WorldWideScience

Sample records for hydrocarbon distribution indexes

  1. DIDA: Distributed Indexing Dispatched Alignment.

    Directory of Open Access Journals (Sweden)

    Hamid Mohamadi

    Full Text Available One essential application in bioinformatics that is affected by the high-throughput sequencing data deluge is the sequence alignment problem, where nucleotide or amino acid sequences are queried against targets to find regions of close similarity. When queries are too many and/or targets are too large, the alignment process becomes computationally challenging. This is usually addressed by preprocessing techniques, where the queries and/or targets are indexed for easy access while searching for matches. When the target is static, such as in an established reference genome, the cost of indexing is amortized by reusing the generated index. However, when the targets are non-static, such as contigs in the intermediate steps of a de novo assembly process, a new index must be computed for each run. To address such scalability problems, we present DIDA, a novel framework that distributes the indexing and alignment tasks into smaller subtasks over a cluster of compute nodes. It provides a workflow beyond the common practice of embarrassingly parallel implementations. DIDA is a cost-effective, scalable and modular framework for the sequence alignment problem in terms of memory usage and runtime. It can be employed in large-scale alignments to draft genomes and intermediate stages of de novo assembly runs. The DIDA source code, sample files and user manual are available through http://www.bcgsc.ca/platform/bioinfo/software/dida. The software is released under the British Columbia Cancer Agency License (BCCA, and is free for academic use.

  2. Correlation between hydrocarbon distribution and water-hydrocarbon ratio in Fischer-Tropsch synthesis

    Institute of Scientific and Technical Information of China (English)

    Xiaofeng Zhou; Qingling Chen; Yuewu Tao; Huixin Weng

    2011-01-01

    In order to shorten the evaluation cycle of cobalt catalyst before the optimized catalyst is fixed on,a mathematical method is proposed to calculate weight percentage of C5+ hydrocarbons.Based on the carbide polymerization mechanism and the main hydrocarbons being linear alkanes and α-olefins,the correlation between hydrocarbon distribution and the molecular mass ratio of water to hydrocarbons is discussed.The result shows the ratio was within the range of 1.125-1.286 and the lower the ratio,the more gaseous hydrocarbons were obtained.Moreover,a linear equation between the weight percentage of C5+ hydrocarbons and the weight ratio of C5+ hydrocarbons to the total water is established.These results are validated by corresponding experiments.The weight percentage of C5+ hydrocarbons could be immediately calculated by this linear equation without detailed gas chromatography (GC) analysis of them.

  3. Sources and distribution of aliphatic and polyaromatic hydrocarbons in sediments from the Neuquen River, Argentine Patagonia.

    Science.gov (United States)

    Monza, Liliana B; Loewy, Ruth M; Savini, Mónica C; Pechen de d'Angelo, Ana M

    2013-01-01

    Spatial distribution and probable sources of aliphatic and polyaromatic hydrocarbons (AHs, PAHs) were investigated in surface sediments collected along the bank of the Neuquen River, Argentina. Total concentrations of aliphatic hydrocarbons ranged between 0.41 and 125 μg/g dw. Six stations presented low values of resolved aliphatic hydrocarbons and the n-alkane distribution indexes applied suggested a clear biogenic source. These values can be considered the baseline levels of aliphatic hydrocarbons for the river sediments. This constitutes important information for the assessment of future impacts since a strong impulse in the exploitation of shale gas and shale oil in these zones is nowadays undergoing. For the other 11 stations, a mixture of aliphatic hydrocarbons of petrogenic and biogenic origin was observed. The spatial distribution reflects local inputs of these pollutants with a significant increase in concentrations in the lower course, where two major cities are located. The highest values of total aliphatic hydrocarbons were found in this sector which, in turn, was the only one where individual PAHs were detected.

  4. Total Petroleum Hydrocarbon Content (TPH) As an Index ...

    African Journals Online (AJOL)

    MICHAEL

    potential for hydrocarbon accumulation and could be evaluated for its efficacy as a tool in phytoremediation exercise ... and biological components of the ecosystem. ... changes of distilled water. .... low molecular weight polynuclear aromatic.

  5. Acute toxicity and effect of some petroleum hydrocarbon on the metabolic index in Etroplus suratensis

    Digital Repository Service at National Institute of Oceanography (India)

    Ansari, Z.A.; Farshchi, P.

    Acute toxicity (LC sub(50)) and effect of some petroleum hydrocarbons (Toluene, Quinoline, Pyridine and Naphthalene) on the metabolic index (oxygen consumption rate) of an estuarine fish. Etroplus suratensis is reported. The LC sub(50) values were...

  6. Numerical modeling of temperature and species distributions in hydrocarbon reservoirs

    Science.gov (United States)

    Bolton, Edward W.; Firoozabadi, Abbas

    2014-01-01

    We examine bulk fluid motion and diffusion of multicomponent hydrocarbon species in porous media in the context of nonequilibrium thermodynamics, with particular focus on the phenomenology induced by horizontal thermal gradients at the upper and lower horizontal boundaries. The problem is formulated with respect to the barycentric (mass-averaged) frame of reference. Thermally induced convection, with fully time-dependent temperature distributions, can lead to nearly constant hydrocarbon composition, with minor unmixing due to thermal gradients near the horizontal boundaries. Alternately, the composition can be vertically segregated due to gravitational effects. Independent and essentially steady solutions have been found to depend on how the compositions are initialized in space and may have implications for reservoir history. We also examine injection (to represent filling) and extraction (to represent leakage) of hydrocarbons at independent points and find a large distortion of the gas-oil contact for low permeability.

  7. The distribution of polycyclic aromatic hydrocarbons in asphaltenes

    Energy Technology Data Exchange (ETDEWEB)

    Ruiz-Morales, Y. [Inst. Mexicano del Petroleo, Lazaro (Mexico). Programa de Ingenieria Molecular; Ballard Andrews, A.; Mullins, O.C. [Schlumberger-Doll Research Center, Cambridge, MA (United States)

    2008-07-01

    The distribution of polycyclic aromatic hydrocarbons (PAHs) in asphaltenes is a strong determinant for asphaltene physical properties. PAHs also provide the UV and visible absorption and emission profiles of asphaltenes. All PAHs absorb light in the UV-visible spectrum and many also emit light in this spectral range. This study combined a molecular orbital theory with an experimental approach to quantitatively link the UV-visible absorption and emission profiles to the asphaltene PAH distribution. Key features of the absorption and emission spectral data were found to be reproduced with PAH distributions centered at 7 fused rings. The study also identified other highly different distributions of PAHs in terms of plausibility to account for the measured optical data. The paper also described the affect that heteroatoms had on the analysis.

  8. Size Distribution of Chlorinated Polycyclic Aromatic Hydrocarbons in Atmospheric Particles.

    Science.gov (United States)

    Kakimoto, Kensaku; Nagayoshi, Haruna; Konishi, Yoshimasa; Kajimura, Keiji; Ohura, Takeshi; Nakano, Takeshi; Hata, Mitsuhiko; Furuuchi, Masami; Tang, Ning; Hayakawa, Kazuichi; Toriba, Akira

    2017-01-01

    The particle size distribution of chlorinated polycyclic aromatic hydrocarbons (ClPAHs) in particulate matter (PM) in Japan is examined for the first time. PM was collected using a PM0.1 air sampler with a six-stage filter. PM was collected in October 2014 and January 2015 to observe potential seasonal variation in the atmospheric behavior and size of PM, including polycyclic aromatic hydrocarbons (PAHs) and ClPAHs. We found that the concentration of PAHs and ClPAHs between 0.5-1.0 μm and 1.0-2.5 μm markedly increase in January (i.e., the winter season). Among the ClPAHs, 1-ClPyrene and 6-ClBenzo[a]Pyrene were the most commonly occurring compounds; further, approximately 15% of ClPAHs were in the nanoparticle phase (<0.1 μm). The relatively high presence of nanoparticles is a potential human health concern because these particles can easily be deposited in the lung periphery. Lastly, we evaluated the aryl hydrocarbon receptor (AhR) ligand activity of PM extracts in each size fraction. The result indicates that PM < 2.5 μm has the strong AhR ligand activity.

  9. Indexing and Searching Distributed Astronomical Data Archives

    Science.gov (United States)

    Jackson, R. E.

    The technology needed to implement a Distributed Astronomical Data Archive (DADA) is available today (e.g., Fullton 1993). Query interface standards are needed, however, before the DADA information will be discoverable. Fortunately, a small number of parameters can describe a large variety of astronomical datasets. One possible set of parameters is (RA, DEC, Wavelength, Time, Intensity) times (Minimum Value, Maximum Value, Resolution, Coverage). These twenty parameters can describe aperture photometry, images, time resolved spectroscopy, etc. These parameters would be used to index each dataset in each catalog. Each catalog would in turn be indexed by the extremum values of the parameters into a catalog of catalogs. Replicating this catalog of catalogs would create a system with no centralized resource to be saturated by multiple users.

  10. Central indexes to the citation distribution: A complement to the h-index

    CERN Document Server

    Dorta-Gonzalez, Pablo; 10.1007/s11192-011-0453-3

    2013-01-01

    The citation distribution of a researcher shows the impact of their production and determines the success of their scientific career. However, its application in scientific evaluation is difficult due to the bi-dimensional character of the distribution. Some bibliometric indexes that try to synthesize in a numerical value the principal characteristics of this distribution have been proposed recently. In contrast with other bibliometric measures, the biases that the distribution tails provoke, are reduced by the h-index. However, some limitations in the discrimination among researchers with different publication habits are presented in this index. This index penalizes selective researchers, distinguished by the large number of citations received, as compared to large producers. In this work, two original sets of indexes, the central area indexes and the central interval indexes, that complement the h-index to include the central shape of the citation distribution, are proposed and compared.

  11. Main controlling factors for hydrocarbon reservoir formation and petroleum distribution in Cratonic Area of Tarim Basin

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The Cratonic Area of the Tarim Basin is located in the central part of the basin, developing primarily with Cambrian marine source rocks and secondly Middle to Upper Ordovician marine and Carboniferous-Permian transitional facies source rocks. The source rocks were matured in the changeable period and space, forming multiple hydrocarbon generating centers during the periods. The Cratonic Area experienced multiple tectonic orogenies, forming several palaeouplifts. The matching condition between effective hydrocarbon generating centers and the palaeouplifts in various periods is the main control factor for the formation and distribution of hydrocarbon reservoirs. The palaeouplifts have experienced multiple hydrocarbon-filling phases, several periods of modifications and even breakdown. The palaeouplifts and the adjacent slopes around the effective hydrocarbon generating center compose the most favorable places for hydrocarbon accumulation. The hydrocarbon phase is related with the evolution of the hydrocarbon generating center. In the Tarim Basin's Cratonic Area, reservoirs were mostly formed during late Hercynian. The originally formed hydrocarbon reservoirs which are adjacent to source kitchens and in the good preservation condition are the most favorable prospecting targets. Hydrocarbon is richly accumulated under the regional caprock, surrounding the faulted trends, and over and below the unconformity surfaces. Reservoirs in the Carboniferous sandstone, Ordovician karstic weathered crust and carbonate rock inside the buried hill compose the main intervals for hydrocarbon accumulation. Carboniferous and Silurian sandstone pinchout reservoirs and carbonate lithologic reservoirs with rich fractures and pores are the main targets for further prospecting.

  12. The bacterial community structure of hydrocarbon-polluted marine environments as the basis for the definition of an ecological index of hydrocarbon exposure.

    Science.gov (United States)

    Lozada, Mariana; Marcos, Magalí S; Commendatore, Marta G; Gil, Mónica N; Dionisi, Hebe M

    2014-09-17

    The aim of this study was to design a molecular biological tool, using information provided by amplicon pyrosequencing of 16S rRNA genes, that could be suitable for environmental assessment and bioremediation in marine ecosystems. We selected 63 bacterial genera that were previously linked to hydrocarbon biodegradation, representing a minimum sample of the bacterial guild associated with this process. We defined an ecological indicator (ecological index of hydrocarbon exposure, EIHE) using the relative abundance values of these genera obtained by pyrotag analysis. This index reflects the proportion of the bacterial community that is potentially capable of biodegrading hydrocarbons. When the bacterial community structures of intertidal sediments from two sites with different pollution histories were analyzed, 16 of the selected genera (25%) were significantly overrepresented with respect to the pristine site, in at least one of the samples from the polluted site. Although the relative abundances of individual genera associated with hydrocarbon biodegradation were generally low in samples from the polluted site, EIHE values were 4 times higher than those in the pristine sample, with at least 5% of the bacterial community in the sediments being represented by the selected genera. EIHE values were also calculated in other oil-exposed marine sediments as well as in seawater using public datasets from experimental systems and field studies. In all cases, the EIHE was significantly higher in oiled than in unpolluted samples, suggesting that this tool could be used as an estimator of the hydrocarbon-degrading potential of microbial communities.

  13. “Complementarity” Feature of Hydrocarbon Distribution in Oil-rich Sag

    Institute of Scientific and Technical Information of China (English)

    DuJinhu; YiShiwei; LuXuejun; WangQuan

    2004-01-01

    Based on the research and exploration of lithostratigraphic reservoir in me Jizhong depression of the Bohai Bay basin and Erlian basin, the hydrocarbon distribution in a continental oil-rich sag has "complementarity" feature, viz. the hydrocarbon resources configuration and plane distribution of the structural reservoir and lithostratigraphic reservoir have the "complementarity". This distribution feature is controlled by many factors such as the macroscopical geological setting, reservoir-forming condition, and the reservoir-forming mechanism of structural reservoir and lithostratigraphic reservoir. More research shows that the "complementarity" of hydrocarbon distribution is prevalent in every kind of continental basin. This "rule" helps to establish a new exploration theory, a scientific exploration program, and make proper exploration deployments in hydrocarbon exploration. Therefore, it is significant for the exploration work in continental petroliferous basins of China.

  14. Characterization of cyanobacterial hydrocarbon composition and distribution of biosynthetic pathways.

    Directory of Open Access Journals (Sweden)

    R Cameron Coates

    Full Text Available Cyanobacteria possess the unique capacity to naturally produce hydrocarbons from fatty acids. Hydrocarbon compositions of thirty-two strains of cyanobacteria were characterized to reveal novel structural features and insights into hydrocarbon biosynthesis in cyanobacteria. This investigation revealed new double bond (2- and 3-heptadecene and methyl group positions (3-, 4- and 5-methylheptadecane for a variety of strains. Additionally, results from this study and literature reports indicate that hydrocarbon production is a universal phenomenon in cyanobacteria. All cyanobacteria possess the capacity to produce hydrocarbons from fatty acids yet not all accomplish this through the same metabolic pathway. One pathway comprises a two-step conversion of fatty acids first to fatty aldehydes and then alkanes that involves a fatty acyl ACP reductase (FAAR and aldehyde deformylating oxygenase (ADO. The second involves a polyketide synthase (PKS pathway that first elongates the acyl chain followed by decarboxylation to produce a terminal alkene (olefin synthase, OLS. Sixty-one strains possessing the FAAR/ADO pathway and twelve strains possessing the OLS pathway were newly identified through bioinformatic analyses. Strains possessing the OLS pathway formed a cohesive phylogenetic clade with the exception of three Moorea strains and Leptolyngbya sp. PCC 6406 which may have acquired the OLS pathway via horizontal gene transfer. Hydrocarbon pathways were identified in one-hundred-forty-two strains of cyanobacteria over a broad phylogenetic range and there were no instances where both the FAAR/ADO and the OLS pathways were found together in the same genome, suggesting an unknown selective pressure maintains one or the other pathway, but not both.

  15. Simulation Opportunity Index, A Simple and Effective Method to Boost the Hydrocarbon Recovery

    KAUST Repository

    Saputra, Wardana

    2016-09-08

    During periods of low oil prices, profitability of field developments drops drastically. To help with this difficulty, a cost-effective method has been proposed to boost the hydrocarbon recovery by optimizing well locations through the Simulated Opportunity Index (SOI). SOI is an intelligent method to identify zones with high potential for production which is empirically calculated from basic rock and fluid properties, and from reservoir pressure as its energy capacity. In order to obtain the best results, the original SOI formula (Molina et al., 2009) was extended to both oil and gas fields. Based on this modified SOI formula, a software program has been developed to locate the best well locations considering multilayer, existing wells, and fault existences. This paper describes how the SOI software helps as a simple, fast, and accurate way to obtain the higher hydrocarbon production than that of trial-error method and previous studies in two different fields located in offshore Indonesia. On one hand, the proposed method could save money by minimizing the required number of wells. On the other hand, it could maximize profit by maximizing recovery.

  16. Distribution of petroleum hydrocarbons in Goa coastal waters

    Digital Repository Service at National Institute of Oceanography (India)

    Fondekar, S.P.; Topgi, R.S.; Noronha, R.J.

    Average hydrocarbon concentrations in water, plankton and sediment samples collected from the central west coast of India between 14 degrees 40'N and 15 degrees 50'N were 30.9 mu g/litre, 46.9 mu g/g dry wt and 7.1 degrees kg/g dry wt respectively...

  17. Seasonal distribution of aliphatic hydrocarbons in the Vaza Barris Estuarine System, Sergipe, Brazil.

    Science.gov (United States)

    Barbosa, José Carlos S; Santos, Lukas G G V; Sant'Anna, Mércia V S; Souza, Michel R R; Damasceno, Flaviana C; Alexandre, Marcelo R

    2016-03-15

    The seasonal assessment of anthropogenic activities in the Vaza Barris estuarine river system, located in the Sergipe state, northeastern Brazil, was performed using the aliphatic hydrocarbon distribution. The aliphatic hydrocarbon and isoprenoid (Pristane and Phytane) concentrations ranged between 0.19 μg g(-1) and 8.5 μg g(-1) of dry weight. Data were analyzed using Kruskal-Wallis test, with significance level set at p n-alkanes/n-C16, Low Molecular Weight/High Molecular Weight ratio (LMW/HMW) and Terrigenous to Aquatic Ratio (TAR) suggested biogenic input of aliphatic hydrocarbons for most samples, with significant contribution of higher plants.

  18. Acute toxicity and effect of some petroleum hydrocarbon on the metabolic index in @iEtroplus suratensis@@

    Digital Repository Service at National Institute of Oceanography (India)

    Ansari, Z.A.; Farshchi, P.

    Acute toxicity (LC@d50@@) and effect of some petroleum hydrocarbons (Toluene, Quinoline, Pyridine and Naphthalene) on the metabolic index (oxygen consumption rate) of an estuarine fish. @iEtroplus suratensis@@ is reported. The LC@d50@@ values were...

  19. Distribution of major hydrocarbon source rocks in the major oil-gas-bearing basins in China

    Institute of Scientific and Technical Information of China (English)

    LIU Luofu; ZHAO Suping; CHEN Lixin; HUO Hong

    2005-01-01

    The distribution characteristics of major hydrocarbon source rocks in the major oil-gas-bearing basins in China were discussed in this paper, and differences between the East and the West basins in tectonic setting, age, lithology, sedimentary environment, and hydrocarbon generation feature and potential were also studied. Considering the Lüliang Mountains-Dalou Mountains as the boundary, source rocks in the East basins are distributed mainly in three NNE-trend subsiding belts, and those in the West basins are distributed in the north and south of the Tianshan Mountains and Qilian Mountains. They are mainly NWW trending and can be divided into four basin groups.

  20. Distributions of polycyclic aromatic hydrocarbons and alkylated polycyclic aromatic hydrocarbons in Osaka Bay, Japan.

    Science.gov (United States)

    Miki, Shizuho; Uno, Seiichi; Ito, Kazuki; Koyama, Jiro; Tanaka, Hiroyuki

    2014-08-30

    Contaminations in sediments by polycyclic aromatic hydrocarbons (PAHs) and alkylated PAHs were investigated at 44 sites in Osaka Bay, Japan. Concentrations of total PAHs and alkylated PAHs were in the range 6.40-7800 ng/g dry weights and 13.7-1700 ng/g dry weights, respectively. The PAH concentrations tended to be higher along the shoreline in the vicinities of big ports, industrialized areas, and densely populated regions such as the cities of Osaka and Kobe. The major sources appeared to be pyrogenic or both pyrogenic and petrogenic at most of the sites. PAH concentrations were remarkably high at a site near Kobe, where the concentrations of dibenzo(a,h)anthracene and benzo(g,h,i)perylene exceeded the effects-range-medium concentration and eight PAHs were above the corresponding effects-range-low concentrations. Those PAHs may have been derived from the great fire associated with the large earthquake in 1995.

  1. A Spatial Distribution Pattern-driven Spatial Index

    Directory of Open Access Journals (Sweden)

    WU Mingguang

    2015-01-01

    Full Text Available Packing spatial data into blocks and processing of global impact of local operations are two important tasks for spatial index to support bulk operations. In this paper, we present a new spatial index called Pattern-tree for bulk operations with spatial distribution pattern analysis. For packing objects into blocks, a new spatial data partitioning method based on the detection of the spatial distribution pattern was presented. This paper introduces a novel spatial index construction algorithm that combines of top-down and bottom-up methods; For processing of local update operations and its global impact, this paper introduces a new algorithm based on change analysis of the spatial distribution pattern. Empirical results demonstrate that performance improvements are achieved in practice in the case of spatial index construction and windows query compared with STLT, GBI and SCB.

  2. Paleozoic Composite Petroleum System of North Africa:Hydrocarbon Distribution and Main Controlling Factors

    Institute of Scientific and Technical Information of China (English)

    Bai Guoping; Zheng Lei

    2007-01-01

    North Africa,which is one of the main oil and gas producing regions in the world,is best known for its sub-salt Paleozoic-Triassic reservoirs and Paleozoic source rocks. Hydrocarbon abundance varies greatly from one structural domain to another areally and from one stratigraphic interval to another vertically. Analyses of the essential elements and geological processes of the Paleozoic petroleum system indicate that the distribution of the Lower Silurian shale source rocks,the development of a thick Mesozoic overburden,the presence of the Upper Triassic-Lower Jurassic evaporite seal are the most important factors governing the distribution of the Paleozoic-sourced hydrocarbons in North Africa. The Mesozoic sequence plays a critical role for hydrocarbons to accumulate by enabling the maturation of the Paleozoic source rocks during the Mesozoic-Paleogene times and preserving the accumulated hydrocarbons. Basins and surrounding uplifts,particularly the latter,with a thick Mesozoic sequence and a regional evaporite seal generally have abundant hydrocarbons. Basins where only a thin Mesozoic overburden was developed tend to have a very poor to moderate hydrocarbon prospectivity.

  3. Inverse cubic law of index fluctuation distribution in Indian markets

    CERN Document Server

    Pan, R K; Pan, Raj Kumar; Sinha, Sitabhra

    2006-01-01

    One of the principal statistical features characterizing the activity in financial markets is the distribution of fluctuations in market indicators such as the index. While the developed stock markets such as the New York Stock Exchange (NYSE) have been found to show heavy-tailed fluctuation distribution, there have been claims that emerging markets behave differently. Here we investigate the distribution of several indices from the Indian financial market, one of the largest emerging markets in the world. We have used both tick-by-tick data from the National Stock Exchange (NSE) and daily closing data from both NSE and Bombay Stock Exchange (BSE). We find that the cumulative distribution of index fluctuations has long tails consistent with a power law having exponent $\\alpha \\approx 3$, independent of the time-scale of observation or the market index used for the analysis. This ``inverse cubic law'' is quantitatively similar to what has been observed in developed markets, thereby providing strong evidence th...

  4. Hydrocarbon Accumulation and Distribution Characteristics of the Silurian in the Tazhong Uplift of Tarim Basin

    Science.gov (United States)

    LÜ, Xiuxiang; BAI, Zhongkai; ZHAO, Fengyun

    Hydrocarbon accumulation of the Silurian in the Tazhong uplift of Tarim basin is characterized by "two sources and three stages". "Two sources" means that the hydrocarbons are derived from two source rocks of the Cambrian and Middle-Upper Ordovician. "Three stages" means that asphalt and movable oil undergoes three hydrocarbon accumulation stages, i.e., Late Caledonian, Late Hercynian, and Yanshanian-Himalayan. The formation of asphalt resulted from the destruction of the hydrocarbons accumulated and migrated in the early stages. The present movable oil, mostly derived from Middle-Upper Ordovician source rock, resulted from the hydrocarbons accumulated in the late stage. There are three types of reservoirs, i.e., anticline structural, stratigraphic lithological, and lava shield reservoirs in the Tazhong uplift. Hydrocarbon accumulation of the Silurian in the Tazhong uplift is controlled by the three factors. (1) The background of uplift structure. Around the ancient uplift, the compounding of many types makes up the composite hydrocarbon accumulation areas. (2) Effective cover. The show of oil gas including asphalt, heavy crude oil, and normal oil is quite active in the Silurian. Asphalt and heavy crude oil are distributed under the red mudstone member and movable oil is distributed under the gray mudstone member. (3) High quality reservoir bed. Sandstone is distributed widely in the Tazhong area. Reservoir pore space can be divided into three types: a) secondary origin-primary origin pore space; b) primary origin-secondary origin pore space, and c) micropore space. Porosity is 3.3-17.4%, and permeability is (0.1-667.97) × 10 -3 μm 2.

  5. Distribution Characteristics and Risk Assessment of Polycyclic Aromatic Hydrocarbons in the Momoge Wetland, China

    Directory of Open Access Journals (Sweden)

    Jianling Xu

    2017-01-01

    Full Text Available The Momoge Nature Reserve is the research object of this study. Through field sampling, laboratory experiments and analysis, the contents, distribution characteristics, source identification, pollution levels and risk levels of polycyclic aromatic hydrocarbons (PAHs in wetland soils were studied. The results show that the sum content of 16 types of PAHs (Σ16 PAH in the wetland soil was within the range (0.029–0.4152 mg/kg. PAHs in wetland soil are primarily 2–3-rings PAHs. PAHs in the Momoge wetland soil have multiple sources: petroleum, combustion of petroleum and coal, and others, of which petroleum and the sum of combustion of petroleum and coal account for 38.0% and 59.3%, respectively. Research, using the standard index and pollution range methods, shows that the content of the PAH labelled Nap, found in the Momoge wetland soil, is excessive; some sampling sites exhibit a low level of pollution. The result of a biotoxicity assessment shows that there are two sampling sites that occasionally present an ecological toxicity hazard. The result of the organic carbon normalization process shows that an ecological risk exists only at sampling site No. 10.

  6. Distribution Characteristics and Risk Assessment of Polycyclic Aromatic Hydrocarbons in the Momoge Wetland, China

    Science.gov (United States)

    Xu, Jianling; Wang, Hanxi; Sheng, Lianxi; Liu, Xuejun; Zheng, Xiaoxue

    2017-01-01

    The Momoge Nature Reserve is the research object of this study. Through field sampling, laboratory experiments and analysis, the contents, distribution characteristics, source identification, pollution levels and risk levels of polycyclic aromatic hydrocarbons (PAHs) in wetland soils were studied. The results show that the sum content of 16 types of PAHs (Σ16 PAH) in the wetland soil was within the range (0.029–0.4152) mg/kg. PAHs in wetland soil are primarily 2–3-rings PAHs. PAHs in the Momoge wetland soil have multiple sources: petroleum, combustion of petroleum and coal, and others, of which petroleum and the sum of combustion of petroleum and coal account for 38.0% and 59.3%, respectively. Research, using the standard index and pollution range methods, shows that the content of the PAH labelled Nap, found in the Momoge wetland soil, is excessive; some sampling sites exhibit a low level of pollution. The result of a biotoxicity assessment shows that there are two sampling sites that occasionally present an ecological toxicity hazard. The result of the organic carbon normalization process shows that an ecological risk exists only at sampling site No. 10.

  7. Poverty Index With Time Varying Consumption and Income Distributions

    OpenAIRE

    2016-01-01

    In a recent work (Chattopadhyay, A. K. et al, Europhys. Lett. {\\bf 91}, 58003, 2010) based on food consumption statistics, we showed how a stochastic agent based model could represent the time variation of the income distribution statistics in a developing economy, thereby defining an alternative \\enquote{poverty index} (PI) that largely agreed with poverty gap index data. This PI used two variables, the probability density function of the income statistics and a consumption deprivation (CD) ...

  8. Interference Imaging of Refractive Index Distribution in Thin Samples

    Directory of Open Access Journals (Sweden)

    Norbert Tarjanyi

    2004-01-01

    Full Text Available There are three versions of interference imaging of refractive index distribution in thin samples suggested in this contribution. These are based on imaging of interference field created by waves reflected from the front and the back sample surface or imaging of interference field of Michelson or Mach-Zehnder interferometer with the sample put in one of the interferometers arm. The work discusses the advantages and disadvantages of these techniques and presents the results of imaging of refrective index distribution in photorefractive record of a quasi-harmonic optical field in thin LiNbO3 crystal sample.

  9. Spatial variation and distribution of polycyclic aromatic hydrocarbons in soil

    Directory of Open Access Journals (Sweden)

    Okoro Duke

    2007-04-01

    Full Text Available An investigative study on polycyclic aromatic hydrocarbons (PAHs in soils of different sampling stations in Effurun metropolis and its environs of the Niger Delta Area of Nigeria was carried out with gas chromatography mass spectrometry (GC-MS. Among the 16 US EPA priority PAHs determined, pyrene was observed to be the most abundant compound at all sites (20 %, followed by fluoranthene (14 %, phenanthrene (12 %, chrysene (10 % and benzo(ghiperylene (6 %. High concentrations of pyrene could be attributed to anthropogenic source such as industrial and vehicular emissions. On the other hand, naphthalene, acenathalene and anthracene accounted for 3.2 %, 1.6 %, and 1.1 %, respectively. The observed trend: Refinery > Ekpan > Enerhen > Water Resources > Alegbo > Ugborikoko > Ugboroke could be attributed to the density of industrial and commercial activities in each area. Clear differences in the total PAH between urban/industrial and rural areas were observed. The results showed that PAH levels in soils from heavily industrial sites were higher in concentrations to the effect that Refinery locations were comparatively higher than all other locations. The higher levels of PAHs observed in the Refinery location are clear indications of combustion emissions and gas flaring from fractionating towers.

  10. On Use of the Variable Zagreb vM2 Index in QSPR: Boiling Points of Benzenoid Hydrocarbons

    Directory of Open Access Journals (Sweden)

    Albin Jurić

    2004-12-01

    Full Text Available The variable Zagreb vM2 index is introduced and applied to the structure-boiling point modeling of benzenoid hydrocarbons. The linear model obtained (thestandard error of estimate for the fit model Sfit=6.8 oC is much better than thecorresponding model based on the original Zagreb M2 index (Sfit=16.4 oC. Surprisingly,the model based on the variable vertex-connectivity index (Sfit=6.8 oC is comparable tothe model based on vM2 index. A comparative study with models based on the vertex-connectivity index, edge-connectivity index and several distance indices favours modelsbased on the variable Zagreb vM2 index and variable vertex-connectivity index.However, the multivariate regression with two-, three- and four-descriptors givesimproved models, the best being the model with four-descriptors (but vM2 index is notamong them with Sfit=5 oC, though the four-descriptor model contaning vM2 index isonly slightly inferior (Sfit=5.3 oC.

  11. Zerber: r-Confidential Indexing for Distributed Documents

    NARCIS (Netherlands)

    Zerr, Sergej; Demidova, Elena; Olmedilla, Daniel; Nejdl, Wolfgang; Winslett, Marianne; Mitra, Soumyadeb

    2008-01-01

    Zerr, S., Demidova, E., Olmedilla, D., Nejdl, W., Winslett, M., & Mitra, S. (2008). Zerber: r-Confidential Indexing for Distributed Documents. In J. Teubner (Eds.), Proceedings of the 11th International Conference on Extending Database Technology (pp. 287-298). March, 25-29, 2008, Nantes, France.

  12. Assessment of molecular marker compounds as an index of the biodegradation of diesel fuel hydrocarbons in soil

    Energy Technology Data Exchange (ETDEWEB)

    Voos, G.; Mills, G.; O`Neill, J.; Jones, W. [Savannah River Ecology Labortory, Aiken, SC (United States)

    1996-10-01

    The weathering of petroleum hydrocarbons in the soil environment is the sum of biological, physical and chemical processes. It is often difficult to clearly discern microbial from abiotic contributions to the overall process. This is especially important in assessing the effectiveness of various in-situ bioremediation technologies. We examined molecular marker compounds, including pristane, phytane, diterpenoid hydrocarbons, farnesane and norpristane, and the ratios n-C17/pristane and n-C18/phytane to evaluate their use as an index of biodegradation of diesel fuel in contaminated soil. The study was conducted using microcosms containing 200 g of contaminated soil. Microcosms were destructively sampled on days 0, 1, 2, 4, 8, 14, 33 and 64 of the experiment. The soil was analyzed for straight-chained, branched-chained, and alicyclic petroleum hydrocarbons using high-resolution gas chromatography. Results indicate that by day 33 of the experiment, pristane and phytane were present at significantly greater concentrations than their corresponding n-alkanes and the other marker compounds analyzed. There is a strong correlation between the amount of pristane and phytane present in the soil and the amount of total extractable petroleum hydrocarbons (TEPH) measured during the course of the experiment.

  13. Poverty Index With Time Varying Consumption and Income Distributions

    CERN Document Server

    Chattopadhyay, Amit K; Mallick, Sushanta K

    2016-01-01

    In a recent work (Chattopadhyay, A. K. et al, Europhys. Lett. {\\bf 91}, 58003, 2010) based on food consumption statistics, we showed how a stochastic agent based model could represent the time variation of the income distribution statistics in a developing economy, thereby defining an alternative \\enquote{poverty index} (PI) that largely agreed with poverty gap index data. This PI used two variables, the probability density function of the income statistics and a consumption deprivation (CD) function, representing the shortfall in the minimum consumption needed for survival. Since the time dependence of the CD function was introduced there through data extrapolation only and not through an endogenous time dependent series, this model left unexplained how the minimum consumption needed for survival varies with time. The present article overcomes these limitations and arrives at a new unified theoretical structure through time varying consumption and income distributions where trade is only allowed when the inc...

  14. Distribution of Heavy Hydrocarbon in Coal Seams and Its Use in Predicting Outburst of Coal

    Institute of Scientific and Technical Information of China (English)

    蒋承林; 李增华; 韩颖

    2003-01-01

    In order to verify whether any special gas component exists in outburst samples or not, coal samples from both outburst coal seams and non-outburst coal seams were collected. Some gases were extracted from the samples and analyzed qualitatively and quantitatively on chromatogram-mass spectrograph. The qualitative analysis show that there is no special gases in coal seams. And the quantitative analysis indicates that the heavy hydrocarbon content in coal samples from outburst coal seams is apparently higher than that from non-outburst district ones, which reflects the damage of geological tectonic movement to coal body in history. Therefore, the heavy hydrocarbon content of coal sample can be used as an index to predict coal outburst.

  15. Generalized Pareto Distribution Model and Its Application to Hydrocarbon Resource Structure Prediction of the Huanghua Depression

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The generalized Pareto distribution model is a kind of hydrocarbon pool size probability statistical method for resource assessment. By introducing the time variable, resource conversion rate and the geological variable, resource density, such model can describe not only different types of basins, but also any exploration samples at different phases of exploration, up to the parent population. It is a dynamic distribution model with profound geological significance and wide applicability. Its basic principle and the process of resource assessment are described in this paper. The petroleum accumulation system is an appropriate assessment unit for such method. The hydrocarbon resource structure of the Huanghua Depression in Bohai Bay Basin was predicted by using this model. The prediction results accord with the knowledge of exploration in the Huanghua Depression, and point out the remaining resources potential and structure of different petroleum accumulation systems, which are of great significance for guiding future exploration in the Huanghua Depression.

  16. The Spectral Index Distribution of EGRET Blazars: Prospects for GLAST

    Energy Technology Data Exchange (ETDEWEB)

    Venters, Tonia M.; Pavlidou, Vasiliki; /SLAC

    2011-11-29

    The intrinsic distribution of spectral indices in GeV energies of gamma-ray-loud blazars is a critical input in determining the spectral shape of the unresolved blazar contribution to the diffuse extragalactic gamma-ray background, as well as an important test of blazar emission theories. We present a maximum-likelihood method of determining the intrinsic spectral index distribution (ISID) of a population of {gamma}-ray emitters which accounts for error in measurement of individual spectral indices, and we apply it to EGRET blazars. We find that the most likely Gaussian ISID for EGRET blazars has a mean of 2.27 and a standard deviation of 0.20. We additionally find some indication that FSRQs and BL Lacs may have different ISIDs (with BL Lacs being harder). We also test for spectral index hardening associated with blazar variability for which we find no evidence. Finally, we produce simulated GLAST spectral index datasets and perform the same analyses. With improved statistics due to the much larger number of resolvable blazars, GLAST data will help us determine the ISIDs with much improved accuracy. Should any difference exist between the ISIDs of BL Lacs and FSRQs or between the ISIDs of blazars in the quiescent and flaring states, GLAST data will be adequate to separate these ISIDs at a significance better than 3{sigma}.

  17. Hydrocarbons in the Hauptsalz formation of the Gorleben salt dome. Content, distribution and origin

    Energy Technology Data Exchange (ETDEWEB)

    Pusch, Maximilian; Hammer, Joerg; Ostertag-Henning, Christian [Federal Institute for Geosciences and Natural Resources (BGR), Hannover (Germany)

    2015-07-01

    In the frame of the geological exploration of the Gorleben salt dome (November 2010 to November 2012) concentrations and compositions of hydrocarbons occuring in the main rock salt (Hauptsalz, Stassfurt series, z2) have been investigated. These exploration works followed former investigations of Gerling et al. (2002) and Bornemann et al. (2008). In order to get fresh, unaltered and representative samples beyond the EDZ (excavation damaged zone) for mineralogical and geochemical analyses, about 45 boreholes have been drilled at the 840 m level of the Gorleben exploration mine. These boreholes have been arranged in equal distances (depending on the mine structure) alongside crosscut 1 west (each 6 m long) and crosscut 1 east (each 9 m long). In addition 20 packer boreholes (10 packer boreholes per crosscut) for pressure build-up recording and hydrocarbon sampling have also been established. Immediately after drilling, core samples from the Hauptsalz for organic geochemical analyses have been retrieved and were dissolved in deionised and degased water. The results of analyses of about 210 samples scattered over all 45 boreholes reveal a total background concentration of hydrocarbons (C{sub 1} to C{sub 40}) of 0,24 mg/kg. 70 samples have concentrations between 1 mg/kg and 50 mg/kg (average 2,66 mg/kg) with 5 outliers up to 442 mg/kg in crosscut 1 west (Hammer et al. 2012, 2013). The drill cores have been investigated and documented by using ultraviolet light (l = 254 nm) in respect of visible indications of the existence of fluorescing aromatic hydrocarbons. Analyses revealed a high level of heterogeneous hydrocarbon distribution in the shape of isolated, irregular streaks, clusters, clouds and occasionally layers mainly located in recrystallized zones of the Hauptsalz. Thin sections and thick sections showed that hydrocarbons in z2HS1 (Knaeuelsalz) and z2HS2 (Streifensalz) samples are either located as black to brownish dendritical fluid inclusions alongside the grain

  18. Distribution of optometric practices relative to deprivation index in Scotland.

    Science.gov (United States)

    Legge, Robin; Strang, Niall C; Loffler, Gunter

    2017-07-19

    The UK National Health Service aims to provide universal availability of healthcare, and eye-care availability was a primary driver in the development of the Scottish General Ophthalmic Services (GOS) model. Accordingly, a relatively equal distribution of optometry practices across socio-economic areas is required. We examined practice distribution relative to deprivation. 672 practices were sampled from nine Health Boards within Scotland. Practices were assigned a deprivation ranking by referencing their postcode with the Scottish Index of Multiple Deprivation (SIMD) tool (Scottish Executive National Statistics: General Report. 2016). Averaged across Health Boards, the share of practices for the five deprivation quintiles was 25, 33, 18, 14 and 11% from most to least deprived area, respectively. Although there was some variation of relative practice distribution in individual Health Boards, 17 of the 45 regions (nine Health Boards, five quintiles) had a close balance between population and share of practices. There was no clear pattern of practice distribution as a function of deprivation rank. Analysis revealed good correlation between practice and population share for each Health Board, and for the combined data (R2 = 0.898, P relatively balanced across socio-economic areas, suggesting that differences in eye-examination uptake across social strata are unrelated to service availability.

  19. The Levels and Distribution of Polycyclic Aromatic Hydrocarbons (PAH Contamination in Bottom Sediments in Manila Bay

    Directory of Open Access Journals (Sweden)

    Evangeline Santiago

    1997-12-01

    Full Text Available The concentration levels of 18 PAH compounds extracted from 19 bottom sediments from the Limay Coast and 16 bottom sediments from the coast along Metro Manila and Cavitc Province of Manila Bay were determined by Gas Chromatography/Mass Spectrometry.The PAH contamination, the levels of other non-PAH petroleum hydrocarbon compounds. and total organic content in the sediments were assessed in relation to the location and depth of the sampling sites. The PAH concentrations and the levels of other petroleum hydrocarbons in the sediments showed that the spatial distribution of PAH and other hydrocarbon contamination in Manila Bay is largely dependent on the proximity of the sediment deposition site to known point sources of pollution. On the western side, the highest levels of PAH contamination normalized to % TOC (1.29 X 104 at Ll2, 1.28 x 104 at Ll6, 0.55 at Ll3, and 0.54 at Ll5 were obtained from sediments collected at deposition sites near the outfall of the Petron Oil Refinery. On the eastern side. sediments located at the effiuent zones of the Paranaque and Malabon Rivers showed excessively higher levels of PAH normalized to % TOC (3.32 x 104 and 2.87 x 104: respectively compared to those obtained from other sites in the area.The PAH contamination in the sediments from Manila Bay is dominated by alkylated naphthalenes and phenanthrenes which are associated with petrogenic sources. This indicates that the surface sediments in Manila Bay are ex-posed to chronic contamination of petroleum hydrocarbons introduced mainly by direct spillage on the western side and by urban run-off on the eastern side.

  20. Use of remotely sensed precipitation and leaf area index in a distributed hydrological model

    DEFF Research Database (Denmark)

    Andersen, Jens; Dybkjær, Gorm Ibsen; Jensen, Karsten Høgh

    2002-01-01

    distributed hydrological modelling, remote sensing, precipitation, leaf area index, NOAA AVHRR, cold cloud duration......distributed hydrological modelling, remote sensing, precipitation, leaf area index, NOAA AVHRR, cold cloud duration...

  1. Toroidally Asymmetric Distributions of Hydrocarbon (CD) Emission and Chemical Sputtering Sources in DIII-D

    Energy Technology Data Exchange (ETDEWEB)

    Groth, M; Brooks, N H; Fenstermacher, M E; Lasnier, C J; McLean, A G; Watkins, J G

    2006-05-16

    Measurements in DIII-D show that the carbon chemical sputtering sources along the inner divertor and center post are toroidally periodic and highest at the upstream tile edge. Imaging with a tangentially viewing camera and visible spectroscopy were used to monitor the emission from molecular hydrocarbons (CH/CD) at 430.8 nm and deuterium neutrals in attached and partially detached divertors of low-confinement mode plasmas. In contrast to the toroidally periodic CD distribution, emission from deuterium neutrals was observed to be toroidally symmetric along the inner strike zone. The toroidal distribution of the measured tile surface temperature in the inner divertor correlates with that of the CD emission, suggesting larger parallel particle and heat fluxes to the upstream tile edge, either due to toroidal tile gaps or height steps between adjacent tiles.

  2. Distribution and sources of polycyclic aromatic hydrocarbons (PAHs) in street dust from the Tokyo Metropolitan area.

    Science.gov (United States)

    Takada, H; Onda, T; Harada, M; Ogura, N

    1991-09-01

    Molecular distributions of polycyclic aromatic hydrocarbons (PAHs) in street dust samples collected from the Tokyo Metropolitan area were determined by capillary gas chromatography following HPLC fractionation. Three- to six-ring PAHs and sulfur-heterocyclics were detected. PAHs in the dusts were dominated by three and four unsubstituted ring systems with significant amounts of their alkyl homologues. PAHs were widely distributed in the streets, with concentrations (sigma COMB) of a few microgram/g dust. Automobile exhaust, asphalt, gasoline fuel, diesel fuel, tyre particles, automobile crankcase oils, and atmospheric fallout were also analysed. The PAH profile, especially the relative abundance of alkyl-PAHs and sulfur-containing heterocyclics, indicated that PAHs in the street dusts from roads carrying heavy traffic are mainly derived from automobile exhausts; dusts from residential areas have a more significant contribution from atmospheric fallout.

  3. Composition and depth distribution of hydrocarbons in Barataria Bay marsh sediments after the Deepwater Horizon oil spill.

    Science.gov (United States)

    Dincer Kırman, Zeynep; Sericano, José L; Wade, Terry L; Bianchi, Thomas S; Marcantonio, Franco; Kolker, Alexander S

    2016-07-01

    In 2010, an estimate 4.1 million barrels of oil were accidentally released into the Gulf of Mexico (GoM) during the Deepwater Horizon (DWH) Oil Spill. One and a half years after this incident, a set of subtidal and intertidal marsh sediment cores were collected from five stations in Barataria Bay, Louisiana, USA, and analyzed to determine the spatial and vertical distributions and source of hydrocarbon residues based on their chemical composition. An archived core, collected before the DWH oil spill from the same area, was also analyzed to assess the pre-spill hydrocarbon distribution in the area. Analyses of aliphatic hydrocarbons, polycyclic aromatic hydrocarbons (PAHs) and stable carbon isotope showed that the distribution of petroleum hydrocarbons in Barataria Bay was patchy and limited in areal extent. Significant TPH and ΣPAH concentrations (77,399 μg/g and 219,065 ng/g, respectively) were detected in the surface sediments of one core (i.e., core A) to a depth of 9 cm. Based on a sedimentation rate of 0.39 cm yr(-1), determined using (137)Cs, the presence of anthropogenic hydrocarbons in these sediment core deposited ca. 50 to 60 years ago. The historical background hydrocarbon concentrations increased significantly at the sediment surface and can be attributed to recent inputs. Although the oil present in the bay's sediments has undergone moderate weathering, biomarker analyses performed on core A samples likely indicated the presence of hydrocarbons from the DWH oil spill. The effects of oiling events on Barataria Bay and other marsh ecosystems in this region remain uncertain, as oil undergoes weathering changes over time.

  4. Effect of strain rate on sooting limits in counterflow diffusion flames of gaseous hydrocarbon fuels: Sooting temperature index and sooting sensitivity index

    KAUST Repository

    Wang, Yu

    2014-05-01

    The effect of the strain rate on the sooting limits in counterflow diffusion flames was investigated in various gaseous hydrocarbon fuels by varying the nitrogen dilution in the fuel and oxidizer streams. The sooting limit was defined as the critical fuel and oxygen mole fraction at which soot started to appear in the elastic light scattering signal. The sooting region for normal alkane fuels at a specified strain rate, in terms of the fuel and oxygen mole fraction, expanded as the number of carbon atoms increased. The alkene fuels (ethylene, propene) tested had a higher propensity for sooting as compared with alkane fuels with the same carbon numbers (ethane, propane). Branched iso-butane had a higher propensity for sooting than did n-butane. An increase in the strain rate reduced the tendency for sooting in all the fuels tested. The sensitivity of the sooting limit to the strain rate was more pronounced for less sooting fuels. When plotted in terms of calculated flame temperature, the critical oxygen mole fraction exhibited an Arrhenius form under sooting limit conditions, which can be utilized to significantly reduce the effort required to determine sooting limits at different strain rates. We found that the limiting temperatures of soot formation flames are viable sooting metrics for quantitatively rating the sooting tendency of various fuels, based on comparisons with threshold soot index and normalized smoke point data. We also introduce a sooting temperature index and a sooting sensitivity index, two quantitative measures to describe sooting propensity and its dependence on strain rate. © 2013 The Combustion Institute.

  5. Distribution and sources of hydrocarbons in surface sediments of Gemlik Bay (Marmara Sea, Turkey).

    Science.gov (United States)

    Unlü, Selma; Alpar, Bedri

    2006-07-01

    Seabottom sediments from Gemlik Bay, one of the most polluted spots in SW Marmara Sea, were analyzed for parent polycyclic aromatic hydrocarbons (PAHs) using gas chromatography-mass spectrometry. The concentration of 14 PAH compounds in sediment samples collected from 61 locations are distributed in a broad spectrum from low to very high concentration levels (50.8-13482 ng g-1). No significant correlation was found between summation operatorPAHs and organic carbon content while summation operatorPAHs increase slightly with silt/clay ratio. Therefore the distribution and concentrations of PAHs would be determined more by direct input, rather than by the type of sediment found locally. The most polluted areas are distributed nearshore eastern (Gemlik) and southern (Kursunlu, Mudanya and Trilye) coasts which are mainly influenced by rapid ecotourism development, direct discharges from rivers, surface run-off and drainage from port areas, domestic and industrial effluent discharges through outfalls and various contaminants from ships. Special PAH compound ratios, such as Phe/Anth, Flu/Py, B[a]A/Chry; LMWPAH/HMWPAH; Per/; Per/summation operatorPAH; Per/summation operator(penta-aromatics) and Flu/(Py+Flu), were calculated to evaluate different hydrocarbon origins and their relative importance. Pyrolytic activity is dominant along the highly-populated eastern and southern coasts. Meanwhile, petrogenic activity mixed with pyrolytic activity is a matter of fact in front of the main industrial-tourism ports and anchoring areas as well. Higher concentration of perylene are distributed along the mostly polluted eastern and southern coastal areas, however, the concentrations of perylene relative to the penta-aromatic isomers are dominant especially in the northern and deepest sectors of the bay, indicating diagenetic origin for the presence of perylene.

  6. Pareto law and Pareto index in the income distribution of Japanese companies

    OpenAIRE

    Atushi Ishikawa

    2004-01-01

    In order to study the phenomenon in detail that income distribution follows Pareto law, we analyze the database of high income companies in Japan. We find a quantitative relation between the average capital of the companies and the Pareto index. The larger the average capital becomes, the smaller the Pareto index becomes. From this relation, we can possibly explain that the Pareto index of company income distribution hardly changes, while the Pareto index of personal income distribution chang...

  7. Total petroleum hydrocarbon distribution in soils and groundwater in Songyuan oilfield, Northeast China.

    Science.gov (United States)

    Teng, Yanguo; Feng, Dan; Song, Liuting; Wang, Jinsheng; Li, Jian

    2013-11-01

    In order to investigate the distribution of the total petroleum hydrocarbons (TPH) in groundwater and soil, a total of 71 groundwater samples (26 unconfined groundwater samples, 37 confined groundwater samples, and 8 deeper confined groundwater samples) and 80 soil samples were collected in the Songyuan oilfield, Northeast China, and the vertical variation and spatial variability of TPH in groundwater and soil were assessed. For the groundwater from the unconfined aquifer, petroleum hydrocarbons were not detected in three samples, and for the other 23 samples, concentrations were in the range 0.01-1.74 mg/l. In the groundwater from the confined aquifer, petroleum hydrocarbons were not detected in two samples, and in the other 35 samples, the concentrations were 0.04-0.82 mg/l. The TPH concentration in unconfined aquifer may be influenced by polluted surface water and polluted soil; for confined aquifer, the injection wells leakage and left open hole wells may be mainly responsible for the pollution. For soils, the concentrations of TPH varied with sampling depth and were 0-15 cm (average concentration, 0.63 mg/g), >40-55 cm (average concentration, 0.36 mg/g), >100-115 cm (average concentration, 0.29 mg/g), and >500-515 cm (average concentration, 0.26 mg/g). The results showed that oil spillage and losses were possibly the main sources of TPH in soil. The consequences concluded here suggested that counter measures such as remediation and long-term monitoring should be commenced in the near future, and effective measures should be taken to assure that the oilfields area would not be a threat to human health.

  8. Characterization of refractive index distribution of polymer optical fiber

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    A focusing method is developed to characterize the refractive index profile of polymer optical fiber (POF). Based on the refractive index profile the theoretical bandwidth and the core index exponentα (α > 0) of POF are calculated. The results show that the value of theoretical bandwidth agrees well with the experimental data.

  9. Distribution of trace metals, aliphatic hydrocarbons and polycyclic aromatic hydrocarbons in sediment cores from the Sicily Channel and the gulf of Tunis (south-western Mediterranean Sea).

    Science.gov (United States)

    Mzoughi, Nadia; Chouba, Lassaad

    2011-01-01

    Under the framework of the IAEA's Technical Co-operation project RAF7/004, international research cruises were carried out in 2004 to assess the distribution of radionuclides and micropollutants in the south-western Mediterranean Sea. Sediments samples had variable concentrations of total aliphatic hydrocarbons and polycyclic aromatic hydrocarbons ranging from 0.2 to 1.8 microg g(-1) and 26.9 to 364.4 ng g(-1), respectively, in the Sicily Channel and from 0.7 to 2.8 microg g(-1) and 14.7 to 618.1 ng g(-1), respectively, in the open sea of the Gulf of Tunis. Hydrocarbon concentrations changed with depth and were relatively high at 3 cm and 10 cm depths. The use of 'fingerprint' ratios of certain isomeric pairs of polycyclic aromatic hydrocarbons (PAH) and the proportion of 2-3 ring and 4-5 ring PAH concentrations showed that the main origins are characteristic of petroleum sources. The ranges of trace metal concentrations, expressed in microgg(-1), in the Sicily Channel and in the Gulf of Tunis, respectively, were: Hg 0.009-0.2 and 0.02-0.1; Pb 9.9-26.1 and 21.2-32.5; Cd 0.06-0.1 and 0.07-0.33; Fe 23.7-28.1 and 29.9-36.2p; Zn 83-99.5 and 83-104; Mn 309.2-752.5 and 651-814; Cu 17.1-18.5 and 33.5-51.3. Sediment metal abundances were in the order: Mn > Zn > Fe > Cu > Pb > Cd > Hg. The results showed significant differences (p < 0.001) for trace metal and hydrocarbon mean concentrations between the two cores. These concentrations are generally similar to the background levels from the Mediterranean Sea and could be affected by physico-chemical conditions and sedimentation rate as well as biodegradation.

  10. Patterns in the uptake, release, distribution, and the transfer of petroleum hydrocarbons in marine organisms

    Energy Technology Data Exchange (ETDEWEB)

    Ba-Akdah, M.A.S.

    1996-12-31

    The uptake and depuration patterns of petroleum hydrocarbons by marine invertebrates was studied using two deposit feeders, Scrobicularia plana (Bivalvia) and Arenicola marina (Polychaeta), and the suspension feeder Mytilus edulis (Bivalvia) using initial concentration of 500 ppm total oil in both sediments and seawater. It was shown that uptake and release of petroleum hydrocarbons was much higher and rapid from seawater than from sediment. The uptake, distribution, release, and the transfer of two PAHs, [9-{sup 14}C]-phenanthrene and [G-{sup 3}H]-benzo(a)pyrene were investigated separately through 3 trophic levels (mussels-amphipods-fish). It appeared that the mussel are capable of accumulating significant levels of these radiolabelled compounds from seawater into their tissues. The highest levels of radioactivity was localized in the visceral mass, followed by the mantle and gills, whereas the lowest content was found in the muscle. The elimination of the radioactivity of {sup 14}C-PHN was more rapid than the {sup 3}H-B(a)P. Gammarus locusta (the second trophic level in this study) freely fed on mussels contaminated with {sup 14}C-PHN or {sup 3}H-B(a)P showed a rapid uptake reaching its maximum in 2 days. The cumulative percentage retaintion ranged between 30-40% of the dose. (Author)

  11. Main Controlling Factors on Hydrocarbon Accumulation and Distribution in Marine Sedimentary Sequences in South China

    Institute of Scientific and Technical Information of China (English)

    Cai Liguo; Zhou Yan; Bai Zhenrui

    2008-01-01

    Multiple source rock assemblages were deposited in the sedimentary provinces in South China in geologic history,and some of them were destructed by and some survived against multiple tectonic movements.Therefore,multiple sources,mixed sources,and uneven distribution of sources occurred in the marine sedimentary basins in South China during the late stage of hydrocarbon pooling.Epidiagenesis of the marine carbonate reservoirs and its modification to reservoir poroperm characteristics determined the formation and the scale of natural gas pools.The exploration practices show that the large to medium gas fields mainly occur in areas with high-quality reservoirs.Detailed study of the paleo-oil accumulations and typical oil and gas reservoirs reveals that the basins experienced multiphase superimposition and modification,leading to the distribution of the Paleozoic paleo-oil accumulations and bitumen in the peripheral areas.The phenomenon that oil and gas production concentrates in the Sichuan basin indicates that the overall sealing conditions of a basin determine the oil/gas potentials and the scale of oil and gas production.This is a critical factor controlling the accumulation and distribution of gas in the marine sequences in South China.The early oil and gas pools in the Yangtze platform left billions of bitumen in the peripheral areas due to the destruction of seals.Since the Himalayan,"late-generation and late-accumulation" gas pools represented by the gas pools in the Sichuan (四川) basin were formed in the marine sedimentary sequences in South China as a result of the change of the sealing conditions.Current gas discoveries appear to be "paleo-generation and paleo-accumulation" gas pools but actually are "late-generation and late-accumulation" gas pools.These patterns of hydrocarbon pooling clearly depict themselves in western Sichuan basin and Weiyuan (威远)gas field.It is revealed that the gas pools in the Sichuan basin were mainly formed as a result of

  12. DISTRIBUTION AND CHARACTERIZATION OF POLYCYCLIC AROMATIC HYDROCARBON COMPOUNDS IN AIRBORNE PARTICULATES OF EAST ASIA

    Institute of Scientific and Technical Information of China (English)

    Yan Liu; Libin Liu; Jin-Ming Lin; Ning Tang; Kazuichi Hayakawa

    2006-01-01

    A review is presented on the distribution and characterization of polycyclic aromatic hydrocarbons (PAHs)and their derivatives, including nitro-PAHs and hydro-PAHs, on atmospheric particulates of East Asia. Generally, PAH compounds with two or three aromatic rings are released mainly into the gas phase, while those containing three or more aromatic rings are associated with particulate matter (PM) emission. Particle-associated PAHs are primarily adsorbed on fine particles, and little associated with coarse particles. Investigation into the concentration level of PAHs in different areas can serve not only to reflect the pollutant status and sources but also to lead to the formulation of control strategies.The results of the present study show that China has more severe PAH pollution than such East Asian countries as Japan and Korea.

  13. Distribution and ecotoxicological significance of polycyclic aromatic hydrocarbons in sediments from Iko River estuary mangrove ecosystem.

    Science.gov (United States)

    Essien, Joseph P; Eduok, Samuel I; Eduok, Stephen I; Olajire, Abass Abiola

    2011-05-01

    The distribution of polycyclic aromatic hydrocarbons (PAHs) in epipelic and benthic sediments from Iko River estuary mangrove ecosystem has been investigated. Total PAHs ranged from 6.10 to 35.27 mg/kg dry weight. Quantitative difference between the total PAHs in epipelic and benthic sediments showed that the benthic sediment known for higher capability to serve as sink for chemical pollutants accumulated less PAHs. This implies that PAHs in the epipelic sediment may plausibly be from industrial sources via runoff and/or of biogenic origin. A strong pyrolytic source fingerprint has been detected with slight influence of petrogenic sources. Total organic carbon normalized PAHs (sum of 16 PAHs, 59.7 to 372.4 mg/kg OC) were under (except for ES3 and BS3) the threshold effects concentrations (TEC, 290 mg/kg OC). Total PAHs in Iko River estuary sediments were in the range between ERL and ERM.

  14. Characterization, Distribution, Sources and Origins of Aliphatic Hydrocarbons from Surface Sediment of Prai Strait, Penang, Malaysia: A Widespread Anthropogenic Input

    Directory of Open Access Journals (Sweden)

    Mahyar Sakari

    2008-07-01

    Full Text Available Persistent organic pollutants such as petroleum hydrocarbons are one of the most serious and important class of pollutants that face to many countries including Malaysia. Aliphatic hydrocarbons contain straight chain alkane; derive from anthropogenic and natural sources to the marine environment. The multi-purpose strait of Prai is located in the Northwest of Peninsular Malaysia plays an important economic role in the Southeast Asia. Twenty surface sediment samples were collected using Eckman dredge to measure the concentration and determine the characterization, sources and origins of the aliphatic hydrocarbons in December 2006. Samples (top 4 cm were extracted with Soxhlet, treated with activated copper and subjected to 2 steps column chromatography for purification and fractionation. Alkane fraction injected into Gas Chromatography–Flame Ionization Detector (GC-FID for instrumental analysis. The results showed that total n-alkane concentrations are ranging from 512 to 10770 ng/mg d. w. Carbon Preferences Index (CPI revealed an extreme widespread anthropogenic input and naturally derived (CPI= 0 to 4.88 hydrocarbons in the study area. The ratio of C31/C19 indicated that natural hydrocarbons are generating from terrestrial vascular plants and transferring by rivers. The characteristics of Major Hydrocarbons provided evidences that oil and its derivatives either fresh or degraded are the major contributors of the pollution in the study area. Statistical approaches also confirmed that 85% of study area affected by oil sources of pollution. It is seen that aliphatic hydrocarbons mostly transfer by lateral input to the marine environment than atmospheric movements.

  15. Polycyclic aromatic hydrocarbons in urban green spaces of Beijing: concentration, spatial distribution and risk assessment.

    Science.gov (United States)

    Zhang, Juan; Wu, Jianzhi; Liu, Yan

    2016-09-01

    A comprehensive investigation of the levels, spatial distribution of polycyclic aromatic hydrocarbons (PAHs) in urban green space soils of Beijing, China, was conducted, and the potential human health risks associated with the levels observed were addressed. The objective of this study was to determine concentration, spatial distribution, and health risk of 15 PAHs in 121 surface soil (0-5 cm) samples collected from four types of green space, such as park green space (PGS), roadside green space (RDS), residential green space (RGS), and attached green space (AGS). Results showed that the highest concentrations of 15 PAHs was in soils of RDS, followed by RGS, PGS, and AGS. The level of PAHs pollution was seriously and mainly distributed in the central and southwest of the city. Incremental lifetime cancer risks (ILCRs) associated with exposures to PAHs in soil was calculated separately for children and adults under normal and extreme conditions. The results showed that ILCRs for urban green space soil of Beijing were low under normal conditions. But individual samples are seriously polluted, and its potential health risks cannot be ignored.

  16. Distribution of particle-phase hydrocarbons, PAHs and OCPs in Tianjin, China

    Energy Technology Data Exchange (ETDEWEB)

    Wu, S.P.; Tao, S.; Zhang, Z.H.; Lan, T.; Zuo, Q. [Peking University, Beijing (China). College of Environmental Science

    2005-12-01

    Aliphatic hydrocarbons, polycyclic aromatic hydrocarbons (PAHs) and organochlorine pesticides (OCPs) were determined in the total suspended particles (TSP) collected from 13 different locations in Tianjin, China, where intensive coal burning for domestic heating in winter takes place and a large quantity of pesticides had been produced and applied. Carbon preference index (CPI), carbon number maximum (C{sub max}) of n-alkane and plant wax index (%wax C{sub n}) indicate that n-alkanes come from both biogenic and petrogenic sources, and biogenic source contributes more n-alkanes in autumn than in winter. Petroleum biomarkers as indicators of petrogenic source such as hopanes and steranes were also detected in both seasons' samples. The sum of 16 PAH concentrations ranged from 69.3 to 2170 ng m{sup -3} in winter and from 7.01 to 40.0 ng m{sup -3} in autumn. Seasonal variations were mainly attributed to the difference in coal combustion emission and meteorological conditions. The results of a source diagnostic analysis suggest that PAHs in TSP. mainly come from coal combustion. Seven OCPs (four hexachlorohexanes (HCHs) and three dichlorodipheny-trichloroethane and metabolites (DDTs)) were detected in most samples. Concentrations of the sum of alpha-, beta-, delta- and gamma-HCH {Sigma} HCH) and the sum of p,p'-DDT, p,p'-DDD and p,p'-DDE {Sigma} DDT) in autumn varied in the ranges of 0.002-0.9 ng m{sup -3} and 0.025-2.21 ng m{sup -3} respectively. In winter, {Sigma} HCH and {Sigma} DDT in TSP ranged from 0.071 to 5.35 ng m{sup -3} and from 0.416 to 3.14 ng m{sup -3} respectively. Both of the illegal application of technical HCH and DDT and the volatilization from topsoil contributed to the particle-phase contents of HCHs and DDTs in the atmosphere.

  17. Distribution, partitioning and sources of polycyclic aromatic hydrocarbons in the water-SPM-sediment system of Lake Chaohu, China

    DEFF Research Database (Denmark)

    Qin, Ning; He, Wei; Kong, Xiang-Zhen

    2014-01-01

    The residual levels of polycyclic aromatic hydrocarbons (PAHs) in the water, suspended particular matter (SPM) and sediment from Lake Chaohu were measured with a gas chromatograph-mass spectrometer (GC-MS). The spatial-temporal distributions and the SPM-water partition of PAHs and their influenci...

  18. Distribution of hydrocarbon-degrading bacteria in the soil environment and their contribution to bioremediation.

    Science.gov (United States)

    Fukuhara, Yuki; Horii, Sachie; Matsuno, Toshihide; Matsumiya, Yoshiki; Mukai, Masaki; Kubo, Motoki

    2013-05-01

    A real-time PCR quantification method for indigenous hydrocarbon-degrading bacteria (HDB) carrying the alkB gene in the soil environment was developed to investigate their distribution in soil. The detection limit of indigenous HDB by the method was 1 × 10(6) cells/g-soil. The indigenous HDB were widely distributed throughout the soil environment and ranged from 3.7 × 10(7) to 5.0 × 10(8) cells/g-soil, and the ratio to total bacteria was 0.1-4.3 %. The dynamics of total bacteria, indigenous HDB, and Rhodococcus erythropolis NDKK6 (carrying alkB R2) during bioremediation were analyzed. During bioremediation with an inorganic nutrient treatment, the numbers of these bacteria were slightly increased. The numbers of HDB (both indigenous bacteria and strain NDKK6) were gradually decreased from the middle stage of bioremediation. Meanwhile, the numbers of these bacteria were highly increased and were maintained during bioremediation with an organic nutrient. The organic treatment led to activation of not only the soil bacteria but also the HDB, so an efficient bioremediation was carried out.

  19. Distribution of polycyclic aromatic hydrocarbons in subcellular root tissues of ryegrass (Lolium multiflorum Lam.

    Directory of Open Access Journals (Sweden)

    Zhang Yi

    2010-09-01

    Full Text Available Abstract Background Because of the increasing quantity and high toxicity to humans of polycyclic aromatic hydrocarbons (PAHs in the environment, several bioremediation mechanisms and protocols have been investigated to restore PAH-contaminated sites. The transport of organic contaminants among plant cells via tissues and their partition in roots, stalks, and leaves resulting from transpiration and lipid content have been extensively investigated. However, information about PAH distributions in intracellular tissues is lacking, thus limiting the further development of a mechanism-based phytoremediation strategy to improve treatment efficiency. Results Pyrene exhibited higher uptake and was more recalcitrant to metabolism in ryegrass roots than was phenanthrene. The kinetic processes of uptake from ryegrass culture medium revealed that these two PAHs were first adsorbed onto root cell walls, and they then penetrated cell membranes and were distributed in intracellular organelle fractions. At the beginning of uptake ( Conclusions Transpiration and the lipid content of root cell fractions are the main drivers of the subcellular partition of PAHs in roots. Initially, PAHs adsorb to plant cell walls, and they then gradually diffuse into subcellular fractions of tissues. The lipid content of intracellular components determines the accumulation of lipophilic compounds, and the diffusion rate is related to the concentration gradient established between cell walls and cell organelles. Our results offer insights into the transport mechanisms of PAHs in ryegrass roots and their diffusion in root cells.

  20. Emission and Size Distribution of Particle-bound Polycyclic Aromatic Hydrocarbons from Residential Wood Combustion

    Science.gov (United States)

    Shen, Guofeng; Wei, Siye; Zhang, Yanyan; Wang, Bin; Wang, Rong; Shen, Huizhong; Li, Wei; Huang, Ye; Chen, Yuanchen; Chen, Han; Tao, Shu

    2015-01-01

    Emissions and size distributions of 28 particle-bound polycyclic aromatic hydrocarbons (PAHs) from residential combustion of 19 fuels in a domestic cooking stove in rural China were studied. Measured emission factors of total PAHs were 1.79±1.55, 12.1±9.1, and 5.36±4.46 mg/kg for fuel wood, brushwood, and bamboo, respectively. Approximate 86.7, 65.0, and 79.7% of the PAHs were associated with fine particulate matter with size less than 2.1 µm for these three types of fuels. Statistically significant difference in emission factors and size distributions of particle-bound PAHs between fuel wood and brushwood was observed, with the former had lower emission factors but more PAHs in finer PM. Mass fraction of the fine particles associated PAHs was found to be positively correlated with fuel density and moisture, and negatively correlated with combustion efficiency. Low and high molecular weight PAHs segregated into the coarse and fine PM, respectively. The high accumulation tendency of the PAHs from residential wood combustion in fine particles implies strong adverse health impact. PMID:25678760

  1. Microscopic spin model for the dynamics of the return distribution of the Korean stock market index

    Science.gov (United States)

    Yang, Jae-Suk; Chae, Seungbyung; Jung, Woo-Sung; Moon, Hie-Tae

    2006-05-01

    In this paper, we studied the dynamics of the log-return distribution of the Korean Composition Stock Price Index (KOSPI) from 1992 to 2004. Based on the microscopic spin model, we found that while the index during the late 1990s showed a power-law distribution, the distribution in the early 2000s was exponential. This change in distribution shape was caused by the duration and velocity, among other parameters, of the information that flowed into the market.

  2. Power tails of index distributions in chinese stock market

    Science.gov (United States)

    Zhang, J. W.; Zhang, Y.; Kleinert, H.

    2007-04-01

    The power α of the Lévy tails of stock market fluctuations discovered in recent years are generally believed to be universal. We show that for the Chinese stock market this is not true, the powers depending strongly on anomalous daily index changes short before market closure, and weakly on the opening data.

  3. Inadequacy of the gamma distribution to calculate the Standardized Precipitation Index

    Directory of Open Access Journals (Sweden)

    Gabriel C. Blain

    2015-12-01

    Full Text Available ABSTRACT The Standardized Precipitation Index was developed as a probability-based index able to monitor rainfall deficit in a standardized or normalized way. Thus, the performance of this drought index is affected by the use of a distribution that does not provide an appropriate fit for the rainfall data. The goal of this study was to evaluate the adjustment of the gamma distribution for the rainfall amounts summed over several time scales (Pelotas, Rio Grande do Sul, Brazil, to assess the goodness-of-fit of alternative distributions to these rainfall series and to evaluate the normality assumption of the Standardized Precipitation Index series calculated from several distributions. Based on the Lilliefors test and on a normality test, it is verified that the gamma distribution is not suitable for calculating this Index in several timescales. The generalized normal distribution presented the best performance among all analysed distributions. It was also concluded that the drought early warning systems and the academic studies should re-evaluate the use of the gamma distribution in the Standardized Precipitation Index calculation algorithm. A computational code that allows calculating this drought index based on the generalized normal distribution has also been provided.

  4. Distribution and Geochemical Implication of Aromatic Hydrocarbons across the Meishan Permian-Triassic Boundary

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Aromatic compounds extracted from sedimentary rocks can reflect environmental conditions, organic sources and maturity. The aromatics, identified in association with mass extinction in particular, would provide a signature assisting our understanding of the causes of the biotic crisis. Aromatic hydrocarbons were fractionated from the total lipid extracts of 37 samples taken from the Permian Triassic boundary (beds 23 to 34) of section B at Meishan(煤山),Zhejiang(浙江)Province in South China. These aromatics were analyzed by using gas chromatography-mass spectrometry (GC-MS). Main compounds identified include naphthalene, phenanthrenes, fluorene, dibenzothiophene, dibenzofuran, fluoranthene, pyrene and some of their methyl homologues. The indices of methyl phenanthrene distribution fraction indicate the comparable maturity (within the oil window, 0.7% - 1.0% of the mean vitrinite reflectance) of the organic matter throughout the whole profile analyzed. The ratio of dibenzothiophene to phenanthrene (DBT/PHN) varies generally at a comparable pace with lithology. Significantly,a gradual decrease of this ratio was observed within bed 24 limestone, which is probably due to the variation of sedimentary environment. This change is in line with the drop in the carbon isotope composition of carbonate, the loss of the Changhsingian reef ecosystem, and the decrease of cyanobacteria abundance within the bacteria population. The coincidence of these records suggests a close relation between the biotic crisis and marine environmental conditions, and these records clearly show the onset of the biotic crisis prior to event bed 25.

  5. Distributions, Sources, and Backward Trajectories of Atmospheric Polycyclic Aromatic Hydrocarbons at Lake Small Baiyangdian, Northern China

    Directory of Open Access Journals (Sweden)

    Ning Qin

    2012-01-01

    Full Text Available Air samples were collected seasonally at Lake Small Baiyangdian, a shallow lake in northern China, between October 2007 and September 2008. Gas phase, particulate phase and dust fall concentrations of polycyclic aromatic hydrocarbons (PAHs were measured using a gas chromatograph-mass spectrometer (GC-MS. The distribution and partitioning of atmospheric PAHs were studied, and the major sources were identified; the backward trajectories of air masses starting from the center of Lake Small Baiyangdian were calculated for the entire year. The following results were obtained: (1 The total concentration of 16 priority controlled PAHs (PAH16 in the gas phase was 417.2±299.8 ng·m−3, in the particulate phase was 150.9±99.2 ng·m−3, and in dust fall was 6930.2±3206.5 ng·g−1. (2 Vehicle emission, coal combustion, and biomass combustion were the major sources in the Small Baiyangdian atmosphere and accounted for 28.9%, 45.1% and 26.0% of the total PAHs, respectively. (3 Winter was dominated by relatively greater PAHs polluted northwesterly air mass pathways. Summer showed a dominant relatively clean southern pathway, whereas the trajectories in autumn and spring might be associated with high pollution from Shanxi or Henan province.

  6. Polycyclic Aromatic Hydrocarbons in the Dagang Oilfield (China: Distribution, Sources, and Risk Assessment

    Directory of Open Access Journals (Sweden)

    Haihua Jiao

    2015-05-01

    Full Text Available The levels of 16 polycyclic aromatic hydrocarbons (PAHs were investigated in 27 upper layer (0–25 cm soil samples collected from the Dagang Oilfield (China in April 2013 to estimate their distribution, possible sources, and potential risks posed. The total concentrations of PAHs (∑PAHs varied between 103.6 µg·kg−1 and 5872 µg·kg−1, with a mean concentration of 919.8 µg·kg−1; increased concentrations were noted along a gradient from arable desert soil (mean 343.5 µg·kg−1, to oil well areas (mean of 627.3 µg·kg−1, to urban and residential zones (mean of 1856 µg·kg−1. Diagnostic ratios showed diverse source of PAHs, including petroleum, liquid fossil fuels, and biomass combustion sources. Combustion sources were most significant for PAHs in arable desert soils and residential zones, while petroleum sources were a significant source of PAHs in oilfield areas. Based ontheir carcinogenity, PAHs were classified as carcinogenic (B or not classified/non-carcinogenic (NB. The total concentrations of carcinogenic PAHs (∑BPAHs varied from 13.3 µg·kg−1 to 4397 µg·kg−1 across all samples, with a mean concentration of 594.4 µg·kg−1. The results suggest that oilfield soil is subject to a certain level of ecological environment risk.

  7. Distribution, partition and removal of polycyclic aromatic hydrocarbons (PAHs) during coking wastewater treatment processes.

    Science.gov (United States)

    Zhang, Wanhui; Wei, Chaohai; An, Guanfeng

    2015-05-01

    In this study, we report the performance of a full-scale conventional activated sludge (A-O1-O2) treatment in eliminating polycyclic aromatic hydrocarbons (PAHs). Both aqueous and solid phases along with the coking wastewater treatment processes were analyzed for the presence of 18 PAHs. It was found that the target compounds occurred widely in raw coking wastewater, treated effluent and sludge samples. In the coking wastewater treatment system, 4-5 ring PAHs were the dominant compounds, while 4 rings PAHs predominated in the sludge samples. Over 98% of the PAH removal was achieved in the coking wastewater treatment plant (WWTP), with the total concentration of PAHs being 21.3 ± 1.9 μg L(-1) in the final effluent. During the coking wastewater treatment processes, the association of the lower molecular weight PAH with suspended solids was generally less than 60%, while the association of higher molecular weight PAHs was greater than 90%. High distribution efficiencies (Kdp and Kds) were found, suggesting that adsorption was the potential removal pathway of PAHs. Finally, the mass balances of PAHs in various stages of the coking WWTP were obtained, and the results indicated that adsorption to sludge was the main removal pathway for PAHs in the coking wastewater treatment processes.

  8. Occurrence and distribution of polycyclic aromatic hydrocarbons in surface sediments of San Diego Bay marinas.

    Science.gov (United States)

    Neira, Carlos; Cossaboon, Jennifer; Mendoza, Guillermo; Hoh, Eunha; Levin, Lisa A

    2017-01-15

    Polycyclic aromatic hydrocarbons (PAHs) have garnered much attention due to their bioaccumulation, carcinogenic properties, and persistence in the environment. Investigation of the spatial distribution, composition, and sources of PAHs in sediments of three recreational marinas in San Diego Bay, California revealed significant differences among marinas, with concentrations in one site exceeding 16,000ngg(-1). 'Hotspots' of PAH concentration suggest an association with stormwater outfalls draining into the basins. High-molecular weight PAHs (4-6 rings) were dominant (>86%); the average percentage of potentially carcinogenic PAHs was high in all sites (61.4-70%) but ecotoxicological risks varied among marinas. Highly toxic benzo(a)pyrene (BaP) was the main contributor (>90%) to the total toxic equivalent quantity (TEQ) in marinas. PAHs in San Diego Bay marina sediments appear to be derived largely from pyrogenic sources, potentially from combustion products that reach the basins by aerial deposition and stormwater drainage from nearby streets and parking lots. Copyright © 2016 Elsevier Ltd. All rights reserved.

  9. Molecular distribution and seasonal variation of hydrocarbons in PM2.5 from Beijing during 2006

    Institute of Scientific and Technical Information of China (English)

    Yushan Li; Junji Cao; Jianjun Li; Jiamao Zhou; Hongmei Xu; Renjian Zhang; Zhiyun Ouyang

    2013-01-01

    Normal (n)-alkanes and polycyclic aromatic hydrocarbons (PAHs) in PM2.s were collected from Beijing in 2006 and analyzed using a thermal desorption-GC/MS technique.Annual average concentrations of n-alkanes and PAHs were 282 ± 96 and 125 ± 150 ng/m3,respectively:both were highest in winter and lowest in summer.C19-C25 compounds dominated the n-alkanes while benzo[b]fluoranthene,benzo[e]pyrene,and phenanthrene were the most abundant PAHs.The n-alkanes exhibited moderate correlations with organic carbon (OC) and elemental carbon (EC) throughout the year,but the relationships between the PAHs,OC and EC differed between the heating and non-heating seasons.The health risks associated with PAHs in winter were more than 40 times those in spring and summer even though the PM2.5 loadings were comparable.Carbon preference index values (<1.5) indicated that the n-alkanes were mostly from fossil fuel combustion.The ratios of indeno[123-cd]pyrene to benzo[ghi]pyrelene in summer and spring were 0.58 ± 0.12 and 0.63 ± 0.09,respectively,suggesting that the PAHs mainly originated from motor vehicles,but higher ratios in winter reflected an increased influence from coal,which is extensively burned for domestic heating.A comprehensive comparison showed that PAH pollution in Beijing has decreased in the past 10 years.

  10. Spatial and Temporal Distribution of Polycyclic Aromatic Hydrocarbons and Heavy Metals in Stormwater Detention Basin Sediments

    Science.gov (United States)

    Schifman, L. A.; Kasaraneni, V. K.; Boving, T. B.; Craver, V.

    2015-12-01

    Stormwater runoff is a conduit for several pollutants such as polycyclic aromatic hydrocarbons (PAHs) into surface and ground water bodies. The control of runoff and pollutants is typically addressed by best management practices, such as retention/detention ponds. While the effectiveness of catchment basins in runoff volume reduction and removal of some contaminants has been established, very little is known about contaminant fate within these structures. Particularly in coastal regions and places with shallow groundwater tables PAH accumulation in the bottom sediments poses a potential threat for groundwater contamination. The concentrations of PAHs accumulated in the sediments of these catchment basins will primarily depend on the sources of runoff origin and the surrounding land use. Here, five stormwater catchment basins along the I-95 corridor in Rhode Island were selected based on the stormwater runoff origin and land use (industrial, urban, highway, and commercial). To study the stratification of PAHs one foot sediment cores were collected and analyzed for 17 PAHs (16 EPA parent PAH and Retene). The concentrations of PAHs in sediments of detention ponds in urban and industrial land use areas ranged from 20 μg/g to 200 μg/g. Generally higher concentrations of contaminants were found in sediments near the pond inlet and a decreasing concentration gradient is observed laterally and vertically throughout the pond. To compare stormwater ponds in various land use settings a new index based on sediment contamination, pond size and age, and catchment area will be presented. Further, it will be investigated whether BMP maintenance has to be targeted towards pollutant removal to maintain an effective stormwater treatment system.

  11. Distribution of polycyclic aromatic hydrocarbons in subcellular root tissues of ryegrass (Lolium multiflorum Lam.)

    Science.gov (United States)

    2010-01-01

    Background Because of the increasing quantity and high toxicity to humans of polycyclic aromatic hydrocarbons (PAHs) in the environment, several bioremediation mechanisms and protocols have been investigated to restore PAH-contaminated sites. The transport of organic contaminants among plant cells via tissues and their partition in roots, stalks, and leaves resulting from transpiration and lipid content have been extensively investigated. However, information about PAH distributions in intracellular tissues is lacking, thus limiting the further development of a mechanism-based phytoremediation strategy to improve treatment efficiency. Results Pyrene exhibited higher uptake and was more recalcitrant to metabolism in ryegrass roots than was phenanthrene. The kinetic processes of uptake from ryegrass culture medium revealed that these two PAHs were first adsorbed onto root cell walls, and they then penetrated cell membranes and were distributed in intracellular organelle fractions. At the beginning of uptake (lipid contents of each component. Phenanthrene and pyrene primarily accumulated in plant root cell walls and organelles, with about 45% of PAHs in each of these two fractions, and the remainder was retained in the dissolved fraction of the cells. Because of its higher lipophilicity, pyrene displayed greater accumulation factors in subcellular walls and organelle fractions than did phenanthrene. Conclusions Transpiration and the lipid content of root cell fractions are the main drivers of the subcellular partition of PAHs in roots. Initially, PAHs adsorb to plant cell walls, and they then gradually diffuse into subcellular fractions of tissues. The lipid content of intracellular components determines the accumulation of lipophilic compounds, and the diffusion rate is related to the concentration gradient established between cell walls and cell organelles. Our results offer insights into the transport mechanisms of PAHs in ryegrass roots and their diffusion in root

  12. Global fate and distribution of polycyclic aromatic hydrocarbons emitted from Europe and Russia

    Science.gov (United States)

    Sehili, Aissa M.; Lammel, Gerhard

    The long-range atmospheric transport (LRT) of polycyclic aromatic hydrocarbons (PAHs) is not fully understood and has hardly been addressed by model studies. By model experiments the LRT of PAH emissions into air from Europe and Russia is studied testing several scenarios of gas-particle partitioning and degradability by reaction with ozone and the hydroxyl and nitrate radicals for two PAHs, benzo[a]pyrene (BAP) and fluoranthene (FLT). The model used is the atmosphere general circulation model ECHAM5 with a dynamic modal aerosol sub-model, HAM, ozone and sulfur species chemistry and bidirectional mass exchange on 2D marine (ocean surface mixed layer) and terrestrial surfaces (top soil layer and vegetation surfaces). After 5 years the substances are found to be mostly distributed to the soil compartment (64-97% as the global mean, varying with substance and season), which after 10 years is still filling; 1-5% are found in air and 2-33% in ocean. It is found that the lifetime and vertical distribution of the substances in the atmosphere and the LRT potential are all significantly influenced by the partitioning and degradation scenario. The total environmental burden is higher when sorption to organic matter and black carbon are considered to determine gas-particle partitioning rather than adsorption to the surface of particulate matter. The effect is +20% for BAP but sevenfold for FLT. Concentrations in Arctic air are mostly underestimated by the model, which is partly explained by emissions not considered in the simulation. The comparison shows, however, that degradation of the sorbed BAP and FLT molecules should be significantly slower than the respective gaseous molecules and that absorptive partitioning is necessary to explain the LRT potential of FLT.

  13. Spatial and temporal distribution of water column total polycyclic aromatic hydrocarbons (PAH) and total petroleum hydrocarbons (TPH) from the Deepwater Horizon (Macondo) incident.

    Science.gov (United States)

    Wade, Terry L; Sericano, José L; Sweet, Stephen T; Knap, Anthony H; Guinasso, Norman L

    2016-02-15

    Pre-spill background concentrations of TPH and PAH in water samples from the Gulf of Mexico are compared with samples (over 20,000) collected during and after the Deepwater Horizon incident (13,000 stations). Samples were collected by multiple response agencies, trustees and BP and reported in the Gulf Science Data. The samples were collected from a few m to over 800 km in all directions from the wellhead. During the incident, samples with the highest concentrations of hydrocarbons were collected proximal to the wellhead or in samples collected from surface slicks and dispersant use. Of the 13,172 water sample TPH concentrations reported, 84% were below 1 μg/L (background). Of the 16,557 water sample PAH concentrations reported, 79% were below 0.056 μg/L (the median field blank, background). The percentage of samples below background increased rapidly after the well was capped. The spatial and temporal distributions of these hydrocarbon data are presented. Copyright © 2016 Elsevier Ltd. All rights reserved.

  14. Poverty index with time-varying consumption and income distributions

    Science.gov (United States)

    Chattopadhyay, Amit K.; Kumar, T. Krishna; Mallick, Sushanta K.

    2017-03-01

    Starting from a stochastic agent-based model to represent market exchange in a developing economy, we study time variations of the probability density function of income with simultaneous variation of the consumption deprivation (CD), where CD represents the shortfall in consumption from the saturation level of an essential commodity, cereal. Together, these two models combine income-expenditure-based market dynamics with time variations in consumption due to income. In this new unified theoretical structure, exchange of trade in assets is only allowed when the income exceeds consumption-deprivation while CD itself is endogenously obtained from a separate kinetic model. Our results reveal that the nature of time variation of the CD function leads to a downward trend in the threshold level of consumption of basic necessities, suggesting a possible dietary transition in terms of lower saturation level of food-grain consumption, possibly through an improvement in the level of living. The new poverty index, defined as CD, is amenable to approximate probabilistic prediction within a short time horizon. A major achievement of this work is the intrinsic independence of the poverty index from an exogenous poverty line, making it more objective for policy formulation as opposed to existing poverty indices in the literature.

  15. Occurrence and distribution of monocyclic aromatic hydrocarbons (BTEX) and the impact on macrobenthic community structure in Lagos lagoon, Nigeria.

    Science.gov (United States)

    Doherty, V F; Otitoloju, A A

    2016-10-01

    The widespread distribution of petroleum products arising from the rapid growth of the petroleum industry in Nigeria has resulted in the pollution of the environment through oil spills involving leakages from tankers, pipelines, tank farms, and dumping of waste petroleum products. The impacts and distribution of major toxic components (benzene, toluene, ethylbenzene, and xylene (BTEX)) of petroleum products in water and sediment samples collected from sampling stations in the Lagos lagoon was investigated over a 2-year period (February 2009-July 2010). The distribution of benthic communities in the different sampling stations of the Lagos lagoon was assessed. The determination of hydrocarbon levels in the samples showed that the levels of total hydrocarbon content (THC) in the water samples around the Atlas Cove and Apapa were high with values ranging from 2.03 to 31.38 mg/l and 4.04 to 22.89 mg/l, respectively. The highest value of total BTEX in the lagoon sediment was also recorded in the Apapa station (450.53 μg/kg), where oil depots and tank farm facilities are located. The study of the macrobenthic community structure showed that the species richness ranged from 1.57 to 2.02 in the reference station, Unilag, while in the Atlas Cove, Iddo, and Apapa stations, it ranged from 1.80 to 2.89, 1.95 to 3.03, and 1.86 to 2.95, respectively. The highest number of organisms (183) was recorded in the reference stations, while the least number (46) was recorded in Apapa. The main hydrocarbon pollution indicator species identified in the impacted aquatic stations were Nais eliguis and Heteromastus filiformis. The levels of hydrocarbon observed in the aquatic environment showed that there is widespread contamination as a result of petroleum product importation, storage, and distribution. The assessment of the monocyclic aromatic hydrocarbon and benthic community will therefore provide important tools for early detection, diagnosis, and management of hydrocarbon pollution

  16. The probability distribution model of air pollution index and its dominants in Kuala Lumpur

    Science.gov (United States)

    AL-Dhurafi, Nasr Ahmed; Razali, Ahmad Mahir; Masseran, Nurulkamal; Zamzuri, Zamira Hasanah

    2016-11-01

    This paper focuses on the statistical modeling for the distributions of air pollution index (API) and its sub-indexes data observed at Kuala Lumpur in Malaysia. Five pollutants or sub-indexes are measured including, carbon monoxide (CO); sulphur dioxide (SO2); nitrogen dioxide (NO2), and; particulate matter (PM10). Four probability distributions are considered, namely log-normal, exponential, Gamma and Weibull in search for the best fit distribution to the Malaysian air pollutants data. In order to determine the best distribution for describing the air pollutants data, five goodness-of-fit criteria's are applied. This will help in minimizing the uncertainty in pollution resource estimates and improving the assessment phase of planning. The conflict in criterion results for selecting the best distribution was overcome by using the weight of ranks method. We found that the Gamma distribution is the best distribution for the majority of air pollutants data in Kuala Lumpur.

  17. Simultaneous measurement of refractive index distribution and topography by integrated transmission and reflection digital holographic microscopy.

    Science.gov (United States)

    Ma, Chaojie; Di, Jianglei; Zhang, Jiwei; Li, Ying; Xi, Teli; Li, Enpu; Zhao, Jianlin

    2016-11-20

    We propose a method for simultaneously measuring dynamic changes of the refractive index distribution and surface topography, which integrates the transmission and reflection digital holographic microscopy based on polarization and angular multiplexing techniques. The complex amplitudes of the transmitted and reflected object waves can be simultaneously retrieved. The phase information of the reflected object wave is directly used to determine the topography of the specimen which corresponds to its physical thickness. Assuming that the refractive index distribution is uniform in the direction of the specimen thickness, the refractive index distribution can be deduced from the phase distributions of the transmitted and reflected object waves without any approximation. The refractive index distribution and dynamic changes of the topography of a tiny deionized water droplet have been measured for the availability of the proposed method.

  18. Explicit expressions of the Pietra index for the generalized function for the size distribution of income

    Science.gov (United States)

    Sarabia, José María; Jordá, Vanesa

    2014-12-01

    The importance of the Pietra index in socioeconomic systems and econophysics has been highlighted by Eliazar and Sokolov (2010). In this paper, we obtain closed expressions for the Pietra index for the generalized function for the size of income proposed by McDonald (1984). This family is composed of three classes of distributions: the generalized gamma distribution (GG), the generalized beta of the first kind (GB1) and the generalized beta of the second kind (GB2). For the different distributions, we obtain closed and simple expressions of the Pietra index, which can be easily computed. We also obtain the Pietra index for other relevant income models including finite mixtures of distributions and the κ-generalized distribution (Clementi et al., 2008). Finally, two empirical applications with real income data are given.

  19. Distributed Data Collection for the ATLAS EventIndex

    CERN Document Server

    Sánchez, Javier; The ATLAS collaboration; Gonzalez de la Hoz, Santiago

    2015-01-01

    The ATLAS EventIndex contains records of all events processed by ATLAS, in all processing stages. These records include the references to the files containing each event (the GUID of the file) and the internal “pointer” to each event in the file. This information is collected by all jobs that run at Tier-0 or on the Grid and process ATLAS events. Each job produces a snippet of information for each permanent output file. This information is packed and transferred to a central broker at CERN using an ActiveMQ messaging system, and then is unpacked, sorted and reformatted in order to be stored and catalogued into a central Hadoop server. This contribution describes in detail the Producer/Consumer architecture to convey this information from the running jobs through the messaging system to the Hadoop server.

  20. Distributed Data Collection for the ATLAS EventIndex

    CERN Document Server

    Sánchez, Javier; The ATLAS collaboration; Gonzalez de la Hoz, Santiago

    2015-01-01

    The ATLAS EventIndex contains records of all events processed by ATLAS, in all processing stages. These records include the references to the files containing each event (the GUID of the file) and the internal “pointer” to each event in the file. This information is collected by all jobs that run at Tier-0 or on the Grid and process ATLAS events. Each job produces a snippet of information for each permanent output file. This information is packed and transfered to a central broker at CERN using an ActiveMQ messaging system, and then is unpacked, sorted and reformatted in order to be stored and catalogued into a central Hadoop server. This talk describes in detail the Producer/Consumer architecture to convey this information from the running jobs through the messaging system to the Hadoop server.

  1. Elk Distributions Relative to Spring Normalized Difference Vegetation Index Values

    Directory of Open Access Journals (Sweden)

    Samuel T. Smallidge

    2010-01-01

    Full Text Available Rocky Mountain elk (Cervus elaphus that winter near San Antonio Mountain in northern New Mexico provide important recreational and economic benefits while creating management challenges related to temporospatial variation in their spring movements. Our objective was to examine spring distributions of elk in relation to vegetative emergence as it progresses across the landscape as measured by remote sensing. Spring distributions of elk were closely associated with greater photosynthetic activity of spring vegetation in 2 of 3 years as determined using NDVI values derived from AVHRR datasets. Observed elk locations were up to 271% greater than expected in the category representing the most photosynthetic activity. This association was not observed when analyses at a finer geographic scale were conducted. Managers facing challenges involving human-wildlife interactions and land-use issues should consider environmental conditions that may influence variation in elk association with greener portions of the landscape.

  2. Long-range atmospheric transport and the distribution of polycyclic aromatic hydrocarbons in Changbai Mountain.

    Science.gov (United States)

    Zhao, Xiangai; Kim, Seung-Kyu; Zhu, Weihong; Kannan, Narayanan; Li, Donghao

    2015-01-01

    The Changbai (also known as "Baekdu") Mountain, on the border between China and North Korea, is the highest mountain (2750 m) in northeastern China. Recently, this mountain region has experienced a dramatic increase in air pollution, not only because of increasing volumes of tourism-derived traffic but also because of the long-range transport of polluted westerly winds passing through major industrial and urban cities in the eastern region of China. To assess the relative importance of the two sources of pollution, 16 polycyclic aromatic hydrocarbons (PAHs) as model substances were determined in the mountain soil. A total of 32 soil samples were collected from different sides of the mountain at different latitudes between July and August of 2009. The ∑PAH concentrations were within the range 38.5-190.1 ng g(-1) on the northern side, 117.7-443.6 ng g(-1) on the southern side, and 75.3-437.3 ng g(-1) on the western side. A progressive increase in the level of ∑PAHs with latitude was observed on the southern and western sides that face the westerly wind with abundant precipitation. However, a similar concentration gradient was not observed on the northern side that receives less rain and is on the leeward direction of the wind. The high-molecular-weight PAH compounds were predominant in the soils on the southern and western sides, while low-molecular-weight PAHs dominated the northern side soils. These findings show that the distribution of PAHs in the mountain soil is strongly influenced by the atmospheric long-range transport and cold trapping.

  3. Distribution and sources of aliphatic hydrocarbons and fatty acids in surface sediments of a tropical estuary south west coast of India (Cochin estuary)

    Digital Repository Service at National Institute of Oceanography (India)

    Gireeshkumar, T.R.; Deepulal, P.M.; Chandramohanakumar, N.

    Surface sediments samples from the Cochin estuary were measured for elemental, stable isotopic and molecular biomarkers (aliphatic hydrocarbons and fatty acids) to study the sources and distribution of sedimentary organic matter. Concentrations...

  4. Spatial and temporal distributions of polycyclic aromatic hydrocarbons in sediments from the Songhua River, China

    Science.gov (United States)

    Dong, D.; Guo, Z.; Liu, X.; Hua, X.; Liang, D.

    2013-12-01

    Polycyclic aromatic hydrocarbons (PAHs), a class of typical persistent organic pollutants, widely exist in the environment and are potentially harmful to human health. They can enter the waters through atmospheric deposition, soil leaching, shipping, sewage discharges and surface runoff. In recent years, many studies on the distributions of PAHs in major rivers, lakes and bays around the world have been carried out. In this study, 9 surface sediments (0-10cm) were sampled from the Songhua River in Jilin and Heilongjiang provinces. The contents of 16 PAHs in the US Environmental Protection Agency list of priority pollutants were determined and their spatial distributions were discussed. Sediment cores (50cm length) in three oxbow lakes in this area were also collected and cut into 2 cm thickness sub-samples. PAHs concentrations in these samples were determined and the cores were dated using a 210Pb geochronology technique. Finally, the sedimentary history of PAHs in the Songhua River since the 1920s was revealed. Results indicated that total concentration of the 16 PAHs analyzed in the surface sediments was 187-2079 ng/g (dry weight), and the mean was 1029 ng/g. Sediments collected from near urban areas (Jilin and Harbin City) contained higher PAHs content. Compared with the domestic and international rivers, the PAHs content in this river sediments is at a medium level. The PAHs profiles showed that 2-3 ring PAHs, especially naphthalene, were dominant in all of the samples. Sedimentary flux can reflect the accumulating history of pollutants better. The PAHs fluxes were low and varied little from the 1920s to 1970s, but higher PAH fluxes were found since the 1980s in each core (Fig. 1). The PAHs sedimentary flux near Harbin City (Shuangcheng) was found changed remarkably. We inferred that the PAHs might be influenced by hydrological conditions, population mobility and economic activity in this area. PAHs sedimentary record in the Songhua River revealed that the

  5. Pareto law and Pareto index in the income distribution of Japanese companies

    Science.gov (United States)

    Ishikawa, Atushi

    2005-04-01

    In order to study the phenomenon in detail that income distribution follows Pareto law, we analyze the database of high income companies in Japan. We find a quantitative relation between the average capital of the companies and the Pareto index. The larger the average capital becomes, the smaller the Pareto index becomes. From this relation, we can possibly explain that the Pareto index of company income distribution hardly changes, while the Pareto index of personal income distribution changes sharply, from a viewpoint of capital (or means). We also find a quantitative relation between the lower bound of capital and the typical scale at which Pareto law breaks. The larger the lower bound of capital becomes, the larger the typical scale becomes. From this result, the reason there is a (no) typical scale at which Pareto law breaks in the income distribution can be understood through (no) constraint, such as the lower bound of capital or means of companies, in the financial system.

  6. Distribution and sources of n-alkanes and polycyclic aromatic hydrocarbons in shellfish of the Egyptian Red Sea coast

    Directory of Open Access Journals (Sweden)

    Ahmed El Nemr

    2016-06-01

    Full Text Available Aromatic hydrocarbons and n-alkanes were analyzed in shellfish collected from 13 different sites along the Egyptian Red Sea coast. All samples were analyzed for n-alkanes (C8–C40 and polycyclic aromatic hydrocarbons (EPA list of PAHs. n-Alkanes in shellfish samples from 13 locations were found to be in the range of 71.0–701.1 ng/g with a mean value of 242.2 ± 192.1 ng/g dry wt. Different indices were calculated for the n-alkanes to assess their sources. These were carbon preference index (CPI, average chain length (ACL, terrigenous/aquatic ratio (TAR, natural n-alkane ratio (NAR and proxy ratio (Paq. Most of the collected samples of n-alkanes were discovered to be from natural sources. Aromatic hydrocarbons (16 PAHs from 13 sites varied between 1.3 and 160.9 ng/g with an average of 47.9 ± 45.5 ng/g dry wt. Benzo(apyrine (BaP, a cancer risk assessment, was calculated for the PAHs and resulted in ranges between 0.08 and 4.47 with an average of 1.25 ng/g dry wt.

  7. Study of weathering effects on the distribution of aromatic steroid hydrocarbons in crude oils and oil residues.

    Science.gov (United States)

    Wang, Chuanyuan; Chen, Bing; Zhang, Baiyu; Guo, Ping; Zhao, Mingming

    2014-01-01

    The composition and distribution of triaromatic steroid hydrocarbons in oil residues after biodegradation and photo-oxidation processes were detected, and the diagnostic ratios for oil spill identification were developed and evaluated based on the relative standard deviation (RSD) and the repeatability limit. The preferential loss of C27 methyl triaromatic steranes (MTAS) relative to C28 MTAS and C29 MTAS was shown during the photo-oxidation process. In contrast to the photochemical degradation, the MTAS with the original 20R biological configuration was preferentially degraded during the biodegradation process. The RSD of most of the diagnostic ratios of MTAS ranged from 9 to 84% during the photo-oxidation process. However, the RSDs of such ratios derived from MTAS were all hydrocarbons retained their molecular compositions after biodegradation and photo-oxidation and most of the diagnostic ratios derived from them could be efficiently used in oil spill identification.

  8. Geochemical interpretation of distribution of aromatic hydrocarbons in components of geologic environment of Pechora, Barents and Kara seas.

    Science.gov (United States)

    Kursheva, Anna; Petrova, Vera; Litvinenko, Ivan; Morgunova, Inna

    2017-04-01

    Information about the hydrocarbons content (including aromatic ones) in components of geologic environment allows to define common factors in distribution and correlation both nature and technogenic component, and also to reveal the sources of contamination. At that, it should be noted, that hydrocarbons are widely spread in lithosphere and create steady geochemical background, variations are caused here by specifics of initial organic matter, conditions of its accumulation and transformation. The basis of the study are the samples of sea water and deep sea sediments (more than 600 stations), collected in western sector of Arctic region (Pechora, Barents and Kara seas) during the scientific-research expeditions of FSBI "VNIIOkeangeologia" for the period 2000-2010. Total content of aromatic hydrocarbons was defined by spectrofluorometric method using analyzer «FLUORAT-Panorama-02». Certification of data was performed on representative samples based on contents and molecule structure of polycyclic aromatic hydrocarbons using GC-MS (Agilent 5973/6850 GC-MS System). Results of spectrofluorometric analysis of lipid fraction of organic matter of bottom sediments allowed to define specific parameters, which characterize various lithofacies groups of sediments. Thus, sandy residues are characterized by low level of aromatic hydrocarbons (ca. 4.3 μg/g) with prevalence of bi- and tri-aromatic compounds (λmax 270-310 nm). This correlates with low sorption capacity of coarse-grained sediments and absence of organic-mineral component, containing the breakdown products of initial organic matter. Tetra- and penta- aromatic structures prevail in clay sediments (ca. 13.0 μg/g), which are typical components of lipid fraction of organic matter of post sedimentation and early diagenetic stages of transformation. At that, changes of spectral characteristic of sediments in stratigraphic sequence completely reflect processes of diagenetic transformation of organic matter, including

  9. Measuring Distributional Inequality: Relative Body Mass Index Distributions by Gender, Race/Ethnicity, and Education, United States (1999–2006

    Directory of Open Access Journals (Sweden)

    Brian C. Houle

    2010-01-01

    Full Text Available Few studies consider obesity inequalities as a distributional property. This study uses relative distribution methods to explore inequalities in body mass index (BMI; kg/m2. Data from 1999–2006 from the National Health and Nutrition Examination Survey were used to compare BMI distributions by gender, Black/White race, and education subgroups in the United States. For men, comparisons between Whites and Blacks show a polarized relative distribution, with more Black men at increased risk of over or underweight. Comparisons by education (overall and within race/ethnic groups effects also show a polarized relative distribution, with more cases of the least educated men at the upper and lower tails of the BMI distribution. For women, Blacks have a greater probability of high BMI values largely due to a right-shifted BMI distribution relative to White women. Women with less education also have a BMI distribution shifted to the right compared to the most educated women.

  10. Global distribution and Gas-particle Partitioning of Polycyclic Aromatic Hydrocarbons - a Modelling Study

    Science.gov (United States)

    Lammel, G.; Sehili, A. M.

    2009-04-01

    Polycyclic aromatic hydrocarbons (PAHs) are emitted in all combustion processes. Some undergo re-volatilisation (multi-hopping). Little is known about degradation pathways and the processes determining gas-particle partitioning (Lohmann & Lammel, 2004). Distribution and fate have no been studied on the global scale so far (except for emissions in Europe and Russia; Sehili & Lammel, 2007). Anthracene (ANT), fluoranthene (FLT) and benzo[a]pyrene (BAP) have been studied under present-day climate and each 3 scenarios of atmospheric degradation and gas-particle partitioning using an atmospheric general circulation model with embedded dynamic aerosol submodel, ECHAM-HAM (Stier et al., 2005) and re-volatilization from ground compartments (Semeena et al., 2006). 10 years were simulated with a time-step of 30 min and 2.8°x2.8° and 19 levels. Emissions were compiled based on emission factors in 27 major types of combustion technologies, scaled to 141 combustion technologies and their global distribution as of 1996 (1°x1°) according to fuel type and the PM1 emission factor (Bond et al., 2004). The emissions were entried uniformly throughout the entire simulation time. Scenarios tested: AD = adsorption (according to the Junge empirical relationship; Pankow, 1987), OB = absorption in organic matter and adsorption to soot (Lohmann & Lammel, 2004) without and DP = with degradation in the atmospheric particulate phase. Gas-particle partitioning in air influences drastically the atmospheric cycling, total environmental fate (e.g. compartmental distributions) and the long-range transport potential (LRTP) of the substances studied. The LRTP is mostly regional. Comparison with observed levels indicate that degradation in the particulate phase must be slower than in the gas-phase. Furthermore, the levels of semivolatile PAHs (ANT and FLT) at high latitudes and a European mid latitude site cannot be explained by partitioning due to adsorption alone, but point to both absorption into

  11. Occurrence and distribution of polycyclic aromatic hydrocarbons (PAHs) in Bolgoda and Beira Lakes, Sri Lanka.

    Science.gov (United States)

    Pathiratne, K A S; De Silva, O C P; Hehemann, David; Atkinson, Ian; Wei, Robert

    2007-08-01

    The pollution of polycyclic aromatic hydrocarbons (PAHs) has been widely used to assess the potential impact of anthropogenic activities on aquatic environments because their occurrence in water is closely tied to urban activities. Many PAHs possess mutagenic and carcinogenic properties (Menzie et al. 1992). PAH distribution and toxic potentials have therefore been the focus of numerous studies in waterways including the Great Lakes (USEPA Report 1994), Yanisei Bay (Dahle et al., 2003), and the Fraser River basin (Yunker et al., 2002). Sri Lanka, a small island nation with a dense population of about 20 million people, faces a multitude of environmental stresses ranging from deforestation to traffic congestion and the deterioration of water quality. This study was undertaken to understand the occurrence, sources, and potential impacts of PAHs in the waterways of Sri Lanka. Two lakes, Beira and Bolgoda, were selected for the study due to their economic value and high level of pollution. Beira Lake, situated in downtown Colombo, the capital city of Sri Lanka, is highly polluted. Sources of pollution are multifarious. For instance, clusters of communities have sprung up along the edges of the lake in recent times and many shacks have been built. These communities are generally not connected to municipal sewer systems and substantial quantities of domestic sewage and untreated wastewaters are discharged directly into the lake. Small industries have also grown rapidly around the lakes, most of which are not believed to have adequate facilities to treat industrial wastewater, especially organic wastes. In addition, Sri Lanka has experienced an upsurge of motor vehicles, including millions of three-wheelers and minivans that are powered by leaded gasoline and diesel fuels. Traffic congestion and severe air pollution due to vehicle emissions are now common daily occurrences and are considered a major potential source of PAHs in the lakes. Although Bolgoda Lake is situated

  12. Distribution of petroleum hydrocarbons and toluene biodegradation, Knox Street fire pits, Fort Bragg, North Carolina

    Science.gov (United States)

    Harden, S.L.; Landmeyer, J.E.

    1996-01-01

    An investigation was conducted at the Knox Street fire pits, Fort Bragg, North Carolina, to monitor the distribution of toluene, ethylbenzene, and xylene (TEX) in soil vapor, ground water, and ground-water/vapor to evaluate if total concentrations of TEX at the site are decreasing with time, and to quantify biodegradation rates of toluene in the unsaturated and saturated zones. Soil-vapor and ground-water samples were collected around the fire pits and ground-water/vapor samples were collected along the ground-water discharge zone, Beaver Creek, on a monthly basis from June 1994 through June 1995. Concentrations of TEX compounds in these samples were determined with a field gas chro- matograph. Laboratory experiments were performed on aquifer sediment samples to measure rates of toluene biodegradation by in situ micro- organisms. Based on field gas chromatographic analytical results, contamination levels of TEX compounds in both soil vapor and ground water appear to decrease downgradient of the fire-pit source area. During the 1-year study period, the observed temporal and spatial trends in soil vapor TEX concentrations appear to reflect differences in the distribution of TEX among solid, aqueous, and gaseous phases within fuel-contaminated soils in the unsaturated zone. Soil temperature and soil moisture are two important factors which influence the distribution of TEX com- pounds among the different phases. Because of the short period of data collection, it was not possible to distinguish between seasonal fluc- tuations in soil vapor TEX concentrations and an overall net decrease in TEX concentrations at the study site. No seasonal trend was observed in total TEX concentrations for ground- water samples collected at the study site. Although the analytical results could not be used to determine if ground-water TEX concen- trations decreased during the study at a specific location, the data were used to examine rate constants of toluene biodegradation. Based on

  13. Distribution of polycyclic aromatic hydrocarbons (PAHs) in rivers and estuaries in Malaysia: a widespread input of petrogenic PAHs.

    Science.gov (United States)

    Zakaria, Mohamad Pauzi; Takada, Hideshige; Tsutsumi, Shinobu; Ohno, Kei; Yamada, Junya; Kouno, Eriko; Kumata, Hidetoshi

    2002-05-01

    This is the first publication on the distribution and sources of polycyclic aromatic hydrocarbons (PAHs) in riverine and coastal sediments in South East Asia where the rapid transfer of land-based pollutants into aquatic environments by heavy rainfall and runoff waters is of great concern. Twenty-nine Malaysian riverine and coastal sediments were analyzed for PAHs (3-7 rings) by gas chromatography mass spectrometry. Total PAHs concentrations in the sediment ranged from 4 to 924 ng/g. Alkylated homologues were abundant for all sediment samples. The ratio of the sum of methylphenanthrenes to phenanthrene (MP/P), an index of petrogenic PAHs contribution, was more than unity for 26 sediment samples and more than 3 for seven samples for urban rivers covering a broad range of locations. The MP/P ratio showed a strong correlation with the total PAHs concentrations, with an r2 value of 0.74. This ratio and all other compositional features indicated that Malaysian urban sediments are heavily impacted by petrogenic PAHs. This finding is in contrast to other studies reported in many industrialized countries where PAHs are mostly of pyrogenic origin. The MP/P ratio was also significantly correlated with higher molecular weight PAHs such as benzo[a]pyrene, suggesting unique PAHs source in Malaysia which contains both petrogenic PAHs and pyrogenic PAHs. PAHs and hopanes fingerprints indicated that used crankcase oil is one of the major contributors of the sedimentary PAHs. Two major routes of inputs to aquatic environments have been identified: (1) spillage and dumping of waste crankcase oil and (2) leakage of crankcase oils from vehicles onto road surfaces, with the subsequent washout by street runoff. N-Cyclohexyl-2-benzothiazolamine (NCBA), a molecular marker of street dust, was detected in the polluted sediments. NCBA and other biomarker profiles confirmed our hypothesis of the input from street dust contained the leaked crankcase oil. The fingerprints excluded crude oil

  14. A new bibliometric index based on the shape of the citation distribution.

    Science.gov (United States)

    Lando, Tommaso; Bertoli-Barsotti, Lucio

    2014-01-01

    In order to improve the h-index in terms of its accuracy and sensitivity to the form of the citation distribution, we propose the new bibliometric index [symbol in text]. The basic idea is to define, for any author with a given number of citations, an "ideal" citation distribution which represents a benchmark in terms of number of papers and number of citations per publication, and to obtain an index which increases its value when the real citation distribution approaches its ideal form. The method is very general because the ideal distribution can be defined differently according to the main objective of the index. In this paper we propose to define it by a "squared-form" distribution: this is consistent with many popular bibliometric indices, which reach their maximum value when the distribution is basically a "square". This approach generally rewards the more regular and reliable researchers, and it seems to be especially suitable for dealing with common situations such as applications for academic positions. To show the advantages of the [symbol in text]-index some mathematical properties are proved and an application to real data is proposed.

  15. On the fractal distribution of primes and prime-indexed primes by the binary image analysis

    Science.gov (United States)

    Cattani, Carlo; Ciancio, Armando

    2016-10-01

    In this paper, the distribution of primes and prime-indexed primes (PIPs) is studied by mapping primes into a binary image which visualizes the distribution of primes. These images show that the distribution of primes (and PIPs) is similar to a Cantor dust, moreover the self-similarity with respect to the order of PIPs (already proven in Batchko (2014)) can be seen as an invariance of the binary images. The index of primes plays the same role of the scale for fractals, so that with respect to the index the distribution of prime-indexed primes is characterized by the self-similarity alike any other fractal. In particular, in order to single out the scale dependence, the PIPs fractal distribution will be evaluated by limiting to two parameters, fractal dimension (δ) and lacunarity (λ), that are usually used to measure the fractal nature. Because of the invariance of the corresponding binary plots, the fractal dimension and lacunarity of primes distribution are invariant with respect to the index of PIPs.

  16. SNR radio spectral index distribution and its correlation with polarization: a case study of Lupus Loop

    CERN Document Server

    Jovanović, V Borka; Borka, D

    2016-01-01

    We use radio-continuum all-sky surveys at 1420 and 408 MHz with the aim to investigate properties of the Galactic radio source Lupus Loop. The survey data at 1435 MHz, with the linear polarization of the southern sky, is also used. We calculate properties of this supernova remnant: the brightness temperature, surface brightness and radio spectral index. For determining borders and calculation of its properties, we use the method we have developed. The non-thermal nature of its radiation is confirmed. The distribution of spectral index over its area is also given. A significant correlation between the radio spectral index distribution and the corresponding polarized intensity distribution inside the loop borders is found, indicating that the polarization maps could provide us information about the distribution of interstellar medium, and thus could represent one additional way to search for new Galactic loops.

  17. SNR radio spectral index distribution and its correlation with polarization. a case study: the Lupus Loop

    Science.gov (United States)

    Borka Jovanović, V.; Jovanović, P.; Borka, D.

    2017-04-01

    We use radio-continuum all-sky surveys at 1420 and 408 MHz with the aim to investigate properties of the Galactic radio source Lupus Loop. The survey data at 1435 MHz, with the linear polarization of the southern sky, are also used. We calculate properties of this supernova remnant: the brightness temperature, surface brightness and radio spectral index. To determine its borders and to calculate its properties, we use the method we have developed. The non-thermal nature of its radiation is confirmed. The distribution of spectral index over its area is also given. A significant correlation between the radio spectral index distribution and the corresponding polarized intensity distribution inside the loop borders is found, indicating that the polarization maps could provide us information about the distribution of the interstellar medium, and thus could represent one additional way to search for new Galactic loops.

  18. Distribution of Ni, V, and petroleum hydrocarbons in recent sediments from the Veracruz Coast, Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Vazquez, F.; Sanchez, M.; Alexander, H.; Delgado, D. (Univ. Nacional Autonoma de Mexico, Mexico City (Mexico))

    1991-05-01

    The coastline of Veracruz is a unique environment due to the presence of extensive coraline systems and of natural oil seeps. Depending on the environmental parameters the coraline system are highly productive and diverse. Changes in these parameters by non-natural processes will cause damage or even the disappearance of these systems. Thus baseline studies in the zone are important in order to establish the natural concentrations of trace metals and the presence of petroleum hydrocarbons originated either from natural oil seeps or accidental spills. In the present paper the concentrations of nickel and vanadium in seawater and in sediments, as well as petroleum hydrocarbons in sediments are described in order to obtain base line information for the assessment of future man-induced alterations of the study area.

  19. Hydrocarbons in sediments along a tropical estuary-shelf transition area: Sources and spatial distribution.

    Science.gov (United States)

    Maciel, Daniele Claudino; de Souza, José Roberto Botelho; Taniguchi, Satie; Bícego, Márcia Caruso; Schettini, Carlos Augusto França; Zanardi-Lamardo, Eliete

    2016-12-15

    Estuaries generally act as sediment traps and may retain a range of contaminants associated to this matrix. Aliphatic hydrocarbons (AHs) were investigated in Capibaribe Estuarine System and adjacent shelf, Northeast of Brazil, to evaluate the contamination and to better understand its functionality related to the coast. Fourteen sediment samples were analyzed, using gas chromatography with flame ionization detection. Total AHs concentrations ranged from 7.5 to 190.3μgg(-1) and n-alkanes ranged from below detection limit (contamination by petroleum hydrocarbons. The concentration decrease (about 90%) towards the adjacent shelf suggested an estuarine high retention capacity but dilution and degradation processes cannot be neglected. Similar AHs characteristics reported in sediments from the adjacent shelf suggested that this system may also export contaminants. Copyright © 2016 Elsevier Ltd. All rights reserved.

  20. [Distribution of various polycyclic aromatic hydrocarbons in reservoir water of Estonia].

    Science.gov (United States)

    Veldre, I A; Itra, A R; Paal'me, L P; Urbas, E R

    1985-01-01

    The paper presents experimental data on different polycyclic aromatic hydrocarbons (PAH) in water, bottom sediments and algae as well as evidence available in literature on their content in exhausts of automobiles, oil shale industry and power station. Attempts are made to reveal differences in sources of the environment pollution with allowance for different PAH/benzo(a)pyrene percentage ratio, but as the PAH ratios are relatively similar in different pollution sources this attempt was a failure.

  1. Effect of spectral index distribution on estimating the AGN radio luminosity function

    CERN Document Server

    Yuan, Zunli; Zhou, Ming; Mao, Jirong

    2016-01-01

    In this paper, we scrutinize the effect of spectral index distribution on estimating the AGN (active galactic nucleus) radio luminosity function (RLF) by a Monte Carlo method. We find that the traditional bivariate RLF estimators can cause bias in varying degree. The bias is especially pronounced for the flat-spectrum radio sources whose spectral index distribution is more scattered. We believe that the bias is caused because the $K$-corrections complicate the truncation boundary on the $L-z$ plane of the sample, but the traditional bivariate RLF estimators have difficulty in dealing with this boundary condition properly. We suggest that the spectral index distribution should be incorporated into the RLF analysis process to obtain a robust estimation. This drives the need for a trivariate function of the form $\\Phi(\\alpha,z,L)$ which we show provides an accurate basis for measuring the RLF.

  2. Effect of Spectral Index Distribution on Estimating the AGN Radio Luminosity Function

    Science.gov (United States)

    Yuan, Zunli; Wang, Jiancheng; Zhou, Ming; Mao, Jirong

    2016-10-01

    In this paper, we scrutinize the effect of spectral index distribution on estimating the active galactic nucleus radio luminosity function (RLF) by a Monte Carlo method. We find that the traditional bivariate RLF estimators can cause bias in varying degrees. The bias is especially pronounced for the flat-spectrum radio sources whose spectral index distribution is more scattered. We believe that the bias is caused because the K-corrections complicate the truncation boundary on the L-z plane of the sample, but the traditional bivariate RLF estimators have difficulty dealing with this boundary condition properly. We suggest that the spectral index distribution should be incorporated into the RLF analysis process to obtain a robust estimation. This drives the need for a trivariate function of the form Φ(α, z, L), which we show provides an accurate basis for measuring the RLF.

  3. Polycyclic aromatic hydrocarbons in soils of Beijing and Tianjin region: vertical distribution, correlation with TOC and transport mechanism

    Institute of Scientific and Technical Information of China (English)

    HE Fengpeng; ZHANG Zhihuan; WAN Yunyang; LU Song; WANG Liang; BU Qingwei

    2009-01-01

    Concentrations and compositions of 20 polycyclic aromatic hydrocarbons (PAHs) or heterocyclic aromatic hydrocarbons (HAHs) were investigated in 16 soil profiles of Beijing and Tianjin region. Transport of high molecular weight PAHs (HMWPAHs) and correlation between total organic carbon (TOC) and the concentrations were also discussed. The results indicated that highly contaminated sites were located at urban or wastewater irrigation areas and pollutants mainly accumulated in topsoil (<40 cm), with a sharp content decrease at the vertical boundary of 30--40 cm. Total PAHs/HAHs concentrations in soils from Tianjin were markedly greater than those from Beijing. Even the contents at bottoms of soil profiles in Tianjin were higher than those in topsoils of Beijing soil profile. HMWPAHs (4-6 rings PAHs) dominated the PAH profiles, exhibiting a uniform distribution of pyrogenic origin between topsoils and deep layers. Furthermore, the percentages of HMWPAHs remained relative constant with the depth of soil profiles, which were consistent with the distribution of particulate matter-associated PAHs in the local atmospheric environments. Therefore, HMWPAHs transport with particulates might be the predominant source found in soil profiles.

  4. Relationship of Social and Lifestyle Factors with Central Fat Distribution Expressed by the Aggregate Fat Distribution Index

    Directory of Open Access Journals (Sweden)

    Suder Agnieszka

    2014-07-01

    Full Text Available Abdominal obesity is caused by several factors and the explanation of the level of its variability also depends on anthropometric indexes applied for its assessment. The aim was to determine the degree of explanation of the abdominal adiposity variation, presented by the aggregate fat distribution index (AFDI, through the socio-economic status and lifestyle. Subjects and methods: A cross-sectional population-based study was conducted on a sample of 259 healthy working males aged 20-30 from the city of Cracow, Poland. A full model was created using a stepwise backward regression with the social and lifestyle data as independent variables and the AFDI as a dependent variable. The AFDI was created by unitarization applied to selected characteristics of fat distribution which were transformed into [0,1] interval (without measurement unit and then added and averaged to form a composite index. The highest autonomous influence on AFDI is ascribed to age (b = 0.2456 p = 0.000, level of motor fitness b=−0.2392 p=0.000, leisure time physical activity (b=−0.1353 p=0.000 and being born in a rural area (b=0.1300 p=0.000. The variables explain 17% (R2=0.1667 of the variation of the central fat distribution. Variation of the abdominal adiposity was explained with the use of AFDI at the level close to the commonly applied indexes.

  5. ASSESSMENT OF ACCURACY OF PRECIPITATION INDEX (SPI DETERMI-NED BY DIFFERENT PROBABILITY DISTRIBUTIONS

    Directory of Open Access Journals (Sweden)

    Edward Gąsiorek

    2014-11-01

    Full Text Available The use of different calculating methods to compute the standardized precipitation index (SPI results in various approximations. Methods based on normal distribution and its transformations, as well as on gamma distribution, give similar results and may be used equally, whereas the lognormal distribution fitting method is significantly discrepant, especially for extreme values of SPI. Therefore, it is problematic which method gives the distribution optimally fitted to empirical data. The aim of this study is to categorize the above mentioned methods according to the degree of approximation to empirical data from the Observatory of Agro- and Hydrometeorology in Wrocław-Swojec from 1964–2009 years.

  6. Distribution of Electrical Field Energy for Conversion of Methane to C2 Hydrocarbons via Dissymmetrical Electric Field Enhanced Plasma

    Institute of Scientific and Technical Information of China (English)

    Baowei Wang; Genhui Xu; Hongwei Sun

    2006-01-01

    Direct conversion of methane into C2 hydrocarbons through alternating current electric field enhanced plasma was studied under room temperature, atmospheric pressure and low power conditions.The distribution of electrical field intensity and distribution of energy were calculated with software that was developed by us according to the charge simulation method. The results indicated that the energy of tip of electrode was 0.36 J/mm3 and it was higher than the methane dissociation energy (0.0553 J/mm3).The methane located at this area can be activated easily. The higher-energy particles produced by dissociation collided with molecules around them and initiated consecutive reactions between free radicals and molecules. The method was proved to be valided and could be taken as a basis for the electrical field study concerned.

  7. Indexed

    CERN Document Server

    Hagy, Jessica

    2008-01-01

    Jessica Hagy is a different kind of thinker. She has an astonishing talent for visualizing relationships, capturing in pictures what is difficult for most of us to express in words. At indexed.blogspot.com, she posts charts, graphs, and Venn diagrams drawn on index cards that reveal in a simple and intuitive way the large and small truths of modern life. Praised throughout the blogosphere as “brilliant,” “incredibly creative,” and “comic genius,” Jessica turns her incisive, deadpan sense of humor on everything from office politics to relationships to religion. With new material along with some of Jessica’s greatest hits, this utterly unique book will thrill readers who demand humor that makes them both laugh and think.

  8. A Distribution-class Locational Marginal Price (DLMP) Index for Enhanced Distribution Systems

    Science.gov (United States)

    Akinbode, Oluwaseyi Wemimo

    The smart grid initiative is the impetus behind changes that are expected to culminate into an enhanced distribution system with the communication and control infrastructure to support advanced distribution system applications and resources such as distributed generation, energy storage systems, and price responsive loads. This research proposes a distribution-class analog of the transmission LMP (DLMP) as an enabler of the advanced applications of the enhanced distribution system. The DLMP is envisioned as a control signal that can incentivize distribution system resources to behave optimally in a manner that benefits economic efficiency and system reliability and that can optimally couple the transmission and the distribution systems. The DLMP is calculated from a two-stage optimization problem; a transmission system OPF and a distribution system OPF. An iterative framework that ensures accurate representation of the distribution system's price sensitive resources for the transmission system problem and vice versa is developed and its convergence problem is discussed. As part of the DLMP calculation framework, a DCOPF formulation that endogenously captures the effect of real power losses is discussed. The formulation uses piecewise linear functions to approximate losses. This thesis explores, with theoretical proofs, the breakdown of the loss approximation technique when non-positive DLMPs/LMPs occur and discusses a mixed integer linear programming formulation that corrects the breakdown. The DLMP is numerically illustrated in traditional and enhanced distribution systems and its superiority to contemporary pricing mechanisms is demonstrated using price responsive loads. Results show that the impact of the inaccuracy of contemporary pricing schemes becomes significant as flexible resources increase. At high elasticity, aggregate load consumption deviated from the optimal consumption by up to about 45 percent when using a flat or time-of-use rate. Individual load

  9. Flatfoot Diagnosis by a Unique Bimodal Distribution of Footprint Index in Children

    OpenAIRE

    Chia-Hsieh Chang; Yu-Chen Chen; Wen-Tien Yang; Pei-Chi Ho; Ai-Wen Hwang; Chien-Hung Chen; Jia-Hao Chang; Liang-Wey Chang

    2014-01-01

    BACKGROUND: More than 1000 scientific papers have been devoted to flatfoot issue. However, a bimodal distribution of flatfoot indices in school-aged children has never been discovered. The purposes of this study were to establish a new classification of flatfoot by characteristic in frequency distribution of footprint index and to endue the classification with discrepancy in physical fitness. METHODS/PRINCIPAL FINDINGS: In a longitudinal survey of physical fitness and body structure, weight b...

  10. Index

    Directory of Open Access Journals (Sweden)

    Antonio Juan Sánchez

    2012-09-01

    Full Text Available The Advances in Distributed Computing and Artificial Intelligence Journal (ISSN: 2255-2863 is an open access journal that publishes articles which contribute new results associated with distributed computing and artificial intelligence, and their application in different areas. The artificial intelligence is changing our society. Its application in distributed environments, such as the Internet, electronic commerce, mobile communications, wireless devices, distributed computing and so on, is increasing and becoming and element of high added value and economic potential in industry and research. These technologies are changing constantly as a result of the large research and technical effort being undertaken in both universities and businesses. The exchange of ideas between scientists and technicians from both academic and business areas is essential to facilitate the development of systems that meet the demands of today's society.

  11. Inequitable distribution of general practitioners in Australia: estimating need through the Robin Hood Index.

    Science.gov (United States)

    Wilkinson, D; Symon, B

    2000-02-01

    From Census data, to document the distribution of general practitioners in Australia and to estimate the number of general practitioners needed to achieve an equitable distribution accounting for community health need. Data on location of general practitioners, population size and crude mortality by statistical division (SD) were obtained from the Australian Bureau of Statistics. The number of patients per general practitioner by SD was calculated and plotted. Using crude mortality to estimate community health need, a ratio of the number of general practitioners per person: mortality was calculated for all Australia and for each SD (the Robin Hood Index). From this, the number of general practitioners needed to achieve equity was calculated. In all, 26,290 general practitioners were identified in 57 SDs. The mean number of people per general practitioner is 707, ranging from 551 to 1887. Capital city SDs have most favourable ratios. The Robin Hood Index for Australia is 1, and ranges from 0.32 (relatively under-served) to 2.46 (relatively over-served). Twelve SDs (21%) including all capital cities and 65% of all Australians, have a Robin Hood Index > 1. To achieve equity per capita 2489 more general practitioners (10% of the current workforce) are needed. To achieve equity by the Robin Hood Index 3351 (13% of the current workforce) are needed. The distribution of general practitioners in Australia is skewed. Nonmetropolitan areas are relatively underserved. Census data and the Robin Hood Index could provide a simple means of identifying areas of need in Australia.

  12. Distribution of selected carcinogenic hydrocarbon and heavy metals in an oil-polluted agriculture zone.

    Science.gov (United States)

    Nwaichi, E O; Wegwu, M O; Nwosu, U L

    2014-12-01

    Owing to the importance of clean and fertile agricultural soil for the continued existence of man, this study investigated the concentrations of total petroleum hydrocarbons (TPHs), polycyclic aromatic hydrocarbons (PAHs) and some heavy metals in soils and selected commonly consumed vegetables and tubers from oil-polluted active agricultural farmland in Gokana of Ogoniland, Rivers State, Nigeria. Samples from Umuchichi, Osisioma Local Government Area in Abia State, Nigeria, a non-oil-polluted area constituted the control. In test and control, up to 3,830 ± 19.6 mgkg(-1) dw and 6,950 ± 68.3 mgkg(-1) dw (exceeding DPR set limits) and 11.3 ± 0.04 mgkg(-1) dw and 186 ± 0.02 mgkg(-1) dw for TPH and PAHs, respectively, were recorded in test soil and plant samples, respectively. Among the metals studied (Pb, Cd, Cr, Mn, Fe and Zn), Pb and Cr uptake exceeded WHO set limits for crops in test samples. Combined sources of pollution were evident from our studies. Bitterleaf and Waterleaf could be tried as bioindicators owing to expressed contaminants uptake pattern.

  13. Controls on the distribution of non-hydrocarbon gases in the Alberta Basin

    Energy Technology Data Exchange (ETDEWEB)

    Hutcheon, I. [Calgary Univ., Dept, of Geology and Geophysics, AB (Canada)

    1999-12-01

    Patterns of the occurrence of the non-hydrocarbon gases hydrogen sulfide, carbon dioxide, helium and nitrogen in the Alberta Basin was investigated. Results show that hydrogen sulfide and carbon dioxide tend to increase to the west and with depth in Devonian and Mississippian strata. Concentrations are higher than in the Cretaceous units. Nitrogen and to some degree helium, tend to show an antipathetic relationship with high hydrogen sulfide and carbon dioxide in Devonian and Mississippian strata. Helium concentrations are relatively high in north central Alberta in the Devonian, and in southern Alberta in the Mannville. Nitrogen in southern Alberta is higher at shallow depths in the Mannville and Colorado groups. Hydrogen sulfide and carbon dioxide is considered to be the product of thermal reduction of sulphate, probably derived from Devonian anhydrite. In the Mannville group hydrogen sulfide is the product of the bacterial reduction of sulphate, driven by incursion of meteoric water from the south that causes mixing of waters from Mississippian carbonate rocks with waters from Mannville elastic rocks. Carbon dioxide in the Colorado group is believed to have been formed by oxidation of organic matter, while the helium observed in the Devonian stratum is likely the result of the mixing of deep crustal rock with atmospheric sources. Correlations with hydrocarbon gases in the Colorado Group suggests that the high nitrogen content is related to bacterial accumulation of natural gas. 63 refs., 36 figs.

  14. Assessment of atmospheric distribution of polychlorinated biphenyls and polycyclic aromatic hydrocarbons using polyparameter model

    Directory of Open Access Journals (Sweden)

    Turk-Sekulić Maja M.

    2011-01-01

    Full Text Available Results of partial or total destruction of industrial plants, military targets, infrastructure, uncontrolled fires and explosions during the conflict period from 1991 to 1999, at the area of Western Balkans, were large amounts of hazardous organic matter that have been generated and emitted in the environment. In order to assess gas/particle partition of seven EPA polychlorinated biphenyls and sixteen EPA polycyclic aromatic hydrocarbons, twenty air samples have been collected at six urban, industrial and highly contaminated localities in Vojvodina. Hi-Vol methodology has been used for collecting ambiental air samples, that simultaneously collects gaseous and particulate phase with polyurethane foam filters (PUF and glass fiber filters (GFF. PUF and GFF filters have been analyzed, and concentration levels of gaseous PCBs and PAHs molecules in gaseous and particulate phase were obtained, converted and expressed through fraction of individual compounds sorbed onto particulate phase of the sample, in total detected quantity. Experimentally gained gas/particle partitioning values of PCBs and PAHs molecules have been compared with PP-LFER model estimated values. Significant deviation has been noticed during comparative analysis of estimated polyparameter model values for complete set of seven PCBs congeners. Much better agreement of experimental and estimated values is for polycyclic aromatic hydrocarbons, especially for molecules with four rings. These results are in a good correlation with literature data where polyparameter model has been used for predicting gas/particle partition of studied group of organic molecules.

  15. Spatial distribution of hydrocarbon reservoirs in the West Korea Bay Basin in the northern part of the Yellow Sea, estimated by 3-D gravity forward modelling

    Science.gov (United States)

    Choi, Sungchan; Ryu, In-Chang; Götze, H.-J.; Chae, Y.

    2017-01-01

    Although an amount of hydrocarbon has been discovered in the West Korea Bay Basin (WKBB), located in the North Korean offshore area, geophysical investigations associated with these hydrocarbon reservoirs are not permitted because of the current geopolitical situation. Interpretation of satellite-derived potential field data can be alternatively used to image the 3-D density distribution in the sedimentary basin associated with hydrocarbon deposits. We interpreted the TRIDENT satellite-derived gravity field data to provide detailed insights into the spatial distribution of sedimentary density structures in the WKBB. We used 3-D forward density modelling for the interpretation that incorporated constraints from existing geological and geophysical information. The gravity data interpretation and the 3-D forward modelling showed that there are two modelled areas in the central subbasin that are characterized by very low density structures, with a maximum density of about 2000 kg m-3, indicating some type of hydrocarbon reservoir. One of the anticipated hydrocarbon reservoirs is located in the southern part of the central subbasin with a volume of about 250 km3 at a depth of about 3000 m in the Cretaceous/Jurassic layer. The other hydrocarbon reservoir should exist in the northern part of the central subbasin, with an average volume of about 300 km3 at a depth of about 2500 m.

  16. BMD PREDICTION OF DEATH IS ENCAPSULATED BY THE MORPHOLOGICAL ATHEROSCLEROSIS CALCIFICATION DISTRIBUTION (MACD) INDEX

    DEFF Research Database (Denmark)

    Ganz, Melanie; Nielsen, Mads; Karsdal, Morten

    2009-01-01

    .3±0.3 years and of which CVD, cancer, and all cause deaths were recorded. The spine BMD and aortic calcification markers, AC24 and the recently proposed Morphological Atherosclerosis Calcification Distribution (MACD) index, were quantified from DXA scans and lateral X-rays respectively. The MACD...

  17. Multi-factors influencing the spatial distribution of polycyclic aromatic hydrocarbons in soils surrounding drinking water protection zone.

    Science.gov (United States)

    Jiao, Wentao; Wang, Tieyu; Lu, Yonglong; Chang, Andrew; Chen, Weiping

    2013-08-01

    We selected the Guanting Reservoir in Beijing, China as a case where an industrial area locates on the upwind corner to study the influence of human activities and natural processes on the distribution of polycyclic aromatic hydrocarbons (PAHs) in soils. Soil PAH concentrations in the study area follow a log-normal probability distribution function, suggesting that distribution of PAH in soils was affected by human activities. Distribution of PAHs in soils was significantly affected by the point source that high PAH concentrations were observed in near industrial area with an obvious declining trend from the northwest to the southeast which was the prevailing wind direction in this area. Away from the influence of point source, distribution of PAHs in soils was found to significantly correlate with total organic carbon content, while the influences of agricultural land uses and type of soil texture on the total soil PAHs contents and ring compositions were quite limited. The results can provide some evidences and data on the pollutant accumulation in drink water protection area influenced by natural processes and human activities.

  18. Index

    Directory of Open Access Journals (Sweden)

    Antonio Juan Sánchez

    2013-08-01

    Full Text Available The Advances in Distributed Computing and Artificial Intelligence Journal (ADCAIJ is an open access journal that publishes articles which contribute new results associated with distributed computing and artificial intelligence,and their application in different areas.The artificial intelligence is changing our society. Its application in distributed environments, such as the Internet, electronic commerce, mobile communications, wireless devices, distributed computing and so on, is increasing and becoming and element of high added value and economic potential in industry and research. These technologies are changing constantly as a result of the large research and technical effort being undertaken in both universities and businesses. The exchange of ideas between scientists and technicians from both academic and business areas is essential to facilitate the development of systems that meet the demands of today's society.We would like to thank all the contributing authors for their hard and highly valuable work. Their work has helped to contribute to the success of this special issue. Finally, the Editors wish to thank Scientific Committee of Advances in Distributed Computing and Artificial Intelligence Journal for the collaboration of this special issue, that notably contributes to improve the quality of the journal. We hope the reader will share our joy and find this special issue very useful.

  19. Index

    Directory of Open Access Journals (Sweden)

    Antonio Juan SÁNCHEZ

    2013-05-01

    Full Text Available The Advances in Distributed Computing and Artificial Intelligence Journal (ADCAIJ is an open access journal that publishes articles which contribute new results associated with distributed computing and artificial intelligence,and their application in different areas. The artificial intelligence is changing our society. Its application in distributed environments, such as the Internet, electronic commerce, mobile communications, wireless devices, distributed computing and so on, is increasing and becoming and element of high added value and economic potential in industry and research. These technologies are changing constantly as a result of the large research and technical effort being undertaken in both universities and businesses. The exchange of ideas between scientists and technicians from both academic and business areas is essential to facilitate the development of systems that meet the demands of today's society. We would like to thank all the contributing authors for their hard and highly valuable work. Their work has helped to contribute to the success of this special issue. Finally, the Editors wish to thank Scientific Committee of Advances in Distributed Computing and Artificial Intelligence Journal for the collaboration of this special issue, that notably contributes to improve the quality of the journal. We hope the reader will share our joy and find this special issue very useful.

  20. Novel Radiobiological Gamma Index for Evaluation of 3-Dimensional Predicted Dose Distribution

    Energy Technology Data Exchange (ETDEWEB)

    Sumida, Iori, E-mail: sumida@radonc.med.osaka-u.ac.jp [Department of Radiation Oncology, Osaka University Graduate School of Medicine, Osaka (Japan); Yamaguchi, Hajime; Kizaki, Hisao; Aboshi, Keiko; Tsujii, Mari; Yoshikawa, Nobuhiko; Yamada, Yuji [Department of Radiation Oncology, NTT West Osaka Hospital, Osaka (Japan); Suzuki, Osamu; Seo, Yuji [Department of Radiation Oncology, Osaka University Graduate School of Medicine, Osaka (Japan); Isohashi, Fumiaki [Department of Radiation Oncology, NTT West Osaka Hospital, Osaka (Japan); Yoshioka, Yasuo [Department of Radiation Oncology, Osaka University Graduate School of Medicine, Osaka (Japan); Ogawa, Kazuhiko [Department of Radiation Oncology, NTT West Osaka Hospital, Osaka (Japan)

    2015-07-15

    Purpose: To propose a gamma index-based dose evaluation index that integrates the radiobiological parameters of tumor control (TCP) and normal tissue complication probabilities (NTCP). Methods and Materials: Fifteen prostate and head and neck (H&N) cancer patients received intensity modulated radiation therapy. Before treatment, patient-specific quality assurance was conducted via beam-by-beam analysis, and beam-specific dose error distributions were generated. The predicted 3-dimensional (3D) dose distribution was calculated by back-projection of relative dose error distribution per beam. A 3D gamma analysis of different organs (prostate: clinical [CTV] and planned target volumes [PTV], rectum, bladder, femoral heads; H&N: gross tumor volume [GTV], CTV, spinal cord, brain stem, both parotids) was performed using predicted and planned dose distributions under 2%/2 mm tolerance and physical gamma passing rate was calculated. TCP and NTCP values were calculated for voxels with physical gamma indices (PGI) >1. We propose a new radiobiological gamma index (RGI) to quantify the radiobiological effects of TCP and NTCP and calculate radiobiological gamma passing rates. Results: The mean RGI gamma passing rates for prostate cases were significantly different compared with those of PGI (P<.03–.001). The mean RGI gamma passing rates for H&N cases (except for GTV) were significantly different compared with those of PGI (P<.001). Differences in gamma passing rates between PGI and RGI were due to dose differences between the planned and predicted dose distributions. Radiobiological gamma distribution was visualized to identify areas where the dose was radiobiologically important. Conclusions: RGI was proposed to integrate radiobiological effects into PGI. This index would assist physicians and medical physicists not only in physical evaluations of treatment delivery accuracy, but also in clinical evaluations of predicted dose distribution.

  1. Hydrocarbon pneumonia

    Science.gov (United States)

    Pneumonia - hydrocarbon ... Coughing Fever Shortness of breath Smell of a hydrocarbon product on the breath Stupor (decreased level of ... Most children who drink or inhale hydrocarbon products and develop ... hydrocarbons may lead to rapid respiratory failure and death.

  2. Flatfoot diagnosis by a unique bimodal distribution of footprint index in children.

    Directory of Open Access Journals (Sweden)

    Chia-Hsieh Chang

    Full Text Available BACKGROUND: More than 1000 scientific papers have been devoted to flatfoot issue. However, a bimodal distribution of flatfoot indices in school-aged children has never been discovered. The purposes of this study were to establish a new classification of flatfoot by characteristic in frequency distribution of footprint index and to endue the classification with discrepancy in physical fitness. METHODS/PRINCIPAL FINDINGS: In a longitudinal survey of physical fitness and body structure, weight bearing footprints and 3 physical fitness related tests were measured in 1228 school-aged children. Frequency distribution of initial data was tested by Kolmogorov-Smirnov test for normality and a unique bimodal distribution of footprint index was identified. The frequency distribution of footprint index manifests two distinct modes, flatfoot and non-flatfoot, by deconvolution and bootstrapping procedures. A constant intersection value of 1.0 in Staheli's arch index and 0.6 in Chippaux-Smirak index could distinguish the two modes of children, and the value was constant in different age, sex, and weight status. The performance of the one leg balance was inferior in flatfoot girls (median, 4.0 seconds in flatfoot girls vs. 4.3 seconds in non-flatfoot girls, p = 0.04, 95% CI 0.404-0.484. DISCUSSION: The natural bimodality lends itself to a flatfoot classification. Bimodality suggests development of the child's foot arch would be a leap from one state to another, rather than a continuous growth as body height and weight. The underlying dynamics of the human foot arch and motor development will trigger research prospects.

  3. Measurements of vertical distributions of bromine oxide, iodine oxide, oxygenated hydrocarbons and ozone over the Eastern Tropical Pacific Ocean

    Science.gov (United States)

    Volkamer, R. M.; Baidar, S.; Dix, B. K.; Apel, E. C.; Hornbrook, R. S.; Pierce, B.; Gao, R.

    2012-12-01

    As part of the Tropical Ocean tRoposphere Exchange of Reactive halogen species and Oxygenated VOC (TORERO) field experiment 17 research flights were conducted with the NSF/NCAR GV aircraft equipped with a combination of chemical in-situ sensors, and remote sensing instruments to characterize air-sea exchange of reactive halogen species, oxygenated hydrocarbons, and aerosols, and their transport into the free troposphere, over different ocean environments of the Humboldt current in the Eastern Tropical Pacific Ocean (42S to 14N Lat.; 70W to 105W Long.). This presentation presents measurements of the spatial distributions of halogen oxide radicals, oxygenated hydrocarbons, and discusses their impact on ozone destruction rates, and the oxidation of atmospheric mercury. Air mass history is assessed by means of the Real-time Air Quality Modeling System (RAQMS), a global meteorological, chemical and aerosol assimilation/forecasting system that assimilates real-time stratospheric ozone retrievals from the Microwave Limb Sounder (MLS), total column ozone from the Ozone Monitoring Instrument (OMI), and aerosol optical depth (AOD) from the Moderate Resolution Imaging Spectroradiometer (MODIS). Reactive halogen species and organic carbon are important in the atmosphere, because they modify HOx radical abundances, influence the reactive chemistry and lifetime of climate active gases (e.g., ozone, methane, dimethyl sulfide), modify aerosol-cloud interactions; halogen radicals can further oxidize atmospheric mercury.

  4. Boiling Point Distribution of Hydrocarbon Types in Diesel Using Solid-Phase Extraction Followed by GC/FID-EIMS

    Institute of Scientific and Technical Information of China (English)

    Li Chengwei; Tian Songbai; Liu Zelong; Zhu Xinyi

    2008-01-01

    In this paper, a method was established to determine the boiling point distribution of hydro-carbon types in diesel. The diesel sample was separated into the saturate and aromatic fractions by means of solid-phase extraction (SPE), and each fraction was analyzed by GC/FID-EIMS. According to the relationship between boiling point and retention time of n-paraffins in the chromatogram, the percent-ages of saturates and aromatics at each temperature interval were calculated. According to the average mass spectra of the saturate and aromatic fractions at each temperature interval, the hydrocarbon types of the sample were identified through summation of characteristic mass fragments. Using this method,the changes in composition of diesel during hydrotreating process were studied. The results showed that hydrogenation of aromatics is the main reaction during the hydrotreating process. The more rings the aromatics have, the easier the hydrogenation reactions would take place. The aromatics were converted into cycloparaffins via the hydrogenation and saturation process, leading to an increase in low boiling point fractions in the hydrotreated oil.

  5. Distribution and sources of polycyclic aromatic hydrocarbons in main aquacultural areas in Guangdong, China

    Institute of Scientific and Technical Information of China (English)

    MASKAOUI Khalid; HU Zhong; ZHOU Junliang; HAN Yali

    2007-01-01

    The environmental quality status of Daya Bay (22.56-22.77°N, 114.51-114.73°E), a main aquaculture area in Guangdong of China, was investigated using 16 polycyclic aromatic hydrocarbon (PAH) sediment samples of the bay. The total concentrations of 16 PAHs varied from 115 to 1 134 ng/g dry weight. The PAH composition pattern in sediments suggest dominance of 4-ring PAHs in Sites 2 and 4, and the ratio of certain related PAHs indicated important pyrolytic and petrogenic sources. The results enhance the understanding of current contamination levels and make a better assessment of likely impacts of organic contamination on ecosystems and the sustainability of local aquaculture in the area especially after the establishment of the Nuclear Power Station by the bay.

  6. Polycyclic aromatic hydrocarbons in coastal sediment of klang strait, Malaysia: distribution pattern, risk assessment and sources.

    Directory of Open Access Journals (Sweden)

    Seyedeh Belin Tavakoly Sany

    Full Text Available Concentration, source, and ecological risk of polycyclic aromatic hydrocarbons (PAHs were investigated in 22 stations from surface sediments in the areas of anthropogenic pollution in the Klang Strait (Malaysia. The total PAH level in the Klang Strait sediment was 994.02±918.1 µg/kg dw. The highest concentration was observed in stations near the coastline and mouth of the Klang River. These locations were dominated by high molecular weight PAHs. The results showed both pyrogenic and petrogenic sources are main sources of PAHs. Further analyses indicated that PAHs primarily originated from pyrogenic sources (coal combustion and vehicular emissions, with significant contribution from petroleum inputs. Regarding ecological risk estimation, only station 13 was moderately polluted, the rest of the stations suffered rare or slight adverse biological effects with PAH exposure in surface sediment, suggesting that PAHs are not considered as contaminants of concern in the Klang Strait.

  7. VERTICAL DISTRIBUTION OF C{sub 3}-HYDROCARBONS IN THE STRATOSPHERE OF TITAN

    Energy Technology Data Exchange (ETDEWEB)

    Li, Cheng; Gao, Peter; Yung, Yuk [Division of Geological and Planetary Science, California Institute of Technology, Pasadena, CA 91125 (United States); Zhang, Xi [Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ 85721 (United States)

    2015-04-20

    Motivated by the recent detection of propene (C{sub 3}H{sub 6}) in the atmosphere of Titan, we use a one-dimensional Titan photochemical model with an updated eddy diffusion profile to systematically study the vertical profiles of the stable species in the C{sub 3}-hydrocarbon family. We find that the stratospheric volume mixing ratio of propene (C{sub 3}H{sub 6}) peaks at 150 km with a value of 5 × 10{sup −9}, which is in good agreement with recent observations by the Composite Infrared Spectrometer on the Cassini spacecraft. Another important species that is currently missing from the hydrocarbon family in Titan's stratosphere is allene (CH{sub 2}CCH{sub 2}), an isomer of methylacetylene (CH{sub 3}C{sub 2}H). We predict that its mixing ratio in the stratosphere is about 10{sup −9}, which is on the margin of the detection limit. CH{sub 2}CCH{sub 2} and CH{sub 3}C{sub 2}H equilibrate at a constant ratio in the stratosphere by hydrogen-exchanging reactions. Thus, by precisely measuring the ratio of CH{sub 2}CCH{sub 2} to CH{sub 3}C{sub 2}H, the abundance of atomic hydrogen in the atmosphere can be inferred. No direct yield for the production of cyclopropane (c-C{sub 3}H{sub 6}) is available. From the discharge experiments of Navarro-González and Ramírez, the abundance of cyclopropane is estimated to be 100 times less than that of C{sub 3}H{sub 6}.

  8. Size distributions of polycyclic aromatic hydrocarbons in urban atmosphere: sorption mechanism and source contributions to respiratory deposition

    Science.gov (United States)

    Lv, Yan; Li, Xiang; Xu, Ting Ting; Cheng, Tian Tao; Yang, Xin; Chen, Jian Min; Iinuma, Yoshiteru; Herrmann, Hartmut

    2016-03-01

    In order to better understand the particle size distribution of polycyclic aromatic hydrocarbons (PAHs) and their source contribution to human respiratory system, size-resolved PAHs have been studied in ambient aerosols at a megacity Shanghai site during a 1-year period (2012-2013). The results showed the PAHs had a bimodal distribution with one mode peak in the fine-particle size range (0.4-2.1 µm) and another mode peak in the coarse-particle size range (3.3-9.0 µm). Along with the increase in ring number of PAHs, the intensity of the fine-mode peak increased, while the coarse-mode peak decreased. Plotting of log(PAH / PM) against log(Dp) showed that all slope values were above -1, suggesting that multiple mechanisms (adsorption and absorption) controlled the particle size distribution of PAHs. The total deposition flux of PAHs in the respiratory tract was calculated as being 8.8 ± 2.0 ng h-1. The highest lifetime cancer risk (LCR) was estimated at 1.5 × 10-6, which exceeded the unit risk of 10-6. The LCR values presented here were mainly influenced by accumulation mode PAHs which came from biomass burning (24 %), coal combustion (25 %), and vehicular emission (27 %). The present study provides us with a mechanistic understanding of the particle size distribution of PAHs and their transport in the human respiratory system, which can help develop better source control strategies.

  9. STANDARDIZED PRECIPITATION INDEX (SPI CALCULATED WITH THE USE OF LOG-NORMAL DISTRIBUTION

    Directory of Open Access Journals (Sweden)

    Edward Gąsiorek

    2014-10-01

    Full Text Available The problem analyzed in this paper is the continuation of research conducted on data from Wrocław-Swojec agro- and hydrometeorology observatory in 1964–2009 period and published in “Infrastruktura i Ekologia Terenów Wiejskich” nr 3/III/2012, pp. 197–208. The paper concerns two methods of calculation of standardized precipitation index (SPI. The first one extracts SPI directly from gamma distribution, since monthly precipitation sums in the 1964–2009 period in Wrocław are gamma distributed. The second method is based on the transformations of data leading to normal distribution. The authors calculate SPI with the use of log-normal distribution and confront it with values obtained by gamma and normal distributions. The aim of this paper is to comparatively assess the SPI values obtained with those three different methods.

  10. On retrieving refractive index of dust-like particles using shape distributions of ellipsoids

    Directory of Open Access Journals (Sweden)

    O. Kemppinen

    2015-06-01

    Full Text Available Ellipsoid-based retrievals are widely used for investigating optical properties of non-ellipsoidal atmospheric particles, such as dust. In this work, the applicability of ellipsoids for retrieving the refractive index of dust-like target model particles from scattering data is investigated. This is a pure modeling study, where stereogrammetrically retrieved model dust shapes are used as targets. The primary objective is to study whether the refractive index of these target particles can be inverted from their scattering matrices using ellipsoidal model particles. To achieve this, first scattering matrices for the target model particles with known refractive indices are computed. On one hand, a non-negative least squares fitting is performed, separately for different scattering matrix elements, for a set of 46 differently shaped ellipsoids by using different assumed refractive indices. Then, the fitting error is evaluated to establish whether the ellipsoidal base best matches the target scattering matrix elements when the correct refractive index is assumed. On the other hand, we also test whether the ellipsoids best match the target data with the correct refractive index, if a predefined (uniform shape distribution for ellipsoids is assumed, instead of optimizing the shape distribution separately for each tested refractive index. The results show that for both of these approaches using the ellipsoids with the true refractive index produces good results, but also that for each element even better results are acquired by using wrong refractive indices. In addition, the best agreement is found for different scattering matrix elements using different refractive indices. The findings imply that the inversion of refractive index of non-ellipsoidal particles may not be reliable using ellipsoids. Furthermore, it is demonstrated that the differences in single-scattering albedo and asymmetry parameter between the best-match ellipsoid ensemble and the

  11. On retrieving refractive index of dust-like particles using shape distributions of ellipsoids

    Science.gov (United States)

    Kemppinen, O.; Nousiainen, T.; Merikallio, S.; Räisänen, P.

    2015-06-01

    Ellipsoid-based retrievals are widely used for investigating optical properties of non-ellipsoidal atmospheric particles, such as dust. In this work, the applicability of ellipsoids for retrieving the refractive index of dust-like target model particles from scattering data is investigated. This is a pure modeling study, where stereogrammetrically retrieved model dust shapes are used as targets. The primary objective is to study whether the refractive index of these target particles can be inverted from their scattering matrices using ellipsoidal model particles. To achieve this, first scattering matrices for the target model particles with known refractive indices are computed. On one hand, a non-negative least squares fitting is performed, separately for different scattering matrix elements, for a set of 46 differently shaped ellipsoids by using different assumed refractive indices. Then, the fitting error is evaluated to establish whether the ellipsoidal base best matches the target scattering matrix elements when the correct refractive index is assumed. On the other hand, we also test whether the ellipsoids best match the target data with the correct refractive index, if a predefined (uniform) shape distribution for ellipsoids is assumed, instead of optimizing the shape distribution separately for each tested refractive index. The results show that for both of these approaches using the ellipsoids with the true refractive index produces good results, but also that for each element even better results are acquired by using wrong refractive indices. In addition, the best agreement is found for different scattering matrix elements using different refractive indices. The findings imply that the inversion of refractive index of non-ellipsoidal particles may not be reliable using ellipsoids. Furthermore, it is demonstrated that the differences in single-scattering albedo and asymmetry parameter between the best-match ellipsoid ensemble and the target particles may

  12. Distribution, sources, and ecological risk assessment of polycyclic aromatic hydrocarbons in surface sediments from the Nantong Coast, China.

    Science.gov (United States)

    Liu, Na; Li, Xian; Zhang, Daolai; Liu, Qiang; Xiang, Lihui; Liu, Ke; Yan, Dongyun; Li, Yue

    2017-01-15

    The distribution, sources, and ecological risk assessment of 16 polycyclic aromatic hydrocarbons (PAHs) in surface sediments from the Nantong coast in China were investigated. The results indicated that the total concentrations of the 16 PAHs in the surface sediments from the study area ranged from 1.4 to 87.1ngg(-1) dw (mean value 19.9ngg(-1) dw), which were generally low compared to the adjacent offshore area and other coastal zones around the world. The selected PAH ratios and the principal components analysis for each site showed that petroleum combustion and petrogenic pollution (mainly caused by petroleum spills) were the dominant PAHs sources in the surface sediments of the coast. The ecological risk assessment indicated that most of the individual PAHs had few negative effects in this area.

  13. Distribution and sources of polycyclic aromatic hydrocarbons in surface sediments from the Bering Sea and western Arctic Ocean.

    Science.gov (United States)

    Zhao, Mengwei; Wang, Weiguo; Liu, Yanguang; Dong, Linsen; Jiao, Liping; Hu, Limin; Fan, Dejiang

    2016-03-15

    To analyze the distribution and sources of polycyclic aromatic hydrocarbons (PAHs) and evaluate their potential ecological risks, the concentrations of 16 PAHs were measured in 43 surface sediment samples from the Bering Sea and western Arctic Ocean. Total PAH (tPAH) concentrations ranged from 36.95 to 150.21 ng/g (dry weight). In descending order, the surface sediment tPAH concentrations were as follows: Canada Basin>northern Chukchi Sea>Chukchi Basin>southern Chukchi Sea>Aleutian Basin>Makarov Basin>Bering Sea shelf. The Bering Sea and western Arctic Ocean mainly received PAHs of pyrogenic origin due to pollution caused by the incomplete combustion of fossil fuels. The concentrations of PAHs in the sediments of the study areas did not exceed effects range low (ERL) values.

  14. Distribution of aliphatic hydrocarbons, polycyclic aromatic hydrocarbons and organochlorinated pollutants in deep-sea sediments of the Southern Cretan margin, Eastern Mediterranean Sea: a baseline assessment.

    Science.gov (United States)

    Mandalakis, Manolis; Polymenakou, Paraskevi N; Tselepides, Anastasios; Lampadariou, Nikolaos

    2014-07-01

    Deep sediments from the southern Cretan margin were analyzed to establish baseline levels for various types of organic pollutants before the anticipated intensification of anthropogenic activities. The total concentration of aliphatic hydrocarbons (ΣAH:326-3758ngg(-1), dry weight) was similar to those reported for deep sediments of the western Mediterranean Sea, while considerably lower levels were measured for polycyclic aromatic hydrocarbons (ΣPAH:9-60ngg(-1)). Source-diagnostic ratios suggested that the aliphatic hydrocarbons in sediments were mainly of terrestrial biogenic origin, while polycyclic aromatic hydrocarbons stemmed from the deposition of long-range transported combustion aerosols. Among the organochlorinated compounds analyzed, β-hexachlorocyclohexane (β-HCH:222-7052pgg(-1)), 1,1,1-trichloro-2,2-bis(4-chlorophenyl)ethane (p,p'-DDT:37-2236pgg(-1)) and polychlorinated biphenyls (ΣPCB:38-1182pgg(-1)) showed the highest abundance in sediments. The presence of HCHs and PCBs was attributed to historical inputs that have undergone extensive weathering, whereas an ongoing fresh input was suggested for p,p'-DDT. Multiple linear regression analysis revealed that the levels of the various pollutants in sediments were controlled by different factors, but with organic carbon content playing a prominent role in most cases.

  15. [Distribution and source apportionment of polycyclic aromatic hydrocarbons (PAHs) in urban rainfall runoff].

    Science.gov (United States)

    Wu, Zi-Lan; Yang, Yi; Liu, Min; Lu, Min; Yu, Ying-Peng; Wang, Qing; Zheng, Xin

    2014-11-01

    Runoff samples were collected from traffic roads, campus, residential road and roof in a typical rain event. Polycyclic aromatic hydrocarbons (PAHs) in both dissolved and particle phases were investigated at impervious surfaces. The PAHs wash-off process at different monitoring sites was analyzed. The scatters of first flush were conducted in a method of fitting power function to quantitatively assess the magnitude of first flush effect (FFE). The sources of PAHs were identified using factor analysis. The results showed that PAHs concentrations in runoff samples varied from 317.21 ng x L(-1) to 10364.3 ng x L(-1) with the maximal and minimal contents of PAHs found on Longwu Road and campus, respectively. The values of event mean concentration ( EMC) varied considerably at different sampling sites. The concentration of washed-off pollutant generally decreased with runoff duration, which showed an obvious attenuation trend. The runoff process indicated the occurrence of FFE at different levels. PAHs mainly came from the incomplete combustion of fossil fuels, oil leakage and coking, and the contribution of each source was different in accordance with various surfaces.

  16. Distribution and Sources of Polycyclic Aromatic Hydrocarbon (PAH) in Marine Environment of China

    Institute of Scientific and Technical Information of China (English)

    ZHENG Jinshu(郑金树); Bruce J. Richardson; O.Shouming; ZHENG Jianhua(郑建华)

    2004-01-01

    Polycyclic aromatic hydrocarbons (PAHs) are potentially carcinogenic and mutagenic compounds that have raised considerable environmental concern. The highest concentrations of PAHs in the coastal sediment samples in China was 5.8-11.0μg/g (dry weight) in the core from the Huangpu River, Shanghai. The second highest concentration of PAHs was 4.42μg/g (dry weight) in surface sediment of Victoria Harbour in Hong Kong, and 5.73μg/g (dry weight) in sediment of Jiaozhou Bay, Qingdao City. The low concentrations of PAHs were always in the sediments far away from industrial zones and cities, and ranged from 0.10 to 0.30μg/g (dry weight). Several environmental parameters are considered for the identification of sources of PAHs in marine environment. High proportion of naphthalene, low molecular weight PAHs and alkylated PAHs, plus high ratio of phenanthrene to anthracene (>15) and low ratio of fluoranthene to pyrene (<1) suggested a petrogenic source. According to these parameters, the Changjiang (Yangtze) River estuary of Shanghai, Jiaozhou Bay of Qingdao City, Zhujiang (Pearl) River mouth, Jiulong River mouth and most of Hong Kong coastal waters were heavily contaminated by PAHs from petrogenic sources. However, PAHs in rural coastal areas were dominated by pyrolytic origin PAHs. This review clearly showed that oil pollution and incomplete combustion of oil, coal and biomass are the main reason for PAHs anormalies in the study areas.

  17. Distribution and risk assessment of polycyclic aromatic hydrocarbons (PAHs) from Liaohe estuarine wetland soils.

    Science.gov (United States)

    Lang, Yinhai; Wang, Nannan; Gao, Huiwang; Bai, Jie

    2012-09-01

    Thirty-one surface soil samples were collected from Liaohe estuarine wetland in October 2008 and May and August 2009. The concentrations of 16 polycyclic aromatic hydrocarbons (PAHs), identified as priority pollutants by the US EPA, were measured by gas chromatography. PAHs were predominated by three- and four-ring compounds. The total PAH concentrations ranged from 704.7 to 1,804.5 μg/kg with a mean value of 1,001.9 μg/kg in October 2008, from 509.7 to 1,936.9 μg/kg with an average of 887.1 μg/kg in May 2009, and from 293.4 to 1,735.9 μg/kg with a mean value of 675.4 μg/kg in August 2009. The PAH concentration detected at most sites shared the same pattern, with maximum concentrations during the autumn (October) and minimum concentrations during the summer (August). The ecological risk assessment of PAHs showed that adverse effects would occasionally occur in the soils from Liaohe estuarine wetland based on the effects range low (ERL)/effects range median and the toxic equivalency factors. The results revealed that some of the individual PAHs were in excess of ERL which implied possible acute adverse biological effects. The BaP(eq) values in some sites surpassed the Dutch target value. Therewith, quite a part of soils in the wetland were subjected to potential ecological risks.

  18. Characterization and distribution of polycyclic aromatic hydrocarbon in sediments of Haihe River, Tianjin, China

    Institute of Scientific and Technical Information of China (English)

    JIANG Bin; ZHENG Hai-long; HUANG Guo-qiang; DING Hui; LI Xin-gang; SUO Hong-tu; LI Rui

    2007-01-01

    In this study sediment samples were collected from 13 sites of Haihe River in Tianjin City,China,sixteen of priority polycyclic aromatic hydrocarbons(PAHs)listed in USEPA were analyzed by means of GC-MS.The total concentrations of PAH ranged from 774.81 to 255371.91 ng/g dw,and two to four rings of PAHs were dominant in sediment samples.Molecular ratios,such as phenanthrene/anthracene.fluoranthene/pyrene and low-molecular-weight PAH/high-molecular-weight PAH,were used to study the possible sources of pollution.It indicated a mixed pattem of parolytic and petrogenic inputs of PAHs in sediments in Haihe River.The petrogenic PAHs may be mainly derived from the leakage of refined products,e.g.,gasoline,diesel fuel and fuel oil vehicle traffics or gas stations from urban area.The pyrolytic PAHs might be from the discharge of industrial wastewater and the emission of atmospheric particles from petrochemical factories.In addition.the levels of PAHs in the urban and industrial areas are far beyond the values reported from other rivers and marine systems reported.This situation may be due to polluted discharging from some petrochemical industrial manufactories and worse traffiC conditions in Tianjin.

  19. Polycyclic aromatic hydrocarbons in surface sediment from Yangpu Bay, China: Distribution, sources and risk assessment.

    Science.gov (United States)

    Li, Ping; Diao, Xiaoping; Zhang, Yu; Xie, Yanli; Yang, Fei; Zhou, Hailong; Han, Qian; Wang, Fuqiang; Cheng, Huamin; Wang, Haihua

    2015-10-15

    The study investigated the occurrence of polycyclic aromatic hydrocarbons (PAHs) in the surface sediment from eleven sites in Yangpu Bay, China in December 2013 (winter) and July 2014 (summer). The 16 US EPA priority PAHs were found in the range of 1583.2-5701.7 ng/g dry weights with an average of 3134.7 ± 1241.3 ng/g in winter and ranged from 2161.8 to 4527.2 ng/g with an average of 3016.6 ± 748.0 ng/g in summer, respectively. The concentrations of the PAHs tended to be relatively high in comparison with other areas from the literatures. The identification using molecular indices analysis indicated that the PAHs originated mainly from pyrogenic and petrogenic sources in most of the sites. According to principle component analysis-multiple linear regression (PCA/MLR) for their source apportionment, the main sources of PAHs were vehicle emissions, petroleum products and biomass combustion. The risk assessment using international sediments quality guidelines and sediments quality criteria indicated that several PAHs, such as Nap, Flu, Phe, Ace, Acy and BghiP in most of the sites would potentially affect organisms in Yangpu Bay.

  20. Size- and density-distributions and sources of polycyclic aromatic hydrocarbons in urban road dust.

    Science.gov (United States)

    Murakami, Michio; Nakajima, Fumiyuki; Furumai, Hiroaki

    2005-11-01

    Polycyclic aromatic hydrocarbons (PAHs) present in size- and density-fractionated road dust were measured to identify the important fractions in urban runoff and to analyse their sources. Road dust was collected from a residential area (Shakujii) and a heavy traffic area (Hongo Street). The sampling of road dust from the residential area was conducted twice in different seasons (autumn and winter). The collected road dust was separated into three or four size-fractions and further fractionated into light (1.7 g/cm3) fractions by using cesium chloride solution. Light particles constituted only 4.0+/-1.4%, 0.69+/-0.03% and 3.4+/-1.0% of the road dust by weight for Shakujii (November), Shakujii (February) and Hongo Street, respectively but contained 28+/-10%, 33+/-3% and 44+/-8% of the total PAHs, respectively. The PAH contents in the light fractions were 1-2 orders of magnitude higher than those in the heavy fractions. In the light fractions, the 12PAH contents in February were significantly higher than the 12PAH contents in November (P0.05). Cluster analysis revealed that there was a significant difference in the PAH profiles between locations rather than between size-fractions, density-fractions and sampling times. Multiple regression analysis indicated that asphalt/pavement was the major source of Shakujii road dust, and that tyre and diesel vehicle exhaust were the major sources of finer and coarser fractions collected from Hongo Street road dust, respectively.

  1. Distribution and sources of polycyclic aromatic hydrocarbon (PAH) in marine environment of China

    Energy Technology Data Exchange (ETDEWEB)

    Zheng Jinshu; Bruce J. Richardson; O. Shouming; Zheng Jianhua [Third Institute of Oceanography, Xiamen (China). State Oceanic Administration

    2004-07-01

    Polycyclic aromatic hydrocarbons (PAHs) are potentially carcinogenic and mutagenic compounds that have raised considerable environmental concern. The highest concentrations of PAHs in the coastal sediment samples in China was 5.8-11.0 {mu}g/g (dry weight) in the core from the Huangpu River, Shanghai. The second highest concentration of PAHs was 4.42 {mu}g/g (dry weight) in surface sediment of Victoria Harbour in Hong Kong, and 5.73 {mu}g/g (dry weight) in sediment of Jiaozhou Bay, Qingdao City. The low concentrations of PAHs were always in the sediments far away from industrial zones and cities, and ranged from 0.10 to 0.30 {mu}g/g (dry weight). Several environmental parameters are considered for the identification of sources of PAHs in marine environment. High proportion of naphthalene, low molecular weight PAHs and alkylated PAHs, plus high ratio of phenanthrene to anthracene ({gt}15) and low ratio of fluoranthene to pyrene ({lt}1) suggested a petrogenic source. According to these parameters, the Changjiang (Yangtze) River estuary of Shanghai, Jiaozhou Bay of Qingdao City, Zhujiang (Pearl) River mouth, Jiulong River mouth and most of Hong Kong coastal waters were heavily contaminated by PAHs from petrogenic sources. However, PAHs in rural coastal areas were dominated by pyrolytic origin PAHs. This review clearly showed that oil pollution and incomplete combustion of oil, coal and biomass are the main reason for PAHs anormalies in the study areas.

  2. Particle size distribution of n-alkanes and polycyclic aromatic hydrocarbons (PAHS) in urban and industrial aerosol of Algiers, Algeria.

    Science.gov (United States)

    Ladji, R; Yassaa, N; Balducci, C; Cecinato, A

    2014-02-01

    The distribution of ambient air n-alkanes and polycyclic aromatic hydrocarbons (PAHs) associated to particles with aerodynamic diameters lesser than 10 μm (PM(10)) into six fractions (five stages and a backup filter) was studied for the first time in Algeria. Investigation took place during September of 2007 at an urban and industrial site of Algiers. Size-resolved samples (particles ≤ 1.5 μm in both urban and industrial atmosphere. In both cases, the n-alkane contents exhibited bimodal or weakly bimodal distribution peaking at the 0.95-1.5-μm size range within the fine mode and at 7.3-10 μm in the coarse mode. Low molecular weight PAHs displayed bimodal patterns peaking at 0.49-0.95 and 7.3-10 μm, while high molecular weight PAHs exhibited mono-modal distribution with maximum in the particles ≤ 0.95 μm in diameter which could induce adverse health effects to the population living in these areas.

  3. Global solar irradiance in Cordoba: Clearness index distributions conditioned to the optical air mass

    Energy Technology Data Exchange (ETDEWEB)

    Varo, M.; Pedros, G.; Martinez-Jimenez, P. [Applied Physics Department, EPS, University of Cordoba, C/Maria Virgen y Madre s/n., Cordoba 14004 (Spain); Aguilera, M.J. [Applied Physics Department, ETSIAM, University of Cordoba, C/Menendez Pidal, s/n., Cordoba, 14004 (Spain)

    2006-07-15

    The biological and photochemical effects of solar radiation and solar energy applications make it really important to characterize the variability of this component. In view of the fact that the clearness index indicates not only the level of availability of solar radiation but also the changes in atmospheric conditions in a given location, since the classic Liu and Jordan study, many papers have dealt with its statistical distribution. Specifically, Tovar et al. [Tovar J, Olmo FJ, Alados-Arboledas L. Solar Energy 1998;62(6):387-393] proposed a model to represent the probability density distributions of the instantaneous clearness index conditioned to the optical air mass from measurements recorded in Granada (Spain). In this work, we have proved the applicability of this model in a different location, Cordoba (Spain), finding that the parameters for fitting the model depend on both the optical air mass and the geographic and climatic conditions. (author)

  4. Distributed Web-Scale Infrastructure For Crawling, Indexing And Search With Semantic Support

    Directory of Open Access Journals (Sweden)

    Stefan Dlugolinsky

    2012-01-01

    Full Text Available In this paper, we describe our work in progress in the scope of web-scale informationextraction and information retrieval utilizing distributed computing. Wepresent a distributed architecture built on top of the MapReduce paradigm forinformation retrieval, information processing and intelligent search supportedby spatial capabilities. Proposed architecture is focused on crawling documentsin several different formats, information extraction, lightweight semantic annotationof the extracted information, indexing of extracted information andfinally on indexing of documents based on the geo-spatial information foundin a document. We demonstrate the architecture on two use cases, where thefirst is search in job offers retrieved from the LinkedIn portal and the second issearch in BBC news feeds and discuss several problems we had to face duringthe implementation. We also discuss spatial search applications for both casesbecause both LinkedIn job offer pages and BBC news feeds contain a lot of spatialinformation to extract and process.

  5. Geographic Distribution of Environmental Relative Moldiness Index Molds in USA Homes

    Directory of Open Access Journals (Sweden)

    Stephen Vesper

    2011-01-01

    Full Text Available Objective. The objective of this study was to quantify and describe the distribution of the 36 molds that make up the Environmental Relative Moldiness Index (ERMI. Materials and Methods. As part of the 2006 American Healthy Homes Survey, settled dust samples were analyzed by mold-specific quantitative PCR (MSQPCR for the 36 ERMI molds. Each species' geographical distribution pattern was examined individually, followed by partitioning analysis in order to identify spatially meaningful patterns. For mapping, the 36 mold populations were divided into disjoint clusters on the basis of their standardized concentrations, and First Principal Component (FPC scores were computed. Results and Conclusions. The partitioning analyses failed to uncover a valid partitioning that yielded compact, well-separated partitions with systematic spatial distributions, either on global or local criteria. Disjoint variable clustering resulted in seven mold clusters. The 36 molds and ERMI values themselves were found to be heterogeneously distributed across the United States of America (USA.

  6. The retest distribution of the visual field summary index mean deviation is close to normal.

    Science.gov (United States)

    Anderson, Andrew J; Cheng, Allan C Y; Lau, Samantha; Le-Pham, Anne; Liu, Victor; Rahman, Farahnaz

    2016-09-01

    When modelling optimum strategies for how best to determine visual field progression in glaucoma, it is commonly assumed that the summary index mean deviation (MD) is normally distributed on repeated testing. Here we tested whether this assumption is correct. We obtained 42 reliable 24-2 Humphrey Field Analyzer SITA standard visual fields from one eye of each of five healthy young observers, with the first two fields excluded from analysis. Previous work has shown that although MD variability is higher in glaucoma, the shape of the MD distribution is similar to that found in normal visual fields. A Shapiro-Wilks test determined any deviation from normality. Kurtosis values for the distributions were also calculated. Data from each observer passed the Shapiro-Wilks normality test. Bootstrapped 95% confidence intervals for kurtosis encompassed the value for a normal distribution in four of five observers. When examined with quantile-quantile plots, distributions were close to normal and showed no consistent deviations across observers. The retest distribution of MD is not significantly different from normal in healthy observers, and so is likely also normally distributed - or nearly so - in those with glaucoma. Our results increase our confidence in the results of influential modelling studies where a normal distribution for MD was assumed. © 2016 The Authors Ophthalmic & Physiological Optics © 2016 The College of Optometrists.

  7. Historical Distribution of Polycyclic Aromatic Hydrocarbons in Shallow Sediments from Lake Chapala, Mexico

    Science.gov (United States)

    Zárate-Del Valle, P. F.; Macías-Pérez, M. P.; Barajas-Martínez, C. D.; Gómez-Hermosillo, C. M.

    2008-12-01

    The incomplete combustion of fossil fuels and burning of vegetation and other organic materials release into the environment pollutants like polycyclic aromatic hydrocarbons (PAHs) which are ubiquitous pollutants. The environmental behavior of PAHs is characterized by very low solubility, high hydrophobic sorptive capacity (kow), low volatility and general chemical stability. These characteristics mean, in practice, that PAHs are environmentally persistent compounds that in aquatic systems, are strongly held to solid surfaces present as both suspended particles and bottom sediment. Additionally, because of their high partition to organic carbon, PAHs show a high rate of bioconcentration and an easy way to enter the food chain. A benthos type sediment core was collected (CHA-C: N20° 15.105'; W103° 03.104') from the depocenter of lake Chapala. The first 40 cm of the sedimentary column representing an ecological history of ~ 150 years (210Pb dating) were cutted every 2 cm (n=20). For each core sectioned, the presence of PAHs was evaluated by GC-MS following methods from the USEPA (EPA 3540C, EPA 3620C, EPA 8270C). For the first 30 cm deep only products resulting of PAHs degradation were identified, namely: Butilisobutilphtalate, 1,2-benzenedicarboxaldehyde, phenol and, cinnamaldehyde; we attibute the presence of these products to a faster transformation of PAHs by photo and metabolic degradation as well as to chemical oxydation. For the 30-40 cm deep, the presence of the follwing PAHs was detected: 1H-indene, 1,2- difluor-3,4,5-trimetylbenzenethylnaphthalene, naphthalene, anthracene, and phenantren. A study is in progress to determine the presence of PAHs in other sites of the lake. We conclude that shallow sediment (40 cm deep) from Lake Chapala could constitute a potentially large pool of PAHs.

  8. Spatial and temporal distribution of polycyclic aromatic hydrocarbons (PAHs) in the atmosphere of Xiamen, China

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Jinping [Key Lab of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021 (China); Guangdong Environmental Monitoring Centre, Guangzhou 510308 (China); Zhang, Fuwang; Xu, Lingling [Key Lab of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021 (China); Graduate School of Chinese Academy of Sciences, Beijing 100049 (China); Chen, Jinsheng, E-mail: jschen@iue.ac.cn [Key Lab of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021 (China); Xu, Ya [Key Lab of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021 (China); Graduate School of Chinese Academy of Sciences, Beijing 100049 (China)

    2011-11-15

    An intensive sampling program was conducted from October 2008 to September 2009 at the five different environmental sites in Xiamen, Fujian Province, to study the spatial and temporal characteristics of Polycyclic Aromatic Hydrocarbons (PAHs) in the gaseous and particulate phase, respectively. The PAHs concentrations at different sites were quite distinct during four seasons. The average concentrations of PAHs in winter were about 8.4 times higher than those in spring, and the concentrations of background were 0.56 times lower than those of industrial area. In addition, the higher temperature in summer affected the particle/gas partitioning of PAHs and led to the higher concentrations of gaseous PAHs. Diagnostic ratios of PAHs, which were employed to indicate the primary sources of PAHs in Xiamen, showed that the traffic vehicle exhaust was the largest contributor and the primary source for PAHs in Xiamen, especially in urban area; while the stationary combustion processes, such as petrochemical factories and power plants, were mainly responsible for PAHs sources in the industrial areas. The health risk of PAHs in the particulate phase was higher than those of the gaseous phase at the five sampling sites. The average toxic equivalent (BaP{sub eq}) of the benzo[a]pyrene values for PAHs were 0.14, 0.32, 1.38 and 3.59 ng m{sup -3} in spring, summer, autumn and winter, respectively. Furthermore, the results of average BaP{sub eq} in all four seasons indicated that the health risks of particulate PAHs were higher than those of the gaseous PAHs at different sampling sites.

  9. Gas hydrate distribution and hydrocarbon maturation north of the Knipovich Ridge, western Svalbard margin

    Science.gov (United States)

    Dumke, Ines; Burwicz, Ewa B.; Berndt, Christian; Klaeschen, Dirk; Feseker, Tomas; Geissler, Wolfram H.; Sarkar, Sudipta

    2016-03-01

    A bottom-simulating reflector (BSR) occurs west of Svalbard in water depths exceeding 600 m, indicating that gas hydrate occurrence in marine sediments is more widespread in this region than anywhere else on the eastern North Atlantic margin. Regional BSR mapping shows the presence of hydrate and free gas in several areas, with the largest area located north of the Knipovich Ridge, a slow spreading ridge segment of the Mid Atlantic Ridge system. Here heat flow is high (up to 330 mW m-2), increasing toward the ridge axis. The coinciding maxima in across-margin BSR width and heat flow suggest that the Knipovich Ridge influenced methane generation in this area. This is supported by recent finds of thermogenic methane at cold seeps north of the ridge termination. To evaluate the source rock potential on the western Svalbard margin, we applied 1-D petroleum system modeling at three sites. The modeling shows that temperature and burial conditions near the ridge were sufficient to produce hydrocarbons. The bulk petroleum mass produced since the Eocene is at least 5 kt and could be as high as ~0.2 Mt. Most likely, source rocks are Miocene organic-rich sediments and a potential Eocene source rock that may exist in the area if early rifting created sufficiently deep depocenters. Thermogenic methane production could thus explain the more widespread presence of gas hydrates north of the Knipovich Ridge. The presence of microbial methane on the upper continental slope and shelf indicates that the origin of methane on the Svalbard margin varies spatially.

  10. Distribution and origins of polycyclic aromatic hydrocarbons (PAHs) in riverine, estuarine, and marine sediments in Thailand.

    Science.gov (United States)

    Boonyatumanond, Ruchaya; Wattayakorn, Gullaya; Togo, Ayako; Takada, Hideshige

    2006-08-01

    To assess the status of polycyclic aromatic hydrocarbon (PAH) contamination in coastal and riverine environments in Thailand, we collected 42 surface sediment samples from canals, a river, an estuary, and coastal areas in Thailand in 2003 and analyzed them for PAHs with 3-7 benzene rings by gas chromatography-mass spectrometry (GC-MS). The total concentration of PAHs ranged from 6 to 8399 ng/g dry weight. The average total PAH concentrations were 2290+/-2556 ng/g dry weight (n=8) in canals, 263+/-174 (n=11) in the river, 179+/-222 (n=9) in the estuary, and 50+/-56 (n=14) in coastal areas. Comparison of the concentration range with a worldwide survey of sedimentary PAH concentrations ranked PAH contamination in Thai sediments as low to moderate. The ratio of the sum of methylphenanthrenes to phenanthrene (MP/P ratio) allows discrimination of PAH sources between petrogenic (>2) and pyrogenic (Chao Phraya River. These pyrogenic PAHs may be atmospherically transported throughout the nation. Middle and lower reaches of the Chao Phraya River, the river mouth, and the upper Gulf of Thailand showed intermediate concentrations and profiles of PAHs, indicating mixtures of petrogenic and pyrogenic origins. Perylene was abundant in sediments, representing up to approximately 60% of total identified PAHs. High inputs of soil due to frequent heavy rains could contribute to the high perylene abundance in the sediments. Sedimentary PAH concentrations decreased offshore with a half distance of approximately 10 km in the upper Gulf off the mouth of the Chao Phraya River. This is probably due to active deposition of laterally transported riverborne particles.

  11. The cone penetration test and 2D imaging resistivity as tools to simulate the distribution of hydrocarbons in soil

    Science.gov (United States)

    Pérez-Corona, M.; García, J. A.; Taller, G.; Polgár, D.; Bustos, E.; Plank, Z.

    2016-02-01

    The purpose of geophysical electrical surveys is to determine the subsurface resistivity distribution by making measurements on the ground surface. From these measurements, the true resistivity of the subsurface can be estimated. The ground resistivity is related to various geological parameters, such as the mineral and fluid content, porosity and degree of water saturation in the rock. Electrical resistivity surveys have been used for many decades in hydrogeological, mining and geotechnical investigations. More recently, they have been used for environmental surveys. To obtain a more accurate subsurface model than is possible with a simple 1-D model, a more complex model must be used. In a 2-D model, the resistivity values are allowed to vary in one horizontal direction (usually referred to as the x direction) but are assumed to be constant in the other horizontal (the y) direction. A more realistic model would be a fully 3-D model where the resistivity values are allowed to change in all three directions. In this research, a simulation of the cone penetration test and 2D imaging resistivity are used as tools to simulate the distribution of hydrocarbons in soil.

  12. Distribution, Levels, and Risk Assessment of Polycyclic Aromatic Hydrocarbons (PAHs in Some Water Bodies along the Coastal Belt of Ghana

    Directory of Open Access Journals (Sweden)

    David Kofi Essumang

    2010-01-01

    Full Text Available The levels and distribution of 24 polycyclic aromatic hydrocarbons (PAHs were determined in six water bodies along the coastal belt of Ghana using gas chromatography with flame-ionization detection (GC/FID. The average total PAHs recorded are from the Pra estuary, 6.3 μg/L; Benya lagoon, 7.5 μg/L; Sakumono lagoon, 10.1 μg/L; lower Volta estuary, 26.3 μg/L; Keta lagoon, 10.6 μg/L; and Narkwa lagoon, 16.1 μg/L.The 12 PAHs that were well distributed in all the coastal waters analyzed include naphthalene, pyrene, fluorene, 2-methylnaphthalene, 2,6-dimethylnaphthalene, acephnaphthalene, acephnaphthene, 1-methylphenanthrene, 2,3,5-trimethylnaphthalene, chrysene, biphenyl, and phenanthrene. The presence of benzo(bfluoranthene, benzo(aanthracene, and benzo(j,kfluoranthene in some of the water bodies is a source of concern as they have been classified by the International Agency for Research on Cancer (IARC and U.S. Environmental Protection Agency (EPA as probable human carcinogens. These water bodies are used for fishing and for some domestic purposes by the people living around them, thereby exposing them to some dangers and the risk of getting cancer. The human health cancer risk assessment carried out also indicates that there is the possibility of some users of the water bodies getting cancer in their lifetime.

  13. Distribution and sources of polycyclic aromatic hydrocarbons in the sediment of a sub-tropical coastal wetland.

    Science.gov (United States)

    Zheng, Gene J; Man, Ben K W; Lam, James C W; Lam, Michael H W; Lam, Paul K S

    2002-03-01

    Sediment cores (0-35cm below surface) from twelve sampling stations in the Mai Po and Inner Deep Bay Ramsar Site of Hong Kong were retrieved in the period March-December 1999. Vertical profiles of 15 priority polycyclic aromatic hydrocarbons (PAHs) in each sediment core were determined. Ranges of total PAH concentration, [sigmaPAH], in the wetland sediment were 0.18-0.83 (N = 0.36) microg/g dried sediment (mudflats) and 0.63-0.96 (x = 0.77) microg/g dried sediment (mangroves). A decreasing trend in depth averaged [sigmaPAH] was observed from the landward end towards the seaward end of the Marshes. On the mudflats, vertical profiles of the PAHs were quite uniform. At the fringe of the Mai Po mangroves, significantly higher concentration of all PAHs was observed at the upper 0 to -8 cm layer. No significant difference in the distribution patterns of the 15 priority PAHs in summer and winter was observed. This indicates that distribution of PAHs in the sediment of the Mai Po Marshes is not very sensitive to sub-tropical climatic changes of the region. Two PAH isomer ratios, [Phen]/([Phen] + [Anthra]) and [Pyrene]/([Pyrene] + [Fluoran]), were used to identify potential sources of PAH contamination in the wetland. Results revealed that local deposition is a more important source than long-range atmospheric transportation.

  14. Sources and distribution of polycyclic aromatic hydrocarbons in street dust from the Chang-Zhu-Tan Region, Hunan, China.

    Science.gov (United States)

    Long, Yongzhen; Dai, Tagen; Wu, Qianhong

    2013-02-01

    Street dusts collected from 20 locations in the Chang-Zhu-Tan (Changsha, Zhuzhou, and Xiangtan) region, Hunan, China, in May to July 2006, were investigated for sources of polycylic aromatic hydrocarbons (PAHs). The individual PAH concentrations were in the range of 10-4316 ng g(-1), and ∑PAHs(16) levels were in the range of 3,515-24,488 ng g(-1), with a mean of 8,760 ng g(-1). The high-molecular-weight PAHs (four to six rings), ranging from 47.51 to 82.11 %, with a mean of 74.79 %, were the dominant PAH compounds in almost all of the dusts. The isomer ratios suggested a rather uniform mixture of coal combustion and petroleum PAH sources. Factor analysis and multiple linear regression analysis indicate that the main sources of the 16 PAHs were coal combustion/vehicle exhaust, coking/petroleum, and plant combustion, with contribution rates of 50.9, 35.01, and 14.08, respectively. The spatial distributions of PAH concentrations were significantly related to the distribution of industries, traffic circulation, and farmland in this region.

  15. Distribution and accumulation of polycyclic aromatic hydrocarbons (PAHs) in the food web of Nansi Lake, China.

    Science.gov (United States)

    Zhang, Guizhai; Pan, Zhaoke; Wang, Xiaoming; Mo, Xiaojie; Li, Xiaoming

    2015-04-01

    The concentrations of polycyclic aromatic hydrocarbons (PAHs) were analyzed in water, sediment, and biota (aquatic plant, shrimp, and fish) of Nansi Lake by gas chromatography-mass spectrometry (GC-MS). The concentrations of total PAHs were 27.54-55.04 ng L(-1) in water, 80.31-639.23 ng g(-1) dry weight (dw) in sediments, 20.92-192.78 ng g(-1) dw in aquatic plants, and 67.3-533.9 ng g(-1) dw in fish and shrimp muscles. The ratios of phenanthrene to anthracene (Ph/An), fluoranthene to pyrene (Flu/Pyr), and low molecular weight to high molecular weight (LMW/HMW) in sediment indicated that the sources of the PAHs were a mixture of pyrolytic and petrogenic contamination at most sampling sites in Nansi Lake. The composition profile of PAHs in plants was similar to that in water and animals with 2-3 ring PAHs being dominant. The 4-6 ring PAHs were the dominant PAH compounds in sediment. There is a positive correlation between sediment and aquatic plants, but their PAH composition profiles were different, implying that aquatic plant absorption of PAHs from sediment is selective and the accumulation of PAHs in aquatic plants is different. The concentration of PAHs in fish showed a positive correlation with plants, reflecting that the PAHs in fish are mainly absorbed from aquatic plants rather than directly from the water. Bioaccumulation of LMW PAHs in aquatic biota was higher than HMW PAHs. The biota-sediment accumulation factor (BSAF) values of total PAHs in the plants Potamogeton lucens Linn and Ceratophyllum demersum Linn were higher than that in most animals. The BSAF values of total PAHs in animals were in the following order: Cyprinus carpio>Macrobrachium nipponense>Carassius auratus>Channa argus. There was no significant relationship between PAH bioaccumulation and trophic levels in Nansi Lake. Risk assessment of PAHs in water, sediment, and animals indicated that the water environment of Nansi Lake is safe at present. It is worthwhile to note that benzo [a

  16. Inverse-cubic law of index fluctuation distribution in Indian markets

    Science.gov (United States)

    Pan, Raj Kumar; Sinha, Sitabhra

    2008-03-01

    One of the principal statistical features characterizing the activity in financial markets is the distribution of fluctuations in market indicators such as the index. While the developed stock markets, e.g., the New York Stock Exchange (NYSE) have been found to show heavy-tailed return distribution with a characteristic power-law exponent, the universality of such behavior has been debated, particularly in regard to emerging markets. Here we investigate the distribution of several indices from the Indian financial market, one of the largest emerging markets in the world. We have used tick-by-tick data from the National Stock Exchange (NSE), as well as, daily closing data from both the NSE and Bombay Stock Exchange (BSE). We find that the cumulative distributions of index returns have long tails consistent with a power law having exponent α ≈ 3, at time scales of both 1 min and 1 day. This "inverse-cubic law" is quantitatively similar to what has been observed in developed markets, thereby providing strong evidence of universality in the behavior of market fluctuations.

  17. Geochemical Variations in Hydrocarbon Components Distribution in a Prograding Deltaic Sequence: A Case Study of the Baram Delta, Offshore Sarawak Basin, Malaysia

    Directory of Open Access Journals (Sweden)

    J. Ben-Awuah

    2014-03-01

    Full Text Available Studies on hydrocarbon distribution have evolved from basic reservoir characterization to complex studies today involving the interactions between oil components and clay minerals and sequential extraction studies on hydrocarbon extracts in reservoir rocks. Findings from such studies include the discovery of variations in oil fractions in reservoirs such as adsorbed oil and free oil. The theory that first oil charge preferentially interacts with clay minerals occurring in pores and as coatings in reservoirs was also proposed by some researchers. Despite, all these studies some aspects of variations in the composition of hydrocarbons in reservoir rocks still need to be investigated further. This study has been carried out particularly because the qualitative and quantitative composition of aromatic and aliphatic components of hydrocarbons in terms of the presence and quantities of hydrocarbon functional groups and how they relate to hydrocarbon migration have not been exhaustively discussed. This study uses Ultra-Violet visible light (UV-vis and Fourier Transform Infra Red (FTIR to characterize variations in hydrocarbon distribution in reservoir quality sandstones from three fields namely BD01, BD02 and BD03 in the Baram Delta, offshore Sarawak and to deduce how these variations relate to differential migration patterns in hydrocarbons. Hydrocarbon extraction was done in the ultra vilolet visible (UV-vis experiment using 0.1M sodium pyrophosphate as solvent whereas in the Fourier Transform Infra Red (FTIR, the experiment was done on very fine powdered samples of the sandstones. Results from both the UV-vis and FTIR experiments indicate a dominance of aromatic functional groups in the samples. Most of the samples have E4/E6 ratio of more than 1 which indicates a high degree of aromacity. The BD01 field sandstones with a maximum porosity of 32% has the highest average E4/E6 ratio of 1.21, followed by the BD02 field sandstones with a maximum

  18. Tsallis statistics and gradually truncated Lévy flight-distribution of an economical index

    Science.gov (United States)

    Gupta, Hari M.; Campanha, José R.

    2002-06-01

    Tsallis postulated a generalized form for entropy and give rise to a new statistics now known as Tsallis statistics. In the present work, we compare the Tsallis statistics with the gradually truncated Lévy flight, and discuss the distribution of an economical index-the Standard and Poor's 500-using the values of standard deviation as calculated by our model. We find that both statistics give almost the same distribution. Thus we feel that gradual truncation of Lévy distribution, after certain critical step size for describing complex systems, is a requirement of generalized thermodynamics or similar. The gradually truncated Lévy flight is based on physical considerations and bring a better physical picture of the dynamics of the whole system. Tsallis statistics gives a theoretical support. Both statistics together can be utilized for the development of a more exact portfolio theory or to understand better the complexities in human and financial behaviors. A comparison of both statistics is made.

  19. Statistical distribution of the clearness index with radiation data integrated over five minute intervals

    Energy Technology Data Exchange (ETDEWEB)

    Jurado, M.; Caridad, J.M. [Universidad de Cordoba (Spain); Ruiz, V. [Universidad de Sevilla (Spain)

    1995-12-31

    In this paper, the influence of the measurement interval of solar radiation data on the cumulative probability distribution of the clearness index is studied. The distribution observed in southern Spain is bimodal using 5 min data, and this property fades away as the data are aggregated over larger time intervals, and it also depends on the air mass. This is used to confirm the existence of two kinds of types of radiation associated with clear or cloudy skies. Also, with 5 min radiation data, a new statistical model is proposed, based on a mixture of two normal distributions, which provides a good fit for the data measured in Seville. 9 refs., 3 figs., 1 tab.

  20. Regional drought assessment using a distributed hydrological model coupled with Standardized Runoff Index

    Science.gov (United States)

    Shen, H.; Yuan, F.; Ren, L.; Ma, M.; Kong, H.; Tong, R.

    2015-05-01

    Drought assessment is essential for coping with frequent droughts nowadays. Owing to the large spatio-temporal variations in hydrometeorology in most regions in China, it is very necessary to use a physically-based hydrological model to produce rational spatial and temporal distributions of hydro-meteorological variables for drought assessment. In this study, the large-scale distributed hydrological model Variable Infiltration Capacity (VIC) was coupled with a modified standardized runoff index (SRI) for drought assessment in the Weihe River basin, northwest China. The result indicates that the coupled model is capable of reasonably reproducing the spatial distribution of drought occurrence. It reflected the spatial heterogeneity of regional drought and improved the physical mechanism of SRI. This model also has potential for drought forecasting, early warning and mitigation, given that accurate meteorological forcing data are available.

  1. Investigation into the distribution of polycyclic aromatic hydrocarbons (PAHs) in wastewater sewage sludge and its resulting pyrolysis bio-oils.

    Science.gov (United States)

    Hu, Yanjun; Li, Guojian; Yan, Mi; Ping, Chuanjuan; Ren, Jianli

    2014-03-01

    This study firstly investigated the distributions of 16 US EPA priority controlled polycyclic aromatic hydrocarbons (PAHs) in seven kinds of different wastewater sewage sludges and bio-oils from the sludge pyrolysis. A lab-scale tube furnace was used to simulate sludge pyrolysis and retrieve condensed oils. PAH determination was conducted with the extraction, concentration, and purification of PAHs in sludge samples and the resulting bio-oils, and then GC-MS analysis. Then, the factors influencing the distributions of different rings of PAHs in pyrolysis bio-oil, such as the chemical characteristics of raw sewage sludge and pyrolysis condition, were analyzed. It was noted that the total amount of PAHs in raw sludge is evidently varied with the sludge resource, with values ranging between 9.19 and 23.68 mg/kg. The middle molar weight (MMW) PAH distribution is dominant. PAH concentrations in sludge pyrolysis bio-oil were ranged from 13.72 to 48.9 mg/kg. The most abundant PAHs were the low molar weight (LMW) PAHs. It could be found that the concentration of LMW PAHs in bio-oil is correlated with MMW PAHs in raw sewage sludge at best, which the correlation coefficient is 0.607. For MMW and HMW (high molar weight) PAHs, they are significantly correlated with HMW PAHs in raw sewage sludge, which the correlation coefficients are 0.672 and 0.580, respectively. The concentration of LMW PAHs in bio-oil is also relatively significant and correlated with the volatile matter content of raw sludge. In addition, it was proved that final temperature and residence time have important influences on PAH generations during the pyrolysis of sewage sludge.

  2. Occurrence and particle-size distributions of polycyclic aromatic hydrocarbons in the ambient air of coking plant.

    Science.gov (United States)

    Liu, Xiaofeng; Peng, Lin; Bai, Huiling; Mu, Ling; Song, Chongfang

    2014-06-01

    The purpose of this study was to characterize the occurrence and size distributions of ten species of polycyclic aromatic hydrocarbons (PAHs) in the ambient air of coking plants. Particulate-matter samples of four size fractions, including ≤2.1, 2.1-4.2, 4.2-10.2, and ≥10.2 μm, were collected using a Staplex234 cascade impactor during August 2009 at two coking plants in Shanxi, China. The PAHs were analyzed by a gas chromatograph equipped with a mass-selective detector. The concentrations of total particulate-matter PAHs were 1,412.7 and 2,241.1 ng/m(3) for plants I and II, and the distributions showed a peak within the 0.1-2.1 μm size range for plant I and the 0.1-4.2 μm for plant II. The size distributions of individual PAHs (except fluoranthene) exhibited a considerable peak within the 0.1-2.1 μm size range in coking plant I, which can be explained by the gas-particle partition mechanism. The ambient air of the coking plant was heavily polluted by PAHs associated with fine particles (≤2.1 μm), and benzo[b]fluoranthene made the largest contribution to total PAHs. The exposure levels of coking-plant workers to PAHs associated with fine particles were higher than to PAHs associated with coarse particles. Benzo[b]fluoranthene, benzo[a]pyrene, and dibenzo[a,h]anthracene should be the primary pollutants monitored in the coking plant. This research constitutes a significant contribution to assessing the exposure risk of coking-plant workers and providing basic data for PAH standards for ambient air in coking plants.

  3. Designing Alternative Transport Methods for the Distributed Data Collection of ATLAS EventIndex Project

    CERN Document Server

    Fernandez Casani, Alvaro; The ATLAS collaboration

    2016-01-01

    One of the key and challenging tasks of the ATLAS EventIndex project is to index and catalog all the produced events not only at CERN but also at hundreds of worldwide grid sites, and convey the data in real time to a central Hadoop instance at CERN. While this distributed data collection is currently operating correctly in production, there are some issues that might impose performance bottlenecks in the future, with an expected rise in the event production and reprocessing rates. In this work, we first describe the current approach based on a messaging system, which conveys the data from the sources to the central catalog, and we identify some weaknesses of this system. Then, we study a promising alternative transport method based on an object store, presenting a performance comparison with the current approach, and the architectural design changes needed to adapt the system to the next run of the ATLAS experiment at CERN.

  4. Distribution of some hydrocarbons in ambient air near Delft and the influence on the formation of secondary air pollutants

    NARCIS (Netherlands)

    Bos, R.; Guicherit, R.; Hoogeveen, A.

    1977-01-01

    The relative concentrations of hydrocarbons in the atmosphere may provide information concerning their origin. It appears that the hydrocarbon composition measured in Delft (The Netherlands) is entirely different for northern and southern wind directions. This points to different sources. The most

  5. Distribution and Bioconcentration of Polycyclic Aromatic Hydrocarbons in Surface Water and Fishes

    Directory of Open Access Journals (Sweden)

    Haiyan Li

    2012-01-01

    Full Text Available To examine spatial distribution and bioconcentration of PAHs, water and fish samples were collected from Pearl River Delta in summer and spring, respectively. Particulate organic carbon, dissolved organic carbon, biodegradable DOC (BDOC, and chlorophyll a were measured. PAHs were dominated by 2- and 3-ring compounds in the water and SPM samples. Aqueous and solid-phase PAHs, respectively, showed significant correlations with total organic matter (TOC in SPM or dissolved organic matter (DOC in the water. The in-situ partitioning coefficients (logKoc, mL/g for the samples were observed to be related to logKow, implying that the hydrophobicity of PAHs is a critical factor in their distribution. It was also observed that BCF increased with the increasing Kow in the viscera of tilapia (logBCF=0.507logKow−1.368, r=0.883. However, most of the observed log BCF values in other different fish tissues at first increased with the increasing of log Kow, then reached a maximum value when logKow is between 5 and 7, and then decreased when logKow is higher than 7, indicating that the value of BCF may vary due to the diversity of fish species.

  6. Entropy maximization under the constraints on the generalized Gini index and its application in modeling income distributions

    Science.gov (United States)

    Khosravi Tanak, A.; Mohtashami Borzadaran, G. R.; Ahmadi, J.

    2015-11-01

    In economics and social sciences, the inequality measures such as Gini index, Pietra index etc., are commonly used to measure the statistical dispersion. There is a generalization of Gini index which includes it as special case. In this paper, we use principle of maximum entropy to approximate the model of income distribution with a given mean and generalized Gini index. Many distributions have been used as descriptive models for the distribution of income. The most widely known of these models are the generalized beta of second kind and its subclass distributions. The obtained maximum entropy distributions are fitted to the US family total money income in 2009, 2011 and 2013 and their relative performances with respect to generalized beta of second kind family are compared.

  7. Concentrations, sources and spatial distribution of polycyclic aromatic hydrocarbons in soils from Beijing, Tianjin and surrounding areas, North China

    Energy Technology Data Exchange (ETDEWEB)

    Wang Wentao [Laboratory for Earth Surface Processes, College of Urban and Environmental Sciences, Peking University, Beijing 100871 (China); Department of Environmental and Molecular Toxicology, Oregon State University, Corvallis, OR 97331 (United States); Massey Simonich, Staci L. [Department of Environmental and Molecular Toxicology, Oregon State University, Corvallis, OR 97331 (United States); Department of Chemistry, Oregon State University, Corvallis, OR 97331 (United States); Xue Miao; Zhao Jingyu; Zhang Na; Wang Rong; Cao Jun [Laboratory for Earth Surface Processes, College of Urban and Environmental Sciences, Peking University, Beijing 100871 (China); Tao Shu, E-mail: taos@urban.pku.edu.c [Laboratory for Earth Surface Processes, College of Urban and Environmental Sciences, Peking University, Beijing 100871 (China)

    2010-05-15

    The concentrations, profiles, sources and spatial distribution of polycyclic aromatic hydrocarbons (PAHs) were determined in 40 surface soil samples collected from Beijing, Tianjin and surrounding areas, North China in 2007, and all sampling sites were far from industrial areas, roadsides and other pollution sources, and across a range of soil types in remote, rural villages and urban areas. The total concentrations of 16 PAHs ranged from 31.6 to 1475.0 ng/g, with an arithmetic average of 336.4 ng/g. The highest PAH concentrations were measured in urban soils, followed by rural village soils and soils from remote locations. The remote-rural village-urban PAH concentration gradient was related to population density, gross domestic product (GDP), long-range atmospheric transport and different types of land use. In addition, the PAH concentration was well correlated with the total organic carbon (TOC) concentration of the soil. The PAH profile suggested that coal combustion and biomass burning were primary PAH sources. - The concentration, profiles and possible sources of PAHs in Beijing, Tianjin and surrounding area soils were studied and related to population density and gross domestic product (GDP).

  8. Concentrations, sources and spatial distribution of polycyclic aromatic hydrocarbons in soils from Beijing, Tianjin and surrounding areas, North China

    Science.gov (United States)

    Wang, Wentao; Massey Simonich, Staci L.; Xue, Miao; Zhao, Jingyu; Zhang, Na; Wang, Rong; Cao, Jun; Tao, Shu

    2013-01-01

    The concentrations, profiles, sources and spatial distribution of polycyclic aromatic hydrocarbons (PAHs) were determined in 40 surface soil samples collected from Beijing, Tianjin and surrounding areas, North China in 2007, and all sampling sites were far from industrial areas, roadsides and other pollution sources, and across a range of soil types in remote, rural villages and urban areas. The total concentrations of 16 PAHs ranged from 31.6 to 1475.0 ng/g, with an arithmetic average of 336.4 ng/g. The highest PAH concentrations were measured in urban soils, followed by rural village soils and soils from remote locations. The remote–rural village–urban PAH concentration gradient was related to population density, gross domestic product (GDP), long-range atmospheric transport and different types of land use. In addition, the PAH concentration was well correlated with the total organic carbon (TOC) concentration of the soil. The PAH profile suggested that coal combustion and biomass burning were primary PAH sources. PMID:20199833

  9. Concentrations, sources and spatial distribution of polycyclic aromatic hydrocarbons in soils from Beijing, Tianjin and surrounding areas, North China

    Energy Technology Data Exchange (ETDEWEB)

    Wang, W.T.; Simonich, S.L.M.; Xue, M.A.; Zhao, J.Y.; Zhang, N.; Wang, R.; Cao, J.; Tao, S. [Peking University, Beijing (China)

    2010-05-15

    The concentrations, profiles, sources and spatial distribution of polycyclic aromatic hydrocarbons (PAHs) were determined in 40 surface soil samples collected from Beijing, Tianjin and surrounding areas, North China in 2007, and all sampling sites were far from industrial areas, roadsides and other pollution sources, and across a range of soil types in remote, rural villages and urban areas. The total concentrations of 16 PAHs ranged from 31.6 to 1475.0 ng/g, with an arithmetic average of 336.4 ng/g. The highest PAH concentrations were measured in urban soils, followed by rural village soils and soils from remote locations. The remote-rural village-urban PAH concentration gradient was related to population density, gross domestic product (GDP), long-range atmospheric transport and different types of land use. In addition, the PAH concentration was well correlated with the total organic carbon (TOC) concentration of the soil. The PAH profile suggested that coal combustion and biomass burning were primary PAH sources.

  10. Distribution, sources and potential toxicological significance of polycyclic aromatic hydrocarbons(PAHs) in Guanting Reservoir sediments, China

    Institute of Scientific and Technical Information of China (English)

    HUANG Sheng-biao; WANG Zi-jian; XU Yi-ping; MA Mei

    2005-01-01

    The Guanting Reservoir lost its function as the second biggest drinking water source for Beijing due to the pollutions from the upstream flow of Yongding River in 1997. From 1998, lots of studies were carryied out to renew the function of Guanting Reservoir as domestic drinking water source before 2008 Olympic Games. This is the first time that polycyclic aromatic hydrocarbon concentrations in the surface sediment of Guanting Reservoir have been analyzed. A distinctive spatial distribution of PAHs was observed. Sediments from four sites along Inlet of Yongding River to reservoir bam had PAHs concentrations of 1377-2855 μg/g dw in descending order. The composition of PAHs is investigated and used to assess petrogenic,combustion and naturally derived of the sediments samples of Guanting Reservoir. Special PAHs ratios, such as phenanthrene/anthracene(P/A) and fluoranthene/pyrene(FI/Pyr) were calculated to assess the relative importance of different origins. The data confirmed a relatively high level of petrogenic contamination in four sites. These high PAHs levels were associated with the input of untreated and partially treated industrial sewage. In addition, the concentrations of PAHs compounds of samples indicated that sediments of reservoir were most likely to pose potential biological impairment.

  11. Polycyclic aromatic hydrocarbons in air on small spatial and temporal scales - II. Mass size distributions and gas-particle partitioning

    Science.gov (United States)

    Lammel, Gerhard; Klánová, Jana; Ilić, Predrag; Kohoutek, Jiří; Gasić, Bojan; Kovacić, Igor; Škrdlíková, Lenka

    2010-12-01

    Polycyclic aromatic hydrocarbons (PAHs) were measured together with inorganic air pollutants at two urban sites and one rural background site in the Banja Luka area, Bosnia and Hercegovina, during 72 h in July 2008 using a high time resolution (5 samples per day) with the aim to study gas-particle partitioning, aerosol mass size distributions and to explore the potential of a higher time resolution (4 h-sampling). In the particulate phase the mass median diameters of the PAHs were found almost exclusively in the accumulation mode (0.1-1.0 μm of size). These were larger for semivolatile PAHs than for non-volatile PAHs. Gas-particle partitioning of semivolatile PAHs was strongly influenced by temperature. The results suggest that the Junge-Pankow model is inadequate to explain the inter-species variation and another process must be significant for phase partitioning which is less temperature sensitive than adsorption. Care should be taken when interpreting slopes m of plots of the type log K p = m log p L0 + b based on 24 h means, as these are found sensitive to the time averaging, i.e. tend to be higher than when based on 12 h-mean samples.

  12. Levels, distribution, and health risks of polycyclic aromatic hydrocarbons in four freshwater edible fish species from the Beijing market.

    Science.gov (United States)

    Wu, Wen-Jing; Qin, Ning; He, Wei; He, Qi-Shuang; Ouyang, Hui-Ling; Xu, Fu-Liu

    2012-01-01

    We first estimated the content of polycyclic aromatic hydrocarbons (PAHs) in the brain, liver, bladder, roe, and muscle of four species of edible freshwater fish from the Beijing market. The distribution characteristics of PAHs in these tissues and organs were analyzed to determine their health risks to humans. The results showed that the residual levels of wet weight and lipid-normalized weight ∑PAHs in various tissues of these fish ranged from 0.51 ng·g(-1) to 28.78 ng·g(-1) and from 93.62 ng·g(-1) to 8203.43 ng·g(-1), respectively. The wet weight contents of ∑PAHs were relatively higher in the brain and lower in the liver and muscle. But the differences were not significant. And the differences of lipid-normalized weight PAHs were significant, which in the bighead carp were found significantly the highest, followed in crucian carp, and the lowest in grass carp and carp. The contents of ∑PAHs were the highest in the liver and the lowest in the brain. In the tissues with a higher lipid content, higher residual levels of PAHs were found. The carcinogenic risks for humans from residual ∑PAHs in the various fish tissues were far below 10(-5).

  13. Concentration level and distribution of polycyclic aromatic hydrocarbons in soil and grass around Mt.Qomolangma,China

    Institute of Scientific and Technical Information of China (English)

    WANG XiaoPing; YAO TanDong; CONG ZhiYuan; YAN XinLiang; KANG ShiChang; ZHANG Yong

    2007-01-01

    High mountains may serve as a condenser for persistent organic pollutants.In the present study,soil and grass samples from Mt.Qomolangma region,China were collected from 4600 to 5620 m a.s.l and were analyzed for polycyclic aromatic hydrocarbons (PAHs) to determine if they are concentrated at colder,more elevated sites and to evaluate their possible resources and fractionation.The total PAHs Concentration in soil samples was<600 ng g-1,the critical value to differentiate PAHs levels in remote and urban regions.This implied the PAHs levels at Mt.Qomolangma are relatively low and what one might expect in such a remote region of the world.These low values may represent a soil background for mid-latitude Northern Hemisphere soils away from the direct influence of an anthropogenic source.As for the distribution pattern,the low molecular weight PAHs were prone to accumulate at higher altitude,while the high molecular weight PAHs inversely related or unrelated with elevation.Based on high concentration of phenanthrene at elevated sample site and the ratios of individual PAHs,we deduced that home-heating combustion and vehicle emission may result in the constitution trait of PAHs in this mountain region.Monsoon traveling over India,Pakistan and other countries with dense population may carry contaminant to Mt.Qomolangma region.

  14. Effect of external surface of HZSM-5 zeolite on product distribution in the conversion of methanol to hydrocarbons

    Institute of Scientific and Technical Information of China (English)

    Junhui Li; Yanan Wang; Wenzhi Jia; Zhiwen Xi; Huanhui Chen; Zhirong Zhu∗; Zhonghua Hu

    2014-01-01

    The external surface of HZSM-5 zeolite was passivated by liquid siliceous deposition and by acidic sites poisoning with lepidine, respectively. Then methanol-to-hydrocarbons (MTH) reaction was investigated over the above as-prepared catalysts and the dissoluble coke on these used catalysts was analyzed by GC-MS, to study the role of the external surface of HZSM-5 in the catalytic reaction. Comparison with the experi-mental results based on parent ZSM-5 showed that the product distribution of MTH reaction was obviously influenced by the external surface. Evidences were listed as follows:(1) the final product on parent HZSM-5 showed higher aromatic selectivity, lower olefin selectivity, lower ra-tio of C2/C3+aliphatics and higher ratio of C3/C4+aliphatics than the reaction mixture produced by the sole catalysis of acidic sites in HZSM-5 channel;(2) a little of pentamethylbenzene and hexamethylbenzene in the product on parent HZSM-5, was produced via multi-methylation of methylbenzene on the external surface. The above conclusion may also be suitable for MTH reaction over other zeolites with 10-ring channel.

  15. Emission, distribution and toxicity of polycyclic aromatic hydrocarbons (PAHs) during municipal solid waste (MSW) and coal co-combustion.

    Science.gov (United States)

    Peng, Nana; Li, Yi; Liu, Zhengang; Liu, Tingting; Gai, Chao

    2016-09-15

    Emission and distribution characteristics of polycyclic aromatic hydrocarbons (PAHs) were investigated during municipal solid waste (MSW) and coal combustion alone and MSW/coal blend (MSW weight fraction of 25%) co-combustion within a temperature range of 500°C-900°C. The results showed that for all combustion experiments, flue gas occupied the highest proportion of total PAHs and fly ash contained more high-ring PAHs. Moreover, the 3- and 4-ring PAHs accounted for the majority of total PAHs and Ant or Phe had the highest concentrations. Compared to coal, MSW combustion generated high levels of total PAHs with the range of 111.28μg/g-10,047.22μg/g and had high toxicity equivalent value (TEQ). MSW/coal co-combustion generated the smallest amounts of total PAHs and had the lowest TEQ than MSW and coal combustion alone. Significant synergistic interactions occurred between MSW and coal during co-combustion and the interactions suppressed the formation of PAHs, especially hazardous high-ring PAHs and decreased the TEQ. The present study indicated that the reduction of the yield and toxicity of PAHs can be achieved by co-combustion of MSW and coal.

  16. The Formation and Distribution of the Marine Hydrocarbon Source Rock in the Tarim Basin, NW China

    Institute of Scientific and Technical Information of China (English)

    CAI Xiyuan; WANG Yi

    2008-01-01

    There are significant differences in type and distribution between marine source rock and continental source rock. According to the lithology, the Cambrian-Ordovician source rock in the Tarim basin is divided into two types: the carbonate source rock and the mud source rock. The two sets of source rocks are developed mainly in three sets of formations, Lower-Middle Cambrian carbonate source rock and mud source rock, Lower-Middle Ordovician mud source rock and Upper Ordovician lime mud source rock. The stratigraphic and areal distributions of the source rocks are controlled by the altitude and the sedimentary facies respectively. The mud source rock is developed in slope-semi deep sea environment. The source rock developed in the slope sedimentary environment is related with the anoxic environment and the one developed in semi deep sea has a close relationship with the up-flowing sea water. The carbonate source rock is developed mainly in platform slope of highstand systems tract and it is usually intimately associated with the salt rock. The Lower-Middle Cambrian carbonate source rock is developed mainly in the Bachu, Tazhong, Taugguzibasi and Yingmaili areas. The Lower-Middle Cambrian mud source rock is mainly developed in the areas east of the line of Kunan 1-Tadong 1. The Lower-Middle Ordovician mud source rock is developed mainly in the east slope of the Manjiaer depression. The carbonate source rock of Early Ordovician is developed mainly in the platform slope of highstand systems tract, such as the south margin of Tabei, the north slope of Tazhong, the Bachu area and Keping area.

  17. Perspectives in using a remotely sensed dryness index in distributed hydrological models at river basin scale

    DEFF Research Database (Denmark)

    Andersen, J.; Sandholt, Inge; Jensen, Karsten Høgh;

    2002-01-01

    Remote Sensing, hydrological modelling, dryness index, surface temperature, vegetation index, Africa, Senegal, soil moisture......Remote Sensing, hydrological modelling, dryness index, surface temperature, vegetation index, Africa, Senegal, soil moisture...

  18. Emergency Service Restoration and Load Balancing in Distribution Networks Using Feeder Loadings Balance Index

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Sang Yule [Anyang University, Anyang (Korea); Jung, Ho Sung; Shin, Myong Chul [Natural Sciences Campus, Suwon (Korea)

    2002-05-01

    This paper presents an algorithm to obtain an approximate optimal solution for the service restoration and load balancing of large scale radial distribution system in a real-time operation environment. Since the problem is formulated as a combinatorial optimization problem, it is difficult to solve a large-scale combinatorial optimization problem accurately within the reasonable computation time. Therefore, in order to find an approximate optimal solution quickly, the authors proposed an algorithm which combines optimization called cyclic best-first search with heuristic based feeder loadings balance index for computational efficiency and robust performance. To demonstrate the validity of the proposed algorithm, numerical calculations are carried out the KEPCO's 108 bus distribution system. (author). 14 refs., 9 figs., 4 tabs.

  19. Privacy-preserving location-based query using location indexes and parallel searching in distributed networks.

    Science.gov (United States)

    Zhong, Cheng; Liu, Lei; Zhao, Jing

    2014-01-01

    An efficient location-based query algorithm of protecting the privacy of the user in the distributed networks is given. This algorithm utilizes the location indexes of the users and multiple parallel threads to search and select quickly all the candidate anonymous sets with more users and their location information with more uniform distribution to accelerate the execution of the temporal-spatial anonymous operations, and it allows the users to configure their custom-made privacy-preserving location query requests. The simulated experiment results show that the proposed algorithm can offer simultaneously the location query services for more users and improve the performance of the anonymous server and satisfy the anonymous location requests of the users.

  20. Spatial distribution, potential risk assessment, and source apportionment of polycyclic aromatic hydrocarbons (PAHs) in sediments of Lake Chaohu, China.

    Science.gov (United States)

    Li, Chaocan; Huo, Shouliang; Yu, Zhiqiang; Xi, Beidou; Zeng, Xiangying; Wu, Fengchang

    2014-10-01

    Twenty-nine sediment samples were collected from Lake Chaohu, a shallow eutrophic lake in Eastern China, and were analyzed for 15 priority polycyclic aromatic hydrocarbons (PAHs) to determine the spatial distribution and exposure risks of PAHs. Three receptor models, the principal component analysis-multiple linear regression (PCA-MLR) model, the positive matrix factorization (PMF) model, and the Unmix model, were used in combination with the PAHs diagnostic ratios to investigate the potential source apportionment of PAHs. A clear gradient in the spatial distribution and the potential toxicity of PAHs was observed from west to east in the sediments of Lake Chaohu. ∑15PAH concentrations and the TEQ were in the range of 80.82-30 365.01 ng g(-1) d.w. and 40.77-614.03, respectively. The highest values of the aforementioned variables were attributed to urban-industrial pollution sources in the west lake region, and the levels decreased away from the river inlets. The three different models yielded excellent correlation coefficients between the predicted and measured levels of the 15 PAH compounds. Similarly, source apportionment results were derived from the three receptor models and the PAH diagnostic ratios, suggesting that the highest contribution to the PAHs was from coal combustion and wood combustion, followed by vehicular emissions. The PMF model yielded the following contributions to the PAHs from gasoline combustion, diesel combustion, unburned petroleum emissions, and wood combustion: 34.49, 24.61, 16.11, 13.01, and 11.78 %, respectively. The PMF model produced more detailed source apportionment results for the PAHs than the PCA-MLR and Unmix models.

  1. Distribution of endophytic bacteria in Alopecurus aequalis Sobol and Oxalis corniculata L. from soils contaminated by polycyclic aromatic hydrocarbons.

    Directory of Open Access Journals (Sweden)

    Anping Peng

    Full Text Available The distributions of endophytic bacteria in Alopecurus aequalis Sobol and Oxalis corniculata L. grown in soils contaminated with different levels of polycyclic aromatic hydrocarbons (PAHs were investigated with polymerase chain reaction followed by denaturing gradient gel electrophoresis technology (PCR-DGGE and cultivation methods. Twelve types of PAHs, at concentrations varying from 0.16 to 180 mg·kg(-1, were observed in the roots and shoots of the two plants. The total PAH concentrations in Alopecurus aequalis Sobol obtained from three different PAH-contaminated stations were 184, 197, and 304 mg·kg(-1, and the total PAH concentrations in Oxalis corniculata L. were 251, 346, and 600 mg·kg(-1, respectively. The PCR-DGGE results showed that the endophytic bacterial communities in the roots and shoots of the two plants were quite different, although most bacteria belonged to Firmicutes, Proteobacteria, Actinobacteria and Bacteroidetes. A total of 68 endophytic bacterial strains were isolated from different tissues of the two plants and classified into three phyla: Firmicutes, Proteobacteria and Bacteroidetes. In both plants, Bacillus spp. and Pseudomonas spp. were the dominant cultivable populations. With an increase in the PAH pollution level, the diversity and distribution of endophytic bacteria in the two plants changed correspondingly, and the number of cultivable endophytic bacterial strains decreased rapidly. Testing of the isolated endophytic bacteria for tolerance to each type of PAH showed that most isolates could grow well on Luria-Bertani media in the presence of different PAHs, and some isolates were able to grow rapidly on a mineral salt medium with a single PAH as the sole carbon and energy source, indicating that these strains may have the potential to degrade PAHs in plants. This research provides the first insight into the characteristics of endophytic bacterial populations under different PAH pollution levels and provides a

  2. Diversity, distribution and hydrocarbon biodegradation capabilities of microbial communities in oil-contaminated cyanobacterial mats from a constructed wetland.

    Directory of Open Access Journals (Sweden)

    Raeid M M Abed

    Full Text Available Various types of cyanobacterial mats were predominant in a wetland, constructed for the remediation of oil-polluted residual waters from an oil field in the desert of the south-eastern Arabian Peninsula, although such mats were rarely found in other wetland systems. There is scarce information on the bacterial diversity, spatial distribution and oil-biodegradation capabilities of freshwater wetland oil-polluted mats. Microbial community analysis by Automated Ribosomal Spacer Analysis (ARISA showed that the different mats hosted distinct microbial communities. Average numbers of operational taxonomic units (OTUsARISA were relatively lower in the mats with higher oil levels and the number of shared OTUsARISA between the mats was 90% of the sequences affiliated to Proteobacteria (41% of total sequences, Cyanobacteria (31%, Bacteriodetes (11.5%, Planctomycetes (7% and Chloroflexi (3%. Known autotrophic (e.g. Rivularia and heterotrophic (e.g. Azospira nitrogen-fixing bacteria as well as purple sulfur and non-sulfur bacteria were frequently encountered in all mats. On the other hand, sequences of known sulfate-reducing bacteria (SRBs were rarely found, indicating that SRBs in the wetland mats probably belong to yet-undescribed novel species. The wetland mats were able to degrade 53-100% of C12-C30 alkanes after 6 weeks of incubation under aerobic conditions. We conclude that oil and ammonia concentrations are the major key players in determining the spatial distribution of the wetland mats' microbial communities and that these mats contribute directly to the removal of hydrocarbons from oil field wastewaters.

  3. The emerging source of polycyclic aromatic hydrocarbons from mining in the Tibetan Plateau: Distributions and contributions in background soils.

    Science.gov (United States)

    Li, Jun; Yuan, Guo-Li; Li, Ping; Sun, Yong; Yu, Hong-Hui; Wang, Gen-Hou

    2017-04-15

    The Tibetan Plateau (TP) serves as the background for persistent organic pollutants around the world. In addition to outside sources, local sources greatly contribute to the environment of the TP in recent decades. Mining activity could serve as an emerging source of polycyclic aromatic hydrocarbons (PAHs), although this issue has been neglected in the TP until now. To investigate the distributions and contributions of PAHs transported from mining activity, forty-one surface soil samples along six sampling directions were collected at a regular distance from the Jiama mining area (JMA) of the TP at altitudes between 3726 and 4863m. The total concentration of 16 PAHs was 52.34±22.58ng/g. The result of the source identification suggested that mining activity represented the primary source for heavy molecular weight (HMW) PAHs in soils, while light molecular weight (LMW) and middle molecular weight (MMW) PAHs were contributed by multiple sources. For HMW PAHs, the concentrations and proportions decreased logarithmically with transport distance from the JMA. Furthermore, the transport distance of HMW PAHs was found to be affected by the prevailing wind direction. In addition to transport from the source area, the distributions of LMW and MMW PAHs were also influenced by the altitude. In the impact area of Jiama mining activity, the soil mass inventory was estimated to be 6.4±0.8tons for HMW PAHs. In future decades, HMW PAHs emitted from Jiama mining activity are projected to exceed 5% of the annual local emission in the TP. Our study evidenced that Tibetan mining activity serves as an important emerging source of PAHs, which would be transported within the TP and threaten the fragile ecosystem of the TP.

  4. Distribution and source apportionment of polycyclic aromatic hydrocarbons in soils and leaves from high-altitude mountains in southwestern china.

    Science.gov (United States)

    Shi, Bingfang; Wu, Qilin; Ouyang, Huixiang; Liu, Xixiang; Ma, Bo; Zuo, Weiyuan; Chen, Shengyu

    2014-11-01

    Several studies have investigated the distribution patterns and geographic sources of polycyclic aromatic hydrocarbons (PAHs) in mountainous areas. Little is known about how different sources contribute to PAH concentrations at different elevations along mountain slopes. To estimate the distribution and sources of PAHs at different altitudes in mountainous areas of southwestern China, samples of soils and leaves from trees were collected from 1000 to 1500 m asl in the Dawangling forest and analyzed for PAHs. Total PAH concentrations ranged from 93.9 to 802.3 ng g (average, 252.3 ng g) in soils and from 4.1 to 100.9 ng g (average, 23.1 ng g) in leaves. Our results suggest that soil PAH levels in the study area could be classified as "weakly contaminated." The PAH levels in leaves from the Dawangling forest were lower than those found in Himalayan spruce needles from the central Himalayas in China and from an agricultural station in southern England. Total PAHs in the Dawangling forest soils increased with elevation, primarily due to the low-molecular-weight PAHs, which accumulated in samples from higher altitudes. In contrast, high-molecular-weight PAHs were inversely related to or unrelated to elevation. The PAH profiles were similar in soils and leaves from all mountainous regions. Diagnostic ratios showed that the PAHs in soils at different altitudes were from different pollution emission sources; therefore, PAHs in the entire study area were probably derived from mixed sources. Cluster analyses confirmed that liquefied petroleum gas, coal/wood combustion, and petroleum combustion were likely the predominant PAH sources in this region.

  5. Distribution of Endophytic Bacteria in Alopecurus aequalis Sobol and Oxalis corniculata L. from Soils Contaminated by Polycyclic Aromatic Hydrocarbons

    Science.gov (United States)

    Peng, Anping; Liu, Juan; Gao, Yanzheng; Chen, Zeyou

    2013-01-01

    The distributions of endophytic bacteria in Alopecurus aequalis Sobol and Oxalis corniculata L. grown in soils contaminated with different levels of polycyclic aromatic hydrocarbons (PAHs) were investigated with polymerase chain reaction followed by denaturing gradient gel electrophoresis technology (PCR-DGGE) and cultivation methods. Twelve types of PAHs, at concentrations varying from 0.16 to 180 mg·kg−1, were observed in the roots and shoots of the two plants. The total PAH concentrations in Alopecurus aequalis Sobol obtained from three different PAH-contaminated stations were 184, 197, and 304 mg·kg−1, and the total PAH concentrations in Oxalis corniculata L. were 251, 346, and 600 mg·kg−1, respectively. The PCR-DGGE results showed that the endophytic bacterial communities in the roots and shoots of the two plants were quite different, although most bacteria belonged to Firmicutes, Proteobacteria, Actinobacteria and Bacteroidetes. A total of 68 endophytic bacterial strains were isolated from different tissues of the two plants and classified into three phyla: Firmicutes, Proteobacteria and Bacteroidetes. In both plants, Bacillus spp. and Pseudomonas spp. were the dominant cultivable populations. With an increase in the PAH pollution level, the diversity and distribution of endophytic bacteria in the two plants changed correspondingly, and the number of cultivable endophytic bacterial strains decreased rapidly. Testing of the isolated endophytic bacteria for tolerance to each type of PAH showed that most isolates could grow well on Luria-Bertani media in the presence of different PAHs, and some isolates were able to grow rapidly on a mineral salt medium with a single PAH as the sole carbon and energy source, indicating that these strains may have the potential to degrade PAHs in plants. This research provides the first insight into the characteristics of endophytic bacterial populations under different PAH pollution levels and provides a species

  6. Distribution pattern of polycyclic aromatic hydrocarbons in particle-size fractions of coking plant soils from different depth.

    Science.gov (United States)

    Liao, Xiaoyong; Ma, Dong; Yan, Xiulan; Yang, Linsheng

    2013-06-01

    The concentrations of 16 priority polycyclic aromatic hydrocarbons (PAHs) in four size fractions (200 μm) in soils at different depth from a heavily contaminated crude benzol production facility of a coking plant were determined using GC-MS. Vertically, elevated total PAHs concentrations were observed in the soils at 3.0-4.5 m (layer B) and 6.0-7.5 m (layer C), relatively lower at 1.5-3.0 m (layer A) and 10.5-12.0 m (layer D). At all sampling sites, the silt (2-20 μm) contained the highest PAHs concentration (ranged from 726 to 2,711 mg/kg). Despite the substantial change in PAHs concentrations in soils with different particle sizes and lithologies, PAHs composition was similarly dominated by 2-3 ring species (86.5-98.3 %), including acenaphthene, fluorene, and phenanthrene. For the contribution of PAHs mass in each fraction to the bulk soil, the 20-200 μm size fraction had the greatest accumulation of PAHs in loamy sand layers at 1.0-7.5 m, increasing with depth; while in deeper sand layer at 10.5-12.0 m, the >200 μm size fraction showed highest percentages and contributed 81 % of total PAHs mass. For individual PAH distribution, the 2-3 ring PAHs were highly concentrated in the small size fraction (PAHs showed the highest concentrations in the 2-20 μm size fraction, increasing with depth. The distribution of PAHs was primarily determined by the sorption on soil organic matter and the characteristics of PAHs. This research should have significant contribution to PAH migration study and remediation design for PAHs-contaminated sites.

  7. Species distribution and population connectivity of deep-sea mussels at hydrocarbon seeps in the Gulf of Mexico.

    Directory of Open Access Journals (Sweden)

    Baptiste Faure

    Full Text Available Hydrocarbon seepage is widespread and patchy in the Gulf of Mexico, and six species of symbiont containing bathymodiolin mussels are found on active seeps over wide and overlapping depth and geographic ranges. We use mitochondrial genes to discriminate among the previously known and a newly discovered species and to assess the connectivity among populations of the same species in the northern Gulf of Mexico (GoM. Our results generally validate the morphologically based distribution of the three previously known GoM species of Bathymodiolus, although we found that approximately 10% of the morphologically based identifications were incorrect and this resulted in some inaccuracies with respect to their previously assigned depth and geographical distribution patterns. These data allowed us to confirm that sympatry of two species of Bathymodiolus within a single patch of mussels is common. A new species of bathymodiolin, Bathymodiolus sp. nov., closely related to B. heckerae was also discovered. The two species live at the same depths but have not been found in sympatry and both have small effective population sizes. We found evidence for genetic structure within populations of the three species of Bathymodiolinae for which we had samples from multiple sites and suggest limited connectivity for populations at some sites. Despite relatively small sample sizes, genetic diversity indices suggest the largest population sizes for B. childressi and Tamu fisheri and the smallest for B. heckerae and B. sp. nov. among the GoM bathymodiolins. Moreover, we detected an excess of rare variants indicating recent demographic changes and population expansions for the four species of bathymodiolins from the Gulf of Mexico.

  8. Species Distribution and Population Connectivity of Deep-Sea Mussels at Hydrocarbon Seeps in the Gulf of Mexico

    Science.gov (United States)

    Faure, Baptiste; Schaeffer, Stephen W.; Fisher, Charles R.

    2015-01-01

    Hydrocarbon seepage is widespread and patchy in the Gulf of Mexico, and six species of symbiont containing bathymodiolin mussels are found on active seeps over wide and overlapping depth and geographic ranges. We use mitochondrial genes to discriminate among the previously known and a newly discovered species and to assess the connectivity among populations of the same species in the northern Gulf of Mexico (GoM). Our results generally validate the morphologically based distribution of the three previously known GoM species of Bathymodiolus, although we found that approximately 10% of the morphologically based identifications were incorrect and this resulted in some inaccuracies with respect to their previously assigned depth and geographical distribution patterns. These data allowed us to confirm that sympatry of two species of Bathymodiolus within a single patch of mussels is common. A new species of bathymodiolin, Bathymodiolus sp. nov., closely related to B. heckerae was also discovered. The two species live at the same depths but have not been found in sympatry and both have small effective population sizes. We found evidence for genetic structure within populations of the three species of Bathymodiolinae for which we had samples from multiple sites and suggest limited connectivity for populations at some sites. Despite relatively small sample sizes, genetic diversity indices suggest the largest population sizes for B. childressi and Tamu fisheri and the smallest for B. heckerae and B. sp. nov. among the GoM bathymodiolins. Moreover, we detected an excess of rare variants indicating recent demographic changes and population expansions for the four species of bathymodiolins from the Gulf of Mexico. PMID:25859657

  9. Hazard Assessment on Chlorine Distribution Use of Chemical Transportation Risk Index

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jeong Gon [Hanwha Chemical Ulsan Site, Ulsan (Korea, Republic of); Byun, Hun Soo [Chonnam National University, Yeosu (Korea, Republic of)

    2014-12-15

    Chlorine is one of the most produced and most used non-flammable chemical substances in the world even though its toxicity and high reactivity cause the ozone layer depletion. However, in modern life, it is impossible to live a good life without using Chlorine and its derivatives since they are being used as an typical ingredient in more than 40 percent of the manufactured goods including medicines, detergents, deodorant, fungicides, herbicides, insecticides, and plastic, etc. Even if Chlorine has been handled and distributed in various business (small and medium-sized businesses, water purification plants, distribution company, etc.), there have been few researches about its possible health hazard and transportation risks. Accordingly, the purpose of this paper is to make a detailed assessment of Chlorinerelated risks and to model an index of chemicals transportation risks that is adequate for domestic circumstances. The assessment of possible health hazard and transportation risks was made on 13 kinds of hazardous chemicals, including liquid chlorine. This research may be contributed to standardizing the risk assessment of Chlorine and other hazardous chemicals by using an index of transportation risks.

  10. Thermal-Induced Refractive Index Change Effects on Distributed Modal Filtering Properties of Rod-Type Photonic Crystal Fibers

    DEFF Research Database (Denmark)

    Coscelli, E.; Poli, Federica; Jørgensen, Mette Marie

    2012-01-01

    The effects of thermally-induced refractive index change on distributed modal filtering rod-type photonic crystal fibers are numerically investigated. Results have shown a significant blue-shift of the single-mode range for increasing temperature.......The effects of thermally-induced refractive index change on distributed modal filtering rod-type photonic crystal fibers are numerically investigated. Results have shown a significant blue-shift of the single-mode range for increasing temperature....

  11. Distribution and potential sources of polycyclic aromatic hydrocarbons in soils around coal-fired power plants in South Africa.

    Science.gov (United States)

    Okedeyi, Olumuyiwa O; Nindi, Mathew M; Dube, Simiso; Awofolu, O R

    2013-03-01

    The distribution and potential sources of 15 polycyclic aromatic hydrocarbons (PAHs) in soils in the vicinity of three South African coal-fired power plants were determined by gas chromatography-mass spectrometry. PAH compound ratios such as phenanthrene/phenanthrene + anthracene (Phen/Phen + Anth) were used to provide reliable estimation of emission sources. The total PAH concentration in the soils around three power plants ranged from 9.73 to 61.24 μg g(-1), a range above the Agency for Toxic Substances and Disease Registry levels of 1.0 μg g(-1) for significantly contaminated site. Calculated values of Phen/Phen + Anth ratio were 0.48 ± 0.08, 0.44 ± 0.05, and 0.38 + 0.04 for Matla, Lethabo, and Rooiwal, respectively. Flouranthene/fluoranthene + pyrene (Flan/Flan + Pyr) were found to be 0.49 ± 0.03 for Matla, 0.44 ± 0.05 for Lethabo, and 0.53 ± 0.08 for Rooiwal. Such values indicate a pyrolytic source of PAHs. Higher molecular weight PAHs (five to six rings) were predominant, suggesting coal combustion sources. A good correlation existed between most of the PAHs implying that these compounds were emitted from similar sources. The carcinogenic potency B[a]P equivalent concentration (B[a] Peq) at the three power plants ranged from 3.61 to 25.25 indicating a high carcinogenic burden. The highest (B[a] Peq) was found in samples collected around Matla power station. It can therefore be concluded that the soils were contaminated with PAHs originating from coal-fired power stations.

  12. Environmental carcinogenic polycyclic aromatic hydrocarbons in soil from Himalayas, India: Implications for spatial distribution, sources apportionment and risk assessment.

    Science.gov (United States)

    Devi, Ningombam Linthoingambi; Yadav, Ishwar Chandra; Shihua, Qi; Dan, Yang; Zhang, Gan; Raha, Priyankar

    2016-02-01

    The Indian Himalayan Region (IHR) is one of the important mountain ecosystems among the global mountain system which support wide variety of flora, fauna, human communities and cultural diversities. Surface soil samples (n = 69) collected from IHR were analysed for 16 priority polycyclic aromatic hydrocarbons (PAH) listed by USEPA. The ∑16PAH concentration in surface soil ranged from 15.3 to 4762 ngg(-1) (mean 458 ngg(-1)). The sum total of low molecular weight PAH (∑LMW-PAHs) (mean 74.0 ngg(-1)) were relatively lower than the high molecular weight PAH (∑HMW-PAHs) (mean 384 ngg(-1)). The concentration of eight carcinogenic PAHs (BaA, CHR, BbF, BkF, BaP, DahA, IcdP, BghiP) were detected high in mountain soil from IHR and ranged from 0.73 to 2729 ngg(-1) (mean 272 ngg(-1)). Based on spatial distribution map, high concentration of HMW- and LMW-PAHs were detected at GS1 site in Guwahati (615 and 4071 ngg(-1)), and lowest concentration of HMW-PAHs were found at IS6 in Itanagar (5.80 ngg(-1)) and LMW-PAHs at DS2 (17.3 ngg(-1)) in Dibrugarh. Total organic carbon (TOC) in mountain soil was poorly connected with ∑PAHs (r(2) = 0.072) and Car-PAHs (r(2) = 0.048), suggesting the little role of TOC in adsorption of PAHs. Isomeric ratio of PAHs showed the source of PAH contamination in IHR is mixed of petrogenic and pyrogenic origin and was affirmed by PAHs composition profile. These source apportionment results were further confirmed by principal component analysis (PCA). Eco-toxicological analysis showed the calculated TEQ for most carcinogenic PAH were 2-4 times more than the Dutch allowed limit, while TEQ of BaP was 25 times high, suggesting increasing trend of carcinogenicity of surface soil.

  13. The Characteristics of Intra-continental Deformation and Hydrocarbon Distribution Controlled by the Himalayan Tectonic Movements in China

    Science.gov (United States)

    JIA, Chengzao

    Based on previous studies and the latest insights from recent petroleum exploration programs, we propose that the characteristics of intra-continental deformation and its distribution, caused by the Himalayan tectonic movements, are controlled by basement framework formed by a collage of microcratons and lithotectonic terranes and dynamic factors such as the Indian/Eurasia collision and subduction of the Pacific plate. The evolution of Himalayan tectonic movements can be resolved by three principal dynamic mechanisms: (1) the uplift of Tibetan Plateau, (2) the coupling of orogenic belts and basins surrounding the Tibetan Plateau, and (3) extensional tectonics in eastern China. The tectonic framework and deformation that resulted from the Himalayan tectonic movements are mainly embodied in four tectonic domains: (1) the uplifted regions of the Tibetan Plateau, (2) the basin-and-range coupling of peripheral Tibetan Plateau, (3) stable regions, and (4) regions of active rifting along the western circum-Pacific margin. Sedimentary basins formed during the Himalayan tectonic movements, can be assorted into three categories: (1) rift basins due to extensional tectonics in east China, such as Bohai Bay Basin and Songliao Basin; (2) basins in central China, controlled by eastward compression of the Tibetan Plateau, which are characteristic of thrusting of basin margin and uplift-denudation in basins; (3) basins in west China such as the Tarim, Junggar and Qaidam Basins, which are associated with north-directed compression and exhibit thrust movements and flexural subsidence along basin margins. Their structural style is that of basin-and-range type. We conclude that Himalayan tectonic movements may have controlled the late hydrocarbon accumulation in China.

  14. Source, distribution, and health risk assessment of polycyclic aromatic hydrocarbons in urban street dust from Tianjin, China.

    Science.gov (United States)

    Yu, Binbin; Xie, Xiujie; Ma, Lena Q; Kan, Haidong; Zhou, Qixing

    2014-02-01

    To better assess and understand potential health risk of urban residents exposed to urban street dust, the total concentration, sources, and distribution of 16 polycyclic aromatic hydrocarbons (PAHs) in 87 urban street dust samples from Tianjin as a Chinese megacity that has undergone rapid urbanization were investigated. In the meantime, potential sources of PAHs were identified using the principal component analysis (PCA), and the risk of residents' exposure to PAHs via urban street dust was calculated using the Incremental Lifetime Cancer Risk (ILCR) model. The results showed that the total PAHs (∑PAHs) in urban street dust from Tianjin ranged from 538 μg kg(-1) to 34.3 mg kg(-1), averaging 7.99 mg kg(-1). According to PCA, the two to three- and four to six-ring PAHs contributed 10.3 and 89.7 % of ∑PAHs, respectively. The ratio of the sum of major combustion specific compounds (ΣCOMB) / ∑PAHs varied from 0.57 to 0.79, averaging 0.64. The ratio of Ant/(Ant + Phe) varied from 0.05 to 0.41, averaging 0.10; Fla/(Fla + Pyr) from 0.40 to 0.68, averaging 0.60; BaA/(BaA + Chry) from 0.29 to 0.51, averaging 0.38; and IcdP/(IcdP + BghiP) from 0.07 to 0.37, averaging 0.22. The biomass combustion, coal combustion, and traffic emission were the main sources of PAHs in urban street dust with the similar proportion. According to the ILCR model, the total cancer risk for children and adults was up to 2.55 × 10(-5) and 9.33 × 10(-5), respectively.

  15. Application of stochastic particle swarm optimization algorithm to determine the graded refractive index distribution in participating media

    Science.gov (United States)

    Wei, Lin-Yang; Qi, Hong; Ren, Ya-Tao; Ruan, Li-Ming

    2016-11-01

    Inverse estimation of the refractive index distribution in one-dimensional participating media with graded refractive index (GRI) is investigated. The forward radiative transfer problem is solved by the Chebyshev collocation spectral method. The stochastic particle swarm optimization (SPSO) algorithm is employed to retrieve three kinds of GRI distribution, i.e. the linear, sinusoidal and quadratic GRI distribution. The retrieval accuracy of GRI distribution with different wall emissivity, optical thickness, absorption coefficients and scattering coefficients are discussed thoroughly. To improve the retrieval accuracy of quadratic GRI distribution, a double-layer model is proposed to supply more measurement information. The influence of measurement errors upon the precision of estimated results is also investigated. Considering the GRI distribution is unknown beforehand in practice, a quadratic function is employed to retrieve the linear GRI by SPSO algorithm. All the results show that the SPSO algorithm is applicable to retrieve different GRI distributions in participating media accurately even with noisy data.

  16. Distribution and sources of aliphatic hydrocarbons and fatty acids in surface sediments of a tropical estuary south west coast of India (Cochin estuary).

    Science.gov (United States)

    Gireeshkumar, T R; Deepulal, P M; Chandramohanakumar, N

    2015-03-01

    Surface sediments samples from the Cochin estuary were measured for elemental, stable isotopic and molecular biomarkers (aliphatic hydrocarbons and fatty acids) to study the sources and distribution of sedimentary organic matter. Concentrations of total organic carbon (TOC), total nitrogen (TN) and stable isotopic ratios of carbon (δ(13)C) ranged from 0.62 to 2.74 %, 0.09 to 0.25 % and -27.5 to 21.7 ‰, respectively. Sedimentary n-alkanes ranged from 6.03 to 43.23 μg g(-1) with an average of 16.79 μg g(-1), while total fatty acids varied from 22.55 to 440.69 μg g(-1). The TOC/TN ratios and δ(13)C suggest a mixture of marine- and terrestrial-derived organic matter in the surface sediments with increasing contributions from marine-derived organic matter towards the seaward side. Long-chain n-alkanes derived from higher plants predominated the inner part of the estuary, while short-chain n-alkanes derived from planktonic sources predominated the bar mouth region. The even carbon preference of the C12-C22 n-alkanes may refer to the direct biogenic contribution from bacteria, fungi and yeast species and to the potential direct petroleum inputs. The presence of odd mid-chain n-alkanes in the sediments indicates the organic matter inputs from submerged and floating macrophytes (water hyacinth). Various molecular indices such as carbon preference index, terrestrial to aquatic ratio, average chain length and the ratios of mid-chain n-alkanes support the aforementioned inferences. The high contribution of odd and branched chain fatty acids along with very low contribution of polyunsaturated fatty acids, suggest the effective utilisation of algae-derived organic matter by bacteria and the effective recycling of labile organic matter in whole settling and deposition processes. The distributional variability of n-alkanes and fatty acids reveals the preferential utilisation of marine-derived organic matter and the selective preservation of terrestrial

  17. Use of remotely sensed precipitation and leaf area index in a distributed hydrological model

    DEFF Research Database (Denmark)

    Andersen, J.; Dybkjær, G.; Jensen, Karsten Høgh

    2002-01-01

    Remotely sensed precipitation from METEOSAT data and leaf area index (LAI) from NOAA AVHRR data is used as input data to the distributed hydrological modelling of three sub catchments (82.000 km(2)) in the Senegal River Basin. Further, root depths of annual vegetation are related to the temporal...... and spatial variation of LAI. The modelling results are compared with results based on conventional input of precipitation and vegetation characteristics. The introduction of remotely sensed LAI shows improvements in the simulated hydrographs, a marked change in the relative proportions of actual...... evapotranspiration comprising canopy evaporation, soil evaporation and transpiration. while no clear trend in the spatial pattern could be found, The remotely sensed precipitation resulted in similar model performances with respect to the simulated hydrographs as with the conventional raingauge input. A simple...

  18. Permafrost distribution in the European Alps: calculation and evaluation of an index map and summary statistics

    Directory of Open Access Journals (Sweden)

    L. Boeckli

    2012-07-01

    Full Text Available The objective of this study is the production of an Alpine Permafrost Index Map (APIM covering the entire European Alps. A unified statistical model that is based on Alpine-wide permafrost observations is used for debris and bedrock surfaces across the entire Alps. The explanatory variables of the model are mean annual air temperatures, potential incoming solar radiation and precipitation. Offset terms were applied to make model predictions for topographic and geomorphic conditions that differ from the terrain features used for model fitting. These offsets are based on literature review and involve some degree of subjective choice during model building. The assessment of the APIM is challenging because limited independent test data are available for comparison and these observations represent point information in a spatially highly variable topography. The APIM provides an index that describes the spatial distribution of permafrost and comes together with an interpretation key that helps to assess map uncertainties and to relate map contents to their actual expression in the terrain. The map can be used as a first resource to estimate permafrost conditions at any given location in the European Alps in a variety of contexts such as research and spatial planning.

    Results show that Switzerland likely is the country with the largest permafrost area in the Alps, followed by Italy, Austria, France and Germany. Slovenia and Liechtenstein may have marginal permafrost areas. In all countries the permafrost area is expected to be larger than the glacier-covered area.

  19. The role of body mass index, insulin, and adiponectin in the relation between fat distribution and bone mineral density

    NARCIS (Netherlands)

    M.C. Zillikens (Carola); A.G. Uitterlinden (André); J.P.T.M. van Leeuwen (Hans); A.L. Berends (Anne); P. Henneman (Peter); J.A.P. Willems van Dijk (Ko); B.A. Oostra (Ben); C.M. van Duijn (Cock); H.A.P. Pols (Huib); F. Rivadeneira Ramirez (Fernando)

    2010-01-01

    textabstractDespite the positive association between body mass index (BMI) and bone mineral density (BMD) and content (BMC), the role of fat distribution in BMD/BMC remains unclear. We examined relationships between BMD/BMC and various measurements of fat distribution and studied the role of BMI, in

  20. Sources and distribution of aliphatic and polyaromatic hydrocarbons in coastal sediments from the Ushuaia Bay (Tierra del Fuego, Patagonia, Argentina).

    Science.gov (United States)

    Commendatore, Marta G; Nievas, Marina L; Amin, Oscar; Esteves, José L

    2012-03-01

    The environmental quality of Ushuaia Bay, located at the southernmost tip of South America, is affected by the anthropogenic pressure of Ushuaia city. In this study, levels and sources of hydrocarbons in coastal sediments were assessed. Aliphatic hydrocarbon fractions ranged between 5.5 and 1185.3 μg/g dry weight and PAHs from not detected to 360 ng/g. Aliphatic diagnostic indices, the nalkanes homologous series occurrence, Aliphatic Unresolved Complex Mixtures (AliUCMs), and pristane and phytane isoprenoids indicated a petrogenic input. Some sites showed biogenic features masked by the anthropogenic signature. Particularly in port areas biodegradation processes were evident. PAH ratios showed a mixture of petrogenic and pyrogenic sources. Aliphatic and aromatic UCMs were strongly correlated, reflecting chronic pollution. Three areas were distinguished inside the bay: (1) east, with low hydrocarbons impact; (2) central, where hydrocarbons accumulation was related to source proximity and sediment characteristics; (3) south-west, where sediment characteristics and current circulation favour hydrocarbons accumulation. Copyright © 2011 Elsevier Ltd. All rights reserved.

  1. Origin and distribution of hydrocarbons and organic matter in the surficial sediments of the Sfax-Kerkennah channel (Tunisia, Southern Mediterranean Sea).

    Science.gov (United States)

    Zaghden, Hatem; Tedetti, Marc; Sayadi, Sami; Serbaji, Mohamed Moncef; Elleuch, Boubaker; Saliot, Alain

    2017-04-15

    We investigated the origin and distribution of aliphatic and polycyclic aromatic hydrocarbons (AHs and PAHs) and organic matter (OM) in surficial sediments of the Sfax-Kerkennah channel in the Gulf of Gabès (Tunisia, Southern Mediterranean Sea). TOC, AH and PAH concentrations ranged 2.3-11.7%, 8-174μgg(-1)sed.dw and 175-10,769ngg(-1)sed.dw, respectively. The lowest concentrations were recorded in the channel (medium sand sediment) and the highest ones in the Sfax harbor (very fine sand sediment). AHs, PAHs and TOC were not correlated for most of the stations. TOC/N and δ(13)C values revealed a mixed origin of OM with both marine and terrestrial sources. Hydrocarbon molecular composition highlighted the dominance of petrogenic AHs and the presence of both petrogenic and pyrogenic PAHs, associated with petroleum products and combustion processes. This work underscores the complex distribution patterns and the multiple sources of OM and hydrocarbons in this highly anthropogenized coastal environment.

  2. Body mass index and distribution of body fat can influence sensory detection and pain sensitivity.

    Science.gov (United States)

    Tashani, O A; Astita, R; Sharp, D; Johnson, M I

    2017-08-01

    The aim of this study was to investigate the influence of body fat percentage and its distribution on sensory detection and pain sensitivity responses to experimentally induced noxious stimuli in otherwise pain-free individuals. Seventy-two participants were divided into three equal groups according to their body mass index (BMI: normal, overweight and obese). Percentage body fat was estimated using a four-site skinfold method. Measurements of cold pressor pain threshold, tolerance and intensity; contact thermal sensory detection and heat pain threshold and tolerance (TSA-II - NeuroSensory Analyzer, Medoc); and blunt pressure pain threshold (algometer, Somedic SenseLab AB) were taken at the waist and thenar eminence. Mean ± SD pressure pain threshold of the obese group (620.72 ± 423.81 kPa) was significantly lower than normal (1154.70 ± 847.18 kPa) and overweight (1285.14 ± 998.89 kPa) groups. Repeated measures ANOVA found significant effects for site for cold detection threshold (F1,68  = 8.3, p = 0.005) and warm detection threshold (F1,68  = 38.69, p = 0.001) with waist having lower sensory detection thresholds than thenar eminence. For heat pain threshold, there were significant effects for site (F1,68  = 4.868, p = 0.031) which was lower for waist compared with thenar eminence (mean difference = 0.89 °C). Obese individuals were more sensitive than non-obese individuals to pressure pain but not to thermal pain. Body sites may vary in their response to different types and intensities of stimuli. The inconsistency of findings within and between research studies should catalyse further research in this field. This study provided evidence that body mass index and distribution of body fat can influence sensory detection and pain sensitivity. Obese individuals were more sensitive than normal range body mass index individuals to pressure pain but not to thermal pain. Pain response varied according to subcutaneous body fat at different body

  3. Distribution of MEG and methanol in well-defined hydrocarbon and water systems: Experimental measurement and modeling using the CPA EoS

    DEFF Research Database (Denmark)

    Riaz, Muhammad; Yussuf, Mustafe A.; Kontogeorgis, Georgios;

    2013-01-01

    and MEG) in various phases is modeled using CPA. The hydrocarbon phase consists of mixture-1 (methane, ethane, n-butane) or mixture-2 (methane, ethane, propane, n-butane, n-heptane, toluene and n-decane). CPA can satisfactorily predict the water content in the gas phase of the multicomponent systems...... + water. These data are satisfactorily correlated (binaries) and predicted (ternaries) using Cubic Plus Association (CPA) equation of state (EoS). CPA is also applied to binary LLE of aromatic hydrocarbon + water and VLE of methane + methanol. Finally the distribution of water and inhibitors (methanol...... containing mixture-1 over a range of temperatures and pressures. Similarly the methanol content in the gas phase of mixture-1 + water + methanol systems is predicted satisfactorily with accuracy within experimental uncertainty. For VLLE of mixture-2. +. water, mixture-2 + MEG + water and mixture-2 + methanol...

  4. Baseline distributions and sources of Polycyclic Aromatic Hydrocarbons (PAHs) in the surface sediments from the Prai and Malacca Rivers, Peninsular Malaysia.

    Science.gov (United States)

    Keshavarzifard, Mehrzad; Zakaria, Mohamad Pauzi; Hwai, Tan Shau; Yusuff, Ferdius Ferdius Mohamat; Mustafa, Shuhaimi; Vaezzadeh, Vahab; Magam, Sami M; Masood, Najat; Alkhadher, Sadeq A A; Abootalebi-Jahromi, Fatemeh

    2014-11-15

    In this study, the surface sediments of the Malacca and Prai Rivers were analyzed to identify the distributions, and sources of Polycyclic Aromatic Hydrocarbons (PAHs). The total PAH concentrations varied from 716 to 1210 and 1102 to 7938 ng g(-1)dw in the sediments of the Malacca and Prai Rivers, respectively. The PAH concentrations can be classified as moderate and high level of pollution in the sediments of the Malacca and Prai Rivers, respectively. The comparison of PAHs with the Sediment Quality Guidelines (SQGs) indicates that the PAHs in the sediments of the Malacca and Prai Rivers may have the potential to cause adverse toxicity effects on the sampled ecosystems. The diagnostic ratios of individual PAHs indicate both petrogenic- and pyrogenic-origin PAHs with dominance of pyrogenic source in both rivers. These findings demonstrate that the environmental regulations in Malaysia have effectively reduced the input of petrogenic petroleum hydrocarbons into rivers.

  5. Aerosol size distribution and refractive index from bistatic lidar angular scattering measurements in the surface layer

    Energy Technology Data Exchange (ETDEWEB)

    Pandithurai, G.; Devara, P.C.S.; Raj, P.E.; Sharma, S. [Indian Inst. of Tropical Meteorology, Pune (India)

    1996-05-01

    The results of an inversion method by iteration for determining the aerosol size distribution and the refractive index of atmospheric aerosols in the surface layer from bistatic lidar angular scattering measurements, followed by a brief description of the experimental and data retrieval techniques are presented. The continuous wave, bistatic Argon ion lidar at the Indian Institute of Tropical Meteorology (IITM), Pune (18{degree}31{prime}N, 73{degree}51{prime}E, 559 m AMSL), India has been used for the measurements. Results of the analysis of 420 samples collected over a 7 years` period indicate mean value of size and refractive indices of 4.0 and 1.6, respectively, with greater fraction of larger particles during premonsoon while smaller particles during post-monsoon months at the lidar site. The retrieved aerosol parameters are compared with those determined from spectroradiometer observations at the same site. The results are found well in agreement with those obtained previously by the authors using the library search method. The above observations of angular distribution of scattered intensity are used with an aerosol model to infer the dominant type of aerosols present in the environment in and around the experimental station.

  6. Spatial distribution of the daily rainfall concentration index in Argentina: comparison with other countries

    Science.gov (United States)

    Llano, María Paula

    2017-08-01

    The precipitation is a meteorological variable studied in Argentina mainly in annual, seasonal and monthly scales. Its variability is a significant climate element and also a critical socioeconomic factor. This study aims to contribute to the knowledge of daily rainfall in Argentina. Daily records of precipitation for 66 stations provided by the Servicio Meteorológico Nacional are used (period 1991-2014). The spatial distribution of the annual precipitation presents an east-west gradient in the north of the country. In monthly scale, there are different precipitation distributions such as a double maximum in the centre-east zone or a single maximum in the northwest in summer time and in the southern Andes range during the winter. To carry out the study, the concentration index (CI) of daily precipitation with a resolution of 1 mm is used. Precipitation in Argentina, given its vast territory, presents a great variability with a wide range of rainfall regimes; CI values are found between 0.54 and 0.68. These values are categorized as high (greater than 0.61) and low (less than 0.58). The north of the country and the Atlantic coast show the highest CI values. The lower values are present in the Andes range and in the south of the country. The results are compared with other studies in the world.

  7. A theoretical drought classification method for the multivariate drought index based on distribution properties of standardized drought indices

    Science.gov (United States)

    Hao, Zengchao; Hao, Fanghua; Singh, Vijay P.; Xia, Youlong; Ouyang, Wei; Shen, Xinyi

    2016-06-01

    Drought indices have been commonly used to characterize different properties of drought and the need to combine multiple drought indices for accurate drought monitoring has been well recognized. Based on linear combinations of multiple drought indices, a variety of multivariate drought indices have recently been developed for comprehensive drought monitoring to integrate drought information from various sources. For operational drought management, it is generally required to determine thresholds of drought severity for drought classification to trigger a mitigation response during a drought event to aid stakeholders and policy makers in decision making. Though the classification of drought categories based on the univariate drought indices has been well studied, drought classification method for the multivariate drought index has been less explored mainly due to the lack of information about its distribution property. In this study, a theoretical drought classification method is proposed for the multivariate drought index, based on a linear combination of multiple indices. Based on the distribution property of the standardized drought index, a theoretical distribution of the linear combined index (LDI) is derived, which can be used for classifying drought with the percentile approach. Application of the proposed method for drought classification of LDI, based on standardized precipitation index (SPI), standardized soil moisture index (SSI), and standardized runoff index (SRI) is illustrated with climate division data from California, United States. Results from comparison with the empirical methods show a satisfactory performance of the proposed method for drought classification.

  8. Co-control of source and heat: the generation and distribution of hydrocarbons controlled by source rocks and heat%源热共控论

    Institute of Scientific and Technical Information of China (English)

    张功成

    2012-01-01

    Hydrocarbon generation is co-controlled by source rocks and heat, which are internal and external controlling factors, respectively. The combination of these two factors controls the generation, scale, phase (oil or gas) behavior and regional distribution pattern of hydrocarbons. The controlling factors of potential hydrocarbon source rocks include the type, abundance and scale of source rocks. Their heat field consists of hot, warm and cold models and there are 3 types of thermal evolution, I. E. Temperature-increasing, temperature-decreasing and complex multi-episode types. In potential hydrocarbon-generating sags, there are 4 kinds of combination between source rocks and heat, namely sufficient source and heat, sufficient source but deficient heat, deficient source but sufficient heat, and deficient source and heat. The sufficient source and heat combination can form hydrocarbon-generating sags including hydrocarbon-prolific or hydrocarbon-bearing sags, and the sufficient source but deficient heat combination or the deficient source but sufficient heat combination can also form hydrocarbon-generating or hydrocarbon-prolific sags on condition that source and heat can complement each other, while the deficient source and heat combination can not form hydrocarbon-bearing sags. In a hydrocarbon province co-controlled by source and heat, oil, gas or oil-gas layers generally have a spatially ordered distribution, which is characterized vertically by a lower oil and upper gas pattern or a lower gas and upper oil pattern, and laterally hy an inner and outer belt pattern, an inner and outer circle pattern, or a zoning pattern. The scale of hydrocarbon reserves in this hydrocarbon province depends mainly on the development of the sufficient source and heat sag, and hydrocarbon-bearing basins in China can be roughly classified into extra-prolific, prolific, medium, small and poor hydrocarbon-bearing basins.%源热共控油气形成,潜在烃源岩是油气形成的内因,

  9. Vertical distribution and anaerobic biodegradation of polycyclic aromatic hydrocarbons in mangrove sediments in Hong Kong, South China

    Energy Technology Data Exchange (ETDEWEB)

    Li, Chun-Hua [Department of Biology and Chemistry, City University of Hong Kong, Tat Chee Avenue, Kowloon (Hong Kong); Zhou, Hong-Wei [Department of Environmental Health Science, School of Public Health and Tropical Medicine, Southern Medical University, Guangzhou (China); Wong, Yuk-Shan [Department of Biology, The Hong Kong University of Science and Technology (Hong Kong); Tam, Nora Fung-Yee, E-mail: bhntam@cityu.edu.hk [Department of Biology and Chemistry, City University of Hong Kong, Tat Chee Avenue, Kowloon (Hong Kong)

    2009-10-15

    The vertical distribution of polycyclic aromatic hydrocarbons (PAHs) at different sediment depths, namely 0-2 cm, 2-4 cm, 4-6 cm, 6-10 cm, 10-15 cm and 15-20 cm, in one of the most contaminated mangrove swamps, Ma Wan, Hong Kong was investigated. It was the first time to study the intrinsic potential of deep sediment to biodegrade PAHs under anaerobic conditions and the abundance of electron acceptors in sediment for anaerobic degradation. Results showed that the total PAHs concentrations (summation of 16 US EPA priority PAHs) increased with sediment depth. The lowest concentration (about 1300 ng g{sup -1} freeze-dried sediment) and the highest value (around 5000 ng g{sup -1} freeze-dried sediment) were found in the surface layer (0-2 cm) and deeper layer (10-15 cm), respectively. The percentage of high molecular weight (HMW) PAHs (4 to 6 rings) to total PAHs was more than 89% at all sediment depths. The ratio of phenanthrene to anthracene was less than 10 while fluoranthene to pyrene was around 1. Negative redox potentials (Eh) were recorded in all of the sediment samples, ranging from - 170 to - 200 mv, with a sharp decrease at a depth of 6 cm then declined slowly to 20 cm. The results suggested that HMW PAHs originated from diesel-powered fishing vessels and were mainly accumulated in deep anaerobic sediments. Among the electron acceptors commonly used by anaerobic bacteria, sulfate was the most dominant, followed by iron(III), nitrate and manganese(IV) was the least. Their concentrations also decreased with sediment depth. The population size of total anaerobic heterotrophic bacteria increased with sediment depth, reaching the peak number in the middle layer (4-6 cm). In contrast, the aerobic heterotrophic bacterial count decreased with sediment depth. It was the first time to apply a modified electron transport system (ETS) method to evaluate the bacterial activities in the fresh sediment under PAH stress. The vertical drop of the ETS activity suggested that

  10. [Distribution Characteristics and Source Analysis of Polycyclic Aromatic Hydrocarbons (PAHs) in Surface Dust of Xi'an City, China].

    Science.gov (United States)

    Wang, Li; Wang, Li-jun; Shi, Xing-min; Lu, Xin-wei

    2016-04-15

    A total of 58 surface dust samples were collected from Xi'an city. The concentrations of 16 priority polycyclic aromatic hydrocarbons (PAHs) were analyzed by gas chromatography with a flame ionization detector (GC-FID). At the same time, the distribution and sources of PAHs in surface dust were studied. The results showed that the concentrations of individual PAH ranged from 14.69 to 6370. 48 microg x kg(-1), and the total concentrations of 16 PAHs (∑16 PAHs) ranged from 5039.67 to 47,738.50 microg x kg(-1), with a mean of 13,845.82 microg x kg(-1). Compared to the Y PAHs levels of other cities, the ∑16 PAHs in surface dust of Xi'an belonged to a relatively higher level. PAHs in surface dust were mainly dominated by high molecular weight PAHs with 4-6 rings and the concentration of 7 carcinogenic PAHs (1 CPAHs) accounted for 46.08% of 3 16PAHs. The mean of ∑16 PAHs in surface dust had the highest concentration at industrial area; followed by the educational area, traffic area, business and traffic area; residential area and parks showed relatively lower concentration. The average content of ∑16 PAHs in surface dust presented an increasing trend along the main urban area--the second ring road--the third ring road. ∑16 PAHs in surface dust had higher concentrations at the industrial areas of the east and west suburbs of Xi'an, the south suburb and the north section of the second ring road; ∑16 PAHs concentrations in the main urban area, north suburb and southeast part of Xi'an were relatively lower. The results of ratio, cluster analysis and principal component analysis showed that PAHs in surface dust were mainly originated from the combustion of fossil fuels and coal combustion. Among them, diesel combustion reached 36.07%, gasoline combustion accounted for 32.31%, and coal combustion was resposbe for 23.40%

  11. Partial index replicated and distributed scheme for full-text search on wireless broadcast

    Indian Academy of Sciences (India)

    Vikas Goel; Anil Kumar Ahlawat; M N Gupta

    2015-10-01

    Information indexing is an extremely useful solution for wireless broadcast channels, because of its energy efficiency. Full text search on the wireless broadcast stream is another popular type of information dissemination access. This research paper discusses indexing schemes for full text search information, using two levels of structure B+ tree and inverted list. The partial replication in the B+ tree indexing scheme is proposed to extend the existing full text search indexing scheme. In the proposed work, the index information of B+ tree has been cut to reduce access time and tuning time: metrics for evaluating indexing schemes. The replication in B+ tree may be done up to a certain level of the indexed informat+ion (Data). Evaluation and analysis of the proposed indexing scheme show an excellent improvement over existing indexing schemes.

  12. Bacterial sources for phenylalkane hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Ellis, L.; Winans, R.E. [Argonne National Lab., IL (United States); Langworthy, T. [Univ. of South Dakota, Vermillion, SD (United States)

    1996-10-01

    The presence of phenylalkane hydrocarbons in geochemical samples has been the source of much controversy. Although an anthropogenic input from detergent sources always appears likely, the distribution of phenylalkane hydrocarbons in some cases far exceeding that attributed to detergent input has led to a reappraisal of this view. Indeed, recent work involving analysis of the lipid hydrocarbon extracts from extant Thermoplasma bacteria has revealed the presence of phenylalkane hydrocarbons. The presence of phenylalkane hydrocarbons in sedimentary organic matter may therefore represent potential biological markers for thermophilic bacteria.

  13. Spatial Distribution of Zeolite ZSM-5 within Catalyst Bodies Affects Selectivity and Stability of Methanol-to-Hydrocarbons Conversion

    NARCIS (Netherlands)

    Castaño, P.; Ruiz-Martinez, J.; Epelde, E.; Gayubo, A.G.; Weckhuysen, B.M.

    2013-01-01

    Solid acids, such as zeolites, are used as catalyst materials in a wide variety of important crude oil refinery, bulk chemical synthesis, and green processes. Examples include fluid catalytic cracking (FCC),[1] methanol-to-hydrocarbons (MTH) conversion,[ 2] plastic waste valorization,[3] and biomass

  14. Application of Topology Index in Aliphatic Aldehydes,Fatty Amines and Aliphatic Hydrocarbons Boiling Point%拓扑指数在脂肪醛、脂肪胺及脂肪烃沸点中的应用

    Institute of Scientific and Technical Information of China (English)

    周长会; 吴启勋; 侯庆高; 高宴梓; 李洪囡; 张瑞

    2013-01-01

    Two matrices and a topological index W were defined,then,topological index W was put into nonlinear regression with the boiling point of aliphatic aldehydes, fatty amines and aliphatic hydrocarbons, respectively, and with good results,the correlation coefficient reaches a good level. The established topological index and two kinds of matrix are easy and convenient to use, which can quickly predict the boiling point of the molecule.%定义了两种矩阵和一种拓扑指数W,将拓扑指数W分别与脂肪醛、脂肪胺及脂肪烃的沸点进行非线性回归,取得了较好的结果,相关性系数达到了良好级别.建立的拓扑指数和两种矩阵简洁方便,可以快速预测分子的沸点.

  15. Fluorescence imaging of lattice re-distribution on step-index direct laser written Nd:YAG waveguide lasers

    Energy Technology Data Exchange (ETDEWEB)

    Martínez de Mendívil, Jon; Pérez Delgado, Alberto; Lifante, Ginés; Jaque, Daniel [Departamento de Física de Materiales, Facultad de Ciencias, Universidad Autónoma de Madrid, Madrid 28049 (Spain); Ródenas, Airán [Departament de Química Física i Inorgànica, Universitat Rovira i Virgili, Tarragona 43007 (Spain); Institute of Photonics and Quantum Sciences, Heriot-Watt University, Edinburgh EH14 4AS (United Kingdom); Benayas, Antonio, E-mail: antonio.benayas@emt.inrs.ca [Departamento de Física de Materiales, Facultad de Ciencias, Universidad Autónoma de Madrid, Madrid 28049 (Spain); Institut National de la Recherche Scientifique, Centre – Énergie Matériaux et Télécommunications, 1650, Boul. Lionel Boulet Varennes, Quebec J3X 1S2 (Canada); Aguiló, Magdalena; Diaz, Francesc [Departament de Química Física i Inorgànica, Universitat Rovira i Virgili, Tarragona 43007 (Spain); Kar, Ajoy K. [Institute of Photonics and Quantum Sciences, Heriot-Watt University, Edinburgh EH14 4AS (United Kingdom)

    2015-01-14

    The laser performance and crystalline micro-structural properties of near-infrared step-index channel waveguides fabricated inside Neodymium doped YAG laser ceramics by means of three-dimensional sub-picosecond pulse laser direct writing are reported. Fluorescence micro-mapping of the waveguide cross-sections reveals that an essential crystal lattice re-distribution has been induced after short pulse irradiation. Such lattice re-distribution is evidenced at the waveguide core corresponding to the laser written refractive index increased volume. The waveguides core surroundings also present diverse changes including slight lattice disorder and bi-axial strain fields. The step-index waveguide laser performance is compared with previous laser fabricated waveguides with a stress-optic guiding mechanism in absence of laser induced lattice re-distribution.

  16. Fluorescence imaging of lattice re-distribution on step-index direct laser written Nd:YAG waveguide lasers

    Science.gov (United States)

    Martínez de Mendívil, Jon; Ródenas, Airán; Benayas, Antonio; Aguiló, Magdalena; Diaz, Francesc; Pérez Delgado, Alberto; Lifante, Ginés; Jaque, Daniel; Kar, Ajoy K.

    2015-01-01

    The laser performance and crystalline micro-structural properties of near-infrared step-index channel waveguides fabricated inside Neodymium doped YAG laser ceramics by means of three-dimensional sub-picosecond pulse laser direct writing are reported. Fluorescence micro-mapping of the waveguide cross-sections reveals that an essential crystal lattice re-distribution has been induced after short pulse irradiation. Such lattice re-distribution is evidenced at the waveguide core corresponding to the laser written refractive index increased volume. The waveguides core surroundings also present diverse changes including slight lattice disorder and bi-axial strain fields. The step-index waveguide laser performance is compared with previous laser fabricated waveguides with a stress-optic guiding mechanism in absence of laser induced lattice re-distribution.

  17. Distributions and source apportionment of sediment-associated polycyclic aromatic hydrocarbons (PAHs) and hopanes in rivers and estuaries of Peninsular Malaysia.

    Science.gov (United States)

    Keshavarzifard, Mehrzad; Zakaria, Mohamad Pauzi; Hwai, Tan Shau; Yusuff, Ferdius Mohamat; Mustafa, Shuhaimi

    2015-06-01

    In this study, the distributions and sources of sediment-associated polycyclic aromatic hydrocarbons (PAHs) and hopanes in the Malaysian rivers and estuaries were evaluated. The concentrations of 16 USEPA PAHs varied from 225.5 to 293.9 (Perlis River), 195.2 to 481.2 (Kedah River), 791.2 to 1995.4 (Merbok River), 231.2 to 426.7 (Perak River), and 3803.2 to 7442.7 ng g(-1) (Klang River) dry weight. PAHs can be classified as moderate in the Perlis, Kedah, and Perak Rivers, moderate to high in the Merbok River, and high to very high in the Klang River. The comparison of PAHs with sediment quality guidelines (SQGs) indicates that occasionally adverse biological effects may occur from total PAHs, low molecular weight (LMW), and high molecular weight (HMW) PAHs at stations 1, 2, and 3 of the Klang River and from total PAHs at station 2 of the Merbok River. The diagnostic ratios of individual PAHs indicate both petrogenic and pyrogenic origin PAHs with significant dominance of pyrogenic sources in the study areas. The results suggest that Malaysian sediments had hopane ratios (C29/C30) similar to MECO suggesting MECO as a major source of the petroleum hydrocarbons found in the sediments, which is consistent with results reported in previous studies. These findings demonstrate that effective and improved environmental regulations in Malaysia have shifted the source of petroleum hydrocarbons from petrogenic to pyrogenic origin.

  18. In-Network Historical Data Storage and Query Processing Based on Distributed Indexing Techniques in Wireless Sensor Networks

    Science.gov (United States)

    Ai, Chunyu; Du, Ruiying; Zhang, Minghong; Li, Yingshu

    Most of existing data processing approaches of wireless sensor networks are real-time. However, historical data of wireless sensor networks are also significant for various applications. No previous study has specifically addressed distributed historical data query processing. In this paper, we propose an Index based Historical Data Query Processing scheme which stores historical data locally and processes queries energy-efficiently by using a distributed index tree. The simulation study shows that our scheme achieves good performance on both query responding delay and network traffic.

  19. The spatial distribution characteristics of a comprehensive drought risk index in southwestern China and underlying causes

    Science.gov (United States)

    Han, Lanying; Zhang, Qiang; Ma, Pengli; Jia, Jianying; Wang, Jinsong

    2016-05-01

    Drought is a serious problem in southwestern China, where drought risk exceeds the national average. Climate change is likely to exacerbate the problem, thereby endangering China's food security. In this paper, we used the analytic hierarchy process and meteorological, geographic, soil, and remote-sensing data to develop a drought risk assessment model based on the drought hazard, environmental vulnerability, sensitivity and exposure of the values at risk, and capacity to prevent or mitigate the problem. Using the model, we assessed the drought risk (defined using a comprehensive drought risk index, R) and its spatial distribution in southwestern China and revealed complex zonality. The eastern part of the study area had an extremely high risk, and risk was generally greater in the north than in the south, and increased from southwest to northeast. The comprehensive risk ( R) was lowest in Yunnan province. It was highest in Sichuan Province and Chongqing Municipality. The contribution of the risk factors to R was highest for the capacity for prevention and mitigation, followed by the drought hazard, sensitivity and exposure, and environmental vulnerability.

  20. Ultra-weak FBG and its refractive index distribution in the drawing optical fiber.

    Science.gov (United States)

    Guo, Huiyong; Liu, Fang; Yuan, Yinquan; Yu, Haihu; Yang, Minghong

    2015-02-23

    For the online writing of ultra-weak fiber Bragg gratings (FBGs) in the drawing optical fibers, the effects of the intensity profile, pulse fluctuation and pulse width of the excimer laser, as well as the transverse and longitudinal vibrations of the optical fiber have been investigated. Firstly, using Lorentz-Loren equation, Gladstone-Dale mixing rule and continuity equation, we have derived the refractive index (RI) fluctuation along the optical fiber and the RI distribution in the FBG, they are linear with the gradient of longitudinal vibration velocity. Then, we have prepared huge amounts of ultra-weak FBGs in the non-moving optical fiber and obtained their reflection spectra, the measured reflection spectra shows that the intensity profile and pulse fluctuation of the excimer laser, as well as the transverse vibration of the optical fiber are little responsible for the inconsistency of ultra-weak FBGs. Finally, the effect of the longitudinal vibration of the optical fiber on the inconsistency of ultra-weak FBGs has been discussed, and the vibration equations of the drawing optical fiber are given in the appendix.

  1. Root Ecological Niche Index and Root Distribution Characteristics of Artificial Phytocommunities in Rehabilitated Fields

    Institute of Scientific and Technical Information of China (English)

    Hu Jianzhong; Zhen Jiali; Shen Jingyu

    2006-01-01

    In the implementation phase of the Conversion of Cropland to Forest and Grassland (CCFG) project in China,it is important,from a scientific point of view,to recognize phytocommunities' characteristics,species compatibility,and ecological function.The ecological niche that roots occupy,their abundance and distribution,and the factors that affect them must be acknowledged.Following the methodology of community ecology,the total root mass of a phytocommunity is measured as cubic volume.Root biomass,length,and the number of roots in every diameter class,for each soil layer and for each plant species,are regarded as observation variables.In the first instance therefore,a new method to calculate the root ecological niche index (REND is proposed,embracing the entire phytocommunity of plantations.Using the new method,the roots of pbytocommunities in Datong County,Qinghai Province (one of the counties selected for the national CCFG experiment),are dealt with in this paper.The results show that most of the vertical distributions of plant roots belong to the type wherein the roots are concentrated in the topsoil layer (0-20 cm),far more than those in the lower soil layers.The RENI of pbytocommunities is higher than that of pure stands or monocultures.The distribution of RENI by root diameter can be divided into four types:J-type,inverse J-type,recumbent S-type,and U-type.RENI is positively correlated with the wet biomass of aboveground level stems,branches,and plant leaves,and with the species richness of phytocommunities.Although the RENIs of plantations in rehabilitated fields are a little lower than those of natural forests,they are higher than those of cultivated crops.The RENIs of three community types (Picea crassifolia+Hippophae rhamnoides ssp.sinensis,H.rhamnoides ssp.sinensis,and P.crassifolia) in rehabilitated fields benefit greatly from the restoration project.The implementation of the CCFG project is important for the increase in RENI and the multiple functions of

  2. Hydrocarbons and Air Pollution: An Annotated Bibliography. Part I., Categories A to E and Part II., Categories F to M and Indexes.

    Science.gov (United States)

    National Air Pollution Control Administration (DHEW), Raleigh, NC.

    This two-part bibliography represents an effort to collect, condense, and organize the literature on the hydrocarbons in relation to air pollution. The approximately 2,300 documents abstracted are all included in the information storage and retrieval system of the National Air Pollution Control Administration's (NAPCA) Air Pollution Technical…

  3. Microbial degradation of petroleum hydrocarbons.

    Science.gov (United States)

    Varjani, Sunita J

    2017-01-01

    Petroleum hydrocarbon pollutants are recalcitrant compounds and are classified as priority pollutants. Cleaning up of these pollutants from environment is a real world problem. Bioremediation has become a major method employed in restoration of petroleum hydrocarbon polluted environments that makes use of natural microbial biodegradation activity. Petroleum hydrocarbons utilizing microorganisms are ubiquitously distributed in environment. They naturally biodegrade pollutants and thereby remove them from the environment. Removal of petroleum hydrocarbon pollutants from environment by applying oleophilic microorganisms (individual isolate/consortium of microorganisms) is ecofriendly and economic. Microbial biodegradation of petroleum hydrocarbon pollutants employs the enzyme catalytic activities of microorganisms to enhance the rate of pollutants degradation. This article provides an overview about bioremediation for petroleum hydrocarbon pollutants. It also includes explanation about hydrocarbon metabolism in microorganisms with a special focus on new insights obtained during past couple of years. Copyright © 2016 Elsevier Ltd. All rights reserved.

  4. Occurrence and distribution of polycyclic aromatic hydrocarbons in mussels from the gulf of Naples, Tyrrhenian Sea, Italy.

    Science.gov (United States)

    Mercogliano, Raffaelina; Santonicola, Serena; De Felice, Alessandra; Anastasio, Aniello; Murru, Nicoletta; Ferrante, Maria Carmela; Cortesi, Maria Luisa

    2016-03-15

    To assess the potential impact of the industrial activity on food safety and risk for consumers, the aim of the study was to evaluate the levels of 14 polycyclic aromatic hydrocarbons (PAH) in 69 samples of wild and farm Mytilus galloprovincialis, collected in sites of coast of Gulf of Naples, Tyrrhenian Sea. All hydrocarbons were found in samples. Higher levels of pyrolytic PAHs were in wild than in farm mussels. Benzo(a)pyrene exceeded the Regulation (EC) n.835/11 levels of 1 μg/kg in 15 samples (71.42%) of wild and 25 samples (65.79%) of farm mussels. System of sum of 4 hydrocarbons exceeded the law level in 15 samples (71.42%) of wild and 21 samples (55.26%) of farm mussels. Wild mussel levels showed a potential impact of pyrolytic sources of PAH on food safety. Occurrence of carcinogenic PAHs should be a cause for concern, in areas where the mussels are being farmed for human consumption.

  5. Assessing regulatory violations of disinfection by-products in water distribution networks using a non-compliance potential index.

    Science.gov (United States)

    Islam, Nilufar; Sadiq, Rehan; Rodriguez, Manuel J; Legay, Christelle

    2016-05-01

    Inactivating pathogens is essential to eradicate waterborne diseases. However, disinfection forms undesirable disinfection by-products (DBPs) in the presence of natural organic matter. Many regulations and guidelines exist to limit DBP exposure for eliminating possible health impacts such as bladder cancer, reproductive effects, and child development effects. In this paper, an index named non-compliance potential (NCP) index is proposed to evaluate regulatory violations by DBPs. The index can serve to evaluate water quality in distribution networks using the Bayesian Belief Network (BBN). BBN is a graphical model to represent contributing variables and their probabilistic relationships. Total trihalomethanes (TTHM), haloacetic acids (HAA5), and free residual chlorine (FRC) are selected as the variables to predict the NCP index. A methodology has been proposed to implement the index using either monitored data, empirical model results (e.g., multiple linear regression), and disinfectant kinetics through EPANET simulations. The index's usefulness is demonstrated through two case studies on municipal distribution systems using both full-scale monitoring and modeled data. The proposed approach can be implemented for data-sparse conditions, making it especially useful for smaller municipal drinking water systems.

  6. Distribution and geological significance of 17α(H)-diahopanes from different hydrocarbon source rocks of Yanchang Formation in Ordos Basin

    Institute of Scientific and Technical Information of China (English)

    ZHANG WenZheng; YANG Hua; HOU LiHui; LIU Fei

    2009-01-01

    Based on GC-MS testing data of many saturated hydrocarbon samples, 17α(H)-30 diahopanes (C30*) are extensively distributed in the lacustrine hydrocarbon source rocks of the Yanchang Formation in Ordos Basin, but show remarkable differences in relative abundance among various source rocks. Generally, Chang 7 high-quality source rock (oil shale) developed in deep lake anoxic environment shows lower C30* content, whereas Chang 6-9 dark mudstone developed in shallow to semi-deep lake, sub-oxidiz- ing environment shows relatively high to high C30* value. Particularly, Chang 7 and Chang 9 black mudstones in Zhidan region in the northeast of the lake basin show extremely high C30* value. A com- parative analysis was made based on lithology, organic types and various geochemical parameters indicative of redox environment, and the results indicate that environmental factors such as redox set- tings and lithology are key factors that control the C30* relative abundance, while organic types and maturity may be minor factors. High to extremely high C30* values are indicative of sub-oxidizing envi- ronment of fresh-brackish water and shallow to semi-deep lake. Therefore, research on C30* relative content and distribution in lacustrine hydrocarbon source rocks in the Yanchang Formation, especially on the difference in C30* between Chang 7 high-quality source rocks (oil shale) and Chang 6-91 source rocks (dark mudstone), will provide an important approach for classification of Mesozoic lacustrine crudes and detailed oil-source correlation in the basin.

  7. Distribution and geological significance of 17α(H)-diahopanes from different hydrocarbon source rocks of Yanchang Formation in Ordos Basin

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Based on GC-MS testing data of many saturated hydrocarbon samples, 17α(H)-C30 diahopanes (C30*) are extensively distributed in the lacustrine hydrocarbon source rocks of the Yanchang Formation in Ordos Basin, but show remarkable differences in relative abundance among various source rocks. Generally, Chang 7 high-quality source rock (oil shale) developed in deep lake anoxic environment shows lower C30* content, whereas Chang 6-9 dark mudstone developed in shallow to semi-deep lake, sub-oxidizing environment shows relatively high to high C30* value. Particularly, Chang 7 and Chang 9 black mudstones in Zhidan region in the northeast of the lake basin show extremely high C30* value. A comparative analysis was made based on lithology, organic types and various geochemical parameters indicative of redox environment, and the results indicate that environmental factors such as redox settings and lithology are key factors that control the C30* relative abundance, while organic types and maturity may be minor factors. High to extremely high C30* values are indicative of sub-oxidizing environment of fresh-brackish water and shallow to semi-deep lake. Therefore, research on C30* relative content and distribution in lacustrine hydrocarbon source rocks in the Yanchang Formation, especially on the difference in C30* between Chang 7 high-quality source rocks (oil shale) and Chang 6-91 source rocks (dark mudstone), will provide an important approach for classification of Mesozoic lacustrine crudes and detailed oil-source correlation in the basin.

  8. Refractive-index distributions generating as light rays a given family of curves lying on a surface.

    Science.gov (United States)

    Borghero, Francesco; Kotoulas, Thomas

    2011-02-01

    In the framework of geometrical optics, we consider the inverse problem consisting in obtaining refractive-index distributions n=n(u,v) of a two-dimensional transparent inhomogeneous isotropic medium from a known family f(u,v)=c of monochromatic light rays, lying on a given regular surface. Using some basic concepts of differential geometry, we establish a first-order linear partial differential equation relating the assigned family of light rays with all possible refractive-index profiles compatible with this family. In particular, we study the refractive-index distribution producing, as light rays, a given family of geodesic lines on some remarkable surfaces. We give appropriate examples to explain the theory.

  9. Distribution Characteristics of Effective Source Rocks and Their Control on Hydrocarbon Accumulation:A Case Study from the Dongying Sag, Eastern China

    Institute of Scientific and Technical Information of China (English)

    ZHU Guangyou; JIN Qiang; ZHANG Shuichang; DAI Jinxing; ZHANG Linye; LI Jian

    2004-01-01

    the basin's margin via lateral migration and the reservoirs are dominated by the buried hill and stratigraphic types, while hydrocarbons generated from source rocks of the brackish lake facies are mainly distributed in the basin's center via vertical migration and characterized by forming lithologic reservoirs. Also, the reservoirs located in the transitional belts have complex types and mostly controlled by faults, characterized by block (structural-lithologic) reservoirs, and the crude oils mainly come from source beds of Es13 and Es24 respectively.

  10. Some quantitative relationships between leaf area index and canopy nitrogen content and distribution.

    Science.gov (United States)

    Yin, Xinyou; Lantinga, Egvert A; Schapendonk, Ad H C M; Zhong, Xuhua

    2003-06-01

    In a previous study (Yin et al. 2000. Annals of Botany 85: 579-585), a generic logarithmic equation for leaf area index (L) in relation to canopy nitrogen content (N) was developed: L=(1/ktn)1n(1+ktnN/nb). The equation has two parameters: the minimum leaf nitrogen required to support photosynthesis (nb), and the leaf nitrogen extinction coefficient (ktn). Relative to nb, there is less information in the literature regarding the variation of ktn. We therefore derived an equation to theoretically estimate the value of ktn. The predicted profile of leaf nitrogen in a canopy using this theoretically estimated value of ktn is slightly more uniform than the profile predicted by the optimum nitrogen distribution that maximizes canopy photosynthesis. Relative to the optimum profile, the predicted profile is somewhat closer to the observed one. Based on the L-N logarithmic equation and the theoretical ktn value, we further quantified early leaf area development of a canopy in relation to nitrogen using simulation analysis. In general, there are two types of relations between L and N, which hold for canopies at different developmental phases. For a fully developed canopy where the lowest leaves are senescing due to nitrogen shortage, the relationship between L and N is described well by the logarithmic model above. For a young, unclosed canopy (i.e. L < 1.0), the relation between L and N is nearly linear. This linearity is virtually the special case of the logarithmic model when applied to a young canopy where its total nitrogen content approaches zero and the amount of nitrogen in its lowest leaves is well above nb. The expected patterns of the L-N relationship are discussed for the phase of transition from young to fully developed canopies.

  11. Analytical Methods for the Determination of the Distribution of Total Petroleum Hydrocarbons in the Water and Sediment of Aquatic Systems: A Review

    Directory of Open Access Journals (Sweden)

    A. O. Adeniji

    2017-01-01

    Full Text Available Several methods of extraction and analytical determination for total petroleum hydrocarbons (TPHCs in aqueous and solid samples are reviewed. Infrared spectroscopy is one of the efficient methods that are being replaced today pursuant to getting rid of some halogenated solvents classified as ozone-depleting substances. The gravimetric method which uses n-hexane as an extraction solvent for the determination of oil and grease, as well as the nonpolar materials, has become a preferred choice, despite being not suitable for volatiles because of the mandatory evaporation step. Other frequently used methods include gas chromatography with a flame ionization detector (FID or mass spectrometric detector (MSD which has the capacity to reveal the type of hydrocarbons present and is applicable to both volatile and semivolatile samples. Ultraviolet fluorescence is another method that is available both as a portable field device and as off-site laboratory equipment. Each of the methods has its own advantages and disadvantages; hence, the choice of method is guided by the type of data needed as discussed in detail in this review. The distribution of TPHC in water and sediments across the globe and the factors influencing the distribution were also reviewed.

  12. Particle phase distribution of polycyclic aromatic hydrocarbons in stormwater — Using humic acid and iron nano-sized colloids as test particles

    DEFF Research Database (Denmark)

    Nielsen, Katrine; Kalmykova, Yuliya; Strömvall, Ann-Margret

    2015-01-01

    The distribution of polycyclic aromatic hydrocarbons (PAHs) in different particulate fractions in stormwater: Total, Particulate, Filtrated, Colloidal and Dissolved fractions, were examined and compared to synthetic suspensions of humic acid colloids and iron nano-sized particles. The distribution...... to a higher extent in the Filtrated fractions. The highest concentrations of PAHs were present in the stormwater with the highest total suspended solids (TSS); the relative amount of the HMWPAHs was highest in the Particulate fractions (particles N 0.7 μm). The highest concentration of PAHs in the Colloidal...... fraction was found in the sample with occurrence of small nano-sized particles (b10 nm). The results show the importance of developing technologies that both can manage particulate matter and effectively remove PAHs present in the Colloidal and Dissolved fractions in stormwater. © 2015 Elsevier B.V. All...

  13. Particle phase distribution of polycyclic aromatic hydrocarbons in stormwater — Using humic acid and iron nano-sized colloids as test particles

    DEFF Research Database (Denmark)

    Nielsen, Katrine; Kalmykova, Yuliya; Strömvall, Ann-Margret;

    2015-01-01

    The distribution of polycyclic aromatic hydrocarbons (PAHs) in different particulate fractions in stormwater: Total, Particulate, Filtrated, Colloidal and Dissolved fractions, were examined and compared to synthetic suspensions of humic acid colloids and iron nano-sized particles. The distribution...... to a higher extent in the Filtrated fractions. The highest concentrations of PAHs were present in the stormwater with the highest total suspended solids (TSS); the relative amount of the HMWPAHs was highest in the Particulate fractions (particles N 0.7 μm). The highest concentration of PAHs in the Colloidal...... fraction was found in the sample with occurrence of small nano-sized particles (b10 nm). The results show the importance of developing technologies that both can manage particulate matter and effectively remove PAHs present in the Colloidal and Dissolved fractions in stormwater. © 2015 Elsevier B.V. All...

  14. 拓扑指数在烃类化合物定量构效关系中的研究进展%Research Progress of Topological Index in QSPR Study of Hydrocarbon Compounds

    Institute of Scientific and Technical Information of China (English)

    侯恩卿; 谢占川; 李秀庆; 杨林

    2011-01-01

    拓扑指数是一种重要的分子结构数学描述符,在烃类化合物的定量构效关系(QSPR)研究中占有重要作用.本文主要从烃类化合物的物理化学性质、热力学性质和色谱保留指数三个方面,综述了近年来分子拓扑指数在烷烃、烯烃、炔烃、卤代烃中的定量构效关系的研究进展.%The topological index is an important mathematical descriptors of molecular structure,plays an important role in the quantitative structure property relationship(QSPR) study of hydrocarbon compounds.This article reviewed the research progress of QSPR study about the properties of hydrocarbon compounds,such as physicochemical properties,thermodynamic properties and chromatographic retention indices by using topological index.

  15. Determination and Distribution of Polycyclic Aromatic Hydrocarbons in Rivers, Sediments and Wastewater Effluents in Vhembe District, South Africa

    Directory of Open Access Journals (Sweden)

    Joshua N. Edokpayi

    2016-03-01

    Full Text Available Polycyclic aromatic hydrocarbons are very toxic and persistent environmental contaminants. This study was undertaken to assess the concentrations and possible sources of 16 PAHs (Polycyclic aromatic hydrocarbons classified by the United State Environmental Protection Agency as priority pollutants in water and sediments of the Mvudi and Nzhelele Rivers. Effluents from Thohoyandou wastewater treatment plant and Siloam waste stabilization ponds were also investigated. Diagnostic ratios were used to evaluate the possible sources of PAHs. PAHs in the water samples were extracted using 1:1 dichloromethane and n-hexane mixtures, while those in the sediment samples were extracted with 1:1 acetone and dichloromethane using an ultrasonication method. The extracts were purified using an SPE technique and reconstituted in n-hexane before analyses with a gas chromatograph time of flight—mass spectrometer. The results obtained indicate the prevalence of high molecular weight PAHs in all the samples. PAHs concentrations in water and sediment samples from all the sampling sites were in the range of 13.174–26.382 mg/L and 27.10–55.93 mg/kg, respectively. Combustion of biomass was identified as the major possible source of PAHs. Effluents from wastewater treatment facilities were also considered as major anthropogenic contributions to the levels of PAHs found in both river water and sediments. Mvudi and Nzhelele Rivers show moderate to high contamination level of PAHs.

  16. Determination and Distribution of Polycyclic Aromatic Hydrocarbons in Rivers, Sediments and Wastewater Effluents in Vhembe District, South Africa.

    Science.gov (United States)

    Edokpayi, Joshua N; Odiyo, John O; Popoola, Oluwaseun E; Msagati, Titus A M

    2016-03-30

    Polycyclic aromatic hydrocarbons are very toxic and persistent environmental contaminants. This study was undertaken to assess the concentrations and possible sources of 16 PAHs (Polycyclic aromatic hydrocarbons) classified by the United State Environmental Protection Agency as priority pollutants in water and sediments of the Mvudi and Nzhelele Rivers. Effluents from Thohoyandou wastewater treatment plant and Siloam waste stabilization ponds were also investigated. Diagnostic ratios were used to evaluate the possible sources of PAHs. PAHs in the water samples were extracted using 1:1 dichloromethane and n-hexane mixtures, while those in the sediment samples were extracted with 1:1 acetone and dichloromethane using an ultrasonication method. The extracts were purified using an SPE technique and reconstituted in n-hexane before analyses with a gas chromatograph time of flight-mass spectrometer. The results obtained indicate the prevalence of high molecular weight PAHs in all the samples. PAHs concentrations in water and sediment samples from all the sampling sites were in the range of 13.174-26.382 mg/L and 27.10-55.93 mg/kg, respectively. Combustion of biomass was identified as the major possible source of PAHs. Effluents from wastewater treatment facilities were also considered as major anthropogenic contributions to the levels of PAHs found in both river water and sediments. Mvudi and Nzhelele Rivers show moderate to high contamination level of PAHs.

  17. Distribution and sources of aliphatic and polycyclic aromatic hydrocarbons in suspended particulate matter in water from two Brazilian estuarine systems

    Science.gov (United States)

    Maioli, Otávio L. G.; Rodrigues, Kamila C.; Knoppers, Bastiaan A.; Azevedo, Débora A.

    2011-07-01

    The levels of selected organic markers, including 17 polycyclic aromatic hydrocarbons (PAHs), 16 of which are classified as priority pollutants by the US-EPA and perylene, aliphatic hydrocarbons (total and linear alkanes) and petroleum biomarkers (hopanes and steranes), were measured in suspended particulate matter (SPM) of the Mundaú-Manguaba estuarine-lagoon system (MMELS) in northeastern Brazil and the Paraíba do Sul River (PSR) estuary in southeastern Brazil, both of which are affected by sugarcane agriculture and urbanization. A total of 33 surface water samples of SPM were collected (22 from the MMELS and 11 from the PSR). The ∑16PAH ranged from 221 to 1243 ng g -1 in the MMELS and from 228 to 1814 ng g -1 in the PSR. Hopane and sterane concentrations in the PSR were higher than in the MMELS due to the input from petrogenic sources in PSR. The contributions of higher plants were also observed by n-alkane analyses. The PAH isomeric ratios indicated that the SPM from MMELS showed characteristics of combustion from biomass or petroleum and PSR was associated to petrogenic input, either from combustion or from unburned petroleum. Three sampling sites located near to the sugarcane plant and mouth of the rivers showed higher PAH concentrations and may largely be considered as highly contaminated. However, levels of n-alkanes and petroleum biomarkers in both study areas were relatively low.

  18. Human Development Inequality Index and Cancer Pattern: a Global Distributive Study.

    Science.gov (United States)

    Rezaeian, Shahab; Khazaei, Salman; Khazaei, Somayeh; Mansori, Kamyar; Sanjari Moghaddam, Ali; Ayubi, Erfan

    2016-01-01

    This study aimed to quantify associations of the human development inequality (HDI) index with incidence, mortality, and mortality to incidence ratios for eight common cancers among different countries. In this ecological study, data about incidence and mortality rates of cancers was obtained from the Global Cancer Project for 169 countries. HDI indices for the same countries was obtained from the United Nations Development Program (UNDP) database. The concentration index was defined as the covariance between cumulative percentage of cancer indicators (incidence, mortality and mortality to incidence ratio) and the cumulative percentage of economic indicators (country economic rank). Results indicated that incidences of cancers of liver, cervix and esophagus were mainly concentrated in countries with a low HDI index while cancers of lung, breast, colorectum, prostate and stomach were concentrated mainly in countries with a high HDI index. The same pattern was observed for mortality from cancer except for prostate cancer that was more concentrated in countries with a low HDI index. Higher MIRs for all cancers were more concentrated in countries with a low HDI index. It was concluded that patterns of cancer occurrence correlate with care disparities at the country level.

  19. Sources and distribution of polycyclic aromatic hydrocarbons in sediments from the Spanish northern continental shelf. Assessment of spatial and temporal trends

    Energy Technology Data Exchange (ETDEWEB)

    Vinas, Lucia, E-mail: lucia.vinas@vi.ieo.e [Instituto Espanol de Oceanografia, Centro Oceanografico de Vigo, Cabo Estai - Canido, 36200 Vigo (Spain); Angeles Franco, M.; Antonio Soriano, J.; Jose Gonzalez, J. [Instituto Espanol de Oceanografia, Centro Oceanografico de Vigo, Cabo Estai - Canido, 36200 Vigo (Spain); Pon, Jordi [Department of Environmental Chemistry, CID-CSIC, Jordi Girona Salgado, 18-26, 08034-Barcelona (Spain); Albaiges, Joan, E-mail: albqam@cid.csic.e [Department of Environmental Chemistry, CID-CSIC, Jordi Girona Salgado, 18-26, 08034-Barcelona (Spain)

    2010-05-15

    The distribution of polycyclic aromatic hydrocarbons was determined in surface sediments collected at 36 stations along the Spanish Northern continental shelf in March and September 2003, and February 2005. Concentrations of PAHs (SIGMA13 parent components) were in the range of 22-47528 mug/kg dw, the highest values corresponding to coastal urban-industrial hotspots and decreasing offshore. Sediment quality guidelines (SQGs) showed that concentrations of total PAHs were below the threshold effect level (TEC) in 27 stations (81%) and above in 7, two of which (Gijon and Bilbao) were above the probable effect concentration (PEC). The detailed study of diagnostic ratios suggested a rather uniform mixture of petrogenic and pyrolytic PAH sources along the continental shelf, with a slight decrease of the latter moving westwards and offshore. In order to assess the incidence of sediment sampling on the variability of the results, selected stations were also monitored in February and September 2004 and September 2005. The average field variance of the values obtained for each station was 31% that decreased to 23% when the values were normalized to TOC. - PAHs in the Spanish Atlantic coastal sediments reflect chronic inputs of petrogenic and pyrolytic hydrocarbons, with a decrease of the latter moving westwards and offshore and representing low to moderate pollution according to established sediment quality guidelines.

  20. Numerical Simulation on Distribution of Products of Typical Hydrocarbon Molecules Pyrolysis%典型烃类分子裂解产物分布数值模拟

    Institute of Scientific and Technical Information of China (English)

    张红梅; 罗殿英; 赵雨波; 南子龙; 邵艳波

    2011-01-01

    利用烃类蒸汽热裂解二维工艺数学模型,选择二维模型原料分子中13种典型烃类分子,通过数学模拟考察烃类分子结构和裂解温度对热裂解产物的影响.结果表明:正构烷烃裂解产物中乙烯收率明显大于异构烷烃,且乙烯收率随着烷烃碳数的增加逐渐增加;异构烷烃裂解产物中丙烯收率大于同碳数的正构烷烃,且丙烯收率随碳数增大而显著减少;异构烷烃裂解生成丁二烯的收率大于其他烷烃;环烷烃中五元环裂解生成乙烯、丙烯和丁二烯(三烯)的收率大于六元环,且随碳数增加而略有增加;各烃类分子裂解生成乙烯和丁二烯的收率随温度的增加而增加,而丙烯的收率随温度的增加而略有降低.%The effects of hydrocarbon structure and pyrolysis temperature on the distribution of products from the pyrolysis of 13 typical hydrocarbon molecules were investigated using the two-dimension mathematical model of hydrocarbon steam pyrolysis. The results showed that the ethylene yield of normal paraffins pyrolysis was significantly higher than that of isoparaffin pyrolysis, and the ethylene yield increased with the increase of carbon number; the propylene yield of isoparaffin pyrolysis was higher than that of normal paraffins pyrolysis, and the propylene yield decreased obviously with the increase of carbon number; the butadiene yield of isoparaffin pyrolysis was higher than that of other paraffins pyrolysis; the total yield of ethylene, propylene and butadiene from the pyrolysis of cycloalkanes with five carbon in the rings was higher than that of cycloalkanes with six carbons in the rings, and increased slightly with the increase of carbon number; With the increase of pyrolysis temperature, the yield of ethylene and butadiene of hydrocarbons pyrolysis increased, while the yield of propylene decreased slightly.

  1. Distribution of polychlorinated biphenyls, phthalic acid esters, polycyclic aromatic hydrocarbons and organochlorine substances in the Moscow River, Russia.

    Science.gov (United States)

    Eremina, Natalia; Paschke, Albrecht; Mazlova, Elena A; Schüürmann, Gerrit

    2016-03-01

    The purpose of this study was to investigate the levels of polychlorinated biphenyl (PCB), phthalic acid esters (PAE), polycyclic aromatic hydrocarbons (PAH) and organochlorine substances (OCP) in the Moscow River water. Some studies have reported the occurrence of these substances in the soil of the Moscow region; however, no study has yet established an overview for these compounds in the Moscow River water. In this study the Moscow River water contamination with PAEs, PAHs and OCPs was determined. Obtained results were associated with the resident area located on the river bank, and the possible contamination sources were considered. The obtained data were compared with the data on the contamination of the different world-wide rivers. This research indicates the further study necessity of the Moscow region to cover more contaminated sites and environmental compartments.

  2. Determining particle size distribution and refractive index in a two-layer tissue phantom by linearly polarized light

    Institute of Scientific and Technical Information of China (English)

    Yong Deng; Qiang Lu; Qingming Luo

    2006-01-01

    We report a new method for measuring particle size distribution (PSD) and refractive index of the top layer in a two-layer tissue phantom simulated epithelium tissue by varying the azimuth angle of incident linearly polarized light. The polarization gating technique is used to decouple the single and multiple scattering components in the returned signal. The theoretical model based on Mie theory is presented and a nonlinear inversion method - floating genetic algorithm - is applied to inverting the azimuth dependence of component of polarization light backscattered. The experiment results demonstrate that the size distribution and refractive index of the scatters of the top layer can be determined by measuring and analyzing the differential signal of the parallel and perpendicular components from a two-layer tissue phantom. The method implies to detect precancerous changes in human epithelial tissue.

  3. Perspectives in using a remotely sensed dryness index in distributed hydrological models at river basin scale

    DEFF Research Database (Denmark)

    Andersen, Jens Asger; Sandholt, Inge; Jensen, Karsten Høgh

    2002-01-01

    -series of precipitation from 112 stations in the basin. The model was calibrated and validated based on river discharge data from nine stations in the basin for 11 years. Calibration and validation results suggested that the spatial resolution of the input data in parts of the area was not sufficient for a satisfactory...... evaluation of the modelling performance. The study further examined the spatial patterns in the model input and output, and it was found that particularly the spatial resolution of the precipitation input had a major impact on the model response. In an attempt to improve the model performance, this study...... examines a remotely sensed dryness index for its relationship to simulated soil moisture and evaporation for six days in the wet season 1990. The index is derived from observations of surface temperature and vegetation index as measured by the NOAA Advanced Very High Resolution Radiometer (AVHRR) sensor...

  4. Particle size distribution of nitrated and oxygenated polycyclic aromatic hydrocarbons (NPAHs and OPAHs on traffic and suburban sites of a European megacity: Paris (France

    Directory of Open Access Journals (Sweden)

    J. Ringuet

    2012-09-01

    Full Text Available The size distribution of particulate nitrated and oxygenated polycyclic aromatic hydrocarbons (NPAHs and OPAHs was determined during two field campaigns at a traffic site in summer 2010 and at a suburban site during the MEGAPOLI (Megacities: Emissions, urban, regional and Global Atmospheric POLlution and climate effects, and Integrated tools for assessment and mitigation experiment in summer 2009. Both, OPAHs and NPAHs were strongly associated (>85% to fine particles (Dp< 2.5 μm increasing the interest of their study on a sanitary point of view. Results showed really different NPAH and OPAH particle size distributions between both sites. At traffic site, clearly bimodal (notably for NPAHs particle size distributions (Dp = 0.14 and 1.4 μm were observed, while the particle size distributions were more scattered at the suburban site, especially for OPAHs. Bimodal particle size distribution observed at traffic site for the NPAH could be assigned to the vehicle emissions and the particle resuspension. Broadest distribution observed at the suburban site could be attributed to the mass transfer of compounds by volatilization/sorption processes during the transport of particles in the atmosphere. Results also showed that the combination of the study of particle size distributions applied to marker compounds (primary: 1-nitropyrene; secondary: 2-nitrofluoranthene and to NPAH or OPAH chemical profiles bring some indications on their primary and/or secondary origin. Indeed, 1,4-anthraquinone seemed only primary emitted by vehicles while 7-nitrobenz[a]anthracene, benz[a]antracen7,12-dione and benzo[b]fluorenone seemed secondarily formed in the atmosphere.

  5. Income distribution and mortality: cross sectional ecological study of the Robin Hood index in the United States.

    Science.gov (United States)

    Kennedy, B P; Kawachi, I; Prothrow-Stith, D

    1996-04-20

    To determine the effect of income inequality as measured by the Robin Hood index and the Gini coefficient on all cause and cause specific mortality in the United States. Cross sectional ecological study. Households in the United States. Disease specific mortality, income, household size, poverty, and smoking rates for each state. The Robin Hood index was positively correlated with total mortality adjusted for age (r = 0.54; P < 0.05). This association remained after adjustment for poverty (P < 0.007), where each percentage increase in the index was associated with' an increase in the total mortality of 21.68 deaths per 100,000. Effects of the index were also found for infant mortality (P = 0.013); coronary heart disease (P = 0.004); malignant neoplasms (P = 0.023); and homicide (P < 0.001). Strong associations were also found between the index and causes of death amenable to medical intervention. The Gini coefficient showed very little correlation with any of the causes of death. Variations between states in the inequality of income were associated with increased mortality from several causes. The size of the gap between the wealthy and less well off--as distinct from the absolute standard of living enjoyed by the poor--seems to matter in its own right. The findings suggest that policies that deal with the growing inequities in income distribution may have an important impact on the health of the population.

  6. Size-dependent distribution and inhalation cancer risk of particle-bound polycyclic aromatic hydrocarbons at a typical e-waste recycling and an urban site.

    Science.gov (United States)

    Luo, Pei; Bao, Lian-Jun; Li, Shao-Meng; Zeng, Eddy Y

    2015-05-01

    Atmospheric particle size distribution of polycyclic aromatic hydrocarbons (PAHs) in a typical e-waste recycling zone and an urban site (Guangzhou) in southern China featured a unimodal peak in 0.56-1.8 μm for 4-6 ring PAHs but no obvious peak for 2-3 ring PAHs at both sites. The atmospheric deposition fluxes of PAHs were estimated at 5.4 ± 2.3 μg m(-2) d(-1) in the e-waste recycling zone and 3.1 ± 0.6 μg m(-2) d(-1) in Guangzhou. In addition, dry and wet deposition fluxes of PAHs were dominated by coarse (Dp > 1.8 μm) and fine particles (Dp e-waste recycling zone and Guangzhou.

  7. On the distribution of the order and index of g (pmod p) over residue classes III

    NARCIS (Netherlands)

    Moree, P.

    2006-01-01

    For a fixed rational number g is not an element of (-1, 0, 1) and integers a and d we consider the sets N-g (a, d), respectively R-g (a, d), of primes p for which the order, respectively the index of g (mod p) is congruent to a (mod d). Under the Generalized Riemann Hypothesis (GRH), it is known tha

  8. Investigation of the distribution of organochlorine and polycyclic aromatic hydrocarbon compounds in the Lower Columbia River using semipermeable-membrane devices

    Science.gov (United States)

    McCarthy, Kathleen A.; Gale, Robert W.

    1999-01-01

    Organochlorine and polycyclic aromatic hydrocarbon compounds are of concern in the Columbia River Basin because of their adverse effects on fish and wildlife. Because these compounds can have important biological consequences at concentrations well below the detection limits associated with conventional water-sampling techniques, we used semipermeable membrane devices (SPMDs) to sample water, and achieved sub-parts-per-quintillion detection limits. We deployed SPMDs during 1997 low-flow conditions and 1998 high-flow conditions at nine main-stem sites and seven tributary sites, spanning approximately 700 miles of the Columbia River. We also collected streambed sediment from three sites. SPMD extracts and sediments were analyzed for polychlorinated dibenzo-p-dioxins, polychlorinated dibenzofurans, polychlorinated biphenyls, organochlorine pesticides and related transformation products, and polycyclic aromatic hydrocarbons. Our data indicate that (1) in the absence of additional sources, mechanisms such as volatilization, dilution, and settling of suspended particles can act to significantly reduce concentrations of contaminants along the river's flow path, (2) elevated concentrations of contaminants in the Portland-Vancouver area are primarily from local rather than upstream sources, (3) elevated concentrations of many compounds tend to be diluted during periods of high discharge, (4) much higher discharge in the main stem considerably dilutes elevated concentrations entering from tributaries, (5) the distribution of hydrophobic organic compounds in streambed sediment is not necessarily indicative of their distribution in the dissolved-phase, and (6) SPMDs can reveal patterns of contaminant occurrence at environmentally relevant concentrations that are undetectable by conventional water-sampling techniques.

  9. Biogeographical distribution analysis of hydrocarbon degrading and biosurfactant producing genes suggests that near-equatorial biomes have higher abundance of genes with potential for bioremediation.

    Science.gov (United States)

    Oliveira, Jorge S; Araújo, Wydemberg J; Figueiredo, Ricardo M; Silva-Portela, Rita C B; de Brito Guerra, Alaine; da Silva Araújo, Sinara Carla; Minnicelli, Carolina; Carlos, Aline Cardoso; de Vasconcelos, Ana Tereza Ribeiro; Freitas, Ana Teresa; Agnez-Lima, Lucymara F

    2017-07-27

    Bacterial and Archaeal communities have a complex, symbiotic role in crude oil bioremediation. Their biosurfactants and degradation enzymes have been in the spotlight, mainly due to the awareness of ecosystem pollution caused by crude oil accidents and their use. Initially, the scientific community studied the role of individual microbial species by characterizing and optimizing their biosurfactant and oil degradation genes, studying their individual distribution. However, with the advances in genomics, in particular with the use of New-Generation-Sequencing and Metagenomics, it is now possible to have a macro view of the complex pathways related to the symbiotic degradation of hydrocarbons and surfactant production. It is now possible, although more challenging, to obtain the DNA information of an entire microbial community before automatically characterizing it. By characterizing and understanding the interconnected role of microorganisms and the role of degradation and biosurfactant genes in an ecosystem, it becomes possible to develop new biotechnological approaches for bioremediation use. This paper analyzes 46 different metagenome samples, spanning 20 biomes from different geographies obtained from different research projects. A metagenomics bioinformatics pipeline, focused on the biodegradation and biosurfactant-production pathways, genes and organisms, was applied. Our main results show that: (1) surfactation and degradation are correlated events, and therefore should be studied together; (2) terrestrial biomes present more degradation genes, especially cyclic compounds, and less surfactation genes, when compared to water biomes; and (3) latitude has a significant influence on the diversity of genes involved in biodegradation and biosurfactant production. This suggests that microbiomes found near the equator are richer in genes that have a role in these processes and thus have a higher biotechnological potential. In this work we have focused on the

  10. The asymptotic distribution of a cluster-index for i.i.d. normal random variables

    OpenAIRE

    Yatracos, Yannis G.

    2009-01-01

    In a sample variance decomposition, with components functions of the sample's spacings, the largest component $\\tilde{I}_n$ is used in cluster detection. It is shown for normal samples that the asymptotic distribution of $\\tilde{I}_n$ is the Gumbel distribution.

  11. Central Body Fat Distribution Associates with Unfavorable Renal Hemodynamics Independent of Body Mass Index

    NARCIS (Netherlands)

    Kwakernaak, Arjan J.; Zelle, Dorien M.; Bakker, Stephan J. L.; Navis, Gerjan

    2013-01-01

    Central distribution of body fat is associated with a higher risk of renal disease, but whether it is the distribution pattern or the overall excess weight that underlies this association is not well understood. Here, we studied the association between waist-to-hip ratio (WHR), which reflects centra

  12. Effect of Shale Distribution on Hydrocarbon Sands Integrated with Anisotropic Rock Physics for AVA Modelling: A Case Study

    Science.gov (United States)

    Ali, Aamir; Zubair; Hussain, Matloob; Rehman, Khaista; Toqeer, Muhammad

    2016-08-01

    Shales can be distributed in sand through four different ways; laminated, structural, dispersed and any combination of these aforementioned styles. A careful analysis of well log data is required for the determination of shale distribution in sand affecting its reservoir quality. The objective of this study is to characterize the effect of shale distribution on reservoir quality of sands using well log data. The correlation of well data in terms of lithology has revealed four sand and three shale layers in Lower Goru Formation acting as a major reservoir in the study area. Our results indicate that the laminated type of shale distribution prevails at the Basal sand level, which does not affect its reservoir quality greatly. The remaining layers of variable vertical extent show a variety of shale distribution models affecting their reservoir quality adversely. We also present anisotropic rock physics modelling for AVA analysis at Basal sand level.

  13. Density and Comparative Refractive Index Study on Mixing Properties of Binary Liquid Mixtures of Eucalyptol with Hydrocarbons at 303.15, 308.15 and 313.15 K

    Directory of Open Access Journals (Sweden)

    Sangita Sharma

    2007-01-01

    Full Text Available Density and refractive index have been experimentally determined for binary liquid mixtures of eucalyptol with hydrocarbons (o-xylene,m-xylene and toluene at 303.15 K, 308.15 K and 313.15 K. A comparative study of Lorentz-Lorenz (L-L, Weiner (W, Heller (H, Gladstone-Dale (G-D, Arago-Biot (A-B, Eykman (Eyk, Newton (Nw, Eyring-John (E-J and Oster (Os relations for determining the refractive index of a liquid has been carried out to test their validity for the three binaries over the entire mole fraction range of eucalyptol at 303.15 K, 308.15 K and 313.15 K. Comparison of various mixing rules has been expressed in terms of average deviation. From the experimentally measured values, refractive index deviations at different temperatures have been computed and fitted to the Redlich-Kister polynomial equation to derive the binary coefficients and standard deviations.

  14. [Pollution characteristics and distribution of polycyclic aromatic hydrocarbons and organochlorine pesticides in groundwater at Xiaodian Sewage Irrigation Area, Taiyuan City].

    Science.gov (United States)

    Li, Jia-le; Zhang, Cai-xiang; Wang, Yan-xin; Liao, Xiao-ping; Yao, Lin-lin; Liu, Min; Xu, Liang

    2015-01-01

    Sewage irrigation has been widely used in areas of water shortage in northern China, and it may introduce organic contaminants into groundwater. To characterize the organic contaminants in groundwater in sewage irrigation area, the Xiaodian sewage irrigation area in Shanxi Province was chosen as the case study area. A total of 16 groundwater samples (13 from shallow aquifer, 3 from deep aquifer) were collected. Polycyclic aromatic hydrocarbons (PAHs) were determined by gas chromatography-mass spectrometry (GC-MS) and organochlorine pesticides (OCPs) were ainalyzed by gas chromatography-electron capture detection (GC-ECD). The results showed that the concentrations of PAHs ranged from 13.98 to 505.89 ng x L(-1) with an average concentration of 115.67 ng x (L)(-1). The 2 and 3 ring-PAHs were the main components, while naphthalene and phenanthrene were most frequently detected. The concentrations of OCPs were in the range of 13.91-103.23 ng x L(-1) with an average concentration of 40.99 ng x L(-1), while alpha-HCH, delta-HCH, o,p'-DDD, Aldrin, Endosulfan-sulfate and HCB were most frequently detected. Overall, shallow aquifers appeared more contaminated with these pollutants than deep aquifers. In the area, the order of the organic contaminants concentration in groundwater was: East Main Channel groundwater was influenced by the sewage irrigation.

  15. Distribution characteristics and source apportionment of polycyclic aromatic hydrocarbons (PAHs) in the Liao River drainage basin, northeast China.

    Science.gov (United States)

    Hu, Jian; Liu, Congqiang; Zhang, Guoping; Zhang, Yanlin; Li, Siliang; Zhao, Zhiqi; Liu, Baojian; Guo, Qinjun

    2016-04-01

    The Liao River drainage basin, which is one of China's seven major rivers basins, is located in northeast China. This region is characterized by important industrial bases including steel factories and oil and chemical plants, all of which have the potential to contribute pollutants to the drainage basin. In this study, 16 polycyclic aromatic hydrocarbons (PAHs) in water and suspended particulate matter (SPM) in the major rivers of the Liao River drainage basin were identified and quantified by gas chromatography mass spectrometry (GC/MS). The total PAH concentrations ranged from 0.4 to 76.5 μg/g (dry weight) in SPM and 32.6 to 108 ng/L in surface water, respectively. Low-ring PAHs (including two- and three-ring PAHs) were dominant in all PAH samples, and the level of low-ring PAHs in surface water was higher than that in SPM. The proportion of two-ring PAHs was the highest, accounting for an average of 68.2 % of the total PAHs in surface water, while the level of three-ring PAHs was the highest in SPM, with an average of 66.3 %. When compared with other river systems, the concentrations of PAHs in the Liao River drainage basin were lower. Identification of the emission sources based on diagnostic ratios suggested petroleum and fossil fuel combustion were important contribution to PAHs in the study area.

  16. Exposure and size distribution of nitrated and oxygenated polycyclic aromatic hydrocarbons among the population using different household fuels.

    Science.gov (United States)

    Shen, Guofeng; Chen, Yuanchen; Du, Wei; Lin, Nan; Wang, Xilong; Cheng, Hefa; Liu, Junfeng; Xue, Chunyu; Liu, Guangqing; Zeng, Eddy Y; Xing, Baoshan; Tao, Shu

    2016-09-01

    Polycyclic aromatic hydrocarbons (PAHs) derivatives like nitrated and oxygenated PAHs are of growing concerns because of considerably higher toxicity and important roles during atmospheric chemical reactions. Residential solid fuel combustion is likely to be one large primary source of these pollutants in developing countries. In this study, inhalation exposure to nitrated and oxygenated PAH derivatives was evaluated among rural residents using carried samplers. The exposure levels of individual nitrated PAHs ranged from 4.04 (9-nitrated phenanthrene) to 89.8 (9-nitrated anthracene) pg/m(3), and of oxy-PAHs were 0.570 (benzo[a]anthracene-7, 12-dione) to 7.99 (Benzanthrone) ng/m(3), generally higher in wood user than that in anthracite user. A majority of derivatives in particle presented in PM2.5 (80% for nitrated naphthalene and over 90% for other targets) and even fine PM1.0. Mass fractions of PAH derivatives in fine and ultra-fine particles were significantly higher than the fractions of corresponding parent PAHs, indicating more adverse health outcomes induced by these derivatives. The inhalation exposure levels for residents adopting wood gasifier burners was significantly lower than the documented results for those burning wood in typical built-in brick stoves, and comparable to those using LPG and electricity, which provided vital information for clean stove development and intervention programs. Copyright © 2016 Elsevier Ltd. All rights reserved.

  17. Distribution and characteristics of polycyclic aromatic hydrocarbons (PAHs) in sediments of Hadhramout coastal area, Gulf of Aden, Yemen

    Science.gov (United States)

    Mostafa, Alaa R.; Wade, Terry L.; Sweet, Stephen T.; Al-Alimi, Abdel Kawi A.; Barakat, Assem O.

    2009-08-01

    To assess the status of polycyclic aromatic hydrocarbon (PAH) contamination in sediments of Hadhramout coastal area, Gulf of Aden, Yemen, 17 surface sediment samples were collected in March-April 2005 and analyzed for PAHs with 2-6 benzene rings by gas chromatography-mass spectrometry (GC-MS). The concentrations of PAHs in surface sediments were in the range of 2.2-604 ng g - 1 (average value: 82.4 ng g - 1 ). PAHs contamination is highest in proximity to harbour activities, near Al-Dhabah petroleum terminal and urban areas. Comparison of the concentration range with a worldwide survey of sedimentary PAH concentrations ranked PAH contamination in Hadhramout coastal sediments as low to moderate. Assessment of PAH sources in Hadhramout coastal sediments suggested that they originated largely from petrogenic sources. PAHs of pyrolytic origin were found in sediments from urbanized areas. Adverse effects on benthic communities are not expected at the levels of PAHs contamination observed from harbour and industrial areas.

  18. Distribution and Source Apportionment of Polycyclic Aromatic Hydrocarbons from Atmospheric Particulate Matter PM2.5 in Beijing

    Institute of Scientific and Technical Information of China (English)

    LIU Dameng; GAO Shaopeng; AN Xianghua

    2008-01-01

    A total of 11 PM2.5 samples were collected from October 2003 to October 2004 at 8 sampling sites in Beijing city.The PM2.5 concentrations are all above the PM2.5 pollution standard(65μg m(-3))established by Environmental Protection Agency,USA(USEPA)in 1997 except for the Ming Tombs site.PM2.5 con-centrations in winter are much higher than in summer.The 16 Polycyclic aromatic hydrocarbons(PAHs)listed as priority pollutants by USEPA in PM2.5 were completely identified and quantified by high perfor-mance liquid chromatography(HPLC)with variable wavelength detector(VWD)and fluorescence detector (FLD)employed.The PM2.5 concentrations indicate that the pollution situation is still serious in Beijing.The sum of 16 PAHs concentrations ranged from 22.17 to 5366 ng m-3.The concentrations of the heavier molecular weight PAHs have a different pollution trend from the lower PAHs.Seasonal variations were mainly attributed to the difference in coal combustion emission and meteorological conditions.The source apportionment analysis suggests that PAHs from PM2.5 in Beijing city mainly come from coal combustion and vehicle exhaust emission.New measures about restricting coal combustion and vehicle exhaust must be established as soon as possible to improve the air pollution situation in Beijing city.

  19. Methylated and unsubstituted polycyclic aromatic hydrocarbons in street dust from Vietnam and India: occurrence, distribution and in vitro toxicity evaluation.

    Science.gov (United States)

    Tuyen, Le Huu; Tue, Nguyen Minh; Takahashi, Shin; Suzuki, Go; Viet, Pham Hung; Subramanian, Annamalai; Bulbule, Kesav A; Parthasarathy, Peethambaram; Ramanathan, Alagappan; Tanabe, Shinsuke

    2014-11-01

    Methylated polycyclic aromatic hydrocarbons (MePAHs), unsubstituted PAHs and AhR-mediated activities were determined in street dust collected from Vietnam and India using a combined approach of chemical analysis and in vitro reporter gene assay. MePAHs and PAHs diagnostic ratios indicated that the main sources of MePAHs in Vietnam were pyrogenic emissions, whereas in India there were mixed sources of pyrogenic and petrogenic emissions. AhR-mediated activities determined by using DR-CALUX assay were observed in urban street dust at mean 40, 29 and 20 ng CALUX-TEQ/g dw for Hanoi, Bangalore and New Delhi, respectively. MePAHs and PAHs contributed only 5% or less to AhR-mediated activity in street dust, indicating the occurrence of unknown AhR agonists. The principal contributors to Theoretical-TEQs among target compounds were methyl benz[a]anthracene, benzo[b]- and benzo[k]fluoranthene. The present study indicates importance of MePAHs in evaluation of toxic risk related to AhR-mediated activity in urban polluted areas.

  20. Distribution and Health Risk Assessment on Dietary Exposure of Polycyclic Aromatic Hydrocarbons in Vegetables in Nanjing, China

    Directory of Open Access Journals (Sweden)

    Minmin Wu

    2016-01-01

    Full Text Available In a market basket study made in Nanjing, China, in which the most common consumed nine kinds of vegetables foodstuffs were sampled, the contents of 16 polycyclic aromatic hydrocarbons (PAHs were analyzed using gas chromatography with mass spectrometer detector (GC-MS. The results showed that the total amount of 16 PAHs was within the range of 60.5~312 ng g−1 (wet weight. The ranking of total concentrations for different types of vegetables in decreasing order was leafy vegetable, fruit vegetable, and rhizome vegetable. Source analysis suggested that coal, oil, or other incomplete combustion of biomass mainly contributed to the concentration of PAHs. The margin of exposure (MOE approach with age/gender group-specific daily dietary exposure level was used to estimate the carcinogenic risk. The calculated total mean MOE in the case of BaP and PAH4 (sum of BaA, CHR, BbF, and BaP was 14960 and 7723, respectively, for local residents. In addition, the MOEs in PAH4 for some groups of both male and female were below the critical limit of 10 000 proposed by EFSA. Therefore, health effect owing to the consumption of vegetables on local residents needs high concern.

  1. Gas- and particle-phase distribution of polycyclic aromatic hydrocarbons in two-stroke, 50-cm 3 moped emissions

    Science.gov (United States)

    Spezzano, Pasquale; Picini, Paolo; Cataldi, Dario

    Gas- and particle-phase polycyclic aromatic hydrocarbons (PAHs) concentrations evaluated in the exhaust of 10 two-stroke, 50-cm 3 mopeds belonging to three different levels of emission legislation (EURO-0, EURO-1 and EURO-2) were used to assess the prevalent mechanism driving the gas/particle partitioning of PAHs in moped exhaust. Sampling was performed on a dynamometer bench both during the "cold-start" and the "hot" phases of the ECE-47 driving cycle. Gas and particulate phase PAHs were collected on polyurethane foam (PUF) plugs and 47-mm Pallflex T60A20 filters, respectively, under isokinetic conditions by using sampling probes inserted into the dilution tunnel of a Constant Volume Sampling - Critical Flow Venturi (CVS-CFV) system. The results show that semi-volatile PAHs were predominantly partitioned to the particle phase. The soluble organic fraction (SOF) of the collected particulates ranged between 72 and 98%. Measured total suspended particulate matter normalized partition coefficients ( Kp) were predicted within a factor of 3-5 by assuming absorption into the organic fraction according to a model developed by Harner and Bidleman [Harner, T., Bidleman, T.F., 1998. Octanol-air partition coefficient for describing particle/gas partitioning of aromatic compounds in urban air. Environmental Science & Technology 32, 1494-1502.]. This suggests that the gas/particle partitioning in moped exhaust is mainly driven by the high fraction of organic matter of the emitted particles and that absorption could be the main partitioning mechanism of PAHs.

  2. Distribution, origin, and potential toxicological significance of polycyclic aromatic hydrocarbons (PAHs) in sediments of Kaohsiung Harbor, Taiwan.

    Science.gov (United States)

    Chen, Chiu-Wen; Chen, Chih-Feng

    2011-01-01

    Sediment samples were collected from 12 locations of Kaohsiung Harbor, Taiwan and analyzed for polycyclic aromatic hydrocarbons (PAHs). Total PAH concentrations varied from 472 to 16,201 ng g(-1) dry weight. The highest PAH concentrations were from the industrial zone docks situated in south Kaohsiung Harbor. Diagnostic ratios showed that the possible source of PAHs in the industrial zone dock could be coal combustion while in the other zones it could be petroleum combustion. The toxic equivalent concentrations (TEQcarc) of PAHs varied from 55 to 1964 ng TEQ g(-1) dry weight. Higher total TEQcarc values were found at industrial zone docks (from 1404 to 1964 ng TEQ g(-1) dry weight). As compared with the US Sediment Quality Guidelines (SQGs), the observed levels of PAHs at industrial zone docks exceeded the effects range low (ERL), and could thus cause acute biological damage. However, the lower levels of PAHs at the other zones would probably not exert adverse biological effects. Copyright © 2011 Elsevier Ltd. All rights reserved.

  3. Distribution and source apportionment of polycyclic aromatic hydrocarbons (PAHs) in forest soils from urban to rural areas in the Pearl River Delta of Southern China.

    Science.gov (United States)

    Xiao, Yihua; Tong, Fuchun; Kuang, Yuanwen; Chen, Bufeng

    2014-03-04

    The upper layer of forest soils (0-20 cm depth) were collected from urban, suburban, and rural areas in the Pearl River Delta of Southern China to estimate the distribution and the possible sources of polycyclic aromatic hydrocarbons (PAHs). Total concentrations of PAHs in the forest soils decreased significantly along the urban-suburban-rural gradient, indicating the influence of anthropogenic emissions on the PAH distribution in forest soils. High and low molecular weight PAHs dominated in the urban and rural forest soils, respectively, implying the difference in emission sources between the areas. The values of PAH isomeric diagnostic ratios indicated that forest soil PAHs were mainly originated from traffic emissions, mixed sources and coal/wood combustion in the urban, suburban and rural areas, respectively. Principal component analysis revealed that traffic emissions, coal burning and residential biomass combustion were the three primary contributors to forest soil PAHs in the Pearl River Delta. Long range transportation of PAHs via atmosphere from urban area might also impact the PAHs distribution in the forest soils of rural area.

  4. Occurrence and seasonal distribution of polycyclic aromatic hydrocarbons and legacy and current-use pesticides in air from a Mediterranean coastal lagoon (Mar Menor, SE Spain).

    Science.gov (United States)

    Carratalá, A; Moreno-González, R; León, V M

    2017-01-01

    The occurrence and seasonal distribution of polycyclic aromatic hydrocarbons (PAHs) and legacy and current-use pesticides (CUPs) in air were characterized around the Mar Menor lagoon using both active and passive sampling devices. The seasonal distribution of these pollutants was determined at 6 points using passive samplers. Passive sampler sampling rates were estimated for all detected analytes using an active sampler, considering preferentially winter data, due to probable losses in active sampling during summer (high temperatures and solar irradiation). The presence of 28 compounds (14 CUPs, 11 PAHs and 3 organochlorinated pesticides) were detected in air by polyurethane passive sampling. The most commonly detected contaminants (>95% of samples) in air were chlorpyrifos, chlorpyrifos-methyl and phenanthrene. The maximum concentrations corresponded to phenanthrene (6000 pg m(-3)) and chlorpyrifos (4900 pg m(-3)). The distribution of contaminants was spatially and seasonally heterogeneous. The highest concentrations of PAHs were found close to the airport, while the highest concentrations of pesticides were found in the influence area of agricultural fields (western stations). PAH and herbicide concentrations were higher in winter than in the other seasons, although some insecticides such as chlorpyrifos were more abundant in autumn. The presence of PAHs and legacy and current-use pesticides in air confirmed their transference potential to marine coastal areas such as the Mar Menor lagoon. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. Distribution and Source Apportionment of Polycyclic Aromatic Hydrocarbons (PAHs in Forest Soils from Urban to Rural Areas in the Pearl River Delta of Southern China

    Directory of Open Access Journals (Sweden)

    Yihua Xiao

    2014-03-01

    Full Text Available The upper layer of forest soils (0–20 cm depth were collected from urban, suburban, and rural areas in the Pearl River Delta of Southern China to estimate the distribution and the possible sources of polycyclic aromatic hydrocarbons (PAHs. Total concentrations of PAHs in the forest soils decreased significantly along the urban–suburban–rural gradient, indicating the influence of anthropogenic emissions on the PAH distribution in forest soils. High and low molecular weight PAHs dominated in the urban and rural forest soils, respectively, implying the difference in emission sources between the areas. The values of PAH isomeric diagnostic ratios indicated that forest soil PAHs were mainly originated from traffic emissions, mixed sources and coal/wood combustion in the urban, suburban and rural areas, respectively. Principal component analysis revealed that traffic emissions, coal burning and residential biomass combustion were the three primary contributors to forest soil PAHs in the Pearl River Delta. Long range transportation of PAHs via atmosphere from urban area might also impact the PAHs distribution in the forest soils of rural area.

  6. New estimators of the extreme value index under random right censoring, for heavy-tailed distributions

    OpenAIRE

    Worms, Julien; Worms, Rym

    2014-01-01

    International audience; This paper presents new approaches for the estimation of the extreme value index in the framework of randomly censored (from the right) samples, based on the ideas of Kaplan-Meier integration and the synthetic data approach of S.Leurgans (1987). These ideas are developed here in the heavy tail case and for the adaptation of the Hill estimator, for which the consistency is proved under first order conditions. Simulations show good performance of the two approaches, with...

  7. Indexed University presses: overlap and geographical distribution in five book assessment databases

    Energy Technology Data Exchange (ETDEWEB)

    Mañana-Rodriguez, J.; Gimenez-Toledo, E

    2016-07-01

    Scholarly books have been a periphery among the objects of study of bibliometrics until recent developments provided tools for assessment purposes. Among scholarly book publishers, University Presses (UPs hereinafter), subject to specific ends and constrains in their publishing activity, might also remain on a second-level periphery despite their relevance as scholarly book publishers. In this study the authors analyze the absolute and relative presence, overlap and uniquely-indexed cases of 503 UPs by country, among five assessment-oriented databases containing data on scholarly book publishers: Book Citation Index, Scopus, Scholarly Publishers Indicators (Spain), the lists of publishers from the Norwegian System (CRISTIN) and the lists of publishers from the Finnish System (JUFO). The comparison between commercial databases and public, national databases points towards a differential pattern: prestigious UPs in the English Speaking world represent larger shares and there is a higher overall percentage of UPs in the commercial databases, while the richness and diversity is higher in the case of national databases. Explicit or de facto biases towards production in English by commercial databases, as well as diverse indexation criteria might explain the differences observed. The analysis of the presence of UPs in different numbers of databases by country also provides a general picture of the average degree of diffusion of UPs among information systems. The analysis of ‘endemic’ UPs, those indexed only in one of the five databases points out to strongly different compositions of UPs in commercial and non-commercial databases. A combination of commercial and non commercial databases seems to be the optimal option for assessment purposes while the validity and desirability of the ongoing debate on the role of UPs can be also concluded. (Author)

  8. Aliphatic hydrocarbons of the fungi.

    Science.gov (United States)

    Weete, J. D.

    1972-01-01

    Review of studies of aliphatic hydrocarbons which have been recently detected in the spores of phytopathogenic fungi, and are found to be structurally very similar to the alkanes of higher plants. It appears that the hydrocarbon components of the few mycelial and yeast forms reported resemble the distribution found in bacteria. The occurence and distribution of these compounds in the fungi is discussed. Suggested functional roles of fungal spore alkanes are presented.

  9. Statistical inference for the lifetime performance index based on generalised order statistics from exponential distribution

    Science.gov (United States)

    Vali Ahmadi, Mohammad; Doostparast, Mahdi; Ahmadi, Jafar

    2015-04-01

    In manufacturing industries, the lifetime of an item is usually characterised by a random variable X and considered to be satisfactory if X exceeds a given lower lifetime limit L. The probability of a satisfactory item is then ηL := P(X ≥ L), called conforming rate. In industrial companies, however, the lifetime performance index, proposed by Montgomery and denoted by CL, is widely used as a process capability index instead of the conforming rate. Assuming a parametric model for the random variable X, we show that there is a connection between the conforming rate and the lifetime performance index. Consequently, the statistical inferences about ηL and CL are equivalent. Hence, we restrict ourselves to statistical inference for CL based on generalised order statistics, which contains several ordered data models such as usual order statistics, progressively Type-II censored data and records. Various point and interval estimators for the parameter CL are obtained and optimal critical regions for the hypothesis testing problems concerning CL are proposed. Finally, two real data-sets on the lifetimes of insulating fluid and ball bearings, due to Nelson (1982) and Caroni (2002), respectively, and a simulated sample are analysed.

  10. CONNECTIVITY INDEX OF ENVIRONMENT VALENCE AND QSPR RESEARCH FOR BOILING POINTS OF SATURATED HYDROCARBON%环价连接性指数与饱和烃沸点的QSPR研究

    Institute of Scientific and Technical Information of China (English)

    沐来龙; 冯长君

    2004-01-01

    In this paper, according to the peak numbers of the nuclear magnetic resonance and the Randic embranchment degree (δi) of carbon atom i, the carbon atom's environment valence gi is defined as. gi =(ti+δi)/2. The gi reflect the characteristic of each carbon atom, and as well as the conjunction detail of the carbon atom with other carbon atoms. So, the gi could distinguish better the chemical environment of each carbon atom in the molecule than δi. A connectivity index of environment valence (mS) and its athwart index (mS') are proposed based on the adjacency matrix and the carbon atom's environment valence gi. Among them, the 0S and 0S' include the characteristic and the connectivity of each carbon atom, the 1S and 1S' reflect the second conjunction between carbon atoms. Based on 0S' and N (the number of carbon atom), a new structural parameter symmetry degree (N∝), is defined as. N∝ =[ (0S's0Sc') N]2/3, and the N∝ reflect the size of the molecule as well as the symmetry of the molecule.The N∝, 0S and Rn (the biggest ring's edge numbers of cycloalkanes) of 474 saturated hydrocarbons (216 paraffins and 258 cycloalkanes) were calculated and correlated with their boiling points. The best regression equation was obtained as follow: In ( 1056 - Tb ) = 6. 9480 - 0. 1040N∝ - 0. 0086890S -0. 009614Rn+0. 01998Rm0.5, n=474, R=0. 9989, F=52627, S=5.63K. The model was checked up by the Jackknife's method. It should have overall steadiness and could be used for predicting the boiling point of saturated hydrocarbons.

  11. Pore Size Distribution as a Soil Physical Quality Index for Agricultural and Pasture Soils in Northeastern Iran

    Institute of Scientific and Technical Information of China (English)

    H.SHAHAB, H.EMAMI; G.H.HAGHNIA; A.KARIMI

    2013-01-01

    Assessment of soil quality is important for optimum production and natural resources conservation.Agricultural and pasture soil qualities of Deh-Sorkh region located at south of Mashhad,northeastern Iran were assessed using the integrated quality index (IQI) and Nemero quality index (NQI) models in combination with two datasets,i.e.,total data set (TDS) and minimum data set (MDS).In this study 6 soil properties considered as MDS were selected out of 18 properties as TDS using principle component analysis.Soil samples were divided into 3 groups based on optimum ranges of 8 soil physical quality indicators.Soil samples with the most indicators at optimum range were selected as group 1 and the samples having fewer indicators at optimum range were located in groups 2 and 3.Optimum ranges of soil pore size distribution functions were also determined as soil physical quality indices based on 8 soil physical quality indicators.Pore size distribution curves of group 1 were considered as the optimum pore size functions.The results showed that relatively high organic carbon contents could improve pore size distribution.Mean comparisons of soil physical quality indicators demonstrated that mean weight diameter of wet aggregates,structural stability index,the slope of moisture retention curve at inflection point,and plant available water content in agricultural land use decreased significantly in relation to pasture land use.In addition,the results demonstrated that the studied MDS could be a suitable representative of TDS.78% of pasture soils had the optimum pore size distribution functions,while this parameter for agricultural soils was only 13%.In general,the soils of the studied region showed high limitations for plant growth according to the studied indicators.

  12. A simple index for the high-citation tail of citation distribution to quantify research performance in countries and institutions.

    Directory of Open Access Journals (Sweden)

    Alonso Rodríguez-Navarro

    Full Text Available BACKGROUND: Conventional scientometric predictors of research performance such as the number of papers, citations, and papers in the top 1% of highly cited papers cannot be validated in terms of the number of Nobel Prize achievements across countries and institutions. The purpose of this paper is to find a bibliometric indicator that correlates with the number of Nobel Prize achievements. METHODOLOGY/PRINCIPAL FINDINGS: This study assumes that the high-citation tail of citation distribution holds most of the information about high scientific performance. Here I propose the x-index, which is calculated from the number of national articles in the top 1% and 0.1% of highly cited papers and has a subtractive term to discount highly cited papers that are not scientific breakthroughs. The x-index, the number of Nobel Prize achievements, and the number of national articles in Nature or Science are highly correlated. The high correlations among these independent parameters demonstrate that they are good measures of high scientific performance because scientific excellence is their only common characteristic. However, the x-index has superior features as compared to the other two parameters. Nobel Prize achievements are low frequency events and their number is an imprecise indicator, which in addition is zero in most institutions; the evaluation of research making use of the number of publications in prestigious journals is not advised. CONCLUSION: The x-index is a simple and precise indicator for high research performance.

  13. Spatial distribution and temporal trends of polycyclic aromatic hydrocarbons in Mytilus galloprovincialis from the Iberian Mediterranean coast.

    Science.gov (United States)

    León, V M; Martínez-Gómez, C; García, I; Campillo, J A; Benedicto, J

    2013-02-01

    Polycyclic aromatic hydrocarbons (PAHs) have been determined in blue mussels (Mytilus galloprovincialis) from several Iberian Mediterranean coastal areas through the implementation of a monitoring programme from Spain in the framework of the Mediterranean Pollution Programme (MED POL). The selected areas correspond to sites with differing degrees of exposure to the main pollution sources (hot spots, coastal and reference areas). The sampling campaigns were performed from 2004 to 2009, with samples being taken from May to June, the non-spawning period for mussels in this area. Thirteen PAHs were determined by high-performance liquid chromatography with specific fluorescence detection. In general, total PAHs concentration was lower than 50 μg kg(-1) d.w., except in areas close to the principal ports and cities (Barcelona, Tarragona, Valencia and Algeciras) where it varies from 75 to 390 μg kg(-1) d.w. Background concentrations have been proposed for PAHs in mussels (23.8 μg kg(-1) d.w.) from Western Mediterranean area. Temporal trends were not statistically significant for PAHs concentrations from 2004 to 2009. Longer monitoring periods would be required to detect a continuous tendency, especially for PAHs because although the efficiency of combustion engines has reduced PAHs emissions, their increasing use could alter this potential reduction. The predominant PAHs were three and four ring congeners in all cases, with the predominance of phenanthrene in mussels sited far from the main PAHs sources. The phenanthrene/anthracene (lower than 10) and fluoranthene/pyrene (higher than 1) ratios indicate that PAHs detected in Spanish Mediterranean coastal mussels are mainly of pyrolytic origin.

  14. Determining Spatial Distribution And Air-Water Exchange Of Polycyclic Aromatic Hydrocarbons In Stormwater Runoff Catchment Basins

    Science.gov (United States)

    Kasaraneni, V. K.; Schifman, L. A.; Craver, V.; Boving, T. B.

    2014-12-01

    Stormwater runoff is a conduit for several pollutants such as polycyclic aromatic hydrocarbons (PAHs) in to surface and ground water bodies. The control of runoff and pollutants is typically addressed by best management practices (BMPs), such as retention/detention ponds or catchment basins in general. The effectiveness of catchment basins in reducing the volume of runoff and removal of some contaminants has been established. However, very little is known about the fate of the contaminants settled within these structures. In coastal regions and places with shallow groundwater tables accumulation of high concentrations of PAHs in the bottom sediments poses a potential threat for groundwater contamination. The concentrations of PAHs accumulated in the sediments of these catchment basins will primarily depend on the sources of runoff origin and the surrounding land use. Due to the physico-chemical characteristics of PAHs, their transport not only can occur in the liquid and solid phase, but it is also possible that gaseous emissions can be produced from BMP systems. For the purpose of this study, five stormwater catchment basins along the I-95 corridor in Rhode Island were selected based on the stormwater runoff origin and covering (industrial, urban, highway, and commercial) land uses. To study the stratification of PAHs sediment cores one foot were collected and analyzed for 31PAHs (16 EPA parent PAH and 15 methylated PAHs). In order to determine whether the catchment basins are a source of atmospheric pollution polyethylene passive samplers were deployed to determine the freely dissolved PAHs in the water column and gas phase PAHs at the air-water interface. This presentation will describe how PAH fluxes move between three environmental compartments (sediments, water column, atmosphere) within the five stormwater catchment basins. Further, it will be investigated whether these BMP structures can act as contaminant sources rather than sinks and whether BMP

  15. Distribution of Severity of Injury/Illness Index according to ICD-10 groups

    DEFF Research Database (Denmark)

    Nielsen, Niels Dalsgaard; Dahl, Michael; Rostgaard-Knudsen, Martin;

    be dispatched to the SIII groups 4-7 (severe illness/injury). Choosing six main groups of diagnoses we describe the individual distribution of SIII to reveal their severity.  METHODS: The local Emergency Medical Service (EMS) system in Aalborg, a small-sized urban city with approximately 200.000 inhabitants...

  16. Spatial distribution and concentration assessment of total petroleum hydrocarbons in the intertidal zone surface sediment of Todos os Santos Bay, Brazil.

    Science.gov (United States)

    Silva, Carine S; Moreira, Icaro T A; de Oliveira, Olivia M C; Queiroz, Antonio F S; Garcia, Karina S; Falcão, Brunno A; Escobar, Narayana F C; Rios, Mariana Cruz

    2014-02-01

    The primary objective of this study was to investigate the concentrations and spatial distribution of the total petroleum hydrocarbons (TPHs) in the intertidal zone surface sediment of Todos os Santos Bay, Brazil, to assess the distribution and degree of contamination by TPHs, measure the level of TPH degradation in the surface sediment, and identify the organic matter sources. The surface sediment used in this study was collected in 50 stations, and TPHs, isoprenoid alkanes (pristane and phytane), and unresolved complex mixture (UCM) were analyzed by gas chromatography with a flame ionization detector. The total concentrations ranged from 0.22 to 40,101 μg g(-1) dry weight and showed a strong correlation with the total organic carbon (TOC) content. The highest TPH concentrations were observed in samples from the mangrove sediments of a river located near a petroleum refinery. Compared with other studies in the world, the TPH concentrations in the intertidal surface sediment of Todos os Santos Bay were below average in certain stations and above average in others. An analysis of the magnitude of UCM (0.11 to 17,323 μg g(-1) dry weight) and the ratios nC17/Pr and nC18/Ph suggest that an advanced state of oil weathering, which indicates previous contamination. The molar C/N ratios varied between 5 and 43, which indicate organic matter with a mixed origin comprising marine and continental contributions.

  17. Distribution of Polycyclic Aromatic Hydrocarbons (PAHs) in sludge organic matter pools as a driving force of their fate during anaerobic digestion.

    Science.gov (United States)

    Aemig, Quentin; Chéron, Claire; Delgenès, Nadine; Jimenez, Julie; Houot, Sabine; Steyer, Jean-Philippe; Patureau, Dominique

    2016-02-01

    The fate of organic matter during anaerobic digestion of sewage sludge was studied in batch systems thanks to a sequential chemical fractionation of the particulate phase coupled to fluorescence spectroscopy. Polycyclic Aromatic Hydrocarbons (PAHs) distribution within the organic pools was characterized from their analysis in the residual fraction after each extraction. Both methods were combined to understand the link between PAHs presence in organic pools and their spectral characterization after extraction. Two batch systems (sludge and inoculum mixture) were set up to study the impact of PAHs spiking on their fate and distribution. The sequential fractionation allowed us to extract and characterize about 50% of total Chemical Oxygen Demand. Moreover, fluorescence spectroscopy helped us to understand the organic pools evolution: the most easily extracted pools composed of protein-like molecules were highly degraded meaning that chemical accessibility mimics the bioaccessibility to degrading microorganisms. PAHs were present in all pools of organic matter but native PAHs were mainly present in low accessible (hardly extractable) fractions and during anaerobic digestion, they accumulated in the non-accessible (non extractable) fraction. Spiked PAHs were more dissipated during anaerobic digestion since spiking made them present in more accessible fractions. During the anaerobic digestion, contrary to native PAHs, spiked ones relocated toward less accessible organic fractions confirming the ageing phenomenon. PCA analysis showed that, in spiked mixture, PAHs presence in organic pools is linked to both PAHs physical-chemical properties and quality/quantity of the associated organic pools.

  18. Polycyclic aromatic hydrocarbons (PAHs) in coastal sediments from urban and industrial areas of Asaluyeh Harbor, Iran: distribution, potential source and ecological risk assessment.

    Science.gov (United States)

    Raeisi, Alireza; Arfaeinia, Hossein; Seifi, Morteza; Shirzad-Siboni, Mehdi; Keshtkar, Mozhgan; Dobaradaran, Sina

    The distribution and toxicity levels of 16 EPA priority pollutant polycyclic aromatic hydrocarbons (PAHs) in the sediments of Asaluyeh shore, Iran were investigated. The total concentrations of the PAHs in surface sediments ranged from 1,054 to 17,448 ng/g dry weights with a mean concentration of 8,067 ng/g. The spatial distribution of PAHs showed that PAH levels are much higher in the industrial areas in comparison with urban areas. Based on diagnostic ratios, pyrogenic activities were dominant sources of PAHs pollution in sediments comparing petroleum sources. The toxic equivalent concentrations (TEQ Carc) of PAHs ranged from 172 to 2,235 ng TEQ/g with mean value of 997.9. Toxicity levels were evaluated using sediment quality guidelines (SQGs) and toxic equivalent factors. Samples were collected from industrial and urban stations in Asaluyeh shores. According to SQGs, ΣPAHs concentrations in sediments of urban areas were below the ERL (effects range low), but the industrial samples had ΣPAHs concentrations between ERL and ERM (effects range median). Furthermore, ΣHPAHs (heavy PAHs) and some individual PAHs in some industrial stations exceeded ERM, indicating adverse ecological risk effects frequently occur. Findings demonstrate that the surface sediment from Asaluyeh shore is highly to very highly contaminated with PAHs.

  19. Wintertime size distribution of polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) in the urban environment: Street- vs rooftop-level measurements

    Science.gov (United States)

    Chrysikou, Loukia P.; Gemenetzis, Panagiotis G.; Samara, Constantini A.

    The size distribution of ambient air particles and associated organic pollutants, such as polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), and organochlorine pesticides (OCPs) including hexachlorocyclohexanes (HCHs), DDT and metabolites, etc., was investigated at a traffic-impacted site of Thessaloniki, Greece. Investigation took place during wintertime of 2006 at two heights above ground: at the street level (1.5 m) and at the rooftop level (15 m). Size-resolved samples (7.5 μm) were concurrently collected from the two height levels using five-stage high volume cascade impactors. At both heights, particle mass exhibited bimodal distribution with peaks in the 0.95-1.5 μm and the 3-7.5 μm size fractions, whereas most organic pollutants exhibited one peak at 0.95-1.5 μm. Apart from the 0.95-1.5 μm fraction, particle concentrations of all size ranges were significantly higher at the street level than at the rooftop as a result of more intensive vehicular emissions and road dust resuspension. On the contrary, the concentrations of most organic pollutants did not differentiate significantly between the two elevations.

  20. Size distributions of polycyclic aromatic hydrocarbons in the atmosphere and estimation of the contribution of ultrafine particles to their lung deposition.

    Science.gov (United States)

    Kawanaka, Youhei; Tsuchiya, Yoshiteru; Yun, Sun-Ja; Sakamoto, Kazuhiko

    2009-09-01

    This is the first estimation of the contribution of ultrafine particles to the lung deposition of particle-bound polycyclic aromatic hydrocarbons (PAHs) in the atmosphere. The size distributions of nine PAHs (4-6 rings) were measured at roadside and suburban sites in winter in Japan. Deposition efficiencies and fluxes of PAHs in ultrafine mode (2.1 microm) to the human respiratory tract were calculated using the LUDEP computer-based model. From 10%-15% and 4.2%-6.9% of target PAHs were distributed in the ultrafine mode in the roadside and suburban atmosphere, respectively. The model calculations showed that as much as 18%-19% and 16%-17% of inhaled PAHs are deposited in the alveolar region of the lung for the roadside and suburban atmosphere, respectively. Total deposition fluxes of target PAHs in the alveolar region were about 1.5-fold greater for the roadside atmosphere than for the suburban atmosphere. Importantly, ultrafine particles were shown to contribute as much as 23%-30% and 10%-16% to PAH deposition in the alveolar region for the roadside and suburban atmosphere, respectively, although the contributions of ultrafine particles to the total particulate matter masswere only 2.3% in the roadside atmosphere and 1.3% in the suburban atmosphere. These results indicated that ultrafine particles are significant contributors to the deposition of PAHs into the alveolar region of the lung.

  1. Characterization of hydrocarbon utilizing fungi from hydrocarbon ...

    African Journals Online (AJOL)

    Prof. Ogunji

    hydrocarbon polluted sediments and water .... ecosystem may result in selective increase or decrease in microbial population (Okpokwasili ... been implicated in degradation of hydrocarbons such as crude oil, polyaromatic hydrocarbons and.

  2. Spectral and spatial characterization of perfluorinated graded-index polymer optical fibers for the distribution of optical wireless communication cells.

    Science.gov (United States)

    Hajjar, Hani Al; Montero, David S; Lallana, Pedro C; Vázquez, Carmen; Fracasso, Bruno

    2015-02-10

    In this paper, the characterization of a perfluorinated graded-index polymer optical fiber (PF-GIPOF) for a high-bitrate indoor optical wireless system is reported. PF-GIPOF is used here to interconnect different optical wireless access points that distribute optical free-space high-bitrate wireless communication cells. The PF-GIPOF channel is first studied in terms of transmission attenuation and frequency response and, in a second step, the spatial power profile distribution at the fiber output is analyzed. Both characterizations are performed under varying restricted mode launch conditions, enabling us to assess the transmission channel performance subject to potential connectorization errors within an environment where the end users may intervene by themselves on the home network infrastructure.

  3. Abdominal aortic calcification quantified by the Morphological Atherosclerotic Calcification Distribution (MACD index is associated with features of the metabolic syndrome

    Directory of Open Access Journals (Sweden)

    Barascuk Natasha

    2011-12-01

    Full Text Available Abstract Background Abdominal aortic calcifications (AAC predict cardiovascular mortality. A new scoring model for AAC, the Morphological Atherosclerotic Calcification Distribution (MACD index may contribute with additional information to the commonly used Aortic Calcification Severity (AC24 score, when predicting death from cardiovascular disease (CVD. In this study we investigated associations of MACD and AC24 with traditional metabolic-syndrome associated risk factors at baseline and after 8.3 years follow-up, to identify biological parameters that may account for the differential performance of these indices. Methods Three hundred and eight healthy women aged 48 to 76 years, were followed for 8.3 ± 0.3 years. AAC was quantified using lumbar radiographs. Baseline data included age, weight, blood pressure, blood lipids, and glucose levels. Pearson correlation coefficients were used to test for relationships. Results At baseline and across all patients, MACD correlated with blood glucose (r2 = 0.1, P Conclusion Patterns of calcification identified by the MACD, but not the AC24 index, appear to contain useful biological information perhaps explaining part of the improved identification of risk of cardiovascular death of the MACD index. Correlations of MACD but not the AC24 with glucose levels at baseline suggest that hyperglycemia may contribute to unique patterns of calcification indicated by the MACD.

  4. Distribution of lymph node metastasis is a prognostic index in patients with stage III colon cancer.

    Science.gov (United States)

    Kobayashi, Hirotoshi; Ueno, Hideki; Hashiguchi, Yojiro; Mochizuki, Hidetaka

    2006-04-01

    In the TNM classification of colorectal carcinoma, N-staging is dependent on the number of metastases; in the Japanese classification system, staging usually has been based on the distribution of metastases (N1, paracolic; N2, along the major vessels; N3, at the root of major vessels). The aim of our study was to examine whether the concept of the distribution of nodal metastasis could improve the TNM classification for colorectal cancer. We studied the survival rates of 485 and 136 patients with stage III colonic and rectal cancer, respectively, who underwent curative surgery between 1979 and 1998. The patients were categorized into 4 groups: group 1, TNM-N1 classified in J-N1; group 2, TNM-N2 in J-N1; group 3, TNM-N1 in J-N2-3; and group 4, TNM-N2 in J-N2-3. In the colon cancer arm, the 5-year survival rates of the patients in groups 1 to 4 were 74%, 51%, 52%, and 54%, respectively. There was a significant difference in survival rate between groups 1 and 3 (P = .0002). Thus, in colon cancer, nodal metastasis along the major vessels was a bad prognostic factor, even though the number of nodes that were involved was cancer arm, the 5-year survival rates of the patients in each group were 65%, 39%, 60%, and 32%, respectively. Only the number of nodal metastases was an independently significant prognostic variable. This study suggests that adding the concept of nodal distribution to the conventional TNM staging of colon cancer will improve the accuracy in the evaluation of the nodal status.

  5. Comparison of regional index flood estimation procedures based on the extreme value type I distribution

    DEFF Research Database (Denmark)

    Kjeldsen, Thomas Rodding; Rosbjerg, Dan

    2002-01-01

    A comparison of different methods for estimating T-year events is presented, all based on the Extreme Value Type I distribution. Series of annual maximum flood from ten gauging stations at the New Zealand South island have been used. Different methods of predicting the 100-year event...... considered applying either a log-linear relationship between at-site mean annual flood and catchment characteristics or a direct log-linear relationship between 100-year events and catchment characteristics. Comparison of the results shows that the existence of at-site measurements significantly diminishes...

  6. Refractive index changes induced by sheet beams with various intensity distributions in LiNbO3:Fe crystal

    Institute of Scientific and Technical Information of China (English)

    ZHANG; Peng; ZHAO; Jianlin; XU; Honglai; SUN; Yidong; YANG

    2005-01-01

    According to the Kukhtarev equations and a simplified model based on the photovoltaic charge carriers transport mechanism, the distributions of the index changes (DICs) in LiNbO3:Fe crystals induced by sheet beams with various intensity profiles are theoretically analyzed. The numerically simulated results coincide with the analytic expressions deduced from the simplified model. The DICs in a LiNbO3:Fe crystal induced by sheet beams with rectangular, Gaussian and square law profiles are measured by using the interferometric method. By employing the analytic expressions, the experimental data points are well fitted. By utilizing the angular spectrum theory and the ray equation, the uniformities of the intensity profiles of the writing beams along the propagation directions and the influences of the self-defocusing effect of the crystal are numerically simulated, respectively. The results show that the experimental results are reliable. The numerically simulated method and the analytic expressions can be both employed to predict the DICs induced by sheet beams with various light intensity profiles. Furthermore, utilizing writing beams with proper intensity profiles, any desired index distributions could be obtained.

  7. Spatial Distribution of Integrated Impact Index of Mega-event A Case Study of Expo '99 Kunming

    Institute of Scientific and Technical Information of China (English)

    DAI Guangquan; BAO Jigang

    2008-01-01

    Taking the affinity between events and media as a conceptualization base,a total of 1032 related news reports of Expo '99 Kunming,gathered from the internet data bank of China INFOBANK from 1992 to 2003,ate used as data sources.After classifying them with a communication research method-the content analysis,a data bank for SPSS is set up,and a mathematic model called the Integrated Impact Index of Expo '99 Kunming is constituted.With the model,the spatial distribution of the total integrated impacts of Expo '99 Kunming on the regions or cities with different regional scales is analysed quantitatively.The conclusions are:1) the Expo '99 Kunming made obvious integrated impacts on the regions or cities of every scale,especially in the venue city and the region-Kunming City and Yunnan Province; 2) it had corresponding impacts on other provinces; 3) the spatial distribution of Integrated Impact Index had a disaggregation with both plane extension and spotted decentralization; and 4) there was a distance decay law in all three scales of regions (Kunming City,Yunnan Province and the whole China),which incarnated the spatial extension law of the integrated impact of a special mega-event.

  8. Occurrence and distribution of polycyclic aromatic hydrocarbons in organo-mineral particles of alluvial sandy soil profiles at a petroleum-contaminated site.

    Science.gov (United States)

    Lu, Zhe; Zeng, Fangang; Xue, Nandong; Li, Fasheng

    2012-09-01

    The occurrence and the distribution of 16 USEPA priority pollutants polycyclic aromatic hydrocarbons (PAHs) were investigated in two alluvial sandy soil profiles and in their four sizes of organo-mineral particles (200 μm coarse sand) beside a typical oil sludge storage site in eastern China. PAHs were mainly enriched in the surface soil (0-20 cm) and the concentrations declined in deeper soils, from 3.68 to 0.128 μg/g in profile 1 and 10.8 to 0.143 μg/g in profile 2 (dry wt.). The PAHs in the upper soil layers of this study site mainly came from combustion pollution, whereas in the lower soil layers petroleum contamination became the major source of PAHs. The content of different sized organo-mineral particles of this alluvial sandy soil decreased in the following order: fine sand>coarse sand>silt>clay. X-ray diffraction (XRD) results showed that all the different sized soil fractions of this study site were dominated by quartz, calcite and feldspar. The particle surface became smoother with size increasing as shown by scanning electron microscope (SEM) images. PAH concentrations varied largely in different sized soil fractions. The highest PAH concentration was associated with clay and decreased in the order: clay>silt>coarse sand>fine sand. Soil organic matter (SOM) content, mineral composition and particle surface characteristics were suggested as three main factors affecting the distribution of PAHs in different sized organo-mineral particles. This study will help to understand the distribution and transport characteristics of PAHs in soil profiles at petroleum-contaminated sites.

  9. Spatial distribution of the dagger nematode Xiphinema index and its associated Grapevine fanleaf virus in French vineyard.

    Science.gov (United States)

    Villate, L; Fievet, V; Hanse, B; Delemarre, F; Plantard, O; Esmenjaud, D; van Helden, M

    2008-08-01

    The nematode Xiphinema index is, economically, the major virus vector in viticulture, transmitting specifically the Grapevine fanleaf virus (GFLV), the most severe grapevine virus disease worldwide. Increased knowledge of the spatial distribution of this nematode, both horizontally and vertically, and of correlative GFLV plant infections, is essential to efficiently control the disease. In two infested blocks of the Bordeaux vineyard, vertical distribution data showed that the highest numbers of individuals occurred at 40 to 110 cm depth, corresponding to the two layers where the highest densities of fine roots were observed. Horizontal distribution based on a 10 x 15 m grid sampling procedure revealed a significant aggregative pattern but no significant neighborhood structure of nematode densities. At a finer scale ( approximately 2 x 2 m), nematode sampling performed in a third block confirmed a significant aggregative pattern, with patches of 6 to 8 m diameter, together with a significant neighborhood structure of nematode densities, thus identifying the relevant sampling scale to describe the nematode distribution. Nematode patches correlate significantly with those of GFLV-infected grapevine plants. Finally, nematode and virus spread were shown to extend preferentially parallel to vine rows, probably due to tillage during mechanical weeding.

  10. Apparatus for hydrocarbon extraction

    Science.gov (United States)

    Bohnert, George W.; Verhulst, Galen G.

    2013-03-19

    Systems and methods for hydrocarbon extraction from hydrocarbon-containing material. Such systems and methods relate to extracting hydrocarbon from hydrocarbon-containing material employing a non-aqueous extractant. Additionally, such systems and methods relate to recovering and reusing non-aqueous extractant employed for extracting hydrocarbon from hydrocarbon-containing material.

  11. Process capability index Cpk for monitoring the thermal performance in the distribution of refrigerated products

    Directory of Open Access Journals (Sweden)

    Antonio Galvão Naclério Novaes

    2016-03-01

    Full Text Available Abstract The temperature of refrigerated products along the cold chain must be kept within pre-defined limits to ensure adequate safety levels and high product quality. Because temperature largely influences microbial activities, the continuous monitoring of the time-temperature history over the distribution process usually allows for the adequate control of the product quality along both short- and medium-distance distribution routes. Time-Temperature Indicators (TTI are composed of temperature measurements taken at various time intervals and are used to feed analytic models that monitor the impacts of temperature on product quality. Process Capability Indices (PCI, however, are calculated using TTI series to evaluate whether the thermal characteristics of the process are within the specified range. In this application, a refrigerated food delivery route is investigated using a simulated annealing algorithm that considers alternative delivery schemes. The objective of this investigation is to minimize the distance traveled while maintaining the vehicle temperature within the prescribed capability level.

  12. Distribution and Source of Polycyclic Aromatic Hydrocarbons (PAHs) in Water Dissolved Phase, Suspended Particulate Matter and Sediment from Weihe River in Northwest China.

    Science.gov (United States)

    Chen, Yuyun; Jia, Rui; Yang, Shengke

    2015-11-06

    Weihe River is a typical river located in the arid and semi-arid regions of Northwest China. In this study, the distribution and sources of 16 polycyclic aromatic hydrocarbons (PAHs) in Weihe River were investigated. The concentrations of ∑PAHs ranged from 351 to 4427 ng/L with a mean value of 835.4 ng/L in water dissolved phase (WDP), from 3557 ng/L to 147,907 ng/L with a mean value of 20,780 ng /L in suspended particulate matter (SPM), and from 362 to 15,667 ng/g dry weight (dw) with a mean value of 2000 ng/g dw in sediment, respectively. The concentrations of PAHs in Weihe River were higher compared with other rivers in the world. In both WDP and sediment, the highest concentrations of ∑PAHs were observed in the middle reach, while the lowest concentrations of ∑PAHs were found in the lower reach. For SPM, however, the PAHs concentrations in the lower reach were highest and the PAHs concentrations in the upper reach were lowest. The ratios of anthracene/(anthracene + phenanthrene) and fluoranthene/ (fluoranthene + pyrene) reflected a pattern of both pyrolytic and petrogenic input of PAHs in Weihe River. The potential ecosystem risk assessment indicated that harmful biological impairments occur frequently in Weihe River.

  13. Distribution and transportation of polycyclic aromatic hydrocarbons (PAHs) at the Humen river mouth in the Pearl River delta and their influencing factors.

    Science.gov (United States)

    Liu, Feng; Yang, Qingshu; Hu, Yujie; Du, Huanhuan; Yuan, Fei

    2014-07-15

    Five different water samples were collected from the surface to the bottom layers at the Humen river mouth in the Pearl River delta during the flood and ebb tides in August 2011, respectively. Changes in the distribution and characteristics of polycyclic aromatic hydrocarbons (PAHs) were examined to explore their transportation process. More than 62 types of PAHs were detected in the water columns. The mean concentration of the total PAHs ranged from 849.33 to 1370.53 ng/l and from 629.21 to 2019.91 ng/l during the flood and ebb tides, respectively. Furthermore, 2-ring PAHs were the most abundant species, followed by 3-ring PAHs. There were different composition patterns of the PAHs during the flood and ebb tides. And the transportation process of PAHs was influenced by their sources and different estuarine hydrodynamics. Analysis of the sources of the PAHs indicated that the PAHs were derived from primarily petroleum and coal combustion sources.

  14. Occurrence, distribution, environmental risk assessment and source apportionment of polycyclic aromatic hydrocarbons (PAHs) in water and sediments of the Liaohe River Basin, China.

    Science.gov (United States)

    Bai, Yangwei; Meng, Wei; Xu, Jian; Zhang, Yuan; Guo, Changsheng; Lv, Jiapei; Wan, Jun

    2014-12-01

    The occurrence and distribution of polycyclic aromatic hydrocarbons (PAHs) were investigated in water and sediments in Liaohe River Basin. The total PAH concentrations ranged from 111.9 to 2,931.6 ng/L in water and from 92.2 to 295,635.2 ng/g dry weight (dw) in sediments. The PAHs in water were dominated by 2-, 3- and 4-ring PAHs, which accounted for 42.8 %, 39.4 % and 14.2 % of the total PAHs, respectively, while in sediment PAHs were dominated by 3-, 4- and 5-ring PAHs, which accounted for 26.5 %, 44.2 % and 17.4 % of the total PAHs, respectively. The benzo[a]pyrene equivalents for water samples showed that in 37 out of 50 sites the values were greater than the national standard, and the environmental risk assessment indicated that high environmental risk of PAHs existed in sediments. Using the molecular ratio method for the source identification it was concluded that PAHs were determined to be from mixed sources (petroleum and combustion) in Liaohe River system and combustion sources in Daliao River system.

  15. Size-distribution of airborne polycyclic aromatic hydrocarbons and other organic source markers in the surroundings of a cement plant powered with alternative fuels.

    Science.gov (United States)

    Sánchez-Soberón, Francisco; van Drooge, Barend L; Rovira, Joaquim; Grimalt, Joan O; Nadal, Martí; Domingo, José L; Schuhmacher, Marta

    2016-04-15

    The distributions of polycyclic aromatic hydrocarbons (PAHs) and molecular tracer organic compounds for biomass combustion, traffic emissions, soil dust, and secondary aerosol processing have been studied in three fractions of ambient air particulate matter (PM10, 2.5, and 1) collected in the vicinity of a cement plant. PAH concentrations were used to estimate the carcinogenic risks in humans. Combustion related compounds, including PAHs, and those from secondary aerosol processing, predominated in the finest (PMcombustion were found in high concentrations, indicating the influence of biomass burning on PM. Most predominant PAHs were five and six rings species, related to a PAH profile characteristic of urban-industrial environments. The concentrations of benzo[a]pyrene varied between 0.2 and 1.0ng/m(3), which is close but lower than the annual limit value of 1ng/m(3) established by law. Exposure and inhalation carcinogenic risks from total PAHs were below the EPA threshold of acceptable risk (1·10(-6)).

  16. Influence of oil and gas field operations on spatial and temporal distributions of atmospheric non-methane hydrocarbons and their effect on ozone formation in winter

    Directory of Open Access Journals (Sweden)

    R. A. Field

    2014-09-01

    Full Text Available Emissions from oil and natural gas development during winter in the Upper Green River Basin of Wyoming are known to drive episodic ozone (O3 production. Contrasting O3 distributions were observed in the winters of 2011 and 2012, with numerous episodes in 2011 compared to none in 2012. During 2011 wintertime O3 episodes at two sites near Boulder Wyoming, situated ∼5 km apart, were observed to sometimes differ. In 2012 the lack of O3 episodes coincided with a reduction in ambient levels of total non-methane hydrocarbons (NMHC. Measurements of speciated NMHC, and other air quality parameters, were performed to better understand emission sources and to determine which compounds are most active in promoting O3 formation. Positive Matrix Factorization (PMF analyses of the data were carried out to help achieve these goals. PMF analyses revealed three contributing factors that were identified with different emission source types: factor 1, combustion/traffic; factor 2, fugitive natural gas; and factor 3, fugitive condensate. Compositional signatures of three contributing factors were identified through comparison with independently derived emission source profiles. Fugitive emissions of natural gas and of condensate were the two principal emission source types for NMHC. A water treatment and recycling facility was found to be a significant source of condensate range NMHC, in particular toluene and m+p-xylene. Emissions from water treatment have an influence upon peak O3 mixing ratios at downwind measurement sites.

  17. Distribution and origin of polycyclic aromatic hydrocarbons in surface sediments from an urban river basin at the Metropolitan Region of Curitiba, Brazil

    Institute of Scientific and Technical Information of China (English)

    Natalicio Ferreira Leite; Patricio Peralta-Zamora; Marco Tadeu Grassi

    2011-01-01

    The concentrations of 16 polycyclic aromatic hydrocarbons (PAHs) were determined in surface sediment samples from nine sites located at the Iguacu River Basin in the Metropolitan Region of Curitiba, Brazil to evaluate their distribution and sources.The total concentration of the PAHs was greater for sediments from highly urbanized areas, while the sediments from the IraíEnvironmental Protection Area (IraíEPA) showed significantly low concentrations.The sediments from the Iguacu and Barigui rivers were classified as highly contaminated, while those from the Cercado and Curralinho rivers were classified as moderately contaminated.The predominance of PAHs containing two to four aromatic rings in most of the samples suggested the direct input of raw sewage into the water resources evaluated.Benzo[g,h,i]perylene, dibenzo[a,h]anthracene and indeno[1,2,3-cd]pyrene were predominant in sediments from the areas under the greatest urban and industrial development.The correlation between thermodynamic stability and the kinetics of evolution presented by the isomeric pairs indicated that combustion is the predominant source of PAHs in the sediments because the combustion of fossil fuels affected most of the points evaluated, followed by combustion of biomass and eventually combustion of oil product inputs.In general, the results showed that areas under strong urban influence, as well as the IraíEPA, receive contributions of PAils from similar sources.

  18. The retention and distribution of parent, alkylated, and N/O/S-containing polycyclic aromatic hydrocarbons on the epidermal tissue of mangrove seedlings.

    Science.gov (United States)

    Li, Ruilong; Tan, Huadong; Zhu, Yaxian; Zhang, Yong

    2017-07-01

    The polycyclic aromatic hydrocarbons (PAHs) located on the epidermal tissues showed distinctive toxic effects to root, while the retention and distribution of PAHs on mangrove seedlings poorly understood. Our results confirmed that the partition coefficients (Kf) of the PAHs retained on the epidermal tissue of mangrove roots, such as Kandelia obovata, Avicennia marina and Aegiceras corniculatum, were much higher than the Poaceae plants roots, for example wheat and maize (Wild et al., 2005). Moreover, to the parent and alkyl PAHs, a well negative correlation was observed between the surface polarity of these three species of mangrove root and the Kf values (p PAHs, these relationships were not obviously due to existing of the π-π, n-π interactions and hydrogen bonding between the N/O/S-containing PAHs and epidermal tissues. The PAHs retained on these three species of mangrove root epidermal tissues formed larger clusters than that of on Poaceae plants, such as wheat and maize (Wild et al., 2005) due to the limitation of the suberization of the root exodermis and endodermis. After exposure of 30 d, rhizo- and endophytic bacteria degraded parts of the N/O/S-containing PAHs to medium-lifetime fluorescence substances. To our knowledge, this is the first time to assess the retention of PAHs on the epidermal tissue of mangrove root, which will improve our understanding of the root uptake PAHs process. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. Abundance, composition and vertical distribution of polycyclic aromatic hydrocarbons in sediments of the Mai Po Inner Deep Bay of Hong Kong.

    Science.gov (United States)

    Zhao, Zhenye; Zhuang, Yi-Xuan; Gu, Ji-Dong

    2012-08-01

    The distribution and changes of polycyclic aromatic hydrocarbons (PAHs) contamination in mangrove sediments of Mai Po Inner Deep Bay Ramsar Site of Hong Kong SAR were investigated. Surface sediments (10 cm) collected from four sampling sites (SZ, SP, MF and M) exhibited significant spatial variations in concentrations of total PAH (with ΣPAHs ranging from 161.7 to 383.7 ng g(-1) dry wt), as well as the composition of 16 US EPA priority PAH compounds. The highest PAHs concentrations were found in the mangrove sediments. Moreover, a sediment core was extracted from mangrove area is used to reconstruct the high-resolution depositional record of PAHs by (210)Pb isotope analysis, showing the amounts of PAHs remained relatively constant for the past 41 years. Urbanization of Shenzhen Economic Zone, the rapid increase in vehicle numbers and energy consumption in the last two decades contributed to the PAHs detected in sediments. The source-diagnostic ratios indicated that pyrogenic input are important throughout the record and the surface sediments, and suggest that diesel fuel combustion, and hence traffic of heavier vehicles, is the most probable cause of PAHs.

  20. Distribution and sources of polycyclic aromatic hydrocarbons in sediments of the Mai Po Inner Deep Bay Ramsar Site in Hong Kong.

    Science.gov (United States)

    Zhao, Zhen-Ye; Chu, Yan-ling; Gu, Ji-Dong

    2012-08-01

    The concentration of total polycyclic aromatic hydrocarbons (∑PAHs) and the 16 US EPA priority individual PAH compounds were analyzed in surface sediments from the Mai Po Inner Deep Bay, Ramsar Site of Hong Kong from December 2001 to Jun 2005, to investigate the spatial variability of anthropogenic pollutants. ∑PAHs concentrations ranged from 36.5 to 256.3 ng g(-1) dry weight with an average of 148.9 ng g(-1), comparable to other urbanized areas of the world, and there was little difference among different sampling times from December 2001 to June 2005. Based on comparison to the results from earlier study, it appears that a decrease of total PAHs concentration has occurred since 1992. Meanwhile, the concentrations of ∑PAHs were positive correlated with total organic carbon contents except sites F and G, suggesting the characteristics of the sediment influences the distribution and concentration of PAHs. There was relatively a good relationship among the individual PAHs and the compounds of fluorene, phenanthrene, anthracene, fluoranthene, pyrene, benzo[a]pyrene and indeno[cd]pyrene yielded a good correlation (r(2) > 0.5) with total PAHs. Principal component analysis and specific PAHs compound ratios (Phe/Ant vs. Flt/Pyr) indicate the pyrogenic origins, especially traffic exhausts, are the dominant sources of PAHs in the Mai Po Inner Deep Bay Nature Reserve.

  1. Sources and distribution of polycyclic aromatic hydrocarbons (PAHs) and organic matter in surface sediments of an estuary under petroleum activity influence, Todos os Santos Bay, Brazil.

    Science.gov (United States)

    Nascimento, Rodrigo A; de Almeida, Marcos; Escobar, Narayana C F; Ferreira, Sergio L C; Mortatti, Jefferson; Queiroz, Antônio F S

    2017-06-30

    The present study evaluated the origin and distribution of polycyclic aromatic hydrocarbons (PAHs) and the organic matter (OM) in the surface sediment of the São Paulo River estuary, Todos os Santos Bay (TSB), Brazil. The samples were collected in the rainy (CP1) and the dry (CP2) seasons. We analyzed the 16 PAHs from the United States Environmental Protection Agency (US EPA) priority pollutant list, total organic carbon (TOC), total nitrogen (N), and stable carbon isotope (δ(13)C). The total concentration of PAHs ranged from 11.45±1.28 to 1825.35±107.96ngg(-1), while TOC ranged from 3.8 to 27.7gkg(-1). CP1 showed the highest concentrations for all parameters. The δ(13)C ratio indicated terrigenous OM (-23.81 to -26.63‰). The TOC/N ratio (C/N) indicated transitional OM (12.32 to 24.39), in addition to the continental origin. The diagnostic ratios of PAHs origin revealed only pyrolytic source, although close to areas with a history of petroleum contamination. Copyright © 2017. Published by Elsevier Ltd.

  2. [Environmental factors on distribution of polycyclic aromatic hydrocarbons in soils from Dashiwei karst giant doline (Tiankeng) in Guangxi, China].

    Science.gov (United States)

    Kong, Xiang-Sheng; Qi, Shi-Hua; Jiang, Zhong-Cheng; Huang, Bao-Jian

    2012-11-01

    With typical Dashiwei karst great doline (Tiankeng) located in Leye county, Guangxi in China as study area, the soil samples of different karst topography were collected and analyzed utilizing GC-MS for the 16 PAHs. Environmental factors were observed by weather instrument. The results showed that the total PAHs concentration in soils of the ground (the positive landform) of Dashiwei great doline ranged from 75.20 ng x g(-1) to 373.79 ng x g(-1), with an average of 120.70 ng x g(-1). In Dashwei great doline (the negative landform), the total PAHs concentration in soils of cliff ranged from 19.88 ng x g(-1) to 330.79 ng x g(-1), with an average of 131.86 ng x g(-1); the concentration of the bottom section ranged from 127.48 ng x g(-1) to 661.62 ng x g(-1), with an average of 395.22 ng x g(-1); and the concentration of the underground river ranged from 1132.11 ng x g(-1) to 1 749.95 ng x g(-1), with an average of 1412.39 ng x g(-1). The PAHs compounds were mainly 4-6 rings PAH. The primary sources of PAHs were pyrogenic sources. The pollution approaches were mainly atmospheric transportation and deposition. As a whole, the spatial distribution of PAHs in soils in Dashiwei doline gradually increased from the surface-the cliff-the bottom-the underground river with the increase of temperature and relative humidity. Accumulation and differentiation of PAHs in a vertical way were showed by "coal trap effect". Environmental factors influencing the distribution of PAHs in soils were majorly temperature, followed by humidity, wind direction and wind speed, and in some parts multi environmental factors worked together. The effect of the environmental factors was bigger in summer than in winter. Monitoring of PAHs discovered that the total PAHs concentration in soils of the bottom was 3.5 times higher in 2007 than in 2006. As a consequence, this study suggested that the accumulation and differentiation of karst doline was related with these important environmental factors.

  3. Microscale spatial distribution and health assessment of PM2.5-bound polycyclic aromatic hydrocarbons (PAHs) at nine communities in Xi'an, China.

    Science.gov (United States)

    Xu, Hongmei; Ho, Steven Sai Hang; Gao, Meiling; Cao, Junji; Guinot, Benjamin; Ho, Kin Fai; Long, Xin; Wang, Jingzhi; Shen, Zhenxing; Liu, Suixin; Zheng, Chunli; Zhang, Qian

    2016-11-01

    Spatial variability of polycyclic aromatic hydrocarbons (PAHs) associated with fine particulate matter (PM2.5) was investigated in Xi'an, China, in summer of 2013. Sixteen priority PAHs were quantified in 24-h integrated air samples collected simultaneously at nine urban and suburban communities. The total quantified PAHs mass concentrations ranged from 32.4 to 104.7 ng m(-3), with an average value of 57.1 ± 23.0 ng m(-3). PAHs were observed higher concentrations at suburban communities (average: 86.3 ng m(-3)) than at urban ones (average: 48.8 ng m(-3)) due to a better enforcement of the pollution control policies at the urban scale, and meanwhile the disorganized management of motor vehicles and massive building constructions in the suburbs. Elevated PAH levels were observed in the industrialized regions (west and northwest of Xi'an) from Kriging interpolation analysis. Satellite-based visual interpretations of land use were also applied for the supporting the spatial distribution of PAHs among the communities. The average benzo[a]pyrene-equivalent toxicity (Σ[BaP]eq) at the nine communities was 6.9 ± 2.2 ng m(-3) during the sampling period, showing a generally similar spatial distribution to PAHs levels. On average, the excess inhalation lifetime cancer risk derived from Σ[BaP]eq indicated that eight persons per million of community residents would develop cancer due to PM2.5-bound PAHs exposure in Xi'an. The great in-city spatial variability of PAHs confirmed the importance of multiple points sampling to conduct exposure health risk assessment.

  4. Occurrence of gaseous and particulate polycyclic aromatic hydrocarbons in the urban atmosphere: study of sources and ambient temperature effect on the gas/particle concentration and distribution

    Energy Technology Data Exchange (ETDEWEB)

    Tsapakis, Manolis [Environmental Chemical Processes Laboratory (ECPL), Department of Chemistry, University of Crete, EL-71409 Heraklion (Greece); Stephanou, Euripides G. [Environmental Chemical Processes Laboratory (ECPL), Department of Chemistry, University of Crete, EL-71409 Heraklion (Greece)]. E-mail: stephanou@chemistry.uoc.gr

    2005-01-01

    The presence of polycyclic aromatic hydrocarbons (PAHs) in an urban region (Heraklion, Greece) and processes that govern their atmospheric fate were studied from November 2000 until February 2002. Sixteen samples were collected, by using an artifact-free sampling device, on a monthly basis and the concentration of PAHs in gas and particulate phase was determined. The most abundant members (gas + particles) were phenanthrene (20.0 {+-} 7.0 ng m{sup -3}), fluoranthene (6.5 {+-} 1.7 ng m{sup -3}), pyrene (6.6 {+-} 2.4 ng m{sup -3}), and chrysene (3.1 {+-} 1.5 ng m{sup -3}). Total concentration (gas + particulate) of PAH ranged from 44.3 to 129.2 ng m{sup -3}, with a mean concentration of 79.3 ng m{sup -3}. Total concentration of PAHs in gas phase ranged from 31.4 to 84.7 ng m{sup -3} with non-observable seasonal variation. Conversely, maximum PAH concentrations in the particulate phase occurred during winter months. Particulate concentration varied from 11.4 to 44.9 ng m{sup -3}, with an average of 25.2 ng m{sup -3}. PAH distribution between gas and particulate phase was in agreement with the sub-cooled vapor pressure. Shift in gas/particle distribution due to difference in ambient temperature elucidated to some extent the seasonal variation of the concentration of PAHs in particles. - Capsule: Ambient PAH partitioning between gas and particle phases vary between compounds and with environmental conditions.

  5. Distribution and composition pattern of polycyclic aromatic hydrocarbons in different tissues of sturgeons collected from Iranian coastline of the Caspian Sea.

    Science.gov (United States)

    Mashroofeh, Abdulreza; Bakhtiari, Alireza Riyahi; Pourkazemi, Mohammad

    2015-02-01

    The levels of 16 polycyclic aromatic hydrocarbons (PAHs) were determined in the liver, kidney, gills and muscle tissues of Persian sturgeon (Acipenser persicus; n=16), and Stellate sturgeon (Acipenser stellatus; n=7) collected from coastal waters of the South Caspian Sea from March and April 2011. The distribution and composition pattern of PAHs in the different tissues of sturgeons, and the effects of lipid content in sturgeon tissues and the octanol-water partition coefficient (Kow) of PAHs congeners on them were analyzed. The levels of total PAHs in the various tissues of Persian sturgeon and Stellate sturgeon ranged from 2.095 to 6.587 and 1.942 to 6.206 μg g(-1)dw, respectively. Stellate sturgeon showed significantly higher levels of heavy PAHs (⩾ 4-rings) than Persian sturgeon. The analysis has revealed a high degree of differential accumulation of the studied PAHs in the tissues of the both species. Low molecular weight PAHs predominated in the sturgeons, accounting for 81.89% of the total PAHs. Among the sixteen tested PAHs, naphthalene was the most dominant congener, followed by phenanthrene and fluorene. The PAHs levels and distribution in the tissues of sturgeons are dependent on both the Kow of PAH congeners and the lipid content in these tissues. There was a significant positive relationship (r=0.868, p<0.005) between lipid content and PAHs levels. The statistically significant negative relationships (p<0.01) were found between log Kow and log-transformed PAHs levels for muscle tissues of both sturgeon species.

  6. Spatial distribution and seasonal variation of atmospheric bulk deposition of polycyclic aromatic hydrocarbons in Beijing-Tianjin region, North China

    Energy Technology Data Exchange (ETDEWEB)

    Wang Wentao [Laboratory for Earth Surface Processes, College of Urban and Environmental Sciences, Peking University, Beijing 100871 (China); Administrative Center for China' s Agenda 21 (ACCA21), Ministry of Science and Technology, Beijing, 100038 (China); Massey Simonich, Staci L.; Giri, Basant [Department of Environmental and Molecular Toxicology and Department of Chemistry, Oregon State University, Corvallis, OR 97331 (United States); Xue Miao; Zhao Jingyu [Laboratory for Earth Surface Processes, College of Urban and Environmental Sciences, Peking University, Beijing 100871 (China); Chen Shejun [State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China); Shen Huizhong; Shen Guofeng; Wang Rong; Cao Jun [Laboratory for Earth Surface Processes, College of Urban and Environmental Sciences, Peking University, Beijing 100871 (China); Tao Shu, E-mail: taos@urban.pku.edu.c [Laboratory for Earth Surface Processes, College of Urban and Environmental Sciences, Peking University, Beijing 100871 (China)

    2011-01-15

    Bulk deposition samples were collected in remote, rural village and urban areas of Beijing-Tianjin region, North China in spring, summer, fall and winter from 2007 to 2008. The annually averaged PAHs concentration and deposition flux were 11.81 {+-} 4.61 {mu}g/g and 5.2 {+-} 3.89 {mu}g/m{sup 2}/day respectively. PHE and FLA had the highest deposition flux, accounting for 35.3% and 20.7% of total deposition flux, respectively. More exposure risk from deposition existed in the fall for the local inhabitants. In addition, the PAHs deposition flux in rural villages (3.91 {mu}g/m{sup 2}/day) and urban areas (8.28 {mu}g/m{sup 2}/day) was 3.8 and 9.1 times higher than in background area (0.82 {mu}g/m{sup 2}/day), respectively. This spatial variation of deposition fluxes of PAHs was related to the PAHs emission sources, local population density and air concentration of PAHs, and the PAHs emission sources alone can explain 36%, 49%, 21% and 30% of the spatial variation in spring, summer, fall and winter, respectively. - The spatial distribution and seasonal variation of PAHs deposition in Beijing-Tianjin region were studied and quantitatively related to PAHs emission density and ambient air concentration.

  7. Pollution level, phase distribution and health risk of polycyclic aromatic hydrocarbons in indoor air at public places of Hangzhou, China

    Energy Technology Data Exchange (ETDEWEB)

    Lu Hao [Department of Environmental Science, Zhejiang University, Hangzhou, Zhejiang, 310028 (China)], E-mail: luhaozju@163.com; Zhu Lizhong [Department of Environmental Science, Zhejiang University, Hangzhou, Zhejiang, 310028 (China)], E-mail: zlz@zju.edu.cn; Chen Shuguang [Department of Environmental Science, Zhejiang University, Hangzhou, Zhejiang, 310028 (China)], E-mail: chenshuguang@zju.edu.cn

    2008-04-15

    PAHs pollution survey in air of public places was conducted in Hangzhou, China. The most serious PAHs pollution was observed in indoor air of shopping centers and the slightest was in train stations. The molecular weight of chrysene (MW 228) appeared to be the dividing line for the PAHs with a larger or smaller distribution in the vapor or particulate phase. Concentrations of 15 PAHs on PM{sub 2.5} accounted for 71.3% of total particulate PAHs, and followed by PM{sub 2.5-10} fraction (17.6%) and >PM{sub 10} fraction (11.1%). In shopping centers and supermarkets, emission of 2-4 rings PAHs occurred from indoor sources, whereas 5-6 rings PAHs predominantly originated from transport of outdoor air. In temples, PAHs in indoor air mainly originated from incense burning. Health risks associated with the inhalation of PAHs were assessed, and naphthalene made the greatest contribution (62.4%) to the total health risks. - Concentrations of PAHs in the air of selected public places in Hangzhou correspond to 10{sup -3} life-time lung cancer risk.

  8. Occurrence and distribution of polycyclic aromatic hydrocarbons in organo-mineral particles of alluvial sandy soil profiles at a petroleum-contaminated site

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Zhe [State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Anwai, Dayangfang 8, Beijing 100012 (China); Department of Chemistry, University of Manitoba, Winnipeg, Manitoba, Canada R3T 2N2 (Canada); School of Environment, Renmin University of China, Zhongguancun Street 59, Beijing 100872 (China); Zeng, Fangang [School of Environment, Renmin University of China, Zhongguancun Street 59, Beijing 100872 (China); Xue, Nandong [State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Anwai, Dayangfang 8, Beijing 100012 (China); Li, Fasheng, E-mail: ligulax@vip.sina.com [State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Anwai, Dayangfang 8, Beijing 100012 (China)

    2012-09-01

    The occurrence and the distribution of 16 USEPA priority pollutants polycyclic aromatic hydrocarbons (PAHs) were investigated in two alluvial sandy soil profiles and in their four sizes of organo-mineral particles (< 2 {mu}m clay, 2-20 {mu}m silt, 20-200 {mu}m fine sand, and > 200 {mu}m coarse sand) beside a typical oil sludge storage site in eastern China. PAHs were mainly enriched in the surface soil (0-20 cm) and the concentrations declined in deeper soils, from 3.68 to 0.128 {mu}g/g in profile 1 and 10.8 to 0.143 {mu}g/g in profile 2 (dry wt.). The PAHs in the upper soil layers of this study site mainly came from combustion pollution, whereas in the lower soil layers petroleum contamination became the major source of PAHs. The content of different sized organo-mineral particles of this alluvial sandy soil decreased in the following order: fine sand > coarse sand > silt > clay. X-ray diffraction (XRD) results showed that all the different sized soil fractions of this study site were dominated by quartz, calcite and feldspar. The particle surface became smoother with size increasing as shown by scanning electron microscope (SEM) images. PAH concentrations varied largely in different sized soil fractions. The highest PAH concentration was associated with clay and decreased in the order: clay > silt > coarse sand > fine sand. Soil organic matter (SOM) content, mineral composition and particle surface characteristics were suggested as three main factors affecting the distribution of PAHs in different sized organo-mineral particles. This study will help to understand the distribution and transport characteristics of PAHs in soil profiles at petroleum-contaminated sites. -- Highlights: Black-Right-Pointing-Pointer PAH concentrations varied largely in different sized fractions. Black-Right-Pointing-Pointer The highest PAH concentrations were associated with clay and decreased in the order: clay > silt > coarse sand > fine sand. Black-Right-Pointing-Pointer Soil organic

  9. Polycyclic aromatic hydrocarbons (PAHs) in multimedia environment of Heshan coal district, Guangxi: distribution, source diagnosis and health risk assessment.

    Science.gov (United States)

    Huang, Huan-Fang; Xing, Xin-Li; Zhang, Ze-Zhou; Qi, Shi-Hua; Yang, Dan; Yuen, Dave A; Sandy, Edward H; Zhou, Ai-Guo; Li, Xiao-Qian

    2016-10-01

    Mining activities are among the major culprits of the wide occurrences of soil and water pollution by PAHs in coal district, which have resulted in ecological fragilities and health risk for local residents. Sixteen PAHs in multimedia environment from the Heshan coal district of Guangxi, South China, were measured, aiming to investigate the contamination level, distribution and possible sources and to estimate the potential health risks of PAHs. The average concentrations of 16 PAHs in the coal, coal gangue, soil, surface water and groundwater were 5114.56, 4551.10, 1280.12 ng g(-1), 426.98 and 381.20 ng L(-1), respectively. Additionally, higher soil and water PAH concentrations were detected in the vicinities of coal or coal gangue dump. Composition analysis, isomeric ratio, Pearson correlation analysis and principal component analysis were performed to diagnose the potential sources of PAHs in different environmental matrices, suggesting the dominant inputs of PAHs from coal/coal combustion and coal gangue in the soil and water. Soil and water guidelines and the incremental lifetime risk (ICLR) were used to assess the health risk, showing that soil and water were heavily contaminated by PAHs, and mean ICLRcoal/coal-gangue and mean ICLRsoil were both significantly higher than the acceptable levels (1 × 10(-4)), posing high potential carcinogenic risk to residents, especially coal workers. This study highlights the environmental pollution problems and public health concerns of coal mining, particularly the potential occupational health hazards of coal miners exposed in Heshan.

  10. Modelling shallow landslide susceptibility by means of a subsurface flow path connectivity index and estimates of soil depth spatial distribution

    Directory of Open Access Journals (Sweden)

    C. Lanni

    2012-11-01

    Full Text Available Topographic index-based hydrological models have gained wide use to describe the hydrological control on the triggering of rainfall-induced shallow landslides at the catchment scale. A common assumption in these models is that a spatially continuous water table occurs simultaneously across the catchment. However, during a rainfall event isolated patches of subsurface saturation form above an impeding layer and their hydrological connectivity is a necessary condition for lateral flow initiation at a point on the hillslope.

    Here, a new hydrological model is presented, which allows us to account for the concept of hydrological connectivity while keeping the simplicity of the topographic index approach. A dynamic topographic index is used to describe the transient lateral flow that is established at a hillslope element when the rainfall amount exceeds a threshold value allowing for (a development of a perched water table above an impeding layer, and (b hydrological connectivity between the hillslope element and its own upslope contributing area. A spatially variable soil depth is the main control of hydrological connectivity in the model. The hydrological model is coupled with the infinite slope stability model and with a scaling model for the rainfall frequency–duration relationship to determine the return period of the critical rainfall needed to cause instability on three catchments located in the Italian Alps, where a survey of soil depth spatial distribution is available. The model is compared with a quasi-dynamic model in which the dynamic nature of the hydrological connectivity is neglected. The results show a better performance of the new model in predicting observed shallow landslides, implying that soil depth spatial variability and connectivity bear a significant control on shallow landsliding.

  11. 现代配电网健康指数理论最新研究进展%Recent Development of Health Index Theory for Modern Distribution Network

    Institute of Scientific and Technical Information of China (English)

    周莉梅; 马钊; 盛万兴

    2016-01-01

    The origin and concept of Health Index for power equipment are briefly introduced and domestic research work related to Health Index concept for distribution network is outlined.Then the definition of Health Index for distribution network is discussed.Research status and recent development of Health Index theory for modern distribution network both domestic and abroad are described and existing problems of distribution assets management and Health Index theory application in China are pointed out.Finally the main problem existing and improvement direction of present Health Index research for distribution network are put forward in the paper.%简要介绍了电力设备健康指数的起源和概念,以及国内在配电网健康指数概念方面的相关研究工作,进而探讨了配电网健康指数的定义;概述了国内外在配电资产管理和健康指数理论方面的研究现状与进展情况,指出了我国在配电资产管理和健康指数理论应用方面存在的一些问题;最后,针对目前配电网健康指数理论研究存在的主要问题提出了未来的改进方向.

  12. Change in the body mass index distribution for women: analysis of surveys from 37 low- and middle-income countries.

    Directory of Open Access Journals (Sweden)

    Fahad Razak

    Full Text Available BACKGROUND: There are well-documented global increases in mean body mass index (BMI and prevalence of overweight (BMI ≥ 25.0 kg/m(2 and obese (BMI ≥ 30.0 kg/m(2. Previous analyses, however, have failed to report whether this weight gain is shared equally across the population. We examined the change in BMI across all segments of the BMI distribution in a wide range of countries, and assessed whether the BMI distribution is changing between cross-sectional surveys conducted at different time points. METHODS AND FINDINGS: We used nationally representative surveys of women between 1991-2008, in 37 low- and middle-income countries from the Demographic Health Surveys ([DHS] n = 732,784. There were a total of 96 country-survey cycles, and the number of survey cycles per country varied between two (21/37 and five (1/37. Using multilevel regression models, between countries and within countries over survey cycles, the change in mean BMI was used to predict the standard deviation of BMI, the prevalence of underweight, overweight, and obese. Changes in median BMI were used to predict the 5th and 95th percentile of the BMI distribution. Quantile-quantile plots were used to examine the change in the BMI distribution between surveys conducted at different times within countries. At the population level, increasing mean BMI is related to increasing standard deviation of BMI, with the BMI at the 95th percentile rising at approximately 2.5 times the rate of the 5th percentile. Similarly, there is an approximately 60% excess increase in prevalence of overweight and 40% excess in obese, relative to the decline in prevalence of underweight. Quantile-quantile plots demonstrate a consistent pattern of unequal weight gain across percentiles of the BMI distribution as mean BMI increases, with increased weight gain at high percentiles of the BMI distribution and little change at low percentiles. Major limitations of these results are that repeated population

  13. Comparison between the probability distribution of returns in the Heston model and empirical data for stock indexes

    Science.gov (United States)

    Silva, A. Christian; Yakovenko, Victor M.

    2003-06-01

    We compare the probability distribution of returns for the three major stock-market indexes (Nasdaq, S&P500, and Dow-Jones) with an analytical formula recently derived by Drăgulescu and Yakovenko for the Heston model with stochastic variance. For the period of 1982-1999, we find a very good agreement between the theory and the data for a wide range of time lags from 1 to 250 days. On the other hand, deviations start to appear when the data for 2000-2002 are included. We interpret this as a statistical evidence of the major change in the market from a positive growth rate in 1980s and 1990s to a negative rate in 2000s.

  14. [Public scientific knowledge distribution in health information, communication and information technology indexed in MEDLINE and LILACS databases].

    Science.gov (United States)

    Packer, Abel Laerte; Tardelli, Adalberto Otranto; Castro, Regina Célia Figueiredo

    2007-01-01

    This study explores the distribution of international, regional and national scientific output in health information and communication, indexed in the MEDLINE and LILACS databases, between 1996 and 2005. A selection of articles was based on the hierarchical structure of Information Science in MeSH vocabulary. Four specific domains were determined: health information, medical informatics, scientific communications on healthcare and healthcare communications. The variables analyzed were: most-covered subjects and journals, author affiliation and publication countries and languages, in both databases. The Information Science category is represented in nearly 5% of MEDLINE and LILACS articles. The four domains under analysis showed a relative annual increase in MEDLINE. The Medical Informatics domain showed the highest number of records in MEDLINE, representing about half of all indexed articles. The importance of Information Science as a whole is more visible in publications from developed countries and the findings indicate the predominance of the United States, with significant growth in scientific output from China and South Korea and, to a lesser extent, Brazil.

  15. Developing a chloramine decay index to understand nitrification: A case study of two chloraminated drinking water distribution systems.

    Science.gov (United States)

    Moradi, Sina; Liu, Sanly; Chow, Christopher W K; van Leeuwen, John; Cook, David; Drikas, Mary; Amal, Rose

    2017-07-01

    The management of chloramine decay and the prevention of nitrification are some of the critical issues faced by water utilities that use chloramine as a disinfectant. In this study, potential association between high performance size exclusion chromatography (HPSEC) data obtained with multiple wavelength Ultraviolet (UV) detection from two drinking water distribution systems in Australia and nitrification occurrence was investigated. An increase in the absorbance signal of HPSEC profiles with UV detection at λ=230nm between apparent molecular weights of 200 to 1000Da was observed at sampling sites that experienced rapid chloramine decay and nitrification while its absorbance signal at λ=254nm decreased. A chloramine decay index (C.D.I) defined as the ratio of area beneath the HPSEC spectra at two different wavelengths of 230 and 254nm, was used in assessing chloramine decay occurrences. The C.D.Is of waters at locations that experienced nitrification were consistently higher than locations not experiencing nitrification. A simulated laboratory study showed that the formation of nitrite/nitrate and/or soluble microbial products and/or the release of extracellular polymeric substances (EPS) during nitrification may contribute to the C.D.I. increase. These findings suggest that C.D.I derived from HPSEC with multiple wavelength UV detection could be an informative index to track the occurrence of rapid chloramine decay and nitrification. Copyright © 2016. Published by Elsevier B.V.

  16. Browse Title Index

    African Journals Online (AJOL)

    Items 201 - 250 of 763 ... ... non point source pollutants in Lake Victoria: A case study of Gaba Landing ... Vol 2, No 7 (2008), Diversity and distribution of medicinal plants in North ... bioremediation of petroleum hydrocarbon contaminated soil from ...

  17. Re-evaluation of pulmonary titanium dioxide nanoparticle distribution using the "relative deposition index": Evidence for clearance through microvasculature

    Directory of Open Access Journals (Sweden)

    Gehr Peter

    2007-08-01

    Full Text Available Abstract Background Translocation of nanoparticles (NP from the pulmonary airways into other pulmonary compartments or the systemic circulation is controversially discussed in the literature. In a previous study it was shown that titanium dioxide (TiO2 NP were "distributed in four lung compartments (air-filled spaces, epithelium/endothelium, connective tissue, capillary lumen in correlation with compartment size". It was concluded that particles can move freely between these tissue compartments. To analyze whether the distribution of TiO2 NP in the lungs is really random or shows a preferential targeting we applied a newly developed method for comparing NP distributions. Methods Rat lungs exposed to an aerosol containing TiO2 NP were prepared for light and electron microscopy at 1 h and at 24 h after exposure. Numbers of TiO2 NP associated with each compartment were counted using energy filtering transmission electron microscopy. Compartment size was estimated by unbiased stereology from systematically sampled light micrographs. Numbers of particles were related to compartment size using a relative deposition index and chi-squared analysis. Results Nanoparticle distribution within the four compartments was not random at 1 h or at 24 h after exposure. At 1 h the connective tissue was the preferential target of the particles. At 24 h the NP were preferentially located in the capillary lumen. Conclusion We conclude that TiO2 NP do not move freely between pulmonary tissue compartments, although they can pass from one compartment to another with relative ease. The residence time of NP in each tissue compartment of the respiratory system depends on the compartment and the time after exposure. It is suggested that a small fraction of TiO2 NP are rapidly transported from the airway lumen to the connective tissue and subsequently released into the systemic circulation.

  18. Hydrocarbons and heavy metals in the different sewer deposits in the ‘Le Marais’ catchment (Paris, France): stocks, distributions and origins

    OpenAIRE

    Rocher, Vincent; Azimi, Sam; Moilleron, Régis; Chebbo, Ghassan

    2004-01-01

    International audience; The knowledge of the pollution stored in combined sewers is of prime importance in terms of management of wet weather flow pollution since sewer deposits play a significant role as source of pollution in combined sewer overflows. This work, which focused on the hydrocarbon (aliphatic and aromatic hydrocarbons) and metallic (Fe, Zn, Pb, Cu and Cd) pollution fixed to the different kinds of sewer deposits (gross bed sediment wGBSx, organic layer wOLx and biofilm), was per...

  19. Education policies and health inequalities: evidence from changes in the distribution of Body Mass Index in France, 1981-2003.

    Science.gov (United States)

    Etile, Fabrice

    2014-03-01

    This paper contributes to the debate over the effectiveness of education policies in reducing overall health inequalities as compared to public health actions directed at the less-educated. Recentered Influence Function (RIF) regressions are used to decompose the contribution of education to the changing distribution of Body Mass Index (BMI) in France, between 1981 and 2003, into a composition effect (the shift in population education due to a massive educational expansion), and a structure effect (a changing educational gradient in BMI). Educational expansion has reduced overall BMI inequality by 3.4% for women and 2.3% for men. However, the structure effect on its own has produced a 10.9% increase in overall inequality for women, due to a steeper education gradient starting from the second quartile of the distribution. This structure effect on overall inequality is also large (7.6%) for men, albeit insignificant as it remains concentrated in the last decile. Educational expansion policies can thus reduce overall BMI inequalities; but attention must still be paid to the BMI gradient in education even for policies addressing overall rather than socioeconomic health inequalities.

  20. Use of partition and redistribution indexes for heavy metal soil distribution after contamination with a multi-element solution

    Energy Technology Data Exchange (ETDEWEB)

    Miretzky, Patricia; Munoz, Carolina; Carrillo-Chavez, Alejandro [Universidad Nacional Autonoma de Mexico, Queretaro (Mexico). Centro de Geociencias; Rodriguez Avendano, Monica [Universidad Autonoma de Queretaro (Mexico). Dept. de Quimica Ambiental

    2011-06-15

    Purpose: Tessier's sequential extraction method is usually used to study metal parting among different phases in soils. The main objective of this study was to determine the redistribution of trace metals which were added simultaneously to a sandy loam soil by use of the fractional distribution and reduced partition indexes and the risk of assessment code (RAC). Materials and methods: Tessier's sequential extraction method was performed on the soil sample. After each extraction, the suspension was subjected to centrifugation and then filtrated. Heavy metal concentrations were determined in each fraction by inductively coupled plasma mass spectrometry. Also, the independent soil total metal concentrations were determined to assess metal recovery. To study the possible redistribution of heavy metals, the soil sample was contacted with a multi-element solution. Afterward, the Tessier's scheme was performed. Results and discussion: The metal distribution pattern showed that the exchangeable fraction carried a very small percentage of the heavy metals, and the less mobile fractions the higher percentages. After metal enrichment, the metal content of the more mobile fractions was higher than for the natural soil. Results indicated that Cu was the most mobile whereas Zn, Ni, and Pb were less mobile. Application of the RAC index showed that Cu had to be considered highly dangerous, and Cd and Cr presented medium risk. After metal enrichment, the soil had a larger affinity for Cr. RAC values indicated an environmental high risk for Cr, Co, and Ni and a very high risk for Cu, Zn, Cd, and Pb. The I R values of heavy metals in the natural soil confirmed that Zn, Ni, and Pb were the more strongly bound to the soil components, and Cu presented higher bioavailability. Whereas, in the metal-loaded soil, the I R values confirmed that Cr was the more strongly bound, and Pb, the more weakly bound. The I R values showed that in the loaded soil, the amount of metals in

  1. Spatial distribution of polycyclic aromatic hydrocarbons in soil, sediment, and combusted residue at an e-waste processing site in southeast China.

    Science.gov (United States)

    Leung, Anna O W; Cheung, Kwai Chung; Wong, Ming Hung

    2015-06-01

    The environmental pollution and health impacts caused by the primitive and crude recycling of e-waste have become urgent global issues. Guiyu, China is a major hotspot of e-waste recycling. In this study, the levels and distribution of polycyclic aromatic hydrocarbons in soil in Guiyu were determined to investigate the effect of e-waste activities on the environment and to identify possible sources of these pollutants. Sediment samples from a local duck pond, water gullies, a river tributary, and combusted residue from e-waste burning sites were also investigated. The general trend found in soil (Σ16 PAHs) was acid leaching site > duck pond > rice field > printer roller dump site > reservoir (control site) and ranged from 95.2 ± 54.2 to 5,210 ± 89.6 ng/g (dry wt). The highest average total PAH concentrations were found in combusted residues of wires, cables, and other computer electrical components located at two e-waste open burning sites (18,600 and 10,800 ± 3,940 ng/g). These were 195- and 113-fold higher than the PAH concentrations of soil at the control site. Sediment PAH concentrations ranged from 37.2 ± 6 to 534 ± 271 ng/g. Results of this study provide further evidence of significant input of PAHs to the environment attributed to crude e-waste recycling.

  2. Characterization of parent and oxygenated-polycyclic aromatic hydrocarbons (PAHs) in Xi'an, China during heating period: An investigation of spatial distribution and transformation.

    Science.gov (United States)

    Wang, Jingzhi; Hang Ho, Steven Sai; Huang, Rujin; Gao, Meiling; Liu, Suixin; Zhao, Shuyu; Cao, Junji; Wang, Gehui; Shen, Zhenxing; Han, Yongming

    2016-09-01

    Polycyclic aromatic hydrocarbons (PAHs) and its oxygenated derivatives (OPAHs) are toxins in PM2.5. Little information has been known for their transformation in the ambient airs. In this study, PM2.5 samples were collected at 19 sampling sites in Xi'an, China during the heating period, which is classified into: urban residential, university, commercial area, suburban region, and industry. Organic compounds including PAHs, OPAHs, hopanes and cholestanes were quantified. The average of total quantified PAHs and OPAHs concentrations were 196.5 ng/m(3) and 29.4 ng/m(3), respectively, which were consistent with other northern cities in China. Statistical analyses showed that there were significant differences on the distributions of PAHs between urban and suburban regions. The industry also had distinguishable profiles compared with urban residential and commercial area for OPAHs. The greater diversity of OPAHs than PAHs might be due to different primary emission sources and transformation and degradation pathways. The ratios of OPAHs to the corresponding parent PAHs, including 9-fluorenone/fluorene, anthraquinone/anthracene, benz[a]anthracene-7,12-dione/benzo[a]anthracene were 6.2, 12.7, and 1.4, respectively, which were much higher than those for the fresh emissions from coal combustion and biomass burning. These prove the importance of secondary formation and transformation of OPAHs in the ambient airs. Biomarkers such as retene, cyclopenta[CD]pyrene and αα-homohopane were characterized for the source apportionment. With Positive Matrix Factorization (PMF) model analysis, biomass burning was recognized as the most dominant pollution sources for PAHs during the heading period, which accounted for a contribution of 37.1%. Vehicle emission (22.8%) and coal combustion (22.6%) were also contributors in Xi'an.

  3. Distribution of persistent organic pollutants, polycyclic aromatic hydrocarbons and trace elements in soil and vegetation following a large scale landfill fire in northern Greece.

    Science.gov (United States)

    Chrysikou, Loukia; Gemenetzis, Panagiotis; Kouras, Athanasios; Manoli, Evangelia; Terzi, Eleni; Samara, Constantini

    2008-02-01

    Polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), organochlorine pesticides (OCPs), including hexaclorocyclohexanes (HCHs) and DDTs, as well as trace elements were determined in soil and vegetation samples collected from the surrounding area of the landfill "Tagarades", the biggest in northern Greece, following a large scale fire involving approximately 50,000 tons of municipal waste. High concentrations of total PAHs, PCBs and heavy metals were found inside the landfill (1475 microg kg(-1) dw, 399 microg kg(-1) dw and 29.8 mg kg(-1) dw, respectively), whereas concentrations in the surrounding soils were by far lower ranging between 11.2-28.1 microg kg(-1) dw for PAHs, 4.02-11.2 microg kg(-1) dw for PCBs and 575-1207 mg kg(-1) dw for heavy metals. The distribution of HCHs and DDTs were quite different since certain soils exhibited equal or higher concentrations than the landfill. In vegetation, the concentrations of PAHs, PCBs, HCHs and DDTs ranged from 14.1-34.7, 3.64-25.9, 1.41-32.1 and 0.61-4.03 microg kg(-1) dw, respectively, while those of heavy metals from 81 to 159 mg kg(-1) dw. The results of the study indicated soil and vegetation pollution levels in the surroundings of the landfill comparable to those reported for other Greek locations. The impact from the landfill fire was not evident partially due to the presence of recent and past inputs from other activities (agriculture, vehicular transport, earlier landfill fires).

  4. Distribution, source analysis, and ecological risk assessment of polycyclic aromatic hydrocarbons in the typical topsoil of the Issyk-Kul Lake Basin.

    Science.gov (United States)

    Liu, Wen; Ma, Long; Abuduwaili, Jilili; Li, Yaoming

    2017-08-01

    The concentration, distribution, compositional characteristics, and pollution sources of 16 polycyclic aromatic hydrocarbons (PAHs) in the topsoil of Issyk-Kul Lake Basin were studied, and their ecological risks were evaluated in this paper. The total concentration of the 16 PAHs was 68.58-475.95 ng g(-1), with an average of 134.45 ng g(-1). Four-ring PAHs accounted for 43.2% of the total PAHs, two- and three-ring PAHs accounted for 39.4%, and five- and six-ring PAHs accounted for 15.8%. The total concentration of the seven carcinogenic PAHs was 7.66-76.04 ng g(-1), with an average of 30.97 ng g(-1). An analysis of the PAH sources through diagnostic ratio analysis and principal component analysis was carried out. The results showed that the regional soil PAHs were mainly derived from coal, wood, and grass combustion, while traffic and regional industry also had small contributions to the PAHs. The pollution-free samples accounted for 75% and the slightly polluted samples accounted for 25% based on the total concentration of the 16 PAHs. An ecological risk assessment showed that 26.7% of Ac and 3.3% of Pyr and DahA might occasionally produce ecological risks. The toxicity was calculated on the basis of benzo[a]pyrene, and the toxicity equivalent was between 2.48 and 13.78 ng g(-1) with an average of 6.23 ng g(-1), which currently does not pose any health risk to human life.

  5. Polycyclic aromatic hydrocarbons in road-deposited sediments, water sediments, and soils in Sydney, Australia: Comparisons of concentration distribution, sources and potential toxicity.

    Science.gov (United States)

    Nguyen, Thuy Chung; Loganathan, Paripurnanda; Nguyen, Tien Vinh; Vigneswaran, Saravanamuthu; Kandasamy, Jaya; Slee, Danny; Stevenson, Gavin; Naidu, Ravi

    2014-06-01

    Sixteen polycyclic aromatic hydrocarbons (PAHs) considered as priority environmental pollutants were analysed in surface natural soils (NS), road-deposited sediments (RDS), and water sediments (WS) at Kogarah in Sydney, Australia. Comparisons were made of their concentration distributions, likely sources and potential toxicities. The concentrations (mg/kg) in NS, RDS, and WS ranged from 0.40 to 7.49 (mean 2.80), 1.65 to 4.00 (mean 2.91), and 0.49 to 5.19 (mean 1.76), respectively. PAHs were dominated by relatively high molecular weight compounds with more than three fused benzene rings, indicating that high temperature combustion processes were their predominant sources. The proportions of high molecular weight PAHs with five or six fused benzene rings were higher in NS than in RDS, whereas the low molecular weight PAHs were higher in RDS. Concentrations of all PAHs compounds were observed to be the lowest in WS. The concentrations of most of the high molecular weight PAHs significantly correlated with each other in RDS and WS. All PAHs (except naphthalene) were significantly correlated in NS suggesting a common PAH source. Ratios for individual diagnostic PAHs demonstrated that the primary source of PAHs in WS and NS was of pyrogenic origin (combustion of petroleum (vehicle exhaust), grass, and wood) while in RDS it was petrogenic (i.e. unburned or leaked fuel and oil, road asphalt, and tyre particles) as well as pyrogenic. The potential toxicities of PAHs calculated using a toxicity equivalent quotient (TEQ) were all low but higher for NS compared to WS and RDS.

  6. Distribution of polycyclic aromatic hydrocarbons in the coastal region off Macao, China: assessment of input sources and transport pathways using compositional analysis.

    Science.gov (United States)

    Mai, Bixian; Qi, Shihua; Zeng, Eddy Y; Yang, Qingshu; Zhang, Gan; Fu, Jiamo; Sheng, Guoying; Peng, Pingan; Wang, Zhishi

    2003-11-01

    The coastal region off Macao is a known depositional zone for persistent organic pollutants (POPs) in the Pearl River Delta and Estuary of southern China and an important gateway for the regional contributions of contamination to the globe. This paper presents a comprehensive assessment of the input sources and transport pathways of polycyclic aromatic hydrocarbons (PAHs) found in the coastal sediments of Macao, based on measurements of 48 2-7 ring PAHs and 7 sulfur/oxygenated (S/O) PAH derivatives in 45 sediment, 13 street dust, and 68 aerosol samples. Total sediment PAHs concentrations ranged from 294 to 12741 ng/g, categorized as moderate contamination compared to other regions of Asia and the world. In addition, the PAH compounds appeared to be bound more strongly to aromatics-rich soot particles than to natural organic matter, implying a prevailing atmospheric transport route for PAHs to Macao's coast. Compositional analysis and principal component analysis (PCA) suggested that different classes of PAHs in the coastal sediments of Macao may have been derived from different input sources via various transport pathways. For example, alkylated and S/O PAHs were likely derived from fossil fuel leakage and transported to sediments by both aerosols particles and street runoff. High-molecular-weight parent PAHs were predominantly originated from automobile exhausts and distributed by direct and indirect atmospheric deposition. Low-molecular-weight parent PAHs, on the other hand, may have stemmed from lower temperature combustion and fossil fuel (such as diesel) spillage from ships and boats and were transported to sediments by river runoff or direct discharge as well as by air-water exchange.

  7. Properties of Polycyclic Aromatic Hydrocarbons in the Northwest Photon Dominated Region of NGC 7023. I. PAH Size, Charge, Composition, and Structure Distribution

    Science.gov (United States)

    Boersma, C.; Bregman, Jesse; Allamandola, L. J

    2013-01-01

    Polycyclic aromatic hydrocarbon (PAH) emission in the Spitzer Infrared Spectrograph spectral map of the northwest photon dominated region (PDR) in NGC 7023 was analyzed exclusively using PAH spectra from the NASA Ames PAH IR Spectroscopic Database (www.astrochem.org/pahdb). The 5-15 micron spectrum at each pixel is fitted using a non-negative-least-squares fitting approach. The fits are of good quality, allowing decomposition of the PAH emission into four subclasses: size, charge, composition, and hydrogen adjacency (structure). Maps tracing PAH subclass distributions across the region paint a coherent astrophysical picture. Once past some 20 seconds of arc from HD 200775, the emission is dominated by the more stable, large, symmetric, compact PAH cations with smaller, neutral PAHs taking over along the lines-of-sight toward the more distant molecular cloud. The boundary between the PDR and the denser cloud material shows up as a distinct discontinuity in the breakdown maps. Noteworthy is the requirement for PANH cations to fit the bulk of the 6.2 and 11.0 micron features and the indication of PAH photo-dehydrogenation and fragmentation close to HD 200775. Decomposition of the spectral maps into "principal" subclass template spectra provides additional insight into the behavior of each subclass. However, the general applicability of this computationally more efficient approach is presently undetermined. This is the first time the spectra of individual PAHs are exclusively used to fit the 5-15 micron region and analyze the spatial behavior of the aromatic infrared bands, providing fundamental, new information about astronomical PAH subpopulations including their dependence on, and response to, changes in local conditions.

  8. Sediment contamination of residential streams in the metropolitan kansas city area, USA: Part I. distribution of polycyclic aromatic hydrocarbon and pesticide-related compounds

    Science.gov (United States)

    Tao, J.; Huggins, D.; Welker, G.; Dias, J.R.; Ingersoll, C.G.; Murowchick, J.B.

    2010-01-01

    This is the first part of a study that evaluates the influence of nonpoint-source contaminants on the sediment quality of five streams within the metropolitan Kansas City area, central United States. Surficial sediment was collected in 2003 from 29 sites along five streams with watersheds that extend from the core of the metropolitan area to its development fringe. Sediment was analyzed for 16 polycyclic aromatic hydrocarbons (PAHs), 3 common polychlorinated biphenyl mixtures (Aroclors), and 25 pesticide-related compounds of eight chemical classes. Multiple PAHs were detected at more than 50% of the sites, and concentrations of total PAHs ranged from 290 to 82,150 ??g/kg (dry weight). The concentration and frequency of detection of PAHs increased with increasing urbanization of the residential watersheds. Four- and five-ring PAH compounds predominated the PAH composition (73-100%), especially fluoranthene and pyrene. The PAH composition profiles along with the diagnostic isomer ratios [e.g., anthracene/(anthracene + phenanthrene), 0.16 ?? 0.03; fluoranthene/(fluoranthene + pyrene), 0.55 ?? 0.01)] indicate that pyrogenic sources (i.e., coal-tar-related operations or materials and traffic-related particles) may be common PAH contributors to these residential streams. Historical-use organochlorine insecticides and their degradates dominated the occurrences of pesticide-related compounds, with chlordane and dieldrin detected in over or nearly 50% of the samples. The occurrence of these historical organic compounds was associated with past urban applications, which may continue to be nonpoint sources replenishing local streams. Concentrations of low molecular weight (LMW; two or three rings) and high molecular weight (HMW; four to six rings) PAHs covaried along individual streams but showed dissimilar distribution patterns between the streams, while the historical pesticide-related compounds generally increased in concentration downstream. Correlations were noted

  9. 中国中西部前陆盆地油气分布控制因素%Dominant factors of hydrocarbon distribution in the foreland basins,central and western China

    Institute of Scientific and Technical Information of China (English)

    宋岩; 赵孟军; 方世虎; 谢会文; 柳少波; 卓勤功

    2012-01-01

    Dominant factors controlling hydrocarbon distribution are analyzed from three aspects: the types, structural units and structural belts of the foreland basins of central and western China. There developed four types of foreland basins in China, superimposed, reformed, presenile, and new-generated foreland basins. Hydrocarbon distribution is different in the four types of basins and is controlled by their respective hydrocarbon accumulation conditions, characteristics and patterns. Thrust belts, fordeeps, slope belts and uplift belts are developed in foreland basins. The difference of these structural units in source rock development and evolution, trap type, hydrocarbon accumulation process, and preservation condition, cause different characteristics of hydrocarbon distribution in different structural belts. The main hydrocarbon enriched structural units are foreland thrust belts, in which the source rock and reservoir-caprock assemblage, structural configuration and the preservation conditions are the critical factors for hydrocarbon accumulation. The configuration of faults and cap rocks in thrust belts determines the features and enrichment regularity of hydrocarbon and indicates hydrocarbon enriched locations and favorable exploration targets in various structural belts.%从中国中西部前陆盆地类型、构造单元和构造带3个层次深入分析控制油气分布的主要因素.中国中西部主要发育叠加型、改造型、早衰型和新生型4种前陆盆地,其油气成藏条件、成藏特征与油气聚集模式决定了不同类型前陆盆地油气分布的差异.前陆盆地发育冲断带、前渊、斜坡带和隆起带等构造单元,不同构造单元在烃源岩发育与演化、圈闭类型及成藏过程、保存条件等方面的差异导致不同构造单元油气分布特征的差异.前陆冲断带是中西部前陆盆地油气富集的主要构造单元,烃源岩与储盖组合、构造特征及保存条件是其油气聚集

  10. Plane Imaging prediction of Hydrocarbon distribution By Adopting the Non-linear Technique%非线性方法油气平面成像预测的研究

    Institute of Scientific and Technical Information of China (English)

    王红罡; 吕炳全; 赵永辉; 孙小刚

    2001-01-01

    系统论和非线性方法为石油地球物理勘探注入了新的动力。本文试通过分形理论结合人工神经网络方法对测井资料进行解释,对油气分布进行平面成像预测。%The integration of Fractal process and artificial neural network analysis by adopting nonlinear techniques adds new power to the explanation of logging curves in geophysical exploration for hydrocarbon. In terms of the method, this paper attempts to make new explanation for logging data and to conduct a plane imaging prediction of hydrocarbon distribution.

  11. A Determination of the Gamma-ray Flux and Photon Spectral Index Distributions of Blazars from the Fermi-LAT 3LAC

    CERN Document Server

    Singal, J

    2015-01-01

    We present a determination of the distributions of gamma-ray photon flux -- the so called LogN-LogS relation -- and photon spectral index for blazars, based on the third extragalactic source catalog of the Fermi Gamma-ray Space Telescope's Large Area Telescope, and considering the photon energy range from 100 MeV to 100 GeV. The dataset consists of the 774 blazars in the so-called "Clean" sample detected with a greater than approximately seven sigma detection threshold and located above $\\pm$20 deg Galactic latitude. We use non-parametric methods verified in previous works to reconstruct the intrinsic distributions from the observed ones which account for the data truncations introduced by observational bias and includes the effects of the possible correlation between the flux and photon index. The intrinsic flux distribution can be represented by a broken power law with a high flux power-law index of -2.43$\\pm$0.08 and a low flux power-law index of -1.87$\\pm$0.10. The intrinsic photon index distribution can ...

  12. Spatio-temporal distribution of vegetation index and its influencing factors—a case study of the Jiaozhou Bay, China

    Science.gov (United States)

    Zheng, Yang; Yu, Ge

    2016-10-01

    The coastal zone is an area characterized by intense interaction between land and sea, high sensitivity to regional environmental changes, and concentrated human activities. Little research has investigated vegetation cover changes in coastal zones resulting from climate change and land-use change, with a lack of knowledge about the driving mechanism. Normalized difference vegetation index (NDVI) can be used as an indicator for change of the coastal environment. In this study, we analyzed the interannual changes and spatial distribution of NDVI in the coastal zone around Jiaozhou Bay in Qingdao, a coastal city undergoing rapid urbanization in northeast China. The underlying causes of NDVI variations were discussed in the context of climate change and land-use change. Results showed that the spatio-temporal distribution of NDVI displayed high spatial variability in the study area and showed a typical trend of gradually increasing from coastal to inland regions. The significant increase area of NDVI was mainly found in newly added construction land, extending along the coastline towards the inland. Land vegetation cover demonstrated a certain response relationship to sea-land climate change and land-based activities. The impact of land-based human activities was slightly greater than that of sea-land climate change for land vegetation cover. The results indicate that promoting ecological policies can build an ecological security framework of vegetation suitable for the resource characteristics of coastal cities. The framework will buffer the negative effects of sea-land climate change and land-based human activities on vegetation cover and thereby achieve the balance of regional development and ecological benefits in the coastal zone.

  13. THERMOCHEMISTRY OF HYDROCARBON RADICALS

    Energy Technology Data Exchange (ETDEWEB)

    Kent M. Ervin, Principal Investigator

    2004-08-17

    Gas phase negative ion chemistry methods are employed to determine enthalpies of formation of hydrocarbon radicals that are important in combustion processes and to investigate the dynamics of ion-molecule reactions. Using guided ion beam tandem mass spectrometry, we measure collisional threshold energies of endoergic proton transfer and hydrogen atom transfer reactions of hydrocarbon molecules with negative reagent ions. The measured reaction threshold energies for proton transfer yield the relative gas phase acidities. In an alternative methodology, competitive collision-induced dissociation of proton-bound ion-molecule complexes provides accurate gas phase acidities relative to a reference acid. Combined with the electron affinity of the R {center_dot} radical, the gas phase acidity yields the RH bond dissociation energy of the corresponding neutral molecule, or equivalently the enthalpy of formation of the R{center_dot} organic radical, using equation: D(R-H) = {Delta}{sub acid}H(RH) + EA(R) - IE(H). The threshold energy for hydrogen abstraction from a hydrocarbon molecule yields its hydrogen atom affinity relative to the reagent anion, providing the RH bond dissociation energy directly. Electronic structure calculations are used to evaluate the possibility of potential energy barriers or dynamical constrictions along the reaction path, and as input for RRKM and phase space theory calculations. In newer experiments, we have measured the product velocity distributions to obtain additional information on the energetics and dynamics of the reactions.

  14. Near-Equipartition Jets with Log-Parabola Electron Energy Distribution and the Blazar Spectral-Index Diagrams

    CERN Document Server

    Dermer, Charles D; Zhang, Li; Finke, Justin D; Lott, Benoit

    2015-01-01

    Fermi-LAT analyses show that the gamma-ray photon spectral indices Gamma_gamma of a large sample of blazars correlate with the vFv peak synchrotron frequency v_s according to the relation Gamma_gamma = d - k log v_s. The same function, with different constants d and k, also describes the relationship between Gamma_gamma and peak Compton frequency v_C. This behavior is derived analytically using an equipartition blazar model with a log-parabola description of the electron energy distribution (EED). In the Thomson regime, k = k_EC = 3b/4 for external Compton processes and k = k_SSC = 9b/16 for synchrotron self-Compton (SSC) processes, where b is the log-parabola width parameter of the EED. The BL Lac object Mrk 501 is fit with a synchrotron/SSC model given by the log-parabola EED, and is best fit away from equipartition. Departures from equipartition are limited by jet power and make small corrections to the spectral-index diagrams. Analytic expressions are compared with numerical values derived from self-Compt...

  15. Effect of arch type and Body Mass Index on plantar pressure distribution during stance phase of gait.

    Science.gov (United States)

    O'Brien, Davida Louise; Tyndyk, Magdalena

    2014-01-01

    Several factors have been associated with the presence of abnormally high plantar foot pressure including: (i) increased body weight, (ii) foot structure and (iii) walking strategy. It is predicted that the biomechanics of the foot is influenced by the structure of the foot, primarily the Medial Longitudinal Arch. The objective of this study was to examine if Body Mass Index and the foot arch have a direct effect on dynamic peak plantar pressure for healthy subjects. Following a clinical lower limb examination, the Tekscan HR mat was utilised for this study, plantar pressure was profiled at specific events during stance phase of gait including heel strike, midstance and toe off. Results indicated to the preferable normal arch as this produced a low plantar pressure distribution in all cases. The 2nd and 3rd metatarsal head region recorded the highest pressure for all arch types during dynamic analysis. The lowest pressure for the normal and overweight BMI was at toe-off. While the obese BMI group showed highest pressure during toe-off. The obese BMI flat arch subcategory indicated to functional ambulation differences. Future work involves comparing this healthy database to a demographically matched diabetic group.

  16. The hydrocarbon sphere

    Energy Technology Data Exchange (ETDEWEB)

    Mandev, P.

    1984-01-01

    The hydrocarbon sphere is understood to be the area in which hydrocarbon compounds are available. It is believed that the lower boundary on the hydrocarbon sphere is most probably located at a depth where the predominant temperatures aid in the destruction of hydrocarbons (300 to 400 degrees centigrade). The upper limit on the hydrocarbon sphere obviously occurs at the earth's surface, where hydrocarbons oxidize to H20 and CO2. Within these ranges, the occurrence of the hydrocarbon sphere may vary from the first few hundred meters to 15 kilometers or more. The hydrocarbon sphere is divided into the external (mantle) sphere in which the primary gas, oil and solid hydrocarbon fields are located, and the internal (metamorphic) sphere containing primarily noncommercial accumulations of hydrocarbon gases and solid carbon containing compounds (anthraxilite, shungite, graphite, etc.) based on the nature and scale of hydrocarbon compound concentrations (natural gas, oil, maltha, asphalt, asphaltite, etc.).

  17. Distribution of Ankle-Brachial Index among Inpatients with Cardiovascular Disease: Analysis Using the Kumamoto University Hospital Medical Database

    Science.gov (United States)

    Soejima, Hirofumi; Kojima, Sunao; Kaikita, Koichi; Yamamuro, Megumi; Izumiya, Yasuhiro; Tsujita, Kenichi; Yamamoto, Eiichiro; Tanaka, Tomoko; Sugamura, Koichi; Arima, Yuichiro; Sakamoto, Kenji; Akasaka, Tomonori; Tabata, Noriaki; Sueta, Daisuke; Miyoshi, Izuru; Usami, Makiko; Ogawa, Hisao

    2016-01-01

    Objective: To describe the distribution of ankle-brachial index (ABI) among Japanese cardiovascular inpatients and to explore risk factors of peripheral arterial disease (PAD) associated with ABI ≤0.9. Materials and Methods: This study was a retrospective analysis using clinical record databases of patients with cardiovascular disease admitted to the Department of Cardiovascular Medicine, Kumamoto University Hospital between 2007 and 2014. Results: Of 3639 patients included in the analysis, male patients accounted for 62.1% and the mean age of patients was 66.1 years. Ischemic heart disease (IHD) was observed in 49.1%. ABI ≤0.9 was observed in 11.3% of all patients, 14.1% in the IHD group and 8.5% in the non-IHD group. Age of ≥65 years (odds ratio [OR]: 2.93, 95% confidence interval [CI]: 2.22–3.86), current smoking (OR: 2.28, 95%CI:1.71–3.04), diabetes (OR: 2.15, 95%CI:1.71–2.71), hypertension (OR: 1.42, 95%CI:1.12–1.81) and chronic kidney disease (OR: 2.52, 95%CI:1.82–3.48) were significantly associated factors with ABI ≤0.9. Conclusions: This study suggests that PAD is prevalent even in patients without IHD. Active management of risk factors, early detection of PAD based on ABI, and therapeutic intervention could be effective in preventing future cardiovascular events or death. PMID:27087869

  18. Process-based distributed hydrological modelling of annual floods in the Upper Zambezi using the Desert Flood Index

    Science.gov (United States)

    Meinhardt, Markus; Sven, Kralisch; Manfred, Fink; Daniel, Butchart-Kuhlmann; Anthony, Chabala; Melanie, Fleischer; Jörg, Helmschrot; Wilson, Phiri; Tina, Trautmann; Henry, Zimba; Imasiku, Nyambe

    2016-04-01

    Wetland areas are especially sensitive to changes in hydrological conditions. The catchment of the Luanginga River, a tributary of the Upper Zambezi which covers about 33000 km², shows this characteristic in an exemplary way. Ranging from the Angolan highlands to the Barotse floodplain of the Zambezi River , it is characterized by an annual flow regime and extensive wetland areas. Due to its annual flooding with peak times in April, the area features exceptionally fertile soils with high agricultural production and is further known for its rich cultural heritage, making it especially sensitive to changes of hydrological conditions . To identify possible changes related to projected climate and land management change, especially in the area of the floodplain, there is a need to apply a process-based distributed hydrological model of the annual floods . Remote sensing techniques have shown to be appropriate to identify the extend of the important flooding and were used to validate the model in space and time. The results of this research can be used as a basis with which to provide evidence-based advice and information for all decision-makers and stakeholders in the region. For this assessment , such a modelling approach is applied to adequately represent hydrological processes and to address key water resources management issues at sub-basin levels. Introducing a wetland simulation extension, the model allows to represent the annual flood regime of the system and thus to address the effect of climate change and upstream land use changes on flow regimes in the downstream watershed. In order to provide a basis for model validation and calibration, the inundated area was determined using the Desert Flood Index (DFI), which was generated from a time series of Landsat images. We will give a short introduction to the study area and related water resources management problems, present the intended model structure and show first simulations and model validation results

  19. Distribution of the h-index in radiation oncology conforms to a variation of power law: implications for assessing academic productivity.

    Science.gov (United States)

    Quigley, Matthew R; Holliday, Emma B; Fuller, Clifton D; Choi, Mehee; Thomas, Charles R

    2012-06-01

    Leaders of academic institutions evaluate academic productivity when deciding to hire, promote, or award resources. This study examined the distribution of the h-index, an assessment of academic standing, among radiation oncologists. The authors collected h-indices for 826 US academic radiation oncologists from a commercial bibliographic database (SCOPUS, Elsevier B.V., NL). Then, logarithmic transformation was performed on h-indices and ranked h-indices, and results were compared to estimates of a power law distribution. The h-index frequency distribution conformed to both the log-linear variation of a power law (r (2) = .99) and the beta distribution with the same fitting exponents as previously described in a power law analysis of the productivity of neurosurgeons. Within radiation oncology, as in neurosurgery, there are exceedingly more faculty with an h-index of 1-2. The distribution fitting the same variation of a power law within two fields suggests applicability to other areas of academia.

  20. Raman characteristics of hydrocarbon and hydrocarbon inclusions

    Institute of Scientific and Technical Information of China (English)

    ZHANG Nai; TIAN ZuoJi; LENG YingYing; WANG HuiTong; SONG FuQing; MENG JianHua

    2007-01-01

    The Raman spectrograms of hydrocarbon standard samples show that: (1) the Raman spectrogram of normal paraffin has very strong peaks of methyl and methylene (from 2700 cm-1 to 2970 cm-1); (2)branch methyl has the particular peak of 748 cm-1±; (3) six cyclic has the particular peak of 804 cm-1±; (4)phenyl has two particular peaks of 988 cm-1± and 3058 cm-1± and the 988 cm-1± peak is stronger than the 3058 cm-1± peak; and (5) hexene has three alkenyl spectrum peaks of 1294 cm-1±, 1635 cm-1± and 2996 cm-1±, with the 1635 cm-1± peak being the strongest, showing that the number of carbon in hydrocarbon does not affect its Raman spectrogram, and the hydrocarbon molecular structure and base groups affect its Raman spectrogram, the same hydrocarbons (such as normal paraffin) have the same Raman spectrogram; the types (such as CH4, C2H6, C3H8) and the content of hydrocarbon in oil inclusions are not estimated by their characteristic Raman peaks. According to the Raman spectrograms of hydrocarbon compositions, the Raman spectrogram of hydrocarbon inclusion can be divided into five types: saturated hydrocarbon Raman spectrogram, fluoresce Raman spectrogram, saturated hydrocarbon bitumen Raman spectrogram, bitumen Raman spectrogram, and ethane Raman spectrogram.And according to the characteristics of Raman spectrogram, hydrocarbon inclusions can be divided into five types: saturated hydrocarbon inclusion, less saturated hydrocarbon (oil or gas) inclusion,saturated hydrocarbon bitumen inclusion, bitumen inclusion, and methane water inclusion.

  1. Raman characteristics of hydrocarbon and hydrocarbon inclusions

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The Raman spectrograms of hydrocarbon standard samples show that: (1) the Raman spectrogram of normal paraffin has very strong peaks of methyl and methylene (from 2700 cm-1 to 2970 cm-1); (2) branch methyl has the particular peak of 748 cm-1±; (3) six cyclic has the particular peak of 804 cm-1±; (4) phenyl has two particular peaks of 988 cm-1± and 3058 cm-1± and the 988 cm-1± peak is stronger than the 3058 cm-1± peak; and (5) hexene has three alkenyl spectrum peaks of 1294 cm-1±, 1635 cm-1± and 2996 cm-1±, with the 1635 cm-1± peak being the strongest, showing that the number of carbon in hy-drocarbon does not affect its Raman spectrogram, and the hydrocarbon molecular structure and base groups affect its Raman spectrogram, the same hydrocarbons (such as normal paraffin) have the same Raman spectrogram; the types (such as CH4, C2H6, C3H8) and the content of hydrocarbon in oil inclu-sions are not estimated by their characteristic Raman peaks. According to the Raman spectrograms of hydrocarbon compositions, the Raman spectrogram of hydrocarbon inclusion can be divided into five types: saturated hydrocarbon Raman spectrogram, fluoresce Raman spectrogram, saturated hydro-carbon bitumen Raman spectrogram, bitumen Raman spectrogram, and ethane Raman spectrogram. And according to the characteristics of Raman spectrogram, hydrocarbon inclusions can be divided into five types: saturated hydrocarbon inclusion, less saturated hydrocarbon (oil or gas) inclusion, saturated hydrocarbon bitumen inclusion, bitumen inclusion, and methane water inclusion.

  2. 玉渊潭底泥中烃类物质研究%Distribution and characterization of hydrocarbons in the sediment of Yuyuantan Lake, Beijing

    Institute of Scientific and Technical Information of China (English)

    孟庆昱; 毕新慧; 徐晓白; 储少岗

    2001-01-01

    Concentration and Distribution of PAHs and n-Alkanes in the sediment of Yuyuantan Lake were investigated. The results showed the changes of environmental quality of Be ijing in the process of industrialization. Samples were collected from different depth intervals. The concentration of PAHs in the top layer was not the highest among three collected samples from Yuyuantan Lake. The sources of PAHs were investigated according to PAHs indexes. The mechanism of adsorption was also studied.%采集玉渊潭不同深度的沉积物样品,测定了其中多环芳烃和正构烷烃的含量.结果表明5-15cm层多环芳烃含量最高,0-5cm层次之,15-25cm层最低.参照若干多环芳烃指数的计算,进行源的识别.正构烷烃含量的分布与多环芳烃类相似.多环芳烃的吸附量与沉积物中的有机碳含量呈很高的相关性,相关系数为0.99.而正构烷烃的吸附量则随沉积物粒径的减小而增高.

  3. Occurrence and distribution of hydrocarbons in the surface microlayer and subsurface water from the urban coastal marine area off Marseilles, Northwestern Mediterranean Sea.

    Science.gov (United States)

    Guigue, Catherine; Tedetti, Marc; Giorgi, Sébastien; Goutx, Madeleine

    2011-12-01

    Aliphatic (AHs) and polycyclic aromatic hydrocarbons (PAHs) were analyzed in dissolved and particulate material from surface microlayer (SML) and subsurface water (SSW) sampled at nearshore observation stations, sewage effluents and harbour sites from Marseilles coastal area (Northwestern Mediterranean) in 2009 and 2010. Dissolved and particulate AH concentrations ranged 0.05-0.41 and 0.04-4.3 μg l(-1) in the SSW, peaking up to 38 and 1366 μg l(-1) in the SML, respectively. Dissolved and particulate PAHs ranged 1.9-98 and 1.9-21 ng l(-1) in the SSW, amounting up 217 and 1597 ng l(-1) in the SML, respectively. In harbours, hydrocarbons were concentrated in the SML, with enrichment factors reaching 1138 for particulate AHs. Besides episodic dominance of biogenic and pyrogenic inputs, a moderate anthropisation from petrogenic sources dominated suggesting the impact of shipping traffic and surface runoffs on this urbanised area. Rainfalls increased hydrocarbon concentrations by a factor 1.9-11.5 in the dissolved phase.

  4. Fast decision tree-based method to index large DNA-protein sequence databases using hybrid distributed-shared memory programming model.

    Science.gov (United States)

    Jaber, Khalid Mohammad; Abdullah, Rosni; Rashid, Nur'Aini Abdul

    2014-01-01

    In recent times, the size of biological databases has increased significantly, with the continuous growth in the number of users and rate of queries; such that some databases have reached the terabyte size. There is therefore, the increasing need to access databases at the fastest rates possible. In this paper, the decision tree indexing model (PDTIM) was parallelised, using a hybrid of distributed and shared memory on resident database; with horizontal and vertical growth through Message Passing Interface (MPI) and POSIX Thread (PThread), to accelerate the index building time. The PDTIM was implemented using 1, 2, 4 and 5 processors on 1, 2, 3 and 4 threads respectively. The results show that the hybrid technique improved the speedup, compared to a sequential version. It could be concluded from results that the proposed PDTIM is appropriate for large data sets, in terms of index building time.

  5. Surrogate markers of visceral adiposity in young adults: waist circumference and body mass index are more accurate than waist hip ratio, model of adipose distribution and visceral adiposity index.

    Directory of Open Access Journals (Sweden)

    Susana Borruel

    Full Text Available Surrogate indexes of visceral adiposity, a major risk factor for metabolic and cardiovascular disorders, are routinely used in clinical practice because objective measurements of visceral adiposity are expensive, may involve exposure to radiation, and their availability is limited. We compared several surrogate indexes of visceral adiposity with ultrasound assessment of subcutaneous and visceral adipose tissue depots in 99 young Caucasian adults, including 20 women without androgen excess, 53 women with polycystic ovary syndrome, and 26 men. Obesity was present in 7, 21, and 7 subjects, respectively. We obtained body mass index (BMI, waist circumference (WC, waist-hip ratio (WHR, model of adipose distribution (MOAD, visceral adiposity index (VAI, and ultrasound measurements of subcutaneous and visceral adipose tissue depots and hepatic steatosis. WC and BMI showed the strongest correlations with ultrasound measurements of visceral adiposity. Only WHR correlated with sex hormones. Linear stepwise regression models including VAI were only slightly stronger than models including BMI or WC in explaining the variability in the insulin sensitivity index (yet BMI and WC had higher individual standardized coefficients of regression, and these models were superior to those including WHR and MOAD. WC showed 0.94 (95% confidence interval 0.88-0.99 and BMI showed 0.91 (0.85-0.98 probability of identifying the presence of hepatic steatosis according to receiver operating characteristic curve analysis. In conclusion, WC and BMI not only the simplest to obtain, but are also the most accurate surrogate markers of visceral adiposity in young adults, and are good indicators of insulin resistance and powerful predictors of the presence of hepatic steatosis.

  6. Abdominal aortic calcification quantified by the Morphological Atherosclerotic Calcification Distribution (MACD) index is associated with features of the metabolic syndrome

    DEFF Research Database (Denmark)

    Barascuk, Natasha; Ganz, Melanie; Nielsen, Mads

    2011-01-01

    . Three hundred and eight healthy women aged 48 to 76 years, were followed for 8.3 ± 0.3 years. AAC was quantified using lumbar radiographs. Baseline data included age, weight, blood pressure, blood lipids, and glucose levels. Pearson correlation coefficients were used to test for relationships....... At baseline and across all patients, MACD correlated with blood glucose (r2 = 0.1, Pcorrelations between baseline biological parameters and the follow-up calcification assessment...... index was not correlated with blood parameters. Patterns of calcification identified by the MACD, but not the AC24 index, appear to contain useful biological information perhaps explaining part of the improved identification of risk of cardiovascular death of the MACD index. Correlations of MACD...

  7. Spectro-ellipsometric studies of sputtered amorphous Titanium dioxide thin films: simultaneous determination of refractive index, extinction coefficient, and void distribution

    CERN Document Server

    Lee, S I; Oh, S G

    1999-01-01

    Amorphous titanium dioxide thin films were deposited onto silicon substrates by using RF magnetron sputtering, and the index of refraction, the extinction coefficient, and the void distribution of these films were simultaneously determined from the analyses of there ellipsometric spectra. In particular, our novel strategy, which combines the merits of multi-sample fitting, the dual dispersion function, and grid search, was proven successful in determining optical constants over a wide energy range, including the energy region where the extinction coefficient was large. Moreover, we found that the void distribution was dependent on the deposition conditions, such as the sputtering power, the substrate temperature, and the substrate surface.

  8. Allelic frequency distributions of 21 non-combined DNA index system STR loci in a Russian ethnic minority group from Inner Mongolia, China*

    OpenAIRE

    Wang, Hong-Dan; Shen, Chun-Mei; Liu, Wen-Juan; Zhang, Yu-Dang; Yang, Guang; Yan, Jiang-wei; Qin, Hai-Xia; Zhu, Bo-Feng

    2013-01-01

    We studied the allelic frequency distributions and statistical forensic parameters of 21 new short tandem repeat (STR) loci and the amelogenin locus, which are not included in the combined DNA index system (CODIS), in a Russian ethnic minority group from the Inner Mongolia Autonomous Region, China. A total of 114 bloodstain samples from unrelated individuals were extracted and co-amplified with four fluorescence-labeled primers in a multiplex polymerase chain reaction (PCR) system. Using capi...

  9. INTEGRAL INDEX OF OPERATION QUALITY FOR EVALUATION OF IMPACT OF DISTRIBUTIVE GENERATION SOURCES ON ELECTRIC NETWORK MODES

    Directory of Open Access Journals (Sweden)

    Petro D. Lezhniuk

    2017-06-01

    Full Text Available Method of operation quality evaluation of electric network, comprising renewable sources of energy (RSE is considered. Integral index that enables to evaluate the impact of RSE on energy losses and its quality as well as balance reliability in electric network is suggested. Mathematical model is constructed, taking into account the assumption that electric network with RSE may be in various operation modes, characterized by different technical economic indices. To determine the integral index of operation quality of electric network with RSE in all possible states tools of Markov processes theory and criterial method are used.

  10. Effects of Catalyst Preparation on Hydrocarbon Product Distribution in Hydrocracking of the Fischer-Tropsch Product with Low Pt-Loaded Catalysts

    Directory of Open Access Journals (Sweden)

    Toshiaki Hanaoka

    2015-11-01

    Full Text Available For the effective production of hydrocarbon liquid fuel in the hydrocracking of the Fischer-Tropsch (FT product, the catalytic performance of Pt-loaded catalysts with low Pt content was investigated using an autoclave at 250 °C, an initial H2 pressure of 0.5 MPa, and a reaction time of 1 h. A screening study using Pt-loaded catalysts with a Pt content of 0.1 wt. % indicated that zeolite supports were more favorable for jet fuel (carbon numbers 9–15 production than amorphous oxide supports. The small particle size of the supported Pt particles and the high amount of medium acid sites for the supports led to higher performance of the Pt-loaded zeolite catalysts. In the hydrocracking reaction over Pt catalysts using the zeolite support with the high amount of medium acid sites, the yields of the corresponding jet fuel at 0.02 and 0.1 wt. % were almost the same. Pt-loaded catalysts with a Pt content of 0.02 wt. % were prepared using water-in-oil (w/o microemulsions and their particle size was controlled between 1.0 and 2.6 nm. While the yield of the corresponding jet fuel was independent of Pt particle size, smaller Pt particles typically promoted the production of lighter hydrocarbons.

  11. Distribution and origins of n-alkanes, hopanes, and steranes in rivers and marine sediments from Southwest Caspian coast, Iran: implications for identifying petroleum hydrocarbon inputs.

    Science.gov (United States)

    Shirneshan, Golshan; Bakhtiari, Alireza Riyahi; Memariani, Mahmoud

    2016-09-01

    The occurrence of n-alkanes and biomarkers (hopane and sterane) in surface sediments from Southwestern coasts of Caspian Sea and 28 rivers arriving to this lake, determined with a gas chromatography-mass spectrometry method, was used to assess the impacts of anthropogenic activities in the studied area. The concentrations of total n-alkanes (Σ21 n-alkane) in costal and riverine sediments varied from 249.2 to 3899.5 and 56 to 1622.4 μg g(-1), respectively. An evaluation of the source diagnostic indices indicated that petroleum related sources (petrogenic) were mainly contributed to n-alkanes in costal and most riverine sediments. Only the hydrocarbons in sediment of 3 rivers were found to be mainly of biogenic origin. Principal component analysis using hopane diagnostic ratios in costal and riverine sediments, and Anzali, Turkmenistan, and Azerbaijan oils were used to identify the sources of hydrocarbons in sediments. It was indicated that the anthropogenic contributions in most of the costal sediment samples are dominated with inputs of oil spills from Turkmenistan and Azerbaijan countries.

  12. Estimation of the distribution of low-intensity ultrasound mechanical index as a parameter affecting the proliferation of spermatogonia stem cells in vitro.

    Science.gov (United States)

    Moghaddam, Zeinab Hormozi; Mokhtari-Dizaji, Manijhe; Movahedin, Mansoureh; Ravari, Mohammad Ehsan

    2017-07-01

    Considering the use of physical and mechanical stimulation, such as low-intensity ultrasound for proliferation and differentiation of stem cells, it is essential to understand the physical and acoustical mechanisms of acoustic waves in vitro. Mechanical index is used for quantifying acoustic cavitation and the relationship between acoustic pressure and the frequency. In this study, modeling of the mechanical index was applied to provide treatment protocol and to understand the effective physical processes on reproducibility of stem cells. Due to low intensity of ultrasound, Rayleigh integral model has been used for acoustic pressure computation. The acoustic pressure and mechanical index equations are modeled and solved to estimate optimal mechanical index for 28, 40, 150kHz and 1MHz frequencies. This model are solved in different intensities and distances from transducer in cylindrical coordinates. Based on the results of the mechanical index, regions with threshold mechanical index of 0.7 were identified for extracting of radiation arrangement to cell medium. Acoustic pressure distribution along the axial and radial was extracted. In order to validate the results of the modeling, the acoustic pressure in the water and near field depth was measured by a piston hydrophone. Results of modeling and experiments show that the model is consistent well to experimental results with 0.91 and 0.90 correlation of coefficient (p<0.05) for 1MHz and 40kHz. Low-intensity ultrasound with 0.40 mechanical index is more effective on enhancing the proliferation rate of the spermatogonia stem cells during the seven days of culture. In contrast, higher mechanical index has a harmful effect on the spermatogonial stem cells. Thus, considering cavitation threshold of different materials is necessary to find effective mechanical index ranges on proliferation for the used frequencies. This acoustic propagation model and ultrasound mechanical index assessments can be used with acceptable

  13. Mechanism of Silurian Hydrocarbon Pool Formation in the Tarim Basin

    Institute of Scientific and Technical Information of China (English)

    Liu Luofu; Guo Yongqiang; Zhao Yande; Li Yan; Chen Yuanzhuang; Chen Lixin; Pang Xiongqi; Xie Qilai; Huo Hong; Zhao Suping; Li Chao; Li Shuangwen

    2007-01-01

    There are three formation stages of Silurian hydrocarbon pools in the Tarim Basin. The widely distributed asphaltic sandstones in the Tazhong (central Tarim) and Tabei (northern Tarim) areas are the results of destruction of hydrocarbon pools formed in the first-stage, and the asphaltic sandstones around the Awati Sag were formed in the second-stage. The hydrocarbon migration characteristics reflected by the residual dry asphalts could represent the migration characteristics of hydrocarbons in the Silurian paleo-pools, while the present movable oil in the Silurian reservoirs is related to the later-stage (the third-stage) hydrocarbon accumulation.

  14. INDEXING AND INDEX FUNDS

    Directory of Open Access Journals (Sweden)

    HAKAN SARITAŞ

    2013-06-01

    Full Text Available Proponents of the efficient market hypothesis believe that active portfolio management is largely wasted effort and unlikely to justify the expenses incurred. Therefore, they advocate a passive investment strategy that makes no attempt to outsmart the market. One common strategy for passive management is indexing where a fund is designed to replicate the performance of a broad-based index of stocks and bonds. Traditionally, indexing was used by institutional investors, but today, the use of index funds proliferated among individual investors. Over the years, both international and domestic index funds have disproportionately outperformed the market more than the actively managed funds have.

  15. Foaming of mixtures of pure hydrocarbons

    Science.gov (United States)

    Robinson, J. V.; Woods, W. W.

    1950-01-01

    Mixtures of pure liquid hydrocarbons are capable of foaming. Nine hydrocarbons were mixed in pairs, in all possible combinations, and four proportions of each combination. These mixtures were sealed in glass tubes, and the foaming was tested by shaking. Mixtures of aliphatic with other aliphatic hydrocarbons, or of alkyl benzenes with other alkyl benzenes, did not foam. Mixtures of aliphatic hydrocarbons with alkyl benzenes did foam. The proportions of the mixtures greatly affected the foaming, the maximum foaming of 12 of 20 pairs being at the composition 20 percent aliphatic hydrocarbon, 80 percent alkyl benzene. Six seconds was the maximum foam lifetime of any of these mixtures. Aeroshell 120 lubricating oil was fractionated into 52 fractions and a residue by extraction with acetone in a fractionating extractor. The index of refraction, foam lifetime, color, and viscosity of these fractions were measured. Low viscosity and high index fractions were extracted first. The viscosity of the fractions extracted rose and the index decreased as fractionation proceeded. Foam lifetimes and color were lowest in the middle fractions. Significance is attached to the observation that none of the foam lifetimes of the fractions or residue is as high as the foam lifetime of the original Aeroshell, indicating that the foaming is not due to a particular foaming constituent, but rather to the entire mixture.

  16. Volatilisation of aromatic hydrocarbons from soil

    DEFF Research Database (Denmark)

    Lindhardt, B.; Christensen, T.H.

    1996-01-01

    The non-steady-state fluxes of aromatic hydrocarbons were measured in the laboratory from the surface of soils contaminated with coal tar Four soil samples from a former gasworks site were used for the experiments. The fluxes were quantified for 11 selected compounds, 4 mono- and 7 polycyclic...... aromatic hydrocarbons, for a period of up to 8 or 16 days. The concentrations of the selected compounds in the soils were between 0.2 and 3,100 mu g/g. The study included the experimental determination of the distribution coefficient of the aromatic hydrocarbons between the sorbed phase and the water under...... saturated conditions. The determined distribution coefficients showed that the aromatic hydrocarbons were more strongly sorbed to the total organic carbon including the coal tar pitch - by a factor of 8 to 25 - than expected for natural organic matter. The fluxes were also estimated using an analytical...

  17. Spatial distributions of sulphur species and sulphate-reducing bacteria provide insights into sulphur redox cycling and biodegradation hot-spots in a hydrocarbon-contaminated aquifer

    Science.gov (United States)

    Einsiedl, Florian; Pilloni, Giovanni; Ruth-Anneser, Bettina; Lueders, Tillman; Griebler, Christian

    2015-05-01

    Dissimilatory sulphate reduction (DSR) has been proven to be one of the most relevant redox reactions in the biodegradation of contaminants in groundwater. However, the possible role of sulphur species of intermediate oxidation state, as well as the role of potential re-oxidative sulphur cycling in biodegradation particularly at the groundwater table are still poorly understood. Here we used a combination of stable isotope measurements of SO42-, H2S, and S0 as well as geochemical profiling of sulphur intermediates with special emphasis on SO32-, S2O32-, and S0 to unravel possible sulphur cycling in the biodegradation of aromatics in a hydrocarbon-contaminated porous aquifer. By linking these results to the quantification of total bacterial rRNA genes and respiratory genes of sulphate reducers, as well as pyrotag sequencing of bacterial communities over depth, light is shed on possible key-organisms involved. Our results substantiate the role of DSR in biodegradation of hydrocarbons (mainly toluene) in the highly active plume fringes above and beneath the plume core. In both zones the concentration of sulphur intermediates (S0, SO32- and S2O32-) was almost twice that of other sampling-depths, indicating intense sulphur redox cycling. The dual isotopic fingerprint of oxygen and sulphur in dissolved sulphate suggested a re-oxidation of reduced sulphur compounds to sulphate especially at the upper fringe zone. An isotopic shift in δ34S of S0 of nearly +4‰ compared to the δ34S values of H2S from the same depth linked to a high abundance (∼10%) of sequence reads related to Sulphuricurvum spp. (Epsilonproteobacteria) in the same depth were indicative of intensive oxidation of S0 to sulphate in this zone. At the lower plume fringe S0 constituted the main inorganic sulphur species, possibly formed by abiotic re-oxidation of H2S with Fe(III)oxides subsequent to sulphate reduction. These results provide first insights into intense sulphur redox cycling in a hydrocarbon

  18. Beta分布在模糊贴近度指标控制图的应用%Application of Beta distribution in fuzzy similarity index control chart

    Institute of Scientific and Technical Information of China (English)

    白莹

    2012-01-01

    In this paper, through the Beta distribution curve characteristics and mathematical analysis, using order statistics maximum likelihood estimation method for estimation of the distribution parameters, and the use of Montecarl method to conduct numerical simulation, the author draws the conclusion that the index of random fluctuation can be described by Beta distribution. Therefore, this paper proposed the similarity index control chart based on Beta distribution which can be applied in fuzzy quality control, and proves its feasibility through the effect analysis.%文中首先通过对Beta分布曲线特性及数学特征的分析,然后运用顺序统计量极大似然估计法对分布参数的估计,以及利用Montecarl方法进行数值模拟,得出了贴近度指标的随机变动可以用Beta分布描述.最后,文中提出建立基于Beta分布的贴近度指标控制图,用于模糊质量控制,并通过效果分析证明其可行性.

  19. Determination of the aromatic hydrocarbon to total hydrocarbon ratio of mineral oil in commercial lubricants.

    Science.gov (United States)

    Uematsu, Yoko; Suzuki, Kumi; Ogimoto, Mami

    2016-01-01

    A method was developed to determine the aromatic hydrocarbon to total hydrocarbon ratio of mineral oil in commercial lubricants; a survey was also conducted of commercial lubricants. Hydrocarbons in lubricants were separated from the matrix components of lubricants using a silica gel solid phase extraction (SPE) column. Normal-phase liquid chromatography (NPLC) coupled with an evaporative light-scattering detector (ELSD) was used to determine the aromatic hydrocarbon to total hydrocarbon ratio. Size exclusion chromatography (SEC) coupled with a diode array detector (DAD) and a refractive index detector (RID) was used to estimate carbon numbers and the presence of aromatic hydrocarbons, which supplemented the results obtained by NPLC/ELSD. Aromatic hydrocarbons were not detected in 12 lubricants specified for use for incidental food contact, but were detected in 13 out of 22 lubricants non-specified for incidental food contact at a ratio up to 18%. They were also detected in 10 out of 12 lubricants collected at food factories at a ratio up to 13%. The centre carbon numbers of hydrocarbons in commercial lubricants were estimated to be between C16 and C50.

  20. Exploit the Bandwidth Capacities of the Perfluorinated Graded Index Polymer Optical Fiber for Multi-Services Distribution

    Directory of Open Access Journals (Sweden)

    Paul Alain Rolland

    2011-06-01

    Full Text Available The study reported here deals with the exploitation of perfluorinated graded index polymer optical fiber bandwidth to add further services in a home/office network. The fiber properties are exhibited in order to check if perfluorinated graded index plastic optical fiber (PFGI-POF is suitable to support a multiplexing transmission. According to the high bandwidth length of plastic fibers, both at 850 nm and 1,300 nm, the extension of the classical baseband existing network is proposed to achieve a dual concept, allowing the indoor coverage of wireless signals transmitted using the Radio over Fiber technology. The simultaneous transmission of a 10 GbE signal and a wireless signal is done respectively at 850 nm and 1,300 nm on a single plastic fiber using wavelength division multiplexing commercially available devices. The penalties have been evaluated both in digital (Bit Error Rate measurement and radiofrequency (Error Vector Magnitude measurement domains.

  1. The index approach to the analysis of spatial distribution and dynamics of the input indicators of the russian innovation system

    Directory of Open Access Journals (Sweden)

    Karpuhin Aleksandr Anatolyevich

    2012-03-01

    Full Text Available The author examines the question of concentration-tratnyh indicators of the Russian innovation system, using the index method. Empirical base of research were statistics as a tool used by a package of data analysis of the social sciences SPSS Base. The objects of investigation were the Federal District, as well as major research centers - Moscow and St. Petersburg, as of 2000-2009.

  2. Size distribution and source apportionment of polycyclic aromatic hydrocarbons (PAHs) in aerosol particle samples from the atmospheric environment of Delhi, India.

    Science.gov (United States)

    Gupta, Sandeep; Kumar, Krishan; Srivastava, Arun; Srivastava, Alok; Jain, V K

    2011-10-15

    Ambient aerosol particles were collected using a five-stage impactor at six different sites in Delhi. The impactor segregates the TSPM into five different sizes (viz. >10.9, 10.9-5.4, 5.4-1.6, 1.6-0.7, and 10.9+10.9 to 5.4+5.4 to 1.6μm) and fine (1.6 to 0.7+<0.7μm). It was observed that the dominant PAHs found were pyrene, benzo(a)pyrene, benzo(ghi)perylene and benzo(b)fluoranthene for both the coarse and fine fractions. Source apportionment of polycyclic aromatic hydrocarbons (PAHs) has been carried out using principal component analysis method (PCA) in both coarse and fine size modes. The major sources identified in this study, responsible for the elevated concentration of PAHs in Delhi, are vehicular emission and coal combustion. Some contribution from biomass burning was also observed.

  3. Cardiovascular Risk Factors and Distributions of the Ankle-Brachial Index among Type 2 Diabetes Mellitus Patients

    Directory of Open Access Journals (Sweden)

    Badaruddoza Doza

    2012-01-01

    Full Text Available Background. The aim of present study is to observe the association between the levels of ankle-brachial index (ABI and cardiovascular risk factors among people with type 2 diabetes mellitus in north India. A cross-sectional study was carried out at a centre for heart and diabetic clinic in the state of Punjab on 1121 subjects (671 males and 450 females with type 2 diabetes mellitus. History of symptoms related to cardiovascular diseases was noted, and blood pressure and anthropometric measurements were recorded. Ankle-brachial index (ABI was measured using ultrasonic Doppler flow detector. Subjects with ABI ≤0.9 and ≥1.30 were classified as having low and high ABI, respectively. Females had a higher BMI and brachial-ankle pulse wave velocity (<0.001. Whereas, males had higher diastolic blood pressure and duration of type 2 diabetes mellitus. The differences of systolic blood pressure and ankle-brachial index were not found significant between the sexes. The prevalence of low ABI (<0.9 was 4.47% in men and 4.67% in women and high ABI (≥1.30 was prevalent in 14% of men and 10.45% of women. Age, BMI, baPWV, and blood pressures were significantly associated with ABI value in both sexes. The results suggested that the ABI might be used as a strong indicator for cardiovascular risk factors in type 2 diabetic subjects.

  4. Influence of bending on power distribution in step-index plastic optical fibers and the calculation of bending loss.

    Science.gov (United States)

    Kovacević, M S; Nikezić, D

    2006-09-10

    A means of calculating optical power distribution in bent multimode optical fibers is proposed. It employs the power-flow equation approximated by the Fokker-Planck equation that is solved by the explicit finite-difference method. Conceptually important steps of this procedure include (i) dividing the full length of the bent optical fiber into a finite number of short, straight segments; (ii) solving the power equation for each segment sequentially to find its output distribution; and (iii) expressing that output distribution in rotated coordinates of the subsequent segment along the curved fiber to determine the input distribution for that subsequent segment and thus enable the calculation of the power flow and output distribution for it. The segment length and bend-induced perturbation of output angles are determined by geometric optics. The resulting power distributions are given at different cross sections along the curved fiber axis. They vary with the radius of fiber curvature and launch conditions. Results are compared to those for straight fiber. Bending loss is calculated as well.

  5. A New Precipitation Index for the Spatiotemporal Distribution of Drought and Flooding in the Reaches of the Yangtze and Huaihe Rivers and Related Characteristics of Atmospheric Circulation

    Institute of Scientific and Technical Information of China (English)

    ZONG Haifeng; ZHANG Qingyun

    2011-01-01

    Characteristics of the spatiotemporal distributions of precipitation anomalies in the reaches of the Yangtze River and Huaihe River (YHR) were studied using EOF method. Four main precipitation patterns for the YHR in summer identified by the first two modes: a region-wide flood over the entire YHR (RWF); a region-wide drought over the entire YHR (RWD); a flood in the south with a drought in the northern region of the Yangtze River (FS-DN); and a drought in the south with a flood in the northern region of the Yangtze River (DS-FN). Based on the first two modes and the actual precipitation departure percentage, a new precipitation index is defined in this paper. The typical flood/drought years associated with the various rainfall patterns defined by this precipitation index are more representative and closer to reality compared to some existing precipitation indexes which just use the area-mean precipitation or the EOF time components individually.The characteristics of atmospheric circulation in summer corresponding to the four main precipitation patterns over the YHR in summer show the features of atmospheric circulation differ in different precipitation pattern years. Although the different patterns share a common main influential circulation system, such as the blocking high over northeastern Asia, the low trough of westerly flows in the mid latitudes, the West Pacific Subtropical High (WPSH), and the high ridge over the Tibet Plateau, the difference in location and intensity of these systems can lead to different distributions of precipitation anomalies.

  6. Spatial distribution of the human development index, HIV infection and AIDS-Tuberculosis comorbidity: Brazil, 1982 - 2007

    Directory of Open Access Journals (Sweden)

    Antonio Luiz Rodrigues-Júnior

    2014-01-01

    Full Text Available INTRODUCTION: AIDS epidemic has given visibility to the incidence of tuberculosis, for being the most frequent opportunistic infection. It is known that individuals who are socially vulnerable are more susceptible to HIV transmission and tuberculosis as well. OBJECTIVE: This study aims to conduct a geoepidemiological study on HIV/AIDS, AIDS-Tuberculosis co-infection and social vulnerability. METHOD: This is an ecological study using incidence rates and the human development index to produce thematic maps and a descriptive analysis of epidemiology. The records of reported cases of HIV/AIDS from 1982 to 2007 were used, considering as cases of AIDS-Tuberculosis those records that were positively diagnosed with tuberculosis and those records with unknown diagnosis of tuberculosis, but showing compatible signs and symptoms with tuberculosis (fever, cough, cachexia and asthenia. RESULTS: The maps allowed the identification of areas with social differences and different patterns of incidence of HIV/AIDS and AIDS-Tuberculosis; regional differences were similar to those found by Josué de Castro, in 1940; regions with higher human development index values also showed higher incidence HIV/AIDS and AIDS-Tuberculosis. CONCLUSION: The prevention of HIV infection must be geographically specific, given socioeconomic and cultural differences. Although official records show decline in AIDS-TB co-infection, treatment of cases of HIV/AIDS should observe the occurrence of opportunistic diseases, which should be notified and/or updated.

  7. A Household-Based Distribution-Sensitive Human Development Index: An Empirical Application to Mexico, Nicaragua and Peru

    Science.gov (United States)

    Lopez-Calva, Luis F.; Ortiz-Juarez, Eduardo

    2012-01-01

    In measuring human development, one of the main concerns relates to the inclusion of a measure that penalizes inequalities in the distribution of achievements across the population. Using indicators from nationally representative household surveys and census data, this paper proposes a straightforward methodology to estimate a household-based…

  8. A Household-Based Distribution-Sensitive Human Development Index: An Empirical Application to Mexico, Nicaragua and Peru

    Science.gov (United States)

    Lopez-Calva, Luis F.; Ortiz-Juarez, Eduardo

    2012-01-01

    In measuring human development, one of the main concerns relates to the inclusion of a measure that penalizes inequalities in the distribution of achievements across the population. Using indicators from nationally representative household surveys and census data, this paper proposes a straightforward methodology to estimate a household-based…

  9. Polycyclic aromatic hydrocarbons in urban soils of different land uses in Beijing, China: distribution, sources and their correlation with the city's urbanization history.

    Science.gov (United States)

    Liu, Shaoda; Xia, Xinghui; Yang, Lingyan; Shen, Mohai; Liu, Ruimin

    2010-05-15

    A total of 127 surface soil samples (0-20 cm) were collected from Beijing's urban district and determined for 16 polycyclic aromatic hydrocarbons (PAHs). The mean concentration of summation SigmaPAHs was 1802.6 ng g(-1) with a standard deviation of 1824.2 ng g(-1). Average summation SigmaPAHs concentration and the percentage of high-molecular weight PAHs (4-6-rings) decreased from inner city to exterior areas. This correlated with the urbanization history of Beijing's urban district and inferred an increasing trend of soil PAHs with accumulation time and age of the urban area. summation SigmaPAHs in different land uses decreased in an order as: culture and education area (CEA)>classical garden (CG), business area (BA)>residential area (RA), roadside area (RSA)>public green space (PGS). PAHs in CEA mainly came from coal combustion, while soils of RSA exhibited clear traffic emission characteristics. PAHs in other land uses came from mixed sources. Principle component analysis followed by multivariate linear regression indicated that coal combustion and vehicle emission contributed about 46.0% and 54.0% to PAHs in Beijing's urban soils, respectively. Risk assessment based on the Canadian soil criterion indicated a low contamination level of PAHs. However, higher contents in some sensitive land uses such as CEA and CG should draw enough attention. Copyright (c) 2010 Elsevier B.V. All rights reserved.

  10. The relative abundance and seasonal distribution correspond with the sources of polycyclic aromatic hydrocarbons (PAHs) in the surface sediments of Chenab River, Pakistan.

    Science.gov (United States)

    Hussain, Imran; Syed, Jabir Hussain; Kamal, Atif; Iqbal, Mehreen; Eqani, Syed-Ali-Mustjab-Akbar-Shah; Bong, Chui Wei; Taqi, Malik Mumtaz; Reichenauer, Thomas G; Zhang, Gan; Malik, Riffat Naseem

    2016-06-01

    Chenab River is one of the most important rivers of Punjab Province (Pakistan) that receives huge input of industrial effluents and municipal sewage from major cities in the Central Punjab, Pakistan. The current study was designed to evaluate the concentration levels and associated ecological risks of USEPA priority polycyclic aromatic hydrocarbons (PAHs) in the surface sediments of Chenab River. Sampling was performed from eight (n = 24) sampling stations of Chenab River and its tributaries. We observed a relatively high abundance of ∑16PAHs during the summer season (i.e. 554 ng g(-1)) versus that in the winter season (i.e. 361 ng g(-1)), with an overall abundance of two-, five- and six-ring PAH congeners. Results also revealed that the nitrate and phosphate contents in the sediments were closely associated with low molecular weight (LMW) and high molecular weight (HMW) PAHs, respectively. Source apportionment results showed that the combustion of fossil fuels appears to be the key source of PAHs in the study area. The risk quotient (RQ) values indicated that seven PAH congeners (i.e. phenanthrene, anthracene, fluoranthene, pyrene, benzo(a)pyrene, chrysene and benzo(a)anthracene) could pose serious threats to the aquatic life of the riverine ecosystem in Pakistan.

  11. Distribution of Polycyclic Aromatic Hydrocarbons between the Particulate and the Gas Phase of Mainstream Cigarette Smoke in Relation to Cigarette Technological Characteristics

    Directory of Open Access Journals (Sweden)

    Kalaitzoglou M

    2014-12-01

    Full Text Available Particulate- and gas-phase polycyclic aromatic hydrocarbons (PAHs were determined in the mainstream smoke (MSS of 59 manufactured cigarette brands (commercially available brands of unknown tobacco and blend type with variable ‘tar’ yields and physical/technological characteristics. Depending on the existence/absence of filter, the ‘tar’ yield indicated on the packet, and the cigarette length and diameter, the examined cigarette brands were classified into 15 groups: non filter (NF, high (H, medium (M, light (L, super light (SL, ultra light (UL, one-tar yields (O, 100 mm long cigarettes (H-100, L-100, SL-100, UL-100, O-100, and slim cigarettes (SL-SLIM, UL-SLIM, O-SLIM. Cigarettes were smoked in a reference smoking machine equipped with glass fibre filters for collection of PAHs bound to total particulate matter (TPM, and polyurethane foam plugs (PUF for collection of gas-phase PAHs. The relationships of gas- and particulate-phase concentrations of PAHs (ng/cig with the contents of typical MSS components, such as TPM, ‘tar’, nicotine and carbon monoxide were investigated. In addition, the phase partitioning of PAHs in MSS was evaluated in relation to the technological characteristics of cigarettes.

  12. Zinc distribution in blood components, inflammatory status, and clinical indexes of disease activity during zinc supplementation in inflammatory rheumatic diseases.

    Science.gov (United States)

    Peretz, A; Nève, J; Jeghers, O; Pelen, F

    1993-05-01

    The effects of zinc supplementation on zinc status and on clinical and biological indicators of inflammation were investigated in 18 patients with chronic inflammatory rheumatic diseases and in 9 healthy control subjects. Patients with mild and recent onset disease were assigned to a 60-d trial to receive either 45 mg Zn (as gluconate)/d or a placebo, while control subjects received the zinc supplement. Baseline mean plasma zinc of the patients was low whereas mononuclear cell zinc content was elevated, suggesting a redistribution of the element related to the inflammatory process rather than to a zinc-deficient state. Zinc supplementation increased plasma zinc to a similar extent in patients and in control subjects, which suggested no impairment of zinc intestinal absorption as a result of the inflammatory process. On the contrary, erythrocyte and leukocyte zinc concentrations were not modified in the two groups examined. No beneficial effect of zinc treatment could be demonstrated on either clinical or inflammation indexes.

  13. A submission model for use in the indexing, searching, and retrieval of distributed pathology case and tissue specimens.

    Science.gov (United States)

    Namini, Ahmad H; Berkowicz, David A; Kohane, Isaac S; Chueh, Henry

    2004-01-01

    This paper describes the Shared Pathology Informatics Network (SPIN) submission model for uploading de-identified XML annotations of pathology case and specimen information to a distributed peer-to-peer network architecture. SPIN use cases, architecture, and technologies, as well as pathology information design is described. With the architecture currently in use by six member institutions, SPIN appears to be a viable, secure methodology to submit pathology information for query and specimen retrieval by investigators

  14. A criterion for assessing homogeneity distribution in hyperspectral images. Part 1: homogeneity index bases and blending processes.

    Science.gov (United States)

    Rosas, Juan G; Blanco, Marcelo

    2012-11-01

    The Process Analytical Technologies (PAT) initiative of the US Food and Drug Administration (US FDA) has established a framework for the development of imaging techniques to determine the real-time distribution of mixture components during the production of solid dosage forms. This study, which is the first in a series of two parts, uses existing mixing indices and a new criterion called the "percentage of homogeneity" (H%) to assess image homogeneity. Image analysis techniques use feature extraction procedures to extract information from images subjected to treatments including colour segmentation and binarization. The surface distribution of components was determined by macropixel analysis, which splits an image into non-overlapping blocks of a preset size and calculates several statistical parameters for the resulting divisional structure. Such parameters were used to compute mixing indices. In this work, we explored the potential of image processing in combination with mixing indices and H% for assessing blending end-point and component distribution on images. As a simplified test, an arrangement of binary and ternary systems of coloured particles was mixed collecting at-line multispectral (MSI) and non-invasive RGB pictures at preset intervals.

  15. Spatial distribution and sources of polycyclic aromatic hydrocarbons (PAHs) in the reservoir sediments after impoundment of Manwan Dam in the middle of Lancang River, China.

    Science.gov (United States)

    An, NanNan; Liu, Shiliang; Yin, Yijie; Cheng, Fangyan; Dong, Shikui; Wu, Xiaoyu

    2016-08-01

    Polycyclic aromatic hydrocarbons (PAHs) have received increasing attentions owing to their carcinogenicity, teratogenicity and environmental toxicity. The studies on the spatial variations, sources identification and potential ecological risk assessment of PAHs in the reservoir sediments after dam construction are becoming new hotpots. Sixteen PAHs contamination levels were investigated from 15 sample sections in the sediments of Manwan Reservoir in the middle of Lancang River, China. Total concentrations of 16 PAHs ranged from 14.4 to 137.7 ng g(-1) dw with a mean concentration of 70.68 ng g(-1) dw. The areas with residential settlement at large tributaries and near dam had higher PAHs concentrations. In the sight of classification of PAHs pollution levels, the sediments of Manwan Reservoir could be considered as low to moderate PAHs polluted levels. One-way analysis of variance for spatial analysis revealed that there were no significant differences (P PAHs at the reservoir head, centre and tail. Moreover, no significant differences (P PAH at the mainstream and tributaries except that BaP showed significant differences (P PAHs in Manwan Reservoir might be mixed, primarily including the petroleum source and coal combustion. As compared with sediment quality guidelines, the observed concentrations of PAHs in all sample sections did not exceed the effects range low (ERL) and the threshold effect level (TEL) values, suggesting that there were little harmful biological toxic effects on the aquatic organisms in Manwan Reservoir. The study provided a comprehensive overview on the PAHs contaminations on the reservoir sediments in the middle Lancang River, which may have an important significances on the international river management.

  16. Distribution, sources, and risk assessment of polycyclic aromatic hydrocarbons (PAHs) in surface water in industrial affected areas of the Three Gorges Reservoir, China.

    Science.gov (United States)

    Zheng, Binghui; Ma, Yingqun; Qin, Yanwen; Zhang, Lei; Zhao, Yanmin; Cao, Wei; Yang, Chenchen; Han, Chaonan

    2016-12-01

    Water samples were collected from wastewater treatment plant (WWTP), drain water (DW), major tributaries (MT), and main course of the Yangtze River (MY) in areas of three industrial parks (IPs) in Chongqing city in the Three Gorges Reservoir (TGR). Sixteen EPA priority polycyclic aromatic hydrocarbon (PAH) pollutants were quantified to identify the effects of industrial activities on water quality of the TGR. The results showed that 11 individual PAHs were quantified and 5 PAHs (naphthalene (Nap), acenaphthylene (Acy), benzo[k]fluoranthene (BkF), indeno[1,2,3-cd]pyrene (InP), and benzo[g,h,i]perylene (BgP)) were under detection limits in all of the water samples. Three-ring and four-ring PAHs were the most detected PAHs. Concentrations of individual PAHs were in the range of not detected (nd) to 24.3 ng/L. Total PAH concentrations for each site ranged from nd to 42.9 ng/L and were lower compared to those in other studies. The mean PAH concentrations for sites WWTP, DW, MT, and MY showed as follows: DW (25.9 ng/L) > MY (15.5 ng/L) > MT (14.0 ng/L) > WWTP (9.3 ng/L), and DW contains the highest PAH concentrations. Source identification ratios showed that petroleum and combustion of biomass coal and petroleum were the main sources of PAHs. The results of potential ecosystem risk assessment indicated that, although PAH concentrations in MT and MY are likely harmless to ecosystem, contaminations of PAHs in DW were listed as middle levels and some management strategies and remediation actions, like strengthen clean production processes and banning illegal sewage discharging activities, etc., should be taken to lighten the ecosystem risk caused by PAHs especially risks caused by water discharging drains.

  17. Temporal and spatial distribution, sources, and potential health risks of ambient polycyclic aromatic hydrocarbons in the Yangtze River Delta (YRD) of eastern China.

    Science.gov (United States)

    Niu, Shan; Dong, Liang; Zhang, Lifei; Zhu, Chaofei; Hai, Reti; Huang, Yeru

    2017-04-01

    In this study, from July 2011 to June 2012, 31 sampling sites were identified in order to investigate the concentrations and sources of polycyclic aromatic hydrocarbons (PAHs), as well as to evaluate their potential health risks in the cities of Suzhou, Wuxi, and Nantong, which are located in the Yangtze River Delta (YRD). The samples were collected by means of passive air sampling (PAS), and the contents of 15 PAHs were detected by gas chromatography-mass spectrometry. The ∑15PAHs concentrations were found to range from 6.48 to 154 ng m(-3), with an average value of 56.8 ± 14.8 ng m(-3). The pollution levels in Suzhou and Nantong were higher than those in Wuxi. Furthermore, the concentrations of the PAHs in the urban sites were determined to be higher than those in the suburban sites for ambient air. The seasonal average contents were found to be at a maximum in autumn, with concentrations reaching 74.1 ng m(-3). Vehicle emissions and coal/biomass combustion were the dominant sources of the PAHs in the ambient air, with the contributions of 48% and 46%, respectively. The BaP TEQ (0.88 ng m(-3)) was found to have surpassed the Chinese and Japanese dioxin emission limit, and in doing so, may have caused a certain degree of risk to human health. Copyright © 2016 Elsevier Ltd. All rights reserved.

  18. Petroleum Geology Characteristics and Hydrocarbon Distribution of Solimoes Basin, Brazil%巴西萨利莫斯盆地油气地质特征及油气分布规律

    Institute of Scientific and Technical Information of China (English)

    庞正炼; 樊太亮; 何辉; 李积林; 唐山; 马腾

    2012-01-01

    two phases, and the phase after the intrusion is more important. Due to the late Jurua tectonic movements, there were also two stages of the accumulation of hydrocarbon, and the later one controls the final distribution of the hydrocarbon. According to the experience of oil and gas exploration in the basin, oil and gas fields mostly locate around the faults, and are also controlled by the distribution of source rock. Hence, areas both with faults and good source rock are favorable areas of oil and gas, especially gas exploration.

  19. Retrieval of the particle size distribution function from the data of lidar sensing under the assumption of known refractive index.

    Science.gov (United States)

    Samoilova, S V; Sviridenkov, M A; Penner, I E

    2016-10-01

    This paper presents a method to retrieve the particle size distribution function from the data of vertical lidar sensing. We have used 462 data models obtained at the Zvenigorod AERONET site obtained in 2011-2012. For each laser shot, we considered both fine (with particle sizes in a range from 0.05 to 0.6 μm) and coarse aerosol fractions (from 0.6 to 10 μm), with emphasize on the coarse fraction. Our suggested method is a modification of the Tikhonov method. The Tikhonov method is not optimal for coarse particles because its stabilizer does not and cannot account for the presence of the coarse mode, i.e., existence of more than one maximum of the size distribution function. The components of the matrix Wu-1 located in quadrants II and IV are sensitive to the change of these parameters. Neglecting this fact will lead again to arbitrary estimates of the contribution of the coarse particles even for exact values on the main diagonal and the two diagonals adjacent to it. Our method allows the coarse fraction up to 2.5 μm to be determined unambiguously. For larger particles (>2.5  μm) we recommend using the available sets of the coefficients, but with the level of values to be determined.

  20. Autoregressive processes with exponentially decaying probability distribution functions: applications to daily variations of a stock market index.

    Science.gov (United States)

    Porto, Markus; Roman, H Eduardo

    2002-04-01

    We consider autoregressive conditional heteroskedasticity (ARCH) processes in which the variance sigma(2)(y) depends linearly on the absolute value of the random variable y as sigma(2)(y) = a+b absolute value of y. While for the standard model, where sigma(2)(y) = a + b y(2), the corresponding probability distribution function (PDF) P(y) decays as a power law for absolute value of y-->infinity, in the linear case it decays exponentially as P(y) approximately exp(-alpha absolute value of y), with alpha = 2/b. We extend these results to the more general case sigma(2)(y) = a+b absolute value of y(q), with 0 history of the ARCH process is taken into account, the resulting PDF becomes a stretched exponential even for q = 1, with a stretched exponent beta = 2/3, in a much better agreement with the empirical data.

  1. Oxygenated Derivatives of Hydrocarbons

    Science.gov (United States)

    For the book entitled “Insect Hydrocarbons: Biology, Biochemistry and Chemical Ecology”, this chapter presents a comprehensive review of the occurrence, structure and function of oxygenated derivatives of hydrocarbons. The book chapter focuses on the occurrence, structural identification and functi...

  2. Hydrocarbon Spectral Database

    Science.gov (United States)

    SRD 115 Hydrocarbon Spectral Database (Web, free access)   All of the rotational spectral lines observed and reported in the open literature for 91 hydrocarbon molecules have been tabulated. The isotopic molecular species, assigned quantum numbers, observed frequency, estimated measurement uncertainty and reference are given for each transition reported.

  3. Estimating the biomass of unevenly distributed aquatic vegetation in a lake using the normalized water-adjusted vegetation index and scale transformation method.

    Science.gov (United States)

    Gao, Yongnian; Gao, Junfeng; Wang, Jing; Wang, Shuangshuang; Li, Qin; Zhai, Shuhua; Zhou, Ya

    2017-12-01

    Satellite remote sensing is advantageous for the mapping and monitoring of aquatic vegetation biomass at large spatial scales. We proposed a scale transformation (CT) method of converting the field sampling-site biomass from the quadrat to pixel scale and a new normalized water-adjusted vegetation index (NWAVI) based on remotely sensed imagery for the biomass estimation of aquatic vegetation (excluding emergent vegetation). We used a modeling approach based on the proposed CT method and NWAVI as well as statistical analyses including linear, quadratic, logarithmic, cubic, exponential, inverse and power regression to estimate the aquatic vegetation biomass, and we evaluated the performance of the biomass estimation. We mapped the spatial distribution and temporal change of the aquatic vegetation biomass using a geographic information system in a test lake in different months. The exponential regression models based on CT and the NWAVI had optimal adjusted R(2), F and Sig. values in both May and August 2013. The scatter plots of the observed versus the predicted biomass showed that most of the validated field sites were near the 1:1 line. The RMSE, ARE and RE values were small. The spatial distribution and change of the aquatic vegetation biomass in the study area showed clear variability. Among the NWAVI-based and other vegetation index-based models, the CT and NWAVI-based models had the largest adjusted R(2), F and the smallest ARE values in both tests. The proposed modeling scheme is effective for the biomass estimation of aquatic vegetation in lakes. It indicated that the proposed method can provide a most accurate spatial distribution map of aquatic vegetation biomass for lake ecological management. More accurate biomass maps of aquatic vegetation are essential for implementing conservation policy and for reducing uncertainties in our understanding of the lake carbon cycle. Copyright © 2017 Elsevier B.V. All rights reserved.

  4. Ethnic variability in the allelic distribution of human aryl hydrocarbon receptor codon 554 and assessment of variant receptor function in vitro.

    Science.gov (United States)

    Wong, J M; Harper, P A; Meyer, U A; Bock, K W; Morike, K; Lagueux, J; Ayotte, P; Tyndale, R F; Sellers, E M; Manchester, D K; Okey, A B

    2001-02-01

    The aryl hydrocarbon receptor (AHR) is a ligand-dependent transcriptional regulator of several genes including the cytochrome P4501 (CYP1) family as well as genes encoding factors involved in cell growth and differentiation. In mice, several polymorphic forms of the AHR are known, some of which have altered affinity for toxic and carcinogenic ligands. Remarkably little genetic variation has been detected in the human AHR gene. In studies on human AHR, Kawajiri et al. (Pharmacogenetics 1995; 5:151-158) reported a variation at codon 554 that results in an amino acid change from arginine to lysine; the frequency of the variant allele in a Japanese population (n = 277) was 0.43. We investigated the Lys554 allele in 386 individuals of various ethnic origins and found the frequency to be: 0.58 in Ivory Coast Africans (n = 58); 0.53 in a mixed African group (n = 20); 0.39 in Caribbean-Africans (n = 55); 0.32 in Canadian Chinese (n = 41); 0.14 in North American Indians (n = 47); 0.12 in French Canadian Caucasians (n = 20); 0.11 in a mixed ethnicity North American group (n = 45); 0.09 in Canadian Inuits (n = 22); and 0.07 in German Caucasians (n = 78). We expressed the human Lys554 allele in an in-vitro transcription-translation system and found that the receptor bearing the R554L substitution had an equivalent ability to that of the wild-type receptor to bind to a dioxin-responsive element following treatment with 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). The Lys554 allele also was equivalent to the wild-type receptor at stimulating CYP1A1 mRNA expression when transfected into TCDD-treated receptor-deficient mouse Hepa-1 cells. It is not yet known if any of the wide variations in allele frequency at codon 554 are related to ethnic differences in susceptibility to adverse effects of environmental chemicals.

  5. Plasma devices for hydrocarbon reformation

    KAUST Repository

    Cha, Min Suk

    2017-02-16

    Plasma devices for hydrocarbon reformation are provided. Methods of using the devices for hydrocarbon reformation are also provided. The devices can include a liquid container to receive a hydrocarbon source, and a plasma torch configured to be submerged in the liquid. The plasma plume from the plasma torch can cause reformation of the hydrocarbon. The device can use a variety of plasma torches that can be arranged in a variety of positions in the liquid container. The devices can be used for the reformation of gaseous hydrocarbons and/or liquid hydrocarbons. The reformation can produce methane, lower hydrocarbons, higher hydrocarbons, hydrogen gas, water, carbon dioxide, carbon monoxide, or a combination thereof.

  6. Plant hydrocarbon recovery process

    Energy Technology Data Exchange (ETDEWEB)

    Dzadzic, P.M.; Price, M.C.; Shih, C.J.; Weil, T.A.

    1982-01-26

    A process for production and recovery of hydrocarbons from hydrocarbon-containing whole plants in a form suitable for use as chemical feedstocks or as hydrocarbon energy sources which process comprises: (A) pulverizing by grinding or chopping hydrocarbon-containing whole plants selected from the group consisting of euphorbiaceae, apocynaceae, asclepiadaceae, compositae, cactaceae and pinaceae families to a suitable particle size, (B) drying and preheating said particles in a reducing atmosphere under positive pressure (C) passing said particles through a thermal conversion zone containing a reducing atmosphere and with a residence time of 1 second to about 30 minutes at a temperature within the range of from about 200* C. To about 1000* C., (D) separately recovering the condensable vapors as liquids and the noncondensable gases in a condition suitable for use as chemical feedstocks or as hydrocarbon fuels.

  7. Percentile distribution of blood pressure readings in relation to body mass index: a populationbased cross-sectional study ADOPOLNOR

    Directory of Open Access Journals (Sweden)

    Krzyżaniak Alicja

    2015-03-01

    Full Text Available Recent upward trends toward elevated blood pressure and increased weight expressed in terms of body mass index in children and adolescents call for regular monitoring of their physical growth and age-related changes in blood pressure. This requires adequate tools - reference values of a normal blood pressure range. The main objective of this study was to provide sex- and BMI-specific percentile reference values for systolic and diastolic blood pressure based on the adolescent Polish population, participants in the ADOPOLNOR study. A cross-sectional survey was carried out on a representative, randomly selected cohort of 4,941; 2,451 male and 2,490 female students aged 10-18 years, residents in Wielkopolska province and its capital, the city of Poznań. All examinations were performed in school nursery rooms during morning hours according to standard procedures. Body height and weight were measured and BMI was calculated. Blood pressure was measured twice on each occasion on the right arm using a fully calibrated TECH MED TM-Z mercury gauge sphygmomanometer with sets of exchangeable cuffs and a clinical stethoscope. The blood pressure classification was determined using the surveillance method. For each participant, the mean of measurements taken on each of the three occasions was calculated and served as his/her final blood pressure value. Using the LMS method, fitted percentile curves were created for BMI-related systolic and diastolic blood pressure. The findings revealed that age related blood pressure pattern was similar in boys and girls. It showed a steady increase of systolic and diastolic blood pressure with age. There was a positive correlation between the systolic and diastolic blood pressure indicating that when systolic blood pressure increased so diastolic did (r=0.61 at p<0.01. Boys were likely to have relatively higher mean values of systolic and diastolic blood pressure and steeper slope for BMI-related change in blood pressure

  8. Allelic frequency distributions of 21 non-combined DNA index system STR loci in a Russian ethnic minority group from Inner Mongolia, China*

    Science.gov (United States)

    Wang, Hong-dan; Shen, Chun-mei; Liu, Wen-juan; Zhang, Yu-dang; Yang, Guang; Yan, Jiang-wei; Qin, Hai-xia; Zhu, Bo-feng

    2013-01-01

    We studied the allelic frequency distributions and statistical forensic parameters of 21 new short tandem repeat (STR) loci and the amelogenin locus, which are not included in the combined DNA index system (CODIS), in a Russian ethnic minority group from the Inner Mongolia Autonomous Region, China. A total of 114 bloodstain samples from unrelated individuals were extracted and co-amplified with four fluorescence-labeled primers in a multiplex polymerase chain reaction (PCR) system. Using capillary electrophoresis, the PCR products of the 21 STR loci were separated and genotyped. A total of 161 alleles were observed in the Russian ethnic minority group, and corresponding allelic frequencies ranged from 0.0044 to 0.5965. The 21 non-CODIS STR loci of the Russian ethnic minority group were characterized by high genetic diversity and therefore may be useful for elucidating the population’s genetic background, for individual identification, and for paternity testing in forensic practice. PMID:23733431

  9. Allelic frequency distributions of 21 non-combined DNA index system STR loci in a Russian ethnic minority group from Inner Mongolia, China.

    Science.gov (United States)

    Wang, Hong-dan; Shen, Chun-mei; Liu, Wen-juan; Zhang, Yu-dang; Yang, Guang; Yan, Jiang-wei; Qin, Hai-xia; Zhu, Bo-feng

    2013-06-01

    We studied the allelic frequency distributions and statistical forensic parameters of 21 new short tandem repeat (STR) loci and the amelogenin locus, which are not included in the combined DNA index system (CODIS), in a Russian ethnic minority group from the Inner Mongolia Autonomous Region, China. A total of 114 bloodstain samples from unrelated individuals were extracted and co-amplified with four fluorescence-labeled primers in a multiplex polymerase chain reaction (PCR) system. Using capillary electrophoresis, the PCR products of the 21 STR loci were separated and genotyped. A total of 161 alleles were observed in the Russian ethnic minority group, and corresponding allelic frequencies ranged from 0.0044 to 0.5965. The 21 non-CODIS STR loci of the Russian ethnic minority group were characterized by high genetic diversity and therefore may be useful for elucidating the population's genetic background, for individual identification, and for paternity testing in forensic practice.

  10. A preliminary evaluation model for reservoir hydrocarbon-generating potential established based on dissolved hydrocarbons in oilfield water

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    A large number of oilfield water samples were analyzed in this work. Research on the relationship between the concentrations and distribution of dissolved hydrocarbons sug gested that the contents and composition of dissolved hydrocarbons varied with the hydrocar bon-generating potential of reservoirs. The concentrations of dissolved hydrocarbons were low in dry layers, water layers and gas-water layers, but high in gas reservoirs and oil reservoirs, especially in gas reservoirs with condensed oil. Series of carbon-number alkanes were usually absent in oilfield water from dry layers, water layers and gas-water layers but abundant in oil field water from oil-water reservoirs, gas reservoirs and oil reservoirs, whose carbon numbers varied most widely in oil reservoirs and least in gas reservoirs. A preliminary evaluation model for reservoir hydrocarbon-generating potential was established based on the characteristics of dissolved hydrocarbons in oilfield water to assist hydrocarbon exploration.

  11. A decade plus of snow distribution observations in a mountain catchment: assessing variability, self-similarity, and the representativeness of an index site

    Science.gov (United States)

    Winstral, A. H.; Marks, D. G.

    2012-12-01

    This study presents an analysis of eleven years of manually sampled snow depth and SWE data at the drift-dominated Reynolds Mountain East catchment (0.36 km^2) in southwestern Idaho, U.S.A. The dataset includes eleven mid-winter surveys and ten surveys that targeted peak accumulation in the early spring. Depths were sampled on the same 30-meter grid covering the entire catchment in each survey. Densities were sampled at a coarser resolution using a depth-stratified random sampling scheme. In 19 of the 21 surveys, snow density increased with increasing depth until an upper limit was attained in the drifts. The coefficient of variation (CV) for mid-winter snow depths varied from 0.46 to 0.75 and was significantly related to seasonal wind speeds (p = 0.02). Energy inputs, correlated inversely to accumulation rates in this catchment, caused variability to increase as melt increased through the season. The CV for all three surveys that took place after peak accumulation exceeded 1.0. Inter-seasonal distributions were strongly correlated - correlation coefficients ranged from 0.70 to 0.97 with a mean of 0.84. An index site with similar site characteristics to NRCS Snotel sites gave reasonable approximations of average catchment SWE in drier years, however as snowfall increased this site increasingly over-estimated basin-wide SWE. Though others have found snow distributions to be reasonably approximated by two-parameter lognormal distributions, Kolmogorov-Smirnov goodness of fit tests rejected this hypothesis (p < 0.01) in 20 of the 21 observed distributions.

  12. 污水处理过程中苯系物和氯代烃三相分布规律%Distributions of BTEX and Chlorinated Hydrocarbons in Three Phases During Wastewater Treatment Processing

    Institute of Scientific and Technical Information of China (English)

    王琨; 杨俊晨; 黄丽坤; 高娜; 赵庆良

    2012-01-01

    为研究污水处理过程中曝气对苯系物中苯、甲苯和二甲苯以及氯代烃中三氯甲烷、四氯化碳、三氯乙烯和四氯乙烯去除的影响,设计了2个反应器,模拟污水处理过程,一个为活性污泥反应器,另一个为没有活性污泥的对照反应器.结果表明,在液相中,30.6%的TOC未经微生物降解而直接因曝气逸散到气相.苯系物的逸散比例达到了100%;三氯甲烷、四氯化碳、三氯乙烯和四氯乙烯的逸散比例分别为27.5%、39.0%、42.4%和38.5%.同时利用密闭水箱研究了生物处理单元中苯系物和氯代烃三相分布规律.在厌氧阶段,固相中苯、甲苯、二甲苯、三氯甲烷、四氯化碳、三氯乙烯和四氯乙烯占总量比例分别为38.7%、43.6%、38.0%、28.8%、24.3%、15.3%和20.5%.在曝气阶段,苯系物全部被去除,氯代烃总量略有下降.二沉池阶段,固相中三氯甲烷、四氯化碳、三氯乙烯、四氯乙烯占总质量的比例分别为5.2%、20.1%、6.8%和0%.%In order to investigate the influence of aeration on removal of BTEX ( benzene, toluene, xylene) and chlorinated hydrocarbons ( chloroform, carbon tetrachloride, trichloroethylene, tetrachloroethylene) during wastewater treatment processing, two lab-scale parallel reactors with and without activated sludge were designed to simulate wastewater treatment processing. The results indicated that 30. 6% of TOC in the liquid phase volatilized during aeration without microbial decomposition. The volatilization ratio of BTEX reached 100% , and the ratios of chloroform, carbon tetrachloride, trichloroethylene and tetrachloroethylene were 27.5% , 39.0% , 42.4% and 38.5% , respectively. At the same time, a dedicated tank was used to study the distribution of BTEX and chlorinated hydrocarbons in the three phases. Under the anaerobic condition, the percentages of benzene, toluene, xylene, chloroform, carbon tetrachloride, trichloroethylene

  13. Influence of age, menopause status, body mass index and physical activity on body composition and body fat distribution in midlife women

    Institute of Scientific and Technical Information of China (English)

    Wei Dai-min; Yu Qi; Zhang Ying; Chen Feng-ling

    2012-01-01

    Objective: To investigate the influence of age,menopause status,body mass index (BMI) and physical activity on body composition and body fat distribution in Chinese midlife women.Methods: The healthy women who underwent anniversary health checkup in Peking Union Medical College Hospital were recruited cross-sectionally.The level of physical activity was determined via International Physical Activity Questionnaire-Short in Chinese Version.The body composition and fat distribution were measured by dualenergy X-ray absorptiometry.Results: A total of 162 women with average age 52 years (40-62 years) were recruited.Multivariate linear regression analysis was performed to test the relationship between age,menopause status,BMI and physical activity and parameters of body composition and body fat distribution.The total fat tissue percentage was positively associated with BMI (standardized partial regression coefficient: b=0.70),menopause status (b=0.19,grading variables 1,2,3 were assigned to represent for reproductive group,menopausal transition group and postmenopausal group,respectively),and negatively associated with physical activity energy expenditure (b=-0.17) with model determination coefficient 0.55.Total body fat-free-tissue mass was positively associated with BMI (b =0.61),negatively associated with menopause status (b =-0.14) with model determination coefficient 0.39.The ratio of trunk fat-tissue mass/total body fat-tissue mass (Tr/T) was positively associated with BMI (b=0.32) and menopause status (b= 0.30) with model determination coefficient 0.20.After adjusted the effects of BMI,menopause status and physical activity,age was not significantly related with total fat tissue percentage,body fat-free-tissue mass,nor ratio of (Tr/T).Conclusion: Menopause impacts body composition and body fat distribution independently.During the process of female reproductive aging,body fat tissue mass and centrally distributed fat tissue mass increase,while body fatfree

  14. Aryl hydrocarbon hydroxylase represents CYP1B1, and not CYP1A1, in human freshly isolated white cells: trimodal distribution of Japanese population according to induction of CYP1B1 mRNA by environmental dioxins.

    Science.gov (United States)

    Toide, Kenji; Yamazaki, Hiroshi; Nagashima, Rikako; Itoh, Keisuke; Iwano, Shunsuke; Takahashi, Yoshiki; Watanabe, Shaw; Kamataki, Tetsuya

    2003-03-01

    The expression level of mRNAs for cytochrome P450 (CYP) 1A1 and 1B1 in freshly prepared white cells from 72 subjects exposed to dioxins at waste incinerators was investigated. The amounts of CYP1B1 mRNA ranged from 0.16 to 671 molecules/10(7) molecules of 18S rRNA, whereas the amounts of CYP1A1 mRNA were dioxins. The inducibility of CYP1B1 mRNA in leukocytes, defined as the ratio of CYP1B1 mRNA to the plasma concentration of dioxins, varied among the subjects. It was found that the subjects showed trimodal distribution according to inducibility: 39 (54.2%), 25 (34.7%), and 8 (11.1%) of 72 subjects were judged as poor, intermediate, and high responders to environmental dioxins, respectively. The amounts of CYP1B1 mRNA in leukocytes of the intermediate and high responders were highly correlated with the plasma concentrations of dioxins (P dioxins is involved in aromatic hydrocarbon hydroxylase activities in human lymphocytes.

  15. Application of a self-organizing map and positive matrix factorization to investigate the spatial distributions and sources of polycyclic aromatic hydrocarbons in soils from Xiangfen County, northern China.

    Science.gov (United States)

    Tao, Shi-Yang; Zhong, Bu-Qing; Lin, Yan; Ma, Jin; Zhou, Yongzhang; Hou, Hong; Zhao, Long; Sun, Zaijin; Qin, Xiaopeng; Shi, Huading

    2017-07-01

    The concentrations of 16 priority polycyclic aromatic hydrocarbons (PAHs) were measured in 128 surface soil samples from Xiangfen County, northern China. The total mass concentration of these PAHs ranged from 52 to 10,524ng/g, with a mean of 723ng/g. Four-ring PAHs contributed almost 50% of the total PAH burden. A self-organizing map and positive matrix factorization were applied to investigate the spatial distribution and source apportionment of PAHs. Three emission sources of PAHs were identified, namely, coking ovens (21.9%), coal/biomass combustion (60.1%), and anthracene oil (18.0%). High concentrations of low-molecular-weight PAHs were particularly apparent in the coking plant zone in the region around Gucheng Town. High-molecular-weight PAHs mainly originated from coal/biomass combustion around Gucheng Town, Xincheng Town, and Taosi Town. PAHs in the soil of Xiangfen County are unlikely to pose a significant cancer risk for the population. Copyright © 2017 Elsevier Inc. All rights reserved.

  16. A basic distributional framework of global deepwater basins and hydrocarbon characteristics%全球深水盆地群分布格局与油气特征

    Institute of Scientific and Technical Information of China (English)

    张功成; 米立军; 屈红军; 冯杨伟; 范玉海

    2011-01-01

    The distribution of global deepwater basins is characterized by a basic framework of "double vertical and horizontal" arrangements. The "double vertical" arrangements refer to two groups of deepwater basins with a submeridional distributional framework, i.e. Atlantic offshore deepwater basins and West Pacific offshore deepwater basins. The former include seven deepwater basins along the eastern Brazilian continental margin, deepwater basins in the Gulf of Mexico, eleven deepwater basins along the West Africa continental margin, deepwater basins in the Mid-Norway continental margin, the North Sea Basin and so on The latter include deepwater basins in the Sea of Japan and the Gippsland Basin in the Southeast of Australia, etc. The "double horizontal" arrangements stand for two groups of deepwater basins with a sublatitudinal distributional framework, i.e. offshore deepwater basins of the Neotethys structural domain and offshore deepwater basins in the circum-North Pole area, the former include four deepwater basins in the northwest shelf of Australia, deepwater basins in the Gulf of Burma, deepwater basins in the Gulf of Arab, etc. The latter include the Barents Sea deepwater basin, the Kara Sea deepwater basin, the Laptev Sea shelf basin, etc. Deepwater basins can be formed in all phases of the Wilson cycle, such as passive continental margin, subducted margin, continent-to-continent collided margin, arc-to-continent collided margin, transform margin, and marginal rift, of which the passive continental margin is the most common phase for the formation of deepwater basins. The Atlantic offshore deepwater basins and the offshore deepwater basins of the Neotethys structural domain have been controlled by the "east-west extension" and "north-south convergency" of the Earth since Mesozoic, respectively. The oil and gas discovered in deepwater basins of the world are distributed in a framework of "one vertical and one horizontal" arrangements, namely, the oil is mainly

  17. Thraustochytrid protists degrade hydrocarbons

    Digital Repository Service at National Institute of Oceanography (India)

    Raikar, M.T.; Raghukumar, S.; Vani, V.; David, J.J.; Chandramohan, D.

    Although thraustochytrid protists are known to be of widespread occurrence in the sea, their hydrocarbon-degrading abilities have never been investigated. We isolated thraustochytrids from coastal waters and sediments of Goa coast by enriching MPN...

  18. The Distribution and the Origin of Oxygenated Non-Hydrocarbons in Soil Profiles in Beijing, China%北京典型土壤剖面含氧非烃化合物分布及成因

    Institute of Scientific and Technical Information of China (English)

    张枝焕; 杨晓洁; 万甜甜; 贺光秀; 朱雷

    2013-01-01

    根据对北京地区6个典型采样点土壤样品的试验分析结果,探讨了含氧非烃化合物的含量、组成及其在采样点剖面上的分布特征,并对其污染源进行了讨论.结果表明,检测到的含氧非烃化合物主要包括C6~C28正构烷酸类、C12~C28正构烷醇类、正构烷酸甲酯类、酞酸酸类、甾醇类和脱氢松香酸等.含氧非烃化合物总质量分数及各类化合物的质量分数均有随深度增大而降低的趋势,其中0~40 cm含氧非烃化合物总质量分数(4.539 ~60.689 μg/g)较高且变化明显,深度大于40 cm的土壤中降至<9.000 μg/g且均趋于稳定.各采样点含氧非烃化合物的总质量分数纵向变化特征与w(TOC)的变化趋势基本一致,表明w(TOC)是控制土壤中含氧非烃化合物分布的重要因素.不同采样点正构烷酸类化合物都以C16为主峰碳,次主峰碳为C18,除个别采样点表层土壤中高碳数正构烷酸存在较明显奇偶优势外,中低碳数正构烷酸偶碳优势不明显,推测其主要来源于化石燃料或原土中的有机质,部分高分子量正构烷酸来源于生物质;正构烷醇类以C22为主峰碳,并具有明显的偶碳优势,主要来源于植物或者微生物源等天然源;酞酸醋中DBP(邻苯二甲酸二丁基酯)、DEHP[邻苯二甲酸二(2-乙基己基)酯]和DIBP(邻苯二甲酸二异丁基酯)质量分数较高,其来源与这些化合物的人为使用有关;甾醇类以β-谷甾醇占优势,并且大部分集中在表层,主要为生物源.%Oxygenated non-hydrocarbons are widely distributed in soil environment and most of the species are toxic,teratogenetic and persistent.They could be fatally harmful to soil ecosystem and human health.Recently,many studies reported that oxygenated nonhydrocarbons widely existed in different environments in Beijing.However,the distribution and the origin of those compounds in soil profiles still remain unclear.To investigate the

  19. Experimental study and evaluation on hydrocarbon generation of macerals

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Some typical coal and maceral samples are selected for oil and gas-generating systematic thermal simulation experiments, Rock-Eval, GC and GC-MS analyses. Results cause productivity curves of extracts and gaseous, light, liquid as well as total hydrocarbon. Effects of macerals and maturation on hydrocarbon productivities and compositions are synthetically discussed. Evaluation indexes and plan on coal-generated oil and gas in bituminous coal rank are suggested according to the data from experiments and analyses.

  20. Hydrocarbon composition products of the catalytic recycling plastics waste

    Directory of Open Access Journals (Sweden)

    Zhaksyntay Kairbekov

    2013-09-01

    Full Text Available The paper represents the IR spectroscopy results of the hydrocarbon composition of products, which is obtained from catalytic processing of plastic wastes. The optimal conditions for the hydrogenation with to producny liquid of products are identified.  These liquid products are enriched with aromatics, paraffinic- naphthenic and unsaturated hydrocarbons. The main characteristics of the distillates received by hydrogenation of plastics (as density, refractive index, iodine number, pour point, cloud point, filtering, sulfur content,  fractional and composition of the hydrocarbon group.

  1. Preliminary Geospatial Analysis of Arctic Ocean Hydrocarbon Resources

    Energy Technology Data Exchange (ETDEWEB)

    Long, Philip E.; Wurstner, Signe K.; Sullivan, E. C.; Schaef, Herbert T.; Bradley, Donald J.

    2008-10-01

    Ice coverage of the Arctic Ocean is predicted to become thinner and to cover less area with time. The combination of more ice-free waters for exploration and navigation, along with increasing demand for hydrocarbons and improvements in technologies for the discovery and exploitation of new hydrocarbon resources have focused attention on the hydrocarbon potential of the Arctic Basin and its margins. The purpose of this document is to 1) summarize results of a review of published hydrocarbon resources in the Arctic, including both conventional oil and gas and methane hydrates and 2) develop a set of digital maps of the hydrocarbon potential of the Arctic Ocean. These maps can be combined with predictions of ice-free areas to enable estimates of the likely regions and sequence of hydrocarbon production development in the Arctic. In this report, conventional oil and gas resources are explicitly linked with potential gas hydrate resources. This has not been attempted previously and is particularly powerful as the likelihood of gas production from marine gas hydrates increases. Available or planned infrastructure, such as pipelines, combined with the geospatial distribution of hydrocarbons is a very strong determinant of the temporal-spatial development of Arctic hydrocarbon resources. Significant unknowns decrease the certainty of predictions for development of hydrocarbon resources. These include: 1) Areas in the Russian Arctic that are poorly mapped, 2) Disputed ownership: primarily the Lomonosov Ridge, 3) Lack of detailed information on gas hydrate distribution, and 4) Technical risk associated with the ability to extract methane gas from gas hydrates. Logistics may control areas of exploration more than hydrocarbon potential. Accessibility, established ownership, and leasing of exploration blocks may trump quality of source rock, reservoir, and size of target. With this in mind, the main areas that are likely to be explored first are the Bering Strait and Chukchi

  2. Bioremediation of petroleum hydrocarbons: catabolic genes, microbial communities, and applications.

    Science.gov (United States)

    Fuentes, Sebastián; Méndez, Valentina; Aguila, Patricia; Seeger, Michael

    2014-06-01

    Bioremediation is an environmental sustainable and cost-effective technology for the cleanup of hydrocarbon-polluted soils and coasts. In spite of that longer times are usually required compared with physicochemical strategies, complete degradation of the pollutant can be achieved, and no further confinement of polluted matrix is needed. Microbial aerobic degradation is achieved by the incorporation of molecular oxygen into the inert hydrocarbon molecule and funneling intermediates into central catabolic pathways. Several families of alkane monooxygenases and ring hydroxylating dioxygenases are distributed mainly among Proteobacteria, Actinobacteria, Firmicutes and Fungi strains. Catabolic routes, regulatory networks, and tolerance/resistance mechanisms have been characterized in model hydrocarbon-degrading bacteria to understand and optimize their metabolic capabilities, providing the basis to enhance microbial fitness in order to improve hydrocarbon removal. However, microbial communities taken as a whole play a key role in hydrocarbon pollution events. Microbial community dynamics during biodegradation is crucial for understanding how they respond and adapt to pollution and remediation. Several strategies have been applied worldwide for the recovery of sites contaminated with persistent organic pollutants, such as polycyclic aromatic hydrocarbons and petroleum derivatives. Common strategies include controlling environmental variables (e.g., oxygen availability, hydrocarbon solubility, nutrient balance) and managing hydrocarbon-degrading microorganisms, in order to overcome the rate-limiting factors that slow down hydrocarbon biodegradation.

  3. Indexing Images.

    Science.gov (United States)

    Rasmussen, Edie M.

    1997-01-01

    Focuses on access to digital image collections by means of manual and automatic indexing. Contains six sections: (1) Studies of Image Systems and their Use; (2) Approaches to Indexing Images; (3) Image Attributes; (4) Concept-Based Indexing; (5) Content-Based Indexing; and (6) Browsing in Image Retrieval. Contains 105 references. (AEF)

  4. Inequality in the distribution of rheumatologists in Brazil: correlation with local of medical residency, Gross Domestic Product and Human Development Index.

    Science.gov (United States)

    de Albuquerque, Cleandro Pires

    2014-01-01

    To assess the distribution of rheumatologists in Brazil and their correlation with Medical Residency specialization offer, Gross Domestic Product (Gdp) And Municipal Human Development Index (HDI-M) of units of the federation (UFs). Query to various official databases, data summarization by techniques for descriptive statistics and cross-referenced information. For correlation analysis, we used the Spearman correlation coefficient (r). There were 1229 rheumatologists regularly registered in the country. The Northern region had only 3.6% of the total (n = 44), while the Southeast had 42.2% (n = 519). The State capitals, added to the five largest municipalities in each UF, concentrated 75.8% of these specialists (n = 931). In total, 49.9% of rheumatologists offered treatment at SUS. A general ratio of 157,809 inhabitants per rheumatologist in Brazil was determined, but with wide variation among UFs with respect to this ratio. In the years 2000-2012, there were 593 Rheumatology Residency graduated physicians in Brazil. We observed a positive correlation among number of rheumatologists compared with GDP (r = 0.94), HDI-M of the State capitals (r = 0.77) and number of Rheumatology Residency graduated physicians (r = 0.79) in UFs. We noted a strong concentration of rheumatologists in State capitals and larger municipalities, with noticeable inequalities also between UFs and country regions. The distribution of these professionals accompanied GDP, HDI-M of the State capital and number of Rheumatology Residency graduated physicians, suggesting that factors related to income opportunities and human development and the place of speciality training may influence the geographical fixation of rheumatologists.

  5. Analysis on accumulation, distribution and origin of polycyclic aromatic hydrocarbons in soils under a coking plant%焦化厂土壤中PAHs的累积、垂向分布特征及来源分析

    Institute of Scientific and Technical Information of China (English)

    贾晓洋; 姜林; 夏天翔; 姚珏君; 梁竞; 樊艳玲; 钟茂生

    2011-01-01

    Anthropogenic polycyclic aromatic hydrocarbons (PAHs) are one of the most major pollutants in soil under coking plants. In order to understand the characteristics of accumulation and vertical distribution of 16 USEPA priority PAHs in soil, GC/MS was used to analyze 16 PAHs in 587 soil samples taken from different depths of 0-18 m under coking plant. The results showed that, the highest and average concentration of total PAHs were 14363. 7 mg · kg-1 and 190. 4 mg · kg-1 respectively, indicating that the soil under coking plant had been polluted. The dominant components were low molecular weight PAHs, accounting for about 85%. The concentrations of PAHs had obvious fluctuation at various layers, and their concentration change was parallel. There was an obvious cumulative effect in 5-6 m soil layer, which might be due to different filtration capability of soil in different layers and PAHs leaching ability. Based on the principal component and Q-clustering analysis, the entire soil profile could be classified into 5 different layers: 0-1 m, 1-3 m, 3-5 m, 5-6 m, 6-18 m. The concentration order of low molecular weight PAHs was 5-6 m>0-1 m>3-5 m >1-3 m>6-18 m, whereas that of high molecular weight PAHs 0-1 m>5-6 m>1-3 m>3-5 m > 6-18 m. Assessment of the PAHs compound ratios, Ant/(Ant + Phe) and Flt/(Flt + Pyr), suggested that coal combustion was the main contamination source of the soil under this coking plant and the emission of coking gas and the leak of coal tar might also be primary contamination routes. In summary, the results in this paper illustrated the accumulation and distribution rules of PAHs in 0-18 m soil profile under a coking plant, and also provided some important data which would be used to manage the soil remediation and environment risk produced by coking industry.%引言多环芳烃(polycyclic aromatic hydrocarbons,PAHs)在环境中普遍存在,由于具有强烈的诱变、致癌和致畸作用而受到越来越多的关注[1].以

  6. 渤海湾盆地沾化凹陷富林洼陷油气来源及分布规律研究%Hydrocarbon origin and distribution regularity in Fulin sub-Sag, Zhanhua Sag, Bohai Bay Basin

    Institute of Scientific and Technical Information of China (English)

    王秀红

    2013-01-01

      通过对渤海湾盆地沾化凹陷富林洼陷原油的生物标志物分布与组合特征分析,认为该区主要存在3类原油:Ⅰ类原油主要分布于东次洼,呈植烷优势,伽马蜡烷含量高,重排甾烷与4-甲基甾烷含量较低,来源于东次洼本身的沙四上亚段烃源岩;Ⅱ类原油分布于中次洼洼陷内部,具有姥鲛烷优势、伽马蜡烷含量低、重排甾烷含量高的特征,纵向上不同储层油气来源存在差异,其中浅部储层油气来源于孤南洼陷沙三下亚段烃源岩,深部储层油气主要来自于富林洼陷沙三下亚段烃源岩;Ⅲ类原油分布于中次洼断裂带附近,成熟度较低,姥鲛烷优势,伽马蜡烷含量中等,C28甾烷含量丰富,孕甾烷和重排甾烷含量较低,为孤南洼陷沙一段与富林洼陷沙三下亚段烃源岩所形成的混源油。%Based on the studies of biomarker distribution and composition of crude oils in the Fulin sub-Sag of the Zhanhua Sag of the Bohai Bay Basin, there are 3 types of crude oil in the study area. The crude oils of typeⅠ mainly exist in the east of the sub-sag, characterized by low Pr/ Ph ratio, high gammacerence content as well as low diasterane and 4-methyl-sterane contents. They are originated from source rocks in the upper subsection of the 4th member of the Shahejie Formation in the east of the sub-sag. The crude oils of type Ⅱ mainly locate in the center of the sub-sag, featured by high Pr/ Ph ratio, low gammacerence content and high diasterane content. The origin for oil and gas is different vertically. Hydrocarbon in the middle and shallow reservoirs is mainly origi-nated from source rocks in the lower subsection of the 3rd member of the Shahejie Formation in the Gunan sub-Sag while hydrocarbon in the deep reservoir is mainly originated from source rocks in the lower subsection of the 3rd member of the Shahejie Formation in the Fulin sub-Sag. The crude oils of type Ⅲ mainly distribute around fault

  7. Distribution of genotypes C825T polymorphism G-protein β3-subunit gene in patients with hypertension depending on body mass index

    Directory of Open Access Journals (Sweden)

    Prystupa L.N.

    2015-09-01

    Full Text Available The aim of the study was to investigate the frequency of genotypes of C825T polymorphism G-protein β3-subunit gene (GNB3 in patients with arterial hypertension (AH, depending on body mass index (BMI. The study involved 155 patients with verified diagnosis of AH (study group and 50 healthy individuals (control group. The patients of the main group were divided into 3 groups according to BMI: I - 35 patients with normal body weight, II - 38 patients with overweight, III - 82 patients with obesity. We used general clinical, anthropometric, instrumental, molecular-genetic and statistical methods. Probability of differences in the frequency of alleles and genotypes was determined using χ² criteria. Pairwise comparison of groups was made using nonparametric Mann-Whitney test. The difference was considered statistically significant at p <0,05. Investigation of the distribution of genotypes C825T polymorphism GNB3 in patients with AH according to BMI showed statistically significant increase in the frequency of genotypes C / T and T / T and T allele in patients with overweight and obesity as compared with patients with normal body weight (χ² = 26 8; p <0.001. The risk of weight increase in AH patients with T allele carriers is 2,2 times higher than in C allele carriers. Association of C825T polymorphism of GNB3 with a tendency to obesity and overweight in patients with AH was proved.

  8. Spatial distribution of tree species governs the spatio-temporal interaction of leaf area index and soil moisture across a forested landscape.

    Directory of Open Access Journals (Sweden)

    Kusum J Naithani

    Full Text Available Quantifying coupled spatio-temporal dynamics of phenology and hydrology and understanding underlying processes is a fundamental challenge in ecohydrology. While variation in phenology and factors influencing it have attracted the attention of ecologists for a long time, the influence of biodiversity on coupled dynamics of phenology and hydrology across a landscape is largely untested. We measured leaf area index (L and volumetric soil water content (θ on a co-located spatial grid to characterize forest phenology and hydrology across a forested catchment in central Pennsylvania during 2010. We used hierarchical Bayesian modeling to quantify spatio-temporal patterns of L and θ. Our results suggest that the spatial distribution of tree species across the landscape created unique spatio-temporal patterns of L, which created patterns of water demand reflected in variable soil moisture across space and time. We found a lag of about 11 days between increase in L and decline in θ. Vegetation and soil moisture become increasingly homogenized and coupled from leaf-onset to maturity but heterogeneous and uncoupled from leaf maturity to senescence. Our results provide insight into spatio-temporal coupling between biodiversity and soil hydrology that is useful to enhance ecohydrological modeling in humid temperate forests.

  9. Spatial distribution of tree species governs the spatio-temporal interaction of leaf area index and soil moisture across a forested landscape.

    Science.gov (United States)

    Naithani, Kusum J; Baldwin, Doug C; Gaines, Katie P; Lin, Henry; Eissenstat, David M

    2013-01-01

    Quantifying coupled spatio-temporal dynamics of phenology and hydrology and understanding underlying processes is a fundamental challenge in ecohydrology. While variation in phenology and factors influencing it have attracted the attention of ecologists for a long time, the influence of biodiversity on coupled dynamics of phenology and hydrology across a landscape is largely untested. We measured leaf area index (L) and volumetric soil water content (θ) on a co-located spatial grid to characterize forest phenology and hydrology across a forested catchment in central Pennsylvania during 2010. We used hierarchical Bayesian modeling to quantify spatio-temporal patterns of L and θ. Our results suggest that the spatial distribution of tree species across the landscape created unique spatio-temporal patterns of L, which created patterns of water demand reflected in variable soil moisture across space and time. We found a lag of about 11 days between increase in L and decline in θ. Vegetation and soil moisture become increasingly homogenized and coupled from leaf-onset to maturity but heterogeneous and uncoupled from leaf maturity to senescence. Our results provide insight into spatio-temporal coupling between biodiversity and soil hydrology that is useful to enhance ecohydrological modeling in humid temperate forests.

  10. Allelic frequency distributions of 21 non-combined DNA index system STR loci in a Russian ethnic minority group from Inner Mongolia, China

    Institute of Scientific and Technical Information of China (English)

    Hong-dan WANG; Chun-mei SHEN; Wen-juan LIU; Yu-dang ZHANG; Guang YANG; Jiang-wei YAN; Hai-xia QIN

    2013-01-01

    We studied the allelic frequency distributions and statistical forensic parameters of 21 new short tandem repeat (STR) loci and the amelogenin locus,which are not included in the combined DNA index system (CODIS),in a Russian ethnic minority group from the Inner Mongolia Autonomous Region,China.A total of 114 bloodstain samples from unrelated individuals were extracted and co-amplified with four fluorescence-labeled primers in a multiplex polymerase chain reaction (PCR) system.Using capillary electrophoresis,the PCR products of the 21 STR loci were separated and genotyped.A total of 161 alleles were observed in the Russian ethnic minority group,and corresponding allelic frequencies ranged from 0.0044 to 0.5965.The 21 non-CODIS STR loci of the Russian ethnic minority group were characterized by high genetic diversity and therefore may be useful for elucidating the population's genetic background,for individual identification,and for paternity testing in forensic practice.

  11. Influence of climatic conditions, topography and soil attributes on the spatial distribution of site productivity index of the species rich forests of Jalisco, Mexico

    Institute of Scientific and Technical Information of China (English)

    Adel Mohamed; Robin M. Reich; Raj Khosla; C. Aguirre-Bravo; Martin Mendoza Briseño

    2014-01-01

    This paper presents an approach based on field data to model the spatial distribution of the site productivity index (SPI) of the diverse forest types in Jalisco, Mexico and the response in SPI to site and cli-matic conditions. A linear regression model was constructed to test the hypothesis that site and climate variables can be used to predict the SPI of the major forest types in Jalisco. SPI varied significantly with topog-raphy (elevation, aspect and slope), soil attributes (pH, sand and silt), climate (temperature and precipitation zones) and forest type. The most important variable in the model was forest type, which accounted for 35% of the variability in SPI. Temperature and precipitation accounted for 8 to 9% of the variability in SPI while the soil attributes accounted for less than 4% of the variability observed in SPI. No significant differences were detected between the observed and predicted SPI for the individual forest types. The linear regression model was used to develop maps of the spatial variability in predicted SPI for the individual forest types in the state. The spatial site productivity models developed in this study provides a basis for understanding the complex relationship that exists between forest productivity and site and climatic conditions in the state. Findings of this study will assist resource managers in making cost-effective decisions about the management of individual forest types in the state of Jalisco, Mexico.

  12. 应用分布式索引提高海量数据查询性能%Improve Big Data Query Performance by Applying Distributed Indexing

    Institute of Scientific and Technical Information of China (English)

    窦晓峰; 陈胜; 王熠航; 麦联叨; 由建宏

    2014-01-01

    In the field of telecommunications precision marketing and ad-hoc query, there are a lot of random queries scenarios on one or more wide-tables (which have more than 50 fields). In the traditional system (the queries are performed on the database directly), the query response time can be optimized less than a few seconds to tens of seconds when the database records size is under 10 million. When the data size reaches tens of millions, hundreds of millions or even more than one billion records, whatever optimization including changing indexing mechanism are unable to meet the second-level concurrency query requirements. In the new query system, we introduce the Solr distributed index layer to solve these problems. The layer will index the database records firstly and queries will access the Solr index layer and not perform on the database directly, therefore, the performance will be improved highly. After a comparison of the two processing patterns in same environment, for the data of 50 million, 20 per concurrent access query scenario, the traditional accessing queries all are timeout; while the other’s queries can be returned within 2 seconds and all are success.%在电信领域的精准化营销、即席查询业务中,存在着大量针对一张宽表或几张宽表(超过50字段)的随机查询场景。传统处理模式(直接查询数据库)在数据量不大(<1000万)时,查询响应时间可优化到几秒至数十秒级,而当数据量到达几千万、上亿甚至十亿记录以上时,此处理模式无论如何优化或更改索引机制,都无法满足秒级并发查询要求。新的处理模式通过引入分布式 Solr 索引层解决上述问题。索引层预先对数据库记录建立索引,查询不再作用于数据库而直接查询索引层,如此,可大幅提高查询性能。经过对两种处理模式的对比验证,在相同环境下,数据量到达5000万,每秒20并发访问的宽表查询场景,传统处理

  13. An investigation into the occurrence and distribution of polycyclic aromatic hydrocarbons in two soil size fractions at a former industrial site in NE England, UK using in situ PFE-GC-MS.

    Science.gov (United States)

    Lorenzi, Damien; Cave, Mark; Dean, John R

    2010-12-01

    Polycyclic aromatic hydrocarbon (PAH) concentrations were determined in 16 topsoils (0-10 cm) collected across the site of a former tar works in NE England. The soils were prepared in the laboratory to two different particle size fractions: 250 μm to PFE) followed by gas chromatography-mass spectrometry (GC-MS). The average total PAH concentration in the soils ranged from 9.0 to 1,404 mg/kg (soil fraction A) and from 6.6 to 872 mg/kg (soil fraction B). These concentrations are high compared with other industrially contaminated soils reported in the international literature, indicating that the tar works warrants further investigation/remediation. A predominance of higher-molecular-weight compounds was determined in the samples, suggesting that the PAHs were of pyrogenic (anthropogenic) origin. Statistical comparison (t-test) of the mean total PAH concentrations in soil fractions A and B indicated that there was a significant difference (95% confidence interval) between the fractions in all but two of the soil samples. Additionally, comparisons of the distributions of individual PAHs (i.e. 16 PAHs × 16 soil samples) in soil fractions A and B demonstrated generally higher PAH concentrations in fraction A (i.e. 65.8% of all individual PAH concentrations were higher in soil fraction A). This is important because fraction A corresponds to the particle size thought to be most important in terms of human contact with soils and potential threats to human health.

  14. Population distribution of the sagittal abdominal diameter (SAD from a representative sample of US adults: comparison of SAD, waist circumference and body mass index for identifying dysglycemia.

    Directory of Open Access Journals (Sweden)

    Henry S Kahn

    Full Text Available The sagittal abdominal diameter (SAD measured in supine position is an alternative adiposity indicator that estimates the quantity of dysfunctional adipose tissue in the visceral depot. However, supine SAD's distribution and its association with health risk at the population level are unknown. Here we describe standardized measurements of SAD, provide the first, national estimates of the SAD distribution among US adults, and test associations of SAD and other adiposity indicators with prevalent dysglycemia.In the 2011-2012 National Health and Nutrition Examination Survey, supine SAD was measured ("abdominal height" between arms of a sliding-beam caliper at the level of the iliac crests. From 4817 non-pregnant adults (age ≥ 20; response rate 88% we used sample weights to estimate SAD's population distribution by sex and age groups. SAD's population mean was 22.5 cm [95% confidence interval 22.2-22.8]; median was 21.9 cm [21.6-22.4]. The mean and median values of SAD were greater for men than women. For the subpopulation without diagnosed diabetes, we compared the abilities of SAD, waist circumference (WC, and body mass index (BMI, kg/m(2 to identify prevalent dysglycemia (HbA1c ≥ 5.7%. For age-adjusted, logistic-regression models in which sex-specific quartiles of SAD were considered simultaneously with quartiles of either WC or BMI, only SAD quartiles 3 (p<0.05 vs quartile 1 and 4 (p<0.001 vs quartile 1 remained associated with increased dysglycemia. Based on continuous adiposity indicators, analyses of the area under the receiver operating characteristic curve (AUC indicated that the dysglycemia model fit for SAD (age-adjusted was 0.734 for men (greater than the AUC for WC, p<0.001 and 0.764 for women (greater than the AUC for WC or BMI, p<0.001.Measured inexpensively by bedside caliper, SAD was associated with dysglycemia independently of WC or BMI. Standardized SAD measurements may enhance assessment of dysfunctional adiposity.

  15. 智能配电网评估指标体系的构建%Assessment index system for smart distribution grids

    Institute of Scientific and Technical Information of China (English)

    王敬敏; 施婷

    2012-01-01

    Assessing the smart distribution grid can measure the effect of its construction and provide experience and building basis for the future smart grid. The need for assessment of smart grid construction impact is introduced. Based on domestic characteristics and research objectives of smart distribution grids, a framework of comprehensive multi-factor assessment and related quantitative formula are provided. Some important definitions and quantitative formulas of e-valuation index are given. The assessment system contains five first grade indices, including reliability and power quality , flexibility and coordination development, utilization and technical equipment as well as economic and social benefits of smart distribution grid. It can provide more objective, comprehensive, and systematic assessment to smart grid construction compared to the traditional evaluation system.%对智能配电网的评估既是事前引导,可以衡量智能配电网的建设效果,同时也是事后总结,能为今后智能电网的建设提供经验和依据.简要介绍了智能配电网建设效果评估的必要性,基于智能配电网的特性和研究目标,结合我国经济社会发展对智能配电网建设的实际需要,从可靠性和电能质量、发展灵活性、协调性和互动性、设备利用率和技术装备水平以及经济性和社会效益5个方面构建了智能配电网三级评估指标体系的初步框架,并给出部分重要评估指标的定义和量化公式.与传统配电网评估指标体系相比,该体系能更为全面、系统的评估智能配电网实际建设效果.

  16. Quantitative Hydrocarbon Surface Analysis

    Science.gov (United States)

    Douglas, Vonnie M.

    2000-01-01

    The elimination of ozone depleting substances, such as carbon tetrachloride, has resulted in the use of new analytical techniques for cleanliness verification and contamination sampling. The last remaining application at Rocketdyne which required a replacement technique was the quantitative analysis of hydrocarbons by infrared spectrometry. This application, which previously utilized carbon tetrachloride, was successfully modified using the SOC-400, a compact portable FTIR manufactured by Surface Optics Corporation. This instrument can quantitatively measure and identify hydrocarbons from solvent flush of hardware as well as directly analyze the surface of metallic components without the use of ozone depleting chemicals. Several sampling accessories are utilized to perform analysis for various applications.

  17. Miscellaneous hydrocarbon solvents.

    Science.gov (United States)

    Bebarta, Vikhyat; DeWitt, Christopher

    2004-08-01

    The solvents discussed in this article are common solvents not categorized as halogenated, aromatic, or botanical. The solvents discussed are categorized into two groups: hydrocarbon mixtures and single agents. The hydrocarbon mixtures discussed are Stoddard solvent, naphtha, and kerosene. The remaining solvents described are n-hexane, methyl n-butyl ketone, dimethylformamide, dimethyl sulfoxide, and butyl mercaptans. Effects common to this group of agents and their unique effects are characterized. Treatment of exposures and toxic effects of these solvents is described, and physiochemical properties and occupational exposure levels are listed.

  18. Bioremediation of Petroleum Hydrocarbon Contaminated Sites

    Energy Technology Data Exchange (ETDEWEB)

    Fallgren, Paul

    2009-03-30

    Bioremediation has been widely applied in the restoration of petroleum hydrocarbon-contaminated. Parameters that may affect the rate and efficiency of biodegradation include temperature, moisture, salinity, nutrient availability, microbial species, and type and concentration of contaminants. Other factors can also affect the success of the bioremediation treatment of contaminants, such as climatic conditions, soil type, soil permeability, contaminant distribution and concentration, and drainage. Western Research Institute in conjunction with TechLink Environmental, Inc. and the U.S. Department of Energy conducted laboratory studies to evaluate major parameters that contribute to the bioremediation of petroleum-contaminated drill cuttings using land farming and to develop a biotreatment cell to expedite biodegradation of hydrocarbons. Physical characteristics such as soil texture, hydraulic conductivity, and water retention were determined for the petroleum hydrocarbon contaminated soil. Soil texture was determined to be loamy sand to sand, and high hydraulic conductivity and low water retention was observed. Temperature appeared to have the greatest influence on biodegradation rates where high temperatures (>50 C) favored biodegradation. High nitrogen content in the form of ammonium enhanced biodegradation as well did the presence of water near field water holding capacity. Urea was not a good source of nitrogen and has detrimental effects for bioremediation for this site soil. Artificial sea water had little effect on biodegradation rates, but biodegradation rates decreased after increasing the concentrations of salts. Biotreatment cell (biocell) tests demonstrated hydrocarbon biodegradation can be enhanced substantially when utilizing a leachate recirculation design where a 72% reduction of hydrocarbon concentration was observed with a 72-h period at a treatment temperature of 50 C. Overall, this study demonstrates the investigation of the effects of

  19. The presence and distribution of polycyclic aromatic hydrocarbons and inorganic elements in water and lakebed materials and the potential for bioconcentration in biota at established sampling sites on Lake Powell, Utah and Arizona

    Science.gov (United States)

    Schonauer, Kurt T.; Hart, Robert J.; Antweiler, Ronald C.

    2014-01-01

    The National Park Service is responsible for monitoring the effects of visitor use on the quality of water, lakebed material (bottom sediments), and biota, in Lake Powell, Utah and Arizona. A sampling program was begun in 2010 to assess the presence, distribution, and concentrations of organic and inorganic compounds in the water column and bottom sediment. In response to an Environmental Impact Statement regarding personal watercraft and as a continuation from previous studies by the U.S. Geological Survey and the National Park Service, Glen Canyon National Recreation Area, water samples were collected and analyzed for polycyclic aromatic hydrocarbons (PAHs) using semipermeable membrane devices and inorganic elements using a fixed-bottle sampler deployed at established monitoring sites during 2010 and 2011. Lakebed material samples were also analyzed for polycyclic aromatic hydrocarbons and inorganic elements, some of which could be harmful to aquatic biota if present at concentrations above established aquatic life criteria. Of the 44 PAH compounds analyzed, 26 individual compounds were detected above the censoring limit in the water column by semipermeable membrane devices. The highest number of compounds detected were at Lone Rock Beach, Wahweap Marina, Rainbow Bridge National Monument, and Antelope Marina which are all located in the southern part of Lake Powell where visitation and boat use is high. Because PAHs can remain near their source, the potential for bioconcentration is highest near these sites. The PAH compound found in the highest concentration was phenol (5,902 nanograms per liter), which is included in the U.S. Environmental Protection Agency’s priority pollutants list. The dissolved inorganic chemistry of water samples measured at the sampling sites in Lake Powell defined three different patterns of elements: (1) concentrations were similar between sites in the upper part of the lake near Farley Canyon downstream to Halls Crossing Marina, a

  20. Apparatus and methods for hydrocarbon extraction

    Science.gov (United States)

    Bohnert, George W.; Verhulst, Galen G.

    2016-04-26

    Systems and methods for hydrocarbon extraction from hydrocarbon-containing material. Such systems and methods relate to extracting hydrocarbon from hydrocarbon-containing material employing a non-aqueous extractant. Additionally, such systems and methods relate to recovering and reusing non-aqueous extractant employed for extracting hydrocarbon from hydrocarbon-containing material.

  1. Optrode for sensing hydrocarbons

    Science.gov (United States)

    Miller, Holly; Milanovich, Fred P.; Hirschfeld, Tomas B.; Miller, Fred S.

    1987-01-01

    A two-phase system employing the Fujiwara reaction is provided for the fluorometric detection of halogenated hydrocarbons. A fiber optic is utilized to illuminate a column of pyridine trapped in a capillary tube coaxially attached at one end to the illuminating end of the fiber optic. A strongly alkaline condition necessary for the reaction is maintained by providing a reservoir of alkali in contact with the column of pyridine, the surface of contact being adjacent to the illuminating end of the fiber optic. A semipermeable membrane caps the other end of the capillary tube, the membrane being preferentially permeable to the halogenated hydrocarbon and but preferentially impermeable to water and pyridine. As the halogenated hydrocarbon diffuses through the membrane and into the column of pyridine, fluorescent reaction products are formed. Light propagated by the fiber optic from a light source, excites the fluorescent products. Light from the fluorescence emission is also collected by the same fiber optic and transmitted to a detector. The intensity of the fluorescence gives a measure of the concentration of the halogenated hydrocarbons.

  2. Analysis of Neogene sequence-structure control over hydrocarbon distribution and accumulation in Huanghekou sag%层序—构造对黄河口凹陷新近系油气分布及成藏的控制作用

    Institute of Scientific and Technical Information of China (English)

    于海波; 王德英; 牛成民; 曾萱; 黄江波

    2012-01-01

    The hydrocarbon is mainly distributed in shallow water delta system of N1m1 in the Huanghekou sag. The hydrocarbon distribution and accumulation are analyzed according to sequence - structure herein. The lower member of Minghuazhen Formation is recognized as 3 long-term cycles and 8 middle-term cycles with high resolution sequence stratigraphy in Neogene. The early phase of ascending half cycles and middle-late phase of descending half cycles form sandbodies development favorable position are the main position of hydrocarbon distribution. Structure setting controls the direction of hydrocarbon migration, and positive structure zones are favorable areas of petroleum migration and accumulation. The faults of connecting deep and shallow strata are the main pathway of petroleum migrating to Neogene in the vertical direction. And, the late-stage faults adjust and distribute hydrocarbon. The sequence-structure controls the hydrocarbon accumulation layer and enrichment degree, and the good matching relation between faults (especially oil-migrating faults) and reservoir-seal assemblage is the main reason accounting for high hydrocarbon accumulation. The sequence-structure determine the effectiveness of the Neogene traps, and formed lithologic-structure, structure-lithologic and lithologic hydrocarbon reservoir.%黄河口凹陷的油气主要分布于新近系明化镇组下段的浅水三角洲沉积体系,从层序—构造角度对其油气分布及成藏进行分析.高分辨率层序地层分析表明,明下段可划分为3个长期基准面旋回和8个中期基准面旋回,基准面上升半旋回早期和下降半旋回中、晚期是储集砂体发育的有利部位,也是油气分布的主要部位;构造背景控制了油气的运移指向,正向构造带是油气长期运移、聚集成藏的有利地区,纵贯深、浅层的断裂是油气垂向运移至新近系的主要通道,晚期断裂主要对油气起到调整和再分配的作用.层序—构造耦

  3. Distribution of body mass index among subjects with COPD in the Middle East and North Africa region: data from the BREATHE study

    Directory of Open Access Journals (Sweden)

    Koniski ML

    2015-08-01

    Full Text Available Marie-Louise Koniski,1 Hocine Salhi,2 Aïcha Lahlou,3 Nauman Rashid,4 Abdelkader El Hasnaoui4 1Respiratory Division, Lebanese American University Medical Center – Rizk Hospital, Beirut, Lebanon; 2Foxymed, Paris, France; 3MS Health, Rabat, Morocco; 4GlaxoSmithKline, Dubai, United Arab Emirates Background: Data describing the potential relationship between chronic obstructive pulmonary disease (COPD and body mass index (BMI are limited within the Middle East and North Africa (MENA region. Objective: To evaluate the distribution of BMI among subjects with COPD in the general population of the MENA region. Methods: This study was a subanalysis of the BREATHE study, a cross-sectional survey of COPD conducted in the general population of ten countries in the MENA region and Pakistan. The study population consisted of subjects screened for COPD who documented their weight and height. A COPD questionnaire was administered to subjects who screened positively for COPD in order to collect data on patient characteristics, symptom severity, management and burden of disease, comorbidities, and health care resource utilization and data allowing calculation of the BMI. The COPD Assessment Test (CAT was administered to those screened positively for COPD to collect data on the impact of respiratory symptoms. Results: Nine hundred and ninety-six subjects with COPD, who completed the detailed COPD questionnaire and documented their weight and height, were included in this analysis. The mean BMI was 27.7±5.7 kg/m2. The proportion of COPD patients with a BMI ≥25 kg/m2 is significantly higher than the proportion with a BMI <25 kg/m2 (64.6% [n=643] vs 35.4% [n=353], respectively; P<0.0001. There were no significant differences between the distribution of BMI, ages, sex, COPD symptoms, exacerbations, CAT scores, COPD-associated health care resource consumption, and GOLD severity groups. However, the occurrence of comorbidities such as diabetes and cardiovascular

  4. Mantle hydrocarbons: abiotic or biotic?

    Science.gov (United States)

    Sugisaki, R; Mimura, K

    1994-06-01

    Analyses of 227 rocks from fifty localities throughout the world showed that mantle derived rocks such as tectonized peridotites in ophiolite sequences (tectonites) arid peridotite xenoliths in alkali basalts contain heavier hydrocarbons (n-alkanes), whereas igneous rocks produced by magmas such as gabbro arid granite lack them. The occurrence of hydrocarbons indicates that they were not derived either from laboratory contamination or from held contamination; these compounds found in the mantle-derived rocks are called here "mantle hydrocarbons." The existence of hydrocarbons correlates with petrogenesis. For example, peridotite cumulates produced by magmatic differentiation lack hydrocarbons whereas peridotite xenoliths derived from the mantle contain them. Gas chromatographic-mass spectrometric records of the mantle hydrocarbons resemble those of aliphatics in meteorites and in petroleum. Features of the hydrocarbons are that (a) the mantle hydrocarbons reside mainly along grain boundaries and in fluid inclusions of minerals; (b) heavier isoprenoids such as pristane and phytane are present; and (c) delta 13C of the mantle hydrocarbons is uniform (about -27%). Possible origins for the mantle hydrocarbons are as follows. (1) They were in organically synthesized by Fischer-Tropsch type reaction in the mantle. (2) They were delivered by meteorites and comets to the early Earth. (3) They were recycled by subduction. The mantle hydrocarbons in the cases of (1) and (2) are abiogenic and those in (3) are mainly biogenic. It appears that hydrocarbons may survive high pressures and temperatures in the mantle, but they are decomposed into lighter hydrocarbon gases such as CH4 at lower pressures when magmas intrude into the crust; consequently, peridotite cumulates do not contain heavier hydrocarbons but possess hydrocarbon gases up to C4H10.

  5. Analysis of hydrocarbons generated in coalbeds

    Science.gov (United States)

    Butala, Steven John M.

    This dissertation describes kinetic calculations using literature data to predict formation rates and product yields of oil and gas at typical low-temperature conditions in coalbeds. These data indicate that gas formation rates from hydrocarbon thermolysis are too low to have generated commercial quantities of natural gas, assuming bulk first-order kinetics. Acid-mineral-catalyzed cracking, transition-metal-catalyzed hydrogenolysis of liquid hydrocarbons, and catalyzed CO2 hydrogenation form gas at high rates. The gaseous product compositions for these reactions are nearly the same as those for typical natural coalbed gases, while those from thermal and catalytic cracking are more representative of atypical coalbed gases. Three Argonne Premium Coals (Upper-Freeport, Pittsburgh #8 and Lewiston-Stockton) were extracted with benzene in both Soxhlet and elevated pressure extraction (EPE) systems. The extracts were compared on the basis of dry mass yield and hydrocarbon profiles obtained by gas chromatography/mass spectrometry. The dry mass yields for the Upper-Freeport coal gave consistent results by both methods, while the yields from the Pittsburgh #8 and Lewiston-Stockton coals were greater by the EPE method. EPE required ˜90 vol. % less solvent compared to Soxhlet extraction. Single-ion-chromatograms of the Soxhlet extracts all exhibited bimodal distributions, while those of the EPE extracts did not. Hydrocarbons analyzed from Greater Green River Basin samples indicate that the natural oils in the basin originated from the coal seams. Analysis of artificially produced oil indicates that hydrous pyrolysis mimics generation of C15+ n-alkanes, but significant variations were found in the branched alkane, low-molecular-weight n-alkanes, and high-molecular-weight aromatic hydrocarbon distributions.

  6. Hydrocarbon charge history of the Paleogene reservoir in the northern Dongpu Depression, Bohai Bay Basin, China

    Directory of Open Access Journals (Sweden)

    You-Lu Jiang

    2016-11-01

    Full Text Available Abstract The hydrocarbon charge history of the Paleogene in the northern Dongpu Depression was analyzed in detail based on a comprehensive analysis of the generation and expulsion history of the major hydrocarbon source rocks, fluorescence microscopic features and fluid inclusion petrography. There were two main stages of hydrocarbon generation and expulsion of oil from the major hydrocarbon source rocks. The first stage was the main hydrocarbon expulsion stage. The fluorescence microscopic features also indicated two stages of hydrocarbon accumulation. Carbonaceous bitumen, asphaltene bitumen and colloidal bitumen reflected an early hydrocarbon charge, whereas the oil bitumen reflected a second hydrocarbon charge. Hydrocarbon inclusions also indicate two distinct charges according to the diagenetic evolution sequence, inclusion petrography features combined with the homogenization temperature and reservoir burial history analysis. According to these comprehensive analysis results, the hydrocarbon charge history of the Paleogene reservoir in the northern Dongpu Depression was divided into two phases. The first phase was from the late Dongying depositional period of the Oligocene to the early uplift stages of the late Paleogene. The second phase was from the late Minghuazhen period of the Pliocene to the Quaternary. Reservoirs formed during the first period were widely distributed covering the entire area. In contrast, reservoirs formed during the second period were mainly distributed near the hydrocarbon generation sags. Vertically, it was characterized by a single phase in the upper layers and two phases in the lower layers of the Paleogene.

  7. Geochemical Significance and Distribution Characterisitics of Polycyclic Aromatic Hydrocarbons from the Jurassic Source Rocks in the Heshituoluogai Basin,Northwest Junggar%准噶尔盆地西北部和什托落盖盆地侏罗系烃源岩芳烃分布特征及地球化学意义

    Institute of Scientific and Technical Information of China (English)

    刘洪军; 秦黎明; 张枝焕

    2012-01-01

    研究了准噶尔盆地西北部和什托落盖盆地侏罗系煤系烃源岩多环芳烃的分布规律。结果表明,该区侏罗系烃源岩中多环芳烃分布广泛,两环芳烃至六环芳烃以及七环芳烃均有分布,单体芳烃主要以四环芳烃和五环芳烃的含量较高,其次为两环芳烃和三环芳烃。研究还表明煤和泥岩的多环芳烃分布极易受沉积相差异发生明显变化,比如侏罗系八道湾组泥岩菲、荧蒽、芘、艹屈、苯并荧蒽与苯并[e]芘的丰度均较高,西山窑组泥岩苝的丰度明显偏高于其余化合物;而八道湾组煤中蒽、芘、苯并[a]芴以及苯并荧蒽丰度较高,西山窑组煤中苯并荧蒽、苯并[e]芘和苯并[a]芴的丰度偏高。另外煤的萘与二苯并噻吩成熟度参数值明显高于泥岩,并且与Pr/Ph值和δ13Caro值呈正相关,与四环芳烃和五环芳烃参数值呈负相关,进一步研究表明多环芳烃比值极易受到有机相类型差异分布影响,仅菲的参数值差异小,泥岩RC值与实测RO值相近,二苯并噻吩/菲值与Pr/Ph值关系和OF/(OF+F)值与SF/(SF+F)值关系反映了侏罗系浅湖相至河流相或三角洲相为开阔水体的弱氧化—强氧化沉积环境。%According to the GC-MS analysis and identification of aromatic hydrocarbon,the distribution of aromatic hydrocarbons is investigated.The results indicate that the distribution of aromatic hydrocarbons is extensive from dinuclear aromatics to heptacyclic aromatics.The relative abundance of tetracyclic and pentacyclic aromatics is apparently higher than that of dinuclear and tricyclic aromatics in Jurassic source rocks.The distribution of PAH in mudstone and coal is easily affected by the sedimentary facies.The relative content of phenanthrene,fluoranthene,pyrene,chrysene,benzofluoranthene and benzo[e]pyrene is higher than other compounds in the mudstone from Badaowan Formation,but in Xishanyao Formation,the content of perylene is

  8. Volatile hydrocarbons and fuel oxygenates: Chapter 12

    Science.gov (United States)

    Cozzarelli, Isabelle M.

    2014-01-01

    Petroleum hydrocarbons and fuel oxygenates are among the most commonly occurring and widely distributed contaminants in the environment. This chapter presents a summary of the sources, transport, fate, and remediation of volatile fuel hydrocarbons and fuel additives in the environment. Much research has focused on the transport and transformation processes of petroleum hydrocarbons and fuel oxygenates, such as benzene, toluene, ethylbenzene, and xylenes and methyl tert‐butyl ether, in groundwater following release from underground storage tanks. Natural attenuation from biodegradation limits the movement of these contaminants and has received considerable attention as an environmental restoration option. This chapter summarizes approaches to environmental restoration, including those that rely on natural attenuation, and also engineered or enhanced remediation. Researchers are increasingly combining several microbial and molecular-based methods to give a complete picture of biodegradation potential and occurrence at contaminated field sites. New insights into the fate of petroleum hydrocarbons and fuel additives have been gained by recent advances in analytical tools and approaches, including stable isotope fractionation, analysis of metabolic intermediates, and direct microbial evidence. However, development of long-term detailed monitoring programs is required to further develop conceptual models of natural attenuation and increase our understanding of the behavior of contaminant mixtures in the subsurface.

  9. Superconductivity in aromatic hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Kubozono, Yoshihiro, E-mail: kubozono@cc.okayama-u.ac.jp [Research Laboratory for Surface Science, Okayama University, Okayama 700-8530 (Japan); Research Center of New Functional Materials for Energy Production, Storage and Transport, Okayama University, Okayama 700-8530 (Japan); Japan Science and Technology Agency, ACT-C, Kawaguchi 332-0012 (Japan); Goto, Hidenori; Jabuchi, Taihei [Research Laboratory for Surface Science, Okayama University, Okayama 700-8530 (Japan); Yokoya, Takayoshi [Research Laboratory for Surface Science, Okayama University, Okayama 700-8530 (Japan); Research Center of New Functional Materials for Energy Production, Storage and Transport, Okayama University, Okayama 700-8530 (Japan); Kambe, Takashi [Department of Physics, Okayama University, Okayama 700-8530 (Japan); Sakai, Yusuke; Izumi, Masanari; Zheng, Lu; Hamao, Shino; Nguyen, Huyen L.T. [Research Laboratory for Surface Science, Okayama University, Okayama 700-8530 (Japan); Sakata, Masafumi; Kagayama, Tomoko; Shimizu, Katsuya [Center of Science and Technology under Extreme Conditions, Osaka University, Osaka 560-8531 (Japan)

    2015-07-15

    Highlights: • Aromatic superconductor is one of core research subjects in superconductivity. Superconductivity is observed in certain metal-doped aromatic hydrocarbons. Some serious problems to be solved exist for future advancement of the research. This article shows the present status of aromatic superconductors. - Abstract: ‘Aromatic hydrocarbon’ implies an organic molecule that satisfies the (4n + 2) π-electron rule and consists of benzene rings. Doping solid aromatic hydrocarbons with metals provides the superconductivity. The first discovery of such superconductivity was made for K-doped picene (K{sub x}picene, five benzene rings). Its superconducting transition temperatures (T{sub c}’s) were 7 and 18 K. Recently, we found a new superconducting K{sub x}picene phase with a T{sub c} as high as 14 K, so we now know that K{sub x}picene possesses multiple superconducting phases. Besides K{sub x}picene, we discovered new superconductors such as Rb{sub x}picene and Ca{sub x}picene. A most serious problem is that the shielding fraction is ⩽15% for K{sub x}picene and Rb{sub x}picene, and it is often ∼1% for other superconductors. Such low shielding fractions have made it difficult to determine the crystal structures of superconducting phases. Nevertheless, many research groups have expended a great deal of effort to make high quality hydrocarbon superconductors in the five years since the discovery of hydrocarbon superconductivity. At the present stage, superconductivity is observed in certain metal-doped aromatic hydrocarbons (picene, phenanthrene and dibenzopentacene), but the shielding fraction remains stubbornly low. The highest priority research area is to prepare aromatic superconductors with a high superconducting volume-fraction. Despite these difficulties, aromatic superconductivity is still a core research target and presents interesting and potentially breakthrough challenges, such as the positive pressure dependence of T{sub c} that is clearly

  10. Membrane separation of hydrocarbons

    Science.gov (United States)

    Chang, Y. Alice; Kulkarni, Sudhir S.; Funk, Edward W.

    1986-01-01

    Mixtures of heavy oils and light hydrocarbons may be separated by passing the mixture through a polymeric membrane. The membrane which is utilized to effect the separation comprises a polymer which is capable of maintaining its integrity in the presence of hydrocarbon compounds and which has been modified by being subjected to the action of a sulfonating agent. Sulfonating agents which may be employed will include fuming sulfuric acid, chlorosulfonic acid, sulfur trioxide, etc., the surface or bulk modified polymer will contain a degree of sulfonation ranging from about 15 to about 50%. The separation process is effected at temperatures ranging from about ambient to about 100.degree. C. and pressures ranging from about 50 to about 1000 psig.

  11. Direct hydrocarbon fuel cells

    Science.gov (United States)

    Barnett, Scott A.; Lai, Tammy; Liu, Jiang

    2010-05-04

    The direct electrochemical oxidation of hydrocarbons in solid oxide fuel cells, to generate greater power densities at lower temperatures without carbon deposition. The performance obtained is comparable to that of fuel cells used for hydrogen, and is achieved by using novel anode composites at low operating temperatures. Such solid oxide fuel cells, regardless of fuel source or operation, can be configured advantageously using the structural geometries of this invention.

  12. Organic geochemistry of the Vindhyan sediments: Implications for hydrocarbons

    Science.gov (United States)

    Dayal, A. M.; Mani, Devleena; Madhavi, T.; Kavitha, S.; Kalpana, M. S.; Patil, D. J.; Sharma, Mukund

    2014-09-01

    The organic geochemical methods of hydrocarbon prospecting involve the characterization of sedimentary organic matter in terms of its abundance, source and thermal maturity, which are essential prerequisites for a hydrocarbon source rock. In the present study, evaluation of organic matter in the outcrop shale samples from the Semri and Kaimur Groups of Vindhyan basin was carried out using Rock Eval pyrolysis. Also, the adsorbed low molecular weight hydrocarbons, methane, ethane, propane and butane, were investigated in the near surface soils to infer the generation of hydrocarbons in the Vindhyan basin. The Total Organic Carbon (TOC) content in shales ranges between 0.04% and 1.43%. The S1 (thermally liberated free hydrocarbons) values range between 0.01-0.09 mgHC/gRock (milligram hydrocarbon per gram of rock sample), whereas the S2 (hydrocarbons from cracking of kerogen) show the values between 0.01 and 0.14 mgHC/gRock. Based on the Tmax (temperature at highest yield of S2) and the hydrogen index (HI) correlations, the organic matter is characterized by Type III kerogen. The adsorbed soil gas, CH4 (C1), C2H6 (C2), C3H8 (C3) and nC4H10, (nC4), concentrations measured in the soil samples from the eastern part of Vindhyan basin (Son Valley) vary from 0 to 186 ppb, 0 to 4 ppb, 0 to 5 ppb, and 0 to 1 ppb, respectively. The stable carbon isotope values for the desorbed methane (δ13C1) and ethane (δ13C2) range between -45.7‰ to -25.2‰ and -35.3‰ to -20.19‰ (VPDB), respectively suggesting a thermogenic source for these hydrocarbons. High concentrations of thermogenic hydrocarbons are characteristic of areas around Sagar, Narsinghpur, Katni and Satna in the Son Valley. The light hydrocarbon concentrations (C1-C4) in near surface soils of the western Vindhyan basin around Chambal Valley have been reported to vary between 1-2547 ppb, 1-558 ppb, 1-181 ppb, 1-37 ppb and 1-32 ppb, respectively with high concentrations around Baran-Jhalawar-Bhanpur-Garot regions (Kumar

  13. Historical polycyclic aromatic and petrogenic hydrocarbon loading in Northern Central Gulf of Mexico shelf sediments

    Energy Technology Data Exchange (ETDEWEB)

    Overton, E.B.; Ashton, B.M.; Miles, M.S. [Louisiana State University, Baton Rouge, LA (United States). Dept. of Environmental Studies

    2005-10-01

    The distribution of selected hydrocarbons within ten dated sediment cores taken from the Mississippi River Bight off coastal Louisiana suggests a chronic contaminant loading from several sources including the river itself, oil and gas exploration in the central Gulf of Mexico (GOM) shelf area, and natural geologic hydrocarbon seeps. Data were grouped as either total polycyclic aromatic hydrocarbons (PAH's), which were indicative of pyrogenic PAH's; or estimated total hopanes (indicative of petrogenic hydrocarbons). The total PAH concentrations and estimated total hopanes begin increasing above background levels (approximately 200 ng g{sup -1}) after the 1950s. The distribution of these hydrocarbons and hopanes within the dated sediment cores suggests that the Mississippi River is a regional source of pyrogenic PAH's, and that the hopanes are from natural geologic hydrocarbon seeps, oil and gas exploration in the GOM, or both. (author)

  14. AP Index

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Planetary Amplitude index - Bartels 1951. The a-index ranges from 0 to 400 and represents a K-value converted to a linear scale in gammas (nanoTeslas)--a scale that...

  15. Speech Indexing

    NARCIS (Netherlands)

    Ordelman, R.J.F.; Jong, de F.M.G.; Leeuwen, van D.A.; Blanken, H.M.; de Vries, A.P.; Blok, H.E.; Feng, L.

    2007-01-01

    This chapter will focus on the automatic extraction of information from the speech in multimedia documents. This approach is often referred to as speech indexing and it can be regarded as a subfield of audio indexing that also incorporates for example the analysis of music and sounds. If the objecti

  16. 吹扫捕集- GC/MS法测定水中卤代烃的质量控制指标研究%Research of Quality Control Index for Halogenated Hydrocarbons in Water Determined by Purge and Trap-GC/MS

    Institute of Scientific and Technical Information of China (English)

    胡冠九; 李娟; 袁力; 夏新; 王荟; 史啸勇

    2011-01-01

    采用吹扫捕集-气相色谱/质谱联用法,通过实际样品测试及全国多家实验室测定数据统计两种方法,针对水中三氯甲烷、四氯化碳、溴仿、二氯甲烷、1,2-二氯乙烷、1,1-二氯乙烯、三氯乙烯、四氯乙烯等8种卤代烃的平行样测定相对偏差、空白加标回收率及实际样品加标回收率等3个指标,研究了每种卤代烃的质控指标评价标准,提出其平行样测定允许最大相对偏差应控制为11.6% ~20.8%;当空白加标质量浓度为0μg/L~100μg/L时,回收率的控制范围为60%~123%;当样品质量浓度为0μg/L~20μg/L时,实际样品加标回收率的控制范围为46%~164%.%Three quality control indexes of eight kinds of halogenated hydrocarbons (Chloroform, Carbon tet-rachloride, Bromoform, Methylene chloride, 1, 2-Dichloroethane, 1, 1 -Dichloroethylene, Trichloroethylene, Tetrachloroethylene ) , including relative bias of duplicates, recovery of blank spike and sample spike, were studied by sample test using purge and trap-gas chromatography-mass spectroscopy, and also by evaluating data collected from many labs national-widely. The quality control index was produced according to every target. The results showed that the maximum relative bias should be within 11.6% ~20. 8% ; the blank recovery should be within 60% -123% when the spiking concentration was 0 μg/L ~ 100 μg/L; the sample recovery should be within 46% ~ 164% when the sample concentration was 0 μg/L ~20 μg/L.

  17. Development of a Regression Kriging Model Conditioned with Sequential Gaussian Simulation to Predict the Spatial Distribution of Site Index for The Savannah River Site.

    Energy Technology Data Exchange (ETDEWEB)

    Edwards, Lloyd [USDA Forest Service, Southern Research Station; Parresol, Bernie [USDA Forest Service, Southern Research Station

    2012-09-17

    The primary research objective of the project is to determine an optimum model to spatially interpolate point derived tree site index (SI). This optimum model will use relevant data from 635 measured sample points to create continuous 40 meter SI raster layer of entire study extent.

  18. Trends in body mass index distribution and prevalence of thinness, overweight and obesity in two cohorts of Surinamese South Asian children in The Netherlands

    NARCIS (Netherlands)

    Wilde, J.A. de; Zandbergen-Harlaar, S.; Buuren, S. van; Middelkoop, B.J.

    2013-01-01

    OBJECTIVES: Asians have a smaller muscle mass and a larger fat mass at the same body mass index (BMI) than most other ethnic groups. Due to a resulting higher cardiometabolic risk, the BMI cut-offs for overweight and obesity were lowered for adults. For Asian children universal criteria apply. The o

  19. AA Index

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The geomagnetic aa index provides a long climatology of global geomagnetic activity using 2 antipodal observatories at Greenwich and Melbourne- IAGA Bulletin 37,...

  20. Walkability Index

    Data.gov (United States)

    U.S. Environmental Protection Agency — The Walkabiliy Index dataset characterizes every Census 2010 block group in the U.S. based on its relative walkability. Walkability depends upon characteristics of...

  1. Hydrocarbon conversion catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Hoek, A.; Huizinga, T.; Maxwell, I.E.

    1989-08-15

    This patent describes a process for hydrocracking hydrocarbon oils into products of lower average molecular weight and lower average boiling point. It comprises contacting a hydrocarbon oil at a temperature between 250{sup 0}C and 500{sup 0}C and a pressure up to 300 bar in the presence of hydrogen with a catalyst consisting essentially of a Y zeolite modified to have a unit cell size below 24.35A, a water absorption capacity (at 25{sup 0}C and a rho/rho/sub o/ value of 0.2) of at least 8% by weight of the zeolite and a pore volume of at least 0.25 ml/g wherein between 10% and 60% of the total pore volume is made up of pores having a diameter of at least 8 nm; an alumina binder and at least one hydrogenation component selected from the group consisting of a Group VI metal, a Group VIII metal and mixtures thereof.

  2. Thermophysical Properties of Hydrocarbon Mixtures

    Science.gov (United States)

    SRD 4 NIST Thermophysical Properties of Hydrocarbon Mixtures (PC database for purchase)   Interactive computer program for predicting thermodynamic and transport properties of pure fluids and fluid mixtures containing up to 20 components. The components are selected from a database of 196 components, mostly hydrocarbons.

  3. Hydrocarbon Receptor Pathway in Dogs

    NARCIS (Netherlands)

    Steenbeek, F.G. van; Spee, B.; Penning, L.C.; Kummeling, A.; Gils, I.H.M.; Grinwis, G.C.M.; Leenen, D. van; Holstege, F.C.P.; Vos-Loohuis, M.; Rothuizen, J.; Leegwater, P.A.J.

    2013-01-01

    The aryl hydrocarbon receptor (AHR) mediates biological responses to toxic chemicals. An unexpected role for AHR in vascularization was suggested when mice lacking AHR displayed impaired closure of the ductus venosus after birth, as did knockout mice for aryl hydrocarbon receptor interacting protein

  4. Hydrocarbon Receptor Pathway in Dogs

    NARCIS (Netherlands)

    Steenbeek, F.G. van; Spee, B.; Penning, L.C.; Kummeling, A.; Gils, I.H.M.; Grinwis, G.C.M.; Leenen, D. van; Holstege, F.C.P.; Vos-Loohuis, M.; Rothuizen, J.; Leegwater, P.A.J.

    The aryl hydrocarbon receptor (AHR) mediates biological responses to toxic chemicals. An unexpected role for AHR in vascularization was suggested when mice lacking AHR displayed impaired closure of the ductus venosus after birth, as did knockout mice for aryl hydrocarbon receptor interacting

  5. Glycemic index and glycemic load in relation to changes in body weight, body fat distribution, and body composition in adult Danes 1-3

    DEFF Research Database (Denmark)

    Hare-Bruun, Helle; Flint, Anne; L. Heitmann, Berit

    2006-01-01

    ABSTRACT Background: A diet with a high glycemic index (GI) and glycemic load (GL) may promote overconsumption of energy and increase the risk of weight gain.Objective: The objective of the study was to investigate the relation between GI and GL of habitual diets and subsequent 6-y changes in body...... born in 1922, 1932, 1942, or 1952. A baseline health examination and a dietary history interview were carried out in 1987 and 1988; a follow-up health examination was performed in 1993 and 1994. Results: Positive associations between GI and changes in bodyweight (¿BW), percentage body fat (%BF......), and waist circumference (¿WC) were observed in women after adjustment for covariates.Significant GI X sex X physical activity interactions for ABSTRACTBackground: A diet with a high glycemic index (GI) and glycemicload (GL) may promote overconsumption of energy and increase therisk of weight gain...

  6. Source Characterization of Polycyclic Aromatic Hydrocarbons by Using Their Molecular Indices: An Overview of Possibilities

    NARCIS (Netherlands)

    Stogiannidis, E.; Laane, R.

    2014-01-01

    The Polycyclic Aromatic Hydrocarbons (PAHs or polyaromatic hydrocarbons) have been extensively studied to understand their distribution, fate and effects in the environment (Haftka 2009; Laane et al. 1999, 2006, 2013; Okuda et al. 2002; Page et al. 1999; Pavlova and Ivanova 2003; Stout et al. 2001a;

  7. A study of hydrocarbons associated with brines from DOE geopressured wells. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Keeley, D.F.

    1993-07-01

    Accomplishments are summarized on the following tasks: distribution coefficients and solubilities, DOE design well sampling, analysis of well samples, review of theoretical models of geopressured reservoir hydrocarbons, monitor for aliphatic hydrocarbons, development of a ph meter probe, DOE design well scrubber analysis, removal and disposition of gas scrubber equipment at Pleasant Bayou Well, and disposition of archived brines.

  8. A study of hydrocarbons associated with brines from DOE geopressured wells

    Energy Technology Data Exchange (ETDEWEB)

    Keeley, D.F.

    1993-01-01

    Accomplishments are summarized on the following tasks: distribution coefficients and solubilities, DOE design well sampling, analysis of well samples, review of theoretical models of geopressured reservoir hydrocarbons, monitor for aliphatic hydrocarbons, development of a ph meter probe, DOE design well scrubber analysis, removal and disposition of gas scrubber equipment at Pleasant Bayou Well, and disposition of archived brines.

  9. Virginia ESI: INDEX (Index Polygons)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains vector polygons representing the boundaries of all hardcopy cartographic products produced as part of the Environmental Sensitivity Index...

  10. Louisiana ESI: INDEX (Index Polygons)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains vector polygons representing the boundaries of all the hardcopy cartographic products produced as part of the Environmental Sensitivity Index...

  11. Maryland ESI: INDEX (Index Polygons)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains vector polygons representing the boundaries of all hardcopy cartographic products produced as part of the Environmental Sensitivity Index...

  12. The presence of pollutant hydrocarbons in estuarine epipelic diatom populations. II. Diatom slimes

    Energy Technology Data Exchange (ETDEWEB)

    Thompson, S.; Eglinton, G.

    1979-01-01

    Diatom slime in sediment from the Severn intertidal estuary was analyzed for polycyclic aromatic hydrocarbons (PAH's) and aliphatic hydrocarbons, using computerized capillary gas chromatography/mass spectrometry. The distributions of these substances in diatoms were compared with those in the underlying sediment and in a sediment-free diatom population. Aliphatic hydrocarbon distribution in slime was about the same as that of separated diatoms and sediment, while PAH distribution in slime was about that of the sediment alone. These results suggest a loss of PAH's from the coalesced sediment in the slime, probably either by a photo-oxidative or catabolic process. 34 references, 2 tables.

  13. Adsorption of hydrocarbons in chalk reservoirs

    Energy Technology Data Exchange (ETDEWEB)

    Madsen, L.

    1996-12-31

    The present work is a study on the wettability of hydrocarbon bearing chalk reservoirs. Wettability is a major factor that influences flow, location and distribution of oil and water in the reservoir. The wettability of the hydrocarbon reservoirs depends on how and to what extent the organic compounds are adsorbed onto the surfaces of calcite, quartz and clay. Organic compounds such as carboxylic acids are found in formation waters from various hydrocarbon reservoirs and in crude oils. In the present investigation the wetting behaviour of chalk is studied by the adsorption of the carboxylic acids onto synthetic calcite, kaolinite, quartz, {alpha}-alumina, and chalk dispersed in an aqueous phase and an organic phase. In the aqueous phase the results clearly demonstrate the differences between the adsorption behaviour of benzoic acid and hexanoic acid onto the surfaces of oxide minerals and carbonates. With NaCl concentration of 0.1 M and with pH {approx_equal} 6 the maximum adsorption of benzoic acid decreases in the order: quartz, {alpha}-alumina, kaolinite. For synthetic calcite and chalk no detectable adsorption was obtaind. In the organic phase the order is reversed. The maximum adsorption of benzoic acid onto the different surfaces decreases in the order: synthetic calcite, chalk, kaolinite and quartz. Also a marked difference in adsorption behaviour between probes with different functional groups onto synthetic calcite from organic phase is observed. The maximum adsorption decreases in the order: benzoic acid, benzyl alcohol and benzylamine. (au) 54 refs.

  14. Petroleum hydrocarbon contamination in surface sediments of Beiluohe Basins, China.

    Science.gov (United States)

    Shi, Helin; Zhang, Li; Yue, Leping; Zheng, Guozhang

    2008-10-01

    Twenty-two surface sediment samples were collected from Beiluohe River, China, in 2005. Saturated hydrocarbons analysis was carried out on different river sediments in order to detect possible contaminations by petroleum development. Total concentrations of hydrocarbons in the sediments ranged from 6.4-147.3 microg g(-1) (dry wt) with an average of 76.8 microg g(-1), revealing relatively low to medium contamination in studied areas in spite of oil development for many years. The THC levels in the mainstream of Beiluohe River were relatively low. Sediment samples with higher total hydrocarbon concentrations were from the sites related to the petroleum activities or urban discharges. Gas chromatographic distribution patterns of n-alkanes are characteristic of petroleum in most samples. They show a strong unresolved complex mixture (UCM) with a small predominance of odd on even numbered n-alkanes. On the other hand, pentacyclic triterpanes and steranes occurred in all analyzed sediments and displayed similar signatures that are characteristic of mature organic matter contribution from oil contaminations. Hydrocarbons of terrestrial origin were also detected in the samples. However, contribution from plantwax hydrocarbons is overshadowed in samples by hydrocarbons of petroleum origin. This is obvious by the presence of the high relative abundance of UCM, and the identification of mature hopane and sterane in samples.

  15. Definition and Application of Topological Index Based on Bond Connectivity

    Institute of Scientific and Technical Information of China (English)

    WANG Zhen-dong; YANG Feng; YANG Hai-lang; LUO Ming-dao; QU Song-sheng

    2003-01-01

    Bond connectivity topological index Si based on chemical bonds was defined by using a matrix method.And Si is formed by atomic parameters such as the number of valence electrons,the number of the highest main quantum of atoms and the bonding electrons and bond parameters such as the length of bonds,the electronegativity difference of bonding atoms.The molecular bond connectivity topological index S is composed of Si.The thermodynamic properties of saturated hydrocarbons,unsaturated hydrocarbons,oxygen organic,methane halide and transitional element compounds and the molecular bond connectivity topological index S have an optimal correlative relationship.

  16. The New Method Judged Horizontal Distribution Pattern by Uniform Angle Index%角尺度判断林木水平分布格局的新方法

    Institute of Scientific and Technical Information of China (English)

    赵中华; 惠刚盈; 胡艳波; 张弓乔

    2016-01-01

    正态分布检验林分(树种)平均角尺度判断林木水平分布格局方法对2个林分/种群的判断结果与 Ripley’s L函数点格局分析方法判断结果完全一致,而聚集指数 R与 Ripley’s L检验的判断结果的差别明显增加,说明置信水平对水平分布格局判断结果影响比较明显。【结论】研究提出的正态分布检验林分(树种)平均角尺度判断林木水平分布格局的方法克服了统一的置信区间不适用于评判抽样调查或群落中数量较少的种群水平分布格局问题,进一步完善了角尺度判断林木水平分布格局理论,提升了角尺度判断林木水平分布格局的准确性与适用范围。%Objective]This paper proposed a new method to judge tree horizontal distribution pattern by uniform angle index in order to further improve the theory of the uniform angle index to judge tree horizontal distribution pattern.[Method]6 000 simulated stands with an area of 70 m × 70 m and with different densities and distribution patterns were produced by stand spatial structure analysis software ( Winkelmass) ,the 2 field-tested broad-leaved korean pine forests in northeast China were then used to verify the accuracy of the new method for judging the stand and population horizontal distribution pattern,and the results were also compared with R aggregation index and Ripley’s L.[Result]According to the conclusion of the mean value of uniform angle index ( W ) of random distribution stand conform to the normal distribution and its relationships with the standard deviation,this contribution proposed the new method of judgment stand/population spatial horizontal distribution pattern by uniform angle index. The 6 000 simulated stands with different density and horizontal distribution patterns were produced by Winkelmass with an area of 70 m × 70 m. The results of simulation data showed that the coincidence rate of uniform angle index normal distribution test method was 100% to different density

  17. Capillary rise dynamics of liquid hydrocarbons in mesoporous silica as explored by gravimetry, optical and neutron imaging: Nano-rheology and determination of pore size distributions from the shape of imbibition fronts

    CERN Document Server

    Gruener, Simon; Schillinger, Burkhard; Egelhaaf, Stefan U; Huber, Patrick

    2015-01-01

    We present gravimetrical, optical, and neutron imaging measurements of the capillarity-driven infiltration of mesoporous silica glass by hydrocarbons. Square-root-of-time Lucas-Washburn invasion kinetics are found for linear alkanes from n-decane (C10) to n-hexacontane (C60) and for squalane, a branched alkane, in porous Vycor with 6.5 nm or 10 nm pore diameter, respectively. Humidity-dependent experiments allow us to study the influence on the imbibition kinetics of water layers adsorbed on the pore walls. Except for the longest molecule studied, C60, the invasion kinetics can be described by bulk fluidity and bulk capillarity, provided we assume a sticking, pore-wall adsorbed boundary layer, i.e. a monolayer of water covered by a monolayer of flat-laying hydrocarbons. For C60, however, an enhanced imbibition speed compared to the value expected in the bulk is found. This suggests the onset of velocity slippage at the silica walls or a reduced shear viscosity due to the transition towards a polymer-like flow...

  18. INDEXING MECHANISM

    Science.gov (United States)

    Kock, L.J.

    1959-09-22

    A device is presented for loading and unloading fuel elements containing material fissionable by neutrons of thermal energy. The device comprises a combination of mechanical features Including a base, a lever pivotally attached to the base, an Indexing plate on the base parallel to the plane of lever rotation and having a plurality of apertures, the apertures being disposed In rows, each aperture having a keyway, an Index pin movably disposed to the plane of lever rotation and having a plurality of apertures, the apertures being disposed in rows, each aperture having a keyway, an index pin movably disposed on the lever normal to the plane rotation, a key on the pin, a sleeve on the lever spaced from and parallel to the index pin, a pair of pulleys and a cable disposed between them, an open collar rotatably attached to the sleeve and linked to one of the pulleys, a pin extending from the collar, and a bearing movably mounted in the sleeve and having at least two longitudinal grooves in the outside surface.

  19. Microbial production of aliphatic hydrocarbons. Progress report, February 1, 1979-September 30, 1979. [Optimization for commercial oily hydrocarbon production

    Energy Technology Data Exchange (ETDEWEB)

    Tornabene, T G

    1979-09-01

    The neutral lipids of nine species of methanogenic bacteria, two thermoacidophiles, two alkalinophiles and 20 algal samples were analyzed. The major components were C/sub 30/, C/sub 25/, and/or C/sub 20/ acyclic isoprenoid hydrocarbons with a continuous range of hydroisoprenoid homologues. The range or acyclic isoprenoids detected were from C/sub 14/ to C/sub 30/. The neutral lipid composition from these bacteria resembles the isoprenoid distribution isolated from ancient sediments and petroleum. Therefore, these findings may have major implications to biological and biogeochemical evolution. In this connection, samples and cores from ancient sediments and future fossil fuel source beds are being analyzed for these neutral lipids as well as the more polar isopranyl glycerol-ether lipids. The derivation of fossil fuels and the biomass accumulations are the focal points of this phase of the study. Ancient and recent sediments, future source beds, and local esturaries are being enriched for microorganisms to establish a range and capability profile for hydrocarbon production. Only a relatively small percent of the microorganisms isolated demonstrated the ability to synthesize hydrocarbons; however, one particular algal isolate demonstrated that it can synthesize hydrocarbons while in a green physiological stage. Greater production is expected in the brown phase of growth. Hydrocarbon biosynthesis studies were conducted in an attempt to better understand the conditions required to maximize hydrocarbon production. The program involved physical and chemical parameters as well as assays of specifically labelled precusors with a cell free enzyme system to measure their conversions to hydrocarbons. The results have indicated a complex one enzyme system is involved in condensation and reduction of two fatty acids into hydrocarbons.

  20. Applied Research on Distribution of Saline-alkali Soil Based on NDVI Index Inversion Technology%基于NDVI指数反演技术的盐碱土壤分布应用研究

    Institute of Scientific and Technical Information of China (English)

    张建杰; 郭彩霞; 王文斌; 苏尚军; 张强

    2013-01-01

    The distribution of saline-alkali soil and the degree of salinity were investigated in the Sanggan River Valley of Datong Basin by the remote sensing image processing methods,such as the supervised classification,NDVI index,etc. The distribution of saline-alkali soil was indicated based on the image of Landsat and NDVI index,and the results were compared with the second soil census and the filed survey. The results showed that the distribution and salinization degree of saline-alkali soil could be reflected dynamically with macroscopic scale by remote sensing information technology.%利用监督分类、NDVI指数等遥感影像处理方法,在大同盆地桑干河流域开展了土壤盐碱地分布及盐渍化程度的应用研究。基于Landsat卫星影像,依据NDVI指数推断了盐碱土壤的分布,与第二次土壤普查和实地调查的结果进行了比较。结果表明,遥感信息技术可以宏观、动态地有效反映出盐碱地的分布及盐渍化程度。

  1. 成品油销售企业顾客满意度指数测评模型研究%Study on Customer Satisfaction Index Model for China’ s Finished Oil Distribution Enterprises

    Institute of Scientific and Technical Information of China (English)

    南剑飞

    2015-01-01

    顾客满意度指数(CSI)是全面、综合地度量顾客满意度(CSD)的一种指标,也是一种全新的宏观经济指标和质量评价指标。介绍了我国成品油销售企业CSI测评的意义,提出了成品油销售企业CSI理论模型与数学模型,并指出了测评中应注意的若干问题,为加强和改善我国成品油销售企业经营管理,提高顾客满意度和忠诚度,增加经济效益与社会效益,增强其整体国际竞争力提供了新思路。%Customer Satisfaction Index ( CSI ) is an index for measuring Customer Satisfaction Degree ( CSD ) completely and comprehensively, as well as a new macro-economic index and quality appraisal index. On the basis of stressing the significance of measurement of CSI for China’ s finished oil distribution enterprises, the theoretic model and mathematic model on CSI for finished oil distribution enterprises were put forward, and the problems that should be noticed in the course of measurement were raised in order to offer a new hint on strengthening and improving their operation and management, raising its CSD and customer loyalty degree, increasing economic benefits and social benefits, and heightening their comprehensive power of international competitiveness.

  2. One century of air deposition of hydrocarbons recorded in travertine in North Tibetan Plateau, China: Sources and evolution.

    Science.gov (United States)

    Yuan, Guo-Li; Wu, Ming-Zhe; Sun, Yong; Li, Jun; Li, Jing-Chao; Wang, Gen-Hou

    2016-08-01

    The characteristic distribution patterns of hydrocarbons have been used for fingerprinting to identify their sources. The historical air depositions of hydrocarbons recorded in natural media help to understand the evolution of the air environment. Travertine is a natural acceptor of air deposition that settles on the ground layer by layer. To reconstruct the historical air environment of hydrocarbons in the North Tibetan Plateau (NTP), a unique background region, twenty-seven travertine samples were collected systematically from a travertine column according to its precipitated year. For each sample, the precipitated year was dated while n-alkanes and polycyclic aromatic hydrocarbons (PAHs) were determined. Based on source identification, the air environment of hydrocarbons in the past century was studied for the region of NTP. Before World War II, the anthropogenic sources of hydrocarbons showed little influence on the air environment. During World War II and China's War of Liberation, hydrocarbons increased significantly, mainly from the use of fossil fuels. Between 1954 and 1963, hydrocarbons in the air decreased significantly because the sources of petroleum combustion decreased. From the mid-1960s through the end of the 1990s, air hydrocarbons, which mainly originated from biomass burning, increased gradually because agriculture and animal husbandry were developing steadily in Tibet and China. From the late 1990s, hydrocarbons in the atmosphere increased rapidly due to the rapid increase of tourism activities, which might increase hydrocarbon emissions from traffic. The reconstruction of the historical air hydrocarbons in NTP clearly reflects the evolution of the region and global development.

  3. Characteristics of hydrocarbon sources and controlling factors of their formation in Pingliang Formation, West Ordos Basin

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    According to organic geochemistry and organic petrology, the hydrocarbon sources in Pingliang Formation, W. Ordos basin, are systematically evaluated. The organic abundance of hydrocarbon source in this research is higher in the upper part of profiles than In the low, and more in mudstone than in carbonate. Most of organic matters become sapropelic, and few are humlc-aapropelic in the regions of Shibangou and Zhuzisan. According to stable isotopes of carbon and oxygen in carbonate rock, boron index and ratios of elements, palaeo-salinity and sedimentary velocity are calculated. The two factors of paleao-salinity and sediment velocity, which control the distribution of organic matters, are discussed.Good relationship is found between water salinity and abundance of organic matter; in contrast, poor correlation is observed between salinity and types of organic matters. The relative sediment velocity in the research regions is also related with organic abundance and types. A low sediment velocity would lead to high abundance and good type of organic matters, and vice versa.

  4. Morphological Atherosclerosis Calcification Distribution (MACD) Index is a Strong Predictor of Cardio-Vascular Death and Include Predictive Power of BMD

    DEFF Research Database (Denmark)

    Christiansen, Claus; Karsdal, Morten; Ganz, Melanie

    Aortic calcification is a major risk factor for cardiovascular disease (CVD) related deaths. We investigated the relation between mortality and aspects of number, size, morphology and distribution of calcified plaques in the lumbar aorta and BMD of postmenopausal women. 308 women aged 48 to 76 were...

  5. Corrosion monitoring along infrastructures using distributed fiber optic sensing

    Science.gov (United States)

    Alhandawi, Khalil B.; Vahdati, Nader; Shiryayev, Oleg; Lawand, Lydia

    2016-04-01

    Pipeline Inspection Gauges (PIGs) are used for internal corrosion inspection of oil pipelines every 3-5 years. However, between inspection intervals, rapid corrosion may occur, potentially resulting in major accidents. The motivation behind this research project was to develop a safe distributed corrosion sensor placed inside oil pipelines continuously monitoring corrosion. The intrinsically safe nature of light provided motivation for researching fiber optic sensors as a solution. The sensing fiber's cladding features polymer plastic that is chemically sensitive to hydrocarbons within crude oil mixtures. A layer of metal, used in the oil pipeline's construction, is deposited on the polymer cladding, which upon corrosion, exposes the cladding to surrounding hydrocarbons. The hydrocarbon's interaction with the cladding locally increases the cladding's refractive index in the radial direction. Light intensity of a traveling pulse is reduced due to local reduction in the modal capacity which is interrogated by Optical Time Domain Reflectometery. Backscattered light is captured in real-time while using time delay to resolve location, allowing real-time spatial monitoring of environmental internal corrosion within pipelines spanning large distances. Step index theoretical solutions were used to calculate the power loss due changes in the intensity profile. The power loss is translated into an attenuation coefficient characterizing the expected OTDR trace which was verified against similar experimental results from the literature. A laboratory scale experiment is being developed to assess the validity of the model and the practicality of the solution.

  6. Differential tectonic evolution and hydrocarbon distribution in clastic strata of petroliferous basins in central-western China%中国中西部盆地差异构造演化与碎屑岩层系油气聚集分布

    Institute of Scientific and Technical Information of China (English)

    方成名; 黄泽光; 段铁军; 胡宗全; 杨帆

    2012-01-01

    The relationship between tectonic evolution and hydrocarbon distribution is complex in major petroliferous basins such as Sichuan, Ordos, Junggar and Tarim in central-western China. Analysis of the tectonic evolution and late differential tectonic modification of these basins shows that the four basins had the simdar process and different geologic timing of tectonic evolution and basin formation, I. E. they all have a similar basin-forming process featuring in transformation from extensional to compressional or transpressional basin. The late tectonic modification of the clastic strata is characterized by lateral aligning and vertical superimposition of three basic structural styles including foreland thrust, differential uplifts and titled structure. Tectonic activity,basin formation and late modification jointly control hydrocarbon accumulation types, sizesand distribution. Simple basin-forming process but diversified tectonic transformation determines that the four basins have similar play types but differential distribution patterns. The basic modification style of the four basins determines their hydrocarbon accumulation types, while the superposition features control the timing and sizes of hydrocarbon accumulation. Based on the understanding of the similarities and differences of tectonic controlling factors on hydrocarbon accumulation among these basins,we put forward a play classification scheme. According to this scheme,we identi- fied 4 play types including palaeo-uplift, slope, foreland folded-thrust and large fault.%对中西部地区盆地构造演化和晚期差异构造改造的分析表明,四大盆地构造-成盆具有“同序异时”的演化特征,即均具有从伸展性盆地向压性或压扭性盆地转化的成盆序列;碎屑岩层系的晚期构造改造由山前冲断、差异隆升和掀斜等3种基本型式在横向上并列和纵向上叠加而成.构造-成盆作用与晚期构造改造共同控制了碎屑岩层系的油气

  7. Glycemic index and glycemic load in relation to changes in body weight, body fat distribution, and body composition in adult Danes

    DEFF Research Database (Denmark)

    Hare-Bruun, Helle; Flint, Anne; Heitmann, Berit L

    2006-01-01

    BACKGROUND: A diet with a high glycemic index (GI) and glycemic load (GL) may promote overconsumption of energy and increase the risk of weight gain. OBJECTIVE: The objective of the study was to investigate the relation between GI and GL of habitual diets and subsequent 6-y changes in body weight...... born in 1922, 1932, 1942, or 1952. A baseline health examination and a dietary history interview were carried out in 1987 and 1988; a follow-up health examination was performed in 1993 and 1994. RESULTS: Positive associations between GI and changes in body weight (DeltaBW), percentage body fat (Delta...... observed in men, and no significant associations with GL were observed in either sex. CONCLUSIONS: High-GI diets may lead to increases in BW, body fat mass, and WC in women, especially in sedentary women, which suggests that physical activity may protect against diet-induced weight gain. No associations...

  8. Recent Shift of Body Mass Index Distribution in Korea: a Population-based Korea National Health Insurance Database, 2002-2013.

    Science.gov (United States)

    Yoon, Yeong Sook; Oh, Sang Woo

    2017-03-01

    We investigated trends of obesity prevalence among adult Koreans. Data from 110,280,952 participants who underwent medical examination provided by the National Health Insurance System from 2002-2013 were analyzed. The prevalence of moderate obesity (body mass index [BMI] 25.0-29.9 kg/m²) was slightly increased from 2002 (30.7%) through 2010 (33.1%) and reached a plateau since 2010 among men but continuously decreased from 22.5% in 2002 to 20.9% in 2013 among women. However, severe obesity (BMI ≥ 30.0 kg/m²) was rapidly increased and the prevalence in 2013 (4.2%) was almost doubled the prevalence in 2002 (2.5%). We observed a steep rise of severe obesity as well as potentially right shifting of the obese category.

  9. Recent Shift of Body Mass Index Distribution in Korea: a Population-based Korea National Health Insurance Database, 2002–2013

    Science.gov (United States)

    2017-01-01

    We investigated trends of obesity prevalence among adult Koreans. Data from 110,280,952 participants who underwent medical examination provided by the National Health Insurance System from 2002–2013 were analyzed. The prevalence of moderate obesity (body mass index [BMI] 25.0–29.9 kg/m2) was slightly increased from 2002 (30.7%) through 2010 (33.1%) and reached a plateau since 2010 among men but continuously decreased from 22.5% in 2002 to 20.9% in 2013 among women. However, severe obesity (BMI ≥ 30.0 kg/m2) was rapidly increased and the prevalence in 2013 (4.2%) was almost doubled the prevalence in 2002 (2.5%). We observed a steep rise of severe obesity as well as potentially right shifting of the obese category. PMID:28145646

  10. Afghanistan Index

    DEFF Research Database (Denmark)

    Linnet, Poul Martin

    2007-01-01

    The Afghanistan index is a compilation of quantitative and qualitative data on the reconstruction and security effort in Afghanistan. The index aims at providing data for benchmarking of the international performance and thus provides the reader with a quick possibility to retrieve valid...... basis. The data are divided into different indicators such as security, polls, drug, social, economic, refugees etc. This represents a practical division and does not indicate that a picture as to for instance security can be obtained by solely looking at the data under security. In order to obtain...... a more valid picture on security this must incorporate an integrated look on all data meaning that for instance the economic data provides an element as to the whole picture of security....

  11. Hydrocarbon Leak Detection Sensor Project

    Data.gov (United States)

    National Aeronautics and Space Administration — FTT is proposing the development of a sensor to detect the presence of hydrocarbons in turbopump Inter-Propellant Seals (IPS). The purpose of the IPS is to prevent...

  12. Growth of hydrocarbon utilizing microorganisms

    Digital Repository Service at National Institute of Oceanography (India)

    Bhosle, N.B.; Mavinkurve, S.

    Two isolates from marine mud having broad spectrum hydrocarbon utilizing profile were identified as Arthrobacter simplex and Candida tropicalis.Both the organisms grew exponentially on crude oil. The cell yield of the organisms was influenced...

  13. SUBJECT INDEX

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    2, 4, 6-trinitrobenzenesulphonic acid, zinc sulfate, experimental colitis, 2003328AC133 antigen, hematopoietic stem cells, fetal blood, immunophe-notyping, 2003138ALR2 gene, eNOS gene, PON1 gene, RAGE gene, 2003179 ATN-ISI, prognosis, acute renal failure, acute tubular necrosis-individual severity index, acute physiology and chronic health evaluation, 2003118 Alzheimer disease, interleukin-1 beta, tumor necrosis factor alpha,

  14. BOILING RANGE DISTRIBUTIONS OF HYDROCARBON MOLECULAR COMPOSITIONS IN DIESEL BY GAS CHROMATOGRAPHY-TIME OF FLIGHT MASS SPECTROMETRY%气相色谱-飞行时间质谱联用仪测定柴油烃类分子组成的馏程分布

    Institute of Scientific and Technical Information of China (English)

    王乃鑫; 刘泽龙; 祝馨怡; 田松柏

    2015-01-01

    利用气相色谱-飞行时间质谱联用仪(GC-TOFMS)建立了测定柴油烃类分子组成的馏程分布的方法,可以得到柴油样品中各种类型烃类在不同馏程段的碳数分布与平均相对分子质量。利用所建方法研究了柴油中各种类型烃类平均分子结构随馏程的变化情况,发现柴油不同馏程段的平均相对分子质量与其芳烃含量和烃类异构化程度有关:芳烃含量越低、烃类异构化程度越高,该馏程段的平均相对分子质量越高。考察了柴油加氢精制前后烃类分子组成的馏程分布变化情况,柴油经加氢精制后,饱和烃的馏程分布基本不变,只是含量有所增加,芳烃的馏程分布在低馏分段没有变化,在高馏分段含量下降,导致产物的平均相对分子质量在高馏分段高于原料的平均相对分子质量。%A method for analysis of boiling range distribution of hydrocarbon molecular composition in diesel by gas chromatography-time of flight mass spectrometry (GC-TOFMS)was established. Car-bon number distributions,average molecular weights and structures of hydrocarbon in different boiling ranges were studied. It is found that the average molecular weight of distillation range was influenced by aromatic content and degree of isomerization. The lower the aromatic content and the higher the isomer-ization degree is,the higher average molecular weight of the boiling range is. The boiling range distri-butions of hydrocarbon molecular compositions in diesel before and after hydrotreating were investiga-ted. For hydrotreated diesel,boiling range distribution of saturated hydrocarbon is basically unchanged, but its concentration increases. Boiling range distribution of aromatic remains the same in low distillate fraction,whereas there is a concentration decrease in high distillate,which results in a higher average molecular weight of product than that of raw material diesel in high distillate fraction.

  15. Observational study of body weight, body fat with segmental fat distribution, visceral fat and body mass index in type 2 diabetic patients

    OpenAIRE

    Sunil Dube; Shanti Viswanathan; Manjree Dube

    2016-01-01

    Background: There has been an increase in the prevalence of non-communicable diseases in the last decade. This prevalence has been steadily increasing and is expected to increase further in the coming decade. The change in our lifestyle plus a sedentary lifestyle has led to this .Various body composition monitoring methods help us evaluate obesity and its association with diabetes. In this study, we analysed the trend of body fat distribution in diabetics. Methods: A multifrequency body c...

  16. Bioassay of polycyclic aromatic hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Van Kirk, E.A.

    1980-08-01

    A positive relationship was found between the photodynamic activity of 24 polycyclic aromatic hydrocarbons versus published results on the mutagenicity, carcinogenicity, and initiation of unscheduled DNA synthesis. Metabolic activation of benzo(a)pyrene resulted in detection of increased mutagenesis in Paramecium tetraurelia as found also in the Ames Salmonella assay. The utility of P. tetraurelia as a biological detector of hazardous polycyclic aromatic hydrocarbons is discussed.

  17. Electrochemical decomposition of chlorinated hydrocarbons

    OpenAIRE

    McGee, Gerard Anthony

    1993-01-01

    This work involves the characterisation of the electrochemical decomposition of chlorinated hydrocarbons. A variety of methods were employed involving the use of catalytic reagents to enhance the rate at which chlorinated organic compounds are reduced. The first reagent used was oxygen which was electrochemically reduced to superoxide in nonaqueous solvents. Superoxide is a reactive intermediate and decomposes chlorinated hydrocarbons. However it was found that since the rate of reaction betw...

  18. LIQUID HYDROCARBON FUEL CELL DEVELOPMENT.

    Science.gov (United States)

    A compound anode consists of a reforming catalyst bed in direct contact with a palladium-silver fuel cell anode. The objective of this study was to...prove the feasibility of operating a compound anode fuel cell on a liquid hydrocarbon and to define the important parameters that influence cell...performance. Both reformer and fuel cell tests were conducted with various liquid hydrocarbon fuels. Included in this report is a description of the

  19. HYDROCARBONS RESERVES IN VENEZUELA

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez Cruz, D.J.

    2007-07-01

    Venezuela is an important player in the energy world, because of its hydrocarbons reserves. The process for calculating oil and associated gas reserves is described bearing in mind that 90% of the gas reserves of Venezuela are associated to oil. Likewise, an analysis is made of the oil reserves figures from 1975 to 2003. Reference is also made to inconsistencies found by international experts and the explanations offered in this respect by the Ministry of Energy and Petroleum (MENPET) and Petroleos de Venezuela (PDVSA) regarding the changes that took place in the 1980s. In turn, Hubbert's Law is explained to determine peak production of conventional oil that a reservoir or field will reach, as well as its relationship with remaining reserves. Emphasis is placed on the interest of the United Nations on this topic. The reserves of associated gas are presented along with their relationship with the different crude oils that are produced and with injected gas, as well as with respect to the possible changes that would take place in the latter if oil reserves are revised. Some recommendations are submitted so that the MENPET starts preparing the pertinent policies ruling reserves. (auth)

  20. Evaluation of hydrocarbon potential

    Energy Technology Data Exchange (ETDEWEB)

    Cashman, P.H.; Trexler, J.H. Jr. [Univ. of Nevada, Reno, NV (United States)

    1992-09-30

    Task 8 is responsible for assessing the hydrocarbon potential of the Yucca Mountain vincinity. Our main focus is source rock stratigraphy in the NTS area in southern Nevada. (In addition, Trexler continues to work on a parallel study of source rock stratigraphy in the oil-producing region of east central Nevada, but this work is not funded by Task 8.) As a supplement to the stratigraphic studies, we are studying the geometry and kinematics of deformation at NTS, particularly as these pertain to reconstructing Paleozoic stratigraphy and to predicting the nature of the Late Paleozoic rocks under Yucca Mountain. Our stratigraphic studies continue to support the interpretation that rocks mapped as the {open_quotes}Eleana Formation{close_quotes} are in fact parts of two different Mississippian units. We have made significant progress in determining the basin histories of both units. These place important constraints on regional paleogeographic and tectonic reconstructions. In addition to continued work on the Eleana, we plan to look at the overlying Tippipah Limestone. Preliminary TOC and maturation data indicate that this may be another potential source rock.

  1. 随机介质内折射率分布对频谱特性的影响%Influence of Refractive Index Distribution on the Frequency Property in Random Media

    Institute of Scientific and Technical Information of China (English)

    刘海; 吕健滔; 王可嘉; 刘劲松

    2011-01-01

    采用时域有限差分法数值求解Maxwell方程组,分析了随机介质折射率分布对其频谱特性的影响.结果表明,折射率空间分布越无序,介质内的局域化现象会增强,被激发的模式会增多,频谱强度也会变大.而散射颗粒的折射率随时间的微小变化也会使介质内模式变多,且折射率变化幅度越大、频率越大、变化越快,模式的频谱强度也会相应增大.各向异性的随机介质可以同时实现时间和空间上折射率的调制.这种理论仿真结果和实验观测现象的一致性将会进一步促进对随机系统物理机制的理解.%The influence of refractive index distribution on the frequency property of optical modes in random media is analyzed by using the finite difference time domain method to numerically solve Maxwell equations. The results indicate that the number and the spectral intensity of the modes existed in random media is growing up with the increase of the randomness intensity of the refractive index distribution. The minor variety of the refractive index of scattering granules also can conduce to the increase of the number of the modes in random media. The spectral intensity of these modes is also determined by the excursion, frequency, and velocity of the variety of refractive index of scattering granules. Anisotropic random media can achieve the modulation of the refractive index in terms of time and space. The agreement between experimental observations and simulations is helpful in understanding the physical mechanism in random systems.

  2. Database Index Technology Based on Virtual Data Accelerate Distribution Recombination%基于虚拟数据加速分布重组的数据库索引技术

    Institute of Scientific and Technical Information of China (English)

    潘晓萌; 王维哲

    2015-01-01

    To improve the information retrieval functions by optimizing index of text database, database index by using the traditional method of single text feature clustering method, clustering feature is inconsistent, safety problems and illegal clustering results output. Proposed one kind based on the virtual data to accelerate the distribution of recombination of data-base index technology, firstly construct the virtual data to accelerate the distribution of recombination model, distribution model improvement of database, improve the ability to index the text data, the need to document set after pretreatment, con-structing text database, weight calculate each candidate expansion terms, need according to the degree of correlation each word with the original query, constitute the database text Extensions word sets, using correlation rules mining rules of words as the expansion has been the virtual data to accelerate the distribution of system state function, construct the rule base, ex-pansion words extracted from the associated with the original query, and query expansion, improvement of realization of da-tabase indexing algorithm. The simulation results show that the algorithm is convergent text database indexing, retrieval pre-cision and the effective connection number is high, the execution time is short, it shows its superiority.%通过对文本数据库的优化索引提高信息检索功能,传统的数据库索引方法采用单层文本特征聚类方法,聚类特征不一致时,存在非法聚类和非法结果输出的安全问题.提出一种基于虚拟数据加速分布重组的数据库索引技术,首先构建虚拟数据加速分布重组模型,改进数据库的分布模型,提高对文本数据的索引能力,把需要的文档集经过预处理后,构建文本数据库,算出各个候选扩展词的权重后,需要根据各个词与原查询词的相关度,构成数据库文本扩展词集合,采用相关规则挖掘的规则词作为扩展,得到了

  3. Contrastive Analysis on Distribution Method for Total Index Budget Based on Sustainable Development%基于可持续发展的总量预算指标分配方法对比分析研究

    Institute of Scientific and Technical Information of China (English)

    曹霞; 张宽; 梁亦欣; 王燕鹏

    2016-01-01

    阐述了总量预算指标分配的概念,结合环境容量承载水平和总量管理的实际,从理论上建立河南各省辖市可用于社会经济发展的总量预算指标分配模型.针对各分析方法的理论模型进行对比分析,确定合理的分配方案,为后续的实证研究和"十三五"时期河南省总量预算管理提供基础.%This paper describes the concept of distribution for total index budget.Combining with environmental carrying ca-pacity level and the total budget management, it establishs the model of distribution method for total index budget that can be used to cities of Henan Province.The study analyzes the theoretical models of analytical method to determine a reasonable method.It provides fundamental menthods for the empirical study and total budget management in the 12th Five-Year Plan of Henan Prov-ince.

  4. Relationship between environmental remote sensing alternate indexes and Oncomelania snail distribution in hilly and mountainous areas%环境遥感替代指标与山丘地区钉螺分布的关系

    Institute of Scientific and Technical Information of China (English)

    董毅; 李朝晖; 冯锡光; 董兴齐

    2011-01-01

    Objective To analyze the relationship between Oncomelania snail distribution and environmental remote sensing indexes in hilly and mountainous areas. Method The normalized different vegetation index (NDVI), land surface temperature (LST), humidity index (Wetness) of 85 snail spots in Dali City were extracted for statistical analysis by TM image, and the land-use types were classified. LST, NDVI, Wetness, snail density and land-use types were overlaid and analyzed by using a weight of suitability model of ArcGIS 9.2, and snail appropriate distribution range in Dali City was calculated. Results The distribution of LST, NDVI, Wetness values of the investigated snail points were approximately normal, and most of the snail points distributed nearby the average values of the remote sensing alternate indexes, then gradually reduced to the ends. More than 90% of the snail spots were distributed in the land type with crops and grassland. The environments in Dali City were divided into unsuitable snail environment (0-14 points), suitable snail environment (15-21 points), and optimum snail environment (22-26 points) by the weight suitability mode. Conclusions Environmental remote sensing indicators can reflect the environmental factors affecting snail distribution directly. Combining remote sensing with GIS and field survey can describe, judge and forecast the distribution of snails.%目的 探讨影响山丘地区钉螺分布的常用环境遥感指标.方法 使用TM遥感图像提取云南省大理市85个螺点的植被指数(NDVI)、地表温度(LST)和湿度指数(Wetness)并进行统计分析,同时进行土地利用的分类;利用ArcGIS 9.2的权重适宜性模型将LST、NDVI、Wetness、钉螺密度、土地利用类型赋值后叠加分析,并计算大理市钉螺适宜分布范围.结果 提取的LST、NDVI、Wetness值均呈近似正态分布,螺点大部分分布在各遥感替代指标均数附近,并向两端逐渐减少,90%以上的螺点分布在代表庄

  5. Effect of 220Rn gas concentration distribution on its transmission from a delay chamber: evolving a CFD-based uniformity index.

    Science.gov (United States)

    Agarwal, T K; Joshi, M; Sahoo, B K; Kanse, S D; Sapra, B K

    2016-03-01

    (220)Rn mitigation can be achieved by delay chamber technique, which relies on the advantage of its short half-life. However, flow rate as well as inlet-outlet position for the delay chamber can have a significant impact on (220)Rn concentration distribution patterns and hence transmission factor. In the present study, computational fluid dynamics simulations to estimate the concentration distribution has been carried out in a chamber of 0.5 m(3) for the combination of six different inlet-outlet positions and five different flow rates. Subsequently, the transmission factor (TF) for the chamber was evaluated and found to be highly dependent on the flow rate and inlet-outlet positions. For ease of scale up, the dependency of TF on the flow rate and the inlet-outlet positions is best summarised by relative transmission factor (RTF), which is the ratio of the TFs for the case of inlet and outlet on different faces to that on the same face.

  6. Polycyclic Aromatic Hydrocarbons

    Science.gov (United States)

    Salama, Farid

    2010-01-01

    Carbonaceous materials play an important role in space. Polycyclic Aromatic Hydrocarbons (PAHs) are a ubiquitous component of the carbonaceous materials. PAHs are the best-known candidates to account for the IR emission bands. They are also thought to be among the carriers of the diffuse interstellar absorption bands (DIBs). PAH ionization states reflect the ionization balance of the medium while PAH size, composition, and structure reflect the energetic and chemical history of the medium. A major challenge is to reproduce in the laboratory the physical conditions that exist in the emission and absorption interstellar zones. The harsh physical conditions of the ISM -low temperature, collisionless, strong UV radiation fields- are simulated in the laboratory by associating a molecular beam with an ionizing discharge to generate a cold plasma expansion. PAH ions and radicals are formed from the neutral precursors in an isolated environment at low temperature and probed with high-sensitivity cavity ringdown spectroscopy in the NUV-NIR range. Carbon nanoparticles are also formed during the short residence time of the precursors in the plasma and are characterized with time-offlight mass spectrometry. These experiments provide unique information on the spectra of large carbonaceous molecules and ions in the gas phase that can now be directly compared to interstellar and circumstellar observations (IR emission bands, DIBs, extinction curve). These findings also hold great potential for understanding the formation process of interstellar carbonaceous grains. We will review recent progress in the experimental and theoretical studies of PAHs, compare the laboratory data with astronomical observations and discuss the global implications.

  7. On the use of the (V,W) Burn-Sensitive Vegetation Index System to monitor the spatiotemporal distribution of burned areas in Portugal

    Science.gov (United States)

    DaCamara, Carlos; Libonati, Renata; Calado, Teresa; Ermida, Sofia; Nunes, Sílvia

    2017-04-01

    The use of remotely sensed information for burned area detection is well established and there is a general consensus about its usefulness from global down to regional levels. In this particular, the combined use of near and middle infrared (NIR and MIR) channels has shown to be particularly suitable to discriminate burned areas in a variety of ecosystems. The so-called (V,W) system [1,2] is a burn-sensitive vegetation index system defined in a transformed NIR-MIR space that has proven to be capable of discriminating burned pixels in the Brazilian biomes. A procedure based on the (V,W) system is here presented that allows discriminating burned areas and dating burning events. The procedure is tested over Portugal using NIR and MIR data from the Terra/Aqua MODIS Level 1B 1 km V5 product (MOD021/MYD021) together with active fire data from the MODIS V5 product Thermal Anomalies/Fire 5-Min L2 Swath 1km (MOD14/ MYD14). First monthly minimum composites of W are computed for July and August 2015. Burned pixels are then identified as the ones that are located close to hot spots (detected during August) and that present low values of composited minimum of W in August (characteristic of a burning event) together with a sharp decrease of composited minimum of W from July to August (that is expected to occur after a burning event). Burned pixels are then successively identified by a seeded region-growing algorithm. The day of burning of each pixel classified as burned is finally identified as the one that maximizes an index of temporal separability computed along the respective time series of available values of W in August. Results obtained are validated using as reference burned scars and dates as identified by the Rapid Damage Assessment (RDA) module developed by the European Forest Fire Information System (EFFIS); the EFFIS mapping process consists of an unsupervised procedure that uses MODIS bands at 250 m resolution combined with information from the CORINE Land Cover

  8. Hydrocarbon Source Rocks in the Deep River and Dan River Triassic Basins, North Carolina

    Science.gov (United States)

    Reid, Jeffrey C.; Milici, Robert C.

    2008-01-01

    This report presents an interpretation of the hydrocarbon source rock potential of the Triassic sedimentary rocks of the Deep River and Dan River basins, North Carolina, based on previously unpublished organic geochemistry data. The organic geochemical data, 87 samples from 28 drill holes, are from the Sanford sub-basin (Cumnock Formation) of the Deep River basin, and from the Dan River basin (Cow Branch Formation). The available organic geochemical data are biased, however, because many of the samples collected for analyses by industry were from drill holes that contained intrusive diabase dikes, sills, and sheets of early Mesozoic age. These intrusive rocks heated and metamorphosed the surrounding sediments and organic matter in the black shale and coal bed source rocks and, thus, masked the source rock potential that they would have had in an unaltered state. In places, heat from the intrusives generated over-mature vitrinite reflectance (%Ro) profiles and metamorphosed the coals to semi-anthracite, anthracite, and coke. The maximum burial depth of these coal beds is unknown, and depth of burial may also have contributed to elevated thermal maturation profiles. The organic geochemistry data show that potential source rocks exist in the Sanford sub-basin and Dan River basin and that the sediments are gas prone rather than oil prone, although both types of hydrocarbons were generated. Total organic carbon (TOC) data for 56 of the samples are greater than the conservative 1.4% TOC threshold necessary for hydrocarbon expulsion. Both the Cow Branch Formation (Dan River basin) and the Cumnock Formation (Deep River basin, Sanford sub-basin) contain potential source rocks for oil, but they are more likely to have yielded natural gas. The organic material in these formations was derived primarily from terrestrial Type III woody (coaly) material and secondarily from lacustrine Type I (algal) material. Both the thermal alteration index (TAI) and vitrinite reflectance data

  9. Effects of arterial blood flow on walls of the abdominal aorta: distributions of wall shear stress and oscillatory shear index determined by phase-contrast magnetic resonance imaging.

    Science.gov (United States)

    Sughimoto, Koichi; Shimamura, Yoshiaki; Tezuka, Chie; Tsubota, Ken'ichi; Liu, Hao; Okumura, Kenichiro; Masuda, Yoshitada; Haneishi, Hideaki

    2016-07-01

    Although abdominal aortic aneurysms (AAAs) occur mostly inferior to the renal artery, the mechanism of the development of AAA in relation to its specific location is not yet clearly understood. The objective of this study was to evaluate the hypothesis that even healthy volunteers may manifest specific flow characteristics of blood flow and alter wall shear or oscillatory shear stress in the areas where AAAs commonly develop. Eight healthy male volunteers were enrolled in this prospective study, aged from 24 to 27. Phase-contrast magnetic resonance imaging (MRI) was performed with electrocardiographic triggering. Flow-sensitive four-dimensional MR imaging of the abdominal aorta, with three-directional velocity encoding, including simple morphological image acquisition, was performed. Information on specific locations on the aortic wall was applied to the flow encodes to calculate wall shear stress (WSS) and oscillatory shear index (OSI). While time-framed WSS showed the highest peak of 1.14 ± 0.25 Pa in the juxtaposition of the renal artery, the WS