectively. Health studies within NSW, Australia carried out by the NSW EPA, have shown increased hospital admissions and excess deaths related to high fine particle pollution episodes. A number of environmental issues are affected by the amount and type of fine-particles in the air. The white and brown hazes that occur in populated cities causing poor visibility are due to light scattering from fine particles. These same particles are easily transported large distances in the lower atmosphere playing a key role in global pollution and climate forcing. Current knowledge of fine-particle concentrations and constituents is very limited. Sources of fine particles are both natural and man-made. Over the past few years considerable work on the characterisation of these particles has been going on at ANSTO using accelerator based ion beam analysis (IBA) methods. X-ray fluorescence using ion beams from accelerators and synchrotron fluorescence are complementary techniques. This is well demonstrated by the plot. PIXE has higher cross sections for low Z elements, but for high Z elements closer to the excitation energy (16keV) synchrotron radiation cross sections are larger. Both techniques are multi-elemental analysis techniques

Analyses of fine paste ceramics

Energy Technology Data Exchange (ETDEWEB)

Sabloff, J A [ed.

1980-01-01

Four chapters are included: history of Brookhaven fine paste ceramics project, chemical and mathematical procedures employed in Mayan fine paste ceramics project, and compositional and archaeological perspectives on the Mayan fine paste ceramics. (DLC)

Source Term Model for Fine Particle Resuspension from Indoor Surfaces

National Research Council Canada - National Science Library

Kim, Yoojeong; Gidwani, Ashok; Sippola, Mark; Sohn, Chang W

2008-01-01

This Phase I effort developed a source term model for particle resuspension from indoor surfaces to be used as a source term boundary condition for CFD simulation of particle transport and dispersion in a building...

Fine-Grained Rate Shaping for Video Streaming over Wireless Networks

Directory of Open Access Journals (Sweden)

Chen Tsuhan

2004-01-01

Full Text Available Video streaming over wireless networks faces challenges of time-varying packet loss rate and fluctuating bandwidth. In this paper, we focus on streaming precoded video that is both source and channel coded. Dynamic rate shaping has been proposed to “shape” the precompressed video to adapt to the fluctuating bandwidth. In our earlier work, rate shaping was extended to shape the channel coded precompressed video, and to take into account the time-varying packet loss rate as well as the fluctuating bandwidth of the wireless networks. However, prior work on rate shaping can only adjust the rate oarsely. In this paper, we propose “fine-grained rate shaping (FGRS” to allow for bandwidth adaptation over a wide range of bandwidth and packet loss rate in fine granularities. The video is precoded with fine granularity scalability (FGS followed by channel coding. Utilizing the fine granularity property of FGS and channel coding, FGRS selectively drops part of the precoded video and still yields decodable bit-stream at the decoder. Moreover, FGRS optimizes video streaming rather than achieves heuristic objectives as conventional methods. A two-stage rate-distortion (RD optimization algorithm is proposed for FGRS. Promising results of FGRS are shown.

The Viking X ray fluorescence experiment - Sampling strategies and laboratory simulations. [Mars soil sampling

Science.gov (United States)

Baird, A. K.; Castro, A. J.; Clark, B. C.; Toulmin, P., III; Rose, H., Jr.; Keil, K.; Gooding, J. L.

1977-01-01

Ten samples of Mars regolith material (six on Viking Lander 1 and four on Viking Lander 2) have been delivered to the X ray fluorescence spectrometers as of March 31, 1977. An additional six samples at least are planned for acquisition in the remaining Extended Mission (to January 1979) for each lander. All samples acquired are Martian fines from the near surface (less than 6-cm depth) of the landing sites except the latest on Viking Lander 1, which is fine material from the bottom of a trench dug to a depth of 25 cm. Several attempts on each lander to acquire fresh rock material (in pebble sizes) for analysis have yielded only cemented surface crustal material (duricrust). Laboratory simulation and experimentation are required both for mission planning of sampling and for interpretation of data returned from Mars. This paper is concerned with the rationale for sample site selections, surface sampler operations, and the supportive laboratory studies needed to interpret X ray results from Mars.

Sediment studies at Bikini Atoll part 1. distribution of fine and coarse components in surface sediments

International Nuclear Information System (INIS)

Noshkin, V. E.; Eagle, R.J.; Robison, W.L.

1997-01-01

In 1979, 21 years after the moratorium on nuclear testing in the Marshall Islands, surface sediment samples (to depths of 2 and 4 cm) were collected from 87 locations over the floor of Bikini lagoon. The main purpose for the collections was to map the distribution of long- lived man-made radionuclides associated with the bottom material. In addition the samples were processed to estimate the fraction of fine and coarse components to show what modifications occurred since the sediment composition was first described in samples collected before testing in 1946. In this report a comparison is made of the amount and distribution of fine material associated with the lagoon surface sediment before and after the testing of nuclear devices. Nuclear testing produced more finely divided material in-the surface sediment layer over large areas of the lagoon and especially in regions of the lagoon and reef adjacent to test sites. Five cratering events at Bikini Atoll generated sufficient material to account for the inventory of new fine material found over the bottom surface of the lagoon. Although the fraction of fine material in the bottom sediments was altered by the nuclear events, the combined processes of formation, transport and deposition were not sufficiently dynamic to alter the geographical features of the major sedimentary components over most of the lagoon floor

Sediment studies at Bikini Atoll part 1. distribution of fine and coarse components in surface sediments

Energy Technology Data Exchange (ETDEWEB)

Noshkin, V. E.; Eagle, R.J.; Robison, W.L.

1997-01-01

In 1979, 21 years after the moratorium on nuclear testing in the Marshall Islands, surface sediment samples (to depths of 2 and 4 cm) were collected from 87 locations over the floor of Bikini lagoon. The main purpose for the collections was to map the distribution of long- lived man-made radionuclides associated with the bottom material. In addition the samples were processed to estimate the fraction of fine and coarse components to show what modifications occurred since the sediment composition was first described in samples collected before testing in 1946. In this report a comparison is made of the amount and distribution of fine material associated with the lagoon surface sediment before and after the testing of nuclear devices. Nuclear testing produced more finely divided material in-the surface sediment layer over large areas of the lagoon and especially in regions of the lagoon and reef adjacent to test sites. Five cratering events at Bikini Atoll generated sufficient material to account for the inventory of new fine material found over the bottom surface of the lagoon. Although the fraction of fine material in the bottom sediments was altered by the nuclear events, the combined processes of formation, transport and deposition were not sufficiently dynamic to alter the geographical features of the major sedimentary components over most of the lagoon floor.

UTLEON3 Exploring Fine-Grain Multi-Threading in FPGAs

CERN Document Server

Daněk, Martin; Kohout, Lukáš; Sýkora, Jaroslav; Bartosinski, Roman

2013-01-01

This book describes a specification, microarchitecture, VHDL implementation and evaluation of a SPARC v8 CPU with fine-grain multi-threading, called micro-threading. The CPU, named UTLEON3, is an alternative platform for exploring CPU multi-threading that is compatible with the industry-standard GRLIB package. The processor microarchitecture was designed to map in an efficient way the data-flow scheme on a classical von Neumann pipelined processing used in common processors, while retaining full binary compatibility with existing legacy programs.  Describes and documents a working SPARC v8, with fine-grain multithreading and fast context switch; Provides VHDL sources for the described processor; Describes a latency-tolerant framework for coupling hardware accelerators to microthreaded processor pipelines; Includes programming by example in the micro-threaded assembly language.    

Coarse-to-fine region selection and matching

KAUST Repository

Yang, Yanchao

2015-10-15

We present a new approach to wide baseline matching. We propose to use a hierarchical decomposition of the image domain and coarse-to-fine selection of regions to match. In contrast to interest point matching methods, which sample salient regions to reduce the cost of comparing all regions in two images, our method eliminates regions systematically to achieve efficiency. One advantage of our approach is that it is not restricted to covariant salient regions, which is too restrictive under large viewpoint and leads to few corresponding regions. Affine invariant matching of regions in the hierarchy is achieved efficiently by a coarse-to-fine search of the affine space. Experiments on two benchmark datasets shows that our method finds more correct correspondence of the image (with fewer false alarms) than other wide baseline methods on large viewpoint change. © 2015 IEEE.

NGST fine guidance sensor

Science.gov (United States)

Rowlands, Neil; Hutchings, John; Murowinski, Richard G.; Alexander, Russ

2003-03-01

Instrumentation for the Next Generation Space Telescope (NGST) is currently in the Phase A definition stage. We have developed a concept for the NGST Fine Guidance Sensor or FGS. The FGS is a detector array based imager which resides in the NGST focal plane. We report here on tradeoff studies aimed at defining an overall configuration of the FGS which will meet the performance and interface requirements. A key performance requirement is a noise equivalent angle of 3 milli-arcseconds to be achieved with 95% probability for any pointing of the observatory in the celestial sphere. A key interface requirement is compatibility with the architecture of the Integrated Science Instrument Module (ISIM). The concept developed consists of two independent and redundant FGS modules, each with a 4' x 2' field of view covered by two 2048 x 2048 infrared detector arrays, providing 60 milli-arcsecond sampling. Performance modeling supporting the choice of this architecture and the trade space considered is presented. Each module has a set of readout electronics which perform star detection, pixel-by-pixel correction, and in fine guiding mode, centroid calculation. These readout electronics communicate with the ISIM Command &Data Handling Units where the FGS control software is based. Rationale for this choice of architecture is also presented.

Receptor models for source apportionment of remote aerosols in Brazil

International Nuclear Information System (INIS)

Artaxo Netto, P.E.

1985-11-01

The PIXE (particle induced X-ray emission), and PESA (proton elastic scattering analysis) method were used in conjunction with receptor models for source apportionment of remote aerosols in Brazil. The PIXE used in the determination of concentration for elements with Z >- 11, has a detection limit of about 1 ng/m 3 . The concentrations of carbon, nitrogen and oxygen in the fine fraction of Amazon Basin aerosols was measured by PESA. We sampled in Jureia (SP), Fernando de Noronha, Arembepe (BA), Firminopolis (GO), Itaberai (GO) and Amazon Basin. For collecting the airbone particles we used cascade impactors, stacked filter units, and streaker samplers. Three receptor models were used: chemical mass balance, stepwise multiple regression analysis and principal factor analysis. The elemental and gravimetric concentrations were explained by the models within the experimental errors. Three sources of aerosol were quantitatively distinguished: marine aerosol, soil dust and aerosols related to forests. The emission of aerosols by vegetation is very clear for all the sampling sites. In Amazon Basin and Jureia it is the major source, responsible for 60 to 80% of airborne concentrations. (Author) [pt

The chemical composition and sources of PM2.5 during the 2009 Chinese New Year's holiday in Shanghai

Science.gov (United States)

Feng, Jialiang; Sun, Peng; Hu, Xiaoling; Zhao, Wei; Wu, Minghong; Fu, Jiamo

2012-11-01

China is virtually shut down during the week-long Chinese New Year's holiday. This implies that the anthropogenic emissions would be greatly decreased during the period thus providing an opportunity to study the air quality in China under reduced emissions, and the drastic emission changes during a short period of time allows the comparison of source contributions under significantly different conditions. Seventeen PM2.5 samples were collected during the 2009 Chinese New Year's holiday in Shanghai to study the composition and sources of the fine particles. Organic carbon (OC), elemental carbon (EC), eight water-soluble ions, fourteen metals and solvent extractable organic compounds (SEOC) including alkanes, hopanes, polycyclic aromatic hydrocarbons (PAHs) and fatty acids were measured. Diagnostic PAH ratios, correlation analysis of OC, EC, n-alkanes, hopanes and PAHs showed that vehicle emissions were the main source of n-alkanes and EC, and an important source of the locally emitted particulate PAHs in urban Shanghai, while coal burning should be the main source of the transported PAHs from the inland areas. The composition of n-fatty acids also provided some clue on the significance of the contribution by kitchen activities. In the New Year's Eve's sample, 75% of the particle mass was estimated to be from fireworks, and K+, SO42 -, Cl-, OC, Al and Ba were the main components. Firework fine particles had high OC/EC ratio and low NO3-/SO42 - ratio.

Fine tuning and MOND in a metamaterial "multiverse".

Science.gov (United States)

Smolyaninov, Igor I; Smolyaninova, Vera N

2017-08-14

We consider the recently suggested model of a multiverse based on a ferrofluid. When the ferrofluid is subjected to a modest external magnetic field, the nanoparticles inside the ferrofluid form small hyperbolic metamaterial domains, which from the electromagnetic standpoint behave as individual "Minkowski universes" exhibiting different "laws of physics", such as different strength of effective gravity, different versions of modified Newtonian dynamics (MOND) and different radiation lifetimes. When the ferrofluid "multiverse" is populated with atomic or molecular species, and these species are excited using an external laser source, the radiation lifetimes of atoms and molecules in these "universes" depend strongly on the individual physical properties of each "universe" via the Purcell effect. Some "universes" are better fine-tuned than others to sustain the excited states of these species. Thus, the ferrofluid-based metamaterial "multiverse" may be used to study models of MOND and to illustrate the fine-tuning mechanism in cosmology.

Ion beam production with sub-milligram samples of material from an ECR source for AMS

Energy Technology Data Exchange (ETDEWEB)

Scott, R., E-mail: scott@phy.anl.gov; Palchan-Hazan, T.; Pardo, R.; Vondrasek, R. [Argonne Tandem Linac Accelerator System (ATLAS), Argonne National Laboratory, Lemont, Illinois 60439 (United States); Bauder, W. [Argonne Tandem Linac Accelerator System (ATLAS), Argonne National Laboratory, Lemont, Illinois 60439 (United States); Nuclear Structure Laboratory, University of Notre Dame, Notre Dame, Indiana 46556 (United States)

2016-02-15

Current accelerator mass spectrometry experiments at the Argonne Tandem Linac Accelerator System facility at Argonne National Laboratory push us to improve the ion source performance with a large number of samples and a need to minimize cross contamination. These experiments can require the creation of ion beams from as little as a few micrograms of material. These low concentration samples push the limit of our current efficiency and stability capabilities of the electron cyclotron resonance ion source. A combination of laser ablation and sputtering techniques coupled with a newly modified multi-sample changer has been used to meet this demand. We will discuss performance, stability, and consumption rates as well as planned improvements.

Sahara Coal: the fine art of collecting fines for profit

Energy Technology Data Exchange (ETDEWEB)

Schreckengost, D.; Arnold, D.

1984-09-01

Because of a change in underground mining methods that caused a considerable increase in the amount of fine sizes in the raw coal, Sahara Coal Co. designed and constructed a unique and simple fine coal system at their Harrisburg, IL prep plant. Before the new system was built, the overload of the fine coal circuit created a cost crunch due to loss of salable coal to slurry ponds, slurry pond cleaning costs, and operating and maintenance costs--each and every one excessive. Motivated by these problems, Sahara designed a prototype system to dewater the minus 28 mesh refuse. The success of the idea permitted fine refuse to be loaded onto the coarse refuse belt. Sahara also realized a large reduction in pond cleaning costs. After a period of testing, an expanded version of the refuse system was installed to dewater and dry the 28 mesh X 0 clean coal. Clean coal output increased about 30 tph. Cost savings justified the expenditures for the refuse and clean coal systems. These benefits, combined with increased coal sales revenue, paid back the project costs in less than a year.

Sampling and chemical analysis by TXRF of size-fractionated ambient aerosols and emissions

International Nuclear Information System (INIS)

John, A.C.; Kuhlbusch, T.A.J.; Fissan, H.; Schmidt, K.-G-; Schmidt, F.; Pfeffer, H.-U.; Gladtke, D.

2000-01-01

Results of recent epidemiological studies led to new European air quality standards which require the monitoring of particles with aerodynamic diameters ≤ 10 μm (PM 10) and ≤ 2.5 μm (PM 2.5) instead of TSP (total suspended particulate matter). As these ambient air limit values will be exceeded most likely at several locations in Europe, so-called 'action plans' have to be set up to reduce particle concentrations, which requires information about sources and processes of PMx aerosols. For chemical characterization of the aerosols, different samplers were used and total reflection x-ray fluorescence analysis (TXRF) was applied beside other methods (elemental and organic carbon analysis, ion chromatography, atomic absorption spectrometry). For TXRF analysis, a specially designed sampling unit was built where the particle size classes 10-2.5 μm and 2.5-1.0 μm were directly impacted on TXRF sample carriers. An electrostatic precipitator (ESP) was used as a back-up filter to collect particles <1 μm directly on a TXRF sample carrier. The sampling unit was calibrated in the laboratory and then used for field measurements to determine the elemental composition of the mentioned particle size fractions. One of the field campaigns was carried out at a measurement site in Duesseldorf, Germany, in November 1999. As the composition of the ambient aerosols may have been influenced by a large construction site directly in the vicinity of the station during the field campaign, not only the aerosol particles, but also construction material was sampled and analyzed by TXRF. As air quality is affected by natural and anthropogenic sources, the emissions of particles ≤ 10 μm and ≤ 2.5 μm, respectively, have to be determined to estimate their contributions to the so called coarse and fine particle modes of ambient air. Therefore, an in-stack particle sampling system was developed according to the new ambient air quality standards. This PM 10/PM 2.5 cascade impactor was

Size-resolved source apportionment of ambient particles by positive matrix factorization at Gosan background site in East Asia

Directory of Open Access Journals (Sweden)

J. S. Han

2006-01-01

Full Text Available Size- and time-resolved aerosol samples were collected using an eight-stage Davis rotating unit for monitoring (DRUM sampler from 29 March to 29 May in 2002 at Gosan, Jeju Island, Korea, which is one of the representative background sites in East Asia. These samples were analyzed using synchrotron X-ray fluorescence for 3-h average concentrations of 19 elements consisting of S, Si, Al, Fe, Ca, Cl, Cu, Zn, Ti, K, Mn, Pb, Ni, V, Se, As, Rb, Cr, Br. The size-resolved data sets were then analyzed using the positive matrix factorization (PMF technique in order to identify possible sources and estimate their contribution to particulate matter mass. PMF analysis uses the uncertainty of the measured data to provide an optimal weighting. Fifteen sources were resolved in eight size ranges (0.07~12 μm and included continental soil, local soil, sea salt, biomass/biofuel burning, coal combustion, oil heating furnace, residual oil fired boiler, municipal incineration, nonferrous metal source, ferrous metal source, gasoline vehicle, diesel vehicle, copper smelter and volcanic emission. PMF analysis of size-resolved source contributions showed that natural sources represented by local soil, sea salt and continental soil contributed about 79% to the predicted primary particulate matter (PM mass in the coarse size range (1.15~12 μm. On the other hand, anthropogenic sources such as coal combustion and biomass/biofuel burning contributed about 60% in the fine size range (0.56~2.5 μm. The diesel vehicle source contributed the most in the ultra-fine size range (0.07~0.56 μm and was responsible for about 52% of the primary PM mass.

Fining of Red Wine Monitored by Multiple Light Scattering.

Science.gov (United States)

Ferrentino, Giovanna; Ramezani, Mohsen; Morozova, Ksenia; Hafner, Daniela; Pedri, Ulrich; Pixner, Konrad; Scampicchio, Matteo

2017-07-12

This work describes a new approach based on multiple light scattering to study red wine clarification processes. The whole spectral signal (1933 backscattering points along the length of each sample vial) were fitted by a multivariate kinetic model that was built with a three-step mechanism, implying (1) adsorption of wine colloids to fining agents, (2) aggregation into larger particles, and (3) sedimentation. Each step is characterized by a reaction rate constant. According to the first reaction, the results showed that gelatin was the most efficient fining agent, concerning the main objective, which was the clarification of the wine, and consequently the increase in its limpidity. Such a trend was also discussed in relation to the results achieved by nephelometry, total phenols, ζ-potential, color, sensory, and electronic nose analyses. Also, higher concentrations of the fining agent (from 5 to 30 g/100 L) or higher temperatures (from 10 to 20 °C) sped up the process. Finally, the advantage of using the whole spectral signal vs classical univariate approaches was demonstrated by comparing the uncertainty associated with the rate constants of the proposed kinetic model. Overall, multiple light scattering technique showed a great potential for studying fining processes compared to classical univariate approaches.

Sterile paper points as a bacterial DNA-contamination source in microbiome profiles of clinical samples

NARCIS (Netherlands)

van der Horst, J.; Buijs, M.J.; Laine, M.L.; Wismeijer, D.; Loos, B.G.; Crielaard, W.; Zaura, E.

2013-01-01

Objectives High throughput sequencing of bacterial DNA from clinical samples provides untargeted, open-ended information on the entire microbial community. The downside of this approach is the vulnerability to DNA contamination from other sources than the clinical sample. Here we describe

Liquid sampling-atmospheric pressure glow discharge as a secondary excitation source: Assessment of plasma characteristics

International Nuclear Information System (INIS)

Manard, Benjamin T.; Gonzalez, Jhanis J.; Sarkar, Arnab; Dong, Meirong; Chirinos, Jose; Mao, Xianglei; Russo, Richard E.; Marcus, R. Kenneth

2014-01-01

The liquid sampling-atmospheric pressure glow discharge (LS-APGD) has been assessed as a secondary excitation source with a parametric evaluation regarding carrier gas flow rate, applied current, and electrode distance. With this parametric evaluation, plasma optical emission was monitored in order to obtain a fundamental understanding with regards to rotational temperature (T rot ), excitation temperature (T exc ), electron number density (n e ), and plasma robustness. Incentive for these studies is not only for a greater overall fundamental knowledge of the APGD, but also in instrumenting a secondary excitation/ionization source following laser ablation (LA). Rotational temperatures were determined through experimentally fitting of the N 2 and OH molecular emission bands while atomic excitation temperatures were calculated using a Boltzmann distribution of He and Mg atomic lines. The rotational and excitation temperatures were determined to be ∼ 1000 K and ∼ 2700 K respectively. Electron number density was calculated to be on the order of ∼ 3 × 10 15 cm −3 utilizing Stark broadening effects of the Hα line of the Balmer series and a He I transition. In addition, those diagnostics were performed introducing magnesium (by solution feed and laser ablation) into the plasma in order to determine any perturbation under heavy matrix sampling. The so-called plasma robustness factor, derived by monitoring Mg II/Mg I emission ratios, is also employed as a reflection of potential perturbations in microplasma energetics across the various operation conditions and sample loadings. While truly a miniaturized source ( 3 volume), the LS-APGD is shown to be quite robust with plasma characteristics and temperatures being unaffected upon introduction of metal species, whether by liquid or laser ablation sample introduction. - Highlights: • Liquid sampling-atmospheric pressure glow discharge (LS-APGD) • LS-APGD as a secondary excitation source for laser-ablated (LA

Characteristics of fine particulate matter and its sources in an industrialized coastal city, Ningbo, Yangtze River Delta, China

Science.gov (United States)

Wang, Weifeng; Yu, Jie; Cui, Yang; He, Jun; Xue, Peng; Cao, Wan; Ying, Hongmei; Gao, Wenkang; Yan, Yingchao; Hu, Bo; Xin, Jinyuan; Wang, Lili; Liu, Zirui; Sun, Yang; Ji, Dongsheng; Wang, Yuesi

2018-05-01

Chemical information is essential in understanding the characteristics of airborne particles, and effectively controlling airborne particulate matter pollution, but it remains unclear in some regions due to the scarcity of measurement data. In the present study, 92 daily PM2.5 (particulate matter with an aerodynamic diameter ≤ 2.5 μm) samples as well as historical observation data of air pollutants were collected in urban Ningbo, one of important industrial cities in the coastal area of the Yangtze River Delta, China in autumn and winter (from Nov. 2014 to Feb. 2015). Various chemical species in PM2.5 were determined including water soluble ions, organic and elemental carbon and elements. Positive matrix factorization model, cluster analysis of back trajectories, potential source contribution function (PSCF) model and concentration-weighted trajectory (CWT) model were used for identifying sources, apportioning contributions from each source and tracking potential areas of sources. The results showed the PM2.5 concentration has been reducing; nonetheless, the concentrations of PM2.5 are still much higher than the World Health Organization guideline with high PM2.5 concentrations observed in autumn and winter for the past few years. During the sampling period, the average PM2.5 mass concentration was 77 μg/m3 with the major components of OC, NO3-, SO42 -, NH4+ and EC, accounting for 24.7, 18.8, 14.5, 11.8 and 6.4% in the total mass concentration, respectively. When the aerosol pollution got worse during the sampling period, the NO3-, SO42 - and NH4+ concentrations increased accordingly and NO3- appeared to increase at fastest rate. SO42 - transported from industrial areas led to slight difference in spatial distribution of SO42 - in Ningbo. More secondary organic carbon was formed and the enrichment factor values of Cu, Ag, Cd, Sn and Pb increased with the degradation of air quality. Ten types of sources were identified for PM2.5 in the autumn and winter of

X-ray absorption fine structure (XAFS) studies of cobalt silicide thin films

International Nuclear Information System (INIS)

Naftel, S.J.; Coulthard, I.; Hu, Y.; Sham, T.K.; Zinke-Allmang, M.

1998-01-01

Cobalt silicide thin films, prepared on Si(100) wafers, have been studied by X-ray absorption near edge structures (XANES) at the Si K-, L 2,3 - and Co K-edges utilizing both total electron (TEY) and fluorescence yield (FLY) detection as well as extended X-ray absorption fine structure (EXAFS) at the Co K-edge. Samples made using DC sputter deposition on clean Si surfaces and MBE were studied along with a bulk CoSi 2 sample. XANES and EXAFS provide information about the electronic structure and morphology of the films. It was found that the films studied have essentially the same structure as bulk CoSi 2 . Both the spectroscopy and materials characterization aspects of XAFS (X-ray absorption fine structures) are discussed

DEVELOPMENT OF FINE MOTOR COORDINATION AND VISUAL-MOTOR INTEGRATION IN PRESCHOOL CHILDREN

OpenAIRE

MEMISEVIC Haris; HADZIC Selmir

2015-01-01

Fine motor skills are prerequisite for many everyday activities and they are a good predictor of a child's later academic outcome. The goal of the present study was to assess the effects of age on the development of fine motor coordination and visual-motor integration in preschool children. The sample for this study consisted of 276 preschool children from Canton Sara­jevo, Bosnia and Herzegovina. We assessed children's motor skills with Beery Visual Motor Integration Test and Lafayette Pegbo...

Spatial and temporal variability in urban fine particulate matter concentrations

International Nuclear Information System (INIS)

Levy, Jonathan I.; Hanna, Steven R.

2011-01-01

Identification of hot spots for urban fine particulate matter (PM 2.5 ) concentrations is complicated by the significant contributions from regional atmospheric transport and the dependence of spatial and temporal variability on averaging time. We focus on PM 2.5 patterns in New York City, which includes significant local sources, street canyons, and upwind contributions to concentrations. A literature synthesis demonstrates that long-term (e.g., one-year) average PM 2.5 concentrations at a small number of widely-distributed monitoring sites would not show substantial variability, whereas short-term (e.g., 1-h) average measurements with high spatial density would show significant variability. Statistical analyses of ambient monitoring data as a function of wind speed and direction reinforce the significance of regional transport but show evidence of local contributions. We conclude that current monitor siting may not adequately capture PM 2.5 variability in an urban area, especially in a mega-city, reinforcing the necessity of dispersion modeling and methods for analyzing high-resolution monitoring observations. - Highlights: →Fine particulate matter (PM 2.5 ) hot spots are hard to identify in urban areas. → Literature conclusions about PM 2.5 hot spots depend on study design and methods. → Hot spots are more likely for short-term concentrations at high spatial density. → Statistical methods illustrate local source impacts beyond regional transport. → Dispersion models and high-resolution monitors are both needed to find hot spots. - Fine particulate matter can vary spatially within large urban areas, in spite of the significant contribution from regional atmospheric transport.

High Heat Load Properties of Ultra Fine Grain Tungsten

International Nuclear Information System (INIS)

Zhou, Z.; Du, J.; Ge, C.; Linke, J.; Pintsuk, G.; Song, S.X.

2007-01-01

Full text of publication follows: Tungsten is increasingly considered as a promising candidate armour materials facing the plasma in tokamaks for medium to high heat flux components (EAST, ASDEX, ITER). Fabrication tungsten with ultra fine grain size is considered as an effective way to ameliorate some disadvantages of tungsten, such as its brittleness at room temperature. But the research data on the performance of ultra fine grain tungsten is still very limit. In this work, high heat load properties of pure ultra-fine grain tungsten have been studied. The ultra fine grain tungsten samples with average grain size of 0.2 μm, 1 μm and 3 μm were fabricated by resistance sintering under ultra high pressure. The annealing experiments for the investigation of the material resistance against grain growth have been done by annealing samples in a vacuum furnace at different temperature holding for 2 hours respectively. It is found that recrystallization and grain growth occur at heating temperature of 1250 deg. c. The finer the initial grain sizes of tungsten, the smaller its grain growth grain. The effects of transient high thermal loads (off normal events like disruptions) on tungsten surface morphology have been performed in electron beam test facility JUDITH. The thermal loads tests have been carried out with 4 ms pulses at different power density of 0.22, 0.33, 0.44, 0.55 and 0.88 GW/m 2 respectively. Horizontal cracks formed for all tungsten samples at 0.44 GW/m 2 . Particle erosions occurred for tungsten with 3 μm size at 0.33 GW/m 2 and for tungsten with 0.2 and 1 μm size at 0.55 GW/m 2 . The weight loss of tungsten with 0.2, 1 and 3 μm size are 2,0.1,0.6 mg respectively at 0.88 GW/m 2 . The effects of a large number of very short transient repetitive thermal loads (ELM-like) on tungsten surface morphology also have been performed by using a fundamental wave of a YAG laser. It is found that tungsten with 0.2 μm size has the best performance. (authors)

High Heat Load Properties of Ultra Fine Grain Tungsten

Energy Technology Data Exchange (ETDEWEB)

Zhou, Z.; Du, J.; Ge, C. [Lab. of Special Ceramic and P/M, University of Science and Technology, 100083 Beijing (China); Linke, J.; Pintsuk, G. [FZJ-Forschungszentrum Juelich GmbH, Association Euratom-FZJ, Institut fur Plasmaphysik, Postfach 1913, D-52425 Juelich (Germany); Song, S.X. [Research Center on Fusion Materials (RCFM), University of Science and Technology Beijing (USTB), 100083 Beijing (China)

2007-07-01

Full text of publication follows: Tungsten is increasingly considered as a promising candidate armour materials facing the plasma in tokamaks for medium to high heat flux components (EAST, ASDEX, ITER). Fabrication tungsten with ultra fine grain size is considered as an effective way to ameliorate some disadvantages of tungsten, such as its brittleness at room temperature. But the research data on the performance of ultra fine grain tungsten is still very limit. In this work, high heat load properties of pure ultra-fine grain tungsten have been studied. The ultra fine grain tungsten samples with average grain size of 0.2 {mu}m, 1 {mu}m and 3 {mu}m were fabricated by resistance sintering under ultra high pressure. The annealing experiments for the investigation of the material resistance against grain growth have been done by annealing samples in a vacuum furnace at different temperature holding for 2 hours respectively. It is found that recrystallization and grain growth occur at heating temperature of 1250 deg. c. The finer the initial grain sizes of tungsten, the smaller its grain growth grain. The effects of transient high thermal loads (off normal events like disruptions) on tungsten surface morphology have been performed in electron beam test facility JUDITH. The thermal loads tests have been carried out with 4 ms pulses at different power density of 0.22, 0.33, 0.44, 0.55 and 0.88 GW/m{sup 2} respectively. Horizontal cracks formed for all tungsten samples at 0.44 GW/m{sup 2}. Particle erosions occurred for tungsten with 3 {mu}m size at 0.33 GW/m{sup 2} and for tungsten with 0.2 and 1 {mu}m size at 0.55 GW/m{sup 2}. The weight loss of tungsten with 0.2, 1 and 3 {mu}m size are 2,0.1,0.6 mg respectively at 0.88 GW/m{sup 2}. The effects of a large number of very short transient repetitive thermal loads (ELM-like) on tungsten surface morphology also have been performed by using a fundamental wave of a YAG laser. It is found that tungsten with 0.2 {mu}m size has

Effects of occupational therapy services on fine motor and functional performance in preschool children.

Science.gov (United States)

Case-Smith, J

2000-01-01

This study examined how performance components and variables in intervention influenced fine motor and functional outcomes in preschool children. In a sample of 44 preschool-aged children with fine motor delays who received occupational therapy services, eight fine motor and functional performance assessments were administered at the beginning and end of the academic year. Data on the format and intervention activities of each occupational therapy session were recorded for 8 months. The children received a mean of 23 sessions, in both individual and group format. Most of the sessions (81%) used fine motor activities; 29% addressed peer interaction, and 16% addressed play skills. Visual motor outcomes were influenced by the number of intervention sessions and percent of sessions with play goals. Fine motor outcomes were most influenced by the therapists' emphasis on play and peer interaction goals; functional outcomes were influenced by number of sessions and percent of sessions that specifically addressed self-care goals. The influence of play on therapy outcomes suggests that a focus on play in intervention activities can enhance fine motor and visual motor performance.

Scratch-induced deformation in fine- and ultrafine-grained bulk alumina

International Nuclear Information System (INIS)

Huang, Lin; Zhang, Zhihui; Zhao, Yonghao; Yao, Wenlong; Mukherjee, Amiya K.; Schoenung, Julie M.

2010-01-01

The nanoscratch behavior of two bulk α-alumina samples with 1.3 μm and 290 nm average grain sizes, respectively, was investigated using a nanoindenter in scratch mode, in combination with atomic force and scanning electron microscopy. A ductile to brittle transition was observed in the fine-grained sample, while the ultrafine-grained sample exhibited predominantly ductile deformation with a fish-bone feature indicative of a stick-slip mechanism. These findings suggest that grain refinement can increase the potential for plastic deformation in ceramics.

Study of nitro-polycyclic aromatic hydrocarbons in fine and coarse atmospheric particles

Science.gov (United States)

Teixeira, Elba Calesso; Garcia, Karine Oliveira; Meincke, Larissa; Leal, Karen Alam

2011-08-01

The purpose of the present study was to evaluate six nitro-polycyclic aromatic hydrocarbons (NPAHs) in fine (MAPA), RS, Brazil. The method used was of NPAHs isolation and derivatization, and subsequent gas chromatography by electron capture detection (CG/ECD). Results revealed a higher concentration of NPAHs, especially 3-nitrofluoranthene and 1-nitropyrene, in fine particles in the sampling sites studied within the MAPA. The diagnostic ratios calculated for PAHs and NPAHs identified the influence of heavy traffic, mainly of diesel emissions. The correlation of NPAHs with other pollutants (NO x, NO 2, NO and O 3) evidence the influence of vehicular emissions in the MAPA. The seasonal variation evidenced higher NPAHs concentrations in the fine particles during winter for most compounds studied.

The Source Equivalence Acceleration Method

International Nuclear Information System (INIS)

Everson, Matthew S.; Forget, Benoit

2015-01-01

Highlights: • We present a new acceleration method, the Source Equivalence Acceleration Method. • SEAM forms an equivalent coarse group problem for any spatial method. • Equivalence is also formed across different spatial methods and angular quadratures. • Testing is conducted using OpenMOC and performance is compared with CMFD. • Results show that SEAM is preferable for very expensive transport calculations. - Abstract: Fine-group whole-core reactor analysis remains one of the long sought goals of the reactor physics community. Such a detailed analysis is typically too computationally expensive to be realized on anything except the largest of supercomputers. Recondensation using the Discrete Generalized Multigroup (DGM) method, though, offers a relatively cheap alternative to solving the fine group transport problem. DGM, however, suffered from inconsistencies when applied to high-order spatial methods. While an exact spatial recondensation method was developed and provided full spatial consistency with the fine group problem, this approach substantially increased memory requirements for realistic problems. The method described in this paper, called the Source Equivalence Acceleration Method (SEAM), forms a coarse-group problem which preserves the fine-group problem even when using higher order spatial methods. SEAM allows recondensation to converge to the fine-group solution with minimal memory requirements and little additional overhead. This method also provides for consistency when using different spatial methods and angular quadratures between the coarse group and fine group problems. SEAM was implemented in OpenMOC, a 2D MOC code developed at MIT, and its performance tested against Coarse Mesh Finite Difference (CMFD) acceleration on the C5G7 benchmark problem and on a 361 group version of the problem. For extremely expensive transport calculations, SEAM was able to outperform CMFD, resulting in speed-ups of 20–45 relative to the normal power

Acclimation of fine root respiration to soil warming involves starch deposition in very fine and fine roots: a case study in Fagus sylvatica saplings.

Science.gov (United States)

Di Iorio, Antonino; Giacomuzzi, Valentino; Chiatante, Donato

2016-03-01

Root activities in terms of respiration and non-structural carbohydrates (NSC) storage and mobilization have been suggested as major physiological roles in fine root lifespan. As more frequent heat waves and drought periods within the next decades are expected, to what extent does thermal acclimation in fine roots represent a mechanism to cope with such upcoming climatic conditions? In this study, the possible changes in very fine (diameter respiration rate and NSC [soluble sugars (SS) and starch] concentrations, were investigated on 2-year-old Fagus sylvatica saplings subjected to a simulated long-lasting heat wave event and to co-occurring soil drying. For both very fine and fine roots, soil temperature (ST) resulted inversely correlated with specific root length, respiration rates and SSs concentration, but directly correlated with root mass, root tissue density and starch concentration. In particular, starch concentration increased under 28 °C for successively decreasing under 21 °C ST. These findings showed that thermal acclimation in very fine and fine roots due to 24 days exposure to high ST (∼ 28 °C), induced starch accumulation. Such 'carbon-savings strategy' should bear the maintenance costs associated to the recovery process in case of restored favorable environmental conditions, such as those occurring at the end of a heat wave event. Drought condition seems to affect the fine root vitality much more under moderate than high temperature condition, making the temporary exposure to high ST less threatening to root vitality than expected. © 2015 Scandinavian Plant Physiology Society.

Passive Acoustic Source Localization at a Low Sampling Rate Based on a Five-Element Cross Microphone Array

Directory of Open Access Journals (Sweden)

Yue Kan

2015-06-01

Full Text Available Accurate acoustic source localization at a low sampling rate (less than 10 kHz is still a challenging problem for small portable systems, especially for a multitasking micro-embedded system. A modification of the generalized cross-correlation (GCC method with the up-sampling (US theory is proposed and defined as the US-GCC method, which can improve the accuracy of the time delay of arrival (TDOA and source location at a low sampling rate. In this work, through the US operation, an input signal with a certain sampling rate can be converted into another signal with a higher frequency. Furthermore, the optimal interpolation factor for the US operation is derived according to localization computation time and the standard deviation (SD of target location estimations. On the one hand, simulation results show that absolute errors of the source locations based on the US-GCC method with an interpolation factor of 15 are approximately from 1/15- to 1/12-times those based on the GCC method, when the initial same sampling rates of both methods are 8 kHz. On the other hand, a simple and small portable passive acoustic source localization platform composed of a five-element cross microphone array has been designed and set up in this paper. The experiments on the established platform, which accurately locates a three-dimensional (3D near-field target at a low sampling rate demonstrate that the proposed method is workable.

Spectral fine structure effects on material and doppler reactivity worth

International Nuclear Information System (INIS)

Greenspan, E.; Karni, Y.

1975-01-01

New formulations concerning the fine structure effects on the reactivity worth of resonances are developed and conclusions are derived following the extension to more general types of perturbations which include: the removal of resonance material at finite temperatures and the temperature variation of part of the resonance material. It is concluded that the flux method can overpredict the reactivity worth of resonance materials more than anticipated. Calculations on the Doppler worth were carried out; the results can be useful for asessing the contribution of the fine structure effects to the large discrepancy that exists between the calculated and measured small sample Doppler worths. (B.G.)

Synthesis and Characterizations of Fine Silica Powder from Rice Husk Ash

International Nuclear Information System (INIS)

Khin Muyar Latt

2011-12-01

The silica content of rice husk ash obtained from the uncontrolled burning temperature of gasifier was 90.4%. The obtained rice husk ash was an amorphous form of silica with low crystallization by XRD. The sodium hydroxide solution, 1.5N, 2N, 2.5N and 3N, respectively was used to prepare sodium silicate solution by extraction method. The product silica was produced by acid precipitation method used 4.5N, 5.5N and 6.5N sulphuric acid solution. The highest yield percent of product silica extraced by 2.5N sodium hydroxide solution at 5N sulphuric acid solution was 88.84%. The crystallize size of product silica containing silicalite as a source of silica was 86nm at this condition. The fine silica powder was produced by acid refluxing mothod used 5.5N, 6N and 6.5N hydrochloric acid solution. 98% of pure fine silica powder can be produced from the product silica by refluxing method. The crystallize size of fine silica powder was 54nm. The distribution of the crystallize size of product silica powder could be found uniform in size and agglomeration. The Fourier Transform Infrared Spectra indicate the hydrogen bonded silinol groups and siloxane groups in product silica and fine silica powder.

Ecological effects and chemical composition of fine sediments in Upper Austrian streams and resulting implications for river management

Science.gov (United States)

Höfler, Sarah; Pichler-Scheder, Christian; Gumpinger, Clemens

2017-04-01

In the current scientific discussion high loads of fine sediments are considered one of the most important causes of river ecosystem degradation worldwide. Especially in intensively used catchment areas changes in the sediment household must be regarded as a reason, which prevents the achievement of the objectives of the European Water Framework Directive (WFD). Therefore, the Upper Austrian Water Authorities have launched two comprehensive studies on the topic. The first one was a survey on the current siltation status of river courses in Upper Austria. The second study deals with two selected catchments in detail, in order to get a clear picture of the impacts of the fines on the aquatic fauna (trout eggs, benthic invertebrates), the chemical composition of these fractions, the crucial hydrogeological processes and to develop possible role models for measures both in the catchments and in the streams. At eight sites within the two catchments sediment and water samples were collected at two dates for detailed chemical analysis. On one date additionally the benthic invertebrate fauna was investigated on the microhabitat level. Thereby it was possible to enhance the understanding of the range of ecological impacts caused by silting-up in different hydro-morphological circumstances and with different fine sediment loads. The water samples as well as the sediment fraction samples ethylbenzene, and xylenes), AOX (adsorbable organohalogens) and various nutrients. Additionally, the basic parameters dry residue, loss on ignition, TC (total carbon), TOC (total organic carbon) and nutrients were analysed. From the sediment eluates and the filtered water decomposition products of pesticides, remains of medical drugs, sweeteners, hormonally active substances and water-soluble elements were analysed. Furthermore, a GIS-based analysis was carried out for the two examined catchments. The model included data gained from a digital elevation model, land use data and digital soil

Optimal Design of Experiments by Combining Coarse and Fine Measurements

Science.gov (United States)

Lee, Alpha A.; Brenner, Michael P.; Colwell, Lucy J.

2017-11-01

In many contexts, it is extremely costly to perform enough high-quality experimental measurements to accurately parametrize a predictive quantitative model. However, it is often much easier to carry out large numbers of experiments that indicate whether each sample is above or below a given threshold. Can many such categorical or "coarse" measurements be combined with a much smaller number of high-resolution or "fine" measurements to yield accurate models? Here, we demonstrate an intuitive strategy, inspired by statistical physics, wherein the coarse measurements are used to identify the salient features of the data, while the fine measurements determine the relative importance of these features. A linear model is inferred from the fine measurements, augmented by a quadratic term that captures the correlation structure of the coarse data. We illustrate our strategy by considering the problems of predicting the antimalarial potency and aqueous solubility of small organic molecules from their 2D molecular structure.

Fine particulate matter in the tropical environment: monsoonal effects, source apportionment, and health risk assessment

OpenAIRE

M. F. Khan; M. F. Khan; M. T. Latif; M. T. Latif; W. H. Saw; N. Amil; N. Amil; M. S. M. Nadzir; M. S. M. Nadzir; M. Sahani; N. M. Tahir; N. M. Tahir; J. X. Chung

2016-01-01

The health implications of PM2.5 in the tropical region of Southeast Asia (SEA) are significant as PM2.5 can pose serious health concerns. PM2.5 concentration and sources here are strongly influenced by changes in the monsoon regime from the south-west quadrant to the north-east quadrant in the region. In this work, PM2.5 samples were collected at a semi-urban area using a high-volume air sampler at different seasons on 24 h basis. Analysis of trace elements and water-sol...

Constraining the Source Craters of the Martian Meteorites: Implications for Prioritiziation of Returned Samples from Mars

Science.gov (United States)

Herd, C. D. K.; Tornabene, L. L.; Bowling, T. J.; Walton, E. L.; Sharp, T. G.; Melosh, H. J.; Hamilton, J. S.; Viviano, C. E.; Ehlmann, B. L.

2018-04-01

We have made advances in constraining the potential source craters of the martian meteorites to a relatively small number. Our results have implications for Mars chronology and the prioritization of samples for Mars Sample Return.

Human impact on fluvial sediments: distinguishing regional and local sources of heavy metals contamination

Science.gov (United States)

Novakova, T.; Matys Grygar, T.; Bábek, O.; Faměra, M.; Mihaljevič, M.; Strnad, L.

2012-04-01

Industrial pollution can provide a useful tool to study spatiotemporal distribution of modern floodplain sediments, trace their provenance, and allow their dating. Regional contamination of southern Moravia (the south-eastern part of the Czech Republic) by heavy metals during the 20th century was determined in fluvial sediments of the Morava River by means of enrichment factors. The influence of local sources and sampling sites heterogeneity were studied in overbank fines with different lithology and facies. For this purpose, samples were obtained from hand-drilled cores from regulated channel banks, with well-defined local sources of contamination (factories in Zlín and Otrokovice) and also from near naturally inundated floodplains in two nature protected areas (at 30 km distance). The analyses were performed by X-ray fluorescence spectroscopy (ED XRF), ICP MS (EDXRF samples calibration, 206Pb/207Pb ratio), magnetic susceptibility, cation exchange capacity (CEC), and 137Cs and 210Pb activities. Enrichment factors (EF) of heavy metals (Pb, Zn, Cu and Cr) and magnetic susceptibility of overbank fines in near-naturally (near annually) inundated areas allowed us to reconstruct historical contamination by heavy metals in the entire study area independently on lithofacies. Measured lithological background values were then used for calculation of EFs in the channel sediments and in floodplain sediments deposited within narrow part of a former floodplain which is now reduced to about one quarter of its original width by flood defences. Sediments from regulated channel banks were found stratigraphically and lithologically "erratic", unreliable for quantification of regional contamination due to a high variability of sedimentary environment. On the other hand, these sediments are very sensitive to the nearby local sources of heavy metals. For a practical work one must first choose whether large scale, i.e. a really averaged regional contamination should be reconstructed

Characteristics and source apportionment of fine haze aerosol in Beijing during the winter of 2013

Directory of Open Access Journals (Sweden)

X. Shang

2018-02-01

Full Text Available For PM2.5 filter samples collected daily at the Chinese Research Academy of Environmental Sciences (Beijing, China from December of 2013 to February of 2014 (the winter period, chemical characteristics and sources were investigated with an emphasis on haze events in different alert levels. During the 3 months, the average PM2.5 concentration was 89 µg m−3, exceeding the Chinese national standard of 75 µg m−3 in 24  h. The maximum PM2.5 concentration was 307 µg m−3, which characterizes developed-type pollution (PM2.5 / PM10>0.5 in the World Health Organization criteria. PM2.5 was dominated by SO42−, NO3−, and pseudo-carbonaceous compounds with obvious differences in concentrations and proportions between non-haze and haze episodes. The non-negative matrix factorization (NMF analysis provided reasonable PM2.5 source profiles, by which five sources were identified: soil dust, traffic emission, biomass combustion, industrial emission, and coal combustion accounting for 13, 22, 12, 28, and 25  % of the total, respectively. The dust impact increased with northwesterlies during non-haze periods and decreased under stagnant conditions during haze periods. A blue alert of heavy air pollution was characterized by the greatest contribution from industrial emissions (61  %. During the Chinese Lantern Festival, an orange alert was issued and biomass combustion was found to be the major source owing to firework explosions. Red-alert haze was almost equally contributed by local traffic and transported coal combustion emissions from the vicinity of Beijing (approximately 40  % each that was distinguished by the highest levels of NO3− and SO42−, respectively. This study also reveals that the severity and source of haze are largely dependent on meteorological conditions.

Fine tuning power diodes with irradiation

International Nuclear Information System (INIS)

Tarneja, K.S.; Bartko, J.; Johnson, J.E.

1976-01-01

Diodes of a particular type are fine tuned with irradiation to optimize the reverse recovery time while minimizing forward voltage drop and providing more uniform electrical characcteristics. The initial and desired minority carrier lifetimes in the anode region of the type are determined as a function of forward voltage drop and reverse recovery time, and the minority carrier radiation damage factor is determined for a desired type of diode and radiation source. The radiation dosage to achieve the desired carrier lifetime with the radiation source is thereafter determined from the function 1/tau = 1/tau 0 + K phi, where tau is the desired minority carrier lifetime, tau 0 is the initial minority carrier lifetime, K is the determined minority carrier radiation damage factor and phi is the radiation dosage. A major surface and preferably the major surface adjoining the anode region of the diodes is then irradiated with the radiation source to the determined radiation dosage. Preferably, the radiation dosage is between about 1 X 10 12 and 5 X 10 13 e/cm 2 , with electron radiation of intensity between 1 and 3 MeV

A persisting secondhand smoke hazard in urban public places: results from fine particulate (PM2.5) air sampling.

Science.gov (United States)

Wilson, Nick; Edwards, Richard; Parry, Rhys

2011-03-04

To assess the need for additional smokefree settings, by measuring secondhand smoke (SHS) in a range of public places in an urban setting. Measurements were made in Wellington City during the 6-year period after the implementation of legislation that made indoor areas of restaurants and bars/pubs smokefree in December 2004, and up to 20 years after the 1990 legislation making most indoor workplaces smokefree. Fine particulate levels (PM2.5) were measured with a portable real-time airborne particle monitor. We collated data from our previously published work involving random sampling, purposeful sampling and convenience sampling of a wide range of settings (in 2006) and from additional sampling of selected indoor and outdoor areas (in 2007-2008 and 2010). The "outdoor" smoking areas of hospitality venues had the highest particulate levels, with a mean value of 72 mcg/m3 (range of maximum values 51-284 mcg/m3) (n=20 sampling periods). These levels are likely to create health hazards for some workers and patrons (i.e., when considered in relation to the WHO air quality guidelines). National survey data also indicate that these venues are the ones where SHS exposure is most frequently reported by non-smokers. Areas inside bars that were adjacent to "outdoor" smoking areas also had high levels, with a mean of 54 mcg/m3 (range of maximum values: 18-239 mcg/m3, for n=13 measurements). In all other settings mean levels were lower (means: 2-22 mcg/m3). These other settings included inside traditional style pubs/sports bars (n=10), bars (n=18), restaurants (n=9), cafes (n=5), inside public buildings (n=15), inside transportation settings (n=15), and various outdoor street/park settings (n=22). During the data collection in all settings made smokefree by law, there was only one occasion of a person observed smoking. The results suggest that compliance in pubs/bars and restaurants has remained extremely high in this city in the nearly six years since implementation of the

Gamma-ray sources

International Nuclear Information System (INIS)

Hermsen, W.

1980-01-01

Results are presented from an analysis of the celestial gamma-ray fine-scale structure based on over half of the data which may ultimately be available from the COS-B satellite. A catalogue consisting of 25 gamma-ray sources measured at energies above 100 MeV is presented. (Auth.)

Effect of diagenesis on pore pressures in fine-grained rocks in the Egersund Basin, Central North Sea

OpenAIRE

Kalani, Mohsen; Zadeh, Mohammad Koochak; Jahren, Jens; Mondol, Nazmul Haque; Faleide, Jan Inge

2015-01-01

- Pore pressure in fine-grained rocks is important with respect to drilling problems such as kicks, blowouts, borehole instability, stuck pipe and lost circulation. In this study, a succession of overpressured, fine-grained, sedimentary rocks located in the Egersund Basin, Central North Sea, was analysed with respect to mineralogical composition, source-rock maturation and log-derived petrophysical properties to highlight the effect of diagenetic processes on the pore pressure. Pe...

Liquid sampling-atmospheric pressure glow discharge as a secondary excitation source: Assessment of plasma characteristics

Energy Technology Data Exchange (ETDEWEB)

Manard, Benjamin T. [Department of Chemistry, Clemson University, Clemson, SC 29634 (United States); Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); Gonzalez, Jhanis J. [Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); Sarkar, Arnab [Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); Fuel Chemistry Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Dong, Meirong; Chirinos, Jose; Mao, Xianglei; Russo, Richard E. [Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); Marcus, R. Kenneth [Department of Chemistry, Clemson University, Clemson, SC 29634 (United States)

2014-04-01

The liquid sampling-atmospheric pressure glow discharge (LS-APGD) has been assessed as a secondary excitation source with a parametric evaluation regarding carrier gas flow rate, applied current, and electrode distance. With this parametric evaluation, plasma optical emission was monitored in order to obtain a fundamental understanding with regards to rotational temperature (T{sub rot}), excitation temperature (T{sub exc}), electron number density (n{sub e}), and plasma robustness. Incentive for these studies is not only for a greater overall fundamental knowledge of the APGD, but also in instrumenting a secondary excitation/ionization source following laser ablation (LA). Rotational temperatures were determined through experimentally fitting of the N{sub 2} and OH molecular emission bands while atomic excitation temperatures were calculated using a Boltzmann distribution of He and Mg atomic lines. The rotational and excitation temperatures were determined to be ∼ 1000 K and ∼ 2700 K respectively. Electron number density was calculated to be on the order of ∼ 3 × 10{sup 15} cm{sup −3} utilizing Stark broadening effects of the Hα line of the Balmer series and a He I transition. In addition, those diagnostics were performed introducing magnesium (by solution feed and laser ablation) into the plasma in order to determine any perturbation under heavy matrix sampling. The so-called plasma robustness factor, derived by monitoring Mg II/Mg I emission ratios, is also employed as a reflection of potential perturbations in microplasma energetics across the various operation conditions and sample loadings. While truly a miniaturized source (< 1 mm{sup 3} volume), the LS-APGD is shown to be quite robust with plasma characteristics and temperatures being unaffected upon introduction of metal species, whether by liquid or laser ablation sample introduction. - Highlights: • Liquid sampling-atmospheric pressure glow discharge (LS-APGD) • LS-APGD as a secondary

Elemental Composition In Airborne Particulate Sample Of Bandung and Lembang Region In 1999

International Nuclear Information System (INIS)

Hidayat, Achmad

2003-01-01

Concentration of airborne particulate of Bandung higher than that of Lembang. The PM2.5 fraction was in the range of 4,3 μg/m 3 to 21,1 μg/m 3 for Bandung area, and 2,9 μg/m 3 to 19,2 μg/m 3 for Lembang area for 24 hours sampling time. The PM10 fraction of Bandung area was in the range of 12,1 μg/m 3 to 44, 1 μg/m 3 , where a s the PM10 fraction of Lembang area was in the range of 5,2 μg/m 3 to 30,6 μg/m 3 . The data much lower than that of National ambient air quality standard for 24 hours, 65 μg/m 3 and 150 μg/m 3 for PM2.5 fraction and PM10 fraction respectively. No clear correlation either concentration of fine or coarse particulate to rainfall. For teen elements, which were Al, Br, Ca, Ce, CI, Cr, Fe, I, Mn, Na, Sb, Sc, V and Zn, were detected. The elements of Br, Ce, CI, Cr, I, Sb and Zn were enriched in fine and coarse of Bandung and Lembang samples, where as AI, Ca, Mn, Na and V were not enriched. The special element of Fe was enriched in fine particulate of Lembang, where as in particulate of Bandung was not enriched. Analysis of coarse particulate samples indicated the similar results to fine particulate except for Ce. The results of analysis explained that pollutant source of Bandung and Lembang were the same. Some elements such as Br, CI and I possibly come from organic material burning; Br and CI could be from motor vehicle; Cr, and Zn could be from paint factory; Zn and Sb could be from refuse incineration; while Ce could be from electronic factory. The calculation results indicated that enrichment factor of elements in fine particulate higher than that of coarse particulate. Furthermore the enrichment factor of element in airborne particulate of Bandung area was higher than that of airborne particulate of Lembang

Impaired perception of temporal fine structure and musical timbre in cochlear implant users.

Science.gov (United States)

Heng, Joseph; Cantarero, Gabriela; Elhilali, Mounya; Limb, Charles J

2011-10-01

Cochlear implant (CI) users demonstrate severe limitations in perceiving musical timbre, a psychoacoustic feature of sound responsible for 'tone color' and one's ability to identify a musical instrument. The reasons for this limitation remain poorly understood. In this study, we sought to examine the relative contributions of temporal envelope and fine structure for timbre judgments, in light of the fact that speech processing strategies employed by CI systems typically employ envelope extraction algorithms. We synthesized "instrumental chimeras" that systematically combined variable amounts of envelope and fine structure in 25% increments from two different source instruments with either sustained or percussive envelopes. CI users and normal hearing (NH) subjects were presented with 150 chimeras and asked to determine which instrument the chimera more closely resembled in a single-interval two-alternative forced choice task. By combining instruments with similar and dissimilar envelopes, we controlled the valence of envelope for timbre identification and compensated for envelope reconstruction from fine structure information. Our results show that NH subjects utilize envelope and fine structure interchangeably, whereas CI subjects demonstrate overwhelming reliance on temporal envelope. When chimeras were created from dissimilar envelope instrument pairs, NH subjects utilized a combination of envelope (p = 0.008) and fine structure information (p = 0.009) to make timbre judgments. In contrast, CI users utilized envelope information almost exclusively to make timbre judgments (p < 0.001) and ignored fine structure information (p = 0.908). Interestingly, when the value of envelope as a cue was reduced, both NH subjects and CI users utilized fine structure information to make timbre judgments (p < 0.001), although the effect was quite weak in CI users. Our findings confirm that impairments in fine structure processing underlie poor perception of musical timbre in CI

DNA analysis of soil extracts can be used to investigate fine root depth distribution of trees

Science.gov (United States)

Bithell, Sean L.; Tran-Nguyen, Lucy T. T.; Hearnden, Mark N.; Hartley, Diana M.

2015-01-01

Understanding the root distribution of trees by soil coring is time-consuming as it requires the separation of roots from soil and classification of roots into particular size classes. This labour-intensive process can limit sample throughput and therefore sampling intensity. We investigated the use of quantitative polymerase chain reaction (qPCR) on soil DNA extractions to determine live fine root DNA density (RDD, mg DNA m−2) for mango (Mangifera indica) trees. The specificity of the qPCR was tested against DNA extracted from 10 mango cultivars and 14 weed species. All mango cultivars and no weeds were detected. Mango DNA was successfully quantified from control soil spiked with mango roots and weed species. The DNA yield of mango root sections stored in moist soil at 23–28 °C declined after 15 days to low concentrations as roots decayed, indicating that dead root materials in moist soil would not cause false-positive results. To separate large roots from samples, a root separation method for field samples was used to target the root fragments remaining in sieved (minimum 2 mm aperture) soil for RDD comparisons. Using this method we compared the seasonal RDD values of fine roots for five mango rootstock cultivars in a field trial. The mean cultivar DNA yields by depth from root fragments in the sieved soil samples had the strongest relationship (adjusted multiple R2 = 0.9307, P < 0.001) with the dry matter (g m−2) of fine (diameter <0.64 mm) roots removed from the soil by sieving. This method provides a species-specific and rapid means of comparing the distribution and concentration of live fine roots of trees in orchards using soil samples up to 500 g. PMID:25552675

Catchment source contributions to the sediment-bound organic matter degrading salmonid spawning gravels in a lowland river, southern England

Energy Technology Data Exchange (ETDEWEB)

Collins, A.L., E-mail: adrian.collins@adas.co.uk [ADAS, Pendeford House, Wobaston Road, Wolverhampton WV9 5AP (United Kingdom); Geography and Environment, University of Southampton, Highfield, Southampton SO17 1BJ (United Kingdom); Williams, L.J.; Zhang, Y.S. [ADAS, Pendeford House, Wobaston Road, Wolverhampton WV9 5AP (United Kingdom); Marius, M. [Civil Engineering and Environment, University of Southampton, Highfield, Southampton S017 1BJ (United Kingdom); Dungait, J.A.J. [Department of Sustainable Systems and Grassland Science, Rothamsted Research—North Wyke, Okehampton, Devon EX20 2SB (United Kingdom); Smallman, D.J. [Civil Engineering and Environment, University of Southampton, Highfield, Southampton S017 1BJ (United Kingdom); Dixon, E.R. [Department of Sustainable Systems and Grassland Science, Rothamsted Research—North Wyke, Okehampton, Devon EX20 2SB (United Kingdom); Stringfellow, A. [Civil Engineering and Environment, University of Southampton, Highfield, Southampton S017 1BJ (United Kingdom); Sear, D.A. [Geography and Environment, University of Southampton, Highfield, Southampton SO17 1BJ (United Kingdom); Jones, J.I. [School of Biological and Chemical Sciences, Queen Mary University of London, Mile End Road, London, E1 4NS (United Kingdom); Naden, P.S. [CEH Wallingford, Maclean Building, Benson Lane, Crowmarsh Gifford, Wallingford, Oxfordshire, OX10 8BB (United Kingdom)

2013-07-01

The ingress of particulate material into freshwater spawning substrates is thought to be contributing to the declining success of salmonids reported over recent years for many rivers. Accordingly, the need for reliable information on the key sources of the sediment problem has progressed up the management agenda. Whilst previous work has focussed on apportioning the sources of minerogenic fine sediment degrading spawning habitats, there remains a need to develop procedures for generating corresponding information for the potentially harmful sediment-bound organic matter that represents an overlooked component of interstitial sediment. A source tracing procedure based on composite signatures combining bulk stable {sup 13}C and {sup 15}N isotope values with organic molecular structures detected using near infrared (NIR) reflectance spectroscopy was therefore used to assess the primary sources of sediment-bound organic matter sampled from artificial spawning redds. Composite signatures were selected using a combination of the Kruskal–Wallis H-test, principal component analysis and GA-driven discriminant function analysis. Interstitial sediment samples were collected using time-integrating basket traps which were inserted at the start of the salmonid spawning season and extracted in conjunction with critical phases of fish development (eyeing, hatch, emergence, late spawning). Over the duration of these four basket extractions, the overall relative frequency-weighted average median (± 95% confidence limits) source contributions to the interstitial sediment-bound organic matter were estimated to be in the order: instream decaying vegetation (39 ± < 1%; full range 0–77%); damaged road verges (28 ± < 1%; full range 0–77%); septic tanks (22 ± < 1%; full range 0–50%), and; farm yard manures/slurries (11 ± < 1%; full range 0–61%). The reported procedure provides a promising basis for understanding the key sources of interstitial sediment-bound organic matter

Phosphorus metabolic disorder of Guizhou semi-fine wool sheep.

Directory of Open Access Journals (Sweden)

Xiaoyun Shen

Full Text Available Guizhou semi-fine wool sheep are affected by a disease, characterized by emaciation, lameness, stiffness in the gait, enlargement of the costochondral junctions, and abnormal curvature in the long bones. The objective of this study was to determine possible relationships between the disease and mineral deficiencies. Samples of tissue and blood were collected from affected and unaffected sheep. Samples of soil and forage were collected from affected and unaffected areas. The samples were used for biochemical analyses and mineral nutrient measurements. Results showed that phosphorus (P concentrations in forage samples from affected areas were significantly lower than those from unaffected areas (P < 0.01 and the mean ratio of calcium (Ca to P in the affected forage was 12:1. Meanwhile, P concentrations of blood, bone, tooth, and wool from the affected sheep were also significantly lower than those from the unaffected group (P < 0.01. Serum P levels of the affected animals were much lower than those of the unaffected ones, whereas serum alkaline phosphatase levels from the affected were significantly higher than those from the unaffected (P < 0.01. Inorganic P levels of the affected sheep were about half of those in the control group. Oral administration of disodium hydrogen phosphate prevented and cured the disease. The study clearly demonstrated that the disease of Guizhou semi-fine wool sheep was mainly caused by the P deficiency in forage, as a result of fenced pasture and animal habitat fragmentation.

Comparison of emissions from on-road sources using a mobile laboratory under various driving and operational sampling modes

Directory of Open Access Journals (Sweden)

M. Zavala

2009-01-01

Full Text Available Mobile sources produce a significant fraction of the total anthropogenic emissions burden in large cities and have harmful effects on air quality at multiple spatial scales. Mobile emissions are intrinsically difficult to estimate due to the large number of parameters affecting the emissions variability within and across vehicles types. The MCMA-2003 Campaign in Mexico City has showed the utility of using a mobile laboratory to sample and characterize specific classes of motor vehicles to better quantify their emissions characteristics as a function of their driving cycles. The technique clearly identifies "high emitter" vehicles via individual exhaust plumes, and also provides fleet average emission rates. We have applied this technique to Mexicali during the Border Ozone Reduction and Air Quality Improvement Program (BORAQIP for the Mexicali-Imperial Valley in 2005. We analyze the variability of measured emission ratios for emitted NO_x, CO, specific VOCs, NH₃, and some primary fine particle components and properties by deploying a mobile laboratory in roadside stationary sampling, chase and fleet average operational sampling modes. The measurements reflect various driving modes characteristic of the urban fleets. The observed variability for all measured gases and particle emission ratios is greater for the chase and roadside stationary sampling than for fleet average measurements. The fleet average sampling mode captured the effects of traffic conditions on the measured on-road emission ratios, allowing the use of fuel-based emission ratios to assess the validity of traditional "bottom-up" emissions inventories. Using the measured on-road emission ratios, we estimate CO and NO_x mobile emissions of 175±62 and 10.4±1.3 metric tons/day, respectively, for the gasoline vehicle fleet in Mexicali. Comparisons with similar on-road emissions data from Mexico City indicated that fleet average NO emission ratios were

Simulating Fine-Scale Marine Pollution Plumes for Autonomous Robotic Environmental Monitoring

Directory of Open Access Journals (Sweden)

Muhammad Fahad

2018-05-01

Full Text Available Marine plumes exhibit characteristics such as intermittency, sinuous structure, shape and flow field coherency, and a time varying concentration profile. Due to the lack of experimental quantification of these characteristics for marine plumes, existing work often assumes marine plumes exhibit behavior similar to aerial plumes and are commonly modeled by filament based Lagrangian models. Our previous field experiments with Rhodamine dye plumes at Makai Research Pier at Oahu, Hawaii revealed that marine plumes show similar characteristics to aerial plumes qualitatively, but quantitatively they are disparate. Based on the field data collected, this paper presents a calibrated Eulerian plume model that exhibits the qualitative and quantitative characteristics exhibited by experimentally generated marine plumes. We propose a modified model with an intermittent source, and implement it in a Robot Operating System (ROS based simulator. Concentration time series of stationary sampling points and dynamic sampling points across cross-sections and plume fronts are collected and analyzed for statistical parameters of the simulated plume. These parameters are then compared with statistical parameters from experimentally generated plumes. The comparison validates that the simulated plumes exhibit fine-scale qualitative and quantitative characteristics similar to experimental plumes. The ROS plume simulator facilitates future evaluations of environmental monitoring strategies by marine robots, and is made available for community use.

Monitoring Fine Sediment; Grande Ronde and John Day Rivers, 2000 Annual Report.

Energy Technology Data Exchange (ETDEWEB)

Rhodes, Jonathan J.; Greene, M. Jonas; Purser, Michael D. (Columbia River Inter-Tribal Fish Commission, Portland, OR)

2001-01-01

Fine sediment in spawning substrate has a major effect on salmon survival from egg to smolt. Basin-wide restoration plans have established targets for fine sediment levels in spawning habitat. The project was initiated to monitor surface fine sediment levels and overwinter intrusion of fine sediment in spring chinook salmon spawning habitat in the North Fork John Day (NFJDR) and Grande Ronde Rivers, for five years. The project is also investigating the potential relationship between surface fine levels and overwinter sedimentation. It will provide data to assess trends in substrate conditions in monitored reaches and whether trends are consistent with efforts to improve salmon habitat conditions. The data on the magnitude of overwinter sedimentation will also be used to estimate salmon survival from egg to emergence. In Sept. 1998, 1999, and Aug. 2000, sites for monitoring overwinter sedimentation were established in salmon spawning habitat in the upper Grande Ronde River, Catherine Creek (a Grande Ronde tributary), the North Fork John Day River (NFJDR), and Granite Creek (a NFJDR tributary). Surface fine sediment levels were measured in these reaches via the grid method and visually estimated to test the relative accuracy of these two methods. In 1999 and 2000, surface fine sediment was also estimated via pebble counts at selected reaches to allow comparison of results among the methods. Overwintering substrate samples were collected in April 1999 and April-May 2000 to estimate the amount of overwinter sedimentation in clean gravels in spawning habitat. Monitoring methods and locations are described.

MRL and SuperFine+MRL: new supertree methods

Science.gov (United States)

2012-01-01

Background Supertree methods combine trees on subsets of the full taxon set together to produce a tree on the entire set of taxa. Of the many supertree methods, the most popular is MRP (Matrix Representation with Parsimony), a method that operates by first encoding the input set of source trees by a large matrix (the "MRP matrix") over {0,1, ?}, and then running maximum parsimony heuristics on the MRP matrix. Experimental studies evaluating MRP in comparison to other supertree methods have established that for large datasets, MRP generally produces trees of equal or greater accuracy than other methods, and can run on larger datasets. A recent development in supertree methods is SuperFine+MRP, a method that combines MRP with a divide-and-conquer approach, and produces more accurate trees in less time than MRP. In this paper we consider a new approach for supertree estimation, called MRL (Matrix Representation with Likelihood). MRL begins with the same MRP matrix, but then analyzes the MRP matrix using heuristics (such as RAxML) for 2-state Maximum Likelihood. Results We compared MRP and SuperFine+MRP with MRL and SuperFine+MRL on simulated and biological datasets. We examined the MRP and MRL scores of each method on a wide range of datasets, as well as the resulting topological accuracy of the trees. Our experimental results show that MRL, coupled with a very good ML heuristic such as RAxML, produced more accurate trees than MRP, and MRL scores were more strongly correlated with topological accuracy than MRP scores. Conclusions SuperFine+MRP, when based upon a good MP heuristic, such as TNT, produces among the best scores for both MRP and MRL, and is generally faster and more topologically accurate than other supertree methods we tested. PMID:22280525

A comparison of color fidelity metrics for light sources using simulation of color samples under lighting conditions

Science.gov (United States)

Kwon, Hyeokjun; Kang, Yoojin; Jang, Junwoo

2017-09-01

Color fidelity has been used as one of indices to evaluate the performance of light sources. Since the Color Rendering Index (CRI) was proposed at CIE, many color fidelity metrics have been proposed to increase the accuracy of the metric. This paper focuses on a comparison of the color fidelity metrics in an aspect of accuracy with human visual assessments. To visually evaluate the color fidelity of light sources, we made a simulator that reproduces the color samples under lighting conditions. In this paper, eighteen color samples of the Macbeth color checker under test light sources and reference illuminant for each of them are simulated and displayed on a well-characterized monitor. With only a spectrum set of the test light source and reference illuminant, color samples under any lighting condition can be reproduced. In this paper, the spectrums of the two LED and two OLED light sources that have similar values of CRI are used for the visual assessment. In addition, the results of the visual assessment are compared with the two color fidelity metrics that include CRI and IES TM-30-15 (Rf), proposed by Illuminating Engineering Society (IES) in 2015. Experimental results indicate that Rf outperforms CRI in terms of the correlation with visual assessment.

Determining the sources of suspended sediment in a Mediterranean groundwater-dominated river: the Na Borges basin (Mallorca, Spain).

Science.gov (United States)

Estrany, Joan; Martinez-Carreras, Nuria

2013-04-01

Tracers have been acknowledged as a useful tool to identify sediment sources, based upon a variety of techniques and chemical and physical sediment properties. Sediment fingerprinting supports the notion that changes in sedimentation rates are not just related to increased/reduced erosion and transport in the same areas, but also to the establishment of different pathways increasing sediment connectivity. The Na Borges is a Mediterranean lowland agricultural river basin (319 km2) where traditional soil and water conservation practices have been applied over millennia to provide effective protection of cultivated land. During the twentieth century, industrialisation and pressure from tourism activities have increased urbanised surfaces, which have impacts on the processes that control streamflow. Within this context, source material sampling was focused in Na Borges on obtaining representative samples from potential sediment sources (comprised topsoil; i.e., 0-2 cm) susceptible to mobilisation by water and subsequent routing to the river channel network, while those representing channel bank sources were collected from actively eroding channel margins and ditches. Samples of road dust and of solids from sewage treatment plants were also collected. During two hydrological years (2004-2006), representative suspended sediment samples for use in source fingerprinting studies were collected at four flow gauging stations and at eight secondary sampling points using time-integrating sampling samplers. Likewise, representative bed-channel sediment samples were obtained using the resuspension approach at eight sampling points in the main stem of the Na Borges River. These deposits represent the fine sediment temporarily stored in the bed-channel and were also used for tracing source contributions. A total of 102 individual time-integrated sediment samples, 40 bulk samples and 48 bed-sediment samples were collected. Upon return to the laboratory, source material samples were

On Basu's proposal: Fines affect bribes

OpenAIRE

Popov, Sergey V.

2017-01-01

I model the connection between the equilibrium bribe amount and the fines imposed on both bribe-taker and bribe-payer. I show that Basu's (2011) proposal to lower the fines imposed on bribe-payers in order to induce more whistleblowing and increase the probability of penalizing corrupt government officials might instead increase bribe amounts. Higher expected fines on bribe-takers will make them charge larger bribes; at the same time, lowering fines for bribe-paying might increase bribe-payer...

Generation and emplacement of fine-grained ejecta in planetary impacts

Science.gov (United States)

Ghent, R.R.; Gupta, V.; Campbell, B.A.; Ferguson, S.A.; Brown, J.C.W.; Fergason, R.L.; Carter, L.M.

2010-01-01

We report here on a survey of distal fine-grained ejecta deposits on the Moon, Mars, and Venus. On all three planets, fine-grained ejecta form circular haloes that extend beyond the continuous ejecta and other types of distal deposits such as run-out lobes or ramparts. Using Earth-based radar images, we find that lunar fine-grained ejecta haloes represent meters-thick deposits with abrupt margins, and are depleted in rocks 1cm in diameter. Martian haloes show low nighttime thermal IR temperatures and thermal inertia, indicating the presence of fine particles estimated to range from ???10??m to 10mm. Using the large sample sizes afforded by global datasets for Venus and Mars, and a complete nearside radar map for the Moon, we establish statistically robust scaling relationships between crater radius R and fine-grained ejecta run-out r for all three planets. On the Moon, ???R-0.18 for craters 5-640km in diameter. For Venus, radar-dark haloes are larger than those on the Moon, but scale as ???R-0.49, consistent with ejecta entrainment in Venus' dense atmosphere. On Mars, fine-ejecta haloes are larger than lunar haloes for a given crater size, indicating entrainment of ejecta by the atmosphere or vaporized subsurface volatiles, but scale as R-0.13, similar to the ballistic lunar scaling. Ejecta suspension in vortices generated by passage of the ejecta curtain is predicted to result in ejecta run-out that scales with crater size as R1/2, and the wind speeds so generated may be insufficient to transport particles at the larger end of the calculated range. The observed scaling and morphology of the low-temperature haloes leads us rather to favor winds generated by early-stage vapor plume expansion as the emplacement mechanism for low-temperature halo materials. ?? 2010 Elsevier Inc.

Liquid sampling-atmospheric pressure glow discharge as a secondary excitation source: Assessment of plasma characteristics

Science.gov (United States)

Manard, Benjamin T.; Gonzalez, Jhanis J.; Sarkar, Arnab; Dong, Meirong; Chirinos, Jose; Mao, Xianglei; Russo, Richard E.; Marcus, R. Kenneth

The liquid sampling-atmospheric pressure glow discharge (LS-APGD) has been assessed as a secondary excitation source with a parametric evaluation regarding carrier gas flow rate, applied current, and electrode distance. With this parametric evaluation, plasma optical emission was monitored in order to obtain a fundamental understanding with regards to rotational temperature (Trot), excitation temperature (Texc), electron number density (ne), and plasma robustness. Incentive for these studies is not only for a greater overall fundamental knowledge of the APGD, but also in instrumenting a secondary excitation/ionization source following laser ablation (LA). Rotational temperatures were determined through experimentally fitting of the N2 and OH molecular emission bands while atomic excitation temperatures were calculated using a Boltzmann distribution of He and Mg atomic lines. The rotational and excitation temperatures were determined to be ~ 1000 K and ~ 2700 K respectively. Electron number density was calculated to be on the order of ~ 3 × 1015 cm- 3 utilizing Stark broadening effects of the Hα line of the Balmer series and a He I transition. In addition, those diagnostics were performed introducing magnesium (by solution feed and laser ablation) into the plasma in order to determine any perturbation under heavy matrix sampling. The so-called plasma robustness factor, derived by monitoring Mg II/Mg I emission ratios, is also employed as a reflection of potential perturbations in microplasma energetics across the various operation conditions and sample loadings. While truly a miniaturized source (laser ablation sample introduction.

Influence of recycled fine aggregates on the resistance of mortars to magnesium sulfate attack

International Nuclear Information System (INIS)

Lee, Seung-Tae

2009-01-01

The influence of recycled fine aggregates, which had been reclaimed from field-demolished concretes, on the resistance of mortar specimens to magnesium sulfate attack was investigated. Mortar specimens were prepared with recycled fine aggregates at different replacement levels (0%, 25%, 50%, 75% and 100% of natural fine aggregate by mass). The mortar specimens were exposed to 4.24% magnesium sulfate solution for about 1 year at ambient temperature, and regularly monitored for visual appearance, compressive strength loss and expansion. Additionally, in order to identify products of magnesium sulfate attack, mortar samples incorporating 0%, 25% and 100% replacement levels of the recycled fine aggregates were examined by X-ray diffraction (XRD) technique. Experimental results confirmed that the use of recycled fine aggregates up to a maximum 50% replacement level is effective under severe magnesium sulfate environment, irrespective of type of recycled fine aggregates. However, the worse performance was observed in mortar specimens incorporating 100% replacement level. It was found that the water absorption of recycled fine aggregates affected deterioration of mortar specimens, especially at a higher replacement level. XRD results indicated that the main cause of deterioration of the mortar specimens was primarily due to the formation of gypsum and thaumasite by magnesium sulfate attack. In addition, it appeared that the conversion of C-S-H into M-S-H by the attack probably influenced mechanical deterioration of mortar specimens with recycled fine aggregates.

Methods of analysis for complex organic aerosol mixtures from urban emission sources of particulate carbon

International Nuclear Information System (INIS)

Mazurek, M.A.; Hildemann, L.M.; Simoneit, B.R.T.

1990-10-01

Organic aerosols comprise approximately 30% by mass of the total fine particulate matter present in urban atmospheres. The chemical composition of such aerosols is complex and reflects input from multiple sources of primary emissions to the atmosphere, as well as from secondary production of carbonaceous aerosol species via photochemical reactions. To identify discrete sources of fine carbonaceous particles in urban atmospheres, analytical methods must reconcile both bulk chemical and molecular properties of the total carbonaceous aerosol fraction. This paper presents an overview of the analytical protocol developed and used in a study of the major sources of fine carbon particles emitted to an urban atmosphere. 23 refs., 1 fig., 2 tabs

Fine-needle aspirate cytology suggesting hepatic lipidosis in four cats with infiltrative hepatic disease.

Science.gov (United States)

Willard, M D; Weeks, B R; Johnson, M

1999-12-01

Four cats are reported in which cytology smears obtained by ultrasound-guided fine needle aspiration of the liver were interpreted as indicative of hepatic lipidosis. However, histopathology of hepatic tissue samples obtained with Tru-Cut-like needles or wedge biopsy revealed that the cats had inflammatory or neoplastic hepatic disease causing their clinical signs. Fine needle aspiration and cytology may not detect infiltrative lesions, particularly those that are nodular, multifocal, or localised around the portal regions. Fine needle aspirate cytology is a useful diagnostic procedure with many advantages, but care must be taken to avoid diagnosing hepatic lipidosis as the cause of illness when an infiltrative lesion is responsible. Copyright 1999 European Society of Feline Medicine.

Primary source of income is associated with differences in HIV risk behaviors in street-recruited samples.

Science.gov (United States)

Essien, E James; Ross, Michael W; Williams, Mark L; Meshack, Angela F; Fernández-Esquer, Maria E; Peters, Ronald J; Ogungbade, GO

2004-06-17

BACKGROUND: The relationship between primary source of income and HIV risk behaviors and the racial/ethnic differences in risk behavior profiles among disadvantaged populations have not been fully explored. This is unusual given that the phenomenon of higher risk in more disadvantaged populations is well-known but the mechanisms remain unclear. We examined the relationship between primary source of income and differences in HIV risk behaviors among four racial/ethnic groups in the southern United States. METHODS: Self-reported data on primary source of income and HIV risk behaviors were collected from 1494 African American, Hispanic, Asian, and White men and women in places of public congregation in Houston, Texas. Data were analyzed using calculation of percentages and by chi-square tests with Yates correction for discontinuity where appropriate. RESULTS: Data revealed that a higher proportion of whites were involved in sex for money exchanges compared to the other racial groups in this sample. The data suggest that similar street sampling approaches are likely to recruit different proportions of people by primary income source and by ethnicity. It may be that the study locations sampled are likely to preferentially attract those involved in illegal activities, specifically the white population involved in sex for drug or money exchanges. Research evidence has shown that people construct highly evolved sexual marketplaces that are localized and most unlikely to cross racial, ethnic, and socioeconomic or geographical boundaries. Thus, the areas that we sampled may have straddled a white sexual marketplace more than that of the other groups, leading to an over-representation of sex exchange in this group. Drug use was highest among those with illegal primary sources of income (sex exchange and drug dealing and theft), and they were also those most likely to have injected drugs rather than administered them by any other route (p primary source of income category. The

The Fine Structure Constant

Indian Academy of Sciences (India)

IAS Admin

The article discusses the importance of the fine structure constant in quantum mechanics, along with the brief history of how it emerged. Al- though Sommerfelds idea of elliptical orbits has been replaced by wave mechanics, the fine struc- ture constant he introduced has remained as an important parameter in the field of ...

Deviation from the superparamagnetic behaviour of fine-particle systems

CERN Document Server

Malaescu, I

2000-01-01

Studies concerning superparamagnetic behaviour of fine magnetic particle systems were performed using static and radiofrequency measurements, in the range 1-60 MHz. The samples were: a ferrofluid with magnetite particles dispersed in kerosene (sample A), magnetite powder (sample B) and the same magnetite powder dispersed in a polymer (sample C). Radiofrequency measurements indicated a maximum in the imaginary part of the complex magnetic susceptibility, for each of the samples, at frequencies with the magnitude order of tens of MHz, the origin of which was assigned to Neel-type relaxation processes. The static measurements showed a Langevin-type dependence of magnetisation M and of susceptibility chi, on the magnetic field for sample A. For samples B and C deviations from this type of dependence were found. These deviations were analysed qualitatively and explained in terms of the interparticle interactions, dispersion medium influence and surface effects.

Response of consumer and research grade indoor air quality monitors to residential sources of fine particles.

Science.gov (United States)

Singer, B C; Delp, W W

2018-04-23

The ability to inexpensively monitor PM 2.5 to identify sources and enable controls would advance residential indoor air quality (IAQ) management. Consumer IAQ monitors incorporating low-cost optical particle sensors and connections with smart home platforms could provide this service if they reliably detect PM 2.5 in homes. In this study, particles from typical residential sources were generated in a 120 m 3 laboratory and time-concentration profiles were measured with 7 consumer monitors (2-3 units each), 2 research monitors (Thermo pDR-1500, MetOne BT-645), a Grimm Mini Wide-Range Aerosol Spectrometer (GRM), and a Tapered Element Oscillating Microbalance with Filter Dynamic Measurement System (FDMS), a Federal Equivalent Method for PM 2.5 . Sources included recreational combustion (candles, cigarettes, incense), cooking activities, an unfiltered ultrasonic humidifier, and dust. FDMS measurements, filter samples, and known densities were used to adjust the GRM to obtain time-resolved mass concentrations. Data from the research monitors and 4 of the consumer monitors-AirBeam, AirVisual, Foobot, Purple Air-were time correlated and within a factor of 2 of the estimated mass concentrations for most sources. All 7 of the consumer and both research monitors substantially under-reported or missed events for which the emitted mass was comprised of particles smaller than 0.3 μm diameter. © 2018 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

VOC source identification from personal and residential indoor, outdoor and workplace microenvironment samples in EXPOLIS-Helsinki, Finland

Energy Technology Data Exchange (ETDEWEB)

Edwards, Rufus D. [KTL-Finnish National Inst. of Public Health, Dept. of Environmental Hygiene, Kuopio (Finland); California Univ., School of Public Health, Berkeley, CA (United States); Jurvelin, J. [KTL-Finnish National Inst. of Public Health, Dept. of Environmental Hygiene, Kuopio (Finland); Jyvaeskylae Polytechnic, School of Engineering and Technology, Jyvaeskylae (Finland); Koistinen, K. [KTL-Finnish National Inst. of Public Health, Dept. of Environmental Hygiene, Kuopio (Finland); Saarela, K. [VTT, Chemical Technology, Espoo (Finland); Jantunen, M. [EC JRC, Inst. of the Environment, Ispra (Italy)

2001-07-01

Principal component analyses (varimax rotation) were used to identify common sources of 30 target volatile organic compounds (VOCs) in residential outdoor, residential indoor and workplace microenvironment and personal 48-h exposure samples, as a component of the EXPOLIS-Helsinki study. Variability in VOC concentrations in residential outdoor microenvironments was dominated by compounds associated with long-range transport of pollutants, followed by traffic emissions, emissions from trees and product emissions. Variability in VOC concentrations in environmental tobacco smoke (ETS) free residential indoor environments was dominated by compounds associated with indoor cleaning products, followed by compounds associated with traffic emissions, long-range transport of pollutants and product emissions. Median indoor/outdoor ratios for compounds typically associated with traffic emissions and long-range transport of pollutants exceeded 1, in some cases quite considerably, indicating substantial indoor source contributions. Changes in the median indoor/outdoor ratios during different seasons reflected different seasonal ventilation patterns as increased ventilation led to dilution of those VOC compounds in the indoor environment that had indoor sources. Variability in workplace VOC concentrations was dominated by compounds associated with traffic emissions followed by product emissions, long-range transport and air fresheners. Variability in VOC concentrations in ETS free personal exposure samples was dominated by compounds associated with traffic emissions, followed by long-range transport, cleaning products and product emissions. VOC sources in personal exposure samples reflected the times spent in different microenvironments, and personal exposure samples were not adequately represented by any one microenvironment, demonstrating the need for personal exposure sampling. (Author)

Mobile sources of polycyclic aromatic hydrocarbons (PAH) and nitro-PAH: Results of samples collected in a roadway tunnel

International Nuclear Information System (INIS)

Benner, B.A. Jr.; Gordon, G.E.; Wise, S.A.

1987-01-01

A recent review article emphasized the need for further characterizations of the carbonaceous fraction of mobile source emissions, particularly with the impending removal of lead alkyl octane boosters and bromine-containing lead scavengers from regular leaded gasolines. The lead and bromine emitted from the combustion of these fuels have been used as tracers of mobile source emissions for a number of years. Single vehicle emission studies have shed light on the relationship between engine operating parameters and the chemical characteristics of the emissions but they are not suitable for use in source apportionment studies which require emission data from a large number of different vehicles. Air particulate samples collected near a busy highway or in a roadway tunnel would be more appropriate for use in estimating the mobile source contribution of organic compounds to a region. Suspended particle samples collected in a heavily-travelled roadway tunnel (Baltimore Harbor Tunnel, Baltimore, Maryland) were characterized for polycyclic aromatic hydrocarbons (PAH) and some nitro-PAH by gas and liquid chromatographic techniques. These samples included those collected on Teflon filters and on glass fiber filters for investigating any differences in samples collected on an inert (Teflon) and more reactive (glass-fiber) medium. All samples collected on Teflon were backed-up with polyurethane foam plugs (PUF) which trapped any inherent vapor-phase PAH as well as any compounds ''blown-off'' the particles during collection

Growth dynamics of fine roots in a coniferous fern forest site close to Forsmark in the central part of Sweden

Energy Technology Data Exchange (ETDEWEB)

Persson, Hans; Stadenberg, Ingela (SLU, Dept. of Ecology and Environmental Research, Uppsala (Sweden))

2007-12-15

The seasonal growth dynamics of live and dead roots for trees and the field layer species (g/m2, varying diameter fractions) and live/dead ratios were analysed at a fresh/moist coniferous fern forest site close to the nuclear power plant at Forsmark in the central eastern parts of Sweden. The changes in depth distribution of fine roots were observed at depth intervals of the top humus horizon down to 40 cm in the mineral soil profile. The bulk of living fine roots of trees (< 1 mm in diameter) were found in the mineral soil horizon the total profile down to 40 cm of the mineral soil, where 89, 82, 83 and 89% of the total amount in the whole profile were found. The upper 2.5 cm part of the humus layer contained 83, 81, 100 and 100% of all roots of the humus layer on the four different sampling occasions. High amounts of living fine roots were found in the upper 10 cm of the mineral soil horizon viz. 84, 76, 91 and 69% of the total mineral soil layer. Consequently, both the top soil horizons of the humus and the mineral soil layers were heavily penetrated by living fine roots. The highest proportion of living fine roots was found in the top 2.5 cm of the humus layer. Accordingly, the live/dead ratio of fine roots (< 1 mm in diameter) decreased from the top of the humus layer to the lower part of mineral soil horizon from 8.0-0.3, 0.8-0.2, 4.4-0.4 and 3.3-0.7 (g g-1) for the four sampling occasions, respectively. We concluded that the decrease in the live/ dead ratio was related to decreased vitality with depth of the fine roots in the soil profile. The highest live/dead ratio was found in the upper 2.5 cm of the humus layer for both the tree and field-layer species. This distribution pattern was most evident for tree fine roots < 1 mm in diameter. The mean fine-root biomass (live tissue < 1 mm in diameter) of tree species for the total profile varied on the four sampling occasions between 317, 113, 139 and 248 g m-2. The related fine root necromass (dead tissue

Polycyclic Aromatic Hydrocarbons Bound to PM 2.5 in Urban Coimbatore, India with Emphasis on Source Apportionment

Directory of Open Access Journals (Sweden)

R. Mohanraj

2012-01-01

Full Text Available Coimbatore is one of the fast growing industrial cities of Southern India with an urban population of 1.9 million. This study attempts to evaluate the trends of airborne fine particulates (PM 2.5 and polyaromatic hydrocarbons (PAH on them. The PM 2.5 mass was collected in polytetra fluoroethylene filters using fine particulate sampler at monthly intervals during March 2009 to February 2010. PAHs were extracted from PM 2.5 and estimated by high-performance liquid chromatography. It is alarming to note that PM 2.5 values ranged between 27.85 and 165.75 μg/m3 and exceeded the air quality standards in many sampling events. The sum of 9 PAHs bound to PM 2.5 in a single sampling event ranged from 4.1 to 1632.3 ng/m3. PAH diagnostic ratios and principal component analysis results revealed vehicular emissions and diesel-powered generators as predominant sources of PAH in Coimbatore.

THE EFFECT OF PLASTICIZER ON MECHANICAL PROPERTIES OF THE CEMENT PASTE WITH FINE GROUND RECYCLED CONCRETE

Directory of Open Access Journals (Sweden)

Jaromír Hrůza

2017-11-01

Full Text Available This article deals with the usage of recycled concrete, which arises from the demolition of concrete structures. The work is focused on the development of mechanical properties (Young's modulus, compressive and flexural strength depending amount of plasticizer in the mixture. In the experiment were prepared three sets of samples with different amounts of plasticizer (0, 0.5 and 1.0 wt. % of cement. Each pair always contained reference samples (only cement and 35 wt. % of fine ground recycled concrete. One of the main reasons for the use of finely ground recycled concrete was a certain substitution of cement in the mixture, which is the most expensive component. Development of Young's modulus was measured by the nondestructive method. The aim of the experiment was to determine the effect of plasticizer on the resulting physical and mechanical properties of cement pastes with fine ground recycled concrete.

Long term fine aerosol analysis by XRF and PIXE techniques in the city of Rijeka, Croatia

International Nuclear Information System (INIS)

Ivošević, Tatjana; Orlić, Ivica; Radović, Iva Bogdanović

2015-01-01

Highlights: • For the first time in Croatia, long term of fine aerosol pollution is reported. - Abstract: The results of a long term, multi elemental XRF and PIXE analysis of fine aerosol pollution in the city of Rijeka, Croatia, are reported for the first time. The samples were collected during a seven months period (6th Aug 2013–28th Feb 2014) on thin stretched Teflon filters and analyzed by energy dispersive X-ray fluorescence (EDXRF) at the Laboratory for Elemental Micro-Analysis (LEMA), University of Rijeka and by Particle Induced X-ray Emission (PIXE) using 1.6 MeV protons at the Laboratory for Ion Beam Interactions (LIBI), Ruđer Bošković Institute, Zagreb. The newly developed micro-XRF system at LEMA provided results for 19 elements in the range from Si to Pb. The PIXE at the LIBI provided information for the same elements as well for the light elements such as Na, Mg and Al. Black carbon was determined with the Laser Integrated Plate Method (LIPM). The results were statistically evaluated by means of the positive matrix factorization (PMF). The seven major pollution sources were identified together with their relative contributions, these are: secondary sulfates, road traffic, smoke, road dust, sea spray, ship emissions and soil dust.

Long term fine aerosol analysis by XRF and PIXE techniques in the city of Rijeka, Croatia

Energy Technology Data Exchange (ETDEWEB)

Ivošević, Tatjana [Faculty of Engineering, University of Rijeka, Vukovarska 58, HR-51000 Rijeka (Croatia); Orlić, Ivica [Department of Physics, University of Rijeka, Radmile Matejčić 2, HR-51000 Rijeka (Croatia); Radović, Iva Bogdanović [Laboratory for Ion Beam Interaction, Ruđer Bošković Institute, Bijenička 54, HR-10000 Zagreb (Croatia)

2015-11-15

Highlights: • For the first time in Croatia, long term of fine aerosol pollution is reported. - Abstract: The results of a long term, multi elemental XRF and PIXE analysis of fine aerosol pollution in the city of Rijeka, Croatia, are reported for the first time. The samples were collected during a seven months period (6th Aug 2013–28th Feb 2014) on thin stretched Teflon filters and analyzed by energy dispersive X-ray fluorescence (EDXRF) at the Laboratory for Elemental Micro-Analysis (LEMA), University of Rijeka and by Particle Induced X-ray Emission (PIXE) using 1.6 MeV protons at the Laboratory for Ion Beam Interactions (LIBI), Ruđer Bošković Institute, Zagreb. The newly developed micro-XRF system at LEMA provided results for 19 elements in the range from Si to Pb. The PIXE at the LIBI provided information for the same elements as well for the light elements such as Na, Mg and Al. Black carbon was determined with the Laser Integrated Plate Method (LIPM). The results were statistically evaluated by means of the positive matrix factorization (PMF). The seven major pollution sources were identified together with their relative contributions, these are: secondary sulfates, road traffic, smoke, road dust, sea spray, ship emissions and soil dust.

Disambiguate: An open-source application for disambiguating two species in next generation sequencing data from grafted samples.

Science.gov (United States)

Ahdesmäki, Miika J; Gray, Simon R; Johnson, Justin H; Lai, Zhongwu

2016-01-01

Grafting of cell lines and primary tumours is a crucial step in the drug development process between cell line studies and clinical trials. Disambiguate is a program for computationally separating the sequencing reads of two species derived from grafted samples. Disambiguate operates on DNA or RNA-seq alignments to the two species and separates the components at very high sensitivity and specificity as illustrated in artificially mixed human-mouse samples. This allows for maximum recovery of data from target tumours for more accurate variant calling and gene expression quantification. Given that no general use open source algorithm accessible to the bioinformatics community exists for the purposes of separating the two species data, the proposed Disambiguate tool presents a novel approach and improvement to performing sequence analysis of grafted samples. Both Python and C++ implementations are available and they are integrated into several open and closed source pipelines. Disambiguate is open source and is freely available at https://github.com/AstraZeneca-NGS/disambiguate.

Fine-Grained Turbidites: Facies, Attributes and Process Implications

Science.gov (United States)

Stow, Dorrik; Omoniyi, Bayonle

2016-04-01

Within turbidite systems, fine-grained sediments are still the poor relation and sport several contrasting facies models linked to process of deposition. These are volumetrically the dominant facies in deepwater and, from a resource perspective, they form important marginal and tight reservoirs, and have great potential for unconventional shale gas, source rocks and seals. They are also significant hosts of metals and rare earth elements. Based on a large number of studies of modern, ancient and subsurface systems, including 1000s of metres of section logging, we define the principal genetic elements of fine-grained deepwater facies, present a new synthesis of facies models and their sedimentary attributes. The principal architectural elements include: non-channelised slope-aprons, channel-fill, channel levee and overbank, turbidite lobes, mass-transport deposits, contourite drifts, basin sheets and drapes. These comprise a variable intercalation of fine-grained facies - thin-bedded and very thin-bedded turbidites, contourites, hemipelagites and pelagites - and associated coarse-grained facies. Characteristic attributes used to discriminate between these different elements are: facies and facies associations; sand-shale ratio, sand and shale geometry and dimensions, sand connectivity; sediment texture and small-scale sedimentary structures; sediment fabric and microfabric; and small-scale vertical sequences of bed thickness. To some extent, we can relate facies and attribute characteristics to different depositional environments. We identify four distinct facies models: (a) silt-laminated mud turbidites, (b) siliciclastic mud turbidites, (c) carbonate mud turbidites, (d) disorganized silty-mud turbidites, and (e) hemiturbidites. Within the grainsize-velocity matrix turbidite plot, these all fall within the region of mean size < 0.063mm, maximum grainsize (one percentile) <0.2mm, and depositional velocity 0.1-0.5 m/s. Silt-laminated turbidites and many mud

36 CFR 910.35 - Fine arts.

Science.gov (United States)

2010-07-01

... 36 Parks, Forests, and Public Property 3 2010-07-01 2010-07-01 false Fine arts. 910.35 Section 910... DEVELOPMENT AREA Standards Uniformly Applicable to the Development Area § 910.35 Fine arts. Fine arts... of art which are appropriate for the development. For information and guidance, a reasonable...

Fine particle water and pH in the Eastern Mediterranean: Sources, variability and implications for nutrients availability

Science.gov (United States)

Bougiatioti, Aikaterini; Nikolaou, Panayiota; Stavroulas, Iasonas; Kouvarakis, Giorgos; Nenes, Athanasios; Weber, Rodney; Kanakidou, Maria; Mihalopoulos, Nikolaos

2016-04-01

total calculated water. Particle pH is also calculated with the help of ISORROPIA-II, and during the studied period, values varied from 0.5 to 2.8, indicating that the aerosol was highly acidic. pH values were also studied depending on the source/origin of the sampled air masses and biomass burning aerosol was found to exhibit the highest values of PM1 pH and the lowest values in total water mass concentrations. The two natural sources, namely mineral and marine origin, contained the largest amounts of total submicron water and the lowest contribution of organic water, as expected. The low pH values estimated for the studied period in the submicron mode and independently of the air masses' origin could potentially have important implications for nutrient availability, especially for phosphorus solubility, which is the nutrient limiting sea water productivity of the Eastern Mediterranean.

Micro Fine Sized Palm Oil Fuel Ash Produced Using a Wind Tunnel Production System

Directory of Open Access Journals (Sweden)

R. Ahmadi

2016-01-01

Full Text Available Micro fine sized palm oil fuel ash (POFA is a new supplementary cementitious material that can increase the strength, durability, and workability of concrete. However, production of this material incurs high cost and is not practical for the construction industry. This paper investigates a simple methodology of producing micro fine sized POFA by means of a laboratory scale wind tunnel system. The raw POFA obtained from an oil palm factory is first calcined to remove carbon residue and then grinded in Los Angeles abrasion machine. The grinded POFA is then blown in the fabricated wind tunnel system for separation into different ranges of particle sizes. The physical, morphological, and chemical properties of the micro fine sized POFA were then investigated using Laser Particle Size Analyser (PSA, nitrogen sorption, and Scanning Electron Microscopy with Energy Dispersive X-Ray (SEM-EDX. A total of 32.1% micro fine sized POFA were collected from each sample blown, with the size range of 1–10 micrometers. The devised laboratory scale of wind tunnel production system is successful in producing micro fine sized POFA and, with modifications, this system is envisaged applicable to be used to commercialize micro fine sized POFA production for the construction industry.

GeneRecon—A coalescent based tool for fine-scale association mapping

DEFF Research Database (Denmark)

Mailund, Thomas; Schierup, Mikkel Heide; Pedersen, Christian Nørgaard Storm

2006-01-01

GeneRecon is a tool for fine-scale association mapping using a coalescence model. GeneRecon takes as input case-control data from phased or unphased SNP and micro-satellite genotypes. The posterior distribution of disease locus position is obtained by Metropolis Hastings sampling in the state space...

Fine-needle trucut biopsy versus fine-needle aspiration cytology with ultrasound guidance in the abdomen

International Nuclear Information System (INIS)

O'Connell, A.M.; Keeling, F.; Given, M.; Logan, M.; Lee, M.J.

2008-01-01

Historically, fine-needle aspiration cytology (FNAC) has varying sensitivity, specificity and accuracy in the diagnosis of abdominal lesions with a high insufficient sampling rate. We compared 20-G fine-needle trucut biopsy (FNTB) with FNAC results in the biopsy of solid abdominal tumours. A retrospective review of 171 (128x 20-G FNTB and 43x FNAC) ultrasound-guided biopsies of abdominal tumours on 157 patients (male : female 85:72, mean age 61.25 years) were carried out. One hundred and seventy-one biopsies were carried out: liver 109, pancreas 19, lumph node 10, omentum 5, right iliac fossa mass 6, adrenal 6 and others 16. An average of 2.06 and 1.97 passes (range 1-4) were carried out per FNTB and FNAC, respectively. A definitive diagnosis was made in 122/128 biopsies (95.3%) and 32/43 biopsies (74.4%) for FNTB and FNAC, respectively. Diagnoses consisted of metastatic liver disease (74/171), pancreatic adenocarcinoma (10/171), lymphoma (8/171) and others (33/171) and benign (29/171). No significant complications occurred in either group. The sensitivity, specificity, positive predictive value, negative predictive value and accuracy were 87, 100, 100, 50, 84.4 and 93.1, 100, 100, 60, 71.4 for FNTB and FNAC, respectively. A greater and more consistent positive diagnosis rate is yielded by 20-G FNTB (95.3%) that FNAC (74.4%). The diagnostic accuracy of FNTB is 84.4% cmopared with 69.8% for FNAC. A greater insufficient sampling rate occurs with FNAC (25.6%) than with FNTB (4.7%). For abdominal biopsy, 20-G FNTB needles have a much higher yield than FNAC with no increase in complications. FNTB is the preferred choice, particularly where cytological assistance at the time of biopsy is unavailable.

Considering Fine Art and Picture Books

Science.gov (United States)

Serafini, Frank

2015-01-01

There has been a close association between picturebook illustrations and works of fine art since the picturebook was first conceived, and many ways these associations among works of fine art and picturebook illustrations and design play out. To make sense of all the various ways picturebook illustrations are associated with works of fine art,…

The durability of concrete containing recycled tyres as a partial replacement of fine aggregate

Science.gov (United States)

Syamir Senin, Mohamad; Shahidan, Shahiron; Syazani Leman, Alif; Othman, Nurulain; Shamsuddin, Shamrul-mar; Ibrahim, M. H. W.; Zuki, S. S. Mohd

2017-11-01

Nowadays, uncontrolled disposal of waste materials such as tyres can affect the environment. Therefore, careful management of waste disposal must be done in order to conserve the environment. Waste tyres can be use as a replacement for both fine aggregate and coarse aggregate in the production of concrete. This research was conducted to assess the durability of concrete containing recycled tyres which have been crushed into fine fragments to replace fine aggregate in the concrete mix. This study presents an overview of the use of waste rubber as a partial replacement of natural fine aggregate in a concrete mix. 36 concrete cubes measuring 100mm × 100mm × 100mm and 12 concrete cubes measuring 150mm × 150mm × 150mm were prepared and added with different percentages of rubber from recycled tyres (0%, 3%, 5% and 7%) as fine aggregate replacement. The results obtained show that the replacement of fine aggregate with 7% of rubber recorded a compressive strength of 43.7MPa while the addition of 3% of rubber in the concrete sample recorded a high compressive strength of 50.8MPa. This shows that there is a decrease in the strength and workability of concrete as the amount of rubber used a replacement for fine aggregate in concrete increases. On the other hand, the water absorption test indicated that concrete which contains rubber has better water absorption ability. In this study, 3% of rubber was found to be the optimal percentage as a partial replacement for fine aggregate in the production of concrete.

Stable carbon and nitrogen isotopic composition of fine mode aerosols (PM2.5 over the Bay of Bengal: impact of continental sources

Directory of Open Access Journals (Sweden)

Srinivas Bikkina

2016-07-01

Full Text Available This study reports on stable carbon (δ13CTC and nitrogen (δ15NTN isotopic composition of total carbon and nitrogen (TC and TN in the fine mode aerosols (PM2.5; N=31 collected over the Bay of Bengal (BoB. The samples represent two distinct wind regimes during the cruise (27 December 2008–28 January 2009; one from the Indo-Gangetic Plain (referred as IGP-outflow and another from Southeast Asia (SEA-outflow. The PM2.5 samples from the IGP-outflow show higher δ13CTC (−25.0 to −22.8 ‰; −23.8±0.6 ‰ than those from the SEA-outflow (−27.4 to −24.7 ‰; −25.3±0.9 ‰. Similarly, δ15NTN varied from +11.8 to +30.6 ‰ (+20.4±5.4 ‰ and +10.4 to +31.7 ‰ (+19.4±6.1 ‰ for IGP- and SEA-outflows, respectively. Based on the literature data, MODIS-derived fire hotspots and back trajectories, we infer that higher δ13CTC in the IGP-outflow is predominantly associated with fossil fuel and biofuel combustion. In contrast, contribution of primary organic aerosols from the combustion of C3 plants or secondary organic aerosol (SOA formation from biomass/biofuel-burning emissions (BBEs can explain the lower δ13CTC values in the SEA-outflow. This inference is based on the significant linear correlations among δ13CTC, water-soluble organic carbon and non-sea-salt potassium (nss-K+, a proxy for BBEs in the SEA-outflow. A significant linear relationship of δ15N with and equivalent mass ratio of / is evident in both the continental outflows. Since abundance dominates the TN over the BoB (>90 %, atmospheric processes affecting its concentration in fine mode aerosols can explain the observed large variability of δ15NTN.

Carbonaceous Aerosols in Fine Particulate Matter of Santiago Metropolitan Area, Chile

Science.gov (United States)

Toro Araya, Richard; Flocchini, Robert; Morales Segura, Rául G. E.; Leiva Guzmán, Manuel A.

2014-01-01

Measurements of carbonaceous aerosols in South American cities are limited, and most existing data are of short term and limited to only a few locations. For 6 years (2002–2007), concentrations of fine particulate matter and organic and elemental carbon were measured continuously in the capital of Chile. The contribution of carbonaceous aerosols to the primary and secondary fractions was estimated at three different sampling sites and in the warm and cool seasons. The results demonstrate that there are significant differences in the levels in both the cold (March to August) and warm (September to February) seasons at all sites studied. The percent contribution of total carbonaceous aerosol fine particulate matter was greater in the cool season (53 ± 41%) than in the warm season (44 ± 18%). On average, the secondary organic carbon in the city corresponded to 29% of the total organic carbon. In cold periods, this proportion may reach an average of 38%. A comparison of the results with the air quality standards for fine particulate matter indicates that the total carbonaceous fraction alone exceeds the World Health Organization standard (10 µg/m3) and the United States Environmental Protection Agency standard (15 µg/m3) for fine particulate matter. PMID:24587753

Carbonaceous Aerosols in Fine Particulate Matter of Santiago Metropolitan Area, Chile

Directory of Open Access Journals (Sweden)

Richard Toro Araya

2014-01-01

Full Text Available Measurements of carbonaceous aerosols in South American cities are limited, and most existing data are of short term and limited to only a few locations. For 6 years (2002–2007, concentrations of fine particulate matter and organic and elemental carbon were measured continuously in the capital of Chile. The contribution of carbonaceous aerosols to the primary and secondary fractions was estimated at three different sampling sites and in the warm and cool seasons. The results demonstrate that there are significant differences in the levels in both the cold (March to August and warm (September to February seasons at all sites studied. The percent contribution of total carbonaceous aerosol fine particulate matter was greater in the cool season (53 ± 41% than in the warm season (44 ± 18%. On average, the secondary organic carbon in the city corresponded to 29% of the total organic carbon. In cold periods, this proportion may reach an average of 38%. A comparison of the results with the air quality standards for fine particulate matter indicates that the total carbonaceous fraction alone exceeds the World Health Organization standard (10 µg/m3 and the United States Environmental Protection Agency standard (15 µg/m3 for fine particulate matter.

Carbonaceous aerosols in fine particulate matter of Santiago Metropolitan Area, Chile.

Science.gov (United States)

Toro Araya, Richard; Flocchini, Robert; Morales Segura, Rául G E; Leiva Guzmán, Manuel A

2014-01-01

Measurements of carbonaceous aerosols in South American cities are limited, and most existing data are of short term and limited to only a few locations. For 6 years (2002-2007), concentrations of fine particulate matter and organic and elemental carbon were measured continuously in the capital of Chile. The contribution of carbonaceous aerosols to the primary and secondary fractions was estimated at three different sampling sites and in the warm and cool seasons. The results demonstrate that there are significant differences in the levels in both the cold (March to August) and warm (September to February) seasons at all sites studied. The percent contribution of total carbonaceous aerosol fine particulate matter was greater in the cool season (53 ± 41%) than in the warm season (44 ± 18%). On average, the secondary organic carbon in the city corresponded to 29% of the total organic carbon. In cold periods, this proportion may reach an average of 38%. A comparison of the results with the air quality standards for fine particulate matter indicates that the total carbonaceous fraction alone exceeds the World Health Organization standard (10 µg/m(3)) and the United States Environmental Protection Agency standard (15 µg/m(3)) for fine particulate matter.

The development of an automatic sample-changer and control instrumentation for isotope-source neutron-activation analysis

International Nuclear Information System (INIS)

Andeweg, A.H.; Watterson, J.I.W.

1983-01-01

An automatic sample-changer was developed at the Council for Mineral Technology for use in isotope-source neutron-activation analysis. Tests show that the sample-changer can transfer a sample of up to 3 kg in mass over a distance of 3 m within 5 s. In addition, instrumentation in the form of a three-stage sequential timer was developed to control the sequence of irradiation transfer and analysis

Fossil and nonfossil carbon in fine particulate matter: A study of five European cities

Science.gov (United States)

Glasius, Marianne; La Cour, Agnete; Lohse, Christian

2011-06-01

Fossil carbon in particulate matter comes from anthropogenic use and combustion of fossil fuels, while nonfossil carbon may originate from both biogenic (e.g., pollen, plant debris, fungal spores, and biogenic secondary organic aerosol (SOA)) and anthropogenic sources (e.g., cooking and residential wood combustion). We investigated the relative contributions of fossil and nonfossil sources to fine carbonaceous aerosols in five European cities by radiocarbon analysis of aerosol samples collected at four types of sites in 2002-2004. The average fraction of nonfossil carbon was 43 ± 11%, with the lowest fraction, 36 ± 7%, at urban curbside sites and the highest fraction, 54 ± 11%, at rural background sites, farthest away from the impact of man-made emissions. Generally, fossil carbon concentrations at urban curbside sites are elevated in comparison to background sites, which is expected because of their proximity to vehicular emissions. Contrary to what might be expected, the concentration of nonfossil carbon is also higher at curbside than at background sites. This may be attributable to differences between site categories in levels of primary biological aerosols, brake and tire wear in resuspended road dust, biofuels, emissions from cooking and residential wood combustion, or processes such as anthropogenic enhancement of biogenic SOA and increased partitioning of semivolatile compounds into the aerosol phase at urban sites. The exact causes should be investigated by future detailed source analyses.

Subsoil erosion dominates the supply of fine sediment to rivers draining into Princess Charlotte Bay, Australia

International Nuclear Information System (INIS)

Olley, Jon; Brooks, Andrew; Spencer, John; Pietsch, Timothy; Borombovits, Daniel

2013-01-01

The Laura–Normanby River (catchment area: 24,350 km 2 ), which drains into Princess Charlotte Bay, has been identified in previous studies as the third largest contributor of sediment to the Great Barrier Reef World Heritage Area. These catchment scale modelling studies also identified surface soil erosion as supplying >80% of the sediment. Here we use activity concentrations of the fallout radionuclides 137 Cs and 210 Pb ex to test the hypothesis that surface soil erosion dominates the supply of fine ( 137 Cs and 210 Pb ex activity concentrations between samples collected using these two methods. Two methods were also used to collect samples to characterise 137 Cs and 210 Pb ex concentrations in sediment derived from surface soil erosion; sampling of surface-wash deposits and deployment of surface runoff traps that collected samples during rain events. While there was no difference in the 137 Cs activity concentrations for samples collected using these two methods, 210 Pb ex activity concentrations were significantly higher in the samples collected using the runoff traps. The higher 210 Pb ex concentrations are shown to be correlated with loss-on-ignition (r 2 = 0.79) and therefore are likely to be related to higher organic concentrations in the runoff trap samples. As a result of these differences we use a three end member mixing model (channel/gully, hillslope surface-wash and hillslope runoff traps) to determine the relative contribution from surface soil erosion. Probability distributions for 137 Cs and 210 Pb ex concentrations were determined for each of the end members, with these distributions then used to estimate the surface soil contribution to each of the collected river sediment samples. The mean estimate of contribution of surface derived sediment for all river samples (n = 70) is 16 ± 2%. This study reinforces the importance of testing model predictions before they are used to target investment in remedial action and adds to the body of evidence

Primary source of income is associated with differences in HIV risk behaviors in street-recruited samples

Directory of Open Access Journals (Sweden)

Fernández-Esquer Maria E

2004-06-01

Full Text Available Abstract Background The relationship between primary source of income and HIV risk behaviors and the racial/ethnic differences in risk behavior profiles among disadvantaged populations have not been fully explored. This is unusual given that the phenomenon of higher risk in more disadvantaged populations is well-known but the mechanisms remain unclear. We examined the relationship between primary source of income and differences in HIV risk behaviors among four racial/ethnic groups in the southern United States. Methods Self-reported data on primary source of income and HIV risk behaviors were collected from 1494 African American, Hispanic, Asian, and White men and women in places of public congregation in Houston, Texas. Data were analyzed using calculation of percentages and by chi-square tests with Yates correction for discontinuity where appropriate. Results Data revealed that a higher proportion of whites were involved in sex for money exchanges compared to the other racial groups in this sample. The data suggest that similar street sampling approaches are likely to recruit different proportions of people by primary income source and by ethnicity. It may be that the study locations sampled are likely to preferentially attract those involved in illegal activities, specifically the white population involved in sex for drug or money exchanges. Research evidence has shown that people construct highly evolved sexual marketplaces that are localized and most unlikely to cross racial, ethnic, and socioeconomic or geographical boundaries. Thus, the areas that we sampled may have straddled a white sexual marketplace more than that of the other groups, leading to an over-representation of sex exchange in this group. Drug use was highest among those with illegal primary sources of income (sex exchange and drug dealing and theft, and they were also those most likely to have injected drugs rather than administered them by any other route (p Conclusions

Long range transport of fine particle windblown soils and coal fired power station emissions into Hanoi between 2001 to 2008

Energy Technology Data Exchange (ETDEWEB)

Cohen, D.D.; Crawford, J.; Stelcer, E.; Vuong, T.B. [Australian Nuclear Science & Technology Organisation, Kirrawee DC, NSW (Australia)

2010-10-15

Fine particulate matter (PM2.5), source fingerprints and their contributions have been measured and reported previously at Hanoi, Vietnam, from 25 April 2001 to 31 December 2008. In this study back trajectories are used to identify long range transport into Hanoi for two of these sources, namely, windblown dust (Soil) from 12 major deserts in China and emissions from 33 coal fired power plants (Coal) in Vietnam and China. There were 28 days of extreme Soil events with concentrations greater than 6 {mu} g m{sup -3} and 25 days of extreme Coal with concentrations greater than 30 {mu} g m{sup -3} from a total of 748 sampling days during the study period. Through the use of back trajectories it was found that long range transport of soil from the Taklamakan and Gobi desert regions (more than 3000 km to the north west) accounted for 76% of the extreme events for Soil. The three local Vietnamese power stations contributed to 15% of the extreme Coal events, while four Chinese power stations between 300 km and 1700 km to the north-east of Hanoi contributed 50% of the total extreme Coal events measured at the Hanoi sampling site.

Characterization of carbonaceous aerosol emissions from selected combustion sources

International Nuclear Information System (INIS)

Martinez, J.P.G.; Espino, M.P.M.; Pabroa, P.C.B.; Bautista, A.T. VII

2015-01-01

Carbonaceous Particulates are carbon-containing solid or liquid matter which form a significant portion of the fine particulate mass (PM2.5) and these have known profound adverse effects on health, climate and visibility. This study aims to characterize carbonaceous aerosol emissions from different combustion sources to establish fingerprints for these for use in the refinement of improvement of the resolution of sources apportionment studies being done by the Philippine Nuclear Research Institute (PNRI), i.e. to resolve vehicular emission sources. Fine air particulate sample were collected in pre-baked Quartz filters using an improvised collection set-up with a Gent sampler. Concentrations of organic and elemental carbon (OC and EC, respectively) in PM2.5 were measured for the different combustion sources—vehicular emissions, tire pyrolysis, and biomass burning, using a thermal-optical method of analysis following the IMPROVE_A protocol. Measured OC ad EC concentrations are shown as percentages with respect to the total carbon (TC) and are illustrated in a 100% stacked chart. Predominance of the EC2 fraction is exhibited in both the diesel fuelled vehicle and tire pyrolysis emissions with EC2/OC2 ratio distinguishing one from the other, EC2/OC2 is 1.63 and 8.41, respectively. Predominance of either OC2 or OC3 fraction is shown in the unleaded gasoline and LPG Fuelled vehicles and in biomass burning with the OC2/OC3 ratio distinguishing one from the others. OC2/OC3 ratios are 1.33 for unleaded gasoline fuelled vehicle, 1.89 for LPG-fuelled vehicle, 0.55 for biomass burning (leaves) and 0.82 biomass burning (wood). The study has shown probable use of the EC2/OC2 and OC2/OC3 ratios to distinguish fingerprints for combustion sources covered in this study. (author)

Fine particle retention within stream storage areas at base flow and in response to a storm event

Science.gov (United States)

Drummond, J. D.; Larsen, L. G.; González-Pinzón, R.; Packman, A. I.; Harvey, Judson

2017-01-01

Fine particles (1–100 µm), including particulate organic carbon (POC) and fine sediment, influence stream ecological functioning because they may contain or have a high affinity to sorb nitrogen and phosphorus. These particles are immobilized within stream storage areas, especially hyporheic sediments and benthic biofilms. However, fine particles are also known to remobilize under all flow conditions. This combination of downstream transport and transient retention, influenced by stream geomorphology, controls the distribution of residence times over which fine particles influence stream ecosystems. The main objective of this study was to quantify immobilization and remobilization rates of fine particles in a third-order sand-and-gravel bed stream (Difficult Run, Virginia, USA) within different geomorphic units of the stream (i.e., pool, lateral cavity, and thalweg). During our field injection experiment, a thunderstorm-driven spate allowed us to observe fine particle dynamics during both base flow and in response to increased flow. Solute and fine particles were measured within stream surface waters, pore waters, sediment cores, and biofilms on cobbles. Measurements were taken at four different subsurface locations with varying geomorphology and at multiple depths. Approximately 68% of injected fine particles were retained during base flow until the onset of the spate. Retention was evident even after the spate, with 15.4% of the fine particles deposited during base flow still retained within benthic biofilms on cobbles and 14.9% within hyporheic sediment after the spate. Thus, through the combination of short-term remobilization and long-term retention, fine particles can serve as sources of carbon and nutrients to downstream ecosystems over a range of time scales.

Fine particle retention within stream storage areas at base flow and in response to a storm event

Science.gov (United States)

Drummond, J. D.; Larsen, L. G.; González-Pinzón, R.; Packman, A. I.; Harvey, J. W.

2017-07-01

Fine particles (1-100 µm), including particulate organic carbon (POC) and fine sediment, influence stream ecological functioning because they may contain or have a high affinity to sorb nitrogen and phosphorus. These particles are immobilized within stream storage areas, especially hyporheic sediments and benthic biofilms. However, fine particles are also known to remobilize under all flow conditions. This combination of downstream transport and transient retention, influenced by stream geomorphology, controls the distribution of residence times over which fine particles influence stream ecosystems. The main objective of this study was to quantify immobilization and remobilization rates of fine particles in a third-order sand-and-gravel bed stream (Difficult Run, Virginia, USA) within different geomorphic units of the stream (i.e., pool, lateral cavity, and thalweg). During our field injection experiment, a thunderstorm-driven spate allowed us to observe fine particle dynamics during both base flow and in response to increased flow. Solute and fine particles were measured within stream surface waters, pore waters, sediment cores, and biofilms on cobbles. Measurements were taken at four different subsurface locations with varying geomorphology and at multiple depths. Approximately 68% of injected fine particles were retained during base flow until the onset of the spate. Retention was evident even after the spate, with 15.4% of the fine particles deposited during base flow still retained within benthic biofilms on cobbles and 14.9% within hyporheic sediment after the spate. Thus, through the combination of short-term remobilization and long-term retention, fine particles can serve as sources of carbon and nutrients to downstream ecosystems over a range of time scales.

Active AirCore Sampling: Constraining Point Sources of Methane and Other Gases with Fixed Wing Unmanned Aerial Systems

Science.gov (United States)

Bent, J. D.; Sweeney, C.; Tans, P. P.; Newberger, T.; Higgs, J. A.; Wolter, S.

2017-12-01

Accurate estimates of point source gas emissions are essential for reconciling top-down and bottom-up greenhouse gas measurements, but sampling such sources is challenging. Remote sensing methods are limited by resolution and cloud cover; aircraft methods are limited by air traffic control clearances, and the need to properly determine boundary layer height. A new sampling approach leverages the ability of unmanned aerial systems (UAS) to measure all the way to the surface near the source of emissions, improving sample resolution, and reducing the need to characterize a wide downstream swath, or measure to the full height of the planetary boundary layer (PBL). The "Active-AirCore" sampler, currently under development, will fly on a fixed wing UAS in Class G airspace, spiraling from the surface to 1200 ft AGL around point sources such as leaking oil wells to measure methane, carbon dioxide and carbon monoxide. The sampler collects a 100-meter long sample "core" of air in an 1/8" passivated stainless steel tube. This "core" is run on a high-precision instrument shortly after the UAS is recovered. Sample values are mapped to a specific geographic location by cross-referencing GPS and flow/pressure metadata, and fluxes are quantified by applying Gauss's theorem to the data, mapped onto the spatial "cylinder" circumscribed by the UAS. The AirCore-Active builds off the sampling ability and analytical approach of the related AirCore sampler, which profiles the atmosphere passively using a balloon launch platform, but will add an active pumping capability needed for near-surface horizontal sampling applications. Here, we show design elements, laboratory and field test results for methane, describe the overall goals of the mission, and discuss how the platform can be adapted, with minimal effort, to measure other gas species.

Comparison between correlated sampling and the perturbation technique of MCNP5 for fixed-source problems

International Nuclear Information System (INIS)

He Tao; Su Bingjing

2011-01-01

Highlights: → The performance of the MCNP differential operator perturbation technique is compared with that of the MCNP correlated sampling method for three types of fixed-source problems. → In terms of precision, the MCNP perturbation technique outperforms correlated sampling for one type of problem but performs comparably with or even under-performs correlated sampling for the other two types of problems. → In terms of accuracy, the MCNP perturbation calculations may predict inaccurate results for some of the test problems. However, the accuracy can be improved if the midpoint correction technique is used. - Abstract: Correlated sampling and the differential operator perturbation technique are two methods that enable MCNP (Monte Carlo N-Particle) to simulate small response change between an original system and a perturbed system. In this work the performance of the MCNP differential operator perturbation technique is compared with that of the MCNP correlated sampling method for three types of fixed-source problems. In terms of precision of predicted response changes, the MCNP perturbation technique outperforms correlated sampling for the problem involving variation of nuclide concentrations in the same direction but performs comparably with or even underperforms correlated sampling for the other two types of problems that involve void or variation of nuclide concentrations in opposite directions. In terms of accuracy, the MCNP differential operator perturbation calculations may predict inaccurate results that deviate from the benchmarks well beyond their uncertainty ranges for some of the test problems. However, the accuracy of the MCNP differential operator perturbation can be improved if the midpoint correction technique is used.

Transport of reservoir fines

DEFF Research Database (Denmark)

Yuan, Hao; Shapiro, Alexander; Stenby, Erling Halfdan

Modeling transport of reservoir fines is of great importance for evaluating the damage of production wells and infectivity decline. The conventional methodology accounts for neither the formation heterogeneity around the wells nor the reservoir fines’ heterogeneity. We have developed an integral...... dispersion equation in modeling the transport and the deposition of reservoir fines. It successfully predicts the unsymmetrical concentration profiles and the hyperexponential deposition in experiments....

Source reconciliation of atmospheric gas-phase and particle-phase pollutants during a severe photochemical smog episode.

Science.gov (United States)

Schauer, James J; Fraser, Matthew P; Cass, Glen R; Simoneit, Bernd R T

2002-09-01

A comprehensive organic compound-based receptor model is developed that can simultaneously apportion the source contributions to atmospheric gas-phase organic compounds, semivolatile organic compounds, fine particle organic compounds, and fine particle mass. The model is applied to ambient data collected at four sites in the south coast region of California during a severe summertime photochemical smog episode, where the model determines the direct primary contributions to atmospheric pollutants from 11 distinct air pollution source types. The 11 sources included in the model are gasoline-powered motor vehicle exhaust, diesel engine exhaust, whole gasoline vapors, gasoline headspace vapors, organic solvent vapors, whole diesel fuel, paved road dust, tire wear debris, meat cooking exhaust, natural gas leakage, and vegetative detritus. Gasoline engine exhaust plus whole gasoline vapors are the predominant sources of volatile organic gases, while gasoline and diesel engine exhaust plus diesel fuel vapors dominate the emissions of semivolatile organic compounds from these sources during the episode studied at all four air monitoring sites. The atmospheric fine particle organic compound mass was composed of noticeable contributions from gasoline-powered motor vehicle exhaust, diesel engine exhaust, meat cooking, and paved road dust with smaller but quantifiable contributions from vegetative detritus and tire wear debris. In addition, secondary organic aerosol, which is formed from the low-vapor pressure products of gas-phase chemical reactions, is found to be a major source of fine particle organic compound mass under the severe photochemical smog conditions studied here. The concentrations of secondary organic aerosol calculated in the present study are compared with previous fine particle source apportionment results for less intense photochemical smog conditions. It is shown that estimated secondary organic aerosol concentrations correlate fairly well with the

Analysis of ancient fine white porcelains by SRXRF and preliminary study of the discriminating criteria

International Nuclear Information System (INIS)

Feng Xiangqian; Feng Songlin; Xu Qing; Zhang Ying; Lei Yong; Fan Dongyu; Cheng Lin; Huang Yuying; He Wei

2002-01-01

30 Samples were chosen from the fine white porcelain shards excavated in Xing, Xing and Jingxing kilns of Hebei province. Their bodies and glaze were analyzed for 19 elements by SRXRF, followed by the cluster analysis and principal factor analysis. The statistical results show that porcelains of each kiln are classified as one class according to their elemental composition. It indicates that provenance of the fine white porcelains may be identified based on their chemical components

Divergence of fine and gross motor skills in prelingually deaf children: implications for cochlear implantation.

Science.gov (United States)

Horn, David L; Pisoni, David B; Miyamoto, Richard T

2006-08-01

The objective of this study was to assess relations between fine and gross motor development and spoken language processing skills in pediatric cochlear implant users. The authors conducted a retrospective analysis of longitudinal data. Prelingually deaf children who received a cochlear implant before age 5 and had no known developmental delay or cognitive impairment were included in the study. Fine and gross motor development were assessed before implantation using the Vineland Adaptive Behavioral Scales, a standardized parental report of adaptive behavior. Fine and gross motor scores reflected a given child's motor functioning with respect to a normative sample of typically developing, normal-hearing children. Relations between these preimplant scores and postimplant spoken language outcomes were assessed. In general, gross motor scores were found to be positively related to chronologic age, whereas the opposite trend was observed for fine motor scores. Fine motor scores were more strongly correlated with postimplant expressive and receptive language scores than gross motor scores. Our findings suggest a disassociation between fine and gross motor development in prelingually deaf children: fine motor skills, in contrast to gross motor skills, tend to be delayed as the prelingually deaf children get older. These findings provide new knowledge about the links between motor and spoken language development and suggest that auditory deprivation may lead to atypical development of certain motor and language skills that share common cortical processing resources.

Disentangling Fine Motor Skills' Relations to Academic Achievement: The Relative Contributions of Visual-Spatial Integration and Visual-Motor Coordination

Science.gov (United States)

Carlson, Abby G.; Rowe, Ellen; Curby, Timothy W.

2013-01-01

Recent research has established a connection between children's fine motor skills and their academic performance. Previous research has focused on fine motor skills measured prior to elementary school, while the present sample included children ages 5-18 years old, making it possible to examine whether this link remains relevant throughout…

The influence of common stimulus parameters on distortion product otoacoustic emission fine structure.

Science.gov (United States)

Johnson, Tiffany A; Baranowski, Lauren G

2012-01-01

To determine whether common approaches to setting stimulus parameters influence the depth of fine structure present in the distortion product otoacoustic emission (DPOAE) response. Because the presence of fine structure has been suggested as a possible source of errors, if one of the common parametric approaches results in reduced fine-structure depth, it may be preferred over other approaches. DPOAE responses were recorded in a group of 21 subjects with normal hearing for 1/3-octave intervals surrounding 3 f2s (1, 2, and 4 kHz) at three L2s (30, 45, and 55 dB SPL). For each f2 and L2 combination, L1 and f2/f1 were set according to three commonly used parametric approaches. These included a simple approach, the approach recommended by Kummer et al., and the approach described by Johnson et al. These three approaches primarily differ in the recommended relationship between L1 and L2. For each parametric approach, DPOAE fine structure was evaluated by varying f2 in small steps. Differences in DPOAE level and DPOAE fine-structure depth across f2, L2, and the various stimulus parameters were evaluated using repeated-measures analysis of variance. As expected, significant variations in DPOAE level were observed across the three parametric approaches. For stimulus levels #45 dB SPL, the simple stimuli resulted in lower DPOAE levels than were observed for other approaches. An unexpected finding was that stimulus parameters developed by Johnson et al., which were believed to produce higher DPOAE levels than other approaches, produced the lowest DPOAE levels of the three approaches when f2 = 4 kHz. Significant differences in fine-structure depth were also observed. Greater fine-structure depth was observed with the simple parameters, although this effect was restricted to L2 # 45 dB SPL. When L2 = 55 dB SPL, all three parametric approaches resulted in equivalent fine-structure depth. A significant difference in fine-structure depth across the 3 f2s was also observed. The

Sources of type III solar microwave bursts

Directory of Open Access Journals (Sweden)

Zhdanov D.A.

2016-06-01

Full Text Available Microwave fine structures allow us to study plasma evolution in an energy release region. The Siberian Solar Radio Telescope (SSRT is a unique instrument designed to examine fine structures at 5.7 GHz. A complex analysis of data from RATAN-600, 4–8 GHz spectropolarimeter, and SSRT, simultaneously with EUV data, made it possible to localize sources of III type microwave bursts in August 10, 2011 event within the entire frequency band of burst occurrence, as well as to determine the most probable region of primary energy release. To localize sources of III type bursts from RATAN-600 data, an original method for data processing has been worked out. At 5.7 GHz, the source of bursts was determined along two coordinates, whereas at 4.5, 4.7, 4.9, 5.1, 5.3, 5.5, and 6.0 GHz, their locations were identified along one coordinate. The size of the burst source at 5.1 GHz was found to be maximum as compared to those at other frequencies.

Source apportionment of fine (PM1.8) and ultrafine (PM0.1) airborne particulate matter during a severe winter pollution episode.

Science.gov (United States)

Kleeman, Michael J; Riddle, Sarah G; Robert, Michael A; Jakober, Chris A; Fine, Phillip M; Hays, Michael D; Schauer, James J; Hannigan, Michael P

2009-01-15

Size-resolved samples of airborne particulate matter (PM) collected during a severe winter pollution episode at three sites in the San Joaquin Valley of California were extracted with organic solvents and analyzed for detailed organic compounds using GC-MS. Six particle size fractions were characterized with diameter (Dp) < 1.8 microm; the smallest size fraction was 0.056 < Dp < 0.1 microm which accounts for the majority of the mass in the ultrafine (PM0.1) size range. Source profiles for ultrafine particles developed during previous studies were applied to the measurements at each sampling site to calculate source contributions to organic carbon (OC) and elemental carbon (EC) concentrations. Ultrafine EC concentrations ranged from 0.03 microg m(-3) during the daytime to 0.18 microg m(-3) during the nighttime. Gasoline fuel, diesel fuel, and lubricating oil combustion products accounted for the majority of the ultrafine EC concentrations, with relatively minor contributions from biomass combustion and meat cooking. Ultrafine OC concentrations ranged from 0.2 microg m(-3) during the daytime to 0.8 microg m(-3) during the nighttime. Wood combustion was found to be the largest source of ultrafine OC. Meat cooking was also identified as a significant potential source of PM0.1 mass but further study is required to verify the contributions from this source. Gasoline fuel, diesel fuel, and lubricating oil combustion products made minor contributions to PM0.1 OC mass. Total ultrafine particulate matter concentrations were dominated by contributions from wood combustion and meat cooking during the current study. Future inhalation exposure studies may wish to target these sources as potential causes of adverse health effects.

Source characterization of ambient fine aerosol in Singapore during a haze episode in 2015

Science.gov (United States)

Hapsari Budisulistiorini, Sri; Riva, Matthieu; Williams, Michael; Miyakawa, Takuma; Komazaki, Yuichi; Chen, Jing; Surratt, Jason; Kuwata, Mikinori

2017-04-01

Recurring transboundary haze from Indonesia peatland fires in the previous decades has significantly elevated particulate matter (PM) concentration in Southeast Asia, particularly during the 2015 El Niño event. Previous studies have investigated chemical composition of particles emitted during haze episodes; however, they were limited to time-integrated samples and the number of identified compounds. Low time-resolution measurement results in co-variance of PM sources; therefore, higher time-resolution measurement is important in PM source apportionment. Between October 10-31, 2015, Aerodyne Time-of-Flight Aerosol Chemical Speciation Monitor (ToF-ACSM) was deployed for real-time chemical characterization of ambient submicron PM (NR-PM1) in Singapore. Simultaneously, PM2.5 filter samples were collected for molecular-level organic aerosol (OA) constituents, organic carbon (OC), elemental carbon (EC) and water-soluble OC (WSOC) analyses. OA constituents were quantified by gas chromatography interfaced to electron ionization mass spectrometry (GC/EI-MS) and ultra-performance liquid chromatography interfaced to electrospray ionization high-resolution quadrupole time-of-flight mass spectrometer operated in the negative ion mode (UPLC/(-)ESI-HR-Q-TOFMS). OA and SO42- are dominant components of the haze particles, accounting for ˜77% and ˜12% of the total NR-PM1 mass, respectively. OC/EC ratio of 4.8 might indicate formation of secondary OA (SOA) and aerosols from biomass burning, including those from peat burning. OA fraction from ToF-ACSM measurements was analyzed for source apportionment using a bilinear model through multi-linear engine algorithm (ME-2) in graphical user interface SoFi (Source Finder). Five OA factors were identified: hydrocarbon-like OA (HOA), biomass burning OA (BBOA), peat burning OA (PBOA), low-volatility oxygenated OA (LV-OOA), and semi-volatile oxygenated OA (SV-OOA). The HOA factor shows a distinct diurnal profile peaking in the morning and

Revised Soil Classification System for Coarse-Fine Mixtures

KAUST Repository

Park, Junghee; Santamarina, Carlos

2017-01-01

Soil classification systems worldwide capture great physical insight and enable geotechnical engineers to anticipate the properties and behavior of soils by grouping them into similar response categories based on their index properties. Yet gravimetric analysis and data trends summarized from published papers reveal critical limitations in soil group boundaries adopted in current systems. In particular, current classification systems fail to capture the dominant role of fines on the mechanical and hydraulic properties of soils. A revised soil classification system (RSCS) for coarse-fine mixtures is proposed herein. Definitions of classification boundaries use low and high void ratios that gravel, sand, and fines may attain. This research adopts emax and emin for gravels and sands, and three distinctive void ratio values for fines: soft eF|10  kPa and stiff eF|1  MPa for mechanical response (at effective stress 10 kPa and 1 MPa, respectively), and viscous λ⋅eF|LL for fluid flow control, where λ=2log(LL−25) and eF|LL is the void ratio at the liquid limit. For classification purposes, these void ratios can be estimated from index properties such as particle shape, the coefficient of uniformity, and the liquid limit. Analytically computed and data-adjusted boundaries are soil-specific, in contrast with the Unified Soil Classification System (USCS). Threshold fractions for mechanical control and for flow control are quite distinct in the proposed system. Therefore, the RSCS uses a two-name nomenclature whereby the first letters identify the component(s) that controls mechanical properties, followed by a letter (shown in parenthesis) that identifies the component that controls fluid flow. Sample charts in this paper and a Microsoft Excel facilitate the implementation of this revised classification system.

Revised Soil Classification System for Coarse-Fine Mixtures

KAUST Repository

Park, Junghee

2017-04-17

Soil classification systems worldwide capture great physical insight and enable geotechnical engineers to anticipate the properties and behavior of soils by grouping them into similar response categories based on their index properties. Yet gravimetric analysis and data trends summarized from published papers reveal critical limitations in soil group boundaries adopted in current systems. In particular, current classification systems fail to capture the dominant role of fines on the mechanical and hydraulic properties of soils. A revised soil classification system (RSCS) for coarse-fine mixtures is proposed herein. Definitions of classification boundaries use low and high void ratios that gravel, sand, and fines may attain. This research adopts emax and emin for gravels and sands, and three distinctive void ratio values for fines: soft eF|10  kPa and stiff eF|1  MPa for mechanical response (at effective stress 10 kPa and 1 MPa, respectively), and viscous λ⋅eF|LL for fluid flow control, where λ=2log(LL−25) and eF|LL is the void ratio at the liquid limit. For classification purposes, these void ratios can be estimated from index properties such as particle shape, the coefficient of uniformity, and the liquid limit. Analytically computed and data-adjusted boundaries are soil-specific, in contrast with the Unified Soil Classification System (USCS). Threshold fractions for mechanical control and for flow control are quite distinct in the proposed system. Therefore, the RSCS uses a two-name nomenclature whereby the first letters identify the component(s) that controls mechanical properties, followed by a letter (shown in parenthesis) that identifies the component that controls fluid flow. Sample charts in this paper and a Microsoft Excel facilitate the implementation of this revised classification system.

Radiocarbon Analysis to Calculate New End-Member Values for Biomass Burning Source Samples Specific to the Bay Area

Science.gov (United States)

Yoon, S.; Kirchstetter, T.; Fairley, D.; Sheesley, R. J.; Tang, X.

2017-12-01

Elemental carbon (EC), also known as black carbon or soot, is an important particulate air pollutant that contributes to climate forcing through absorption of solar radiation and to adverse human health impacts through inhalation. Both fossil fuel combustion and biomass burning, via residential firewood burning, agricultural burning, wild fires, and controlled burns, are significant sources of EC. Our ability to successfully control ambient EC concentrations requires understanding the contribution of these different emission sources. Radiocarbon (14C) analysis has been increasingly used as an apportionment tool to distinguish between EC from fossil fuel and biomass combustion sources. However, there are uncertainties associated with this method including: 1) uncertainty associated with the isolation of EC to be used for radiocarbon analysis (e.g., inclusion of organic carbon, blank contamination, recovery of EC, etc.) 2) uncertainty associated with the radiocarbon signature of the end member. The objective of this research project is to utilize laboratory experiments to evaluate some of these uncertainties, particularly for EC sources that significantly impact the San Francisco Bay Area. Source samples of EC only and a mix of EC and organic carbon (OC) were produced for this study to represent known emission sources and to approximate the mixing of EC and OC that would be present in the atmosphere. These samples include a combination of methane flame soot, various wood smoke samples (i.e. cedar, oak, sugar pine, pine at various ages, etc.), meat cooking, and smoldering cellulose smoke. EC fractions were isolated using a Sunset Laboratory's thermal optical transmittance carbon analyzer. For 14C analysis, samples were sent to Woods Hole Oceanographic Institution for isotope analysis using an accelerated mass spectrometry. End member values and uncertainties for the EC isolation utilizing this method will be reported.

Photoionization Modeling of Infrared Fine-Structure Lines in Luminous Galaxies with Central Dust-Bounded Nebulae

National Research Council Canada - National Science Library

Fischer, Jacqueline; Allen, Robert; Dudley, C. C; Satyapal, Shobita; Luhman, Michael L; Wolfire, Mark G; Smith, Howard A

2001-01-01

Far-infrared spectroscopy of a small sample of IR-bright galaxies taken with the Infrared Space Observatory Long Wavelength Spectrometer has revealed a dramatic progression extending from strong fine...

Fine Guidance Sensing for Coronagraphic Observatories

Science.gov (United States)

Brugarolas, Paul; Alexander, James W.; Trauger, John T.; Moody, Dwight C.

2011-01-01

Three options have been developed for Fine Guidance Sensing (FGS) for coronagraphic observatories using a Fine Guidance Camera within a coronagraphic instrument. Coronagraphic observatories require very fine precision pointing in order to image faint objects at very small distances from a target star. The Fine Guidance Camera measures the direction to the target star. The first option, referred to as Spot, was to collect all of the light reflected from a coronagraph occulter onto a focal plane, producing an Airy-type point spread function (PSF). This would allow almost all of the starlight from the central star to be used for centroiding. The second approach, referred to as Punctured Disk, collects the light that bypasses a central obscuration, producing a PSF with a punctured central disk. The final approach, referred to as Lyot, collects light after passing through the occulter at the Lyot stop. The study includes generation of representative images for each option by the science team, followed by an engineering evaluation of a centroiding or a photometric algorithm for each option. After the alignment of the coronagraph to the fine guidance system, a "nulling" point on the FGS focal point is determined by calibration. This alignment is implemented by a fine alignment mechanism that is part of the fine guidance camera selection mirror. If the star images meet the modeling assumptions, and the star "centroid" can be driven to that nulling point, the contrast for the coronagraph will be maximized.

The PM2.5 Fine Particle Background Network of the German Meteorological Service-First Results

Directory of Open Access Journals (Sweden)

Uwe Kaminski

2013-04-01

Full Text Available Since 2009, the measurement of the background concentration of the fine particle fraction has been a part of the climate-monitoring program of the German Meteorological Service (DWD. These particles are of high health relevance as a critical air pollutant affecting processes like the scattering and absorption of solar radiation and influencing cloud formation and visibility. At 12 weather stations, the coarse (2.5 to 10 l m and the fine particle fractions (PM2.5 are measured by means of passive and active samplers. First results are presented for the mass concentrations of coarse and fine particles as well as for the black carbon (BC content and the concentration of certain inorganic ions of fine particles. There is not only a seasonal correlation between the fraction of fine and coarse particles, but also a correlation with the location (urban background or rural background. With the help of light microscopy, coarse particles can be differentiated for a geogenic (predominantly wind blown mineral and sea salt particles of natural origin and road abrasion and for an anthropogenic opaque component (combustion residues, e.g. fly ash and non-exhaust vehicle emissions, e.g. abrasion particles of brakes and tires. Measuring the fine fraction and the coarse fraction separately instead of PM10 allows for a better source allocation and thus is a more appropriate method for the improvement of the air quality in, e.g. low emission zones.

Characteristics of prepared gamma-ray calibration sources for radioactivity measurement of environmental and radiation control samples

International Nuclear Information System (INIS)

Samat, S.B.; Oi, Yoshihiro; Taki, Mitsumasa; Manabe, Iwao; Yoshida, Makoto; Minami, Kentaro

1995-03-01

Several types of calibration source having different density were prepared using one or combinations of those materials, namely foam cement, liquid, glass beads, polystyrene foam bead and hard plastic bead for gamma-ray spectrometry of the samples with different densities and shapes(variable height with constant base area). For each type of the source, a few sources were prepared to examine characteristics in such cases as (a) different heights but constant density, and (b) constant height and constant density. For the foam cement source, several sources with different densities and a constant height were prepared. All the sources were measured with a gamma-ray spectrometry system and the results were discussed. This report also presents the results obtained from the experiments for the evaluation of (1) the variation of detector efficiency-energy with gamma-ray energy, and (2) the variation of detector efficiency with density of the sources. (author)

Identification of magnetic minerals in the fine-grain sediment on the Bengawan Solo River

Science.gov (United States)

Purnama, B.; Kusuma, R.; Legowo, B.; Suharyana; Wijayanta, A. T.

2018-03-01

The magnetic mineral content in the fine sediment of Bengawan Solo River is discussed. The fine sediment is obtained on the upper part of the tributary of Bengawan Solo River. Magnetic minerals are separated using permanent magnets. Furthermore the magnetic minerals are overnight dried using oven at 100°C. FTIR characterization indicate that the magnetic minerals in the fine sediment of Bengawan Solo River have the same characteristics as minerals in Cilacap and Purwokerto areas. Magnetic minerals are estimated to form at wave number k = 569.03 cm-1. This hematite content increase to 70.67% after anealling treatment at 600°C for 4 hours in atmosphere condition. This result is interesting because the heating process increases the hematite content. Within results, the magnetic properties of the sample will change.

The Laboratory Study of Shear Strength of the Overconsolidated and Quasi - Overconsolidated Fine - Grained Soil

Science.gov (United States)

Strozyk, Joanna

2017-12-01

The paper presents results of laboratory shear strength test conducted on fine-grained soil samples with different grain size distribution and with different geological age and stress history. The Triaxial Isotopic Consolidation Undrained Tests (TXCIU) were performed under different consolidation stress in normal and overconsolidadion stress state on the samples with natural structure. Soil samples were selected from soil series of different age and geological origins: overconsolidated sensu stricto Miopliocene silty clay (siCl) and quasi overconsolidated Pleistocene clayey silt (clSi). Paper pointed out that overconsolidated sensu stricto and quasi overconsolidated fine-grained soil in same stress and environmental condition could show almost similar behaviour, and in other condition could behave significantly different. The correct evaluation of geotechnical parameters, the possibility of predicting their time-correct ability is only possible with appropriately recognized geological past and past processes that accompanied the soil formation.

Releasable activity and maximum permissible leakage rate within a transport cask of Tehran Research Reactor fuel samples

Directory of Open Access Journals (Sweden)

Rezaeian Mahdi

2015-01-01

Full Text Available Containment of a transport cask during both normal and accident conditions is important to the health and safety of the public and of the operators. Based on IAEA regulations, releasable activity and maximum permissible volumetric leakage rate within the cask containing fuel samples of Tehran Research Reactor enclosed in an irradiated capsule are calculated. The contributions to the total activity from the four sources of gas, volatile, fines, and corrosion products are treated separately. These calculations are necessary to identify an appropriate leak test that must be performed on the cask and the results can be utilized as the source term for dose evaluation in the safety assessment of the cask.

Improving Hyperspectral Image Classification Method for Fine Land Use Assessment Application Using Semisupervised Machine Learning

Directory of Open Access Journals (Sweden)

Chunyang Wang

2015-01-01

Full Text Available Study on land use/cover can reflect changing rules of population, economy, agricultural structure adjustment, policy, and traffic and provide better service for the regional economic development and urban evolution. The study on fine land use/cover assessment using hyperspectral image classification is a focal growing area in many fields. Semisupervised learning method which takes a large number of unlabeled samples and minority labeled samples, improving classification and predicting the accuracy effectively, has been a new research direction. In this paper, we proposed improving fine land use/cover assessment based on semisupervised hyperspectral classification method. The test analysis of study area showed that the advantages of semisupervised classification method could improve the high precision overall classification and objective assessment of land use/cover results.

Fine and gross motor skills differ between healthy-weight and obese children.

Science.gov (United States)

Gentier, Ilse; D'Hondt, Eva; Shultz, Sarah; Deforche, Benedicte; Augustijn, Mireille; Hoorne, Sofie; Verlaecke, Katja; De Bourdeaudhuij, Ilse; Lenoir, Matthieu

2013-11-01

Within the obesity literature, focus is put on the link between weight status and gross motor skills. However, research on fine motor skills in the obese (OB) childhood population is limited. Therefore, the present study focused on possible weight related differences in gross as well as fine motor skill tasks. Thirty-four OB children (12 ♀ and 22 ♂, aged 7-13 years) were recruited prior to participating in a multidisciplinary treatment program at the Zeepreventorium (De Haan, Belgium). Additionally, a control group of 34 age and gender-matched healthy-weight (HW) children was included in the study. Anthropometric measures were recorded and gross and fine motor skills were assessed using the Bruininks-Oseretsky Test of Motor Proficiency, second edition (BOT-2). Results were analyzed by independent samples t-tests, multivariate analysis of variance, and a chi-squared test. Being OB was detrimental for all subtests evaluating gross motor skill performance (i.e., upper-limb coordination, bilateral coordination, balance, running speed and agility, and strength). Furthermore, OB children performed worse in fine motor precision and a manual dexterity task, when compared to their HW peers. No group differences existed for the fine motor integration task. Our study provides evidence that lower motor competence in OB children is not limited to gross motor skills alone; OB children are also affected by fine motor skill problems. Further investigation is warranted to provide possible explanations for these differences. It is tentatively suggested that OB children experience difficulties with the integration and processing of sensory information. Future research is needed to explore whether this assumption is correct and what the underlying mechanism(s) could be. Copyright © 2013 Elsevier Ltd. All rights reserved.

Ultra fine grained Ti prepared by severe plastic deformation

Science.gov (United States)

Lukáč, F.; Čížek, J.; Knapp, J.; Procházka, I.; Zháňal, P.; Islamgaliev, R. K.

2016-01-01

The positron annihilation spectroscopy was employed for characterisation of defects in pure Ti with ultra fine grained (UFG) structure. UFG Ti samples were prepared by two techniques based on severe plastic deformation (SPD): (i) high pressure torsion (HPT) and (ii) equal channel angular pressing (ECAP). Although HPT is the most efficient technique for grain refinement, the size of HPT-deformed specimens is limited. On the other hand, ECAP is less efficient in grain refinement but enables to produce larger samples more suitable for industrial applications. Characterisation of defects by positron annihilation spectroscopy was accompanied by hardness testing in order to monitor the development of mechanical properties of UFG Ti.

Pelletization of fine coals. Final report

Energy Technology Data Exchange (ETDEWEB)

Sastry, K.V.S.

1995-12-31

Coal is one of the most abundant energy resources in the US with nearly 800 million tons of it being mined annually. Process and environmental demands for low-ash, low-sulfur coals and economic constraints for high productivity are leading the coal industry to use such modern mining methods as longwall mining and such newer coal processing techniques as froth flotation, oil agglomeration, chemical cleaning and synthetic fuel production. All these processes are faced with one common problem area--fine coals. Dealing effectively with these fine coals during handling, storage, transportation, and/or processing continues to be a challenge facing the industry. Agglomeration by the unit operation of pelletization consists of tumbling moist fines in drums or discs. Past experimental work and limited commercial practice have shown that pelletization can alleviate the problems associated with fine coals. However, it was recognized that there exists a serious need for delineating the fundamental principles of fine coal pelletization. Accordingly, a research program has been carried involving four specific topics: (i) experimental investigation of coal pelletization kinetics, (ii) understanding the surface principles of coal pelletization, (iii) modeling of coal pelletization processes, and (iv) simulation of fine coal pelletization circuits. This report summarizes the major findings and provides relevant details of the research effort.

An Einstein-Cartan Fine Structure Constant Definition

Directory of Open Access Journals (Sweden)

Stone R. A. Jr.

2010-01-01

Full Text Available The fine structure constant definition given in Stone R.A. Jr. Progress in Physics, 2010, v.1, 11-13 is compared to an Einstein-Cartan fine structure constant definition. It is shown that the Einstein-Cartan definition produces the correct pure theory value, just not the measure value. To produce the measured value, the pure theory Einstein-Cartan fine structure constant requires only the new variables and spin coupling of the fine structure constant definition in [1].

NEXAFS spectroscopy with a laser plasma x-ray source on soil samples

International Nuclear Information System (INIS)

Sedlmair, J; Geber, S-C; Thieme, J; Peth, C; Mann, K

2009-01-01

Humic substances are post-mortal organic substances without an exact chemical structure. Their large specific surface is important for transport processes, especially in soils. We analyzed the NEXAFS spectra of humic substances, from which the amount of certain chemical compounds such as aromatic and aliphatic groups can be verified by the resonances of their binding energy. For the experiments, a compact table-top setup working with a laser plasma source was used. NEXAFS makes it possible to distinguish between samples, even if they contain the same composits, because information about the specific functional groups in the sample is supplied. The evaluation was carried out using the program SpecFit. It was developed on IDL within our group and allows to fit the NEXAFS-data with a combination of arctangent, Gaussian and Lorentzian curves.

NEXAFS spectroscopy with a laser plasma x-ray source on soil samples

Energy Technology Data Exchange (ETDEWEB)

Sedlmair, J; Geber, S-C; Thieme, J [Institute for X-Ray Physics, Georg-August-University Goettingen, Friedrich-Hund-Platz 1, D-37077 (Germany); Peth, C; Mann, K, E-mail: jsedlma@gwdg.d [Laser-Laboratorium Goettingen e.V., Hans-Adolf-Krebs-Weg 1, D-37077 (Germany)

2009-09-01

Humic substances are post-mortal organic substances without an exact chemical structure. Their large specific surface is important for transport processes, especially in soils. We analyzed the NEXAFS spectra of humic substances, from which the amount of certain chemical compounds such as aromatic and aliphatic groups can be verified by the resonances of their binding energy. For the experiments, a compact table-top setup working with a laser plasma source was used. NEXAFS makes it possible to distinguish between samples, even if they contain the same composits, because information about the specific functional groups in the sample is supplied. The evaluation was carried out using the program SpecFit. It was developed on IDL within our group and allows to fit the NEXAFS-data with a combination of arctangent, Gaussian and Lorentzian curves.

Chemical characterzation of fine particle emissions from the fireplace combustion of woods grown in the Southern United States.

Science.gov (United States)

Fine, Philip M; Cass, Glen R; Simoneit, Bernd R T

2002-04-01

The fireplace combustion of wood is a significant and largely unregulated source of fine particle pollution in the United States. Source apportionment techniques that use particulate organic compounds as tracers have been successful in determining the contribution of wood smoke to ambient fine particle levels in specific areas in California. To apply these techniques to the rest of the United States, the differences in emissions profiles between different wood smoke sources and fuel types should be resolved. To this end, a series of fireplace source tests was conducted on six fuel wood species found in the Southern United States to determine fine particulate emission factors for total mass, ionic and elemental species, elemental and organic carbon, and over 250 individual organic compounds. The wood species tested, chosen for their high abundance and availability in the Southern U.S. region, were yellow poplar, white ash, sweetgum, mockernut hickory, loblolly pine, and slash pine. The differences in the emissions of compounds such as substituted phenols and resin acids help to distinguish between the smoke from hardwood and softwood combustion. Levoglucosan, a cellulose pyrolysis product which may serve as a tracer for wood smoke in general, was quantified in the emissions from all the wood species burned. The furofuran lignan, yangambin, which was emitted in significant quantities from yellow poplar combustion and not detected in any of the other North American wood smokes, is a potential species-specific molecular tracer which may be useful in qualitatively identifying particulate emissions from a specific geographical area where yellow poplar is being burned.

Optical and mechanical design of the extended x-ray absorption fine structure (EXAFS) beam-line at Indus-II synchrotron source

International Nuclear Information System (INIS)

Das, N.C.; Jha, S.N.; Bhattacharyya, D.; Sinha, A.K.; Mishra, V.K.; Verma, Vishnu; Ghosh, A.K.

2002-11-01

An extended x-ray absorption fine structure (EXAFS) beam line for x-ray absorption studies using energy dispersive geometry and position sensitive detector is being designed for the INDUS-II Synchrotron source. The beam line would be used for doing x-ray absorption experiments involving measurements of fme structures above the absorption edge of different species of atoms in a material The results of the above experiments would lead to the determination of different important structural parameters of materials viz.. inter-atomic distance. co-ordination number, degree of disorder and radial distribution function etc. The optical design of the beam line has been completed based on the working principle that a single crystal bent in the shape of an ellipse by a crystal bender would act as a dispersing as well as focusing element. The mechanical design of the beam line including the crystal bender has also been completed and discussed here. Calculations have been done to detennine the temperature profile on the different components of the beam line under exposure to synchrotron radiation and proper cooling channels have been designed to bring down the heat load on the components. (author)

A Study of Early Fine Motor Intervention in Down's Syndrome Children

Science.gov (United States)

Aparicio, Teresa Sanz; Balana, Javier Menendez

2009-01-01

The marked delay in acquisition of fine motor skills in trisomic-21/Down's syndrome children is undeniable. In this study, we began with an affirmation that the cause of this deficit could be found in a different environment for which early intervention is essential. A sample of 30 Down's syndrome children was used to study at different ages: six…

47 CFR 76.943 - Fines.

Science.gov (United States)

2010-10-01

... TELEVISION SERVICE Cable Rate Regulation § 76.943 Fines. (a) A franchising authority may impose fines or... specifically at the cable operator, provided the franchising authority has such power under state or local laws. (b) If a cable operator willfully fails to comply with the terms of any franchising authority's order...

Ion beam analysis techniques for the elemental fingerprinting of fine particle smoke from vegetation burning in NSW

Energy Technology Data Exchange (ETDEWEB)

Cohen, D. [Australian Nuclear Science and Technology Organisation, Lucas Heights, NSW (Australia)

1996-12-31

Accelerator based ion beam analysis (IBA) techniques, including PIXE, PIGME, RBS and PESA, have been used to analyse elemental compositions of airborne particles covering a 60,000 square kilometres area of Wollongong, Sydney and Newcastle. These IBA techniques provide elemental concentrations for over 20 different elements from hydrogen to lead, they include H, C, N, O, F, Na, Al, Si, P, S, Cl, K, Ca, Ti, V, Cr, Mn, Fe, Cu, Ni, Zn, Br and Pb. The four ion beam techniques are performed simultaneously on the 3MV Van de Graaff accelerator at ANSTO and have been described in detail elsewhere. They are sufficiently sensitive to analyse for many of these elements to levels around 10 ng/m{sup 3} or less in about five minutes of accelerator running time per filter. This is more than adequate for aerosol analyses as most filters contain around 150 {mu}g/cm{sup 2} of material which corresponds to about 10{mu}g/m{sup 3} of fine particles in the atmosphere. For this work fine particles are those with diameters less than 2.5{mu}m. Fine particle data has been collected twice a week and analysed for each of the above elements by ANSTO since 1991 at more than 25 different sites throughout NSW. This large dataset set allows us to not only determine the composition of fine particles and to look for signature elements for particular sources but also to use multivariate statistics to define elemental source fingerprints and then to determine the percentage contributions of these fingerprints to the total fine particle mass in the atmosphere. This paper describes the application of these techniques to the study of domestic wood fires and vegetation burning in NSW over a two year period from 1992-93. It also presents, for the first time, fine particle data related to the January 1994 bushfires in NSW. 6 refs., 1 tab., 5 figs.

Ion beam analysis techniques for the elemental fingerprinting of fine particle smoke from vegetation burning in NSW

International Nuclear Information System (INIS)

Cohen, D.

1996-01-01

Accelerator based ion beam analysis (IBA) techniques, including PIXE, PIGME, RBS and PESA, have been used to analyse elemental compositions of airborne particles covering a 60,000 square kilometres area of Wollongong, Sydney and Newcastle. These IBA techniques provide elemental concentrations for over 20 different elements from hydrogen to lead, they include H, C, N, O, F, Na, Al, Si, P, S, Cl, K, Ca, Ti, V, Cr, Mn, Fe, Cu, Ni, Zn, Br and Pb. The four ion beam techniques are performed simultaneously on the 3MV Van de Graaff accelerator at ANSTO and have been described in detail elsewhere. They are sufficiently sensitive to analyse for many of these elements to levels around 10 ng/m 3 or less in about five minutes of accelerator running time per filter. This is more than adequate for aerosol analyses as most filters contain around 150 μg/cm 2 of material which corresponds to about 10μg/m 3 of fine particles in the atmosphere. For this work fine particles are those with diameters less than 2.5μm. Fine particle data has been collected twice a week and analysed for each of the above elements by ANSTO since 1991 at more than 25 different sites throughout NSW. This large dataset set allows us to not only determine the composition of fine particles and to look for signature elements for particular sources but also to use multivariate statistics to define elemental source fingerprints and then to determine the percentage contributions of these fingerprints to the total fine particle mass in the atmosphere. This paper describes the application of these techniques to the study of domestic wood fires and vegetation burning in NSW over a two year period from 1992-93. It also presents, for the first time, fine particle data related to the January 1994 bushfires in NSW. 6 refs., 1 tab., 5 figs

Ion beam analysis techniques for the elemental fingerprinting of fine particle smoke from vegetation burning in NSW

Energy Technology Data Exchange (ETDEWEB)

Cohen, D [Australian Nuclear Science and Technology Organisation, Lucas Heights, NSW (Australia)

1997-12-31

Accelerator based ion beam analysis (IBA) techniques, including PIXE, PIGME, RBS and PESA, have been used to analyse elemental compositions of airborne particles covering a 60,000 square kilometres area of Wollongong, Sydney and Newcastle. These IBA techniques provide elemental concentrations for over 20 different elements from hydrogen to lead, they include H, C, N, O, F, Na, Al, Si, P, S, Cl, K, Ca, Ti, V, Cr, Mn, Fe, Cu, Ni, Zn, Br and Pb. The four ion beam techniques are performed simultaneously on the 3MV Van de Graaff accelerator at ANSTO and have been described in detail elsewhere. They are sufficiently sensitive to analyse for many of these elements to levels around 10 ng/m{sup 3} or less in about five minutes of accelerator running time per filter. This is more than adequate for aerosol analyses as most filters contain around 150 {mu}g/cm{sup 2} of material which corresponds to about 10{mu}g/m{sup 3} of fine particles in the atmosphere. For this work fine particles are those with diameters less than 2.5{mu}m. Fine particle data has been collected twice a week and analysed for each of the above elements by ANSTO since 1991 at more than 25 different sites throughout NSW. This large dataset set allows us to not only determine the composition of fine particles and to look for signature elements for particular sources but also to use multivariate statistics to define elemental source fingerprints and then to determine the percentage contributions of these fingerprints to the total fine particle mass in the atmosphere. This paper describes the application of these techniques to the study of domestic wood fires and vegetation burning in NSW over a two year period from 1992-93. It also presents, for the first time, fine particle data related to the January 1994 bushfires in NSW. 6 refs., 1 tab., 5 figs.